[PATCH 4/5] media: ov8865: 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/ov8865.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/media/i2c/ov8865.c b/drivers/media/i2c/ov8865.c
index cae1866134a0..fe86b166b28b 100644
--- a/drivers/media/i2c/ov8865.c
+++ b/drivers/media/i2c/ov8865.c
@@ -688,6 +688,7 @@ struct ov8865_sensor {
 	struct i2c_client *i2c_client;
 	struct gpio_desc *reset;
 	struct gpio_desc *powerdown;
+	struct gpio_desc *privacy_led;
 	struct regulator *avdd;
 	struct regulator *dvdd;
 	struct regulator *dovdd;
@@ -2432,10 +2433,12 @@ static int ov8865_sensor_power(struct ov8865_sensor *sensor, bool on)
 
 		gpiod_set_value_cansleep(sensor->reset, 0);
 		gpiod_set_value_cansleep(sensor->powerdown, 0);
+		gpiod_set_value_cansleep(sensor->privacy_led, 1);
 
 		/* Time to enter streaming mode according to power timings. */
 		usleep_range(10000, 12000);
 	} else {
+		gpiod_set_value_cansleep(sensor->privacy_led, 0);
 		gpiod_set_value_cansleep(sensor->powerdown, 1);
 		gpiod_set_value_cansleep(sensor->reset, 1);
 
@@ -3009,6 +3012,12 @@ static int ov8865_probe(struct i2c_client *client)
 		goto error_endpoint;
 	}
 
+	sensor->privacy_led = devm_gpiod_get_optional(dev, "privacy-led", GPIOD_OUT_LOW);
+	if (IS_ERR(sensor->privacy_led)) {
+		ret = PTR_ERR(sensor->privacy_led);
+		goto error_endpoint;
+	}
+
 	/* External Clock */
 
 	sensor->extclk = devm_clk_get(dev, NULL);
-- 
2.38.1