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>

1 files changed, 25 insertions, 21 deletions

diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
index 7c4ce812d735..a83ca27aa99f 100644
--- 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;