ASoC: Enhance default WM8958 microphone detection

Actively manage the detection rate for microphones with WM8958, providing
improved power consumption and maximising the benefit from the hardware
debounce.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c
index 207bccd..027bf68 100644 (file)
--- a/sound/soc/codecs/wm8994.c
+++ b/sound/soc/codecs/wm8994.c
@@ -53,6 +53,56 @@ static int wm8994_retune_mobile_base[] = {
        WM8994_AIF2_EQ_GAINS_1,
 };
 
+static void wm8958_default_micdet(u16 status, void *data);
+
+static const struct {
+       int sysclk;
+       bool idle;
+       int start;
+       int rate;
+} wm8958_micd_rates[] = {
+       { 32768,       true,  1, 4 },
+       { 32768,       false, 1, 1 },
+       { 44100 * 256, true,  7, 6 },
+       { 44100 * 256, false, 7, 6 },
+};
+
+static void wm8958_micd_set_rate(struct snd_soc_codec *codec)
+{
+       struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
+       int best, i, sysclk, val;
+       bool idle;
+
+       if (wm8994->jack_cb != wm8958_default_micdet)
+               return;
+
+       idle = !wm8994->jack_mic;
+
+       sysclk = snd_soc_read(codec, WM8994_CLOCKING_1);
+       if (sysclk & WM8994_SYSCLK_SRC)
+               sysclk = wm8994->aifclk[1];
+       else
+               sysclk = wm8994->aifclk[0];
+
+       best = 0;
+       for (i = 0; i < ARRAY_SIZE(wm8958_micd_rates); i++) {
+               if (wm8958_micd_rates[i].idle != idle)
+                       continue;
+               if (abs(wm8958_micd_rates[i].sysclk - sysclk) <
+                   abs(wm8958_micd_rates[best].sysclk - sysclk))
+                       best = i;
+               else if (wm8958_micd_rates[best].idle != idle)
+                       best = i;
+       }
+
+       val = wm8958_micd_rates[best].start << WM8958_MICD_BIAS_STARTTIME_SHIFT
+               | wm8958_micd_rates[best].rate << WM8958_MICD_RATE_SHIFT;
+
+       snd_soc_update_bits(codec, WM8958_MIC_DETECT_1,
+                           WM8958_MICD_BIAS_STARTTIME_MASK |
+                           WM8958_MICD_RATE_MASK, val);
+}
+
 static int wm8994_readable(struct snd_soc_codec *codec, unsigned int reg)
 {
        struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
@@ -221,8 +271,10 @@ static int configure_clock(struct snd_soc_codec *codec)
         */
 
        /* If they're equal it doesn't matter which is used */
-       if (wm8994->aifclk[0] == wm8994->aifclk[1])
+       if (wm8994->aifclk[0] == wm8994->aifclk[1]) {
+               wm8958_micd_set_rate(codec);
                return 0;
+       }
 
        if (wm8994->aifclk[0] < wm8994->aifclk[1])
                new = WM8994_SYSCLK_SRC;
@@ -236,6 +288,8 @@ static int configure_clock(struct snd_soc_codec *codec)
 
        snd_soc_dapm_sync(&codec->dapm);
 
+       wm8958_micd_set_rate(codec);
+
        return 0;
 }
 
@@ -2987,21 +3041,56 @@ static void wm8958_default_micdet(u16 status, void *data)
 {
        struct snd_soc_codec *codec = data;
        struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
-       int report = 0;
 
        /* If nothing present then clear our statuses */
-       if (!(status & WM8958_MICD_STS))
-               goto done;
+       if (!(status & WM8958_MICD_STS)) {
+               dev_dbg(codec->dev, "Detected open circuit\n");
+               wm8994->jack_mic = false;
+               wm8994->detecting = true;
+
+               wm8958_micd_set_rate(codec);
 
-       report = SND_JACK_MICROPHONE;
+               snd_soc_jack_report(wm8994->micdet[0].jack, 0,
+                                   SND_JACK_BTN_0 | SND_JACK_HEADSET);
+
+               return;
+       }
 
-       /* Everything else is buttons; just assign slots */
-       if (status & 0x1c)
-               report |= SND_JACK_BTN_0;
+       /* If the measurement is showing a high impedence we've got a
+        * microphone.
+        */
+       if (wm8994->detecting && (status & 0x600)) {
+               dev_dbg(codec->dev, "Detected microphone\n");
+
+               wm8994->detecting = false;
+               wm8994->jack_mic = true;
+
+               wm8958_micd_set_rate(codec);
+
+               snd_soc_jack_report(wm8994->micdet[0].jack, SND_JACK_HEADSET,
+                                   SND_JACK_HEADSET);
+       }
 
-done:
-       snd_soc_jack_report(wm8994->micdet[0].jack, report,
-                           SND_JACK_BTN_0 | SND_JACK_MICROPHONE);
+
+       if (wm8994->detecting && status & 0x4) {
+               dev_dbg(codec->dev, "Detected headphone\n");
+               wm8994->detecting = false;
+
+               wm8958_micd_set_rate(codec);
+
+               snd_soc_jack_report(wm8994->micdet[0].jack, SND_JACK_HEADPHONE,
+                                   SND_JACK_HEADSET);
+       }
+
+       /* Report short circuit as a button */
+       if (wm8994->jack_mic) {
+               if (status & 0x4)
+                       snd_soc_jack_report(wm8994->micdet[0].jack,
+                                           SND_JACK_BTN_0, SND_JACK_BTN_0);
+               else
+                       snd_soc_jack_report(wm8994->micdet[0].jack,
+                                           0, SND_JACK_BTN_0);
+       }
 }
 
 /**
@@ -3047,6 +3136,15 @@ int wm8958_mic_detect(struct snd_soc_codec *codec, struct snd_soc_jack *jack,
                wm8994->jack_cb = cb;
                wm8994->jack_cb_data = cb_data;
 
+               wm8994->detecting = true;
+               wm8994->jack_mic = false;
+
+               wm8958_micd_set_rate(codec);
+
+               /* Detect microphones and short circuits */
+               snd_soc_update_bits(codec, WM8958_MIC_DETECT_2,
+                                   WM8958_MICD_LVL_SEL_MASK, 0x41);
+
                snd_soc_update_bits(codec, WM8958_MIC_DETECT_1,
                                    WM8958_MICD_ENA, WM8958_MICD_ENA);
        } else {

diff --git a/sound/soc/codecs/wm8994.h b/sound/soc/codecs/wm8994.h
index f4f1355..1087425 100644 (file)
--- a/sound/soc/codecs/wm8994.h
+++ b/sound/soc/codecs/wm8994.h
@@ -126,6 +126,8 @@ struct wm8994_priv {
        struct soc_enum enh_eq_enum;
 
        struct wm8994_micdet micdet[2];
+       bool detecting;
+       bool jack_mic;
 
        wm8958_micdet_cb jack_cb;
        void *jack_cb_data;