extcon: arizona: Simplify HPDET based identification

Rather than measuring both HP channels we can simply directly measure the
microphone impedance and then rely on MICDET for final confirmation of the
presence of a suitable microphone. This improves the overall performance
of the identification process.

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

diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
index 7c4ce812d73547ae076f7a28c73909b405e73f41..a83ca27aa99f254161ea1d76f9641708377ce061 100644 (file)
--- a/drivers/extcon/extcon-arizona.c
+++ b/drivers/extcon/extcon-arizona.c
@@ -459,7 +459,8 @@ static int arizona_hpdet_read(struct arizona_extcon_info *info)
        return val;
 }
 
-static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
+static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading,
+                              bool *mic)
 {
        struct arizona *arizona = info->arizona;
        int id_gpio = arizona->pdata.hpdet_id_gpio;
@@ -470,11 +471,9 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
         */
        if (arizona->pdata.hpdet_acc_id) {
                info->hpdet_res[info->num_hpdet_res++] = *reading;
-               info->hpdet_res[info->num_hpdet_res++] = *reading;
 
                /* Only check the mic directly if we didn't already ID it */
-               if (id_gpio && info->num_hpdet_res == 2 &&
-                   !((info->hpdet_res[0] > info->hpdet_res[1] * 2))) {
+               if (id_gpio && info->num_hpdet_res == 1) {
                        dev_dbg(arizona->dev, "Measuring mic\n");
 
                        regmap_update_bits(arizona->regmap,
@@ -493,10 +492,8 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
                }
 
                /* OK, got both.  Now, compare... */
-               dev_dbg(arizona->dev, "HPDET measured %d %d %d\n",
-                       info->hpdet_res[0], info->hpdet_res[1],
-                       info->hpdet_res[2]);
-
+               dev_dbg(arizona->dev, "HPDET measured %d %d\n",
+                       info->hpdet_res[0], info->hpdet_res[1]);
 
                /* Take the headphone impedance for the main report */
                *reading = info->hpdet_res[0];
@@ -512,13 +509,11 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
                }
 
                /*
-                * Either the two grounds measure differently or we
-                * measure the mic as high impedance.
+                * If we measure the mic as 
                 */
-               if ((info->hpdet_res[0] > info->hpdet_res[1] * 2) ||
-                   (id_gpio && info->hpdet_res[2] > 1257)) {
+               if (!id_gpio || info->hpdet_res[1] > 50) {
                        dev_dbg(arizona->dev, "Detected mic\n");
-                       info->mic = true;
+                       *mic = true;
                        info->detecting = true;
                } else {
                        dev_dbg(arizona->dev, "Detected headphone\n");
@@ -541,6 +536,7 @@ static irqreturn_t arizona_hpdet_irq(int irq, void *data)
        int id_gpio = arizona->pdata.hpdet_id_gpio;
        int report = ARIZONA_CABLE_HEADPHONE;
        int ret, reading;
+       bool mic = false;
 
        mutex_lock(&info->lock);
 
@@ -576,7 +572,7 @@ static irqreturn_t arizona_hpdet_irq(int irq, void *data)
                           ARIZONA_HP_IMPEDANCE_RANGE_MASK | ARIZONA_HP_POLL,
                           0);
 
-       ret = arizona_hpdet_do_id(info, &reading);
+       ret = arizona_hpdet_do_id(info, &reading, &mic);
        if (ret == -EAGAIN) {
                goto out;
        } else if (ret < 0) {
@@ -606,7 +602,7 @@ done:
                           ARIZONA_ACCDET_MODE_MASK, ARIZONA_ACCDET_MODE_MIC);
 
        /* If we have a mic then reenable MICDET */
-       if (info->mic)
+       if (mic || info->mic)
                arizona_start_mic(info);
 
        if (info->hpdet_active) {
@@ -681,6 +677,8 @@ err:
 static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info)
 {
        struct arizona *arizona = info->arizona;
+       int hp_reading = 32;
+       bool mic;
        int ret;
 
        dev_dbg(arizona->dev, "Starting identification via HPDET\n");
@@ -702,12 +700,18 @@ static void arizona_start_hpdet_acc_id(struct arizona_extcon_info *info)
                goto err;
        }
 
-       ret = regmap_update_bits(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1,
-                                ARIZONA_HP_POLL, ARIZONA_HP_POLL);
-       if (ret != 0) {
-               dev_err(arizona->dev, "Can't start HPDETL measurement: %d\n",
-                       ret);
-               goto err;
+       if (arizona->pdata.hpdet_acc_id_line) {
+               ret = regmap_update_bits(arizona->regmap,
+                                        ARIZONA_HEADPHONE_DETECT_1,
+                                        ARIZONA_HP_POLL, ARIZONA_HP_POLL);
+               if (ret != 0) {
+                       dev_err(arizona->dev,
+                               "Can't start HPDETL measurement: %d\n",
+                               ret);
+                       goto err;
+               }
+       } else {
+               arizona_hpdet_do_id(info, &hp_reading, &mic);
        }
 
        return;

diff --git a/include/linux/mfd/arizona/pdata.h b/include/linux/mfd/arizona/pdata.h
index 008b8c40549f05f3c7900e014bc2014c73c3ffca..45c84777c624fcd4893eb73d2c93e89d5d4ddae2 100644 (file)
--- a/include/linux/mfd/arizona/pdata.h
+++ b/include/linux/mfd/arizona/pdata.h
@@ -128,6 +128,9 @@ struct arizona_pdata {
        /** Use the headphone detect circuit to identify the accessory */
        bool hpdet_acc_id;
 
+       /** Check for line output with HPDET method */
+       bool hpdet_acc_id_line;
+
        /** GPIO used for mic isolation with HPDET */
        int hpdet_id_gpio;