media: adv7183: Convert to GPIO descriptors

This driver is using two GPIO numbers passed as platform data.

No board file in the kernel defines this however, so we can
just change the mechanism without side effects.

Let's just switch it to use GPIO descriptors and add some
comments on how to provide these.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

drivers/media/i2c/adv7183.c

@@ -7,7 +7,7 @@
 
 #include <linux/delay.h>
 #include <linux/errno.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -28,8 +28,8 @@ struct adv7183 {
 	v4l2_std_id std; /* Current set standard */
 	u32 input;
 	u32 output;
-	unsigned reset_pin;
-	unsigned oe_pin;
+	struct gpio_desc *reset_pin;
+	struct gpio_desc *oe_pin;
 	struct v4l2_mbus_framefmt fmt;
 };
 
@@ -465,9 +465,9 @@ static int adv7183_s_stream(struct v4l2_subdev *sd, int enable)
 	struct adv7183 *decoder = to_adv7183(sd);
 
 	if (enable)
-		gpio_set_value(decoder->oe_pin, 0);
+		gpiod_set_value(decoder->oe_pin, 1);
 	else
-		gpio_set_value(decoder->oe_pin, 1);
+		gpiod_set_value(decoder->oe_pin, 0);
 	udelay(1);
 	return 0;
 }
@@ -531,7 +531,6 @@ static int adv7183_probe(struct i2c_client *client,
 	struct v4l2_subdev_format fmt = {
 		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
 	};
-	const unsigned *pin_array;
 
 	/* Check if the adapter supports the needed features */
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
@@ -540,29 +539,28 @@ static int adv7183_probe(struct i2c_client *client,
 	v4l_info(client, "chip found @ 0x%02x (%s)\n",
 			client->addr << 1, client->adapter->name);
 
-	pin_array = client->dev.platform_data;
-	if (pin_array == NULL)
-		return -EINVAL;
-
 	decoder = devm_kzalloc(&client->dev, sizeof(*decoder), GFP_KERNEL);
 	if (decoder == NULL)
 		return -ENOMEM;
 
-	decoder->reset_pin = pin_array[0];
-	decoder->oe_pin = pin_array[1];
-
-	if (devm_gpio_request_one(&client->dev, decoder->reset_pin,
-				  GPIOF_OUT_INIT_LOW, "ADV7183 Reset")) {
-		v4l_err(client, "failed to request GPIO %d\n", decoder->reset_pin);
-		return -EBUSY;
-	}
-
-	if (devm_gpio_request_one(&client->dev, decoder->oe_pin,
-				  GPIOF_OUT_INIT_HIGH,
-				  "ADV7183 Output Enable")) {
-		v4l_err(client, "failed to request GPIO %d\n", decoder->oe_pin);
-		return -EBUSY;
-	}
+	/*
+	 * Requesting high will assert reset, the line should be
+	 * flagged as active low in descriptor table or machine description.
+	 */
+	decoder->reset_pin = devm_gpiod_get(&client->dev, "reset",
+					    GPIOD_OUT_HIGH);
+	if (IS_ERR(decoder->reset_pin))
+		return PTR_ERR(decoder->reset_pin);
+	gpiod_set_consumer_name(decoder->reset_pin, "ADV7183 Reset");
+	/*
+	 * Requesting low will start with output disabled, the line should be
+	 * flagged as active low in descriptor table or machine description.
+	 */
+	decoder->oe_pin = devm_gpiod_get(&client->dev, "oe",
+					 GPIOD_OUT_LOW);
+	if (IS_ERR(decoder->oe_pin))
+		return PTR_ERR(decoder->oe_pin);
+	gpiod_set_consumer_name(decoder->reset_pin, "ADV7183 Output Enable");
 
 	sd = &decoder->sd;
 	v4l2_i2c_subdev_init(sd, client, &adv7183_ops);
@@ -594,7 +592,8 @@ static int adv7183_probe(struct i2c_client *client,
 	/* reset chip */
 	/* reset pulse width at least 5ms */
 	mdelay(10);
-	gpio_set_value(decoder->reset_pin, 1);
+	/* De-assert reset line (descriptor tagged active low) */
+	gpiod_set_value(decoder->reset_pin, 0);
 	/* wait 5ms before any further i2c writes are performed */
 	mdelay(5);