[media] soc-camera: Add soc_mbus_image_size

The function returns the minimum size of an image for a given number of
bytes per line (as per the V4L2 specification), width and format.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/soc_mediabus.c

@@ -397,6 +397,24 @@ s32 soc_mbus_bytes_per_line(u32 width, const struct soc_mbus_pixelfmt *mf)
 }
 EXPORT_SYMBOL(soc_mbus_bytes_per_line);
 
+s32 soc_mbus_image_size(const struct soc_mbus_pixelfmt *mf,
+			u32 bytes_per_line, u32 height)
+{
+	if (mf->layout == SOC_MBUS_LAYOUT_PACKED)
+		return bytes_per_line * height;
+
+	switch (mf->packing) {
+	case SOC_MBUS_PACKING_2X8_PADHI:
+	case SOC_MBUS_PACKING_2X8_PADLO:
+		return bytes_per_line * height * 2;
+	case SOC_MBUS_PACKING_1_5X8:
+		return bytes_per_line * height * 3 / 2;
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(soc_mbus_image_size);
+
 const struct soc_mbus_pixelfmt *soc_mbus_find_fmtdesc(
 	enum v4l2_mbus_pixelcode code,
 	const struct soc_mbus_lookup *lookup,

include/media/soc_mediabus.h

@@ -99,6 +99,8 @@ const struct soc_mbus_pixelfmt *soc_mbus_find_fmtdesc(
 const struct soc_mbus_pixelfmt *soc_mbus_get_fmtdesc(
 	enum v4l2_mbus_pixelcode code);
 s32 soc_mbus_bytes_per_line(u32 width, const struct soc_mbus_pixelfmt *mf);
+s32 soc_mbus_image_size(const struct soc_mbus_pixelfmt *mf,
+			u32 bytes_per_line, u32 height);
 int soc_mbus_samples_per_pixel(const struct soc_mbus_pixelfmt *mf,
 			unsigned int *numerator, unsigned int *denominator);
 unsigned int soc_mbus_config_compatible(const struct v4l2_mbus_config *cfg,