[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, 14 insertions, 3 deletions

diff --git a/drivers/media/i2c/soc_camera/mt9m001.c b/drivers/media/i2c/soc_camera/mt9m001.c
index cd71230c51a9..d85be41ffa1d 100644
--- a/drivers/media/i2c/soc_camera/mt9m001.c
+++ b/drivers/media/i2c/soc_camera/mt9m001.c
@@ -490,6 +490,10 @@ static int mt9m001_video_probe(struct soc_camera_link *icl,
 	unsigned long flags;
 	int ret;
 
+	ret = mt9m001_s_power(&mt9m001->subdev, 1);
+	if (ret < 0)
+		return ret;
+
 	/* Enable the chip */
 	data = reg_write(client, MT9M001_CHIP_ENABLE, 1);
 	dev_dbg(&client->dev, "write: %d\n", data);
@@ -511,7 +515,8 @@ static int mt9m001_video_probe(struct soc_camera_link *icl,
 	default:
 		dev_err(&client->dev,
 			"No MT9M001 chip detected, register read %x\n", data);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto done;
 	}
 
 	mt9m001->num_fmts = 0;
@@ -540,11 +545,17 @@ static int mt9m001_video_probe(struct soc_camera_link *icl,
 		 data == 0x8431 ? "C12STM" : "C12ST");
 
 	ret = mt9m001_init(client);
-	if (ret < 0)
+	if (ret < 0) {
 		dev_err(&client->dev, "Failed to initialise the camera\n");
+		goto done;
+	}
 
 	/* mt9m001_init() has reset the chip, returning registers to defaults */
-	return v4l2_ctrl_handler_setup(&mt9m001->hdl);
+	ret = v4l2_ctrl_handler_setup(&mt9m001->hdl);
+
+done:
+	mt9m001_s_power(&mt9m001->subdev, 0);
+	return ret;
 }
 
 static void mt9m001_video_remove(struct soc_camera_link *icl)