Commit 8c961bcc authored by Mark Brown's avatar Mark Brown
Browse files

ASoC: Allow CODECs to ask soc-cache to suppress physical writes 



Currently the soc-cache code will always write to the device, meaning
that we need the device to be powered and active at pretty much all
times the system is active.  Allowing cache only writes lays some
groundwork for future enhancements to allow devices to be put into a
full off state when the audio subsystem is idle.

Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent 0f69d978

include/sound/soc.h

+1 −0
Original line number Diff line number Diff line
@@ -423,6 +423,7 @@ struct snd_soc_codec { 
	short reg_cache_step;



	unsigned int idle_bias_off:1; /* Use BIAS_OFF instead of STANDBY */

	unsigned int cache_only:1;  /* Suppress writes to hardware */



	/* dapm */

	u32 pop_time;

sound/soc/soc-cache.c

+24 −2
Original line number Diff line number Diff line
@@ -38,6 +38,10 @@ static int snd_soc_4_12_write(struct snd_soc_codec *codec, unsigned int reg, 


	if (reg < codec->reg_cache_size)

		cache[reg] = value;



	if (codec->cache_only)

		return 0;



	ret = codec->hw_write(codec->control_data, data, 2);

	if (ret == 2)

		return 0;
@@ -100,6 +104,10 @@ static int snd_soc_7_9_write(struct snd_soc_codec *codec, unsigned int reg, 


	if (reg < codec->reg_cache_size)

		cache[reg] = value;



	if (codec->cache_only)

		return 0;



	ret = codec->hw_write(codec->control_data, data, 2);

	if (ret == 2)

		return 0;
@@ -153,6 +161,9 @@ static int snd_soc_8_8_write(struct snd_soc_codec *codec, unsigned int reg, 
	if (reg < codec->reg_cache_size)

		cache[reg] = value;



	if (codec->cache_only)

		return 0;



	if (codec->hw_write(codec->control_data, data, 2) == 2)

		return 0;

	else
@@ -181,6 +192,9 @@ static int snd_soc_8_16_write(struct snd_soc_codec *codec, unsigned int reg, 
	if (!snd_soc_codec_volatile_register(codec, reg))

		reg_cache[reg] = value;



	if (codec->cache_only)

		return 0;



	if (codec->hw_write(codec->control_data, data, 3) == 3)

		return 0;

	else
@@ -193,11 +207,15 @@ static unsigned int snd_soc_8_16_read(struct snd_soc_codec *codec, 
	u16 *cache = codec->reg_cache;



	if (reg >= codec->reg_cache_size ||

	    snd_soc_codec_volatile_register(codec, reg))

	    snd_soc_codec_volatile_register(codec, reg)) {

		if (codec->cache_only)

			return -EINVAL;



		return codec->hw_read(codec, reg);

	else

	} else {

		return cache[reg];

	}

}



#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))

static unsigned int snd_soc_8_16_read_i2c(struct snd_soc_codec *codec,
@@ -294,6 +312,10 @@ static int snd_soc_16_8_write(struct snd_soc_codec *codec, unsigned int reg, 
	reg &= 0xff;

	if (reg < codec->reg_cache_size)

		cache[reg] = value;



	if (codec->cache_only)

		return 0;



	ret = codec->hw_write(codec->control_data, data, 3);

	if (ret == 3)

		return 0;

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