From d2d58384fc5d4c0fe2d8e34bc2d15a90a9bb372a Mon Sep 17 00:00:00 2001
From: "Antonino A. Daplas" <adaplas@gmail.com>
Date: Fri, 9 Sep 2005 13:04:31 -0700
Subject: [PATCH] vesafb: Add blanking support

Add rudimentary support by manipulating the VGA registers.  However, not
all vesa modes are VGA compatible, so VGA compatiblity is checked first.
Only 2 levels are supported, powerup and powerdown.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 drivers/video/vesafb.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

(limited to 'drivers')

diff --git a/drivers/video/vesafb.c b/drivers/video/vesafb.c
index a272592b0373..1ca80264c7b0 100644
--- a/drivers/video/vesafb.c
+++ b/drivers/video/vesafb.c
@@ -19,6 +19,7 @@
 #include <linux/fb.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
+#include <video/vga.h>
 #include <asm/io.h>
 #include <asm/mtrr.h>
 
@@ -54,6 +55,7 @@ static unsigned short  *pmi_base  = NULL;
 static void            (*pmi_start)(void);
 static void            (*pmi_pal)(void);
 static int             depth;
+static int             vga_compat;
 
 /* --------------------------------------------------------------------- */
 
@@ -86,6 +88,37 @@ static int vesafb_pan_display(struct fb_var_screeninfo *var,
 	return 0;
 }
 
+static int vesafb_blank(int blank, struct fb_info *info)
+{
+	int err = 1;
+
+	if (vga_compat) {
+		int loop = 10000;
+		u8 seq = 0, crtc17 = 0;
+
+		err = 0;
+
+		if (blank) {
+			seq = 0x20;
+			crtc17 = 0x00;
+		} else {
+			seq = 0x00;
+			crtc17 = 0x80;
+		}
+
+		vga_wseq(NULL, 0x00, 0x01);
+		seq |= vga_rseq(NULL, 0x01) & ~0x20;
+		vga_wseq(NULL, 0x00, seq);
+
+		crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
+		while (loop--);
+		vga_wcrt(NULL, 0x17, crtc17);
+		vga_wseq(NULL, 0x00, 0x03);
+	}
+
+	return err;
+}
+
 static void vesa_setpalette(int regno, unsigned red, unsigned green,
 			    unsigned blue)
 {
@@ -176,6 +209,7 @@ static struct fb_ops vesafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= vesafb_setcolreg,
 	.fb_pan_display	= vesafb_pan_display,
+	.fb_blank       = vesafb_blank,
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
@@ -429,6 +463,10 @@ static int __init vesafb_probe(struct device *device)
 	info->flags = FBINFO_FLAG_DEFAULT |
 		(ypan) ? FBINFO_HWACCEL_YPAN : 0;
 
+	vga_compat = (screen_info.capabilities & 2) ? 0 : 1;
+	printk("vesafb: Mode is %sVGA compatible\n",
+	       (vga_compat) ? "" : "not ");
+
 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
 		err = -ENOMEM;
 		goto err;
-- 
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