[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, 15 insertions, 22 deletions

diff --git a/drivers/media/i2c/soc_camera/mt9t031.c b/drivers/media/i2c/soc_camera/mt9t031.c
index 9666e202e395..d74607adc585 100644
--- a/drivers/media/i2c/soc_camera/mt9t031.c
+++ b/drivers/media/i2c/soc_camera/mt9t031.c
@@ -161,14 +161,6 @@ static int mt9t031_idle(struct i2c_client *client)
 	return ret >= 0 ? 0 : -EIO;
 }
 
-static int mt9t031_disable(struct i2c_client *client)
-{
-	/* Disable the chip */
-	reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);
-
-	return 0;
-}
-
 static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
@@ -643,9 +635,15 @@ static int mt9t031_video_probe(struct i2c_client *client)
 	s32 data;
 	int ret;
 
-	/* Enable the chip */
-	data = reg_write(client, MT9T031_CHIP_ENABLE, 1);
-	dev_dbg(&client->dev, "write: %d\n", data);
+	ret = mt9t031_s_power(&mt9t031->subdev, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = mt9t031_idle(client);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to initialise the camera\n");
+		goto done;
+	}
 
 	/* Read out the chip version register */
 	data = reg_read(client, MT9T031_CHIP_VERSION);
@@ -657,16 +655,16 @@ static int mt9t031_video_probe(struct i2c_client *client)
 	default:
 		dev_err(&client->dev,
 			"No MT9T031 chip detected, register read %x\n", data);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto done;
 	}
 
 	dev_info(&client->dev, "Detected a MT9T031 chip ID %x\n", data);
 
-	ret = mt9t031_idle(client);
-	if (ret < 0)
-		dev_err(&client->dev, "Failed to initialise the camera\n");
-	else
-		v4l2_ctrl_handler_setup(&mt9t031->hdl);
+	ret = v4l2_ctrl_handler_setup(&mt9t031->hdl);
+
+done:
+	mt9t031_s_power(&mt9t031->subdev, 0);
 
 	return ret;
 }
@@ -817,12 +815,7 @@ static int mt9t031_probe(struct i2c_client *client,
 	mt9t031->xskip = 1;
 	mt9t031->yskip = 1;
 
-	mt9t031_idle(client);
-
 	ret = mt9t031_video_probe(client);
-
-	mt9t031_disable(client);
-
 	if (ret) {
 		v4l2_ctrl_handler_free(&mt9t031->hdl);
 		kfree(mt9t031);