[media] media: adv7180: add power pin control

Some targets control the ADV7180 power pin via a gpio, so add
optional support for "powerdown" pin control.

Signed-off-by: Steve Longerbeam <[e-mail]>
Tested-by: Tim Harvey <[e-mail]>
Acked-by: Lars-Peter Clausen <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

Documentation/devicetree/bindings/media/i2c/adv7180.txt

···
 		"adi,adv7282"
 		"adi,adv7282-m"
 
+Optional Properties :
+- powerdown-gpios: reference to the GPIO connected to the powerdown pin,
+  if any.
+
+
 Example:
 
 	i2c0@1c22000 {

drivers/media/i2c/Kconfig

···
 
 config VIDEO_ADV7180
 	tristate "Analog Devices ADV7180 decoder"
-	depends on VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API
+	depends on GPIOLIB && VIDEO_V4L2 && I2C && VIDEO_V4L2_SUBDEV_API
 	---help---
 	  Support for the Analog Devices ADV7180 video decoder.
 

drivers/media/i2c/adv7180.c

···
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/of.h>
+#include <linux/gpio/consumer.h>
 #include <linux/videodev2.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-event.h>
···
 	struct media_pad	pad;
 	struct mutex		mutex; /* mutual excl. when accessing chip */
 	int			irq;
+	struct gpio_desc	*pwdn_gpio;
 	v4l2_std_id		curr_norm;
 	bool			powered;
 	bool			streaming;
···
 	*norm = state->curr_norm;
 
 	return 0;
+}
+
+static void adv7180_set_power_pin(struct adv7180_state *state, bool on)
+{
+	if (!state->pwdn_gpio)
+		return;
+
+	if (on) {
+		gpiod_set_value_cansleep(state->pwdn_gpio, 0);
+		usleep_range(5000, 10000);
+	} else {
+		gpiod_set_value_cansleep(state->pwdn_gpio, 1);
+	}
 }
 
 static int adv7180_set_power(struct adv7180_state *state, bool on)
···
 
 	mutex_lock(&state->mutex);
 
+	adv7180_set_power_pin(state, true);
+
 	adv7180_write(state, ADV7180_REG_PWR_MAN, ADV7180_PWR_MAN_RES);
 	usleep_range(5000, 10000);
 
···
 	state->client = client;
 	state->field = V4L2_FIELD_INTERLACED;
 	state->chip_info = (struct adv7180_chip_info *)id->driver_data;
+
+	state->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
+						   GPIOD_OUT_HIGH);
+	if (IS_ERR(state->pwdn_gpio)) {
+		ret = PTR_ERR(state->pwdn_gpio);
+		v4l_err(client, "request for power pin failed: %d\n", ret);
+		return ret;
+	}
 
 	if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2) {
 		state->csi_client = i2c_new_dummy(client->adapter,
···
 		i2c_unregister_device(state->vpp_client);
 	if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2)
 		i2c_unregister_device(state->csi_client);
+
+	adv7180_set_power_pin(state, false);
 
 	mutex_destroy(&state->mutex);