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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Linux I2C core4 *5 * Copyright (C) 1995-99 Simon G. Vogl6 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>7 * Mux support by Rodolfo Giometti <giometti@enneenne.com> and8 * Michael Lawnick <michael.lawnick.ext@nsn.com>9 *10 * Copyright (C) 2013-2017 Wolfram Sang <wsa@kernel.org>11 */12 13#define pr_fmt(fmt) "i2c-core: " fmt14 15#include <dt-bindings/i2c/i2c.h>16#include <linux/acpi.h>17#include <linux/clk/clk-conf.h>18#include <linux/completion.h>19#include <linux/debugfs.h>20#include <linux/delay.h>21#include <linux/err.h>22#include <linux/errno.h>23#include <linux/gpio/consumer.h>24#include <linux/i2c.h>25#include <linux/i2c-smbus.h>26#include <linux/idr.h>27#include <linux/init.h>28#include <linux/interrupt.h>29#include <linux/irqflags.h>30#include <linux/jump_label.h>31#include <linux/kernel.h>32#include <linux/module.h>33#include <linux/mutex.h>34#include <linux/of_device.h>35#include <linux/of.h>36#include <linux/of_irq.h>37#include <linux/pinctrl/consumer.h>38#include <linux/pinctrl/devinfo.h>39#include <linux/pm_domain.h>40#include <linux/pm_runtime.h>41#include <linux/pm_wakeirq.h>42#include <linux/property.h>43#include <linux/rwsem.h>44#include <linux/slab.h>45 46#include "i2c-core.h"47 48#define CREATE_TRACE_POINTS49#include <trace/events/i2c.h>50 51#define I2C_ADDR_OFFSET_TEN_BIT 0xa00052#define I2C_ADDR_OFFSET_SLAVE 0x100053 54#define I2C_ADDR_7BITS_MAX 0x7755#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)56 57#define I2C_ADDR_DEVICE_ID 0x7c58 59/*60 * core_lock protects i2c_adapter_idr, and guarantees that device detection,61 * deletion of detected devices are serialized62 */63static DEFINE_MUTEX(core_lock);64static DEFINE_IDR(i2c_adapter_idr);65 66static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);67 68static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key);69static bool is_registered;70 71static struct dentry *i2c_debugfs_root;72 73int i2c_transfer_trace_reg(void)74{75 static_branch_inc(&i2c_trace_msg_key);76 return 0;77}78 79void i2c_transfer_trace_unreg(void)80{81 static_branch_dec(&i2c_trace_msg_key);82}83 84const char *i2c_freq_mode_string(u32 bus_freq_hz)85{86 switch (bus_freq_hz) {87 case I2C_MAX_STANDARD_MODE_FREQ:88 return "Standard Mode (100 kHz)";89 case I2C_MAX_FAST_MODE_FREQ:90 return "Fast Mode (400 kHz)";91 case I2C_MAX_FAST_MODE_PLUS_FREQ:92 return "Fast Mode Plus (1.0 MHz)";93 case I2C_MAX_TURBO_MODE_FREQ:94 return "Turbo Mode (1.4 MHz)";95 case I2C_MAX_HIGH_SPEED_MODE_FREQ:96 return "High Speed Mode (3.4 MHz)";97 case I2C_MAX_ULTRA_FAST_MODE_FREQ:98 return "Ultra Fast Mode (5.0 MHz)";99 default:100 return "Unknown Mode";101 }102}103EXPORT_SYMBOL_GPL(i2c_freq_mode_string);104 105const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,106 const struct i2c_client *client)107{108 if (!(id && client))109 return NULL;110 111 while (id->name[0]) {112 if (strcmp(client->name, id->name) == 0)113 return id;114 id++;115 }116 return NULL;117}118EXPORT_SYMBOL_GPL(i2c_match_id);119 120const void *i2c_get_match_data(const struct i2c_client *client)121{122 struct i2c_driver *driver = to_i2c_driver(client->dev.driver);123 const struct i2c_device_id *match;124 const void *data;125 126 data = device_get_match_data(&client->dev);127 if (!data) {128 match = i2c_match_id(driver->id_table, client);129 if (!match)130 return NULL;131 132 data = (const void *)match->driver_data;133 }134 135 return data;136}137EXPORT_SYMBOL(i2c_get_match_data);138 139static int i2c_device_match(struct device *dev, const struct device_driver *drv)140{141 struct i2c_client *client = i2c_verify_client(dev);142 const struct i2c_driver *driver;143 144 145 /* Attempt an OF style match */146 if (i2c_of_match_device(drv->of_match_table, client))147 return 1;148 149 /* Then ACPI style match */150 if (acpi_driver_match_device(dev, drv))151 return 1;152 153 driver = to_i2c_driver(drv);154 155 /* Finally an I2C match */156 if (i2c_match_id(driver->id_table, client))157 return 1;158 159 return 0;160}161 162static int i2c_device_uevent(const struct device *dev, struct kobj_uevent_env *env)163{164 const struct i2c_client *client = to_i2c_client(dev);165 int rc;166 167 rc = of_device_uevent_modalias(dev, env);168 if (rc != -ENODEV)169 return rc;170 171 rc = acpi_device_uevent_modalias(dev, env);172 if (rc != -ENODEV)173 return rc;174 175 return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);176}177 178/* i2c bus recovery routines */179static int get_scl_gpio_value(struct i2c_adapter *adap)180{181 return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod);182}183 184static void set_scl_gpio_value(struct i2c_adapter *adap, int val)185{186 gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val);187}188 189static int get_sda_gpio_value(struct i2c_adapter *adap)190{191 return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);192}193 194static void set_sda_gpio_value(struct i2c_adapter *adap, int val)195{196 gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);197}198 199static int i2c_generic_bus_free(struct i2c_adapter *adap)200{201 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;202 int ret = -EOPNOTSUPP;203 204 if (bri->get_bus_free)205 ret = bri->get_bus_free(adap);206 else if (bri->get_sda)207 ret = bri->get_sda(adap);208 209 if (ret < 0)210 return ret;211 212 return ret ? 0 : -EBUSY;213}214 215/*216 * We are generating clock pulses. ndelay() determines durating of clk pulses.217 * We will generate clock with rate 100 KHz and so duration of both clock levels218 * is: delay in ns = (10^6 / 100) / 2219 */220#define RECOVERY_NDELAY 5000221#define RECOVERY_CLK_CNT 9222 223int i2c_generic_scl_recovery(struct i2c_adapter *adap)224{225 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;226 int i = 0, scl = 1, ret = 0;227 228 if (bri->prepare_recovery)229 bri->prepare_recovery(adap);230 if (bri->pinctrl)231 pinctrl_select_state(bri->pinctrl, bri->pins_gpio);232 233 /*234 * If we can set SDA, we will always create a STOP to ensure additional235 * pulses will do no harm. This is achieved by letting SDA follow SCL236 * half a cycle later. Check the 'incomplete_write_byte' fault injector237 * for details. Note that we must honour tsu:sto, 4us, but lets use 5us238 * here for simplicity.239 */240 bri->set_scl(adap, scl);241 ndelay(RECOVERY_NDELAY);242 if (bri->set_sda)243 bri->set_sda(adap, scl);244 ndelay(RECOVERY_NDELAY / 2);245 246 /*247 * By this time SCL is high, as we need to give 9 falling-rising edges248 */249 while (i++ < RECOVERY_CLK_CNT * 2) {250 if (scl) {251 /* SCL shouldn't be low here */252 if (!bri->get_scl(adap)) {253 dev_err(&adap->dev,254 "SCL is stuck low, exit recovery\n");255 ret = -EBUSY;256 break;257 }258 }259 260 scl = !scl;261 bri->set_scl(adap, scl);262 /* Creating STOP again, see above */263 if (scl) {264 /* Honour minimum tsu:sto */265 ndelay(RECOVERY_NDELAY);266 } else {267 /* Honour minimum tf and thd:dat */268 ndelay(RECOVERY_NDELAY / 2);269 }270 if (bri->set_sda)271 bri->set_sda(adap, scl);272 ndelay(RECOVERY_NDELAY / 2);273 274 if (scl) {275 ret = i2c_generic_bus_free(adap);276 if (ret == 0)277 break;278 }279 }280 281 /* If we can't check bus status, assume recovery worked */282 if (ret == -EOPNOTSUPP)283 ret = 0;284 285 if (bri->unprepare_recovery)286 bri->unprepare_recovery(adap);287 if (bri->pinctrl)288 pinctrl_select_state(bri->pinctrl, bri->pins_default);289 290 return ret;291}292EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);293 294int i2c_recover_bus(struct i2c_adapter *adap)295{296 if (!adap->bus_recovery_info)297 return -EBUSY;298 299 dev_dbg(&adap->dev, "Trying i2c bus recovery\n");300 return adap->bus_recovery_info->recover_bus(adap);301}302EXPORT_SYMBOL_GPL(i2c_recover_bus);303 304static void i2c_gpio_init_pinctrl_recovery(struct i2c_adapter *adap)305{306 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;307 struct device *dev = &adap->dev;308 struct pinctrl *p = bri->pinctrl ?: dev_pinctrl(dev->parent);309 310 bri->pinctrl = p;311 312 /*313 * we can't change states without pinctrl, so remove the states if314 * populated315 */316 if (!p) {317 bri->pins_default = NULL;318 bri->pins_gpio = NULL;319 return;320 }321 322 if (!bri->pins_default) {323 bri->pins_default = pinctrl_lookup_state(p,324 PINCTRL_STATE_DEFAULT);325 if (IS_ERR(bri->pins_default)) {326 dev_dbg(dev, PINCTRL_STATE_DEFAULT " state not found for GPIO recovery\n");327 bri->pins_default = NULL;328 }329 }330 if (!bri->pins_gpio) {331 bri->pins_gpio = pinctrl_lookup_state(p, "gpio");332 if (IS_ERR(bri->pins_gpio))333 bri->pins_gpio = pinctrl_lookup_state(p, "recovery");334 335 if (IS_ERR(bri->pins_gpio)) {336 dev_dbg(dev, "no gpio or recovery state found for GPIO recovery\n");337 bri->pins_gpio = NULL;338 }339 }340 341 /* for pinctrl state changes, we need all the information */342 if (bri->pins_default && bri->pins_gpio) {343 dev_info(dev, "using pinctrl states for GPIO recovery");344 } else {345 bri->pinctrl = NULL;346 bri->pins_default = NULL;347 bri->pins_gpio = NULL;348 }349}350 351static int i2c_gpio_init_generic_recovery(struct i2c_adapter *adap)352{353 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;354 struct device *dev = &adap->dev;355 struct gpio_desc *gpiod;356 int ret = 0;357 358 /*359 * don't touch the recovery information if the driver is not using360 * generic SCL recovery361 */362 if (bri->recover_bus && bri->recover_bus != i2c_generic_scl_recovery)363 return 0;364 365 /*366 * pins might be taken as GPIO, so we should inform pinctrl about367 * this and move the state to GPIO368 */369 if (bri->pinctrl)370 pinctrl_select_state(bri->pinctrl, bri->pins_gpio);371 372 /*373 * if there is incomplete or no recovery information, see if generic374 * GPIO recovery is available375 */376 if (!bri->scl_gpiod) {377 gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);378 if (PTR_ERR(gpiod) == -EPROBE_DEFER) {379 ret = -EPROBE_DEFER;380 goto cleanup_pinctrl_state;381 }382 if (!IS_ERR(gpiod)) {383 bri->scl_gpiod = gpiod;384 bri->recover_bus = i2c_generic_scl_recovery;385 dev_info(dev, "using generic GPIOs for recovery\n");386 }387 }388 389 /* SDA GPIOD line is optional, so we care about DEFER only */390 if (!bri->sda_gpiod) {391 /*392 * We have SCL. Pull SCL low and wait a bit so that SDA glitches393 * have no effect.394 */395 gpiod_direction_output(bri->scl_gpiod, 0);396 udelay(10);397 gpiod = devm_gpiod_get(dev, "sda", GPIOD_IN);398 399 /* Wait a bit in case of a SDA glitch, and then release SCL. */400 udelay(10);401 gpiod_direction_output(bri->scl_gpiod, 1);402 403 if (PTR_ERR(gpiod) == -EPROBE_DEFER) {404 ret = -EPROBE_DEFER;405 goto cleanup_pinctrl_state;406 }407 if (!IS_ERR(gpiod))408 bri->sda_gpiod = gpiod;409 }410 411cleanup_pinctrl_state:412 /* change the state of the pins back to their default state */413 if (bri->pinctrl)414 pinctrl_select_state(bri->pinctrl, bri->pins_default);415 416 return ret;417}418 419static int i2c_gpio_init_recovery(struct i2c_adapter *adap)420{421 i2c_gpio_init_pinctrl_recovery(adap);422 return i2c_gpio_init_generic_recovery(adap);423}424 425static int i2c_init_recovery(struct i2c_adapter *adap)426{427 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;428 bool is_error_level = true;429 char *err_str;430 431 if (!bri)432 return 0;433 434 if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)435 return -EPROBE_DEFER;436 437 if (!bri->recover_bus) {438 err_str = "no suitable method provided";439 is_error_level = false;440 goto err;441 }442 443 if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {444 bri->get_scl = get_scl_gpio_value;445 bri->set_scl = set_scl_gpio_value;446 if (bri->sda_gpiod) {447 bri->get_sda = get_sda_gpio_value;448 /* FIXME: add proper flag instead of '0' once available */449 if (gpiod_get_direction(bri->sda_gpiod) == 0)450 bri->set_sda = set_sda_gpio_value;451 }452 } else if (bri->recover_bus == i2c_generic_scl_recovery) {453 /* Generic SCL recovery */454 if (!bri->set_scl || !bri->get_scl) {455 err_str = "no {get|set}_scl() found";456 goto err;457 }458 if (!bri->set_sda && !bri->get_sda) {459 err_str = "either get_sda() or set_sda() needed";460 goto err;461 }462 }463 464 return 0;465 err:466 if (is_error_level)467 dev_err(&adap->dev, "Not using recovery: %s\n", err_str);468 else469 dev_dbg(&adap->dev, "Not using recovery: %s\n", err_str);470 adap->bus_recovery_info = NULL;471 472 return -EINVAL;473}474 475static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)476{477 struct i2c_adapter *adap = client->adapter;478 unsigned int irq;479 480 if (!adap->host_notify_domain)481 return -ENXIO;482 483 if (client->flags & I2C_CLIENT_TEN)484 return -EINVAL;485 486 irq = irq_create_mapping(adap->host_notify_domain, client->addr);487 488 return irq > 0 ? irq : -ENXIO;489}490 491static int i2c_device_probe(struct device *dev)492{493 struct i2c_client *client = i2c_verify_client(dev);494 struct i2c_driver *driver;495 bool do_power_on;496 int status;497 498 if (!client)499 return 0;500 501 client->irq = client->init_irq;502 503 if (!client->irq) {504 int irq = -ENOENT;505 506 if (client->flags & I2C_CLIENT_HOST_NOTIFY) {507 dev_dbg(dev, "Using Host Notify IRQ\n");508 /* Keep adapter active when Host Notify is required */509 pm_runtime_get_sync(&client->adapter->dev);510 irq = i2c_smbus_host_notify_to_irq(client);511 } else if (dev->of_node) {512 irq = of_irq_get_byname(dev->of_node, "irq");513 if (irq == -EINVAL || irq == -ENODATA)514 irq = of_irq_get(dev->of_node, 0);515 } else if (ACPI_COMPANION(dev)) {516 bool wake_capable;517 518 irq = i2c_acpi_get_irq(client, &wake_capable);519 if (irq > 0 && wake_capable)520 client->flags |= I2C_CLIENT_WAKE;521 }522 if (irq == -EPROBE_DEFER) {523 status = irq;524 goto put_sync_adapter;525 }526 527 if (irq < 0)528 irq = 0;529 530 client->irq = irq;531 }532 533 driver = to_i2c_driver(dev->driver);534 535 /*536 * An I2C ID table is not mandatory, if and only if, a suitable OF537 * or ACPI ID table is supplied for the probing device.538 */539 if (!driver->id_table &&540 !acpi_driver_match_device(dev, dev->driver) &&541 !i2c_of_match_device(dev->driver->of_match_table, client)) {542 status = -ENODEV;543 goto put_sync_adapter;544 }545 546 if (client->flags & I2C_CLIENT_WAKE) {547 int wakeirq;548 549 wakeirq = of_irq_get_byname(dev->of_node, "wakeup");550 if (wakeirq == -EPROBE_DEFER) {551 status = wakeirq;552 goto put_sync_adapter;553 }554 555 device_init_wakeup(&client->dev, true);556 557 if (wakeirq > 0 && wakeirq != client->irq)558 status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);559 else if (client->irq > 0)560 status = dev_pm_set_wake_irq(dev, client->irq);561 else562 status = 0;563 564 if (status)565 dev_warn(&client->dev, "failed to set up wakeup irq\n");566 }567 568 dev_dbg(dev, "probe\n");569 570 status = of_clk_set_defaults(dev->of_node, false);571 if (status < 0)572 goto err_clear_wakeup_irq;573 574 do_power_on = !i2c_acpi_waive_d0_probe(dev);575 status = dev_pm_domain_attach(&client->dev, do_power_on);576 if (status)577 goto err_clear_wakeup_irq;578 579 client->devres_group_id = devres_open_group(&client->dev, NULL,580 GFP_KERNEL);581 if (!client->devres_group_id) {582 status = -ENOMEM;583 goto err_detach_pm_domain;584 }585 586 if (driver->probe)587 status = driver->probe(client);588 else589 status = -EINVAL;590 591 /*592 * Note that we are not closing the devres group opened above so593 * even resources that were attached to the device after probe is594 * run are released when i2c_device_remove() is executed. This is595 * needed as some drivers would allocate additional resources,596 * for example when updating firmware.597 */598 599 if (status)600 goto err_release_driver_resources;601 602 return 0;603 604err_release_driver_resources:605 devres_release_group(&client->dev, client->devres_group_id);606err_detach_pm_domain:607 dev_pm_domain_detach(&client->dev, do_power_on);608err_clear_wakeup_irq:609 dev_pm_clear_wake_irq(&client->dev);610 device_init_wakeup(&client->dev, false);611put_sync_adapter:612 if (client->flags & I2C_CLIENT_HOST_NOTIFY)613 pm_runtime_put_sync(&client->adapter->dev);614 615 return status;616}617 618static void i2c_device_remove(struct device *dev)619{620 struct i2c_client *client = to_i2c_client(dev);621 struct i2c_driver *driver;622 623 driver = to_i2c_driver(dev->driver);624 if (driver->remove) {625 dev_dbg(dev, "remove\n");626 627 driver->remove(client);628 }629 630 devres_release_group(&client->dev, client->devres_group_id);631 632 dev_pm_domain_detach(&client->dev, true);633 634 dev_pm_clear_wake_irq(&client->dev);635 device_init_wakeup(&client->dev, false);636 637 client->irq = 0;638 if (client->flags & I2C_CLIENT_HOST_NOTIFY)639 pm_runtime_put(&client->adapter->dev);640}641 642static void i2c_device_shutdown(struct device *dev)643{644 struct i2c_client *client = i2c_verify_client(dev);645 struct i2c_driver *driver;646 647 if (!client || !dev->driver)648 return;649 driver = to_i2c_driver(dev->driver);650 if (driver->shutdown)651 driver->shutdown(client);652 else if (client->irq > 0)653 disable_irq(client->irq);654}655 656static void i2c_client_dev_release(struct device *dev)657{658 kfree(to_i2c_client(dev));659}660 661static ssize_t662name_show(struct device *dev, struct device_attribute *attr, char *buf)663{664 return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?665 to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);666}667static DEVICE_ATTR_RO(name);668 669static ssize_t670modalias_show(struct device *dev, struct device_attribute *attr, char *buf)671{672 struct i2c_client *client = to_i2c_client(dev);673 int len;674 675 len = of_device_modalias(dev, buf, PAGE_SIZE);676 if (len != -ENODEV)677 return len;678 679 len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);680 if (len != -ENODEV)681 return len;682 683 return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);684}685static DEVICE_ATTR_RO(modalias);686 687static struct attribute *i2c_dev_attrs[] = {688 &dev_attr_name.attr,689 /* modalias helps coldplug: modprobe $(cat .../modalias) */690 &dev_attr_modalias.attr,691 NULL692};693ATTRIBUTE_GROUPS(i2c_dev);694 695const struct bus_type i2c_bus_type = {696 .name = "i2c",697 .match = i2c_device_match,698 .probe = i2c_device_probe,699 .remove = i2c_device_remove,700 .shutdown = i2c_device_shutdown,701};702EXPORT_SYMBOL_GPL(i2c_bus_type);703 704const struct device_type i2c_client_type = {705 .groups = i2c_dev_groups,706 .uevent = i2c_device_uevent,707 .release = i2c_client_dev_release,708};709EXPORT_SYMBOL_GPL(i2c_client_type);710 711 712/**713 * i2c_verify_client - return parameter as i2c_client, or NULL714 * @dev: device, probably from some driver model iterator715 *716 * When traversing the driver model tree, perhaps using driver model717 * iterators like @device_for_each_child(), you can't assume very much718 * about the nodes you find. Use this function to avoid oopses caused719 * by wrongly treating some non-I2C device as an i2c_client.720 */721struct i2c_client *i2c_verify_client(struct device *dev)722{723 return (dev->type == &i2c_client_type)724 ? to_i2c_client(dev)725 : NULL;726}727EXPORT_SYMBOL(i2c_verify_client);728 729 730/* Return a unique address which takes the flags of the client into account */731static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)732{733 unsigned short addr = client->addr;734 735 /* For some client flags, add an arbitrary offset to avoid collisions */736 if (client->flags & I2C_CLIENT_TEN)737 addr |= I2C_ADDR_OFFSET_TEN_BIT;738 739 if (client->flags & I2C_CLIENT_SLAVE)740 addr |= I2C_ADDR_OFFSET_SLAVE;741 742 return addr;743}744 745/* This is a permissive address validity check, I2C address map constraints746 * are purposely not enforced, except for the general call address. */747static int i2c_check_addr_validity(unsigned int addr, unsigned short flags)748{749 if (flags & I2C_CLIENT_TEN) {750 /* 10-bit address, all values are valid */751 if (addr > 0x3ff)752 return -EINVAL;753 } else {754 /* 7-bit address, reject the general call address */755 if (addr == 0x00 || addr > 0x7f)756 return -EINVAL;757 }758 return 0;759}760 761/* And this is a strict address validity check, used when probing. If a762 * device uses a reserved address, then it shouldn't be probed. 7-bit763 * addressing is assumed, 10-bit address devices are rare and should be764 * explicitly enumerated. */765int i2c_check_7bit_addr_validity_strict(unsigned short addr)766{767 /*768 * Reserved addresses per I2C specification:769 * 0x00 General call address / START byte770 * 0x01 CBUS address771 * 0x02 Reserved for different bus format772 * 0x03 Reserved for future purposes773 * 0x04-0x07 Hs-mode master code774 * 0x78-0x7b 10-bit slave addressing775 * 0x7c-0x7f Reserved for future purposes776 */777 if (addr < 0x08 || addr > 0x77)778 return -EINVAL;779 return 0;780}781 782static int __i2c_check_addr_busy(struct device *dev, void *addrp)783{784 struct i2c_client *client = i2c_verify_client(dev);785 int addr = *(int *)addrp;786 787 if (client && i2c_encode_flags_to_addr(client) == addr)788 return -EBUSY;789 return 0;790}791 792/* walk up mux tree */793static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)794{795 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);796 int result;797 798 result = device_for_each_child(&adapter->dev, &addr,799 __i2c_check_addr_busy);800 801 if (!result && parent)802 result = i2c_check_mux_parents(parent, addr);803 804 return result;805}806 807/* recurse down mux tree */808static int i2c_check_mux_children(struct device *dev, void *addrp)809{810 int result;811 812 if (dev->type == &i2c_adapter_type)813 result = device_for_each_child(dev, addrp,814 i2c_check_mux_children);815 else816 result = __i2c_check_addr_busy(dev, addrp);817 818 return result;819}820 821static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)822{823 struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);824 int result = 0;825 826 if (parent)827 result = i2c_check_mux_parents(parent, addr);828 829 if (!result)830 result = device_for_each_child(&adapter->dev, &addr,831 i2c_check_mux_children);832 833 return result;834}835 836/**837 * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment838 * @adapter: Target I2C bus segment839 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT840 * locks only this branch in the adapter tree841 */842static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,843 unsigned int flags)844{845 rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));846}847 848/**849 * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment850 * @adapter: Target I2C bus segment851 * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT852 * trylocks only this branch in the adapter tree853 */854static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,855 unsigned int flags)856{857 return rt_mutex_trylock(&adapter->bus_lock);858}859 860/**861 * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment862 * @adapter: Target I2C bus segment863 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT864 * unlocks only this branch in the adapter tree865 */866static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,867 unsigned int flags)868{869 rt_mutex_unlock(&adapter->bus_lock);870}871 872static void i2c_dev_set_name(struct i2c_adapter *adap,873 struct i2c_client *client,874 struct i2c_board_info const *info)875{876 struct acpi_device *adev = ACPI_COMPANION(&client->dev);877 878 if (info && info->dev_name) {879 dev_set_name(&client->dev, "i2c-%s", info->dev_name);880 return;881 }882 883 if (adev) {884 dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));885 return;886 }887 888 dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),889 i2c_encode_flags_to_addr(client));890}891 892int i2c_dev_irq_from_resources(const struct resource *resources,893 unsigned int num_resources)894{895 struct irq_data *irqd;896 int i;897 898 for (i = 0; i < num_resources; i++) {899 const struct resource *r = &resources[i];900 901 if (resource_type(r) != IORESOURCE_IRQ)902 continue;903 904 if (r->flags & IORESOURCE_BITS) {905 irqd = irq_get_irq_data(r->start);906 if (!irqd)907 break;908 909 irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);910 }911 912 return r->start;913 }914 915 return 0;916}917 918/*919 * Serialize device instantiation in case it can be instantiated explicitly920 * and by auto-detection921 */922static int i2c_lock_addr(struct i2c_adapter *adap, unsigned short addr,923 unsigned short flags)924{925 if (!(flags & I2C_CLIENT_TEN) &&926 test_and_set_bit(addr, adap->addrs_in_instantiation))927 return -EBUSY;928 929 return 0;930}931 932static void i2c_unlock_addr(struct i2c_adapter *adap, unsigned short addr,933 unsigned short flags)934{935 if (!(flags & I2C_CLIENT_TEN))936 clear_bit(addr, adap->addrs_in_instantiation);937}938 939/**940 * i2c_new_client_device - instantiate an i2c device941 * @adap: the adapter managing the device942 * @info: describes one I2C device; bus_num is ignored943 * Context: can sleep944 *945 * Create an i2c device. Binding is handled through driver model946 * probe()/remove() methods. A driver may be bound to this device when we947 * return from this function, or any later moment (e.g. maybe hotplugging will948 * load the driver module). This call is not appropriate for use by mainboard949 * initialization logic, which usually runs during an arch_initcall() long950 * before any i2c_adapter could exist.951 *952 * This returns the new i2c client, which may be saved for later use with953 * i2c_unregister_device(); or an ERR_PTR to describe the error.954 */955struct i2c_client *956i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)957{958 struct i2c_client *client;959 bool need_put = false;960 int status;961 962 client = kzalloc(sizeof *client, GFP_KERNEL);963 if (!client)964 return ERR_PTR(-ENOMEM);965 966 client->adapter = adap;967 968 client->dev.platform_data = info->platform_data;969 client->flags = info->flags;970 client->addr = info->addr;971 972 client->init_irq = info->irq;973 if (!client->init_irq)974 client->init_irq = i2c_dev_irq_from_resources(info->resources,975 info->num_resources);976 977 strscpy(client->name, info->type, sizeof(client->name));978 979 status = i2c_check_addr_validity(client->addr, client->flags);980 if (status) {981 dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",982 client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);983 goto out_err_silent;984 }985 986 status = i2c_lock_addr(adap, client->addr, client->flags);987 if (status)988 goto out_err_silent;989 990 /* Check for address business */991 status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));992 if (status)993 goto out_err;994 995 client->dev.parent = &client->adapter->dev;996 client->dev.bus = &i2c_bus_type;997 client->dev.type = &i2c_client_type;998 client->dev.of_node = of_node_get(info->of_node);999 client->dev.fwnode = info->fwnode;1000 1001 device_enable_async_suspend(&client->dev);1002 1003 if (info->swnode) {1004 status = device_add_software_node(&client->dev, info->swnode);1005 if (status) {1006 dev_err(&adap->dev,1007 "Failed to add software node to client %s: %d\n",1008 client->name, status);1009 goto out_err_put_of_node;1010 }1011 }1012 1013 i2c_dev_set_name(adap, client, info);1014 status = device_register(&client->dev);1015 if (status)1016 goto out_remove_swnode;1017 1018 dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",1019 client->name, dev_name(&client->dev));1020 1021 i2c_unlock_addr(adap, client->addr, client->flags);1022 1023 return client;1024 1025out_remove_swnode:1026 device_remove_software_node(&client->dev);1027 need_put = true;1028out_err_put_of_node:1029 of_node_put(info->of_node);1030out_err:1031 dev_err(&adap->dev,1032 "Failed to register i2c client %s at 0x%02x (%d)\n",1033 client->name, client->addr, status);1034 i2c_unlock_addr(adap, client->addr, client->flags);1035out_err_silent:1036 if (need_put)1037 put_device(&client->dev);1038 else1039 kfree(client);1040 return ERR_PTR(status);1041}1042EXPORT_SYMBOL_GPL(i2c_new_client_device);1043 1044/**1045 * i2c_unregister_device - reverse effect of i2c_new_*_device()1046 * @client: value returned from i2c_new_*_device()1047 * Context: can sleep1048 */1049void i2c_unregister_device(struct i2c_client *client)1050{1051 if (IS_ERR_OR_NULL(client))1052 return;1053 1054 if (client->dev.of_node) {1055 of_node_clear_flag(client->dev.of_node, OF_POPULATED);1056 of_node_put(client->dev.of_node);1057 }1058 1059 if (ACPI_COMPANION(&client->dev))1060 acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));1061 device_remove_software_node(&client->dev);1062 device_unregister(&client->dev);1063}1064EXPORT_SYMBOL_GPL(i2c_unregister_device);1065 1066/**1067 * i2c_find_device_by_fwnode() - find an i2c_client for the fwnode1068 * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_client1069 *1070 * Look up and return the &struct i2c_client corresponding to the @fwnode.1071 * If no client can be found, or @fwnode is NULL, this returns NULL.1072 *1073 * The user must call put_device(&client->dev) once done with the i2c client.1074 */1075struct i2c_client *i2c_find_device_by_fwnode(struct fwnode_handle *fwnode)1076{1077 struct i2c_client *client;1078 struct device *dev;1079 1080 if (!fwnode)1081 return NULL;1082 1083 dev = bus_find_device_by_fwnode(&i2c_bus_type, fwnode);1084 if (!dev)1085 return NULL;1086 1087 client = i2c_verify_client(dev);1088 if (!client)1089 put_device(dev);1090 1091 return client;1092}1093EXPORT_SYMBOL(i2c_find_device_by_fwnode);1094 1095 1096static const struct i2c_device_id dummy_id[] = {1097 { "dummy", },1098 { "smbus_host_notify", },1099 { }1100};1101 1102static int dummy_probe(struct i2c_client *client)1103{1104 return 0;1105}1106 1107static struct i2c_driver dummy_driver = {1108 .driver.name = "dummy",1109 .probe = dummy_probe,1110 .id_table = dummy_id,1111};1112 1113/**1114 * i2c_new_dummy_device - return a new i2c device bound to a dummy driver1115 * @adapter: the adapter managing the device1116 * @address: seven bit address to be used1117 * Context: can sleep1118 *1119 * This returns an I2C client bound to the "dummy" driver, intended for use1120 * with devices that consume multiple addresses. Examples of such chips1121 * include various EEPROMS (like 24c04 and 24c08 models).1122 *1123 * These dummy devices have two main uses. First, most I2C and SMBus calls1124 * except i2c_transfer() need a client handle; the dummy will be that handle.1125 * And second, this prevents the specified address from being bound to a1126 * different driver.1127 *1128 * This returns the new i2c client, which should be saved for later use with1129 * i2c_unregister_device(); or an ERR_PTR to describe the error.1130 */1131struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address)1132{1133 struct i2c_board_info info = {1134 I2C_BOARD_INFO("dummy", address),1135 };1136 1137 return i2c_new_client_device(adapter, &info);1138}1139EXPORT_SYMBOL_GPL(i2c_new_dummy_device);1140 1141static void devm_i2c_release_dummy(void *client)1142{1143 i2c_unregister_device(client);1144}1145 1146/**1147 * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver1148 * @dev: device the managed resource is bound to1149 * @adapter: the adapter managing the device1150 * @address: seven bit address to be used1151 * Context: can sleep1152 *1153 * This is the device-managed version of @i2c_new_dummy_device. It returns the1154 * new i2c client or an ERR_PTR in case of an error.1155 */1156struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,1157 struct i2c_adapter *adapter,1158 u16 address)1159{1160 struct i2c_client *client;1161 int ret;1162 1163 client = i2c_new_dummy_device(adapter, address);1164 if (IS_ERR(client))1165 return client;1166 1167 ret = devm_add_action_or_reset(dev, devm_i2c_release_dummy, client);1168 if (ret)1169 return ERR_PTR(ret);1170 1171 return client;1172}1173EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);1174 1175/**1176 * i2c_new_ancillary_device - Helper to get the instantiated secondary address1177 * and create the associated device1178 * @client: Handle to the primary client1179 * @name: Handle to specify which secondary address to get1180 * @default_addr: Used as a fallback if no secondary address was specified1181 * Context: can sleep1182 *1183 * I2C clients can be composed of multiple I2C slaves bound together in a single1184 * component. The I2C client driver then binds to the master I2C slave and needs1185 * to create I2C dummy clients to communicate with all the other slaves.1186 *1187 * This function creates and returns an I2C dummy client whose I2C address is1188 * retrieved from the platform firmware based on the given slave name. If no1189 * address is specified by the firmware default_addr is used.1190 *1191 * On DT-based platforms the address is retrieved from the "reg" property entry1192 * cell whose "reg-names" value matches the slave name.1193 *1194 * This returns the new i2c client, which should be saved for later use with1195 * i2c_unregister_device(); or an ERR_PTR to describe the error.1196 */1197struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,1198 const char *name,1199 u16 default_addr)1200{1201 struct device_node *np = client->dev.of_node;1202 u32 addr = default_addr;1203 int i;1204 1205 if (np) {1206 i = of_property_match_string(np, "reg-names", name);1207 if (i >= 0)1208 of_property_read_u32_index(np, "reg", i, &addr);1209 }1210 1211 dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);1212 return i2c_new_dummy_device(client->adapter, addr);1213}1214EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);1215 1216/* ------------------------------------------------------------------------- */1217 1218/* I2C bus adapters -- one roots each I2C or SMBUS segment */1219 1220static void i2c_adapter_dev_release(struct device *dev)1221{1222 struct i2c_adapter *adap = to_i2c_adapter(dev);1223 complete(&adap->dev_released);1224}1225 1226unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)1227{1228 unsigned int depth = 0;1229 struct device *parent;1230 1231 for (parent = adapter->dev.parent; parent; parent = parent->parent)1232 if (parent->type == &i2c_adapter_type)1233 depth++;1234 1235 WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,1236 "adapter depth exceeds lockdep subclass limit\n");1237 1238 return depth;1239}1240EXPORT_SYMBOL_GPL(i2c_adapter_depth);1241 1242/*1243 * Let users instantiate I2C devices through sysfs. This can be used when1244 * platform initialization code doesn't contain the proper data for1245 * whatever reason. Also useful for drivers that do device detection and1246 * detection fails, either because the device uses an unexpected address,1247 * or this is a compatible device with different ID register values.1248 *1249 * Parameter checking may look overzealous, but we really don't want1250 * the user to provide incorrect parameters.1251 */1252static ssize_t1253new_device_store(struct device *dev, struct device_attribute *attr,1254 const char *buf, size_t count)1255{1256 struct i2c_adapter *adap = to_i2c_adapter(dev);1257 struct i2c_board_info info;1258 struct i2c_client *client;1259 char *blank, end;1260 int res;1261 1262 memset(&info, 0, sizeof(struct i2c_board_info));1263 1264 blank = strchr(buf, ' ');1265 if (!blank) {1266 dev_err(dev, "%s: Missing parameters\n", "new_device");1267 return -EINVAL;1268 }1269 if (blank - buf > I2C_NAME_SIZE - 1) {1270 dev_err(dev, "%s: Invalid device name\n", "new_device");1271 return -EINVAL;1272 }1273 memcpy(info.type, buf, blank - buf);1274 1275 /* Parse remaining parameters, reject extra parameters */1276 res = sscanf(++blank, "%hi%c", &info.addr, &end);1277 if (res < 1) {1278 dev_err(dev, "%s: Can't parse I2C address\n", "new_device");1279 return -EINVAL;1280 }1281 if (res > 1 && end != '\n') {1282 dev_err(dev, "%s: Extra parameters\n", "new_device");1283 return -EINVAL;1284 }1285 1286 if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {1287 info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;1288 info.flags |= I2C_CLIENT_TEN;1289 }1290 1291 if (info.addr & I2C_ADDR_OFFSET_SLAVE) {1292 info.addr &= ~I2C_ADDR_OFFSET_SLAVE;1293 info.flags |= I2C_CLIENT_SLAVE;1294 }1295 1296 client = i2c_new_client_device(adap, &info);1297 if (IS_ERR(client))1298 return PTR_ERR(client);1299 1300 /* Keep track of the added device */1301 mutex_lock(&adap->userspace_clients_lock);1302 list_add_tail(&client->detected, &adap->userspace_clients);1303 mutex_unlock(&adap->userspace_clients_lock);1304 dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",1305 info.type, info.addr);1306 1307 return count;1308}1309static DEVICE_ATTR_WO(new_device);1310 1311/*1312 * And of course let the users delete the devices they instantiated, if1313 * they got it wrong. This interface can only be used to delete devices1314 * instantiated by i2c_sysfs_new_device above. This guarantees that we1315 * don't delete devices to which some kernel code still has references.1316 *1317 * Parameter checking may look overzealous, but we really don't want1318 * the user to delete the wrong device.1319 */1320static ssize_t1321delete_device_store(struct device *dev, struct device_attribute *attr,1322 const char *buf, size_t count)1323{1324 struct i2c_adapter *adap = to_i2c_adapter(dev);1325 struct i2c_client *client, *next;1326 unsigned short addr;1327 char end;1328 int res;1329 1330 /* Parse parameters, reject extra parameters */1331 res = sscanf(buf, "%hi%c", &addr, &end);1332 if (res < 1) {1333 dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");1334 return -EINVAL;1335 }1336 if (res > 1 && end != '\n') {1337 dev_err(dev, "%s: Extra parameters\n", "delete_device");1338 return -EINVAL;1339 }1340 1341 /* Make sure the device was added through sysfs */1342 res = -ENOENT;1343 mutex_lock_nested(&adap->userspace_clients_lock,1344 i2c_adapter_depth(adap));1345 list_for_each_entry_safe(client, next, &adap->userspace_clients,1346 detected) {1347 if (i2c_encode_flags_to_addr(client) == addr) {1348 dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",1349 "delete_device", client->name, client->addr);1350 1351 list_del(&client->detected);1352 i2c_unregister_device(client);1353 res = count;1354 break;1355 }1356 }1357 mutex_unlock(&adap->userspace_clients_lock);1358 1359 if (res < 0)1360 dev_err(dev, "%s: Can't find device in list\n",1361 "delete_device");1362 return res;1363}1364static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,1365 delete_device_store);1366 1367static struct attribute *i2c_adapter_attrs[] = {1368 &dev_attr_name.attr,1369 &dev_attr_new_device.attr,1370 &dev_attr_delete_device.attr,1371 NULL1372};1373ATTRIBUTE_GROUPS(i2c_adapter);1374 1375const struct device_type i2c_adapter_type = {1376 .groups = i2c_adapter_groups,1377 .release = i2c_adapter_dev_release,1378};1379EXPORT_SYMBOL_GPL(i2c_adapter_type);1380 1381/**1382 * i2c_verify_adapter - return parameter as i2c_adapter or NULL1383 * @dev: device, probably from some driver model iterator1384 *1385 * When traversing the driver model tree, perhaps using driver model1386 * iterators like @device_for_each_child(), you can't assume very much1387 * about the nodes you find. Use this function to avoid oopses caused1388 * by wrongly treating some non-I2C device as an i2c_adapter.1389 */1390struct i2c_adapter *i2c_verify_adapter(struct device *dev)1391{1392 return (dev->type == &i2c_adapter_type)1393 ? to_i2c_adapter(dev)1394 : NULL;1395}1396EXPORT_SYMBOL(i2c_verify_adapter);1397 1398static void i2c_scan_static_board_info(struct i2c_adapter *adapter)1399{1400 struct i2c_devinfo *devinfo;1401 1402 down_read(&__i2c_board_lock);1403 list_for_each_entry(devinfo, &__i2c_board_list, list) {1404 if (devinfo->busnum == adapter->nr &&1405 IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info)))1406 dev_err(&adapter->dev,1407 "Can't create device at 0x%02x\n",1408 devinfo->board_info.addr);1409 }1410 up_read(&__i2c_board_lock);1411}1412 1413static int i2c_do_add_adapter(struct i2c_driver *driver,1414 struct i2c_adapter *adap)1415{1416 /* Detect supported devices on that bus, and instantiate them */1417 i2c_detect(adap, driver);1418 1419 return 0;1420}1421 1422static int __process_new_adapter(struct device_driver *d, void *data)1423{1424 return i2c_do_add_adapter(to_i2c_driver(d), data);1425}1426 1427static const struct i2c_lock_operations i2c_adapter_lock_ops = {1428 .lock_bus = i2c_adapter_lock_bus,1429 .trylock_bus = i2c_adapter_trylock_bus,1430 .unlock_bus = i2c_adapter_unlock_bus,1431};1432 1433static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap)1434{1435 struct irq_domain *domain = adap->host_notify_domain;1436 irq_hw_number_t hwirq;1437 1438 if (!domain)1439 return;1440 1441 for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++)1442 irq_dispose_mapping(irq_find_mapping(domain, hwirq));1443 1444 irq_domain_remove(domain);1445 adap->host_notify_domain = NULL;1446}1447 1448static int i2c_host_notify_irq_map(struct irq_domain *h,1449 unsigned int virq,1450 irq_hw_number_t hw_irq_num)1451{1452 irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);1453 1454 return 0;1455}1456 1457static const struct irq_domain_ops i2c_host_notify_irq_ops = {1458 .map = i2c_host_notify_irq_map,1459};1460 1461static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap)1462{1463 struct irq_domain *domain;1464 1465 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY))1466 return 0;1467 1468 domain = irq_domain_create_linear(adap->dev.parent->fwnode,1469 I2C_ADDR_7BITS_COUNT,1470 &i2c_host_notify_irq_ops, adap);1471 if (!domain)1472 return -ENOMEM;1473 1474 adap->host_notify_domain = domain;1475 1476 return 0;1477}1478 1479/**1480 * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct1481 * I2C client.1482 * @adap: the adapter1483 * @addr: the I2C address of the notifying device1484 * Context: can't sleep1485 *1486 * Helper function to be called from an I2C bus driver's interrupt1487 * handler. It will schedule the Host Notify IRQ.1488 */1489int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)1490{1491 int irq;1492 1493 if (!adap)1494 return -EINVAL;1495 1496 dev_dbg(&adap->dev, "Detected HostNotify from address 0x%02x", addr);1497 1498 irq = irq_find_mapping(adap->host_notify_domain, addr);1499 if (irq <= 0)1500 return -ENXIO;1501 1502 generic_handle_irq_safe(irq);1503 1504 return 0;1505}1506EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify);1507 1508static int i2c_register_adapter(struct i2c_adapter *adap)1509{1510 int res = -EINVAL;1511 1512 /* Can't register until after driver model init */1513 if (WARN_ON(!is_registered)) {1514 res = -EAGAIN;1515 goto out_list;1516 }1517 1518 /* Sanity checks */1519 if (WARN(!adap->name[0], "i2c adapter has no name"))1520 goto out_list;1521 1522 if (!adap->algo) {1523 pr_err("adapter '%s': no algo supplied!\n", adap->name);1524 goto out_list;1525 }1526 1527 if (!adap->lock_ops)1528 adap->lock_ops = &i2c_adapter_lock_ops;1529 1530 adap->locked_flags = 0;1531 rt_mutex_init(&adap->bus_lock);1532 rt_mutex_init(&adap->mux_lock);1533 mutex_init(&adap->userspace_clients_lock);1534 INIT_LIST_HEAD(&adap->userspace_clients);1535 1536 /* Set default timeout to 1 second if not already set */1537 if (adap->timeout == 0)1538 adap->timeout = HZ;1539 1540 /* register soft irqs for Host Notify */1541 res = i2c_setup_host_notify_irq_domain(adap);1542 if (res) {1543 pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n",1544 adap->name, res);1545 goto out_list;1546 }1547 1548 dev_set_name(&adap->dev, "i2c-%d", adap->nr);1549 adap->dev.bus = &i2c_bus_type;1550 adap->dev.type = &i2c_adapter_type;1551 device_initialize(&adap->dev);1552 1553 /*1554 * This adapter can be used as a parent immediately after device_add(),1555 * setup runtime-pm (especially ignore-children) before hand.1556 */1557 device_enable_async_suspend(&adap->dev);1558 pm_runtime_no_callbacks(&adap->dev);1559 pm_suspend_ignore_children(&adap->dev, true);1560 pm_runtime_enable(&adap->dev);1561 1562 res = device_add(&adap->dev);1563 if (res) {1564 pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);1565 goto out_list;1566 }1567 1568 adap->debugfs = debugfs_create_dir(dev_name(&adap->dev), i2c_debugfs_root);1569 1570 res = i2c_setup_smbus_alert(adap);1571 if (res)1572 goto out_reg;1573 1574 res = i2c_init_recovery(adap);1575 if (res == -EPROBE_DEFER)1576 goto out_reg;1577 1578 dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);1579 1580 /* create pre-declared device nodes */1581 of_i2c_register_devices(adap);1582 i2c_acpi_install_space_handler(adap);1583 i2c_acpi_register_devices(adap);1584 1585 if (adap->nr < __i2c_first_dynamic_bus_num)1586 i2c_scan_static_board_info(adap);1587 1588 /* Notify drivers */1589 mutex_lock(&core_lock);1590 bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);1591 mutex_unlock(&core_lock);1592 1593 return 0;1594 1595out_reg:1596 debugfs_remove_recursive(adap->debugfs);1597 init_completion(&adap->dev_released);1598 device_unregister(&adap->dev);1599 wait_for_completion(&adap->dev_released);1600out_list:1601 mutex_lock(&core_lock);1602 idr_remove(&i2c_adapter_idr, adap->nr);1603 mutex_unlock(&core_lock);1604 return res;1605}1606 1607/**1608 * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -11609 * @adap: the adapter to register (with adap->nr initialized)1610 * Context: can sleep1611 *1612 * See i2c_add_numbered_adapter() for details.1613 */1614static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)1615{1616 int id;1617 1618 mutex_lock(&core_lock);1619 id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);1620 mutex_unlock(&core_lock);1621 if (WARN(id < 0, "couldn't get idr"))1622 return id == -ENOSPC ? -EBUSY : id;1623 1624 return i2c_register_adapter(adap);1625}1626 1627/**1628 * i2c_add_adapter - declare i2c adapter, use dynamic bus number1629 * @adapter: the adapter to add1630 * Context: can sleep1631 *1632 * This routine is used to declare an I2C adapter when its bus number1633 * doesn't matter or when its bus number is specified by an dt alias.1634 * Examples of bases when the bus number doesn't matter: I2C adapters1635 * dynamically added by USB links or PCI plugin cards.1636 *1637 * When this returns zero, a new bus number was allocated and stored1638 * in adap->nr, and the specified adapter became available for clients.1639 * Otherwise, a negative errno value is returned.1640 */1641int i2c_add_adapter(struct i2c_adapter *adapter)1642{1643 struct device *dev = &adapter->dev;1644 int id;1645 1646 if (dev->of_node) {1647 id = of_alias_get_id(dev->of_node, "i2c");1648 if (id >= 0) {1649 adapter->nr = id;1650 return __i2c_add_numbered_adapter(adapter);1651 }1652 }1653 1654 mutex_lock(&core_lock);1655 id = idr_alloc(&i2c_adapter_idr, adapter,1656 __i2c_first_dynamic_bus_num, 0, GFP_KERNEL);1657 mutex_unlock(&core_lock);1658 if (WARN(id < 0, "couldn't get idr"))1659 return id;1660 1661 adapter->nr = id;1662 1663 return i2c_register_adapter(adapter);1664}1665EXPORT_SYMBOL(i2c_add_adapter);1666 1667/**1668 * i2c_add_numbered_adapter - declare i2c adapter, use static bus number1669 * @adap: the adapter to register (with adap->nr initialized)1670 * Context: can sleep1671 *1672 * This routine is used to declare an I2C adapter when its bus number1673 * matters. For example, use it for I2C adapters from system-on-chip CPUs,1674 * or otherwise built in to the system's mainboard, and where i2c_board_info1675 * is used to properly configure I2C devices.1676 *1677 * If the requested bus number is set to -1, then this function will behave1678 * identically to i2c_add_adapter, and will dynamically assign a bus number.1679 *1680 * If no devices have pre-been declared for this bus, then be sure to1681 * register the adapter before any dynamically allocated ones. Otherwise1682 * the required bus ID may not be available.1683 *1684 * When this returns zero, the specified adapter became available for1685 * clients using the bus number provided in adap->nr. Also, the table1686 * of I2C devices pre-declared using i2c_register_board_info() is scanned,1687 * and the appropriate driver model device nodes are created. Otherwise, a1688 * negative errno value is returned.1689 */1690int i2c_add_numbered_adapter(struct i2c_adapter *adap)1691{1692 if (adap->nr == -1) /* -1 means dynamically assign bus id */1693 return i2c_add_adapter(adap);1694 1695 return __i2c_add_numbered_adapter(adap);1696}1697EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);1698 1699static void i2c_do_del_adapter(struct i2c_driver *driver,1700 struct i2c_adapter *adapter)1701{1702 struct i2c_client *client, *_n;1703 1704 /* Remove the devices we created ourselves as the result of hardware1705 * probing (using a driver's detect method) */1706 list_for_each_entry_safe(client, _n, &driver->clients, detected) {1707 if (client->adapter == adapter) {1708 dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",1709 client->name, client->addr);1710 list_del(&client->detected);1711 i2c_unregister_device(client);1712 }1713 }1714}1715 1716static int __unregister_client(struct device *dev, void *dummy)1717{1718 struct i2c_client *client = i2c_verify_client(dev);1719 if (client && strcmp(client->name, "dummy"))1720 i2c_unregister_device(client);1721 return 0;1722}1723 1724static int __unregister_dummy(struct device *dev, void *dummy)1725{1726 struct i2c_client *client = i2c_verify_client(dev);1727 i2c_unregister_device(client);1728 return 0;1729}1730 1731static int __process_removed_adapter(struct device_driver *d, void *data)1732{1733 i2c_do_del_adapter(to_i2c_driver(d), data);1734 return 0;1735}1736 1737/**1738 * i2c_del_adapter - unregister I2C adapter1739 * @adap: the adapter being unregistered1740 * Context: can sleep1741 *1742 * This unregisters an I2C adapter which was previously registered1743 * by @i2c_add_adapter or @i2c_add_numbered_adapter.1744 */1745void i2c_del_adapter(struct i2c_adapter *adap)1746{1747 struct i2c_adapter *found;1748 struct i2c_client *client, *next;1749 1750 /* First make sure that this adapter was ever added */1751 mutex_lock(&core_lock);1752 found = idr_find(&i2c_adapter_idr, adap->nr);1753 mutex_unlock(&core_lock);1754 if (found != adap) {1755 pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);1756 return;1757 }1758 1759 i2c_acpi_remove_space_handler(adap);1760 /* Tell drivers about this removal */1761 mutex_lock(&core_lock);1762 bus_for_each_drv(&i2c_bus_type, NULL, adap,1763 __process_removed_adapter);1764 mutex_unlock(&core_lock);1765 1766 /* Remove devices instantiated from sysfs */1767 mutex_lock_nested(&adap->userspace_clients_lock,1768 i2c_adapter_depth(adap));1769 list_for_each_entry_safe(client, next, &adap->userspace_clients,1770 detected) {1771 dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,1772 client->addr);1773 list_del(&client->detected);1774 i2c_unregister_device(client);1775 }1776 mutex_unlock(&adap->userspace_clients_lock);1777 1778 /* Detach any active clients. This can't fail, thus we do not1779 * check the returned value. This is a two-pass process, because1780 * we can't remove the dummy devices during the first pass: they1781 * could have been instantiated by real devices wishing to clean1782 * them up properly, so we give them a chance to do that first. */1783 device_for_each_child(&adap->dev, NULL, __unregister_client);1784 device_for_each_child(&adap->dev, NULL, __unregister_dummy);1785 1786 /* device name is gone after device_unregister */1787 dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);1788 1789 pm_runtime_disable(&adap->dev);1790 1791 i2c_host_notify_irq_teardown(adap);1792 1793 debugfs_remove_recursive(adap->debugfs);1794 1795 /* wait until all references to the device are gone1796 *1797 * FIXME: This is old code and should ideally be replaced by an1798 * alternative which results in decoupling the lifetime of the struct1799 * device from the i2c_adapter, like spi or netdev do. Any solution1800 * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!1801 */1802 init_completion(&adap->dev_released);1803 device_unregister(&adap->dev);1804 wait_for_completion(&adap->dev_released);1805 1806 /* free bus id */1807 mutex_lock(&core_lock);1808 idr_remove(&i2c_adapter_idr, adap->nr);1809 mutex_unlock(&core_lock);1810 1811 /* Clear the device structure in case this adapter is ever going to be1812 added again */1813 memset(&adap->dev, 0, sizeof(adap->dev));1814}1815EXPORT_SYMBOL(i2c_del_adapter);1816 1817static void devm_i2c_del_adapter(void *adapter)1818{1819 i2c_del_adapter(adapter);1820}1821 1822/**1823 * devm_i2c_add_adapter - device-managed variant of i2c_add_adapter()1824 * @dev: managing device for adding this I2C adapter1825 * @adapter: the adapter to add1826 * Context: can sleep1827 *1828 * Add adapter with dynamic bus number, same with i2c_add_adapter()1829 * but the adapter will be auto deleted on driver detach.1830 */1831int devm_i2c_add_adapter(struct device *dev, struct i2c_adapter *adapter)1832{1833 int ret;1834 1835 ret = i2c_add_adapter(adapter);1836 if (ret)1837 return ret;1838 1839 return devm_add_action_or_reset(dev, devm_i2c_del_adapter, adapter);1840}1841EXPORT_SYMBOL_GPL(devm_i2c_add_adapter);1842 1843static int i2c_dev_or_parent_fwnode_match(struct device *dev, const void *data)1844{1845 if (dev_fwnode(dev) == data)1846 return 1;1847 1848 if (dev->parent && dev_fwnode(dev->parent) == data)1849 return 1;1850 1851 return 0;1852}1853 1854/**1855 * i2c_find_adapter_by_fwnode() - find an i2c_adapter for the fwnode1856 * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter1857 *1858 * Look up and return the &struct i2c_adapter corresponding to the @fwnode.1859 * If no adapter can be found, or @fwnode is NULL, this returns NULL.1860 *1861 * The user must call put_device(&adapter->dev) once done with the i2c adapter.1862 */1863struct i2c_adapter *i2c_find_adapter_by_fwnode(struct fwnode_handle *fwnode)1864{1865 struct i2c_adapter *adapter;1866 struct device *dev;1867 1868 if (!fwnode)1869 return NULL;1870 1871 dev = bus_find_device(&i2c_bus_type, NULL, fwnode,1872 i2c_dev_or_parent_fwnode_match);1873 if (!dev)1874 return NULL;1875 1876 adapter = i2c_verify_adapter(dev);1877 if (!adapter)1878 put_device(dev);1879 1880 return adapter;1881}1882EXPORT_SYMBOL(i2c_find_adapter_by_fwnode);1883 1884/**1885 * i2c_get_adapter_by_fwnode() - find an i2c_adapter for the fwnode1886 * @fwnode: &struct fwnode_handle corresponding to the &struct i2c_adapter1887 *1888 * Look up and return the &struct i2c_adapter corresponding to the @fwnode,1889 * and increment the adapter module's use count. If no adapter can be found,1890 * or @fwnode is NULL, this returns NULL.1891 *1892 * The user must call i2c_put_adapter(adapter) once done with the i2c adapter.1893 * Note that this is different from i2c_find_adapter_by_node().1894 */1895struct i2c_adapter *i2c_get_adapter_by_fwnode(struct fwnode_handle *fwnode)1896{1897 struct i2c_adapter *adapter;1898 1899 adapter = i2c_find_adapter_by_fwnode(fwnode);1900 if (!adapter)1901 return NULL;1902 1903 if (!try_module_get(adapter->owner)) {1904 put_device(&adapter->dev);1905 adapter = NULL;1906 }1907 1908 return adapter;1909}1910EXPORT_SYMBOL(i2c_get_adapter_by_fwnode);1911 1912static void i2c_parse_timing(struct device *dev, char *prop_name, u32 *cur_val_p,1913 u32 def_val, bool use_def)1914{1915 int ret;1916 1917 ret = device_property_read_u32(dev, prop_name, cur_val_p);1918 if (ret && use_def)1919 *cur_val_p = def_val;1920 1921 dev_dbg(dev, "%s: %u\n", prop_name, *cur_val_p);1922}1923 1924/**1925 * i2c_parse_fw_timings - get I2C related timing parameters from firmware1926 * @dev: The device to scan for I2C timing properties1927 * @t: the i2c_timings struct to be filled with values1928 * @use_defaults: bool to use sane defaults derived from the I2C specification1929 * when properties are not found, otherwise don't update1930 *1931 * Scan the device for the generic I2C properties describing timing parameters1932 * for the signal and fill the given struct with the results. If a property was1933 * not found and use_defaults was true, then maximum timings are assumed which1934 * are derived from the I2C specification. If use_defaults is not used, the1935 * results will be as before, so drivers can apply their own defaults before1936 * calling this helper. The latter is mainly intended for avoiding regressions1937 * of existing drivers which want to switch to this function. New drivers1938 * almost always should use the defaults.1939 */1940void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)1941{1942 bool u = use_defaults;1943 u32 d;1944 1945 i2c_parse_timing(dev, "clock-frequency", &t->bus_freq_hz,1946 I2C_MAX_STANDARD_MODE_FREQ, u);1947 1948 d = t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ ? 1000 :1949 t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;1950 i2c_parse_timing(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns, d, u);1951 1952 d = t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ ? 300 : 120;1953 i2c_parse_timing(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns, d, u);1954 1955 i2c_parse_timing(dev, "i2c-scl-internal-delay-ns",1956 &t->scl_int_delay_ns, 0, u);1957 i2c_parse_timing(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns,1958 t->scl_fall_ns, u);1959 i2c_parse_timing(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns, 0, u);1960 i2c_parse_timing(dev, "i2c-digital-filter-width-ns",1961 &t->digital_filter_width_ns, 0, u);1962 i2c_parse_timing(dev, "i2c-analog-filter-cutoff-frequency",1963 &t->analog_filter_cutoff_freq_hz, 0, u);1964}1965EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);1966 1967/* ------------------------------------------------------------------------- */1968 1969int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data))1970{1971 int res;1972 1973 mutex_lock(&core_lock);1974 res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);1975 mutex_unlock(&core_lock);1976 1977 return res;1978}1979EXPORT_SYMBOL_GPL(i2c_for_each_dev);1980 1981static int __process_new_driver(struct device *dev, void *data)1982{1983 if (dev->type != &i2c_adapter_type)1984 return 0;1985 return i2c_do_add_adapter(data, to_i2c_adapter(dev));1986}1987 1988/*1989 * An i2c_driver is used with one or more i2c_client (device) nodes to access1990 * i2c slave chips, on a bus instance associated with some i2c_adapter.1991 */1992 1993int i2c_register_driver(struct module *owner, struct i2c_driver *driver)1994{1995 int res;1996 1997 /* Can't register until after driver model init */1998 if (WARN_ON(!is_registered))1999 return -EAGAIN;2000 2001 /* add the driver to the list of i2c drivers in the driver core */2002 driver->driver.owner = owner;2003 driver->driver.bus = &i2c_bus_type;2004 INIT_LIST_HEAD(&driver->clients);2005 2006 /* When registration returns, the driver core2007 * will have called probe() for all matching-but-unbound devices.2008 */2009 res = driver_register(&driver->driver);2010 if (res)2011 return res;2012 2013 pr_debug("driver [%s] registered\n", driver->driver.name);2014 2015 /* Walk the adapters that are already present */2016 i2c_for_each_dev(driver, __process_new_driver);2017 2018 return 0;2019}2020EXPORT_SYMBOL(i2c_register_driver);2021 2022static int __process_removed_driver(struct device *dev, void *data)2023{2024 if (dev->type == &i2c_adapter_type)2025 i2c_do_del_adapter(data, to_i2c_adapter(dev));2026 return 0;2027}2028 2029/**2030 * i2c_del_driver - unregister I2C driver2031 * @driver: the driver being unregistered2032 * Context: can sleep2033 */2034void i2c_del_driver(struct i2c_driver *driver)2035{2036 i2c_for_each_dev(driver, __process_removed_driver);2037 2038 driver_unregister(&driver->driver);2039 pr_debug("driver [%s] unregistered\n", driver->driver.name);2040}2041EXPORT_SYMBOL(i2c_del_driver);2042 2043/* ------------------------------------------------------------------------- */2044 2045struct i2c_cmd_arg {2046 unsigned cmd;2047 void *arg;2048};2049 2050static int i2c_cmd(struct device *dev, void *_arg)2051{2052 struct i2c_client *client = i2c_verify_client(dev);2053 struct i2c_cmd_arg *arg = _arg;2054 struct i2c_driver *driver;2055 2056 if (!client || !client->dev.driver)2057 return 0;2058 2059 driver = to_i2c_driver(client->dev.driver);2060 if (driver->command)2061 driver->command(client, arg->cmd, arg->arg);2062 return 0;2063}2064 2065void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)2066{2067 struct i2c_cmd_arg cmd_arg;2068 2069 cmd_arg.cmd = cmd;2070 cmd_arg.arg = arg;2071 device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);2072}2073EXPORT_SYMBOL(i2c_clients_command);2074 2075static int __init i2c_init(void)2076{2077 int retval;2078 2079 retval = of_alias_get_highest_id("i2c");2080 2081 down_write(&__i2c_board_lock);2082 if (retval >= __i2c_first_dynamic_bus_num)2083 __i2c_first_dynamic_bus_num = retval + 1;2084 up_write(&__i2c_board_lock);2085 2086 retval = bus_register(&i2c_bus_type);2087 if (retval)2088 return retval;2089 2090 is_registered = true;2091 2092 i2c_debugfs_root = debugfs_create_dir("i2c", NULL);2093 2094 retval = i2c_add_driver(&dummy_driver);2095 if (retval)2096 goto class_err;2097 2098 if (IS_ENABLED(CONFIG_OF_DYNAMIC))2099 WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));2100 if (IS_ENABLED(CONFIG_ACPI))2101 WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));2102 2103 return 0;2104 2105class_err:2106 is_registered = false;2107 bus_unregister(&i2c_bus_type);2108 return retval;2109}2110 2111static void __exit i2c_exit(void)2112{2113 if (IS_ENABLED(CONFIG_ACPI))2114 WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));2115 if (IS_ENABLED(CONFIG_OF_DYNAMIC))2116 WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));2117 i2c_del_driver(&dummy_driver);2118 debugfs_remove_recursive(i2c_debugfs_root);2119 bus_unregister(&i2c_bus_type);2120 tracepoint_synchronize_unregister();2121}2122 2123/* We must initialize early, because some subsystems register i2c drivers2124 * in subsys_initcall() code, but are linked (and initialized) before i2c.2125 */2126postcore_initcall(i2c_init);2127module_exit(i2c_exit);2128 2129/* ----------------------------------------------------2130 * the functional interface to the i2c busses.2131 * ----------------------------------------------------2132 */2133 2134/* Check if val is exceeding the quirk IFF quirk is non 0 */2135#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))2136 2137static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)2138{2139 dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",2140 err_msg, msg->addr, msg->len,2141 msg->flags & I2C_M_RD ? "read" : "write");2142 return -EOPNOTSUPP;2143}2144 2145static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)2146{2147 const struct i2c_adapter_quirks *q = adap->quirks;2148 int max_num = q->max_num_msgs, i;2149 bool do_len_check = true;2150 2151 if (q->flags & I2C_AQ_COMB) {2152 max_num = 2;2153 2154 /* special checks for combined messages */2155 if (num == 2) {2156 if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)2157 return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");2158 2159 if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))2160 return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");2161 2162 if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)2163 return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");2164 2165 if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))2166 return i2c_quirk_error(adap, &msgs[0], "msg too long");2167 2168 if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))2169 return i2c_quirk_error(adap, &msgs[1], "msg too long");2170 2171 do_len_check = false;2172 }2173 }2174 2175 if (i2c_quirk_exceeded(num, max_num))2176 return i2c_quirk_error(adap, &msgs[0], "too many messages");2177 2178 for (i = 0; i < num; i++) {2179 u16 len = msgs[i].len;2180 2181 if (msgs[i].flags & I2C_M_RD) {2182 if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))2183 return i2c_quirk_error(adap, &msgs[i], "msg too long");2184 2185 if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)2186 return i2c_quirk_error(adap, &msgs[i], "no zero length");2187 } else {2188 if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))2189 return i2c_quirk_error(adap, &msgs[i], "msg too long");2190 2191 if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)2192 return i2c_quirk_error(adap, &msgs[i], "no zero length");2193 }2194 }2195 2196 return 0;2197}2198 2199/**2200 * __i2c_transfer - unlocked flavor of i2c_transfer2201 * @adap: Handle to I2C bus2202 * @msgs: One or more messages to execute before STOP is issued to2203 * terminate the operation; each message begins with a START.2204 * @num: Number of messages to be executed.2205 *2206 * Returns negative errno, else the number of messages executed.2207 *2208 * Adapter lock must be held when calling this function. No debug logging2209 * takes place.2210 */2211int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)2212{2213 unsigned long orig_jiffies;2214 int ret, try;2215 2216 if (!adap->algo->master_xfer) {2217 dev_dbg(&adap->dev, "I2C level transfers not supported\n");2218 return -EOPNOTSUPP;2219 }2220 2221 if (WARN_ON(!msgs || num < 1))2222 return -EINVAL;2223 2224 ret = __i2c_check_suspended(adap);2225 if (ret)2226 return ret;2227 2228 if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))2229 return -EOPNOTSUPP;2230 2231 /*2232 * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets2233 * enabled. This is an efficient way of keeping the for-loop from2234 * being executed when not needed.2235 */2236 if (static_branch_unlikely(&i2c_trace_msg_key)) {2237 int i;2238 for (i = 0; i < num; i++)2239 if (msgs[i].flags & I2C_M_RD)2240 trace_i2c_read(adap, &msgs[i], i);2241 else2242 trace_i2c_write(adap, &msgs[i], i);2243 }2244 2245 /* Retry automatically on arbitration loss */2246 orig_jiffies = jiffies;2247 for (ret = 0, try = 0; try <= adap->retries; try++) {2248 if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)2249 ret = adap->algo->master_xfer_atomic(adap, msgs, num);2250 else2251 ret = adap->algo->master_xfer(adap, msgs, num);2252 2253 if (ret != -EAGAIN)2254 break;2255 if (time_after(jiffies, orig_jiffies + adap->timeout))2256 break;2257 }2258 2259 if (static_branch_unlikely(&i2c_trace_msg_key)) {2260 int i;2261 for (i = 0; i < ret; i++)2262 if (msgs[i].flags & I2C_M_RD)2263 trace_i2c_reply(adap, &msgs[i], i);2264 trace_i2c_result(adap, num, ret);2265 }2266 2267 return ret;2268}2269EXPORT_SYMBOL(__i2c_transfer);2270 2271/**2272 * i2c_transfer - execute a single or combined I2C message2273 * @adap: Handle to I2C bus2274 * @msgs: One or more messages to execute before STOP is issued to2275 * terminate the operation; each message begins with a START.2276 * @num: Number of messages to be executed.2277 *2278 * Returns negative errno, else the number of messages executed.2279 *2280 * Note that there is no requirement that each message be sent to2281 * the same slave address, although that is the most common model.2282 */2283int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)2284{2285 int ret;2286 2287 /* REVISIT the fault reporting model here is weak:2288 *2289 * - When we get an error after receiving N bytes from a slave,2290 * there is no way to report "N".2291 *2292 * - When we get a NAK after transmitting N bytes to a slave,2293 * there is no way to report "N" ... or to let the master2294 * continue executing the rest of this combined message, if2295 * that's the appropriate response.2296 *2297 * - When for example "num" is two and we successfully complete2298 * the first message but get an error part way through the2299 * second, it's unclear whether that should be reported as2300 * one (discarding status on the second message) or errno2301 * (discarding status on the first one).2302 */2303 ret = __i2c_lock_bus_helper(adap);2304 if (ret)2305 return ret;2306 2307 ret = __i2c_transfer(adap, msgs, num);2308 i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);2309 2310 return ret;2311}2312EXPORT_SYMBOL(i2c_transfer);2313 2314/**2315 * i2c_transfer_buffer_flags - issue a single I2C message transferring data2316 * to/from a buffer2317 * @client: Handle to slave device2318 * @buf: Where the data is stored2319 * @count: How many bytes to transfer, must be less than 64k since msg.len is u162320 * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads2321 *2322 * Returns negative errno, or else the number of bytes transferred.2323 */2324int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,2325 int count, u16 flags)2326{2327 int ret;2328 struct i2c_msg msg = {2329 .addr = client->addr,2330 .flags = flags | (client->flags & I2C_M_TEN),2331 .len = count,2332 .buf = buf,2333 };2334 2335 ret = i2c_transfer(client->adapter, &msg, 1);2336 2337 /*2338 * If everything went ok (i.e. 1 msg transferred), return #bytes2339 * transferred, else error code.2340 */2341 return (ret == 1) ? count : ret;2342}2343EXPORT_SYMBOL(i2c_transfer_buffer_flags);2344 2345/**2346 * i2c_get_device_id - get manufacturer, part id and die revision of a device2347 * @client: The device to query2348 * @id: The queried information2349 *2350 * Returns negative errno on error, zero on success.2351 */2352int i2c_get_device_id(const struct i2c_client *client,2353 struct i2c_device_identity *id)2354{2355 struct i2c_adapter *adap = client->adapter;2356 union i2c_smbus_data raw_id;2357 int ret;2358 2359 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))2360 return -EOPNOTSUPP;2361 2362 raw_id.block[0] = 3;2363 ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,2364 I2C_SMBUS_READ, client->addr << 1,2365 I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);2366 if (ret)2367 return ret;2368 2369 id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);2370 id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);2371 id->die_revision = raw_id.block[3] & 0x7;2372 return 0;2373}2374EXPORT_SYMBOL_GPL(i2c_get_device_id);2375 2376/**2377 * i2c_client_get_device_id - get the driver match table entry of a device2378 * @client: the device to query. The device must be bound to a driver2379 *2380 * Returns a pointer to the matching entry if found, NULL otherwise.2381 */2382const struct i2c_device_id *i2c_client_get_device_id(const struct i2c_client *client)2383{2384 const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);2385 2386 return i2c_match_id(drv->id_table, client);2387}2388EXPORT_SYMBOL_GPL(i2c_client_get_device_id);2389 2390/* ----------------------------------------------------2391 * the i2c address scanning function2392 * Will not work for 10-bit addresses!2393 * ----------------------------------------------------2394 */2395 2396/*2397 * Legacy default probe function, mostly relevant for SMBus. The default2398 * probe method is a quick write, but it is known to corrupt the 24RF082399 * EEPROMs due to a state machine bug, and could also irreversibly2400 * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,2401 * we use a short byte read instead. Also, some bus drivers don't implement2402 * quick write, so we fallback to a byte read in that case too.2403 * On x86, there is another special case for FSC hardware monitoring chips,2404 * which want regular byte reads (address 0x73.) Fortunately, these are the2405 * only known chips using this I2C address on PC hardware.2406 * Returns 1 if probe succeeded, 0 if not.2407 */2408static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)2409{2410 int err;2411 union i2c_smbus_data dummy;2412 2413#ifdef CONFIG_X862414 if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)2415 && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))2416 err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,2417 I2C_SMBUS_BYTE_DATA, &dummy);2418 else2419#endif2420 if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)2421 && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))2422 err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,2423 I2C_SMBUS_QUICK, NULL);2424 else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))2425 err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,2426 I2C_SMBUS_BYTE, &dummy);2427 else {2428 dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",2429 addr);2430 err = -EOPNOTSUPP;2431 }2432 2433 return err >= 0;2434}2435 2436static int i2c_detect_address(struct i2c_client *temp_client,2437 struct i2c_driver *driver)2438{2439 struct i2c_board_info info;2440 struct i2c_adapter *adapter = temp_client->adapter;2441 int addr = temp_client->addr;2442 int err;2443 2444 /* Make sure the address is valid */2445 err = i2c_check_7bit_addr_validity_strict(addr);2446 if (err) {2447 dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",2448 addr);2449 return err;2450 }2451 2452 /* Skip if already in use (7 bit, no need to encode flags) */2453 if (i2c_check_addr_busy(adapter, addr))2454 return 0;2455 2456 /* Make sure there is something at this address */2457 if (!i2c_default_probe(adapter, addr))2458 return 0;2459 2460 /* Finally call the custom detection function */2461 memset(&info, 0, sizeof(struct i2c_board_info));2462 info.addr = addr;2463 err = driver->detect(temp_client, &info);2464 if (err) {2465 /* -ENODEV is returned if the detection fails. We catch it2466 here as this isn't an error. */2467 return err == -ENODEV ? 0 : err;2468 }2469 2470 /* Consistency check */2471 if (info.type[0] == '\0') {2472 dev_err(&adapter->dev,2473 "%s detection function provided no name for 0x%x\n",2474 driver->driver.name, addr);2475 } else {2476 struct i2c_client *client;2477 2478 /* Detection succeeded, instantiate the device */2479 if (adapter->class & I2C_CLASS_DEPRECATED)2480 dev_warn(&adapter->dev,2481 "This adapter will soon drop class based instantiation of devices. "2482 "Please make sure client 0x%02x gets instantiated by other means. "2483 "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n",2484 info.addr);2485 2486 dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",2487 info.type, info.addr);2488 client = i2c_new_client_device(adapter, &info);2489 if (!IS_ERR(client))2490 list_add_tail(&client->detected, &driver->clients);2491 else2492 dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",2493 info.type, info.addr);2494 }2495 return 0;2496}2497 2498static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)2499{2500 const unsigned short *address_list;2501 struct i2c_client *temp_client;2502 int i, err = 0;2503 2504 address_list = driver->address_list;2505 if (!driver->detect || !address_list)2506 return 0;2507 2508 /* Warn that the adapter lost class based instantiation */2509 if (adapter->class == I2C_CLASS_DEPRECATED) {2510 dev_dbg(&adapter->dev,2511 "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. "2512 "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n",2513 driver->driver.name);2514 return 0;2515 }2516 2517 /* Stop here if the classes do not match */2518 if (!(adapter->class & driver->class))2519 return 0;2520 2521 /* Set up a temporary client to help detect callback */2522 temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);2523 if (!temp_client)2524 return -ENOMEM;2525 temp_client->adapter = adapter;2526 2527 for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {2528 dev_dbg(&adapter->dev,2529 "found normal entry for adapter %d, addr 0x%02x\n",2530 i2c_adapter_id(adapter), address_list[i]);2531 temp_client->addr = address_list[i];2532 err = i2c_detect_address(temp_client, driver);2533 if (unlikely(err))2534 break;2535 }2536 2537 kfree(temp_client);2538 return err;2539}2540 2541int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)2542{2543 return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,2544 I2C_SMBUS_QUICK, NULL) >= 0;2545}2546EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);2547 2548struct i2c_client *2549i2c_new_scanned_device(struct i2c_adapter *adap,2550 struct i2c_board_info *info,2551 unsigned short const *addr_list,2552 int (*probe)(struct i2c_adapter *adap, unsigned short addr))2553{2554 int i;2555 2556 if (!probe)2557 probe = i2c_default_probe;2558 2559 for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {2560 /* Check address validity */2561 if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {2562 dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n",2563 addr_list[i]);2564 continue;2565 }2566 2567 /* Check address availability (7 bit, no need to encode flags) */2568 if (i2c_check_addr_busy(adap, addr_list[i])) {2569 dev_dbg(&adap->dev,2570 "Address 0x%02x already in use, not probing\n",2571 addr_list[i]);2572 continue;2573 }2574 2575 /* Test address responsiveness */2576 if (probe(adap, addr_list[i]))2577 break;2578 }2579 2580 if (addr_list[i] == I2C_CLIENT_END) {2581 dev_dbg(&adap->dev, "Probing failed, no device found\n");2582 return ERR_PTR(-ENODEV);2583 }2584 2585 info->addr = addr_list[i];2586 return i2c_new_client_device(adap, info);2587}2588EXPORT_SYMBOL_GPL(i2c_new_scanned_device);2589 2590struct i2c_adapter *i2c_get_adapter(int nr)2591{2592 struct i2c_adapter *adapter;2593 2594 mutex_lock(&core_lock);2595 adapter = idr_find(&i2c_adapter_idr, nr);2596 if (!adapter)2597 goto exit;2598 2599 if (try_module_get(adapter->owner))2600 get_device(&adapter->dev);2601 else2602 adapter = NULL;2603 2604 exit:2605 mutex_unlock(&core_lock);2606 return adapter;2607}2608EXPORT_SYMBOL(i2c_get_adapter);2609 2610void i2c_put_adapter(struct i2c_adapter *adap)2611{2612 if (!adap)2613 return;2614 2615 module_put(adap->owner);2616 /* Should be last, otherwise we risk use-after-free with 'adap' */2617 put_device(&adap->dev);2618}2619EXPORT_SYMBOL(i2c_put_adapter);2620 2621/**2622 * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg2623 * @msg: the message to be checked2624 * @threshold: the minimum number of bytes for which using DMA makes sense.2625 * Should at least be 1.2626 *2627 * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO.2628 * Or a valid pointer to be used with DMA. After use, release it by2629 * calling i2c_put_dma_safe_msg_buf().2630 *2631 * This function must only be called from process context!2632 */2633u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold)2634{2635 /* also skip 0-length msgs for bogus thresholds of 0 */2636 if (!threshold)2637 pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n",2638 msg->addr);2639 if (msg->len < threshold || msg->len == 0)2640 return NULL;2641 2642 if (msg->flags & I2C_M_DMA_SAFE)2643 return msg->buf;2644 2645 pr_debug("using bounce buffer for addr=0x%02x, len=%d\n",2646 msg->addr, msg->len);2647 2648 if (msg->flags & I2C_M_RD)2649 return kzalloc(msg->len, GFP_KERNEL);2650 else2651 return kmemdup(msg->buf, msg->len, GFP_KERNEL);2652}2653EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf);2654 2655/**2656 * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg2657 * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL.2658 * @msg: the message which the buffer corresponds to2659 * @xferred: bool saying if the message was transferred2660 */2661void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred)2662{2663 if (!buf || buf == msg->buf)2664 return;2665 2666 if (xferred && msg->flags & I2C_M_RD)2667 memcpy(msg->buf, buf, msg->len);2668 2669 kfree(buf);2670}2671EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf);2672 2673MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");2674MODULE_DESCRIPTION("I2C-Bus main module");2675MODULE_LICENSE("GPL");2676