[PATCH 1/6] media: ov5693: Add support for a privacy-led GPIO

[Hans de Goede <hdegoede@redhat.com>]

Add support for a privacy-led GPIO.

Making the privacy LED to controlable from userspace, as using the LED
class subsystem would do, would make it too easy for spy-ware to disable
the LED.

To avoid this have the sensor driver directly control the LED.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Note an additional advantage of directly controlling the GPIO is that
GPIOs are tied directly to consumer devices. Where as with a LED class
device, there would need to be some mechanism to tie the right LED
(e.g front or back) to the right sensor.
---
 drivers/media/i2c/ov5693.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/media/i2c/ov5693.c b/drivers/media/i2c/ov5693.c
index a97ec132ba3a..e3c3bed69ad6 100644
--- a/drivers/media/i2c/ov5693.c
+++ b/drivers/media/i2c/ov5693.c
@@ -156,6 +156,7 @@ struct ov5693_device {
 
 	struct gpio_desc *reset;
 	struct gpio_desc *powerdown;
+	struct gpio_desc *privacy_led;
 	struct regulator_bulk_data supplies[OV5693_NUM_SUPPLIES];
 	struct clk *xvclk;
 
@@ -789,6 +790,7 @@ static int ov5693_sensor_init(struct ov5693_device *ov5693)
 
 static void ov5693_sensor_powerdown(struct ov5693_device *ov5693)
 {
+	gpiod_set_value_cansleep(ov5693->privacy_led, 0);
 	gpiod_set_value_cansleep(ov5693->reset, 1);
 	gpiod_set_value_cansleep(ov5693->powerdown, 1);
 
@@ -818,6 +820,7 @@ static int ov5693_sensor_powerup(struct ov5693_device *ov5693)
 
 	gpiod_set_value_cansleep(ov5693->powerdown, 0);
 	gpiod_set_value_cansleep(ov5693->reset, 0);
+	gpiod_set_value_cansleep(ov5693->privacy_led, 1);
 
 	usleep_range(5000, 7500);
 
@@ -1325,6 +1328,13 @@ static int ov5693_configure_gpios(struct ov5693_device *ov5693)
 		return PTR_ERR(ov5693->powerdown);
 	}
 
+	ov5693->privacy_led = devm_gpiod_get_optional(ov5693->dev, "privacy-led",
+						      GPIOD_OUT_LOW);
+	if (IS_ERR(ov5693->privacy_led)) {
+		dev_err(ov5693->dev, "Error fetching privacy-led GPIO\n");
+		return PTR_ERR(ov5693->privacy_led);
+	}
+
 	return 0;
 }
 
-- 
2.38.1