ASoC: Initial WM8903 microphone bias and short detection

Provide support for WM8903 microphone presence and short detection
using the GPIOs to route out a logic signal suitable for handling
using snd_soc_jack_add_gpios() on the processor GPIOs.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

include/sound/wm8903.h

@@ -14,6 +14,28 @@
 /* Used to enable configuration of a GPIO to all zeros */
 #define WM8903_GPIO_NO_CONFIG 0x8000
 
+/*
+ * R6 (0x06) - Mic Bias Control 0
+ */
+#define WM8903_MICDET_HYST_ENA                  0x0080  /* MICDET_HYST_ENA */
+#define WM8903_MICDET_HYST_ENA_MASK             0x0080  /* MICDET_HYST_ENA */
+#define WM8903_MICDET_HYST_ENA_SHIFT                 7  /* MICDET_HYST_ENA */
+#define WM8903_MICDET_HYST_ENA_WIDTH                 1  /* MICDET_HYST_ENA */
+#define WM8903_MICDET_THR_MASK                  0x0070  /* MICDET_THR - [6:4] */
+#define WM8903_MICDET_THR_SHIFT                      4  /* MICDET_THR - [6:4] */
+#define WM8903_MICDET_THR_WIDTH                      3  /* MICDET_THR - [6:4] */
+#define WM8903_MICSHORT_THR_MASK                0x000C  /* MICSHORT_THR - [3:2] */
+#define WM8903_MICSHORT_THR_SHIFT                    2  /* MICSHORT_THR - [3:2] */
+#define WM8903_MICSHORT_THR_WIDTH                    2  /* MICSHORT_THR - [3:2] */
+#define WM8903_MICDET_ENA                       0x0002  /* MICDET_ENA */
+#define WM8903_MICDET_ENA_MASK                  0x0002  /* MICDET_ENA */
+#define WM8903_MICDET_ENA_SHIFT                      1  /* MICDET_ENA */
+#define WM8903_MICDET_ENA_WIDTH                      1  /* MICDET_ENA */
+#define WM8903_MICBIAS_ENA                      0x0001  /* MICBIAS_ENA */
+#define WM8903_MICBIAS_ENA_MASK                 0x0001  /* MICBIAS_ENA */
+#define WM8903_MICBIAS_ENA_SHIFT                     0  /* MICBIAS_ENA */
+#define WM8903_MICBIAS_ENA_WIDTH                     1  /* MICBIAS_ENA */
+
 /*
  * R116 (0x74) - GPIO Control 1
  */
@@ -210,6 +232,13 @@
 #define WM8903_GP5_DB_WIDTH                          1  /* GP5_DB */
 
 struct wm8903_platform_data {
+        /* Default register value for R6 (Mic bias), used to configure
+	 * microphone detection.  In conjunction with gpio_cfg this
+	 * can be used to route the microphone status signals out onto
+	 * the GPIOs for use with snd_soc_jack_add_gpios().
+	 */
+	u16 micdet_cfg;
+
 	u32 gpio_cfg[5];       /* Default register values for GPIO pin mux */
 };
 

sound/soc/codecs/wm8903.c

@@ -11,7 +11,6 @@
  *
  * TODO:
  *  - TDM mode configuration.
- *  - Mic detect.
  *  - Digital microphone support.
  *  - Interrupt support (mic detect and sequencer).
  */
@@ -246,10 +245,10 @@ static int wm8903_run_sequence(struct snd_soc_codec *codec, unsigned int start)
 
 	BUG_ON(start > 48);
 
-	/* Enable the sequencer */
+	/* Enable the sequencer if it's not already on */
 	reg[0] = snd_soc_read(codec, WM8903_WRITE_SEQUENCER_0);
-	reg[0] |= WM8903_WSEQ_ENA;
-	snd_soc_write(codec, WM8903_WRITE_SEQUENCER_0, reg[0]);
+	snd_soc_write(codec, WM8903_WRITE_SEQUENCER_0,
+		      reg[0] | WM8903_WSEQ_ENA);
 
 	dev_dbg(&i2c->dev, "Starting sequence at %d\n", start);
 
@@ -268,9 +267,8 @@ static int wm8903_run_sequence(struct snd_soc_codec *codec, unsigned int start)
 
 	dev_dbg(&i2c->dev, "Sequence complete\n");
 
-	/* Disable the sequencer again */
-	snd_soc_write(codec, WM8903_WRITE_SEQUENCER_0,
-		     reg[0] & ~WM8903_WSEQ_ENA);
+	/* Disable the sequencer again if we enabled it */
+	snd_soc_write(codec, WM8903_WRITE_SEQUENCER_0, reg[0]);
 
 	return 0;
 }
@@ -1578,7 +1576,7 @@ static __devinit int wm8903_i2c_probe(struct i2c_client *i2c,
 
 	wm8903_reset(codec);
 
-	/* Set up GPIOs */
+	/* Set up GPIOs and microphone detection */
 	if (pdata) {
 		for (i = 0; i < ARRAY_SIZE(pdata->gpio_cfg); i++) {
 			if (!pdata->gpio_cfg[i])
@@ -1587,6 +1585,16 @@ static __devinit int wm8903_i2c_probe(struct i2c_client *i2c,
 			snd_soc_write(codec, WM8903_GPIO_CONTROL_1 + i,
 				      pdata->gpio_cfg[i] & 0xffff);
 		}
+
+		snd_soc_write(codec, WM8903_MIC_BIAS_CONTROL_0,
+			      pdata->micdet_cfg);
+
+		/* Microphone detection needs the WSEQ clock */
+		if (pdata->micdet_cfg)
+			snd_soc_update_bits(codec, WM8903_WRITE_SEQUENCER_0,
+					    WM8903_WSEQ_ENA, WM8903_WSEQ_ENA);
+
+		wm8903->mic_delay = pdata->micdet_delay;
 	}
 
 	/* power on device */

sound/soc/codecs/wm8903.h

@@ -172,28 +172,6 @@ extern struct snd_soc_codec_device soc_codec_dev_wm8903;
 #define WM8903_VMID_RES_250K                         3
 #define WM8903_VMID_RES_5K                           4
 
-/*
- * R6 (0x06) - Mic Bias Control 0
- */
-#define WM8903_MICDET_HYST_ENA                  0x0080  /* MICDET_HYST_ENA */
-#define WM8903_MICDET_HYST_ENA_MASK             0x0080  /* MICDET_HYST_ENA */
-#define WM8903_MICDET_HYST_ENA_SHIFT                 7  /* MICDET_HYST_ENA */
-#define WM8903_MICDET_HYST_ENA_WIDTH                 1  /* MICDET_HYST_ENA */
-#define WM8903_MICDET_THR_MASK                  0x0070  /* MICDET_THR - [6:4] */
-#define WM8903_MICDET_THR_SHIFT                      4  /* MICDET_THR - [6:4] */
-#define WM8903_MICDET_THR_WIDTH                      3  /* MICDET_THR - [6:4] */
-#define WM8903_MICSHORT_THR_MASK                0x000C  /* MICSHORT_THR - [3:2] */
-#define WM8903_MICSHORT_THR_SHIFT                    2  /* MICSHORT_THR - [3:2] */
-#define WM8903_MICSHORT_THR_WIDTH                    2  /* MICSHORT_THR - [3:2] */
-#define WM8903_MICDET_ENA                       0x0002  /* MICDET_ENA */
-#define WM8903_MICDET_ENA_MASK                  0x0002  /* MICDET_ENA */
-#define WM8903_MICDET_ENA_SHIFT                      1  /* MICDET_ENA */
-#define WM8903_MICDET_ENA_WIDTH                      1  /* MICDET_ENA */
-#define WM8903_MICBIAS_ENA                      0x0001  /* MICBIAS_ENA */
-#define WM8903_MICBIAS_ENA_MASK                 0x0001  /* MICBIAS_ENA */
-#define WM8903_MICBIAS_ENA_SHIFT                     0  /* MICBIAS_ENA */
-#define WM8903_MICBIAS_ENA_WIDTH                     1  /* MICBIAS_ENA */
-
 /*
  * R8 (0x08) - Analogue DAC 0
  */