Intel FB: support for interlaced video modes

Intel framebuffer now supports interlaced video modes.

Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/intelfb/intelfbhw.c b/drivers/video/intelfb/intelfbhw.c
index 6a47682..04d0e0f 100644
--- a/drivers/video/intelfb/intelfbhw.c
+++ b/drivers/video/intelfb/intelfbhw.c
@@ -323,11 +323,7 @@
 		return 1;
 	}
 
-	/* Check for interlaced/doublescan modes. */
-	if (var->vmode & FB_VMODE_INTERLACED) {
-		WRN_MSG("Mode is interlaced.\n");
-		return 1;
-	}
+	/* Check for doublescan modes. */
 	if (var->vmode & FB_VMODE_DOUBLE) {
 		WRN_MSG("Mode is double-scan.\n");
 		return 1;
@@ -1220,6 +1216,12 @@
 
 	/* Set the palette to 8-bit mode. */
 	*pipe_conf &= ~PIPECONF_GAMMA;
+
+	if (var->vmode & FB_VMODE_INTERLACED)
+		*pipe_conf |= PIPECONF_INTERLACE_W_FIELD_INDICATION;
+	else
+		*pipe_conf &= ~PIPECONF_INTERLACE_MASK;
+
 	return 0;
 }
 
diff --git a/drivers/video/intelfb/intelfbhw.h b/drivers/video/intelfb/intelfbhw.h
index 8c54ba8..cfcd537 100644
--- a/drivers/video/intelfb/intelfbhw.h
+++ b/drivers/video/intelfb/intelfbhw.h
@@ -286,6 +286,10 @@
 #define PIPECONF_UNLOCKED		0
 #define PIPECONF_GAMMA			(1 << 24)
 #define PIPECONF_PALETTE		0
+#define PIPECONF_PROGRESSIVE			(0 << 21)
+#define PIPECONF_INTERLACE_W_FIELD_INDICATION	(6 << 21)
+#define PIPECONF_INTERLACE_FIELD_0_ONLY		(7 << 21)
+#define PIPECONF_INTERLACE_MASK			(7 << 21)
 
 #define DISPARB			0x70030
 #define DISPARB_AEND_MASK		0x1ff