Initial revision

1 files changed, 100 insertions, 0 deletions

diff --git a/lib_ppc/time.c b/lib_ppc/time.c
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+/*
+ * (C) Copyright 2000, 2001
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+
+
+/* ------------------------------------------------------------------------- */
+
+/*
+ * This function is intended for SHORT delays only.
+ * It will overflow at around 10 seconds @ 400MHz,
+ * or 20 seconds @ 200MHz.
+ */
+unsigned long usec2ticks(unsigned long usec)
+{
+	ulong ticks;
+
+	if (usec < 1000) {
+		ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
+	} else {
+		ticks = ((usec / 10) * (get_tbclk() / 100000));
+	}
+
+	return (ticks);
+}
+
+/* ------------------------------------------------------------------------- */
+
+/*
+ * We implement the delay by converting the delay (the number of
+ * microseconds to wait) into a number of time base ticks; then we
+ * watch the time base until it has incremented by that amount.
+ */
+void udelay(unsigned long usec)
+{
+	ulong ticks = usec2ticks (usec);
+
+	wait_ticks (ticks);
+}
+
+/* ------------------------------------------------------------------------- */
+
+unsigned long ticks2usec(unsigned long ticks)
+{
+	ulong tbclk = get_tbclk();
+
+	/* usec = ticks * 1000000 / tbclk
+	 * Multiplication would overflow at ~4.2e3 ticks,
+	 * so we break it up into
+	 * usec = ( ( ticks * 1000) / tbclk ) * 1000;
+	 */
+	ticks *= 1000L;
+	ticks /= tbclk;
+	ticks *= 1000L;
+
+	return ((ulong)ticks);
+}
+
+/* ------------------------------------------------------------------------- */
+
+int init_timebase (void)
+{
+#ifdef	CONFIG_8xx
+	volatile immap_t *immap = (immap_t *) CFG_IMMR;
+
+	/* unlock */
+	immap->im_sitk.sitk_tbk = KAPWR_KEY;
+#endif
+
+	/* reset */
+	asm ("li 3,0 ; mttbu 3 ; mttbl 3 ;");
+
+#ifdef	CONFIG_8xx
+	/* enable */
+	immap->im_sit.sit_tbscr |= TBSCR_TBE;
+#endif
+	return (0);
+}
+/* ------------------------------------------------------------------------- */
+