1 files changed, 58 insertions, 0 deletions

diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay.S
new file mode 100644
index 000000000000..3c7f7e675dd8
--- /dev/null
+++ b/arch/arm/lib/delay.S
@@ -0,0 +1,58 @@
+/*
+ *  linux/arch/arm/lib/delay.S
+ *
+ *  Copyright (C) 1995, 1996 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+                .text
+
+LC0:            .word   loops_per_jiffy
+
+/*
+ * 0 <= r0 <= 2000
+ */
+ENTRY(__udelay)
+                mov     r2,     #0x6800
+                orr     r2, r2, #0x00db
+                mul     r0, r2, r0
+ENTRY(__const_udelay)                           @ 0 <= r0 <= 0x01ffffff
+                ldr     r2, LC0
+                ldr     r2, [r2]                @ max = 0x0fffffff
+                mov     r0, r0, lsr #11         @ max = 0x00003fff
+                mov     r2, r2, lsr #11         @ max = 0x0003ffff
+                mul     r0, r2, r0              @ max = 2^32-1
+                movs    r0, r0, lsr #6
+                RETINSTR(moveq,pc,lr)
+
+/*
+ * loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
+ *
+ * Oh, if only we had a cycle counter...
+ */
+
+@ Delay routine
+ENTRY(__delay)
+                subs    r0, r0, #1
+#if 0
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+                RETINSTR(movls,pc,lr)
+                subs    r0, r0, #1
+#endif
+                bhi     __delay
+                RETINSTR(mov,pc,lr)