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 * TODO: 16 * - Rework topology 17 * - s/chip_id/chip_loc 18 * - s/cfam/chip (cfam_id -> chip_id etc...) 19 */ 20 21 #include <linux/crc4.h> 22 #include <linux/device.h> 23 #include <linux/fsi.h> 24 #include <linux/idr.h> 25 #include <linux/module.h> 26 #include <linux/of.h> 27 #include <linux/slab.h> 28 #include <linux/bitops.h> 29 #include <linux/cdev.h> 30 #include <linux/fs.h> 31 #include <linux/uaccess.h> 32 33 #include "fsi-master.h" 34 35 #define CREATE_TRACE_POINTS 36 #include <trace/events/fsi.h> 37 38 #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) 39 #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) 40 #define FSI_SLAVE_CONF_SLOTS_SHIFT 16 41 #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) 42 #define FSI_SLAVE_CONF_VERSION_SHIFT 12 43 #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) 44 #define FSI_SLAVE_CONF_TYPE_SHIFT 4 45 #define FSI_SLAVE_CONF_CRC_SHIFT 4 46 #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) 47 #define FSI_SLAVE_CONF_DATA_BITS 28 48 49 #define FSI_PEEK_BASE 0x410 50 51 static const int engine_page_size = 0x400; 52 53 #define FSI_SLAVE_BASE 0x800 54 55 /* 56 * FSI slave engine control register offsets 57 */ 58 #define FSI_SMODE 0x0 /* R/W: Mode register */ 59 #define FSI_SISC 0x8 /* R/W: Interrupt condition */ 60 #define FSI_SSTAT 0x14 /* R : Slave status */ 61 #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ 62 63 /* 64 * SMODE fields 65 */ 66 #define FSI_SMODE_WSC 0x80000000 /* Warm start done */ 67 #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ 68 #define FSI_SMODE_SID_SHIFT 24 /* ID shift */ 69 #define FSI_SMODE_SID_MASK 3 /* ID Mask */ 70 #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ 71 #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ 72 #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ 73 #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ 74 #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ 75 #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ 76 77 /* 78 * LLMODE fields 79 */ 80 #define FSI_LLMODE_ASYNC 0x1 81 82 #define FSI_SLAVE_SIZE_23b 0x800000 83 84 static DEFINE_IDA(master_ida); 85 86 struct fsi_slave { 87 struct device dev; 88 struct fsi_master *master; 89 struct cdev cdev; 90 int cdev_idx; 91 int id; /* FSI address */ 92 int link; /* FSI link# */ 93 u32 cfam_id; 94 int chip_id; 95 uint32_t size; /* size of slave address space */ 96 u8 t_send_delay; 97 u8 t_echo_delay; 98 }; 99 100 #define to_fsi_master(d) container_of(d, struct fsi_master, dev) 101 #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) 102 103 static const int slave_retries = 2; 104 static int discard_errors; 105 106 static dev_t fsi_base_dev; 107 static DEFINE_IDA(fsi_minor_ida); 108 #define FSI_CHAR_MAX_DEVICES 0x1000 109 110 /* Legacy /dev numbering: 4 devices per chip, 16 chips */ 111 #define FSI_CHAR_LEGACY_TOP 64 112 113 static int fsi_master_read(struct fsi_master *master, int link, 114 uint8_t slave_id, uint32_t addr, void *val, size_t size); 115 static int fsi_master_write(struct fsi_master *master, int link, 116 uint8_t slave_id, uint32_t addr, const void *val, size_t size); 117 static int fsi_master_break(struct fsi_master *master, int link); 118 119 /* 120 * fsi_device_read() / fsi_device_write() / fsi_device_peek() 121 * 122 * FSI endpoint-device support 123 * 124 * Read / write / peek accessors for a client 125 * 126 * Parameters: 127 * dev: Structure passed to FSI client device drivers on probe(). 128 * addr: FSI address of given device. Client should pass in its base address 129 * plus desired offset to access its register space. 130 * val: For read/peek this is the value read at the specified address. For 131 * write this is value to write to the specified address. 132 * The data in val must be FSI bus endian (big endian). 133 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. 134 * Addresses must be aligned on size boundaries or an error will result. 135 */ 136 int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, 137 size_t size) 138 { 139 if (addr > dev->size || size > dev->size || addr > dev->size - size) 140 return -EINVAL; 141 142 return fsi_slave_read(dev->slave, dev->addr + addr, val, size); 143 } 144 EXPORT_SYMBOL_GPL(fsi_device_read); 145 146 int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, 147 size_t size) 148 { 149 if (addr > dev->size || size > dev->size || addr > dev->size - size) 150 return -EINVAL; 151 152 return fsi_slave_write(dev->slave, dev->addr + addr, val, size); 153 } 154 EXPORT_SYMBOL_GPL(fsi_device_write); 155 156 int fsi_device_peek(struct fsi_device *dev, void *val) 157 { 158 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); 159 160 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); 161 } 162 163 static void fsi_device_release(struct device *_device) 164 { 165 struct fsi_device *device = to_fsi_dev(_device); 166 167 of_node_put(device->dev.of_node); 168 kfree(device); 169 } 170 171 static struct fsi_device *fsi_create_device(struct fsi_slave *slave) 172 { 173 struct fsi_device *dev; 174 175 dev = kzalloc(sizeof(*dev), GFP_KERNEL); 176 if (!dev) 177 return NULL; 178 179 dev->dev.parent = &slave->dev; 180 dev->dev.bus = &fsi_bus_type; 181 dev->dev.release = fsi_device_release; 182 183 return dev; 184 } 185 186 /* FSI slave support */ 187 static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, 188 uint8_t *idp) 189 { 190 uint32_t addr = *addrp; 191 uint8_t id = *idp; 192 193 if (addr > slave->size) 194 return -EINVAL; 195 196 /* For 23 bit addressing, we encode the extra two bits in the slave 197 * id (and the slave's actual ID needs to be 0). 198 */ 199 if (addr > 0x1fffff) { 200 if (slave->id != 0) 201 return -EINVAL; 202 id = (addr >> 21) & 0x3; 203 addr &= 0x1fffff; 204 } 205 206 *addrp = addr; 207 *idp = id; 208 return 0; 209 } 210 211 static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) 212 { 213 struct fsi_master *master = slave->master; 214 __be32 irq, stat; 215 int rc, link; 216 uint8_t id; 217 218 link = slave->link; 219 id = slave->id; 220 221 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 222 &irq, sizeof(irq)); 223 if (rc) 224 return rc; 225 226 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, 227 &stat, sizeof(stat)); 228 if (rc) 229 return rc; 230 231 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", 232 be32_to_cpu(stat), be32_to_cpu(irq)); 233 234 /* clear interrupts */ 235 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, 236 &irq, sizeof(irq)); 237 } 238 239 /* Encode slave local bus echo delay */ 240 static inline uint32_t fsi_smode_echodly(int x) 241 { 242 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; 243 } 244 245 /* Encode slave local bus send delay */ 246 static inline uint32_t fsi_smode_senddly(int x) 247 { 248 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; 249 } 250 251 /* Encode slave local bus clock rate ratio */ 252 static inline uint32_t fsi_smode_lbcrr(int x) 253 { 254 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; 255 } 256 257 /* Encode slave ID */ 258 static inline uint32_t fsi_smode_sid(int x) 259 { 260 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; 261 } 262 263 static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly) 264 { 265 return FSI_SMODE_WSC | FSI_SMODE_ECRC 266 | fsi_smode_sid(id) 267 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1) 268 | fsi_smode_lbcrr(0x8); 269 } 270 271 static int fsi_slave_set_smode(struct fsi_slave *slave) 272 { 273 uint32_t smode; 274 __be32 data; 275 276 /* set our smode register with the slave ID field to 0; this enables 277 * extended slave addressing 278 */ 279 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay); 280 data = cpu_to_be32(smode); 281 282 return fsi_master_write(slave->master, slave->link, slave->id, 283 FSI_SLAVE_BASE + FSI_SMODE, 284 &data, sizeof(data)); 285 } 286 287 static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, 288 uint32_t addr, size_t size) 289 { 290 struct fsi_master *master = slave->master; 291 int rc, link; 292 uint32_t reg; 293 uint8_t id, send_delay, echo_delay; 294 295 if (discard_errors) 296 return -1; 297 298 link = slave->link; 299 id = slave->id; 300 301 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", 302 write ? "write" : "read", addr, size); 303 304 /* try a simple clear of error conditions, which may fail if we've lost 305 * communication with the slave 306 */ 307 rc = fsi_slave_report_and_clear_errors(slave); 308 if (!rc) 309 return 0; 310 311 /* send a TERM and retry */ 312 if (master->term) { 313 rc = master->term(master, link, id); 314 if (!rc) { 315 rc = fsi_master_read(master, link, id, 0, 316 ®, sizeof(reg)); 317 if (!rc) 318 rc = fsi_slave_report_and_clear_errors(slave); 319 if (!rc) 320 return 0; 321 } 322 } 323 324 send_delay = slave->t_send_delay; 325 echo_delay = slave->t_echo_delay; 326 327 /* getting serious, reset the slave via BREAK */ 328 rc = fsi_master_break(master, link); 329 if (rc) 330 return rc; 331 332 slave->t_send_delay = send_delay; 333 slave->t_echo_delay = echo_delay; 334 335 rc = fsi_slave_set_smode(slave); 336 if (rc) 337 return rc; 338 339 if (master->link_config) 340 master->link_config(master, link, 341 slave->t_send_delay, 342 slave->t_echo_delay); 343 344 return fsi_slave_report_and_clear_errors(slave); 345 } 346 347 int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, 348 void *val, size_t size) 349 { 350 uint8_t id = slave->id; 351 int rc, err_rc, i; 352 353 rc = fsi_slave_calc_addr(slave, &addr, &id); 354 if (rc) 355 return rc; 356 357 for (i = 0; i < slave_retries; i++) { 358 rc = fsi_master_read(slave->master, slave->link, 359 id, addr, val, size); 360 if (!rc) 361 break; 362 363 err_rc = fsi_slave_handle_error(slave, false, addr, size); 364 if (err_rc) 365 break; 366 } 367 368 return rc; 369 } 370 EXPORT_SYMBOL_GPL(fsi_slave_read); 371 372 int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, 373 const void *val, size_t size) 374 { 375 uint8_t id = slave->id; 376 int rc, err_rc, i; 377 378 rc = fsi_slave_calc_addr(slave, &addr, &id); 379 if (rc) 380 return rc; 381 382 for (i = 0; i < slave_retries; i++) { 383 rc = fsi_master_write(slave->master, slave->link, 384 id, addr, val, size); 385 if (!rc) 386 break; 387 388 err_rc = fsi_slave_handle_error(slave, true, addr, size); 389 if (err_rc) 390 break; 391 } 392 393 return rc; 394 } 395 EXPORT_SYMBOL_GPL(fsi_slave_write); 396 397 extern int fsi_slave_claim_range(struct fsi_slave *slave, 398 uint32_t addr, uint32_t size) 399 { 400 if (addr + size < addr) 401 return -EINVAL; 402 403 if (addr + size > slave->size) 404 return -EINVAL; 405 406 /* todo: check for overlapping claims */ 407 return 0; 408 } 409 EXPORT_SYMBOL_GPL(fsi_slave_claim_range); 410 411 extern void fsi_slave_release_range(struct fsi_slave *slave, 412 uint32_t addr, uint32_t size) 413 { 414 } 415 EXPORT_SYMBOL_GPL(fsi_slave_release_range); 416 417 static bool fsi_device_node_matches(struct device *dev, struct device_node *np, 418 uint32_t addr, uint32_t size) 419 { 420 unsigned int len, na, ns; 421 const __be32 *prop; 422 uint32_t psize; 423 424 na = of_n_addr_cells(np); 425 ns = of_n_size_cells(np); 426 427 if (na != 1 || ns != 1) 428 return false; 429 430 prop = of_get_property(np, "reg", &len); 431 if (!prop || len != 8) 432 return false; 433 434 if (of_read_number(prop, 1) != addr) 435 return false; 436 437 psize = of_read_number(prop + 1, 1); 438 if (psize != size) { 439 dev_warn(dev, 440 "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", 441 of_node_full_name(np), psize, size); 442 } 443 444 return true; 445 } 446 447 /* Find a matching node for the slave engine at @address, using @size bytes 448 * of space. Returns NULL if not found, or a matching node with refcount 449 * already incremented. 450 */ 451 static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) 452 { 453 struct device_node *parent, *np; 454 455 parent = dev_of_node(&dev->slave->dev); 456 if (!parent) 457 return NULL; 458 459 for_each_child_of_node(parent, np) { 460 if (fsi_device_node_matches(&dev->dev, np, 461 dev->addr, dev->size)) 462 return np; 463 } 464 465 return NULL; 466 } 467 468 static int fsi_slave_scan(struct fsi_slave *slave) 469 { 470 uint32_t engine_addr; 471 int rc, i; 472 473 /* 474 * scan engines 475 * 476 * We keep the peek mode and slave engines for the core; so start 477 * at the third slot in the configuration table. We also need to 478 * skip the chip ID entry at the start of the address space. 479 */ 480 engine_addr = engine_page_size * 3; 481 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { 482 uint8_t slots, version, type, crc; 483 struct fsi_device *dev; 484 uint32_t conf; 485 __be32 data; 486 487 rc = fsi_slave_read(slave, (i + 1) * sizeof(data), 488 &data, sizeof(data)); 489 if (rc) { 490 dev_warn(&slave->dev, 491 "error reading slave registers\n"); 492 return -1; 493 } 494 conf = be32_to_cpu(data); 495 496 crc = crc4(0, conf, 32); 497 if (crc) { 498 dev_warn(&slave->dev, 499 "crc error in slave register at 0x%04x\n", 500 i); 501 return -1; 502 } 503 504 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) 505 >> FSI_SLAVE_CONF_SLOTS_SHIFT; 506 version = (conf & FSI_SLAVE_CONF_VERSION_MASK) 507 >> FSI_SLAVE_CONF_VERSION_SHIFT; 508 type = (conf & FSI_SLAVE_CONF_TYPE_MASK) 509 >> FSI_SLAVE_CONF_TYPE_SHIFT; 510 511 /* 512 * Unused address areas are marked by a zero type value; this 513 * skips the defined address areas 514 */ 515 if (type != 0 && slots != 0) { 516 517 /* create device */ 518 dev = fsi_create_device(slave); 519 if (!dev) 520 return -ENOMEM; 521 522 dev->slave = slave; 523 dev->engine_type = type; 524 dev->version = version; 525 dev->unit = i; 526 dev->addr = engine_addr; 527 dev->size = slots * engine_page_size; 528 529 dev_dbg(&slave->dev, 530 "engine[%i]: type %x, version %x, addr %x size %x\n", 531 dev->unit, dev->engine_type, version, 532 dev->addr, dev->size); 533 534 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", 535 slave->master->idx, slave->link, 536 slave->id, i - 2); 537 dev->dev.of_node = fsi_device_find_of_node(dev); 538 539 rc = device_register(&dev->dev); 540 if (rc) { 541 dev_warn(&slave->dev, "add failed: %d\n", rc); 542 put_device(&dev->dev); 543 } 544 } 545 546 engine_addr += slots * engine_page_size; 547 548 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) 549 break; 550 } 551 552 return 0; 553 } 554 555 static ssize_t fsi_slave_sysfs_raw_read(struct file *file, 556 struct kobject *kobj, struct bin_attribute *attr, char *buf, 557 loff_t off, size_t count) 558 { 559 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 560 size_t total_len, read_len; 561 int rc; 562 563 if (off < 0) 564 return -EINVAL; 565 566 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 567 return -EINVAL; 568 569 for (total_len = 0; total_len < count; total_len += read_len) { 570 read_len = min_t(size_t, count, 4); 571 read_len -= off & 0x3; 572 573 rc = fsi_slave_read(slave, off, buf + total_len, read_len); 574 if (rc) 575 return rc; 576 577 off += read_len; 578 } 579 580 return count; 581 } 582 583 static ssize_t fsi_slave_sysfs_raw_write(struct file *file, 584 struct kobject *kobj, struct bin_attribute *attr, 585 char *buf, loff_t off, size_t count) 586 { 587 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); 588 size_t total_len, write_len; 589 int rc; 590 591 if (off < 0) 592 return -EINVAL; 593 594 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 595 return -EINVAL; 596 597 for (total_len = 0; total_len < count; total_len += write_len) { 598 write_len = min_t(size_t, count, 4); 599 write_len -= off & 0x3; 600 601 rc = fsi_slave_write(slave, off, buf + total_len, write_len); 602 if (rc) 603 return rc; 604 605 off += write_len; 606 } 607 608 return count; 609 } 610 611 static const struct bin_attribute fsi_slave_raw_attr = { 612 .attr = { 613 .name = "raw", 614 .mode = 0600, 615 }, 616 .size = 0, 617 .read = fsi_slave_sysfs_raw_read, 618 .write = fsi_slave_sysfs_raw_write, 619 }; 620 621 static void fsi_slave_release(struct device *dev) 622 { 623 struct fsi_slave *slave = to_fsi_slave(dev); 624 625 fsi_free_minor(slave->dev.devt); 626 of_node_put(dev->of_node); 627 kfree(slave); 628 } 629 630 static bool fsi_slave_node_matches(struct device_node *np, 631 int link, uint8_t id) 632 { 633 unsigned int len, na, ns; 634 const __be32 *prop; 635 636 na = of_n_addr_cells(np); 637 ns = of_n_size_cells(np); 638 639 /* Ensure we have the correct format for addresses and sizes in 640 * reg properties 641 */ 642 if (na != 2 || ns != 0) 643 return false; 644 645 prop = of_get_property(np, "reg", &len); 646 if (!prop || len != 8) 647 return false; 648 649 return (of_read_number(prop, 1) == link) && 650 (of_read_number(prop + 1, 1) == id); 651 } 652 653 /* Find a matching node for the slave at (link, id). Returns NULL if none 654 * found, or a matching node with refcount already incremented. 655 */ 656 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, 657 int link, uint8_t id) 658 { 659 struct device_node *parent, *np; 660 661 parent = dev_of_node(&master->dev); 662 if (!parent) 663 return NULL; 664 665 for_each_child_of_node(parent, np) { 666 if (fsi_slave_node_matches(np, link, id)) 667 return np; 668 } 669 670 return NULL; 671 } 672 673 static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count, 674 loff_t *offset) 675 { 676 struct fsi_slave *slave = filep->private_data; 677 size_t total_len, read_len; 678 loff_t off = *offset; 679 ssize_t rc; 680 681 if (off < 0) 682 return -EINVAL; 683 684 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 685 return -EINVAL; 686 687 for (total_len = 0; total_len < count; total_len += read_len) { 688 __be32 data; 689 690 read_len = min_t(size_t, count, 4); 691 read_len -= off & 0x3; 692 693 rc = fsi_slave_read(slave, off, &data, read_len); 694 if (rc) 695 goto fail; 696 rc = copy_to_user(buf + total_len, &data, read_len); 697 if (rc) { 698 rc = -EFAULT; 699 goto fail; 700 } 701 off += read_len; 702 } 703 rc = count; 704 fail: 705 *offset = off; 706 return count; 707 } 708 709 static ssize_t cfam_write(struct file *filep, const char __user *buf, 710 size_t count, loff_t *offset) 711 { 712 struct fsi_slave *slave = filep->private_data; 713 size_t total_len, write_len; 714 loff_t off = *offset; 715 ssize_t rc; 716 717 718 if (off < 0) 719 return -EINVAL; 720 721 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) 722 return -EINVAL; 723 724 for (total_len = 0; total_len < count; total_len += write_len) { 725 __be32 data; 726 727 write_len = min_t(size_t, count, 4); 728 write_len -= off & 0x3; 729 730 rc = copy_from_user(&data, buf + total_len, write_len); 731 if (rc) { 732 rc = -EFAULT; 733 goto fail; 734 } 735 rc = fsi_slave_write(slave, off, &data, write_len); 736 if (rc) 737 goto fail; 738 off += write_len; 739 } 740 rc = count; 741 fail: 742 *offset = off; 743 return count; 744 } 745 746 static loff_t cfam_llseek(struct file *file, loff_t offset, int whence) 747 { 748 switch (whence) { 749 case SEEK_CUR: 750 break; 751 case SEEK_SET: 752 file->f_pos = offset; 753 break; 754 default: 755 return -EINVAL; 756 } 757 758 return offset; 759 } 760 761 static int cfam_open(struct inode *inode, struct file *file) 762 { 763 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev); 764 765 file->private_data = slave; 766 767 return 0; 768 } 769 770 static const struct file_operations cfam_fops = { 771 .owner = THIS_MODULE, 772 .open = cfam_open, 773 .llseek = cfam_llseek, 774 .read = cfam_read, 775 .write = cfam_write, 776 }; 777 778 static ssize_t send_term_store(struct device *dev, 779 struct device_attribute *attr, 780 const char *buf, size_t count) 781 { 782 struct fsi_slave *slave = to_fsi_slave(dev); 783 struct fsi_master *master = slave->master; 784 785 if (!master->term) 786 return -ENODEV; 787 788 master->term(master, slave->link, slave->id); 789 return count; 790 } 791 792 static DEVICE_ATTR_WO(send_term); 793 794 static ssize_t slave_send_echo_show(struct device *dev, 795 struct device_attribute *attr, 796 char *buf) 797 { 798 struct fsi_slave *slave = to_fsi_slave(dev); 799 800 return sprintf(buf, "%u\n", slave->t_send_delay); 801 } 802 803 static ssize_t slave_send_echo_store(struct device *dev, 804 struct device_attribute *attr, const char *buf, size_t count) 805 { 806 struct fsi_slave *slave = to_fsi_slave(dev); 807 struct fsi_master *master = slave->master; 808 unsigned long val; 809 int rc; 810 811 if (kstrtoul(buf, 0, &val) < 0) 812 return -EINVAL; 813 814 if (val < 1 || val > 16) 815 return -EINVAL; 816 817 if (!master->link_config) 818 return -ENXIO; 819 820 /* Current HW mandates that send and echo delay are identical */ 821 slave->t_send_delay = val; 822 slave->t_echo_delay = val; 823 824 rc = fsi_slave_set_smode(slave); 825 if (rc < 0) 826 return rc; 827 if (master->link_config) 828 master->link_config(master, slave->link, 829 slave->t_send_delay, 830 slave->t_echo_delay); 831 832 return count; 833 } 834 835 static DEVICE_ATTR(send_echo_delays, 0600, 836 slave_send_echo_show, slave_send_echo_store); 837 838 static ssize_t chip_id_show(struct device *dev, 839 struct device_attribute *attr, 840 char *buf) 841 { 842 struct fsi_slave *slave = to_fsi_slave(dev); 843 844 return sprintf(buf, "%d\n", slave->chip_id); 845 } 846 847 static DEVICE_ATTR_RO(chip_id); 848 849 static ssize_t cfam_id_show(struct device *dev, 850 struct device_attribute *attr, 851 char *buf) 852 { 853 struct fsi_slave *slave = to_fsi_slave(dev); 854 855 return sprintf(buf, "0x%x\n", slave->cfam_id); 856 } 857 858 static DEVICE_ATTR_RO(cfam_id); 859 860 static struct attribute *cfam_attr[] = { 861 &dev_attr_send_echo_delays.attr, 862 &dev_attr_chip_id.attr, 863 &dev_attr_cfam_id.attr, 864 &dev_attr_send_term.attr, 865 NULL, 866 }; 867 868 static const struct attribute_group cfam_attr_group = { 869 .attrs = cfam_attr, 870 }; 871 872 static const struct attribute_group *cfam_attr_groups[] = { 873 &cfam_attr_group, 874 NULL, 875 }; 876 877 static char *cfam_devnode(struct device *dev, umode_t *mode, 878 kuid_t *uid, kgid_t *gid) 879 { 880 struct fsi_slave *slave = to_fsi_slave(dev); 881 882 #ifdef CONFIG_FSI_NEW_DEV_NODE 883 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx); 884 #else 885 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx); 886 #endif 887 } 888 889 static const struct device_type cfam_type = { 890 .name = "cfam", 891 .devnode = cfam_devnode, 892 .groups = cfam_attr_groups 893 }; 894 895 static char *fsi_cdev_devnode(struct device *dev, umode_t *mode, 896 kuid_t *uid, kgid_t *gid) 897 { 898 #ifdef CONFIG_FSI_NEW_DEV_NODE 899 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev)); 900 #else 901 return kasprintf(GFP_KERNEL, "%s", dev_name(dev)); 902 #endif 903 } 904 905 const struct device_type fsi_cdev_type = { 906 .name = "fsi-cdev", 907 .devnode = fsi_cdev_devnode, 908 }; 909 EXPORT_SYMBOL_GPL(fsi_cdev_type); 910 911 /* Backward compatible /dev/ numbering in "old style" mode */ 912 static int fsi_adjust_index(int index) 913 { 914 #ifdef CONFIG_FSI_NEW_DEV_NODE 915 return index; 916 #else 917 return index + 1; 918 #endif 919 } 920 921 static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type, 922 dev_t *out_dev, int *out_index) 923 { 924 int cid = slave->chip_id; 925 int id; 926 927 /* Check if we qualify for legacy numbering */ 928 if (cid >= 0 && cid < 16 && type < 4) { 929 /* Try reserving the legacy number */ 930 id = (cid << 4) | type; 931 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); 932 if (id >= 0) { 933 *out_index = fsi_adjust_index(cid); 934 *out_dev = fsi_base_dev + id; 935 return 0; 936 } 937 /* Other failure */ 938 if (id != -ENOSPC) 939 return id; 940 /* Fallback to non-legacy allocation */ 941 } 942 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP, 943 FSI_CHAR_MAX_DEVICES, GFP_KERNEL); 944 if (id < 0) 945 return id; 946 *out_index = fsi_adjust_index(id); 947 *out_dev = fsi_base_dev + id; 948 return 0; 949 } 950 951 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type, 952 dev_t *out_dev, int *out_index) 953 { 954 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index); 955 } 956 EXPORT_SYMBOL_GPL(fsi_get_new_minor); 957 958 void fsi_free_minor(dev_t dev) 959 { 960 ida_simple_remove(&fsi_minor_ida, MINOR(dev)); 961 } 962 EXPORT_SYMBOL_GPL(fsi_free_minor); 963 964 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) 965 { 966 uint32_t cfam_id; 967 struct fsi_slave *slave; 968 uint8_t crc; 969 __be32 data, llmode; 970 int rc; 971 972 /* Currently, we only support single slaves on a link, and use the 973 * full 23-bit address range 974 */ 975 if (id != 0) 976 return -EINVAL; 977 978 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data)); 979 if (rc) { 980 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", 981 link, id, rc); 982 return -ENODEV; 983 } 984 cfam_id = be32_to_cpu(data); 985 986 crc = crc4(0, cfam_id, 32); 987 if (crc) { 988 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n", 989 link, id); 990 return -EIO; 991 } 992 993 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", 994 cfam_id, master->idx, link, id); 995 996 /* If we're behind a master that doesn't provide a self-running bus 997 * clock, put the slave into async mode 998 */ 999 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { 1000 llmode = cpu_to_be32(FSI_LLMODE_ASYNC); 1001 rc = fsi_master_write(master, link, id, 1002 FSI_SLAVE_BASE + FSI_LLMODE, 1003 &llmode, sizeof(llmode)); 1004 if (rc) 1005 dev_warn(&master->dev, 1006 "can't set llmode on slave:%02x:%02x %d\n", 1007 link, id, rc); 1008 } 1009 1010 /* We can communicate with a slave; create the slave device and 1011 * register. 1012 */ 1013 slave = kzalloc(sizeof(*slave), GFP_KERNEL); 1014 if (!slave) 1015 return -ENOMEM; 1016 1017 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); 1018 slave->dev.type = &cfam_type; 1019 slave->dev.parent = &master->dev; 1020 slave->dev.of_node = fsi_slave_find_of_node(master, link, id); 1021 slave->dev.release = fsi_slave_release; 1022 device_initialize(&slave->dev); 1023 slave->cfam_id = cfam_id; 1024 slave->master = master; 1025 slave->link = link; 1026 slave->id = id; 1027 slave->size = FSI_SLAVE_SIZE_23b; 1028 slave->t_send_delay = 16; 1029 slave->t_echo_delay = 16; 1030 1031 /* Get chip ID if any */ 1032 slave->chip_id = -1; 1033 if (slave->dev.of_node) { 1034 uint32_t prop; 1035 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop)) 1036 slave->chip_id = prop; 1037 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; 1052 } 1053 1054 rc = fsi_slave_set_smode(slave); 1055 if (rc) { 1056 dev_warn(&master->dev, 1057 "can't set smode on slave:%02x:%02x %d\n", 1058 link, id, rc); 1059 kfree(slave); 1060 return -ENODEV; 1061 } 1062 if (master->link_config) 1063 master->link_config(master, link, 1064 slave->t_send_delay, 1065 slave->t_echo_delay); 1066 1067 /* Legacy raw file -> to be removed */ 1068 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); 1069 if (rc) 1070 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); 1071 1072 1073 rc = fsi_slave_scan(slave); 1074 if (rc) 1075 dev_dbg(&master->dev, "failed during slave scan with: %d\n", 1076 rc); 1077 1078 return rc; 1079 1080 err_free: 1081 put_device(&slave->dev); 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