linux-stable/sound/soc/soc-cache.c

201 lines
4.6 KiB
C

/*
* 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;
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);
if (!codec->reg_cache)
return 0;
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);
*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);
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;
WARN_ON(!snd_soc_codec_writable_register(codec, i));
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);