media: i2c: ov2659: Add optional pwrdn gpio handling

On some board it is possible that the sensor 'powerdown'
pin might be controlled with a gpio instead of being
tied to the proper value.

This patch add support to specify an optional gpio
which will be set at probe time.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
Acked-by: Manisha Agrawal <manisha.agrawal@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>

drivers/media/i2c/Kconfig

@@ -628,7 +628,7 @@ config VIDEO_OV2640
 config VIDEO_OV2659
 	tristate "OmniVision OV2659 sensor support"
 	depends on VIDEO_V4L2 && I2C
-	depends on MEDIA_CAMERA_SUPPORT
+	depends on MEDIA_CAMERA_SUPPORT && GPIOLIB
 	select V4L2_FWNODE
 	---help---
 	  This is a Video4Linux2 sensor driver for the OmniVision

drivers/media/i2c/ov2659.c

@@ -32,6 +32,8 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_graph.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/videodev2.h>
@@ -232,6 +234,8 @@ struct ov2659 {
 	struct sensor_register *format_ctrl_regs;
 	struct ov2659_pll_ctrl pll;
 	int streaming;
+	/* used to control the sensor powerdownN pin */
+	struct gpio_desc *pwrdn_gpio;
 };
 
 static const struct sensor_register ov2659_init_regs[] = {
@@ -1390,6 +1394,7 @@ static int ov2659_probe(struct i2c_client *client,
 	struct v4l2_subdev *sd;
 	struct ov2659 *ov2659;
 	struct clk *clk;
+	struct gpio_desc *gpio;
 	int ret;
 
 	if (!pdata) {
@@ -1413,6 +1418,13 @@ static int ov2659_probe(struct i2c_client *client,
 	    ov2659->xvclk_frequency > 27000000)
 		return -EINVAL;
 
+	/* Optional gpio don't fail if not present */
+	gpio = devm_gpiod_get_optional(&client->dev, "pwrdn", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpio))
+		return PTR_ERR(gpio);
+
+	ov2659->pwrdn_gpio = gpio;
+
 	v4l2_ctrl_handler_init(&ov2659->ctrls, 2);
 	ov2659->link_frequency =
 			v4l2_ctrl_new_std(&ov2659->ctrls, &ov2659_ctrl_ops,