summaryrefslogtreecommitdiff
path: root/arch/mn10300/lib/delay.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mn10300/lib/delay.c')
-rw-r--r--arch/mn10300/lib/delay.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/mn10300/lib/delay.c b/arch/mn10300/lib/delay.c
new file mode 100644
index 000000000000..cce66bc0822d
--- /dev/null
+++ b/arch/mn10300/lib/delay.c
@@ -0,0 +1,50 @@
+/* MN10300 Short delay interpolation routines
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <asm/div64.h>
+
+/*
+ * basic delay loop
+ */
+void __delay(unsigned long loops)
+{
+ int d0;
+
+ asm volatile(
+ " bra 1f \n"
+ " .align 4 \n"
+ "1: bra 2f \n"
+ " .align 4 \n"
+ "2: add -1,%0 \n"
+ " bne 2b \n"
+ : "=&d" (d0)
+ : "0" (loops));
+}
+EXPORT_SYMBOL(__delay);
+
+/*
+ * handle a delay specified in terms of microseconds
+ */
+void __udelay(unsigned long usecs)
+{
+ signed long ioclk, stop;
+
+ /* usecs * CLK / 1E6 */
+ stop = __muldiv64u(usecs, MN10300_TSCCLK, 1000000);
+ stop = TMTSCBC - stop;
+
+ do {
+ ioclk = TMTSCBC;
+ } while (stop < ioclk);
+}
+EXPORT_SYMBOL(__udelay);