media: i2c: imx219: Scale the pixel rate for analog binning

When the analog binning mode is used for high framerate operation, the
pixel rate is effectively doubled. Account for this when setting up the
pixel clock rate, and applying the vblank and exposure controls.

The previous logic only used analog binning for RAW8, but normal binning
limits the framerate on RAW10 480p [1]. So with this patch we switch to
using special binning (with 2x pixel rate) wherever possible.

Backport of commit f513997 upstream.

[1]: #5493

Co-developed-by: Naushir Patuck <[email protected]>
Signed-off-by: Naushir Patuck <[email protected]>
Co-developed-by: Vinay Varma <[email protected]>
Signed-off-by: Vinay Varma <[email protected]>
Signed-off-by: Jai Luthra <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>

Author: jailuthra

drivers/media/i2c/imx219.c

@@ -148,6 +148,12 @@
 #define IMX219_PIXEL_ARRAY_WIDTH	3280U
 #define IMX219_PIXEL_ARRAY_HEIGHT	2464U
 
+enum binning_mode {
+	BINNING_NONE = IMX219_BINNING_NONE,
+	BINNING_X2 = IMX219_BINNING_X2,
+	BINNING_ANALOG_X2 = IMX219_BINNING_X2_ANALOG,
+};
+
 /* Mode : resolution and related config&values */
 struct imx219_mode {
 	/* Frame width */
@@ -324,13 +330,13 @@ static const struct imx219_mode supported_modes[] = {
 		.vts_def = 1763,
 	},
 	{
-		/* 2x2 binned 30fps mode */
+		/* 2x2 binned 60fps mode */
 		.width = 1640,
 		.height = 1232,
 		.vts_def = 1763,
 	},
 	{
-		/* 640x480 30fps mode */
+		/* 640x480 60fps mode */
 		.width = 640,
 		.height = 480,
 		.vts_def = 1763,
@@ -385,6 +391,59 @@ static u32 imx219_get_format_code(struct imx219 *imx219, u32 code)
 	return imx219_mbus_formats[i];
 }
 
+static u32 imx219_get_format_bpp(const struct v4l2_mbus_framefmt *format)
+{
+	switch (format->code) {
+	case MEDIA_BUS_FMT_SRGGB8_1X8:
+	case MEDIA_BUS_FMT_SGRBG8_1X8:
+	case MEDIA_BUS_FMT_SGBRG8_1X8:
+	case MEDIA_BUS_FMT_SBGGR8_1X8:
+		return 8;
+
+	case MEDIA_BUS_FMT_SRGGB10_1X10:
+	case MEDIA_BUS_FMT_SGRBG10_1X10:
+	case MEDIA_BUS_FMT_SGBRG10_1X10:
+	case MEDIA_BUS_FMT_SBGGR10_1X10:
+	default:
+		return 10;
+	}
+}
+
+static enum binning_mode imx219_get_binning(struct imx219 *imx219, u8 *bin_h,
+					    u8 *bin_v)
+{
+	struct v4l2_subdev_state *state =
+		v4l2_subdev_get_locked_active_state(&imx219->sd);
+	const struct v4l2_mbus_framefmt *format =
+		v4l2_subdev_state_get_format(state, 0);
+	const struct v4l2_rect *crop = v4l2_subdev_state_get_crop(state, 0);
+
+	*bin_h = crop->width / format->width;
+	*bin_v = crop->height / format->height;
+
+	if (*bin_h == 2 && *bin_v == 2)
+		return BINNING_ANALOG_X2;
+	else if (*bin_h == 2 || *bin_v == 2)
+		/*
+		 * Don't use analog binning if only one dimension
+		 * is binned, as it crops the other dimension
+		 */
+		return BINNING_X2;
+	else
+		return BINNING_NONE;
+}
+
+static inline u32 imx219_get_rate_factor(struct imx219 *imx219)
+{
+	u8 bin_h, bin_v;
+	enum binning_mode binning = imx219_get_binning(imx219, &bin_h, &bin_v);
+
+	if (binning == BINNING_ANALOG_X2)
+		return 2;
+
+	return 1;
+}
+
 /* -----------------------------------------------------------------------------
  * Controls
  */
@@ -396,10 +455,12 @@ static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
 	struct i2c_client *client = v4l2_get_subdevdata(&imx219->sd);
 	const struct v4l2_mbus_framefmt *format;
 	struct v4l2_subdev_state *state;
+	u32 rate_factor;
 	int ret = 0;
 
 	state = v4l2_subdev_get_locked_active_state(&imx219->sd);
 	format = v4l2_subdev_state_get_format(state, 0);
+	rate_factor = imx219_get_rate_factor(imx219);
 
 	if (ctrl->id == V4L2_CID_VBLANK) {
 		int exposure_max, exposure_def;
@@ -428,7 +489,7 @@ static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
 		break;
 	case V4L2_CID_EXPOSURE:
 		cci_write(imx219->regmap, IMX219_REG_EXPOSURE,
-			  ctrl->val, &ret);
+			  ctrl->val / rate_factor, &ret);
 		break;
 	case V4L2_CID_DIGITAL_GAIN:
 		cci_write(imx219->regmap, IMX219_REG_DIGITAL_GAIN,
@@ -445,7 +506,7 @@ static int imx219_set_ctrl(struct v4l2_ctrl *ctrl)
 		break;
 	case V4L2_CID_VBLANK:
 		cci_write(imx219->regmap, IMX219_REG_VTS,
-			  format->height + ctrl->val, &ret);
+			  (format->height + ctrl->val) / rate_factor, &ret);
 		break;
 	case V4L2_CID_TEST_PATTERN_RED:
 		cci_write(imx219->regmap, IMX219_REG_TESTP_RED,
@@ -613,29 +674,14 @@ static int imx219_set_framefmt(struct imx219 *imx219,
 {
 	const struct v4l2_mbus_framefmt *format;
 	const struct v4l2_rect *crop;
-	unsigned int bpp;
-	u64 bin_h, bin_v;
+	enum binning_mode binning;
+	u8 bin_h, bin_v;
+	u32 bpp;
 	int ret = 0;
 
 	format = v4l2_subdev_state_get_format(state, 0);
 	crop = v4l2_subdev_state_get_crop(state, 0);
-
-	switch (format->code) {
-	case MEDIA_BUS_FMT_SRGGB8_1X8:
-	case MEDIA_BUS_FMT_SGRBG8_1X8:
-	case MEDIA_BUS_FMT_SGBRG8_1X8:
-	case MEDIA_BUS_FMT_SBGGR8_1X8:
-		bpp = 8;
-		break;
-
-	case MEDIA_BUS_FMT_SRGGB10_1X10:
-	case MEDIA_BUS_FMT_SGRBG10_1X10:
-	case MEDIA_BUS_FMT_SGBRG10_1X10:
-	case MEDIA_BUS_FMT_SBGGR10_1X10:
-	default:
-		bpp = 10;
-		break;
-	}
+	bpp = imx219_get_format_bpp(format);
 
 	cci_write(imx219->regmap, IMX219_REG_X_ADD_STA_A,
 		  crop->left - IMX219_PIXEL_ARRAY_LEFT, &ret);
@@ -646,28 +692,11 @@ static int imx219_set_framefmt(struct imx219 *imx219,
 	cci_write(imx219->regmap, IMX219_REG_Y_ADD_END_A,
 		  crop->top - IMX219_PIXEL_ARRAY_TOP + crop->height - 1, &ret);
 
-	switch (crop->width / format->width) {
-	case 1:
-	default:
-		bin_h = IMX219_BINNING_NONE;
-		break;
-	case 2:
-		bin_h = bpp == 8 ? IMX219_BINNING_X2_ANALOG : IMX219_BINNING_X2;
-		break;
-	}
-
-	switch (crop->height / format->height) {
-	case 1:
-	default:
-		bin_v = IMX219_BINNING_NONE;
-		break;
-	case 2:
-		bin_v = bpp == 8 ? IMX219_BINNING_X2_ANALOG : IMX219_BINNING_X2;
-		break;
-	}
-
-	cci_write(imx219->regmap, IMX219_REG_BINNING_MODE_H, bin_h, &ret);
-	cci_write(imx219->regmap, IMX219_REG_BINNING_MODE_V, bin_v, &ret);
+	binning = imx219_get_binning(imx219, &bin_h, &bin_v);
+	cci_write(imx219->regmap, IMX219_REG_BINNING_MODE_H,
+		  (bin_h == 2) ? binning : BINNING_NONE, &ret);
+	cci_write(imx219->regmap, IMX219_REG_BINNING_MODE_V,
+		  (bin_v == 2) ? binning : BINNING_NONE, &ret);
 
 	cci_write(imx219->regmap, IMX219_REG_X_OUTPUT_SIZE,
 		  format->width, &ret);
@@ -873,6 +902,7 @@ static int imx219_set_pad_format(struct v4l2_subdev *sd,
 		int exposure_max;
 		int exposure_def;
 		int hblank;
+		int pixel_rate;
 
 		/* Update limits and set FPS to default */
 		__v4l2_ctrl_modify_range(imx219->vblank, IMX219_VBLANK_MIN,
@@ -896,6 +926,12 @@ 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_get_pixel_rate(imx219) *
+			     imx219_get_rate_factor(imx219);
+		__v4l2_ctrl_modify_range(imx219->pixel_rate, pixel_rate,
+					 pixel_rate, 1, pixel_rate);
 	}
 
 	return 0;