fbdev: detect primary display device

Add function helper, fb_is_primary_device().  Given struct fb_info, it will
return a nonzero value if the device is the primary display.

Currently, only the i386 is supported where the function checks for the
IORESOURCE_ROM_SHADOW flag.

Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/asm-i386/fb.h b/include/asm-i386/fb.h
index d30073c75586..d1c6297d4a61 100644
--- a/include/asm-i386/fb.h
+++ b/include/asm-i386/fb.h
@@ -1,9 +1,12 @@
 #ifndef _ASM_FB_H_
 #define _ASM_FB_H_
 
+#include <linux/fb.h>
 #include <linux/fs.h>
 #include <asm/page.h>
 
+extern int fb_is_primary_device(struct fb_info *info);
+
 static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
                                 unsigned long off)
 {