ASoC: Add WM8958 microphone detection support

The WM8958 contains an advanced accessory detection feature which allows
detection of up to seven different impedence levels on the microphone
bias output, including detection of video outputs. Since some of the
more involved accessory interfaces may involve noticable interactions
with external components a simple detection scheme is provided by
default with the option to provide custom handling of accessory detect.

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

1 files changed, 150 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c
index b30b2dd3f1f4..948677b581b1 100644
--- a/sound/soc/codecs/wm8994.c
+++ b/sound/soc/codecs/wm8994.c
@@ -21,6 +21,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <sound/core.h>
+#include <sound/jack.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
@@ -95,6 +96,11 @@ struct wm8994_priv {
 
         struct wm8994_micdet micdet[2];
 
+        wm8958_micdet_cb jack_cb;
+        void *jack_cb_data;
+        bool jack_is_mic;
+        bool jack_is_video;
+
         int revision;
         struct wm8994_pdata *pdata;
 };
@@ -140,6 +146,7 @@ static int wm8994_volatile(unsigned int reg)
         case WM8994_LDO_1:
         case WM8994_LDO_2:
         case WM8958_DSP2_EXECCONTROL:
+        case WM8958_MIC_DETECT_3:
                 return 1;
         default:
                 return 0;
@@ -2633,6 +2640,133 @@ static irqreturn_t wm8994_mic_irq(int irq, void *data)
         return IRQ_HANDLED;
 }
 
+/* Default microphone detection handler for WM8958 - the user can
+ * override this if they wish.
+ */
+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)) {
+                wm8994->jack_is_video = false;
+                wm8994->jack_is_mic = false;
+                goto done;
+        }
+
+        /* Assume anything over 475 ohms is a microphone and remember
+         * that we've seen one (since buttons override it) */
+        if (status & 0x600)
+                wm8994->jack_is_mic = true;
+        if (wm8994->jack_is_mic)
+                report |= SND_JACK_MICROPHONE;
+
+        /* Video has an impedence of approximately 75 ohms; assume
+         * this isn't used as a button and remember it since buttons
+         * override it. */
+        if (status & 0x40)
+                wm8994->jack_is_video = true;
+        if (wm8994->jack_is_video)
+                report |= SND_JACK_VIDEOOUT;
+
+        /* Everything else is buttons; just assign slots */
+        if (status & 0x4)
+                report |= SND_JACK_BTN_0;
+        if (status & 0x8)
+                report |= SND_JACK_BTN_1;
+        if (status & 0x10)
+                report |= SND_JACK_BTN_2;
+        if (status & 0x20)
+                report |= SND_JACK_BTN_3;
+        if (status & 0x80)
+                report |= SND_JACK_BTN_4;
+        if (status & 0x100)
+                report |= SND_JACK_BTN_5;
+
+done:
+        snd_soc_jack_report(wm8994->micdet[0].jack,
+                            SND_JACK_BTN_0 | SND_JACK_BTN_1 | SND_JACK_BTN_2 |
+                            SND_JACK_BTN_3 | SND_JACK_BTN_4 | SND_JACK_BTN_5 |
+                            SND_JACK_MICROPHONE | SND_JACK_VIDEOOUT,
+                            report);
+}
+
+/**
+ * wm8958_mic_detect - Enable microphone detection via the WM8958 IRQ
+ *
+ * @codec:   WM8958 codec
+ * @jack:    jack to report detection events on
+ *
+ * Enable microphone detection functionality for the WM8958.  By
+ * default simple detection which supports the detection of up to 6
+ * buttons plus video and microphone functionality is supported.
+ *
+ * The WM8958 has an advanced jack detection facility which is able to
+ * support complex accessory detection, especially when used in
+ * conjunction with external circuitry.  In order to provide maximum
+ * flexiblity a callback is provided which allows a completely custom
+ * detection algorithm.
+ */
+int wm8958_mic_detect(struct snd_soc_codec *codec, struct snd_soc_jack *jack,
+                      wm8958_micdet_cb cb, void *cb_data)
+{
+        struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
+        struct wm8994 *control = codec->control_data;
+
+        if (control->type != WM8958)
+                return -EINVAL;
+
+        if (jack) {
+                if (!cb) {
+                        dev_dbg(codec->dev, "Using default micdet callback\n");
+                        cb = wm8958_default_micdet;
+                        cb_data = codec;
+                }
+
+                wm8994->micdet[0].jack = jack;
+                wm8994->jack_cb = cb;
+                wm8994->jack_cb_data = cb_data;
+
+                snd_soc_update_bits(codec, WM8958_MIC_DETECT_1,
+                                    WM8958_MICD_ENA, WM8958_MICD_ENA);
+        } else {
+                snd_soc_update_bits(codec, WM8958_MIC_DETECT_1,
+                                    WM8958_MICD_ENA, 0);
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(wm8958_mic_detect);
+
+static irqreturn_t wm8958_mic_irq(int irq, void *data)
+{
+        struct wm8994_priv *wm8994 = data;
+        struct snd_soc_codec *codec = wm8994->codec;
+        int reg;
+
+        reg = snd_soc_read(codec, WM8958_MIC_DETECT_3);
+        if (reg < 0) {
+                dev_err(codec->dev, "Failed to read mic detect status: %d\n",
+                        reg);
+                return IRQ_NONE;
+        }
+
+        if (!(reg & WM8958_MICD_VALID)) {
+                dev_dbg(codec->dev, "Mic detect data not valid\n");
+                goto out;
+        }
+
+        if (wm8994->jack_cb)
+                wm8994->jack_cb(reg, wm8994->jack_cb_data);
+        else
+                dev_warn(codec->dev, "Accessory detection with no callback\n");
+
+out:
+        return IRQ_HANDLED;
+}
+
 static int wm8994_codec_probe(struct snd_soc_codec *codec)
 {
         struct wm8994 *control;
@@ -2732,6 +2866,17 @@ static int wm8994_codec_probe(struct snd_soc_codec *codec)
                                  "Failed to request Mic2 short IRQ: %d\n",
                                  ret);
                 break;
+
+        case WM8958:
+                ret = wm8994_request_irq(codec->control_data,
+                                         WM8994_IRQ_MIC1_DET,
+                                         wm8958_mic_irq, "Mic detect",
+                                         wm8994);
+                if (ret != 0)
+                        dev_warn(codec->dev,
+                                 "Failed to request Mic detect IRQ: %d\n",
+                                 ret);
+                break;
         }
 
         /* Remember if AIFnLRCLK is configured as a GPIO.  This should be
@@ -2866,6 +3011,11 @@ static int  wm8994_codec_remove(struct snd_soc_codec *codec)
                 wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_DET,
                                 wm8994);
                 break;
+
+        case WM8958:
+                wm8994_free_irq(codec->control_data, WM8994_IRQ_MIC1_DET,
+                                wm8994);
+                break;
         }
         kfree(wm8994->retune_mobile_texts);
         kfree(wm8994->drc_texts);