media: imx477: Compute line_length_pix based on link frequency

As we now support variable link frequency, compute the minimum
line_length value that the sensor will work with, and set
V4L2_CID_HBLANK based on that number.

Signed-off-by: Dave Stevenson <[email protected]>

Author: 6by9

drivers/media/i2c/imx477.c

@@ -154,9 +154,6 @@ struct imx477_mode {
 	/* Frame height */
 	unsigned int height;
 
-	/* H-timing in pixels */
-	unsigned int line_length_pix;
-
 	/* Analog crop rectangle. */
 	struct v4l2_rect crop;
 
@@ -857,7 +854,6 @@ static const struct imx477_mode supported_modes_12bit[] = {
 		/* 12MPix 10fps mode */
 		.width = 4056,
 		.height = 3040,
-		.line_length_pix = 24000,
 		.crop = {
 			.left = IMX477_PIXEL_ARRAY_LEFT,
 			.top = IMX477_PIXEL_ARRAY_TOP,
@@ -874,7 +870,6 @@ static const struct imx477_mode supported_modes_12bit[] = {
 		/* 12MPix cropped 16:9  mode */
 		.width = 4056,
 		.height = 2160,
-		.line_length_pix = 24000,
 		.crop = {
 			.left = IMX477_PIXEL_ARRAY_LEFT,
 			.top = IMX477_PIXEL_ARRAY_TOP + 440,
@@ -891,7 +886,6 @@ static const struct imx477_mode supported_modes_12bit[] = {
 		/* 2x2 binned 40fps mode */
 		.width = 2028,
 		.height = 1520,
-		.line_length_pix = 12740,
 		.crop = {
 			.left = IMX477_PIXEL_ARRAY_LEFT,
 			.top = IMX477_PIXEL_ARRAY_TOP,
@@ -908,7 +902,6 @@ static const struct imx477_mode supported_modes_12bit[] = {
 		/* 1080p 50fps cropped mode */
 		.width = 2028,
 		.height = 1080,
-		.line_length_pix = 12740,
 		.crop = {
 			.left = IMX477_PIXEL_ARRAY_LEFT,
 			.top = IMX477_PIXEL_ARRAY_TOP + 440,
@@ -928,7 +921,6 @@ static const struct imx477_mode supported_modes_10bit[] = {
 		/* 120fps. 2x2 binned and cropped */
 		.width = 1332,
 		.height = 990,
-		.line_length_pix = 6664,
 		.crop = {
 			/*
 			 * FIXME: the analog crop rectangle is actually
@@ -1412,6 +1404,7 @@ static int imx477_get_pad_format(struct v4l2_subdev *sd,
 static void imx477_set_framing_limits(struct imx477 *imx477)
 {
 	unsigned int hblank_min;
+	u64 line_length_min;
 	const struct imx477_mode *mode = imx477->mode;
 
 	/* Default to no long exposure multiplier. */
@@ -1428,7 +1421,11 @@ static void imx477_set_framing_limits(struct imx477 *imx477)
 	__v4l2_ctrl_s_ctrl(imx477->vblank,
 			   mode->frm_length_default - mode->height);
 
-	hblank_min = mode->line_length_pix - mode->width;
+	line_length_min = mode->width * 12 /*BPP*/ * (u64)IMX477_PIXEL_RATE;
+	do_div(line_length_min, imx477->link_freq_value * 2 * 2 /*LANES*/);
+	line_length_min += 500;	/* Allow for HS<>LP transitions */
+
+	hblank_min = line_length_min - mode->width;
 	__v4l2_ctrl_modify_range(imx477->hblank, hblank_min,
 				 IMX477_LINE_LENGTH_MAX, 1, hblank_min);
 	__v4l2_ctrl_s_ctrl(imx477->hblank, hblank_min);