[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>

3 files changed, 45 insertions, 1 deletions

diff --git a/arch/i386/boot/video.S b/arch/i386/boot/video.S
index 0587477c99f2..02bf625a681b 100644
--- a/arch/i386/boot/video.S
+++ b/arch/i386/boot/video.S
@@ -97,6 +97,7 @@
 #define PARAM_VESAPM_OFF        0x30
 #define PARAM_LFB_PAGES         0x32
 #define PARAM_VESA_ATTRIB       0x34
+#define PARAM_CAPABILITIES      0x36
 
 /* Define DO_STORE according to CONFIG_VIDEO_RETAIN */
 #ifdef CONFIG_VIDEO_RETAIN
@@ -233,6 +234,10 @@ mopar_gr:
         movw    18(%di), %ax
         movl    %eax, %fs:(PARAM_LFB_SIZE)
 
+# store mode capabilities
+        movl    10(%di), %eax
+        movl    %eax, %fs:(PARAM_CAPABILITIES)
+
 # switching the DAC to 8-bit is for <= 8 bpp only
         movw    %fs:(PARAM_LFB_DEPTH), %ax
         cmpw    $8, %ax
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;
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 59ff42c629ec..1267f88ece6e 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -74,7 +74,8 @@ struct screen_info {
         u16 vesapm_off;         /* 0x30 */
         u16 pages;              /* 0x32 */
         u16 vesa_attributes;    /* 0x34 */
-                                /* 0x36 -- 0x3f reserved for future expansion */
+        u32  capabilities;      /* 0x36 */
+                                /* 0x3a -- 0x3f reserved for future expansion */
 };
 
 extern struct screen_info screen_info;