[PATCH] mbxfb: Add YUV video overlay support

This patch adds a way to create and use the video plane (YUV overlay) and
scaling video scaling features of the chip.

The overlay is configured, resized and modified using a device specific
ioctl.

Also included in this patch:
  - If no platform data was passed, print an error and exit instead of crashing.
  - Added a write_reg(_dly) macro. This improves readability when
    manipulating chip registers. (no more udelay() after each write).
  - Comments about some issues.
Signed-off-by: Raphael Assenat <raph@8d.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Acked-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/video/mbxfb.h

 #ifndef __MBX_FB_H
 #define __MBX_FB_H
 
+#include <asm/ioctl.h>
+#include <asm/types.h>
+
 struct mbxfb_val {
 	unsigned int	defval;
 	unsigned int	min;
@@ -25,4 +28,32 @@ struct mbxfb_platform_data {
 		int (*remove)(struct fb_info *fb);
 };
 
+/* planar */
+#define MBXFB_FMT_YUV12		0
+
+/* packed */
+#define MBXFB_FMT_UY0VY1	1
+#define MBXFB_FMT_VY0UY1	2
+#define MBXFB_FMT_Y0UY1V	3
+#define MBXFB_FMT_Y0VY1U	4
+struct mbxfb_overlaySetup {
+	__u32 enable;
+	__u32 x, y;
+	__u32 width, height;
+	__u32 alpha;
+	__u32 fmt;
+	__u32 mem_offset;
+	__u32 scaled_width;
+	__u32 scaled_height;
+
+	/* Filled by the driver */
+	__u32 U_offset;
+	__u32 V_offset;
+
+	__u16 Y_stride;
+	__u16 UV_stride;
+};
+
+#define MBXFB_IOCX_OVERLAY	_IOWR(0xF4, 0x00,struct mbxfb_overlaySetup)
+
 #endif /* __MBX_FB_H */