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 ssize_t fsi_slave_sysfs_raw_read(struct file *file, 548 struct kobject *kobj, struct bin_attribute *attr, char *buf, 549 loff_t off, size_t count) 550 { 551 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 552 size_t total_len, read_len; 553 int rc; 554 555 if (off < 0) 556 return -EINVAL; 557 558 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 559 return -EINVAL; 560 561 for (total_len = 0; total_len < count; total_len += read_len) { 562 read_len = min_t(size_t, count, 4); 563 read_len -= off & 0x3; 564 565 rc = fsi_slave_read(slave, off, buf + total_len, read_len); 566 if (rc) 567 return rc; 568 569 off += read_len; 570 } 571 572 return count; 573 } 574 575 static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 576 struct kobject *kobj, struct bin_attribute *attr, 577 char *buf, loff_t off, size_t count) 578 { 579 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 580 size_t total_len, write_len; 581 int rc; 582 583 if (off < 0) 584 return -EINVAL; 585 586 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 587 return -EINVAL; 588 589 for (total_len = 0; total_len < count; total_len += write_len) { 590 write_len = min_t(size_t, count, 4); 591 write_len -= off & 0x3; 592 593 rc = fsi_slave_write(slave, off, buf + total_len, write_len); 594 if (rc) 595 return rc; 596 597 off += write_len; 598 } 599 600 return count; 601 } 602 603 static const struct bin_attribute fsi_slave_raw_attr = { 604 .attr = { 605 .name = "raw", 606 .mode = 0600, 607 }, 608 .size = 0, 609 .read = fsi_slave_sysfs_raw_read, 610 .write = fsi_slave_sysfs_raw_write, 611 }; 612 613 static void fsi_slave_release(struct device *dev) 614 { 615 struct fsi_slave *slave = to_fsi_slave(dev); 616 617 fsi_free_minor(slave->dev.devt); 618 of_node_put(dev->of_node); 619 kfree(slave); 620 } 621 622 static bool fsi_slave_node_matches(struct device_node *np, 623 int link, uint8_t id) 624 { 625 unsigned int len, na, ns; 626 const __be32 *prop; 627 628 na = of_n_addr_cells(np); 629 ns = of_n_size_cells(np); 630 631 /* Ensure we have the correct format for addresses and sizes in 632 * reg properties 633 */ 634 if (na != 2 || ns != 0) 635 return false; 636 637 prop = of_get_property(np, "reg", &len); 638 if (!prop || len != 8) 639 return false; 640 641 return (of_read_number(prop, 1) == link) && 642 (of_read_number(prop + 1, 1) == id); 643 } 644 645 /* Find a matching node for the slave at (link, id). Returns NULL if none 646 * found, or a matching node with refcount already incremented. 647 */ 648 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, 649 int link, uint8_t id) 650 { 651 struct device_node *parent, *np; 652 653 parent = dev_of_node(&master->dev); 654 if (!parent) 655 return NULL; 656 657 for_each_child_of_node(parent, np) { 658 if (fsi_slave_node_matches(np, link, id)) 659 return np; 660 } 661 662 return NULL; 663 } 664 665 static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count, 666 loff_t *offset) 667 { 668 struct fsi_slave *slave = filep->private_data; 669 size_t total_len, read_len; 670 loff_t off = *offset; 671 ssize_t rc; 672 673 if (off < 0) 674 return -EINVAL; 675 676 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 677 return -EINVAL; 678 679 for (total_len = 0; total_len < count; total_len += read_len) { 680 __be32 data; 681 682 read_len = min_t(size_t, count, 4); 683 read_len -= off & 0x3; 684 685 rc = fsi_slave_read(slave, off, &data, read_len); 686 if (rc) 687 goto fail; 688 rc = copy_to_user(buf + total_len, &data, read_len); 689 if (rc) { 690 rc = -EFAULT; 691 goto fail; 692 } 693 off += read_len; 694 } 695 rc = count; 696 fail: 697 *offset = off; 698 return count; 699 } 700 701 static ssize_t cfam_write(struct file *filep, const char __user *buf, 702 size_t count, loff_t *offset) 703 { 704 struct fsi_slave *slave = filep->private_data; 705 size_t total_len, write_len; 706 loff_t off = *offset; 707 ssize_t rc; 708 709 710 if (off < 0) 711 return -EINVAL; 712 713 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 714 return -EINVAL; 715 716 for (total_len = 0; total_len < count; total_len += write_len) { 717 __be32 data; 718 719 write_len = min_t(size_t, count, 4); 720 write_len -= off & 0x3; 721 722 rc = copy_from_user(&data, buf + total_len, write_len); 723 if (rc) { 724 rc = -EFAULT; 725 goto fail; 726 } 727 rc = fsi_slave_write(slave, off, &data, write_len); 728 if (rc) 729 goto fail; 730 off += write_len; 731 } 732 rc = count; 733 fail: 734 *offset = off; 735 return count; 736 } 737 738 static loff_t cfam_llseek(struct file *file, loff_t offset, int whence) 739 { 740 switch (whence) { 741 case SEEK_CUR: 742 break; 743 case SEEK_SET: 744 file->f_pos = offset; 745 break; 746 default: 747 return -EINVAL; 748 } 749 750 return offset; 751 } 752 753 static int cfam_open(struct inode *inode, struct file *file) 754 { 755 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev); 756 757 file->private_data = slave; 758 759 return 0; 760 } 761 762 static const struct file_operations cfam_fops = { 763 .owner = THIS_MODULE, 764 .open = cfam_open, 765 .llseek = cfam_llseek, 766 .read = cfam_read, 767 .write = cfam_write, 768 }; 769 770 static ssize_t send_term_store(struct device *dev, 771 struct device_attribute *attr, 772 const char *buf, size_t count) 773 { 774 struct fsi_slave *slave = to_fsi_slave(dev); 775 struct fsi_master *master = slave->master; 776 777 if (!master->term) 778 return -ENODEV; 779 780 master->term(master, slave->link, slave->id); 781 return count; 782 } 783 784 static DEVICE_ATTR_WO(send_term); 785 786 static ssize_t slave_send_echo_show(struct device *dev, 787 struct device_attribute *attr, 788 char *buf) 789 { 790 struct fsi_slave *slave = to_fsi_slave(dev); 791 792 return sprintf(buf, "%u\n", slave->t_send_delay); 793 } 794 795 static ssize_t slave_send_echo_store(struct device *dev, 796 struct device_attribute *attr, const char *buf, size_t count) 797 { 798 struct fsi_slave *slave = to_fsi_slave(dev); 799 struct fsi_master *master = slave->master; 800 unsigned long val; 801 int rc; 802 803 if (kstrtoul(buf, 0, &val) < 0) 804 return -EINVAL; 805 806 if (val < 1 || val > 16) 807 return -EINVAL; 808 809 if (!master->link_config) 810 return -ENXIO; 811 812 /* Current HW mandates that send and echo delay are identical */ 813 slave->t_send_delay = val; 814 slave->t_echo_delay = val; 815 816 rc = fsi_slave_set_smode(slave); 817 if (rc < 0) 818 return rc; 819 if (master->link_config) 820 master->link_config(master, slave->link, 821 slave->t_send_delay, 822 slave->t_echo_delay); 823 824 return count; 825 } 826 827 static DEVICE_ATTR(send_echo_delays, 0600, 828 slave_send_echo_show, slave_send_echo_store); 829 830 static ssize_t chip_id_show(struct device *dev, 831 struct device_attribute *attr, 832 char *buf) 833 { 834 struct fsi_slave *slave = to_fsi_slave(dev); 835 836 return sprintf(buf, "%d\n", slave->chip_id); 837 } 838 839 static DEVICE_ATTR_RO(chip_id); 840 841 static ssize_t cfam_id_show(struct device *dev, 842 struct device_attribute *attr, 843 char *buf) 844 { 845 struct fsi_slave *slave = to_fsi_slave(dev); 846 847 return sprintf(buf, "0x%x\n", slave->cfam_id); 848 } 849 850 static DEVICE_ATTR_RO(cfam_id); 851 852 static struct attribute *cfam_attr[] = { 853 &dev_attr_send_echo_delays.attr, 854 &dev_attr_chip_id.attr, 855 &dev_attr_cfam_id.attr, 856 &dev_attr_send_term.attr, 857 NULL, 858 }; 859 860 static const struct attribute_group cfam_attr_group = { 861 .attrs = cfam_attr, 862 }; 863 864 static const struct attribute_group *cfam_attr_groups[] = { 865 &cfam_attr_group, 866 NULL, 867 }; 868 869 static char *cfam_devnode(struct device *dev, umode_t *mode, 870 kuid_t *uid, kgid_t *gid) 871 { 872 struct fsi_slave *slave = to_fsi_slave(dev); 873 874 #ifdef CONFIG_FSI_NEW_DEV_NODE 875 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx); 876 #else 877 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx); 878 #endif 879 } 880 881 static const struct device_type cfam_type = { 882 .name = "cfam", 883 .devnode = cfam_devnode, 884 .groups = cfam_attr_groups 885 }; 886 887 static char *fsi_cdev_devnode(struct device *dev, umode_t *mode, 888 kuid_t *uid, kgid_t *gid) 889 { 890 #ifdef CONFIG_FSI_NEW_DEV_NODE 891 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev)); 892 #else 893 return kasprintf(GFP_KERNEL, "%s", dev_name(dev)); 894 #endif 895 } 896 897 const struct device_type fsi_cdev_type = { 898 .name = "fsi-cdev", 899 .devnode = fsi_cdev_devnode, 900 }; 901 EXPORT_SYMBOL_GPL(fsi_cdev_type); 902 903 /* Backward compatible /dev/ numbering in "old style" mode */ 904 static int fsi_adjust_index(int index) 905 { 906 #ifdef CONFIG_FSI_NEW_DEV_NODE 907 return index; 908 #else 909 return index + 1; 910 #endif 911 } 912 913 static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type, 914 dev_t *out_dev, int *out_index) 915 { 916 int cid = slave->chip_id; 917 int id; 918 919 /* Check if we qualify for legacy numbering */ 920 if (cid >= 0 && cid < 16 && type < 4) { 921 /* Try reserving the legacy number */ 922 id = (cid << 4) | type; 923 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); 924 if (id >= 0) { 925 *out_index = fsi_adjust_index(cid); 926 *out_dev = fsi_base_dev + id; 927 return 0; 928 } 929 /* Other failure */ 930 if (id != -ENOSPC) 931 return id; 932 /* Fallback to non-legacy allocation */ 933 } 934 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP, 935 FSI_CHAR_MAX_DEVICES, GFP_KERNEL); 936 if (id < 0) 937 return id; 938 *out_index = fsi_adjust_index(id); 939 *out_dev = fsi_base_dev + id; 940 return 0; 941 } 942 943 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type, 944 dev_t *out_dev, int *out_index) 945 { 946 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index); 947 } 948 EXPORT_SYMBOL_GPL(fsi_get_new_minor); 949 950 void fsi_free_minor(dev_t dev) 951 { 952 ida_simple_remove(&fsi_minor_ida, MINOR(dev)); 953 } 954 EXPORT_SYMBOL_GPL(fsi_free_minor); 955 956 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 957 { 958 uint32_t cfam_id; 959 struct fsi_slave *slave; 960 uint8_t crc; 961 __be32 data, llmode; 962 int rc; 963 964 /* Currently, we only support single slaves on a link, and use the 965 * full 23-bit address range 966 */ 967 if (id != 0) 968 return -EINVAL; 969 970 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data)); 971 if (rc) { 972 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 973 link, id, rc); 974 return -ENODEV; 975 } 976 cfam_id = be32_to_cpu(data); 977 978 crc = crc4(0, cfam_id, 32); 979 if (crc) { 980 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n", 981 link, id); 982 return -EIO; 983 } 984 985 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 986 cfam_id, master->idx, link, id); 987 988 /* If we're behind a master that doesn't provide a self-running bus 989 * clock, put the slave into async mode 990 */ 991 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 992 llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 993 rc = fsi_master_write(master, link, id, 994 FSI_SLAVE_BASE + FSI_LLMODE, 995 &llmode, sizeof(llmode)); 996 if (rc) 997 dev_warn(&master->dev, 998 "can't set llmode on slave:%02x:%02x %d\n", 999 link, id, rc); 1000 } 1001 1002 /* We can communicate with a slave; create the slave device and 1003 * register. 1004 */ 1005 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 1006 if (!slave) 1007 return -ENOMEM; 1008 1009 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 1010 slave->dev.type = &cfam_type; 1011 slave->dev.parent = &master->dev; 1012 slave->dev.of_node = fsi_slave_find_of_node(master, link, id); 1013 slave->dev.release = fsi_slave_release; 1014 device_initialize(&slave->dev); 1015 slave->cfam_id = cfam_id; 1016 slave->master = master; 1017 slave->link = link; 1018 slave->id = id; 1019 slave->size = FSI_SLAVE_SIZE_23b; 1020 slave->t_send_delay = 16; 1021 slave->t_echo_delay = 16; 1022 1023 /* Get chip ID if any */ 1024 slave->chip_id = -1; 1025 if (slave->dev.of_node) { 1026 uint32_t prop; 1027 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop)) 1028 slave->chip_id = prop; 1029 1030 } 1031 1032 rc = fsi_slave_set_smode(slave); 1033 if (rc) { 1034 dev_warn(&master->dev, 1035 "can't set smode on slave:%02x:%02x %d\n", 1036 link, id, rc); 1037 goto err_free; 1038 } 1039 1040 /* Allocate a minor in the FSI space */ 1041 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt, 1042 &slave->cdev_idx); 1043 if (rc) 1044 goto err_free; 1045 1046 /* Create chardev for userspace access */ 1047 cdev_init(&slave->cdev, &cfam_fops); 1048 rc = cdev_device_add(&slave->cdev, &slave->dev); 1049 if (rc) { 1050 dev_err(&slave->dev, "Error %d creating slave device\n", rc); 1051 goto err_free_ida; 1052 } 1053 1054 /* Now that we have the cdev registered with the core, any fatal 1055 * failures beyond this point will need to clean up through 1056 * cdev_device_del(). Fortunately though, nothing past here is fatal. 1057 */ 1058 1059 if (master->link_config) 1060 master->link_config(master, link, 1061 slave->t_send_delay, 1062 slave->t_echo_delay); 1063 1064 /* Legacy raw file -> to be removed */ 1065 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 1066 if (rc) 1067 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 1068 1069 1070 rc = fsi_slave_scan(slave); 1071 if (rc) 1072 dev_dbg(&master->dev, "failed during slave scan with: %d\n", 1073 rc); 1074 1075 return 0; 1076 1077 err_free_ida: 1078 fsi_free_minor(slave->dev.devt); 1079 err_free: 1080 of_node_put(slave->dev.of_node); 1081 kfree(slave); 1082 return rc; 1083 } 1084 1085 /* FSI master support */ 1086 static int fsi_check_access(uint32_t addr, size_t size) 1087 { 1088 if (size == 4) { 1089 if (addr & 0x3) 1090 return -EINVAL; 1091 } else if (size == 2) { 1092 if (addr & 0x1) 1093 return -EINVAL; 1094 } else if (size != 1) 1095 return -EINVAL; 1096 1097 return 0; 1098 } 1099 1100 static int fsi_master_read(struct fsi_master *master, int link, 1101 uint8_t slave_id, uint32_t addr, void *val, size_t size) 1102 { 1103 int rc; 1104 1105 trace_fsi_master_read(master, link, slave_id, addr, size); 1106 1107 rc = fsi_check_access(addr, size); 1108 if (!rc) 1109 rc = master->read(master, link, slave_id, addr, val, size); 1110 1111 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 1112 false, val, rc); 1113 1114 return rc; 1115 } 1116 1117 static int fsi_master_write(struct fsi_master *master, int link, 1118 uint8_t slave_id, uint32_t addr, const void *val, size_t size) 1119 { 1120 int rc; 1121 1122 trace_fsi_master_write(master, link, slave_id, addr, size, val); 1123 1124 rc = fsi_check_access(addr, size); 1125 if (!rc) 1126 rc = master->write(master, link, slave_id, addr, val, size); 1127 1128 trace_fsi_master_rw_result(master, link, slave_id, addr, size, 1129 true, val, rc); 1130 1131 return rc; 1132 } 1133 1134 static int fsi_master_link_enable(struct fsi_master *master, int link) 1135 { 1136 if (master->link_enable) 1137 return master->link_enable(master, link); 1138 1139 return 0; 1140 } 1141 1142 /* 1143 * Issue a break command on this link 1144 */ 1145 static int fsi_master_break(struct fsi_master *master, int link) 1146 { 1147 int rc = 0; 1148 1149 trace_fsi_master_break(master, link); 1150 1151 if (master->send_break) 1152 rc = master->send_break(master, link); 1153 if (master->link_config) 1154 master->link_config(master, link, 16, 16); 1155 1156 return rc; 1157 } 1158 1159 static int fsi_master_scan(struct fsi_master *master) 1160 { 1161 int link, rc; 1162 1163 for (link = 0; link < master->n_links; link++) { 1164 rc = fsi_master_link_enable(master, link); 1165 if (rc) { 1166 dev_dbg(&master->dev, 1167 "enable link %d failed: %d\n", link, rc); 1168 continue; 1169 } 1170 rc = fsi_master_break(master, link); 1171 if (rc) { 1172 dev_dbg(&master->dev, 1173 "break to link %d failed: %d\n", link, rc); 1174 continue; 1175 } 1176 1177 fsi_slave_init(master, link, 0); 1178 } 1179 1180 return 0; 1181 } 1182 1183 static int fsi_slave_remove_device(struct device *dev, void *arg) 1184 { 1185 device_unregister(dev); 1186 return 0; 1187 } 1188 1189 static int fsi_master_remove_slave(struct device *dev, void *arg) 1190 { 1191 struct fsi_slave *slave = to_fsi_slave(dev); 1192 1193 device_for_each_child(dev, NULL, fsi_slave_remove_device); 1194 cdev_device_del(&slave->cdev, &slave->dev); 1195 put_device(dev); 1196 return 0; 1197 } 1198 1199 static void fsi_master_unscan(struct fsi_master *master) 1200 { 1201 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); 1202 } 1203 1204 int fsi_master_rescan(struct fsi_master *master) 1205 { 1206 int rc; 1207 1208 mutex_lock(&master->scan_lock); 1209 fsi_master_unscan(master); 1210 rc = fsi_master_scan(master); 1211 mutex_unlock(&master->scan_lock); 1212 1213 return rc; 1214 } 1215 EXPORT_SYMBOL_GPL(fsi_master_rescan); 1216 1217 static ssize_t master_rescan_store(struct device *dev, 1218 struct device_attribute *attr, const char *buf, size_t count) 1219 { 1220 struct fsi_master *master = to_fsi_master(dev); 1221 int rc; 1222 1223 rc = fsi_master_rescan(master); 1224 if (rc < 0) 1225 return rc; 1226 1227 return count; 1228 } 1229 1230 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); 1231 1232 static ssize_t master_break_store(struct device *dev, 1233 struct device_attribute *attr, const char *buf, size_t count) 1234 { 1235 struct fsi_master *master = to_fsi_master(dev); 1236 1237 fsi_master_break(master, 0); 1238 1239 return count; 1240 } 1241 1242 static DEVICE_ATTR(break, 0200, NULL, master_break_store); 1243 1244 int fsi_master_register(struct fsi_master *master) 1245 { 1246 int rc; 1247 struct device_node *np; 1248 1249 mutex_init(&master->scan_lock); 1250 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); 1251 dev_set_name(&master->dev, "fsi%d", master->idx); 1252 1253 rc = device_register(&master->dev); 1254 if (rc) { 1255 ida_simple_remove(&master_ida, master->idx); 1256 return rc; 1257 } 1258 1259 rc = device_create_file(&master->dev, &dev_attr_rescan); 1260 if (rc) { 1261 device_del(&master->dev); 1262 ida_simple_remove(&master_ida, master->idx); 1263 return rc; 1264 } 1265 1266 rc = device_create_file(&master->dev, &dev_attr_break); 1267 if (rc) { 1268 device_del(&master->dev); 1269 ida_simple_remove(&master_ida, master->idx); 1270 return rc; 1271 } 1272 1273 np = dev_of_node(&master->dev); 1274 if (!of_property_read_bool(np, "no-scan-on-init")) { 1275 mutex_lock(&master->scan_lock); 1276 fsi_master_scan(master); 1277 mutex_unlock(&master->scan_lock); 1278 } 1279 1280 return 0; 1281 } 1282 EXPORT_SYMBOL_GPL(fsi_master_register); 1283 1284 void fsi_master_unregister(struct fsi_master *master) 1285 { 1286 if (master->idx >= 0) { 1287 ida_simple_remove(&master_ida, master->idx); 1288 master->idx = -1; 1289 } 1290 1291 mutex_lock(&master->scan_lock); 1292 fsi_master_unscan(master); 1293 mutex_unlock(&master->scan_lock); 1294 device_unregister(&master->dev); 1295 } 1296 EXPORT_SYMBOL_GPL(fsi_master_unregister); 1297 1298 /* FSI core & Linux bus type definitions */ 1299 1300 static int fsi_bus_match(struct device *dev, struct device_driver *drv) 1301 { 1302 struct fsi_device *fsi_dev = to_fsi_dev(dev); 1303 struct fsi_driver *fsi_drv = to_fsi_drv(drv); 1304 const struct fsi_device_id *id; 1305 1306 if (!fsi_drv->id_table) 1307 return 0; 1308 1309 for (id = fsi_drv->id_table; id->engine_type; id++) { 1310 if (id->engine_type != fsi_dev->engine_type) 1311 continue; 1312 if (id->version == FSI_VERSION_ANY || 1313 id->version == fsi_dev->version) 1314 return 1; 1315 } 1316 1317 return 0; 1318 } 1319 1320 int fsi_driver_register(struct fsi_driver *fsi_drv) 1321 { 1322 if (!fsi_drv) 1323 return -EINVAL; 1324 if (!fsi_drv->id_table) 1325 return -EINVAL; 1326 1327 return driver_register(&fsi_drv->drv); 1328 } 1329 EXPORT_SYMBOL_GPL(fsi_driver_register); 1330 1331 void fsi_driver_unregister(struct fsi_driver *fsi_drv) 1332 { 1333 driver_unregister(&fsi_drv->drv); 1334 } 1335 EXPORT_SYMBOL_GPL(fsi_driver_unregister); 1336 1337 struct bus_type fsi_bus_type = { 1338 .name = "fsi", 1339 .match = fsi_bus_match, 1340 }; 1341 EXPORT_SYMBOL_GPL(fsi_bus_type); 1342 1343 static int __init fsi_init(void) 1344 { 1345 int rc; 1346 1347 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi"); 1348 if (rc) 1349 return rc; 1350 rc = bus_register(&fsi_bus_type); 1351 if (rc) 1352 goto fail_bus; 1353 return 0; 1354 1355 fail_bus: 1356 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); 1357 return rc; 1358 } 1359 postcore_initcall(fsi_init); 1360 1361 static void fsi_exit(void) 1362 { 1363 bus_unregister(&fsi_bus_type); 1364 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); 1365 ida_destroy(&fsi_minor_ida); 1366 } 1367 module_exit(fsi_exit); 1368 module_param(discard_errors, int, 0664); 1369 MODULE_LICENSE("GPL"); 1370 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); 1371