From f53525dcd552088d3097b3d85464e1911d1b843e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 4 May 2000 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2000-05-04

---
 carrera/screen.c |  5 ++++
 carrera/screen.h |  1 +
 pc/screen.h      |  1 -
 pc/vgamach64xx.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/carrera/screen.c b/carrera/screen.c
index 750467be56986b85a4f173abe7f7fceded19af8b..f432a9b4ea0a52ac26abe7aea1f52adbc3fb594c 100644
--- a/carrera/screen.c
+++ b/carrera/screen.c
@@ -608,3 +608,8 @@ screenunload(Rectangle r, uchar *data, int tl, int l, int dolock)
 	}
 	unlock(&screenlock);
 }
+
+void
+blankscreen(int)
+{
+}
diff --git a/carrera/screen.h b/carrera/screen.h
index e2263272d22f9cf237baffcc2d4a71e35a9c5700..2e600cc2f910c2d04a24124c0df55eabc9a6a4e8 100644
--- a/carrera/screen.h
+++ b/carrera/screen.h
@@ -17,3 +17,4 @@ void		setcursor(Cursor*);
 
 void		mousectl(char*[], int);
 void		mousetrack(int, int, int);
+void		blankscreen(int);
diff --git a/pc/screen.h b/pc/screen.h
index 97791ae8b4984a16fa6aed1d4a012a27584f64b3..7177d8cf4e8a5ecddf1b62c5a7abeb0ba6487e94 100644
--- a/pc/screen.h
+++ b/pc/screen.h
@@ -68,7 +68,6 @@ struct VGAdev {
 	ulong	(*linear)(VGAscr*, int*, int*);
 	void	(*drawinit)(VGAscr*);
 	int	(*fill)(VGAscr*, Rectangle, ulong);
-
 };
 
 struct VGAcur {
diff --git a/pc/vgamach64xx.c b/pc/vgamach64xx.c
index ee6627ccafb45537f1cafedc482a1e0c32a08f75..a5ca070414c719da7d06fbde4ec2d754881571ff 100644
--- a/pc/vgamach64xx.c
+++ b/pc/vgamach64xx.c
@@ -64,6 +64,8 @@ mach64xxenable(VGAscr* scr)
 	if(scr->io)
 		return;
 	if(p = mach64xxpci()){
+		scr->id = p->did;
+
 		/*
 		 * The CT doesn't always have the I/O base address
 		 * in the PCI base registers. There is a way to find
@@ -181,6 +183,22 @@ enum {
 	ClrCmpMask,
 	DpChainMask,
 	SrcOffPitch,	
+	LcdIndex,
+	LcdData,
+};
+
+enum {
+	LCD_ConfigPanel = 0,
+	LCD_GenCtrl,
+	LCD_DstnCntl,
+	LCD_HfbPitchAddr,
+	LCD_HorzStretch,
+	LCD_VertStretch,
+	LCD_ExtVertStretch,
+	LCD_LtGio,
+	LCD_PowerMngmnt,
+	LCD_ZvgPio,
+	Nlcd,
 };
 
 static uchar mmoffset[] = {
@@ -191,6 +209,8 @@ static uchar mmoffset[] = {
 	[CurHVposn]	0x1B,
 	[CurHVoff]	0x1C,
 	[BusCntl]		0x28,
+	[LcdIndex]	0x29,
+	[LcdData]	0x2A,
 	[GenTestCntl]	0x34,
 	[DstOffPitch]	0x40,
 	[DstYX]		0x43,
@@ -254,6 +274,26 @@ iow32(VGAscr* scr, int r, ulong l)
 		outl((mmoffset[r]<<2)+scr->io, l);
 }
 
+static ulong
+lcdr32(VGAscr *scr, ulong r)
+{
+	ulong or;
+
+	or = ior32(scr, LcdIndex);
+	iow32(scr, LcdIndex, (or&~0x0F) | (r&0x0F));
+	return ior32(scr, LcdData);
+}
+
+static void
+lcdw32(VGAscr *scr, ulong r, ulong v)
+{
+	ulong or;
+
+	or = ior32(scr, LcdIndex);
+	iow32(scr, LcdIndex, (or&~0x0F) | (r&0x0F));
+	iow32(scr, LcdData, v);
+}
+
 static void
 mach64xxcurdisable(VGAscr* scr)
 {
@@ -660,6 +700,7 @@ mach64hwscroll(VGAscr *scr, Rectangle r, Rectangle sr)
 
 /*
  * This should work, but doesn't.
+ * It messes up the screen timings for some reason.
  */
 static void
 mach64blank(VGAscr *scr, int blank)
@@ -672,6 +713,37 @@ mach64blank(VGAscr *scr, int blank)
 	iow32(scr, CrtcGenCtl, ctl);
 }
 
+/*
+ * We squirrel away whether the LCD and/or CRT were
+ * on when we were called to blank the screen, and
+ * restore the old state.  If we are called to blank the
+ * screen when it is already blank, we don't update the state.
+ * Such a call sequence should not happen, though.
+ *
+ * We could try forcing the chip into power management
+ * mode instead, but I'm not sure how that would interact
+ * with screen updates going on while the screen is blanked.
+ */
+static void
+mach64lcdblank(VGAscr *scr, int blank)
+{
+	static int crtlcd;
+	ulong x;
+
+	if(blank) {
+		x = lcdr32(scr, LCD_GenCtrl);
+		if(x & 3) {
+			crtlcd = x & 3;
+			lcdw32(scr, LCD_GenCtrl,  x&~3);
+		}
+	} else {
+		if(crtlcd == 0)
+			crtlcd = 2;	/* lcd only */
+		x = lcdr32(scr, LCD_GenCtrl);
+		lcdw32(scr, LCD_GenCtrl, x | crtlcd);
+	}
+}
+
 static void
 mach64xxdrawinit(VGAscr *scr)
 {
@@ -681,9 +753,10 @@ mach64xxdrawinit(VGAscr *scr)
 		scr->scroll = mach64hwscroll;
 	}
 /*	scr->blank = mach64blank; */
+	if(scr->id == ('L'<<8)|'P')	/* Rage LT PRO */
+		scr->blank = mach64lcdblank;
 }
 
-
 VGAdev vgamach64xxdev = {
 	"mach64xx",