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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/lib/delay.S
downloadlinux-linaro-stable-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/arm/lib/delay.S')
-rw-r--r--arch/arm/lib/delay.S58
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)