[media] soc-camera: Push probe-time power management to drivers

Several client drivers access the hardware at probe time, for instance
to read the probe chip ID. Such chips need to be powered up when being
probed.

soc-camera handles this by powering chips up in the soc-camera probe
implementation. However, this will break with non soc-camera hosts that
don't perform the same operations.

Fix the problem by pushing the power up/down from the soc-camera core
down to individual drivers on a needs basis.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 16 insertions, 5 deletions

diff --git a/drivers/media/i2c/soc_camera/ov5642.c b/drivers/media/i2c/soc_camera/ov5642.c
index 61824c6..d886c0b 100644
--- a/drivers/media/i2c/soc_camera/ov5642.c
+++ b/drivers/media/i2c/soc_camera/ov5642.c
@@ -980,29 +980,40 @@ static struct v4l2_subdev_ops ov5642_subdev_ops = {
 
 static int ov5642_video_probe(struct i2c_client *client)
 {
+	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
 	int ret;
 	u8 id_high, id_low;
 	u16 id;
 
+	ret = ov5642_s_power(subdev, 1);
+	if (ret < 0)
+		return ret;
+
 	/* Read sensor Model ID */
 	ret = reg_read(client, REG_CHIP_ID_HIGH, &id_high);
 	if (ret < 0)
-		return ret;
+		goto done;
 
 	id = id_high << 8;
 
 	ret = reg_read(client, REG_CHIP_ID_LOW, &id_low);
 	if (ret < 0)
-		return ret;
+		goto done;
 
 	id |= id_low;
 
 	dev_info(&client->dev, "Chip ID 0x%04x detected\n", id);
 
-	if (id != 0x5642)
-		return -ENODEV;
+	if (id != 0x5642) {
+		ret = -ENODEV;
+		goto done;
+	}
 
-	return 0;
+	ret = 0;
+
+done:
+	ov5642_s_power(subdev, 0);
+	return ret;
 }
 
 static int ov5642_probe(struct i2c_client *client,