[PATCH v2 0/2] Add reset-gpios handling for max98927

The max98927 codec on some devices (i.e. Xiaomi Mi A2 Lite phone) require
hardware-resetting the codec by driving a reset-gpio. This series add
support for it through an optional reset-gpios property.

Alejandro Tafalla (2):
  ASoC: max98927: Handle reset gpio when probing i2c
  dt-bindings: sound: max98927: Add reset-gpios optional property

 .../devicetree/bindings/sound/max9892x.txt        |  3 +++
 sound/soc/codecs/max98927.c                       | 15 +++++++++++++++
 2 files changed, 18 insertions(+)

-- 
2.32.0

Drive the reset gpio if defined in the DTS node.

Signed-off-by: Alejandro Tafalla <redacted>
---
 sound/soc/codecs/max98927.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sound/soc/codecs/max98927.c b/sound/soc/codecs/max98927.c
index 8b206ee77709..84a159de4b26 100644
--- a/sound/soc/codecs/max98927.c
+++ b/sound/soc/codecs/max98927.c

@@ -868,6 +868,7 @@ static int max98927_i2c_probe(struct i2c_client *i2c,
 	int ret = 0, value;
 	int reg = 0;
 	struct max98927_priv *max98927 = NULL;
+	struct gpio_desc *reset_gpio;
 
 	max98927 = devm_kzalloc(&i2c->dev,
 		sizeof(*max98927), GFP_KERNEL);

@@ -898,6 +899,20 @@ static int max98927_i2c_probe(struct i2c_client *i2c,
 		return ret;
 	}
 
+	reset_gpio
+		= devm_gpiod_get_optional(&i2c->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(reset_gpio)) {
+		ret = PTR_ERR(reset_gpio);
+		return dev_err_probe(&i2c->dev, ret,
+			"failed to request GPIO reset pin");
+	}
+
+	if (reset_gpio) {
+		usleep_range(8000, 10000);
+		gpiod_set_value_cansleep(reset_gpio, 1);
+		usleep_range(1000, 5000);
+	}
+
 	/* Check Revision ID */
 	ret = regmap_read(max98927->regmap,
 		MAX98927_R01FF_REV_ID, &reg);

-- 
2.32.0

Add the reset-gpios as an optional property because some devices might
not need it to work properly.

Signed-off-by: Alejandro Tafalla <redacted>
---
 Documentation/devicetree/bindings/sound/max9892x.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/sound/max9892x.txt b/Documentation/devicetree/bindings/sound/max9892x.txt
index f6171591ddc6..98cb9ba5b328 100644
--- a/Documentation/devicetree/bindings/sound/max9892x.txt
+++ b/Documentation/devicetree/bindings/sound/max9892x.txt

@@ -30,6 +30,9 @@ Required properties:
 
   - reg : the I2C address of the device for I2C
 
+Optional properties:
+  - reset-gpios : GPIO to reset the device
+
 Example:
 
 codec: max98927@3a {

-- 
2.32.0

On Mon, Aug 30, 2021 at 1:48 PM Alejandro Tafalla [off-list ref] wrote:

Drive the reset gpio if defined in the DTS node.

...

+       reset_gpio
+               = devm_gpiod_get_optional(&i2c->dev, "reset", GPIOD_OUT_LOW);

A bit of a strange indentation, shouldn't it be one line?

+       if (IS_ERR(reset_gpio)) {

It simply as

               return dev_err_probe(&i2c->dev, PTR_ERR(reset_gpio),
                       "failed to request GPIO reset pin");

+       }

-- 
With Best Regards,
Andy Shevchenko

On Mon, 30 Aug 2021 12:44:24 +0200, Alejandro Tafalla wrote:

Add the reset-gpios as an optional property because some devices might
not need it to work properly.

Signed-off-by: Alejandro Tafalla <redacted>
---
 Documentation/devicetree/bindings/sound/max9892x.txt | 3 +++
 1 file changed, 3 insertions(+)

Acked-by: Rob Herring <robh@kernel.org>

On lunes, 30 de agosto de 2021 12:56:23 (CEST) Andy Shevchenko wrote:

It simply as

               return dev_err_probe(&i2c->dev, PTR_ERR(reset_gpio),
                       "failed to request GPIO reset pin");

quoted

+       }

Alright, I'll make that change. Thank you.