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->format.format_reg && map->format.format_val))
 346                 goto err_map;
 347
 348         map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 349         if (map->work_buf == NULL) {
 350                 ret = -ENOMEM;
 351                 goto err_map;
 352         }
 353
 354         regmap_debugfs_init(map, config->name);
 355
 356         ret = regcache_init(map, config);
 357         if (ret < 0)
 358                 goto err_free_workbuf;
 359
 360         return map;
 361
 362 err_free_workbuf:
 363         kfree(map->work_buf);
 364 err_map:
 365         kfree(map);
 366 err:
 367         return ERR_PTR(ret);
 368 }
 369 EXPORT_SYMBOL_GPL(regmap_init);
 370
 371 static void devm_regmap_release(struct device *dev, void *res)
 372 {
 373         regmap_exit(*(struct regmap **)res);
 374 }
 375
 376 /**
 377  * devm_regmap_init(): Initialise managed register map
 378  *
 379  * @dev: Device that will be interacted with
 380  * @bus: Bus-specific callbacks to use with device
 381  * @bus_context: Data passed to bus-specific callbacks
 382  * @config: Configuration for register map
 383  *
 384  * The return value will be an ERR_PTR() on error or a valid pointer
 385  * to a struct regmap.  This function should generally not be called
 386  * directly, it should be called by bus-specific init functions.  The
 387  * map will be automatically freed by the device management code.
 388  */
 389 struct regmap *devm_regmap_init(struct device *dev,
 390                                 const struct regmap_bus *bus,
 391                                 void *bus_context,
 392                                 const struct regmap_config *config)
 393 {
 394         struct regmap **ptr, *regmap;
 395
 396         ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
 397         if (!ptr)
 398                 return ERR_PTR(-ENOMEM);
 399
 400         regmap = regmap_init(dev, bus, bus_context, config);
 401         if (!IS_ERR(regmap)) {
 402                 *ptr = regmap;
 403                 devres_add(dev, ptr);
 404         } else {
 405                 devres_free(ptr);
 406         }
 407
 408         return regmap;
 409 }
 410 EXPORT_SYMBOL_GPL(devm_regmap_init);
 411
 412 /**
 413  * regmap_reinit_cache(): Reinitialise the current register cache
 414  *
 415  * @map: Register map to operate on.
 416  * @config: New configuration.  Only the cache data will be used.
 417  *
 418  * Discard any existing register cache for the map and initialize a
 419  * new cache.  This can be used to restore the cache to defaults or to
 420  * update the cache configuration to reflect runtime discovery of the
 421  * hardware.
 422  */
 423 int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 424 {
 425         int ret;
 426
 427         map->lock(map);
 428
 429         regcache_exit(map);
 430         regmap_debugfs_exit(map);
 431
 432         map->max_register = config->max_register;
 433         map->writeable_reg = config->writeable_reg;
 434         map->readable_reg = config->readable_reg;
 435         map->volatile_reg = config->volatile_reg;
 436         map->precious_reg = config->precious_reg;
 437         map->cache_type = config->cache_type;
 438
 439         regmap_debugfs_init(map, config->name);
 440
 441         map->cache_bypass = false;
 442         map->cache_only = false;
 443
 444         ret = regcache_init(map, config);
 445
 446         map->unlock(map);
 447
 448         return ret;
 449 }
 450
 451 /**
 452  * regmap_exit(): Free a previously allocated register map
 453  */
 454 void regmap_exit(struct regmap *map)
 455 {
 456         regcache_exit(map);
 457         regmap_debugfs_exit(map);
 458         if (map->bus->free_context)
 459                 map->bus->free_context(map->bus_context);
 460         kfree(map->work_buf);
 461         kfree(map);
 462 }
 463 EXPORT_SYMBOL_GPL(regmap_exit);
 464
 465 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 466                              const void *val, size_t val_len)
 467 {
 468         u8 *u8 = map->work_buf;
 469         void *buf;
 470         int ret = -ENOTSUPP;
 471         size_t len;
 472         int i;
 473
 474         /* Check for unwritable registers before we start */
 475         if (map->writeable_reg)
 476                 for (i = 0; i < val_len / map->format.val_bytes; i++)
 477                         if (!map->writeable_reg(map->dev,
 478                                                 reg + (i * map->reg_stride)))
 479                                 return -EINVAL;
 480
 481         if (!map->cache_bypass && map->format.parse_val) {
 482                 unsigned int ival;
 483                 int val_bytes = map->format.val_bytes;
 484                 for (i = 0; i < val_len / val_bytes; i++) {
 485                         memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
 486                         ival = map->format.parse_val(map->work_buf);
 487                         ret = regcache_write(map, reg + (i * map->reg_stride),
 488                                              ival);
 489                         if (ret) {
 490                                 dev_err(map->dev,
 491                                    "Error in caching of register: %u ret: %d\n",
 492                                         reg + i, ret);
 493                                 return ret;
 494                         }
 495                 }
 496                 if (map->cache_only) {
 497                         map->cache_dirty = true;
 498                         return 0;
 499                 }
 500         }
 501
 502         map->format.format_reg(map->work_buf, reg, map->reg_shift);
 503
 504         u8[0] |= map->write_flag_mask;
 505
 506         trace_regmap_hw_write_start(map->dev, reg,
 507                                     val_len / map->format.val_bytes);
 508
 509         /* If we're doing a single register write we can probably just
 510          * send the work_buf directly, otherwise try to do a gather
 511          * write.
 512          */
 513         if (val == (map->work_buf + map->format.pad_bytes +
 514                     map->format.reg_bytes))
 515                 ret = map->bus->write(map->bus_context, map->work_buf,
 516                                       map->format.reg_bytes +
 517                                       map->format.pad_bytes +
 518                                       val_len);
 519         else if (map->bus->gather_write)
 520                 ret = map->bus->gather_write(map->bus_context, map->work_buf,
 521                                              map->format.reg_bytes +
 522                                              map->format.pad_bytes,
 523                                              val, val_len);
 524
 525         /* If that didn't work fall back on linearising by hand. */
 526         if (ret == -ENOTSUPP) {
 527                 len = map->format.reg_bytes + map->format.pad_bytes + val_len;
 528                 buf = kzalloc(len, GFP_KERNEL);
 529                 if (!buf)
 530                         return -ENOMEM;
 531
 532                 memcpy(buf, map->work_buf, map->format.reg_bytes);
 533                 memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
 534                        val, val_len);
 535                 ret = map->bus->write(map->bus_context, buf, len);
 536
 537                 kfree(buf);
 538         }
 539
 540         trace_regmap_hw_write_done(map->dev, reg,
 541                                    val_len / map->format.val_bytes);
 542
 543         return ret;
 544 }
 545
 546 int _regmap_write(struct regmap *map, unsigned int reg,
 547                   unsigned int val)
 548 {
 549         int ret;
 550         BUG_ON(!map->format.format_write && !map->format.format_val);
 551
 552         if (!map->cache_bypass && map->format.format_write) {
 553                 ret = regcache_write(map, reg, val);
 554                 if (ret != 0)
 555                         return ret;
 556                 if (map->cache_only) {
 557                         map->cache_dirty = true;
 558                         return 0;
 559                 }
 560         }
 561
 562         trace_regmap_reg_write(map->dev, reg, val);
 563
 564         if (map->format.format_write) {
 565                 map->format.format_write(map, reg, val);
 566
 567                 trace_regmap_hw_write_start(map->dev, reg, 1);
 568
 569                 ret = map->bus->write(map->bus_context, map->work_buf,
 570                                       map->format.buf_size);
 571
 572                 trace_regmap_hw_write_done(map->dev, reg, 1);
 573
 574                 return ret;
 575         } else {
 576                 map->format.format_val(map->work_buf + map->format.reg_bytes
 577                                        + map->format.pad_bytes, val, 0);
 578                 return _regmap_raw_write(map, reg,
 579                                          map->work_buf +
 580                                          map->format.reg_bytes +
 581                                          map->format.pad_bytes,
 582                                          map->format.val_bytes);
 583         }
 584 }
 585
 586 /**
 587  * regmap_write(): Write a value to a single register
 588  *
 589  * @map: Register map to write to
 590  * @reg: Register to write to
 591  * @val: Value to be written
 592  *
 593  * A value of zero will be returned on success, a negative errno will
 594  * be returned in error cases.
 595  */
 596 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
 597 {
 598         int ret;
 599
 600         if (reg % map->reg_stride)
 601                 return -EINVAL;
 602
 603         map->lock(map);
 604
 605         ret = _regmap_write(map, reg, val);
 606
 607         map->unlock(map);
 608
 609         return ret;
 610 }
 611 EXPORT_SYMBOL_GPL(regmap_write);
 612
 613 /**
 614  * regmap_raw_write(): Write raw values to one or more registers
 615  *
 616  * @map: Register map to write to
 617  * @reg: Initial register to write to
 618  * @val: Block of data to be written, laid out for direct transmission to the
 619  *       device
 620  * @val_len: Length of data pointed to by val.
 621  *
 622  * This function is intended to be used for things like firmware
 623  * download where a large block of data needs to be transferred to the
 624  * device.  No formatting will be done on the data provided.
 625  *
 626  * A value of zero will be returned on success, a negative errno will
 627  * be returned in error cases.
 628  */
 629 int regmap_raw_write(struct regmap *map, unsigned int reg,
 630                      const void *val, size_t val_len)
 631 {
 632         int ret;
 633
 634         if (val_len % map->format.val_bytes)
 635                 return -EINVAL;
 636         if (reg % map->reg_stride)
 637                 return -EINVAL;
 638
 639         map->lock(map);
 640
 641         ret = _regmap_raw_write(map, reg, val, val_len);
 642
 643         map->unlock(map);
 644
 645         return ret;
 646 }
 647 EXPORT_SYMBOL_GPL(regmap_raw_write);
 648
 649 /*
 650  * regmap_bulk_write(): Write multiple registers to the device
 651  *
 652  * @map: Register map to write to
 653  * @reg: First register to be write from
 654  * @val: Block of data to be written, in native register size for device
 655  * @val_count: Number of registers to write
 656  *
 657  * This function is intended to be used for writing a large block of
 658  * data to be device either in single transfer or multiple transfer.
 659  *
 660  * A value of zero will be returned on success, a negative errno will
 661  * be returned in error cases.
 662  */
 663 int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 664                      size_t val_count)
 665 {
 666         int ret = 0, i;
 667         size_t val_bytes = map->format.val_bytes;
 668         void *wval;
 669
 670         if (!map->format.parse_val)
 671                 return -EINVAL;
 672         if (reg % map->reg_stride)
 673                 return -EINVAL;
 674
 675         map->lock(map);
 676
 677         /* No formatting is require if val_byte is 1 */
 678         if (val_bytes == 1) {
 679                 wval = (void *)val;
 680         } else {
 681                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
 682                 if (!wval) {
 683                         ret = -ENOMEM;
 684                         dev_err(map->dev, "Error in memory allocation\n");
 685                         goto out;
 686                 }
 687                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 688                         map->format.parse_val(wval + i);
 689         }
 690         /*
 691          * Some devices does not support bulk write, for
 692          * them we have a series of single write operations.
 693          */
 694         if (map->use_single_rw) {
 695                 for (i = 0; i < val_count; i++) {
 696                         ret = regmap_raw_write(map,
 697                                                 reg + (i * map->reg_stride),
 698                                                 val + (i * val_bytes),
 699                                                 val_bytes);
 700                         if (ret != 0)
 701                                 return ret;
 702                 }
 703         } else {
 704                 ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
 705         }
 706
 707         if (val_bytes != 1)
 708                 kfree(wval);
 709
 710 out:
 711         map->unlock(map);
 712         return ret;
 713 }
 714 EXPORT_SYMBOL_GPL(regmap_bulk_write);
 715
 716 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 717                             unsigned int val_len)
 718 {
 719         u8 *u8 = map->work_buf;
 720         int ret;
 721
 722         map->format.format_reg(map->work_buf, reg, map->reg_shift);
 723
 724         /*
 725          * Some buses or devices flag reads by setting the high bits in the
 726          * register addresss; since it's always the high bits for all
 727          * current formats we can do this here rather than in
 728          * formatting.  This may break if we get interesting formats.
 729          */
 730         u8[0] |= map->read_flag_mask;
 731
 732         trace_regmap_hw_read_start(map->dev, reg,
 733                                    val_len / map->format.val_bytes);
 734
 735         ret = map->bus->read(map->bus_context, map->work_buf,
 736                              map->format.reg_bytes + map->format.pad_bytes,
 737                              val, val_len);
 738
 739         trace_regmap_hw_read_done(map->dev, reg,
 740                                   val_len / map->format.val_bytes);
 741
 742         return ret;
 743 }
 744
 745 static int _regmap_read(struct regmap *map, unsigned int reg,
 746                         unsigned int *val)
 747 {
 748         int ret;
 749
 750         if (!map->cache_bypass) {
 751                 ret = regcache_read(map, reg, val);
 752                 if (ret == 0)
 753                         return 0;
 754         }
 755
 756         if (!map->format.parse_val)
 757                 return -EINVAL;
 758
 759         if (map->cache_only)
 760                 return -EBUSY;
 761
 762         ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
 763         if (ret == 0) {
 764                 *val = map->format.parse_val(map->work_buf);
 765                 trace_regmap_reg_read(map->dev, reg, *val);
 766         }
 767
 768         return ret;
 769 }
 770
 771 /**
 772  * regmap_read(): Read a value from a single register
 773  *
 774  * @map: Register map to write to
 775  * @reg: Register to be read from
 776  * @val: Pointer to store read value
 777  *
 778  * A value of zero will be returned on success, a negative errno will
 779  * be returned in error cases.
 780  */
 781 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
 782 {
 783         int ret;
 784
 785         if (reg % map->reg_stride)
 786                 return -EINVAL;
 787
 788         map->lock(map);
 789
 790         ret = _regmap_read(map, reg, val);
 791
 792         map->unlock(map);
 793
 794         return ret;
 795 }
 796 EXPORT_SYMBOL_GPL(regmap_read);
 797
 798 /**
 799  * regmap_raw_read(): Read raw data from the device
 800  *
 801  * @map: Register map to write to
 802  * @reg: First register to be read from
 803  * @val: Pointer to store read value
 804  * @val_len: Size of data to read
 805  *
 806  * A value of zero will be returned on success, a negative errno will
 807  * be returned in error cases.
 808  */
 809 int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 810                     size_t val_len)
 811 {
 812         size_t val_bytes = map->format.val_bytes;
 813         size_t val_count = val_len / val_bytes;
 814         unsigned int v;
 815         int ret, i;
 816
 817         if (val_len % map->format.val_bytes)
 818                 return -EINVAL;
 819         if (reg % map->reg_stride)
 820                 return -EINVAL;
 821
 822         map->lock(map);
 823
 824         if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
 825             map->cache_type == REGCACHE_NONE) {
 826                 /* Physical block read if there's no cache involved */
 827                 ret = _regmap_raw_read(map, reg, val, val_len);
 828
 829         } else {
 830                 /* Otherwise go word by word for the cache; should be low
 831                  * cost as we expect to hit the cache.
 832                  */
 833                 for (i = 0; i < val_count; i++) {
 834                         ret = _regmap_read(map, reg + (i * map->reg_stride),
 835                                            &v);
 836                         if (ret != 0)
 837                                 goto out;
 838
 839                         map->format.format_val(val + (i * val_bytes), v, 0);
 840                 }
 841         }
 842
 843  out:
 844         map->unlock(map);
 845
 846         return ret;
 847 }
 848 EXPORT_SYMBOL_GPL(regmap_raw_read);
 849
 850 /**
 851  * regmap_bulk_read(): Read multiple registers from the device
 852  *
 853  * @map: Register map to write to
 854  * @reg: First register to be read from
 855  * @val: Pointer to store read value, in native register size for device
 856  * @val_count: Number of registers to read
 857  *
 858  * A value of zero will be returned on success, a negative errno will
 859  * be returned in error cases.
 860  */
 861 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 862                      size_t val_count)
 863 {
 864         int ret, i;
 865         size_t val_bytes = map->format.val_bytes;
 866         bool vol = regmap_volatile_range(map, reg, val_count);
 867
 868         if (!map->format.parse_val)
 869                 return -EINVAL;
 870         if (reg % map->reg_stride)
 871                 return -EINVAL;
 872
 873         if (vol || map->cache_type == REGCACHE_NONE) {
 874                 /*
 875                  * Some devices does not support bulk read, for
 876                  * them we have a series of single read operations.
 877                  */
 878                 if (map->use_single_rw) {
 879                         for (i = 0; i < val_count; i++) {
 880                                 ret = regmap_raw_read(map,
 881                                                 reg + (i * map->reg_stride),
 882                                                 val + (i * val_bytes),
 883                                                 val_bytes);
 884                                 if (ret != 0)
 885                                         return ret;
 886                         }
 887                 } else {
 888                         ret = regmap_raw_read(map, reg, val,
 889                                               val_bytes * val_count);
 890                         if (ret != 0)
 891                                 return ret;
 892                 }
 893
 894                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
 895                         map->format.parse_val(val + i);
 896         } else {
 897                 for (i = 0; i < val_count; i++) {
 898                         ret = regmap_read(map, reg + (i * map->reg_stride),
 899                                           val + (i * val_bytes));
 900                         if (ret != 0)
 901                                 return ret;
 902                 }
 903         }
 904
 905         return 0;
 906 }
 907 EXPORT_SYMBOL_GPL(regmap_bulk_read);
 908
 909 static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 910                                unsigned int mask, unsigned int val,
 911                                bool *change)
 912 {
 913         int ret;
 914         unsigned int tmp, orig;
 915
 916         map->lock(map);
 917
 918         ret = _regmap_read(map, reg, &orig);
 919         if (ret != 0)
 920                 goto out;
 921
 922         tmp = orig & ~mask;
 923         tmp |= val & mask;
 924
 925         if (tmp != orig) {
 926                 ret = _regmap_write(map, reg, tmp);
 927                 *change = true;
 928         } else {
 929                 *change = false;
 930         }
 931
 932 out:
 933         map->unlock(map);
 934
 935         return ret;
 936 }
 937
 938 /**
 939  * regmap_update_bits: Perform a read/modify/write cycle on the register map
 940  *
 941  * @map: Register map to update
 942  * @reg: Register to update
 943  * @mask: Bitmask to change
 944  * @val: New value for bitmask
 945  *
 946  * Returns zero for success, a negative number on error.
 947  */
 948 int regmap_update_bits(struct regmap *map, unsigned int reg,
 949                        unsigned int mask, unsigned int val)
 950 {
 951         bool change;
 952         return _regmap_update_bits(map, reg, mask, val, &change);
 953 }
 954 EXPORT_SYMBOL_GPL(regmap_update_bits);
 955
 956 /**
 957  * regmap_update_bits_check: Perform a read/modify/write cycle on the
 958  *                           register map and report if updated
 959  *
 960  * @map: Register map to update
 961  * @reg: Register to update
 962  * @mask: Bitmask to change
 963  * @val: New value for bitmask
 964  * @change: Boolean indicating if a write was done
 965  *
 966  * Returns zero for success, a negative number on error.
 967  */
 968 int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 969                              unsigned int mask, unsigned int val,
 970                              bool *change)
 971 {
 972         return _regmap_update_bits(map, reg, mask, val, change);
 973 }
 974 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
 975
 976 /**
 977  * regmap_register_patch: Register and apply register updates to be applied
 978  *                        on device initialistion
 979  *
 980  * @map: Register map to apply updates to.
 981  * @regs: Values to update.
 982  * @num_regs: Number of entries in regs.
 983  *
 984  * Register a set of register updates to be applied to the device
 985  * whenever the device registers are synchronised with the cache and
 986  * apply them immediately.  Typically this is used to apply
 987  * corrections to be applied to the device defaults on startup, such
 988  * as the updates some vendors provide to undocumented registers.
 989  */
 990 int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
 991                           int num_regs)
 992 {
 993         int i, ret;
 994         bool bypass;
 995
 996         /* If needed the implementation can be extended to support this */
 997         if (map->patch)
 998                 return -EBUSY;
 999
1000         map->lock(map);
1001
1002         bypass = map->cache_bypass;
1003
1004         map->cache_bypass = true;
1005
1006         /* Write out first; it's useful to apply even if we fail later. */
1007         for (i = 0; i < num_regs; i++) {
1008                 ret = _regmap_write(map, regs[i].reg, regs[i].def);
1009                 if (ret != 0) {
1010                         dev_err(map->dev, "Failed to write %x = %x: %d\n",
1011                                 regs[i].reg, regs[i].def, ret);
1012                         goto out;
1013                 }
1014         }
1015
1016         map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
1017         if (map->patch != NULL) {
1018                 memcpy(map->patch, regs,
1019                        num_regs * sizeof(struct reg_default));
1020                 map->patch_regs = num_regs;
1021         } else {
1022                 ret = -ENOMEM;
1023         }
1024
1025 out:
1026         map->cache_bypass = bypass;
1027
1028         map->unlock(map);
1029
1030         return ret;
1031 }
1032 EXPORT_SYMBOL_GPL(regmap_register_patch);
1033
1034 /*
1035  * regmap_get_val_bytes(): Report the size of a register value
1036  *
1037  * Report the size of a register value, mainly intended to for use by
1038  * generic infrastructure built on top of regmap.
1039  */
1040 int regmap_get_val_bytes(struct regmap *map)
1041 {
1042         if (map->format.format_write)
1043                 return -EINVAL;
1044
1045         return map->format.val_bytes;
1046 }
1047 EXPORT_SYMBOL_GPL(regmap_get_val_bytes);
1048
1049 static int __init regmap_initcall(void)
1050 {
1051         regmap_debugfs_initcall();
1052
1053         return 0;
1054 }
1055 postcore_initcall(regmap_initcall);