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\n");
  25                 return -ENODEV;
  26         }
  27
  28         if (!bus->ops) {
  29                 dev_err(bus->dev, "SoundWire Bus ops are not set\n");
  30                 return -EINVAL;
  31         }
  32
  33         mutex_init(&bus->msg_lock);
  34         mutex_init(&bus->bus_lock);
  35         INIT_LIST_HEAD(&bus->slaves);
  36         INIT_LIST_HEAD(&bus->m_rt_list);
  37
  38         /*
  39          * Initialize multi_link flag
  40          * TODO: populate this flag by reading property from FW node
  41          */
  42         bus->multi_link = false;
  43         if (bus->ops->read_prop) {
  44                 ret = bus->ops->read_prop(bus);
  45                 if (ret < 0) {
  46                         dev_err(bus->dev,
  47                                 "Bus read properties failed:%d\n", ret);
  48                         return ret;
  49                 }
  50         }
  51
  52         sdw_bus_debugfs_init(bus);
  53
  54         /*
  55          * Device numbers in SoundWire are 0 through 15. Enumeration device
  56          * number (0), Broadcast device number (15), Group numbers (12 and
  57          * 13) and Master device number (14) are not used for assignment so
  58          * mask these and other higher bits.
  59          */
  60
  61         /* Set higher order bits */
  62         *bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
  63
  64         /* Set enumuration device number and broadcast device number */
  65         set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
  66         set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
  67
  68         /* Set group device numbers and master device number */
  69         set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
  70         set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
  71         set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
  72
  73         /*
  74          * SDW is an enumerable bus, but devices can be powered off. So,
  75          * they won't be able to report as present.
  76          *
  77          * Create Slave devices based on Slaves described in
  78          * the respective firmware (ACPI/DT)
  79          */
  80         if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
  81                 ret = sdw_acpi_find_slaves(bus);
  82         else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
  83                 ret = sdw_of_find_slaves(bus);
  84         else
  85                 ret = -ENOTSUPP; /* No ACPI/DT so error out */
  86
  87         if (ret) {
  88                 dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
  89                 return ret;
  90         }
  91
  92         /*
  93          * Initialize clock values based on Master properties. The max
  94          * frequency is read from max_clk_freq property. Current assumption
  95          * is that the bus will start at highest clock frequency when
  96          * powered on.
  97          *
  98          * Default active bank will be 0 as out of reset the Slaves have
  99          * to start with bank 0 (Table 40 of Spec)
 100          */
 101         prop = &bus->prop;
 102         bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
 103         bus->params.curr_dr_freq = bus->params.max_dr_freq;
 104         bus->params.curr_bank = SDW_BANK0;
 105         bus->params.next_bank = SDW_BANK1;
 106
 107         return 0;
 108 }
 109 EXPORT_SYMBOL(sdw_add_bus_master);
 110
 111 static int sdw_delete_slave(struct device *dev, void *data)
 112 {
 113         struct sdw_slave *slave = dev_to_sdw_dev(dev);
 114         struct sdw_bus *bus = slave->bus;
 115
 116         sdw_slave_debugfs_exit(slave);
 117
 118         mutex_lock(&bus->bus_lock);
 119
 120         if (slave->dev_num) /* clear dev_num if assigned */
 121                 clear_bit(slave->dev_num, bus->assigned);
 122
 123         list_del_init(&slave->node);
 124         mutex_unlock(&bus->bus_lock);
 125
 126         device_unregister(dev);
 127         return 0;
 128 }
 129
 130 /**
 131  * sdw_delete_bus_master() - delete the bus master instance
 132  * @bus: bus to be deleted
 133  *
 134  * Remove the instance, delete the child devices.
 135  */
 136 void sdw_delete_bus_master(struct sdw_bus *bus)
 137 {
 138         device_for_each_child(bus->dev, NULL, sdw_delete_slave);
 139
 140         sdw_bus_debugfs_exit(bus);
 141 }
 142 EXPORT_SYMBOL(sdw_delete_bus_master);
 143
 144 /*
 145  * SDW IO Calls
 146  */
 147
 148 static inline int find_response_code(enum sdw_command_response resp)
 149 {
 150         switch (resp) {
 151         case SDW_CMD_OK:
 152                 return 0;
 153
 154         case SDW_CMD_IGNORED:
 155                 return -ENODATA;
 156
 157         case SDW_CMD_TIMEOUT:
 158                 return -ETIMEDOUT;
 159
 160         default:
 161                 return -EIO;
 162         }
 163 }
 164
 165 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 166 {
 167         int retry = bus->prop.err_threshold;
 168         enum sdw_command_response resp;
 169         int ret = 0, i;
 170
 171         for (i = 0; i <= retry; i++) {
 172                 resp = bus->ops->xfer_msg(bus, msg);
 173                 ret = find_response_code(resp);
 174
 175                 /* if cmd is ok or ignored return */
 176                 if (ret == 0 || ret == -ENODATA)
 177                         return ret;
 178         }
 179
 180         return ret;
 181 }
 182
 183 static inline int do_transfer_defer(struct sdw_bus *bus,
 184                                     struct sdw_msg *msg,
 185                                     struct sdw_defer *defer)
 186 {
 187         int retry = bus->prop.err_threshold;
 188         enum sdw_command_response resp;
 189         int ret = 0, i;
 190
 191         defer->msg = msg;
 192         defer->length = msg->len;
 193         init_completion(&defer->complete);
 194
 195         for (i = 0; i <= retry; i++) {
 196                 resp = bus->ops->xfer_msg_defer(bus, msg, defer);
 197                 ret = find_response_code(resp);
 198                 /* if cmd is ok or ignored return */
 199                 if (ret == 0 || ret == -ENODATA)
 200                         return ret;
 201         }
 202
 203         return ret;
 204 }
 205
 206 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)
 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->reset_page_addr(bus, dev_num);
 214                 ret = find_response_code(resp);
 215                 /* if cmd is ok or ignored return */
 216                 if (ret == 0 || ret == -ENODATA)
 217                         return ret;
 218         }
 219
 220         return ret;
 221 }
 222
 223 /**
 224  * sdw_transfer() - Synchronous transfer message to a SDW Slave device
 225  * @bus: SDW bus
 226  * @msg: SDW message to be xfered
 227  */
 228 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
 229 {
 230         int ret;
 231
 232         mutex_lock(&bus->msg_lock);
 233
 234         ret = do_transfer(bus, msg);
 235         if (ret != 0 && ret != -ENODATA)
 236                 dev_err(bus->dev, "trf on Slave %d failed:%d\n",
 237                         msg->dev_num, ret);
 238
 239         if (msg->page)
 240                 sdw_reset_page(bus, msg->dev_num);
 241
 242         mutex_unlock(&bus->msg_lock);
 243
 244         return ret;
 245 }
 246
 247 /**
 248  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
 249  * @bus: SDW bus
 250  * @msg: SDW message to be xfered
 251  * @defer: Defer block for signal completion
 252  *
 253  * Caller needs to hold the msg_lock lock while calling this
 254  */
 255 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
 256                        struct sdw_defer *defer)
 257 {
 258         int ret;
 259
 260         if (!bus->ops->xfer_msg_defer)
 261                 return -ENOTSUPP;
 262
 263         ret = do_transfer_defer(bus, msg, defer);
 264         if (ret != 0 && ret != -ENODATA)
 265                 dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
 266                         msg->dev_num, ret);
 267
 268         if (msg->page)
 269                 sdw_reset_page(bus, msg->dev_num);
 270
 271         return ret;
 272 }
 273
 274 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
 275                  u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
 276 {
 277         memset(msg, 0, sizeof(*msg));
 278         msg->addr = addr; /* addr is 16 bit and truncated here */
 279         msg->len = count;
 280         msg->dev_num = dev_num;
 281         msg->flags = flags;
 282         msg->buf = buf;
 283
 284         if (addr < SDW_REG_NO_PAGE) { /* no paging area */
 285                 return 0;
 286         } else if (addr >= SDW_REG_MAX) { /* illegal addr */
 287                 pr_err("SDW: Invalid address %x passed\n", addr);
 288                 return -EINVAL;
 289         }
 290
 291         if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
 292                 if (slave && !slave->prop.paging_support)
 293                         return 0;
 294                 /* no need for else as that will fall-through to paging */
 295         }
 296
 297         /* paging mandatory */
 298         if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
 299                 pr_err("SDW: Invalid device for paging :%d\n", dev_num);
 300                 return -EINVAL;
 301         }
 302
 303         if (!slave) {
 304                 pr_err("SDW: No slave for paging addr\n");
 305                 return -EINVAL;
 306         } else if (!slave->prop.paging_support) {
 307                 dev_err(&slave->dev,
 308                         "address %x needs paging but no support\n", addr);
 309                 return -EINVAL;
 310         }
 311
 312         msg->addr_page1 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE1_MASK));
 313         msg->addr_page2 = (addr >> SDW_REG_SHIFT(SDW_SCP_ADDRPAGE2_MASK));
 314         msg->addr |= BIT(15);
 315         msg->page = true;
 316
 317         return 0;
 318 }
 319
 320 /**
 321  * sdw_nread() - Read "n" contiguous SDW Slave registers
 322  * @slave: SDW Slave
 323  * @addr: Register address
 324  * @count: length
 325  * @val: Buffer for values to be read
 326  */
 327 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 328 {
 329         struct sdw_msg msg;
 330         int ret;
 331
 332         ret = sdw_fill_msg(&msg, slave, addr, count,
 333                            slave->dev_num, SDW_MSG_FLAG_READ, val);
 334         if (ret < 0)
 335                 return ret;
 336
 337         ret = pm_runtime_get_sync(slave->bus->dev);
 338         if (ret < 0)
 339                 return ret;
 340
 341         ret = sdw_transfer(slave->bus, &msg);
 342         pm_runtime_put(slave->bus->dev);
 343
 344         return ret;
 345 }
 346 EXPORT_SYMBOL(sdw_nread);
 347
 348 /**
 349  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
 350  * @slave: SDW Slave
 351  * @addr: Register address
 352  * @count: length
 353  * @val: Buffer for values to be read
 354  */
 355 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
 356 {
 357         struct sdw_msg msg;
 358         int ret;
 359
 360         ret = sdw_fill_msg(&msg, slave, addr, count,
 361                            slave->dev_num, SDW_MSG_FLAG_WRITE, val);
 362         if (ret < 0)
 363                 return ret;
 364
 365         ret = pm_runtime_get_sync(slave->bus->dev);
 366         if (ret < 0)
 367                 return ret;
 368
 369         ret = sdw_transfer(slave->bus, &msg);
 370         pm_runtime_put(slave->bus->dev);
 371
 372         return ret;
 373 }
 374 EXPORT_SYMBOL(sdw_nwrite);
 375
 376 /**
 377  * sdw_read() - Read a SDW Slave register
 378  * @slave: SDW Slave
 379  * @addr: Register address
 380  */
 381 int sdw_read(struct sdw_slave *slave, u32 addr)
 382 {
 383         u8 buf;
 384         int ret;
 385
 386         ret = sdw_nread(slave, addr, 1, &buf);
 387         if (ret < 0)
 388                 return ret;
 389         else
 390                 return buf;
 391 }
 392 EXPORT_SYMBOL(sdw_read);
 393
 394 /**
 395  * sdw_write() - Write a SDW Slave register
 396  * @slave: SDW Slave
 397  * @addr: Register address
 398  * @value: Register value
 399  */
 400 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
 401 {
 402         return sdw_nwrite(slave, addr, 1, &value);
 403 }
 404 EXPORT_SYMBOL(sdw_write);
 405
 406 /*
 407  * SDW alert handling
 408  */
 409
 410 /* called with bus_lock held */
 411 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
 412 {
 413         struct sdw_slave *slave = NULL;
 414
 415         list_for_each_entry(slave, &bus->slaves, node) {
 416                 if (slave->dev_num == i)
 417                         return slave;
 418         }
 419
 420         return NULL;
 421 }
 422
 423 static int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
 424 {
 425         if (slave->id.mfg_id != id.mfg_id ||
 426             slave->id.part_id != id.part_id ||
 427             slave->id.class_id != id.class_id ||
 428             (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
 429              slave->id.unique_id != id.unique_id))
 430                 return -ENODEV;
 431
 432         return 0;
 433 }
 434
 435 /* called with bus_lock held */
 436 static int sdw_get_device_num(struct sdw_slave *slave)
 437 {
 438         int bit;
 439
 440         bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
 441         if (bit == SDW_MAX_DEVICES) {
 442                 bit = -ENODEV;
 443                 goto err;
 444         }
 445
 446         /*
 447          * Do not update dev_num in Slave data structure here,
 448          * Update once program dev_num is successful
 449          */
 450         set_bit(bit, slave->bus->assigned);
 451
 452 err:
 453         return bit;
 454 }
 455
 456 static int sdw_assign_device_num(struct sdw_slave *slave)
 457 {
 458         int ret, dev_num;
 459
 460         /* check first if device number is assigned, if so reuse that */
 461         if (!slave->dev_num) {
 462                 mutex_lock(&slave->bus->bus_lock);
 463                 dev_num = sdw_get_device_num(slave);
 464                 mutex_unlock(&slave->bus->bus_lock);
 465                 if (dev_num < 0) {
 466                         dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
 467                                 dev_num);
 468                         return dev_num;
 469                 }
 470         } else {
 471                 dev_info(slave->bus->dev,
 472                          "Slave already registered dev_num:%d\n",
 473                          slave->dev_num);
 474
 475                 /* Clear the slave->dev_num to transfer message on device 0 */
 476                 dev_num = slave->dev_num;
 477                 slave->dev_num = 0;
 478         }
 479
 480         ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
 481         if (ret < 0) {
 482                 dev_err(&slave->dev, "Program device_num %d failed: %d\n",
 483                         dev_num, ret);
 484                 return ret;
 485         }
 486
 487         /* After xfer of msg, restore dev_num */
 488         slave->dev_num = dev_num;
 489
 490         return 0;
 491 }
 492
 493 void sdw_extract_slave_id(struct sdw_bus *bus,
 494                           u64 addr, struct sdw_slave_id *id)
 495 {
 496         dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
 497
 498         /*
 499          * Spec definition
 500          *   Register           Bit     Contents
 501          *   DevId_0 [7:4]      47:44   sdw_version
 502          *   DevId_0 [3:0]      43:40   unique_id
 503          *   DevId_1            39:32   mfg_id [15:8]
 504          *   DevId_2            31:24   mfg_id [7:0]
 505          *   DevId_3            23:16   part_id [15:8]
 506          *   DevId_4            15:08   part_id [7:0]
 507          *   DevId_5            07:00   class_id
 508          */
 509         id->sdw_version = (addr >> 44) & GENMASK(3, 0);
 510         id->unique_id = (addr >> 40) & GENMASK(3, 0);
 511         id->mfg_id = (addr >> 24) & GENMASK(15, 0);
 512         id->part_id = (addr >> 8) & GENMASK(15, 0);
 513         id->class_id = addr & GENMASK(7, 0);
 514
 515         dev_dbg(bus->dev,
 516                 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",
 517                                 id->class_id, id->part_id, id->mfg_id,
 518                                 id->unique_id, id->sdw_version);
 519 }
 520
 521 static int sdw_program_device_num(struct sdw_bus *bus)
 522 {
 523         u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
 524         struct sdw_slave *slave, *_s;
 525         struct sdw_slave_id id;
 526         struct sdw_msg msg;
 527         bool found = false;
 528         int count = 0, ret;
 529         u64 addr;
 530
 531         /* No Slave, so use raw xfer api */
 532         ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
 533                            SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
 534         if (ret < 0)
 535                 return ret;
 536
 537         do {
 538                 ret = sdw_transfer(bus, &msg);
 539                 if (ret == -ENODATA) { /* end of device id reads */
 540                         dev_dbg(bus->dev, "No more devices to enumerate\n");
 541                         ret = 0;
 542                         break;
 543                 }
 544                 if (ret < 0) {
 545                         dev_err(bus->dev, "DEVID read fail:%d\n", ret);
 546                         break;
 547                 }
 548
 549                 /*
 550                  * Construct the addr and extract. Cast the higher shift
 551                  * bits to avoid truncation due to size limit.
 552                  */
 553                 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
 554                         ((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
 555                         ((u64)buf[0] << 40);
 556
 557                 sdw_extract_slave_id(bus, addr, &id);
 558
 559                 /* Now compare with entries */
 560                 list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
 561                         if (sdw_compare_devid(slave, id) == 0) {
 562                                 found = true;
 563
 564                                 /*
 565                                  * Assign a new dev_num to this Slave and
 566                                  * not mark it present. It will be marked
 567                                  * present after it reports ATTACHED on new
 568                                  * dev_num
 569                                  */
 570                                 ret = sdw_assign_device_num(slave);
 571                                 if (ret) {
 572                                         dev_err(slave->bus->dev,
 573                                                 "Assign dev_num failed:%d\n",
 574                                                 ret);
 575                                         return ret;
 576                                 }
 577
 578                                 break;
 579                         }
 580                 }
 581
 582                 if (!found) {
 583                         /* TODO: Park this device in Group 13 */
 584                         dev_err(bus->dev, "Slave Entry not found\n");
 585                 }
 586
 587                 count++;
 588
 589                 /*
 590                  * Check till error out or retry (count) exhausts.
 591                  * Device can drop off and rejoin during enumeration
 592                  * so count till twice the bound.
 593                  */
 594
 595         } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
 596
 597         return ret;
 598 }
 599
 600 static void sdw_modify_slave_status(struct sdw_slave *slave,
 601                                     enum sdw_slave_status status)
 602 {
 603         mutex_lock(&slave->bus->bus_lock);
 604         slave->status = status;
 605         mutex_unlock(&slave->bus->bus_lock);
 606 }
 607
 608 int sdw_configure_dpn_intr(struct sdw_slave *slave,
 609                            int port, bool enable, int mask)
 610 {
 611         u32 addr;
 612         int ret;
 613         u8 val = 0;
 614
 615         addr = SDW_DPN_INTMASK(port);
 616
 617         /* Set/Clear port ready interrupt mask */
 618         if (enable) {
 619                 val |= mask;
 620                 val |= SDW_DPN_INT_PORT_READY;
 621         } else {
 622                 val &= ~(mask);
 623                 val &= ~SDW_DPN_INT_PORT_READY;
 624         }
 625
 626         ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
 627         if (ret < 0)
 628                 dev_err(slave->bus->dev,
 629                         "SDW_DPN_INTMASK write failed:%d\n", val);
 630
 631         return ret;
 632 }
 633
 634 static int sdw_initialize_slave(struct sdw_slave *slave)
 635 {
 636         struct sdw_slave_prop *prop = &slave->prop;
 637         int ret;
 638         u8 val;
 639
 640         /*
 641          * Set bus clash, parity and SCP implementation
 642          * defined interrupt mask
 643          * TODO: Read implementation defined interrupt mask
 644          * from Slave property
 645          */
 646         val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
 647                                         SDW_SCP_INT1_PARITY;
 648
 649         /* Enable SCP interrupts */
 650         ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
 651         if (ret < 0) {
 652                 dev_err(slave->bus->dev,
 653                         "SDW_SCP_INTMASK1 write failed:%d\n", ret);
 654                 return ret;
 655         }
 656
 657         /* No need to continue if DP0 is not present */
 658         if (!slave->prop.dp0_prop)
 659                 return 0;
 660
 661         /* Enable DP0 interrupts */
 662         val = prop->dp0_prop->imp_def_interrupts;
 663         val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
 664
 665         ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
 666         if (ret < 0) {
 667                 dev_err(slave->bus->dev,
 668                         "SDW_DP0_INTMASK read failed:%d\n", ret);
 669                 return val;
 670         }
 671
 672         return 0;
 673 }
 674
 675 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
 676 {
 677         u8 clear = 0, impl_int_mask;
 678         int status, status2, ret, count = 0;
 679
 680         status = sdw_read(slave, SDW_DP0_INT);
 681         if (status < 0) {
 682                 dev_err(slave->bus->dev,
 683                         "SDW_DP0_INT read failed:%d\n", status);
 684                 return status;
 685         }
 686
 687         do {
 688                 if (status & SDW_DP0_INT_TEST_FAIL) {
 689                         dev_err(&slave->dev, "Test fail for port 0\n");
 690                         clear |= SDW_DP0_INT_TEST_FAIL;
 691                 }
 692
 693                 /*
 694                  * Assumption: PORT_READY interrupt will be received only for
 695                  * ports implementing Channel Prepare state machine (CP_SM)
 696                  */
 697
 698                 if (status & SDW_DP0_INT_PORT_READY) {
 699                         complete(&slave->port_ready[0]);
 700                         clear |= SDW_DP0_INT_PORT_READY;
 701                 }
 702
 703                 if (status & SDW_DP0_INT_BRA_FAILURE) {
 704                         dev_err(&slave->dev, "BRA failed\n");
 705                         clear |= SDW_DP0_INT_BRA_FAILURE;
 706                 }
 707
 708                 impl_int_mask = SDW_DP0_INT_IMPDEF1 |
 709                         SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
 710
 711                 if (status & impl_int_mask) {
 712                         clear |= impl_int_mask;
 713                         *slave_status = clear;
 714                 }
 715
 716                 /* clear the interrupt */
 717                 ret = sdw_write(slave, SDW_DP0_INT, clear);
 718                 if (ret < 0) {
 719                         dev_err(slave->bus->dev,
 720                                 "SDW_DP0_INT write failed:%d\n", ret);
 721                         return ret;
 722                 }
 723
 724                 /* Read DP0 interrupt again */
 725                 status2 = sdw_read(slave, SDW_DP0_INT);
 726                 if (status2 < 0) {
 727                         dev_err(slave->bus->dev,
 728                                 "SDW_DP0_INT read failed:%d\n", status2);
 729                         return status2;
 730                 }
 731                 status &= status2;
 732
 733                 count++;
 734
 735                 /* we can get alerts while processing so keep retrying */
 736         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 737
 738         if (count == SDW_READ_INTR_CLEAR_RETRY)
 739                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read\n");
 740
 741         return ret;
 742 }
 743
 744 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
 745                                      int port, u8 *slave_status)
 746 {
 747         u8 clear = 0, impl_int_mask;
 748         int status, status2, ret, count = 0;
 749         u32 addr;
 750
 751         if (port == 0)
 752                 return sdw_handle_dp0_interrupt(slave, slave_status);
 753
 754         addr = SDW_DPN_INT(port);
 755         status = sdw_read(slave, addr);
 756         if (status < 0) {
 757                 dev_err(slave->bus->dev,
 758                         "SDW_DPN_INT read failed:%d\n", status);
 759
 760                 return status;
 761         }
 762
 763         do {
 764                 if (status & SDW_DPN_INT_TEST_FAIL) {
 765                         dev_err(&slave->dev, "Test fail for port:%d\n", port);
 766                         clear |= SDW_DPN_INT_TEST_FAIL;
 767                 }
 768
 769                 /*
 770                  * Assumption: PORT_READY interrupt will be received only
 771                  * for ports implementing CP_SM.
 772                  */
 773                 if (status & SDW_DPN_INT_PORT_READY) {
 774                         complete(&slave->port_ready[port]);
 775                         clear |= SDW_DPN_INT_PORT_READY;
 776                 }
 777
 778                 impl_int_mask = SDW_DPN_INT_IMPDEF1 |
 779                         SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
 780
 781                 if (status & impl_int_mask) {
 782                         clear |= impl_int_mask;
 783                         *slave_status = clear;
 784                 }
 785
 786                 /* clear the interrupt */
 787                 ret = sdw_write(slave, addr, clear);
 788                 if (ret < 0) {
 789                         dev_err(slave->bus->dev,
 790                                 "SDW_DPN_INT write failed:%d\n", ret);
 791                         return ret;
 792                 }
 793
 794                 /* Read DPN interrupt again */
 795                 status2 = sdw_read(slave, addr);
 796                 if (status2 < 0) {
 797                         dev_err(slave->bus->dev,
 798                                 "SDW_DPN_INT read failed:%d\n", status2);
 799                         return status2;
 800                 }
 801                 status &= status2;
 802
 803                 count++;
 804
 805                 /* we can get alerts while processing so keep retrying */
 806         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 807
 808         if (count == SDW_READ_INTR_CLEAR_RETRY)
 809                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
 810
 811         return ret;
 812 }
 813
 814 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 815 {
 816         struct sdw_slave_intr_status slave_intr;
 817         u8 clear = 0, bit, port_status[15] = {0};
 818         int port_num, stat, ret, count = 0;
 819         unsigned long port;
 820         bool slave_notify = false;
 821         u8 buf, buf2[2], _buf, _buf2[2];
 822
 823         sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 824
 825         /* Read Instat 1, Instat 2 and Instat 3 registers */
 826         ret = sdw_read(slave, SDW_SCP_INT1);
 827         if (ret < 0) {
 828                 dev_err(slave->bus->dev,
 829                         "SDW_SCP_INT1 read failed:%d\n", ret);
 830                 return ret;
 831         }
 832         buf = ret;
 833
 834         ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
 835         if (ret < 0) {
 836                 dev_err(slave->bus->dev,
 837                         "SDW_SCP_INT2/3 read failed:%d\n", ret);
 838                 return ret;
 839         }
 840
 841         do {
 842                 /*
 843                  * Check parity, bus clash and Slave (impl defined)
 844                  * interrupt
 845                  */
 846                 if (buf & SDW_SCP_INT1_PARITY) {
 847                         dev_err(&slave->dev, "Parity error detected\n");
 848                         clear |= SDW_SCP_INT1_PARITY;
 849                 }
 850
 851                 if (buf & SDW_SCP_INT1_BUS_CLASH) {
 852                         dev_err(&slave->dev, "Bus clash error detected\n");
 853                         clear |= SDW_SCP_INT1_BUS_CLASH;
 854                 }
 855
 856                 /*
 857                  * When bus clash or parity errors are detected, such errors
 858                  * are unlikely to be recoverable errors.
 859                  * TODO: In such scenario, reset bus. Make this configurable
 860                  * via sysfs property with bus reset being the default.
 861                  */
 862
 863                 if (buf & SDW_SCP_INT1_IMPL_DEF) {
 864                         dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
 865                         clear |= SDW_SCP_INT1_IMPL_DEF;
 866                         slave_notify = true;
 867                 }
 868
 869                 /* Check port 0 - 3 interrupts */
 870                 port = buf & SDW_SCP_INT1_PORT0_3;
 871
 872                 /* To get port number corresponding to bits, shift it */
 873                 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3);
 874                 for_each_set_bit(bit, &port, 8) {
 875                         sdw_handle_port_interrupt(slave, bit,
 876                                                   &port_status[bit]);
 877                 }
 878
 879                 /* Check if cascade 2 interrupt is present */
 880                 if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
 881                         port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
 882                         for_each_set_bit(bit, &port, 8) {
 883                                 /* scp2 ports start from 4 */
 884                                 port_num = bit + 3;
 885                                 sdw_handle_port_interrupt(slave,
 886                                                 port_num,
 887                                                 &port_status[port_num]);
 888                         }
 889                 }
 890
 891                 /* now check last cascade */
 892                 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
 893                         port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
 894                         for_each_set_bit(bit, &port, 8) {
 895                                 /* scp3 ports start from 11 */
 896                                 port_num = bit + 10;
 897                                 sdw_handle_port_interrupt(slave,
 898                                                 port_num,
 899                                                 &port_status[port_num]);
 900                         }
 901                 }
 902
 903                 /* Update the Slave driver */
 904                 if (slave_notify && slave->ops &&
 905                     slave->ops->interrupt_callback) {
 906                         slave_intr.control_port = clear;
 907                         memcpy(slave_intr.port, &port_status,
 908                                sizeof(slave_intr.port));
 909
 910                         slave->ops->interrupt_callback(slave, &slave_intr);
 911                 }
 912
 913                 /* Ack interrupt */
 914                 ret = sdw_write(slave, SDW_SCP_INT1, clear);
 915                 if (ret < 0) {
 916                         dev_err(slave->bus->dev,
 917                                 "SDW_SCP_INT1 write failed:%d\n", ret);
 918                         return ret;
 919                 }
 920
 921                 /*
 922                  * Read status again to ensure no new interrupts arrived
 923                  * while servicing interrupts.
 924                  */
 925                 ret = sdw_read(slave, SDW_SCP_INT1);
 926                 if (ret < 0) {
 927                         dev_err(slave->bus->dev,
 928                                 "SDW_SCP_INT1 read failed:%d\n", ret);
 929                         return ret;
 930                 }
 931                 _buf = ret;
 932
 933                 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
 934                 if (ret < 0) {
 935                         dev_err(slave->bus->dev,
 936                                 "SDW_SCP_INT2/3 read failed:%d\n", ret);
 937                         return ret;
 938                 }
 939
 940                 /* Make sure no interrupts are pending */
 941                 buf &= _buf;
 942                 buf2[0] &= _buf2[0];
 943                 buf2[1] &= _buf2[1];
 944                 stat = buf || buf2[0] || buf2[1];
 945
 946                 /*
 947                  * Exit loop if Slave is continuously in ALERT state even
 948                  * after servicing the interrupt multiple times.
 949                  */
 950                 count++;
 951
 952                 /* we can get alerts while processing so keep retrying */
 953         } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 954
 955         if (count == SDW_READ_INTR_CLEAR_RETRY)
 956                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
 957
 958         return ret;
 959 }
 960
 961 static int sdw_update_slave_status(struct sdw_slave *slave,
 962                                    enum sdw_slave_status status)
 963 {
 964         if (slave->ops && slave->ops->update_status)
 965                 return slave->ops->update_status(slave, status);
 966
 967         return 0;
 968 }
 969
 970 /**
 971  * sdw_handle_slave_status() - Handle Slave status
 972  * @bus: SDW bus instance
 973  * @status: Status for all Slave(s)
 974  */
 975 int sdw_handle_slave_status(struct sdw_bus *bus,
 976                             enum sdw_slave_status status[])
 977 {
 978         enum sdw_slave_status prev_status;
 979         struct sdw_slave *slave;
 980         int i, ret = 0;
 981
 982         if (status[0] == SDW_SLAVE_ATTACHED) {
 983                 dev_dbg(bus->dev, "Slave attached, programming device number\n");
 984                 ret = sdw_program_device_num(bus);
 985                 if (ret)
 986                         dev_err(bus->dev, "Slave attach failed: %d\n", ret);
 987                 /*
 988                  * programming a device number will have side effects,
 989                  * so we deal with other devices at a later time
 990                  */
 991                 return ret;
 992         }
 993
 994         /* Continue to check other slave statuses */
 995         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
 996                 mutex_lock(&bus->bus_lock);
 997                 if (test_bit(i, bus->assigned) == false) {
 998                         mutex_unlock(&bus->bus_lock);
 999                         continue;
1000                 }
1001                 mutex_unlock(&bus->bus_lock);
1002
1003                 slave = sdw_get_slave(bus, i);
1004                 if (!slave)
1005                         continue;
1006
1007                 switch (status[i]) {
1008                 case SDW_SLAVE_UNATTACHED:
1009                         if (slave->status == SDW_SLAVE_UNATTACHED)
1010                                 break;
1011
1012                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1013                         break;
1014
1015                 case SDW_SLAVE_ALERT:
1016                         ret = sdw_handle_slave_alerts(slave);
1017                         if (ret)
1018                                 dev_err(bus->dev,
1019                                         "Slave %d alert handling failed: %d\n",
1020                                         i, ret);
1021                         break;
1022
1023                 case SDW_SLAVE_ATTACHED:
1024                         if (slave->status == SDW_SLAVE_ATTACHED)
1025                                 break;
1026
1027                         prev_status = slave->status;
1028                         sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1029
1030                         if (prev_status == SDW_SLAVE_ALERT)
1031                                 break;
1032
1033                         ret = sdw_initialize_slave(slave);
1034                         if (ret)
1035                                 dev_err(bus->dev,
1036                                         "Slave %d initialization failed: %d\n",
1037                                         i, ret);
1038
1039                         break;
1040
1041                 default:
1042                         dev_err(bus->dev, "Invalid slave %d status:%d\n",
1043                                 i, status[i]);
1044                         break;
1045                 }
1046
1047                 ret = sdw_update_slave_status(slave, status[i]);
1048                 if (ret)
1049                         dev_err(slave->bus->dev,
1050                                 "Update Slave status failed:%d\n", ret);
1051         }
1052
1053         return ret;
1054 }
1055 EXPORT_SYMBOL(sdw_handle_slave_status);