linux-kernel - [PATCH 2/2] input: atmel_mxt_ts: Add support for optional regulator

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Date:   Sun, 15 Mar 2020 11:04:16 +0100
From:   Paul Cercueil <paul@...pouillou.net>
To:     Nick Dyer <nick@...anahar.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>
Cc:     linux-input@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH 2/2] input: atmel_mxt_ts: Add support for optional regulator

Add support for an optional "vdd" regulator, as some platforms require a
regulator to be enabled for the touchscreen to be enabled.

Signed-off-by: Paul Cercueil <paul@...pouillou.net>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 25 +++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index ae60442efda0..b3511dad475a 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -22,6 +22,7 @@
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/property.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/gpio/consumer.h>
 #include <asm/unaligned.h>
@@ -308,6 +309,7 @@ struct mxt_data {
 	struct t7_config t7_cfg;
 	struct mxt_dbg dbg;
 	struct gpio_desc *reset_gpio;
+	struct regulator *vdd;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -3103,6 +3105,22 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	disable_irq(client->irq);
 
+	data->vdd = devm_regulator_get_optional(&client->dev, "vdd");
+	if (IS_ERR(data->vdd)) {
+		error = PTR_ERR(data->vdd);
+		dev_err(&client->dev, "Failed to get regulator: %d\n", error);
+		return error;
+	}
+
+	if (data->vdd) {
+		error = regulator_enable(data->vdd);
+		if (error) {
+			dev_err(&client->dev,
+				"Failed to enable regulator: %d\n", error);
+			return error;
+		}
+	}
+
 	if (data->reset_gpio) {
 		msleep(MXT_RESET_GPIO_TIME);
 		gpiod_set_value(data->reset_gpio, 1);
@@ -3111,7 +3129,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	error = mxt_initialize(data);
 	if (error)
-		return error;
+		goto err_disable_regulator;
 
 	error = sysfs_create_group(&client->dev.kobj, &mxt_attr_group);
 	if (error) {
@@ -3125,6 +3143,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 err_free_object:
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
+err_disable_regulator:
+	if (data->vdd)
+		regulator_disable(data->vdd);
 	return error;
 }
 
@@ -3136,6 +3157,8 @@ static int mxt_remove(struct i2c_client *client)
 	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
+	if (data->vdd)
+		regulator_disable(data->vdd);
 
 	return 0;
 }
-- 
2.25.1