1 files changed, 69 insertions, 0 deletions

diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay.S
new file mode 100644
index 00000000000..3c9a05c8d20
--- /dev/null
+++ b/arch/arm/lib/delay.S
@@ -0,0 +1,69 @@
+/*
+ *  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>
+#include <asm/param.h>
+                .text
+
+.LC0:           .word   loops_per_jiffy
+.LC1:           .word   (2199023*HZ)>>11
+
+/*
+ * r0  <= 2000
+ * lpj <= 0x01ffffff (max. 3355 bogomips)
+ * HZ  <= 1000
+ */
+
+ENTRY(__udelay)
+                ldr     r2, .LC1
+                mul     r0, r2, r0
+ENTRY(__const_udelay)                           @ 0 <= r0 <= 0x7fffff06
+                mov     r1, #-1
+                ldr     r2, .LC0
+                ldr     r2, [r2]                @ max = 0x01ffffff
+                add     r0, r0, r1, lsr #32-14
+                mov     r0, r0, lsr #14         @ max = 0x0001ffff
+                add     r2, r2, r1, lsr #32-10
+                mov     r2, r2, lsr #10         @ max = 0x00007fff
+                mul     r0, r2, r0              @ max = 2^32-1
+                add     r0, r0, r1, lsr #32-6
+                movs    r0, r0, lsr #6
+                moveq   pc, lr
+
+/*
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
+ *
+ * Oh, if only we had a cycle counter...
+ */
+
+@ Delay routine
+ENTRY(__delay)
+                subs    r0, r0, #1
+#if 0
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+                movls   pc, lr
+                subs    r0, r0, #1
+#endif
+                bhi     __delay
+                mov     pc, lr
+ENDPROC(__udelay)
+ENDPROC(__const_udelay)
+ENDPROC(__delay)