atmel_lcdfb: use spare bits in 32bpp mode as alpha channel

Set var->transp.offset and var->transp.length in 32bpp mode to indicate
that the 8 otherwise unused bits can be used for transparency.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index 69ec93ce436a..235b618b4117 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -219,8 +219,11 @@ static int atmel_lcdfb_check_var(struct fb_var_screeninfo *var,
                 var->blue.offset = 10;
                 var->red.length = var->green.length = var->blue.length = 5;
                 break;
-        case 24:
         case 32:
+                var->transp.offset = 24;
+                var->transp.length = 8;
+                /* fall through */
+        case 24:
                 var->red.offset = 0;
                 var->green.offset = 8;
                 var->blue.offset = 16;