1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) 2 // Copyright(c) 2015-17 Intel Corporation. 3 4 #include <linux/acpi.h> 5 #include <linux/mod_devicetable.h> 6 #include <linux/pm_runtime.h> 7 #include <linux/soundwire/sdw_registers.h> 8 #include <linux/soundwire/sdw.h> 9 #include "bus.h" 10 11 /** 12 * sdw_add_bus_master() - add a bus Master instance 13 * @bus: bus instance 14 * 15 * Initializes the bus instance, read properties and create child 16 * devices. 17 */ 18 int sdw_add_bus_master(struct sdw_bus *bus) 19 { 20 struct sdw_master_prop *prop = NULL; 21 int ret; 22 23 if (!bus->dev) { 24 pr_err("SoundWire bus has no device\n"); 25 return -ENODEV; 26 } 27 28 if (!bus->ops) { 29 dev_err(bus->dev, "SoundWire Bus ops are not set\n"); 30 return -EINVAL; 31 } 32 33 mutex_init(&bus->msg_lock); 34 mutex_init(&bus->bus_lock); 35 INIT_LIST_HEAD(&bus->slaves); 36 INIT_LIST_HEAD(&bus->m_rt_list); 37 38 /* 39 * Initialize multi_link flag 40 * TODO: populate this flag by reading property from FW node 41 */ 42 bus->multi_link = false; 43 if (bus->ops->read_prop) { 44 ret = bus->ops->read_prop(bus); 45 if (ret < 0) { 46 dev_err(bus->dev, 47 "Bus read properties failed:%d\n", ret); 48 return ret; 49 } 50 } 51 52 /* 53 * Device numbers in SoundWire are 0 through 15. Enumeration device 54 * number (0), Broadcast device number (15), Group numbers (12 and 55 * 13) and Master device number (14) are not used for assignment so 56 * mask these and other higher bits. 57 */ 58 59 /* Set higher order bits */ 60 *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM); 61 62 /* Set enumuration device number and broadcast device number */ 63 set_bit(SDW_ENUM_DEV_NUM, bus->assigned); 64 set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned); 65 66 /* Set group device numbers and master device number */ 67 set_bit(SDW_GROUP12_DEV_NUM, bus->assigned); 68 set_bit(SDW_GROUP13_DEV_NUM, bus->assigned); 69 set_bit(SDW_MASTER_DEV_NUM, bus->assigned); 70 71 /* 72 * SDW is an enumerable bus, but devices can be powered off. So, 73 * they won't be able to report as present. 74 * 75 * Create Slave devices based on Slaves described in 76 * the respective firmware (ACPI/DT) 77 */ 78 if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev)) 79 ret = sdw_acpi_find_slaves(bus); 80 else 81 ret = -ENOTSUPP; /* No ACPI/DT so error out */ 82 83 if (ret) { 84 dev_err(bus->dev, "Finding slaves failed:%d\n", ret); 85 return ret; 86 } 87 88 /* 89 * Initialize clock values based on Master properties. The max 90 * frequency is read from max_clk_freq property. Current assumption 91 * is that the bus will start at highest clock frequency when 92 * powered on. 93 * 94 * Default active bank will be 0 as out of reset the Slaves have 95 * to start with bank 0 (Table 40 of Spec) 96 */ 97 prop = &bus->prop; 98 bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR; 99 bus->params.curr_dr_freq = bus->params.max_dr_freq; 100 bus->params.curr_bank = SDW_BANK0; 101 bus->params.next_bank = SDW_BANK1; 102 103 return 0; 104 } 105 EXPORT_SYMBOL(sdw_add_bus_master); 106 107 static int sdw_delete_slave(struct device *dev, void *data) 108 { 109 struct sdw_slave *slave = dev_to_sdw_dev(dev); 110 struct sdw_bus *bus = slave->bus; 111 112 mutex_lock(&bus->bus_lock); 113 114 if (slave->dev_num) /* clear dev_num if assigned */ 115 clear_bit(slave->dev_num, bus->assigned); 116 117 list_del_init(&slave->node); 118 mutex_unlock(&bus->bus_lock); 119 120 device_unregister(dev); 121 return 0; 122 } 123 124 /** 125 * sdw_delete_bus_master() - delete the bus master instance 126 * @bus: bus to be deleted 127 * 128 * Remove the instance, delete the child devices. 129 */ 130 void sdw_delete_bus_master(struct sdw_bus *bus) 131 { 132 device_for_each_child(bus->dev, NULL, sdw_delete_slave); 133 } 134 EXPORT_SYMBOL(sdw_delete_bus_master); 135 136 /* 137 * SDW IO Calls 138 */ 139 140 static inline int find_response_code(enum sdw_command_response resp) 141 { 142 switch (resp) { 143 case SDW_CMD_OK: 144 return 0; 145 146 case SDW_CMD_IGNORED: 147 return -ENODATA; 148 149 case SDW_CMD_TIMEOUT: 150 return -ETIMEDOUT; 151 152 default: 153 return -EIO; 154 } 155 } 156 157 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg) 158 { 159 int retry = bus->prop.err_threshold; 160 enum sdw_command_response resp; 161 int ret = 0, i; 162 163 for (i = 0; i <= retry; i++) { 164 resp = bus->ops->xfer_msg(bus, msg); 165 ret = find_response_code(resp); 166 167 /* if cmd is ok or ignored return */ 168 if (ret == 0 || ret == -ENODATA) 169 return ret; 170 } 171 172 return ret; 173 } 174 175 static inline int do_transfer_defer(struct sdw_bus *bus, 176 struct sdw_msg *msg, 177 struct sdw_defer *defer) 178 { 179 int retry = bus->prop.err_threshold; 180 enum sdw_command_response resp; 181 int ret = 0, i; 182 183 defer->msg = msg; 184 defer->length = msg->len; 185 init_completion(&defer->complete); 186 187 for (i = 0; i <= retry; i++) { 188 resp = bus->ops->xfer_msg_defer(bus, msg, defer); 189 ret = find_response_code(resp); 190 /* if cmd is ok or ignored return */ 191 if (ret == 0 || ret == -ENODATA) 192 return ret; 193 } 194 195 return ret; 196 } 197 198 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num) 199 { 200 int retry = bus->prop.err_threshold; 201 enum sdw_command_response resp; 202 int ret = 0, i; 203 204 for (i = 0; i <= retry; i++) { 205 resp = bus->ops->reset_page_addr(bus, dev_num); 206 ret = find_response_code(resp); 207 /* if cmd is ok or ignored return */ 208 if (ret == 0 || ret == -ENODATA) 209 return ret; 210 } 211 212 return ret; 213 } 214 215 /** 216 * sdw_transfer() - Synchronous transfer message to a SDW Slave device 217 * @bus: SDW bus 218 * @msg: SDW message to be xfered 219 */ 220 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg) 221 { 222 int ret; 223 224 mutex_lock(&bus->msg_lock); 225 226 ret = do_transfer(bus, msg); 227 if (ret != 0 && ret != -ENODATA) 228 dev_err(bus->dev, "trf on Slave %d failed:%d\n", 229 msg->dev_num, ret); 230 231 if (msg->page) 232 sdw_reset_page(bus, msg->dev_num); 233 234 mutex_unlock(&bus->msg_lock); 235 236 return ret; 237 } 238 239 /** 240 * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device 241 * @bus: SDW bus 242 * @msg: SDW message to be xfered 243 * @defer: Defer block for signal completion 244 * 245 * Caller needs to hold the msg_lock lock while calling this 246 */ 247 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg, 248 struct sdw_defer *defer) 249 { 250 int ret; 251 252 if (!bus->ops->xfer_msg_defer) 253 return -ENOTSUPP; 254 255 ret = do_transfer_defer(bus, msg, defer); 256 if (ret != 0 && ret != -ENODATA) 257 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n", 258 msg->dev_num, ret); 259 260 if (msg->page) 261 sdw_reset_page(bus, msg->dev_num); 262 263 return ret; 264 } 265 266 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, 267 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf) 268 { 269 memset(msg, 0, sizeof(*msg)); 270 msg->addr = addr; /* addr is 16 bit and truncated here */ 271 msg->len = count; 272 msg->dev_num = dev_num; 273 msg->flags = flags; 274 msg->buf = buf; 275 276 if (addr < SDW_REG_NO_PAGE) { /* no paging area */ 277 return 0; 278 } else if (addr >= SDW_REG_MAX) { /* illegal addr */ 279 pr_err("SDW: Invalid address %x passed\n", addr); 280 return -EINVAL; 281 } 282 283 if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */ 284 if (slave && !slave->prop.paging_support) 285 return 0; 286 /* no need for else as that will fall-through to paging */ 287 } 288 289 /* paging mandatory */ 290 if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) { 291 pr_err("SDW: Invalid device for paging :%d\n", dev_num); 292 return -EINVAL; 293 } 294 295 if (!slave) { 296 pr_err("SDW: No slave for paging addr\n"); 297 return -EINVAL; 298 } else if (!slave->prop.paging_support) { 299 dev_err(&slave->dev, 300 "address %x needs paging but no support\n", addr); 301 return -EINVAL; 302 } 303 304 msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK)); 305 msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK)); 306 msg->addr |= BIT(15); 307 msg->page = true; 308 309 return 0; 310 } 311 312 /** 313 * sdw_nread() - Read "n" contiguous SDW Slave registers 314 * @slave: SDW Slave 315 * @addr: Register address 316 * @count: length 317 * @val: Buffer for values to be read 318 */ 319 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) 320 { 321 struct sdw_msg msg; 322 int ret; 323 324 ret = sdw_fill_msg(&msg, slave, addr, count, 325 slave->dev_num, SDW_MSG_FLAG_READ, val); 326 if (ret < 0) 327 return ret; 328 329 ret = pm_runtime_get_sync(slave->bus->dev); 330 if (ret < 0) 331 return ret; 332 333 ret = sdw_transfer(slave->bus, &msg); 334 pm_runtime_put(slave->bus->dev); 335 336 return ret; 337 } 338 EXPORT_SYMBOL(sdw_nread); 339 340 /** 341 * sdw_nwrite() - Write "n" contiguous SDW Slave registers 342 * @slave: SDW Slave 343 * @addr: Register address 344 * @count: length 345 * @val: Buffer for values to be read 346 */ 347 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) 348 { 349 struct sdw_msg msg; 350 int ret; 351 352 ret = sdw_fill_msg(&msg, slave, addr, count, 353 slave->dev_num, SDW_MSG_FLAG_WRITE, val); 354 if (ret < 0) 355 return ret; 356 357 ret = pm_runtime_get_sync(slave->bus->dev); 358 if (ret < 0) 359 return ret; 360 361 ret = sdw_transfer(slave->bus, &msg); 362 pm_runtime_put(slave->bus->dev); 363 364 return ret; 365 } 366 EXPORT_SYMBOL(sdw_nwrite); 367 368 /** 369 * sdw_read() - Read a SDW Slave register 370 * @slave: SDW Slave 371 * @addr: Register address 372 */ 373 int sdw_read(struct sdw_slave *slave, u32 addr) 374 { 375 u8 buf; 376 int ret; 377 378 ret = sdw_nread(slave, addr, 1, &buf); 379 if (ret < 0) 380 return ret; 381 else 382 return buf; 383 } 384 EXPORT_SYMBOL(sdw_read); 385 386 /** 387 * sdw_write() - Write a SDW Slave register 388 * @slave: SDW Slave 389 * @addr: Register address 390 * @value: Register value 391 */ 392 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value) 393 { 394 return sdw_nwrite(slave, addr, 1, &value); 395 } 396 EXPORT_SYMBOL(sdw_write); 397 398 /* 399 * SDW alert handling 400 */ 401 402 /* called with bus_lock held */ 403 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i) 404 { 405 struct sdw_slave *slave = NULL; 406 407 list_for_each_entry(slave, &bus->slaves, node) { 408 if (slave->dev_num == i) 409 return slave; 410 } 411 412 return NULL; 413 } 414 415 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id) 416 { 417 if (slave->id.unique_id != id.unique_id || 418 slave->id.mfg_id != id.mfg_id || 419 slave->id.part_id != id.part_id || 420 slave->id.class_id != id.class_id) 421 return -ENODEV; 422 423 return 0; 424 } 425 426 /* called with bus_lock held */ 427 static int sdw_get_device_num(struct sdw_slave *slave) 428 { 429 int bit; 430 431 bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES); 432 if (bit == SDW_MAX_DEVICES) { 433 bit = -ENODEV; 434 goto err; 435 } 436 437 /* 438 * Do not update dev_num in Slave data structure here, 439 * Update once program dev_num is successful 440 */ 441 set_bit(bit, slave->bus->assigned); 442 443 err: 444 return bit; 445 } 446 447 static int sdw_assign_device_num(struct sdw_slave *slave) 448 { 449 int ret, dev_num; 450 451 /* check first if device number is assigned, if so reuse that */ 452 if (!slave->dev_num) { 453 mutex_lock(&slave->bus->bus_lock); 454 dev_num = sdw_get_device_num(slave); 455 mutex_unlock(&slave->bus->bus_lock); 456 if (dev_num < 0) { 457 dev_err(slave->bus->dev, "Get dev_num failed: %d\n", 458 dev_num); 459 return dev_num; 460 } 461 } else { 462 dev_info(slave->bus->dev, 463 "Slave already registered dev_num:%d\n", 464 slave->dev_num); 465 466 /* Clear the slave->dev_num to transfer message on device 0 */ 467 dev_num = slave->dev_num; 468 slave->dev_num = 0; 469 } 470 471 ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num); 472 if (ret < 0) { 473 dev_err(&slave->dev, "Program device_num failed: %d\n", ret); 474 return ret; 475 } 476 477 /* After xfer of msg, restore dev_num */ 478 slave->dev_num = dev_num; 479 480 return 0; 481 } 482 483 void sdw_extract_slave_id(struct sdw_bus *bus, 484 u64 addr, struct sdw_slave_id *id) 485 { 486 dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr); 487 488 /* 489 * Spec definition 490 * Register Bit Contents 491 * DevId_0 [7:4] 47:44 sdw_version 492 * DevId_0 [3:0] 43:40 unique_id 493 * DevId_1 39:32 mfg_id [15:8] 494 * DevId_2 31:24 mfg_id [7:0] 495 * DevId_3 23:16 part_id [15:8] 496 * DevId_4 15:08 part_id [7:0] 497 * DevId_5 07:00 class_id 498 */ 499 id->sdw_version = (addr >> 44) & GENMASK(3, 0); 500 id->unique_id = (addr >> 40) & GENMASK(3, 0); 501 id->mfg_id = (addr >> 24) & GENMASK(15, 0); 502 id->part_id = (addr >> 8) & GENMASK(15, 0); 503 id->class_id = addr & GENMASK(7, 0); 504 505 dev_dbg(bus->dev, 506 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n", 507 id->class_id, id->part_id, id->mfg_id, 508 id->unique_id, id->sdw_version); 509 } 510 511 static int sdw_program_device_num(struct sdw_bus *bus) 512 { 513 u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0}; 514 struct sdw_slave *slave, *_s; 515 struct sdw_slave_id id; 516 struct sdw_msg msg; 517 bool found = false; 518 int count = 0, ret; 519 u64 addr; 520 521 /* No Slave, so use raw xfer api */ 522 ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0, 523 SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf); 524 if (ret < 0) 525 return ret; 526 527 do { 528 ret = sdw_transfer(bus, &msg); 529 if (ret == -ENODATA) { /* end of device id reads */ 530 ret = 0; 531 break; 532 } 533 if (ret < 0) { 534 dev_err(bus->dev, "DEVID read fail:%d\n", ret); 535 break; 536 } 537 538 /* 539 * Construct the addr and extract. Cast the higher shift 540 * bits to avoid truncation due to size limit. 541 */ 542 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) | 543 ((u64)buf[2] << 24) | ((u64)buf[1] << 32) | 544 ((u64)buf[0] << 40); 545 546 sdw_extract_slave_id(bus, addr, &id); 547 548 /* Now compare with entries */ 549 list_for_each_entry_safe(slave, _s, &bus->slaves, node) { 550 if (sdw_compare_devid(slave, id) == 0) { 551 found = true; 552 553 /* 554 * Assign a new dev_num to this Slave and 555 * not mark it present. It will be marked 556 * present after it reports ATTACHED on new 557 * dev_num 558 */ 559 ret = sdw_assign_device_num(slave); 560 if (ret) { 561 dev_err(slave->bus->dev, 562 "Assign dev_num failed:%d\n", 563 ret); 564 return ret; 565 } 566 567 break; 568 } 569 } 570 571 if (!found) { 572 /* TODO: Park this device in Group 13 */ 573 dev_err(bus->dev, "Slave Entry not found\n"); 574 } 575 576 count++; 577 578 /* 579 * Check till error out or retry (count) exhausts. 580 * Device can drop off and rejoin during enumeration 581 * so count till twice the bound. 582 */ 583 584 } while (ret == 0 && count < (SDW_MAX_DEVICES * 2)); 585 586 return ret; 587 } 588 589 static void sdw_modify_slave_status(struct sdw_slave *slave, 590 enum sdw_slave_status status) 591 { 592 mutex_lock(&slave->bus->bus_lock); 593 slave->status = status; 594 mutex_unlock(&slave->bus->bus_lock); 595 } 596 597 int sdw_configure_dpn_intr(struct sdw_slave *slave, 598 int port, bool enable, int mask) 599 { 600 u32 addr; 601 int ret; 602 u8 val = 0; 603 604 addr = SDW_DPN_INTMASK(port); 605 606 /* Set/Clear port ready interrupt mask */ 607 if (enable) { 608 val |= mask; 609 val |= SDW_DPN_INT_PORT_READY; 610 } else { 611 val &= ~(mask); 612 val &= ~SDW_DPN_INT_PORT_READY; 613 } 614 615 ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val); 616 if (ret < 0) 617 dev_err(slave->bus->dev, 618 "SDW_DPN_INTMASK write failed:%d\n", val); 619 620 return ret; 621 } 622 623 static int sdw_initialize_slave(struct sdw_slave *slave) 624 { 625 struct sdw_slave_prop *prop = &slave->prop; 626 int ret; 627 u8 val; 628 629 /* 630 * Set bus clash, parity and SCP implementation 631 * defined interrupt mask 632 * TODO: Read implementation defined interrupt mask 633 * from Slave property 634 */ 635 val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH | 636 SDW_SCP_INT1_PARITY; 637 638 /* Enable SCP interrupts */ 639 ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val); 640 if (ret < 0) { 641 dev_err(slave->bus->dev, 642 "SDW_SCP_INTMASK1 write failed:%d\n", ret); 643 return ret; 644 } 645 646 /* No need to continue if DP0 is not present */ 647 if (!slave->prop.dp0_prop) 648 return 0; 649 650 /* Enable DP0 interrupts */ 651 val = prop->dp0_prop->imp_def_interrupts; 652 val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE; 653 654 ret = sdw_update(slave, SDW_DP0_INTMASK, val, val); 655 if (ret < 0) { 656 dev_err(slave->bus->dev, 657 "SDW_DP0_INTMASK read failed:%d\n", ret); 658 return val; 659 } 660 661 return 0; 662 } 663 664 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status) 665 { 666 u8 clear = 0, impl_int_mask; 667 int status, status2, ret, count = 0; 668 669 status = sdw_read(slave, SDW_DP0_INT); 670 if (status < 0) { 671 dev_err(slave->bus->dev, 672 "SDW_DP0_INT read failed:%d\n", status); 673 return status; 674 } 675 676 do { 677 if (status & SDW_DP0_INT_TEST_FAIL) { 678 dev_err(&slave->dev, "Test fail for port 0\n"); 679 clear |= SDW_DP0_INT_TEST_FAIL; 680 } 681 682 /* 683 * Assumption: PORT_READY interrupt will be received only for 684 * ports implementing Channel Prepare state machine (CP_SM) 685 */ 686 687 if (status & SDW_DP0_INT_PORT_READY) { 688 complete(&slave->port_ready[0]); 689 clear |= SDW_DP0_INT_PORT_READY; 690 } 691 692 if (status & SDW_DP0_INT_BRA_FAILURE) { 693 dev_err(&slave->dev, "BRA failed\n"); 694 clear |= SDW_DP0_INT_BRA_FAILURE; 695 } 696 697 impl_int_mask = SDW_DP0_INT_IMPDEF1 | 698 SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3; 699 700 if (status & impl_int_mask) { 701 clear |= impl_int_mask; 702 *slave_status = clear; 703 } 704 705 /* clear the interrupt */ 706 ret = sdw_write(slave, SDW_DP0_INT, clear); 707 if (ret < 0) { 708 dev_err(slave->bus->dev, 709 "SDW_DP0_INT write failed:%d\n", ret); 710 return ret; 711 } 712 713 /* Read DP0 interrupt again */ 714 status2 = sdw_read(slave, SDW_DP0_INT); 715 if (status2 < 0) { 716 dev_err(slave->bus->dev, 717 "SDW_DP0_INT read failed:%d\n", status2); 718 return status2; 719 } 720 status &= status2; 721 722 count++; 723 724 /* we can get alerts while processing so keep retrying */ 725 } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY); 726 727 if (count == SDW_READ_INTR_CLEAR_RETRY) 728 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read\n"); 729 730 return ret; 731 } 732 733 static int sdw_handle_port_interrupt(struct sdw_slave *slave, 734 int port, u8 *slave_status) 735 { 736 u8 clear = 0, impl_int_mask; 737 int status, status2, ret, count = 0; 738 u32 addr; 739 740 if (port == 0) 741 return sdw_handle_dp0_interrupt(slave, slave_status); 742 743 addr = SDW_DPN_INT(port); 744 status = sdw_read(slave, addr); 745 if (status < 0) { 746 dev_err(slave->bus->dev, 747 "SDW_DPN_INT read failed:%d\n", status); 748 749 return status; 750 } 751 752 do { 753 if (status & SDW_DPN_INT_TEST_FAIL) { 754 dev_err(&slave->dev, "Test fail for port:%d\n", port); 755 clear |= SDW_DPN_INT_TEST_FAIL; 756 } 757 758 /* 759 * Assumption: PORT_READY interrupt will be received only 760 * for ports implementing CP_SM. 761 */ 762 if (status & SDW_DPN_INT_PORT_READY) { 763 complete(&slave->port_ready[port]); 764 clear |= SDW_DPN_INT_PORT_READY; 765 } 766 767 impl_int_mask = SDW_DPN_INT_IMPDEF1 | 768 SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3; 769 770 if (status & impl_int_mask) { 771 clear |= impl_int_mask; 772 *slave_status = clear; 773 } 774 775 /* clear the interrupt */ 776 ret = sdw_write(slave, addr, clear); 777 if (ret < 0) { 778 dev_err(slave->bus->dev, 779 "SDW_DPN_INT write failed:%d\n", ret); 780 return ret; 781 } 782 783 /* Read DPN interrupt again */ 784 status2 = sdw_read(slave, addr); 785 if (status2 < 0) { 786 dev_err(slave->bus->dev, 787 "SDW_DPN_INT read failed:%d\n", status2); 788 return status2; 789 } 790 status &= status2; 791 792 count++; 793 794 /* we can get alerts while processing so keep retrying */ 795 } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY); 796 797 if (count == SDW_READ_INTR_CLEAR_RETRY) 798 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read"); 799 800 return ret; 801 } 802 803 static int sdw_handle_slave_alerts(struct sdw_slave *slave) 804 { 805 struct sdw_slave_intr_status slave_intr; 806 u8 clear = 0, bit, port_status[15]; 807 int port_num, stat, ret, count = 0; 808 unsigned long port; 809 bool slave_notify = false; 810 u8 buf, buf2[2], _buf, _buf2[2]; 811 812 sdw_modify_slave_status(slave, SDW_SLAVE_ALERT); 813 814 /* Read Instat 1, Instat 2 and Instat 3 registers */ 815 ret = sdw_read(slave, SDW_SCP_INT1); 816 if (ret < 0) { 817 dev_err(slave->bus->dev, 818 "SDW_SCP_INT1 read failed:%d\n", ret); 819 return ret; 820 } 821 buf = ret; 822 823 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2); 824 if (ret < 0) { 825 dev_err(slave->bus->dev, 826 "SDW_SCP_INT2/3 read failed:%d\n", ret); 827 return ret; 828 } 829 830 do { 831 /* 832 * Check parity, bus clash and Slave (impl defined) 833 * interrupt 834 */ 835 if (buf & SDW_SCP_INT1_PARITY) { 836 dev_err(&slave->dev, "Parity error detected\n"); 837 clear |= SDW_SCP_INT1_PARITY; 838 } 839 840 if (buf & SDW_SCP_INT1_BUS_CLASH) { 841 dev_err(&slave->dev, "Bus clash error detected\n"); 842 clear |= SDW_SCP_INT1_BUS_CLASH; 843 } 844 845 /* 846 * When bus clash or parity errors are detected, such errors 847 * are unlikely to be recoverable errors. 848 * TODO: In such scenario, reset bus. Make this configurable 849 * via sysfs property with bus reset being the default. 850 */ 851 852 if (buf & SDW_SCP_INT1_IMPL_DEF) { 853 dev_dbg(&slave->dev, "Slave impl defined interrupt\n"); 854 clear |= SDW_SCP_INT1_IMPL_DEF; 855 slave_notify = true; 856 } 857 858 /* Check port 0 - 3 interrupts */ 859 port = buf & SDW_SCP_INT1_PORT0_3; 860 861 /* To get port number corresponding to bits, shift it */ 862 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3); 863 for_each_set_bit(bit, &port, 8) { 864 sdw_handle_port_interrupt(slave, bit, 865 &port_status[bit]); 866 } 867 868 /* Check if cascade 2 interrupt is present */ 869 if (buf & SDW_SCP_INT1_SCP2_CASCADE) { 870 port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10; 871 for_each_set_bit(bit, &port, 8) { 872 /* scp2 ports start from 4 */ 873 port_num = bit + 3; 874 sdw_handle_port_interrupt(slave, 875 port_num, 876 &port_status[port_num]); 877 } 878 } 879 880 /* now check last cascade */ 881 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) { 882 port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14; 883 for_each_set_bit(bit, &port, 8) { 884 /* scp3 ports start from 11 */ 885 port_num = bit + 10; 886 sdw_handle_port_interrupt(slave, 887 port_num, 888 &port_status[port_num]); 889 } 890 } 891 892 /* Update the Slave driver */ 893 if (slave_notify && slave->ops && 894 slave->ops->interrupt_callback) { 895 slave_intr.control_port = clear; 896 memcpy(slave_intr.port, &port_status, 897 sizeof(slave_intr.port)); 898 899 slave->ops->interrupt_callback(slave, &slave_intr); 900 } 901 902 /* Ack interrupt */ 903 ret = sdw_write(slave, SDW_SCP_INT1, clear); 904 if (ret < 0) { 905 dev_err(slave->bus->dev, 906 "SDW_SCP_INT1 write failed:%d\n", ret); 907 return ret; 908 } 909 910 /* 911 * Read status again to ensure no new interrupts arrived 912 * while servicing interrupts. 913 */ 914 ret = sdw_read(slave, SDW_SCP_INT1); 915 if (ret < 0) { 916 dev_err(slave->bus->dev, 917 "SDW_SCP_INT1 read failed:%d\n", ret); 918 return ret; 919 } 920 _buf = ret; 921 922 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2); 923 if (ret < 0) { 924 dev_err(slave->bus->dev, 925 "SDW_SCP_INT2/3 read failed:%d\n", ret); 926 return ret; 927 } 928 929 /* Make sure no interrupts are pending */ 930 buf &= _buf; 931 buf2[0] &= _buf2[0]; 932 buf2[1] &= _buf2[1]; 933 stat = buf || buf2[0] || buf2[1]; 934 935 /* 936 * Exit loop if Slave is continuously in ALERT state even 937 * after servicing the interrupt multiple times. 938 */ 939 count++; 940 941 /* we can get alerts while processing so keep retrying */ 942 } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY); 943 944 if (count == SDW_READ_INTR_CLEAR_RETRY) 945 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n"); 946 947 return ret; 948 } 949 950 static int sdw_update_slave_status(struct sdw_slave *slave, 951 enum sdw_slave_status status) 952 { 953 if (slave->ops && slave->ops->update_status) 954 return slave->ops->update_status(slave, status); 955 956 return 0; 957 } 958 959 /** 960 * sdw_handle_slave_status() - Handle Slave status 961 * @bus: SDW bus instance 962 * @status: Status for all Slave(s) 963 */ 964 int sdw_handle_slave_status(struct sdw_bus *bus, 965 enum sdw_slave_status status[]) 966 { 967 enum sdw_slave_status prev_status; 968 struct sdw_slave *slave; 969 int i, ret = 0; 970 971 if (status[0] == SDW_SLAVE_ATTACHED) { 972 ret = sdw_program_device_num(bus); 973 if (ret) 974 dev_err(bus->dev, "Slave attach failed: %d\n", ret); 975 } 976 977 /* Continue to check other slave statuses */ 978 for (i = 1; i <= SDW_MAX_DEVICES; i++) { 979 mutex_lock(&bus->bus_lock); 980 if (test_bit(i, bus->assigned) == false) { 981 mutex_unlock(&bus->bus_lock); 982 continue; 983 } 984 mutex_unlock(&bus->bus_lock); 985 986 slave = sdw_get_slave(bus, i); 987 if (!slave) 988 continue; 989 990 switch (status[i]) { 991 case SDW_SLAVE_UNATTACHED: 992 if (slave->status == SDW_SLAVE_UNATTACHED) 993 break; 994 995 sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); 996 break; 997 998 case SDW_SLAVE_ALERT: 999 ret = sdw_handle_slave_alerts(slave); 1000 if (ret) 1001 dev_err(bus->dev, 1002 "Slave %d alert handling failed: %d\n", 1003 i, ret); 1004 break; 1005 1006 case SDW_SLAVE_ATTACHED: 1007 if (slave->status == SDW_SLAVE_ATTACHED) 1008 break; 1009 1010 prev_status = slave->status; 1011 sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED); 1012 1013 if (prev_status == SDW_SLAVE_ALERT) 1014 break; 1015 1016 ret = sdw_initialize_slave(slave); 1017 if (ret) 1018 dev_err(bus->dev, 1019 "Slave %d initialization failed: %d\n", 1020 i, ret); 1021 1022 break; 1023 1024 default: 1025 dev_err(bus->dev, "Invalid slave %d status:%d\n", 1026 i, status[i]); 1027 break; 1028 } 1029 1030 ret = sdw_update_slave_status(slave, status[i]); 1031 if (ret) 1032 dev_err(slave->bus->dev, 1033 "Update Slave status failed:%d\n", ret); 1034 } 1035 1036 return ret; 1037 } 1038 EXPORT_SYMBOL(sdw_handle_slave_status); 1039