| 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 | |
| 20 | static 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 | |
| 45 | static 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 | |
| 68 | int 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 | if (!reg_size) |
| 76 | return 0; |
| 77 | |
| 78 | mutex_init(&codec->cache_rw_mutex); |
| 79 | |
| 80 | dev_dbg(codec->dev, "ASoC: Initializing cache for %s codec\n", |
| 81 | codec->component.name); |
| 82 | |
| 83 | if (codec_drv->reg_cache_default) |
| 84 | codec->reg_cache = kmemdup(codec_drv->reg_cache_default, |
| 85 | reg_size, GFP_KERNEL); |
| 86 | else |
| 87 | codec->reg_cache = kzalloc(reg_size, GFP_KERNEL); |
| 88 | if (!codec->reg_cache) |
| 89 | return -ENOMEM; |
| 90 | |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | /* |
| 95 | * NOTE: keep in mind that this function might be called |
| 96 | * multiple times. |
| 97 | */ |
| 98 | int snd_soc_cache_exit(struct snd_soc_codec *codec) |
| 99 | { |
| 100 | dev_dbg(codec->dev, "ASoC: Destroying cache for %s codec\n", |
| 101 | codec->component.name); |
| 102 | kfree(codec->reg_cache); |
| 103 | codec->reg_cache = NULL; |
| 104 | return 0; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * snd_soc_cache_read: Fetch the value of a given register from the cache. |
| 109 | * |
| 110 | * @codec: CODEC to configure. |
| 111 | * @reg: The register index. |
| 112 | * @value: The value to be returned. |
| 113 | */ |
| 114 | int snd_soc_cache_read(struct snd_soc_codec *codec, |
| 115 | unsigned int reg, unsigned int *value) |
| 116 | { |
| 117 | if (!value) |
| 118 | return -EINVAL; |
| 119 | |
| 120 | mutex_lock(&codec->cache_rw_mutex); |
| 121 | if (!ZERO_OR_NULL_PTR(codec->reg_cache)) |
| 122 | *value = snd_soc_get_cache_val(codec->reg_cache, reg, |
| 123 | codec->driver->reg_word_size); |
| 124 | mutex_unlock(&codec->cache_rw_mutex); |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | EXPORT_SYMBOL_GPL(snd_soc_cache_read); |
| 129 | |
| 130 | /** |
| 131 | * snd_soc_cache_write: Set the value of a given register in the cache. |
| 132 | * |
| 133 | * @codec: CODEC to configure. |
| 134 | * @reg: The register index. |
| 135 | * @value: The new register value. |
| 136 | */ |
| 137 | int snd_soc_cache_write(struct snd_soc_codec *codec, |
| 138 | unsigned int reg, unsigned int value) |
| 139 | { |
| 140 | mutex_lock(&codec->cache_rw_mutex); |
| 141 | if (!ZERO_OR_NULL_PTR(codec->reg_cache)) |
| 142 | snd_soc_set_cache_val(codec->reg_cache, reg, value, |
| 143 | codec->driver->reg_word_size); |
| 144 | mutex_unlock(&codec->cache_rw_mutex); |
| 145 | |
| 146 | return 0; |
| 147 | } |
| 148 | EXPORT_SYMBOL_GPL(snd_soc_cache_write); |
| 149 | |
| 150 | static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec) |
| 151 | { |
| 152 | int i; |
| 153 | int ret; |
| 154 | const struct snd_soc_codec_driver *codec_drv; |
| 155 | unsigned int val; |
| 156 | |
| 157 | codec_drv = codec->driver; |
| 158 | for (i = 0; i < codec_drv->reg_cache_size; ++i) { |
| 159 | ret = snd_soc_cache_read(codec, i, &val); |
| 160 | if (ret) |
| 161 | return ret; |
| 162 | if (codec_drv->reg_cache_default) |
| 163 | if (snd_soc_get_cache_val(codec_drv->reg_cache_default, |
| 164 | i, codec_drv->reg_word_size) == val) |
| 165 | continue; |
| 166 | |
| 167 | ret = snd_soc_write(codec, i, val); |
| 168 | if (ret) |
| 169 | return ret; |
| 170 | dev_dbg(codec->dev, "ASoC: Synced register %#x, value = %#x\n", |
| 171 | i, val); |
| 172 | } |
| 173 | return 0; |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * snd_soc_cache_sync: Sync the register cache with the hardware. |
| 178 | * |
| 179 | * @codec: CODEC to configure. |
| 180 | * |
| 181 | * Any registers that should not be synced should be marked as |
| 182 | * volatile. In general drivers can choose not to use the provided |
| 183 | * syncing functionality if they so require. |
| 184 | */ |
| 185 | int snd_soc_cache_sync(struct snd_soc_codec *codec) |
| 186 | { |
| 187 | const char *name = "flat"; |
| 188 | int ret; |
| 189 | |
| 190 | if (!codec->cache_sync) |
| 191 | return 0; |
| 192 | |
| 193 | dev_dbg(codec->dev, "ASoC: Syncing cache for %s codec\n", |
| 194 | codec->component.name); |
| 195 | trace_snd_soc_cache_sync(codec, name, "start"); |
| 196 | ret = snd_soc_flat_cache_sync(codec); |
| 197 | if (!ret) |
| 198 | codec->cache_sync = 0; |
| 199 | trace_snd_soc_cache_sync(codec, name, "end"); |
| 200 | return ret; |
| 201 | } |
| 202 | EXPORT_SYMBOL_GPL(snd_soc_cache_sync); |