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/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         /*
  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, "Bus read properties failed:%d", ret);
  47                         return ret;
  48                 }
  49         }
  50
  51         /*
  52          * Device numbers in SoundWire are 0 thru 15. Enumeration device
  53          * number (0), Broadcast device number (15), Group numbers (12 and
  54          * 13) and Master device number (14) are not used for assignment so
  55          * mask these and other higher bits.
  56          */
  57
  58         /* Set higher order bits */
  59         *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
  60
  61         /* Set enumuration device number and broadcast device number */
  62         set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
  63         set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
  64
  65         /* Set group device numbers and master device number */
  66         set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
  67         set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
  68         set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
  69
  70         /*
  71          * SDW is an enumerable bus, but devices can be powered off. So,
  72          * they won't be able to report as present.
  73          *
  74          * Create Slave devices based on Slaves described in
  75          * the respective firmware (ACPI/DT)
  76          */
  77         if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
  78                 ret = sdw_acpi_find_slaves(bus);
  79         else
  80                 ret = -ENOTSUPP; /* No ACPI/DT so error out */
  81
  82         if (ret) {
  83                 dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
  84                 return ret;
  85         }
  86
  87         /*
  88          * Initialize clock values based on Master properties. The max
  89          * frequency is read from max_freq property. Current assumption
  90          * is that the bus will start at highest clock frequency when
  91          * powered on.
  92          *
  93          * Default active bank will be 0 as out of reset the Slaves have
  94          * to start with bank 0 (Table 40 of Spec)
  95          */
  96         prop = &bus->prop;
  97         bus->params.max_dr_freq = prop->max_freq * SDW_DOUBLE_RATE_FACTOR;
  98         bus->params.curr_dr_freq = bus->params.max_dr_freq;
  99         bus->params.curr_bank = SDW_BANK0;
 100         bus->params.next_bank = SDW_BANK1;
 101
 102         return 0;
 103 }
 104 EXPORT_SYMBOL(sdw_add_bus_master);
 105
 106 static int sdw_delete_slave(struct device *dev, void *data)
 107 {
 108         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 109         struct sdw_bus *bus = slave->bus;
 110
 111         mutex_lock(&bus->bus_lock);
 112
 113         if (slave->dev_num) /* clear dev_num if assigned */
 114                 clear_bit(slave->dev_num, bus->assigned);
 115
 116         list_del_init(&slave->node);
 117         mutex_unlock(&bus->bus_lock);
 118
 119         device_unregister(dev);
 120         return 0;
 121 }
 122
 123 /**
 124  * sdw_delete_bus_master() - delete the bus master instance
 125  * @bus: bus to be deleted
 126  *
 127  * Remove the instance, delete the child devices.
 128  */
 129 void sdw_delete_bus_master(struct sdw_bus *bus)
 130 {
 131         device_for_each_child(bus->dev, NULL, sdw_delete_slave);
 132 }
 133 EXPORT_SYMBOL(sdw_delete_bus_master);
 134
 135 /*
 136  * SDW IO Calls
 137  */
 138
 139 static inline int find_response_code(enum sdw_command_response resp)
 140 {
 141         switch (resp) {
 142         case SDW_CMD_OK:
 143                 return 0;
 144
 145         case SDW_CMD_IGNORED:
 146                 return -ENODATA;
 147
 148         case SDW_CMD_TIMEOUT:
 149                 return -ETIMEDOUT;
 150
 151         default:
 152                 return -EIO;
 153         }
 154 }
 155
 156 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 157 {
 158         int retry = bus->prop.err_threshold;
 159         enum sdw_command_response resp;
 160         int ret = 0, i;
 161
 162         for (i = 0; i <= retry; i++) {
 163                 resp = bus->ops->xfer_msg(bus, msg);
 164                 ret = find_response_code(resp);
 165
 166                 /* if cmd is ok or ignored return */
 167                 if (ret == 0 || ret == -ENODATA)
 168                         return ret;
 169         }
 170
 171         return ret;
 172 }
 173
 174 static inline int do_transfer_defer(struct sdw_bus *bus,
 175                         struct sdw_msg *msg, struct sdw_defer *defer)
 176 {
 177         int retry = bus->prop.err_threshold;
 178         enum sdw_command_response resp;
 179         int ret = 0, i;
 180
 181         defer->msg = msg;
 182         defer->length = msg->len;
 183         init_completion(&defer->complete);
 184
 185         for (i = 0; i <= retry; i++) {
 186                 resp = bus->ops->xfer_msg_defer(bus, msg, defer);
 187                 ret = find_response_code(resp);
 188                 /* if cmd is ok or ignored return */
 189                 if (ret == 0 || ret == -ENODATA)
 190                         return ret;
 191         }
 192
 193         return ret;
 194 }
 195
 196 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)
 197 {
 198         int retry = bus->prop.err_threshold;
 199         enum sdw_command_response resp;
 200         int ret = 0, i;
 201
 202         for (i = 0; i <= retry; i++) {
 203                 resp = bus->ops->reset_page_addr(bus, dev_num);
 204                 ret = find_response_code(resp);
 205                 /* if cmd is ok or ignored return */
 206                 if (ret == 0 || ret == -ENODATA)
 207                         return ret;
 208         }
 209
 210         return ret;
 211 }
 212
 213 /**
 214  * sdw_transfer() - Synchronous transfer message to a SDW Slave device
 215  * @bus: SDW bus
 216  * @msg: SDW message to be xfered
 217  */
 218 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 219 {
 220         int ret;
 221
 222         mutex_lock(&bus->msg_lock);
 223
 224         ret = do_transfer(bus, msg);
 225         if (ret != 0 && ret != -ENODATA)
 226                 dev_err(bus->dev, "trf on Slave %d failed:%d\n",
 227                                 msg->dev_num, ret);
 228
 229         if (msg->page)
 230                 sdw_reset_page(bus, msg->dev_num);
 231
 232         mutex_unlock(&bus->msg_lock);
 233
 234         return ret;
 235 }
 236
 237 /**
 238  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
 239  * @bus: SDW bus
 240  * @msg: SDW message to be xfered
 241  * @defer: Defer block for signal completion
 242  *
 243  * Caller needs to hold the msg_lock lock while calling this
 244  */
 245 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
 246                                 struct sdw_defer *defer)
 247 {
 248         int ret;
 249
 250         if (!bus->ops->xfer_msg_defer)
 251                 return -ENOTSUPP;
 252
 253         ret = do_transfer_defer(bus, msg, defer);
 254         if (ret != 0 && ret != -ENODATA)
 255                 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
 256                                 msg->dev_num, ret);
 257
 258         if (msg->page)
 259                 sdw_reset_page(bus, msg->dev_num);
 260
 261         return ret;
 262 }
 263
 264
 265 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
 266                 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
 267 {
 268         memset(msg, 0, sizeof(*msg));
 269         msg->addr = addr; /* addr is 16 bit and truncated here */
 270         msg->len = count;
 271         msg->dev_num = dev_num;
 272         msg->flags = flags;
 273         msg->buf = buf;
 274         msg->ssp_sync = false;
 275         msg->page = false;
 276
 277         if (addr < SDW_REG_NO_PAGE) { /* no paging area */
 278                 return 0;
 279         } else if (addr >= SDW_REG_MAX) { /* illegal addr */
 280                 pr_err("SDW: Invalid address %x passed\n", addr);
 281                 return -EINVAL;
 282         }
 283
 284         if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
 285                 if (slave && !slave->prop.paging_support)
 286                         return 0;
 287                 /* no need for else as that will fall thru to paging */
 288         }
 289
 290         /* paging mandatory */
 291         if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
 292                 pr_err("SDW: Invalid device for paging :%d\n", dev_num);
 293                 return -EINVAL;
 294         }
 295
 296         if (!slave) {
 297                 pr_err("SDW: No slave for paging addr\n");
 298                 return -EINVAL;
 299         } else if (!slave->prop.paging_support) {
 300                 dev_err(&slave->dev,
 301                         "address %x needs paging but no support", addr);
 302                 return -EINVAL;
 303         }
 304
 305         msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK));
 306         msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK));
 307         msg->addr |= BIT(15);
 308         msg->page = true;
 309
 310         return 0;
 311 }
 312
 313 /**
 314  * sdw_nread() - Read "n" contiguous SDW Slave registers
 315  * @slave: SDW Slave
 316  * @addr: Register address
 317  * @count: length
 318  * @val: Buffer for values to be read
 319  */
 320 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 321 {
 322         struct sdw_msg msg;
 323         int ret;
 324
 325         ret = sdw_fill_msg(&msg, slave, addr, count,
 326                         slave->dev_num, SDW_MSG_FLAG_READ, val);
 327         if (ret < 0)
 328                 return ret;
 329
 330         ret = pm_runtime_get_sync(slave->bus->dev);
 331         if (ret < 0)
 332                 return ret;
 333
 334         ret = sdw_transfer(slave->bus, &msg);
 335         pm_runtime_put(slave->bus->dev);
 336
 337         return ret;
 338 }
 339 EXPORT_SYMBOL(sdw_nread);
 340
 341 /**
 342  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
 343  * @slave: SDW Slave
 344  * @addr: Register address
 345  * @count: length
 346  * @val: Buffer for values to be read
 347  */
 348 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 349 {
 350         struct sdw_msg msg;
 351         int ret;
 352
 353         ret = sdw_fill_msg(&msg, slave, addr, count,
 354                         slave->dev_num, SDW_MSG_FLAG_WRITE, val);
 355         if (ret < 0)
 356                 return ret;
 357
 358         ret = pm_runtime_get_sync(slave->bus->dev);
 359         if (ret < 0)
 360                 return ret;
 361
 362         ret = sdw_transfer(slave->bus, &msg);
 363         pm_runtime_put(slave->bus->dev);
 364
 365         return ret;
 366 }
 367 EXPORT_SYMBOL(sdw_nwrite);
 368
 369 /**
 370  * sdw_read() - Read a SDW Slave register
 371  * @slave: SDW Slave
 372  * @addr: Register address
 373  */
 374 int sdw_read(struct sdw_slave *slave, u32 addr)
 375 {
 376         u8 buf;
 377         int ret;
 378
 379         ret = sdw_nread(slave, addr, 1, &buf);
 380         if (ret < 0)
 381                 return ret;
 382         else
 383                 return buf;
 384 }
 385 EXPORT_SYMBOL(sdw_read);
 386
 387 /**
 388  * sdw_write() - Write a SDW Slave register
 389  * @slave: SDW Slave
 390  * @addr: Register address
 391  * @value: Register value
 392  */
 393 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
 394 {
 395         return sdw_nwrite(slave, addr, 1, &value);
 396
 397 }
 398 EXPORT_SYMBOL(sdw_write);
 399
 400 /*
 401  * SDW alert handling
 402  */
 403
 404 /* called with bus_lock held */
 405 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
 406 {
 407         struct sdw_slave *slave = NULL;
 408
 409         list_for_each_entry(slave, &bus->slaves, node) {
 410                 if (slave->dev_num == i)
 411                         return slave;
 412         }
 413
 414         return NULL;
 415 }
 416
 417 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
 418 {
 419
 420         if ((slave->id.unique_id != id.unique_id) ||
 421             (slave->id.mfg_id != id.mfg_id) ||
 422             (slave->id.part_id != id.part_id) ||
 423             (slave->id.class_id != id.class_id))
 424                 return -ENODEV;
 425
 426         return 0;
 427 }
 428
 429 /* called with bus_lock held */
 430 static int sdw_get_device_num(struct sdw_slave *slave)
 431 {
 432         int bit;
 433
 434         bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
 435         if (bit == SDW_MAX_DEVICES) {
 436                 bit = -ENODEV;
 437                 goto err;
 438         }
 439
 440         /*
 441          * Do not update dev_num in Slave data structure here,
 442          * Update once program dev_num is successful
 443          */
 444         set_bit(bit, slave->bus->assigned);
 445
 446 err:
 447         return bit;
 448 }
 449
 450 static int sdw_assign_device_num(struct sdw_slave *slave)
 451 {
 452         int ret, dev_num;
 453
 454         /* check first if device number is assigned, if so reuse that */
 455         if (!slave->dev_num) {
 456                 mutex_lock(&slave->bus->bus_lock);
 457                 dev_num = sdw_get_device_num(slave);
 458                 mutex_unlock(&slave->bus->bus_lock);
 459                 if (dev_num < 0) {
 460                         dev_err(slave->bus->dev, "Get dev_num failed: %d",
 461                                                                 dev_num);
 462                         return dev_num;
 463                 }
 464         } else {
 465                 dev_info(slave->bus->dev,
 466                                 "Slave already registered dev_num:%d",
 467                                 slave->dev_num);
 468
 469                 /* Clear the slave->dev_num to transfer message on device 0 */
 470                 dev_num = slave->dev_num;
 471                 slave->dev_num = 0;
 472
 473         }
 474
 475         ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
 476         if (ret < 0) {
 477                 dev_err(&slave->dev, "Program device_num failed: %d", ret);
 478                 return ret;
 479         }
 480
 481         /* After xfer of msg, restore dev_num */
 482         slave->dev_num = dev_num;
 483
 484         return 0;
 485 }
 486
 487 void sdw_extract_slave_id(struct sdw_bus *bus,
 488                         u64 addr, struct sdw_slave_id *id)
 489 {
 490         dev_dbg(bus->dev, "SDW Slave Addr: %llx", addr);
 491
 492         /*
 493          * Spec definition
 494          *   Register           Bit     Contents
 495          *   DevId_0 [7:4]      47:44   sdw_version
 496          *   DevId_0 [3:0]      43:40   unique_id
 497          *   DevId_1            39:32   mfg_id [15:8]
 498          *   DevId_2            31:24   mfg_id [7:0]
 499          *   DevId_3            23:16   part_id [15:8]
 500          *   DevId_4            15:08   part_id [7:0]
 501          *   DevId_5            07:00   class_id
 502          */
 503         id->sdw_version = (addr >> 44) & GENMASK(3, 0);
 504         id->unique_id = (addr >> 40) & GENMASK(3, 0);
 505         id->mfg_id = (addr >> 24) & GENMASK(15, 0);
 506         id->part_id = (addr >> 8) & GENMASK(15, 0);
 507         id->class_id = addr & GENMASK(7, 0);
 508
 509         dev_dbg(bus->dev,
 510                 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x",
 511                                 id->class_id, id->part_id, id->mfg_id,
 512                                 id->unique_id, id->sdw_version);
 513
 514 }
 515
 516 static int sdw_program_device_num(struct sdw_bus *bus)
 517 {
 518         u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
 519         struct sdw_slave *slave, *_s;
 520         struct sdw_slave_id id;
 521         struct sdw_msg msg;
 522         bool found = false;
 523         int count = 0, ret;
 524         u64 addr;
 525
 526         /* No Slave, so use raw xfer api */
 527         ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
 528                         SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
 529         if (ret < 0)
 530                 return ret;
 531
 532         do {
 533                 ret = sdw_transfer(bus, &msg);
 534                 if (ret == -ENODATA) { /* end of device id reads */
 535                         ret = 0;
 536                         break;
 537                 }
 538                 if (ret < 0) {
 539                         dev_err(bus->dev, "DEVID read fail:%d\n", ret);
 540                         break;
 541                 }
 542
 543                 /*
 544                  * Construct the addr and extract. Cast the higher shift
 545                  * bits to avoid truncation due to size limit.
 546                  */
 547                 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
 548                         ((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
 549                         ((u64)buf[0] << 40);
 550
 551                 sdw_extract_slave_id(bus, addr, &id);
 552
 553                 /* Now compare with entries */
 554                 list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
 555                         if (sdw_compare_devid(slave, id) == 0) {
 556                                 found = true;
 557
 558                                 /*
 559                                  * Assign a new dev_num to this Slave and
 560                                  * not mark it present. It will be marked
 561                                  * present after it reports ATTACHED on new
 562                                  * dev_num
 563                                  */
 564                                 ret = sdw_assign_device_num(slave);
 565                                 if (ret) {
 566                                         dev_err(slave->bus->dev,
 567                                                 "Assign dev_num failed:%d",
 568                                                 ret);
 569                                         return ret;
 570                                 }
 571
 572                                 break;
 573                         }
 574                 }
 575
 576                 if (found == false) {
 577                         /* TODO: Park this device in Group 13 */
 578                         dev_err(bus->dev, "Slave Entry not found");
 579                 }
 580
 581                 count++;
 582
 583                 /*
 584                  * Check till error out or retry (count) exhausts.
 585                  * Device can drop off and rejoin during enumeration
 586                  * so count till twice the bound.
 587                  */
 588
 589         } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
 590
 591         return ret;
 592 }
 593
 594 static void sdw_modify_slave_status(struct sdw_slave *slave,
 595                                 enum sdw_slave_status status)
 596 {
 597         mutex_lock(&slave->bus->bus_lock);
 598         slave->status = status;
 599         mutex_unlock(&slave->bus->bus_lock);
 600 }
 601
 602 int sdw_configure_dpn_intr(struct sdw_slave *slave,
 603                         int port, bool enable, int mask)
 604 {
 605         u32 addr;
 606         int ret;
 607         u8 val = 0;
 608
 609         addr = SDW_DPN_INTMASK(port);
 610
 611         /* Set/Clear port ready interrupt mask */
 612         if (enable) {
 613                 val |= mask;
 614                 val |= SDW_DPN_INT_PORT_READY;
 615         } else {
 616                 val &= ~(mask);
 617                 val &= ~SDW_DPN_INT_PORT_READY;
 618         }
 619
 620         ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
 621         if (ret < 0)
 622                 dev_err(slave->bus->dev,
 623                                 "SDW_DPN_INTMASK write failed:%d", val);
 624
 625         return ret;
 626 }
 627
 628 static int sdw_initialize_slave(struct sdw_slave *slave)
 629 {
 630         struct sdw_slave_prop *prop = &slave->prop;
 631         int ret;
 632         u8 val;
 633
 634         /*
 635          * Set bus clash, parity and SCP implementation
 636          * defined interrupt mask
 637          * TODO: Read implementation defined interrupt mask
 638          * from Slave property
 639          */
 640         val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
 641                                         SDW_SCP_INT1_PARITY;
 642
 643         /* Enable SCP interrupts */
 644         ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
 645         if (ret < 0) {
 646                 dev_err(slave->bus->dev,
 647                                 "SDW_SCP_INTMASK1 write failed:%d", ret);
 648                 return ret;
 649         }
 650
 651         /* No need to continue if DP0 is not present */
 652         if (!slave->prop.dp0_prop)
 653                 return 0;
 654
 655         /* Enable DP0 interrupts */
 656         val = prop->dp0_prop->device_interrupts;
 657         val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
 658
 659         ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
 660         if (ret < 0) {
 661                 dev_err(slave->bus->dev,
 662                                 "SDW_DP0_INTMASK read failed:%d", ret);
 663                 return val;
 664         }
 665
 666         return 0;
 667 }
 668
 669 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
 670 {
 671         u8 clear = 0, impl_int_mask;
 672         int status, status2, ret, count = 0;
 673
 674         status = sdw_read(slave, SDW_DP0_INT);
 675         if (status < 0) {
 676                 dev_err(slave->bus->dev,
 677                                 "SDW_DP0_INT read failed:%d", status);
 678                 return status;
 679         }
 680
 681         do {
 682
 683                 if (status & SDW_DP0_INT_TEST_FAIL) {
 684                         dev_err(&slave->dev, "Test fail for port 0");
 685                         clear |= SDW_DP0_INT_TEST_FAIL;
 686                 }
 687
 688                 /*
 689                  * Assumption: PORT_READY interrupt will be received only for
 690                  * ports implementing Channel Prepare state machine (CP_SM)
 691                  */
 692
 693                 if (status & SDW_DP0_INT_PORT_READY) {
 694                         complete(&slave->port_ready[0]);
 695                         clear |= SDW_DP0_INT_PORT_READY;
 696                 }
 697
 698                 if (status & SDW_DP0_INT_BRA_FAILURE) {
 699                         dev_err(&slave->dev, "BRA failed");
 700                         clear |= SDW_DP0_INT_BRA_FAILURE;
 701                 }
 702
 703                 impl_int_mask = SDW_DP0_INT_IMPDEF1 |
 704                         SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
 705
 706                 if (status & impl_int_mask) {
 707                         clear |= impl_int_mask;
 708                         *slave_status = clear;
 709                 }
 710
 711                 /* clear the interrupt */
 712                 ret = sdw_write(slave, SDW_DP0_INT, clear);
 713                 if (ret < 0) {
 714                         dev_err(slave->bus->dev,
 715                                 "SDW_DP0_INT write failed:%d", ret);
 716                         return ret;
 717                 }
 718
 719                 /* Read DP0 interrupt again */
 720                 status2 = sdw_read(slave, SDW_DP0_INT);
 721                 if (status2 < 0) {
 722                         dev_err(slave->bus->dev,
 723                                 "SDW_DP0_INT read failed:%d", status2);
 724                         return status2;
 725                 }
 726                 status &= status2;
 727
 728                 count++;
 729
 730                 /* we can get alerts while processing so keep retrying */
 731         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 732
 733         if (count == SDW_READ_INTR_CLEAR_RETRY)
 734                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read");
 735
 736         return ret;
 737 }
 738
 739 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
 740                 int port, u8 *slave_status)
 741 {
 742         u8 clear = 0, impl_int_mask;
 743         int status, status2, ret, count = 0;
 744         u32 addr;
 745
 746         if (port == 0)
 747                 return sdw_handle_dp0_interrupt(slave, slave_status);
 748
 749         addr = SDW_DPN_INT(port);
 750         status = sdw_read(slave, addr);
 751         if (status < 0) {
 752                 dev_err(slave->bus->dev,
 753                                 "SDW_DPN_INT read failed:%d", status);
 754
 755                 return status;
 756         }
 757
 758         do {
 759
 760                 if (status & SDW_DPN_INT_TEST_FAIL) {
 761                         dev_err(&slave->dev, "Test fail for port:%d", port);
 762                         clear |= SDW_DPN_INT_TEST_FAIL;
 763                 }
 764
 765                 /*
 766                  * Assumption: PORT_READY interrupt will be received only
 767                  * for ports implementing CP_SM.
 768                  */
 769                 if (status & SDW_DPN_INT_PORT_READY) {
 770                         complete(&slave->port_ready[port]);
 771                         clear |= SDW_DPN_INT_PORT_READY;
 772                 }
 773
 774                 impl_int_mask = SDW_DPN_INT_IMPDEF1 |
 775                         SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
 776
 777
 778                 if (status & impl_int_mask) {
 779                         clear |= impl_int_mask;
 780                         *slave_status = clear;
 781                 }
 782
 783                 /* clear the interrupt */
 784                 ret = sdw_write(slave, addr, clear);
 785                 if (ret < 0) {
 786                         dev_err(slave->bus->dev,
 787                                         "SDW_DPN_INT write failed:%d", ret);
 788                         return ret;
 789                 }
 790
 791                 /* Read DPN interrupt again */
 792                 status2 = sdw_read(slave, addr);
 793                 if (status2 < 0) {
 794                         dev_err(slave->bus->dev,
 795                                         "SDW_DPN_INT read failed:%d", status2);
 796                         return status2;
 797                 }
 798                 status &= status2;
 799
 800                 count++;
 801
 802                 /* we can get alerts while processing so keep retrying */
 803         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 804
 805         if (count == SDW_READ_INTR_CLEAR_RETRY)
 806                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
 807
 808         return ret;
 809 }
 810
 811 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 812 {
 813         struct sdw_slave_intr_status slave_intr;
 814         u8 clear = 0, bit, port_status[15];
 815         int port_num, stat, ret, count = 0;
 816         unsigned long port;
 817         bool slave_notify = false;
 818         u8 buf, buf2[2], _buf, _buf2[2];
 819
 820         sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 821
 822         /* Read Instat 1, Instat 2 and Instat 3 registers */
 823         buf = ret = sdw_read(slave, SDW_SCP_INT1);
 824         if (ret < 0) {
 825                 dev_err(slave->bus->dev,
 826                                         "SDW_SCP_INT1 read failed:%d", ret);
 827                 return ret;
 828         }
 829
 830         ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
 831         if (ret < 0) {
 832                 dev_err(slave->bus->dev,
 833                                         "SDW_SCP_INT2/3 read failed:%d", ret);
 834                 return ret;
 835         }
 836
 837         do {
 838                 /*
 839                  * Check parity, bus clash and Slave (impl defined)
 840                  * interrupt
 841                  */
 842                 if (buf & SDW_SCP_INT1_PARITY) {
 843                         dev_err(&slave->dev, "Parity error detected");
 844                         clear |= SDW_SCP_INT1_PARITY;
 845                 }
 846
 847                 if (buf & SDW_SCP_INT1_BUS_CLASH) {
 848                         dev_err(&slave->dev, "Bus clash error detected");
 849                         clear |= SDW_SCP_INT1_BUS_CLASH;
 850                 }
 851
 852                 /*
 853                  * When bus clash or parity errors are detected, such errors
 854                  * are unlikely to be recoverable errors.
 855                  * TODO: In such scenario, reset bus. Make this configurable
 856                  * via sysfs property with bus reset being the default.
 857                  */
 858
 859                 if (buf & SDW_SCP_INT1_IMPL_DEF) {
 860                         dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
 861                         clear |= SDW_SCP_INT1_IMPL_DEF;
 862                         slave_notify = true;
 863                 }
 864
 865                 /* Check port 0 - 3 interrupts */
 866                 port = buf & SDW_SCP_INT1_PORT0_3;
 867
 868                 /* To get port number corresponding to bits, shift it */
 869                 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3);
 870                 for_each_set_bit(bit, &port, 8) {
 871                         sdw_handle_port_interrupt(slave, bit,
 872                                                 &port_status[bit]);
 873
 874                 }
 875
 876                 /* Check if cascade 2 interrupt is present */
 877                 if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
 878                         port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
 879                         for_each_set_bit(bit, &port, 8) {
 880                                 /* scp2 ports start from 4 */
 881                                 port_num = bit + 3;
 882                                 sdw_handle_port_interrupt(slave,
 883                                                 port_num,
 884                                                 &port_status[port_num]);
 885                         }
 886                 }
 887
 888                 /* now check last cascade */
 889                 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
 890                         port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
 891                         for_each_set_bit(bit, &port, 8) {
 892                                 /* scp3 ports start from 11 */
 893                                 port_num = bit + 10;
 894                                 sdw_handle_port_interrupt(slave,
 895                                                 port_num,
 896                                                 &port_status[port_num]);
 897                         }
 898                 }
 899
 900                 /* Update the Slave driver */
 901                 if (slave_notify && (slave->ops) &&
 902                                         (slave->ops->interrupt_callback)) {
 903                         slave_intr.control_port = clear;
 904                         memcpy(slave_intr.port, &port_status,
 905                                                 sizeof(slave_intr.port));
 906
 907                         slave->ops->interrupt_callback(slave, &slave_intr);
 908                 }
 909
 910                 /* Ack interrupt */
 911                 ret = sdw_write(slave, SDW_SCP_INT1, clear);
 912                 if (ret < 0) {
 913                         dev_err(slave->bus->dev,
 914                                         "SDW_SCP_INT1 write failed:%d", ret);
 915                         return ret;
 916                 }
 917
 918                 /*
 919                  * Read status again to ensure no new interrupts arrived
 920                  * while servicing interrupts.
 921                  */
 922                 _buf = ret = sdw_read(slave, SDW_SCP_INT1);
 923                 if (ret < 0) {
 924                         dev_err(slave->bus->dev,
 925                                         "SDW_SCP_INT1 read failed:%d", ret);
 926                         return ret;
 927                 }
 928
 929                 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
 930                 if (ret < 0) {
 931                         dev_err(slave->bus->dev,
 932                                         "SDW_SCP_INT2/3 read failed:%d", ret);
 933                         return ret;
 934                 }
 935
 936                 /* Make sure no interrupts are pending */
 937                 buf &= _buf;
 938                 buf2[0] &= _buf2[0];
 939                 buf2[1] &= _buf2[1];
 940                 stat = buf || buf2[0] || buf2[1];
 941
 942                 /*
 943                  * Exit loop if Slave is continuously in ALERT state even
 944                  * after servicing the interrupt multiple times.
 945                  */
 946                 count++;
 947
 948                 /* we can get alerts while processing so keep retrying */
 949         } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 950
 951         if (count == SDW_READ_INTR_CLEAR_RETRY)
 952                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read");
 953
 954         return ret;
 955 }
 956
 957 static int sdw_update_slave_status(struct sdw_slave *slave,
 958                                 enum sdw_slave_status status)
 959 {
 960         if ((slave->ops) && (slave->ops->update_status))
 961                 return slave->ops->update_status(slave, status);
 962
 963         return 0;
 964 }
 965
 966 /**
 967  * sdw_handle_slave_status() - Handle Slave status
 968  * @bus: SDW bus instance
 969  * @status: Status for all Slave(s)
 970  */
 971 int sdw_handle_slave_status(struct sdw_bus *bus,
 972                         enum sdw_slave_status status[])
 973 {
 974         enum sdw_slave_status prev_status;
 975         struct sdw_slave *slave;
 976         int i, ret = 0;
 977
 978         if (status[0] == SDW_SLAVE_ATTACHED) {
 979                 ret = sdw_program_device_num(bus);
 980                 if (ret)
 981                         dev_err(bus->dev, "Slave attach failed: %d", ret);
 982         }
 983
 984         /* Continue to check other slave statuses */
 985         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
 986                 mutex_lock(&bus->bus_lock);
 987                 if (test_bit(i, bus->assigned) == false) {
 988                         mutex_unlock(&bus->bus_lock);
 989                         continue;
 990                 }
 991                 mutex_unlock(&bus->bus_lock);
 992
 993                 slave = sdw_get_slave(bus, i);
 994                 if (!slave)
 995                         continue;
 996
 997                 switch (status[i]) {
 998                 case SDW_SLAVE_UNATTACHED:
 999                         if (slave->status == SDW_SLAVE_UNATTACHED)
1000                                 break;
1001
1002                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1003                         break;
1004
1005                 case SDW_SLAVE_ALERT:
1006                         ret = sdw_handle_slave_alerts(slave);
1007                         if (ret)
1008                                 dev_err(bus->dev,
1009                                         "Slave %d alert handling failed: %d",
1010                                         i, ret);
1011                         break;
1012
1013                 case SDW_SLAVE_ATTACHED:
1014                         if (slave->status == SDW_SLAVE_ATTACHED)
1015                                 break;
1016
1017                         prev_status = slave->status;
1018                         sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1019
1020                         if (prev_status == SDW_SLAVE_ALERT)
1021                                 break;
1022
1023                         ret = sdw_initialize_slave(slave);
1024                         if (ret)
1025                                 dev_err(bus->dev,
1026                                         "Slave %d initialization failed: %d",
1027                                         i, ret);
1028
1029                         break;
1030
1031                 default:
1032                         dev_err(bus->dev, "Invalid slave %d status:%d",
1033                                                         i, status[i]);
1034                         break;
1035                 }
1036
1037                 ret = sdw_update_slave_status(slave, status[i]);
1038                 if (ret)
1039                         dev_err(slave->bus->dev,
1040                                 "Update Slave status failed:%d", ret);
1041
1042         }
1043
1044         return ret;
1045 }
1046 EXPORT_SYMBOL(sdw_handle_slave_status);