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.unique_id != id.unique_id ||
 426             slave->id.mfg_id != id.mfg_id ||
 427             slave->id.part_id != id.part_id ||
 428             slave->id.class_id != id.class_id)
 429                 return -ENODEV;
 430
 431         return 0;
 432 }
 433
 434 /* called with bus_lock held */
 435 static int sdw_get_device_num(struct sdw_slave *slave)
 436 {
 437         int bit;
 438
 439         bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
 440         if (bit == SDW_MAX_DEVICES) {
 441                 bit = -ENODEV;
 442                 goto err;
 443         }
 444
 445         /*
 446          * Do not update dev_num in Slave data structure here,
 447          * Update once program dev_num is successful
 448          */
 449         set_bit(bit, slave->bus->assigned);
 450
 451 err:
 452         return bit;
 453 }
 454
 455 static int sdw_assign_device_num(struct sdw_slave *slave)
 456 {
 457         int ret, dev_num;
 458
 459         /* check first if device number is assigned, if so reuse that */
 460         if (!slave->dev_num) {
 461                 mutex_lock(&slave->bus->bus_lock);
 462                 dev_num = sdw_get_device_num(slave);
 463                 mutex_unlock(&slave->bus->bus_lock);
 464                 if (dev_num < 0) {
 465                         dev_err(slave->bus->dev, "Get dev_num failed: %d\n",
 466                                 dev_num);
 467                         return dev_num;
 468                 }
 469         } else {
 470                 dev_info(slave->bus->dev,
 471                          "Slave already registered dev_num:%d\n",
 472                          slave->dev_num);
 473
 474                 /* Clear the slave->dev_num to transfer message on device 0 */
 475                 dev_num = slave->dev_num;
 476                 slave->dev_num = 0;
 477         }
 478
 479         ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);
 480         if (ret < 0) {
 481                 dev_err(&slave->dev, "Program device_num %d failed: %d\n",
 482                         dev_num, ret);
 483                 return ret;
 484         }
 485
 486         /* After xfer of msg, restore dev_num */
 487         slave->dev_num = dev_num;
 488
 489         return 0;
 490 }
 491
 492 void sdw_extract_slave_id(struct sdw_bus *bus,
 493                           u64 addr, struct sdw_slave_id *id)
 494 {
 495         dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
 496
 497         /*
 498          * Spec definition
 499          *   Register           Bit     Contents
 500          *   DevId_0 [7:4]      47:44   sdw_version
 501          *   DevId_0 [3:0]      43:40   unique_id
 502          *   DevId_1            39:32   mfg_id [15:8]
 503          *   DevId_2            31:24   mfg_id [7:0]
 504          *   DevId_3            23:16   part_id [15:8]
 505          *   DevId_4            15:08   part_id [7:0]
 506          *   DevId_5            07:00   class_id
 507          */
 508         id->sdw_version = (addr >> 44) & GENMASK(3, 0);
 509         id->unique_id = (addr >> 40) & GENMASK(3, 0);
 510         id->mfg_id = (addr >> 24) & GENMASK(15, 0);
 511         id->part_id = (addr >> 8) & GENMASK(15, 0);
 512         id->class_id = addr & GENMASK(7, 0);
 513
 514         dev_dbg(bus->dev,
 515                 "SDW Slave class_id %x, part_id %x, mfg_id %x, unique_id %x, version %x\n",
 516                                 id->class_id, id->part_id, id->mfg_id,
 517                                 id->unique_id, id->sdw_version);
 518 }
 519
 520 static int sdw_program_device_num(struct sdw_bus *bus)
 521 {
 522         u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
 523         struct sdw_slave *slave, *_s;
 524         struct sdw_slave_id id;
 525         struct sdw_msg msg;
 526         bool found = false;
 527         int count = 0, ret;
 528         u64 addr;
 529
 530         /* No Slave, so use raw xfer api */
 531         ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
 532                            SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
 533         if (ret < 0)
 534                 return ret;
 535
 536         do {
 537                 ret = sdw_transfer(bus, &msg);
 538                 if (ret == -ENODATA) { /* end of device id reads */
 539                         dev_dbg(bus->dev, "No more devices to enumerate\n");
 540                         ret = 0;
 541                         break;
 542                 }
 543                 if (ret < 0) {
 544                         dev_err(bus->dev, "DEVID read fail:%d\n", ret);
 545                         break;
 546                 }
 547
 548                 /*
 549                  * Construct the addr and extract. Cast the higher shift
 550                  * bits to avoid truncation due to size limit.
 551                  */
 552                 addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
 553                         ((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
 554                         ((u64)buf[0] << 40);
 555
 556                 sdw_extract_slave_id(bus, addr, &id);
 557
 558                 /* Now compare with entries */
 559                 list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
 560                         if (sdw_compare_devid(slave, id) == 0) {
 561                                 found = true;
 562
 563                                 /*
 564                                  * Assign a new dev_num to this Slave and
 565                                  * not mark it present. It will be marked
 566                                  * present after it reports ATTACHED on new
 567                                  * dev_num
 568                                  */
 569                                 ret = sdw_assign_device_num(slave);
 570                                 if (ret) {
 571                                         dev_err(slave->bus->dev,
 572                                                 "Assign dev_num failed:%d\n",
 573                                                 ret);
 574                                         return ret;
 575                                 }
 576
 577                                 break;
 578                         }
 579                 }
 580
 581                 if (!found) {
 582                         /* TODO: Park this device in Group 13 */
 583                         dev_err(bus->dev, "Slave Entry not found\n");
 584                 }
 585
 586                 count++;
 587
 588                 /*
 589                  * Check till error out or retry (count) exhausts.
 590                  * Device can drop off and rejoin during enumeration
 591                  * so count till twice the bound.
 592                  */
 593
 594         } while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
 595
 596         return ret;
 597 }
 598
 599 static void sdw_modify_slave_status(struct sdw_slave *slave,
 600                                     enum sdw_slave_status status)
 601 {
 602         mutex_lock(&slave->bus->bus_lock);
 603         slave->status = status;
 604         mutex_unlock(&slave->bus->bus_lock);
 605 }
 606
 607 int sdw_configure_dpn_intr(struct sdw_slave *slave,
 608                            int port, bool enable, int mask)
 609 {
 610         u32 addr;
 611         int ret;
 612         u8 val = 0;
 613
 614         addr = SDW_DPN_INTMASK(port);
 615
 616         /* Set/Clear port ready interrupt mask */
 617         if (enable) {
 618                 val |= mask;
 619                 val |= SDW_DPN_INT_PORT_READY;
 620         } else {
 621                 val &= ~(mask);
 622                 val &= ~SDW_DPN_INT_PORT_READY;
 623         }
 624
 625         ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
 626         if (ret < 0)
 627                 dev_err(slave->bus->dev,
 628                         "SDW_DPN_INTMASK write failed:%d\n", val);
 629
 630         return ret;
 631 }
 632
 633 static int sdw_initialize_slave(struct sdw_slave *slave)
 634 {
 635         struct sdw_slave_prop *prop = &slave->prop;
 636         int ret;
 637         u8 val;
 638
 639         /*
 640          * Set bus clash, parity and SCP implementation
 641          * defined interrupt mask
 642          * TODO: Read implementation defined interrupt mask
 643          * from Slave property
 644          */
 645         val = SDW_SCP_INT1_IMPL_DEF | SDW_SCP_INT1_BUS_CLASH |
 646                                         SDW_SCP_INT1_PARITY;
 647
 648         /* Enable SCP interrupts */
 649         ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
 650         if (ret < 0) {
 651                 dev_err(slave->bus->dev,
 652                         "SDW_SCP_INTMASK1 write failed:%d\n", ret);
 653                 return ret;
 654         }
 655
 656         /* No need to continue if DP0 is not present */
 657         if (!slave->prop.dp0_prop)
 658                 return 0;
 659
 660         /* Enable DP0 interrupts */
 661         val = prop->dp0_prop->imp_def_interrupts;
 662         val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
 663
 664         ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
 665         if (ret < 0) {
 666                 dev_err(slave->bus->dev,
 667                         "SDW_DP0_INTMASK read failed:%d\n", ret);
 668                 return val;
 669         }
 670
 671         return 0;
 672 }
 673
 674 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
 675 {
 676         u8 clear = 0, impl_int_mask;
 677         int status, status2, ret, count = 0;
 678
 679         status = sdw_read(slave, SDW_DP0_INT);
 680         if (status < 0) {
 681                 dev_err(slave->bus->dev,
 682                         "SDW_DP0_INT read failed:%d\n", status);
 683                 return status;
 684         }
 685
 686         do {
 687                 if (status & SDW_DP0_INT_TEST_FAIL) {
 688                         dev_err(&slave->dev, "Test fail for port 0\n");
 689                         clear |= SDW_DP0_INT_TEST_FAIL;
 690                 }
 691
 692                 /*
 693                  * Assumption: PORT_READY interrupt will be received only for
 694                  * ports implementing Channel Prepare state machine (CP_SM)
 695                  */
 696
 697                 if (status & SDW_DP0_INT_PORT_READY) {
 698                         complete(&slave->port_ready[0]);
 699                         clear |= SDW_DP0_INT_PORT_READY;
 700                 }
 701
 702                 if (status & SDW_DP0_INT_BRA_FAILURE) {
 703                         dev_err(&slave->dev, "BRA failed\n");
 704                         clear |= SDW_DP0_INT_BRA_FAILURE;
 705                 }
 706
 707                 impl_int_mask = SDW_DP0_INT_IMPDEF1 |
 708                         SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
 709
 710                 if (status & impl_int_mask) {
 711                         clear |= impl_int_mask;
 712                         *slave_status = clear;
 713                 }
 714
 715                 /* clear the interrupt */
 716                 ret = sdw_write(slave, SDW_DP0_INT, clear);
 717                 if (ret < 0) {
 718                         dev_err(slave->bus->dev,
 719                                 "SDW_DP0_INT write failed:%d\n", ret);
 720                         return ret;
 721                 }
 722
 723                 /* Read DP0 interrupt again */
 724                 status2 = sdw_read(slave, SDW_DP0_INT);
 725                 if (status2 < 0) {
 726                         dev_err(slave->bus->dev,
 727                                 "SDW_DP0_INT read failed:%d\n", status2);
 728                         return status2;
 729                 }
 730                 status &= status2;
 731
 732                 count++;
 733
 734                 /* we can get alerts while processing so keep retrying */
 735         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 736
 737         if (count == SDW_READ_INTR_CLEAR_RETRY)
 738                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on DP0 read\n");
 739
 740         return ret;
 741 }
 742
 743 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
 744                                      int port, u8 *slave_status)
 745 {
 746         u8 clear = 0, impl_int_mask;
 747         int status, status2, ret, count = 0;
 748         u32 addr;
 749
 750         if (port == 0)
 751                 return sdw_handle_dp0_interrupt(slave, slave_status);
 752
 753         addr = SDW_DPN_INT(port);
 754         status = sdw_read(slave, addr);
 755         if (status < 0) {
 756                 dev_err(slave->bus->dev,
 757                         "SDW_DPN_INT read failed:%d\n", status);
 758
 759                 return status;
 760         }
 761
 762         do {
 763                 if (status & SDW_DPN_INT_TEST_FAIL) {
 764                         dev_err(&slave->dev, "Test fail for port:%d\n", port);
 765                         clear |= SDW_DPN_INT_TEST_FAIL;
 766                 }
 767
 768                 /*
 769                  * Assumption: PORT_READY interrupt will be received only
 770                  * for ports implementing CP_SM.
 771                  */
 772                 if (status & SDW_DPN_INT_PORT_READY) {
 773                         complete(&slave->port_ready[port]);
 774                         clear |= SDW_DPN_INT_PORT_READY;
 775                 }
 776
 777                 impl_int_mask = SDW_DPN_INT_IMPDEF1 |
 778                         SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
 779
 780                 if (status & impl_int_mask) {
 781                         clear |= impl_int_mask;
 782                         *slave_status = clear;
 783                 }
 784
 785                 /* clear the interrupt */
 786                 ret = sdw_write(slave, addr, clear);
 787                 if (ret < 0) {
 788                         dev_err(slave->bus->dev,
 789                                 "SDW_DPN_INT write failed:%d\n", ret);
 790                         return ret;
 791                 }
 792
 793                 /* Read DPN interrupt again */
 794                 status2 = sdw_read(slave, addr);
 795                 if (status2 < 0) {
 796                         dev_err(slave->bus->dev,
 797                                 "SDW_DPN_INT read failed:%d\n", status2);
 798                         return status2;
 799                 }
 800                 status &= status2;
 801
 802                 count++;
 803
 804                 /* we can get alerts while processing so keep retrying */
 805         } while (status != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 806
 807         if (count == SDW_READ_INTR_CLEAR_RETRY)
 808                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on port read");
 809
 810         return ret;
 811 }
 812
 813 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 814 {
 815         struct sdw_slave_intr_status slave_intr;
 816         u8 clear = 0, bit, port_status[15] = {0};
 817         int port_num, stat, ret, count = 0;
 818         unsigned long port;
 819         bool slave_notify = false;
 820         u8 buf, buf2[2], _buf, _buf2[2];
 821
 822         sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
 823
 824         /* Read Instat 1, Instat 2 and Instat 3 registers */
 825         ret = sdw_read(slave, SDW_SCP_INT1);
 826         if (ret < 0) {
 827                 dev_err(slave->bus->dev,
 828                         "SDW_SCP_INT1 read failed:%d\n", ret);
 829                 return ret;
 830         }
 831         buf = ret;
 832
 833         ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
 834         if (ret < 0) {
 835                 dev_err(slave->bus->dev,
 836                         "SDW_SCP_INT2/3 read failed:%d\n", ret);
 837                 return ret;
 838         }
 839
 840         do {
 841                 /*
 842                  * Check parity, bus clash and Slave (impl defined)
 843                  * interrupt
 844                  */
 845                 if (buf & SDW_SCP_INT1_PARITY) {
 846                         dev_err(&slave->dev, "Parity error detected\n");
 847                         clear |= SDW_SCP_INT1_PARITY;
 848                 }
 849
 850                 if (buf & SDW_SCP_INT1_BUS_CLASH) {
 851                         dev_err(&slave->dev, "Bus clash error detected\n");
 852                         clear |= SDW_SCP_INT1_BUS_CLASH;
 853                 }
 854
 855                 /*
 856                  * When bus clash or parity errors are detected, such errors
 857                  * are unlikely to be recoverable errors.
 858                  * TODO: In such scenario, reset bus. Make this configurable
 859                  * via sysfs property with bus reset being the default.
 860                  */
 861
 862                 if (buf & SDW_SCP_INT1_IMPL_DEF) {
 863                         dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
 864                         clear |= SDW_SCP_INT1_IMPL_DEF;
 865                         slave_notify = true;
 866                 }
 867
 868                 /* Check port 0 - 3 interrupts */
 869                 port = buf & SDW_SCP_INT1_PORT0_3;
 870
 871                 /* To get port number corresponding to bits, shift it */
 872                 port = port >> SDW_REG_SHIFT(SDW_SCP_INT1_PORT0_3);
 873                 for_each_set_bit(bit, &port, 8) {
 874                         sdw_handle_port_interrupt(slave, bit,
 875                                                   &port_status[bit]);
 876                 }
 877
 878                 /* Check if cascade 2 interrupt is present */
 879                 if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
 880                         port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
 881                         for_each_set_bit(bit, &port, 8) {
 882                                 /* scp2 ports start from 4 */
 883                                 port_num = bit + 3;
 884                                 sdw_handle_port_interrupt(slave,
 885                                                 port_num,
 886                                                 &port_status[port_num]);
 887                         }
 888                 }
 889
 890                 /* now check last cascade */
 891                 if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
 892                         port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
 893                         for_each_set_bit(bit, &port, 8) {
 894                                 /* scp3 ports start from 11 */
 895                                 port_num = bit + 10;
 896                                 sdw_handle_port_interrupt(slave,
 897                                                 port_num,
 898                                                 &port_status[port_num]);
 899                         }
 900                 }
 901
 902                 /* Update the Slave driver */
 903                 if (slave_notify && slave->ops &&
 904                     slave->ops->interrupt_callback) {
 905                         slave_intr.control_port = clear;
 906                         memcpy(slave_intr.port, &port_status,
 907                                sizeof(slave_intr.port));
 908
 909                         slave->ops->interrupt_callback(slave, &slave_intr);
 910                 }
 911
 912                 /* Ack interrupt */
 913                 ret = sdw_write(slave, SDW_SCP_INT1, clear);
 914                 if (ret < 0) {
 915                         dev_err(slave->bus->dev,
 916                                 "SDW_SCP_INT1 write failed:%d\n", ret);
 917                         return ret;
 918                 }
 919
 920                 /*
 921                  * Read status again to ensure no new interrupts arrived
 922                  * while servicing interrupts.
 923                  */
 924                 ret = sdw_read(slave, SDW_SCP_INT1);
 925                 if (ret < 0) {
 926                         dev_err(slave->bus->dev,
 927                                 "SDW_SCP_INT1 read failed:%d\n", ret);
 928                         return ret;
 929                 }
 930                 _buf = ret;
 931
 932                 ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
 933                 if (ret < 0) {
 934                         dev_err(slave->bus->dev,
 935                                 "SDW_SCP_INT2/3 read failed:%d\n", ret);
 936                         return ret;
 937                 }
 938
 939                 /* Make sure no interrupts are pending */
 940                 buf &= _buf;
 941                 buf2[0] &= _buf2[0];
 942                 buf2[1] &= _buf2[1];
 943                 stat = buf || buf2[0] || buf2[1];
 944
 945                 /*
 946                  * Exit loop if Slave is continuously in ALERT state even
 947                  * after servicing the interrupt multiple times.
 948                  */
 949                 count++;
 950
 951                 /* we can get alerts while processing so keep retrying */
 952         } while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
 953
 954         if (count == SDW_READ_INTR_CLEAR_RETRY)
 955                 dev_warn(slave->bus->dev, "Reached MAX_RETRY on alert read\n");
 956
 957         return ret;
 958 }
 959
 960 static int sdw_update_slave_status(struct sdw_slave *slave,
 961                                    enum sdw_slave_status status)
 962 {
 963         if (slave->ops && slave->ops->update_status)
 964                 return slave->ops->update_status(slave, status);
 965
 966         return 0;
 967 }
 968
 969 /**
 970  * sdw_handle_slave_status() - Handle Slave status
 971  * @bus: SDW bus instance
 972  * @status: Status for all Slave(s)
 973  */
 974 int sdw_handle_slave_status(struct sdw_bus *bus,
 975                             enum sdw_slave_status status[])
 976 {
 977         enum sdw_slave_status prev_status;
 978         struct sdw_slave *slave;
 979         int i, ret = 0;
 980
 981         if (status[0] == SDW_SLAVE_ATTACHED) {
 982                 dev_dbg(bus->dev, "Slave attached, programming device number\n");
 983                 ret = sdw_program_device_num(bus);
 984                 if (ret)
 985                         dev_err(bus->dev, "Slave attach failed: %d\n", ret);
 986                 /*
 987                  * programming a device number will have side effects,
 988                  * so we deal with other devices at a later time
 989                  */
 990                 return ret;
 991         }
 992
 993         /* Continue to check other slave statuses */
 994         for (i = 1; i <= SDW_MAX_DEVICES; i++) {
 995                 mutex_lock(&bus->bus_lock);
 996                 if (test_bit(i, bus->assigned) == false) {
 997                         mutex_unlock(&bus->bus_lock);
 998                         continue;
 999                 }
1000                 mutex_unlock(&bus->bus_lock);
1001
1002                 slave = sdw_get_slave(bus, i);
1003                 if (!slave)
1004                         continue;
1005
1006                 switch (status[i]) {
1007                 case SDW_SLAVE_UNATTACHED:
1008                         if (slave->status == SDW_SLAVE_UNATTACHED)
1009                                 break;
1010
1011                         sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1012                         break;
1013
1014                 case SDW_SLAVE_ALERT:
1015                         ret = sdw_handle_slave_alerts(slave);
1016                         if (ret)
1017                                 dev_err(bus->dev,
1018                                         "Slave %d alert handling failed: %d\n",
1019                                         i, ret);
1020                         break;
1021
1022                 case SDW_SLAVE_ATTACHED:
1023                         if (slave->status == SDW_SLAVE_ATTACHED)
1024                                 break;
1025
1026                         prev_status = slave->status;
1027                         sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1028
1029                         if (prev_status == SDW_SLAVE_ALERT)
1030                                 break;
1031
1032                         ret = sdw_initialize_slave(slave);
1033                         if (ret)
1034                                 dev_err(bus->dev,
1035                                         "Slave %d initialization failed: %d\n",
1036                                         i, ret);
1037
1038                         break;
1039
1040                 default:
1041                         dev_err(bus->dev, "Invalid slave %d status:%d\n",
1042                                 i, status[i]);
1043                         break;
1044                 }
1045
1046                 ret = sdw_update_slave_status(slave, status[i]);
1047                 if (ret)
1048                         dev_err(slave->bus->dev,
1049                                 "Update Slave status failed:%d\n", ret);
1050         }
1051
1052         return ret;
1053 }
1054 EXPORT_SYMBOL(sdw_handle_slave_status);