fbdev: Add FOURCC-based format configuration API
This API will be used to support YUV frame buffer formats in a standard
way.
Last but not least, create a much needed fbdev API documentation and
document the format setting APIs.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index ad93629..ac9141b 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -967,6 +967,20 @@
memcmp(&info->var, var, sizeof(struct fb_var_screeninfo))) {
u32 activate = var->activate;
+ /* When using FOURCC mode, make sure the red, green, blue and
+ * transp fields are set to 0.
+ */
+ if ((info->fix.capabilities & FB_CAP_FOURCC) &&
+ var->grayscale > 1) {
+ if (var->red.offset || var->green.offset ||
+ var->blue.offset || var->transp.offset ||
+ var->red.length || var->green.length ||
+ var->blue.length || var->transp.length ||
+ var->red.msb_right || var->green.msb_right ||
+ var->blue.msb_right || var->transp.msb_right)
+ return -EINVAL;
+ }
+
if (!info->fbops->fb_check_var) {
*var = info->var;
goto done;