[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>

1 files changed, 38 insertions, 0 deletions

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;