drivers/soundwire/bus.c

   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/delay.h>
   6 #include <linux/mod_devicetable.h>
   7 #include <linux/pm_runtime.h>
   8 #include <linux/soundwire/sdw_registers.h>
   9 #include <linux/soundwire/sdw.h>
  10 #include "bus.h"
  11 #include "sysfs_local.h"
  12
  13 static DEFINE_IDA(sdw_ida);
  14
  15 static int sdw_get_id(struct sdw_bus *bus)
  16 {
  17         int rc = ida_alloc(&sdw_ida, GFP_KERNEL);
  18
  19         if (rc < 0)
  20                 return rc;
  21
  22         bus->id = rc;
  23         return 0;
  24 }
  25
  26 /**
  27  * sdw_bus_master_add() - add a bus Master instance
  28  * @bus: bus instance
  29  * @parent: parent device
  30  * @fwnode: firmware node handle
  31  *
  32  * Initializes the bus instance, read properties and create child
  33  * devices.
  34  */
  35 int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
  36                        struct fwnode_handle *fwnode)
  37 {
  38         struct sdw_master_prop *prop = NULL;
  39         int ret;
  40
  41         if (!parent) {
  42                 pr_err("SoundWire parent device is not set\n");
  43                 return -ENODEV;
  44         }
  45
  46         ret = sdw_get_id(bus);
  47         if (ret) {
  48                 dev_err(parent, "Failed to get bus id\n");
  49                 return ret;
  50         }
  51
  52         ret = sdw_master_device_add(bus, parent, fwnode);
  53         if (ret) {
  54                 dev_err(parent, "Failed to add master device at link %d\n",
  55                         bus->link_id);
  56                 return ret;
  57         }
  58
  59         if (!bus->ops) {
  60                 dev_err(bus->dev, "SoundWire Bus ops are not set\n");
  61                 return -EINVAL;
  62         }
  63
  64         if (!bus->compute_params) {
  65                 dev_err(bus->dev,
  66                         "Bandwidth allocation not configured, compute_params no set\n");
  67                 return -EINVAL;
  68         }
  69
  70         mutex_init(&bus->msg_lock);
  71         mutex_init(&bus->bus_lock);
  72         INIT_LIST_HEAD(&bus->slaves);
  73         INIT_LIST_HEAD(&bus->m_rt_list);
  74
  75         /*
  76          * Initialize multi_link flag
  77          * TODO: populate this flag by reading property from FW node
  78          */
  79         bus->multi_link = false;
  80         if (bus->ops->read_prop) {
  81                 ret = bus->ops->read_prop(bus);
  82                 if (ret < 0) {
  83                         dev_err(bus->dev,
  84                                 "Bus read properties failed:%d\n", ret);
  85                         return ret;
  86                 }
  87         }
  88
  89         sdw_bus_debugfs_init(bus);
  90
  91         /*
  92          * Device numbers in SoundWire are 0 through 15. Enumeration device
  93          * number (0), Broadcast device number (15), Group numbers (12 and
  94          * 13) and Master device number (14) are not used for assignment so
  95          * mask these and other higher bits.
  96          */
  97
  98         /* Set higher order bits */
  99         *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
 100
 101         /* Set enumuration device number and broadcast device number */
 102         set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
 103         set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
 104
 105         /* Set group device numbers and master device number */
 106         set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
 107         set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
 108         set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
 109
 110         /*
 111          * SDW is an enumerable bus, but devices can be powered off. So,
 112          * they won't be able to report as present.
 113          *
 114          * Create Slave devices based on Slaves described in
 115          * the respective firmware (ACPI/DT)
 116          */
 117         if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
 118                 ret = sdw_acpi_find_slaves(bus);
 119         else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
 120                 ret = sdw_of_find_slaves(bus);
 121         else
 122                 ret = -ENOTSUPP; /* No ACPI/DT so error out */
 123
 124         if (ret) {
 125                 dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
 126                 return ret;
 127         }
 128
 129         /*
 130          * Initialize clock values based on Master properties. The max
 131          * frequency is read from max_clk_freq property. Current assumption
 132          * is that the bus will start at highest clock frequency when
 133          * powered on.
 134          *
 135          * Default active bank will be 0 as out of reset the Slaves have
 136          * to start with bank 0 (Table 40 of Spec)
 137          */
 138         prop = &bus->prop;
 139         bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
 140         bus->params.curr_dr_freq = bus->params.max_dr_freq;
 141         bus->params.curr_bank = SDW_BANK0;
 142         bus->params.next_bank = SDW_BANK1;
 143
 144         return 0;
 145 }
 146 EXPORT_SYMBOL(sdw_bus_master_add);
 147
 148 static int sdw_delete_slave(struct device *dev, void *data)
 149 {
 150         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 151         struct sdw_bus *bus = slave->bus;
 152
 153         pm_runtime_disable(dev);
 154
 155         sdw_slave_debugfs_exit(slave);
 156
 157         mutex_lock(&bus->bus_lock);
 158
 159         if (slave->dev_num) /* clear dev_num if assigned */
 160                 clear_bit(slave->dev_num, bus->assigned);
 161
 162         list_del_init(&slave->node);
 163         mutex_unlock(&bus->bus_lock);
 164
 165         device_unregister(dev);
 166         return 0;
 167 }
 168
 169 /**
 170  * sdw_bus_master_delete() - delete the bus master instance
 171  * @bus: bus to be deleted
 172  *
 173  * Remove the instance, delete the child devices.
 174  */
 175 void sdw_bus_master_delete(struct sdw_bus *bus)
 176 {
 177         device_for_each_child(bus->dev, NULL, sdw_delete_slave);
 178         sdw_master_device_del(bus);
 179
 180         sdw_bus_debugfs_exit(bus);
 181         ida_free(&sdw_ida, bus->id);
 182 }
 183 EXPORT_SYMBOL(sdw_bus_master_delete);
 184
 185 /*
 186  * SDW IO Calls
 187  */
 188
 189 static inline int find_response_code(enum sdw_command_response resp)
 190 {
 191         switch (resp) {
 192         case SDW_CMD_OK:
 193                 return 0;
 194
 195         case SDW_CMD_IGNORED:
 196                 return -ENODATA;
 197
 198         case SDW_CMD_TIMEOUT:
 199                 return -ETIMEDOUT;
 200
 201         default:
 202                 return -EIO;
 203         }
 204 }
 205
 206 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 207 {
 208         int retry = bus->prop.err_threshold;
 209         enum sdw_command_response resp;
 210         int ret = 0, i;
 211
 212         for (i = 0; i <= retry; i++) {
 213                 resp = bus->ops->xfer_msg(bus, msg);
 214                 ret = find_response_code(resp);
 215
 216                 /* if cmd is ok or ignored return */
 217                 if (ret == 0 || ret == -ENODATA)
 218                         return ret;
 219         }
 220
 221         return ret;
 222 }
 223
 224 static inline int do_transfer_defer(struct sdw_bus *bus,
 225                                     struct sdw_msg *msg,
 226                                     struct sdw_defer *defer)
 227 {
 228         int retry = bus->prop.err_threshold;
 229         enum sdw_command_response resp;
 230         int ret = 0, i;
 231
 232         defer->msg = msg;
 233         defer->length = msg->len;
 234         init_completion(&defer->complete);
 235
 236         for (i = 0; i <= retry; i++) {
 237                 resp = bus->ops->xfer_msg_defer(bus, msg, defer);
 238                 ret = find_response_code(resp);
 239                 /* if cmd is ok or ignored return */
 240                 if (ret == 0 || ret == -ENODATA)
 241                         return ret;
 242         }
 243
 244         return ret;
 245 }
 246
 247 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)
 248 {
 249         int retry = bus->prop.err_threshold;
 250         enum sdw_command_response resp;
 251         int ret = 0, i;
 252
 253         for (i = 0; i <= retry; i++) {
 254                 resp = bus->ops->reset_page_addr(bus, dev_num);
 255                 ret = find_response_code(resp);
 256                 /* if cmd is ok or ignored return */
 257                 if (ret == 0 || ret == -ENODATA)
 258                         return ret;
 259         }
 260
 261         return ret;
 262 }
 263
 264 static int sdw_transfer_unlocked(struct sdw_bus *bus, struct sdw_msg *msg)
 265 {
 266         int ret;
 267
 268         ret = do_transfer(bus, msg);
 269         if (ret != 0 && ret != -ENODATA)
 270                 dev_err(bus->dev, "trf on Slave %d failed:%d\n",
 271                         msg->dev_num, ret);
 272
 273         if (msg->page)
 274                 sdw_reset_page(bus, msg->dev_num);
 275
 276         return ret;
 277 }
 278
 279 /**
 280  * sdw_transfer() - Synchronous transfer message to a SDW Slave device
 281  * @bus: SDW bus
 282  * @msg: SDW message to be xfered
 283  */
 284 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 285 {
 286         int ret;
 287
 288         mutex_lock(&bus->msg_lock);
 289
 290         ret = sdw_transfer_unlocked(bus, msg);
 291
 292         mutex_unlock(&bus->msg_lock);
 293
 294         return ret;
 295 }
 296
 297 /**
 298  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
 299  * @bus: SDW bus
 300  * @msg: SDW message to be xfered
 301  * @defer: Defer block for signal completion
 302  *
 303  * Caller needs to hold the msg_lock lock while calling this
 304  */
 305 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
 306                        struct sdw_defer *defer)
 307 {
 308         int ret;
 309
 310         if (!bus->ops->xfer_msg_defer)
 311                 return -ENOTSUPP;
 312
 313         ret = do_transfer_defer(bus, msg, defer);
 314         if (ret != 0 && ret != -ENODATA)
 315                 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
 316                         msg->dev_num, ret);
 317
 318         if (msg->page)
 319                 sdw_reset_page(bus, msg->dev_num);
 320
 321         return ret;
 322 }
 323
 324 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
 325                  u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
 326 {
 327         memset(msg, 0, sizeof(*msg));
 328         msg->addr = addr; /* addr is 16 bit and truncated here */
 329         msg->len = count;
 330         msg->dev_num = dev_num;
 331         msg->flags = flags;
 332         msg->buf = buf;
 333
 334         if (addr < SDW_REG_NO_PAGE) /* no paging area */
 335                 return 0;
 336
 337         if (addr >= SDW_REG_MAX) { /* illegal addr */
 338                 pr_err("SDW: Invalid address %x passed\n", addr);
 339                 return -EINVAL;
 340         }
 341
 342         if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
 343                 if (slave && !slave->prop.paging_support)
 344                         return 0;
 345                 /* no need for else as that will fall-through to paging */
 346         }
 347
 348         /* paging mandatory */
 349         if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
 350                 pr_err("SDW: Invalid device for paging :%d\n", dev_num);
 351                 return -EINVAL;
 352         }
 353
 354         if (!slave) {
 355                 pr_err("SDW: No slave for paging addr\n");
 356                 return -EINVAL;
 357         }
 358
 359         if (!slave->prop.paging_support) {
 360                 dev_err(&slave->dev,
 361                         "address %x needs paging but no support\n", addr);
 362                 return -EINVAL;
 363         }
 364
 365         msg->addr_page1 = FIELD_GET(SDW_SCP_ADDRPAGE1_MASK, addr);
 366         msg->addr_page2 = FIELD_GET(SDW_SCP_ADDRPAGE2_MASK, addr);
 367         msg->addr |= BIT(15);
 368         msg->page = true;
 369
 370         return 0;
 371 }
 372
 373 /*
 374  * Read/Write IO functions.
 375  * no_pm versions can only be called by the bus, e.g. while enumerating or
 376  * handling suspend-resume sequences.
 377  * all clients need to use the pm versions
 378  */
 379
 380 static int
 381 sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 382 {
 383         struct sdw_msg msg;
 384         int ret;
 385
 386         ret = sdw_fill_msg(&msg, slave, addr, count,
 387                            slave->dev_num, SDW_MSG_FLAG_READ, val);
 388         if (ret < 0)
 389                 return ret;
 390
 391         return sdw_transfer(slave->bus, &msg);
 392 }
 393
 394 static int
 395 sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 396 {
 397         struct sdw_msg msg;
 398         int ret;
 399
 400         ret = sdw_fill_msg(&msg, slave, addr, count,
 401                            slave->dev_num, SDW_MSG_FLAG_WRITE, val);
 402         if (ret < 0)
 403                 return ret;
 404
 405         return sdw_transfer(slave->bus, &msg);
 406 }
 407
 408 static int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
 409 {
 410         return sdw_nwrite_no_pm(slave, addr, 1, &value);
 411 }
 412
 413 static int
 414 sdw_bread_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr)
 415 {
 416         struct sdw_msg msg;
 417         u8 buf;
 418         int ret;
 419
 420         ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
 421                            SDW_MSG_FLAG_READ, &buf);
 422         if (ret)
 423                 return ret;
 424
 425         ret = sdw_transfer(bus, &msg);
 426         if (ret < 0)
 427                 return ret;
 428
 429         return buf;
 430 }
 431
 432 static int
 433 sdw_bwrite_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
 434 {
 435         struct sdw_msg msg;
 436         int ret;
 437
 438         ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
 439                            SDW_MSG_FLAG_WRITE, &value);
 440         if (ret)
 441                 return ret;
 442
 443         return sdw_transfer(bus, &msg);
 444 }
 445
 446 int sdw_bread_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr)
 447 {
 448         struct sdw_msg msg;
 449         u8 buf;
 450         int ret;
 451
 452         ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
 453                            SDW_MSG_FLAG_READ, &buf);
 454         if (ret)
 455                 return ret;
 456
 457         ret = sdw_transfer_unlocked(bus, &msg);
 458         if (ret < 0)
 459                 return ret;
 460
 461         return buf;
 462 }
 463 EXPORT_SYMBOL(sdw_bread_no_pm_unlocked);
 464
 465 int sdw_bwrite_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
 466 {
 467         struct sdw_msg msg;
 468         int ret;
 469
 470         ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
 471                            SDW_MSG_FLAG_WRITE, &value);
 472         if (ret)
 473                 return ret;
 474
 475         return sdw_transfer_unlocked(bus, &msg);
 476 }
 477 EXPORT_SYMBOL(sdw_bwrite_no_pm_unlocked);
 478
 479 static int
 480 sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
 481 {
 482         u8 buf;
 483         int ret;
 484
 485         ret = sdw_nread_no_pm(slave, addr, 1, &buf);
 486         if (ret < 0)
 487                 return ret;
 488         else
 489                 return buf;
 490 }
 491
 492 /**
 493  * sdw_nread() - Read "n" contiguous SDW Slave registers
 494  * @slave: SDW Slave
 495  * @addr: Register address
 496  * @count: length
 497  * @val: Buffer for values to be read
 498  */
 499 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 500 {
 501         int ret;
 502
 503         ret = pm_runtime_get_sync(slave->bus->dev);
 504         if (ret < 0 && ret != -EACCES) {
 505                 pm_runtime_put_noidle(slave->bus->dev);
 506                 return ret;
 507         }
 508
 509         ret = sdw_nread_no_pm(slave, addr, count, val);
 510
 511         pm_runtime_mark_last_busy(slave->bus->dev);
 512         pm_runtime_put(slave->bus->dev);
 513
 514         return ret;
 515 }
 516 EXPORT_SYMBOL(sdw_nread);
 517
 518 /**
 519  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
 520  * @slave: SDW Slave
 521  * @addr: Register address
 522  * @count: length
 523  * @val: Buffer for values to be read
 524  */
 525 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 526 {
 527         int ret;
 528
 529         ret = pm_runtime_get_sync(slave->bus->dev);
 530         if (ret < 0 && ret != -EACCES) {
 531                 pm_runtime_put_noidle(slave->bus->dev);
 532                 return ret;
 533         }
 534
 535         ret = sdw_nwrite_no_pm(slave, addr, count, val);
 536
 537         pm_runtime_mark_last_busy(slave->bus->dev);
 538         pm_runtime_put(slave->bus->dev);
 539
 540         return ret;
 541 }
 542 EXPORT_SYMBOL(sdw_nwrite);
 543
 544 /**
 545  * sdw_read() - Read a SDW Slave register
 546  * @slave: SDW Slave
 547  * @addr: Register address
 548  */
 549 int sdw_read(struct sdw_slave *slave, u32 addr)
 550 {
 551         u8 buf;
 552         int ret;
 553
 554         ret = sdw_nread(slave, addr, 1, &buf);
 555         if (ret < 0)
 556                 return ret;
 557
 558         return buf;
 559 }
 560 EXPORT_SYMBOL(sdw_read);
 561
 562 /**
 563  * sdw_write() - Write a SDW Slave register
 564  * @slave: SDW Slave
 565  * @addr: Register address
 566  * @value: Register value
 567  */
 568 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
 569 {
 570         return sdw_nwrite(slave, addr, 1, &value);
 571 }
 572 EXPORT_SYMBOL(sdw_write);
 573
 574 /*
 575  * SDW alert handling
 576  */
 577
 578 /* called with bus_lock held */
 579 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
 580 {
 581         struct sdw_slave *slave = NULL;
 582
 583         list_for_each_entry(slave, &bus->slaves, node) {
 584                 if (slave->dev_num == i)
 585                         return slave;
 586         }
 587
 588         return NULL;
 589 }
 590
 591 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
 592 {
 593         if (slave->id.mfg_id != id.mfg_id ||
 594             slave->id.part_id != id.part_id ||
 595             slave->id.class_id != id.class_id ||
 596             (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
 597              slave->id.unique_id != id.unique_id))
 598                 return -ENODEV;
 599
 600         return 0;
 601 }
 602
 603 /* called with bus_lock held */
 604 static int sdw_get_device_num(struct sdw_slave *slave)
 605 {
 606         int bit;
 607
 608         bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
 609         if (bit == SDW_MAX_DEVICES) {
 610                 bit = -ENODEV;
 611                 goto err;
 612         }
 613
 614         /*
 615          * Do not update dev_num in Slave data structure here,
 616          * Update once program dev_num is successful
 617          */
 618         set_bit(bit, slave->bus->assigned);
 619
 620 err:
 621         return bit;
 622 }
 623
 624 static int sdw_assign_device_num(struct sdw_slave *slave)
 625 {
 626         int ret, dev_num;
 627         bool new_device = false;
 628
 629         /* check first if device number is assigned, if so reuse that */
 630         if (!slave->dev_num) {
 631                 if (!slave->dev_num_sticky) {
 632                         mutex_lock(&slave->bus->bus_lock);
 633                         dev_num = sdw_get_device_num(slave);
 634                         mutex_unlock(&slave->bus->bus_lock);
 635                         if (dev_num < 0) {
 636                                 dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
 637                                         dev_num);
 638                                 return dev_num;
 639                         }
 640                         slave->dev_num = dev_num;
 641                         slave->dev_num_sticky = dev_num;
 642                         new_device = true;
 643                 } else {
 644                         slave->dev_num = slave->dev_num_sticky;
 645                 }
 646         }
 647
 648         if (!new_device)
 649                 dev_dbg(slave->bus->dev,
 650                         "Slave already registered, reusing dev_num:%d\n",
 651                         slave->dev_num);
 652
 653         /* Clear the slave->dev_num to transfer message on device 0 */
 654         dev_num = slave->dev_num;
 655         slave->dev_num = 0;
 656
 657         ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
 658         if (ret < 0) {
 659                 dev_err(&slave->dev, "Program device_num %d failed: %d\n",
 660                         dev_num, ret);
 661                 return ret;
 662         }
 663
 664         /* After xfer of msg, restore dev_num */
 665         slave->dev_num = slave->dev_num_sticky;
 666
 667         return 0;
 668 }
 669
 670 void sdw_extract_slave_id(struct sdw_bus *bus,
 671                           u64 addr, struct sdw_slave_id *id)
 672 {
 673         dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
 674
 675         id->sdw_version = SDW_VERSION(addr);
 676         id->unique_id = SDW_UNIQUE_ID(addr);
 677         id->mfg_id = SDW_MFG_ID(addr);
 678         id->part_id = SDW_PART_ID(addr);
 679         id->class_id = SDW_CLASS_ID(addr);
 680
 681         dev_dbg(bus->dev,
 682                 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",
 683                                 id->class_id, id->part_id, id->mfg_id,
 684                                 id->unique_id, id->sdw_version);
 685 }
 686
 687 static int sdw_program_device_num(struct sdw_bus *bus)
 688 {
 689         u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
 690         struct sdw_slave *slave, *_s;
 691         struct sdw_slave_id id;
 692         struct sdw_msg msg;
 693         bool found = false;
 694         int count = 0, ret;
 695         u64 addr;
 696
 697         /* No Slave, so use raw xfer api */
 698         ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
 699                            SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
 700         if (ret < 0)
 701                 return ret;
 702
 703         do {
 704                 ret = sdw_transfer(bus, &msg);
 705                 if (ret == -ENODATA) { /* end of device id reads */
 706                         dev_dbg(bus->dev, "No more devices to enumerate\n");
 707                         ret = 0;
 708                         break;
 709                 }
 710                 if (ret < 0) {
 711                         dev_err(bus->dev, "DEVID read fail:%d\n", ret);
 712                         break;
 713                 }
 714
 715                 /*
 716                  * Construct the addr and extract. Cast the higher shift
 717                  * bits to avoid truncation due to size limit.
 718                  */
 719                 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
 720                         ((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
 721                         ((u64)buf[0] << 40);
 722
 723                 sdw_extract_slave_id(bus, addr, &id);
 724
 725                 /* Now compare with entries */
 726                 list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
 727                         if (sdw_compare_devid(slave, id) == 0) {
 728                                 found = true;
 729
 730                                 /*
 731                                  * Assign a new dev_num to this Slave and
 732                                  * not mark it present. It will be marked
 733                                  * present after it reports ATTACHED on new
 734                                  * dev_num
 735                                  */
 736                                 ret = sdw_assign_device_num(slave);
 737                                 if (ret) {
 738                                         dev_err(slave->bus->dev,
 739                                                 "Assign dev_num failed:%d\n",
 740                                                 ret);
 741                                         return ret;
 742                                 }
 743
 744                                 break;
 745                         }
 746                 }
 747
 748                 if (!found) {
 749                         /* TODO: Park this device in Group 13 */
 750
 751                         /*
 752                          * add Slave device even if there is no platform
 753                          * firmware description. There will be no driver probe
 754                          * but the user/integration will be able to see the
 755                          * device, enumeration status and device number in sysfs
 756                          */
 757                         sdw_slave_add(bus, &id, NULL);
 758
 759                         dev_err(bus->dev, "Slave Entry not found\n");
 760                 }
 761
 762                 count++;
 763
 764                 /*
 765                  * Check till error out or retry (count) exhausts.
 766                  * Device can drop off and rejoin during enumeration
 767                  * so count till twice the bound.
 768                  */
 769
 770         } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
 771
 772         return ret;
 773 }
 774
 775 static void sdw_modify_slave_status(struct sdw_slave *slave,
 776                                     enum sdw_slave_status status)
 777 {
 778         mutex_lock(&slave->bus->bus_lock);
 779
 780         dev_vdbg(&slave->dev,
 781                  "%s: changing status slave %d status %d new status %d\n",
 782                  __func__, slave->dev_num, slave->status, status);
 783
 784         if (status == SDW_SLAVE_UNATTACHED) {
 785                 dev_dbg(&slave->dev,
 786                         "%s: initializing completion for Slave %d\n",
 787                         __func__, slave->dev_num);
 788
 789                 init_completion(&slave->enumeration_complete);
 790                 init_completion(&slave->initialization_complete);
 791
 792         } else if ((status == SDW_SLAVE_ATTACHED) &&
 793                    (slave->status == SDW_SLAVE_UNATTACHED)) {
 794                 dev_dbg(&slave->dev,
 795                         "%s: signaling completion for Slave %d\n",
 796                         __func__, slave->dev_num);
 797
 798                 complete(&slave->enumeration_complete);
 799         }
 800         slave->status = status;
 801         mutex_unlock(&slave->bus->bus_lock);
 802 }
 803
 804 static enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave)
 805 {
 806         enum sdw_clk_stop_mode mode;
 807
 808         /*
 809          * Query for clock stop mode if Slave implements
 810          * ops->get_clk_stop_mode, else read from property.
 811          */
 812         if (slave->ops && slave->ops->get_clk_stop_mode) {
 813                 mode = slave->ops->get_clk_stop_mode(slave);
 814         } else {
 815                 if (slave->prop.clk_stop_mode1)
 816                         mode = SDW_CLK_STOP_MODE1;
 817                 else
 818                         mode = SDW_CLK_STOP_MODE0;
 819         }
 820
 821         return mode;
 822 }
 823
 824 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
 825                                        enum sdw_clk_stop_mode mode,
 826                                        enum sdw_clk_stop_type type)
 827 {
 828         int ret;
 829
 830         if (slave->ops && slave->ops->clk_stop) {
 831                 ret = slave->ops->clk_stop(slave, mode, type);
 832                 if (ret < 0) {
 833                         dev_err(&slave->dev,
 834                                 "Clk Stop type =%d failed: %d\n", type, ret);
 835                         return ret;
 836                 }
 837         }
 838
 839         return 0;
 840 }
 841
 842 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
 843                                       enum sdw_clk_stop_mode mode,
 844                                       bool prepare)
 845 {
 846         bool wake_en;
 847         u32 val = 0;
 848         int ret;
 849
 850         wake_en = slave->prop.wake_capable;
 851
 852         if (prepare) {
 853                 val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
 854
 855                 if (mode == SDW_CLK_STOP_MODE1)
 856                         val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
 857
 858                 if (wake_en)
 859                         val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
 860         } else {
 861                 val = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
 862
 863                 val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
 864         }
 865
 866         ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
 867
 868         if (ret != 0)
 869                 dev_err(&slave->dev,
 870                         "Clock Stop prepare failed for slave: %d", ret);
 871
 872         return ret;
 873 }
 874
 875 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
 876 {
 877         int retry = bus->clk_stop_timeout;
 878         int val;
 879
 880         do {
 881                 val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT) &
 882                         SDW_SCP_STAT_CLK_STP_NF;
 883                 if (!val) {
 884                         dev_info(bus->dev, "clock stop prep/de-prep done slave:%d",
 885                                  dev_num);
 886                         return 0;
 887                 }
 888
 889                 usleep_range(1000, 1500);
 890                 retry--;
 891         } while (retry);
 892
 893         dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d",
 894                 dev_num);
 895
 896         return -ETIMEDOUT;
 897 }
 898
 899 /**
 900  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
 901  *
 902  * @bus: SDW bus instance
 903  *
 904  * Query Slave for clock stop mode and prepare for that mode.
 905  */
 906 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
 907 {
 908         enum sdw_clk_stop_mode slave_mode;
 909         bool simple_clk_stop = true;
 910         struct sdw_slave *slave;
 911         bool is_slave = false;
 912         int ret = 0;
 913
 914         /*
 915          * In order to save on transition time, prepare
 916          * each Slave and then wait for all Slave(s) to be
 917          * prepared for clock stop.
 918          */
 919         list_for_each_entry(slave, &bus->slaves, node) {
 920                 if (!slave->dev_num)
 921                         continue;
 922
 923                 if (slave->status != SDW_SLAVE_ATTACHED &&
 924                     slave->status != SDW_SLAVE_ALERT)
 925                         continue;
 926
 927                 /* Identify if Slave(s) are available on Bus */
 928                 is_slave = true;
 929
 930                 slave_mode = sdw_get_clk_stop_mode(slave);
 931                 slave->curr_clk_stop_mode = slave_mode;
 932
 933                 ret = sdw_slave_clk_stop_callback(slave, slave_mode,
 934                                                   SDW_CLK_PRE_PREPARE);
 935                 if (ret < 0) {
 936                         dev_err(&slave->dev,
 937                                 "pre-prepare failed:%d", ret);
 938                         return ret;
 939                 }
 940
 941                 ret = sdw_slave_clk_stop_prepare(slave,
 942                                                  slave_mode, true);
 943                 if (ret < 0) {
 944                         dev_err(&slave->dev,
 945                                 "pre-prepare failed:%d", ret);
 946                         return ret;
 947                 }
 948
 949                 if (slave_mode == SDW_CLK_STOP_MODE1)
 950                         simple_clk_stop = false;
 951         }
 952
 953         if (is_slave && !simple_clk_stop) {
 954                 ret = sdw_bus_wait_for_clk_prep_deprep(bus,
 955                                                        SDW_BROADCAST_DEV_NUM);
 956                 if (ret < 0)
 957                         return ret;
 958         }
 959
 960         /* Don't need to inform slaves if there is no slave attached */
 961         if (!is_slave)
 962                 return ret;
 963
 964         /* Inform slaves that prep is done */
 965         list_for_each_entry(slave, &bus->slaves, node) {
 966                 if (!slave->dev_num)
 967                         continue;
 968
 969                 if (slave->status != SDW_SLAVE_ATTACHED &&
 970                     slave->status != SDW_SLAVE_ALERT)
 971                         continue;
 972
 973                 slave_mode = slave->curr_clk_stop_mode;
 974
 975                 if (slave_mode == SDW_CLK_STOP_MODE1) {
 976                         ret = sdw_slave_clk_stop_callback(slave,
 977                                                           slave_mode,
 978                                                           SDW_CLK_POST_PREPARE);
 979
 980                         if (ret < 0) {
 981                                 dev_err(&slave->dev,
 982                                         "post-prepare failed:%d", ret);
 983                         }
 984                 }
 985         }
 986
 987         return ret;
 988 }
 989 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
 990
 991 /**
 992  * sdw_bus_clk_stop: stop bus clock
 993  *
 994  * @bus: SDW bus instance
 995  *
 996  * After preparing the Slaves for clock stop, stop the clock by broadcasting
 997  * write to SCP_CTRL register.
 998  */
 999 int sdw_bus_clk_stop(struct sdw_bus *bus)
1000 {
1001         int ret;
1002
1003         /*
1004          * broadcast clock stop now, attached Slaves will ACK this,
1005          * unattached will ignore
1006          */
1007         ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1008                                SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1009         if (ret < 0) {
1010                 if (ret == -ENODATA)
1011                         dev_dbg(bus->dev,
1012                                 "ClockStopNow Broadcast msg ignored %d", ret);
1013                 else
1014                         dev_err(bus->dev,
1015                                 "ClockStopNow Broadcast msg failed %d", ret);
1016                 return ret;
1017         }
1018
1019         return 0;
1020 }
1021 EXPORT_SYMBOL(sdw_bus_clk_stop);
1022
1023 /**
1024  * sdw_bus_exit_clk_stop: Exit clock stop mode
1025  *
1026  * @bus: SDW bus instance
1027  *
1028  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1029  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1030  * back.
1031  */
1032 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1033 {
1034         enum sdw_clk_stop_mode mode;
1035         bool simple_clk_stop = true;
1036         struct sdw_slave *slave;
1037         bool is_slave = false;
1038         int ret;
1039
1040         /*
1041          * In order to save on transition time, de-prepare
1042          * each Slave and then wait for all Slave(s) to be
1043          * de-prepared after clock resume.
1044          */
1045         list_for_each_entry(slave, &bus->slaves, node) {
1046                 if (!slave->dev_num)
1047                         continue;
1048
1049                 if (slave->status != SDW_SLAVE_ATTACHED &&
1050                     slave->status != SDW_SLAVE_ALERT)
1051                         continue;
1052
1053                 /* Identify if Slave(s) are available on Bus */
1054                 is_slave = true;
1055
1056                 mode = slave->curr_clk_stop_mode;
1057
1058                 if (mode == SDW_CLK_STOP_MODE1) {
1059                         simple_clk_stop = false;
1060                         continue;
1061                 }
1062
1063                 ret = sdw_slave_clk_stop_callback(slave, mode,
1064                                                   SDW_CLK_PRE_DEPREPARE);
1065                 if (ret < 0)
1066                         dev_warn(&slave->dev,
1067                                  "clk stop deprep failed:%d", ret);
1068
1069                 ret = sdw_slave_clk_stop_prepare(slave, mode,
1070                                                  false);
1071
1072                 if (ret < 0)
1073                         dev_warn(&slave->dev,
1074                                  "clk stop deprep failed:%d", ret);
1075         }
1076
1077         if (is_slave && !simple_clk_stop)
1078                 sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1079
1080         /*
1081          * Don't need to call slave callback function if there is no slave
1082          * attached
1083          */
1084         if (!is_slave)
1085                 return 0;
1086
1087         list_for_each_entry(slave, &bus->slaves, node) {
1088                 if (!slave->dev_num)
1089                         continue;
1090
1091                 if (slave->status != SDW_SLAVE_ATTACHED &&
1092                     slave->status != SDW_SLAVE_ALERT)
1093                         continue;
1094
1095                 mode = slave->curr_clk_stop_mode;
1096                 sdw_slave_clk_stop_callback(slave, mode,
1097                                             SDW_CLK_POST_DEPREPARE);
1098         }
1099
1100         return 0;
1101 }
1102 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1103
1104 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1105                            int port, bool enable, int mask)
1106 {
1107         u32 addr;
1108         int ret;
1109         u8 val = 0;
1110
1111         if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1112                 dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1113                         enable ? "on" : "off");
1114                 mask |= SDW_DPN_INT_TEST_FAIL;
1115         }
1116
1117         addr = SDW_DPN_INTMASK(port);
1118
1119         /* Set/Clear port ready interrupt mask */
1120         if (enable) {
1121                 val |= mask;
1122                 val |= SDW_DPN_INT_PORT_READY;
1123         } else {
1124                 val &= ~(mask);
1125                 val &= ~SDW_DPN_INT_PORT_READY;
1126         }
1127
1128         ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1129         if (ret < 0)
1130                 dev_err(slave->bus->dev,
1131                         "SDW_DPN_INTMASK write failed:%d\n", val);
1132
1133         return ret;
1134 }
1135
1136 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1137 {
1138         u32 mclk_freq = slave->bus->prop.mclk_freq;
1139         u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1140         unsigned int scale;
1141         u8 scale_index;
1142         u8 base;
1143         int ret;
1144
1145         /*
1146          * frequency base and scale registers are required for SDCA
1147          * devices. They may also be used for 1.2+/non-SDCA devices,
1148          * but we will need a DisCo property to cover this case
1149          */
1150         if (!slave->id.class_id)
1151                 return 0;
1152
1153         if (!mclk_freq) {
1154                 dev_err(&slave->dev,
1155                         "no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1156                 return -EINVAL;
1157         }
1158
1159         /*
1160          * map base frequency using Table 89 of SoundWire 1.2 spec.
1161          * The order of the tests just follows the specification, this
1162          * is not a selection between possible values or a search for
1163          * the best value but just a mapping.  Only one case per platform
1164          * is relevant.
1165          * Some BIOS have inconsistent values for mclk_freq but a
1166          * correct root so we force the mclk_freq to avoid variations.
1167          */
1168         if (!(19200000 % mclk_freq)) {
1169                 mclk_freq = 19200000;
1170                 base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1171         } else if (!(24000000 % mclk_freq)) {
1172                 mclk_freq = 24000000;
1173                 base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1174         } else if (!(24576000 % mclk_freq)) {
1175                 mclk_freq = 24576000;
1176                 base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1177         } else if (!(22579200 % mclk_freq)) {
1178                 mclk_freq = 22579200;
1179                 base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1180         } else if (!(32000000 % mclk_freq)) {
1181                 mclk_freq = 32000000;
1182                 base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1183         } else {
1184                 dev_err(&slave->dev,
1185                         "Unsupported clock base, mclk %d\n",
1186                         mclk_freq);
1187                 return -EINVAL;
1188         }
1189
1190         if (mclk_freq % curr_freq) {
1191                 dev_err(&slave->dev,
1192                         "mclk %d is not multiple of bus curr_freq %d\n",
1193                         mclk_freq, curr_freq);
1194                 return -EINVAL;
1195         }
1196
1197         scale = mclk_freq / curr_freq;
1198
1199         /*
1200          * map scale to Table 90 of SoundWire 1.2 spec - and check
1201          * that the scale is a power of two and maximum 64
1202          */
1203         scale_index = ilog2(scale);
1204
1205         if (BIT(scale_index) != scale || scale_index > 6) {
1206                 dev_err(&slave->dev,
1207                         "No match found for scale %d, bus mclk %d curr_freq %d\n",
1208                         scale, mclk_freq, curr_freq);
1209                 return -EINVAL;
1210         }
1211         scale_index++;
1212
1213         ret = sdw_write(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1214         if (ret < 0) {
1215                 dev_err(&slave->dev,
1216                         "SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1217                 return ret;
1218         }
1219
1220         /* initialize scale for both banks */
1221         ret = sdw_write(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1222         if (ret < 0) {
1223                 dev_err(&slave->dev,
1224                         "SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1225                 return ret;
1226         }
1227         ret = sdw_write(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1228         if (ret < 0)
1229                 dev_err(&slave->dev,
1230                         "SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1231
1232         dev_dbg(&slave->dev,
1233                 "Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1234                 base, scale_index, mclk_freq, curr_freq);
1235
1236         return ret;
1237 }
1238
1239 static int sdw_initialize_slave(struct sdw_slave *slave)
1240 {
1241         struct sdw_slave_prop *prop = &slave->prop;
1242         int ret;
1243         u8 val;
1244
1245         ret = sdw_slave_set_frequency(slave);
1246         if (ret < 0)
1247                 return ret;
1248
1249         /*
1250          * Set SCP_INT1_MASK register, typically bus clash and
1251          * implementation-defined interrupt mask. The Parity detection
1252          * may not always be correct on startup so its use is
1253          * device-dependent, it might e.g. only be enabled in
1254          * steady-state after a couple of frames.
1255          */
1256         val = slave->prop.scp_int1_mask;
1257
1258         /* Enable SCP interrupts */
1259         ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
1260         if (ret < 0) {
1261                 dev_err(slave->bus->dev,
1262                         "SDW_SCP_INTMASK1 write failed:%d\n", ret);
1263                 return ret;
1264         }
1265
1266         /* No need to continue if DP0 is not present */
1267         if (!slave->prop.dp0_prop)
1268                 return 0;
1269
1270         /* Enable DP0 interrupts */
1271         val = prop->dp0_prop->imp_def_interrupts;
1272         val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1273
1274         ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
1275         if (ret < 0)
1276                 dev_err(slave->bus->dev,
1277                         "SDW_DP0_INTMASK read failed:%d\n", ret);
1278         return ret;
1279 }
1280
1281 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1282 {
1283         u8 clear = 0, impl_int_mask;
1284         int status, status2, ret, count = 0;
1285
1286         status = sdw_read(slave, SDW_DP0_INT);
1287         if (status < 0) {
1288                 dev_err(slave->bus->dev,
1289                         "SDW_DP0_INT read failed:%d\n", status);
1290                 return status;
1291         }
1292
1293         do {
1294                 if (status & SDW_DP0_INT_TEST_FAIL) {
1295                         dev_err(&slave->dev, "Test fail for port 0\n");
1296                         clear |= SDW_DP0_INT_TEST_FAIL;
1297                 }
1298
1299                 /*
1300                  * Assumption: PORT_READY interrupt will be received only for
1301                  * ports implementing Channel Prepare state machine (CP_SM)
1302                  */
1303
1304                 if (status & SDW_DP0_INT_PORT_READY) {
1305                         complete(&slave->port_ready[0]);
1306                         clear |= SDW_DP0_INT_PORT_READY;
1307                 }
1308
1309                 if (status & SDW_DP0_INT_BRA_FAILURE) {
1310                         dev_err(&slave->dev, "BRA failed\n");
1311                         clear |= SDW_DP0_INT_BRA_FAILURE;
1312                 }
1313
1314                 impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1315                         SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1316
1317                 if (status & impl_int_mask) {
1318                         clear |= impl_int_mask;
1319                         *slave_status = clear;
1320                 }
1321
1322                 /* clear the interrupt */
1323                 ret = sdw_write(slave, SDW_DP0_INT, clear);
1324                 if (ret < 0) {
1325                         dev_err(slave->bus->dev,
1326                                 "SDW_DP0_INT write failed:%d\n", ret);
1327                         return ret;
1328                 }
1329
1330                 /* Read DP0 interrupt again */
1331                 status2 = sdw_read(slave, SDW_DP0_INT);
1332                 if (status2 < 0) {
1333                         dev_err(slave->bus->dev,
1334                                 "SDW_DP0_INT read failed:%d\n", status2);
1335                         return status2;
1336                 }
1337                 status &= status2;
1338
1339                 count++;
1340
1341                 /* we can get alerts while processing so keep retrying */
1342         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1343
1344         if (count == SDW_READ_INTR_CLEAR_RETRY)
1345                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read\n");
1346
1347         return ret;
1348 }
1349
1350 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1351                                      int port, u8 *slave_status)
1352 {
1353         u8 clear = 0, impl_int_mask;
1354         int status, status2, ret, count = 0;
1355         u32 addr;
1356
1357         if (port == 0)
1358                 return sdw_handle_dp0_interrupt(slave, slave_status);
1359
1360         addr = SDW_DPN_INT(port);
1361         status = sdw_read(slave, addr);
1362         if (status < 0) {
1363                 dev_err(slave->bus->dev,
1364                         "SDW_DPN_INT read failed:%d\n", status);
1365
1366                 return status;
1367         }
1368
1369         do {
1370                 if (status & SDW_DPN_INT_TEST_FAIL) {
1371                         dev_err(&slave->dev, "Test fail for port:%d\n", port);
1372                         clear |= SDW_DPN_INT_TEST_FAIL;
1373                 }
1374
1375                 /*
1376                  * Assumption: PORT_READY interrupt will be received only
1377                  * for ports implementing CP_SM.
1378                  */
1379                 if (status & SDW_DPN_INT_PORT_READY) {
1380                         complete(&slave->port_ready[port]);
1381                         clear |= SDW_DPN_INT_PORT_READY;
1382                 }
1383
1384                 impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1385                         SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1386
1387                 if (status & impl_int_mask) {
1388                         clear |= impl_int_mask;
1389                         *slave_status = clear;
1390                 }
1391
1392                 /* clear the interrupt */
1393                 ret = sdw_write(slave, addr, clear);
1394                 if (ret < 0) {
1395                         dev_err(slave->bus->dev,
1396                                 "SDW_DPN_INT write failed:%d\n", ret);
1397                         return ret;
1398                 }
1399
1400                 /* Read DPN interrupt again */
1401                 status2 = sdw_read(slave, addr);
1402                 if (status2 < 0) {
1403                         dev_err(slave->bus->dev,
1404                                 "SDW_DPN_INT read failed:%d\n", status2);
1405                         return status2;
1406                 }
1407                 status &= status2;
1408
1409                 count++;
1410
1411                 /* we can get alerts while processing so keep retrying */
1412         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1413
1414         if (count == SDW_READ_INTR_CLEAR_RETRY)
1415                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
1416
1417         return ret;
1418 }
1419
1420 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1421 {
1422         struct sdw_slave_intr_status slave_intr;
1423         u8 clear = 0, bit, port_status[15] = {0};
1424         int port_num, stat, ret, count = 0;
1425         unsigned long port;
1426         bool slave_notify = false;
1427         u8 buf, buf2[2], _buf, _buf2[2];
1428         bool parity_check;
1429         bool parity_quirk;
1430
1431         sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1432
1433         ret = pm_runtime_get_sync(&slave->dev);
1434         if (ret < 0 && ret != -EACCES) {
1435                 dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
1436                 pm_runtime_put_noidle(slave->bus->dev);
1437                 return ret;
1438         }
1439
1440         /* Read Intstat 1, Intstat 2 and Intstat 3 registers */
1441         ret = sdw_read(slave, SDW_SCP_INT1);
1442         if (ret < 0) {
1443                 dev_err(slave->bus->dev,
1444                         "SDW_SCP_INT1 read failed:%d\n", ret);
1445                 goto io_err;
1446         }
1447         buf = ret;
1448
1449         ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
1450         if (ret < 0) {
1451                 dev_err(slave->bus->dev,
1452                         "SDW_SCP_INT2/3 read failed:%d\n", ret);
1453                 goto io_err;
1454         }
1455
1456         do {
1457                 /*
1458                  * Check parity, bus clash and Slave (impl defined)
1459                  * interrupt
1460                  */
1461                 if (buf & SDW_SCP_INT1_PARITY) {
1462                         parity_check = slave->prop.scp_int1_mask & SDW_SCP_INT1_PARITY;
1463                         parity_quirk = !slave->first_interrupt_done &&
1464                                 (slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY);
1465
1466                         if (parity_check && !parity_quirk)
1467                                 dev_err(&slave->dev, "Parity error detected\n");
1468                         clear |= SDW_SCP_INT1_PARITY;
1469                 }
1470
1471                 if (buf & SDW_SCP_INT1_BUS_CLASH) {
1472                         if (slave->prop.scp_int1_mask & SDW_SCP_INT1_BUS_CLASH)
1473                                 dev_err(&slave->dev, "Bus clash detected\n");
1474                         clear |= SDW_SCP_INT1_BUS_CLASH;
1475                 }
1476
1477                 /*
1478                  * When bus clash or parity errors are detected, such errors
1479                  * are unlikely to be recoverable errors.
1480                  * TODO: In such scenario, reset bus. Make this configurable
1481                  * via sysfs property with bus reset being the default.
1482                  */
1483
1484                 if (buf & SDW_SCP_INT1_IMPL_DEF) {
1485                         if (slave->prop.scp_int1_mask & SDW_SCP_INT1_IMPL_DEF) {
1486                                 dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
1487                                 slave_notify = true;
1488                         }
1489                         clear |= SDW_SCP_INT1_IMPL_DEF;
1490                 }
1491
1492                 /* Check port 0 - 3 interrupts */
1493                 port = buf & SDW_SCP_INT1_PORT0_3;
1494
1495                 /* To get port number corresponding to bits, shift it */
1496                 port = FIELD_GET(SDW_SCP_INT1_PORT0_3, port);
1497                 for_each_set_bit(bit, &port, 8) {
1498                         sdw_handle_port_interrupt(slave, bit,
1499                                                   &port_status[bit]);
1500                 }
1501
1502                 /* Check if cascade 2 interrupt is present */
1503                 if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
1504                         port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
1505                         for_each_set_bit(bit, &port, 8) {
1506                                 /* scp2 ports start from 4 */
1507                                 port_num = bit + 3;
1508                                 sdw_handle_port_interrupt(slave,
1509                                                 port_num,
1510                                                 &port_status[port_num]);
1511                         }
1512                 }
1513
1514                 /* now check last cascade */
1515                 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
1516                         port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
1517                         for_each_set_bit(bit, &port, 8) {
1518                                 /* scp3 ports start from 11 */
1519                                 port_num = bit + 10;
1520                                 sdw_handle_port_interrupt(slave,
1521                                                 port_num,
1522                                                 &port_status[port_num]);
1523                         }
1524                 }
1525
1526                 /* Update the Slave driver */
1527                 if (slave_notify && slave->ops &&
1528                     slave->ops->interrupt_callback) {
1529                         slave_intr.control_port = clear;
1530                         memcpy(slave_intr.port, &port_status,
1531                                sizeof(slave_intr.port));
1532
1533                         slave->ops->interrupt_callback(slave, &slave_intr);
1534                 }
1535
1536                 /* Ack interrupt */
1537                 ret = sdw_write(slave, SDW_SCP_INT1, clear);
1538                 if (ret < 0) {
1539                         dev_err(slave->bus->dev,
1540                                 "SDW_SCP_INT1 write failed:%d\n", ret);
1541                         goto io_err;
1542                 }
1543
1544                 /* at this point all initial interrupt sources were handled */
1545                 slave->first_interrupt_done = true;
1546
1547                 /*
1548                  * Read status again to ensure no new interrupts arrived
1549                  * while servicing interrupts.
1550                  */
1551                 ret = sdw_read(slave, SDW_SCP_INT1);
1552                 if (ret < 0) {
1553                         dev_err(slave->bus->dev,
1554                                 "SDW_SCP_INT1 read failed:%d\n", ret);
1555                         goto io_err;
1556                 }
1557                 _buf = ret;
1558
1559                 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
1560                 if (ret < 0) {
1561                         dev_err(slave->bus->dev,
1562                                 "SDW_SCP_INT2/3 read failed:%d\n", ret);
1563                         goto io_err;
1564                 }
1565
1566                 /* Make sure no interrupts are pending */
1567                 buf &= _buf;
1568                 buf2[0] &= _buf2[0];
1569                 buf2[1] &= _buf2[1];
1570                 stat = buf || buf2[0] || buf2[1];
1571
1572                 /*
1573                  * Exit loop if Slave is continuously in ALERT state even
1574                  * after servicing the interrupt multiple times.
1575                  */
1576                 count++;
1577
1578                 /* we can get alerts while processing so keep retrying */
1579         } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1580
1581         if (count == SDW_READ_INTR_CLEAR_RETRY)
1582                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
1583
1584 io_err:
1585         pm_runtime_mark_last_busy(&slave->dev);
1586         pm_runtime_put_autosuspend(&slave->dev);
1587
1588         return ret;
1589 }
1590
1591 static int sdw_update_slave_status(struct sdw_slave *slave,
1592                                    enum sdw_slave_status status)
1593 {
1594         unsigned long time;
1595
1596         if (!slave->probed) {
1597                 /*
1598                  * the slave status update is typically handled in an
1599                  * interrupt thread, which can race with the driver
1600                  * probe, e.g. when a module needs to be loaded.
1601                  *
1602                  * make sure the probe is complete before updating
1603                  * status.
1604                  */
1605                 time = wait_for_completion_timeout(&slave->probe_complete,
1606                                 msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
1607                 if (!time) {
1608                         dev_err(&slave->dev, "Probe not complete, timed out\n");
1609                         return -ETIMEDOUT;
1610                 }
1611         }
1612
1613         if (!slave->ops || !slave->ops->update_status)
1614                 return 0;
1615
1616         return slave->ops->update_status(slave, status);
1617 }
1618
1619 /**
1620  * sdw_handle_slave_status() - Handle Slave status
1621  * @bus: SDW bus instance
1622  * @status: Status for all Slave(s)
1623  */
1624 int sdw_handle_slave_status(struct sdw_bus *bus,
1625                             enum sdw_slave_status status[])
1626 {
1627         enum sdw_slave_status prev_status;
1628         struct sdw_slave *slave;
1629         bool attached_initializing;
1630         int i, ret = 0;
1631
1632         /* first check if any Slaves fell off the bus */
1633         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1634                 mutex_lock(&bus->bus_lock);
1635                 if (test_bit(i, bus->assigned) == false) {
1636                         mutex_unlock(&bus->bus_lock);
1637                         continue;
1638                 }
1639                 mutex_unlock(&bus->bus_lock);
1640
1641                 slave = sdw_get_slave(bus, i);
1642                 if (!slave)
1643                         continue;
1644
1645                 if (status[i] == SDW_SLAVE_UNATTACHED &&
1646                     slave->status != SDW_SLAVE_UNATTACHED)
1647                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1648         }
1649
1650         if (status[0] == SDW_SLAVE_ATTACHED) {
1651                 dev_dbg(bus->dev, "Slave attached, programming device number\n");
1652                 ret = sdw_program_device_num(bus);
1653                 if (ret)
1654                         dev_err(bus->dev, "Slave attach failed: %d\n", ret);
1655                 /*
1656                  * programming a device number will have side effects,
1657                  * so we deal with other devices at a later time
1658                  */
1659                 return ret;
1660         }
1661
1662         /* Continue to check other slave statuses */
1663         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1664                 mutex_lock(&bus->bus_lock);
1665                 if (test_bit(i, bus->assigned) == false) {
1666                         mutex_unlock(&bus->bus_lock);
1667                         continue;
1668                 }
1669                 mutex_unlock(&bus->bus_lock);
1670
1671                 slave = sdw_get_slave(bus, i);
1672                 if (!slave)
1673                         continue;
1674
1675                 attached_initializing = false;
1676
1677                 switch (status[i]) {
1678                 case SDW_SLAVE_UNATTACHED:
1679                         if (slave->status == SDW_SLAVE_UNATTACHED)
1680                                 break;
1681
1682                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1683                         break;
1684
1685                 case SDW_SLAVE_ALERT:
1686                         ret = sdw_handle_slave_alerts(slave);
1687                         if (ret)
1688                                 dev_err(bus->dev,
1689                                         "Slave %d alert handling failed: %d\n",
1690                                         i, ret);
1691                         break;
1692
1693                 case SDW_SLAVE_ATTACHED:
1694                         if (slave->status == SDW_SLAVE_ATTACHED)
1695                                 break;
1696
1697                         prev_status = slave->status;
1698                         sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1699
1700                         if (prev_status == SDW_SLAVE_ALERT)
1701                                 break;
1702
1703                         attached_initializing = true;
1704
1705                         ret = sdw_initialize_slave(slave);
1706                         if (ret)
1707                                 dev_err(bus->dev,
1708                                         "Slave %d initialization failed: %d\n",
1709                                         i, ret);
1710
1711                         break;
1712
1713                 default:
1714                         dev_err(bus->dev, "Invalid slave %d status:%d\n",
1715                                 i, status[i]);
1716                         break;
1717                 }
1718
1719                 ret = sdw_update_slave_status(slave, status[i]);
1720                 if (ret)
1721                         dev_err(slave->bus->dev,
1722                                 "Update Slave status failed:%d\n", ret);
1723                 if (attached_initializing)
1724                         complete(&slave->initialization_complete);
1725         }
1726
1727         return ret;
1728 }
1729 EXPORT_SYMBOL(sdw_handle_slave_status);
1730
1731 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1732 {
1733         struct sdw_slave *slave;
1734         int i;
1735
1736         /* Check all non-zero devices */
1737         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1738                 mutex_lock(&bus->bus_lock);
1739                 if (test_bit(i, bus->assigned) == false) {
1740                         mutex_unlock(&bus->bus_lock);
1741                         continue;
1742                 }
1743                 mutex_unlock(&bus->bus_lock);
1744
1745                 slave = sdw_get_slave(bus, i);
1746                 if (!slave)
1747                         continue;
1748
1749                 if (slave->status != SDW_SLAVE_UNATTACHED) {
1750                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1751                         slave->first_interrupt_done = false;
1752                 }
1753
1754                 /* keep track of request, used in pm_runtime resume */
1755                 slave->unattach_request = request;
1756         }
1757 }
1758 EXPORT_SYMBOL(sdw_clear_slave_status);