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: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Harsha Priya <priya.harsha@intel.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

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: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Harsha Priya <priya.harsha@intel.com> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Vinod Koul · Mark Brown
1 parent 42aee9b43e
Showing 2 changed files with 147 additions and 4 deletions Side-by-side Diff
sound/soc/codecs/sn95031.c
sound/soc/codecs/sn95031.h
@@ -40,13 +40,130 @@
 #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 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;
@@ -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;
...	...	@@ -40,13 +40,130 @@
40	40	#define SN95031_RATES (SNDRV_PCM_RATE_48000 \| SNDRV_PCM_RATE_44100)
41	41	#define SN95031_FORMATS (SNDRV_PCM_FMTBIT_S24_LE \| SNDRV_PCM_FMTBIT_S16_LE)
42	42
	43	+/* adc helper functions */
	44	+
	45	+/* enables mic bias voltage */
	46	+static void sn95031_enable_mic_bias(struct snd_soc_codec *codec)
	47	+{
	48	+ snd_soc_write(codec, SN95031_VAUD, BIT(2)\|BIT(1)\|BIT(0));
	49	+ snd_soc_update_bits(codec, SN95031_MICBIAS, BIT(2), BIT(2));
	50	+}
	51	+
	52	+/* Enable/Disable the ADC depending on the argument */
	53	+static void configure_adc(struct snd_soc_codec *sn95031_codec, int val)
	54	+{
	55	+ int value = snd_soc_read(sn95031_codec, SN95031_ADC1CNTL1);
	56	+
	57	+ if (val) {
	58	+ /* Enable and start the ADC */
	59	+ value \|= (SN95031_ADC_ENBL \| SN95031_ADC_START);
	60	+ value &= (~SN95031_ADC_NO_LOOP);
	61	+ } else {
	62	+ /* Just stop the ADC */
	63	+ value &= (~SN95031_ADC_START);
	64	+ }
	65	+ snd_soc_write(sn95031_codec, SN95031_ADC1CNTL1, value);
	66	+}
	67	+
43	68	/*
44		- * todo:
45		- * capture paths
46		- * jack detection
47		- * PM functions
	69	+ * finds an empty channel for conversion
	70	+ * If the ADC is not enabled then start using 0th channel
	71	+ * itself. Otherwise find an empty channel by looking for a
	72	+ * channel in which the stopbit is set to 1. returns the index
	73	+ * of the first free channel if succeeds or an error code.
	74	+ *
	75	+ * Context: can sleep
	76	+ *
48	77	*/
	78	+static int find_free_channel(struct snd_soc_codec *sn95031_codec)
	79	+{
	80	+ int ret = 0, i, value;
49	81
	82	+ /* check whether ADC is enabled */
	83	+ value = snd_soc_read(sn95031_codec, SN95031_ADC1CNTL1);
	84	+
	85	+ if ((value & SN95031_ADC_ENBL) == 0)
	86	+ return 0;
	87	+
	88	+ /* ADC is already enabled; Looking for an empty channel */
	89	+ for (i = 0; i < SN95031_ADC_CHANLS_MAX; i++) {
	90	+ value = snd_soc_read(sn95031_codec,
	91	+ SN95031_ADC_CHNL_START_ADDR + i);
	92	+ if (value & SN95031_STOPBIT_MASK) {
	93	+ ret = i;
	94	+ break;
	95	+ }
	96	+ }
	97	+ return (ret > SN95031_ADC_LOOP_MAX) ? (-EINVAL) : ret;
	98	+}
	99	+
	100	+/* Initialize the ADC for reading micbias values. Can sleep. */
	101	+static int sn95031_initialize_adc(struct snd_soc_codec *sn95031_codec)
	102	+{
	103	+ int base_addr, chnl_addr;
	104	+ int value;
	105	+ static int channel_index;
	106	+
	107	+ /* Index of the first channel in which the stop bit is set */
	108	+ channel_index = find_free_channel(sn95031_codec);
	109	+ if (channel_index < 0) {
	110	+ pr_err("No free ADC channels");
	111	+ return channel_index;
	112	+ }
	113	+
	114	+ base_addr = SN95031_ADC_CHNL_START_ADDR + channel_index;
	115	+
	116	+ if (!(channel_index == 0 \|\| channel_index == SN95031_ADC_LOOP_MAX)) {
	117	+ /* Reset stop bit for channels other than 0 and 12 */
	118	+ value = snd_soc_read(sn95031_codec, base_addr);
	119	+ /* Set the stop bit to zero */
	120	+ snd_soc_write(sn95031_codec, base_addr, value & 0xEF);
	121	+ /* Index of the first free channel */
	122	+ base_addr++;
	123	+ channel_index++;
	124	+ }
	125	+
	126	+ /* Since this is the last channel, set the stop bit
	127	+ to 1 by ORing the DIE_SENSOR_CODE with 0x10 */
	128	+ snd_soc_write(sn95031_codec, base_addr,
	129	+ SN95031_AUDIO_DETECT_CODE \| 0x10);
	130	+
	131	+ chnl_addr = SN95031_ADC_DATA_START_ADDR + 2 * channel_index;
	132	+ pr_debug("mid_initialize : %x", chnl_addr);
	133	+ configure_adc(sn95031_codec, 1);
	134	+ return chnl_addr;
	135	+}
	136	+
	137	+
	138	+/* reads the ADC registers and gets the mic bias value in mV. */
	139	+static unsigned int sn95031_get_mic_bias(struct snd_soc_codec *codec)
	140	+{
	141	+ u16 adc_adr = sn95031_initialize_adc(codec);
	142	+ u16 adc_val1, adc_val2;
	143	+ unsigned int mic_bias;
	144	+
	145	+ sn95031_enable_mic_bias(codec);
	146	+
	147	+ /* Enable the sound card for conversion before reading */
	148	+ snd_soc_write(codec, SN95031_ADC1CNTL3, 0x05);
	149	+ /* Re-toggle the RRDATARD bit */
	150	+ snd_soc_write(codec, SN95031_ADC1CNTL3, 0x04);
	151	+
	152	+ /* Read the higher bits of data */
	153	+ msleep(1000);
	154	+ adc_val1 = snd_soc_read(codec, adc_adr);
	155	+ adc_adr++;
	156	+ adc_val2 = snd_soc_read(codec, adc_adr);
	157	+
	158	+ /* Adding lower two bits to the higher bits */
	159	+ mic_bias = (adc_val1 << 2) + (adc_val2 & 3);
	160	+ mic_bias = (mic_bias * SN95031_ADC_ONE_LSB_MULTIPLIER) / 1000;
	161	+ pr_debug("mic bias = %dmV\n", mic_bias);
	162	+ return mic_bias;
	163	+}
	164	+EXPORT_SYMBOL_GPL(sn95031_get_mic_bias);
	165	+/end - adc helper functions /
	166	+
50	167	static inline unsigned int sn95031_read(struct snd_soc_codec *codec,
51	168	unsigned int reg)
52	169	{
...	...	@@ -663,6 +780,8 @@
663	780
664	781	static int sn95031_get_headset_state(struct snd_soc_jack *mfld_jack)
665	782	{
	783	+ int micbias = sn95031_get_mic_bias(mfld_jack->codec);
	784	+
666	785	/* Defaulting to HEADSET for now.
667	786	* will change after adding soc-jack detection apis */
668	787	int jack_type = SND_JACK_HEADSET;
...	...	@@ -96,7 +96,31 @@
96	96	#define SN95031_SSR5 0x384
97	97	#define SN95031_SSR6 0x385
98	98
	99	+/* ADC registers */
	100	+
	101	+#define SN95031_ADC1CNTL1 0x1C0
	102	+#define SN95031_ADC_ENBL 0x10
	103	+#define SN95031_ADC_START 0x08
	104	+#define SN95031_ADC1CNTL3 0x1C2
	105	+#define SN95031_ADCTHERM_ENBL 0x04
	106	+#define SN95031_ADCRRDATA_ENBL 0x05
	107	+#define SN95031_STOPBIT_MASK 16
	108	+#define SN95031_ADCTHERM_MASK 4
	109	+#define SN95031_ADC_CHANLS_MAX 15 /* Number of ADC channels */
	110	+#define SN95031_ADC_LOOP_MAX (SN95031_ADC_CHANLS_MAX - 1)
	111	+#define SN95031_ADC_NO_LOOP 0x07
99	112	#define SN95031_AUDIO_GPIO_CTRL 0x070
	113	+
	114	+/* ADC channel code values */
	115	+#define SN95031_AUDIO_DETECT_CODE 0x06
	116	+
	117	+/* ADC base addresses */
	118	+#define SN95031_ADC_CHNL_START_ADDR 0x1C5 /* increments by 1 */
	119	+#define SN95031_ADC_DATA_START_ADDR 0x1D4 /* increments by 2 */
	120	+/* multipier to convert to mV */
	121	+#define SN95031_ADC_ONE_LSB_MULTIPLIER 2346
	122	+
	123	+
100	124	struct mfld_jack_data {
101	125	int intr_id;
102	126	int micbias_vol;