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-rw-r--r--arch/arm/lib/delay-loop.S67
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
new file mode 100644
index 00000000000..36b668d8e12
--- /dev/null
+++ b/arch/arm/lib/delay-loop.S
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+/*
+ * 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/delay.h>
+ .text
+
+.LC0: .word loops_per_jiffy
+.LC1: .word UDELAY_MULT
+
+/*
+ * r0 <= 2000
+ * lpj <= 0x01ffffff (max. 3355 bogomips)
+ * HZ <= 1000
+ */
+
+ENTRY(__loop_udelay)
+ ldr r2, .LC1
+ mul r0, r2, r0
+ENTRY(__loop_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
+ */
+
+@ Delay routine
+ENTRY(__loop_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 __loop_delay
+ mov pc, lr
+ENDPROC(__loop_udelay)
+ENDPROC(__loop_const_udelay)
+ENDPROC(__loop_delay)