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_32(void *buf, unsigned int val)
 130 {
 131         __be32 *b = buf;
 132
 133         b[0] = cpu_to_be32(val);
 134 }
 135
 136 static unsigned int regmap_parse_8(void *buf)
 137 {
 138         u8 *b = buf;
 139
 140         return b[0];
 141 }
 142
 143 static unsigned int regmap_parse_16(void *buf)
 144 {
 145         __be16 *b = buf;
 146
 147         b[0] = be16_to_cpu(b[0]);
 148
 149         return b[0];
 150 }
 151
 152 static unsigned int regmap_parse_32(void *buf)
 153 {
 154         __be32 *b = buf;
 155
 156         b[0] = be32_to_cpu(b[0]);
 157
 158         return b[0];
 159 }
 160
 161 /**
 162  * regmap_init(): Initialise register map
 163  *
 164  * @dev: Device that will be interacted with
 165  * @bus: Bus-specific callbacks to use with device
 166  * @config: Configuration for register map
 167  *
 168  * The return value will be an ERR_PTR() on error or a valid pointer to
 169  * a struct regmap.  This function should generally not be called
 170  * directly, it should be called by bus-specific init functions.
 171  */
 172 struct regmap *regmap_init(struct device *dev,
 173                            const struct regmap_bus *bus,
 174                            const struct regmap_config *config)
 175 {
 176         struct regmap *map;
 177         int ret = -EINVAL;
 178
 179         if (!bus || !config)
 180                 goto err;
 181
 182         map = kzalloc(sizeof(*map), GFP_KERNEL);
 183         if (map == NULL) {
 184                 ret = -ENOMEM;
 185                 goto err;
 186         }
 187
 188         mutex_init(&map->lock);
 189         map->format.buf_size = (config->reg_bits + config->val_bits) / 8;
 190         map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
 191         map->format.pad_bytes = config->pad_bits / 8;
 192         map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
 193         map->format.buf_size += map->format.pad_bytes;
 194         map->dev = dev;
 195         map->bus = bus;
 196         map->max_register = config->max_register;
 197         map->writeable_reg = config->writeable_reg;
 198         map->readable_reg = config->readable_reg;
 199         map->volatile_reg = config->volatile_reg;
 200         map->precious_reg = config->precious_reg;
 201         map->cache_type = config->cache_type;
 202
 203         if (config->read_flag_mask || config->write_flag_mask) {
 204                 map->read_flag_mask = config->read_flag_mask;
 205                 map->write_flag_mask = config->write_flag_mask;
 206         } else {
 207                 map->read_flag_mask = bus->read_flag_mask;
 208         }
 209
 210         switch (config->reg_bits) {
 211         case 2:
 212                 switch (config->val_bits) {
 213                 case 6:
 214                         map->format.format_write = regmap_format_2_6_write;
 215                         break;
 216                 default:
 217                         goto err_map;
 218                 }
 219                 break;
 220
 221         case 4:
 222                 switch (config->val_bits) {
 223                 case 12:
 224                         map->format.format_write = regmap_format_4_12_write;
 225                         break;
 226                 default:
 227                         goto err_map;
 228                 }
 229                 break;
 230
 231         case 7:
 232                 switch (config->val_bits) {
 233                 case 9:
 234                         map->format.format_write = regmap_format_7_9_write;
 235                         break;
 236                 default:
 237                         goto err_map;
 238                 }
 239                 break;
 240
 241         case 10:
 242                 switch (config->val_bits) {
 243                 case 14:
 244                         map->format.format_write = regmap_format_10_14_write;
 245                         break;
 246                 default:
 247                         goto err_map;
 248                 }
 249                 break;
 250
 251         case 8:
 252                 map->format.format_reg = regmap_format_8;
 253                 break;
 254
 255         case 16:
 256                 map->format.format_reg = regmap_format_16;
 257                 break;
 258
 259         case 32:
 260                 map->format.format_reg = regmap_format_32;
 261                 break;
 262
 263         default:
 264                 goto err_map;
 265         }
 266
 267         switch (config->val_bits) {
 268         case 8:
 269                 map->format.format_val = regmap_format_8;
 270                 map->format.parse_val = regmap_parse_8;
 271                 break;
 272         case 16:
 273                 map->format.format_val = regmap_format_16;
 274                 map->format.parse_val = regmap_parse_16;
 275                 break;
 276         case 32:
 277                 map->format.format_val = regmap_format_32;
 278                 map->format.parse_val = regmap_parse_32;
 279                 break;
 280         }
 281
 282         if (!map->format.format_write &&
 283             !(map->format.format_reg && map->format.format_val))
 284                 goto err_map;
 285
 286         map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 287         if (map->work_buf == NULL) {
 288                 ret = -ENOMEM;
 289                 goto err_map;
 290         }
 291
 292         regmap_debugfs_init(map);
 293
 294         ret = regcache_init(map, config);
 295         if (ret < 0)
 296                 goto err_free_workbuf;
 297
 298         return map;
 299
 300 err_free_workbuf:
 301         kfree(map->work_buf);
 302 err_map:
 303         kfree(map);
 304 err:
 305         return ERR_PTR(ret);
 306 }
 307 EXPORT_SYMBOL_GPL(regmap_init);
 308
 309 static void devm_regmap_release(struct device *dev, void *res)
 310 {
 311         regmap_exit(*(struct regmap **)res);
 312 }
 313
 314 /**
 315  * devm_regmap_init(): Initialise managed register map
 316  *
 317  * @dev: Device that will be interacted with
 318  * @bus: Bus-specific callbacks to use with device
 319  * @config: Configuration for register map
 320  *
 321  * The return value will be an ERR_PTR() on error or a valid pointer
 322  * to a struct regmap.  This function should generally not be called
 323  * directly, it should be called by bus-specific init functions.  The
 324  * map will be automatically freed by the device management code.
 325  */
 326 struct regmap *devm_regmap_init(struct device *dev,
 327                                 const struct regmap_bus *bus,
 328                                 const struct regmap_config *config)
 329 {
 330         struct regmap **ptr, *regmap;
 331
 332         ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
 333         if (!ptr)
 334                 return ERR_PTR(-ENOMEM);
 335
 336         regmap = regmap_init(dev, bus, config);
 337         if (!IS_ERR(regmap)) {
 338                 *ptr = regmap;
 339                 devres_add(dev, ptr);
 340         } else {
 341                 devres_free(ptr);
 342         }
 343
 344         return regmap;
 345 }
 346 EXPORT_SYMBOL_GPL(devm_regmap_init);
 347
 348 /**
 349  * regmap_reinit_cache(): Reinitialise the current register cache
 350  *
 351  * @map: Register map to operate on.
 352  * @config: New configuration.  Only the cache data will be used.
 353  *
 354  * Discard any existing register cache for the map and initialize a
 355  * new cache.  This can be used to restore the cache to defaults or to
 356  * update the cache configuration to reflect runtime discovery of the
 357  * hardware.
 358  */
 359 int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 360 {
 361         int ret;
 362
 363         mutex_lock(&map->lock);
 364
 365         regcache_exit(map);
 366         regmap_debugfs_exit(map);
 367
 368         map->max_register = config->max_register;
 369         map->writeable_reg = config->writeable_reg;
 370         map->readable_reg = config->readable_reg;
 371         map->volatile_reg = config->volatile_reg;
 372         map->precious_reg = config->precious_reg;
 373         map->cache_type = config->cache_type;
 374
 375         regmap_debugfs_init(map);
 376
 377         map->cache_bypass = false;
 378         map->cache_only = false;
 379
 380         ret = regcache_init(map, config);
 381
 382         mutex_unlock(&map->lock);
 383
 384         return ret;
 385 }
 386
 387 /**
 388  * regmap_exit(): Free a previously allocated register map
 389  */
 390 void regmap_exit(struct regmap *map)
 391 {
 392         regcache_exit(map);
 393         regmap_debugfs_exit(map);
 394         kfree(map->work_buf);
 395         kfree(map);
 396 }
 397 EXPORT_SYMBOL_GPL(regmap_exit);
 398
 399 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 400                              const void *val, size_t val_len)
 401 {
 402         u8 *u8 = map->work_buf;
 403         void *buf;
 404         int ret = -ENOTSUPP;
 405         size_t len;
 406         int i;
 407
 408         /* Check for unwritable registers before we start */
 409         if (map->writeable_reg)
 410                 for (i = 0; i < val_len / map->format.val_bytes; i++)
 411                         if (!map->writeable_reg(map->dev, reg + i))
 412                                 return -EINVAL;
 413
 414         if (!map->cache_bypass && map->format.parse_val) {
 415                 unsigned int ival;
 416                 int val_bytes = map->format.val_bytes;
 417                 for (i = 0; i < val_len / val_bytes; i++) {
 418                         memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
 419                         ival = map->format.parse_val(map->work_buf);
 420                         ret = regcache_write(map, reg + i, ival);
 421                         if (ret) {
 422                                 dev_err(map->dev,
 423                                    "Error in caching of register: %u ret: %d\n",
 424                                         reg + i, ret);
 425                                 return ret;
 426                         }
 427                 }
 428                 if (map->cache_only) {
 429                         map->cache_dirty = true;
 430                         return 0;
 431                 }
 432         }
 433
 434         map->format.format_reg(map->work_buf, reg);
 435
 436         u8[0] |= map->write_flag_mask;
 437
 438         trace_regmap_hw_write_start(map->dev, reg,
 439                                     val_len / map->format.val_bytes);
 440
 441         /* If we're doing a single register write we can probably just
 442          * send the work_buf directly, otherwise try to do a gather
 443          * write.
 444          */
 445         if (val == (map->work_buf + map->format.pad_bytes +
 446                     map->format.reg_bytes))
 447                 ret = map->bus->write(map->dev, map->work_buf,
 448                                       map->format.reg_bytes +
 449                                       map->format.pad_bytes +
 450                                       val_len);
 451         else if (map->bus->gather_write)
 452                 ret = map->bus->gather_write(map->dev, map->work_buf,
 453                                              map->format.reg_bytes +
 454                                              map->format.pad_bytes,
 455                                              val, val_len);
 456
 457         /* If that didn't work fall back on linearising by hand. */
 458         if (ret == -ENOTSUPP) {
 459                 len = map->format.reg_bytes + map->format.pad_bytes + val_len;
 460                 buf = kzalloc(len, GFP_KERNEL);
 461                 if (!buf)
 462                         return -ENOMEM;
 463
 464                 memcpy(buf, map->work_buf, map->format.reg_bytes);
 465                 memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
 466                        val, val_len);
 467                 ret = map->bus->write(map->dev, buf, len);
 468
 469                 kfree(buf);
 470         }
 471
 472         trace_regmap_hw_write_done(map->dev, reg,
 473                                    val_len / map->format.val_bytes);
 474
 475         return ret;
 476 }
 477
 478 int _regmap_write(struct regmap *map, unsigned int reg,
 479                   unsigned int val)
 480 {
 481         int ret;
 482         BUG_ON(!map->format.format_write && !map->format.format_val);
 483
 484         if (!map->cache_bypass && map->format.format_write) {
 485                 ret = regcache_write(map, reg, val);
 486                 if (ret != 0)
 487                         return ret;
 488                 if (map->cache_only) {
 489                         map->cache_dirty = true;
 490                         return 0;
 491                 }
 492         }
 493
 494         trace_regmap_reg_write(map->dev, reg, val);
 495
 496         if (map->format.format_write) {
 497                 map->format.format_write(map, reg, val);
 498
 499                 trace_regmap_hw_write_start(map->dev, reg, 1);
 500
 501                 ret = map->bus->write(map->dev, map->work_buf,
 502                                       map->format.buf_size);
 503
 504                 trace_regmap_hw_write_done(map->dev, reg, 1);
 505
 506                 return ret;
 507         } else {
 508                 map->format.format_val(map->work_buf + map->format.reg_bytes
 509                                        + map->format.pad_bytes, val);
 510                 return _regmap_raw_write(map, reg,
 511                                          map->work_buf +
 512                                          map->format.reg_bytes +
 513                                          map->format.pad_bytes,
 514                                          map->format.val_bytes);
 515         }
 516 }
 517
 518 /**
 519  * regmap_write(): Write a value to a single register
 520  *
 521  * @map: Register map to write to
 522  * @reg: Register to write to
 523  * @val: Value to be written
 524  *
 525  * A value of zero will be returned on success, a negative errno will
 526  * be returned in error cases.
 527  */
 528 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
 529 {
 530         int ret;
 531
 532         mutex_lock(&map->lock);
 533
 534         ret = _regmap_write(map, reg, val);
 535
 536         mutex_unlock(&map->lock);
 537
 538         return ret;
 539 }
 540 EXPORT_SYMBOL_GPL(regmap_write);
 541
 542 /**
 543  * regmap_raw_write(): Write raw values to one or more registers
 544  *
 545  * @map: Register map to write to
 546  * @reg: Initial register to write to
 547  * @val: Block of data to be written, laid out for direct transmission to the
 548  *       device
 549  * @val_len: Length of data pointed to by val.
 550  *
 551  * This function is intended to be used for things like firmware
 552  * download where a large block of data needs to be transferred to the
 553  * device.  No formatting will be done on the data provided.
 554  *
 555  * A value of zero will be returned on success, a negative errno will
 556  * be returned in error cases.
 557  */
 558 int regmap_raw_write(struct regmap *map, unsigned int reg,
 559                      const void *val, size_t val_len)
 560 {
 561         int ret;
 562
 563         mutex_lock(&map->lock);
 564
 565         ret = _regmap_raw_write(map, reg, val, val_len);
 566
 567         mutex_unlock(&map->lock);
 568
 569         return ret;
 570 }
 571 EXPORT_SYMBOL_GPL(regmap_raw_write);
 572
 573 /*
 574  * regmap_bulk_write(): Write multiple registers to the device
 575  *
 576  * @map: Register map to write to
 577  * @reg: First register to be write from
 578  * @val: Block of data to be written, in native register size for device
 579  * @val_count: Number of registers to write
 580  *
 581  * This function is intended to be used for writing a large block of
 582  * data to be device either in single transfer or multiple transfer.
 583  *
 584  * A value of zero will be returned on success, a negative errno will
 585  * be returned in error cases.
 586  */
 587 int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 588                      size_t val_count)
 589 {
 590         int ret = 0, i;
 591         size_t val_bytes = map->format.val_bytes;
 592         void *wval;
 593
 594         if (!map->format.parse_val)
 595                 return -EINVAL;
 596
 597         mutex_lock(&map->lock);
 598
 599         /* No formatting is require if val_byte is 1 */
 600         if (val_bytes == 1) {
 601                 wval = (void *)val;
 602         } else {
 603                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
 604                 if (!wval) {
 605                         ret = -ENOMEM;
 606                         dev_err(map->dev, "Error in memory allocation\n");
 607                         goto out;
 608                 }
 609                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 610                         map->format.parse_val(wval + i);
 611         }
 612         ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
 613
 614         if (val_bytes != 1)
 615                 kfree(wval);
 616
 617 out:
 618         mutex_unlock(&map->lock);
 619         return ret;
 620 }
 621 EXPORT_SYMBOL_GPL(regmap_bulk_write);
 622
 623 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 624                             unsigned int val_len)
 625 {
 626         u8 *u8 = map->work_buf;
 627         int ret;
 628
 629         map->format.format_reg(map->work_buf, reg);
 630
 631         /*
 632          * Some buses or devices flag reads by setting the high bits in the
 633          * register addresss; since it's always the high bits for all
 634          * current formats we can do this here rather than in
 635          * formatting.  This may break if we get interesting formats.
 636          */
 637         u8[0] |= map->read_flag_mask;
 638
 639         trace_regmap_hw_read_start(map->dev, reg,
 640                                    val_len / map->format.val_bytes);
 641
 642         ret = map->bus->read(map->dev, map->work_buf,
 643                              map->format.reg_bytes + map->format.pad_bytes,
 644                              val, val_len);
 645
 646         trace_regmap_hw_read_done(map->dev, reg,
 647                                   val_len / map->format.val_bytes);
 648
 649         return ret;
 650 }
 651
 652 static int _regmap_read(struct regmap *map, unsigned int reg,
 653                         unsigned int *val)
 654 {
 655         int ret;
 656
 657         if (!map->cache_bypass) {
 658                 ret = regcache_read(map, reg, val);
 659                 if (ret == 0)
 660                         return 0;
 661         }
 662
 663         if (!map->format.parse_val)
 664                 return -EINVAL;
 665
 666         if (map->cache_only)
 667                 return -EBUSY;
 668
 669         ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
 670         if (ret == 0) {
 671                 *val = map->format.parse_val(map->work_buf);
 672                 trace_regmap_reg_read(map->dev, reg, *val);
 673         }
 674
 675         return ret;
 676 }
 677
 678 /**
 679  * regmap_read(): Read a value from a single register
 680  *
 681  * @map: Register map to write to
 682  * @reg: Register to be read from
 683  * @val: Pointer to store read value
 684  *
 685  * A value of zero will be returned on success, a negative errno will
 686  * be returned in error cases.
 687  */
 688 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
 689 {
 690         int ret;
 691
 692         mutex_lock(&map->lock);
 693
 694         ret = _regmap_read(map, reg, val);
 695
 696         mutex_unlock(&map->lock);
 697
 698         return ret;
 699 }
 700 EXPORT_SYMBOL_GPL(regmap_read);
 701
 702 /**
 703  * regmap_raw_read(): Read raw data from the device
 704  *
 705  * @map: Register map to write to
 706  * @reg: First register to be read from
 707  * @val: Pointer to store read value
 708  * @val_len: Size of data to read
 709  *
 710  * A value of zero will be returned on success, a negative errno will
 711  * be returned in error cases.
 712  */
 713 int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 714                     size_t val_len)
 715 {
 716         size_t val_bytes = map->format.val_bytes;
 717         size_t val_count = val_len / val_bytes;
 718         unsigned int v;
 719         int ret, i;
 720
 721         mutex_lock(&map->lock);
 722
 723         if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
 724             map->cache_type == REGCACHE_NONE) {
 725                 /* Physical block read if there's no cache involved */
 726                 ret = _regmap_raw_read(map, reg, val, val_len);
 727
 728         } else {
 729                 /* Otherwise go word by word for the cache; should be low
 730                  * cost as we expect to hit the cache.
 731                  */
 732                 for (i = 0; i < val_count; i++) {
 733                         ret = _regmap_read(map, reg + i, &v);
 734                         if (ret != 0)
 735                                 goto out;
 736
 737                         map->format.format_val(val + (i * val_bytes), v);
 738                 }
 739         }
 740
 741  out:
 742         mutex_unlock(&map->lock);
 743
 744         return ret;
 745 }
 746 EXPORT_SYMBOL_GPL(regmap_raw_read);
 747
 748 /**
 749  * regmap_bulk_read(): Read multiple registers from the device
 750  *
 751  * @map: Register map to write to
 752  * @reg: First register to be read from
 753  * @val: Pointer to store read value, in native register size for device
 754  * @val_count: Number of registers to read
 755  *
 756  * A value of zero will be returned on success, a negative errno will
 757  * be returned in error cases.
 758  */
 759 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 760                      size_t val_count)
 761 {
 762         int ret, i;
 763         size_t val_bytes = map->format.val_bytes;
 764         bool vol = regmap_volatile_range(map, reg, val_count);
 765
 766         if (!map->format.parse_val)
 767                 return -EINVAL;
 768
 769         if (vol || map->cache_type == REGCACHE_NONE) {
 770                 ret = regmap_raw_read(map, reg, val, val_bytes * val_count);
 771                 if (ret != 0)
 772                         return ret;
 773
 774                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 775                         map->format.parse_val(val + i);
 776         } else {
 777                 for (i = 0; i < val_count; i++) {
 778                         ret = regmap_read(map, reg + i, val + (i * val_bytes));
 779                         if (ret != 0)
 780                                 return ret;
 781                 }
 782         }
 783
 784         return 0;
 785 }
 786 EXPORT_SYMBOL_GPL(regmap_bulk_read);
 787
 788 static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 789                                unsigned int mask, unsigned int val,
 790                                bool *change)
 791 {
 792         int ret;
 793         unsigned int tmp, orig;
 794
 795         mutex_lock(&map->lock);
 796
 797         ret = _regmap_read(map, reg, &orig);
 798         if (ret != 0)
 799                 goto out;
 800
 801         tmp = orig & ~mask;
 802         tmp |= val & mask;
 803
 804         if (tmp != orig) {
 805                 ret = _regmap_write(map, reg, tmp);
 806                 *change = true;
 807         } else {
 808                 *change = false;
 809         }
 810
 811 out:
 812         mutex_unlock(&map->lock);
 813
 814         return ret;
 815 }
 816
 817 /**
 818  * regmap_update_bits: Perform a read/modify/write cycle on the register map
 819  *
 820  * @map: Register map to update
 821  * @reg: Register to update
 822  * @mask: Bitmask to change
 823  * @val: New value for bitmask
 824  *
 825  * Returns zero for success, a negative number on error.
 826  */
 827 int regmap_update_bits(struct regmap *map, unsigned int reg,
 828                        unsigned int mask, unsigned int val)
 829 {
 830         bool change;
 831         return _regmap_update_bits(map, reg, mask, val, &change);
 832 }
 833 EXPORT_SYMBOL_GPL(regmap_update_bits);
 834
 835 /**
 836  * regmap_update_bits_check: Perform a read/modify/write cycle on the
 837  *                           register map and report if updated
 838  *
 839  * @map: Register map to update
 840  * @reg: Register to update
 841  * @mask: Bitmask to change
 842  * @val: New value for bitmask
 843  * @change: Boolean indicating if a write was done
 844  *
 845  * Returns zero for success, a negative number on error.
 846  */
 847 int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 848                              unsigned int mask, unsigned int val,
 849                              bool *change)
 850 {
 851         return _regmap_update_bits(map, reg, mask, val, change);
 852 }
 853 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
 854
 855 /**
 856  * regmap_register_patch: Register and apply register updates to be applied
 857  *                        on device initialistion
 858  *
 859  * @map: Register map to apply updates to.
 860  * @regs: Values to update.
 861  * @num_regs: Number of entries in regs.
 862  *
 863  * Register a set of register updates to be applied to the device
 864  * whenever the device registers are synchronised with the cache and
 865  * apply them immediately.  Typically this is used to apply
 866  * corrections to be applied to the device defaults on startup, such
 867  * as the updates some vendors provide to undocumented registers.
 868  */
 869 int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
 870                           int num_regs)
 871 {
 872         int i, ret;
 873         bool bypass;
 874
 875         /* If needed the implementation can be extended to support this */
 876         if (map->patch)
 877                 return -EBUSY;
 878
 879         mutex_lock(&map->lock);
 880
 881         bypass = map->cache_bypass;
 882
 883         map->cache_bypass = true;
 884
 885         /* Write out first; it's useful to apply even if we fail later. */
 886         for (i = 0; i < num_regs; i++) {
 887                 ret = _regmap_write(map, regs[i].reg, regs[i].def);
 888                 if (ret != 0) {
 889                         dev_err(map->dev, "Failed to write %x = %x: %d\n",
 890                                 regs[i].reg, regs[i].def, ret);
 891                         goto out;
 892                 }
 893         }
 894
 895         map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
 896         if (map->patch != NULL) {
 897                 memcpy(map->patch, regs,
 898                        num_regs * sizeof(struct reg_default));
 899                 map->patch_regs = num_regs;
 900         } else {
 901                 ret = -ENOMEM;
 902         }
 903
 904 out:
 905         map->cache_bypass = bypass;
 906
 907         mutex_unlock(&map->lock);
 908
 909         return ret;
 910 }
 911 EXPORT_SYMBOL_GPL(regmap_register_patch);
 912
 913 /*
 914  * regmap_get_val_bytes(): Report the size of a register value
 915  *
 916  * Report the size of a register value, mainly intended to for use by
 917  * generic infrastructure built on top of regmap.
 918  */
 919 int regmap_get_val_bytes(struct regmap *map)
 920 {
 921         if (map->format.format_write)
 922                 return -EINVAL;
 923
 924         return map->format.val_bytes;
 925 }
 926 EXPORT_SYMBOL_GPL(regmap_get_val_bytes);
 927
 928 static int __init regmap_initcall(void)
 929 {
 930         regmap_debugfs_initcall();
 931
 932         return 0;
 933 }
 934 postcore_initcall(regmap_initcall);