linux/sound/soc/soc-io.c
Mark Brown 3ebb5c9b10 ASoC: Squash error codes from regmap down to -1 on read
The ASoC code always uses -1 as the error code due to reporting errors in
band with the value. Ensure we don't confuse anything by making sure we
don't pass actual error codes back into the rest of the code on read.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-10-09 14:35:59 +01:00

163 lines
4.3 KiB
C

/*
* soc-io.c -- ASoC register I/O helpers
*
* Copyright 2009-2011 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 <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/regmap.h>
#include <sound/soc.h>
#include <trace/events/asoc.h>
#ifdef CONFIG_REGMAP
static int hw_write(struct snd_soc_codec *codec, unsigned int reg,
unsigned int value)
{
int ret;
if (!snd_soc_codec_volatile_register(codec, reg) &&
reg < codec->driver->reg_cache_size &&
!codec->cache_bypass) {
ret = snd_soc_cache_write(codec, reg, value);
if (ret < 0)
return -1;
}
if (codec->cache_only) {
codec->cache_sync = 1;
return 0;
}
return regmap_write(codec->control_data, reg, value);
}
static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
{
int ret;
unsigned int val;
if (reg >= codec->driver->reg_cache_size ||
snd_soc_codec_volatile_register(codec, reg) ||
codec->cache_bypass) {
if (codec->cache_only)
return -1;
ret = regmap_read(codec->control_data, reg, &val);
if (ret == 0)
return val;
else
return -1;
}
ret = snd_soc_cache_read(codec, reg, &val);
if (ret < 0)
return -1;
return val;
}
/* Primitive bulk write support for soc-cache. The data pointed to by
* `data' needs to already be in the form the hardware expects. Any
* data written through this function will not go through the cache as
* it only handles writing to volatile or out of bounds registers.
*
* This is currently only supported for devices using the regmap API
* wrappers.
*/
static int snd_soc_hw_bulk_write_raw(struct snd_soc_codec *codec,
unsigned int reg,
const void *data, size_t len)
{
/* To ensure that we don't get out of sync with the cache, check
* whether the base register is volatile or if we've directly asked
* to bypass the cache. Out of bounds registers are considered
* volatile.
*/
if (!codec->cache_bypass
&& !snd_soc_codec_volatile_register(codec, reg)
&& reg < codec->driver->reg_cache_size)
return -EINVAL;
return regmap_raw_write(codec->control_data, reg, data, len);
}
/**
* snd_soc_codec_set_cache_io: Set up standard I/O functions.
*
* @codec: CODEC to configure.
* @addr_bits: Number of bits of register address data.
* @data_bits: Number of bits of data per register.
* @control: Control bus used.
*
* Register formats are frequently shared between many I2C and SPI
* devices. In order to promote code reuse the ASoC core provides
* some standard implementations of CODEC read and write operations
* which can be set up using this function.
*
* The caller is responsible for allocating and initialising the
* actual cache.
*
* Note that at present this code cannot be used by CODECs with
* volatile registers.
*/
int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
int addr_bits, int data_bits,
enum snd_soc_control_type control)
{
struct regmap_config config;
memset(&config, 0, sizeof(config));
codec->write = hw_write;
codec->read = hw_read;
codec->bulk_write_raw = snd_soc_hw_bulk_write_raw;
config.reg_bits = addr_bits;
config.val_bits = data_bits;
switch (control) {
#if defined(CONFIG_REGMAP_I2C) || defined(CONFIG_REGMAP_I2C_MODULE)
case SND_SOC_I2C:
codec->control_data = regmap_init_i2c(to_i2c_client(codec->dev),
&config);
break;
#endif
#if defined(CONFIG_REGMAP_SPI) || defined(CONFIG_REGMAP_SPI_MODULE)
case SND_SOC_SPI:
codec->control_data = regmap_init_spi(to_spi_device(codec->dev),
&config);
break;
#endif
case SND_SOC_REGMAP:
/* Device has made its own regmap arrangements */
break;
default:
return -EINVAL;
}
if (IS_ERR(codec->control_data))
return PTR_ERR(codec->control_data);
return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
#else
int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
int addr_bits, int data_bits,
enum snd_soc_control_type control)
{
return -ENOTSUPP;
}
EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
#endif