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"); 25 return -ENODEV; 26 } 27 28 if (!bus->ops) { 29 dev_err(bus->dev, "SoundWire Bus ops are not set"); 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 if (bus->ops->read_prop) { 39 ret = bus->ops->read_prop(bus); 40 if (ret < 0) { 41 dev_err(bus->dev, "Bus read properties failed:%d", ret); 42 return ret; 43 } 44 } 45 46 /* 47 * Device numbers in SoundWire are 0 thru 15. Enumeration device 48 * number (0), Broadcast device number (15), Group numbers (12 and 49 * 13) and Master device number (14) are not used for assignment so 50 * mask these and other higher bits. 51 */ 52 53 /* Set higher order bits */ 54 *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM); 55 56 /* Set enumuration device number and broadcast device number */ 57 set_bit(SDW_ENUM_DEV_NUM, bus->assigned); 58 set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned); 59 60 /* Set group device numbers and master device number */ 61 set_bit(SDW_GROUP12_DEV_NUM, bus->assigned); 62 set_bit(SDW_GROUP13_DEV_NUM, bus->assigned); 63 set_bit(SDW_MASTER_DEV_NUM, bus->assigned); 64 65 /* 66 * SDW is an enumerable bus, but devices can be powered off. So, 67 * they won't be able to report as present. 68 * 69 * Create Slave devices based on Slaves described in 70 * the respective firmware (ACPI/DT) 71 */ 72 if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev)) 73 ret = sdw_acpi_find_slaves(bus); 74 else 75 ret = -ENOTSUPP; /* No ACPI/DT so error out */ 76 77 if (ret) { 78 dev_err(bus->dev, "Finding slaves failed:%d\n", ret); 79 return ret; 80 } 81 82 /* 83 * Initialize clock values based on Master properties. The max 84 * frequency is read from max_freq property. Current assumption 85 * is that the bus will start at highest clock frequency when 86 * powered on. 87 * 88 * Default active bank will be 0 as out of reset the Slaves have 89 * to start with bank 0 (Table 40 of Spec) 90 */ 91 prop = &bus->prop; 92 bus->params.max_dr_freq = prop->max_freq * SDW_DOUBLE_RATE_FACTOR; 93 bus->params.curr_dr_freq = bus->params.max_dr_freq; 94 bus->params.curr_bank = SDW_BANK0; 95 bus->params.next_bank = SDW_BANK1; 96 97 return 0; 98 } 99 EXPORT_SYMBOL(sdw_add_bus_master); 100 101 static int sdw_delete_slave(struct device *dev, void *data) 102 { 103 struct sdw_slave *slave = dev_to_sdw_dev(dev); 104 struct sdw_bus *bus = slave->bus; 105 106 mutex_lock(&bus->bus_lock); 107 108 if (slave->dev_num) /* clear dev_num if assigned */ 109 clear_bit(slave->dev_num, bus->assigned); 110 111 list_del_init(&slave->node); 112 mutex_unlock(&bus->bus_lock); 113 114 device_unregister(dev); 115 return 0; 116 } 117 118 /** 119 * sdw_delete_bus_master() - delete the bus master instance 120 * @bus: bus to be deleted 121 * 122 * Remove the instance, delete the child devices. 123 */ 124 void sdw_delete_bus_master(struct sdw_bus *bus) 125 { 126 device_for_each_child(bus->dev, NULL, sdw_delete_slave); 127 } 128 EXPORT_SYMBOL(sdw_delete_bus_master); 129 130 /* 131 * SDW IO Calls 132 */ 133 134 static inline int find_response_code(enum sdw_command_response resp) 135 { 136 switch (resp) { 137 case SDW_CMD_OK: 138 return 0; 139 140 case SDW_CMD_IGNORED: 141 return -ENODATA; 142 143 case SDW_CMD_TIMEOUT: 144 return -ETIMEDOUT; 145 146 default: 147 return -EIO; 148 } 149 } 150 151 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg) 152 { 153 int retry = bus->prop.err_threshold; 154 enum sdw_command_response resp; 155 int ret = 0, i; 156 157 for (i = 0; i <= retry; i++) { 158 resp = bus->ops->xfer_msg(bus, msg); 159 ret = find_response_code(resp); 160 161 /* if cmd is ok or ignored return */ 162 if (ret == 0 || ret == -ENODATA) 163 return ret; 164 } 165 166 return ret; 167 } 168 169 static inline int do_transfer_defer(struct sdw_bus *bus, 170 struct sdw_msg *msg, struct sdw_defer *defer) 171 { 172 int retry = bus->prop.err_threshold; 173 enum sdw_command_response resp; 174 int ret = 0, i; 175 176 defer->msg = msg; 177 defer->length = msg->len; 178 179 for (i = 0; i <= retry; i++) { 180 resp = bus->ops->xfer_msg_defer(bus, msg, defer); 181 ret = find_response_code(resp); 182 /* if cmd is ok or ignored return */ 183 if (ret == 0 || ret == -ENODATA) 184 return ret; 185 } 186 187 return ret; 188 } 189 190 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num) 191 { 192 int retry = bus->prop.err_threshold; 193 enum sdw_command_response resp; 194 int ret = 0, i; 195 196 for (i = 0; i <= retry; i++) { 197 resp = bus->ops->reset_page_addr(bus, dev_num); 198 ret = find_response_code(resp); 199 /* if cmd is ok or ignored return */ 200 if (ret == 0 || ret == -ENODATA) 201 return ret; 202 } 203 204 return ret; 205 } 206 207 /** 208 * sdw_transfer() - Synchronous transfer message to a SDW Slave device 209 * @bus: SDW bus 210 * @msg: SDW message to be xfered 211 */ 212 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg) 213 { 214 int ret; 215 216 mutex_lock(&bus->msg_lock); 217 218 ret = do_transfer(bus, msg); 219 if (ret != 0 && ret != -ENODATA) 220 dev_err(bus->dev, "trf on Slave %d failed:%d\n", 221 msg->dev_num, ret); 222 223 if (msg->page) 224 sdw_reset_page(bus, msg->dev_num); 225 226 mutex_unlock(&bus->msg_lock); 227 228 return ret; 229 } 230 231 /** 232 * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device 233 * @bus: SDW bus 234 * @msg: SDW message to be xfered 235 * @defer: Defer block for signal completion 236 * 237 * Caller needs to hold the msg_lock lock while calling this 238 */ 239 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg, 240 struct sdw_defer *defer) 241 { 242 int ret; 243 244 if (!bus->ops->xfer_msg_defer) 245 return -ENOTSUPP; 246 247 ret = do_transfer_defer(bus, msg, defer); 248 if (ret != 0 && ret != -ENODATA) 249 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n", 250 msg->dev_num, ret); 251 252 if (msg->page) 253 sdw_reset_page(bus, msg->dev_num); 254 255 return ret; 256 } 257 258 259 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave, 260 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf) 261 { 262 memset(msg, 0, sizeof(*msg)); 263 msg->addr = addr; /* addr is 16 bit and truncated here */ 264 msg->len = count; 265 msg->dev_num = dev_num; 266 msg->flags = flags; 267 msg->buf = buf; 268 msg->ssp_sync = false; 269 msg->page = false; 270 271 if (addr < SDW_REG_NO_PAGE) { /* no paging area */ 272 return 0; 273 } else if (addr >= SDW_REG_MAX) { /* illegal addr */ 274 pr_err("SDW: Invalid address %x passed\n", addr); 275 return -EINVAL; 276 } 277 278 if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */ 279 if (slave && !slave->prop.paging_support) 280 return 0; 281 /* no need for else as that will fall thru to paging */ 282 } 283 284 /* paging mandatory */ 285 if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) { 286 pr_err("SDW: Invalid device for paging :%d\n", dev_num); 287 return -EINVAL; 288 } 289 290 if (!slave) { 291 pr_err("SDW: No slave for paging addr\n"); 292 return -EINVAL; 293 } else if (!slave->prop.paging_support) { 294 dev_err(&slave->dev, 295 "address %x needs paging but no support", addr); 296 return -EINVAL; 297 } 298 299 msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK)); 300 msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK)); 301 msg->addr |= BIT(15); 302 msg->page = true; 303 304 return 0; 305 } 306 307 /** 308 * sdw_nread() - Read "n" contiguous SDW Slave registers 309 * @slave: SDW Slave 310 * @addr: Register address 311 * @count: length 312 * @val: Buffer for values to be read 313 */ 314 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) 315 { 316 struct sdw_msg msg; 317 int ret; 318 319 ret = sdw_fill_msg(&msg, slave, addr, count, 320 slave->dev_num, SDW_MSG_FLAG_READ, val); 321 if (ret < 0) 322 return ret; 323 324 ret = pm_runtime_get_sync(slave->bus->dev); 325 if (ret < 0) 326 return ret; 327 328 ret = sdw_transfer(slave->bus, &msg); 329 pm_runtime_put(slave->bus->dev); 330 331 return ret; 332 } 333 EXPORT_SYMBOL(sdw_nread); 334 335 /** 336 * sdw_nwrite() - Write "n" contiguous SDW Slave registers 337 * @slave: SDW Slave 338 * @addr: Register address 339 * @count: length 340 * @val: Buffer for values to be read 341 */ 342 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) 343 { 344 struct sdw_msg msg; 345 int ret; 346 347 ret = sdw_fill_msg(&msg, slave, addr, count, 348 slave->dev_num, SDW_MSG_FLAG_WRITE, val); 349 if (ret < 0) 350 return ret; 351 352 ret = pm_runtime_get_sync(slave->bus->dev); 353 if (ret < 0) 354 return ret; 355 356 ret = sdw_transfer(slave->bus, &msg); 357 pm_runtime_put(slave->bus->dev); 358 359 return ret; 360 } 361 EXPORT_SYMBOL(sdw_nwrite); 362 363 /** 364 * sdw_read() - Read a SDW Slave register 365 * @slave: SDW Slave 366 * @addr: Register address 367 */ 368 int sdw_read(struct sdw_slave *slave, u32 addr) 369 { 370 u8 buf; 371 int ret; 372 373 ret = sdw_nread(slave, addr, 1, &buf); 374 if (ret < 0) 375 return ret; 376 else 377 return buf; 378 } 379 EXPORT_SYMBOL(sdw_read); 380 381 /** 382 * sdw_write() - Write a SDW Slave register 383 * @slave: SDW Slave 384 * @addr: Register address 385 * @value: Register value 386 */ 387 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value) 388 { 389 return sdw_nwrite(slave, addr, 1, &value); 390 391 } 392 EXPORT_SYMBOL(sdw_write); 393 394 /* 395 * SDW alert handling 396 */ 397 398 /* called with bus_lock held */ 399 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i) 400 { 401 struct sdw_slave *slave = NULL; 402 403 list_for_each_entry(slave, &bus->slaves, node) { 404 if (slave->dev_num == i) 405 return slave; 406 } 407 408 return NULL; 409 } 410 411 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id) 412 { 413 414 if ((slave->id.unique_id != id.unique_id) || 415 (slave->id.mfg_id != id.mfg_id) || 416 (slave->id.part_id != id.part_id) || 417 (slave->id.class_id != id.class_id)) 418 return -ENODEV; 419 420 return 0; 421 } 422 423 /* called with bus_lock held */ 424 static int sdw_get_device_num(struct sdw_slave *slave) 425 { 426 int bit; 427 428 bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES); 429 if (bit == SDW_MAX_DEVICES) { 430 bit = -ENODEV; 431 goto err; 432 } 433 434 /* 435 * Do not update dev_num in Slave data structure here, 436 * Update once program dev_num is successful 437 */ 438 set_bit(bit, slave->bus->assigned); 439 440 err: 441 return bit; 442 } 443 444 static int sdw_assign_device_num(struct sdw_slave *slave) 445 { 446 int ret, dev_num; 447 448 /* check first if device number is assigned, if so reuse that */ 449 if (!slave->dev_num) { 450 mutex_lock(&slave->bus->bus_lock); 451 dev_num = sdw_get_device_num(slave); 452 mutex_unlock(&slave->bus->bus_lock); 453 if (dev_num < 0) { 454 dev_err(slave->bus->dev, "Get dev_num failed: %d", 455 dev_num); 456 return dev_num; 457 } 458 } else { 459 dev_info(slave->bus->dev, 460 "Slave already registered dev_num:%d", 461 slave->dev_num); 462 463 /* Clear the slave->dev_num to transfer message on device 0 */ 464 dev_num = slave->dev_num; 465 slave->dev_num = 0; 466 467 } 468 469 ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num); 470 if (ret < 0) { 471 dev_err(&slave->dev, "Program device_num failed: %d", ret); 472 return ret; 473 } 474 475 /* After xfer of msg, restore dev_num */ 476 slave->dev_num = dev_num; 477 478 return 0; 479 } 480 481 void sdw_extract_slave_id(struct sdw_bus *bus, 482 u64 addr, struct sdw_slave_id *id) 483 { 484 dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr); 485 486 /* 487 * Spec definition 488 * Register Bit Contents 489 * DevId_0 [7:4] 47:44 sdw_version 490 * DevId_0 [3:0] 43:40 unique_id 491 * DevId_1 39:32 mfg_id [15:8] 492 * DevId_2 31:24 mfg_id [7:0] 493 * DevId_3 23:16 part_id [15:8] 494 * DevId_4 15:08 part_id [7:0] 495 * DevId_5 07:00 class_id 496 */ 497 id->sdw_version = (addr >> 44) & GENMASK(3, 0); 498 id->unique_id = (addr >> 40) & GENMASK(3, 0); 499 id->mfg_id = (addr >> 24) & GENMASK(15, 0); 500 id->part_id = (addr >> 8) & GENMASK(15, 0); 501 id->class_id = addr & GENMASK(7, 0); 502 503 dev_dbg(bus->dev, 504 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x", 505 id->class_id, id->part_id, id->mfg_id, 506 id->unique_id, id->sdw_version); 507 508 } 509 510 static int sdw_program_device_num(struct sdw_bus *bus) 511 { 512 u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0}; 513 struct sdw_slave *slave, *_s; 514 struct sdw_slave_id id; 515 struct sdw_msg msg; 516 bool found = false; 517 int count = 0, ret; 518 u64 addr; 519 520 /* No Slave, so use raw xfer api */ 521 ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0, 522 SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf); 523 if (ret < 0) 524 return ret; 525 526 do { 527 ret = sdw_transfer(bus, &msg); 528 if (ret == -ENODATA) { /* end of device id reads */ 529 ret = 0; 530 break; 531 } 532 if (ret < 0) { 533 dev_err(bus->dev, "DEVID read fail:%d\n", ret); 534 break; 535 } 536 537 /* 538 * Construct the addr and extract. Cast the higher shift 539 * bits to avoid truncation due to size limit. 540 */ 541 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) | 542 ((u64)buf[2] << 24) | ((u64)buf[1] << 32) | 543 ((u64)buf[0] << 40); 544 545 sdw_extract_slave_id(bus, addr, &id); 546 547 /* Now compare with entries */ 548 list_for_each_entry_safe(slave, _s, &bus->slaves, node) { 549 if (sdw_compare_devid(slave, id) == 0) { 550 found = true; 551 552 /* 553 * Assign a new dev_num to this Slave and 554 * not mark it present. It will be marked 555 * present after it reports ATTACHED on new 556 * dev_num 557 */ 558 ret = sdw_assign_device_num(slave); 559 if (ret) { 560 dev_err(slave->bus->dev, 561 "Assign dev_num failed:%d", 562 ret); 563 return ret; 564 } 565 566 break; 567 } 568 } 569 570 if (found == false) { 571 /* TODO: Park this device in Group 13 */ 572 dev_err(bus->dev, "Slave Entry not found"); 573 } 574 575 count++; 576 577 /* 578 * Check till error out or retry (count) exhausts. 579 * Device can drop off and rejoin during enumeration 580 * so count till twice the bound. 581 */ 582 583 } while (ret == 0 && count < (SDW_MAX_DEVICES * 2)); 584 585 return ret; 586 } 587 588 static void sdw_modify_slave_status(struct sdw_slave *slave, 589 enum sdw_slave_status status) 590 { 591 mutex_lock(&slave->bus->bus_lock); 592 slave->status = status; 593 mutex_unlock(&slave->bus->bus_lock); 594 } 595 596 int sdw_configure_dpn_intr(struct sdw_slave *slave, 597 int port, bool enable, int mask) 598 { 599 u32 addr; 600 int ret; 601 u8 val = 0; 602 603 addr = SDW_DPN_INTMASK(port); 604 605 /* Set/Clear port ready interrupt mask */ 606 if (enable) { 607 val |= mask; 608 val |= SDW_DPN_INT_PORT_READY; 609 } else { 610 val &= ~(mask); 611 val &= ~SDW_DPN_INT_PORT_READY; 612 } 613 614 ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val); 615 if (ret < 0) 616 dev_err(slave->bus->dev, 617 "SDW_DPN_INTMASK write failed:%d", val); 618 619 return ret; 620 } 621 622 static int sdw_initialize_slave(struct sdw_slave *slave) 623 { 624 struct sdw_slave_prop *prop = &slave->prop; 625 int ret; 626 u8 val; 627 628 /* 629 * Set bus clash, parity and SCP implementation 630 * defined interrupt mask 631 * TODO: Read implementation defined interrupt mask 632 * from Slave property 633 */ 634 val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH | 635 SDW_SCP_INT1_PARITY; 636 637 /* Enable SCP interrupts */ 638 ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val); 639 if (ret < 0) { 640 dev_err(slave->bus->dev, 641 "SDW_SCP_INTMASK1 write failed:%d", ret); 642 return ret; 643 } 644 645 /* No need to continue if DP0 is not present */ 646 if (!slave->prop.dp0_prop) 647 return 0; 648 649 /* Enable DP0 interrupts */ 650 val = prop->dp0_prop->device_interrupts; 651 val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE; 652 653 ret = sdw_update(slave, SDW_DP0_INTMASK, val, val); 654 if (ret < 0) { 655 dev_err(slave->bus->dev, 656 "SDW_DP0_INTMASK read failed:%d", ret); 657 return val; 658 } 659 660 return 0; 661 } 662 663 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status) 664 { 665 u8 clear = 0, impl_int_mask; 666 int status, status2, ret, count = 0; 667 668 status = sdw_read(slave, SDW_DP0_INT); 669 if (status < 0) { 670 dev_err(slave->bus->dev, 671 "SDW_DP0_INT read failed:%d", status); 672 return status; 673 } 674 675 do { 676 677 if (status & SDW_DP0_INT_TEST_FAIL) { 678 dev_err(&slave->dev, "Test fail for port 0"); 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"); 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", 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", 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"); 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", status); 748 749 return status; 750 } 751 752 do { 753 754 if (status & SDW_DPN_INT_TEST_FAIL) { 755 dev_err(&slave->dev, "Test fail for port:%d", port); 756 clear |= SDW_DPN_INT_TEST_FAIL; 757 } 758 759 /* 760 * Assumption: PORT_READY interrupt will be received only 761 * for ports implementing CP_SM. 762 */ 763 if (status & SDW_DPN_INT_PORT_READY) { 764 complete(&slave->port_ready[port]); 765 clear |= SDW_DPN_INT_PORT_READY; 766 } 767 768 impl_int_mask = SDW_DPN_INT_IMPDEF1 | 769 SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3; 770 771 772 if (status & impl_int_mask) { 773 clear |= impl_int_mask; 774 *slave_status = clear; 775 } 776 777 /* clear the interrupt */ 778 ret = sdw_write(slave, addr, clear); 779 if (ret < 0) { 780 dev_err(slave->bus->dev, 781 "SDW_DPN_INT write failed:%d", ret); 782 return ret; 783 } 784 785 /* Read DPN interrupt again */ 786 status2 = sdw_read(slave, addr); 787 if (status2 < 0) { 788 dev_err(slave->bus->dev, 789 "SDW_DPN_INT read failed:%d", status2); 790 return status2; 791 } 792 status &= status2; 793 794 count++; 795 796 /* we can get alerts while processing so keep retrying */ 797 } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY); 798 799 if (count == SDW_READ_INTR_CLEAR_RETRY) 800 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read"); 801 802 return ret; 803 } 804 805 static int sdw_handle_slave_alerts(struct sdw_slave *slave) 806 { 807 struct sdw_slave_intr_status slave_intr; 808 u8 clear = 0, bit, port_status[15]; 809 int port_num, stat, ret, count = 0; 810 unsigned long port; 811 bool slave_notify = false; 812 u8 buf, buf2[2], _buf, _buf2[2]; 813 814 sdw_modify_slave_status(slave, SDW_SLAVE_ALERT); 815 816 /* Read Instat 1, Instat 2 and Instat 3 registers */ 817 buf = ret = sdw_read(slave, SDW_SCP_INT1); 818 if (ret < 0) { 819 dev_err(slave->bus->dev, 820 "SDW_SCP_INT1 read failed:%d", ret); 821 return ret; 822 } 823 824 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2); 825 if (ret < 0) { 826 dev_err(slave->bus->dev, 827 "SDW_SCP_INT2/3 read failed:%d", ret); 828 return ret; 829 } 830 831 do { 832 /* 833 * Check parity, bus clash and Slave (impl defined) 834 * interrupt 835 */ 836 if (buf & SDW_SCP_INT1_PARITY) { 837 dev_err(&slave->dev, "Parity error detected"); 838 clear |= SDW_SCP_INT1_PARITY; 839 } 840 841 if (buf & SDW_SCP_INT1_BUS_CLASH) { 842 dev_err(&slave->dev, "Bus clash error detected"); 843 clear |= SDW_SCP_INT1_BUS_CLASH; 844 } 845 846 /* 847 * When bus clash or parity errors are detected, such errors 848 * are unlikely to be recoverable errors. 849 * TODO: In such scenario, reset bus. Make this configurable 850 * via sysfs property with bus reset being the default. 851 */ 852 853 if (buf & SDW_SCP_INT1_IMPL_DEF) { 854 dev_dbg(&slave->dev, "Slave impl defined interrupt\n"); 855 clear |= SDW_SCP_INT1_IMPL_DEF; 856 slave_notify = true; 857 } 858 859 /* Check port 0 - 3 interrupts */ 860 port = buf & SDW_SCP_INT1_PORT0_3; 861 862 /* To get port number corresponding to bits, shift it */ 863 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3); 864 for_each_set_bit(bit, &port, 8) { 865 sdw_handle_port_interrupt(slave, bit, 866 &port_status[bit]); 867 868 } 869 870 /* Check if cascade 2 interrupt is present */ 871 if (buf & SDW_SCP_INT1_SCP2_CASCADE) { 872 port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10; 873 for_each_set_bit(bit, &port, 8) { 874 /* scp2 ports start from 4 */ 875 port_num = bit + 3; 876 sdw_handle_port_interrupt(slave, 877 port_num, 878 &port_status[port_num]); 879 } 880 } 881 882 /* now check last cascade */ 883 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) { 884 port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14; 885 for_each_set_bit(bit, &port, 8) { 886 /* scp3 ports start from 11 */ 887 port_num = bit + 10; 888 sdw_handle_port_interrupt(slave, 889 port_num, 890 &port_status[port_num]); 891 } 892 } 893 894 /* Update the Slave driver */ 895 if (slave_notify && (slave->ops) && 896 (slave->ops->interrupt_callback)) { 897 slave_intr.control_port = clear; 898 memcpy(slave_intr.port, &port_status, 899 sizeof(slave_intr.port)); 900 901 slave->ops->interrupt_callback(slave, &slave_intr); 902 } 903 904 /* Ack interrupt */ 905 ret = sdw_write(slave, SDW_SCP_INT1, clear); 906 if (ret < 0) { 907 dev_err(slave->bus->dev, 908 "SDW_SCP_INT1 write failed:%d", ret); 909 return ret; 910 } 911 912 /* 913 * Read status again to ensure no new interrupts arrived 914 * while servicing interrupts. 915 */ 916 _buf = ret = sdw_read(slave, SDW_SCP_INT1); 917 if (ret < 0) { 918 dev_err(slave->bus->dev, 919 "SDW_SCP_INT1 read failed:%d", ret); 920 return ret; 921 } 922 923 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2); 924 if (ret < 0) { 925 dev_err(slave->bus->dev, 926 "SDW_SCP_INT2/3 read failed:%d", ret); 927 return ret; 928 } 929 930 /* Make sure no interrupts are pending */ 931 buf &= _buf; 932 buf2[0] &= _buf2[0]; 933 buf2[1] &= _buf2[1]; 934 stat = buf || buf2[0] || buf2[1]; 935 936 /* 937 * Exit loop if Slave is continuously in ALERT state even 938 * after servicing the interrupt multiple times. 939 */ 940 count++; 941 942 /* we can get alerts while processing so keep retrying */ 943 } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY); 944 945 if (count == SDW_READ_INTR_CLEAR_RETRY) 946 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read"); 947 948 return ret; 949 } 950 951 static int sdw_update_slave_status(struct sdw_slave *slave, 952 enum sdw_slave_status status) 953 { 954 if ((slave->ops) && (slave->ops->update_status)) 955 return slave->ops->update_status(slave, status); 956 957 return 0; 958 } 959 960 /** 961 * sdw_handle_slave_status() - Handle Slave status 962 * @bus: SDW bus instance 963 * @status: Status for all Slave(s) 964 */ 965 int sdw_handle_slave_status(struct sdw_bus *bus, 966 enum sdw_slave_status status[]) 967 { 968 enum sdw_slave_status prev_status; 969 struct sdw_slave *slave; 970 int i, ret = 0; 971 972 if (status[0] == SDW_SLAVE_ATTACHED) { 973 ret = sdw_program_device_num(bus); 974 if (ret) 975 dev_err(bus->dev, "Slave attach failed: %d", ret); 976 } 977 978 /* Continue to check other slave statuses */ 979 for (i = 1; i <= SDW_MAX_DEVICES; i++) { 980 mutex_lock(&bus->bus_lock); 981 if (test_bit(i, bus->assigned) == false) { 982 mutex_unlock(&bus->bus_lock); 983 continue; 984 } 985 mutex_unlock(&bus->bus_lock); 986 987 slave = sdw_get_slave(bus, i); 988 if (!slave) 989 continue; 990 991 switch (status[i]) { 992 case SDW_SLAVE_UNATTACHED: 993 if (slave->status == SDW_SLAVE_UNATTACHED) 994 break; 995 996 sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED); 997 break; 998 999 case SDW_SLAVE_ALERT: 1000 ret = sdw_handle_slave_alerts(slave); 1001 if (ret) 1002 dev_err(bus->dev, 1003 "Slave %d alert handling failed: %d", 1004 i, ret); 1005 break; 1006 1007 case SDW_SLAVE_ATTACHED: 1008 if (slave->status == SDW_SLAVE_ATTACHED) 1009 break; 1010 1011 prev_status = slave->status; 1012 sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED); 1013 1014 if (prev_status == SDW_SLAVE_ALERT) 1015 break; 1016 1017 ret = sdw_initialize_slave(slave); 1018 if (ret) 1019 dev_err(bus->dev, 1020 "Slave %d initialization failed: %d", 1021 i, ret); 1022 1023 break; 1024 1025 default: 1026 dev_err(bus->dev, "Invalid slave %d status:%d", 1027 i, status[i]); 1028 break; 1029 } 1030 1031 ret = sdw_update_slave_status(slave, status[i]); 1032 if (ret) 1033 dev_err(slave->bus->dev, 1034 "Update Slave status failed:%d", ret); 1035 1036 } 1037 1038 return ret; 1039 } 1040 EXPORT_SYMBOL(sdw_handle_slave_status); 1041