blob: 4eb4333a0efb28a23c76f2cfb6f509f57017c369 [file] [log] [blame]
/*
* 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>
static unsigned int snd_soc_7_9_read(struct snd_soc_codec *codec,
unsigned int reg)
{
u16 *cache = codec->reg_cache;
if (reg >= codec->reg_cache_size)
return -1;
return cache[reg];
}
static int snd_soc_7_9_write(struct snd_soc_codec *codec, unsigned int reg,
unsigned int value)
{
u16 *cache = codec->reg_cache;
u8 data[2];
int ret;
BUG_ON(codec->volatile_register);
data[0] = (reg << 1) | ((value >> 8) & 0x0001);
data[1] = value & 0x00ff;
if (reg < codec->reg_cache_size)
cache[reg] = value;
ret = codec->hw_write(codec->control_data, data, 2);
if (ret == 2)
return 0;
if (ret < 0)
return ret;
else
return -EIO;
}
static struct {
int addr_bits;
int data_bits;
int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
unsigned int (*read)(struct snd_soc_codec *, unsigned int);
} io_types[] = {
{ 7, 9, snd_soc_7_9_write, snd_soc_7_9_read },
};
/**
* snd_soc_codec_set_cache_io: Set up standard I/O functions.
*
* @codec: CODEC to configure.
* @type: Type of cache.
* @addr_bits: Number of bits of register address data.
* @data_bits: Number of bits of data per register.
*
* 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)
{
int i;
/* We don't support volatile registers yet - refactoring of
* the hw_read operation will be required to do so. */
if (codec->volatile_register) {
printk(KERN_ERR "Volatile registers not yet supported\n");
return -EINVAL;
}
for (i = 0; i < ARRAY_SIZE(io_types); i++)
if (io_types[i].addr_bits == addr_bits &&
io_types[i].data_bits == data_bits)
break;
if (i == ARRAY_SIZE(io_types)) {
printk(KERN_ERR
"No I/O functions for %d bit address %d bit data\n",
addr_bits, data_bits);
return -EINVAL;
}
codec->write = io_types[i].write;
codec->read = io_types[i].read;
return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);