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From:   Mike Looijmans <mike.looijmans@topic.nl>
To:     linux-input@vger.kernel.org, devicetree@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, dmitry.torokhov@gmail.com,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        martink@posteo.de, geert+renesas@glider.be, john@metanate.com,
        hechtb@gmail.com, Mike Looijmans <mike.looijmans@topic.nl>
Subject: [PATCH] Input: st1232 - Support power supply regulators
Date:   Tue, 24 May 2022 10:12:16 +0200
Message-Id: <20220524081216.8550-1-mike.looijmans@topic.nl>
Precedence: bulk

Add support for the VDD and IOVDD power supply inputs. This allows the
chip to share its supplies with other components (e.g. panel) and manage
them.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
 .../input/touchscreen/sitronix,st1232.yaml    |  6 +++
 drivers/input/touchscreen/st1232.c            | 54 ++++++++++++++++---
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml b/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
index 1d8ca19fd37a..240be8d49232 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/sitronix,st1232.yaml
@@ -28,6 +28,12 @@ properties:
     description: A phandle to the reset GPIO
     maxItems: 1
 
+  vdd-supply:
+    description: Power supply regulator for the chip
+
+  vddio-supply:
+    description: Power supply regulator for the I2C bus
+
 required:
   - compatible
   - reg
diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index e38ba3e4f183..d9c9f6f1f11a 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -44,6 +44,11 @@
 #define REG_XY_COORDINATES	0x12
 #define ST_TS_MAX_FINGERS	10
 
+enum st1232_regulators {
+	ST1232_REGULATOR_VDD,
+	ST1232_REGULATOR_IOVDD,
+};
+
 struct st_chip_info {
 	bool	have_z;
 	u16	max_area;
@@ -56,6 +61,7 @@ struct st1232_ts_data {
 	struct touchscreen_properties prop;
 	struct dev_pm_qos_request low_latency_req;
 	struct gpio_desc *reset_gpio;
+	struct regulator_bulk_data regulators[2];
 	const struct st_chip_info *chip_info;
 	int read_buf_len;
 	u8 *read_buf;
@@ -197,17 +203,36 @@ static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
+static int st1232_ts_power_on(struct st1232_ts_data *ts)
+{
+	int err;
+
+	err = regulator_bulk_enable(ARRAY_SIZE(ts->regulators), ts->regulators);
+	if (err)
+		return err;
+
+	usleep_range(5000, 6000);
+
+	if (ts->reset_gpio)
+		gpiod_set_value_cansleep(ts->reset_gpio, 0);
+
+	return 0;
+}
+
+static void st1232_ts_power_off(struct st1232_ts_data *ts)
 {
 	if (ts->reset_gpio)
-		gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
+		gpiod_set_value_cansleep(ts->reset_gpio, 1);
+	usleep_range(100, 150);
+	regulator_bulk_disable(ARRAY_SIZE(ts->regulators), ts->regulators);
 }
 
-static void st1232_ts_power_off(void *data)
+static void st1232_ts_power_off_action(void *data)
 {
-	st1232_ts_power(data, false);
+	st1232_ts_power_off(data);
 }
 
+
 static const struct st_chip_info st1232_chip_info = {
 	.have_z		= true,
 	.max_area	= 0xff,
@@ -266,6 +291,14 @@ static int st1232_ts_probe(struct i2c_client *client,
 	ts->client = client;
 	ts->input_dev = input_dev;
 
+	ts->regulators[ST1232_REGULATOR_VDD].supply = "vdd";
+	ts->regulators[ST1232_REGULATOR_IOVDD].supply = "iovdd";
+	error = devm_regulator_bulk_get(&client->dev,
+					ARRAY_SIZE(ts->regulators),
+					ts->regulators);
+	if (error)
+		return error;
+
 	ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
 						 GPIOD_OUT_HIGH);
 	if (IS_ERR(ts->reset_gpio)) {
@@ -275,9 +308,14 @@ static int st1232_ts_probe(struct i2c_client *client,
 		return error;
 	}
 
-	st1232_ts_power(ts, true);
+	error = st1232_ts_power_on(ts);
+	if (error) {
+		dev_err(&client->dev, "Failed to power on: %d\n", error);
+		return error;
+	}
 
-	error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
+	error = devm_add_action_or_reset(&client->dev,
+					 st1232_ts_power_off_action, ts);
 	if (error) {
 		dev_err(&client->dev,
 			"Failed to install power off action: %d\n", error);
@@ -348,7 +386,7 @@ static int __maybe_unused st1232_ts_suspend(struct device *dev)
 	disable_irq(client->irq);
 
 	if (!device_may_wakeup(&client->dev))
-		st1232_ts_power(ts, false);
+		st1232_ts_power_off(ts);
 
 	return 0;
 }
@@ -359,7 +397,7 @@ static int __maybe_unused st1232_ts_resume(struct device *dev)
 	struct st1232_ts_data *ts = i2c_get_clientdata(client);
 
 	if (!device_may_wakeup(&client->dev))
-		st1232_ts_power(ts, true);
+		st1232_ts_power_on(ts);
 
 	enable_irq(client->irq);
 
-- 
2.17.1