drivers/base/regmap/regmap.c

   1 /*
   2  * Register map access API
   3  *
   4  * Copyright 2011 Wolfson Microelectronics plc
   5  *
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/slab.h>
  15 #include <linux/export.h>
  16 #include <linux/mutex.h>
  17 #include <linux/err.h>
  18
  19 #define CREATE_TRACE_POINTS
  20 #include <trace/events/regmap.h>
  21
  22 #include "internal.h"
  23
  24 bool regmap_writeable(struct regmap *map, unsigned int reg)
  25 {
  26         if (map->max_register && reg > map->max_register)
  27                 return false;
  28
  29         if (map->writeable_reg)
  30                 return map->writeable_reg(map->dev, reg);
  31
  32         return true;
  33 }
  34
  35 bool regmap_readable(struct regmap *map, unsigned int reg)
  36 {
  37         if (map->max_register && reg > map->max_register)
  38                 return false;
  39
  40         if (map->format.format_write)
  41                 return false;
  42
  43         if (map->readable_reg)
  44                 return map->readable_reg(map->dev, reg);
  45
  46         return true;
  47 }
  48
  49 bool regmap_volatile(struct regmap *map, unsigned int reg)
  50 {
  51         if (!regmap_readable(map, reg))
  52                 return false;
  53
  54         if (map->volatile_reg)
  55                 return map->volatile_reg(map->dev, reg);
  56
  57         return true;
  58 }
  59
  60 bool regmap_precious(struct regmap *map, unsigned int reg)
  61 {
  62         if (!regmap_readable(map, reg))
  63                 return false;
  64
  65         if (map->precious_reg)
  66                 return map->precious_reg(map->dev, reg);
  67
  68         return false;
  69 }
  70
  71 static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
  72         unsigned int num)
  73 {
  74         unsigned int i;
  75
  76         for (i = 0; i < num; i++)
  77                 if (!regmap_volatile(map, reg + i))
  78                         return false;
  79
  80         return true;
  81 }
  82
  83 static void regmap_format_2_6_write(struct regmap *map,
  84                                      unsigned int reg, unsigned int val)
  85 {
  86         u8 *out = map->work_buf;
  87
  88         *out = (reg << 6) | val;
  89 }
  90
  91 static void regmap_format_4_12_write(struct regmap *map,
  92                                      unsigned int reg, unsigned int val)
  93 {
  94         __be16 *out = map->work_buf;
  95         *out = cpu_to_be16((reg << 12) | val);
  96 }
  97
  98 static void regmap_format_7_9_write(struct regmap *map,
  99                                     unsigned int reg, unsigned int val)
 100 {
 101         __be16 *out = map->work_buf;
 102         *out = cpu_to_be16((reg << 9) | val);
 103 }
 104
 105 static void regmap_format_10_14_write(struct regmap *map,
 106                                     unsigned int reg, unsigned int val)
 107 {
 108         u8 *out = map->work_buf;
 109
 110         out[2] = val;
 111         out[1] = (val >> 8) | (reg << 6);
 112         out[0] = reg >> 2;
 113 }
 114
 115 static void regmap_format_8(void *buf, unsigned int val, unsigned int shift)
 116 {
 117         u8 *b = buf;
 118
 119         b[0] = val << shift;
 120 }
 121
 122 static void regmap_format_16(void *buf, unsigned int val, unsigned int shift)
 123 {
 124         __be16 *b = buf;
 125
 126         b[0] = cpu_to_be16(val << shift);
 127 }
 128
 129 static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)
 130 {
 131         u8 *b = buf;
 132
 133         val <<= shift;
 134
 135         b[0] = val >> 16;
 136         b[1] = val >> 8;
 137         b[2] = val;
 138 }
 139
 140 static void regmap_format_32(void *buf, unsigned int val, unsigned int shift)
 141 {
 142         __be32 *b = buf;
 143
 144         b[0] = cpu_to_be32(val << shift);
 145 }
 146
 147 static unsigned int regmap_parse_8(void *buf)
 148 {
 149         u8 *b = buf;
 150
 151         return b[0];
 152 }
 153
 154 static unsigned int regmap_parse_16(void *buf)
 155 {
 156         __be16 *b = buf;
 157
 158         b[0] = be16_to_cpu(b[0]);
 159
 160         return b[0];
 161 }
 162
 163 static unsigned int regmap_parse_24(void *buf)
 164 {
 165         u8 *b = buf;
 166         unsigned int ret = b[2];
 167         ret |= ((unsigned int)b[1]) << 8;
 168         ret |= ((unsigned int)b[0]) << 16;
 169
 170         return ret;
 171 }
 172
 173 static unsigned int regmap_parse_32(void *buf)
 174 {
 175         __be32 *b = buf;
 176
 177         b[0] = be32_to_cpu(b[0]);
 178
 179         return b[0];
 180 }
 181
 182 static void regmap_lock_mutex(struct regmap *map)
 183 {
 184         mutex_lock(&map->mutex);
 185 }
 186
 187 static void regmap_unlock_mutex(struct regmap *map)
 188 {
 189         mutex_unlock(&map->mutex);
 190 }
 191
 192 static void regmap_lock_spinlock(struct regmap *map)
 193 {
 194         spin_lock(&map->spinlock);
 195 }
 196
 197 static void regmap_unlock_spinlock(struct regmap *map)
 198 {
 199         spin_unlock(&map->spinlock);
 200 }
 201
 202 /**
 203  * regmap_init(): Initialise register map
 204  *
 205  * @dev: Device that will be interacted with
 206  * @bus: Bus-specific callbacks to use with device
 207  * @bus_context: Data passed to bus-specific callbacks
 208  * @config: Configuration for register map
 209  *
 210  * The return value will be an ERR_PTR() on error or a valid pointer to
 211  * a struct regmap.  This function should generally not be called
 212  * directly, it should be called by bus-specific init functions.
 213  */
 214 struct regmap *regmap_init(struct device *dev,
 215                            const struct regmap_bus *bus,
 216                            void *bus_context,
 217                            const struct regmap_config *config)
 218 {
 219         struct regmap *map;
 220         int ret = -EINVAL;
 221
 222         if (!bus || !config)
 223                 goto err;
 224
 225         map = kzalloc(sizeof(*map), GFP_KERNEL);
 226         if (map == NULL) {
 227                 ret = -ENOMEM;
 228                 goto err;
 229         }
 230
 231         if (bus->fast_io) {
 232                 spin_lock_init(&map->spinlock);
 233                 map->lock = regmap_lock_spinlock;
 234                 map->unlock = regmap_unlock_spinlock;
 235         } else {
 236                 mutex_init(&map->mutex);
 237                 map->lock = regmap_lock_mutex;
 238                 map->unlock = regmap_unlock_mutex;
 239         }
 240         map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
 241         map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
 242         map->format.pad_bytes = config->pad_bits / 8;
 243         map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
 244         map->format.buf_size += map->format.pad_bytes;
 245         map->reg_shift = config->pad_bits % 8;
 246         if (config->reg_stride)
 247                 map->reg_stride = config->reg_stride;
 248         else
 249                 map->reg_stride = 1;
 250         map->use_single_rw = config->use_single_rw;
 251         map->dev = dev;
 252         map->bus = bus;
 253         map->bus_context = bus_context;
 254         map->max_register = config->max_register;
 255         map->writeable_reg = config->writeable_reg;
 256         map->readable_reg = config->readable_reg;
 257         map->volatile_reg = config->volatile_reg;
 258         map->precious_reg = config->precious_reg;
 259         map->cache_type = config->cache_type;
 260
 261         if (config->read_flag_mask || config->write_flag_mask) {
 262                 map->read_flag_mask = config->read_flag_mask;
 263                 map->write_flag_mask = config->write_flag_mask;
 264         } else {
 265                 map->read_flag_mask = bus->read_flag_mask;
 266         }
 267
 268         switch (config->reg_bits + map->reg_shift) {
 269         case 2:
 270                 switch (config->val_bits) {
 271                 case 6:
 272                         map->format.format_write = regmap_format_2_6_write;
 273                         break;
 274                 default:
 275                         goto err_map;
 276                 }
 277                 break;
 278
 279         case 4:
 280                 switch (config->val_bits) {
 281                 case 12:
 282                         map->format.format_write = regmap_format_4_12_write;
 283                         break;
 284                 default:
 285                         goto err_map;
 286                 }
 287                 break;
 288
 289         case 7:
 290                 switch (config->val_bits) {
 291                 case 9:
 292                         map->format.format_write = regmap_format_7_9_write;
 293                         break;
 294                 default:
 295                         goto err_map;
 296                 }
 297                 break;
 298
 299         case 10:
 300                 switch (config->val_bits) {
 301                 case 14:
 302                         map->format.format_write = regmap_format_10_14_write;
 303                         break;
 304                 default:
 305                         goto err_map;
 306                 }
 307                 break;
 308
 309         case 8:
 310                 map->format.format_reg = regmap_format_8;
 311                 break;
 312
 313         case 16:
 314                 map->format.format_reg = regmap_format_16;
 315                 break;
 316
 317         case 32:
 318                 map->format.format_reg = regmap_format_32;
 319                 break;
 320
 321         default:
 322                 goto err_map;
 323         }
 324
 325         switch (config->val_bits) {
 326         case 8:
 327                 map->format.format_val = regmap_format_8;
 328                 map->format.parse_val = regmap_parse_8;
 329                 break;
 330         case 16:
 331                 map->format.format_val = regmap_format_16;
 332                 map->format.parse_val = regmap_parse_16;
 333                 break;
 334         case 24:
 335                 map->format.format_val = regmap_format_24;
 336                 map->format.parse_val = regmap_parse_24;
 337                 break;
 338         case 32:
 339                 map->format.format_val = regmap_format_32;
 340                 map->format.parse_val = regmap_parse_32;
 341                 break;
 342         }
 343
 344         if (map->format.format_write)
 345                 map->use_single_rw = true;
 346
 347         if (!map->format.format_write &&
 348             !(map->format.format_reg && map->format.format_val))
 349                 goto err_map;
 350
 351         map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 352         if (map->work_buf == NULL) {
 353                 ret = -ENOMEM;
 354                 goto err_map;
 355         }
 356
 357         regmap_debugfs_init(map, config->name);
 358
 359         ret = regcache_init(map, config);
 360         if (ret < 0)
 361                 goto err_free_workbuf;
 362
 363         return map;
 364
 365 err_free_workbuf:
 366         kfree(map->work_buf);
 367 err_map:
 368         kfree(map);
 369 err:
 370         return ERR_PTR(ret);
 371 }
 372 EXPORT_SYMBOL_GPL(regmap_init);
 373
 374 static void devm_regmap_release(struct device *dev, void *res)
 375 {
 376         regmap_exit(*(struct regmap **)res);
 377 }
 378
 379 /**
 380  * devm_regmap_init(): Initialise managed register map
 381  *
 382  * @dev: Device that will be interacted with
 383  * @bus: Bus-specific callbacks to use with device
 384  * @bus_context: Data passed to bus-specific callbacks
 385  * @config: Configuration for register map
 386  *
 387  * The return value will be an ERR_PTR() on error or a valid pointer
 388  * to a struct regmap.  This function should generally not be called
 389  * directly, it should be called by bus-specific init functions.  The
 390  * map will be automatically freed by the device management code.
 391  */
 392 struct regmap *devm_regmap_init(struct device *dev,
 393                                 const struct regmap_bus *bus,
 394                                 void *bus_context,
 395                                 const struct regmap_config *config)
 396 {
 397         struct regmap **ptr, *regmap;
 398
 399         ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
 400         if (!ptr)
 401                 return ERR_PTR(-ENOMEM);
 402
 403         regmap = regmap_init(dev, bus, bus_context, config);
 404         if (!IS_ERR(regmap)) {
 405                 *ptr = regmap;
 406                 devres_add(dev, ptr);
 407         } else {
 408                 devres_free(ptr);
 409         }
 410
 411         return regmap;
 412 }
 413 EXPORT_SYMBOL_GPL(devm_regmap_init);
 414
 415 /**
 416  * regmap_reinit_cache(): Reinitialise the current register cache
 417  *
 418  * @map: Register map to operate on.
 419  * @config: New configuration.  Only the cache data will be used.
 420  *
 421  * Discard any existing register cache for the map and initialize a
 422  * new cache.  This can be used to restore the cache to defaults or to
 423  * update the cache configuration to reflect runtime discovery of the
 424  * hardware.
 425  */
 426 int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 427 {
 428         int ret;
 429
 430         map->lock(map);
 431
 432         regcache_exit(map);
 433         regmap_debugfs_exit(map);
 434
 435         map->max_register = config->max_register;
 436         map->writeable_reg = config->writeable_reg;
 437         map->readable_reg = config->readable_reg;
 438         map->volatile_reg = config->volatile_reg;
 439         map->precious_reg = config->precious_reg;
 440         map->cache_type = config->cache_type;
 441
 442         regmap_debugfs_init(map, config->name);
 443
 444         map->cache_bypass = false;
 445         map->cache_only = false;
 446
 447         ret = regcache_init(map, config);
 448
 449         map->unlock(map);
 450
 451         return ret;
 452 }
 453
 454 /**
 455  * regmap_exit(): Free a previously allocated register map
 456  */
 457 void regmap_exit(struct regmap *map)
 458 {
 459         regcache_exit(map);
 460         regmap_debugfs_exit(map);
 461         if (map->bus->free_context)
 462                 map->bus->free_context(map->bus_context);
 463         kfree(map->work_buf);
 464         kfree(map);
 465 }
 466 EXPORT_SYMBOL_GPL(regmap_exit);
 467
 468 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 469                              const void *val, size_t val_len)
 470 {
 471         u8 *u8 = map->work_buf;
 472         void *buf;
 473         int ret = -ENOTSUPP;
 474         size_t len;
 475         int i;
 476
 477         /* Check for unwritable registers before we start */
 478         if (map->writeable_reg)
 479                 for (i = 0; i < val_len / map->format.val_bytes; i++)
 480                         if (!map->writeable_reg(map->dev,
 481                                                 reg + (i * map->reg_stride)))
 482                                 return -EINVAL;
 483
 484         if (!map->cache_bypass && map->format.parse_val) {
 485                 unsigned int ival;
 486                 int val_bytes = map->format.val_bytes;
 487                 for (i = 0; i < val_len / val_bytes; i++) {
 488                         memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
 489                         ival = map->format.parse_val(map->work_buf);
 490                         ret = regcache_write(map, reg + (i * map->reg_stride),
 491                                              ival);
 492                         if (ret) {
 493                                 dev_err(map->dev,
 494                                    "Error in caching of register: %u ret: %d\n",
 495                                         reg + i, ret);
 496                                 return ret;
 497                         }
 498                 }
 499                 if (map->cache_only) {
 500                         map->cache_dirty = true;
 501                         return 0;
 502                 }
 503         }
 504
 505         map->format.format_reg(map->work_buf, reg, map->reg_shift);
 506
 507         u8[0] |= map->write_flag_mask;
 508
 509         trace_regmap_hw_write_start(map->dev, reg,
 510                                     val_len / map->format.val_bytes);
 511
 512         /* If we're doing a single register write we can probably just
 513          * send the work_buf directly, otherwise try to do a gather
 514          * write.
 515          */
 516         if (val == (map->work_buf + map->format.pad_bytes +
 517                     map->format.reg_bytes))
 518                 ret = map->bus->write(map->bus_context, map->work_buf,
 519                                       map->format.reg_bytes +
 520                                       map->format.pad_bytes +
 521                                       val_len);
 522         else if (map->bus->gather_write)
 523                 ret = map->bus->gather_write(map->bus_context, map->work_buf,
 524                                              map->format.reg_bytes +
 525                                              map->format.pad_bytes,
 526                                              val, val_len);
 527
 528         /* If that didn't work fall back on linearising by hand. */
 529         if (ret == -ENOTSUPP) {
 530                 len = map->format.reg_bytes + map->format.pad_bytes + val_len;
 531                 buf = kzalloc(len, GFP_KERNEL);
 532                 if (!buf)
 533                         return -ENOMEM;
 534
 535                 memcpy(buf, map->work_buf, map->format.reg_bytes);
 536                 memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
 537                        val, val_len);
 538                 ret = map->bus->write(map->bus_context, buf, len);
 539
 540                 kfree(buf);
 541         }
 542
 543         trace_regmap_hw_write_done(map->dev, reg,
 544                                    val_len / map->format.val_bytes);
 545
 546         return ret;
 547 }
 548
 549 int _regmap_write(struct regmap *map, unsigned int reg,
 550                   unsigned int val)
 551 {
 552         int ret;
 553         BUG_ON(!map->format.format_write && !map->format.format_val);
 554
 555         if (!map->cache_bypass && map->format.format_write) {
 556                 ret = regcache_write(map, reg, val);
 557                 if (ret != 0)
 558                         return ret;
 559                 if (map->cache_only) {
 560                         map->cache_dirty = true;
 561                         return 0;
 562                 }
 563         }
 564
 565         trace_regmap_reg_write(map->dev, reg, val);
 566
 567         if (map->format.format_write) {
 568                 map->format.format_write(map, reg, val);
 569
 570                 trace_regmap_hw_write_start(map->dev, reg, 1);
 571
 572                 ret = map->bus->write(map->bus_context, map->work_buf,
 573                                       map->format.buf_size);
 574
 575                 trace_regmap_hw_write_done(map->dev, reg, 1);
 576
 577                 return ret;
 578         } else {
 579                 map->format.format_val(map->work_buf + map->format.reg_bytes
 580                                        + map->format.pad_bytes, val, 0);
 581                 return _regmap_raw_write(map, reg,
 582                                          map->work_buf +
 583                                          map->format.reg_bytes +
 584                                          map->format.pad_bytes,
 585                                          map->format.val_bytes);
 586         }
 587 }
 588
 589 /**
 590  * regmap_write(): Write a value to a single register
 591  *
 592  * @map: Register map to write to
 593  * @reg: Register to write to
 594  * @val: Value to be written
 595  *
 596  * A value of zero will be returned on success, a negative errno will
 597  * be returned in error cases.
 598  */
 599 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
 600 {
 601         int ret;
 602
 603         if (reg % map->reg_stride)
 604                 return -EINVAL;
 605
 606         map->lock(map);
 607
 608         ret = _regmap_write(map, reg, val);
 609
 610         map->unlock(map);
 611
 612         return ret;
 613 }
 614 EXPORT_SYMBOL_GPL(regmap_write);
 615
 616 /**
 617  * regmap_raw_write(): Write raw values to one or more registers
 618  *
 619  * @map: Register map to write to
 620  * @reg: Initial register to write to
 621  * @val: Block of data to be written, laid out for direct transmission to the
 622  *       device
 623  * @val_len: Length of data pointed to by val.
 624  *
 625  * This function is intended to be used for things like firmware
 626  * download where a large block of data needs to be transferred to the
 627  * device.  No formatting will be done on the data provided.
 628  *
 629  * A value of zero will be returned on success, a negative errno will
 630  * be returned in error cases.
 631  */
 632 int regmap_raw_write(struct regmap *map, unsigned int reg,
 633                      const void *val, size_t val_len)
 634 {
 635         int ret;
 636
 637         if (val_len % map->format.val_bytes)
 638                 return -EINVAL;
 639         if (reg % map->reg_stride)
 640                 return -EINVAL;
 641
 642         map->lock(map);
 643
 644         ret = _regmap_raw_write(map, reg, val, val_len);
 645
 646         map->unlock(map);
 647
 648         return ret;
 649 }
 650 EXPORT_SYMBOL_GPL(regmap_raw_write);
 651
 652 /*
 653  * regmap_bulk_write(): Write multiple registers to the device
 654  *
 655  * @map: Register map to write to
 656  * @reg: First register to be write from
 657  * @val: Block of data to be written, in native register size for device
 658  * @val_count: Number of registers to write
 659  *
 660  * This function is intended to be used for writing a large block of
 661  * data to be device either in single transfer or multiple transfer.
 662  *
 663  * A value of zero will be returned on success, a negative errno will
 664  * be returned in error cases.
 665  */
 666 int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 667                      size_t val_count)
 668 {
 669         int ret = 0, i;
 670         size_t val_bytes = map->format.val_bytes;
 671         void *wval;
 672
 673         if (!map->format.parse_val)
 674                 return -EINVAL;
 675         if (reg % map->reg_stride)
 676                 return -EINVAL;
 677
 678         map->lock(map);
 679
 680         /* No formatting is require if val_byte is 1 */
 681         if (val_bytes == 1) {
 682                 wval = (void *)val;
 683         } else {
 684                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
 685                 if (!wval) {
 686                         ret = -ENOMEM;
 687                         dev_err(map->dev, "Error in memory allocation\n");
 688                         goto out;
 689                 }
 690                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 691                         map->format.parse_val(wval + i);
 692         }
 693         /*
 694          * Some devices does not support bulk write, for
 695          * them we have a series of single write operations.
 696          */
 697         if (map->use_single_rw) {
 698                 for (i = 0; i < val_count; i++) {
 699                         ret = regmap_raw_write(map,
 700                                                 reg + (i * map->reg_stride),
 701                                                 val + (i * val_bytes),
 702                                                 val_bytes);
 703                         if (ret != 0)
 704                                 return ret;
 705                 }
 706         } else {
 707                 ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
 708         }
 709
 710         if (val_bytes != 1)
 711                 kfree(wval);
 712
 713 out:
 714         map->unlock(map);
 715         return ret;
 716 }
 717 EXPORT_SYMBOL_GPL(regmap_bulk_write);
 718
 719 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 720                             unsigned int val_len)
 721 {
 722         u8 *u8 = map->work_buf;
 723         int ret;
 724
 725         map->format.format_reg(map->work_buf, reg, map->reg_shift);
 726
 727         /*
 728          * Some buses or devices flag reads by setting the high bits in the
 729          * register addresss; since it's always the high bits for all
 730          * current formats we can do this here rather than in
 731          * formatting.  This may break if we get interesting formats.
 732          */
 733         u8[0] |= map->read_flag_mask;
 734
 735         trace_regmap_hw_read_start(map->dev, reg,
 736                                    val_len / map->format.val_bytes);
 737
 738         ret = map->bus->read(map->bus_context, map->work_buf,
 739                              map->format.reg_bytes + map->format.pad_bytes,
 740                              val, val_len);
 741
 742         trace_regmap_hw_read_done(map->dev, reg,
 743                                   val_len / map->format.val_bytes);
 744
 745         return ret;
 746 }
 747
 748 static int _regmap_read(struct regmap *map, unsigned int reg,
 749                         unsigned int *val)
 750 {
 751         int ret;
 752
 753         if (!map->cache_bypass) {
 754                 ret = regcache_read(map, reg, val);
 755                 if (ret == 0)
 756                         return 0;
 757         }
 758
 759         if (!map->format.parse_val)
 760                 return -EINVAL;
 761
 762         if (map->cache_only)
 763                 return -EBUSY;
 764
 765         ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
 766         if (ret == 0) {
 767                 *val = map->format.parse_val(map->work_buf);
 768                 trace_regmap_reg_read(map->dev, reg, *val);
 769         }
 770
 771         return ret;
 772 }
 773
 774 /**
 775  * regmap_read(): Read a value from a single register
 776  *
 777  * @map: Register map to write to
 778  * @reg: Register to be read from
 779  * @val: Pointer to store read value
 780  *
 781  * A value of zero will be returned on success, a negative errno will
 782  * be returned in error cases.
 783  */
 784 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
 785 {
 786         int ret;
 787
 788         if (reg % map->reg_stride)
 789                 return -EINVAL;
 790
 791         map->lock(map);
 792
 793         ret = _regmap_read(map, reg, val);
 794
 795         map->unlock(map);
 796
 797         return ret;
 798 }
 799 EXPORT_SYMBOL_GPL(regmap_read);
 800
 801 /**
 802  * regmap_raw_read(): Read raw data from the device
 803  *
 804  * @map: Register map to write to
 805  * @reg: First register to be read from
 806  * @val: Pointer to store read value
 807  * @val_len: Size of data to read
 808  *
 809  * A value of zero will be returned on success, a negative errno will
 810  * be returned in error cases.
 811  */
 812 int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 813                     size_t val_len)
 814 {
 815         size_t val_bytes = map->format.val_bytes;
 816         size_t val_count = val_len / val_bytes;
 817         unsigned int v;
 818         int ret, i;
 819
 820         if (val_len % map->format.val_bytes)
 821                 return -EINVAL;
 822         if (reg % map->reg_stride)
 823                 return -EINVAL;
 824
 825         map->lock(map);
 826
 827         if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
 828             map->cache_type == REGCACHE_NONE) {
 829                 /* Physical block read if there's no cache involved */
 830                 ret = _regmap_raw_read(map, reg, val, val_len);
 831
 832         } else {
 833                 /* Otherwise go word by word for the cache; should be low
 834                  * cost as we expect to hit the cache.
 835                  */
 836                 for (i = 0; i < val_count; i++) {
 837                         ret = _regmap_read(map, reg + (i * map->reg_stride),
 838                                            &v);
 839                         if (ret != 0)
 840                                 goto out;
 841
 842                         map->format.format_val(val + (i * val_bytes), v, 0);
 843                 }
 844         }
 845
 846  out:
 847         map->unlock(map);
 848
 849         return ret;
 850 }
 851 EXPORT_SYMBOL_GPL(regmap_raw_read);
 852
 853 /**
 854  * regmap_bulk_read(): Read multiple registers from the device
 855  *
 856  * @map: Register map to write to
 857  * @reg: First register to be read from
 858  * @val: Pointer to store read value, in native register size for device
 859  * @val_count: Number of registers to read
 860  *
 861  * A value of zero will be returned on success, a negative errno will
 862  * be returned in error cases.
 863  */
 864 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 865                      size_t val_count)
 866 {
 867         int ret, i;
 868         size_t val_bytes = map->format.val_bytes;
 869         bool vol = regmap_volatile_range(map, reg, val_count);
 870
 871         if (!map->format.parse_val)
 872                 return -EINVAL;
 873         if (reg % map->reg_stride)
 874                 return -EINVAL;
 875
 876         if (vol || map->cache_type == REGCACHE_NONE) {
 877                 /*
 878                  * Some devices does not support bulk read, for
 879                  * them we have a series of single read operations.
 880                  */
 881                 if (map->use_single_rw) {
 882                         for (i = 0; i < val_count; i++) {
 883                                 ret = regmap_raw_read(map,
 884                                                 reg + (i * map->reg_stride),
 885                                                 val + (i * val_bytes),
 886                                                 val_bytes);
 887                                 if (ret != 0)
 888                                         return ret;
 889                         }
 890                 } else {
 891                         ret = regmap_raw_read(map, reg, val,
 892                                               val_bytes * val_count);
 893                         if (ret != 0)
 894                                 return ret;
 895                 }
 896
 897                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 898                         map->format.parse_val(val + i);
 899         } else {
 900                 for (i = 0; i < val_count; i++) {
 901                         ret = regmap_read(map, reg + (i * map->reg_stride),
 902                                           val + (i * val_bytes));
 903                         if (ret != 0)
 904                                 return ret;
 905                 }
 906         }
 907
 908         return 0;
 909 }
 910 EXPORT_SYMBOL_GPL(regmap_bulk_read);
 911
 912 static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 913                                unsigned int mask, unsigned int val,
 914                                bool *change)
 915 {
 916         int ret;
 917         unsigned int tmp, orig;
 918
 919         map->lock(map);
 920
 921         ret = _regmap_read(map, reg, &orig);
 922         if (ret != 0)
 923                 goto out;
 924
 925         tmp = orig & ~mask;
 926         tmp |= val & mask;
 927
 928         if (tmp != orig) {
 929                 ret = _regmap_write(map, reg, tmp);
 930                 *change = true;
 931         } else {
 932                 *change = false;
 933         }
 934
 935 out:
 936         map->unlock(map);
 937
 938         return ret;
 939 }
 940
 941 /**
 942  * regmap_update_bits: Perform a read/modify/write cycle on the register map
 943  *
 944  * @map: Register map to update
 945  * @reg: Register to update
 946  * @mask: Bitmask to change
 947  * @val: New value for bitmask
 948  *
 949  * Returns zero for success, a negative number on error.
 950  */
 951 int regmap_update_bits(struct regmap *map, unsigned int reg,
 952                        unsigned int mask, unsigned int val)
 953 {
 954         bool change;
 955         return _regmap_update_bits(map, reg, mask, val, &change);
 956 }
 957 EXPORT_SYMBOL_GPL(regmap_update_bits);
 958
 959 /**
 960  * regmap_update_bits_check: Perform a read/modify/write cycle on the
 961  *                           register map and report if updated
 962  *
 963  * @map: Register map to update
 964  * @reg: Register to update
 965  * @mask: Bitmask to change
 966  * @val: New value for bitmask
 967  * @change: Boolean indicating if a write was done
 968  *
 969  * Returns zero for success, a negative number on error.
 970  */
 971 int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 972                              unsigned int mask, unsigned int val,
 973                              bool *change)
 974 {
 975         return _regmap_update_bits(map, reg, mask, val, change);
 976 }
 977 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
 978
 979 /**
 980  * regmap_register_patch: Register and apply register updates to be applied
 981  *                        on device initialistion
 982  *
 983  * @map: Register map to apply updates to.
 984  * @regs: Values to update.
 985  * @num_regs: Number of entries in regs.
 986  *
 987  * Register a set of register updates to be applied to the device
 988  * whenever the device registers are synchronised with the cache and
 989  * apply them immediately.  Typically this is used to apply
 990  * corrections to be applied to the device defaults on startup, such
 991  * as the updates some vendors provide to undocumented registers.
 992  */
 993 int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
 994                           int num_regs)
 995 {
 996         int i, ret;
 997         bool bypass;
 998
 999         /* If needed the implementation can be extended to support this */
1000         if (map->patch)
1001                 return -EBUSY;
1002
1003         map->lock(map);
1004
1005         bypass = map->cache_bypass;
1006
1007         map->cache_bypass = true;
1008
1009         /* Write out first; it's useful to apply even if we fail later. */
1010         for (i = 0; i < num_regs; i++) {
1011                 ret = _regmap_write(map, regs[i].reg, regs[i].def);
1012                 if (ret != 0) {
1013                         dev_err(map->dev, "Failed to write %x = %x: %d\n",
1014                                 regs[i].reg, regs[i].def, ret);
1015                         goto out;
1016                 }
1017         }
1018
1019         map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
1020         if (map->patch != NULL) {
1021                 memcpy(map->patch, regs,
1022                        num_regs * sizeof(struct reg_default));
1023                 map->patch_regs = num_regs;
1024         } else {
1025                 ret = -ENOMEM;
1026         }
1027
1028 out:
1029         map->cache_bypass = bypass;
1030
1031         map->unlock(map);
1032
1033         return ret;
1034 }
1035 EXPORT_SYMBOL_GPL(regmap_register_patch);
1036
1037 /*
1038  * regmap_get_val_bytes(): Report the size of a register value
1039  *
1040  * Report the size of a register value, mainly intended to for use by
1041  * generic infrastructure built on top of regmap.
1042  */
1043 int regmap_get_val_bytes(struct regmap *map)
1044 {
1045         if (map->format.format_write)
1046                 return -EINVAL;
1047
1048         return map->format.val_bytes;
1049 }
1050 EXPORT_SYMBOL_GPL(regmap_get_val_bytes);
1051
1052 static int __init regmap_initcall(void)
1053 {
1054         regmap_debugfs_initcall();
1055
1056         return 0;
1057 }
1058 postcore_initcall(regmap_initcall);