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From:   =?UTF-8?q?Pawe=C5=82=20Chmiel?= <pawel.mikolaj.chmiel@gmail.com>
To:     nick@shmanahar.org
Cc:     dmitry.torokhov@gmail.com, robh+dt@kernel.org,
        mark.rutland@arm.com, nicolas.ferre@microchip.com,
        alexandre.belloni@bootlin.com, linux-input@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        =?UTF-8?q?Pawe=C5=82=20Chmiel?= <pawel.mikolaj.chmiel@gmail.com>
Subject: [PATCH 1/2] Input: atmel_mxt_ts: Add support for optional regulators.
Date:   Fri, 13 Jul 2018 20:30:07 +0200
Message-Id: <1531506608-24479-2-git-send-email-pawel.mikolaj.chmiel@gmail.com>
In-Reply-To: <1531506608-24479-1-git-send-email-pawel.mikolaj.chmiel@gmail.com>
References: <1531506608-24479-1-git-send-email-pawel.mikolaj.chmiel@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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This patch adds optional regulators, which can be used to power
up touchscreen. After enabling regulators, we need to wait 150msec.
This value is taken from official driver.

It was tested on Samsung Galaxy i9000 (based on Samsung S5PV210 SOC).

Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 45 ++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 54fe190fd4bc..a7625ec8fb9f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -27,6 +27,7 @@
 #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 <linux/property.h>
@@ -198,6 +199,7 @@ enum t100_type {
 #define MXT_RESET_INVALID_CHG	100	/* msec */
 #define MXT_RESET_TIME		200	/* msec */
 #define MXT_RESET_TIMEOUT	3000	/* msec */
+#define MXT_REGULATOR_DELAY	150	/* msec */
 #define MXT_CRC_TIMEOUT		1000	/* msec */
 #define MXT_FW_RESET_TIME	3000	/* msec */
 #define MXT_FW_CHG_TIMEOUT	300	/* msec */
@@ -310,6 +312,8 @@ struct mxt_data {
 	struct t7_config t7_cfg;
 	struct mxt_dbg dbg;
 	struct gpio_desc *reset_gpio;
+	struct regulator *vdd_reg;
+	struct regulator *avdd_reg;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -3076,6 +3080,40 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return error;
 	}
 
+	data->vdd_reg = devm_regulator_get_optional(&client->dev, "vdd");
+	if (IS_ERR(data->vdd_reg)) {
+		error = PTR_ERR(data->vdd_reg);
+		dev_err(&client->dev, "Failed to get vdd regulator: %d\n",
+			error);
+		return error;
+	}
+
+	if (data->vdd_reg) {
+		error = regulator_enable(data->vdd_reg);
+		if (error) {
+			dev_err(&client->dev, "Failed to enable vdd regulator: %d\n",
+				error);
+			return error;
+		}
+	}
+
+	data->avdd_reg = devm_regulator_get_optional(&client->dev, "avdd");
+	if (IS_ERR(data->avdd_reg)) {
+		error = PTR_ERR(data->avdd_reg);
+		dev_err(&client->dev, "Failed to get avdd regulator: %d\n",
+			error);
+		return error;
+	}
+
+	if (data->avdd_reg) {
+		error = regulator_enable(data->avdd_reg);
+		if (error) {
+			dev_err(&client->dev, "Failed to enable avdd regulator: %d\n",
+				error);
+			return error;
+		}
+	}
+
 	error = devm_request_threaded_irq(&client->dev, client->irq,
 					  NULL, mxt_interrupt, IRQF_ONESHOT,
 					  client->name, data);
@@ -3086,6 +3124,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	disable_irq(client->irq);
 
+	if (!IS_ERR(data->vdd_reg) || !IS_ERR(data->avdd_reg))
+		msleep(MXT_REGULATOR_DELAY);
+
 	if (data->reset_gpio) {
 		msleep(MXT_RESET_GPIO_TIME);
 		gpiod_set_value(data->reset_gpio, 1);
@@ -3116,6 +3157,10 @@ static int mxt_remove(struct i2c_client *client)
 	struct mxt_data *data = i2c_get_clientdata(client);
 
 	disable_irq(data->irq);
+	if (!IS_ERR(data->avdd_reg))
+		regulator_disable(data->avdd_reg);
+	if (!IS_ERR(data->vdd_reg))
+		regulator_disable(data->vdd_reg);
 	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
-- 
2.7.4