[PATCH v2 3/5] media: ov2680: Add vblank control

[Hans de Goede <hdegoede@redhat.com>]

Add vblank control to allow changing the framerate /
higher exposure values.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Add error checking to __v4l2_ctrl_modify_range() and
  __v4l2_ctrl_s_ctrl() calls
---
 drivers/media/i2c/ov2680.c | 56 +++++++++++++++++++++++++++++++++-----
 1 file changed, 49 insertions(+), 7 deletions(-)

diff --git a/drivers/media/i2c/ov2680.c b/drivers/media/i2c/ov2680.c
index 6c3d7862b2aa..1a246c87d289 100644
--- a/drivers/media/i2c/ov2680.c
+++ b/drivers/media/i2c/ov2680.c
@@ -75,6 +75,8 @@
 #define OV2680_ACTIVE_START_TOP			8
 #define OV2680_MIN_CROP_WIDTH			2
 #define OV2680_MIN_CROP_HEIGHT			2
+#define OV2680_MIN_VBLANK			4
+#define OV2680_MAX_VBLANK			0xffff
 
 /* Fixed pre-div of 1/2 */
 #define OV2680_PLL_PREDIV0			2
@@ -84,7 +86,7 @@
 
 /* 66MHz pixel clock: 66MHz / 1704 * 1294 = 30fps */
 #define OV2680_PIXELS_PER_LINE			1704
-#define OV2680_LINES_PER_FRAME			1294
+#define OV2680_LINES_PER_FRAME_30FPS		1294
 
 /* Max exposure time is VTS - 8 */
 #define OV2680_INTEGRATION_TIME_MARGIN		8
@@ -127,6 +129,7 @@ struct ov2680_ctrls {
 	struct v4l2_ctrl *test_pattern;
 	struct v4l2_ctrl *link_freq;
 	struct v4l2_ctrl *pixel_rate;
+	struct v4l2_ctrl *vblank;
 };
 
 struct ov2680_mode {
@@ -394,8 +397,7 @@ static int ov2680_set_mode(struct ov2680_dev *sensor)
 		  sensor->mode.v_output_size, &ret);
 	cci_write(sensor->regmap, OV2680_REG_TIMING_HTS,
 		  OV2680_PIXELS_PER_LINE, &ret);
-	cci_write(sensor->regmap, OV2680_REG_TIMING_VTS,
-		  OV2680_LINES_PER_FRAME, &ret);
+	/* VTS gets set by the vblank ctrl */
 	cci_write(sensor->regmap, OV2680_REG_ISP_X_WIN, 0, &ret);
 	cci_write(sensor->regmap, OV2680_REG_ISP_Y_WIN, 0, &ret);
 	cci_write(sensor->regmap, OV2680_REG_X_INC, inc, &ret);
@@ -469,6 +471,15 @@ static int ov2680_exposure_set(struct ov2680_dev *sensor, u32 exp)
 			 NULL);
 }
 
+static int ov2680_exposure_update_range(struct ov2680_dev *sensor)
+{
+	int exp_max = sensor->mode.fmt.height + sensor->ctrls.vblank->val -
+		      OV2680_INTEGRATION_TIME_MARGIN;
+
+	return __v4l2_ctrl_modify_range(sensor->ctrls.exposure, 0, exp_max,
+					1, exp_max);
+}
+
 static int ov2680_stream_enable(struct ov2680_dev *sensor)
 {
 	int ret;
@@ -635,7 +646,7 @@ static int ov2680_set_fmt(struct v4l2_subdev *sd,
 	struct v4l2_mbus_framefmt *try_fmt;
 	const struct v4l2_rect *crop;
 	unsigned int width, height;
-	int ret = 0;
+	int def, max, ret = 0;
 
 	crop = __ov2680_get_pad_crop(sensor, sd_state, format->pad,
 				     format->which);
@@ -664,6 +675,21 @@ static int ov2680_set_fmt(struct v4l2_subdev *sd,
 	sensor->mode.fmt = format->format;
 	ov2680_calc_mode(sensor);
 
+	/* vblank range is height dependent adjust and reset to default */
+	max = OV2680_MAX_VBLANK - height;
+	def = OV2680_LINES_PER_FRAME_30FPS - height;
+	ret = __v4l2_ctrl_modify_range(sensor->ctrls.vblank, OV2680_MIN_VBLANK,
+				       max, 1, def);
+	if (ret)
+		goto unlock;
+
+	ret = __v4l2_ctrl_s_ctrl(sensor->ctrls.vblank, def);
+	if (ret)
+		goto unlock;
+
+	/* exposure range depends on vts which may have changed */
+	ret = ov2680_exposure_update_range(sensor);
+
 unlock:
 	mutex_unlock(&sensor->lock);
 
@@ -833,6 +859,13 @@ static int ov2680_s_ctrl(struct v4l2_ctrl *ctrl)
 	struct ov2680_dev *sensor = to_ov2680_dev(sd);
 	int ret;
 
+	/* Update exposure range on vblank changes */
+	if (ctrl->id == V4L2_CID_VBLANK) {
+		ret = ov2680_exposure_update_range(sensor);
+		if (ret)
+			return ret;
+	}
+
 	/* Only apply changes to the controls if the device is powered up */
 	if (!pm_runtime_get_if_in_use(sensor->sd.dev)) {
 		ov2680_set_bayer_order(sensor, &sensor->mode.fmt);
@@ -855,6 +888,10 @@ static int ov2680_s_ctrl(struct v4l2_ctrl *ctrl)
 	case V4L2_CID_TEST_PATTERN:
 		ret = ov2680_test_pattern_set(sensor, ctrl->val);
 		break;
+	case V4L2_CID_VBLANK:
+		ret = cci_write(sensor->regmap, OV2680_REG_TIMING_VTS,
+				sensor->mode.fmt.height + ctrl->val, NULL);
+		break;
 	default:
 		ret = -EINVAL;
 		break;
@@ -913,8 +950,7 @@ static int ov2680_v4l2_register(struct ov2680_dev *sensor)
 	const struct v4l2_ctrl_ops *ops = &ov2680_ctrl_ops;
 	struct ov2680_ctrls *ctrls = &sensor->ctrls;
 	struct v4l2_ctrl_handler *hdl = &ctrls->handler;
-	int exp_max = OV2680_LINES_PER_FRAME - OV2680_INTEGRATION_TIME_MARGIN;
-	int ret = 0;
+	int def, max, ret = 0;
 
 	v4l2_i2c_subdev_init(&sensor->sd, client, &ov2680_subdev_ops);
 	sensor->sd.internal_ops = &ov2680_internal_ops;
@@ -939,8 +975,9 @@ static int ov2680_v4l2_register(struct ov2680_dev *sensor)
 					ARRAY_SIZE(test_pattern_menu) - 1,
 					0, 0, test_pattern_menu);
 
+	max = OV2680_LINES_PER_FRAME_30FPS - OV2680_INTEGRATION_TIME_MARGIN;
 	ctrls->exposure = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_EXPOSURE,
-					    0, exp_max, 1, exp_max);
+					    0, max, 1, max);
 
 	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_ANALOGUE_GAIN,
 					0, 1023, 1, 250);
@@ -951,6 +988,11 @@ static int ov2680_v4l2_register(struct ov2680_dev *sensor)
 					      0, sensor->pixel_rate,
 					      1, sensor->pixel_rate);
 
+	max = OV2680_MAX_VBLANK - OV2680_DEFAULT_HEIGHT;
+	def = OV2680_LINES_PER_FRAME_30FPS - OV2680_DEFAULT_HEIGHT;
+	ctrls->vblank = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VBLANK,
+					  OV2680_MIN_VBLANK, max, 1, def);
+
 	if (hdl->error) {
 		ret = hdl->error;
 		goto cleanup_entity;
-- 
2.44.0