media: ov5647: Advertise the correct exposure range

Exposure is clipped by the VTS of the mode, so it needs to be updated
when this is changed.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/ov5647.c

@@ -73,6 +73,11 @@
 #define OV5647_VBLANK_MIN		4
 #define OV5647_VTS_MAX			32767
 
+#define OV5647_EXPOSURE_MIN		4
+#define OV5647_EXPOSURE_STEP		1
+#define OV5647_EXPOSURE_DEFAULT		1000
+#define OV5647_EXPOSURE_MAX		65535
+
 struct regval_list {
 	u16 addr;
 	u8 data;
@@ -107,6 +112,7 @@ struct ov5647 {
 	struct v4l2_ctrl		*pixel_rate;
 	struct v4l2_ctrl		*hblank;
 	struct v4l2_ctrl		*vblank;
+	struct v4l2_ctrl		*exposure;
 };
 
 static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
@@ -1092,6 +1098,7 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
 	struct v4l2_mbus_framefmt *fmt = &format->format;
 	const struct ov5647_mode *ov5647_mode_list;
 	struct ov5647 *sensor = to_sensor(sd);
+
 	const struct ov5647_mode *mode;
 	unsigned int num_modes;
 	unsigned int i;
@@ -1123,6 +1130,7 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
 	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
 		*v4l2_subdev_get_try_format(sd, cfg, format->pad) = mode->format;
 	} else {
+		int exposure_max, exposure_def;
 		int hblank, vblank;
 
 		sensor->mode = mode;
@@ -1138,6 +1146,13 @@ static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
 					 OV5647_VTS_MAX - mode->format.height,
 					 1, vblank);
 		__v4l2_ctrl_s_ctrl(sensor->vblank, vblank);
+
+		exposure_max = mode->vts - 4;
+		exposure_def = min(exposure_max, OV5647_EXPOSURE_DEFAULT);
+		__v4l2_ctrl_modify_range(sensor->exposure,
+					 sensor->exposure->minimum,
+					 exposure_max, sensor->exposure->step,
+					 exposure_def);
 	}
 	*fmt = mode->format;
 	mutex_unlock(&sensor->lock);
@@ -1324,6 +1339,18 @@ static int ov5647_s_ctrl(struct v4l2_ctrl *ctrl)
 
 	/* v4l2_ctrl_lock() locks our own mutex */
 
+	if (ctrl->id == V4L2_CID_VBLANK) {
+		int exposure_max, exposure_def;
+
+		/* Update max exposure while meeting expected vblanking */
+		exposure_max = sensor->mode->format.height + ctrl->val - 4;
+		exposure_def = min(exposure_max, OV5647_EXPOSURE_DEFAULT);
+		__v4l2_ctrl_modify_range(sensor->exposure,
+					 sensor->exposure->minimum,
+					 exposure_max, sensor->exposure->step,
+					 exposure_def);
+	}
+
 	/*
 	 * If the device is not powered up by the host driver do
 	 * not apply any controls to H/W at this time. Instead
@@ -1369,7 +1396,7 @@ static const struct v4l2_ctrl_ops ov5647_ctrl_ops = {
 static int ov5647_init_controls(struct ov5647 *sensor)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&sensor->sd);
-	int hblank;
+	int hblank, exposure_max, exposure_def;
 
 	v4l2_ctrl_handler_init(&sensor->ctrls, 8);
 
@@ -1383,9 +1410,13 @@ static int ov5647_init_controls(struct ov5647 *sensor)
 			       V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL,
 			       0, V4L2_EXPOSURE_MANUAL);
 
-	/* min: 4 lines; max: 0xffff lines; default: 1000 lines. */
-	v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_ctrl_ops,
-			  V4L2_CID_EXPOSURE, 4, 65535, 1, 1000);
+	exposure_max = sensor->mode->vts - 4;
+	exposure_def = min(exposure_max, OV5647_EXPOSURE_DEFAULT);
+	sensor->exposure = v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_ctrl_ops,
+					     V4L2_CID_EXPOSURE,
+					     OV5647_EXPOSURE_MIN,
+					     exposure_max, OV5647_EXPOSURE_STEP,
+					     exposure_def);
 
 	/* min: 16 = 1.0x; max (10 bits); default: 32 = 2.0x. */
 	v4l2_ctrl_new_std(&sensor->ctrls, &ov5647_ctrl_ops,