extcon: arizona: Support direct microphone measurement via HPDET

With some GPIO control it is possible to detect microphones in a wider
range of configurations by directly measuring the microphone impedance
when the HPDET method cannot distinguish between the behaviour of the
two grounds. Allow a GPIO to be provided in platform data and use it to
implement this behaviour.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
index ba9525ee4706216d41008ee49c9163e002821624..de141f72c8e5cce51e2ca9b24dd626cc87a49fb1 100644 (file)
--- a/drivers/extcon/extcon-arizona.c
+++ b/drivers/extcon/extcon-arizona.c
@@ -56,7 +56,7 @@ struct arizona_extcon_info {
        bool hpdet_active;
 
        int num_hpdet_res;
-       unsigned int hpdet_res[2];
+       unsigned int hpdet_res[3];
 
        bool mic;
        bool detecting;
@@ -313,6 +313,7 @@ static int arizona_hpdet_read(struct arizona_extcon_info *info)
 static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
 {
        struct arizona *arizona = info->arizona;
+       int id_gpio = arizona->pdata.hpdet_id_gpio;
        int ret;
 
        /*
@@ -338,9 +339,27 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading)
                                           ARIZONA_ACCESSORY_DETECT_MODE_1,
                                           ARIZONA_ACCDET_SRC,
                                           ~info->micd_modes[0].src);
+
                        regmap_update_bits(arizona->regmap,
                                           ARIZONA_HEADPHONE_DETECT_1,
-                                          ARIZONA_HP_POLL, 0);
+                                          ARIZONA_HP_POLL, ARIZONA_HP_POLL);
+                       return -EAGAIN;
+               }
+
+               /* 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))) {
+                       dev_dbg(arizona->dev, "Measuring mic\n");
+
+                       regmap_update_bits(arizona->regmap,
+                                          ARIZONA_ACCESSORY_DETECT_MODE_1,
+                                          ARIZONA_ACCDET_MODE_MASK |
+                                          ARIZONA_ACCDET_SRC,
+                                          ARIZONA_ACCDET_MODE_HPR |
+                                          info->micd_modes[0].src);
+
+                       gpio_set_value_cansleep(id_gpio, 1);
+
                        regmap_update_bits(arizona->regmap,
                                           ARIZONA_HEADPHONE_DETECT_1,
                                           ARIZONA_HP_POLL, ARIZONA_HP_POLL);
@@ -348,10 +367,16 @@ 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\n",
-                       info->hpdet_res[0], info->hpdet_res[1]);
+               dev_dbg(arizona->dev, "HPDET measured %d %d %d\n",
+                       info->hpdet_res[0], info->hpdet_res[1],
+                       info->hpdet_res[2]);
 
-               if (info->hpdet_res[0] > info->hpdet_res[1] * 2) {
+               /*
+                * Either the two grounds measure differently or we
+                * measure the mic as high impedance.
+                */
+               if ((info->hpdet_res[0] > info->hpdet_res[1] * 2) ||
+                   (id_gpio && info->hpdet_res[2] > 10)) {
                        dev_dbg(arizona->dev, "Detected mic\n");
                        info->mic = true;
                        ret = extcon_set_cable_state_(&info->edev,
@@ -382,6 +407,7 @@ static irqreturn_t arizona_hpdet_irq(int irq, void *data)
 {
        struct arizona_extcon_info *info = data;
        struct arizona *arizona = info->arizona;
+       int id_gpio = arizona->pdata.hpdet_id_gpio;
        int report = ARIZONA_CABLE_HEADPHONE;
        int ret, reading;
 
@@ -446,6 +472,8 @@ static irqreturn_t arizona_hpdet_irq(int irq, void *data)
                dev_warn(arizona->dev, "Failed to undo magic: %d\n", ret);
 
 done:
+       if (id_gpio)
+               gpio_set_value_cansleep(id_gpio, 0);
 
        /* Revert back to MICDET mode */
        regmap_update_bits(arizona->regmap,
@@ -854,6 +882,18 @@ static int arizona_extcon_probe(struct platform_device *pdev)
                }
        }
 
+       if (arizona->pdata.hpdet_id_gpio > 0) {
+               ret = devm_gpio_request_one(&pdev->dev,
+                                           arizona->pdata.hpdet_id_gpio,
+                                           GPIOF_OUT_INIT_LOW,
+                                           "HPDET");
+               if (ret != 0) {
+                       dev_err(arizona->dev, "Failed to request GPIO%d: %d\n",
+                               arizona->pdata.hpdet_id_gpio, ret);
+                       goto err_register;
+               }
+       }
+
        if (arizona->pdata.micd_bias_start_time)
                regmap_update_bits(arizona->regmap, ARIZONA_MIC_DETECT_1,
                                   ARIZONA_MICD_BIAS_STARTTIME_MASK,

diff --git a/include/linux/mfd/arizona/pdata.h b/include/linux/mfd/arizona/pdata.h
index 7c0878778357cff5665f5ad78c6e1d2a476f1308..bcbe4fda87cb9465442827146c645d7e3b09ef12 100644 (file)
--- a/include/linux/mfd/arizona/pdata.h
+++ b/include/linux/mfd/arizona/pdata.h
@@ -102,6 +102,9 @@ struct arizona_pdata {
        /** Use the headphone detect circuit to identify the accessory */
        bool hpdet_acc_id;
 
+       /** GPIO used for mic isolation with HPDET */
+       int hpdet_id_gpio;
+
        /** GPIO for mic detection polarity */
        int micd_pol_gpio;