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-rw-r--r--lib_ppc/ticks.S65
1 files changed, 65 insertions, 0 deletions
diff --git a/lib_ppc/ticks.S b/lib_ppc/ticks.S
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+/*
+ * (C) Copyright 2000, 2001
+ * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
+ * base on code by
+ * 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 <ppc_asm.tmpl>
+#include <ppc_defs.h>
+#include <config.h>
+#include <watchdog.h>
+
+/*
+ * unsigned long long get_ticks(void);
+ *
+ * read timebase as "long long"
+ */
+ .globl get_ticks
+get_ticks:
+1: mftbu r3
+ mftb r4
+ mftbu r5
+ cmp 0,r3,r5
+ bne 1b
+ blr
+
+/*
+ * Delay for a number of ticks
+ */
+ .globl wait_ticks
+wait_ticks:
+ mflr r8 /* save link register */
+ mr r7, r3 /* save tick count */
+ bl get_ticks /* Get start time */
+
+ /* Calculate end time */
+ addc r7, r4, r7 /* Compute end time lower */
+ addze r6, r3 /* and end time upper */
+
+ WATCHDOG_RESET /* Trigger watchdog, if needed */
+1: bl get_ticks /* Get current time */
+ subfc r4, r4, r7 /* Subtract current time from end time */
+ subfe. r3, r3, r6
+ bge 1b /* Loop until time expired */
+
+ mtlr r8 /* restore link register */
+ blr