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 		cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] =
42 				map->reg_defaults[i].def;
43 
44 	return 0;
45 }
46 
47 static int regcache_flat_exit(struct regmap *map)
48 {
49 	kfree(map->cache);
50 	map->cache = NULL;
51 
52 	return 0;
53 }
54 
55 static int regcache_flat_read(struct regmap *map,
56 			      unsigned int reg, unsigned int *value)
57 {
58 	unsigned int *cache = map->cache;
59 
60 	*value = cache[regcache_flat_get_index(map, reg)];
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 
70 	cache[regcache_flat_get_index(map, reg)] = value;
71 
72 	return 0;
73 }
74 
75 struct regcache_ops regcache_flat_ops = {
76 	.type = REGCACHE_FLAT,
77 	.name = "flat",
78 	.init = regcache_flat_init,
79 	.exit = regcache_flat_exit,
80 	.read = regcache_flat_read,
81 	.write = regcache_flat_write,
82 };
83