drivers/base/regmap/regcache-flat.c

   1 /*
   2  * Register cache access API - flat caching support
   3  *
   4  * Copyright 2012 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/seq_file.h>
  15 #include <linux/slab.h>
  16
  17 #include "internal.h"
  18
  19 static inline unsigned int regcache_flat_get_index(const struct regmap *map,
  20                                                    unsigned int reg)
  21 {
  22         return regcache_get_index_by_order(map, reg);
  23 }
  24
  25 static int regcache_flat_init(struct regmap *map)
  26 {
  27         int i;
  28         unsigned int *cache;
  29
  30         if (!map || map->reg_stride_order < 0 || !map->max_register)
  31                 return -EINVAL;
  32
  33         map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
  34                              + 1, sizeof(unsigned int), GFP_KERNEL);
  35         if (!map->cache)
  36                 return -ENOMEM;
  37
  38         cache = map->cache;
  39
  40         for (i = 0; i < map->num_reg_defaults; i++) {
  41                 unsigned int reg = map->reg_defaults[i].reg;
  42                 unsigned int index = regcache_flat_get_index(map, reg);
  43
  44                 cache[index] = map->reg_defaults[i].def;
  45         }
  46
  47         return 0;
  48 }
  49
  50 static int regcache_flat_exit(struct regmap *map)
  51 {
  52         kfree(map->cache);
  53         map->cache = NULL;
  54
  55         return 0;
  56 }
  57
  58 static int regcache_flat_read(struct regmap *map,
  59                               unsigned int reg, unsigned int *value)
  60 {
  61         unsigned int *cache = map->cache;
  62         unsigned int index = regcache_flat_get_index(map, reg);
  63
  64         *value = cache[index];
  65
  66         return 0;
  67 }
  68
  69 static int regcache_flat_write(struct regmap *map, unsigned int reg,
  70                                unsigned int value)
  71 {
  72         unsigned int *cache = map->cache;
  73         unsigned int index = regcache_flat_get_index(map, reg);
  74
  75         cache[index] = value;
  76
  77         return 0;
  78 }
  79
  80 struct regcache_ops regcache_flat_ops = {
  81         .type = REGCACHE_FLAT,
  82         .name = "flat",
  83         .init = regcache_flat_init,
  84         .exit = regcache_flat_exit,
  85         .read = regcache_flat_read,
  86         .write = regcache_flat_write,
  87 };