1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * FSI core driver 4 * 5 * Copyright (C) IBM Corporation 2016 6 * 7 * TODO: 8 * - Rework topology 9 * - s/chip_id/chip_loc 10 * - 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/slab.h> 20 #include <linux/bitops.h> 21 #include <linux/cdev.h> 22 #include <linux/fs.h> 23 #include <linux/uaccess.h> 24 25 #include "fsi-master.h" 26 27 #define CREATE_TRACE_POINTS 28 #include <trace/events/fsi.h> 29 30 #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) 31 #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) 32 #define FSI_SLAVE_CONF_SLOTS_SHIFT 16 33 #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) 34 #define FSI_SLAVE_CONF_VERSION_SHIFT 12 35 #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) 36 #define FSI_SLAVE_CONF_TYPE_SHIFT 4 37 #define FSI_SLAVE_CONF_CRC_SHIFT 4 38 #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) 39 #define FSI_SLAVE_CONF_DATA_BITS 28 40 41 #define FSI_PEEK_BASE 0x410 42 43 static const int engine_page_size = 0x400; 44 45 #define FSI_SLAVE_BASE 0x800 46 47 /* 48 * FSI slave engine control register offsets 49 */ 50 #define FSI_SMODE 0x0 /* R/W: Mode register */ 51 #define FSI_SISC 0x8 /* R/W: Interrupt condition */ 52 #define FSI_SSTAT 0x14 /* R : Slave status */ 53 #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ 54 55 /* 56 * SMODE fields 57 */ 58 #define FSI_SMODE_WSC 0x80000000 /* Warm start done */ 59 #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ 60 #define FSI_SMODE_SID_SHIFT 24 /* ID shift */ 61 #define FSI_SMODE_SID_MASK 3 /* ID Mask */ 62 #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ 63 #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ 64 #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ 65 #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ 66 #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ 67 #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ 68 69 /* 70 * LLMODE fields 71 */ 72 #define FSI_LLMODE_ASYNC 0x1 73 74 #define FSI_SLAVE_SIZE_23b 0x800000 75 76 static DEFINE_IDA(master_ida); 77 78 struct fsi_slave { 79 struct device dev; 80 struct fsi_master *master; 81 struct cdev cdev; 82 int cdev_idx; 83 int id; /* FSI address */ 84 int link; /* FSI link# */ 85 u32 cfam_id; 86 int chip_id; 87 uint32_t size; /* size of slave address space */ 88 u8 t_send_delay; 89 u8 t_echo_delay; 90 }; 91 92 #define to_fsi_master(d) container_of(d, struct fsi_master, dev) 93 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) 94 95 static const int slave_retries = 2; 96 static int discard_errors; 97 98 static dev_t fsi_base_dev; 99 static DEFINE_IDA(fsi_minor_ida); 100 #define FSI_CHAR_MAX_DEVICES 0x1000 101 102 /* Legacy /dev numbering: 4 devices per chip, 16 chips */ 103 #define FSI_CHAR_LEGACY_TOP 64 104 105 static int fsi_master_read(struct fsi_master *master, int link, 106 uint8_t slave_id, uint32_t addr, void *val, size_t size); 107 static int fsi_master_write(struct fsi_master *master, int link, 108 uint8_t slave_id, uint32_t addr, const void *val, size_t size); 109 static int fsi_master_break(struct fsi_master *master, int link); 110 111 /* 112 * fsi_device_read() / fsi_device_write() / fsi_device_peek() 113 * 114 * FSI endpoint-device support 115 * 116 * Read / write / peek accessors for a client 117 * 118 * Parameters: 119 * dev: Structure passed to FSI client device drivers on probe(). 120 * addr: FSI address of given device. Client should pass in its base address 121 * plus desired offset to access its register space. 122 * val: For read/peek this is the value read at the specified address. For 123 * write this is value to write to the specified address. 124 * The data in val must be FSI bus endian (big endian). 125 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. 126 * Addresses must be aligned on size boundaries or an error will result. 127 */ 128 int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, 129 size_t size) 130 { 131 if (addr > dev->size || size > dev->size || addr > dev->size - size) 132 return -EINVAL; 133 134 return fsi_slave_read(dev->slave, dev->addr + addr, val, size); 135 } 136 EXPORT_SYMBOL_GPL(fsi_device_read); 137 138 int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, 139 size_t size) 140 { 141 if (addr > dev->size || size > dev->size || addr > dev->size - size) 142 return -EINVAL; 143 144 return fsi_slave_write(dev->slave, dev->addr + addr, val, size); 145 } 146 EXPORT_SYMBOL_GPL(fsi_device_write); 147 148 int fsi_device_peek(struct fsi_device *dev, void *val) 149 { 150 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); 151 152 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); 153 } 154 155 static void fsi_device_release(struct device *_device) 156 { 157 struct fsi_device *device = to_fsi_dev(_device); 158 159 of_node_put(device->dev.of_node); 160 kfree(device); 161 } 162 163 static struct fsi_device *fsi_create_device(struct fsi_slave *slave) 164 { 165 struct fsi_device *dev; 166 167 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 168 if (!dev) 169 return NULL; 170 171 dev->dev.parent = &slave->dev; 172 dev->dev.bus = &fsi_bus_type; 173 dev->dev.release = fsi_device_release; 174 175 return dev; 176 } 177 178 /* FSI slave support */ 179 static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, 180 uint8_t *idp) 181 { 182 uint32_t addr = *addrp; 183 uint8_t id = *idp; 184 185 if (addr > slave->size) 186 return -EINVAL; 187 188 /* For 23 bit addressing, we encode the extra two bits in the slave 189 * id (and the slave's actual ID needs to be 0). 190 */ 191 if (addr > 0x1fffff) { 192 if (slave->id != 0) 193 return -EINVAL; 194 id = (addr >> 21) & 0x3; 195 addr &= 0x1fffff; 196 } 197 198 *addrp = addr; 199 *idp = id; 200 return 0; 201 } 202 203 static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) 204 { 205 struct fsi_master *master = slave->master; 206 __be32 irq, stat; 207 int rc, link; 208 uint8_t id; 209 210 link = slave->link; 211 id = slave->id; 212 213 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 214 &irq, sizeof(irq)); 215 if (rc) 216 return rc; 217 218 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, 219 &stat, sizeof(stat)); 220 if (rc) 221 return rc; 222 223 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", 224 be32_to_cpu(stat), be32_to_cpu(irq)); 225 226 /* clear interrupts */ 227 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 228 &irq, sizeof(irq)); 229 } 230 231 /* Encode slave local bus echo delay */ 232 static inline uint32_t fsi_smode_echodly(int x) 233 { 234 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; 235 } 236 237 /* Encode slave local bus send delay */ 238 static inline uint32_t fsi_smode_senddly(int x) 239 { 240 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; 241 } 242 243 /* Encode slave local bus clock rate ratio */ 244 static inline uint32_t fsi_smode_lbcrr(int x) 245 { 246 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; 247 } 248 249 /* Encode slave ID */ 250 static inline uint32_t fsi_smode_sid(int x) 251 { 252 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; 253 } 254 255 static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly) 256 { 257 return FSI_SMODE_WSC | FSI_SMODE_ECRC 258 | fsi_smode_sid(id) 259 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1) 260 | fsi_smode_lbcrr(0x8); 261 } 262 263 static int fsi_slave_set_smode(struct fsi_slave *slave) 264 { 265 uint32_t smode; 266 __be32 data; 267 268 /* set our smode register with the slave ID field to 0; this enables 269 * extended slave addressing 270 */ 271 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay); 272 data = cpu_to_be32(smode); 273 274 return fsi_master_write(slave->master, slave->link, slave->id, 275 FSI_SLAVE_BASE + FSI_SMODE, 276 &data, sizeof(data)); 277 } 278 279 static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, 280 uint32_t addr, size_t size) 281 { 282 struct fsi_master *master = slave->master; 283 int rc, link; 284 uint32_t reg; 285 uint8_t id, send_delay, echo_delay; 286 287 if (discard_errors) 288 return -1; 289 290 link = slave->link; 291 id = slave->id; 292 293 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", 294 write ? "write" : "read", addr, size); 295 296 /* try a simple clear of error conditions, which may fail if we've lost 297 * communication with the slave 298 */ 299 rc = fsi_slave_report_and_clear_errors(slave); 300 if (!rc) 301 return 0; 302 303 /* send a TERM and retry */ 304 if (master->term) { 305 rc = master->term(master, link, id); 306 if (!rc) { 307 rc = fsi_master_read(master, link, id, 0, 308 ®, sizeof(reg)); 309 if (!rc) 310 rc = fsi_slave_report_and_clear_errors(slave); 311 if (!rc) 312 return 0; 313 } 314 } 315 316 send_delay = slave->t_send_delay; 317 echo_delay = slave->t_echo_delay; 318 319 /* getting serious, reset the slave via BREAK */ 320 rc = fsi_master_break(master, link); 321 if (rc) 322 return rc; 323 324 slave->t_send_delay = send_delay; 325 slave->t_echo_delay = echo_delay; 326 327 rc = fsi_slave_set_smode(slave); 328 if (rc) 329 return rc; 330 331 if (master->link_config) 332 master->link_config(master, link, 333 slave->t_send_delay, 334 slave->t_echo_delay); 335 336 return fsi_slave_report_and_clear_errors(slave); 337 } 338 339 int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, 340 void *val, size_t size) 341 { 342 uint8_t id = slave->id; 343 int rc, err_rc, i; 344 345 rc = fsi_slave_calc_addr(slave, &addr, &id); 346 if (rc) 347 return rc; 348 349 for (i = 0; i < slave_retries; i++) { 350 rc = fsi_master_read(slave->master, slave->link, 351 id, addr, val, size); 352 if (!rc) 353 break; 354 355 err_rc = fsi_slave_handle_error(slave, false, addr, size); 356 if (err_rc) 357 break; 358 } 359 360 return rc; 361 } 362 EXPORT_SYMBOL_GPL(fsi_slave_read); 363 364 int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, 365 const void *val, size_t size) 366 { 367 uint8_t id = slave->id; 368 int rc, err_rc, i; 369 370 rc = fsi_slave_calc_addr(slave, &addr, &id); 371 if (rc) 372 return rc; 373 374 for (i = 0; i < slave_retries; i++) { 375 rc = fsi_master_write(slave->master, slave->link, 376 id, addr, val, size); 377 if (!rc) 378 break; 379 380 err_rc = fsi_slave_handle_error(slave, true, addr, size); 381 if (err_rc) 382 break; 383 } 384 385 return rc; 386 } 387 EXPORT_SYMBOL_GPL(fsi_slave_write); 388 389 extern int fsi_slave_claim_range(struct fsi_slave *slave, 390 uint32_t addr, uint32_t size) 391 { 392 if (addr + size < addr) 393 return -EINVAL; 394 395 if (addr + size > slave->size) 396 return -EINVAL; 397 398 /* todo: check for overlapping claims */ 399 return 0; 400 } 401 EXPORT_SYMBOL_GPL(fsi_slave_claim_range); 402 403 extern void fsi_slave_release_range(struct fsi_slave *slave, 404 uint32_t addr, uint32_t size) 405 { 406 } 407 EXPORT_SYMBOL_GPL(fsi_slave_release_range); 408 409 static bool fsi_device_node_matches(struct device *dev, struct device_node *np, 410 uint32_t addr, uint32_t size) 411 { 412 unsigned int len, na, ns; 413 const __be32 *prop; 414 uint32_t psize; 415 416 na = of_n_addr_cells(np); 417 ns = of_n_size_cells(np); 418 419 if (na != 1 || ns != 1) 420 return false; 421 422 prop = of_get_property(np, "reg", &len); 423 if (!prop || len != 8) 424 return false; 425 426 if (of_read_number(prop, 1) != addr) 427 return false; 428 429 psize = of_read_number(prop + 1, 1); 430 if (psize != size) { 431 dev_warn(dev, 432 "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", 433 of_node_full_name(np), psize, size); 434 } 435 436 return true; 437 } 438 439 /* Find a matching node for the slave engine at @address, using @size bytes 440 * of space. Returns NULL if not found, or a matching node with refcount 441 * already incremented. 442 */ 443 static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) 444 { 445 struct device_node *parent, *np; 446 447 parent = dev_of_node(&dev->slave->dev); 448 if (!parent) 449 return NULL; 450 451 for_each_child_of_node(parent, np) { 452 if (fsi_device_node_matches(&dev->dev, np, 453 dev->addr, dev->size)) 454 return np; 455 } 456 457 return NULL; 458 } 459 460 static int fsi_slave_scan(struct fsi_slave *slave) 461 { 462 uint32_t engine_addr; 463 int rc, i; 464 465 /* 466 * scan engines 467 * 468 * We keep the peek mode and slave engines for the core; so start 469 * at the third slot in the configuration table. We also need to 470 * skip the chip ID entry at the start of the address space. 471 */ 472 engine_addr = engine_page_size * 3; 473 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { 474 uint8_t slots, version, type, crc; 475 struct fsi_device *dev; 476 uint32_t conf; 477 __be32 data; 478 479 rc = fsi_slave_read(slave, (i + 1) * sizeof(data), 480 &data, sizeof(data)); 481 if (rc) { 482 dev_warn(&slave->dev, 483 "error reading slave registers\n"); 484 return -1; 485 } 486 conf = be32_to_cpu(data); 487 488 crc = crc4(0, conf, 32); 489 if (crc) { 490 dev_warn(&slave->dev, 491 "crc error in slave register at 0x%04x\n", 492 i); 493 return -1; 494 } 495 496 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) 497 >> FSI_SLAVE_CONF_SLOTS_SHIFT; 498 version = (conf & FSI_SLAVE_CONF_VERSION_MASK) 499 >> FSI_SLAVE_CONF_VERSION_SHIFT; 500 type = (conf & FSI_SLAVE_CONF_TYPE_MASK) 501 >> FSI_SLAVE_CONF_TYPE_SHIFT; 502 503 /* 504 * Unused address areas are marked by a zero type value; this 505 * skips the defined address areas 506 */ 507 if (type != 0 && slots != 0) { 508 509 /* create device */ 510 dev = fsi_create_device(slave); 511 if (!dev) 512 return -ENOMEM; 513 514 dev->slave = slave; 515 dev->engine_type = type; 516 dev->version = version; 517 dev->unit = i; 518 dev->addr = engine_addr; 519 dev->size = slots * engine_page_size; 520 521 dev_dbg(&slave->dev, 522 "engine[%i]: type %x, version %x, addr %x size %x\n", 523 dev->unit, dev->engine_type, version, 524 dev->addr, dev->size); 525 526 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", 527 slave->master->idx, slave->link, 528 slave->id, i - 2); 529 dev->dev.of_node = fsi_device_find_of_node(dev); 530 531 rc = device_register(&dev->dev); 532 if (rc) { 533 dev_warn(&slave->dev, "add failed: %d\n", rc); 534 put_device(&dev->dev); 535 } 536 } 537 538 engine_addr += slots * engine_page_size; 539 540 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) 541 break; 542 } 543 544 return 0; 545 } 546 547 static unsigned long aligned_access_size(size_t offset, size_t count) 548 { 549 unsigned long offset_unit, count_unit; 550 551 /* Criteria: 552 * 553 * 1. Access size must be less than or equal to the maximum access 554 * width or the highest power-of-two factor of offset 555 * 2. Access size must be less than or equal to the amount specified by 556 * count 557 * 558 * The access width is optimal if we can calculate 1 to be strictly 559 * equal while still satisfying 2. 560 */ 561 562 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */ 563 offset_unit = BIT(__builtin_ctzl(offset | 4)); 564 565 /* Find 2 by the top bit of count */ 566 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count)); 567 568 /* Constrain the maximum access width to the minimum of both criteria */ 569 return BIT(__builtin_ctzl(offset_unit | count_unit)); 570 } 571 572 static ssize_t fsi_slave_sysfs_raw_read(struct file *file, 573 struct kobject *kobj, struct bin_attribute *attr, char *buf, 574 loff_t off, size_t count) 575 { 576 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 577 size_t total_len, read_len; 578 int rc; 579 580 if (off < 0) 581 return -EINVAL; 582 583 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 584 return -EINVAL; 585 586 for (total_len = 0; total_len < count; total_len += read_len) { 587 read_len = aligned_access_size(off, count - total_len); 588 589 rc = fsi_slave_read(slave, off, buf + total_len, read_len); 590 if (rc) 591 return rc; 592 593 off += read_len; 594 } 595 596 return count; 597 } 598 599 static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 600 struct kobject *kobj, struct bin_attribute *attr, 601 char *buf, loff_t off, size_t count) 602 { 603 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 604 size_t total_len, write_len; 605 int rc; 606 607 if (off < 0) 608 return -EINVAL; 609 610 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 611 return -EINVAL; 612 613 for (total_len = 0; total_len < count; total_len += write_len) { 614 write_len = aligned_access_size(off, count - total_len); 615 616 rc = fsi_slave_write(slave, off, buf + total_len, write_len); 617 if (rc) 618 return rc; 619 620 off += write_len; 621 } 622 623 return count; 624 } 625 626 static const struct bin_attribute fsi_slave_raw_attr = { 627 .attr = { 628 .name = "raw", 629 .mode = 0600, 630 }, 631 .size = 0, 632 .read = fsi_slave_sysfs_raw_read, 633 .write = fsi_slave_sysfs_raw_write, 634 }; 635 636 static void fsi_slave_release(struct device *dev) 637 { 638 struct fsi_slave *slave = to_fsi_slave(dev); 639 640 fsi_free_minor(slave->dev.devt); 641 of_node_put(dev->of_node); 642 kfree(slave); 643 } 644 645 static bool fsi_slave_node_matches(struct device_node *np, 646 int link, uint8_t id) 647 { 648 unsigned int len, na, ns; 649 const __be32 *prop; 650 651 na = of_n_addr_cells(np); 652 ns = of_n_size_cells(np); 653 654 /* Ensure we have the correct format for addresses and sizes in 655 * reg properties 656 */ 657 if (na != 2 || ns != 0) 658 return false; 659 660 prop = of_get_property(np, "reg", &len); 661 if (!prop || len != 8) 662 return false; 663 664 return (of_read_number(prop, 1) == link) && 665 (of_read_number(prop + 1, 1) == id); 666 } 667 668 /* Find a matching node for the slave at (link, id). Returns NULL if none 669 * found, or a matching node with refcount already incremented. 670 */ 671 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, 672 int link, uint8_t id) 673 { 674 struct device_node *parent, *np; 675 676 parent = dev_of_node(&master->dev); 677 if (!parent) 678 return NULL; 679 680 for_each_child_of_node(parent, np) { 681 if (fsi_slave_node_matches(np, link, id)) 682 return np; 683 } 684 685 return NULL; 686 } 687 688 static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count, 689 loff_t *offset) 690 { 691 struct fsi_slave *slave = filep->private_data; 692 size_t total_len, read_len; 693 loff_t off = *offset; 694 ssize_t rc; 695 696 if (off < 0) 697 return -EINVAL; 698 699 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 700 return -EINVAL; 701 702 for (total_len = 0; total_len < count; total_len += read_len) { 703 __be32 data; 704 705 read_len = min_t(size_t, count, 4); 706 read_len -= off & 0x3; 707 708 rc = fsi_slave_read(slave, off, &data, read_len); 709 if (rc) 710 goto fail; 711 rc = copy_to_user(buf + total_len, &data, read_len); 712 if (rc) { 713 rc = -EFAULT; 714 goto fail; 715 } 716 off += read_len; 717 } 718 rc = count; 719 fail: 720 *offset = off; 721 return count; 722 } 723 724 static ssize_t cfam_write(struct file *filep, const char __user *buf, 725 size_t count, loff_t *offset) 726 { 727 struct fsi_slave *slave = filep->private_data; 728 size_t total_len, write_len; 729 loff_t off = *offset; 730 ssize_t rc; 731 732 733 if (off < 0) 734 return -EINVAL; 735 736 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 737 return -EINVAL; 738 739 for (total_len = 0; total_len < count; total_len += write_len) { 740 __be32 data; 741 742 write_len = min_t(size_t, count, 4); 743 write_len -= off & 0x3; 744 745 rc = copy_from_user(&data, buf + total_len, write_len); 746 if (rc) { 747 rc = -EFAULT; 748 goto fail; 749 } 750 rc = fsi_slave_write(slave, off, &data, write_len); 751 if (rc) 752 goto fail; 753 off += write_len; 754 } 755 rc = count; 756 fail: 757 *offset = off; 758 return count; 759 } 760 761 static loff_t cfam_llseek(struct file *file, loff_t offset, int whence) 762 { 763 switch (whence) { 764 case SEEK_CUR: 765 break; 766 case SEEK_SET: 767 file->f_pos = offset; 768 break; 769 default: 770 return -EINVAL; 771 } 772 773 return offset; 774 } 775 776 static int cfam_open(struct inode *inode, struct file *file) 777 { 778 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev); 779 780 file->private_data = slave; 781 782 return 0; 783 } 784 785 static const struct file_operations cfam_fops = { 786 .owner = THIS_MODULE, 787 .open = cfam_open, 788 .llseek = cfam_llseek, 789 .read = cfam_read, 790 .write = cfam_write, 791 }; 792 793 static ssize_t send_term_store(struct device *dev, 794 struct device_attribute *attr, 795 const char *buf, size_t count) 796 { 797 struct fsi_slave *slave = to_fsi_slave(dev); 798 struct fsi_master *master = slave->master; 799 800 if (!master->term) 801 return -ENODEV; 802 803 master->term(master, slave->link, slave->id); 804 return count; 805 } 806 807 static DEVICE_ATTR_WO(send_term); 808 809 static ssize_t slave_send_echo_show(struct device *dev, 810 struct device_attribute *attr, 811 char *buf) 812 { 813 struct fsi_slave *slave = to_fsi_slave(dev); 814 815 return sprintf(buf, "%u\n", slave->t_send_delay); 816 } 817 818 static ssize_t slave_send_echo_store(struct device *dev, 819 struct device_attribute *attr, const char *buf, size_t count) 820 { 821 struct fsi_slave *slave = to_fsi_slave(dev); 822 struct fsi_master *master = slave->master; 823 unsigned long val; 824 int rc; 825 826 if (kstrtoul(buf, 0, &val) < 0) 827 return -EINVAL; 828 829 if (val < 1 || val > 16) 830 return -EINVAL; 831 832 if (!master->link_config) 833 return -ENXIO; 834 835 /* Current HW mandates that send and echo delay are identical */ 836 slave->t_send_delay = val; 837 slave->t_echo_delay = val; 838 839 rc = fsi_slave_set_smode(slave); 840 if (rc < 0) 841 return rc; 842 if (master->link_config) 843 master->link_config(master, slave->link, 844 slave->t_send_delay, 845 slave->t_echo_delay); 846 847 return count; 848 } 849 850 static DEVICE_ATTR(send_echo_delays, 0600, 851 slave_send_echo_show, slave_send_echo_store); 852 853 static ssize_t chip_id_show(struct device *dev, 854 struct device_attribute *attr, 855 char *buf) 856 { 857 struct fsi_slave *slave = to_fsi_slave(dev); 858 859 return sprintf(buf, "%d\n", slave->chip_id); 860 } 861 862 static DEVICE_ATTR_RO(chip_id); 863 864 static ssize_t cfam_id_show(struct device *dev, 865 struct device_attribute *attr, 866 char *buf) 867 { 868 struct fsi_slave *slave = to_fsi_slave(dev); 869 870 return sprintf(buf, "0x%x\n", slave->cfam_id); 871 } 872 873 static DEVICE_ATTR_RO(cfam_id); 874 875 static struct attribute *cfam_attr[] = { 876 &dev_attr_send_echo_delays.attr, 877 &dev_attr_chip_id.attr, 878 &dev_attr_cfam_id.attr, 879 &dev_attr_send_term.attr, 880 NULL, 881 }; 882 883 static const struct attribute_group cfam_attr_group = { 884 .attrs = cfam_attr, 885 }; 886 887 static const struct attribute_group *cfam_attr_groups[] = { 888 &cfam_attr_group, 889 NULL, 890 }; 891 892 static char *cfam_devnode(struct device *dev, umode_t *mode, 893 kuid_t *uid, kgid_t *gid) 894 { 895 struct fsi_slave *slave = to_fsi_slave(dev); 896 897 #ifdef CONFIG_FSI_NEW_DEV_NODE 898 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx); 899 #else 900 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx); 901 #endif 902 } 903 904 static const struct device_type cfam_type = { 905 .name = "cfam", 906 .devnode = cfam_devnode, 907 .groups = cfam_attr_groups 908 }; 909 910 static char *fsi_cdev_devnode(struct device *dev, umode_t *mode, 911 kuid_t *uid, kgid_t *gid) 912 { 913 #ifdef CONFIG_FSI_NEW_DEV_NODE 914 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev)); 915 #else 916 return kasprintf(GFP_KERNEL, "%s", dev_name(dev)); 917 #endif 918 } 919 920 const struct device_type fsi_cdev_type = { 921 .name = "fsi-cdev", 922 .devnode = fsi_cdev_devnode, 923 }; 924 EXPORT_SYMBOL_GPL(fsi_cdev_type); 925 926 /* Backward compatible /dev/ numbering in "old style" mode */ 927 static int fsi_adjust_index(int index) 928 { 929 #ifdef CONFIG_FSI_NEW_DEV_NODE 930 return index; 931 #else 932 return index + 1; 933 #endif 934 } 935 936 static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type, 937 dev_t *out_dev, int *out_index) 938 { 939 int cid = slave->chip_id; 940 int id; 941 942 /* Check if we qualify for legacy numbering */ 943 if (cid >= 0 && cid < 16 && type < 4) { 944 /* Try reserving the legacy number */ 945 id = (cid << 4) | type; 946 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); 947 if (id >= 0) { 948 *out_index = fsi_adjust_index(cid); 949 *out_dev = fsi_base_dev + id; 950 return 0; 951 } 952 /* Other failure */ 953 if (id != -ENOSPC) 954 return id; 955 /* Fallback to non-legacy allocation */ 956 } 957 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP, 958 FSI_CHAR_MAX_DEVICES, GFP_KERNEL); 959 if (id < 0) 960 return id; 961 *out_index = fsi_adjust_index(id); 962 *out_dev = fsi_base_dev + id; 963 return 0; 964 } 965 966 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type, 967 dev_t *out_dev, int *out_index) 968 { 969 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index); 970 } 971 EXPORT_SYMBOL_GPL(fsi_get_new_minor); 972 973 void fsi_free_minor(dev_t dev) 974 { 975 ida_simple_remove(&fsi_minor_ida, MINOR(dev)); 976 } 977 EXPORT_SYMBOL_GPL(fsi_free_minor); 978 979 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 980 { 981 uint32_t cfam_id; 982 struct fsi_slave *slave; 983 uint8_t crc; 984 __be32 data, llmode; 985 int rc; 986 987 /* Currently, we only support single slaves on a link, and use the 988 * full 23-bit address range 989 */ 990 if (id != 0) 991 return -EINVAL; 992 993 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data)); 994 if (rc) { 995 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 996 link, id, rc); 997 return -ENODEV; 998 } 999 cfam_id = be32_to_cpu(data); 1000 1001 crc = crc4(0, cfam_id, 32); 1002 if (crc) { 1003 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n", 1004 link, id); 1005 return -EIO; 1006 } 1007 1008 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 1009 cfam_id, master->idx, link, id); 1010 1011 /* If we're behind a master that doesn't provide a self-running bus 1012 * clock, put the slave into async mode 1013 */ 1014 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 1015 llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 1016 rc = fsi_master_write(master, link, id, 1017 FSI_SLAVE_BASE + FSI_LLMODE, 1018 &llmode, sizeof(llmode)); 1019 if (rc) 1020 dev_warn(&master->dev, 1021 "can't set llmode on slave:%02x:%02x %d\n", 1022 link, id, rc); 1023 } 1024 1025 /* We can communicate with a slave; create the slave device and 1026 * register. 1027 */ 1028 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 1029 if (!slave) 1030 return -ENOMEM; 1031 1032 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 1033 slave->dev.type = &cfam_type; 1034 slave->dev.parent = &master->dev; 1035 slave->dev.of_node = fsi_slave_find_of_node(master, link, id); 1036 slave->dev.release = fsi_slave_release; 1037 device_initialize(&slave->dev); 1038 slave->cfam_id = cfam_id; 1039 slave->master = master; 1040 slave->link = link; 1041 slave->id = id; 1042 slave->size = FSI_SLAVE_SIZE_23b; 1043 slave->t_send_delay = 16; 1044 slave->t_echo_delay = 16; 1045 1046 /* Get chip ID if any */ 1047 slave->chip_id = -1; 1048 if (slave->dev.of_node) { 1049 uint32_t prop; 1050 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop)) 1051 slave->chip_id = prop; 1052 1053 } 1054 1055 rc = fsi_slave_set_smode(slave); 1056 if (rc) { 1057 dev_warn(&master->dev, 1058 "can't set smode on slave:%02x:%02x %d\n", 1059 link, id, rc); 1060 goto err_free; 1061 } 1062 1063 /* Allocate a minor in the FSI space */ 1064 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt, 1065 &slave->cdev_idx); 1066 if (rc) 1067 goto err_free; 1068 1069 /* Create chardev for userspace access */ 1070 cdev_init(&slave->cdev, &cfam_fops); 1071 rc = cdev_device_add(&slave->cdev, &slave->dev); 1072 if (rc) { 1073 dev_err(&slave->dev, "Error %d creating slave device\n", rc); 1074 goto err_free_ida; 1075 } 1076 1077 /* Now that we have the cdev registered with the core, any fatal 1078 * failures beyond this point will need to clean up through 1079 * cdev_device_del(). Fortunately though, nothing past here is fatal. 1080 */ 1081 1082 if (master->link_config) 1083 master->link_config(master, link, 1084 slave->t_send_delay, 1085 slave->t_echo_delay); 1086 1087 /* Legacy raw file -> to be removed */ 1088 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 1089 if (rc) 1090 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 1091 1092 1093 rc = fsi_slave_scan(slave); 1094 if (rc) 1095 dev_dbg(&master->dev, "failed during slave scan with: %d\n", 1096 rc); 1097 1098 return 0; 1099 1100 err_free_ida: 1101 fsi_free_minor(slave->dev.devt); 1102 err_free: 1103 of_node_put(slave->dev.of_node); 1104 kfree(slave); 1105 return rc; 1106 } 1107 1108 /* FSI master support */ 1109 static int fsi_check_access(uint32_t addr, size_t size) 1110 { 1111 if (size == 4) { 1112 if (addr & 0x3) 1113 return -EINVAL; 1114 } else if (size == 2) { 1115 if (addr & 0x1) 1116 return -EINVAL; 1117 } else if (size != 1) 1118 return -EINVAL; 1119 1120 return 0; 1121 } 1122 1123 static int fsi_master_read(struct fsi_master *master, int link, 1124 uint8_t slave_id, uint32_t addr, void *val, size_t size) 1125 { 1126 int rc; 1127 1128 trace_fsi_master_read(master, link, slave_id, addr, size); 1129 1130 rc = fsi_check_access(addr, size); 1131 if (!rc) 1132 rc = master->read(master, link, slave_id, addr, val, size); 1133 1134 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 1135 false, val, rc); 1136 1137 return rc; 1138 } 1139 1140 static int fsi_master_write(struct fsi_master *master, int link, 1141 uint8_t slave_id, uint32_t addr, const void *val, size_t size) 1142 { 1143 int rc; 1144 1145 trace_fsi_master_write(master, link, slave_id, addr, size, val); 1146 1147 rc = fsi_check_access(addr, size); 1148 if (!rc) 1149 rc = master->write(master, link, slave_id, addr, val, size); 1150 1151 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 1152 true, val, rc); 1153 1154 return rc; 1155 } 1156 1157 static int fsi_master_link_enable(struct fsi_master *master, int link) 1158 { 1159 if (master->link_enable) 1160 return master->link_enable(master, link); 1161 1162 return 0; 1163 } 1164 1165 /* 1166 * Issue a break command on this link 1167 */ 1168 static int fsi_master_break(struct fsi_master *master, int link) 1169 { 1170 int rc = 0; 1171 1172 trace_fsi_master_break(master, link); 1173 1174 if (master->send_break) 1175 rc = master->send_break(master, link); 1176 if (master->link_config) 1177 master->link_config(master, link, 16, 16); 1178 1179 return rc; 1180 } 1181 1182 static int fsi_master_scan(struct fsi_master *master) 1183 { 1184 int link, rc; 1185 1186 for (link = 0; link < master->n_links; link++) { 1187 rc = fsi_master_link_enable(master, link); 1188 if (rc) { 1189 dev_dbg(&master->dev, 1190 "enable link %d failed: %d\n", link, rc); 1191 continue; 1192 } 1193 rc = fsi_master_break(master, link); 1194 if (rc) { 1195 dev_dbg(&master->dev, 1196 "break to link %d failed: %d\n", link, rc); 1197 continue; 1198 } 1199 1200 fsi_slave_init(master, link, 0); 1201 } 1202 1203 return 0; 1204 } 1205 1206 static int fsi_slave_remove_device(struct device *dev, void *arg) 1207 { 1208 device_unregister(dev); 1209 return 0; 1210 } 1211 1212 static int fsi_master_remove_slave(struct device *dev, void *arg) 1213 { 1214 struct fsi_slave *slave = to_fsi_slave(dev); 1215 1216 device_for_each_child(dev, NULL, fsi_slave_remove_device); 1217 cdev_device_del(&slave->cdev, &slave->dev); 1218 put_device(dev); 1219 return 0; 1220 } 1221 1222 static void fsi_master_unscan(struct fsi_master *master) 1223 { 1224 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); 1225 } 1226 1227 int fsi_master_rescan(struct fsi_master *master) 1228 { 1229 int rc; 1230 1231 mutex_lock(&master->scan_lock); 1232 fsi_master_unscan(master); 1233 rc = fsi_master_scan(master); 1234 mutex_unlock(&master->scan_lock); 1235 1236 return rc; 1237 } 1238 EXPORT_SYMBOL_GPL(fsi_master_rescan); 1239 1240 static ssize_t master_rescan_store(struct device *dev, 1241 struct device_attribute *attr, const char *buf, size_t count) 1242 { 1243 struct fsi_master *master = to_fsi_master(dev); 1244 int rc; 1245 1246 rc = fsi_master_rescan(master); 1247 if (rc < 0) 1248 return rc; 1249 1250 return count; 1251 } 1252 1253 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); 1254 1255 static ssize_t master_break_store(struct device *dev, 1256 struct device_attribute *attr, const char *buf, size_t count) 1257 { 1258 struct fsi_master *master = to_fsi_master(dev); 1259 1260 fsi_master_break(master, 0); 1261 1262 return count; 1263 } 1264 1265 static DEVICE_ATTR(break, 0200, NULL, master_break_store); 1266 1267 static struct attribute *master_attrs[] = { 1268 &dev_attr_break.attr, 1269 &dev_attr_rescan.attr, 1270 NULL 1271 }; 1272 1273 ATTRIBUTE_GROUPS(master); 1274 1275 static struct class fsi_master_class = { 1276 .name = "fsi-master", 1277 .dev_groups = master_groups, 1278 }; 1279 1280 int fsi_master_register(struct fsi_master *master) 1281 { 1282 int rc; 1283 struct device_node *np; 1284 1285 mutex_init(&master->scan_lock); 1286 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); 1287 dev_set_name(&master->dev, "fsi%d", master->idx); 1288 master->dev.class = &fsi_master_class; 1289 1290 rc = device_register(&master->dev); 1291 if (rc) { 1292 ida_simple_remove(&master_ida, master->idx); 1293 return rc; 1294 } 1295 1296 np = dev_of_node(&master->dev); 1297 if (!of_property_read_bool(np, "no-scan-on-init")) { 1298 mutex_lock(&master->scan_lock); 1299 fsi_master_scan(master); 1300 mutex_unlock(&master->scan_lock); 1301 } 1302 1303 return 0; 1304 } 1305 EXPORT_SYMBOL_GPL(fsi_master_register); 1306 1307 void fsi_master_unregister(struct fsi_master *master) 1308 { 1309 if (master->idx >= 0) { 1310 ida_simple_remove(&master_ida, master->idx); 1311 master->idx = -1; 1312 } 1313 1314 mutex_lock(&master->scan_lock); 1315 fsi_master_unscan(master); 1316 mutex_unlock(&master->scan_lock); 1317 device_unregister(&master->dev); 1318 } 1319 EXPORT_SYMBOL_GPL(fsi_master_unregister); 1320 1321 /* FSI core & Linux bus type definitions */ 1322 1323 static int fsi_bus_match(struct device *dev, struct device_driver *drv) 1324 { 1325 struct fsi_device *fsi_dev = to_fsi_dev(dev); 1326 struct fsi_driver *fsi_drv = to_fsi_drv(drv); 1327 const struct fsi_device_id *id; 1328 1329 if (!fsi_drv->id_table) 1330 return 0; 1331 1332 for (id = fsi_drv->id_table; id->engine_type; id++) { 1333 if (id->engine_type != fsi_dev->engine_type) 1334 continue; 1335 if (id->version == FSI_VERSION_ANY || 1336 id->version == fsi_dev->version) 1337 return 1; 1338 } 1339 1340 return 0; 1341 } 1342 1343 int fsi_driver_register(struct fsi_driver *fsi_drv) 1344 { 1345 if (!fsi_drv) 1346 return -EINVAL; 1347 if (!fsi_drv->id_table) 1348 return -EINVAL; 1349 1350 return driver_register(&fsi_drv->drv); 1351 } 1352 EXPORT_SYMBOL_GPL(fsi_driver_register); 1353 1354 void fsi_driver_unregister(struct fsi_driver *fsi_drv) 1355 { 1356 driver_unregister(&fsi_drv->drv); 1357 } 1358 EXPORT_SYMBOL_GPL(fsi_driver_unregister); 1359 1360 struct bus_type fsi_bus_type = { 1361 .name = "fsi", 1362 .match = fsi_bus_match, 1363 }; 1364 EXPORT_SYMBOL_GPL(fsi_bus_type); 1365 1366 static int __init fsi_init(void) 1367 { 1368 int rc; 1369 1370 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi"); 1371 if (rc) 1372 return rc; 1373 rc = bus_register(&fsi_bus_type); 1374 if (rc) 1375 goto fail_bus; 1376 1377 rc = class_register(&fsi_master_class); 1378 if (rc) 1379 goto fail_class; 1380 1381 return 0; 1382 1383 fail_class: 1384 bus_unregister(&fsi_bus_type); 1385 fail_bus: 1386 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); 1387 return rc; 1388 } 1389 postcore_initcall(fsi_init); 1390 1391 static void fsi_exit(void) 1392 { 1393 class_unregister(&fsi_master_class); 1394 bus_unregister(&fsi_bus_type); 1395 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); 1396 ida_destroy(&fsi_minor_ida); 1397 } 1398 module_exit(fsi_exit); 1399 module_param(discard_errors, int, 0664); 1400 MODULE_LICENSE("GPL"); 1401 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); 1402