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 
15 static 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 
21 static 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(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 
46 static int regcache_flat_exit(struct regmap *map)
47 {
48 	kfree(map->cache);
49 	map->cache = NULL;
50 
51 	return 0;
52 }
53 
54 static 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 
65 static 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 
76 struct 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