media: i2c: Switch exposure control unit to lines

The ov8865 driver currently has the unit of the V4L2_CID_EXPOSURE control
as 1/16th of a line. This is what the sensor expects, but isn't very
intuitive. Switch the control to be in units of a line and simply do the
16x multiplication before passing the value to the sensor.

The datasheet for this sensor gives minimum exposure as 2 lines, so take
the opportunity to correct the lower bounds of the control.

Signed-off-by: Daniel Scally <djrscally@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/ov8865.c

@@ -2126,6 +2126,9 @@ static int ov8865_exposure_configure(struct ov8865_sensor *sensor, u32 exposure)
 {
 	int ret;
 
+	/* The sensor stores exposure in units of 1/16th of a line */
+	exposure *= 16;
+
 	ret = ov8865_write(sensor, OV8865_EXPOSURE_CTRL_HH_REG,
 			   OV8865_EXPOSURE_CTRL_HH(exposure));
 	if (ret)
@@ -2527,8 +2530,8 @@ static int ov8865_ctrls_init(struct ov8865_sensor *sensor)
 
 	/* Exposure */
 
-	ctrls->exposure = v4l2_ctrl_new_std(handler, ops, V4L2_CID_EXPOSURE, 16,
-					    1048575, 16, 512);
+	ctrls->exposure = v4l2_ctrl_new_std(handler, ops, V4L2_CID_EXPOSURE, 2,
+					    65535, 1, 32);
 
 	/* Gain */