ASoC: wm8996: Handle failures to determine accessory polarity

If we get an indeterminate impedance with both headset polarities then
give up and report the accessory as a headphone rather than continually
retrying.

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

1 files changed, 26 insertions, 12 deletions

diff --git a/sound/soc/codecs/wm8996.c b/sound/soc/codecs/wm8996.c
index 8e8f8d1fef91..cde11ca9d9e4 100644
--- a/sound/soc/codecs/wm8996.c
+++ b/sound/soc/codecs/wm8996.c
@@ -90,6 +90,7 @@ struct wm8996_priv {
         struct snd_soc_jack *jack;
         bool detecting;
         bool jack_mic;
+        int jack_flips;
         wm8996_polarity_fn polarity_cb;
 
 #ifdef CONFIG_GPIOLIB
@@ -2437,6 +2438,7 @@ int wm8996_detect(struct snd_soc_codec *codec, struct snd_soc_jack *jack,
         wm8996->jack = jack;
         wm8996->detecting = true;
         wm8996->polarity_cb = polarity_cb;
+        wm8996->jack_flips = 0;
 
         if (wm8996->polarity_cb)
                 wm8996->polarity_cb(codec, 0);
@@ -2552,6 +2554,19 @@ static void wm8996_hpdet_start(struct snd_soc_codec *codec)
                             WM8996_HP_POLL, WM8996_HP_POLL);
 }
 
+static void wm8996_report_headphone(struct snd_soc_codec *codec)
+{
+        dev_dbg(codec->dev, "Headphone detected\n");
+        wm8996_hpdet_start(codec);
+
+        /* Increase the detection rate a bit for responsiveness. */
+        snd_soc_update_bits(codec, WM8996_MIC_DETECT_1,
+                            WM8996_MICD_RATE_MASK |
+                            WM8996_MICD_BIAS_STARTTIME_MASK,
+                            7 << WM8996_MICD_RATE_SHIFT |
+                            7 << WM8996_MICD_BIAS_STARTTIME_SHIFT);
+}
+
 static void wm8996_micd(struct snd_soc_codec *codec)
 {
         struct wm8996_priv *wm8996 = snd_soc_codec_get_drvdata(codec);
@@ -2571,6 +2586,7 @@ static void wm8996_micd(struct snd_soc_codec *codec)
                 dev_dbg(codec->dev, "Jack removal detected\n");
                 wm8996->jack_mic = false;
                 wm8996->detecting = true;
+                wm8996->jack_flips = 0;
                 snd_soc_jack_report(wm8996->jack, 0,
                                     SND_JACK_LINEOUT | SND_JACK_HEADSET |
                                     SND_JACK_BTN_0);
@@ -2611,9 +2627,17 @@ static void wm8996_micd(struct snd_soc_codec *codec)
         /* If we detected a lower impedence during initial startup
          * then we probably have the wrong polarity, flip it.  Don't
          * do this for the lowest impedences to speed up detection of
-         * plain headphones.
+         * plain headphones.  If both polarities report a low
+         * impedence then give up and report headphones.
          */
         if (wm8996->detecting && (val & 0x3f0)) {
+                wm8996->jack_flips++;
+
+                if (wm8996->jack_flips > 1) {
+                        wm8996_report_headphone(codec);
+                        return;
+                }
+
                 reg = snd_soc_read(codec, WM8996_ACCESSORY_DETECT_MODE_2);
                 reg ^= WM8996_HPOUT1FB_SRC | WM8996_MICD_SRC |
                         WM8996_MICD_BIAS_SRC;
@@ -2640,17 +2664,7 @@ static void wm8996_micd(struct snd_soc_codec *codec)
                         snd_soc_jack_report(wm8996->jack, SND_JACK_BTN_0,
                                             SND_JACK_BTN_0);
                 } else if (wm8996->detecting) {
-                        dev_dbg(codec->dev, "Headphone detected\n");
-                        wm8996_hpdet_start(codec);
-
-                        /* Increase the detection rate a bit for
-                         * responsiveness.
-                         */
-                        snd_soc_update_bits(codec, WM8996_MIC_DETECT_1,
-                                            WM8996_MICD_RATE_MASK |
-                                            WM8996_MICD_BIAS_STARTTIME_MASK,
-                                            7 << WM8996_MICD_RATE_SHIFT |
-                                            7 << WM8996_MICD_BIAS_STARTTIME_SHIFT);
+                        wm8996_report_headphone(codec);
                 }
         }
 }