Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * soc-cache.c -- ASoC register cache helpers
3 *
4 * Copyright 2009 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 it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 */
13
14#include <sound/soc.h>
15#include <linux/export.h>
16#include <linux/slab.h>
17
18#include <trace/events/asoc.h>
19
20static bool snd_soc_set_cache_val(void *base, unsigned int idx,
21 unsigned int val, unsigned int word_size)
22{
23 switch (word_size) {
24 case 1: {
25 u8 *cache = base;
26 if (cache[idx] == val)
27 return true;
28 cache[idx] = val;
29 break;
30 }
31 case 2: {
32 u16 *cache = base;
33 if (cache[idx] == val)
34 return true;
35 cache[idx] = val;
36 break;
37 }
38 default:
39 WARN(1, "Invalid word_size %d\n", word_size);
40 break;
41 }
42 return false;
43}
44
45static unsigned int snd_soc_get_cache_val(const void *base, unsigned int idx,
46 unsigned int word_size)
47{
48 if (!base)
49 return -1;
50
51 switch (word_size) {
52 case 1: {
53 const u8 *cache = base;
54 return cache[idx];
55 }
56 case 2: {
57 const u16 *cache = base;
58 return cache[idx];
59 }
60 default:
61 WARN(1, "Invalid word_size %d\n", word_size);
62 break;
63 }
64 /* unreachable */
65 return -1;
66}
67
68int snd_soc_cache_init(struct snd_soc_codec *codec)
69{
70 const struct snd_soc_codec_driver *codec_drv = codec->driver;
71 size_t reg_size;
72
73 reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size;
74
75 mutex_init(&codec->cache_rw_mutex);
76
77 dev_dbg(codec->dev, "ASoC: Initializing cache for %s codec\n",
78 codec->name);
79
80 if (codec_drv->reg_cache_default)
81 codec->reg_cache = kmemdup(codec_drv->reg_cache_default,
82 reg_size, GFP_KERNEL);
83 else
84 codec->reg_cache = kzalloc(reg_size, GFP_KERNEL);
85 if (!codec->reg_cache)
86 return -ENOMEM;
87
88 return 0;
89}
90
91/*
92 * NOTE: keep in mind that this function might be called
93 * multiple times.
94 */
95int snd_soc_cache_exit(struct snd_soc_codec *codec)
96{
97 dev_dbg(codec->dev, "ASoC: Destroying cache for %s codec\n",
98 codec->name);
99 if (!codec->reg_cache)
100 return 0;
101 kfree(codec->reg_cache);
102 codec->reg_cache = NULL;
103 return 0;
104}
105
106/**
107 * snd_soc_cache_read: Fetch the value of a given register from the cache.
108 *
109 * @codec: CODEC to configure.
110 * @reg: The register index.
111 * @value: The value to be returned.
112 */
113int snd_soc_cache_read(struct snd_soc_codec *codec,
114 unsigned int reg, unsigned int *value)
115{
116 if (!value)
117 return -EINVAL;
118
119 mutex_lock(&codec->cache_rw_mutex);
120 *value = snd_soc_get_cache_val(codec->reg_cache, reg,
121 codec->driver->reg_word_size);
122 mutex_unlock(&codec->cache_rw_mutex);
123
124 return 0;
125}
126EXPORT_SYMBOL_GPL(snd_soc_cache_read);
127
128/**
129 * snd_soc_cache_write: Set the value of a given register in the cache.
130 *
131 * @codec: CODEC to configure.
132 * @reg: The register index.
133 * @value: The new register value.
134 */
135int snd_soc_cache_write(struct snd_soc_codec *codec,
136 unsigned int reg, unsigned int value)
137{
138 mutex_lock(&codec->cache_rw_mutex);
139 snd_soc_set_cache_val(codec->reg_cache, reg, value,
140 codec->driver->reg_word_size);
141 mutex_unlock(&codec->cache_rw_mutex);
142
143 return 0;
144}
145EXPORT_SYMBOL_GPL(snd_soc_cache_write);
146
147static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec)
148{
149 int i;
150 int ret;
151 const struct snd_soc_codec_driver *codec_drv;
152 unsigned int val;
153
154 codec_drv = codec->driver;
155 for (i = 0; i < codec_drv->reg_cache_size; ++i) {
156 ret = snd_soc_cache_read(codec, i, &val);
157 if (ret)
158 return ret;
159 if (codec_drv->reg_cache_default)
160 if (snd_soc_get_cache_val(codec_drv->reg_cache_default,
161 i, codec_drv->reg_word_size) == val)
162 continue;
163
164 WARN_ON(!snd_soc_codec_writable_register(codec, i));
165
166 ret = snd_soc_write(codec, i, val);
167 if (ret)
168 return ret;
169 dev_dbg(codec->dev, "ASoC: Synced register %#x, value = %#x\n",
170 i, val);
171 }
172 return 0;
173}
174
175/**
176 * snd_soc_cache_sync: Sync the register cache with the hardware.
177 *
178 * @codec: CODEC to configure.
179 *
180 * Any registers that should not be synced should be marked as
181 * volatile. In general drivers can choose not to use the provided
182 * syncing functionality if they so require.
183 */
184int snd_soc_cache_sync(struct snd_soc_codec *codec)
185{
186 const char *name = "flat";
187 int ret;
188
189 if (!codec->cache_sync)
190 return 0;
191
192 dev_dbg(codec->dev, "ASoC: Syncing cache for %s codec\n",
193 codec->name);
194 trace_snd_soc_cache_sync(codec, name, "start");
195 ret = snd_soc_flat_cache_sync(codec);
196 if (!ret)
197 codec->cache_sync = 0;
198 trace_snd_soc_cache_sync(codec, name, "end");
199 return ret;
200}
201EXPORT_SYMBOL_GPL(snd_soc_cache_sync);