1 /* 2 * FSI core driver 3 * 4 * Copyright (C) IBM Corporation 2016 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/crc4.h> 17 #include <linux/device.h> 18 #include <linux/fsi.h> 19 #include <linux/idr.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/slab.h> 23 #include <linux/bitops.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 int id; 82 int link; 83 uint32_t size; /* size of slave address space */ 84 }; 85 86 #define to_fsi_master(d) container_of(d, struct fsi_master, dev) 87 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) 88 89 static const int slave_retries = 2; 90 static int discard_errors; 91 92 static int fsi_master_read(struct fsi_master *master, int link, 93 uint8_t slave_id, uint32_t addr, void *val, size_t size); 94 static int fsi_master_write(struct fsi_master *master, int link, 95 uint8_t slave_id, uint32_t addr, const void *val, size_t size); 96 static int fsi_master_break(struct fsi_master *master, int link); 97 98 /* 99 * fsi_device_read() / fsi_device_write() / fsi_device_peek() 100 * 101 * FSI endpoint-device support 102 * 103 * Read / write / peek accessors for a client 104 * 105 * Parameters: 106 * dev: Structure passed to FSI client device drivers on probe(). 107 * addr: FSI address of given device. Client should pass in its base address 108 * plus desired offset to access its register space. 109 * val: For read/peek this is the value read at the specified address. For 110 * write this is value to write to the specified address. 111 * The data in val must be FSI bus endian (big endian). 112 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. 113 * Addresses must be aligned on size boundaries or an error will result. 114 */ 115 int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, 116 size_t size) 117 { 118 if (addr > dev->size || size > dev->size || addr > dev->size - size) 119 return -EINVAL; 120 121 return fsi_slave_read(dev->slave, dev->addr + addr, val, size); 122 } 123 EXPORT_SYMBOL_GPL(fsi_device_read); 124 125 int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, 126 size_t size) 127 { 128 if (addr > dev->size || size > dev->size || addr > dev->size - size) 129 return -EINVAL; 130 131 return fsi_slave_write(dev->slave, dev->addr + addr, val, size); 132 } 133 EXPORT_SYMBOL_GPL(fsi_device_write); 134 135 int fsi_device_peek(struct fsi_device *dev, void *val) 136 { 137 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); 138 139 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); 140 } 141 142 static void fsi_device_release(struct device *_device) 143 { 144 struct fsi_device *device = to_fsi_dev(_device); 145 146 of_node_put(device->dev.of_node); 147 kfree(device); 148 } 149 150 static struct fsi_device *fsi_create_device(struct fsi_slave *slave) 151 { 152 struct fsi_device *dev; 153 154 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 155 if (!dev) 156 return NULL; 157 158 dev->dev.parent = &slave->dev; 159 dev->dev.bus = &fsi_bus_type; 160 dev->dev.release = fsi_device_release; 161 162 return dev; 163 } 164 165 /* FSI slave support */ 166 static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, 167 uint8_t *idp) 168 { 169 uint32_t addr = *addrp; 170 uint8_t id = *idp; 171 172 if (addr > slave->size) 173 return -EINVAL; 174 175 /* For 23 bit addressing, we encode the extra two bits in the slave 176 * id (and the slave's actual ID needs to be 0). 177 */ 178 if (addr > 0x1fffff) { 179 if (slave->id != 0) 180 return -EINVAL; 181 id = (addr >> 21) & 0x3; 182 addr &= 0x1fffff; 183 } 184 185 *addrp = addr; 186 *idp = id; 187 return 0; 188 } 189 190 static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) 191 { 192 struct fsi_master *master = slave->master; 193 uint32_t irq, stat; 194 int rc, link; 195 uint8_t id; 196 197 link = slave->link; 198 id = slave->id; 199 200 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 201 &irq, sizeof(irq)); 202 if (rc) 203 return rc; 204 205 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, 206 &stat, sizeof(stat)); 207 if (rc) 208 return rc; 209 210 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", 211 be32_to_cpu(stat), be32_to_cpu(irq)); 212 213 /* clear interrupts */ 214 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 215 &irq, sizeof(irq)); 216 } 217 218 static int fsi_slave_set_smode(struct fsi_master *master, int link, int id); 219 220 static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, 221 uint32_t addr, size_t size) 222 { 223 struct fsi_master *master = slave->master; 224 int rc, link; 225 uint32_t reg; 226 uint8_t id; 227 228 if (discard_errors) 229 return -1; 230 231 link = slave->link; 232 id = slave->id; 233 234 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", 235 write ? "write" : "read", addr, size); 236 237 /* try a simple clear of error conditions, which may fail if we've lost 238 * communication with the slave 239 */ 240 rc = fsi_slave_report_and_clear_errors(slave); 241 if (!rc) 242 return 0; 243 244 /* send a TERM and retry */ 245 if (master->term) { 246 rc = master->term(master, link, id); 247 if (!rc) { 248 rc = fsi_master_read(master, link, id, 0, 249 ®, sizeof(reg)); 250 if (!rc) 251 rc = fsi_slave_report_and_clear_errors(slave); 252 if (!rc) 253 return 0; 254 } 255 } 256 257 /* getting serious, reset the slave via BREAK */ 258 rc = fsi_master_break(master, link); 259 if (rc) 260 return rc; 261 262 rc = fsi_slave_set_smode(master, link, id); 263 if (rc) 264 return rc; 265 266 return fsi_slave_report_and_clear_errors(slave); 267 } 268 269 int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, 270 void *val, size_t size) 271 { 272 uint8_t id = slave->id; 273 int rc, err_rc, i; 274 275 rc = fsi_slave_calc_addr(slave, &addr, &id); 276 if (rc) 277 return rc; 278 279 for (i = 0; i < slave_retries; i++) { 280 rc = fsi_master_read(slave->master, slave->link, 281 id, addr, val, size); 282 if (!rc) 283 break; 284 285 err_rc = fsi_slave_handle_error(slave, false, addr, size); 286 if (err_rc) 287 break; 288 } 289 290 return rc; 291 } 292 EXPORT_SYMBOL_GPL(fsi_slave_read); 293 294 int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, 295 const void *val, size_t size) 296 { 297 uint8_t id = slave->id; 298 int rc, err_rc, i; 299 300 rc = fsi_slave_calc_addr(slave, &addr, &id); 301 if (rc) 302 return rc; 303 304 for (i = 0; i < slave_retries; i++) { 305 rc = fsi_master_write(slave->master, slave->link, 306 id, addr, val, size); 307 if (!rc) 308 break; 309 310 err_rc = fsi_slave_handle_error(slave, true, addr, size); 311 if (err_rc) 312 break; 313 } 314 315 return rc; 316 } 317 EXPORT_SYMBOL_GPL(fsi_slave_write); 318 319 extern int fsi_slave_claim_range(struct fsi_slave *slave, 320 uint32_t addr, uint32_t size) 321 { 322 if (addr + size < addr) 323 return -EINVAL; 324 325 if (addr + size > slave->size) 326 return -EINVAL; 327 328 /* todo: check for overlapping claims */ 329 return 0; 330 } 331 EXPORT_SYMBOL_GPL(fsi_slave_claim_range); 332 333 extern void fsi_slave_release_range(struct fsi_slave *slave, 334 uint32_t addr, uint32_t size) 335 { 336 } 337 EXPORT_SYMBOL_GPL(fsi_slave_release_range); 338 339 static bool fsi_device_node_matches(struct device *dev, struct device_node *np, 340 uint32_t addr, uint32_t size) 341 { 342 unsigned int len, na, ns; 343 const __be32 *prop; 344 uint32_t psize; 345 346 na = of_n_addr_cells(np); 347 ns = of_n_size_cells(np); 348 349 if (na != 1 || ns != 1) 350 return false; 351 352 prop = of_get_property(np, "reg", &len); 353 if (!prop || len != 8) 354 return false; 355 356 if (of_read_number(prop, 1) != addr) 357 return false; 358 359 psize = of_read_number(prop + 1, 1); 360 if (psize != size) { 361 dev_warn(dev, 362 "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", 363 of_node_full_name(np), psize, size); 364 } 365 366 return true; 367 } 368 369 /* Find a matching node for the slave engine at @address, using @size bytes 370 * of space. Returns NULL if not found, or a matching node with refcount 371 * already incremented. 372 */ 373 static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) 374 { 375 struct device_node *parent, *np; 376 377 parent = dev_of_node(&dev->slave->dev); 378 if (!parent) 379 return NULL; 380 381 for_each_child_of_node(parent, np) { 382 if (fsi_device_node_matches(&dev->dev, np, 383 dev->addr, dev->size)) 384 return np; 385 } 386 387 return NULL; 388 } 389 390 static int fsi_slave_scan(struct fsi_slave *slave) 391 { 392 uint32_t engine_addr; 393 uint32_t conf; 394 int rc, i; 395 396 /* 397 * scan engines 398 * 399 * We keep the peek mode and slave engines for the core; so start 400 * at the third slot in the configuration table. We also need to 401 * skip the chip ID entry at the start of the address space. 402 */ 403 engine_addr = engine_page_size * 3; 404 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { 405 uint8_t slots, version, type, crc; 406 struct fsi_device *dev; 407 408 rc = fsi_slave_read(slave, (i + 1) * sizeof(conf), 409 &conf, sizeof(conf)); 410 if (rc) { 411 dev_warn(&slave->dev, 412 "error reading slave registers\n"); 413 return -1; 414 } 415 conf = be32_to_cpu(conf); 416 417 crc = crc4(0, conf, 32); 418 if (crc) { 419 dev_warn(&slave->dev, 420 "crc error in slave register at 0x%04x\n", 421 i); 422 return -1; 423 } 424 425 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) 426 >> FSI_SLAVE_CONF_SLOTS_SHIFT; 427 version = (conf & FSI_SLAVE_CONF_VERSION_MASK) 428 >> FSI_SLAVE_CONF_VERSION_SHIFT; 429 type = (conf & FSI_SLAVE_CONF_TYPE_MASK) 430 >> FSI_SLAVE_CONF_TYPE_SHIFT; 431 432 /* 433 * Unused address areas are marked by a zero type value; this 434 * skips the defined address areas 435 */ 436 if (type != 0 && slots != 0) { 437 438 /* create device */ 439 dev = fsi_create_device(slave); 440 if (!dev) 441 return -ENOMEM; 442 443 dev->slave = slave; 444 dev->engine_type = type; 445 dev->version = version; 446 dev->unit = i; 447 dev->addr = engine_addr; 448 dev->size = slots * engine_page_size; 449 450 dev_dbg(&slave->dev, 451 "engine[%i]: type %x, version %x, addr %x size %x\n", 452 dev->unit, dev->engine_type, version, 453 dev->addr, dev->size); 454 455 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", 456 slave->master->idx, slave->link, 457 slave->id, i - 2); 458 dev->dev.of_node = fsi_device_find_of_node(dev); 459 460 rc = device_register(&dev->dev); 461 if (rc) { 462 dev_warn(&slave->dev, "add failed: %d\n", rc); 463 put_device(&dev->dev); 464 } 465 } 466 467 engine_addr += slots * engine_page_size; 468 469 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) 470 break; 471 } 472 473 return 0; 474 } 475 476 static ssize_t fsi_slave_sysfs_raw_read(struct file *file, 477 struct kobject *kobj, struct bin_attribute *attr, char *buf, 478 loff_t off, size_t count) 479 { 480 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 481 size_t total_len, read_len; 482 int rc; 483 484 if (off < 0) 485 return -EINVAL; 486 487 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 488 return -EINVAL; 489 490 for (total_len = 0; total_len < count; total_len += read_len) { 491 read_len = min_t(size_t, count, 4); 492 read_len -= off & 0x3; 493 494 rc = fsi_slave_read(slave, off, buf + total_len, read_len); 495 if (rc) 496 return rc; 497 498 off += read_len; 499 } 500 501 return count; 502 } 503 504 static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 505 struct kobject *kobj, struct bin_attribute *attr, 506 char *buf, loff_t off, size_t count) 507 { 508 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 509 size_t total_len, write_len; 510 int rc; 511 512 if (off < 0) 513 return -EINVAL; 514 515 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 516 return -EINVAL; 517 518 for (total_len = 0; total_len < count; total_len += write_len) { 519 write_len = min_t(size_t, count, 4); 520 write_len -= off & 0x3; 521 522 rc = fsi_slave_write(slave, off, buf + total_len, write_len); 523 if (rc) 524 return rc; 525 526 off += write_len; 527 } 528 529 return count; 530 } 531 532 static const struct bin_attribute fsi_slave_raw_attr = { 533 .attr = { 534 .name = "raw", 535 .mode = 0600, 536 }, 537 .size = 0, 538 .read = fsi_slave_sysfs_raw_read, 539 .write = fsi_slave_sysfs_raw_write, 540 }; 541 542 static ssize_t fsi_slave_sysfs_term_write(struct file *file, 543 struct kobject *kobj, struct bin_attribute *attr, 544 char *buf, loff_t off, size_t count) 545 { 546 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 547 struct fsi_master *master = slave->master; 548 549 if (!master->term) 550 return -ENODEV; 551 552 master->term(master, slave->link, slave->id); 553 return count; 554 } 555 556 static const struct bin_attribute fsi_slave_term_attr = { 557 .attr = { 558 .name = "term", 559 .mode = 0200, 560 }, 561 .size = 0, 562 .write = fsi_slave_sysfs_term_write, 563 }; 564 565 /* Encode slave local bus echo delay */ 566 static inline uint32_t fsi_smode_echodly(int x) 567 { 568 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; 569 } 570 571 /* Encode slave local bus send delay */ 572 static inline uint32_t fsi_smode_senddly(int x) 573 { 574 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; 575 } 576 577 /* Encode slave local bus clock rate ratio */ 578 static inline uint32_t fsi_smode_lbcrr(int x) 579 { 580 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; 581 } 582 583 /* Encode slave ID */ 584 static inline uint32_t fsi_smode_sid(int x) 585 { 586 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; 587 } 588 589 static uint32_t fsi_slave_smode(int id) 590 { 591 return FSI_SMODE_WSC | FSI_SMODE_ECRC 592 | fsi_smode_sid(id) 593 | fsi_smode_echodly(0xf) | fsi_smode_senddly(0xf) 594 | fsi_smode_lbcrr(0x8); 595 } 596 597 static int fsi_slave_set_smode(struct fsi_master *master, int link, int id) 598 { 599 uint32_t smode; 600 601 /* set our smode register with the slave ID field to 0; this enables 602 * extended slave addressing 603 */ 604 smode = fsi_slave_smode(id); 605 smode = cpu_to_be32(smode); 606 607 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE, 608 &smode, sizeof(smode)); 609 } 610 611 static void fsi_slave_release(struct device *dev) 612 { 613 struct fsi_slave *slave = to_fsi_slave(dev); 614 615 of_node_put(dev->of_node); 616 kfree(slave); 617 } 618 619 static bool fsi_slave_node_matches(struct device_node *np, 620 int link, uint8_t id) 621 { 622 unsigned int len, na, ns; 623 const __be32 *prop; 624 625 na = of_n_addr_cells(np); 626 ns = of_n_size_cells(np); 627 628 /* Ensure we have the correct format for addresses and sizes in 629 * reg properties 630 */ 631 if (na != 2 || ns != 0) 632 return false; 633 634 prop = of_get_property(np, "reg", &len); 635 if (!prop || len != 8) 636 return false; 637 638 return (of_read_number(prop, 1) == link) && 639 (of_read_number(prop + 1, 1) == id); 640 } 641 642 /* Find a matching node for the slave at (link, id). Returns NULL if none 643 * found, or a matching node with refcount already incremented. 644 */ 645 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, 646 int link, uint8_t id) 647 { 648 struct device_node *parent, *np; 649 650 parent = dev_of_node(&master->dev); 651 if (!parent) 652 return NULL; 653 654 for_each_child_of_node(parent, np) { 655 if (fsi_slave_node_matches(np, link, id)) 656 return np; 657 } 658 659 return NULL; 660 } 661 662 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 663 { 664 uint32_t chip_id, llmode; 665 struct fsi_slave *slave; 666 uint8_t crc; 667 int rc; 668 669 /* Currently, we only support single slaves on a link, and use the 670 * full 23-bit address range 671 */ 672 if (id != 0) 673 return -EINVAL; 674 675 rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id)); 676 if (rc) { 677 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 678 link, id, rc); 679 return -ENODEV; 680 } 681 chip_id = be32_to_cpu(chip_id); 682 683 crc = crc4(0, chip_id, 32); 684 if (crc) { 685 dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", 686 link, id); 687 return -EIO; 688 } 689 690 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 691 chip_id, master->idx, link, id); 692 693 rc = fsi_slave_set_smode(master, link, id); 694 if (rc) { 695 dev_warn(&master->dev, 696 "can't set smode on slave:%02x:%02x %d\n", 697 link, id, rc); 698 return -ENODEV; 699 } 700 701 /* If we're behind a master that doesn't provide a self-running bus 702 * clock, put the slave into async mode 703 */ 704 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 705 llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 706 rc = fsi_master_write(master, link, id, 707 FSI_SLAVE_BASE + FSI_LLMODE, 708 &llmode, sizeof(llmode)); 709 if (rc) 710 dev_warn(&master->dev, 711 "can't set llmode on slave:%02x:%02x %d\n", 712 link, id, rc); 713 } 714 715 /* We can communicate with a slave; create the slave device and 716 * register. 717 */ 718 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 719 if (!slave) 720 return -ENOMEM; 721 722 slave->master = master; 723 slave->dev.parent = &master->dev; 724 slave->dev.of_node = fsi_slave_find_of_node(master, link, id); 725 slave->dev.release = fsi_slave_release; 726 slave->link = link; 727 slave->id = id; 728 slave->size = FSI_SLAVE_SIZE_23b; 729 730 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 731 rc = device_register(&slave->dev); 732 if (rc < 0) { 733 dev_warn(&master->dev, "failed to create slave device: %d\n", 734 rc); 735 put_device(&slave->dev); 736 return rc; 737 } 738 739 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 740 if (rc) 741 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 742 743 rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr); 744 if (rc) 745 dev_warn(&slave->dev, "failed to create term attr: %d\n", rc); 746 747 rc = fsi_slave_scan(slave); 748 if (rc) 749 dev_dbg(&master->dev, "failed during slave scan with: %d\n", 750 rc); 751 752 return rc; 753 } 754 755 /* FSI master support */ 756 static int fsi_check_access(uint32_t addr, size_t size) 757 { 758 if (size == 4) { 759 if (addr & 0x3) 760 return -EINVAL; 761 } else if (size == 2) { 762 if (addr & 0x1) 763 return -EINVAL; 764 } else if (size != 1) 765 return -EINVAL; 766 767 return 0; 768 } 769 770 static int fsi_master_read(struct fsi_master *master, int link, 771 uint8_t slave_id, uint32_t addr, void *val, size_t size) 772 { 773 int rc; 774 775 trace_fsi_master_read(master, link, slave_id, addr, size); 776 777 rc = fsi_check_access(addr, size); 778 if (!rc) 779 rc = master->read(master, link, slave_id, addr, val, size); 780 781 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 782 false, val, rc); 783 784 return rc; 785 } 786 787 static int fsi_master_write(struct fsi_master *master, int link, 788 uint8_t slave_id, uint32_t addr, const void *val, size_t size) 789 { 790 int rc; 791 792 trace_fsi_master_write(master, link, slave_id, addr, size, val); 793 794 rc = fsi_check_access(addr, size); 795 if (!rc) 796 rc = master->write(master, link, slave_id, addr, val, size); 797 798 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 799 true, val, rc); 800 801 return rc; 802 } 803 804 static int fsi_master_link_enable(struct fsi_master *master, int link) 805 { 806 if (master->link_enable) 807 return master->link_enable(master, link); 808 809 return 0; 810 } 811 812 /* 813 * Issue a break command on this link 814 */ 815 static int fsi_master_break(struct fsi_master *master, int link) 816 { 817 trace_fsi_master_break(master, link); 818 819 if (master->send_break) 820 return master->send_break(master, link); 821 822 return 0; 823 } 824 825 static int fsi_master_scan(struct fsi_master *master) 826 { 827 int link, rc; 828 829 for (link = 0; link < master->n_links; link++) { 830 rc = fsi_master_link_enable(master, link); 831 if (rc) { 832 dev_dbg(&master->dev, 833 "enable link %d failed: %d\n", link, rc); 834 continue; 835 } 836 rc = fsi_master_break(master, link); 837 if (rc) { 838 dev_dbg(&master->dev, 839 "break to link %d failed: %d\n", link, rc); 840 continue; 841 } 842 843 fsi_slave_init(master, link, 0); 844 } 845 846 return 0; 847 } 848 849 static int fsi_slave_remove_device(struct device *dev, void *arg) 850 { 851 device_unregister(dev); 852 return 0; 853 } 854 855 static int fsi_master_remove_slave(struct device *dev, void *arg) 856 { 857 device_for_each_child(dev, NULL, fsi_slave_remove_device); 858 device_unregister(dev); 859 return 0; 860 } 861 862 static void fsi_master_unscan(struct fsi_master *master) 863 { 864 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); 865 } 866 867 int fsi_master_rescan(struct fsi_master *master) 868 { 869 fsi_master_unscan(master); 870 return fsi_master_scan(master); 871 } 872 EXPORT_SYMBOL_GPL(fsi_master_rescan); 873 874 static ssize_t master_rescan_store(struct device *dev, 875 struct device_attribute *attr, const char *buf, size_t count) 876 { 877 struct fsi_master *master = to_fsi_master(dev); 878 int rc; 879 880 rc = fsi_master_rescan(master); 881 if (rc < 0) 882 return rc; 883 884 return count; 885 } 886 887 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); 888 889 static ssize_t master_break_store(struct device *dev, 890 struct device_attribute *attr, const char *buf, size_t count) 891 { 892 struct fsi_master *master = to_fsi_master(dev); 893 894 fsi_master_break(master, 0); 895 896 return count; 897 } 898 899 static DEVICE_ATTR(break, 0200, NULL, master_break_store); 900 901 int fsi_master_register(struct fsi_master *master) 902 { 903 int rc; 904 struct device_node *np; 905 906 if (!master) 907 return -EINVAL; 908 909 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); 910 dev_set_name(&master->dev, "fsi%d", master->idx); 911 912 rc = device_register(&master->dev); 913 if (rc) { 914 ida_simple_remove(&master_ida, master->idx); 915 return rc; 916 } 917 918 rc = device_create_file(&master->dev, &dev_attr_rescan); 919 if (rc) { 920 device_unregister(&master->dev); 921 ida_simple_remove(&master_ida, master->idx); 922 return rc; 923 } 924 925 rc = device_create_file(&master->dev, &dev_attr_break); 926 if (rc) { 927 device_unregister(&master->dev); 928 ida_simple_remove(&master_ida, master->idx); 929 return rc; 930 } 931 932 np = dev_of_node(&master->dev); 933 if (!of_property_read_bool(np, "no-scan-on-init")) 934 fsi_master_scan(master); 935 936 return 0; 937 } 938 EXPORT_SYMBOL_GPL(fsi_master_register); 939 940 void fsi_master_unregister(struct fsi_master *master) 941 { 942 if (master->idx >= 0) { 943 ida_simple_remove(&master_ida, master->idx); 944 master->idx = -1; 945 } 946 947 fsi_master_unscan(master); 948 device_unregister(&master->dev); 949 } 950 EXPORT_SYMBOL_GPL(fsi_master_unregister); 951 952 /* FSI core & Linux bus type definitions */ 953 954 static int fsi_bus_match(struct device *dev, struct device_driver *drv) 955 { 956 struct fsi_device *fsi_dev = to_fsi_dev(dev); 957 struct fsi_driver *fsi_drv = to_fsi_drv(drv); 958 const struct fsi_device_id *id; 959 960 if (!fsi_drv->id_table) 961 return 0; 962 963 for (id = fsi_drv->id_table; id->engine_type; id++) { 964 if (id->engine_type != fsi_dev->engine_type) 965 continue; 966 if (id->version == FSI_VERSION_ANY || 967 id->version == fsi_dev->version) 968 return 1; 969 } 970 971 return 0; 972 } 973 974 int fsi_driver_register(struct fsi_driver *fsi_drv) 975 { 976 if (!fsi_drv) 977 return -EINVAL; 978 if (!fsi_drv->id_table) 979 return -EINVAL; 980 981 return driver_register(&fsi_drv->drv); 982 } 983 EXPORT_SYMBOL_GPL(fsi_driver_register); 984 985 void fsi_driver_unregister(struct fsi_driver *fsi_drv) 986 { 987 driver_unregister(&fsi_drv->drv); 988 } 989 EXPORT_SYMBOL_GPL(fsi_driver_unregister); 990 991 struct bus_type fsi_bus_type = { 992 .name = "fsi", 993 .match = fsi_bus_match, 994 }; 995 EXPORT_SYMBOL_GPL(fsi_bus_type); 996 997 static int __init fsi_init(void) 998 { 999 return bus_register(&fsi_bus_type); 1000 } 1001 postcore_initcall(fsi_init); 1002 1003 static void fsi_exit(void) 1004 { 1005 bus_unregister(&fsi_bus_type); 1006 } 1007 module_exit(fsi_exit); 1008 module_param(discard_errors, int, 0664); 1009 MODULE_LICENSE("GPL"); 1010 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); 1011