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-rw-r--r--arch/unicore32/lib/delay.S51
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/unicore32/lib/delay.S b/arch/unicore32/lib/delay.S
new file mode 100644
index 0000000000000..24664c009e78a
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+++ b/arch/unicore32/lib/delay.S
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+/*
+ * linux/arch/unicore32/lib/delay.S
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * 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)
+ ldw r2, .LC1
+ mul r0, r2, r0
+ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
+ ldw r2, .LC0
+ ldw r2, [r2] @ max = 0x01ffffff
+ mov r0, r0 >> #14 @ max = 0x0001ffff
+ mov r2, r2 >> #10 @ max = 0x00007fff
+ mul r0, r2, r0 @ max = 2^32-1
+ mov.a r0, r0 >> #6
+ cmoveq pc, lr
+
+/*
+ * loops = r0 * HZ * loops_per_jiffy / 1000000
+ *
+ * Oh, if only we had a cycle counter...
+ */
+
+@ Delay routine
+ENTRY(__delay)
+ sub.a r0, r0, #2
+ bua __delay
+ mov pc, lr
+ENDPROC(__udelay)
+ENDPROC(__const_udelay)
+ENDPROC(__delay)