video: Allow driver to specify the line length

At present line_length is always calculated in video_post_probe(). But
some hardware may use a different line length, e.g. with a 1366-wide
display.

Allow the driver to set this value if needed.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NAnatolij Gustschin <agust@denx.de>

drivers/pci/pci_rom.c

@@ -331,6 +331,7 @@ int vbe_setup_video_priv(struct vesa_mode_info *vesa,
 		return log_msg_ret("No x resolution", -ENXIO);
 	uc_priv->xsize = vesa->x_resolution;
 	uc_priv->ysize = vesa->y_resolution;
+	uc_priv->line_length = vesa->bytes_per_scanline;
 	switch (vesa->bits_per_pixel) {
 	case 32:
 	case 24:

drivers/video/video-uclass.c

@@ -226,7 +226,9 @@ static int video_post_probe(struct udevice *dev)
 
 	/* Set up the line and display size */
 	priv->fb = map_sysmem(plat->base, plat->size);
-	priv->line_length = priv->xsize * VNBYTES(priv->bpix);
+	if (!priv->line_length)
+		priv->line_length = priv->xsize * VNBYTES(priv->bpix);
+
 	priv->fb_size = priv->line_length * priv->ysize;
 
 	/* Set up colors  */

include/video.h

@@ -61,7 +61,9 @@ enum video_log2_bpp {
  * @font_size:	Font size in pixels (0 to use a default value)
  * @fb:		Frame buffer
  * @fb_size:	Frame buffer size
- * @line_length:	Length of each frame buffer line, in bytes
+ * @line_length:	Length of each frame buffer line, in bytes. This can be
+ *		set by the driver, but if not, the uclass will set it after
+ *		probing
  * @colour_fg:	Foreground colour (pixel value)
  * @colour_bg:	Background colour (pixel value)
  * @flush_dcache:	true to enable flushing of the data cache after