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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * FSI core driver4 *5 * Copyright (C) IBM Corporation 20166 *7 * TODO:8 * - Rework topology9 * - s/chip_id/chip_loc10 * - s/cfam/chip (cfam_id -> chip_id etc...)11 */12 13#include <linux/crc4.h>14#include <linux/device.h>15#include <linux/fsi.h>16#include <linux/idr.h>17#include <linux/module.h>18#include <linux/of.h>19#include <linux/of_address.h>20#include <linux/of_device.h>21#include <linux/slab.h>22#include <linux/bitops.h>23#include <linux/cdev.h>24#include <linux/fs.h>25#include <linux/uaccess.h>26 27#include "fsi-master.h"28#include "fsi-slave.h"29 30#define CREATE_TRACE_POINTS31#include <trace/events/fsi.h>32 33#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)34#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)35#define FSI_SLAVE_CONF_SLOTS_SHIFT 1636#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)37#define FSI_SLAVE_CONF_VERSION_SHIFT 1238#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)39#define FSI_SLAVE_CONF_TYPE_SHIFT 440#define FSI_SLAVE_CONF_CRC_SHIFT 441#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)42#define FSI_SLAVE_CONF_DATA_BITS 2843 44#define FSI_PEEK_BASE 0x41045 46static const int engine_page_size = 0x400;47 48#define FSI_SLAVE_BASE 0x80049 50/*51 * FSI slave engine control register offsets52 */53#define FSI_SMODE 0x0 /* R/W: Mode register */54#define FSI_SISC 0x8 /* R/W: Interrupt condition */55#define FSI_SSTAT 0x14 /* R : Slave status */56#define FSI_SLBUS 0x30 /* W : LBUS Ownership */57#define FSI_LLMODE 0x100 /* R/W: Link layer mode register */58 59/*60 * SMODE fields61 */62#define FSI_SMODE_WSC 0x80000000 /* Warm start done */63#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */64#define FSI_SMODE_SID_SHIFT 24 /* ID shift */65#define FSI_SMODE_SID_MASK 3 /* ID Mask */66#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */67#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */68#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */69#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */70#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */71#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */72 73/*74 * SLBUS fields75 */76#define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */77 78/*79 * LLMODE fields80 */81#define FSI_LLMODE_ASYNC 0x182 83#define FSI_SLAVE_SIZE_23b 0x80000084 85static DEFINE_IDA(master_ida);86 87static const int slave_retries = 2;88static int discard_errors;89 90static dev_t fsi_base_dev;91static DEFINE_IDA(fsi_minor_ida);92#define FSI_CHAR_MAX_DEVICES 0x100093 94/* Legacy /dev numbering: 4 devices per chip, 16 chips */95#define FSI_CHAR_LEGACY_TOP 6496 97static int fsi_master_read(struct fsi_master *master, int link,98 uint8_t slave_id, uint32_t addr, void *val, size_t size);99static int fsi_master_write(struct fsi_master *master, int link,100 uint8_t slave_id, uint32_t addr, const void *val, size_t size);101static int fsi_master_break(struct fsi_master *master, int link);102 103/*104 * fsi_device_read() / fsi_device_write() / fsi_device_peek()105 *106 * FSI endpoint-device support107 *108 * Read / write / peek accessors for a client109 *110 * Parameters:111 * dev: Structure passed to FSI client device drivers on probe().112 * addr: FSI address of given device. Client should pass in its base address113 * plus desired offset to access its register space.114 * val: For read/peek this is the value read at the specified address. For115 * write this is value to write to the specified address.116 * The data in val must be FSI bus endian (big endian).117 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.118 * Addresses must be aligned on size boundaries or an error will result.119 */120int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,121 size_t size)122{123 if (addr > dev->size || size > dev->size || addr > dev->size - size)124 return -EINVAL;125 126 return fsi_slave_read(dev->slave, dev->addr + addr, val, size);127}128EXPORT_SYMBOL_GPL(fsi_device_read);129 130int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,131 size_t size)132{133 if (addr > dev->size || size > dev->size || addr > dev->size - size)134 return -EINVAL;135 136 return fsi_slave_write(dev->slave, dev->addr + addr, val, size);137}138EXPORT_SYMBOL_GPL(fsi_device_write);139 140int fsi_device_peek(struct fsi_device *dev, void *val)141{142 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));143 144 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));145}146 147static void fsi_device_release(struct device *_device)148{149 struct fsi_device *device = to_fsi_dev(_device);150 151 of_node_put(device->dev.of_node);152 kfree(device);153}154 155static struct fsi_device *fsi_create_device(struct fsi_slave *slave)156{157 struct fsi_device *dev;158 159 dev = kzalloc(sizeof(*dev), GFP_KERNEL);160 if (!dev)161 return NULL;162 163 dev->dev.parent = &slave->dev;164 dev->dev.bus = &fsi_bus_type;165 dev->dev.release = fsi_device_release;166 167 return dev;168}169 170/* FSI slave support */171static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,172 uint8_t *idp)173{174 uint32_t addr = *addrp;175 uint8_t id = *idp;176 177 if (addr > slave->size)178 return -EINVAL;179 180 /* For 23 bit addressing, we encode the extra two bits in the slave181 * id (and the slave's actual ID needs to be 0).182 */183 if (addr > 0x1fffff) {184 if (slave->id != 0)185 return -EINVAL;186 id = (addr >> 21) & 0x3;187 addr &= 0x1fffff;188 }189 190 *addrp = addr;191 *idp = id;192 return 0;193}194 195static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave)196{197 struct fsi_master *master = slave->master;198 __be32 irq, stat;199 int rc, link;200 uint8_t id;201 202 link = slave->link;203 id = slave->id;204 205 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC,206 &irq, sizeof(irq));207 if (rc)208 return rc;209 210 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT,211 &stat, sizeof(stat));212 if (rc)213 return rc;214 215 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n",216 be32_to_cpu(stat), be32_to_cpu(irq));217 218 /* clear interrupts */219 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC,220 &irq, sizeof(irq));221}222 223/* Encode slave local bus echo delay */224static inline uint32_t fsi_smode_echodly(int x)225{226 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;227}228 229/* Encode slave local bus send delay */230static inline uint32_t fsi_smode_senddly(int x)231{232 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;233}234 235/* Encode slave local bus clock rate ratio */236static inline uint32_t fsi_smode_lbcrr(int x)237{238 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;239}240 241/* Encode slave ID */242static inline uint32_t fsi_smode_sid(int x)243{244 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;245}246 247static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)248{249 return FSI_SMODE_WSC | FSI_SMODE_ECRC250 | fsi_smode_sid(id)251 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1)252 | fsi_smode_lbcrr(0x8);253}254 255static int fsi_slave_set_smode(struct fsi_slave *slave)256{257 uint32_t smode;258 __be32 data;259 260 /* set our smode register with the slave ID field to 0; this enables261 * extended slave addressing262 */263 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay);264 data = cpu_to_be32(smode);265 266 return fsi_master_write(slave->master, slave->link, slave->id,267 FSI_SLAVE_BASE + FSI_SMODE,268 &data, sizeof(data));269}270 271static int fsi_slave_handle_error(struct fsi_slave *slave, bool write,272 uint32_t addr, size_t size)273{274 struct fsi_master *master = slave->master;275 int rc, link;276 uint32_t reg;277 uint8_t id, send_delay, echo_delay;278 279 if (discard_errors)280 return -1;281 282 link = slave->link;283 id = slave->id;284 285 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]",286 write ? "write" : "read", addr, size);287 288 /* try a simple clear of error conditions, which may fail if we've lost289 * communication with the slave290 */291 rc = fsi_slave_report_and_clear_errors(slave);292 if (!rc)293 return 0;294 295 /* send a TERM and retry */296 if (master->term) {297 rc = master->term(master, link, id);298 if (!rc) {299 rc = fsi_master_read(master, link, id, 0,300 ®, sizeof(reg));301 if (!rc)302 rc = fsi_slave_report_and_clear_errors(slave);303 if (!rc)304 return 0;305 }306 }307 308 send_delay = slave->t_send_delay;309 echo_delay = slave->t_echo_delay;310 311 /* getting serious, reset the slave via BREAK */312 rc = fsi_master_break(master, link);313 if (rc)314 return rc;315 316 slave->t_send_delay = send_delay;317 slave->t_echo_delay = echo_delay;318 319 rc = fsi_slave_set_smode(slave);320 if (rc)321 return rc;322 323 if (master->link_config)324 master->link_config(master, link,325 slave->t_send_delay,326 slave->t_echo_delay);327 328 return fsi_slave_report_and_clear_errors(slave);329}330 331int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,332 void *val, size_t size)333{334 uint8_t id = slave->id;335 int rc, err_rc, i;336 337 rc = fsi_slave_calc_addr(slave, &addr, &id);338 if (rc)339 return rc;340 341 for (i = 0; i < slave_retries; i++) {342 rc = fsi_master_read(slave->master, slave->link,343 id, addr, val, size);344 if (!rc)345 break;346 347 err_rc = fsi_slave_handle_error(slave, false, addr, size);348 if (err_rc)349 break;350 }351 352 return rc;353}354EXPORT_SYMBOL_GPL(fsi_slave_read);355 356int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,357 const void *val, size_t size)358{359 uint8_t id = slave->id;360 int rc, err_rc, i;361 362 rc = fsi_slave_calc_addr(slave, &addr, &id);363 if (rc)364 return rc;365 366 for (i = 0; i < slave_retries; i++) {367 rc = fsi_master_write(slave->master, slave->link,368 id, addr, val, size);369 if (!rc)370 break;371 372 err_rc = fsi_slave_handle_error(slave, true, addr, size);373 if (err_rc)374 break;375 }376 377 return rc;378}379EXPORT_SYMBOL_GPL(fsi_slave_write);380 381int fsi_slave_claim_range(struct fsi_slave *slave,382 uint32_t addr, uint32_t size)383{384 if (addr + size < addr)385 return -EINVAL;386 387 if (addr + size > slave->size)388 return -EINVAL;389 390 /* todo: check for overlapping claims */391 return 0;392}393EXPORT_SYMBOL_GPL(fsi_slave_claim_range);394 395void fsi_slave_release_range(struct fsi_slave *slave,396 uint32_t addr, uint32_t size)397{398}399EXPORT_SYMBOL_GPL(fsi_slave_release_range);400 401static bool fsi_device_node_matches(struct device *dev, struct device_node *np,402 uint32_t addr, uint32_t size)403{404 u64 paddr, psize;405 406 if (of_property_read_reg(np, 0, &paddr, &psize))407 return false;408 409 if (paddr != addr)410 return false;411 412 if (psize != size) {413 dev_warn(dev,414 "node %pOF matches probed address, but not size (got 0x%llx, expected 0x%x)",415 np, psize, size);416 }417 418 return true;419}420 421/* Find a matching node for the slave engine at @address, using @size bytes422 * of space. Returns NULL if not found, or a matching node with refcount423 * already incremented.424 */425static struct device_node *fsi_device_find_of_node(struct fsi_device *dev)426{427 struct device_node *parent, *np;428 429 parent = dev_of_node(&dev->slave->dev);430 if (!parent)431 return NULL;432 433 for_each_child_of_node(parent, np) {434 if (fsi_device_node_matches(&dev->dev, np,435 dev->addr, dev->size))436 return np;437 }438 439 return NULL;440}441 442static int fsi_slave_scan(struct fsi_slave *slave)443{444 uint32_t engine_addr;445 int rc, i;446 447 /*448 * scan engines449 *450 * We keep the peek mode and slave engines for the core; so start451 * at the third slot in the configuration table. We also need to452 * skip the chip ID entry at the start of the address space.453 */454 engine_addr = engine_page_size * 3;455 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {456 uint8_t slots, version, type, crc;457 struct fsi_device *dev;458 uint32_t conf;459 __be32 data;460 461 rc = fsi_slave_read(slave, (i + 1) * sizeof(data),462 &data, sizeof(data));463 if (rc) {464 dev_warn(&slave->dev,465 "error reading slave registers\n");466 return -1;467 }468 conf = be32_to_cpu(data);469 470 crc = crc4(0, conf, 32);471 if (crc) {472 dev_warn(&slave->dev,473 "crc error in slave register at 0x%04x\n",474 i);475 return -1;476 }477 478 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)479 >> FSI_SLAVE_CONF_SLOTS_SHIFT;480 version = (conf & FSI_SLAVE_CONF_VERSION_MASK)481 >> FSI_SLAVE_CONF_VERSION_SHIFT;482 type = (conf & FSI_SLAVE_CONF_TYPE_MASK)483 >> FSI_SLAVE_CONF_TYPE_SHIFT;484 485 /*486 * Unused address areas are marked by a zero type value; this487 * skips the defined address areas488 */489 if (type != 0 && slots != 0) {490 491 /* create device */492 dev = fsi_create_device(slave);493 if (!dev)494 return -ENOMEM;495 496 dev->slave = slave;497 dev->engine_type = type;498 dev->version = version;499 dev->unit = i;500 dev->addr = engine_addr;501 dev->size = slots * engine_page_size;502 503 trace_fsi_dev_init(dev);504 505 dev_dbg(&slave->dev,506 "engine[%i]: type %x, version %x, addr %x size %x\n",507 dev->unit, dev->engine_type, version,508 dev->addr, dev->size);509 510 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",511 slave->master->idx, slave->link,512 slave->id, i - 2);513 dev->dev.of_node = fsi_device_find_of_node(dev);514 515 rc = device_register(&dev->dev);516 if (rc) {517 dev_warn(&slave->dev, "add failed: %d\n", rc);518 put_device(&dev->dev);519 }520 }521 522 engine_addr += slots * engine_page_size;523 524 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))525 break;526 }527 528 return 0;529}530 531static unsigned long aligned_access_size(size_t offset, size_t count)532{533 unsigned long offset_unit, count_unit;534 535 /* Criteria:536 *537 * 1. Access size must be less than or equal to the maximum access538 * width or the highest power-of-two factor of offset539 * 2. Access size must be less than or equal to the amount specified by540 * count541 *542 * The access width is optimal if we can calculate 1 to be strictly543 * equal while still satisfying 2.544 */545 546 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */547 offset_unit = BIT(__builtin_ctzl(offset | 4));548 549 /* Find 2 by the top bit of count */550 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count));551 552 /* Constrain the maximum access width to the minimum of both criteria */553 return BIT(__builtin_ctzl(offset_unit | count_unit));554}555 556static ssize_t fsi_slave_sysfs_raw_read(struct file *file,557 struct kobject *kobj, struct bin_attribute *attr, char *buf,558 loff_t off, size_t count)559{560 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));561 size_t total_len, read_len;562 int rc;563 564 if (off < 0)565 return -EINVAL;566 567 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)568 return -EINVAL;569 570 for (total_len = 0; total_len < count; total_len += read_len) {571 read_len = aligned_access_size(off, count - total_len);572 573 rc = fsi_slave_read(slave, off, buf + total_len, read_len);574 if (rc)575 return rc;576 577 off += read_len;578 }579 580 return count;581}582 583static ssize_t fsi_slave_sysfs_raw_write(struct file *file,584 struct kobject *kobj, struct bin_attribute *attr,585 char *buf, loff_t off, size_t count)586{587 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));588 size_t total_len, write_len;589 int rc;590 591 if (off < 0)592 return -EINVAL;593 594 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)595 return -EINVAL;596 597 for (total_len = 0; total_len < count; total_len += write_len) {598 write_len = aligned_access_size(off, count - total_len);599 600 rc = fsi_slave_write(slave, off, buf + total_len, write_len);601 if (rc)602 return rc;603 604 off += write_len;605 }606 607 return count;608}609 610static const struct bin_attribute fsi_slave_raw_attr = {611 .attr = {612 .name = "raw",613 .mode = 0600,614 },615 .size = 0,616 .read = fsi_slave_sysfs_raw_read,617 .write = fsi_slave_sysfs_raw_write,618};619 620static void fsi_slave_release(struct device *dev)621{622 struct fsi_slave *slave = to_fsi_slave(dev);623 624 fsi_free_minor(slave->dev.devt);625 of_node_put(dev->of_node);626 kfree(slave);627}628 629static bool fsi_slave_node_matches(struct device_node *np,630 int link, uint8_t id)631{632 u64 addr;633 634 if (of_property_read_reg(np, 0, &addr, NULL))635 return false;636 637 return addr == (((u64)link << 32) | id);638}639 640/* Find a matching node for the slave at (link, id). Returns NULL if none641 * found, or a matching node with refcount already incremented.642 */643static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,644 int link, uint8_t id)645{646 struct device_node *parent, *np;647 648 parent = dev_of_node(&master->dev);649 if (!parent)650 return NULL;651 652 for_each_child_of_node(parent, np) {653 if (fsi_slave_node_matches(np, link, id))654 return np;655 }656 657 return NULL;658}659 660static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,661 loff_t *offset)662{663 struct fsi_slave *slave = filep->private_data;664 size_t total_len, read_len;665 loff_t off = *offset;666 ssize_t rc;667 668 if (off < 0)669 return -EINVAL;670 671 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)672 return -EINVAL;673 674 for (total_len = 0; total_len < count; total_len += read_len) {675 __be32 data;676 677 read_len = min_t(size_t, count, 4);678 read_len -= off & 0x3;679 680 rc = fsi_slave_read(slave, off, &data, read_len);681 if (rc)682 goto fail;683 rc = copy_to_user(buf + total_len, &data, read_len);684 if (rc) {685 rc = -EFAULT;686 goto fail;687 }688 off += read_len;689 }690 rc = count;691 fail:692 *offset = off;693 return rc;694}695 696static ssize_t cfam_write(struct file *filep, const char __user *buf,697 size_t count, loff_t *offset)698{699 struct fsi_slave *slave = filep->private_data;700 size_t total_len, write_len;701 loff_t off = *offset;702 ssize_t rc;703 704 705 if (off < 0)706 return -EINVAL;707 708 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)709 return -EINVAL;710 711 for (total_len = 0; total_len < count; total_len += write_len) {712 __be32 data;713 714 write_len = min_t(size_t, count, 4);715 write_len -= off & 0x3;716 717 rc = copy_from_user(&data, buf + total_len, write_len);718 if (rc) {719 rc = -EFAULT;720 goto fail;721 }722 rc = fsi_slave_write(slave, off, &data, write_len);723 if (rc)724 goto fail;725 off += write_len;726 }727 rc = count;728 fail:729 *offset = off;730 return rc;731}732 733static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)734{735 switch (whence) {736 case SEEK_CUR:737 break;738 case SEEK_SET:739 file->f_pos = offset;740 break;741 default:742 return -EINVAL;743 }744 745 return offset;746}747 748static int cfam_open(struct inode *inode, struct file *file)749{750 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);751 752 file->private_data = slave;753 754 return 0;755}756 757static const struct file_operations cfam_fops = {758 .owner = THIS_MODULE,759 .open = cfam_open,760 .llseek = cfam_llseek,761 .read = cfam_read,762 .write = cfam_write,763};764 765static ssize_t send_term_store(struct device *dev,766 struct device_attribute *attr,767 const char *buf, size_t count)768{769 struct fsi_slave *slave = to_fsi_slave(dev);770 struct fsi_master *master = slave->master;771 772 if (!master->term)773 return -ENODEV;774 775 master->term(master, slave->link, slave->id);776 return count;777}778 779static DEVICE_ATTR_WO(send_term);780 781static ssize_t slave_send_echo_show(struct device *dev,782 struct device_attribute *attr,783 char *buf)784{785 struct fsi_slave *slave = to_fsi_slave(dev);786 787 return sprintf(buf, "%u\n", slave->t_send_delay);788}789 790static ssize_t slave_send_echo_store(struct device *dev,791 struct device_attribute *attr, const char *buf, size_t count)792{793 struct fsi_slave *slave = to_fsi_slave(dev);794 struct fsi_master *master = slave->master;795 unsigned long val;796 int rc;797 798 if (kstrtoul(buf, 0, &val) < 0)799 return -EINVAL;800 801 if (val < 1 || val > 16)802 return -EINVAL;803 804 if (!master->link_config)805 return -ENXIO;806 807 /* Current HW mandates that send and echo delay are identical */808 slave->t_send_delay = val;809 slave->t_echo_delay = val;810 811 rc = fsi_slave_set_smode(slave);812 if (rc < 0)813 return rc;814 if (master->link_config)815 master->link_config(master, slave->link,816 slave->t_send_delay,817 slave->t_echo_delay);818 819 return count;820}821 822static DEVICE_ATTR(send_echo_delays, 0600,823 slave_send_echo_show, slave_send_echo_store);824 825static ssize_t chip_id_show(struct device *dev,826 struct device_attribute *attr,827 char *buf)828{829 struct fsi_slave *slave = to_fsi_slave(dev);830 831 return sprintf(buf, "%d\n", slave->chip_id);832}833 834static DEVICE_ATTR_RO(chip_id);835 836static ssize_t cfam_id_show(struct device *dev,837 struct device_attribute *attr,838 char *buf)839{840 struct fsi_slave *slave = to_fsi_slave(dev);841 842 return sprintf(buf, "0x%x\n", slave->cfam_id);843}844 845static DEVICE_ATTR_RO(cfam_id);846 847static struct attribute *cfam_attr[] = {848 &dev_attr_send_echo_delays.attr,849 &dev_attr_chip_id.attr,850 &dev_attr_cfam_id.attr,851 &dev_attr_send_term.attr,852 NULL,853};854 855static const struct attribute_group cfam_attr_group = {856 .attrs = cfam_attr,857};858 859static const struct attribute_group *cfam_attr_groups[] = {860 &cfam_attr_group,861 NULL,862};863 864static char *cfam_devnode(const struct device *dev, umode_t *mode,865 kuid_t *uid, kgid_t *gid)866{867 const struct fsi_slave *slave = to_fsi_slave(dev);868 869#ifdef CONFIG_FSI_NEW_DEV_NODE870 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);871#else872 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);873#endif874}875 876static const struct device_type cfam_type = {877 .name = "cfam",878 .devnode = cfam_devnode,879 .groups = cfam_attr_groups880};881 882static char *fsi_cdev_devnode(const struct device *dev, umode_t *mode,883 kuid_t *uid, kgid_t *gid)884{885#ifdef CONFIG_FSI_NEW_DEV_NODE886 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));887#else888 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));889#endif890}891 892const struct device_type fsi_cdev_type = {893 .name = "fsi-cdev",894 .devnode = fsi_cdev_devnode,895};896EXPORT_SYMBOL_GPL(fsi_cdev_type);897 898/* Backward compatible /dev/ numbering in "old style" mode */899static int fsi_adjust_index(int index)900{901#ifdef CONFIG_FSI_NEW_DEV_NODE902 return index;903#else904 return index + 1;905#endif906}907 908static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,909 dev_t *out_dev, int *out_index)910{911 int cid = slave->chip_id;912 int id;913 914 /* Check if we qualify for legacy numbering */915 if (cid >= 0 && cid < 16 && type < 4) {916 /*917 * Try reserving the legacy number, which has 0 - 0x3f reserved918 * in the ida range. cid goes up to 0xf and type contains two919 * bits, so construct the id with the below two bit shift.920 */921 id = (cid << 2) | type;922 id = ida_alloc_range(&fsi_minor_ida, id, id, GFP_KERNEL);923 if (id >= 0) {924 *out_index = fsi_adjust_index(cid);925 *out_dev = fsi_base_dev + id;926 return 0;927 }928 /* Other failure */929 if (id != -ENOSPC)930 return id;931 /* Fallback to non-legacy allocation */932 }933 id = ida_alloc_range(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,934 FSI_CHAR_MAX_DEVICES - 1, GFP_KERNEL);935 if (id < 0)936 return id;937 *out_index = fsi_adjust_index(id);938 *out_dev = fsi_base_dev + id;939 return 0;940}941 942static const char *const fsi_dev_type_names[] = {943 "cfam",944 "sbefifo",945 "scom",946 "occ",947};948 949int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,950 dev_t *out_dev, int *out_index)951{952 if (fdev->dev.of_node) {953 int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);954 955 if (aid >= 0) {956 /* Use the same scheme as the legacy numbers. */957 int id = (aid << 2) | type;958 959 id = ida_alloc_range(&fsi_minor_ida, id, id, GFP_KERNEL);960 if (id >= 0) {961 *out_index = aid;962 *out_dev = fsi_base_dev + id;963 return 0;964 }965 966 if (id != -ENOSPC)967 return id;968 }969 }970 971 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);972}973EXPORT_SYMBOL_GPL(fsi_get_new_minor);974 975void fsi_free_minor(dev_t dev)976{977 ida_free(&fsi_minor_ida, MINOR(dev));978}979EXPORT_SYMBOL_GPL(fsi_free_minor);980 981static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)982{983 uint32_t cfam_id;984 struct fsi_slave *slave;985 uint8_t crc;986 __be32 data, llmode, slbus;987 int rc;988 989 /* Currently, we only support single slaves on a link, and use the990 * full 23-bit address range991 */992 if (id != 0)993 return -EINVAL;994 995 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data));996 if (rc) {997 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",998 link, id, rc);999 return -ENODEV;1000 }1001 cfam_id = be32_to_cpu(data);1002 1003 crc = crc4(0, cfam_id, 32);1004 if (crc) {1005 trace_fsi_slave_invalid_cfam(master, link, cfam_id);1006 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",1007 link, id);1008 return -EIO;1009 }1010 1011 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",1012 cfam_id, master->idx, link, id);1013 1014 /* If we're behind a master that doesn't provide a self-running bus1015 * clock, put the slave into async mode1016 */1017 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {1018 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);1019 rc = fsi_master_write(master, link, id,1020 FSI_SLAVE_BASE + FSI_LLMODE,1021 &llmode, sizeof(llmode));1022 if (rc)1023 dev_warn(&master->dev,1024 "can't set llmode on slave:%02x:%02x %d\n",1025 link, id, rc);1026 }1027 1028 /* We can communicate with a slave; create the slave device and1029 * register.1030 */1031 slave = kzalloc(sizeof(*slave), GFP_KERNEL);1032 if (!slave)1033 return -ENOMEM;1034 1035 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);1036 slave->dev.type = &cfam_type;1037 slave->dev.parent = &master->dev;1038 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);1039 slave->dev.release = fsi_slave_release;1040 device_initialize(&slave->dev);1041 slave->cfam_id = cfam_id;1042 slave->master = master;1043 slave->link = link;1044 slave->id = id;1045 slave->size = FSI_SLAVE_SIZE_23b;1046 slave->t_send_delay = 16;1047 slave->t_echo_delay = 16;1048 1049 /* Get chip ID if any */1050 slave->chip_id = -1;1051 if (slave->dev.of_node) {1052 uint32_t prop;1053 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))1054 slave->chip_id = prop;1055 1056 }1057 1058 slbus = cpu_to_be32(FSI_SLBUS_FORCE);1059 rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS,1060 &slbus, sizeof(slbus));1061 if (rc)1062 dev_warn(&master->dev,1063 "can't set slbus on slave:%02x:%02x %d\n", link, id,1064 rc);1065 1066 rc = fsi_slave_set_smode(slave);1067 if (rc) {1068 dev_warn(&master->dev,1069 "can't set smode on slave:%02x:%02x %d\n",1070 link, id, rc);1071 goto err_free;1072 }1073 1074 /* Allocate a minor in the FSI space */1075 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,1076 &slave->cdev_idx);1077 if (rc)1078 goto err_free;1079 1080 trace_fsi_slave_init(slave);1081 1082 /* Create chardev for userspace access */1083 cdev_init(&slave->cdev, &cfam_fops);1084 rc = cdev_device_add(&slave->cdev, &slave->dev);1085 if (rc) {1086 dev_err(&slave->dev, "Error %d creating slave device\n", rc);1087 goto err_free_ida;1088 }1089 1090 /* Now that we have the cdev registered with the core, any fatal1091 * failures beyond this point will need to clean up through1092 * cdev_device_del(). Fortunately though, nothing past here is fatal.1093 */1094 1095 if (master->link_config)1096 master->link_config(master, link,1097 slave->t_send_delay,1098 slave->t_echo_delay);1099 1100 /* Legacy raw file -> to be removed */1101 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);1102 if (rc)1103 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);1104 1105 1106 rc = fsi_slave_scan(slave);1107 if (rc)1108 dev_dbg(&master->dev, "failed during slave scan with: %d\n",1109 rc);1110 1111 return 0;1112 1113err_free_ida:1114 fsi_free_minor(slave->dev.devt);1115err_free:1116 of_node_put(slave->dev.of_node);1117 kfree(slave);1118 return rc;1119}1120 1121/* FSI master support */1122static int fsi_check_access(uint32_t addr, size_t size)1123{1124 if (size == 4) {1125 if (addr & 0x3)1126 return -EINVAL;1127 } else if (size == 2) {1128 if (addr & 0x1)1129 return -EINVAL;1130 } else if (size != 1)1131 return -EINVAL;1132 1133 return 0;1134}1135 1136static int fsi_master_read(struct fsi_master *master, int link,1137 uint8_t slave_id, uint32_t addr, void *val, size_t size)1138{1139 int rc;1140 1141 trace_fsi_master_read(master, link, slave_id, addr, size);1142 1143 rc = fsi_check_access(addr, size);1144 if (!rc)1145 rc = master->read(master, link, slave_id, addr, val, size);1146 1147 trace_fsi_master_rw_result(master, link, slave_id, addr, size,1148 false, val, rc);1149 1150 return rc;1151}1152 1153static int fsi_master_write(struct fsi_master *master, int link,1154 uint8_t slave_id, uint32_t addr, const void *val, size_t size)1155{1156 int rc;1157 1158 trace_fsi_master_write(master, link, slave_id, addr, size, val);1159 1160 rc = fsi_check_access(addr, size);1161 if (!rc)1162 rc = master->write(master, link, slave_id, addr, val, size);1163 1164 trace_fsi_master_rw_result(master, link, slave_id, addr, size,1165 true, val, rc);1166 1167 return rc;1168}1169 1170static int fsi_master_link_disable(struct fsi_master *master, int link)1171{1172 if (master->link_enable)1173 return master->link_enable(master, link, false);1174 1175 return 0;1176}1177 1178static int fsi_master_link_enable(struct fsi_master *master, int link)1179{1180 if (master->link_enable)1181 return master->link_enable(master, link, true);1182 1183 return 0;1184}1185 1186/*1187 * Issue a break command on this link1188 */1189static int fsi_master_break(struct fsi_master *master, int link)1190{1191 int rc = 0;1192 1193 trace_fsi_master_break(master, link);1194 1195 if (master->send_break)1196 rc = master->send_break(master, link);1197 if (master->link_config)1198 master->link_config(master, link, 16, 16);1199 1200 return rc;1201}1202 1203static int fsi_master_scan(struct fsi_master *master)1204{1205 int link, rc;1206 1207 trace_fsi_master_scan(master, true);1208 for (link = 0; link < master->n_links; link++) {1209 rc = fsi_master_link_enable(master, link);1210 if (rc) {1211 dev_dbg(&master->dev,1212 "enable link %d failed: %d\n", link, rc);1213 continue;1214 }1215 rc = fsi_master_break(master, link);1216 if (rc) {1217 fsi_master_link_disable(master, link);1218 dev_dbg(&master->dev,1219 "break to link %d failed: %d\n", link, rc);1220 continue;1221 }1222 1223 rc = fsi_slave_init(master, link, 0);1224 if (rc)1225 fsi_master_link_disable(master, link);1226 }1227 1228 return 0;1229}1230 1231static int fsi_slave_remove_device(struct device *dev, void *arg)1232{1233 device_unregister(dev);1234 return 0;1235}1236 1237static int fsi_master_remove_slave(struct device *dev, void *arg)1238{1239 struct fsi_slave *slave = to_fsi_slave(dev);1240 1241 device_for_each_child(dev, NULL, fsi_slave_remove_device);1242 cdev_device_del(&slave->cdev, &slave->dev);1243 put_device(dev);1244 return 0;1245}1246 1247static void fsi_master_unscan(struct fsi_master *master)1248{1249 trace_fsi_master_scan(master, false);1250 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);1251}1252 1253int fsi_master_rescan(struct fsi_master *master)1254{1255 int rc;1256 1257 mutex_lock(&master->scan_lock);1258 fsi_master_unscan(master);1259 rc = fsi_master_scan(master);1260 mutex_unlock(&master->scan_lock);1261 1262 return rc;1263}1264EXPORT_SYMBOL_GPL(fsi_master_rescan);1265 1266static ssize_t master_rescan_store(struct device *dev,1267 struct device_attribute *attr, const char *buf, size_t count)1268{1269 struct fsi_master *master = to_fsi_master(dev);1270 int rc;1271 1272 rc = fsi_master_rescan(master);1273 if (rc < 0)1274 return rc;1275 1276 return count;1277}1278 1279static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);1280 1281static ssize_t master_break_store(struct device *dev,1282 struct device_attribute *attr, const char *buf, size_t count)1283{1284 struct fsi_master *master = to_fsi_master(dev);1285 1286 fsi_master_break(master, 0);1287 1288 return count;1289}1290 1291static DEVICE_ATTR(break, 0200, NULL, master_break_store);1292 1293static struct attribute *master_attrs[] = {1294 &dev_attr_break.attr,1295 &dev_attr_rescan.attr,1296 NULL1297};1298 1299ATTRIBUTE_GROUPS(master);1300 1301static struct class fsi_master_class = {1302 .name = "fsi-master",1303 .dev_groups = master_groups,1304};1305 1306int fsi_master_register(struct fsi_master *master)1307{1308 int rc;1309 struct device_node *np;1310 1311 mutex_init(&master->scan_lock);1312 1313 /* Alloc the requested index if it's non-zero */1314 if (master->idx) {1315 master->idx = ida_alloc_range(&master_ida, master->idx,1316 master->idx, GFP_KERNEL);1317 } else {1318 master->idx = ida_alloc(&master_ida, GFP_KERNEL);1319 }1320 1321 if (master->idx < 0)1322 return master->idx;1323 1324 if (!dev_name(&master->dev))1325 dev_set_name(&master->dev, "fsi%d", master->idx);1326 1327 master->dev.class = &fsi_master_class;1328 1329 mutex_lock(&master->scan_lock);1330 rc = device_register(&master->dev);1331 if (rc) {1332 ida_free(&master_ida, master->idx);1333 goto out;1334 }1335 1336 np = dev_of_node(&master->dev);1337 if (!of_property_read_bool(np, "no-scan-on-init")) {1338 fsi_master_scan(master);1339 }1340out:1341 mutex_unlock(&master->scan_lock);1342 return rc;1343}1344EXPORT_SYMBOL_GPL(fsi_master_register);1345 1346void fsi_master_unregister(struct fsi_master *master)1347{1348 int idx = master->idx;1349 1350 trace_fsi_master_unregister(master);1351 1352 mutex_lock(&master->scan_lock);1353 fsi_master_unscan(master);1354 master->n_links = 0;1355 mutex_unlock(&master->scan_lock);1356 1357 device_unregister(&master->dev);1358 ida_free(&master_ida, idx);1359}1360EXPORT_SYMBOL_GPL(fsi_master_unregister);1361 1362/* FSI core & Linux bus type definitions */1363 1364static int fsi_bus_match(struct device *dev, const struct device_driver *drv)1365{1366 struct fsi_device *fsi_dev = to_fsi_dev(dev);1367 const struct fsi_driver *fsi_drv = to_fsi_drv(drv);1368 const struct fsi_device_id *id;1369 1370 if (!fsi_drv->id_table)1371 return 0;1372 1373 for (id = fsi_drv->id_table; id->engine_type; id++) {1374 if (id->engine_type != fsi_dev->engine_type)1375 continue;1376 if (id->version == FSI_VERSION_ANY ||1377 id->version == fsi_dev->version) {1378 if (drv->of_match_table) {1379 if (of_driver_match_device(dev, drv))1380 return 1;1381 } else {1382 return 1;1383 }1384 }1385 }1386 1387 return 0;1388}1389 1390int fsi_driver_register(struct fsi_driver *fsi_drv)1391{1392 if (!fsi_drv)1393 return -EINVAL;1394 if (!fsi_drv->id_table)1395 return -EINVAL;1396 1397 return driver_register(&fsi_drv->drv);1398}1399EXPORT_SYMBOL_GPL(fsi_driver_register);1400 1401void fsi_driver_unregister(struct fsi_driver *fsi_drv)1402{1403 driver_unregister(&fsi_drv->drv);1404}1405EXPORT_SYMBOL_GPL(fsi_driver_unregister);1406 1407struct bus_type fsi_bus_type = {1408 .name = "fsi",1409 .match = fsi_bus_match,1410};1411EXPORT_SYMBOL_GPL(fsi_bus_type);1412 1413static int __init fsi_init(void)1414{1415 int rc;1416 1417 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");1418 if (rc)1419 return rc;1420 rc = bus_register(&fsi_bus_type);1421 if (rc)1422 goto fail_bus;1423 1424 rc = class_register(&fsi_master_class);1425 if (rc)1426 goto fail_class;1427 1428 return 0;1429 1430 fail_class:1431 bus_unregister(&fsi_bus_type);1432 fail_bus:1433 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);1434 return rc;1435}1436postcore_initcall(fsi_init);1437 1438static void fsi_exit(void)1439{1440 class_unregister(&fsi_master_class);1441 bus_unregister(&fsi_bus_type);1442 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);1443 ida_destroy(&fsi_minor_ida);1444}1445module_exit(fsi_exit);1446module_param(discard_errors, int, 0664);1447MODULE_DESCRIPTION("FSI core driver");1448MODULE_LICENSE("GPL");1449MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");1450