Input: pixcir_i2c - add support for wake and enable gpios

On some devices the wake and enable pins of the pixcir touchscreen
controller are connected to gpios and these must be controlled by the
driver for the device to operate properly.

Signed-off-by: Sander Vermin <sander@vermin.nl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Documentation/devicetree/bindings/input/touchscreen/pixcir_i2c_ts.txt

@@ -9,7 +9,9 @@ Required properties:
 - touchscreen-size-y: vertical resolution of touchscreen (in pixels)
 
 Optional properties:
-- reset-gpio: GPIO connected to the RESET line of the chip
+- reset-gpios: GPIO connected to the RESET line of the chip
+- enable-gpios: GPIO connected to the ENABLE line of the chip
+- wake-gpios: GPIO connected to the WAKE line of the chip
 
 Example:
 

drivers/input/touchscreen/pixcir_i2c_ts.c

@@ -38,6 +38,8 @@ struct pixcir_i2c_ts_data {
 	struct input_dev *input;
 	struct gpio_desc *gpio_attb;
 	struct gpio_desc *gpio_reset;
+	struct gpio_desc *gpio_enable;
+	struct gpio_desc *gpio_wake;
 	const struct pixcir_i2c_chip_data *chip;
 	int max_fingers;	/* Max fingers supported in this instance */
 	bool running;
@@ -208,6 +210,11 @@ static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 	struct device *dev = &ts->client->dev;
 	int ret;
 
+	if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
+		if (ts->gpio_wake)
+			gpiod_set_value_cansleep(ts->gpio_wake, 1);
+	}
+
 	ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
 	if (ret < 0) {
 		dev_err(dev, "%s: can't read reg 0x%x : %d\n",
@@ -228,6 +235,11 @@ static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
 		return ret;
 	}
 
+	if (mode == PIXCIR_POWER_HALT) {
+		if (ts->gpio_wake)
+			gpiod_set_value_cansleep(ts->gpio_wake, 0);
+	}
+
 	return 0;
 }
 
@@ -302,6 +314,11 @@ static int pixcir_start(struct pixcir_i2c_ts_data *ts)
 	struct device *dev = &ts->client->dev;
 	int error;
 
+	if (ts->gpio_enable) {
+		gpiod_set_value_cansleep(ts->gpio_enable, 1);
+		msleep(100);
+	}
+
 	/* LEVEL_TOUCH interrupt with active low polarity */
 	error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
 	if (error) {
@@ -343,6 +360,9 @@ static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
 	/* Wait till running ISR is complete */
 	synchronize_irq(ts->client->irq);
 
+	if (ts->gpio_enable)
+		gpiod_set_value_cansleep(ts->gpio_enable, 0);
+
 	return 0;
 }
 
@@ -534,6 +554,27 @@ static int pixcir_i2c_ts_probe(struct i2c_client *client,
 		return error;
 	}
 
+	tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(tsdata->gpio_wake)) {
+		error = PTR_ERR(tsdata->gpio_wake);
+		if (error != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get wake gpio: %d\n", error);
+		return error;
+	}
+
+	tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
+						      GPIOD_OUT_HIGH);
+	if (IS_ERR(tsdata->gpio_enable)) {
+		error = PTR_ERR(tsdata->gpio_enable);
+		if (error != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get enable gpio: %d\n", error);
+		return error;
+	}
+
+	if (tsdata->gpio_enable)
+		msleep(100);
+
 	error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
 					  IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 					  client->name, tsdata);