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 };
88