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 #include <linux/rbtree.h>
  19 #include <linux/sched.h>
  20
  21 #define CREATE_TRACE_POINTS
  22 #include <trace/events/regmap.h>
  23
  24 #include "internal.h"
  25
  26 /*
  27  * Sometimes for failures during very early init the trace
  28  * infrastructure isn't available early enough to be used.  For this
  29  * sort of problem defining LOG_DEVICE will add printks for basic
  30  * register I/O on a specific device.
  31  */
  32 #undef LOG_DEVICE
  33
  34 static int _regmap_update_bits(struct regmap *map, unsigned int reg,
  35                                unsigned int mask, unsigned int val,
  36                                bool *change);
  37
  38 static int _regmap_bus_read(void *context, unsigned int reg,
  39                             unsigned int *val);
  40 static int _regmap_bus_formatted_write(void *context, unsigned int reg,
  41                                        unsigned int val);
  42 static int _regmap_bus_raw_write(void *context, unsigned int reg,
  43                                  unsigned int val);
  44
  45 static void async_cleanup(struct work_struct *work)
  46 {
  47         struct regmap_async *async = container_of(work, struct regmap_async,
  48                                                   cleanup);
  49
  50         kfree(async->work_buf);
  51         kfree(async);
  52 }
  53
  54 bool regmap_reg_in_ranges(unsigned int reg,
  55                           const struct regmap_range *ranges,
  56                           unsigned int nranges)
  57 {
  58         const struct regmap_range *r;
  59         int i;
  60
  61         for (i = 0, r = ranges; i < nranges; i++, r++)
  62                 if (regmap_reg_in_range(reg, r))
  63                         return true;
  64         return false;
  65 }
  66 EXPORT_SYMBOL_GPL(regmap_reg_in_ranges);
  67
  68 static bool _regmap_check_range_table(struct regmap *map,
  69                                       unsigned int reg,
  70                                       const struct regmap_access_table *table)
  71 {
  72         /* Check "no ranges" first */
  73         if (regmap_reg_in_ranges(reg, table->no_ranges, table->n_no_ranges))
  74                 return false;
  75
  76         /* In case zero "yes ranges" are supplied, any reg is OK */
  77         if (!table->n_yes_ranges)
  78                 return true;
  79
  80         return regmap_reg_in_ranges(reg, table->yes_ranges,
  81                                     table->n_yes_ranges);
  82 }
  83
  84 bool regmap_writeable(struct regmap *map, unsigned int reg)
  85 {
  86         if (map->max_register && reg > map->max_register)
  87                 return false;
  88
  89         if (map->writeable_reg)
  90                 return map->writeable_reg(map->dev, reg);
  91
  92         if (map->wr_table)
  93                 return _regmap_check_range_table(map, reg, map->wr_table);
  94
  95         return true;
  96 }
  97
  98 bool regmap_readable(struct regmap *map, unsigned int reg)
  99 {
 100         if (map->max_register && reg > map->max_register)
 101                 return false;
 102
 103         if (map->format.format_write)
 104                 return false;
 105
 106         if (map->readable_reg)
 107                 return map->readable_reg(map->dev, reg);
 108
 109         if (map->rd_table)
 110                 return _regmap_check_range_table(map, reg, map->rd_table);
 111
 112         return true;
 113 }
 114
 115 bool regmap_volatile(struct regmap *map, unsigned int reg)
 116 {
 117         if (!regmap_readable(map, reg))
 118                 return false;
 119
 120         if (map->volatile_reg)
 121                 return map->volatile_reg(map->dev, reg);
 122
 123         if (map->volatile_table)
 124                 return _regmap_check_range_table(map, reg, map->volatile_table);
 125
 126         return true;
 127 }
 128
 129 bool regmap_precious(struct regmap *map, unsigned int reg)
 130 {
 131         if (!regmap_readable(map, reg))
 132                 return false;
 133
 134         if (map->precious_reg)
 135                 return map->precious_reg(map->dev, reg);
 136
 137         if (map->precious_table)
 138                 return _regmap_check_range_table(map, reg, map->precious_table);
 139
 140         return false;
 141 }
 142
 143 static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
 144         size_t num)
 145 {
 146         unsigned int i;
 147
 148         for (i = 0; i < num; i++)
 149                 if (!regmap_volatile(map, reg + i))
 150                         return false;
 151
 152         return true;
 153 }
 154
 155 static void regmap_format_2_6_write(struct regmap *map,
 156                                      unsigned int reg, unsigned int val)
 157 {
 158         u8 *out = map->work_buf;
 159
 160         *out = (reg << 6) | val;
 161 }
 162
 163 static void regmap_format_4_12_write(struct regmap *map,
 164                                      unsigned int reg, unsigned int val)
 165 {
 166         __be16 *out = map->work_buf;
 167         *out = cpu_to_be16((reg << 12) | val);
 168 }
 169
 170 static void regmap_format_7_9_write(struct regmap *map,
 171                                     unsigned int reg, unsigned int val)
 172 {
 173         __be16 *out = map->work_buf;
 174         *out = cpu_to_be16((reg << 9) | val);
 175 }
 176
 177 static void regmap_format_10_14_write(struct regmap *map,
 178                                     unsigned int reg, unsigned int val)
 179 {
 180         u8 *out = map->work_buf;
 181
 182         out[2] = val;
 183         out[1] = (val >> 8) | (reg << 6);
 184         out[0] = reg >> 2;
 185 }
 186
 187 static void regmap_format_8(void *buf, unsigned int val, unsigned int shift)
 188 {
 189         u8 *b = buf;
 190
 191         b[0] = val << shift;
 192 }
 193
 194 static void regmap_format_16_be(void *buf, unsigned int val, unsigned int shift)
 195 {
 196         __be16 *b = buf;
 197
 198         b[0] = cpu_to_be16(val << shift);
 199 }
 200
 201 static void regmap_format_16_native(void *buf, unsigned int val,
 202                                     unsigned int shift)
 203 {
 204         *(u16 *)buf = val << shift;
 205 }
 206
 207 static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)
 208 {
 209         u8 *b = buf;
 210
 211         val <<= shift;
 212
 213         b[0] = val >> 16;
 214         b[1] = val >> 8;
 215         b[2] = val;
 216 }
 217
 218 static void regmap_format_32_be(void *buf, unsigned int val, unsigned int shift)
 219 {
 220         __be32 *b = buf;
 221
 222         b[0] = cpu_to_be32(val << shift);
 223 }
 224
 225 static void regmap_format_32_native(void *buf, unsigned int val,
 226                                     unsigned int shift)
 227 {
 228         *(u32 *)buf = val << shift;
 229 }
 230
 231 static unsigned int regmap_parse_8(void *buf)
 232 {
 233         u8 *b = buf;
 234
 235         return b[0];
 236 }
 237
 238 static unsigned int regmap_parse_16_be(void *buf)
 239 {
 240         __be16 *b = buf;
 241
 242         b[0] = be16_to_cpu(b[0]);
 243
 244         return b[0];
 245 }
 246
 247 static unsigned int regmap_parse_16_native(void *buf)
 248 {
 249         return *(u16 *)buf;
 250 }
 251
 252 static unsigned int regmap_parse_24(void *buf)
 253 {
 254         u8 *b = buf;
 255         unsigned int ret = b[2];
 256         ret |= ((unsigned int)b[1]) << 8;
 257         ret |= ((unsigned int)b[0]) << 16;
 258
 259         return ret;
 260 }
 261
 262 static unsigned int regmap_parse_32_be(void *buf)
 263 {
 264         __be32 *b = buf;
 265
 266         b[0] = be32_to_cpu(b[0]);
 267
 268         return b[0];
 269 }
 270
 271 static unsigned int regmap_parse_32_native(void *buf)
 272 {
 273         return *(u32 *)buf;
 274 }
 275
 276 static void regmap_lock_mutex(void *__map)
 277 {
 278         struct regmap *map = __map;
 279         mutex_lock(&map->mutex);
 280 }
 281
 282 static void regmap_unlock_mutex(void *__map)
 283 {
 284         struct regmap *map = __map;
 285         mutex_unlock(&map->mutex);
 286 }
 287
 288 static void regmap_lock_spinlock(void *__map)
 289 {
 290         struct regmap *map = __map;
 291         spin_lock(&map->spinlock);
 292 }
 293
 294 static void regmap_unlock_spinlock(void *__map)
 295 {
 296         struct regmap *map = __map;
 297         spin_unlock(&map->spinlock);
 298 }
 299
 300 static void dev_get_regmap_release(struct device *dev, void *res)
 301 {
 302         /*
 303          * We don't actually have anything to do here; the goal here
 304          * is not to manage the regmap but to provide a simple way to
 305          * get the regmap back given a struct device.
 306          */
 307 }
 308
 309 static bool _regmap_range_add(struct regmap *map,
 310                               struct regmap_range_node *data)
 311 {
 312         struct rb_root *root = &map->range_tree;
 313         struct rb_node **new = &(root->rb_node), *parent = NULL;
 314
 315         while (*new) {
 316                 struct regmap_range_node *this =
 317                         container_of(*new, struct regmap_range_node, node);
 318
 319                 parent = *new;
 320                 if (data->range_max < this->range_min)
 321                         new = &((*new)->rb_left);
 322                 else if (data->range_min > this->range_max)
 323                         new = &((*new)->rb_right);
 324                 else
 325                         return false;
 326         }
 327
 328         rb_link_node(&data->node, parent, new);
 329         rb_insert_color(&data->node, root);
 330
 331         return true;
 332 }
 333
 334 static struct regmap_range_node *_regmap_range_lookup(struct regmap *map,
 335                                                       unsigned int reg)
 336 {
 337         struct rb_node *node = map->range_tree.rb_node;
 338
 339         while (node) {
 340                 struct regmap_range_node *this =
 341                         container_of(node, struct regmap_range_node, node);
 342
 343                 if (reg < this->range_min)
 344                         node = node->rb_left;
 345                 else if (reg > this->range_max)
 346                         node = node->rb_right;
 347                 else
 348                         return this;
 349         }
 350
 351         return NULL;
 352 }
 353
 354 static void regmap_range_exit(struct regmap *map)
 355 {
 356         struct rb_node *next;
 357         struct regmap_range_node *range_node;
 358
 359         next = rb_first(&map->range_tree);
 360         while (next) {
 361                 range_node = rb_entry(next, struct regmap_range_node, node);
 362                 next = rb_next(&range_node->node);
 363                 rb_erase(&range_node->node, &map->range_tree);
 364                 kfree(range_node);
 365         }
 366
 367         kfree(map->selector_work_buf);
 368 }
 369
 370 /**
 371  * regmap_init(): Initialise register map
 372  *
 373  * @dev: Device that will be interacted with
 374  * @bus: Bus-specific callbacks to use with device
 375  * @bus_context: Data passed to bus-specific callbacks
 376  * @config: Configuration for register map
 377  *
 378  * The return value will be an ERR_PTR() on error or a valid pointer to
 379  * a struct regmap.  This function should generally not be called
 380  * directly, it should be called by bus-specific init functions.
 381  */
 382 struct regmap *regmap_init(struct device *dev,
 383                            const struct regmap_bus *bus,
 384                            void *bus_context,
 385                            const struct regmap_config *config)
 386 {
 387         struct regmap *map, **m;
 388         int ret = -EINVAL;
 389         enum regmap_endian reg_endian, val_endian;
 390         int i, j;
 391
 392         if (!config)
 393                 goto err;
 394
 395         map = kzalloc(sizeof(*map), GFP_KERNEL);
 396         if (map == NULL) {
 397                 ret = -ENOMEM;
 398                 goto err;
 399         }
 400
 401         if (config->lock && config->unlock) {
 402                 map->lock = config->lock;
 403                 map->unlock = config->unlock;
 404                 map->lock_arg = config->lock_arg;
 405         } else {
 406                 if ((bus && bus->fast_io) ||
 407                     config->fast_io) {
 408                         spin_lock_init(&map->spinlock);
 409                         map->lock = regmap_lock_spinlock;
 410                         map->unlock = regmap_unlock_spinlock;
 411                 } else {
 412                         mutex_init(&map->mutex);
 413                         map->lock = regmap_lock_mutex;
 414                         map->unlock = regmap_unlock_mutex;
 415                 }
 416                 map->lock_arg = map;
 417         }
 418         map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
 419         map->format.pad_bytes = config->pad_bits / 8;
 420         map->format.val_bytes = DIV_ROUND_UP(config->val_bits, 8);
 421         map->format.buf_size = DIV_ROUND_UP(config->reg_bits +
 422                         config->val_bits + config->pad_bits, 8);
 423         map->reg_shift = config->pad_bits % 8;
 424         if (config->reg_stride)
 425                 map->reg_stride = config->reg_stride;
 426         else
 427                 map->reg_stride = 1;
 428         map->use_single_rw = config->use_single_rw;
 429         map->dev = dev;
 430         map->bus = bus;
 431         map->bus_context = bus_context;
 432         map->max_register = config->max_register;
 433         map->wr_table = config->wr_table;
 434         map->rd_table = config->rd_table;
 435         map->volatile_table = config->volatile_table;
 436         map->precious_table = config->precious_table;
 437         map->writeable_reg = config->writeable_reg;
 438         map->readable_reg = config->readable_reg;
 439         map->volatile_reg = config->volatile_reg;
 440         map->precious_reg = config->precious_reg;
 441         map->cache_type = config->cache_type;
 442         map->name = config->name;
 443
 444         spin_lock_init(&map->async_lock);
 445         INIT_LIST_HEAD(&map->async_list);
 446         init_waitqueue_head(&map->async_waitq);
 447
 448         if (config->read_flag_mask || config->write_flag_mask) {
 449                 map->read_flag_mask = config->read_flag_mask;
 450                 map->write_flag_mask = config->write_flag_mask;
 451         } else if (bus) {
 452                 map->read_flag_mask = bus->read_flag_mask;
 453         }
 454
 455         if (!bus) {
 456                 map->reg_read  = config->reg_read;
 457                 map->reg_write = config->reg_write;
 458
 459                 map->defer_caching = false;
 460                 goto skip_format_initialization;
 461         } else {
 462                 map->reg_read  = _regmap_bus_read;
 463         }
 464
 465         reg_endian = config->reg_format_endian;
 466         if (reg_endian == REGMAP_ENDIAN_DEFAULT)
 467                 reg_endian = bus->reg_format_endian_default;
 468         if (reg_endian == REGMAP_ENDIAN_DEFAULT)
 469                 reg_endian = REGMAP_ENDIAN_BIG;
 470
 471         val_endian = config->val_format_endian;
 472         if (val_endian == REGMAP_ENDIAN_DEFAULT)
 473                 val_endian = bus->val_format_endian_default;
 474         if (val_endian == REGMAP_ENDIAN_DEFAULT)
 475                 val_endian = REGMAP_ENDIAN_BIG;
 476
 477         switch (config->reg_bits + map->reg_shift) {
 478         case 2:
 479                 switch (config->val_bits) {
 480                 case 6:
 481                         map->format.format_write = regmap_format_2_6_write;
 482                         break;
 483                 default:
 484                         goto err_map;
 485                 }
 486                 break;
 487
 488         case 4:
 489                 switch (config->val_bits) {
 490                 case 12:
 491                         map->format.format_write = regmap_format_4_12_write;
 492                         break;
 493                 default:
 494                         goto err_map;
 495                 }
 496                 break;
 497
 498         case 7:
 499                 switch (config->val_bits) {
 500                 case 9:
 501                         map->format.format_write = regmap_format_7_9_write;
 502                         break;
 503                 default:
 504                         goto err_map;
 505                 }
 506                 break;
 507
 508         case 10:
 509                 switch (config->val_bits) {
 510                 case 14:
 511                         map->format.format_write = regmap_format_10_14_write;
 512                         break;
 513                 default:
 514                         goto err_map;
 515                 }
 516                 break;
 517
 518         case 8:
 519                 map->format.format_reg = regmap_format_8;
 520                 break;
 521
 522         case 16:
 523                 switch (reg_endian) {
 524                 case REGMAP_ENDIAN_BIG:
 525                         map->format.format_reg = regmap_format_16_be;
 526                         break;
 527                 case REGMAP_ENDIAN_NATIVE:
 528                         map->format.format_reg = regmap_format_16_native;
 529                         break;
 530                 default:
 531                         goto err_map;
 532                 }
 533                 break;
 534
 535         case 24:
 536                 if (reg_endian != REGMAP_ENDIAN_BIG)
 537                         goto err_map;
 538                 map->format.format_reg = regmap_format_24;
 539                 break;
 540
 541         case 32:
 542                 switch (reg_endian) {
 543                 case REGMAP_ENDIAN_BIG:
 544                         map->format.format_reg = regmap_format_32_be;
 545                         break;
 546                 case REGMAP_ENDIAN_NATIVE:
 547                         map->format.format_reg = regmap_format_32_native;
 548                         break;
 549                 default:
 550                         goto err_map;
 551                 }
 552                 break;
 553
 554         default:
 555                 goto err_map;
 556         }
 557
 558         switch (config->val_bits) {
 559         case 8:
 560                 map->format.format_val = regmap_format_8;
 561                 map->format.parse_val = regmap_parse_8;
 562                 break;
 563         case 16:
 564                 switch (val_endian) {
 565                 case REGMAP_ENDIAN_BIG:
 566                         map->format.format_val = regmap_format_16_be;
 567                         map->format.parse_val = regmap_parse_16_be;
 568                         break;
 569                 case REGMAP_ENDIAN_NATIVE:
 570                         map->format.format_val = regmap_format_16_native;
 571                         map->format.parse_val = regmap_parse_16_native;
 572                         break;
 573                 default:
 574                         goto err_map;
 575                 }
 576                 break;
 577         case 24:
 578                 if (val_endian != REGMAP_ENDIAN_BIG)
 579                         goto err_map;
 580                 map->format.format_val = regmap_format_24;
 581                 map->format.parse_val = regmap_parse_24;
 582                 break;
 583         case 32:
 584                 switch (val_endian) {
 585                 case REGMAP_ENDIAN_BIG:
 586                         map->format.format_val = regmap_format_32_be;
 587                         map->format.parse_val = regmap_parse_32_be;
 588                         break;
 589                 case REGMAP_ENDIAN_NATIVE:
 590                         map->format.format_val = regmap_format_32_native;
 591                         map->format.parse_val = regmap_parse_32_native;
 592                         break;
 593                 default:
 594                         goto err_map;
 595                 }
 596                 break;
 597         }
 598
 599         if (map->format.format_write) {
 600                 if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 601                     (val_endian != REGMAP_ENDIAN_BIG))
 602                         goto err_map;
 603                 map->use_single_rw = true;
 604         }
 605
 606         if (!map->format.format_write &&
 607             !(map->format.format_reg && map->format.format_val))
 608                 goto err_map;
 609
 610         map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 611         if (map->work_buf == NULL) {
 612                 ret = -ENOMEM;
 613                 goto err_map;
 614         }
 615
 616         if (map->format.format_write) {
 617                 map->defer_caching = false;
 618                 map->reg_write = _regmap_bus_formatted_write;
 619         } else if (map->format.format_val) {
 620                 map->defer_caching = true;
 621                 map->reg_write = _regmap_bus_raw_write;
 622         }
 623
 624 skip_format_initialization:
 625
 626         map->range_tree = RB_ROOT;
 627         for (i = 0; i < config->num_ranges; i++) {
 628                 const struct regmap_range_cfg *range_cfg = &config->ranges[i];
 629                 struct regmap_range_node *new;
 630
 631                 /* Sanity check */
 632                 if (range_cfg->range_max < range_cfg->range_min) {
 633                         dev_err(map->dev, "Invalid range %d: %d < %d\n", i,
 634                                 range_cfg->range_max, range_cfg->range_min);
 635                         goto err_range;
 636                 }
 637
 638                 if (range_cfg->range_max > map->max_register) {
 639                         dev_err(map->dev, "Invalid range %d: %d > %d\n", i,
 640                                 range_cfg->range_max, map->max_register);
 641                         goto err_range;
 642                 }
 643
 644                 if (range_cfg->selector_reg > map->max_register) {
 645                         dev_err(map->dev,
 646                                 "Invalid range %d: selector out of map\n", i);
 647                         goto err_range;
 648                 }
 649
 650                 if (range_cfg->window_len == 0) {
 651                         dev_err(map->dev, "Invalid range %d: window_len 0\n",
 652                                 i);
 653                         goto err_range;
 654                 }
 655
 656                 /* Make sure, that this register range has no selector
 657                    or data window within its boundary */
 658                 for (j = 0; j < config->num_ranges; j++) {
 659                         unsigned sel_reg = config->ranges[j].selector_reg;
 660                         unsigned win_min = config->ranges[j].window_start;
 661                         unsigned win_max = win_min +
 662                                            config->ranges[j].window_len - 1;
 663
 664                         if (range_cfg->range_min <= sel_reg &&
 665                             sel_reg <= range_cfg->range_max) {
 666                                 dev_err(map->dev,
 667                                         "Range %d: selector for %d in window\n",
 668                                         i, j);
 669                                 goto err_range;
 670                         }
 671
 672                         if (!(win_max < range_cfg->range_min ||
 673                               win_min > range_cfg->range_max)) {
 674                                 dev_err(map->dev,
 675                                         "Range %d: window for %d in window\n",
 676                                         i, j);
 677                                 goto err_range;
 678                         }
 679                 }
 680
 681                 new = kzalloc(sizeof(*new), GFP_KERNEL);
 682                 if (new == NULL) {
 683                         ret = -ENOMEM;
 684                         goto err_range;
 685                 }
 686
 687                 new->map = map;
 688                 new->name = range_cfg->name;
 689                 new->range_min = range_cfg->range_min;
 690                 new->range_max = range_cfg->range_max;
 691                 new->selector_reg = range_cfg->selector_reg;
 692                 new->selector_mask = range_cfg->selector_mask;
 693                 new->selector_shift = range_cfg->selector_shift;
 694                 new->window_start = range_cfg->window_start;
 695                 new->window_len = range_cfg->window_len;
 696
 697                 if (_regmap_range_add(map, new) == false) {
 698                         dev_err(map->dev, "Failed to add range %d\n", i);
 699                         kfree(new);
 700                         goto err_range;
 701                 }
 702
 703                 if (map->selector_work_buf == NULL) {
 704                         map->selector_work_buf =
 705                                 kzalloc(map->format.buf_size, GFP_KERNEL);
 706                         if (map->selector_work_buf == NULL) {
 707                                 ret = -ENOMEM;
 708                                 goto err_range;
 709                         }
 710                 }
 711         }
 712
 713         ret = regcache_init(map, config);
 714         if (ret != 0)
 715                 goto err_range;
 716
 717         regmap_debugfs_init(map, config->name);
 718
 719         /* Add a devres resource for dev_get_regmap() */
 720         m = devres_alloc(dev_get_regmap_release, sizeof(*m), GFP_KERNEL);
 721         if (!m) {
 722                 ret = -ENOMEM;
 723                 goto err_debugfs;
 724         }
 725         *m = map;
 726         devres_add(dev, m);
 727
 728         return map;
 729
 730 err_debugfs:
 731         regmap_debugfs_exit(map);
 732         regcache_exit(map);
 733 err_range:
 734         regmap_range_exit(map);
 735         kfree(map->work_buf);
 736 err_map:
 737         kfree(map);
 738 err:
 739         return ERR_PTR(ret);
 740 }
 741 EXPORT_SYMBOL_GPL(regmap_init);
 742
 743 static void devm_regmap_release(struct device *dev, void *res)
 744 {
 745         regmap_exit(*(struct regmap **)res);
 746 }
 747
 748 /**
 749  * devm_regmap_init(): Initialise managed register map
 750  *
 751  * @dev: Device that will be interacted with
 752  * @bus: Bus-specific callbacks to use with device
 753  * @bus_context: Data passed to bus-specific callbacks
 754  * @config: Configuration for register map
 755  *
 756  * The return value will be an ERR_PTR() on error or a valid pointer
 757  * to a struct regmap.  This function should generally not be called
 758  * directly, it should be called by bus-specific init functions.  The
 759  * map will be automatically freed by the device management code.
 760  */
 761 struct regmap *devm_regmap_init(struct device *dev,
 762                                 const struct regmap_bus *bus,
 763                                 void *bus_context,
 764                                 const struct regmap_config *config)
 765 {
 766         struct regmap **ptr, *regmap;
 767
 768         ptr = devres_alloc(devm_regmap_release, sizeof(*ptr), GFP_KERNEL);
 769         if (!ptr)
 770                 return ERR_PTR(-ENOMEM);
 771
 772         regmap = regmap_init(dev, bus, bus_context, config);
 773         if (!IS_ERR(regmap)) {
 774                 *ptr = regmap;
 775                 devres_add(dev, ptr);
 776         } else {
 777                 devres_free(ptr);
 778         }
 779
 780         return regmap;
 781 }
 782 EXPORT_SYMBOL_GPL(devm_regmap_init);
 783
 784 /**
 785  * regmap_reinit_cache(): Reinitialise the current register cache
 786  *
 787  * @map: Register map to operate on.
 788  * @config: New configuration.  Only the cache data will be used.
 789  *
 790  * Discard any existing register cache for the map and initialize a
 791  * new cache.  This can be used to restore the cache to defaults or to
 792  * update the cache configuration to reflect runtime discovery of the
 793  * hardware.
 794  *
 795  * No explicit locking is done here, the user needs to ensure that
 796  * this function will not race with other calls to regmap.
 797  */
 798 int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 799 {
 800         regcache_exit(map);
 801         regmap_debugfs_exit(map);
 802
 803         map->max_register = config->max_register;
 804         map->writeable_reg = config->writeable_reg;
 805         map->readable_reg = config->readable_reg;
 806         map->volatile_reg = config->volatile_reg;
 807         map->precious_reg = config->precious_reg;
 808         map->cache_type = config->cache_type;
 809
 810         regmap_debugfs_init(map, config->name);
 811
 812         map->cache_bypass = false;
 813         map->cache_only = false;
 814
 815         return regcache_init(map, config);
 816 }
 817 EXPORT_SYMBOL_GPL(regmap_reinit_cache);
 818
 819 /**
 820  * regmap_exit(): Free a previously allocated register map
 821  */
 822 void regmap_exit(struct regmap *map)
 823 {
 824         regcache_exit(map);
 825         regmap_debugfs_exit(map);
 826         regmap_range_exit(map);
 827         if (map->bus && map->bus->free_context)
 828                 map->bus->free_context(map->bus_context);
 829         kfree(map->work_buf);
 830         kfree(map);
 831 }
 832 EXPORT_SYMBOL_GPL(regmap_exit);
 833
 834 static int dev_get_regmap_match(struct device *dev, void *res, void *data)
 835 {
 836         struct regmap **r = res;
 837         if (!r || !*r) {
 838                 WARN_ON(!r || !*r);
 839                 return 0;
 840         }
 841
 842         /* If the user didn't specify a name match any */
 843         if (data)
 844                 return (*r)->name == data;
 845         else
 846                 return 1;
 847 }
 848
 849 /**
 850  * dev_get_regmap(): Obtain the regmap (if any) for a device
 851  *
 852  * @dev: Device to retrieve the map for
 853  * @name: Optional name for the register map, usually NULL.
 854  *
 855  * Returns the regmap for the device if one is present, or NULL.  If
 856  * name is specified then it must match the name specified when
 857  * registering the device, if it is NULL then the first regmap found
 858  * will be used.  Devices with multiple register maps are very rare,
 859  * generic code should normally not need to specify a name.
 860  */
 861 struct regmap *dev_get_regmap(struct device *dev, const char *name)
 862 {
 863         struct regmap **r = devres_find(dev, dev_get_regmap_release,
 864                                         dev_get_regmap_match, (void *)name);
 865
 866         if (!r)
 867                 return NULL;
 868         return *r;
 869 }
 870 EXPORT_SYMBOL_GPL(dev_get_regmap);
 871
 872 static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 873                                struct regmap_range_node *range,
 874                                unsigned int val_num)
 875 {
 876         void *orig_work_buf;
 877         unsigned int win_offset;
 878         unsigned int win_page;
 879         bool page_chg;
 880         int ret;
 881
 882         win_offset = (*reg - range->range_min) % range->window_len;
 883         win_page = (*reg - range->range_min) / range->window_len;
 884
 885         if (val_num > 1) {
 886                 /* Bulk write shouldn't cross range boundary */
 887                 if (*reg + val_num - 1 > range->range_max)
 888                         return -EINVAL;
 889
 890                 /* ... or single page boundary */
 891                 if (val_num > range->window_len - win_offset)
 892                         return -EINVAL;
 893         }
 894
 895         /* It is possible to have selector register inside data window.
 896            In that case, selector register is located on every page and
 897            it needs no page switching, when accessed alone. */
 898         if (val_num > 1 ||
 899             range->window_start + win_offset != range->selector_reg) {
 900                 /* Use separate work_buf during page switching */
 901                 orig_work_buf = map->work_buf;
 902                 map->work_buf = map->selector_work_buf;
 903
 904                 ret = _regmap_update_bits(map, range->selector_reg,
 905                                           range->selector_mask,
 906                                           win_page << range->selector_shift,
 907                                           &page_chg);
 908
 909                 map->work_buf = orig_work_buf;
 910
 911                 if (ret != 0)
 912                         return ret;
 913         }
 914
 915         *reg = range->window_start + win_offset;
 916
 917         return 0;
 918 }
 919
 920 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 921                              const void *val, size_t val_len, bool async)
 922 {
 923         struct regmap_range_node *range;
 924         unsigned long flags;
 925         u8 *u8 = map->work_buf;
 926         void *work_val = map->work_buf + map->format.reg_bytes +
 927                 map->format.pad_bytes;
 928         void *buf;
 929         int ret = -ENOTSUPP;
 930         size_t len;
 931         int i;
 932
 933         BUG_ON(!map->bus);
 934
 935         /* Check for unwritable registers before we start */
 936         if (map->writeable_reg)
 937                 for (i = 0; i < val_len / map->format.val_bytes; i++)
 938                         if (!map->writeable_reg(map->dev,
 939                                                 reg + (i * map->reg_stride)))
 940                                 return -EINVAL;
 941
 942         if (!map->cache_bypass && map->format.parse_val) {
 943                 unsigned int ival;
 944                 int val_bytes = map->format.val_bytes;
 945                 for (i = 0; i < val_len / val_bytes; i++) {
 946                         memcpy(map->work_buf, val + (i * val_bytes), val_bytes);
 947                         ival = map->format.parse_val(map->work_buf);
 948                         ret = regcache_write(map, reg + (i * map->reg_stride),
 949                                              ival);
 950                         if (ret) {
 951                                 dev_err(map->dev,
 952                                         "Error in caching of register: %x ret: %d\n",
 953                                         reg + i, ret);
 954                                 return ret;
 955                         }
 956                 }
 957                 if (map->cache_only) {
 958                         map->cache_dirty = true;
 959                         return 0;
 960                 }
 961         }
 962
 963         range = _regmap_range_lookup(map, reg);
 964         if (range) {
 965                 int val_num = val_len / map->format.val_bytes;
 966                 int win_offset = (reg - range->range_min) % range->window_len;
 967                 int win_residue = range->window_len - win_offset;
 968
 969                 /* If the write goes beyond the end of the window split it */
 970                 while (val_num > win_residue) {
 971                         dev_dbg(map->dev, "Writing window %d/%zu\n",
 972                                 win_residue, val_len / map->format.val_bytes);
 973                         ret = _regmap_raw_write(map, reg, val, win_residue *
 974                                                 map->format.val_bytes, async);
 975                         if (ret != 0)
 976                                 return ret;
 977
 978                         reg += win_residue;
 979                         val_num -= win_residue;
 980                         val += win_residue * map->format.val_bytes;
 981                         val_len -= win_residue * map->format.val_bytes;
 982
 983                         win_offset = (reg - range->range_min) %
 984                                 range->window_len;
 985                         win_residue = range->window_len - win_offset;
 986                 }
 987
 988                 ret = _regmap_select_page(map, &reg, range, val_num);
 989                 if (ret != 0)
 990                         return ret;
 991         }
 992
 993         map->format.format_reg(map->work_buf, reg, map->reg_shift);
 994
 995         u8[0] |= map->write_flag_mask;
 996
 997         if (async && map->bus->async_write) {
 998                 struct regmap_async *async = map->bus->async_alloc();
 999                 if (!async)
1000                         return -ENOMEM;
1001
1002                 async->work_buf = kzalloc(map->format.buf_size,
1003                                           GFP_KERNEL | GFP_DMA);
1004                 if (!async->work_buf) {
1005                         kfree(async);
1006                         return -ENOMEM;
1007                 }
1008
1009                 INIT_WORK(&async->cleanup, async_cleanup);
1010                 async->map = map;
1011
1012                 /* If the caller supplied the value we can use it safely. */
1013                 memcpy(async->work_buf, map->work_buf, map->format.pad_bytes +
1014                        map->format.reg_bytes + map->format.val_bytes);
1015                 if (val == work_val)
1016                         val = async->work_buf + map->format.pad_bytes +
1017                                 map->format.reg_bytes;
1018
1019                 spin_lock_irqsave(&map->async_lock, flags);
1020                 list_add_tail(&async->list, &map->async_list);
1021                 spin_unlock_irqrestore(&map->async_lock, flags);
1022
1023                 ret = map->bus->async_write(map->bus_context, async->work_buf,
1024                                             map->format.reg_bytes +
1025                                             map->format.pad_bytes,
1026                                             val, val_len, async);
1027
1028                 if (ret != 0) {
1029                         dev_err(map->dev, "Failed to schedule write: %d\n",
1030                                 ret);
1031
1032                         spin_lock_irqsave(&map->async_lock, flags);
1033                         list_del(&async->list);
1034                         spin_unlock_irqrestore(&map->async_lock, flags);
1035
1036                         kfree(async->work_buf);
1037                         kfree(async);
1038                 }
1039         }
1040
1041         trace_regmap_hw_write_start(map->dev, reg,
1042                                     val_len / map->format.val_bytes);
1043
1044         /* If we're doing a single register write we can probably just
1045          * send the work_buf directly, otherwise try to do a gather
1046          * write.
1047          */
1048         if (val == work_val)
1049                 ret = map->bus->write(map->bus_context, map->work_buf,
1050                                       map->format.reg_bytes +
1051                                       map->format.pad_bytes +
1052                                       val_len);
1053         else if (map->bus->gather_write)
1054                 ret = map->bus->gather_write(map->bus_context, map->work_buf,
1055                                              map->format.reg_bytes +
1056                                              map->format.pad_bytes,
1057                                              val, val_len);
1058
1059         /* If that didn't work fall back on linearising by hand. */
1060         if (ret == -ENOTSUPP) {
1061                 len = map->format.reg_bytes + map->format.pad_bytes + val_len;
1062                 buf = kzalloc(len, GFP_KERNEL);
1063                 if (!buf)
1064                         return -ENOMEM;
1065
1066                 memcpy(buf, map->work_buf, map->format.reg_bytes);
1067                 memcpy(buf + map->format.reg_bytes + map->format.pad_bytes,
1068                        val, val_len);
1069                 ret = map->bus->write(map->bus_context, buf, len);
1070
1071                 kfree(buf);
1072         }
1073
1074         trace_regmap_hw_write_done(map->dev, reg,
1075                                    val_len / map->format.val_bytes);
1076
1077         return ret;
1078 }
1079
1080 static int _regmap_bus_formatted_write(void *context, unsigned int reg,
1081                                        unsigned int val)
1082 {
1083         int ret;
1084         struct regmap_range_node *range;
1085         struct regmap *map = context;
1086
1087         BUG_ON(!map->bus || !map->format.format_write);
1088
1089         range = _regmap_range_lookup(map, reg);
1090         if (range) {
1091                 ret = _regmap_select_page(map, &reg, range, 1);
1092                 if (ret != 0)
1093                         return ret;
1094         }
1095
1096         map->format.format_write(map, reg, val);
1097
1098         trace_regmap_hw_write_start(map->dev, reg, 1);
1099
1100         ret = map->bus->write(map->bus_context, map->work_buf,
1101                               map->format.buf_size);
1102
1103         trace_regmap_hw_write_done(map->dev, reg, 1);
1104
1105         return ret;
1106 }
1107
1108 static int _regmap_bus_raw_write(void *context, unsigned int reg,
1109                                  unsigned int val)
1110 {
1111         struct regmap *map = context;
1112
1113         BUG_ON(!map->bus || !map->format.format_val);
1114
1115         map->format.format_val(map->work_buf + map->format.reg_bytes
1116                                + map->format.pad_bytes, val, 0);
1117         return _regmap_raw_write(map, reg,
1118                                  map->work_buf +
1119                                  map->format.reg_bytes +
1120                                  map->format.pad_bytes,
1121                                  map->format.val_bytes, false);
1122 }
1123
1124 static inline void *_regmap_map_get_context(struct regmap *map)
1125 {
1126         return (map->bus) ? map : map->bus_context;
1127 }
1128
1129 int _regmap_write(struct regmap *map, unsigned int reg,
1130                   unsigned int val)
1131 {
1132         int ret;
1133         void *context = _regmap_map_get_context(map);
1134
1135         if (!map->cache_bypass && !map->defer_caching) {
1136                 ret = regcache_write(map, reg, val);
1137                 if (ret != 0)
1138                         return ret;
1139                 if (map->cache_only) {
1140                         map->cache_dirty = true;
1141                         return 0;
1142                 }
1143         }
1144
1145 #ifdef LOG_DEVICE
1146         if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
1147                 dev_info(map->dev, "%x <= %x\n", reg, val);
1148 #endif
1149
1150         trace_regmap_reg_write(map->dev, reg, val);
1151
1152         return map->reg_write(context, reg, val);
1153 }
1154
1155 /**
1156  * regmap_write(): Write a value to a single register
1157  *
1158  * @map: Register map to write to
1159  * @reg: Register to write to
1160  * @val: Value to be written
1161  *
1162  * A value of zero will be returned on success, a negative errno will
1163  * be returned in error cases.
1164  */
1165 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
1166 {
1167         int ret;
1168
1169         if (reg % map->reg_stride)
1170                 return -EINVAL;
1171
1172         map->lock(map->lock_arg);
1173
1174         ret = _regmap_write(map, reg, val);
1175
1176         map->unlock(map->lock_arg);
1177
1178         return ret;
1179 }
1180 EXPORT_SYMBOL_GPL(regmap_write);
1181
1182 /**
1183  * regmap_raw_write(): Write raw values to one or more registers
1184  *
1185  * @map: Register map to write to
1186  * @reg: Initial register to write to
1187  * @val: Block of data to be written, laid out for direct transmission to the
1188  *       device
1189  * @val_len: Length of data pointed to by val.
1190  *
1191  * This function is intended to be used for things like firmware
1192  * download where a large block of data needs to be transferred to the
1193  * device.  No formatting will be done on the data provided.
1194  *
1195  * A value of zero will be returned on success, a negative errno will
1196  * be returned in error cases.
1197  */
1198 int regmap_raw_write(struct regmap *map, unsigned int reg,
1199                      const void *val, size_t val_len)
1200 {
1201         int ret;
1202
1203         if (!map->bus)
1204                 return -EINVAL;
1205         if (val_len % map->format.val_bytes)
1206                 return -EINVAL;
1207         if (reg % map->reg_stride)
1208                 return -EINVAL;
1209
1210         map->lock(map->lock_arg);
1211
1212         ret = _regmap_raw_write(map, reg, val, val_len, false);
1213
1214         map->unlock(map->lock_arg);
1215
1216         return ret;
1217 }
1218 EXPORT_SYMBOL_GPL(regmap_raw_write);
1219
1220 /*
1221  * regmap_bulk_write(): Write multiple registers to the device
1222  *
1223  * @map: Register map to write to
1224  * @reg: First register to be write from
1225  * @val: Block of data to be written, in native register size for device
1226  * @val_count: Number of registers to write
1227  *
1228  * This function is intended to be used for writing a large block of
1229  * data to the device either in single transfer or multiple transfer.
1230  *
1231  * A value of zero will be returned on success, a negative errno will
1232  * be returned in error cases.
1233  */
1234 int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
1235                      size_t val_count)
1236 {
1237         int ret = 0, i;
1238         size_t val_bytes = map->format.val_bytes;
1239         void *wval;
1240
1241         if (!map->bus)
1242                 return -EINVAL;
1243         if (!map->format.parse_val)
1244                 return -EINVAL;
1245         if (reg % map->reg_stride)
1246                 return -EINVAL;
1247
1248         map->lock(map->lock_arg);
1249
1250         /* No formatting is require if val_byte is 1 */
1251         if (val_bytes == 1) {
1252                 wval = (void *)val;
1253         } else {
1254                 wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
1255                 if (!wval) {
1256                         ret = -ENOMEM;
1257                         dev_err(map->dev, "Error in memory allocation\n");
1258                         goto out;
1259                 }
1260                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
1261                         map->format.parse_val(wval + i);
1262         }
1263         /*
1264          * Some devices does not support bulk write, for
1265          * them we have a series of single write operations.
1266          */
1267         if (map->use_single_rw) {
1268                 for (i = 0; i < val_count; i++) {
1269                         ret = regmap_raw_write(map,
1270                                                reg + (i * map->reg_stride),
1271                                                val + (i * val_bytes),
1272                                                val_bytes);
1273                         if (ret != 0)
1274                                 return ret;
1275                 }
1276         } else {
1277                 ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count,
1278                                         false);
1279         }
1280
1281         if (val_bytes != 1)
1282                 kfree(wval);
1283
1284 out:
1285         map->unlock(map->lock_arg);
1286         return ret;
1287 }
1288 EXPORT_SYMBOL_GPL(regmap_bulk_write);
1289
1290 /**
1291  * regmap_raw_write_async(): Write raw values to one or more registers
1292  *                           asynchronously
1293  *
1294  * @map: Register map to write to
1295  * @reg: Initial register to write to
1296  * @val: Block of data to be written, laid out for direct transmission to the
1297  *       device.  Must be valid until regmap_async_complete() is called.
1298  * @val_len: Length of data pointed to by val.
1299  *
1300  * This function is intended to be used for things like firmware
1301  * download where a large block of data needs to be transferred to the
1302  * device.  No formatting will be done on the data provided.
1303  *
1304  * If supported by the underlying bus the write will be scheduled
1305  * asynchronously, helping maximise I/O speed on higher speed buses
1306  * like SPI.  regmap_async_complete() can be called to ensure that all
1307  * asynchrnous writes have been completed.
1308  *
1309  * A value of zero will be returned on success, a negative errno will
1310  * be returned in error cases.
1311  */
1312 int regmap_raw_write_async(struct regmap *map, unsigned int reg,
1313                            const void *val, size_t val_len)
1314 {
1315         int ret;
1316
1317         if (val_len % map->format.val_bytes)
1318                 return -EINVAL;
1319         if (reg % map->reg_stride)
1320                 return -EINVAL;
1321
1322         map->lock(map->lock_arg);
1323
1324         ret = _regmap_raw_write(map, reg, val, val_len, true);
1325
1326         map->unlock(map->lock_arg);
1327
1328         return ret;
1329 }
1330 EXPORT_SYMBOL_GPL(regmap_raw_write_async);
1331
1332 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
1333                             unsigned int val_len)
1334 {
1335         struct regmap_range_node *range;
1336         u8 *u8 = map->work_buf;
1337         int ret;
1338
1339         BUG_ON(!map->bus);
1340
1341         range = _regmap_range_lookup(map, reg);
1342         if (range) {
1343                 ret = _regmap_select_page(map, &reg, range,
1344                                           val_len / map->format.val_bytes);
1345                 if (ret != 0)
1346                         return ret;
1347         }
1348
1349         map->format.format_reg(map->work_buf, reg, map->reg_shift);
1350
1351         /*
1352          * Some buses or devices flag reads by setting the high bits in the
1353          * register addresss; since it's always the high bits for all
1354          * current formats we can do this here rather than in
1355          * formatting.  This may break if we get interesting formats.
1356          */
1357         u8[0] |= map->read_flag_mask;
1358
1359         trace_regmap_hw_read_start(map->dev, reg,
1360                                    val_len / map->format.val_bytes);
1361
1362         ret = map->bus->read(map->bus_context, map->work_buf,
1363                              map->format.reg_bytes + map->format.pad_bytes,
1364                              val, val_len);
1365
1366         trace_regmap_hw_read_done(map->dev, reg,
1367                                   val_len / map->format.val_bytes);
1368
1369         return ret;
1370 }
1371
1372 static int _regmap_bus_read(void *context, unsigned int reg,
1373                             unsigned int *val)
1374 {
1375         int ret;
1376         struct regmap *map = context;
1377
1378         if (!map->format.parse_val)
1379                 return -EINVAL;
1380
1381         ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
1382         if (ret == 0)
1383                 *val = map->format.parse_val(map->work_buf);
1384
1385         return ret;
1386 }
1387
1388 static int _regmap_read(struct regmap *map, unsigned int reg,
1389                         unsigned int *val)
1390 {
1391         int ret;
1392         void *context = _regmap_map_get_context(map);
1393
1394         BUG_ON(!map->reg_read);
1395
1396         if (!map->cache_bypass) {
1397                 ret = regcache_read(map, reg, val);
1398                 if (ret == 0)
1399                         return 0;
1400         }
1401
1402         if (map->cache_only)
1403                 return -EBUSY;
1404
1405         ret = map->reg_read(context, reg, val);
1406         if (ret == 0) {
1407 #ifdef LOG_DEVICE
1408                 if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
1409                         dev_info(map->dev, "%x => %x\n", reg, *val);
1410 #endif
1411
1412                 trace_regmap_reg_read(map->dev, reg, *val);
1413
1414                 if (!map->cache_bypass)
1415                         regcache_write(map, reg, *val);
1416         }
1417
1418         return ret;
1419 }
1420
1421 /**
1422  * regmap_read(): Read a value from a single register
1423  *
1424  * @map: Register map to write to
1425  * @reg: Register to be read from
1426  * @val: Pointer to store read value
1427  *
1428  * A value of zero will be returned on success, a negative errno will
1429  * be returned in error cases.
1430  */
1431 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
1432 {
1433         int ret;
1434
1435         if (reg % map->reg_stride)
1436                 return -EINVAL;
1437
1438         map->lock(map->lock_arg);
1439
1440         ret = _regmap_read(map, reg, val);
1441
1442         map->unlock(map->lock_arg);
1443
1444         return ret;
1445 }
1446 EXPORT_SYMBOL_GPL(regmap_read);
1447
1448 /**
1449  * regmap_raw_read(): Read raw data from the device
1450  *
1451  * @map: Register map to write to
1452  * @reg: First register to be read from
1453  * @val: Pointer to store read value
1454  * @val_len: Size of data to read
1455  *
1456  * A value of zero will be returned on success, a negative errno will
1457  * be returned in error cases.
1458  */
1459 int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
1460                     size_t val_len)
1461 {
1462         size_t val_bytes = map->format.val_bytes;
1463         size_t val_count = val_len / val_bytes;
1464         unsigned int v;
1465         int ret, i;
1466
1467         if (!map->bus)
1468                 return -EINVAL;
1469         if (val_len % map->format.val_bytes)
1470                 return -EINVAL;
1471         if (reg % map->reg_stride)
1472                 return -EINVAL;
1473
1474         map->lock(map->lock_arg);
1475
1476         if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
1477             map->cache_type == REGCACHE_NONE) {
1478                 /* Physical block read if there's no cache involved */
1479                 ret = _regmap_raw_read(map, reg, val, val_len);
1480
1481         } else {
1482                 /* Otherwise go word by word for the cache; should be low
1483                  * cost as we expect to hit the cache.
1484                  */
1485                 for (i = 0; i < val_count; i++) {
1486                         ret = _regmap_read(map, reg + (i * map->reg_stride),
1487                                            &v);
1488                         if (ret != 0)
1489                                 goto out;
1490
1491                         map->format.format_val(val + (i * val_bytes), v, 0);
1492                 }
1493         }
1494
1495  out:
1496         map->unlock(map->lock_arg);
1497
1498         return ret;
1499 }
1500 EXPORT_SYMBOL_GPL(regmap_raw_read);
1501
1502 /**
1503  * regmap_bulk_read(): Read multiple registers from the device
1504  *
1505  * @map: Register map to write to
1506  * @reg: First register to be read from
1507  * @val: Pointer to store read value, in native register size for device
1508  * @val_count: Number of registers to read
1509  *
1510  * A value of zero will be returned on success, a negative errno will
1511  * be returned in error cases.
1512  */
1513 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
1514                      size_t val_count)
1515 {
1516         int ret, i;
1517         size_t val_bytes = map->format.val_bytes;
1518         bool vol = regmap_volatile_range(map, reg, val_count);
1519
1520         if (!map->bus)
1521                 return -EINVAL;
1522         if (!map->format.parse_val)
1523                 return -EINVAL;
1524         if (reg % map->reg_stride)
1525                 return -EINVAL;
1526
1527         if (vol || map->cache_type == REGCACHE_NONE) {
1528                 /*
1529                  * Some devices does not support bulk read, for
1530                  * them we have a series of single read operations.
1531                  */
1532                 if (map->use_single_rw) {
1533                         for (i = 0; i < val_count; i++) {
1534                                 ret = regmap_raw_read(map,
1535                                                 reg + (i * map->reg_stride),
1536                                                 val + (i * val_bytes),
1537                                                 val_bytes);
1538                                 if (ret != 0)
1539                                         return ret;
1540                         }
1541                 } else {
1542                         ret = regmap_raw_read(map, reg, val,
1543                                               val_bytes * val_count);
1544                         if (ret != 0)
1545                                 return ret;
1546                 }
1547
1548                 for (i = 0; i < val_count * val_bytes; i += val_bytes)
1549                         map->format.parse_val(val + i);
1550         } else {
1551                 for (i = 0; i < val_count; i++) {
1552                         unsigned int ival;
1553                         ret = regmap_read(map, reg + (i * map->reg_stride),
1554                                           &ival);
1555                         if (ret != 0)
1556                                 return ret;
1557                         memcpy(val + (i * val_bytes), &ival, val_bytes);
1558                 }
1559         }
1560
1561         return 0;
1562 }
1563 EXPORT_SYMBOL_GPL(regmap_bulk_read);
1564
1565 static int _regmap_update_bits(struct regmap *map, unsigned int reg,
1566                                unsigned int mask, unsigned int val,
1567                                bool *change)
1568 {
1569         int ret;
1570         unsigned int tmp, orig;
1571
1572         ret = _regmap_read(map, reg, &orig);
1573         if (ret != 0)
1574                 return ret;
1575
1576         tmp = orig & ~mask;
1577         tmp |= val & mask;
1578
1579         if (tmp != orig) {
1580                 ret = _regmap_write(map, reg, tmp);
1581                 *change = true;
1582         } else {
1583                 *change = false;
1584         }
1585
1586         return ret;
1587 }
1588
1589 /**
1590  * regmap_update_bits: Perform a read/modify/write cycle on the register map
1591  *
1592  * @map: Register map to update
1593  * @reg: Register to update
1594  * @mask: Bitmask to change
1595  * @val: New value for bitmask
1596  *
1597  * Returns zero for success, a negative number on error.
1598  */
1599 int regmap_update_bits(struct regmap *map, unsigned int reg,
1600                        unsigned int mask, unsigned int val)
1601 {
1602         bool change;
1603         int ret;
1604
1605         map->lock(map->lock_arg);
1606         ret = _regmap_update_bits(map, reg, mask, val, &change);
1607         map->unlock(map->lock_arg);
1608
1609         return ret;
1610 }
1611 EXPORT_SYMBOL_GPL(regmap_update_bits);
1612
1613 /**
1614  * regmap_update_bits_check: Perform a read/modify/write cycle on the
1615  *                           register map and report if updated
1616  *
1617  * @map: Register map to update
1618  * @reg: Register to update
1619  * @mask: Bitmask to change
1620  * @val: New value for bitmask
1621  * @change: Boolean indicating if a write was done
1622  *
1623  * Returns zero for success, a negative number on error.
1624  */
1625 int regmap_update_bits_check(struct regmap *map, unsigned int reg,
1626                              unsigned int mask, unsigned int val,
1627                              bool *change)
1628 {
1629         int ret;
1630
1631         map->lock(map->lock_arg);
1632         ret = _regmap_update_bits(map, reg, mask, val, change);
1633         map->unlock(map->lock_arg);
1634         return ret;
1635 }
1636 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
1637
1638 void regmap_async_complete_cb(struct regmap_async *async, int ret)
1639 {
1640         struct regmap *map = async->map;
1641         bool wake;
1642
1643         spin_lock(&map->async_lock);
1644
1645         list_del(&async->list);
1646         wake = list_empty(&map->async_list);
1647
1648         if (ret != 0)
1649                 map->async_ret = ret;
1650
1651         spin_unlock(&map->async_lock);
1652
1653         schedule_work(&async->cleanup);
1654
1655         if (wake)
1656                 wake_up(&map->async_waitq);
1657 }
1658 EXPORT_SYMBOL_GPL(regmap_async_complete_cb);
1659
1660 static int regmap_async_is_done(struct regmap *map)
1661 {
1662         unsigned long flags;
1663         int ret;
1664
1665         spin_lock_irqsave(&map->async_lock, flags);
1666         ret = list_empty(&map->async_list);
1667         spin_unlock_irqrestore(&map->async_lock, flags);
1668
1669         return ret;
1670 }
1671
1672 /**
1673  * regmap_async_complete: Ensure all asynchronous I/O has completed.
1674  *
1675  * @map: Map to operate on.
1676  *
1677  * Blocks until any pending asynchronous I/O has completed.  Returns
1678  * an error code for any failed I/O operations.
1679  */
1680 int regmap_async_complete(struct regmap *map)
1681 {
1682         unsigned long flags;
1683         int ret;
1684
1685         /* Nothing to do with no async support */
1686         if (!map->bus->async_write)
1687                 return 0;
1688
1689         wait_event(map->async_waitq, regmap_async_is_done(map));
1690
1691         spin_lock_irqsave(&map->async_lock, flags);
1692         ret = map->async_ret;
1693         map->async_ret = 0;
1694         spin_unlock_irqrestore(&map->async_lock, flags);
1695
1696         return ret;
1697 }
1698 EXPORT_SYMBOL_GPL(regmap_async_complete);
1699
1700 /**
1701  * regmap_register_patch: Register and apply register updates to be applied
1702  *                        on device initialistion
1703  *
1704  * @map: Register map to apply updates to.
1705  * @regs: Values to update.
1706  * @num_regs: Number of entries in regs.
1707  *
1708  * Register a set of register updates to be applied to the device
1709  * whenever the device registers are synchronised with the cache and
1710  * apply them immediately.  Typically this is used to apply
1711  * corrections to be applied to the device defaults on startup, such
1712  * as the updates some vendors provide to undocumented registers.
1713  */
1714 int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
1715                           int num_regs)
1716 {
1717         int i, ret;
1718         bool bypass;
1719
1720         /* If needed the implementation can be extended to support this */
1721         if (map->patch)
1722                 return -EBUSY;
1723
1724         map->lock(map->lock_arg);
1725
1726         bypass = map->cache_bypass;
1727
1728         map->cache_bypass = true;
1729
1730         /* Write out first; it's useful to apply even if we fail later. */
1731         for (i = 0; i < num_regs; i++) {
1732                 ret = _regmap_write(map, regs[i].reg, regs[i].def);
1733                 if (ret != 0) {
1734                         dev_err(map->dev, "Failed to write %x = %x: %d\n",
1735                                 regs[i].reg, regs[i].def, ret);
1736                         goto out;
1737                 }
1738         }
1739
1740         map->patch = kcalloc(num_regs, sizeof(struct reg_default), GFP_KERNEL);
1741         if (map->patch != NULL) {
1742                 memcpy(map->patch, regs,
1743                        num_regs * sizeof(struct reg_default));
1744                 map->patch_regs = num_regs;
1745         } else {
1746                 ret = -ENOMEM;
1747         }
1748
1749 out:
1750         map->cache_bypass = bypass;
1751
1752         map->unlock(map->lock_arg);
1753
1754         return ret;
1755 }
1756 EXPORT_SYMBOL_GPL(regmap_register_patch);
1757
1758 /*
1759  * regmap_get_val_bytes(): Report the size of a register value
1760  *
1761  * Report the size of a register value, mainly intended to for use by
1762  * generic infrastructure built on top of regmap.
1763  */
1764 int regmap_get_val_bytes(struct regmap *map)
1765 {
1766         if (map->format.format_write)
1767                 return -EINVAL;
1768
1769         return map->format.val_bytes;
1770 }
1771 EXPORT_SYMBOL_GPL(regmap_get_val_bytes);
1772
1773 static int __init regmap_initcall(void)
1774 {
1775         regmap_debugfs_initcall();
1776
1777         return 0;
1778 }
1779 postcore_initcall(regmap_initcall);