[PATCH v4 2/4] Input: goodix - Add AVDD28-supply regulator support

[Jagan Teki <jagan@amarulasolutions.com>]

Goodix CTP controllers have AVDD28 pin connected to voltage
regulator which may not be turned on by default, like for GT5663.

Add support for such ctp used boards by adding voltage regulator
handling code to goodix ctp driver.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/input/touchscreen/goodix.c | 44 ++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index f2d9c2c41885..e92b90be1ac2 100644
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -27,6 +27,7 @@
 #include <linux/delay.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/of.h>
@@ -47,6 +48,7 @@ struct goodix_ts_data {
 	struct touchscreen_properties prop;
 	unsigned int max_touch_num;
 	unsigned int int_trigger_type;
+	struct regulator *avdd28;
 	struct gpio_desc *gpiod_int;
 	struct gpio_desc *gpiod_rst;
 	u16 id;
@@ -761,6 +763,13 @@ static void goodix_config_cb(const struct firmware *cfg, void *ctx)
 	complete_all(&ts->firmware_loading_complete);
 }
 
+static void goodix_disable_regulator(void *arg)
+{
+	struct goodix_ts_data *ts = arg;
+
+	regulator_disable(ts->avdd28);
+}
+
 static int goodix_ts_probe(struct i2c_client *client,
 			   const struct i2c_device_id *id)
 {
@@ -786,25 +795,46 @@ static int goodix_ts_probe(struct i2c_client *client,
 	if (error)
 		return error;
 
+	ts->avdd28 = devm_regulator_get(&client->dev, "AVDD28");
+	if (IS_ERR(ts->avdd28)) {
+		error = PTR_ERR(ts->avdd28);
+		if (error != -EPROBE_DEFER)
+			dev_err(&client->dev,
+				"Failed to get AVDD28 regulator: %d\n", error);
+		return error;
+	}
+
+	/* power the controller */
+	error = regulator_enable(ts->avdd28);
+	if (error) {
+		dev_err(&client->dev, "Controller fail to enable AVDD28\n");
+		return error;
+	}
+
+	error = devm_add_action_or_reset(&client->dev,
+					 goodix_disable_regulator, ts);
+	if (error)
+		return error;
+
 	if (ts->gpiod_int && ts->gpiod_rst) {
 		/* reset the controller */
 		error = goodix_reset(ts);
 		if (error) {
 			dev_err(&client->dev, "Controller reset failed.\n");
-			return error;
+			goto error;
 		}
 	}
 
 	error = goodix_i2c_test(client);
 	if (error) {
 		dev_err(&client->dev, "I2C communication failure: %d\n", error);
-		return error;
+		goto error;
 	}
 
 	error = goodix_read_version(ts);
 	if (error) {
 		dev_err(&client->dev, "Read version failed.\n");
-		return error;
+		goto error;
 	}
 
 	ts->chip = goodix_get_chip_data(ts->id);
@@ -823,17 +853,21 @@ static int goodix_ts_probe(struct i2c_client *client,
 			dev_err(&client->dev,
 				"Failed to invoke firmware loader: %d\n",
 				error);
-			return error;
+			goto error;
 		}
 
 		return 0;
 	} else {
 		error = goodix_configure_dev(ts);
 		if (error)
-			return error;
+			goto error;
 	}
 
 	return 0;
+
+error:
+	regulator_disable(ts->avdd28);
+	return error;
 }
 
 static int goodix_ts_remove(struct i2c_client *client)
-- 
2.18.0.321.gffc6fa0e3