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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/arm/lib/delay.S
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/arm/lib/delay.S')
-rw-r--r--arch/arm/lib/delay.S69
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)