Initial revisionXORG-STABLE

1 files changed, 99 insertions, 0 deletions

diff --git a/src/smi_dac.c b/src/smi_dac.c
new file mode 100644
index 0000000..627b892
--- /dev/null
+++ b/src/smi_dac.c
@@ -0,0 +1,99 @@
+/* Header:   //Mercury/Projects/archives/XFree86/4.0/smi_dac.c-arc   1.8   27 Nov 2000 15:47:08   Frido  $ */
+
+/*
+Copyright (C) 1994-1998 The XFree86 Project, Inc.  All Rights Reserved.
+Copyright (C) 2000 Silicon Motion, Inc.  All Rights Reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FIT-
+NESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+XFREE86 PROJECT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the names of the XFree86 Project and
+Silicon Motion shall not be used in advertising or otherwise to promote the
+sale, use or other dealings in this Software without prior written
+authorization from the XFree86 Project and Silicon Motion.
+*/
+/* $XFree86: xc/programs/Xserver/hw/xfree86/drivers/siliconmotion/smi_dac.c,v 1.2 2001/11/30 12:11:59 eich Exp $ */
+
+#include "smi.h"
+
+#define BASE_FREQ	14.31818	/* MHz */
+
+void
+SMI_CommonCalcClock(int scrnIndex, long freq, int min_m, int min_n1, 
+		    int max_n1, int min_n2, int max_n2, long freq_min, 
+		    long freq_max, unsigned char *mdiv, unsigned char *ndiv)
+{
+	double div, diff, best_diff;
+	unsigned int m;
+	unsigned char n1, n2;
+	unsigned char best_n1 = 63, best_n2 = 3, best_m = 255;
+
+	double ffreq     = freq     / 1000.0 / BASE_FREQ;
+	double ffreq_min = freq_min / 1000.0 / BASE_FREQ;
+	double ffreq_max = freq_max / 1000.0 / BASE_FREQ;
+
+	if (ffreq < ffreq_min / (1 << max_n2))
+	{
+		xf86DrvMsg(scrnIndex,X_WARNING,"invalid frequency %1.3f MHz  [freq >= %1.3f MHz]\n",
+				ffreq * BASE_FREQ, ffreq_min * BASE_FREQ / (1 << max_n2));
+		ffreq = ffreq_min / (1 << max_n2);
+	}
+	if (ffreq > ffreq_max / (1 << min_n2))
+	{
+		xf86DrvMsg(scrnIndex,X_WARNING,"invalid frequency %1.3f MHz  [freq <= %1.3f MHz]\n",
+				ffreq * BASE_FREQ, ffreq_max * BASE_FREQ / (1 << min_n2));
+		ffreq = ffreq_max / (1 << min_n2);
+	}
+
+	/* work out suitable timings */
+	best_diff = ffreq;
+
+	for (n2 = min_n2; n2 <= max_n2; n2++)
+	{
+		for (n1 = min_n1; n1 <= max_n1; n1++)
+		{
+			m = (int)(ffreq * n1 * (1 << n2) + 0.5);
+			if ( (m < min_m) || (m > 255) )
+			{
+				continue;
+			}
+			div = (double)(m) / (double)(n1);
+			if ( (div >= ffreq_min) && (div <= ffreq_max) )
+			{
+				diff = ffreq - div / (1 << n2);
+				if (diff < 0.0)
+				{
+					diff = -diff;
+				}
+				if (diff < best_diff)
+				{
+					best_diff = diff;
+					best_m    = m;
+					best_n1   = n1;
+					best_n2   = n2;
+				}
+			}
+		}
+	}
+
+	DEBUG((VERBLEV, "Clock parameters for %1.6f MHz: m=%d, n1=%d, n2=%d\n",
+			((double)(best_m) / (double)(best_n1) / (1 << best_n2)) * BASE_FREQ,
+			best_m, best_n1, best_n2));
+
+	*ndiv = best_n1 | (best_n2 << 6);
+	*mdiv = best_m;
+}