ENGR00113667 MX233 ALSA: Add reg_cache to keep amixer settings

Add reg_cache to keep the reg values of audio module in cache, by this it is
able to save all amixer settings, like volume, switch configure, etc, when
system suspend, and restore all of them when system resume.

Signed-off-by: Lionel Xu <r63889@freescale.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/sound/soc/codecs/stmp378x_codec.c b/sound/soc/codecs/stmp378x_codec.c
index 0893894efef5..c8a72b8efa4f 100644
--- a/sound/soc/codecs/stmp378x_codec.c
+++ b/sound/soc/codecs/stmp378x_codec.c
@@ -80,12 +80,22 @@ static u32 adc_regmap[] = {
 	HW_AUDIOIN_DATA_ADDR,
 };
 
+static u16 stmp378x_audio_regs[ADC_REGNUM];
+
 /*
  * ALSA core supports only 16 bit registers. It means we have to simulate it
  * by virtually splitting a 32bit ADC/DAC registers into two halves
  * high (bits 31:16) and low (bits 15:0). The routins abow detects which part
  * of 32bit register is accessed.
  */
+static void stmp378x_codec_write_cache(struct snd_soc_codec *codec,
+					unsigned int reg, unsigned int value)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg < ADC_REGNUM)
+		cache[reg] = value;
+}
+
 static int stmp378x_codec_write(struct snd_soc_codec *codec,
 				unsigned int reg, unsigned int value)
 {
@@ -95,6 +105,8 @@ static int stmp378x_codec_write(struct snd_soc_codec *codec,
 	if (reg >= ADC_REGNUM)
 		return -EIO;
 
+	stmp378x_codec_write_cache(codec, reg, value);
+
 	if (reg & 0x1) {
 		mask <<= 16;
 		value <<= 16;
@@ -122,6 +134,37 @@ static unsigned int stmp378x_codec_read(struct snd_soc_codec *codec,
 	return reg_val & 0xffff;
 }
 
+static unsigned int stmp378x_codec_read_cache(struct snd_soc_codec *codec,
+						unsigned int reg)
+{
+	u16 *cache = codec->reg_cache;
+	if (reg >= ADC_REGNUM)
+		return -EINVAL;
+	return cache[reg];
+}
+
+static void stmp378x_codec_sync_reg_cache(struct snd_soc_codec *codec)
+{
+	int reg;
+	for (reg = 0; reg < ADC_REGNUM; reg += 1)
+		stmp378x_codec_write_cache(codec, reg,
+					   stmp378x_codec_read(codec, reg));
+}
+
+
+static int stmp378x_codec_restore_reg(struct snd_soc_codec *codec, unsigned int reg)
+{
+	unsigned int cached_val, hw_val;
+
+	cached_val = stmp378x_codec_read_cache(codec, reg);
+	hw_val = stmp378x_codec_read(codec, reg);
+
+	if (hw_val != cached_val)
+		return stmp378x_codec_write(codec, reg, cached_val);
+
+	return 0;
+}
+
 static const char *stmp378x_codec_adc_input_sel[] =
 				{"Mic", "Line In 1", "Head Phone", "Line In 2"};
 
@@ -572,6 +615,9 @@ stmp378x_codec_init(struct snd_soc_codec *codec)
 	stmp378x_codec_dac_enable(stmp378x_adc);
 	stmp378x_codec_adc_enable(stmp378x_adc);
 
+	/*Sync regs and cache*/
+	stmp378x_codec_sync_reg_cache(codec);
+
 	stmp378x_codec_add_controls(codec);
 	stmp378x_codec_add_widgets(codec);
 }
@@ -638,6 +684,9 @@ static int stmp378x_codec_probe(struct platform_device *pdev)
 	codec->write = stmp378x_codec_write;
 	codec->dai = &stmp378x_codec_dai;
 	codec->num_dai = 1;
+	codec->reg_cache_size = sizeof(stmp378x_audio_regs) >> 1;
+	codec->reg_cache_step = 1;
+	codec->reg_cache = (void *)&stmp378x_audio_regs;
 	socdev->codec = codec;
 
 	mutex_init(&codec->mutex);
@@ -752,6 +801,19 @@ static int stmp378x_codec_resume(struct platform_device *pdev)
 	stmp378x_codec_dac_enable(stmp378x_adc);
 	stmp378x_codec_adc_enable(stmp378x_adc);
 
+	/*restore registers relevant to amixer controls*/
+	stmp378x_codec_restore_reg(codec, DAC_CTRL_L);
+	stmp378x_codec_restore_reg(codec, DAC_VOLUME_L);
+	stmp378x_codec_restore_reg(codec, DAC_VOLUME_H);
+	stmp378x_codec_restore_reg(codec, DAC_HPVOL_L);
+	stmp378x_codec_restore_reg(codec, DAC_HPVOL_H);
+	stmp378x_codec_restore_reg(codec, DAC_SPEAKERCTRL_H);
+	stmp378x_codec_restore_reg(codec, ADC_VOLUME_L);
+	stmp378x_codec_restore_reg(codec, ADC_VOLUME_H);
+	stmp378x_codec_restore_reg(codec, ADC_ADCVOL_L);
+	stmp378x_codec_restore_reg(codec, ADC_ADCVOL_H);
+	stmp378x_codec_restore_reg(codec, ADC_MICLINE_L);
+
 	ret = 0;
 
 out: