vga: make kernel vga drivers more stupid

previously, we had to maintain 3 sets of pci vid/did's:

1) in /lib/vgadb for detection
2) in the userspace driver in aux/vga
3) in the kernel mode driver

this change makes the kernel mode driver more dumb in
the cases where possible. we let userspace do the pci
enumeration and if needed, it can set the pci address
of the vga card. kernel mode drivers can assume to get
the right pci device passed in scr->pci for enable()
and linear() functions and just do very basic sanity
checking before mapping framebuffer and mmio regions.

vgalinearpciid() was removed as userspace is responsible
to pick pci device.

theres a new vgactl message "pcidev" where userspace
can set the bus address. we initialize scr->pci in
vgareset() to the first pci graphics card found. this
should cover cases when an old aux/vga binary is used
that doesnt use the new pcidev message.

userspace drivers will now use the pci device that got
a match from /lib/vgadb and skip ther own enumeration.
this way, vga cards can be made to work by simply adding
an entry in vgadb with no need to modify userspace or
kernelspace drivers. this is not always possible if
the driver derives information from the specific card
model.

1 files changed, 22 insertions, 23 deletions

diff --git a/sys/src/cmd/aux/vga/i81x.c b/sys/src/cmd/aux/vga/i81x.c
index b1fdf74be..9ee726b33 100644
--- a/sys/src/cmd/aux/vga/i81x.c
+++ b/sys/src/cmd/aux/vga/i81x.c
@@ -25,7 +25,7 @@ typedef struct {
 static void
 snarf(Vga* vga, Ctlr* ctlr)
 {
-	int f, i;
+	int i;
 	uchar *mmio;
 	ulong *rp;
 	Pcidev *p;
@@ -33,31 +33,30 @@ snarf(Vga* vga, Ctlr* ctlr)
 
 	if(vga->private == nil){
 		vga->private = alloc(sizeof(I81x));
-		p = nil;
-		while((p = pcimatch(p, 0x8086, 0)) != nil) {
-			switch(p->did) {
-			default:
-				continue;
-			case 0x7121:	/* Vanilla 82810 */
-			case 0x7123:	/* 810-DC100, DELL OptiPlex GX100 */
-			case 0x7125:	/* 82810E */
-			case 0x1102:	/* 82815 FSB limited to 100MHz */
-			case 0x1112:	/* 82815 no AGP */
-			case 0x1132:	/* 82815 fully featured Solano */
-			case 0x3577:	/* IBM R31 uses intel 830M chipset */
-				vga->f[1] = 230000000;		/* MAX speed of internal DAC (Hz)*/
+		p = vga->pci;
+		if(p == nil){
+			while((p = pcimatch(p, 0x8086, 0)) != nil) {
+				switch(p->did) {
+				default:
+					continue;
+				case 0x7121:	/* Vanilla 82810 */
+				case 0x7123:	/* 810-DC100, DELL OptiPlex GX100 */
+				case 0x7125:	/* 82810E */
+				case 0x1102:	/* 82815 FSB limited to 100MHz */
+				case 0x1112:	/* 82815 no AGP */
+				case 0x1132:	/* 82815 fully featured Solano */
+				case 0x3577:	/* IBM R31 uses intel 830M chipset */
+					break;
+				}
 				break;
 			}
-			break;
+			if(p == nil)
+				error("%s: Intel 81x graphics function not found\n", ctlr->name);
 		}
-		if(p == nil)
-			error("%s: Intel 81x graphics function not found\n", ctlr->name);
-
-		if((f = open("#v/vgactl", OWRITE)) < 0)
-			error("%s: can't open vgactl\n", ctlr->name);
-		if(write(f, "type i81x", 9) != 9)
-			error("%s: can't set type\n", ctlr->name);
-		close(f);
+		vga->f[1] = 230000000;		/* MAX speed of internal DAC (Hz)*/
+
+		vgactlpci(p);
+		vgactlw("type", "i81x");
 
 		mmio = segattach(0, "i81xmmio", 0, p->mem[1].size);
 		if(mmio == (void*)-1)