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