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Commit 36633237 authored by Vinod Koul's avatar Vinod Koul Committed by Mark Brown
Browse files

ASoC: sn95031: Add support for reading mic bias 



This patch adds support to read the mic bias voltage
when a jack is inserted. It uses ADC to measure.

Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Signed-off-by: default avatarHarsha Priya <priya.harsha@intel.com>
Acked-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 42aee9b4

sound/soc/codecs/sn95031.c

+123 −4
Original line number Diff line number Diff line
@@ -40,12 +40,129 @@ 
#define SN95031_RATES (SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_44100)

#define SN95031_FORMATS (SNDRV_PCM_FMTBIT_S24_LE | SNDRV_PCM_FMTBIT_S16_LE)



/* adc helper functions */



/* enables mic bias voltage */

static void sn95031_enable_mic_bias(struct snd_soc_codec *codec)

{

	snd_soc_write(codec, SN95031_VAUD, BIT(2)|BIT(1)|BIT(0));

	snd_soc_update_bits(codec, SN95031_MICBIAS, BIT(2), BIT(2));

}



/* Enable/Disable the ADC depending on the argument */

static void configure_adc(struct snd_soc_codec *sn95031_codec, int val)

{

	int value = snd_soc_read(sn95031_codec, SN95031_ADC1CNTL1);



	if (val) {

		/* Enable and start the ADC */

		value |= (SN95031_ADC_ENBL | SN95031_ADC_START);

		value &= (~SN95031_ADC_NO_LOOP);

	} else {

		/* Just stop the ADC */

		value &= (~SN95031_ADC_START);

	}

	snd_soc_write(sn95031_codec, SN95031_ADC1CNTL1, value);

}



/*

 * todo:

 * capture paths

 * jack detection

 * PM functions

 * finds an empty channel for conversion

 * If the ADC is not enabled then start using 0th channel

 * itself. Otherwise find an empty channel by looking for a

 * channel in which the stopbit is set to 1. returns the index

 * of the first free channel if succeeds or an error code.

 *

 * Context: can sleep

 *

 */

static int find_free_channel(struct snd_soc_codec *sn95031_codec)

{

	int ret = 0, i, value;



	/* check whether ADC is enabled */

	value = snd_soc_read(sn95031_codec, SN95031_ADC1CNTL1);



	if ((value & SN95031_ADC_ENBL) == 0)

		return 0;



	/* ADC is already enabled; Looking for an empty channel */

	for (i = 0; i <	SN95031_ADC_CHANLS_MAX; i++) {

		value = snd_soc_read(sn95031_codec,

				SN95031_ADC_CHNL_START_ADDR + i);

		if (value & SN95031_STOPBIT_MASK) {

			ret = i;

			break;

		}

	}

	return (ret > SN95031_ADC_LOOP_MAX) ? (-EINVAL) : ret;

}



/* Initialize the ADC for reading micbias values. Can sleep. */

static int sn95031_initialize_adc(struct snd_soc_codec *sn95031_codec)

{

	int base_addr, chnl_addr;

	int value;

	static int channel_index;



	/* Index of the first channel in which the stop bit is set */

	channel_index = find_free_channel(sn95031_codec);

	if (channel_index < 0) {

		pr_err("No free ADC channels");

		return channel_index;

	}



	base_addr = SN95031_ADC_CHNL_START_ADDR + channel_index;



	if (!(channel_index == 0 || channel_index ==  SN95031_ADC_LOOP_MAX)) {

		/* Reset stop bit for channels other than 0 and 12 */

		value = snd_soc_read(sn95031_codec, base_addr);

		/* Set the stop bit to zero */

		snd_soc_write(sn95031_codec, base_addr, value & 0xEF);

		/* Index of the first free channel */

		base_addr++;

		channel_index++;

	}



	/* Since this is the last channel, set the stop bit

	   to 1 by ORing the DIE_SENSOR_CODE with 0x10 */

	snd_soc_write(sn95031_codec, base_addr,

				SN95031_AUDIO_DETECT_CODE | 0x10);



	chnl_addr = SN95031_ADC_DATA_START_ADDR + 2 * channel_index;

	pr_debug("mid_initialize : %x", chnl_addr);

	configure_adc(sn95031_codec, 1);

	return chnl_addr;

}





/* reads the ADC registers and gets the mic bias value in mV. */

static unsigned int sn95031_get_mic_bias(struct snd_soc_codec *codec)

{

	u16 adc_adr = sn95031_initialize_adc(codec);

	u16 adc_val1, adc_val2;

	unsigned int mic_bias;



	sn95031_enable_mic_bias(codec);



	/* Enable the sound card for conversion before reading */

	snd_soc_write(codec, SN95031_ADC1CNTL3, 0x05);

	/* Re-toggle the RRDATARD bit */

	snd_soc_write(codec, SN95031_ADC1CNTL3, 0x04);



	/* Read the higher bits of data */

	msleep(1000);

	adc_val1 = snd_soc_read(codec, adc_adr);

	adc_adr++;

	adc_val2 = snd_soc_read(codec, adc_adr);



	/* Adding lower two bits to the higher bits */

	mic_bias = (adc_val1 << 2) + (adc_val2 & 3);

	mic_bias = (mic_bias * SN95031_ADC_ONE_LSB_MULTIPLIER) / 1000;

	pr_debug("mic bias = %dmV\n", mic_bias);

	return mic_bias;

}

EXPORT_SYMBOL_GPL(sn95031_get_mic_bias);

/*end - adc helper functions */



static inline unsigned int sn95031_read(struct snd_soc_codec *codec,

			unsigned int reg)
@@ -663,6 +780,8 @@ static inline void sn95031_enable_jack_btn(struct snd_soc_codec *codec) 


static int sn95031_get_headset_state(struct snd_soc_jack *mfld_jack)

{

	int micbias = sn95031_get_mic_bias(mfld_jack->codec);



	/* Defaulting to HEADSET for now.

	 * will change after adding soc-jack detection apis */

	int jack_type = SND_JACK_HEADSET;

sound/soc/codecs/sn95031.h

+24 −0
Original line number Diff line number Diff line
@@ -96,7 +96,31 @@ 
#define SN95031_SSR5			0x384

#define SN95031_SSR6			0x385



/* ADC registers */



#define SN95031_ADC1CNTL1 0x1C0

#define SN95031_ADC_ENBL 0x10

#define SN95031_ADC_START 0x08

#define SN95031_ADC1CNTL3 0x1C2

#define SN95031_ADCTHERM_ENBL 0x04

#define SN95031_ADCRRDATA_ENBL 0x05

#define SN95031_STOPBIT_MASK 16

#define SN95031_ADCTHERM_MASK 4

#define SN95031_ADC_CHANLS_MAX 15 /* Number of ADC channels */

#define SN95031_ADC_LOOP_MAX (SN95031_ADC_CHANLS_MAX - 1)

#define SN95031_ADC_NO_LOOP 0x07

#define SN95031_AUDIO_GPIO_CTRL 0x070



/* ADC channel code values */

#define SN95031_AUDIO_DETECT_CODE 0x06



/* ADC base addresses */

#define SN95031_ADC_CHNL_START_ADDR 0x1C5 /* increments by 1 */

#define SN95031_ADC_DATA_START_ADDR 0x1D4  /* increments by 2 */

/* multipier to convert to mV */

#define SN95031_ADC_ONE_LSB_MULTIPLIER 2346





struct mfld_jack_data {

	int intr_id;

	int micbias_vol;