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.

Leonardo Valencia <leoval@anixcorp.com>

Notes:
Sat Aug 12 01:46:10 EDT 2006 rsc
    Thanks!  This is great.
    Could you resubmit with tabs instead of
    spaces and mimicking the indentation style
    of the surrounding code?
    
    Thanks.


Reference: /n/sources/patch/sorry/mga4xx-fixes
Date: Wed Aug  9 10:57:41 CES 2006
Signed-off-by: leoval@anixcorp.com
Reviewed-by: rsc

--- /sys/src/cmd/aux/vga/mga4xx.c	Wed Aug  9 10:57:33 2006
+++ /sys/src/cmd/aux/vga/mga4xx.c	Wed Aug  9 10:57:30 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 driver).
+                     : by Leonardo Valencia <leoval@anixcorp.com>
 
      Greets and Acknowledgements go to :
      	- Sylvain Chipaux <a.k.a. asle>.
@@ -454,9 +457,10 @@
 	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)
+
+        cmd[13] = '0' + depth;
+        
+        if(write(fd, cmd, 14) != 14)
 		error("mga: can't set palette depth to %d\n", depth);
 
 	close(fd);
@@ -1067,6 +1071,7 @@
 	Ctlr*	c;
 	int	i;
 	ulong	t;
+        int     bppShift;
 
 	mga = vga->private;
 	mode = vga->mode;
@@ -1075,8 +1080,27 @@
 
 	ctlr->flag |= Ulinear;
 
-	if ((mode->z != 32) && (mode->z != 8))
-		error("depth %d not supported !\n", mode->z);
+        /*
+         * 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 +1162,7 @@
 	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 +1200,9 @@
 	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 +1547,12 @@
 	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;
@@ -1569,10 +1599,11 @@
 	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 +1628,13 @@
 
 	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 +1643,7 @@
 			mgawrite8(mga, RAMDACPALDATA, i);
 		}
 	}
+      
 	trace("mga: Palette initialised !\n");
 
 	/* Enable Cursor */
--- /sys/src/9/pc/vgamga4xx.c	Wed Aug  9 10:57:38 2006
+++ /sys/src/9/pc/vgamga4xx.c	Wed Aug  9 10:57:37 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);
@@ -488,6 +490,12 @@
 	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);
 		break;