linux/sound/soc/soc-cache.c
Mark Brown b5fc40d3b3 ASoC: cache: Fix error code when not using ASoC level cache
It is not an error to have no cache so we shouldn't return an error code
and cause our callers to fail, just silently do nothing instead.  Thanks
to Jarkko for identify the problematic commit.

Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reported-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-06-02 16:08:21 +01:00

204 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;
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);