Generic udelay() with watchdog support

According to the PPC reference implementation the udelay() function is
responsible for resetting the watchdog timer as frequently as needed.
Most other architectures do not meet that requirement, so long-running
operations might result in a watchdog reset.

This patch adds a generic udelay() function which takes care of
resetting the watchdog before calling an architecture-specific
__udelay().

Signed-off-by: Ingo van Lil <inguin@gmx.de>

1 files changed, 43 insertions, 0 deletions

diff --git a/lib_generic/time.c b/lib_generic/time.c
new file mode 100644
index 0000000..a309c26
--- /dev/null
+++ b/lib_generic/time.c
@@ -0,0 +1,43 @@
+/*
+ * (C) Copyright 2000-2009
+ * 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>
+#include <watchdog.h>
+
+#ifndef CONFIG_WD_PERIOD
+# define CONFIG_WD_PERIOD	(10 * 1000 * 1000)	/* 10 seconds default*/
+#endif
+
+/* ------------------------------------------------------------------------- */
+
+void udelay(unsigned long usec)
+{
+	ulong kv;
+
+	do {
+		WATCHDOG_RESET();
+		kv = usec > CONFIG_WD_PERIOD ? CONFIG_WD_PERIOD : usec;
+		__udelay (kv);
+		usec -= kv;
+	} while(usec);
+}