/*
   * 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);

  }

  /**
   * 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