Import sources from 2011-03-30 iso image

1 files changed, 117 insertions, 0 deletions

diff --git a/sys/src/cmd/aux/vga/icd2061a.c b/sys/src/cmd/aux/vga/icd2061a.c
new file mode 100755
index 000000000..24eae0dfa
--- /dev/null
+++ b/sys/src/cmd/aux/vga/icd2061a.c
@@ -0,0 +1,117 @@
+/*
+ * IC Designs ICD2061A Dual Programmable Graphics Clock Generator.
+ */
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+
+#include "pci.h"
+#include "vga.h"
+
+enum {
+	Prescale	= 2,			/* P counter prescale (default) */
+	NIndex		= 14,			/* number of index field values */
+};
+
+/*
+ * For an index value of x, the appropriate VCO range
+ * is >= index[x] && <= index[x+1]. The higher index is
+ * prefered if VCO is on a boundary.
+ */
+static ulong index[NIndex] = {
+	 50000000,
+	 51000000,
+	 53200000,
+	 58500000,
+	 60700000,
+	 64400000,
+	 66800000,
+	 73500000,
+	 75600000,
+	 80900000,
+	 83200000,
+	 91500000,
+	100000000,
+	120000000,
+};
+
+static void
+init(Vga* vga, Ctlr* ctlr)
+{
+	int f;
+	ulong d, dmax, fmin, n;
+
+	if(ctlr->flag & Finit)
+		return;
+
+	if(vga->f[0] == 0)
+		vga->f[0] = vga->mode->frequency;
+
+	if(vga->mode->z > 8)
+		error("depth %d not supported\n", vga->mode->z);
+
+	/*
+	 * Post-VCO divisor. Constraint:
+	 * 	50MHz <= vga->f <= 120MHz
+	 */
+	for(vga->p[0] = 0; vga->f[0] <= 50000000; vga->p[0]++)
+		vga->f[0] <<= 1;
+
+	/*
+	 * Determine index.
+	 */
+	for(vga->i[0] = NIndex-1; vga->f[0] < index[vga->i[0]] && vga->i[0]; vga->i[0]--)
+		;
+
+	/*
+	 * Denominator. Constraints:
+	 *	200KHz <= RefFreq/d <= 1MHz
+	 * and
+	 *	3 <= d <= 129
+	 *
+	 * Numerator. Constraint:
+	 *	4 <= n <= 130
+	 */
+	d = RefFreq/1000000 > 3 ? RefFreq/1000000: 3;
+	dmax = RefFreq/200000 < 129 ? RefFreq/200000: 129;
+
+	/*
+	 * Now look for values of p and q that give
+	 * the least error for
+	 *	vga->f = (Prescale*RefFreq*n/d);
+	 */
+	vga->d[0] = d;
+	vga->n[0] = 4;
+	for(fmin = vga->f[0]; d <= dmax; d++){
+		for(n = 4; n <= 130; n++){
+			f = vga->f[0] - (Prescale*RefFreq*n/d);
+			if(f < 0)
+				f = -f;
+			if(f < fmin){
+				fmin = f;
+				vga->d[0] = d;
+				vga->n[0] = n;
+			}
+		}
+	}
+
+	/*
+	 * The serial word to be loaded into the icd2061a is
+	 *	(2<<21)|(vga->i<<17)|((vga->n)<<10)|(vga->p<<7)|vga->d
+	 * Always select ICD2061A REG2.
+	 */
+	vga->f[0] = (Prescale*RefFreq*vga->n[0]/vga->d[0]);
+	vga->d[0] -= 2;
+	vga->n[0] -= 3;
+
+	ctlr->flag |= Finit;
+}
+
+Ctlr icd2061a = {
+	"icd2061a",
+	0,				/* snarf */
+	0,				/* options */
+	init,				/* init */
+	0,				/* load */
+	0,				/* dump */
+};