2006-08-07: Patches for the Matrox 4xx driver to support 16 an 24 bits modes (in addition to the existant 8 and 32). Also the G200 cards now work with hardware acceleration.

2006-08-12: Resubmit of the previous patch with corrected indentation, tabs are now used instead of hardcoded space (sorry about that one).

Leonardo Valencia <leoval@anixcorp.com>

Notes:
Sat Aug 12 02:30:08 EDT 2006 rsc
    That was fast!  Thanks.


Reference: /n/sources/patch/applied/mga4xx-newmodes-resub
Date: Sat Aug 12 08:28:34 CES 2006
Signed-off-by: leoval@anixcorp.com
Reviewed-by: rsc

--- /sys/src/9/pc/vgamga4xx.c	Sat Aug 12 08:28:25 2006
+++ /sys/src/9/pc/vgamga4xx.c	Sat Aug 12 08:28:24 2006
@@ -2,6 +2,10 @@
 /*
  * Matrox G200, G400 and G450.
  * Written by Philippe Anel <xigh@free.fr>
+ *
+ *  2006-08-07 : Minor fix to allow the G200 cards to work fine. YDSTORG is now initialized.
+ *             : Also support for 16 and 24 bit modes is added.
+ *             : by Leonardo Valencia <leoval@anixcorp.com>
  */
 
 #include "u.h"
@@ -43,6 +47,7 @@
  	SRCORG			= 0x2cb4,
 	PITCH			= 0x1c8c,
 	DSTORG			= 0x2cb8,
+	YDSTORG			= 0x1c94,
 	PLNWRT			= 0x1c1c,
 	ZORG			= 0x1c0c,
 	MACCESS			= 0x1c04,
@@ -465,18 +470,15 @@
 mga4xxdrawinit(VGAscr *scr)
 {
 	uchar *mga;
- 	Pcidev *p;
-
-	p = mgapcimatch();
-	if(p->did == MGA200)
-		return;
 
 	if(scr->mmio == 0)
 		return;
+
 	mga = (uchar*)scr->mmio;
 
 	mgawrite32(mga, SRCORG, 0);
 	mgawrite32(mga, DSTORG, 0);
+	mgawrite32(mga, YDSTORG, 0);
 	mgawrite32(mga, ZORG, 0);
 	mgawrite32(mga, PLNWRT, ~0);
 	mgawrite32(mga, FCOL, 0xffff0000);
@@ -487,6 +489,12 @@
 	switch(scr->gscreen->depth){
 	case 8:
 		mgawrite32(mga, MACCESS, 0);
+		break;
+	case 16:
+		mgawrite32(mga, MACCESS, 1);
+		break;
+	case 24:
+		mgawrite32(mga, MACCESS, 3);
 		break;
 	case 32:
 		mgawrite32(mga, MACCESS, 2);
--- /sys/src/cmd/aux/vga/mga4xx.c	Sat Aug 12 08:28:30 2006
+++ /sys/src/cmd/aux/vga/mga4xx.c	Sat Aug 12 08:28:28 2006
@@ -9,6 +9,9 @@
 	- 2001-09-06 : Added Full 2D Accel ! (see drivers in /sys/src/9/pc)
 	- 2001-10-01 : Rid Fix.
 	- 2006-04-01 : Add MGA550 support.
+	- 2006-08-07 : Add support for 16 and 24bits modes.
+				HW accel now works for the G200 cards too (see kernel).
+				by Leonardo Valencia <leoval@anixcorp.com>
 
      Greets and Acknowledgements go to :
      	- Sylvain Chipaux <a.k.a. asle>.
@@ -454,7 +457,7 @@
 	fd = open("#v/vgactl", OWRITE);
 	if(fd < 0)
 		error("mga: can't open vgactl\n");
-	
+
 	cmd[13] = '0' + depth;
 	if(write(fd, cmd, 14) != 14)
 		error("mga: can't set palette depth to %d\n", depth);
@@ -1067,6 +1070,7 @@
 	Ctlr*	c;
 	int	i;
 	ulong	t;
+	int     bppShift;
 
 	mga = vga->private;
 	mode = vga->mode;
@@ -1075,8 +1079,27 @@
 
 	ctlr->flag |= Ulinear;
 
-	if ((mode->z != 32) && (mode->z != 8))
+	/*
+	 * Set the right bppShitf based on depth
+	 */
+
+	switch(mode->z) {
+	case 8: 
+		bppShift = 0;
+		break;
+	case 16:
+		bppShift = 1;
+		break;
+	case 24:
+		bppShift = 0;
+		break;
+	case 32:
+		bppShift = 2;
+		break;
+	default:
+		bppShift = 0;
 		error("depth %d not supported !\n", mode->z);
+	}
 
 	if (mode->interlace)
 		error("interlaced mode not supported !\n");
@@ -1138,7 +1161,7 @@
 	mga->linecomp =		mode->y;
 	mga->hsyncsel = 		0;					/* Do not double lines ... */
 	mga->startadd =		0;
-	mga->offset =			(vga->virtx * mode->z) / 128;
+	mga->offset =		(mode->z==24) ? (vga->virtx * 3) >> (4 - bppShift) : vga->virtx >> (4-bppShift);
 	/* No Zoom */
 	mga->maxscan = 		0;
 	/* Not used in Power Graphic mode */
@@ -1176,9 +1199,9 @@
 	mga->crtcrstN =		1;
 
 	mga->mgamode = 		1;
-	mga->scale =			(mode->z == 8) ? 0 : 3;	/* 8 or 32 bits mode */
+	mga->scale   =		(mode->z == 24) ? ((1 << bppShift)*3)-1 : (1 << bppShift)-1;
 	
-	mga->crtcprotect =		1;
+	mga->crtcprotect =      1;
 	mga->winsize = 		0;
 	mga->winfreq = 		0;
 
@@ -1523,6 +1546,12 @@
 	case 8:
 		dacset(mga, Dac_Xmulctrl, _8bitsPerPixel, ColorDepth);	
 		break;
+	case 16:
+		dacset(mga, Dac_Xmulctrl, _16bitsPerPixel, ColorDepth);	
+		break;
+	case 24:
+		dacset(mga, Dac_Xmulctrl, _24bitsPerPixel, ColorDepth);	
+		break;
 	case 32:
 		dacset(mga, Dac_Xmulctrl, _32bitsPerPixel, ColorDepth);
 		break;
@@ -1569,11 +1598,12 @@
 	trace("mga: crtcext MgaMode loaded !\n");
 	if (ultradebug) Bflush(&stdout);
 
-	if (mode->z == 32) {
+	if (mode->z == 32 || mode->z == 24 ) {
 		/* Initialize Big Endian Mode ! */
 		mgawrite32(mga, 0x1e54, 0x02 << 16);
 	}
 
+
 	/* Set final misc ... enable mapping ... */
 	miscset(mga, mga->misc | Misc_rammapen, 0);
 
@@ -1597,7 +1627,13 @@
 
 	trace("mga: Loaded [bis]!\n" );
 
-	if (mode->z != 8) {
+	/*
+	 * TODO: In 16bpp mode, what is the correct palette ?
+	 *       in the meantime lets use the default one,
+	 *       which has a weird color combination.
+	 */
+
+	if (mode->z != 8 && mode ->z != 16) {
 		/* Initialize Palette */
 		mgawrite8(mga, RAMDACIDX, 0);
 		for (i = 0; i < 0x100; i++) {
@@ -1606,6 +1642,7 @@
 			mgawrite8(mga, RAMDACPALDATA, i);
 		}
 	}
+      
 	trace("mga: Palette initialised !\n");
 
 	/* Enable Cursor */