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/slab.h> 22 #include <linux/bitops.h> 23 24 #include "fsi-master.h" 25 26 #define CREATE_TRACE_POINTS 27 #include <trace/events/fsi.h> 28 29 #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) 30 #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) 31 #define FSI_SLAVE_CONF_SLOTS_SHIFT 16 32 #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) 33 #define FSI_SLAVE_CONF_VERSION_SHIFT 12 34 #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) 35 #define FSI_SLAVE_CONF_TYPE_SHIFT 4 36 #define FSI_SLAVE_CONF_CRC_SHIFT 4 37 #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) 38 #define FSI_SLAVE_CONF_DATA_BITS 28 39 40 #define FSI_PEEK_BASE 0x410 41 42 static const int engine_page_size = 0x400; 43 44 #define FSI_SLAVE_BASE 0x800 45 46 /* 47 * FSI slave engine control register offsets 48 */ 49 #define FSI_SMODE 0x0 /* R/W: Mode register */ 50 #define FSI_SISC 0x8 /* R/W: Interrupt condition */ 51 #define FSI_SSTAT 0x14 /* R : Slave status */ 52 #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ 53 54 /* 55 * SMODE fields 56 */ 57 #define FSI_SMODE_WSC 0x80000000 /* Warm start done */ 58 #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ 59 #define FSI_SMODE_SID_SHIFT 24 /* ID shift */ 60 #define FSI_SMODE_SID_MASK 3 /* ID Mask */ 61 #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ 62 #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ 63 #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ 64 #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ 65 #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ 66 #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ 67 68 /* 69 * LLMODE fields 70 */ 71 #define FSI_LLMODE_ASYNC 0x1 72 73 #define FSI_SLAVE_SIZE_23b 0x800000 74 75 static DEFINE_IDA(master_ida); 76 77 struct fsi_slave { 78 struct device dev; 79 struct fsi_master *master; 80 int id; 81 int link; 82 uint32_t size; /* size of slave address space */ 83 }; 84 85 #define to_fsi_master(d) container_of(d, struct fsi_master, dev) 86 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) 87 88 static const int slave_retries = 2; 89 static int discard_errors; 90 91 static int fsi_master_read(struct fsi_master *master, int link, 92 uint8_t slave_id, uint32_t addr, void *val, size_t size); 93 static int fsi_master_write(struct fsi_master *master, int link, 94 uint8_t slave_id, uint32_t addr, const void *val, size_t size); 95 static int fsi_master_break(struct fsi_master *master, int link); 96 97 /* 98 * fsi_device_read() / fsi_device_write() / fsi_device_peek() 99 * 100 * FSI endpoint-device support 101 * 102 * Read / write / peek accessors for a client 103 * 104 * Parameters: 105 * dev: Structure passed to FSI client device drivers on probe(). 106 * addr: FSI address of given device. Client should pass in its base address 107 * plus desired offset to access its register space. 108 * val: For read/peek this is the value read at the specified address. For 109 * write this is value to write to the specified address. 110 * The data in val must be FSI bus endian (big endian). 111 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. 112 * Addresses must be aligned on size boundaries or an error will result. 113 */ 114 int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, 115 size_t size) 116 { 117 if (addr > dev->size || size > dev->size || addr > dev->size - size) 118 return -EINVAL; 119 120 return fsi_slave_read(dev->slave, dev->addr + addr, val, size); 121 } 122 EXPORT_SYMBOL_GPL(fsi_device_read); 123 124 int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, 125 size_t size) 126 { 127 if (addr > dev->size || size > dev->size || addr > dev->size - size) 128 return -EINVAL; 129 130 return fsi_slave_write(dev->slave, dev->addr + addr, val, size); 131 } 132 EXPORT_SYMBOL_GPL(fsi_device_write); 133 134 int fsi_device_peek(struct fsi_device *dev, void *val) 135 { 136 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); 137 138 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); 139 } 140 141 static void fsi_device_release(struct device *_device) 142 { 143 struct fsi_device *device = to_fsi_dev(_device); 144 145 kfree(device); 146 } 147 148 static struct fsi_device *fsi_create_device(struct fsi_slave *slave) 149 { 150 struct fsi_device *dev; 151 152 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 153 if (!dev) 154 return NULL; 155 156 dev->dev.parent = &slave->dev; 157 dev->dev.bus = &fsi_bus_type; 158 dev->dev.release = fsi_device_release; 159 160 return dev; 161 } 162 163 /* FSI slave support */ 164 static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, 165 uint8_t *idp) 166 { 167 uint32_t addr = *addrp; 168 uint8_t id = *idp; 169 170 if (addr > slave->size) 171 return -EINVAL; 172 173 /* For 23 bit addressing, we encode the extra two bits in the slave 174 * id (and the slave's actual ID needs to be 0). 175 */ 176 if (addr > 0x1fffff) { 177 if (slave->id != 0) 178 return -EINVAL; 179 id = (addr >> 21) & 0x3; 180 addr &= 0x1fffff; 181 } 182 183 *addrp = addr; 184 *idp = id; 185 return 0; 186 } 187 188 static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) 189 { 190 struct fsi_master *master = slave->master; 191 uint32_t irq, stat; 192 int rc, link; 193 uint8_t id; 194 195 link = slave->link; 196 id = slave->id; 197 198 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 199 &irq, sizeof(irq)); 200 if (rc) 201 return rc; 202 203 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, 204 &stat, sizeof(stat)); 205 if (rc) 206 return rc; 207 208 dev_info(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", 209 be32_to_cpu(stat), be32_to_cpu(irq)); 210 211 /* clear interrupts */ 212 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 213 &irq, sizeof(irq)); 214 } 215 216 static int fsi_slave_set_smode(struct fsi_master *master, int link, int id); 217 218 static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, 219 uint32_t addr, size_t size) 220 { 221 struct fsi_master *master = slave->master; 222 int rc, link; 223 uint32_t reg; 224 uint8_t id; 225 226 if (discard_errors) 227 return -1; 228 229 link = slave->link; 230 id = slave->id; 231 232 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", 233 write ? "write" : "read", addr, size); 234 235 /* try a simple clear of error conditions, which may fail if we've lost 236 * communication with the slave 237 */ 238 rc = fsi_slave_report_and_clear_errors(slave); 239 if (!rc) 240 return 0; 241 242 /* send a TERM and retry */ 243 if (master->term) { 244 rc = master->term(master, link, id); 245 if (!rc) { 246 rc = fsi_master_read(master, link, id, 0, 247 ®, sizeof(reg)); 248 if (!rc) 249 rc = fsi_slave_report_and_clear_errors(slave); 250 if (!rc) 251 return 0; 252 } 253 } 254 255 /* getting serious, reset the slave via BREAK */ 256 rc = fsi_master_break(master, link); 257 if (rc) 258 return rc; 259 260 rc = fsi_slave_set_smode(master, link, id); 261 if (rc) 262 return rc; 263 264 return fsi_slave_report_and_clear_errors(slave); 265 } 266 267 int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, 268 void *val, size_t size) 269 { 270 uint8_t id = slave->id; 271 int rc, err_rc, i; 272 273 rc = fsi_slave_calc_addr(slave, &addr, &id); 274 if (rc) 275 return rc; 276 277 for (i = 0; i < slave_retries; i++) { 278 rc = fsi_master_read(slave->master, slave->link, 279 id, addr, val, size); 280 if (!rc) 281 break; 282 283 err_rc = fsi_slave_handle_error(slave, false, addr, size); 284 if (err_rc) 285 break; 286 } 287 288 return rc; 289 } 290 EXPORT_SYMBOL_GPL(fsi_slave_read); 291 292 int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, 293 const void *val, size_t size) 294 { 295 uint8_t id = slave->id; 296 int rc, err_rc, i; 297 298 rc = fsi_slave_calc_addr(slave, &addr, &id); 299 if (rc) 300 return rc; 301 302 for (i = 0; i < slave_retries; i++) { 303 rc = fsi_master_write(slave->master, slave->link, 304 id, addr, val, size); 305 if (!rc) 306 break; 307 308 err_rc = fsi_slave_handle_error(slave, true, addr, size); 309 if (err_rc) 310 break; 311 } 312 313 return rc; 314 } 315 EXPORT_SYMBOL_GPL(fsi_slave_write); 316 317 extern int fsi_slave_claim_range(struct fsi_slave *slave, 318 uint32_t addr, uint32_t size) 319 { 320 if (addr + size < addr) 321 return -EINVAL; 322 323 if (addr + size > slave->size) 324 return -EINVAL; 325 326 /* todo: check for overlapping claims */ 327 return 0; 328 } 329 EXPORT_SYMBOL_GPL(fsi_slave_claim_range); 330 331 extern void fsi_slave_release_range(struct fsi_slave *slave, 332 uint32_t addr, uint32_t size) 333 { 334 } 335 EXPORT_SYMBOL_GPL(fsi_slave_release_range); 336 337 static int fsi_slave_scan(struct fsi_slave *slave) 338 { 339 uint32_t engine_addr; 340 uint32_t conf; 341 int rc, i; 342 343 /* 344 * scan engines 345 * 346 * We keep the peek mode and slave engines for the core; so start 347 * at the third slot in the configuration table. We also need to 348 * skip the chip ID entry at the start of the address space. 349 */ 350 engine_addr = engine_page_size * 3; 351 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { 352 uint8_t slots, version, type, crc; 353 struct fsi_device *dev; 354 355 rc = fsi_slave_read(slave, (i + 1) * sizeof(conf), 356 &conf, sizeof(conf)); 357 if (rc) { 358 dev_warn(&slave->dev, 359 "error reading slave registers\n"); 360 return -1; 361 } 362 conf = be32_to_cpu(conf); 363 364 crc = crc4(0, conf, 32); 365 if (crc) { 366 dev_warn(&slave->dev, 367 "crc error in slave register at 0x%04x\n", 368 i); 369 return -1; 370 } 371 372 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) 373 >> FSI_SLAVE_CONF_SLOTS_SHIFT; 374 version = (conf & FSI_SLAVE_CONF_VERSION_MASK) 375 >> FSI_SLAVE_CONF_VERSION_SHIFT; 376 type = (conf & FSI_SLAVE_CONF_TYPE_MASK) 377 >> FSI_SLAVE_CONF_TYPE_SHIFT; 378 379 /* 380 * Unused address areas are marked by a zero type value; this 381 * skips the defined address areas 382 */ 383 if (type != 0 && slots != 0) { 384 385 /* create device */ 386 dev = fsi_create_device(slave); 387 if (!dev) 388 return -ENOMEM; 389 390 dev->slave = slave; 391 dev->engine_type = type; 392 dev->version = version; 393 dev->unit = i; 394 dev->addr = engine_addr; 395 dev->size = slots * engine_page_size; 396 397 dev_dbg(&slave->dev, 398 "engine[%i]: type %x, version %x, addr %x size %x\n", 399 dev->unit, dev->engine_type, version, 400 dev->addr, dev->size); 401 402 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", 403 slave->master->idx, slave->link, 404 slave->id, i - 2); 405 406 rc = device_register(&dev->dev); 407 if (rc) { 408 dev_warn(&slave->dev, "add failed: %d\n", rc); 409 put_device(&dev->dev); 410 } 411 } 412 413 engine_addr += slots * engine_page_size; 414 415 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) 416 break; 417 } 418 419 return 0; 420 } 421 422 static ssize_t fsi_slave_sysfs_raw_read(struct file *file, 423 struct kobject *kobj, struct bin_attribute *attr, char *buf, 424 loff_t off, size_t count) 425 { 426 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 427 size_t total_len, read_len; 428 int rc; 429 430 if (off < 0) 431 return -EINVAL; 432 433 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 434 return -EINVAL; 435 436 for (total_len = 0; total_len < count; total_len += read_len) { 437 read_len = min_t(size_t, count, 4); 438 read_len -= off & 0x3; 439 440 rc = fsi_slave_read(slave, off, buf + total_len, read_len); 441 if (rc) 442 return rc; 443 444 off += read_len; 445 } 446 447 return count; 448 } 449 450 static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 451 struct kobject *kobj, struct bin_attribute *attr, 452 char *buf, loff_t off, size_t count) 453 { 454 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 455 size_t total_len, write_len; 456 int rc; 457 458 if (off < 0) 459 return -EINVAL; 460 461 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 462 return -EINVAL; 463 464 for (total_len = 0; total_len < count; total_len += write_len) { 465 write_len = min_t(size_t, count, 4); 466 write_len -= off & 0x3; 467 468 rc = fsi_slave_write(slave, off, buf + total_len, write_len); 469 if (rc) 470 return rc; 471 472 off += write_len; 473 } 474 475 return count; 476 } 477 478 static const struct bin_attribute fsi_slave_raw_attr = { 479 .attr = { 480 .name = "raw", 481 .mode = 0600, 482 }, 483 .size = 0, 484 .read = fsi_slave_sysfs_raw_read, 485 .write = fsi_slave_sysfs_raw_write, 486 }; 487 488 static ssize_t fsi_slave_sysfs_term_write(struct file *file, 489 struct kobject *kobj, struct bin_attribute *attr, 490 char *buf, loff_t off, size_t count) 491 { 492 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 493 struct fsi_master *master = slave->master; 494 495 if (!master->term) 496 return -ENODEV; 497 498 master->term(master, slave->link, slave->id); 499 return count; 500 } 501 502 static const struct bin_attribute fsi_slave_term_attr = { 503 .attr = { 504 .name = "term", 505 .mode = 0200, 506 }, 507 .size = 0, 508 .write = fsi_slave_sysfs_term_write, 509 }; 510 511 /* Encode slave local bus echo delay */ 512 static inline uint32_t fsi_smode_echodly(int x) 513 { 514 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; 515 } 516 517 /* Encode slave local bus send delay */ 518 static inline uint32_t fsi_smode_senddly(int x) 519 { 520 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; 521 } 522 523 /* Encode slave local bus clock rate ratio */ 524 static inline uint32_t fsi_smode_lbcrr(int x) 525 { 526 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; 527 } 528 529 /* Encode slave ID */ 530 static inline uint32_t fsi_smode_sid(int x) 531 { 532 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; 533 } 534 535 static uint32_t fsi_slave_smode(int id) 536 { 537 return FSI_SMODE_WSC | FSI_SMODE_ECRC 538 | fsi_smode_sid(id) 539 | fsi_smode_echodly(0xf) | fsi_smode_senddly(0xf) 540 | fsi_smode_lbcrr(0x8); 541 } 542 543 static int fsi_slave_set_smode(struct fsi_master *master, int link, int id) 544 { 545 uint32_t smode; 546 547 /* set our smode register with the slave ID field to 0; this enables 548 * extended slave addressing 549 */ 550 smode = fsi_slave_smode(id); 551 smode = cpu_to_be32(smode); 552 553 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE, 554 &smode, sizeof(smode)); 555 } 556 557 static void fsi_slave_release(struct device *dev) 558 { 559 struct fsi_slave *slave = to_fsi_slave(dev); 560 561 kfree(slave); 562 } 563 564 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 565 { 566 uint32_t chip_id, llmode; 567 struct fsi_slave *slave; 568 uint8_t crc; 569 int rc; 570 571 /* Currently, we only support single slaves on a link, and use the 572 * full 23-bit address range 573 */ 574 if (id != 0) 575 return -EINVAL; 576 577 rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id)); 578 if (rc) { 579 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 580 link, id, rc); 581 return -ENODEV; 582 } 583 chip_id = be32_to_cpu(chip_id); 584 585 crc = crc4(0, chip_id, 32); 586 if (crc) { 587 dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", 588 link, id); 589 return -EIO; 590 } 591 592 dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 593 chip_id, master->idx, link, id); 594 595 rc = fsi_slave_set_smode(master, link, id); 596 if (rc) { 597 dev_warn(&master->dev, 598 "can't set smode on slave:%02x:%02x %d\n", 599 link, id, rc); 600 return -ENODEV; 601 } 602 603 /* If we're behind a master that doesn't provide a self-running bus 604 * clock, put the slave into async mode 605 */ 606 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 607 llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 608 rc = fsi_master_write(master, link, id, 609 FSI_SLAVE_BASE + FSI_LLMODE, 610 &llmode, sizeof(llmode)); 611 if (rc) 612 dev_warn(&master->dev, 613 "can't set llmode on slave:%02x:%02x %d\n", 614 link, id, rc); 615 } 616 617 /* We can communicate with a slave; create the slave device and 618 * register. 619 */ 620 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 621 if (!slave) 622 return -ENOMEM; 623 624 slave->master = master; 625 slave->dev.parent = &master->dev; 626 slave->dev.release = fsi_slave_release; 627 slave->link = link; 628 slave->id = id; 629 slave->size = FSI_SLAVE_SIZE_23b; 630 631 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 632 rc = device_register(&slave->dev); 633 if (rc < 0) { 634 dev_warn(&master->dev, "failed to create slave device: %d\n", 635 rc); 636 put_device(&slave->dev); 637 return rc; 638 } 639 640 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 641 if (rc) 642 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 643 644 rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr); 645 if (rc) 646 dev_warn(&slave->dev, "failed to create term attr: %d\n", rc); 647 648 rc = fsi_slave_scan(slave); 649 if (rc) 650 dev_dbg(&master->dev, "failed during slave scan with: %d\n", 651 rc); 652 653 return rc; 654 } 655 656 /* FSI master support */ 657 static int fsi_check_access(uint32_t addr, size_t size) 658 { 659 if (size != 1 && size != 2 && size != 4) 660 return -EINVAL; 661 662 if ((addr & 0x3) != (size & 0x3)) 663 return -EINVAL; 664 665 return 0; 666 } 667 668 static int fsi_master_read(struct fsi_master *master, int link, 669 uint8_t slave_id, uint32_t addr, void *val, size_t size) 670 { 671 int rc; 672 673 trace_fsi_master_read(master, link, slave_id, addr, size); 674 675 rc = fsi_check_access(addr, size); 676 if (!rc) 677 rc = master->read(master, link, slave_id, addr, val, size); 678 679 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 680 false, val, rc); 681 682 return rc; 683 } 684 685 static int fsi_master_write(struct fsi_master *master, int link, 686 uint8_t slave_id, uint32_t addr, const void *val, size_t size) 687 { 688 int rc; 689 690 trace_fsi_master_write(master, link, slave_id, addr, size, val); 691 692 rc = fsi_check_access(addr, size); 693 if (!rc) 694 rc = master->write(master, link, slave_id, addr, val, size); 695 696 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 697 true, val, rc); 698 699 return rc; 700 } 701 702 static int fsi_master_link_enable(struct fsi_master *master, int link) 703 { 704 if (master->link_enable) 705 return master->link_enable(master, link); 706 707 return 0; 708 } 709 710 /* 711 * Issue a break command on this link 712 */ 713 static int fsi_master_break(struct fsi_master *master, int link) 714 { 715 trace_fsi_master_break(master, link); 716 717 if (master->send_break) 718 return master->send_break(master, link); 719 720 return 0; 721 } 722 723 static int fsi_master_scan(struct fsi_master *master) 724 { 725 int link, rc; 726 727 for (link = 0; link < master->n_links; link++) { 728 rc = fsi_master_link_enable(master, link); 729 if (rc) { 730 dev_dbg(&master->dev, 731 "enable link %d failed: %d\n", link, rc); 732 continue; 733 } 734 rc = fsi_master_break(master, link); 735 if (rc) { 736 dev_dbg(&master->dev, 737 "break to link %d failed: %d\n", link, rc); 738 continue; 739 } 740 741 fsi_slave_init(master, link, 0); 742 } 743 744 return 0; 745 } 746 747 static int fsi_slave_remove_device(struct device *dev, void *arg) 748 { 749 device_unregister(dev); 750 return 0; 751 } 752 753 static int fsi_master_remove_slave(struct device *dev, void *arg) 754 { 755 device_for_each_child(dev, NULL, fsi_slave_remove_device); 756 device_unregister(dev); 757 return 0; 758 } 759 760 static void fsi_master_unscan(struct fsi_master *master) 761 { 762 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); 763 } 764 765 static ssize_t master_rescan_store(struct device *dev, 766 struct device_attribute *attr, const char *buf, size_t count) 767 { 768 struct fsi_master *master = to_fsi_master(dev); 769 int rc; 770 771 fsi_master_unscan(master); 772 rc = fsi_master_scan(master); 773 if (rc < 0) 774 return rc; 775 776 return count; 777 } 778 779 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); 780 781 static ssize_t master_break_store(struct device *dev, 782 struct device_attribute *attr, const char *buf, size_t count) 783 { 784 struct fsi_master *master = to_fsi_master(dev); 785 786 fsi_master_break(master, 0); 787 788 return count; 789 } 790 791 static DEVICE_ATTR(break, 0200, NULL, master_break_store); 792 793 int fsi_master_register(struct fsi_master *master) 794 { 795 int rc; 796 797 if (!master) 798 return -EINVAL; 799 800 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); 801 dev_set_name(&master->dev, "fsi%d", master->idx); 802 803 rc = device_register(&master->dev); 804 if (rc) { 805 ida_simple_remove(&master_ida, master->idx); 806 return rc; 807 } 808 809 rc = device_create_file(&master->dev, &dev_attr_rescan); 810 if (rc) { 811 device_unregister(&master->dev); 812 ida_simple_remove(&master_ida, master->idx); 813 return rc; 814 } 815 816 rc = device_create_file(&master->dev, &dev_attr_break); 817 if (rc) { 818 device_unregister(&master->dev); 819 ida_simple_remove(&master_ida, master->idx); 820 return rc; 821 } 822 823 fsi_master_scan(master); 824 825 return 0; 826 } 827 EXPORT_SYMBOL_GPL(fsi_master_register); 828 829 void fsi_master_unregister(struct fsi_master *master) 830 { 831 if (master->idx >= 0) { 832 ida_simple_remove(&master_ida, master->idx); 833 master->idx = -1; 834 } 835 836 fsi_master_unscan(master); 837 device_unregister(&master->dev); 838 } 839 EXPORT_SYMBOL_GPL(fsi_master_unregister); 840 841 /* FSI core & Linux bus type definitions */ 842 843 static int fsi_bus_match(struct device *dev, struct device_driver *drv) 844 { 845 struct fsi_device *fsi_dev = to_fsi_dev(dev); 846 struct fsi_driver *fsi_drv = to_fsi_drv(drv); 847 const struct fsi_device_id *id; 848 849 if (!fsi_drv->id_table) 850 return 0; 851 852 for (id = fsi_drv->id_table; id->engine_type; id++) { 853 if (id->engine_type != fsi_dev->engine_type) 854 continue; 855 if (id->version == FSI_VERSION_ANY || 856 id->version == fsi_dev->version) 857 return 1; 858 } 859 860 return 0; 861 } 862 863 int fsi_driver_register(struct fsi_driver *fsi_drv) 864 { 865 if (!fsi_drv) 866 return -EINVAL; 867 if (!fsi_drv->id_table) 868 return -EINVAL; 869 870 return driver_register(&fsi_drv->drv); 871 } 872 EXPORT_SYMBOL_GPL(fsi_driver_register); 873 874 void fsi_driver_unregister(struct fsi_driver *fsi_drv) 875 { 876 driver_unregister(&fsi_drv->drv); 877 } 878 EXPORT_SYMBOL_GPL(fsi_driver_unregister); 879 880 struct bus_type fsi_bus_type = { 881 .name = "fsi", 882 .match = fsi_bus_match, 883 }; 884 EXPORT_SYMBOL_GPL(fsi_bus_type); 885 886 static int __init fsi_init(void) 887 { 888 return bus_register(&fsi_bus_type); 889 } 890 postcore_initcall(fsi_init); 891 892 static void fsi_exit(void) 893 { 894 bus_unregister(&fsi_bus_type); 895 } 896 module_exit(fsi_exit); 897 module_param(discard_errors, int, 0664); 898 MODULE_LICENSE("GPL"); 899 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); 900