drivers/base/regmap/regcache-flat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Register cache access API - flat caching support
   4 //
   5 // Copyright 2012 Wolfson Microelectronics plc
   6 //
   7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   8
   9 #include <linux/device.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/slab.h>
  12
  13 #include "internal.h"
  14
  15 static inline unsigned int regcache_flat_get_index(const struct regmap *map,
  16                                                    unsigned int reg)
  17 {
  18         return regcache_get_index_by_order(map, reg);
  19 }
  20
  21 static int regcache_flat_init(struct regmap *map)
  22 {
  23         int i;
  24         unsigned int *cache;
  25
  26         if (!map || map->reg_stride_order < 0 || !map->max_register)
  27                 return -EINVAL;
  28
  29         map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
  30                              + 1, sizeof(unsigned int), GFP_KERNEL);
  31         if (!map->cache)
  32                 return -ENOMEM;
  33
  34         cache = map->cache;
  35
  36         for (i = 0; i < map->num_reg_defaults; i++) {
  37                 unsigned int reg = map->reg_defaults[i].reg;
  38                 unsigned int index = regcache_flat_get_index(map, reg);
  39
  40                 cache[index] = map->reg_defaults[i].def;
  41         }
  42
  43         return 0;
  44 }
  45
  46 static int regcache_flat_exit(struct regmap *map)
  47 {
  48         kfree(map->cache);
  49         map->cache = NULL;
  50
  51         return 0;
  52 }
  53
  54 static int regcache_flat_read(struct regmap *map,
  55                               unsigned int reg, unsigned int *value)
  56 {
  57         unsigned int *cache = map->cache;
  58         unsigned int index = regcache_flat_get_index(map, reg);
  59
  60         *value = cache[index];
  61
  62         return 0;
  63 }
  64
  65 static int regcache_flat_write(struct regmap *map, unsigned int reg,
  66                                unsigned int value)
  67 {
  68         unsigned int *cache = map->cache;
  69         unsigned int index = regcache_flat_get_index(map, reg);
  70
  71         cache[index] = value;
  72
  73         return 0;
  74 }
  75
  76 struct regcache_ops regcache_flat_ops = {
  77         .type = REGCACHE_FLAT,
  78         .name = "flat",
  79         .init = regcache_flat_init,
  80         .exit = regcache_flat_exit,
  81         .read = regcache_flat_read,
  82         .write = regcache_flat_write,
  83 };