media: i2c: imx219: Scale the pixel clock rate for the 640x480 mode

The 640x480 mode uses a special binning mode for high framerate operation where
the pixel rate is effectively doubled. Account for this when setting up the
pixel clock rate, and applying the vblank and exposure controls.

Signed-off-by: Naushir Patuck <[email protected]>

Author: naushir

drivers/media/i2c/imx219.c

@@ -153,6 +153,9 @@ struct imx219_mode {
 
 	/* Default register values */
 	struct imx219_reg_list reg_list;
+
+	/* Relative pixel clock rate factor for the mode. */
+	unsigned int rate_factor;
 };
 
 /*
@@ -495,6 +498,7 @@ static const struct imx219_mode supported_modes[] = {
 			.num_of_regs = ARRAY_SIZE(mode_3280x2464_regs),
 			.regs = mode_3280x2464_regs,
 		},
+		.rate_factor = 1,
 	},
 	{
 		/* 1080P 30fps cropped */
@@ -511,6 +515,7 @@ static const struct imx219_mode supported_modes[] = {
 			.num_of_regs = ARRAY_SIZE(mode_1920_1080_regs),
 			.regs = mode_1920_1080_regs,
 		},
+		.rate_factor = 1,
 	},
 	{
 		/* 2x2 binned 30fps mode */
@@ -527,6 +532,7 @@ static const struct imx219_mode supported_modes[] = {
 			.num_of_regs = ARRAY_SIZE(mode_1640_1232_regs),
 			.regs = mode_1640_1232_regs,
 		},
+		.rate_factor = 1,
 	},
 	{
 		/* 640x480 30fps mode */
@@ -543,6 +549,11 @@ static const struct imx219_mode supported_modes[] = {
 			.num_of_regs = ARRAY_SIZE(mode_640_480_regs),
 			.regs = mode_640_480_regs,
 		},
+		/*
+		 * This mode uses a special 2x2 binning that doubles the
+		 * the internal pixel clock rate.
+		 */
+		.rate_factor = 2,
 	},
 };
 
@@ -765,7 +776,8 @@ static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
 		break;
 	case V4L2_CID_EXPOSURE:
 		ret = imx219_write_reg(imx219, IMX219_REG_EXPOSURE,
-				       IMX219_REG_VALUE_16BIT, ctrl->val);
+				       IMX219_REG_VALUE_16BIT,
+				       ctrl->val / imx219->mode->rate_factor);
 		break;
 	case V4L2_CID_DIGITAL_GAIN:
 		ret = imx219_write_reg(imx219, IMX219_REG_DIGITAL_GAIN,
@@ -785,7 +797,8 @@ static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
 	case V4L2_CID_VBLANK:
 		ret = imx219_write_reg(imx219, IMX219_REG_VTS,
 				       IMX219_REG_VALUE_16BIT,
-				       imx219->mode->height + ctrl->val);
+				       (imx219->mode->height + ctrl->val) /
+						imx219->mode->rate_factor);
 		break;
 	case V4L2_CID_TEST_PATTERN_RED:
 		ret = imx219_write_reg(imx219, IMX219_REG_TESTP_RED,
@@ -957,7 +970,7 @@ static int imx219_set_pad_format(struct v4l2_subdev *sd,
 	struct imx219 *imx219 = to_imx219(sd);
 	const struct imx219_mode *mode;
 	struct v4l2_mbus_framefmt *framefmt;
-	int exposure_max, exposure_def, hblank;
+	int exposure_max, exposure_def, hblank, pixel_rate;
 	unsigned int i;
 
 	if (fmt->pad >= NUM_PADS)
@@ -1018,6 +1031,12 @@ static int imx219_set_pad_format(struct v4l2_subdev *sd,
 			hblank = IMX219_PPL_DEFAULT - mode->width;
 			__v4l2_ctrl_modify_range(imx219->hblank, hblank, hblank,
 						 1, hblank);
+
+			/* Scale the pixel rate based on the mode specific factor */
+			pixel_rate =
+				IMX219_PIXEL_RATE * imx219->mode->rate_factor;
+			__v4l2_ctrl_modify_range(imx219->pixel_rate, pixel_rate,
+						 pixel_rate, 1, pixel_rate);
 		}
 	} else {
 		if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
@@ -1362,7 +1381,7 @@ static int imx219_init_controls(struct imx219 *imx219)
 	struct v4l2_ctrl_handler *ctrl_hdlr;
 	unsigned int height = imx219->mode->height;
 	struct v4l2_fwnode_device_properties props;
-	int exposure_max, exposure_def, hblank;
+	int exposure_max, exposure_def, hblank, pixel_rate;
 	int i, ret;
 
 	ctrl_hdlr = &imx219->ctrl_handler;
@@ -1374,11 +1393,11 @@ static int imx219_init_controls(struct imx219 *imx219)
 	ctrl_hdlr->lock = &imx219->mutex;
 
 	/* By default, PIXEL_RATE is read only */
+	pixel_rate = IMX219_PIXEL_RATE * imx219->mode->rate_factor;
 	imx219->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx219_ctrl_ops,
 					       V4L2_CID_PIXEL_RATE,
-					       IMX219_PIXEL_RATE,
-					       IMX219_PIXEL_RATE, 1,
-					       IMX219_PIXEL_RATE);
+					       pixel_rate, pixel_rate,
+					       1, pixel_rate);
 
 	imx219->link_freq =
 		v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx219_ctrl_ops,