soc-io.c

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/*
 * 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 <linux/export.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);
}

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;
    int ret;

    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 */
        codec->using_regmap = true;
        if (!codec->control_data)
            codec->control_data = dev_get_regmap(codec->dev, NULL);

        if (codec->control_data) {
            ret = regmap_get_val_bytes(codec->control_data);
            /* Errors are legitimate for non-integer byte
             * multiples */
            if (ret > 0)
                codec->val_bytes = ret;
        }
        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