soc-io.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 <sound/soc.h>

#include <trace/events/asoc.h>

#ifdef CONFIG_SPI_MASTER
static int do_spi_write(void *control, const char *data, int len)
{
	struct spi_device *spi = control;
	int ret;

	ret = spi_write(spi, data, len);
	if (ret < 0)
		return ret;

	return len;
}
#endif

static int do_hw_write(struct snd_soc_codec *codec, unsigned int reg,
		       unsigned int value, const void *data, int len)
{
	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;
	}

	ret = codec->hw_write(codec->control_data, data, len);
	if (ret == len)
		return 0;
	if (ret < 0)
		return ret;
	else
		return -EIO;
}

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;

		BUG_ON(!codec->hw_read);
		return codec->hw_read(codec, reg);
	}

	ret = snd_soc_cache_read(codec, reg, &val);
	if (ret < 0)
		return -1;
	return val;
}

static int snd_soc_4_12_write(struct snd_soc_codec *codec, unsigned int reg,
			      unsigned int value)
{
	u16 data;

	data = cpu_to_be16((reg << 12) | (value & 0xffffff));

	return do_hw_write(codec, reg, value, &data, 2);
}

static int snd_soc_7_9_write(struct snd_soc_codec *codec, unsigned int reg,
			     unsigned int value)
{
	u16 data;

	data = cpu_to_be16((reg << 9) | (value & 0x1ff));

	return do_hw_write(codec, reg, value, &data, 2);
}

static int snd_soc_8_8_write(struct snd_soc_codec *codec, unsigned int reg,
			     unsigned int value)
{
	u8 data[2];

	reg &= 0xff;
	data[0] = reg;
	data[1] = value & 0xff;

	return do_hw_write(codec, reg, value, data, 2);
}

static int snd_soc_8_16_write(struct snd_soc_codec *codec, unsigned int reg,
			      unsigned int value)
{
	u8 data[3];
	u16 val = cpu_to_be16(value);

	data[0] = reg;
	memcpy(&data[1], &val, sizeof(val));

	return do_hw_write(codec, reg, value, data, 3);
}

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
static unsigned int do_i2c_read(struct snd_soc_codec *codec,
				void *reg, int reglen,
				void *data, int datalen)
{
	struct i2c_msg xfer[2];
	int ret;
	struct i2c_client *client = codec->control_data;

	/* Write register */
	xfer[0].addr = client->addr;
	xfer[0].flags = 0;
	xfer[0].len = reglen;
	xfer[0].buf = reg;

	/* Read data */
	xfer[1].addr = client->addr;
	xfer[1].flags = I2C_M_RD;
	xfer[1].len = datalen;
	xfer[1].buf = data;

	ret = i2c_transfer(client->adapter, xfer, 2);
	if (ret == 2)
		return 0;
	else if (ret < 0)
		return ret;
	else
		return -EIO;
}
#endif

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
static unsigned int snd_soc_8_8_read_i2c(struct snd_soc_codec *codec,
					 unsigned int r)
{
	u8 reg = r;
	u8 data;
	int ret;

	ret = do_i2c_read(codec, &reg, 1, &data, 1);
	if (ret < 0)
		return 0;
	return data;
}
#else
#define snd_soc_8_8_read_i2c NULL
#endif

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
static unsigned int snd_soc_8_16_read_i2c(struct snd_soc_codec *codec,
					  unsigned int r)
{
	u8 reg = r;
	u16 data;
	int ret;

	ret = do_i2c_read(codec, &reg, 1, &data, 2);
	if (ret < 0)
		return 0;
	return (data >> 8) | ((data & 0xff) << 8);
}
#else
#define snd_soc_8_16_read_i2c NULL
#endif

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
static unsigned int snd_soc_16_8_read_i2c(struct snd_soc_codec *codec,
					  unsigned int r)
{
	u16 reg = r;
	u8 data;
	int ret;

	ret = do_i2c_read(codec, &reg, 2, &data, 1);
	if (ret < 0)
		return 0;
	return data;
}
#else
#define snd_soc_16_8_read_i2c NULL
#endif

static int snd_soc_16_8_write(struct snd_soc_codec *codec, unsigned int reg,
			      unsigned int value)
{
	u8 data[3];
	u16 rval = cpu_to_be16(reg);

	memcpy(data, &rval, sizeof(rval));
	data[2] = value;

	return do_hw_write(codec, reg, value, data, 3);
}

#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
static unsigned int snd_soc_16_16_read_i2c(struct snd_soc_codec *codec,
					   unsigned int r)
{
	u16 reg = cpu_to_be16(r);
	u16 data;
	int ret;

	ret = do_i2c_read(codec, &reg, 2, &data, 2);
	if (ret < 0)
		return 0;
	return be16_to_cpu(data);
}
#else
#define snd_soc_16_16_read_i2c NULL
#endif

static int snd_soc_16_16_write(struct snd_soc_codec *codec, unsigned int reg,
			       unsigned int value)
{
	u16 data[2];

	data[0] = cpu_to_be16(reg);
	data[1] = cpu_to_be16(value);

	return do_hw_write(codec, reg, value, data, sizeof(data));
}

/* Primitive bulk write support for soc-cache.  The data pointed to by
 * `data' needs to already be in the form the hardware expects
 * including any leading register specific data.  Any data written
 * through this function will not go through the cache as it only
 * handles writing to volatile or out of bounds registers.
 */
static int snd_soc_hw_bulk_write_raw(struct snd_soc_codec *codec, unsigned int reg,
				     const void *data, size_t len)
{
	int ret;

	/* 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;

	switch (codec->control_type) {
#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
	case SND_SOC_I2C:
		ret = i2c_master_send(to_i2c_client(codec->dev), data, len);
		break;
#endif
#if defined(CONFIG_SPI_MASTER)
	case SND_SOC_SPI:
		ret = spi_write(to_spi_device(codec->dev), data, len);
		break;
#endif
	default:
		BUG();
	}

	if (ret == len)
		return 0;
	if (ret < 0)
		return ret;
	else
		return -EIO;
}

static struct {
	int addr_bits;
	int data_bits;
	int (*write)(struct snd_soc_codec *codec, unsigned int, unsigned int);
	unsigned int (*read)(struct snd_soc_codec *, unsigned int);
	unsigned int (*i2c_read)(struct snd_soc_codec *, unsigned int);
} io_types[] = {
	{
		.addr_bits = 4, .data_bits = 12,
		.write = snd_soc_4_12_write,
	},
	{
		.addr_bits = 7, .data_bits = 9,
		.write = snd_soc_7_9_write,
	},
	{
		.addr_bits = 8, .data_bits = 8,
		.write = snd_soc_8_8_write,
		.i2c_read = snd_soc_8_8_read_i2c,
	},
	{
		.addr_bits = 8, .data_bits = 16,
		.write = snd_soc_8_16_write,
		.i2c_read = snd_soc_8_16_read_i2c,
	},
	{
		.addr_bits = 16, .data_bits = 8,
		.write = snd_soc_16_8_write,
		.i2c_read = snd_soc_16_8_read_i2c,
	},
	{
		.addr_bits = 16, .data_bits = 16,
		.write = snd_soc_16_16_write,
		.i2c_read = snd_soc_16_16_read_i2c,
	},
};

/**
 * 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)
{
	int i;

	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 = hw_read;
	codec->bulk_write_raw = snd_soc_hw_bulk_write_raw;

	switch (control) {
	case SND_SOC_I2C:
#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
		codec->hw_write = (hw_write_t)i2c_master_send;
#endif
		if (io_types[i].i2c_read)
			codec->hw_read = io_types[i].i2c_read;

		codec->control_data = container_of(codec->dev,
						   struct i2c_client,
						   dev);
		break;

	case SND_SOC_SPI:
#ifdef CONFIG_SPI_MASTER
		codec->hw_write = do_spi_write;
#endif

		codec->control_data = container_of(codec->dev,
						   struct spi_device,
						   dev);
		break;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);