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_is_set)
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
46static int regcache_flat_exit(struct regmap *map)
47{
48	kfree(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