[media] ov2640: make GPIOLIB an optional dependency

As warned by kbuild test robot:
	warning: (VIDEO_EM28XX_V4L2) selects VIDEO_OV2640 which has unmet direct dependencies (MEDIA_SUPPORT && VIDEO_V4L2 && I2C && GPIOLIB && MEDIA_CAMERA_SUPPORT)

The em28xx driver can use ov2640, but it doesn't depend
(or use) the GPIOLIB in order to power off/on the sensor.

So, as we want to allow both usages with and without
GPIOLIB, make its dependency optional.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

2 files changed, 5 insertions, 2 deletions

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 40bb4bdc51da..fd181c99ce11 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -519,7 +519,7 @@ config VIDEO_SMIAPP_PLL
 
 config VIDEO_OV2640
         tristate "OmniVision OV2640 sensor support"
-        depends on VIDEO_V4L2 && I2C && GPIOLIB
+        depends on VIDEO_V4L2 && I2C
         depends on MEDIA_CAMERA_SUPPORT
         help
           This is a Video4Linux2 sensor-level driver for the OmniVision
diff --git a/drivers/media/i2c/ov2640.c b/drivers/media/i2c/ov2640.c
index d55ca37dc12f..9c00ed3543f8 100644
--- a/drivers/media/i2c/ov2640.c
+++ b/drivers/media/i2c/ov2640.c
@@ -743,13 +743,16 @@ static int ov2640_s_power(struct v4l2_subdev *sd, int on)
         struct i2c_client *client = v4l2_get_subdevdata(sd);
         struct ov2640_priv *priv = to_ov2640(client);
 
-        gpiod_direction_output(priv->pwdn_gpio, !on);
+#ifdef CONFIG_GPIOLIB
+        if (priv->pwdn_gpio)
+                gpiod_direction_output(priv->pwdn_gpio, !on);
         if (on && priv->resetb_gpio) {
                 /* Active the resetb pin to perform a reset pulse */
                 gpiod_direction_output(priv->resetb_gpio, 1);
                 usleep_range(3000, 5000);
                 gpiod_direction_output(priv->resetb_gpio, 0);
         }
+#endif
         return 0;
 }