brintos / linux-shallow public Read only

1// SPDX-License-Identifier: GPL-2.0-or-later2// SPI init/core code3//4// Copyright (C) 2005 David Brownell5// Copyright (C) 2008 Secret Lab Technologies Ltd.6 7#include <linux/acpi.h>8#include <linux/cache.h>9#include <linux/clk/clk-conf.h>10#include <linux/delay.h>11#include <linux/device.h>12#include <linux/dmaengine.h>13#include <linux/dma-mapping.h>14#include <linux/export.h>15#include <linux/gpio/consumer.h>16#include <linux/highmem.h>17#include <linux/idr.h>18#include <linux/init.h>19#include <linux/ioport.h>20#include <linux/kernel.h>21#include <linux/kthread.h>22#include <linux/mod_devicetable.h>23#include <linux/mutex.h>24#include <linux/of_device.h>25#include <linux/of_irq.h>26#include <linux/percpu.h>27#include <linux/platform_data/x86/apple.h>28#include <linux/pm_domain.h>29#include <linux/pm_runtime.h>30#include <linux/property.h>31#include <linux/ptp_clock_kernel.h>32#include <linux/sched/rt.h>33#include <linux/slab.h>34#include <linux/spi/spi.h>35#include <linux/spi/spi-mem.h>36#include <uapi/linux/sched/types.h>37 38#define CREATE_TRACE_POINTS39#include <trace/events/spi.h>40EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);41EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);42 43#include "internals.h"44 45static DEFINE_IDR(spi_master_idr);46 47static void spidev_release(struct device *dev)48{49	struct spi_device	*spi = to_spi_device(dev);50 51	spi_controller_put(spi->controller);52	kfree(spi->driver_override);53	free_percpu(spi->pcpu_statistics);54	kfree(spi);55}56 57static ssize_t58modalias_show(struct device *dev, struct device_attribute *a, char *buf)59{60	const struct spi_device	*spi = to_spi_device(dev);61	int len;62 63	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);64	if (len != -ENODEV)65		return len;66 67	return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);68}69static DEVICE_ATTR_RO(modalias);70 71static ssize_t driver_override_store(struct device *dev,72				     struct device_attribute *a,73				     const char *buf, size_t count)74{75	struct spi_device *spi = to_spi_device(dev);76	int ret;77 78	ret = driver_set_override(dev, &spi->driver_override, buf, count);79	if (ret)80		return ret;81 82	return count;83}84 85static ssize_t driver_override_show(struct device *dev,86				    struct device_attribute *a, char *buf)87{88	const struct spi_device *spi = to_spi_device(dev);89	ssize_t len;90 91	device_lock(dev);92	len = sysfs_emit(buf, "%s\n", spi->driver_override ? : "");93	device_unlock(dev);94	return len;95}96static DEVICE_ATTR_RW(driver_override);97 98static struct spi_statistics __percpu *spi_alloc_pcpu_stats(struct device *dev)99{100	struct spi_statistics __percpu *pcpu_stats;101 102	if (dev)103		pcpu_stats = devm_alloc_percpu(dev, struct spi_statistics);104	else105		pcpu_stats = alloc_percpu_gfp(struct spi_statistics, GFP_KERNEL);106 107	if (pcpu_stats) {108		int cpu;109 110		for_each_possible_cpu(cpu) {111			struct spi_statistics *stat;112 113			stat = per_cpu_ptr(pcpu_stats, cpu);114			u64_stats_init(&stat->syncp);115		}116	}117	return pcpu_stats;118}119 120static ssize_t spi_emit_pcpu_stats(struct spi_statistics __percpu *stat,121				   char *buf, size_t offset)122{123	u64 val = 0;124	int i;125 126	for_each_possible_cpu(i) {127		const struct spi_statistics *pcpu_stats;128		u64_stats_t *field;129		unsigned int start;130		u64 inc;131 132		pcpu_stats = per_cpu_ptr(stat, i);133		field = (void *)pcpu_stats + offset;134		do {135			start = u64_stats_fetch_begin(&pcpu_stats->syncp);136			inc = u64_stats_read(field);137		} while (u64_stats_fetch_retry(&pcpu_stats->syncp, start));138		val += inc;139	}140	return sysfs_emit(buf, "%llu\n", val);141}142 143#define SPI_STATISTICS_ATTRS(field, file)				\144static ssize_t spi_controller_##field##_show(struct device *dev,	\145					     struct device_attribute *attr, \146					     char *buf)			\147{									\148	struct spi_controller *ctlr = container_of(dev,			\149					 struct spi_controller, dev);	\150	return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \151}									\152static struct device_attribute dev_attr_spi_controller_##field = {	\153	.attr = { .name = file, .mode = 0444 },				\154	.show = spi_controller_##field##_show,				\155};									\156static ssize_t spi_device_##field##_show(struct device *dev,		\157					 struct device_attribute *attr,	\158					char *buf)			\159{									\160	struct spi_device *spi = to_spi_device(dev);			\161	return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \162}									\163static struct device_attribute dev_attr_spi_device_##field = {		\164	.attr = { .name = file, .mode = 0444 },				\165	.show = spi_device_##field##_show,				\166}167 168#define SPI_STATISTICS_SHOW_NAME(name, file, field)			\169static ssize_t spi_statistics_##name##_show(struct spi_statistics __percpu *stat, \170					    char *buf)			\171{									\172	return spi_emit_pcpu_stats(stat, buf,				\173			offsetof(struct spi_statistics, field));	\174}									\175SPI_STATISTICS_ATTRS(name, file)176 177#define SPI_STATISTICS_SHOW(field)					\178	SPI_STATISTICS_SHOW_NAME(field, __stringify(field),		\179				 field)180 181SPI_STATISTICS_SHOW(messages);182SPI_STATISTICS_SHOW(transfers);183SPI_STATISTICS_SHOW(errors);184SPI_STATISTICS_SHOW(timedout);185 186SPI_STATISTICS_SHOW(spi_sync);187SPI_STATISTICS_SHOW(spi_sync_immediate);188SPI_STATISTICS_SHOW(spi_async);189 190SPI_STATISTICS_SHOW(bytes);191SPI_STATISTICS_SHOW(bytes_rx);192SPI_STATISTICS_SHOW(bytes_tx);193 194#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number)		\195	SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index,		\196				 "transfer_bytes_histo_" number,	\197				 transfer_bytes_histo[index])198SPI_STATISTICS_TRANSFER_BYTES_HISTO(0,  "0-1");199SPI_STATISTICS_TRANSFER_BYTES_HISTO(1,  "2-3");200SPI_STATISTICS_TRANSFER_BYTES_HISTO(2,  "4-7");201SPI_STATISTICS_TRANSFER_BYTES_HISTO(3,  "8-15");202SPI_STATISTICS_TRANSFER_BYTES_HISTO(4,  "16-31");203SPI_STATISTICS_TRANSFER_BYTES_HISTO(5,  "32-63");204SPI_STATISTICS_TRANSFER_BYTES_HISTO(6,  "64-127");205SPI_STATISTICS_TRANSFER_BYTES_HISTO(7,  "128-255");206SPI_STATISTICS_TRANSFER_BYTES_HISTO(8,  "256-511");207SPI_STATISTICS_TRANSFER_BYTES_HISTO(9,  "512-1023");208SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");209SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");210SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");211SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");212SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");213SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");214SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");215 216SPI_STATISTICS_SHOW(transfers_split_maxsize);217 218static struct attribute *spi_dev_attrs[] = {219	&dev_attr_modalias.attr,220	&dev_attr_driver_override.attr,221	NULL,222};223 224static const struct attribute_group spi_dev_group = {225	.attrs  = spi_dev_attrs,226};227 228static struct attribute *spi_device_statistics_attrs[] = {229	&dev_attr_spi_device_messages.attr,230	&dev_attr_spi_device_transfers.attr,231	&dev_attr_spi_device_errors.attr,232	&dev_attr_spi_device_timedout.attr,233	&dev_attr_spi_device_spi_sync.attr,234	&dev_attr_spi_device_spi_sync_immediate.attr,235	&dev_attr_spi_device_spi_async.attr,236	&dev_attr_spi_device_bytes.attr,237	&dev_attr_spi_device_bytes_rx.attr,238	&dev_attr_spi_device_bytes_tx.attr,239	&dev_attr_spi_device_transfer_bytes_histo0.attr,240	&dev_attr_spi_device_transfer_bytes_histo1.attr,241	&dev_attr_spi_device_transfer_bytes_histo2.attr,242	&dev_attr_spi_device_transfer_bytes_histo3.attr,243	&dev_attr_spi_device_transfer_bytes_histo4.attr,244	&dev_attr_spi_device_transfer_bytes_histo5.attr,245	&dev_attr_spi_device_transfer_bytes_histo6.attr,246	&dev_attr_spi_device_transfer_bytes_histo7.attr,247	&dev_attr_spi_device_transfer_bytes_histo8.attr,248	&dev_attr_spi_device_transfer_bytes_histo9.attr,249	&dev_attr_spi_device_transfer_bytes_histo10.attr,250	&dev_attr_spi_device_transfer_bytes_histo11.attr,251	&dev_attr_spi_device_transfer_bytes_histo12.attr,252	&dev_attr_spi_device_transfer_bytes_histo13.attr,253	&dev_attr_spi_device_transfer_bytes_histo14.attr,254	&dev_attr_spi_device_transfer_bytes_histo15.attr,255	&dev_attr_spi_device_transfer_bytes_histo16.attr,256	&dev_attr_spi_device_transfers_split_maxsize.attr,257	NULL,258};259 260static const struct attribute_group spi_device_statistics_group = {261	.name  = "statistics",262	.attrs  = spi_device_statistics_attrs,263};264 265static const struct attribute_group *spi_dev_groups[] = {266	&spi_dev_group,267	&spi_device_statistics_group,268	NULL,269};270 271static struct attribute *spi_controller_statistics_attrs[] = {272	&dev_attr_spi_controller_messages.attr,273	&dev_attr_spi_controller_transfers.attr,274	&dev_attr_spi_controller_errors.attr,275	&dev_attr_spi_controller_timedout.attr,276	&dev_attr_spi_controller_spi_sync.attr,277	&dev_attr_spi_controller_spi_sync_immediate.attr,278	&dev_attr_spi_controller_spi_async.attr,279	&dev_attr_spi_controller_bytes.attr,280	&dev_attr_spi_controller_bytes_rx.attr,281	&dev_attr_spi_controller_bytes_tx.attr,282	&dev_attr_spi_controller_transfer_bytes_histo0.attr,283	&dev_attr_spi_controller_transfer_bytes_histo1.attr,284	&dev_attr_spi_controller_transfer_bytes_histo2.attr,285	&dev_attr_spi_controller_transfer_bytes_histo3.attr,286	&dev_attr_spi_controller_transfer_bytes_histo4.attr,287	&dev_attr_spi_controller_transfer_bytes_histo5.attr,288	&dev_attr_spi_controller_transfer_bytes_histo6.attr,289	&dev_attr_spi_controller_transfer_bytes_histo7.attr,290	&dev_attr_spi_controller_transfer_bytes_histo8.attr,291	&dev_attr_spi_controller_transfer_bytes_histo9.attr,292	&dev_attr_spi_controller_transfer_bytes_histo10.attr,293	&dev_attr_spi_controller_transfer_bytes_histo11.attr,294	&dev_attr_spi_controller_transfer_bytes_histo12.attr,295	&dev_attr_spi_controller_transfer_bytes_histo13.attr,296	&dev_attr_spi_controller_transfer_bytes_histo14.attr,297	&dev_attr_spi_controller_transfer_bytes_histo15.attr,298	&dev_attr_spi_controller_transfer_bytes_histo16.attr,299	&dev_attr_spi_controller_transfers_split_maxsize.attr,300	NULL,301};302 303static const struct attribute_group spi_controller_statistics_group = {304	.name  = "statistics",305	.attrs  = spi_controller_statistics_attrs,306};307 308static const struct attribute_group *spi_master_groups[] = {309	&spi_controller_statistics_group,310	NULL,311};312 313static void spi_statistics_add_transfer_stats(struct spi_statistics __percpu *pcpu_stats,314					      struct spi_transfer *xfer,315					      struct spi_message *msg)316{317	int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;318	struct spi_statistics *stats;319 320	if (l2len < 0)321		l2len = 0;322 323	get_cpu();324	stats = this_cpu_ptr(pcpu_stats);325	u64_stats_update_begin(&stats->syncp);326 327	u64_stats_inc(&stats->transfers);328	u64_stats_inc(&stats->transfer_bytes_histo[l2len]);329 330	u64_stats_add(&stats->bytes, xfer->len);331	if (spi_valid_txbuf(msg, xfer))332		u64_stats_add(&stats->bytes_tx, xfer->len);333	if (spi_valid_rxbuf(msg, xfer))334		u64_stats_add(&stats->bytes_rx, xfer->len);335 336	u64_stats_update_end(&stats->syncp);337	put_cpu();338}339 340/*341 * modalias support makes "modprobe $MODALIAS" new-style hotplug work,342 * and the sysfs version makes coldplug work too.343 */344static const struct spi_device_id *spi_match_id(const struct spi_device_id *id, const char *name)345{346	while (id->name[0]) {347		if (!strcmp(name, id->name))348			return id;349		id++;350	}351	return NULL;352}353 354const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)355{356	const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);357 358	return spi_match_id(sdrv->id_table, sdev->modalias);359}360EXPORT_SYMBOL_GPL(spi_get_device_id);361 362const void *spi_get_device_match_data(const struct spi_device *sdev)363{364	const void *match;365 366	match = device_get_match_data(&sdev->dev);367	if (match)368		return match;369 370	return (const void *)spi_get_device_id(sdev)->driver_data;371}372EXPORT_SYMBOL_GPL(spi_get_device_match_data);373 374static int spi_match_device(struct device *dev, const struct device_driver *drv)375{376	const struct spi_device	*spi = to_spi_device(dev);377	const struct spi_driver	*sdrv = to_spi_driver(drv);378 379	/* Check override first, and if set, only use the named driver */380	if (spi->driver_override)381		return strcmp(spi->driver_override, drv->name) == 0;382 383	/* Attempt an OF style match */384	if (of_driver_match_device(dev, drv))385		return 1;386 387	/* Then try ACPI */388	if (acpi_driver_match_device(dev, drv))389		return 1;390 391	if (sdrv->id_table)392		return !!spi_match_id(sdrv->id_table, spi->modalias);393 394	return strcmp(spi->modalias, drv->name) == 0;395}396 397static int spi_uevent(const struct device *dev, struct kobj_uevent_env *env)398{399	const struct spi_device		*spi = to_spi_device(dev);400	int rc;401 402	rc = acpi_device_uevent_modalias(dev, env);403	if (rc != -ENODEV)404		return rc;405 406	return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);407}408 409static int spi_probe(struct device *dev)410{411	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);412	struct spi_device		*spi = to_spi_device(dev);413	int ret;414 415	ret = of_clk_set_defaults(dev->of_node, false);416	if (ret)417		return ret;418 419	if (dev->of_node) {420		spi->irq = of_irq_get(dev->of_node, 0);421		if (spi->irq == -EPROBE_DEFER)422			return -EPROBE_DEFER;423		if (spi->irq < 0)424			spi->irq = 0;425	}426 427	ret = dev_pm_domain_attach(dev, true);428	if (ret)429		return ret;430 431	if (sdrv->probe) {432		ret = sdrv->probe(spi);433		if (ret)434			dev_pm_domain_detach(dev, true);435	}436 437	return ret;438}439 440static void spi_remove(struct device *dev)441{442	const struct spi_driver		*sdrv = to_spi_driver(dev->driver);443 444	if (sdrv->remove)445		sdrv->remove(to_spi_device(dev));446 447	dev_pm_domain_detach(dev, true);448}449 450static void spi_shutdown(struct device *dev)451{452	if (dev->driver) {453		const struct spi_driver	*sdrv = to_spi_driver(dev->driver);454 455		if (sdrv->shutdown)456			sdrv->shutdown(to_spi_device(dev));457	}458}459 460const struct bus_type spi_bus_type = {461	.name		= "spi",462	.dev_groups	= spi_dev_groups,463	.match		= spi_match_device,464	.uevent		= spi_uevent,465	.probe		= spi_probe,466	.remove		= spi_remove,467	.shutdown	= spi_shutdown,468};469EXPORT_SYMBOL_GPL(spi_bus_type);470 471/**472 * __spi_register_driver - register a SPI driver473 * @owner: owner module of the driver to register474 * @sdrv: the driver to register475 * Context: can sleep476 *477 * Return: zero on success, else a negative error code.478 */479int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)480{481	sdrv->driver.owner = owner;482	sdrv->driver.bus = &spi_bus_type;483 484	/*485	 * For Really Good Reasons we use spi: modaliases not of:486	 * modaliases for DT so module autoloading won't work if we487	 * don't have a spi_device_id as well as a compatible string.488	 */489	if (sdrv->driver.of_match_table) {490		const struct of_device_id *of_id;491 492		for (of_id = sdrv->driver.of_match_table; of_id->compatible[0];493		     of_id++) {494			const char *of_name;495 496			/* Strip off any vendor prefix */497			of_name = strnchr(of_id->compatible,498					  sizeof(of_id->compatible), ',');499			if (of_name)500				of_name++;501			else502				of_name = of_id->compatible;503 504			if (sdrv->id_table) {505				const struct spi_device_id *spi_id;506 507				spi_id = spi_match_id(sdrv->id_table, of_name);508				if (spi_id)509					continue;510			} else {511				if (strcmp(sdrv->driver.name, of_name) == 0)512					continue;513			}514 515			pr_warn("SPI driver %s has no spi_device_id for %s\n",516				sdrv->driver.name, of_id->compatible);517		}518	}519 520	return driver_register(&sdrv->driver);521}522EXPORT_SYMBOL_GPL(__spi_register_driver);523 524/*-------------------------------------------------------------------------*/525 526/*527 * SPI devices should normally not be created by SPI device drivers; that528 * would make them board-specific.  Similarly with SPI controller drivers.529 * Device registration normally goes into like arch/.../mach.../board-YYY.c530 * with other readonly (flashable) information about mainboard devices.531 */532 533struct boardinfo {534	struct list_head	list;535	struct spi_board_info	board_info;536};537 538static LIST_HEAD(board_list);539static LIST_HEAD(spi_controller_list);540 541/*542 * Used to protect add/del operation for board_info list and543 * spi_controller list, and their matching process also used544 * to protect object of type struct idr.545 */546static DEFINE_MUTEX(board_lock);547 548/**549 * spi_alloc_device - Allocate a new SPI device550 * @ctlr: Controller to which device is connected551 * Context: can sleep552 *553 * Allows a driver to allocate and initialize a spi_device without554 * registering it immediately.  This allows a driver to directly555 * fill the spi_device with device parameters before calling556 * spi_add_device() on it.557 *558 * Caller is responsible to call spi_add_device() on the returned559 * spi_device structure to add it to the SPI controller.  If the caller560 * needs to discard the spi_device without adding it, then it should561 * call spi_dev_put() on it.562 *563 * Return: a pointer to the new device, or NULL.564 */565struct spi_device *spi_alloc_device(struct spi_controller *ctlr)566{567	struct spi_device	*spi;568 569	if (!spi_controller_get(ctlr))570		return NULL;571 572	spi = kzalloc(sizeof(*spi), GFP_KERNEL);573	if (!spi) {574		spi_controller_put(ctlr);575		return NULL;576	}577 578	spi->pcpu_statistics = spi_alloc_pcpu_stats(NULL);579	if (!spi->pcpu_statistics) {580		kfree(spi);581		spi_controller_put(ctlr);582		return NULL;583	}584 585	spi->controller = ctlr;586	spi->dev.parent = &ctlr->dev;587	spi->dev.bus = &spi_bus_type;588	spi->dev.release = spidev_release;589	spi->mode = ctlr->buswidth_override_bits;590 591	device_initialize(&spi->dev);592	return spi;593}594EXPORT_SYMBOL_GPL(spi_alloc_device);595 596static void spi_dev_set_name(struct spi_device *spi)597{598	struct device *dev = &spi->dev;599	struct fwnode_handle *fwnode = dev_fwnode(dev);600 601	if (is_acpi_device_node(fwnode)) {602		dev_set_name(dev, "spi-%s", acpi_dev_name(to_acpi_device_node(fwnode)));603		return;604	}605 606	if (is_software_node(fwnode)) {607		dev_set_name(dev, "spi-%pfwP", fwnode);608		return;609	}610 611	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),612		     spi_get_chipselect(spi, 0));613}614 615/*616 * Zero(0) is a valid physical CS value and can be located at any617 * logical CS in the spi->chip_select[]. If all the physical CS618 * are initialized to 0 then It would be difficult to differentiate619 * between a valid physical CS 0 & an unused logical CS whose physical620 * CS can be 0. As a solution to this issue initialize all the CS to -1.621 * Now all the unused logical CS will have -1 physical CS value & can be622 * ignored while performing physical CS validity checks.623 */624#define SPI_INVALID_CS		((s8)-1)625 626static inline bool is_valid_cs(s8 chip_select)627{628	return chip_select != SPI_INVALID_CS;629}630 631static inline int spi_dev_check_cs(struct device *dev,632				   struct spi_device *spi, u8 idx,633				   struct spi_device *new_spi, u8 new_idx)634{635	u8 cs, cs_new;636	u8 idx_new;637 638	cs = spi_get_chipselect(spi, idx);639	for (idx_new = new_idx; idx_new < SPI_CS_CNT_MAX; idx_new++) {640		cs_new = spi_get_chipselect(new_spi, idx_new);641		if (is_valid_cs(cs) && is_valid_cs(cs_new) && cs == cs_new) {642			dev_err(dev, "chipselect %u already in use\n", cs_new);643			return -EBUSY;644		}645	}646	return 0;647}648 649static int spi_dev_check(struct device *dev, void *data)650{651	struct spi_device *spi = to_spi_device(dev);652	struct spi_device *new_spi = data;653	int status, idx;654 655	if (spi->controller == new_spi->controller) {656		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {657			status = spi_dev_check_cs(dev, spi, idx, new_spi, 0);658			if (status)659				return status;660		}661	}662	return 0;663}664 665static void spi_cleanup(struct spi_device *spi)666{667	if (spi->controller->cleanup)668		spi->controller->cleanup(spi);669}670 671static int __spi_add_device(struct spi_device *spi)672{673	struct spi_controller *ctlr = spi->controller;674	struct device *dev = ctlr->dev.parent;675	int status, idx;676	u8 cs;677 678	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {679		/* Chipselects are numbered 0..max; validate. */680		cs = spi_get_chipselect(spi, idx);681		if (is_valid_cs(cs) && cs >= ctlr->num_chipselect) {682			dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx),683				ctlr->num_chipselect);684			return -EINVAL;685		}686	}687 688	/*689	 * Make sure that multiple logical CS doesn't map to the same physical CS.690	 * For example, spi->chip_select[0] != spi->chip_select[1] and so on.691	 */692	if (!spi_controller_is_target(ctlr)) {693		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {694			status = spi_dev_check_cs(dev, spi, idx, spi, idx + 1);695			if (status)696				return status;697		}698	}699 700	/* Set the bus ID string */701	spi_dev_set_name(spi);702 703	/*704	 * We need to make sure there's no other device with this705	 * chipselect **BEFORE** we call setup(), else we'll trash706	 * its configuration.707	 */708	status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);709	if (status)710		return status;711 712	/* Controller may unregister concurrently */713	if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&714	    !device_is_registered(&ctlr->dev)) {715		return -ENODEV;716	}717 718	if (ctlr->cs_gpiods) {719		u8 cs;720 721		for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) {722			cs = spi_get_chipselect(spi, idx);723			if (is_valid_cs(cs))724				spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]);725		}726	}727 728	/*729	 * Drivers may modify this initial i/o setup, but will730	 * normally rely on the device being setup.  Devices731	 * using SPI_CS_HIGH can't coexist well otherwise...732	 */733	status = spi_setup(spi);734	if (status < 0) {735		dev_err(dev, "can't setup %s, status %d\n",736				dev_name(&spi->dev), status);737		return status;738	}739 740	/* Device may be bound to an active driver when this returns */741	status = device_add(&spi->dev);742	if (status < 0) {743		dev_err(dev, "can't add %s, status %d\n",744				dev_name(&spi->dev), status);745		spi_cleanup(spi);746	} else {747		dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));748	}749 750	return status;751}752 753/**754 * spi_add_device - Add spi_device allocated with spi_alloc_device755 * @spi: spi_device to register756 *757 * Companion function to spi_alloc_device.  Devices allocated with758 * spi_alloc_device can be added onto the SPI bus with this function.759 *760 * Return: 0 on success; negative errno on failure761 */762int spi_add_device(struct spi_device *spi)763{764	struct spi_controller *ctlr = spi->controller;765	int status;766 767	/* Set the bus ID string */768	spi_dev_set_name(spi);769 770	mutex_lock(&ctlr->add_lock);771	status = __spi_add_device(spi);772	mutex_unlock(&ctlr->add_lock);773	return status;774}775EXPORT_SYMBOL_GPL(spi_add_device);776 777static void spi_set_all_cs_unused(struct spi_device *spi)778{779	u8 idx;780 781	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)782		spi_set_chipselect(spi, idx, SPI_INVALID_CS);783}784 785/**786 * spi_new_device - instantiate one new SPI device787 * @ctlr: Controller to which device is connected788 * @chip: Describes the SPI device789 * Context: can sleep790 *791 * On typical mainboards, this is purely internal; and it's not needed792 * after board init creates the hard-wired devices.  Some development793 * platforms may not be able to use spi_register_board_info though, and794 * this is exported so that for example a USB or parport based adapter795 * driver could add devices (which it would learn about out-of-band).796 *797 * Return: the new device, or NULL.798 */799struct spi_device *spi_new_device(struct spi_controller *ctlr,800				  struct spi_board_info *chip)801{802	struct spi_device	*proxy;803	int			status;804 805	/*806	 * NOTE:  caller did any chip->bus_num checks necessary.807	 *808	 * Also, unless we change the return value convention to use809	 * error-or-pointer (not NULL-or-pointer), troubleshootability810	 * suggests syslogged diagnostics are best here (ugh).811	 */812 813	proxy = spi_alloc_device(ctlr);814	if (!proxy)815		return NULL;816 817	WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));818 819	/* Use provided chip-select for proxy device */820	spi_set_all_cs_unused(proxy);821	spi_set_chipselect(proxy, 0, chip->chip_select);822 823	proxy->max_speed_hz = chip->max_speed_hz;824	proxy->mode = chip->mode;825	proxy->irq = chip->irq;826	strscpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));827	proxy->dev.platform_data = (void *) chip->platform_data;828	proxy->controller_data = chip->controller_data;829	proxy->controller_state = NULL;830	/*831	 * By default spi->chip_select[0] will hold the physical CS number,832	 * so set bit 0 in spi->cs_index_mask.833	 */834	proxy->cs_index_mask = BIT(0);835 836	if (chip->swnode) {837		status = device_add_software_node(&proxy->dev, chip->swnode);838		if (status) {839			dev_err(&ctlr->dev, "failed to add software node to '%s': %d\n",840				chip->modalias, status);841			goto err_dev_put;842		}843	}844 845	status = spi_add_device(proxy);846	if (status < 0)847		goto err_dev_put;848 849	return proxy;850 851err_dev_put:852	device_remove_software_node(&proxy->dev);853	spi_dev_put(proxy);854	return NULL;855}856EXPORT_SYMBOL_GPL(spi_new_device);857 858/**859 * spi_unregister_device - unregister a single SPI device860 * @spi: spi_device to unregister861 *862 * Start making the passed SPI device vanish. Normally this would be handled863 * by spi_unregister_controller().864 */865void spi_unregister_device(struct spi_device *spi)866{867	if (!spi)868		return;869 870	if (spi->dev.of_node) {871		of_node_clear_flag(spi->dev.of_node, OF_POPULATED);872		of_node_put(spi->dev.of_node);873	}874	if (ACPI_COMPANION(&spi->dev))875		acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));876	device_remove_software_node(&spi->dev);877	device_del(&spi->dev);878	spi_cleanup(spi);879	put_device(&spi->dev);880}881EXPORT_SYMBOL_GPL(spi_unregister_device);882 883static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,884					      struct spi_board_info *bi)885{886	struct spi_device *dev;887 888	if (ctlr->bus_num != bi->bus_num)889		return;890 891	dev = spi_new_device(ctlr, bi);892	if (!dev)893		dev_err(ctlr->dev.parent, "can't create new device for %s\n",894			bi->modalias);895}896 897/**898 * spi_register_board_info - register SPI devices for a given board899 * @info: array of chip descriptors900 * @n: how many descriptors are provided901 * Context: can sleep902 *903 * Board-specific early init code calls this (probably during arch_initcall)904 * with segments of the SPI device table.  Any device nodes are created later,905 * after the relevant parent SPI controller (bus_num) is defined.  We keep906 * this table of devices forever, so that reloading a controller driver will907 * not make Linux forget about these hard-wired devices.908 *909 * Other code can also call this, e.g. a particular add-on board might provide910 * SPI devices through its expansion connector, so code initializing that board911 * would naturally declare its SPI devices.912 *913 * The board info passed can safely be __initdata ... but be careful of914 * any embedded pointers (platform_data, etc), they're copied as-is.915 *916 * Return: zero on success, else a negative error code.917 */918int spi_register_board_info(struct spi_board_info const *info, unsigned n)919{920	struct boardinfo *bi;921	int i;922 923	if (!n)924		return 0;925 926	bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);927	if (!bi)928		return -ENOMEM;929 930	for (i = 0; i < n; i++, bi++, info++) {931		struct spi_controller *ctlr;932 933		memcpy(&bi->board_info, info, sizeof(*info));934 935		mutex_lock(&board_lock);936		list_add_tail(&bi->list, &board_list);937		list_for_each_entry(ctlr, &spi_controller_list, list)938			spi_match_controller_to_boardinfo(ctlr,939							  &bi->board_info);940		mutex_unlock(&board_lock);941	}942 943	return 0;944}945 946/*-------------------------------------------------------------------------*/947 948/* Core methods for SPI resource management */949 950/**951 * spi_res_alloc - allocate a spi resource that is life-cycle managed952 *                 during the processing of a spi_message while using953 *                 spi_transfer_one954 * @spi:     the SPI device for which we allocate memory955 * @release: the release code to execute for this resource956 * @size:    size to alloc and return957 * @gfp:     GFP allocation flags958 *959 * Return: the pointer to the allocated data960 *961 * This may get enhanced in the future to allocate from a memory pool962 * of the @spi_device or @spi_controller to avoid repeated allocations.963 */964static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release,965			   size_t size, gfp_t gfp)966{967	struct spi_res *sres;968 969	sres = kzalloc(sizeof(*sres) + size, gfp);970	if (!sres)971		return NULL;972 973	INIT_LIST_HEAD(&sres->entry);974	sres->release = release;975 976	return sres->data;977}978 979/**980 * spi_res_free - free an SPI resource981 * @res: pointer to the custom data of a resource982 */983static void spi_res_free(void *res)984{985	struct spi_res *sres = container_of(res, struct spi_res, data);986 987	if (!res)988		return;989 990	WARN_ON(!list_empty(&sres->entry));991	kfree(sres);992}993 994/**995 * spi_res_add - add a spi_res to the spi_message996 * @message: the SPI message997 * @res:     the spi_resource998 */999static void spi_res_add(struct spi_message *message, void *res)1000{1001	struct spi_res *sres = container_of(res, struct spi_res, data);1002 1003	WARN_ON(!list_empty(&sres->entry));1004	list_add_tail(&sres->entry, &message->resources);1005}1006 1007/**1008 * spi_res_release - release all SPI resources for this message1009 * @ctlr:  the @spi_controller1010 * @message: the @spi_message1011 */1012static void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)1013{1014	struct spi_res *res, *tmp;1015 1016	list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {1017		if (res->release)1018			res->release(ctlr, message, res->data);1019 1020		list_del(&res->entry);1021 1022		kfree(res);1023	}1024}1025 1026/*-------------------------------------------------------------------------*/1027#define spi_for_each_valid_cs(spi, idx)				\1028	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)		\1029		if (!(spi->cs_index_mask & BIT(idx))) {} else1030 1031static inline bool spi_is_last_cs(struct spi_device *spi)1032{1033	u8 idx;1034	bool last = false;1035 1036	spi_for_each_valid_cs(spi, idx) {1037		if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx))1038			last = true;1039	}1040	return last;1041}1042 1043static void spi_toggle_csgpiod(struct spi_device *spi, u8 idx, bool enable, bool activate)1044{1045	/*1046	 * Historically ACPI has no means of the GPIO polarity and1047	 * thus the SPISerialBus() resource defines it on the per-chip1048	 * basis. In order to avoid a chain of negations, the GPIO1049	 * polarity is considered being Active High. Even for the cases1050	 * when _DSD() is involved (in the updated versions of ACPI)1051	 * the GPIO CS polarity must be defined Active High to avoid1052	 * ambiguity. That's why we use enable, that takes SPI_CS_HIGH1053	 * into account.1054	 */1055	if (has_acpi_companion(&spi->dev))1056		gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), !enable);1057	else1058		/* Polarity handled by GPIO library */1059		gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), activate);1060 1061	if (activate)1062		spi_delay_exec(&spi->cs_setup, NULL);1063	else1064		spi_delay_exec(&spi->cs_inactive, NULL);1065}1066 1067static void spi_set_cs(struct spi_device *spi, bool enable, bool force)1068{1069	bool activate = enable;1070	u8 idx;1071 1072	/*1073	 * Avoid calling into the driver (or doing delays) if the chip select1074	 * isn't actually changing from the last time this was called.1075	 */1076	if (!force && ((enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&1077			spi_is_last_cs(spi)) ||1078		       (!enable && spi->controller->last_cs_index_mask == spi->cs_index_mask &&1079			!spi_is_last_cs(spi))) &&1080	    (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))1081		return;1082 1083	trace_spi_set_cs(spi, activate);1084 1085	spi->controller->last_cs_index_mask = spi->cs_index_mask;1086	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)1087		spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : SPI_INVALID_CS;1088	spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;1089 1090	if (spi->mode & SPI_CS_HIGH)1091		enable = !enable;1092 1093	/*1094	 * Handle chip select delays for GPIO based CS or controllers without1095	 * programmable chip select timing.1096	 */1097	if ((spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) && !activate)1098		spi_delay_exec(&spi->cs_hold, NULL);1099 1100	if (spi_is_csgpiod(spi)) {1101		if (!(spi->mode & SPI_NO_CS)) {1102			spi_for_each_valid_cs(spi, idx) {1103				if (spi_get_csgpiod(spi, idx))1104					spi_toggle_csgpiod(spi, idx, enable, activate);1105			}1106		}1107		/* Some SPI masters need both GPIO CS & slave_select */1108		if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) &&1109		    spi->controller->set_cs)1110			spi->controller->set_cs(spi, !enable);1111	} else if (spi->controller->set_cs) {1112		spi->controller->set_cs(spi, !enable);1113	}1114 1115	if (spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) {1116		if (activate)1117			spi_delay_exec(&spi->cs_setup, NULL);1118		else1119			spi_delay_exec(&spi->cs_inactive, NULL);1120	}1121}1122 1123#ifdef CONFIG_HAS_DMA1124static int spi_map_buf_attrs(struct spi_controller *ctlr, struct device *dev,1125			     struct sg_table *sgt, void *buf, size_t len,1126			     enum dma_data_direction dir, unsigned long attrs)1127{1128	const bool vmalloced_buf = is_vmalloc_addr(buf);1129	unsigned int max_seg_size = dma_get_max_seg_size(dev);1130#ifdef CONFIG_HIGHMEM1131	const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&1132				(unsigned long)buf < (PKMAP_BASE +1133					(LAST_PKMAP * PAGE_SIZE)));1134#else1135	const bool kmap_buf = false;1136#endif1137	int desc_len;1138	int sgs;1139	struct page *vm_page;1140	struct scatterlist *sg;1141	void *sg_buf;1142	size_t min;1143	int i, ret;1144 1145	if (vmalloced_buf || kmap_buf) {1146		desc_len = min_t(unsigned long, max_seg_size, PAGE_SIZE);1147		sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);1148	} else if (virt_addr_valid(buf)) {1149		desc_len = min_t(size_t, max_seg_size, ctlr->max_dma_len);1150		sgs = DIV_ROUND_UP(len, desc_len);1151	} else {1152		return -EINVAL;1153	}1154 1155	ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);1156	if (ret != 0)1157		return ret;1158 1159	sg = &sgt->sgl[0];1160	for (i = 0; i < sgs; i++) {1161 1162		if (vmalloced_buf || kmap_buf) {1163			/*1164			 * Next scatterlist entry size is the minimum between1165			 * the desc_len and the remaining buffer length that1166			 * fits in a page.1167			 */1168			min = min_t(size_t, desc_len,1169				    min_t(size_t, len,1170					  PAGE_SIZE - offset_in_page(buf)));1171			if (vmalloced_buf)1172				vm_page = vmalloc_to_page(buf);1173			else1174				vm_page = kmap_to_page(buf);1175			if (!vm_page) {1176				sg_free_table(sgt);1177				return -ENOMEM;1178			}1179			sg_set_page(sg, vm_page,1180				    min, offset_in_page(buf));1181		} else {1182			min = min_t(size_t, len, desc_len);1183			sg_buf = buf;1184			sg_set_buf(sg, sg_buf, min);1185		}1186 1187		buf += min;1188		len -= min;1189		sg = sg_next(sg);1190	}1191 1192	ret = dma_map_sgtable(dev, sgt, dir, attrs);1193	if (ret < 0) {1194		sg_free_table(sgt);1195		return ret;1196	}1197 1198	return 0;1199}1200 1201int spi_map_buf(struct spi_controller *ctlr, struct device *dev,1202		struct sg_table *sgt, void *buf, size_t len,1203		enum dma_data_direction dir)1204{1205	return spi_map_buf_attrs(ctlr, dev, sgt, buf, len, dir, 0);1206}1207 1208static void spi_unmap_buf_attrs(struct spi_controller *ctlr,1209				struct device *dev, struct sg_table *sgt,1210				enum dma_data_direction dir,1211				unsigned long attrs)1212{1213	dma_unmap_sgtable(dev, sgt, dir, attrs);1214	sg_free_table(sgt);1215	sgt->orig_nents = 0;1216	sgt->nents = 0;1217}1218 1219void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,1220		   struct sg_table *sgt, enum dma_data_direction dir)1221{1222	spi_unmap_buf_attrs(ctlr, dev, sgt, dir, 0);1223}1224 1225static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)1226{1227	struct device *tx_dev, *rx_dev;1228	struct spi_transfer *xfer;1229	int ret;1230 1231	if (!ctlr->can_dma)1232		return 0;1233 1234	if (ctlr->dma_tx)1235		tx_dev = ctlr->dma_tx->device->dev;1236	else if (ctlr->dma_map_dev)1237		tx_dev = ctlr->dma_map_dev;1238	else1239		tx_dev = ctlr->dev.parent;1240 1241	if (ctlr->dma_rx)1242		rx_dev = ctlr->dma_rx->device->dev;1243	else if (ctlr->dma_map_dev)1244		rx_dev = ctlr->dma_map_dev;1245	else1246		rx_dev = ctlr->dev.parent;1247 1248	ret = -ENOMSG;1249	list_for_each_entry(xfer, &msg->transfers, transfer_list) {1250		/* The sync is done before each transfer. */1251		unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;1252 1253		if (!ctlr->can_dma(ctlr, msg->spi, xfer))1254			continue;1255 1256		if (xfer->tx_buf != NULL) {1257			ret = spi_map_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,1258						(void *)xfer->tx_buf,1259						xfer->len, DMA_TO_DEVICE,1260						attrs);1261			if (ret != 0)1262				return ret;1263 1264			xfer->tx_sg_mapped = true;1265		}1266 1267		if (xfer->rx_buf != NULL) {1268			ret = spi_map_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,1269						xfer->rx_buf, xfer->len,1270						DMA_FROM_DEVICE, attrs);1271			if (ret != 0) {1272				spi_unmap_buf_attrs(ctlr, tx_dev,1273						&xfer->tx_sg, DMA_TO_DEVICE,1274						attrs);1275 1276				return ret;1277			}1278 1279			xfer->rx_sg_mapped = true;1280		}1281	}1282	/* No transfer has been mapped, bail out with success */1283	if (ret)1284		return 0;1285 1286	ctlr->cur_rx_dma_dev = rx_dev;1287	ctlr->cur_tx_dma_dev = tx_dev;1288 1289	return 0;1290}1291 1292static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)1293{1294	struct device *rx_dev = ctlr->cur_rx_dma_dev;1295	struct device *tx_dev = ctlr->cur_tx_dma_dev;1296	struct spi_transfer *xfer;1297 1298	list_for_each_entry(xfer, &msg->transfers, transfer_list) {1299		/* The sync has already been done after each transfer. */1300		unsigned long attrs = DMA_ATTR_SKIP_CPU_SYNC;1301 1302		if (xfer->rx_sg_mapped)1303			spi_unmap_buf_attrs(ctlr, rx_dev, &xfer->rx_sg,1304					    DMA_FROM_DEVICE, attrs);1305		xfer->rx_sg_mapped = false;1306 1307		if (xfer->tx_sg_mapped)1308			spi_unmap_buf_attrs(ctlr, tx_dev, &xfer->tx_sg,1309					    DMA_TO_DEVICE, attrs);1310		xfer->tx_sg_mapped = false;1311	}1312 1313	return 0;1314}1315 1316static void spi_dma_sync_for_device(struct spi_controller *ctlr,1317				    struct spi_transfer *xfer)1318{1319	struct device *rx_dev = ctlr->cur_rx_dma_dev;1320	struct device *tx_dev = ctlr->cur_tx_dma_dev;1321 1322	if (xfer->tx_sg_mapped)1323		dma_sync_sgtable_for_device(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);1324	if (xfer->rx_sg_mapped)1325		dma_sync_sgtable_for_device(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);1326}1327 1328static void spi_dma_sync_for_cpu(struct spi_controller *ctlr,1329				 struct spi_transfer *xfer)1330{1331	struct device *rx_dev = ctlr->cur_rx_dma_dev;1332	struct device *tx_dev = ctlr->cur_tx_dma_dev;1333 1334	if (xfer->rx_sg_mapped)1335		dma_sync_sgtable_for_cpu(rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);1336	if (xfer->tx_sg_mapped)1337		dma_sync_sgtable_for_cpu(tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);1338}1339#else /* !CONFIG_HAS_DMA */1340static inline int __spi_map_msg(struct spi_controller *ctlr,1341				struct spi_message *msg)1342{1343	return 0;1344}1345 1346static inline int __spi_unmap_msg(struct spi_controller *ctlr,1347				  struct spi_message *msg)1348{1349	return 0;1350}1351 1352static void spi_dma_sync_for_device(struct spi_controller *ctrl,1353				    struct spi_transfer *xfer)1354{1355}1356 1357static void spi_dma_sync_for_cpu(struct spi_controller *ctrl,1358				 struct spi_transfer *xfer)1359{1360}1361#endif /* !CONFIG_HAS_DMA */1362 1363static inline int spi_unmap_msg(struct spi_controller *ctlr,1364				struct spi_message *msg)1365{1366	struct spi_transfer *xfer;1367 1368	list_for_each_entry(xfer, &msg->transfers, transfer_list) {1369		/*1370		 * Restore the original value of tx_buf or rx_buf if they are1371		 * NULL.1372		 */1373		if (xfer->tx_buf == ctlr->dummy_tx)1374			xfer->tx_buf = NULL;1375		if (xfer->rx_buf == ctlr->dummy_rx)1376			xfer->rx_buf = NULL;1377	}1378 1379	return __spi_unmap_msg(ctlr, msg);1380}1381 1382static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)1383{1384	struct spi_transfer *xfer;1385	void *tmp;1386	unsigned int max_tx, max_rx;1387 1388	if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX))1389		&& !(msg->spi->mode & SPI_3WIRE)) {1390		max_tx = 0;1391		max_rx = 0;1392 1393		list_for_each_entry(xfer, &msg->transfers, transfer_list) {1394			if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&1395			    !xfer->tx_buf)1396				max_tx = max(xfer->len, max_tx);1397			if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&1398			    !xfer->rx_buf)1399				max_rx = max(xfer->len, max_rx);1400		}1401 1402		if (max_tx) {1403			tmp = krealloc(ctlr->dummy_tx, max_tx,1404				       GFP_KERNEL | GFP_DMA | __GFP_ZERO);1405			if (!tmp)1406				return -ENOMEM;1407			ctlr->dummy_tx = tmp;1408		}1409 1410		if (max_rx) {1411			tmp = krealloc(ctlr->dummy_rx, max_rx,1412				       GFP_KERNEL | GFP_DMA);1413			if (!tmp)1414				return -ENOMEM;1415			ctlr->dummy_rx = tmp;1416		}1417 1418		if (max_tx || max_rx) {1419			list_for_each_entry(xfer, &msg->transfers,1420					    transfer_list) {1421				if (!xfer->len)1422					continue;1423				if (!xfer->tx_buf)1424					xfer->tx_buf = ctlr->dummy_tx;1425				if (!xfer->rx_buf)1426					xfer->rx_buf = ctlr->dummy_rx;1427			}1428		}1429	}1430 1431	return __spi_map_msg(ctlr, msg);1432}1433 1434static int spi_transfer_wait(struct spi_controller *ctlr,1435			     struct spi_message *msg,1436			     struct spi_transfer *xfer)1437{1438	struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;1439	struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;1440	u32 speed_hz = xfer->speed_hz;1441	unsigned long long ms;1442 1443	if (spi_controller_is_target(ctlr)) {1444		if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {1445			dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");1446			return -EINTR;1447		}1448	} else {1449		if (!speed_hz)1450			speed_hz = 100000;1451 1452		/*1453		 * For each byte we wait for 8 cycles of the SPI clock.1454		 * Since speed is defined in Hz and we want milliseconds,1455		 * use respective multiplier, but before the division,1456		 * otherwise we may get 0 for short transfers.1457		 */1458		ms = 8LL * MSEC_PER_SEC * xfer->len;1459		do_div(ms, speed_hz);1460 1461		/*1462		 * Increase it twice and add 200 ms tolerance, use1463		 * predefined maximum in case of overflow.1464		 */1465		ms += ms + 200;1466		if (ms > UINT_MAX)1467			ms = UINT_MAX;1468 1469		ms = wait_for_completion_timeout(&ctlr->xfer_completion,1470						 msecs_to_jiffies(ms));1471 1472		if (ms == 0) {1473			SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);1474			SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);1475			dev_err(&msg->spi->dev,1476				"SPI transfer timed out\n");1477			return -ETIMEDOUT;1478		}1479 1480		if (xfer->error & SPI_TRANS_FAIL_IO)1481			return -EIO;1482	}1483 1484	return 0;1485}1486 1487static void _spi_transfer_delay_ns(u32 ns)1488{1489	if (!ns)1490		return;1491	if (ns <= NSEC_PER_USEC) {1492		ndelay(ns);1493	} else {1494		u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC);1495 1496		if (us <= 10)1497			udelay(us);1498		else1499			usleep_range(us, us + DIV_ROUND_UP(us, 10));1500	}1501}1502 1503int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)1504{1505	u32 delay = _delay->value;1506	u32 unit = _delay->unit;1507	u32 hz;1508 1509	if (!delay)1510		return 0;1511 1512	switch (unit) {1513	case SPI_DELAY_UNIT_USECS:1514		delay *= NSEC_PER_USEC;1515		break;1516	case SPI_DELAY_UNIT_NSECS:1517		/* Nothing to do here */1518		break;1519	case SPI_DELAY_UNIT_SCK:1520		/* Clock cycles need to be obtained from spi_transfer */1521		if (!xfer)1522			return -EINVAL;1523		/*1524		 * If there is unknown effective speed, approximate it1525		 * by underestimating with half of the requested Hz.1526		 */1527		hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;1528		if (!hz)1529			return -EINVAL;1530 1531		/* Convert delay to nanoseconds */1532		delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz);1533		break;1534	default:1535		return -EINVAL;1536	}1537 1538	return delay;1539}1540EXPORT_SYMBOL_GPL(spi_delay_to_ns);1541 1542int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)1543{1544	int delay;1545 1546	might_sleep();1547 1548	if (!_delay)1549		return -EINVAL;1550 1551	delay = spi_delay_to_ns(_delay, xfer);1552	if (delay < 0)1553		return delay;1554 1555	_spi_transfer_delay_ns(delay);1556 1557	return 0;1558}1559EXPORT_SYMBOL_GPL(spi_delay_exec);1560 1561static void _spi_transfer_cs_change_delay(struct spi_message *msg,1562					  struct spi_transfer *xfer)1563{1564	u32 default_delay_ns = 10 * NSEC_PER_USEC;1565	u32 delay = xfer->cs_change_delay.value;1566	u32 unit = xfer->cs_change_delay.unit;1567	int ret;1568 1569	/* Return early on "fast" mode - for everything but USECS */1570	if (!delay) {1571		if (unit == SPI_DELAY_UNIT_USECS)1572			_spi_transfer_delay_ns(default_delay_ns);1573		return;1574	}1575 1576	ret = spi_delay_exec(&xfer->cs_change_delay, xfer);1577	if (ret) {1578		dev_err_once(&msg->spi->dev,1579			     "Use of unsupported delay unit %i, using default of %luus\n",1580			     unit, default_delay_ns / NSEC_PER_USEC);1581		_spi_transfer_delay_ns(default_delay_ns);1582	}1583}1584 1585void spi_transfer_cs_change_delay_exec(struct spi_message *msg,1586						  struct spi_transfer *xfer)1587{1588	_spi_transfer_cs_change_delay(msg, xfer);1589}1590EXPORT_SYMBOL_GPL(spi_transfer_cs_change_delay_exec);1591 1592/*1593 * spi_transfer_one_message - Default implementation of transfer_one_message()1594 *1595 * This is a standard implementation of transfer_one_message() for1596 * drivers which implement a transfer_one() operation.  It provides1597 * standard handling of delays and chip select management.1598 */1599static int spi_transfer_one_message(struct spi_controller *ctlr,1600				    struct spi_message *msg)1601{1602	struct spi_transfer *xfer;1603	bool keep_cs = false;1604	int ret = 0;1605	struct spi_statistics __percpu *statm = ctlr->pcpu_statistics;1606	struct spi_statistics __percpu *stats = msg->spi->pcpu_statistics;1607 1608	xfer = list_first_entry(&msg->transfers, struct spi_transfer, transfer_list);1609	spi_set_cs(msg->spi, !xfer->cs_off, false);1610 1611	SPI_STATISTICS_INCREMENT_FIELD(statm, messages);1612	SPI_STATISTICS_INCREMENT_FIELD(stats, messages);1613 1614	list_for_each_entry(xfer, &msg->transfers, transfer_list) {1615		trace_spi_transfer_start(msg, xfer);1616 1617		spi_statistics_add_transfer_stats(statm, xfer, msg);1618		spi_statistics_add_transfer_stats(stats, xfer, msg);1619 1620		if (!ctlr->ptp_sts_supported) {1621			xfer->ptp_sts_word_pre = 0;1622			ptp_read_system_prets(xfer->ptp_sts);1623		}1624 1625		if ((xfer->tx_buf || xfer->rx_buf) && xfer->len) {1626			reinit_completion(&ctlr->xfer_completion);1627 1628fallback_pio:1629			spi_dma_sync_for_device(ctlr, xfer);1630			ret = ctlr->transfer_one(ctlr, msg->spi, xfer);1631			if (ret < 0) {1632				spi_dma_sync_for_cpu(ctlr, xfer);1633 1634				if ((xfer->tx_sg_mapped || xfer->rx_sg_mapped) &&1635				    (xfer->error & SPI_TRANS_FAIL_NO_START)) {1636					__spi_unmap_msg(ctlr, msg);1637					ctlr->fallback = true;1638					xfer->error &= ~SPI_TRANS_FAIL_NO_START;1639					goto fallback_pio;1640				}1641 1642				SPI_STATISTICS_INCREMENT_FIELD(statm,1643							       errors);1644				SPI_STATISTICS_INCREMENT_FIELD(stats,1645							       errors);1646				dev_err(&msg->spi->dev,1647					"SPI transfer failed: %d\n", ret);1648				goto out;1649			}1650 1651			if (ret > 0) {1652				ret = spi_transfer_wait(ctlr, msg, xfer);1653				if (ret < 0)1654					msg->status = ret;1655			}1656 1657			spi_dma_sync_for_cpu(ctlr, xfer);1658		} else {1659			if (xfer->len)1660				dev_err(&msg->spi->dev,1661					"Bufferless transfer has length %u\n",1662					xfer->len);1663		}1664 1665		if (!ctlr->ptp_sts_supported) {1666			ptp_read_system_postts(xfer->ptp_sts);1667			xfer->ptp_sts_word_post = xfer->len;1668		}1669 1670		trace_spi_transfer_stop(msg, xfer);1671 1672		if (msg->status != -EINPROGRESS)1673			goto out;1674 1675		spi_transfer_delay_exec(xfer);1676 1677		if (xfer->cs_change) {1678			if (list_is_last(&xfer->transfer_list,1679					 &msg->transfers)) {1680				keep_cs = true;1681			} else {1682				if (!xfer->cs_off)1683					spi_set_cs(msg->spi, false, false);1684				_spi_transfer_cs_change_delay(msg, xfer);1685				if (!list_next_entry(xfer, transfer_list)->cs_off)1686					spi_set_cs(msg->spi, true, false);1687			}1688		} else if (!list_is_last(&xfer->transfer_list, &msg->transfers) &&1689			   xfer->cs_off != list_next_entry(xfer, transfer_list)->cs_off) {1690			spi_set_cs(msg->spi, xfer->cs_off, false);1691		}1692 1693		msg->actual_length += xfer->len;1694	}1695 1696out:1697	if (ret != 0 || !keep_cs)1698		spi_set_cs(msg->spi, false, false);1699 1700	if (msg->status == -EINPROGRESS)1701		msg->status = ret;1702 1703	if (msg->status && ctlr->handle_err)1704		ctlr->handle_err(ctlr, msg);1705 1706	spi_finalize_current_message(ctlr);1707 1708	return ret;1709}1710 1711/**1712 * spi_finalize_current_transfer - report completion of a transfer1713 * @ctlr: the controller reporting completion1714 *1715 * Called by SPI drivers using the core transfer_one_message()1716 * implementation to notify it that the current interrupt driven1717 * transfer has finished and the next one may be scheduled.1718 */1719void spi_finalize_current_transfer(struct spi_controller *ctlr)1720{1721	complete(&ctlr->xfer_completion);1722}1723EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);1724 1725static void spi_idle_runtime_pm(struct spi_controller *ctlr)1726{1727	if (ctlr->auto_runtime_pm) {1728		pm_runtime_mark_last_busy(ctlr->dev.parent);1729		pm_runtime_put_autosuspend(ctlr->dev.parent);1730	}1731}1732 1733static int __spi_pump_transfer_message(struct spi_controller *ctlr,1734		struct spi_message *msg, bool was_busy)1735{1736	struct spi_transfer *xfer;1737	int ret;1738 1739	if (!was_busy && ctlr->auto_runtime_pm) {1740		ret = pm_runtime_get_sync(ctlr->dev.parent);1741		if (ret < 0) {1742			pm_runtime_put_noidle(ctlr->dev.parent);1743			dev_err(&ctlr->dev, "Failed to power device: %d\n",1744				ret);1745 1746			msg->status = ret;1747			spi_finalize_current_message(ctlr);1748 1749			return ret;1750		}1751	}1752 1753	if (!was_busy)1754		trace_spi_controller_busy(ctlr);1755 1756	if (!was_busy && ctlr->prepare_transfer_hardware) {1757		ret = ctlr->prepare_transfer_hardware(ctlr);1758		if (ret) {1759			dev_err(&ctlr->dev,1760				"failed to prepare transfer hardware: %d\n",1761				ret);1762 1763			if (ctlr->auto_runtime_pm)1764				pm_runtime_put(ctlr->dev.parent);1765 1766			msg->status = ret;1767			spi_finalize_current_message(ctlr);1768 1769			return ret;1770		}1771	}1772 1773	trace_spi_message_start(msg);1774 1775	if (ctlr->prepare_message) {1776		ret = ctlr->prepare_message(ctlr, msg);1777		if (ret) {1778			dev_err(&ctlr->dev, "failed to prepare message: %d\n",1779				ret);1780			msg->status = ret;1781			spi_finalize_current_message(ctlr);1782			return ret;1783		}1784		msg->prepared = true;1785	}1786 1787	ret = spi_map_msg(ctlr, msg);1788	if (ret) {1789		msg->status = ret;1790		spi_finalize_current_message(ctlr);1791		return ret;1792	}1793 1794	if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {1795		list_for_each_entry(xfer, &msg->transfers, transfer_list) {1796			xfer->ptp_sts_word_pre = 0;1797			ptp_read_system_prets(xfer->ptp_sts);1798		}1799	}1800 1801	/*1802	 * Drivers implementation of transfer_one_message() must arrange for1803	 * spi_finalize_current_message() to get called. Most drivers will do1804	 * this in the calling context, but some don't. For those cases, a1805	 * completion is used to guarantee that this function does not return1806	 * until spi_finalize_current_message() is done accessing1807	 * ctlr->cur_msg.1808	 * Use of the following two flags enable to opportunistically skip the1809	 * use of the completion since its use involves expensive spin locks.1810	 * In case of a race with the context that calls1811	 * spi_finalize_current_message() the completion will always be used,1812	 * due to strict ordering of these flags using barriers.1813	 */1814	WRITE_ONCE(ctlr->cur_msg_incomplete, true);1815	WRITE_ONCE(ctlr->cur_msg_need_completion, false);1816	reinit_completion(&ctlr->cur_msg_completion);1817	smp_wmb(); /* Make these available to spi_finalize_current_message() */1818 1819	ret = ctlr->transfer_one_message(ctlr, msg);1820	if (ret) {1821		dev_err(&ctlr->dev,1822			"failed to transfer one message from queue\n");1823		return ret;1824	}1825 1826	WRITE_ONCE(ctlr->cur_msg_need_completion, true);1827	smp_mb(); /* See spi_finalize_current_message()... */1828	if (READ_ONCE(ctlr->cur_msg_incomplete))1829		wait_for_completion(&ctlr->cur_msg_completion);1830 1831	return 0;1832}1833 1834/**1835 * __spi_pump_messages - function which processes SPI message queue1836 * @ctlr: controller to process queue for1837 * @in_kthread: true if we are in the context of the message pump thread1838 *1839 * This function checks if there is any SPI message in the queue that1840 * needs processing and if so call out to the driver to initialize hardware1841 * and transfer each message.1842 *1843 * Note that it is called both from the kthread itself and also from1844 * inside spi_sync(); the queue extraction handling at the top of the1845 * function should deal with this safely.1846 */1847static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)1848{1849	struct spi_message *msg;1850	bool was_busy = false;1851	unsigned long flags;1852	int ret;1853 1854	/* Take the I/O mutex */1855	mutex_lock(&ctlr->io_mutex);1856 1857	/* Lock queue */1858	spin_lock_irqsave(&ctlr->queue_lock, flags);1859 1860	/* Make sure we are not already running a message */1861	if (ctlr->cur_msg)1862		goto out_unlock;1863 1864	/* Check if the queue is idle */1865	if (list_empty(&ctlr->queue) || !ctlr->running) {1866		if (!ctlr->busy)1867			goto out_unlock;1868 1869		/* Defer any non-atomic teardown to the thread */1870		if (!in_kthread) {1871			if (!ctlr->dummy_rx && !ctlr->dummy_tx &&1872			    !ctlr->unprepare_transfer_hardware) {1873				spi_idle_runtime_pm(ctlr);1874				ctlr->busy = false;1875				ctlr->queue_empty = true;1876				trace_spi_controller_idle(ctlr);1877			} else {1878				kthread_queue_work(ctlr->kworker,1879						   &ctlr->pump_messages);1880			}1881			goto out_unlock;1882		}1883 1884		ctlr->busy = false;1885		spin_unlock_irqrestore(&ctlr->queue_lock, flags);1886 1887		kfree(ctlr->dummy_rx);1888		ctlr->dummy_rx = NULL;1889		kfree(ctlr->dummy_tx);1890		ctlr->dummy_tx = NULL;1891		if (ctlr->unprepare_transfer_hardware &&1892		    ctlr->unprepare_transfer_hardware(ctlr))1893			dev_err(&ctlr->dev,1894				"failed to unprepare transfer hardware\n");1895		spi_idle_runtime_pm(ctlr);1896		trace_spi_controller_idle(ctlr);1897 1898		spin_lock_irqsave(&ctlr->queue_lock, flags);1899		ctlr->queue_empty = true;1900		goto out_unlock;1901	}1902 1903	/* Extract head of queue */1904	msg = list_first_entry(&ctlr->queue, struct spi_message, queue);1905	ctlr->cur_msg = msg;1906 1907	list_del_init(&msg->queue);1908	if (ctlr->busy)1909		was_busy = true;1910	else1911		ctlr->busy = true;1912	spin_unlock_irqrestore(&ctlr->queue_lock, flags);1913 1914	ret = __spi_pump_transfer_message(ctlr, msg, was_busy);1915	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);1916 1917	ctlr->cur_msg = NULL;1918	ctlr->fallback = false;1919 1920	mutex_unlock(&ctlr->io_mutex);1921 1922	/* Prod the scheduler in case transfer_one() was busy waiting */1923	if (!ret)1924		cond_resched();1925	return;1926 1927out_unlock:1928	spin_unlock_irqrestore(&ctlr->queue_lock, flags);1929	mutex_unlock(&ctlr->io_mutex);1930}1931 1932/**1933 * spi_pump_messages - kthread work function which processes spi message queue1934 * @work: pointer to kthread work struct contained in the controller struct1935 */1936static void spi_pump_messages(struct kthread_work *work)1937{1938	struct spi_controller *ctlr =1939		container_of(work, struct spi_controller, pump_messages);1940 1941	__spi_pump_messages(ctlr, true);1942}1943 1944/**1945 * spi_take_timestamp_pre - helper to collect the beginning of the TX timestamp1946 * @ctlr: Pointer to the spi_controller structure of the driver1947 * @xfer: Pointer to the transfer being timestamped1948 * @progress: How many words (not bytes) have been transferred so far1949 * @irqs_off: If true, will disable IRQs and preemption for the duration of the1950 *	      transfer, for less jitter in time measurement. Only compatible1951 *	      with PIO drivers. If true, must follow up with1952 *	      spi_take_timestamp_post or otherwise system will crash.1953 *	      WARNING: for fully predictable results, the CPU frequency must1954 *	      also be under control (governor).1955 *1956 * This is a helper for drivers to collect the beginning of the TX timestamp1957 * for the requested byte from the SPI transfer. The frequency with which this1958 * function must be called (once per word, once for the whole transfer, once1959 * per batch of words etc) is arbitrary as long as the @tx buffer offset is1960 * greater than or equal to the requested byte at the time of the call. The1961 * timestamp is only taken once, at the first such call. It is assumed that1962 * the driver advances its @tx buffer pointer monotonically.1963 */1964void spi_take_timestamp_pre(struct spi_controller *ctlr,1965			    struct spi_transfer *xfer,1966			    size_t progress, bool irqs_off)1967{1968	if (!xfer->ptp_sts)1969		return;1970 1971	if (xfer->timestamped)1972		return;1973 1974	if (progress > xfer->ptp_sts_word_pre)1975		return;1976 1977	/* Capture the resolution of the timestamp */1978	xfer->ptp_sts_word_pre = progress;1979 1980	if (irqs_off) {1981		local_irq_save(ctlr->irq_flags);1982		preempt_disable();1983	}1984 1985	ptp_read_system_prets(xfer->ptp_sts);1986}1987EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);1988 1989/**1990 * spi_take_timestamp_post - helper to collect the end of the TX timestamp1991 * @ctlr: Pointer to the spi_controller structure of the driver1992 * @xfer: Pointer to the transfer being timestamped1993 * @progress: How many words (not bytes) have been transferred so far1994 * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.1995 *1996 * This is a helper for drivers to collect the end of the TX timestamp for1997 * the requested byte from the SPI transfer. Can be called with an arbitrary1998 * frequency: only the first call where @tx exceeds or is equal to the1999 * requested word will be timestamped.2000 */2001void spi_take_timestamp_post(struct spi_controller *ctlr,2002			     struct spi_transfer *xfer,2003			     size_t progress, bool irqs_off)2004{2005	if (!xfer->ptp_sts)2006		return;2007 2008	if (xfer->timestamped)2009		return;2010 2011	if (progress < xfer->ptp_sts_word_post)2012		return;2013 2014	ptp_read_system_postts(xfer->ptp_sts);2015 2016	if (irqs_off) {2017		local_irq_restore(ctlr->irq_flags);2018		preempt_enable();2019	}2020 2021	/* Capture the resolution of the timestamp */2022	xfer->ptp_sts_word_post = progress;2023 2024	xfer->timestamped = 1;2025}2026EXPORT_SYMBOL_GPL(spi_take_timestamp_post);2027 2028/**2029 * spi_set_thread_rt - set the controller to pump at realtime priority2030 * @ctlr: controller to boost priority of2031 *2032 * This can be called because the controller requested realtime priority2033 * (by setting the ->rt value before calling spi_register_controller()) or2034 * because a device on the bus said that its transfers needed realtime2035 * priority.2036 *2037 * NOTE: at the moment if any device on a bus says it needs realtime then2038 * the thread will be at realtime priority for all transfers on that2039 * controller.  If this eventually becomes a problem we may see if we can2040 * find a way to boost the priority only temporarily during relevant2041 * transfers.2042 */2043static void spi_set_thread_rt(struct spi_controller *ctlr)2044{2045	dev_info(&ctlr->dev,2046		"will run message pump with realtime priority\n");2047	sched_set_fifo(ctlr->kworker->task);2048}2049 2050static int spi_init_queue(struct spi_controller *ctlr)2051{2052	ctlr->running = false;2053	ctlr->busy = false;2054	ctlr->queue_empty = true;2055 2056	ctlr->kworker = kthread_create_worker(0, dev_name(&ctlr->dev));2057	if (IS_ERR(ctlr->kworker)) {2058		dev_err(&ctlr->dev, "failed to create message pump kworker\n");2059		return PTR_ERR(ctlr->kworker);2060	}2061 2062	kthread_init_work(&ctlr->pump_messages, spi_pump_messages);2063 2064	/*2065	 * Controller config will indicate if this controller should run the2066	 * message pump with high (realtime) priority to reduce the transfer2067	 * latency on the bus by minimising the delay between a transfer2068	 * request and the scheduling of the message pump thread. Without this2069	 * setting the message pump thread will remain at default priority.2070	 */2071	if (ctlr->rt)2072		spi_set_thread_rt(ctlr);2073 2074	return 0;2075}2076 2077/**2078 * spi_get_next_queued_message() - called by driver to check for queued2079 * messages2080 * @ctlr: the controller to check for queued messages2081 *2082 * If there are more messages in the queue, the next message is returned from2083 * this call.2084 *2085 * Return: the next message in the queue, else NULL if the queue is empty.2086 */2087struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)2088{2089	struct spi_message *next;2090	unsigned long flags;2091 2092	/* Get a pointer to the next message, if any */2093	spin_lock_irqsave(&ctlr->queue_lock, flags);2094	next = list_first_entry_or_null(&ctlr->queue, struct spi_message,2095					queue);2096	spin_unlock_irqrestore(&ctlr->queue_lock, flags);2097 2098	return next;2099}2100EXPORT_SYMBOL_GPL(spi_get_next_queued_message);2101 2102/*2103 * __spi_unoptimize_message - shared implementation of spi_unoptimize_message()2104 *                            and spi_maybe_unoptimize_message()2105 * @msg: the message to unoptimize2106 *2107 * Peripheral drivers should use spi_unoptimize_message() and callers inside2108 * core should use spi_maybe_unoptimize_message() rather than calling this2109 * function directly.2110 *2111 * It is not valid to call this on a message that is not currently optimized.2112 */2113static void __spi_unoptimize_message(struct spi_message *msg)2114{2115	struct spi_controller *ctlr = msg->spi->controller;2116 2117	if (ctlr->unoptimize_message)2118		ctlr->unoptimize_message(msg);2119 2120	spi_res_release(ctlr, msg);2121 2122	msg->optimized = false;2123	msg->opt_state = NULL;2124}2125 2126/*2127 * spi_maybe_unoptimize_message - unoptimize msg not managed by a peripheral2128 * @msg: the message to unoptimize2129 *2130 * This function is used to unoptimize a message if and only if it was2131 * optimized by the core (via spi_maybe_optimize_message()).2132 */2133static void spi_maybe_unoptimize_message(struct spi_message *msg)2134{2135	if (!msg->pre_optimized && msg->optimized &&2136	    !msg->spi->controller->defer_optimize_message)2137		__spi_unoptimize_message(msg);2138}2139 2140/**2141 * spi_finalize_current_message() - the current message is complete2142 * @ctlr: the controller to return the message to2143 *2144 * Called by the driver to notify the core that the message in the front of the2145 * queue is complete and can be removed from the queue.2146 */2147void spi_finalize_current_message(struct spi_controller *ctlr)2148{2149	struct spi_transfer *xfer;2150	struct spi_message *mesg;2151	int ret;2152 2153	mesg = ctlr->cur_msg;2154 2155	if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {2156		list_for_each_entry(xfer, &mesg->transfers, transfer_list) {2157			ptp_read_system_postts(xfer->ptp_sts);2158			xfer->ptp_sts_word_post = xfer->len;2159		}2160	}2161 2162	if (unlikely(ctlr->ptp_sts_supported))2163		list_for_each_entry(xfer, &mesg->transfers, transfer_list)2164			WARN_ON_ONCE(xfer->ptp_sts && !xfer->timestamped);2165 2166	spi_unmap_msg(ctlr, mesg);2167 2168	if (mesg->prepared && ctlr->unprepare_message) {2169		ret = ctlr->unprepare_message(ctlr, mesg);2170		if (ret) {2171			dev_err(&ctlr->dev, "failed to unprepare message: %d\n",2172				ret);2173		}2174	}2175 2176	mesg->prepared = false;2177 2178	spi_maybe_unoptimize_message(mesg);2179 2180	WRITE_ONCE(ctlr->cur_msg_incomplete, false);2181	smp_mb(); /* See __spi_pump_transfer_message()... */2182	if (READ_ONCE(ctlr->cur_msg_need_completion))2183		complete(&ctlr->cur_msg_completion);2184 2185	trace_spi_message_done(mesg);2186 2187	mesg->state = NULL;2188	if (mesg->complete)2189		mesg->complete(mesg->context);2190}2191EXPORT_SYMBOL_GPL(spi_finalize_current_message);2192 2193static int spi_start_queue(struct spi_controller *ctlr)2194{2195	unsigned long flags;2196 2197	spin_lock_irqsave(&ctlr->queue_lock, flags);2198 2199	if (ctlr->running || ctlr->busy) {2200		spin_unlock_irqrestore(&ctlr->queue_lock, flags);2201		return -EBUSY;2202	}2203 2204	ctlr->running = true;2205	ctlr->cur_msg = NULL;2206	spin_unlock_irqrestore(&ctlr->queue_lock, flags);2207 2208	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);2209 2210	return 0;2211}2212 2213static int spi_stop_queue(struct spi_controller *ctlr)2214{2215	unsigned int limit = 500;2216	unsigned long flags;2217 2218	/*2219	 * This is a bit lame, but is optimized for the common execution path.2220	 * A wait_queue on the ctlr->busy could be used, but then the common2221	 * execution path (pump_messages) would be required to call wake_up or2222	 * friends on every SPI message. Do this instead.2223	 */2224	do {2225		spin_lock_irqsave(&ctlr->queue_lock, flags);2226		if (list_empty(&ctlr->queue) && !ctlr->busy) {2227			ctlr->running = false;2228			spin_unlock_irqrestore(&ctlr->queue_lock, flags);2229			return 0;2230		}2231		spin_unlock_irqrestore(&ctlr->queue_lock, flags);2232		usleep_range(10000, 11000);2233	} while (--limit);2234 2235	return -EBUSY;2236}2237 2238static int spi_destroy_queue(struct spi_controller *ctlr)2239{2240	int ret;2241 2242	ret = spi_stop_queue(ctlr);2243 2244	/*2245	 * kthread_flush_worker will block until all work is done.2246	 * If the reason that stop_queue timed out is that the work will never2247	 * finish, then it does no good to call flush/stop thread, so2248	 * return anyway.2249	 */2250	if (ret) {2251		dev_err(&ctlr->dev, "problem destroying queue\n");2252		return ret;2253	}2254 2255	kthread_destroy_worker(ctlr->kworker);2256 2257	return 0;2258}2259 2260static int __spi_queued_transfer(struct spi_device *spi,2261				 struct spi_message *msg,2262				 bool need_pump)2263{2264	struct spi_controller *ctlr = spi->controller;2265	unsigned long flags;2266 2267	spin_lock_irqsave(&ctlr->queue_lock, flags);2268 2269	if (!ctlr->running) {2270		spin_unlock_irqrestore(&ctlr->queue_lock, flags);2271		return -ESHUTDOWN;2272	}2273	msg->actual_length = 0;2274	msg->status = -EINPROGRESS;2275 2276	list_add_tail(&msg->queue, &ctlr->queue);2277	ctlr->queue_empty = false;2278	if (!ctlr->busy && need_pump)2279		kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);2280 2281	spin_unlock_irqrestore(&ctlr->queue_lock, flags);2282	return 0;2283}2284 2285/**2286 * spi_queued_transfer - transfer function for queued transfers2287 * @spi: SPI device which is requesting transfer2288 * @msg: SPI message which is to handled is queued to driver queue2289 *2290 * Return: zero on success, else a negative error code.2291 */2292static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)2293{2294	return __spi_queued_transfer(spi, msg, true);2295}2296 2297static int spi_controller_initialize_queue(struct spi_controller *ctlr)2298{2299	int ret;2300 2301	ctlr->transfer = spi_queued_transfer;2302	if (!ctlr->transfer_one_message)2303		ctlr->transfer_one_message = spi_transfer_one_message;2304 2305	/* Initialize and start queue */2306	ret = spi_init_queue(ctlr);2307	if (ret) {2308		dev_err(&ctlr->dev, "problem initializing queue\n");2309		goto err_init_queue;2310	}2311	ctlr->queued = true;2312	ret = spi_start_queue(ctlr);2313	if (ret) {2314		dev_err(&ctlr->dev, "problem starting queue\n");2315		goto err_start_queue;2316	}2317 2318	return 0;2319 2320err_start_queue:2321	spi_destroy_queue(ctlr);2322err_init_queue:2323	return ret;2324}2325 2326/**2327 * spi_flush_queue - Send all pending messages in the queue from the callers'2328 *		     context2329 * @ctlr: controller to process queue for2330 *2331 * This should be used when one wants to ensure all pending messages have been2332 * sent before doing something. Is used by the spi-mem code to make sure SPI2333 * memory operations do not preempt regular SPI transfers that have been queued2334 * before the spi-mem operation.2335 */2336void spi_flush_queue(struct spi_controller *ctlr)2337{2338	if (ctlr->transfer == spi_queued_transfer)2339		__spi_pump_messages(ctlr, false);2340}2341 2342/*-------------------------------------------------------------------------*/2343 2344#if defined(CONFIG_OF)2345static void of_spi_parse_dt_cs_delay(struct device_node *nc,2346				     struct spi_delay *delay, const char *prop)2347{2348	u32 value;2349 2350	if (!of_property_read_u32(nc, prop, &value)) {2351		if (value > U16_MAX) {2352			delay->value = DIV_ROUND_UP(value, 1000);2353			delay->unit = SPI_DELAY_UNIT_USECS;2354		} else {2355			delay->value = value;2356			delay->unit = SPI_DELAY_UNIT_NSECS;2357		}2358	}2359}2360 2361static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,2362			   struct device_node *nc)2363{2364	u32 value, cs[SPI_CS_CNT_MAX];2365	int rc, idx;2366 2367	/* Mode (clock phase/polarity/etc.) */2368	if (of_property_read_bool(nc, "spi-cpha"))2369		spi->mode |= SPI_CPHA;2370	if (of_property_read_bool(nc, "spi-cpol"))2371		spi->mode |= SPI_CPOL;2372	if (of_property_read_bool(nc, "spi-3wire"))2373		spi->mode |= SPI_3WIRE;2374	if (of_property_read_bool(nc, "spi-lsb-first"))2375		spi->mode |= SPI_LSB_FIRST;2376	if (of_property_read_bool(nc, "spi-cs-high"))2377		spi->mode |= SPI_CS_HIGH;2378 2379	/* Device DUAL/QUAD mode */2380	if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {2381		switch (value) {2382		case 0:2383			spi->mode |= SPI_NO_TX;2384			break;2385		case 1:2386			break;2387		case 2:2388			spi->mode |= SPI_TX_DUAL;2389			break;2390		case 4:2391			spi->mode |= SPI_TX_QUAD;2392			break;2393		case 8:2394			spi->mode |= SPI_TX_OCTAL;2395			break;2396		default:2397			dev_warn(&ctlr->dev,2398				"spi-tx-bus-width %d not supported\n",2399				value);2400			break;2401		}2402	}2403 2404	if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {2405		switch (value) {2406		case 0:2407			spi->mode |= SPI_NO_RX;2408			break;2409		case 1:2410			break;2411		case 2:2412			spi->mode |= SPI_RX_DUAL;2413			break;2414		case 4:2415			spi->mode |= SPI_RX_QUAD;2416			break;2417		case 8:2418			spi->mode |= SPI_RX_OCTAL;2419			break;2420		default:2421			dev_warn(&ctlr->dev,2422				"spi-rx-bus-width %d not supported\n",2423				value);2424			break;2425		}2426	}2427 2428	if (spi_controller_is_target(ctlr)) {2429		if (!of_node_name_eq(nc, "slave")) {2430			dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",2431				nc);2432			return -EINVAL;2433		}2434		return 0;2435	}2436 2437	if (ctlr->num_chipselect > SPI_CS_CNT_MAX) {2438		dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n");2439		return -EINVAL;2440	}2441 2442	spi_set_all_cs_unused(spi);2443 2444	/* Device address */2445	rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1,2446						 SPI_CS_CNT_MAX);2447	if (rc < 0) {2448		dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",2449			nc, rc);2450		return rc;2451	}2452	if (rc > ctlr->num_chipselect) {2453		dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n",2454			nc, rc);2455		return rc;2456	}2457	if ((of_property_read_bool(nc, "parallel-memories")) &&2458	    (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) {2459		dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n");2460		return -EINVAL;2461	}2462	for (idx = 0; idx < rc; idx++)2463		spi_set_chipselect(spi, idx, cs[idx]);2464 2465	/*2466	 * By default spi->chip_select[0] will hold the physical CS number,2467	 * so set bit 0 in spi->cs_index_mask.2468	 */2469	spi->cs_index_mask = BIT(0);2470 2471	/* Device speed */2472	if (!of_property_read_u32(nc, "spi-max-frequency", &value))2473		spi->max_speed_hz = value;2474 2475	/* Device CS delays */2476	of_spi_parse_dt_cs_delay(nc, &spi->cs_setup, "spi-cs-setup-delay-ns");2477	of_spi_parse_dt_cs_delay(nc, &spi->cs_hold, "spi-cs-hold-delay-ns");2478	of_spi_parse_dt_cs_delay(nc, &spi->cs_inactive, "spi-cs-inactive-delay-ns");2479 2480	return 0;2481}2482 2483static struct spi_device *2484of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)2485{2486	struct spi_device *spi;2487	int rc;2488 2489	/* Alloc an spi_device */2490	spi = spi_alloc_device(ctlr);2491	if (!spi) {2492		dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);2493		rc = -ENOMEM;2494		goto err_out;2495	}2496 2497	/* Select device driver */2498	rc = of_alias_from_compatible(nc, spi->modalias,2499				      sizeof(spi->modalias));2500	if (rc < 0) {2501		dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);2502		goto err_out;2503	}2504 2505	rc = of_spi_parse_dt(ctlr, spi, nc);2506	if (rc)2507		goto err_out;2508 2509	/* Store a pointer to the node in the device structure */2510	of_node_get(nc);2511 2512	device_set_node(&spi->dev, of_fwnode_handle(nc));2513 2514	/* Register the new device */2515	rc = spi_add_device(spi);2516	if (rc) {2517		dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);2518		goto err_of_node_put;2519	}2520 2521	return spi;2522 2523err_of_node_put:2524	of_node_put(nc);2525err_out:2526	spi_dev_put(spi);2527	return ERR_PTR(rc);2528}2529 2530/**2531 * of_register_spi_devices() - Register child devices onto the SPI bus2532 * @ctlr:	Pointer to spi_controller device2533 *2534 * Registers an spi_device for each child node of controller node which2535 * represents a valid SPI slave.2536 */2537static void of_register_spi_devices(struct spi_controller *ctlr)2538{2539	struct spi_device *spi;2540	struct device_node *nc;2541 2542	for_each_available_child_of_node(ctlr->dev.of_node, nc) {2543		if (of_node_test_and_set_flag(nc, OF_POPULATED))2544			continue;2545		spi = of_register_spi_device(ctlr, nc);2546		if (IS_ERR(spi)) {2547			dev_warn(&ctlr->dev,2548				 "Failed to create SPI device for %pOF\n", nc);2549			of_node_clear_flag(nc, OF_POPULATED);2550		}2551	}2552}2553#else2554static void of_register_spi_devices(struct spi_controller *ctlr) { }2555#endif2556 2557/**2558 * spi_new_ancillary_device() - Register ancillary SPI device2559 * @spi:         Pointer to the main SPI device registering the ancillary device2560 * @chip_select: Chip Select of the ancillary device2561 *2562 * Register an ancillary SPI device; for example some chips have a chip-select2563 * for normal device usage and another one for setup/firmware upload.2564 *2565 * This may only be called from main SPI device's probe routine.2566 *2567 * Return: 0 on success; negative errno on failure2568 */2569struct spi_device *spi_new_ancillary_device(struct spi_device *spi,2570					     u8 chip_select)2571{2572	struct spi_controller *ctlr = spi->controller;2573	struct spi_device *ancillary;2574	int rc;2575 2576	/* Alloc an spi_device */2577	ancillary = spi_alloc_device(ctlr);2578	if (!ancillary) {2579		rc = -ENOMEM;2580		goto err_out;2581	}2582 2583	strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));2584 2585	/* Use provided chip-select for ancillary device */2586	spi_set_all_cs_unused(ancillary);2587	spi_set_chipselect(ancillary, 0, chip_select);2588 2589	/* Take over SPI mode/speed from SPI main device */2590	ancillary->max_speed_hz = spi->max_speed_hz;2591	ancillary->mode = spi->mode;2592	/*2593	 * By default spi->chip_select[0] will hold the physical CS number,2594	 * so set bit 0 in spi->cs_index_mask.2595	 */2596	ancillary->cs_index_mask = BIT(0);2597 2598	WARN_ON(!mutex_is_locked(&ctlr->add_lock));2599 2600	/* Register the new device */2601	rc = __spi_add_device(ancillary);2602	if (rc) {2603		dev_err(&spi->dev, "failed to register ancillary device\n");2604		goto err_out;2605	}2606 2607	return ancillary;2608 2609err_out:2610	spi_dev_put(ancillary);2611	return ERR_PTR(rc);2612}2613EXPORT_SYMBOL_GPL(spi_new_ancillary_device);2614 2615#ifdef CONFIG_ACPI2616struct acpi_spi_lookup {2617	struct spi_controller 	*ctlr;2618	u32			max_speed_hz;2619	u32			mode;2620	int			irq;2621	u8			bits_per_word;2622	u8			chip_select;2623	int			n;2624	int			index;2625};2626 2627static int acpi_spi_count(struct acpi_resource *ares, void *data)2628{2629	struct acpi_resource_spi_serialbus *sb;2630	int *count = data;2631 2632	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)2633		return 1;2634 2635	sb = &ares->data.spi_serial_bus;2636	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)2637		return 1;2638 2639	*count = *count + 1;2640 2641	return 1;2642}2643 2644/**2645 * acpi_spi_count_resources - Count the number of SpiSerialBus resources2646 * @adev:	ACPI device2647 *2648 * Return: the number of SpiSerialBus resources in the ACPI-device's2649 * resource-list; or a negative error code.2650 */2651int acpi_spi_count_resources(struct acpi_device *adev)2652{2653	LIST_HEAD(r);2654	int count = 0;2655	int ret;2656 2657	ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);2658	if (ret < 0)2659		return ret;2660 2661	acpi_dev_free_resource_list(&r);2662 2663	return count;2664}2665EXPORT_SYMBOL_GPL(acpi_spi_count_resources);2666 2667static void acpi_spi_parse_apple_properties(struct acpi_device *dev,2668					    struct acpi_spi_lookup *lookup)2669{2670	const union acpi_object *obj;2671 2672	if (!x86_apple_machine)2673		return;2674 2675	if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)2676	    && obj->buffer.length >= 4)2677		lookup->max_speed_hz  = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;2678 2679	if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)2680	    && obj->buffer.length == 8)2681		lookup->bits_per_word = *(u64 *)obj->buffer.pointer;2682 2683	if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)2684	    && obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)2685		lookup->mode |= SPI_LSB_FIRST;2686 2687	if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)2688	    && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)2689		lookup->mode |= SPI_CPOL;2690 2691	if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)2692	    && obj->buffer.length == 8 &&  *(u64 *)obj->buffer.pointer)2693		lookup->mode |= SPI_CPHA;2694}2695 2696static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)2697{2698	struct acpi_spi_lookup *lookup = data;2699	struct spi_controller *ctlr = lookup->ctlr;2700 2701	if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {2702		struct acpi_resource_spi_serialbus *sb;2703		acpi_handle parent_handle;2704		acpi_status status;2705 2706		sb = &ares->data.spi_serial_bus;2707		if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {2708 2709			if (lookup->index != -1 && lookup->n++ != lookup->index)2710				return 1;2711 2712			status = acpi_get_handle(NULL,2713						 sb->resource_source.string_ptr,2714						 &parent_handle);2715 2716			if (ACPI_FAILURE(status))2717				return -ENODEV;2718 2719			if (ctlr) {2720				if (!device_match_acpi_handle(ctlr->dev.parent, parent_handle))2721					return -ENODEV;2722			} else {2723				struct acpi_device *adev;2724 2725				adev = acpi_fetch_acpi_dev(parent_handle);2726				if (!adev)2727					return -ENODEV;2728 2729				ctlr = acpi_spi_find_controller_by_adev(adev);2730				if (!ctlr)2731					return -EPROBE_DEFER;2732 2733				lookup->ctlr = ctlr;2734			}2735 2736			/*2737			 * ACPI DeviceSelection numbering is handled by the2738			 * host controller driver in Windows and can vary2739			 * from driver to driver. In Linux we always expect2740			 * 0 .. max - 1 so we need to ask the driver to2741			 * translate between the two schemes.2742			 */2743			if (ctlr->fw_translate_cs) {2744				int cs = ctlr->fw_translate_cs(ctlr,2745						sb->device_selection);2746				if (cs < 0)2747					return cs;2748				lookup->chip_select = cs;2749			} else {2750				lookup->chip_select = sb->device_selection;2751			}2752 2753			lookup->max_speed_hz = sb->connection_speed;2754			lookup->bits_per_word = sb->data_bit_length;2755 2756			if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)2757				lookup->mode |= SPI_CPHA;2758			if (sb->clock_polarity == ACPI_SPI_START_HIGH)2759				lookup->mode |= SPI_CPOL;2760			if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)2761				lookup->mode |= SPI_CS_HIGH;2762		}2763	} else if (lookup->irq < 0) {2764		struct resource r;2765 2766		if (acpi_dev_resource_interrupt(ares, 0, &r))2767			lookup->irq = r.start;2768	}2769 2770	/* Always tell the ACPI core to skip this resource */2771	return 1;2772}2773 2774/**2775 * acpi_spi_device_alloc - Allocate a spi device, and fill it in with ACPI information2776 * @ctlr: controller to which the spi device belongs2777 * @adev: ACPI Device for the spi device2778 * @index: Index of the spi resource inside the ACPI Node2779 *2780 * This should be used to allocate a new SPI device from and ACPI Device node.2781 * The caller is responsible for calling spi_add_device to register the SPI device.2782 *2783 * If ctlr is set to NULL, the Controller for the SPI device will be looked up2784 * using the resource.2785 * If index is set to -1, index is not used.2786 * Note: If index is -1, ctlr must be set.2787 *2788 * Return: a pointer to the new device, or ERR_PTR on error.2789 */2790struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,2791					 struct acpi_device *adev,2792					 int index)2793{2794	acpi_handle parent_handle = NULL;2795	struct list_head resource_list;2796	struct acpi_spi_lookup lookup = {};2797	struct spi_device *spi;2798	int ret;2799 2800	if (!ctlr && index == -1)2801		return ERR_PTR(-EINVAL);2802 2803	lookup.ctlr		= ctlr;2804	lookup.irq		= -1;2805	lookup.index		= index;2806	lookup.n		= 0;2807 2808	INIT_LIST_HEAD(&resource_list);2809	ret = acpi_dev_get_resources(adev, &resource_list,2810				     acpi_spi_add_resource, &lookup);2811	acpi_dev_free_resource_list(&resource_list);2812 2813	if (ret < 0)2814		/* Found SPI in _CRS but it points to another controller */2815		return ERR_PTR(ret);2816 2817	if (!lookup.max_speed_hz &&2818	    ACPI_SUCCESS(acpi_get_parent(adev->handle, &parent_handle)) &&2819	    device_match_acpi_handle(lookup.ctlr->dev.parent, parent_handle)) {2820		/* Apple does not use _CRS but nested devices for SPI slaves */2821		acpi_spi_parse_apple_properties(adev, &lookup);2822	}2823 2824	if (!lookup.max_speed_hz)2825		return ERR_PTR(-ENODEV);2826 2827	spi = spi_alloc_device(lookup.ctlr);2828	if (!spi) {2829		dev_err(&lookup.ctlr->dev, "failed to allocate SPI device for %s\n",2830			dev_name(&adev->dev));2831		return ERR_PTR(-ENOMEM);2832	}2833 2834	spi_set_all_cs_unused(spi);2835	spi_set_chipselect(spi, 0, lookup.chip_select);2836 2837	ACPI_COMPANION_SET(&spi->dev, adev);2838	spi->max_speed_hz	= lookup.max_speed_hz;2839	spi->mode		|= lookup.mode;2840	spi->irq		= lookup.irq;2841	spi->bits_per_word	= lookup.bits_per_word;2842	/*2843	 * By default spi->chip_select[0] will hold the physical CS number,2844	 * so set bit 0 in spi->cs_index_mask.2845	 */2846	spi->cs_index_mask	= BIT(0);2847 2848	return spi;2849}2850EXPORT_SYMBOL_GPL(acpi_spi_device_alloc);2851 2852static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,2853					    struct acpi_device *adev)2854{2855	struct spi_device *spi;2856 2857	if (acpi_bus_get_status(adev) || !adev->status.present ||2858	    acpi_device_enumerated(adev))2859		return AE_OK;2860 2861	spi = acpi_spi_device_alloc(ctlr, adev, -1);2862	if (IS_ERR(spi)) {2863		if (PTR_ERR(spi) == -ENOMEM)2864			return AE_NO_MEMORY;2865		else2866			return AE_OK;2867	}2868 2869	acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,2870			  sizeof(spi->modalias));2871 2872	if (spi->irq < 0)2873		spi->irq = acpi_dev_gpio_irq_get(adev, 0);2874 2875	acpi_device_set_enumerated(adev);2876 2877	adev->power.flags.ignore_parent = true;2878	if (spi_add_device(spi)) {2879		adev->power.flags.ignore_parent = false;2880		dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",2881			dev_name(&adev->dev));2882		spi_dev_put(spi);2883	}2884 2885	return AE_OK;2886}2887 2888static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,2889				       void *data, void **return_value)2890{2891	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);2892	struct spi_controller *ctlr = data;2893 2894	if (!adev)2895		return AE_OK;2896 2897	return acpi_register_spi_device(ctlr, adev);2898}2899 2900#define SPI_ACPI_ENUMERATE_MAX_DEPTH		322901 2902static void acpi_register_spi_devices(struct spi_controller *ctlr)2903{2904	acpi_status status;2905	acpi_handle handle;2906 2907	handle = ACPI_HANDLE(ctlr->dev.parent);2908	if (!handle)2909		return;2910 2911	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,2912				     SPI_ACPI_ENUMERATE_MAX_DEPTH,2913				     acpi_spi_add_device, NULL, ctlr, NULL);2914	if (ACPI_FAILURE(status))2915		dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");2916}2917#else2918static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}2919#endif /* CONFIG_ACPI */2920 2921static void spi_controller_release(struct device *dev)2922{2923	struct spi_controller *ctlr;2924 2925	ctlr = container_of(dev, struct spi_controller, dev);2926	kfree(ctlr);2927}2928 2929static struct class spi_master_class = {2930	.name		= "spi_master",2931	.dev_release	= spi_controller_release,2932	.dev_groups	= spi_master_groups,2933};2934 2935#ifdef CONFIG_SPI_SLAVE2936/**2937 * spi_target_abort - abort the ongoing transfer request on an SPI slave2938 *		     controller2939 * @spi: device used for the current transfer2940 */2941int spi_target_abort(struct spi_device *spi)2942{2943	struct spi_controller *ctlr = spi->controller;2944 2945	if (spi_controller_is_target(ctlr) && ctlr->target_abort)2946		return ctlr->target_abort(ctlr);2947 2948	return -ENOTSUPP;2949}2950EXPORT_SYMBOL_GPL(spi_target_abort);2951 2952static ssize_t slave_show(struct device *dev, struct device_attribute *attr,2953			  char *buf)2954{2955	struct spi_controller *ctlr = container_of(dev, struct spi_controller,2956						   dev);2957	struct device *child;2958 2959	child = device_find_any_child(&ctlr->dev);2960	return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL);2961}2962 2963static ssize_t slave_store(struct device *dev, struct device_attribute *attr,2964			   const char *buf, size_t count)2965{2966	struct spi_controller *ctlr = container_of(dev, struct spi_controller,2967						   dev);2968	struct spi_device *spi;2969	struct device *child;2970	char name[32];2971	int rc;2972 2973	rc = sscanf(buf, "%31s", name);2974	if (rc != 1 || !name[0])2975		return -EINVAL;2976 2977	child = device_find_any_child(&ctlr->dev);2978	if (child) {2979		/* Remove registered slave */2980		device_unregister(child);2981		put_device(child);2982	}2983 2984	if (strcmp(name, "(null)")) {2985		/* Register new slave */2986		spi = spi_alloc_device(ctlr);2987		if (!spi)2988			return -ENOMEM;2989 2990		strscpy(spi->modalias, name, sizeof(spi->modalias));2991 2992		rc = spi_add_device(spi);2993		if (rc) {2994			spi_dev_put(spi);2995			return rc;2996		}2997	}2998 2999	return count;3000}3001 3002static DEVICE_ATTR_RW(slave);3003 3004static struct attribute *spi_slave_attrs[] = {3005	&dev_attr_slave.attr,3006	NULL,3007};3008 3009static const struct attribute_group spi_slave_group = {3010	.attrs = spi_slave_attrs,3011};3012 3013static const struct attribute_group *spi_slave_groups[] = {3014	&spi_controller_statistics_group,3015	&spi_slave_group,3016	NULL,3017};3018 3019static struct class spi_slave_class = {3020	.name		= "spi_slave",3021	.dev_release	= spi_controller_release,3022	.dev_groups	= spi_slave_groups,3023};3024#else3025extern struct class spi_slave_class;	/* dummy */3026#endif3027 3028/**3029 * __spi_alloc_controller - allocate an SPI master or slave controller3030 * @dev: the controller, possibly using the platform_bus3031 * @size: how much zeroed driver-private data to allocate; the pointer to this3032 *	memory is in the driver_data field of the returned device, accessible3033 *	with spi_controller_get_devdata(); the memory is cacheline aligned;3034 *	drivers granting DMA access to portions of their private data need to3035 *	round up @size using ALIGN(size, dma_get_cache_alignment()).3036 * @slave: flag indicating whether to allocate an SPI master (false) or SPI3037 *	slave (true) controller3038 * Context: can sleep3039 *3040 * This call is used only by SPI controller drivers, which are the3041 * only ones directly touching chip registers.  It's how they allocate3042 * an spi_controller structure, prior to calling spi_register_controller().3043 *3044 * This must be called from context that can sleep.3045 *3046 * The caller is responsible for assigning the bus number and initializing the3047 * controller's methods before calling spi_register_controller(); and (after3048 * errors adding the device) calling spi_controller_put() to prevent a memory3049 * leak.3050 *3051 * Return: the SPI controller structure on success, else NULL.3052 */3053struct spi_controller *__spi_alloc_controller(struct device *dev,3054					      unsigned int size, bool slave)3055{3056	struct spi_controller	*ctlr;3057	size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());3058 3059	if (!dev)3060		return NULL;3061 3062	ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);3063	if (!ctlr)3064		return NULL;3065 3066	device_initialize(&ctlr->dev);3067	INIT_LIST_HEAD(&ctlr->queue);3068	spin_lock_init(&ctlr->queue_lock);3069	spin_lock_init(&ctlr->bus_lock_spinlock);3070	mutex_init(&ctlr->bus_lock_mutex);3071	mutex_init(&ctlr->io_mutex);3072	mutex_init(&ctlr->add_lock);3073	ctlr->bus_num = -1;3074	ctlr->num_chipselect = 1;3075	ctlr->slave = slave;3076	if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)3077		ctlr->dev.class = &spi_slave_class;3078	else3079		ctlr->dev.class = &spi_master_class;3080	ctlr->dev.parent = dev;3081	pm_suspend_ignore_children(&ctlr->dev, true);3082	spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);3083 3084	return ctlr;3085}3086EXPORT_SYMBOL_GPL(__spi_alloc_controller);3087 3088static void devm_spi_release_controller(struct device *dev, void *ctlr)3089{3090	spi_controller_put(*(struct spi_controller **)ctlr);3091}3092 3093/**3094 * __devm_spi_alloc_controller - resource-managed __spi_alloc_controller()3095 * @dev: physical device of SPI controller3096 * @size: how much zeroed driver-private data to allocate3097 * @slave: whether to allocate an SPI master (false) or SPI slave (true)3098 * Context: can sleep3099 *3100 * Allocate an SPI controller and automatically release a reference on it3101 * when @dev is unbound from its driver.  Drivers are thus relieved from3102 * having to call spi_controller_put().3103 *3104 * The arguments to this function are identical to __spi_alloc_controller().3105 *3106 * Return: the SPI controller structure on success, else NULL.3107 */3108struct spi_controller *__devm_spi_alloc_controller(struct device *dev,3109						   unsigned int size,3110						   bool slave)3111{3112	struct spi_controller **ptr, *ctlr;3113 3114	ptr = devres_alloc(devm_spi_release_controller, sizeof(*ptr),3115			   GFP_KERNEL);3116	if (!ptr)3117		return NULL;3118 3119	ctlr = __spi_alloc_controller(dev, size, slave);3120	if (ctlr) {3121		ctlr->devm_allocated = true;3122		*ptr = ctlr;3123		devres_add(dev, ptr);3124	} else {3125		devres_free(ptr);3126	}3127 3128	return ctlr;3129}3130EXPORT_SYMBOL_GPL(__devm_spi_alloc_controller);3131 3132/**3133 * spi_get_gpio_descs() - grab chip select GPIOs for the master3134 * @ctlr: The SPI master to grab GPIO descriptors for3135 */3136static int spi_get_gpio_descs(struct spi_controller *ctlr)3137{3138	int nb, i;3139	struct gpio_desc **cs;3140	struct device *dev = &ctlr->dev;3141	unsigned long native_cs_mask = 0;3142	unsigned int num_cs_gpios = 0;3143 3144	nb = gpiod_count(dev, "cs");3145	if (nb < 0) {3146		/* No GPIOs at all is fine, else return the error */3147		if (nb == -ENOENT)3148			return 0;3149		return nb;3150	}3151 3152	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);3153 3154	cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),3155			  GFP_KERNEL);3156	if (!cs)3157		return -ENOMEM;3158	ctlr->cs_gpiods = cs;3159 3160	for (i = 0; i < nb; i++) {3161		/*3162		 * Most chipselects are active low, the inverted3163		 * semantics are handled by special quirks in gpiolib,3164		 * so initializing them GPIOD_OUT_LOW here means3165		 * "unasserted", in most cases this will drive the physical3166		 * line high.3167		 */3168		cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,3169						      GPIOD_OUT_LOW);3170		if (IS_ERR(cs[i]))3171			return PTR_ERR(cs[i]);3172 3173		if (cs[i]) {3174			/*3175			 * If we find a CS GPIO, name it after the device and3176			 * chip select line.3177			 */3178			char *gpioname;3179 3180			gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",3181						  dev_name(dev), i);3182			if (!gpioname)3183				return -ENOMEM;3184			gpiod_set_consumer_name(cs[i], gpioname);3185			num_cs_gpios++;3186			continue;3187		}3188 3189		if (ctlr->max_native_cs && i >= ctlr->max_native_cs) {3190			dev_err(dev, "Invalid native chip select %d\n", i);3191			return -EINVAL;3192		}3193		native_cs_mask |= BIT(i);3194	}3195 3196	ctlr->unused_native_cs = ffs(~native_cs_mask) - 1;3197 3198	if ((ctlr->flags & SPI_CONTROLLER_GPIO_SS) && num_cs_gpios &&3199	    ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {3200		dev_err(dev, "No unused native chip select available\n");3201		return -EINVAL;3202	}3203 3204	return 0;3205}3206 3207static int spi_controller_check_ops(struct spi_controller *ctlr)3208{3209	/*3210	 * The controller may implement only the high-level SPI-memory like3211	 * operations if it does not support regular SPI transfers, and this is3212	 * valid use case.3213	 * If ->mem_ops or ->mem_ops->exec_op is NULL, we request that at least3214	 * one of the ->transfer_xxx() method be implemented.3215	 */3216	if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {3217		if (!ctlr->transfer && !ctlr->transfer_one &&3218		   !ctlr->transfer_one_message) {3219			return -EINVAL;3220		}3221	}3222 3223	return 0;3224}3225 3226/* Allocate dynamic bus number using Linux idr */3227static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end)3228{3229	int id;3230 3231	mutex_lock(&board_lock);3232	id = idr_alloc(&spi_master_idr, ctlr, start, end, GFP_KERNEL);3233	mutex_unlock(&board_lock);3234	if (WARN(id < 0, "couldn't get idr"))3235		return id == -ENOSPC ? -EBUSY : id;3236	ctlr->bus_num = id;3237	return 0;3238}3239 3240/**3241 * spi_register_controller - register SPI master or slave controller3242 * @ctlr: initialized master, originally from spi_alloc_master() or3243 *	spi_alloc_slave()3244 * Context: can sleep3245 *3246 * SPI controllers connect to their drivers using some non-SPI bus,3247 * such as the platform bus.  The final stage of probe() in that code3248 * includes calling spi_register_controller() to hook up to this SPI bus glue.3249 *3250 * SPI controllers use board specific (often SOC specific) bus numbers,3251 * and board-specific addressing for SPI devices combines those numbers3252 * with chip select numbers.  Since SPI does not directly support dynamic3253 * device identification, boards need configuration tables telling which3254 * chip is at which address.3255 *3256 * This must be called from context that can sleep.  It returns zero on3257 * success, else a negative error code (dropping the controller's refcount).3258 * After a successful return, the caller is responsible for calling3259 * spi_unregister_controller().3260 *3261 * Return: zero on success, else a negative error code.3262 */3263int spi_register_controller(struct spi_controller *ctlr)3264{3265	struct device		*dev = ctlr->dev.parent;3266	struct boardinfo	*bi;3267	int			first_dynamic;3268	int			status;3269	int			idx;3270 3271	if (!dev)3272		return -ENODEV;3273 3274	/*3275	 * Make sure all necessary hooks are implemented before registering3276	 * the SPI controller.3277	 */3278	status = spi_controller_check_ops(ctlr);3279	if (status)3280		return status;3281 3282	if (ctlr->bus_num < 0)3283		ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi");3284	if (ctlr->bus_num >= 0) {3285		/* Devices with a fixed bus num must check-in with the num */3286		status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1);3287		if (status)3288			return status;3289	}3290	if (ctlr->bus_num < 0) {3291		first_dynamic = of_alias_get_highest_id("spi");3292		if (first_dynamic < 0)3293			first_dynamic = 0;3294		else3295			first_dynamic++;3296 3297		status = spi_controller_id_alloc(ctlr, first_dynamic, 0);3298		if (status)3299			return status;3300	}3301	ctlr->bus_lock_flag = 0;3302	init_completion(&ctlr->xfer_completion);3303	init_completion(&ctlr->cur_msg_completion);3304	if (!ctlr->max_dma_len)3305		ctlr->max_dma_len = INT_MAX;3306 3307	/*3308	 * Register the device, then userspace will see it.3309	 * Registration fails if the bus ID is in use.3310	 */3311	dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);3312 3313	if (!spi_controller_is_target(ctlr) && ctlr->use_gpio_descriptors) {3314		status = spi_get_gpio_descs(ctlr);3315		if (status)3316			goto free_bus_id;3317		/*3318		 * A controller using GPIO descriptors always3319		 * supports SPI_CS_HIGH if need be.3320		 */3321		ctlr->mode_bits |= SPI_CS_HIGH;3322	}3323 3324	/*3325	 * Even if it's just one always-selected device, there must3326	 * be at least one chipselect.3327	 */3328	if (!ctlr->num_chipselect) {3329		status = -EINVAL;3330		goto free_bus_id;3331	}3332 3333	/* Setting last_cs to SPI_INVALID_CS means no chip selected */3334	for (idx = 0; idx < SPI_CS_CNT_MAX; idx++)3335		ctlr->last_cs[idx] = SPI_INVALID_CS;3336 3337	status = device_add(&ctlr->dev);3338	if (status < 0)3339		goto free_bus_id;3340	dev_dbg(dev, "registered %s %s\n",3341			spi_controller_is_target(ctlr) ? "target" : "host",3342			dev_name(&ctlr->dev));3343 3344	/*3345	 * If we're using a queued driver, start the queue. Note that we don't3346	 * need the queueing logic if the driver is only supporting high-level3347	 * memory operations.3348	 */3349	if (ctlr->transfer) {3350		dev_info(dev, "controller is unqueued, this is deprecated\n");3351	} else if (ctlr->transfer_one || ctlr->transfer_one_message) {3352		status = spi_controller_initialize_queue(ctlr);3353		if (status) {3354			device_del(&ctlr->dev);3355			goto free_bus_id;3356		}3357	}3358	/* Add statistics */3359	ctlr->pcpu_statistics = spi_alloc_pcpu_stats(dev);3360	if (!ctlr->pcpu_statistics) {3361		dev_err(dev, "Error allocating per-cpu statistics\n");3362		status = -ENOMEM;3363		goto destroy_queue;3364	}3365 3366	mutex_lock(&board_lock);3367	list_add_tail(&ctlr->list, &spi_controller_list);3368	list_for_each_entry(bi, &board_list, list)3369		spi_match_controller_to_boardinfo(ctlr, &bi->board_info);3370	mutex_unlock(&board_lock);3371 3372	/* Register devices from the device tree and ACPI */3373	of_register_spi_devices(ctlr);3374	acpi_register_spi_devices(ctlr);3375	return status;3376 3377destroy_queue:3378	spi_destroy_queue(ctlr);3379free_bus_id:3380	mutex_lock(&board_lock);3381	idr_remove(&spi_master_idr, ctlr->bus_num);3382	mutex_unlock(&board_lock);3383	return status;3384}3385EXPORT_SYMBOL_GPL(spi_register_controller);3386 3387static void devm_spi_unregister(struct device *dev, void *res)3388{3389	spi_unregister_controller(*(struct spi_controller **)res);3390}3391 3392/**3393 * devm_spi_register_controller - register managed SPI master or slave3394 *	controller3395 * @dev:    device managing SPI controller3396 * @ctlr: initialized controller, originally from spi_alloc_master() or3397 *	spi_alloc_slave()3398 * Context: can sleep3399 *3400 * Register a SPI device as with spi_register_controller() which will3401 * automatically be unregistered and freed.3402 *3403 * Return: zero on success, else a negative error code.3404 */3405int devm_spi_register_controller(struct device *dev,3406				 struct spi_controller *ctlr)3407{3408	struct spi_controller **ptr;3409	int ret;3410 3411	ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);3412	if (!ptr)3413		return -ENOMEM;3414 3415	ret = spi_register_controller(ctlr);3416	if (!ret) {3417		*ptr = ctlr;3418		devres_add(dev, ptr);3419	} else {3420		devres_free(ptr);3421	}3422 3423	return ret;3424}3425EXPORT_SYMBOL_GPL(devm_spi_register_controller);3426 3427static int __unregister(struct device *dev, void *null)3428{3429	spi_unregister_device(to_spi_device(dev));3430	return 0;3431}3432 3433/**3434 * spi_unregister_controller - unregister SPI master or slave controller3435 * @ctlr: the controller being unregistered3436 * Context: can sleep3437 *3438 * This call is used only by SPI controller drivers, which are the3439 * only ones directly touching chip registers.3440 *3441 * This must be called from context that can sleep.3442 *3443 * Note that this function also drops a reference to the controller.3444 */3445void spi_unregister_controller(struct spi_controller *ctlr)3446{3447	struct spi_controller *found;3448	int id = ctlr->bus_num;3449 3450	/* Prevent addition of new devices, unregister existing ones */3451	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))3452		mutex_lock(&ctlr->add_lock);3453 3454	device_for_each_child(&ctlr->dev, NULL, __unregister);3455 3456	/* First make sure that this controller was ever added */3457	mutex_lock(&board_lock);3458	found = idr_find(&spi_master_idr, id);3459	mutex_unlock(&board_lock);3460	if (ctlr->queued) {3461		if (spi_destroy_queue(ctlr))3462			dev_err(&ctlr->dev, "queue remove failed\n");3463	}3464	mutex_lock(&board_lock);3465	list_del(&ctlr->list);3466	mutex_unlock(&board_lock);3467 3468	device_del(&ctlr->dev);3469 3470	/* Free bus id */3471	mutex_lock(&board_lock);3472	if (found == ctlr)3473		idr_remove(&spi_master_idr, id);3474	mutex_unlock(&board_lock);3475 3476	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))3477		mutex_unlock(&ctlr->add_lock);3478 3479	/*3480	 * Release the last reference on the controller if its driver3481	 * has not yet been converted to devm_spi_alloc_master/slave().3482	 */3483	if (!ctlr->devm_allocated)3484		put_device(&ctlr->dev);3485}3486EXPORT_SYMBOL_GPL(spi_unregister_controller);3487 3488static inline int __spi_check_suspended(const struct spi_controller *ctlr)3489{3490	return ctlr->flags & SPI_CONTROLLER_SUSPENDED ? -ESHUTDOWN : 0;3491}3492 3493static inline void __spi_mark_suspended(struct spi_controller *ctlr)3494{3495	mutex_lock(&ctlr->bus_lock_mutex);3496	ctlr->flags |= SPI_CONTROLLER_SUSPENDED;3497	mutex_unlock(&ctlr->bus_lock_mutex);3498}3499 3500static inline void __spi_mark_resumed(struct spi_controller *ctlr)3501{3502	mutex_lock(&ctlr->bus_lock_mutex);3503	ctlr->flags &= ~SPI_CONTROLLER_SUSPENDED;3504	mutex_unlock(&ctlr->bus_lock_mutex);3505}3506 3507int spi_controller_suspend(struct spi_controller *ctlr)3508{3509	int ret = 0;3510 3511	/* Basically no-ops for non-queued controllers */3512	if (ctlr->queued) {3513		ret = spi_stop_queue(ctlr);3514		if (ret)3515			dev_err(&ctlr->dev, "queue stop failed\n");3516	}3517 3518	__spi_mark_suspended(ctlr);3519	return ret;3520}3521EXPORT_SYMBOL_GPL(spi_controller_suspend);3522 3523int spi_controller_resume(struct spi_controller *ctlr)3524{3525	int ret = 0;3526 3527	__spi_mark_resumed(ctlr);3528 3529	if (ctlr->queued) {3530		ret = spi_start_queue(ctlr);3531		if (ret)3532			dev_err(&ctlr->dev, "queue restart failed\n");3533	}3534	return ret;3535}3536EXPORT_SYMBOL_GPL(spi_controller_resume);3537 3538/*-------------------------------------------------------------------------*/3539 3540/* Core methods for spi_message alterations */3541 3542static void __spi_replace_transfers_release(struct spi_controller *ctlr,3543					    struct spi_message *msg,3544					    void *res)3545{3546	struct spi_replaced_transfers *rxfer = res;3547	size_t i;3548 3549	/* Call extra callback if requested */3550	if (rxfer->release)3551		rxfer->release(ctlr, msg, res);3552 3553	/* Insert replaced transfers back into the message */3554	list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);3555 3556	/* Remove the formerly inserted entries */3557	for (i = 0; i < rxfer->inserted; i++)3558		list_del(&rxfer->inserted_transfers[i].transfer_list);3559}3560 3561/**3562 * spi_replace_transfers - replace transfers with several transfers3563 *                         and register change with spi_message.resources3564 * @msg:           the spi_message we work upon3565 * @xfer_first:    the first spi_transfer we want to replace3566 * @remove:        number of transfers to remove3567 * @insert:        the number of transfers we want to insert instead3568 * @release:       extra release code necessary in some circumstances3569 * @extradatasize: extra data to allocate (with alignment guarantees3570 *                 of struct @spi_transfer)3571 * @gfp:           gfp flags3572 *3573 * Returns: pointer to @spi_replaced_transfers,3574 *          PTR_ERR(...) in case of errors.3575 */3576static struct spi_replaced_transfers *spi_replace_transfers(3577	struct spi_message *msg,3578	struct spi_transfer *xfer_first,3579	size_t remove,3580	size_t insert,3581	spi_replaced_release_t release,3582	size_t extradatasize,3583	gfp_t gfp)3584{3585	struct spi_replaced_transfers *rxfer;3586	struct spi_transfer *xfer;3587	size_t i;3588 3589	/* Allocate the structure using spi_res */3590	rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,3591			      struct_size(rxfer, inserted_transfers, insert)3592			      + extradatasize,3593			      gfp);3594	if (!rxfer)3595		return ERR_PTR(-ENOMEM);3596 3597	/* The release code to invoke before running the generic release */3598	rxfer->release = release;3599 3600	/* Assign extradata */3601	if (extradatasize)3602		rxfer->extradata =3603			&rxfer->inserted_transfers[insert];3604 3605	/* Init the replaced_transfers list */3606	INIT_LIST_HEAD(&rxfer->replaced_transfers);3607 3608	/*3609	 * Assign the list_entry after which we should reinsert3610	 * the @replaced_transfers - it may be spi_message.messages!3611	 */3612	rxfer->replaced_after = xfer_first->transfer_list.prev;3613 3614	/* Remove the requested number of transfers */3615	for (i = 0; i < remove; i++) {3616		/*3617		 * If the entry after replaced_after it is msg->transfers3618		 * then we have been requested to remove more transfers3619		 * than are in the list.3620		 */3621		if (rxfer->replaced_after->next == &msg->transfers) {3622			dev_err(&msg->spi->dev,3623				"requested to remove more spi_transfers than are available\n");3624			/* Insert replaced transfers back into the message */3625			list_splice(&rxfer->replaced_transfers,3626				    rxfer->replaced_after);3627 3628			/* Free the spi_replace_transfer structure... */3629			spi_res_free(rxfer);3630 3631			/* ...and return with an error */3632			return ERR_PTR(-EINVAL);3633		}3634 3635		/*3636		 * Remove the entry after replaced_after from list of3637		 * transfers and add it to list of replaced_transfers.3638		 */3639		list_move_tail(rxfer->replaced_after->next,3640			       &rxfer->replaced_transfers);3641	}3642 3643	/*3644	 * Create copy of the given xfer with identical settings3645	 * based on the first transfer to get removed.3646	 */3647	for (i = 0; i < insert; i++) {3648		/* We need to run in reverse order */3649		xfer = &rxfer->inserted_transfers[insert - 1 - i];3650 3651		/* Copy all spi_transfer data */3652		memcpy(xfer, xfer_first, sizeof(*xfer));3653 3654		/* Add to list */3655		list_add(&xfer->transfer_list, rxfer->replaced_after);3656 3657		/* Clear cs_change and delay for all but the last */3658		if (i) {3659			xfer->cs_change = false;3660			xfer->delay.value = 0;3661		}3662	}3663 3664	/* Set up inserted... */3665	rxfer->inserted = insert;3666 3667	/* ...and register it with spi_res/spi_message */3668	spi_res_add(msg, rxfer);3669 3670	return rxfer;3671}3672 3673static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,3674					struct spi_message *msg,3675					struct spi_transfer **xferp,3676					size_t maxsize)3677{3678	struct spi_transfer *xfer = *xferp, *xfers;3679	struct spi_replaced_transfers *srt;3680	size_t offset;3681	size_t count, i;3682 3683	/* Calculate how many we have to replace */3684	count = DIV_ROUND_UP(xfer->len, maxsize);3685 3686	/* Create replacement */3687	srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, GFP_KERNEL);3688	if (IS_ERR(srt))3689		return PTR_ERR(srt);3690	xfers = srt->inserted_transfers;3691 3692	/*3693	 * Now handle each of those newly inserted spi_transfers.3694	 * Note that the replacements spi_transfers all are preset3695	 * to the same values as *xferp, so tx_buf, rx_buf and len3696	 * are all identical (as well as most others)3697	 * so we just have to fix up len and the pointers.3698	 */3699 3700	/*3701	 * The first transfer just needs the length modified, so we3702	 * run it outside the loop.3703	 */3704	xfers[0].len = min_t(size_t, maxsize, xfer[0].len);3705 3706	/* All the others need rx_buf/tx_buf also set */3707	for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {3708		/* Update rx_buf, tx_buf and DMA */3709		if (xfers[i].rx_buf)3710			xfers[i].rx_buf += offset;3711		if (xfers[i].tx_buf)3712			xfers[i].tx_buf += offset;3713 3714		/* Update length */3715		xfers[i].len = min(maxsize, xfers[i].len - offset);3716	}3717 3718	/*3719	 * We set up xferp to the last entry we have inserted,3720	 * so that we skip those already split transfers.3721	 */3722	*xferp = &xfers[count - 1];3723 3724	/* Increment statistics counters */3725	SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics,3726				       transfers_split_maxsize);3727	SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics,3728				       transfers_split_maxsize);3729 3730	return 0;3731}3732 3733/**3734 * spi_split_transfers_maxsize - split spi transfers into multiple transfers3735 *                               when an individual transfer exceeds a3736 *                               certain size3737 * @ctlr:    the @spi_controller for this transfer3738 * @msg:   the @spi_message to transform3739 * @maxsize:  the maximum when to apply this3740 *3741 * This function allocates resources that are automatically freed during the3742 * spi message unoptimize phase so this function should only be called from3743 * optimize_message callbacks.3744 *3745 * Return: status of transformation3746 */3747int spi_split_transfers_maxsize(struct spi_controller *ctlr,3748				struct spi_message *msg,3749				size_t maxsize)3750{3751	struct spi_transfer *xfer;3752	int ret;3753 3754	/*3755	 * Iterate over the transfer_list,3756	 * but note that xfer is advanced to the last transfer inserted3757	 * to avoid checking sizes again unnecessarily (also xfer does3758	 * potentially belong to a different list by the time the3759	 * replacement has happened).3760	 */3761	list_for_each_entry(xfer, &msg->transfers, transfer_list) {3762		if (xfer->len > maxsize) {3763			ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,3764							   maxsize);3765			if (ret)3766				return ret;3767		}3768	}3769 3770	return 0;3771}3772EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);3773 3774 3775/**3776 * spi_split_transfers_maxwords - split SPI transfers into multiple transfers3777 *                                when an individual transfer exceeds a3778 *                                certain number of SPI words3779 * @ctlr:     the @spi_controller for this transfer3780 * @msg:      the @spi_message to transform3781 * @maxwords: the number of words to limit each transfer to3782 *3783 * This function allocates resources that are automatically freed during the3784 * spi message unoptimize phase so this function should only be called from3785 * optimize_message callbacks.3786 *3787 * Return: status of transformation3788 */3789int spi_split_transfers_maxwords(struct spi_controller *ctlr,3790				 struct spi_message *msg,3791				 size_t maxwords)3792{3793	struct spi_transfer *xfer;3794 3795	/*3796	 * Iterate over the transfer_list,3797	 * but note that xfer is advanced to the last transfer inserted3798	 * to avoid checking sizes again unnecessarily (also xfer does3799	 * potentially belong to a different list by the time the3800	 * replacement has happened).3801	 */3802	list_for_each_entry(xfer, &msg->transfers, transfer_list) {3803		size_t maxsize;3804		int ret;3805 3806		maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word));3807		if (xfer->len > maxsize) {3808			ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,3809							   maxsize);3810			if (ret)3811				return ret;3812		}3813	}3814 3815	return 0;3816}3817EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords);3818 3819/*-------------------------------------------------------------------------*/3820 3821/*3822 * Core methods for SPI controller protocol drivers. Some of the3823 * other core methods are currently defined as inline functions.3824 */3825 3826static int __spi_validate_bits_per_word(struct spi_controller *ctlr,3827					u8 bits_per_word)3828{3829	if (ctlr->bits_per_word_mask) {3830		/* Only 32 bits fit in the mask */3831		if (bits_per_word > 32)3832			return -EINVAL;3833		if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))3834			return -EINVAL;3835	}3836 3837	return 0;3838}3839 3840/**3841 * spi_set_cs_timing - configure CS setup, hold, and inactive delays3842 * @spi: the device that requires specific CS timing configuration3843 *3844 * Return: zero on success, else a negative error code.3845 */3846static int spi_set_cs_timing(struct spi_device *spi)3847{3848	struct device *parent = spi->controller->dev.parent;3849	int status = 0;3850 3851	if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) {3852		if (spi->controller->auto_runtime_pm) {3853			status = pm_runtime_get_sync(parent);3854			if (status < 0) {3855				pm_runtime_put_noidle(parent);3856				dev_err(&spi->controller->dev, "Failed to power device: %d\n",3857					status);3858				return status;3859			}3860 3861			status = spi->controller->set_cs_timing(spi);3862			pm_runtime_mark_last_busy(parent);3863			pm_runtime_put_autosuspend(parent);3864		} else {3865			status = spi->controller->set_cs_timing(spi);3866		}3867	}3868	return status;3869}3870 3871/**3872 * spi_setup - setup SPI mode and clock rate3873 * @spi: the device whose settings are being modified3874 * Context: can sleep, and no requests are queued to the device3875 *3876 * SPI protocol drivers may need to update the transfer mode if the3877 * device doesn't work with its default.  They may likewise need3878 * to update clock rates or word sizes from initial values.  This function3879 * changes those settings, and must be called from a context that can sleep.3880 * Except for SPI_CS_HIGH, which takes effect immediately, the changes take3881 * effect the next time the device is selected and data is transferred to3882 * or from it.  When this function returns, the SPI device is deselected.3883 *3884 * Note that this call will fail if the protocol driver specifies an option3885 * that the underlying controller or its driver does not support.  For3886 * example, not all hardware supports wire transfers using nine bit words,3887 * LSB-first wire encoding, or active-high chipselects.3888 *3889 * Return: zero on success, else a negative error code.3890 */3891int spi_setup(struct spi_device *spi)3892{3893	unsigned	bad_bits, ugly_bits;3894	int		status;3895 3896	/*3897	 * Check mode to prevent that any two of DUAL, QUAD and NO_MOSI/MISO3898	 * are set at the same time.3899	 */3900	if ((hweight_long(spi->mode &3901		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_NO_TX)) > 1) ||3902	    (hweight_long(spi->mode &3903		(SPI_RX_DUAL | SPI_RX_QUAD | SPI_NO_RX)) > 1)) {3904		dev_err(&spi->dev,3905		"setup: can not select any two of dual, quad and no-rx/tx at the same time\n");3906		return -EINVAL;3907	}3908	/* If it is SPI_3WIRE mode, DUAL and QUAD should be forbidden */3909	if ((spi->mode & SPI_3WIRE) && (spi->mode &3910		(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |3911		 SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))3912		return -EINVAL;3913	/* Check against conflicting MOSI idle configuration */3914	if ((spi->mode & SPI_MOSI_IDLE_LOW) && (spi->mode & SPI_MOSI_IDLE_HIGH)) {3915		dev_err(&spi->dev,3916			"setup: MOSI configured to idle low and high at the same time.\n");3917		return -EINVAL;3918	}3919	/*3920	 * Help drivers fail *cleanly* when they need options3921	 * that aren't supported with their current controller.3922	 * SPI_CS_WORD has a fallback software implementation,3923	 * so it is ignored here.3924	 */3925	bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD |3926				 SPI_NO_TX | SPI_NO_RX);3927	ugly_bits = bad_bits &3928		    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |3929		     SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);3930	if (ugly_bits) {3931		dev_warn(&spi->dev,3932			 "setup: ignoring unsupported mode bits %x\n",3933			 ugly_bits);3934		spi->mode &= ~ugly_bits;3935		bad_bits &= ~ugly_bits;3936	}3937	if (bad_bits) {3938		dev_err(&spi->dev, "setup: unsupported mode bits %x\n",3939			bad_bits);3940		return -EINVAL;3941	}3942 3943	if (!spi->bits_per_word) {3944		spi->bits_per_word = 8;3945	} else {3946		/*3947		 * Some controllers may not support the default 8 bits-per-word3948		 * so only perform the check when this is explicitly provided.3949		 */3950		status = __spi_validate_bits_per_word(spi->controller,3951						      spi->bits_per_word);3952		if (status)3953			return status;3954	}3955 3956	if (spi->controller->max_speed_hz &&3957	    (!spi->max_speed_hz ||3958	     spi->max_speed_hz > spi->controller->max_speed_hz))3959		spi->max_speed_hz = spi->controller->max_speed_hz;3960 3961	mutex_lock(&spi->controller->io_mutex);3962 3963	if (spi->controller->setup) {3964		status = spi->controller->setup(spi);3965		if (status) {3966			mutex_unlock(&spi->controller->io_mutex);3967			dev_err(&spi->controller->dev, "Failed to setup device: %d\n",3968				status);3969			return status;3970		}3971	}3972 3973	status = spi_set_cs_timing(spi);3974	if (status) {3975		mutex_unlock(&spi->controller->io_mutex);3976		return status;3977	}3978 3979	if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {3980		status = pm_runtime_resume_and_get(spi->controller->dev.parent);3981		if (status < 0) {3982			mutex_unlock(&spi->controller->io_mutex);3983			dev_err(&spi->controller->dev, "Failed to power device: %d\n",3984				status);3985			return status;3986		}3987 3988		/*3989		 * We do not want to return positive value from pm_runtime_get,3990		 * there are many instances of devices calling spi_setup() and3991		 * checking for a non-zero return value instead of a negative3992		 * return value.3993		 */3994		status = 0;3995 3996		spi_set_cs(spi, false, true);3997		pm_runtime_mark_last_busy(spi->controller->dev.parent);3998		pm_runtime_put_autosuspend(spi->controller->dev.parent);3999	} else {4000		spi_set_cs(spi, false, true);4001	}4002 4003	mutex_unlock(&spi->controller->io_mutex);4004 4005	if (spi->rt && !spi->controller->rt) {4006		spi->controller->rt = true;4007		spi_set_thread_rt(spi->controller);4008	}4009 4010	trace_spi_setup(spi, status);4011 4012	dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n",4013			spi->mode & SPI_MODE_X_MASK,4014			(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",4015			(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",4016			(spi->mode & SPI_3WIRE) ? "3wire, " : "",4017			(spi->mode & SPI_LOOP) ? "loopback, " : "",4018			spi->bits_per_word, spi->max_speed_hz,4019			status);4020 4021	return status;4022}4023EXPORT_SYMBOL_GPL(spi_setup);4024 4025static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,4026				       struct spi_device *spi)4027{4028	int delay1, delay2;4029 4030	delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);4031	if (delay1 < 0)4032		return delay1;4033 4034	delay2 = spi_delay_to_ns(&spi->word_delay, xfer);4035	if (delay2 < 0)4036		return delay2;4037 4038	if (delay1 < delay2)4039		memcpy(&xfer->word_delay, &spi->word_delay,4040		       sizeof(xfer->word_delay));4041 4042	return 0;4043}4044 4045static int __spi_validate(struct spi_device *spi, struct spi_message *message)4046{4047	struct spi_controller *ctlr = spi->controller;4048	struct spi_transfer *xfer;4049	int w_size;4050 4051	if (list_empty(&message->transfers))4052		return -EINVAL;4053 4054	message->spi = spi;4055 4056	/*4057	 * Half-duplex links include original MicroWire, and ones with4058	 * only one data pin like SPI_3WIRE (switches direction) or where4059	 * either MOSI or MISO is missing.  They can also be caused by4060	 * software limitations.4061	 */4062	if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||4063	    (spi->mode & SPI_3WIRE)) {4064		unsigned flags = ctlr->flags;4065 4066		list_for_each_entry(xfer, &message->transfers, transfer_list) {4067			if (xfer->rx_buf && xfer->tx_buf)4068				return -EINVAL;4069			if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)4070				return -EINVAL;4071			if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)4072				return -EINVAL;4073		}4074	}4075 4076	/*4077	 * Set transfer bits_per_word and max speed as spi device default if4078	 * it is not set for this transfer.4079	 * Set transfer tx_nbits and rx_nbits as single transfer default4080	 * (SPI_NBITS_SINGLE) if it is not set for this transfer.4081	 * Ensure transfer word_delay is at least as long as that required by4082	 * device itself.4083	 */4084	message->frame_length = 0;4085	list_for_each_entry(xfer, &message->transfers, transfer_list) {4086		xfer->effective_speed_hz = 0;4087		message->frame_length += xfer->len;4088		if (!xfer->bits_per_word)4089			xfer->bits_per_word = spi->bits_per_word;4090 4091		if (!xfer->speed_hz)4092			xfer->speed_hz = spi->max_speed_hz;4093 4094		if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)4095			xfer->speed_hz = ctlr->max_speed_hz;4096 4097		if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))4098			return -EINVAL;4099 4100		/*4101		 * SPI transfer length should be multiple of SPI word size4102		 * where SPI word size should be power-of-two multiple.4103		 */4104		if (xfer->bits_per_word <= 8)4105			w_size = 1;4106		else if (xfer->bits_per_word <= 16)4107			w_size = 2;4108		else4109			w_size = 4;4110 4111		/* No partial transfers accepted */4112		if (xfer->len % w_size)4113			return -EINVAL;4114 4115		if (xfer->speed_hz && ctlr->min_speed_hz &&4116		    xfer->speed_hz < ctlr->min_speed_hz)4117			return -EINVAL;4118 4119		if (xfer->tx_buf && !xfer->tx_nbits)4120			xfer->tx_nbits = SPI_NBITS_SINGLE;4121		if (xfer->rx_buf && !xfer->rx_nbits)4122			xfer->rx_nbits = SPI_NBITS_SINGLE;4123		/*4124		 * Check transfer tx/rx_nbits:4125		 * 1. check the value matches one of single, dual and quad4126		 * 2. check tx/rx_nbits match the mode in spi_device4127		 */4128		if (xfer->tx_buf) {4129			if (spi->mode & SPI_NO_TX)4130				return -EINVAL;4131			if (xfer->tx_nbits != SPI_NBITS_SINGLE &&4132				xfer->tx_nbits != SPI_NBITS_DUAL &&4133				xfer->tx_nbits != SPI_NBITS_QUAD &&4134				xfer->tx_nbits != SPI_NBITS_OCTAL)4135				return -EINVAL;4136			if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&4137				!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))4138				return -EINVAL;4139			if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&4140				!(spi->mode & SPI_TX_QUAD))4141				return -EINVAL;4142		}4143		/* Check transfer rx_nbits */4144		if (xfer->rx_buf) {4145			if (spi->mode & SPI_NO_RX)4146				return -EINVAL;4147			if (xfer->rx_nbits != SPI_NBITS_SINGLE &&4148				xfer->rx_nbits != SPI_NBITS_DUAL &&4149				xfer->rx_nbits != SPI_NBITS_QUAD &&4150				xfer->rx_nbits != SPI_NBITS_OCTAL)4151				return -EINVAL;4152			if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&4153				!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))4154				return -EINVAL;4155			if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&4156				!(spi->mode & SPI_RX_QUAD))4157				return -EINVAL;4158		}4159 4160		if (_spi_xfer_word_delay_update(xfer, spi))4161			return -EINVAL;4162	}4163 4164	message->status = -EINPROGRESS;4165 4166	return 0;4167}4168 4169/*4170 * spi_split_transfers - generic handling of transfer splitting4171 * @msg: the message to split4172 *4173 * Under certain conditions, a SPI controller may not support arbitrary4174 * transfer sizes or other features required by a peripheral. This function4175 * will split the transfers in the message into smaller transfers that are4176 * supported by the controller.4177 *4178 * Controllers with special requirements not covered here can also split4179 * transfers in the optimize_message() callback.4180 *4181 * Context: can sleep4182 * Return: zero on success, else a negative error code4183 */4184static int spi_split_transfers(struct spi_message *msg)4185{4186	struct spi_controller *ctlr = msg->spi->controller;4187	struct spi_transfer *xfer;4188	int ret;4189 4190	/*4191	 * If an SPI controller does not support toggling the CS line on each4192	 * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO4193	 * for the CS line, we can emulate the CS-per-word hardware function by4194	 * splitting transfers into one-word transfers and ensuring that4195	 * cs_change is set for each transfer.4196	 */4197	if ((msg->spi->mode & SPI_CS_WORD) &&4198	    (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) {4199		ret = spi_split_transfers_maxwords(ctlr, msg, 1);4200		if (ret)4201			return ret;4202 4203		list_for_each_entry(xfer, &msg->transfers, transfer_list) {4204			/* Don't change cs_change on the last entry in the list */4205			if (list_is_last(&xfer->transfer_list, &msg->transfers))4206				break;4207 4208			xfer->cs_change = 1;4209		}4210	} else {4211		ret = spi_split_transfers_maxsize(ctlr, msg,4212						  spi_max_transfer_size(msg->spi));4213		if (ret)4214			return ret;4215	}4216 4217	return 0;4218}4219 4220/*4221 * __spi_optimize_message - shared implementation for spi_optimize_message()4222 *                          and spi_maybe_optimize_message()4223 * @spi: the device that will be used for the message4224 * @msg: the message to optimize4225 *4226 * Peripheral drivers will call spi_optimize_message() and the spi core will4227 * call spi_maybe_optimize_message() instead of calling this directly.4228 *4229 * It is not valid to call this on a message that has already been optimized.4230 *4231 * Return: zero on success, else a negative error code4232 */4233static int __spi_optimize_message(struct spi_device *spi,4234				  struct spi_message *msg)4235{4236	struct spi_controller *ctlr = spi->controller;4237	int ret;4238 4239	ret = __spi_validate(spi, msg);4240	if (ret)4241		return ret;4242 4243	ret = spi_split_transfers(msg);4244	if (ret)4245		return ret;4246 4247	if (ctlr->optimize_message) {4248		ret = ctlr->optimize_message(msg);4249		if (ret) {4250			spi_res_release(ctlr, msg);4251			return ret;4252		}4253	}4254 4255	msg->optimized = true;4256 4257	return 0;4258}4259 4260/*4261 * spi_maybe_optimize_message - optimize message if it isn't already pre-optimized4262 * @spi: the device that will be used for the message4263 * @msg: the message to optimize4264 * Return: zero on success, else a negative error code4265 */4266static int spi_maybe_optimize_message(struct spi_device *spi,4267				      struct spi_message *msg)4268{4269	if (spi->controller->defer_optimize_message) {4270		msg->spi = spi;4271		return 0;4272	}4273 4274	if (msg->pre_optimized)4275		return 0;4276 4277	return __spi_optimize_message(spi, msg);4278}4279 4280/**4281 * spi_optimize_message - do any one-time validation and setup for a SPI message4282 * @spi: the device that will be used for the message4283 * @msg: the message to optimize4284 *4285 * Peripheral drivers that reuse the same message repeatedly may call this to4286 * perform as much message prep as possible once, rather than repeating it each4287 * time a message transfer is performed to improve throughput and reduce CPU4288 * usage.4289 *4290 * Once a message has been optimized, it cannot be modified with the exception4291 * of updating the contents of any xfer->tx_buf (the pointer can't be changed,4292 * only the data in the memory it points to).4293 *4294 * Calls to this function must be balanced with calls to spi_unoptimize_message()4295 * to avoid leaking resources.4296 *4297 * Context: can sleep4298 * Return: zero on success, else a negative error code4299 */4300int spi_optimize_message(struct spi_device *spi, struct spi_message *msg)4301{4302	int ret;4303 4304	/*4305	 * Pre-optimization is not supported and optimization is deferred e.g.4306	 * when using spi-mux.4307	 */4308	if (spi->controller->defer_optimize_message)4309		return 0;4310 4311	ret = __spi_optimize_message(spi, msg);4312	if (ret)4313		return ret;4314 4315	/*4316	 * This flag indicates that the peripheral driver called spi_optimize_message()4317	 * and therefore we shouldn't unoptimize message automatically when finalizing4318	 * the message but rather wait until spi_unoptimize_message() is called4319	 * by the peripheral driver.4320	 */4321	msg->pre_optimized = true;4322 4323	return 0;4324}4325EXPORT_SYMBOL_GPL(spi_optimize_message);4326 4327/**4328 * spi_unoptimize_message - releases any resources allocated by spi_optimize_message()4329 * @msg: the message to unoptimize4330 *4331 * Calls to this function must be balanced with calls to spi_optimize_message().4332 *4333 * Context: can sleep4334 */4335void spi_unoptimize_message(struct spi_message *msg)4336{4337	if (msg->spi->controller->defer_optimize_message)4338		return;4339 4340	__spi_unoptimize_message(msg);4341	msg->pre_optimized = false;4342}4343EXPORT_SYMBOL_GPL(spi_unoptimize_message);4344 4345static int __spi_async(struct spi_device *spi, struct spi_message *message)4346{4347	struct spi_controller *ctlr = spi->controller;4348	struct spi_transfer *xfer;4349 4350	/*4351	 * Some controllers do not support doing regular SPI transfers. Return4352	 * ENOTSUPP when this is the case.4353	 */4354	if (!ctlr->transfer)4355		return -ENOTSUPP;4356 4357	SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async);4358	SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async);4359 4360	trace_spi_message_submit(message);4361 4362	if (!ctlr->ptp_sts_supported) {4363		list_for_each_entry(xfer, &message->transfers, transfer_list) {4364			xfer->ptp_sts_word_pre = 0;4365			ptp_read_system_prets(xfer->ptp_sts);4366		}4367	}4368 4369	return ctlr->transfer(spi, message);4370}4371 4372static void devm_spi_unoptimize_message(void *msg)4373{4374	spi_unoptimize_message(msg);4375}4376 4377/**4378 * devm_spi_optimize_message - managed version of spi_optimize_message()4379 * @dev: the device that manages @msg (usually @spi->dev)4380 * @spi: the device that will be used for the message4381 * @msg: the message to optimize4382 * Return: zero on success, else a negative error code4383 *4384 * spi_unoptimize_message() will automatically be called when the device is4385 * removed.4386 */4387int devm_spi_optimize_message(struct device *dev, struct spi_device *spi,4388			      struct spi_message *msg)4389{4390	int ret;4391 4392	ret = spi_optimize_message(spi, msg);4393	if (ret)4394		return ret;4395 4396	return devm_add_action_or_reset(dev, devm_spi_unoptimize_message, msg);4397}4398EXPORT_SYMBOL_GPL(devm_spi_optimize_message);4399 4400/**4401 * spi_async - asynchronous SPI transfer4402 * @spi: device with which data will be exchanged4403 * @message: describes the data transfers, including completion callback4404 * Context: any (IRQs may be blocked, etc)4405 *4406 * This call may be used in_irq and other contexts which can't sleep,4407 * as well as from task contexts which can sleep.4408 *4409 * The completion callback is invoked in a context which can't sleep.4410 * Before that invocation, the value of message->status is undefined.4411 * When the callback is issued, message->status holds either zero (to4412 * indicate complete success) or a negative error code.  After that4413 * callback returns, the driver which issued the transfer request may4414 * deallocate the associated memory; it's no longer in use by any SPI4415 * core or controller driver code.4416 *4417 * Note that although all messages to a spi_device are handled in4418 * FIFO order, messages may go to different devices in other orders.4419 * Some device might be higher priority, or have various "hard" access4420 * time requirements, for example.4421 *4422 * On detection of any fault during the transfer, processing of4423 * the entire message is aborted, and the device is deselected.4424 * Until returning from the associated message completion callback,4425 * no other spi_message queued to that device will be processed.4426 * (This rule applies equally to all the synchronous transfer calls,4427 * which are wrappers around this core asynchronous primitive.)4428 *4429 * Return: zero on success, else a negative error code.4430 */4431int spi_async(struct spi_device *spi, struct spi_message *message)4432{4433	struct spi_controller *ctlr = spi->controller;4434	int ret;4435	unsigned long flags;4436 4437	ret = spi_maybe_optimize_message(spi, message);4438	if (ret)4439		return ret;4440 4441	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);4442 4443	if (ctlr->bus_lock_flag)4444		ret = -EBUSY;4445	else4446		ret = __spi_async(spi, message);4447 4448	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);4449 4450	return ret;4451}4452EXPORT_SYMBOL_GPL(spi_async);4453 4454static void __spi_transfer_message_noqueue(struct spi_controller *ctlr, struct spi_message *msg)4455{4456	bool was_busy;4457	int ret;4458 4459	mutex_lock(&ctlr->io_mutex);4460 4461	was_busy = ctlr->busy;4462 4463	ctlr->cur_msg = msg;4464	ret = __spi_pump_transfer_message(ctlr, msg, was_busy);4465	if (ret)4466		dev_err(&ctlr->dev, "noqueue transfer failed\n");4467	ctlr->cur_msg = NULL;4468	ctlr->fallback = false;4469 4470	if (!was_busy) {4471		kfree(ctlr->dummy_rx);4472		ctlr->dummy_rx = NULL;4473		kfree(ctlr->dummy_tx);4474		ctlr->dummy_tx = NULL;4475		if (ctlr->unprepare_transfer_hardware &&4476		    ctlr->unprepare_transfer_hardware(ctlr))4477			dev_err(&ctlr->dev,4478				"failed to unprepare transfer hardware\n");4479		spi_idle_runtime_pm(ctlr);4480	}4481 4482	mutex_unlock(&ctlr->io_mutex);4483}4484 4485/*-------------------------------------------------------------------------*/4486 4487/*4488 * Utility methods for SPI protocol drivers, layered on4489 * top of the core.  Some other utility methods are defined as4490 * inline functions.4491 */4492 4493static void spi_complete(void *arg)4494{4495	complete(arg);4496}4497 4498static int __spi_sync(struct spi_device *spi, struct spi_message *message)4499{4500	DECLARE_COMPLETION_ONSTACK(done);4501	unsigned long flags;4502	int status;4503	struct spi_controller *ctlr = spi->controller;4504 4505	if (__spi_check_suspended(ctlr)) {4506		dev_warn_once(&spi->dev, "Attempted to sync while suspend\n");4507		return -ESHUTDOWN;4508	}4509 4510	status = spi_maybe_optimize_message(spi, message);4511	if (status)4512		return status;4513 4514	SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync);4515	SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync);4516 4517	/*4518	 * Checking queue_empty here only guarantees async/sync message4519	 * ordering when coming from the same context. It does not need to4520	 * guard against reentrancy from a different context. The io_mutex4521	 * will catch those cases.4522	 */4523	if (READ_ONCE(ctlr->queue_empty) && !ctlr->must_async) {4524		message->actual_length = 0;4525		message->status = -EINPROGRESS;4526 4527		trace_spi_message_submit(message);4528 4529		SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate);4530		SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate);4531 4532		__spi_transfer_message_noqueue(ctlr, message);4533 4534		return message->status;4535	}4536 4537	/*4538	 * There are messages in the async queue that could have originated4539	 * from the same context, so we need to preserve ordering.4540	 * Therefor we send the message to the async queue and wait until they4541	 * are completed.4542	 */4543	message->complete = spi_complete;4544	message->context = &done;4545 4546	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);4547	status = __spi_async(spi, message);4548	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);4549 4550	if (status == 0) {4551		wait_for_completion(&done);4552		status = message->status;4553	}4554	message->complete = NULL;4555	message->context = NULL;4556 4557	return status;4558}4559 4560/**4561 * spi_sync - blocking/synchronous SPI data transfers4562 * @spi: device with which data will be exchanged4563 * @message: describes the data transfers4564 * Context: can sleep4565 *4566 * This call may only be used from a context that may sleep.  The sleep4567 * is non-interruptible, and has no timeout.  Low-overhead controller4568 * drivers may DMA directly into and out of the message buffers.4569 *4570 * Note that the SPI device's chip select is active during the message,4571 * and then is normally disabled between messages.  Drivers for some4572 * frequently-used devices may want to minimize costs of selecting a chip,4573 * by leaving it selected in anticipation that the next message will go4574 * to the same chip.  (That may increase power usage.)4575 *4576 * Also, the caller is guaranteeing that the memory associated with the4577 * message will not be freed before this call returns.4578 *4579 * Return: zero on success, else a negative error code.4580 */4581int spi_sync(struct spi_device *spi, struct spi_message *message)4582{4583	int ret;4584 4585	mutex_lock(&spi->controller->bus_lock_mutex);4586	ret = __spi_sync(spi, message);4587	mutex_unlock(&spi->controller->bus_lock_mutex);4588 4589	return ret;4590}4591EXPORT_SYMBOL_GPL(spi_sync);4592 4593/**4594 * spi_sync_locked - version of spi_sync with exclusive bus usage4595 * @spi: device with which data will be exchanged4596 * @message: describes the data transfers4597 * Context: can sleep4598 *4599 * This call may only be used from a context that may sleep.  The sleep4600 * is non-interruptible, and has no timeout.  Low-overhead controller4601 * drivers may DMA directly into and out of the message buffers.4602 *4603 * This call should be used by drivers that require exclusive access to the4604 * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must4605 * be released by a spi_bus_unlock call when the exclusive access is over.4606 *4607 * Return: zero on success, else a negative error code.4608 */4609int spi_sync_locked(struct spi_device *spi, struct spi_message *message)4610{4611	return __spi_sync(spi, message);4612}4613EXPORT_SYMBOL_GPL(spi_sync_locked);4614 4615/**4616 * spi_bus_lock - obtain a lock for exclusive SPI bus usage4617 * @ctlr: SPI bus master that should be locked for exclusive bus access4618 * Context: can sleep4619 *4620 * This call may only be used from a context that may sleep.  The sleep4621 * is non-interruptible, and has no timeout.4622 *4623 * This call should be used by drivers that require exclusive access to the4624 * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the4625 * exclusive access is over. Data transfer must be done by spi_sync_locked4626 * and spi_async_locked calls when the SPI bus lock is held.4627 *4628 * Return: always zero.4629 */4630int spi_bus_lock(struct spi_controller *ctlr)4631{4632	unsigned long flags;4633 4634	mutex_lock(&ctlr->bus_lock_mutex);4635 4636	spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);4637	ctlr->bus_lock_flag = 1;4638	spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);4639 4640	/* Mutex remains locked until spi_bus_unlock() is called */4641 4642	return 0;4643}4644EXPORT_SYMBOL_GPL(spi_bus_lock);4645 4646/**4647 * spi_bus_unlock - release the lock for exclusive SPI bus usage4648 * @ctlr: SPI bus master that was locked for exclusive bus access4649 * Context: can sleep4650 *4651 * This call may only be used from a context that may sleep.  The sleep4652 * is non-interruptible, and has no timeout.4653 *4654 * This call releases an SPI bus lock previously obtained by an spi_bus_lock4655 * call.4656 *4657 * Return: always zero.4658 */4659int spi_bus_unlock(struct spi_controller *ctlr)4660{4661	ctlr->bus_lock_flag = 0;4662 4663	mutex_unlock(&ctlr->bus_lock_mutex);4664 4665	return 0;4666}4667EXPORT_SYMBOL_GPL(spi_bus_unlock);4668 4669/* Portable code must never pass more than 32 bytes */4670#define	SPI_BUFSIZ	max(32, SMP_CACHE_BYTES)4671 4672static u8	*buf;4673 4674/**4675 * spi_write_then_read - SPI synchronous write followed by read4676 * @spi: device with which data will be exchanged4677 * @txbuf: data to be written (need not be DMA-safe)4678 * @n_tx: size of txbuf, in bytes4679 * @rxbuf: buffer into which data will be read (need not be DMA-safe)4680 * @n_rx: size of rxbuf, in bytes4681 * Context: can sleep4682 *4683 * This performs a half duplex MicroWire style transaction with the4684 * device, sending txbuf and then reading rxbuf.  The return value4685 * is zero for success, else a negative errno status code.4686 * This call may only be used from a context that may sleep.4687 *4688 * Parameters to this routine are always copied using a small buffer.4689 * Performance-sensitive or bulk transfer code should instead use4690 * spi_{async,sync}() calls with DMA-safe buffers.4691 *4692 * Return: zero on success, else a negative error code.4693 */4694int spi_write_then_read(struct spi_device *spi,4695		const void *txbuf, unsigned n_tx,4696		void *rxbuf, unsigned n_rx)4697{4698	static DEFINE_MUTEX(lock);4699 4700	int			status;4701	struct spi_message	message;4702	struct spi_transfer	x[2];4703	u8			*local_buf;4704 4705	/*4706	 * Use preallocated DMA-safe buffer if we can. We can't avoid4707	 * copying here, (as a pure convenience thing), but we can4708	 * keep heap costs out of the hot path unless someone else is4709	 * using the pre-allocated buffer or the transfer is too large.4710	 */4711	if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {4712		local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),4713				    GFP_KERNEL | GFP_DMA);4714		if (!local_buf)4715			return -ENOMEM;4716	} else {4717		local_buf = buf;4718	}4719 4720	spi_message_init(&message);4721	memset(x, 0, sizeof(x));4722	if (n_tx) {4723		x[0].len = n_tx;4724		spi_message_add_tail(&x[0], &message);4725	}4726	if (n_rx) {4727		x[1].len = n_rx;4728		spi_message_add_tail(&x[1], &message);4729	}4730 4731	memcpy(local_buf, txbuf, n_tx);4732	x[0].tx_buf = local_buf;4733	x[1].rx_buf = local_buf + n_tx;4734 4735	/* Do the I/O */4736	status = spi_sync(spi, &message);4737	if (status == 0)4738		memcpy(rxbuf, x[1].rx_buf, n_rx);4739 4740	if (x[0].tx_buf == buf)4741		mutex_unlock(&lock);4742	else4743		kfree(local_buf);4744 4745	return status;4746}4747EXPORT_SYMBOL_GPL(spi_write_then_read);4748 4749/*-------------------------------------------------------------------------*/4750 4751#if IS_ENABLED(CONFIG_OF_DYNAMIC)4752/* Must call put_device() when done with returned spi_device device */4753static struct spi_device *of_find_spi_device_by_node(struct device_node *node)4754{4755	struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);4756 4757	return dev ? to_spi_device(dev) : NULL;4758}4759 4760/* The spi controllers are not using spi_bus, so we find it with another way */4761static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)4762{4763	struct device *dev;4764 4765	dev = class_find_device_by_of_node(&spi_master_class, node);4766	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))4767		dev = class_find_device_by_of_node(&spi_slave_class, node);4768	if (!dev)4769		return NULL;4770 4771	/* Reference got in class_find_device */4772	return container_of(dev, struct spi_controller, dev);4773}4774 4775static int of_spi_notify(struct notifier_block *nb, unsigned long action,4776			 void *arg)4777{4778	struct of_reconfig_data *rd = arg;4779	struct spi_controller *ctlr;4780	struct spi_device *spi;4781 4782	switch (of_reconfig_get_state_change(action, arg)) {4783	case OF_RECONFIG_CHANGE_ADD:4784		ctlr = of_find_spi_controller_by_node(rd->dn->parent);4785		if (ctlr == NULL)4786			return NOTIFY_OK;	/* Not for us */4787 4788		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {4789			put_device(&ctlr->dev);4790			return NOTIFY_OK;4791		}4792 4793		/*4794		 * Clear the flag before adding the device so that fw_devlink4795		 * doesn't skip adding consumers to this device.4796		 */4797		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;4798		spi = of_register_spi_device(ctlr, rd->dn);4799		put_device(&ctlr->dev);4800 4801		if (IS_ERR(spi)) {4802			pr_err("%s: failed to create for '%pOF'\n",4803					__func__, rd->dn);4804			of_node_clear_flag(rd->dn, OF_POPULATED);4805			return notifier_from_errno(PTR_ERR(spi));4806		}4807		break;4808 4809	case OF_RECONFIG_CHANGE_REMOVE:4810		/* Already depopulated? */4811		if (!of_node_check_flag(rd->dn, OF_POPULATED))4812			return NOTIFY_OK;4813 4814		/* Find our device by node */4815		spi = of_find_spi_device_by_node(rd->dn);4816		if (spi == NULL)4817			return NOTIFY_OK;	/* No? not meant for us */4818 4819		/* Unregister takes one ref away */4820		spi_unregister_device(spi);4821 4822		/* And put the reference of the find */4823		put_device(&spi->dev);4824		break;4825	}4826 4827	return NOTIFY_OK;4828}4829 4830static struct notifier_block spi_of_notifier = {4831	.notifier_call = of_spi_notify,4832};4833#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */4834extern struct notifier_block spi_of_notifier;4835#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */4836 4837#if IS_ENABLED(CONFIG_ACPI)4838static int spi_acpi_controller_match(struct device *dev, const void *data)4839{4840	return ACPI_COMPANION(dev->parent) == data;4841}4842 4843struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)4844{4845	struct device *dev;4846 4847	dev = class_find_device(&spi_master_class, NULL, adev,4848				spi_acpi_controller_match);4849	if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))4850		dev = class_find_device(&spi_slave_class, NULL, adev,4851					spi_acpi_controller_match);4852	if (!dev)4853		return NULL;4854 4855	return container_of(dev, struct spi_controller, dev);4856}4857EXPORT_SYMBOL_GPL(acpi_spi_find_controller_by_adev);4858 4859static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)4860{4861	struct device *dev;4862 4863	dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);4864	return to_spi_device(dev);4865}4866 4867static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,4868			   void *arg)4869{4870	struct acpi_device *adev = arg;4871	struct spi_controller *ctlr;4872	struct spi_device *spi;4873 4874	switch (value) {4875	case ACPI_RECONFIG_DEVICE_ADD:4876		ctlr = acpi_spi_find_controller_by_adev(acpi_dev_parent(adev));4877		if (!ctlr)4878			break;4879 4880		acpi_register_spi_device(ctlr, adev);4881		put_device(&ctlr->dev);4882		break;4883	case ACPI_RECONFIG_DEVICE_REMOVE:4884		if (!acpi_device_enumerated(adev))4885			break;4886 4887		spi = acpi_spi_find_device_by_adev(adev);4888		if (!spi)4889			break;4890 4891		spi_unregister_device(spi);4892		put_device(&spi->dev);4893		break;4894	}4895 4896	return NOTIFY_OK;4897}4898 4899static struct notifier_block spi_acpi_notifier = {4900	.notifier_call = acpi_spi_notify,4901};4902#else4903extern struct notifier_block spi_acpi_notifier;4904#endif4905 4906static int __init spi_init(void)4907{4908	int	status;4909 4910	buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);4911	if (!buf) {4912		status = -ENOMEM;4913		goto err0;4914	}4915 4916	status = bus_register(&spi_bus_type);4917	if (status < 0)4918		goto err1;4919 4920	status = class_register(&spi_master_class);4921	if (status < 0)4922		goto err2;4923 4924	if (IS_ENABLED(CONFIG_SPI_SLAVE)) {4925		status = class_register(&spi_slave_class);4926		if (status < 0)4927			goto err3;4928	}4929 4930	if (IS_ENABLED(CONFIG_OF_DYNAMIC))4931		WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));4932	if (IS_ENABLED(CONFIG_ACPI))4933		WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));4934 4935	return 0;4936 4937err3:4938	class_unregister(&spi_master_class);4939err2:4940	bus_unregister(&spi_bus_type);4941err1:4942	kfree(buf);4943	buf = NULL;4944err0:4945	return status;4946}4947 4948/*4949 * A board_info is normally registered in arch_initcall(),4950 * but even essential drivers wait till later.4951 *4952 * REVISIT only boardinfo really needs static linking. The rest (device and4953 * driver registration) _could_ be dynamically linked (modular) ... Costs4954 * include needing to have boardinfo data structures be much more public.4955 */4956postcore_initcall(spi_init);4957