gpu: ipu-v3: Add ipu_stride_to_bytes()

Adds ipu_stride_to_bytes(), which converts a pixel stride to bytes,
suitable for passing to cpmem.

Signed-off-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/ipu-v3/ipu-common.c

@@ -126,6 +126,36 @@ enum ipu_color_space ipu_mbus_code_to_colorspace(u32 mbus_code)
 }
 EXPORT_SYMBOL_GPL(ipu_mbus_code_to_colorspace);
 
+int ipu_stride_to_bytes(u32 pixel_stride, u32 pixelformat)
+{
+	switch (pixelformat) {
+	case V4L2_PIX_FMT_YUV420:
+	case V4L2_PIX_FMT_YVU420:
+		/*
+		 * for the planar YUV formats, the stride passed to
+		 * cpmem must be the stride in bytes of the Y plane.
+		 * And all the planar YUV formats have an 8-bit
+		 * Y component.
+		 */
+		return (8 * pixel_stride) >> 3;
+	case V4L2_PIX_FMT_RGB565:
+	case V4L2_PIX_FMT_YUYV:
+	case V4L2_PIX_FMT_UYVY:
+		return (16 * pixel_stride) >> 3;
+	case V4L2_PIX_FMT_BGR24:
+	case V4L2_PIX_FMT_RGB24:
+		return (24 * pixel_stride) >> 3;
+	case V4L2_PIX_FMT_BGR32:
+	case V4L2_PIX_FMT_RGB32:
+		return (32 * pixel_stride) >> 3;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(ipu_stride_to_bytes);
+
 int ipu_degrees_to_rot_mode(enum ipu_rotate_mode *mode, int degrees,
 			    bool hflip, bool vflip)
 {