mn10300: add the MN10300/AM33 architecture to the kernel

[pandora-kernel.git] / arch / mn10300 / lib / delay.c

diff --git a/arch/mn10300/lib/delay.c b/arch/mn10300/lib/delay.c
new file mode 100644 (file)
index 0000000..cce66bc
--- /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);