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
15static 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
21static 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(n: regcache_flat_get_index(map, reg: map->max_register)
30 + 1, size: 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
46static int regcache_flat_exit(struct regmap *map)
47{
48 kfree(objp: map->cache);
49 map->cache = NULL;
50
51 return 0;
52}
53
54static 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
65static 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
76struct 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};
84

source code of linux/drivers/base/regmap/regcache-flat.c