Commit 11b8fca5 authored by Timur Tabi's avatar Timur Tabi Committed by Mark Brown
Browse files

ASoC: cs4270: use the built-in register cache support 



Update the CS4270 driver to use ASoC's internal codec register cache feature.
This change allows ASoC to perform the low-level I2C operations necessary to
read the register cache.  Support is also added for initializing the register
cache with an array of known power-on default values.

The CS4270 driver was handling the register cache itself, but somwhere along
the conversion to multi-compaonent, this feature broke.

Signed-off-by: default avatarTimur Tabi <timur@freescale.com>
Acked-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent b60fc60c

sound/soc/codecs/cs4270.c

+48 −113
Original line number Diff line number Diff line
@@ -106,6 +106,21 @@ 
#define CS4270_MUTE_DAC_A	0x01

#define CS4270_MUTE_DAC_B	0x02



/* Power-on default values for the registers

 *

 * This array contains the power-on default values of the registers, with the

 * exception of the "CHIPID" register (01h).  The lower four bits of that

 * register contain the hardware revision, so it is treated as volatile.

 *

 * Also note that on the CS4270, the first readable register is 1, but ASoC

 * assumes the first register is 0.  Therfore, the array must have an entry for

 * register 0, but we use cs4270_reg_is_readable() to tell ASoC that it can't

 * be read.

 */

static const u8 cs4270_default_reg_cache[CS4270_LASTREG + 1] = {

	0x00, 0x00, 0x00, 0x30, 0x00, 0x60, 0x20, 0x00, 0x00

};



static const char *supply_names[] = {

	"va", "vd", "vlc"

};
@@ -178,6 +193,20 @@ static struct cs4270_mode_ratios cs4270_mode_ratios[] = { 
/* The number of MCLK/LRCK ratios supported by the CS4270 */

#define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)



static int cs4270_reg_is_readable(unsigned int reg)

{

	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);

}



static int cs4270_reg_is_volatile(unsigned int reg)

{

	/* Unreadable registers are considered volatile */

	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))

		return 1;



	return reg == CS4270_CHIPID;

}



/**

 * cs4270_set_dai_sysclk - determine the CS4270 samples rates.

 * @codec_dai: the codec DAI
@@ -262,97 +291,6 @@ static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai, 
	return ret;

}



/**

 * cs4270_fill_cache - pre-fill the CS4270 register cache.

 * @codec: the codec for this CS4270

 *

 * This function fills in the CS4270 register cache by reading the register

 * values from the hardware.

 *

 * This CS4270 registers are cached to avoid excessive I2C I/O operations.

 * After the initial read to pre-fill the cache, the CS4270 never updates

 * the register values, so we won't have a cache coherency problem.

 *

 * We use the auto-increment feature of the CS4270 to read all registers in

 * one shot.

 */

static int cs4270_fill_cache(struct snd_soc_codec *codec)

{

	u8 *cache = codec->reg_cache;

	struct i2c_client *i2c_client = codec->control_data;

	s32 length;



	length = i2c_smbus_read_i2c_block_data(i2c_client,

		CS4270_FIRSTREG | CS4270_I2C_INCR, CS4270_NUMREGS, cache);



	if (length != CS4270_NUMREGS) {

		dev_err(codec->dev, "i2c read failure, addr=0x%x\n",

		       i2c_client->addr);

		return -EIO;

	}



	return 0;

}



/**

 * cs4270_read_reg_cache - read from the CS4270 register cache.

 * @codec: the codec for this CS4270

 * @reg: the register to read

 *

 * This function returns the value for a given register.  It reads only from

 * the register cache, not the hardware itself.

 *

 * This CS4270 registers are cached to avoid excessive I2C I/O operations.

 * After the initial read to pre-fill the cache, the CS4270 never updates

 * the register values, so we won't have a cache coherency problem.

 */

static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,

	unsigned int reg)

{

	u8 *cache = codec->reg_cache;



	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))

		return -EIO;



	return cache[reg - CS4270_FIRSTREG];

}



/**

 * cs4270_i2c_write - write to a CS4270 register via the I2C bus.

 * @codec: the codec for this CS4270

 * @reg: the register to write

 * @value: the value to write to the register

 *

 * This function writes the given value to the given CS4270 register, and

 * also updates the register cache.

 *

 * Note that we don't use the hw_write function pointer of snd_soc_codec.

 * That's because it's too clunky: the hw_write_t prototype does not match

 * i2c_smbus_write_byte_data(), and it's just another layer of overhead.

 */

static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,

			    unsigned int value)

{

	u8 *cache = codec->reg_cache;



	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))

		return -EIO;



	/* Only perform an I2C operation if the new value is different */

	if (cache[reg - CS4270_FIRSTREG] != value) {

		struct i2c_client *client = codec->control_data;

		if (i2c_smbus_write_byte_data(client, reg, value)) {

			dev_err(codec->dev, "i2c write failed\n");

			return -EIO;

		}



		/* We've written to the hardware, so update the cache */

		cache[reg - CS4270_FIRSTREG] = value;

	}



	return 0;

}



/**

 * cs4270_hw_params - program the CS4270 with the given hardware parameters.

 * @substream: the audio stream
@@ -550,15 +488,16 @@ static struct snd_soc_dai_driver cs4270_dai = { 
static int cs4270_probe(struct snd_soc_codec *codec)

{

	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);

	int i, ret, reg;

	int i, ret;



	codec->control_data = cs4270->control_data;



	/* The I2C interface is set up, so pre-fill our register cache */



	ret = cs4270_fill_cache(codec);

	/* Tell ASoC what kind of I/O to use to read the registers.  ASoC will

	 * then do the I2C transactions itself.

	 */

	ret = snd_soc_codec_set_cache_io(codec, 8, 8, cs4270->control_type);

	if (ret < 0) {

		dev_err(codec->dev, "failed to fill register cache\n");

		dev_err(codec->dev, "failed to set cache I/O (ret=%i)\n", ret);

		return ret;

	}
@@ -567,10 +506,7 @@ static int cs4270_probe(struct snd_soc_codec *codec) 
	 * this feature disabled by default.  An application (e.g. alsactl) can

	 * re-enabled it by using the controls.

	 */



	reg = cs4270_read_reg_cache(codec, CS4270_MUTE);

	reg &= ~CS4270_MUTE_AUTO;

	ret = cs4270_i2c_write(codec, CS4270_MUTE, reg);

	ret = snd_soc_update_bits(codec, CS4270_MUTE, CS4270_MUTE_AUTO, 0);

	if (ret < 0) {

		dev_err(codec->dev, "i2c write failed\n");

		return ret;
@@ -581,10 +517,8 @@ static int cs4270_probe(struct snd_soc_codec *codec) 
	 * playback has started.  An application (e.g. alsactl) can

	 * re-enabled it by using the controls.

	 */



	reg = cs4270_read_reg_cache(codec, CS4270_TRANS);

	reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);

	ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);

	ret = snd_soc_update_bits(codec, CS4270_TRANS,

		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);

	if (ret < 0) {

		dev_err(codec->dev, "i2c write failed\n");

		return ret;
@@ -707,15 +641,16 @@ static int cs4270_soc_resume(struct snd_soc_codec *codec) 
 * Assign this variable to the codec_dev field of the machine driver's

 * snd_soc_device structure.

 */

static struct snd_soc_codec_driver soc_codec_device_cs4270 = {

static const struct snd_soc_codec_driver soc_codec_device_cs4270 = {

	.probe =		cs4270_probe,

	.remove =		cs4270_remove,

	.suspend =		cs4270_soc_suspend,

	.resume =		cs4270_soc_resume,

	.read = cs4270_read_reg_cache,

	.write = cs4270_i2c_write,

	.reg_cache_size = CS4270_NUMREGS,

	.volatile_register =	cs4270_reg_is_volatile,

	.readable_register =	cs4270_reg_is_readable,

	.reg_cache_size =	CS4270_LASTREG + 1,

	.reg_word_size =	sizeof(u8),

	.reg_cache_default =	cs4270_default_reg_cache,

};



/**

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