Re: [PATCH] input: touchscreen: silead: Add regulator support

On some tablets the touchscreen controller is powered by seperate
regulators, add support for this.

Signed-off-by: Hans de Goede <redacted>
---
 .../bindings/input/touchscreen/silead_gsl1680.txt  |  2 +
 drivers/input/touchscreen/silead.c                 | 51 ++++++++++++++++++++--
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
index 37a9370..65eb4c7 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt

@@ -22,6 +22,8 @@ Optional properties:
 - touchscreen-inverted-y  : See touchscreen.txt
 - touchscreen-swapped-x-y : See touchscreen.txt
 - silead,max-fingers	  : maximum number of fingers the touchscreen can detect
+- vddio-supply		  : regulator phandle for controller VDDIO
+- avdd-supply		  : regulator phandle for controller AVDD
 
 Example:
 

diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
index 7379fe1..04992c5 100644
--- a/drivers/input/touchscreen/silead.c
+++ b/drivers/input/touchscreen/silead.c

@@ -29,6 +29,7 @@
 #include <linux/input/touchscreen.h>
 #include <linux/pm.h>
 #include <linux/irq.h>
+#include <linux/regulator/consumer.h>
 
 #include <asm/unaligned.h>
 

@@ -72,6 +73,8 @@ enum silead_ts_power {
 struct silead_ts_data {
 	struct i2c_client *client;
 	struct gpio_desc *gpio_power;
+	struct regulator *vddio;
+	struct regulator *avdd;
 	struct input_dev *input;
 	char fw_name[64];
 	struct touchscreen_properties prop;

@@ -463,21 +466,52 @@ static int silead_ts_probe(struct i2c_client *client,
 	if (client->irq <= 0)
 		return -ENODEV;
 
+	data->vddio = devm_regulator_get_optional(dev, "vddio");

+	if (IS_ERR(data->vddio)) {
+		if (PTR_ERR(data->vddio) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		data->vddio = NULL;
+	}
+
+	data->avdd = devm_regulator_get_optional(dev, "avdd");
+	if (IS_ERR(data->avdd)) {
+		if (PTR_ERR(data->avdd) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		data->avdd = NULL;
+	}
+
+	/*
+	 * Enable regulators at probe and disable them at remove, we need
+	 * to keep the chip powered otherwise it forgets its firmware.
+	 */
+	if (data->vddio) {
+		error = regulator_enable(data->vddio);
+		if (error)
+			return error;
+	}
+
+	if (data->avdd) {
+		error = regulator_enable(data->avdd);
+		if (error)
+			goto disable_vddio;
+	}