From: Vinod Koul vinod.koul@intel.com
This patch adds support to read the mic bias voltage when a jack is inserted. It uses ADC to measure.
Signed-off-by: Vinod Koul vinod.koul@intel.com Signed-off-by: Harsha Priya priya.harsha@intel.com --- sound/soc/codecs/sn95031.c | 127 ++++++++++++++++++++++++++++++++++++++++++-- sound/soc/codecs/sn95031.h | 24 ++++++++ 2 files changed, 147 insertions(+), 4 deletions(-)
diff --git a/sound/soc/codecs/sn95031.c b/sound/soc/codecs/sn95031.c index b49d790..4cc0017 100644 --- a/sound/soc/codecs/sn95031.c +++ b/sound/soc/codecs/sn95031.c @@ -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; diff --git a/sound/soc/codecs/sn95031.h b/sound/soc/codecs/sn95031.h index 2dbae61..20376d2 100644 --- a/sound/soc/codecs/sn95031.h +++ b/sound/soc/codecs/sn95031.h @@ -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;