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, 6 insertions, 0 deletions

diff --git a/include/asm-sh/fb.h b/include/asm-sh/fb.h
index 4bf5b88d90bf..d92e99cd8c8a 100644
--- a/include/asm-sh/fb.h
+++ b/include/asm-sh/fb.h
@@ -1,6 +1,7 @@
 #ifndef _ASM_FB_H_
 #define _ASM_FB_H_
 
+#include <linux/fb.h>
 #include <linux/fs.h>
 #include <asm/page.h>
 
@@ -10,4 +11,9 @@ static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
         vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 }
 
+static inline int fb_is_primary_device(struct fb_info *info)
+{
+        return 0;
+}
+
 #endif /* _ASM_FB_H_ */