diff options
Diffstat (limited to 'sound/soc/soc-cache.c')
| -rw-r--r-- | sound/soc/soc-cache.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c new file mode 100644 index 00000000000..00e70b6c7da --- /dev/null +++ b/sound/soc/soc-cache.c @@ -0,0 +1,203 @@ +/* + * soc-cache.c -- ASoC register cache helpers + * + * Copyright 2009 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <sound/soc.h> +#include <linux/export.h> +#include <linux/slab.h> + +#include <trace/events/asoc.h> + +static bool snd_soc_set_cache_val(void *base, unsigned int idx, + unsigned int val, unsigned int word_size) +{ + switch (word_size) { + case 1: { + u8 *cache = base; + if (cache[idx] == val) + return true; + cache[idx] = val; + break; + } + case 2: { + u16 *cache = base; + if (cache[idx] == val) + return true; + cache[idx] = val; + break; + } + default: + WARN(1, "Invalid word_size %d\n", word_size); + break; + } + return false; +} + +static unsigned int snd_soc_get_cache_val(const void *base, unsigned int idx, + unsigned int word_size) +{ + if (!base) + return -1; + + switch (word_size) { + case 1: { + const u8 *cache = base; + return cache[idx]; + } + case 2: { + const u16 *cache = base; + return cache[idx]; + } + default: + WARN(1, "Invalid word_size %d\n", word_size); + break; + } + /* unreachable */ + return -1; +} + +int snd_soc_cache_init(struct snd_soc_codec *codec) +{ + const struct snd_soc_codec_driver *codec_drv = codec->driver; + size_t reg_size; + + reg_size = codec_drv->reg_cache_size * codec_drv->reg_word_size; + + if (!reg_size) + return 0; + + mutex_init(&codec->cache_rw_mutex); + + dev_dbg(codec->dev, "ASoC: Initializing cache for %s codec\n", + codec->name); + + if (codec_drv->reg_cache_default) + codec->reg_cache = kmemdup(codec_drv->reg_cache_default, + reg_size, GFP_KERNEL); + else + codec->reg_cache = kzalloc(reg_size, GFP_KERNEL); + if (!codec->reg_cache) + return -ENOMEM; + + return 0; +} + +/* + * NOTE: keep in mind that this function might be called + * multiple times. + */ +int snd_soc_cache_exit(struct snd_soc_codec *codec) +{ + dev_dbg(codec->dev, "ASoC: Destroying cache for %s codec\n", + codec->name); + + kfree(codec->reg_cache); + codec->reg_cache = NULL; + return 0; +} + +/** + * snd_soc_cache_read: Fetch the value of a given register from the cache. + * + * @codec: CODEC to configure. + * @reg: The register index. + * @value: The value to be returned. + */ +int snd_soc_cache_read(struct snd_soc_codec *codec, + unsigned int reg, unsigned int *value) +{ + if (!value) + return -EINVAL; + + mutex_lock(&codec->cache_rw_mutex); + if (!ZERO_OR_NULL_PTR(codec->reg_cache)) + *value = snd_soc_get_cache_val(codec->reg_cache, reg, + codec->driver->reg_word_size); + mutex_unlock(&codec->cache_rw_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(snd_soc_cache_read); + +/** + * snd_soc_cache_write: Set the value of a given register in the cache. + * + * @codec: CODEC to configure. + * @reg: The register index. + * @value: The new register value. + */ +int snd_soc_cache_write(struct snd_soc_codec *codec, + unsigned int reg, unsigned int value) +{ + mutex_lock(&codec->cache_rw_mutex); + if (!ZERO_OR_NULL_PTR(codec->reg_cache)) + snd_soc_set_cache_val(codec->reg_cache, reg, value, + codec->driver->reg_word_size); + mutex_unlock(&codec->cache_rw_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(snd_soc_cache_write); + +static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec) +{ + int i; + int ret; + const struct snd_soc_codec_driver *codec_drv; + unsigned int val; + + codec_drv = codec->driver; + for (i = 0; i < codec_drv->reg_cache_size; ++i) { + ret = snd_soc_cache_read(codec, i, &val); + if (ret) + return ret; + if (codec_drv->reg_cache_default) + if (snd_soc_get_cache_val(codec_drv->reg_cache_default, + i, codec_drv->reg_word_size) == val) + continue; + + ret = snd_soc_write(codec, i, val); + if (ret) + return ret; + dev_dbg(codec->dev, "ASoC: Synced register %#x, value = %#x\n", + i, val); + } + return 0; +} + +/** + * snd_soc_cache_sync: Sync the register cache with the hardware. + * + * @codec: CODEC to configure. + * + * Any registers that should not be synced should be marked as + * volatile. In general drivers can choose not to use the provided + * syncing functionality if they so require. + */ +int snd_soc_cache_sync(struct snd_soc_codec *codec) +{ + const char *name = "flat"; + int ret; + + if (!codec->cache_sync) + return 0; + + dev_dbg(codec->dev, "ASoC: Syncing cache for %s codec\n", + codec->name); + trace_snd_soc_cache_sync(codec, name, "start"); + ret = snd_soc_flat_cache_sync(codec); + if (!ret) + codec->cache_sync = 0; + trace_snd_soc_cache_sync(codec, name, "end"); + return ret; +} +EXPORT_SYMBOL_GPL(snd_soc_cache_sync); |