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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-08-02 10:55:55 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-08-02 21:32:35 +0100
commit4baa9922430662431231ac637adedddbb0cfb2d7 (patch)
treee8fb765ce3e41c01f33de34a0bc9494f0ae19818 /arch/arm/include/asm/delay.h
parentff4db0a043a5dee7180bdffd178e61cd02812c68 (diff)
[ARM] move include/asm-arm to arch/arm/include/asm
Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/delay.h')
-rw-r--r--arch/arm/include/asm/delay.h44
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/include/asm/delay.h b/arch/arm/include/asm/delay.h
new file mode 100644
index 00000000000..b2deda18154
--- /dev/null
+++ b/arch/arm/include/asm/delay.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 1995-2004 Russell King
+ *
+ * Delay routines, using a pre-computed "loops_per_second" value.
+ */
+#ifndef __ASM_ARM_DELAY_H
+#define __ASM_ARM_DELAY_H
+
+#include <asm/param.h> /* HZ */
+
+extern void __delay(int loops);
+
+/*
+ * This function intentionally does not exist; if you see references to
+ * it, it means that you're calling udelay() with an out of range value.
+ *
+ * With currently imposed limits, this means that we support a max delay
+ * of 2000us. Further limits: HZ<=1000 and bogomips<=3355
+ */
+extern void __bad_udelay(void);
+
+/*
+ * division by multiplication: you don't have to worry about
+ * loss of precision.
+ *
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays. This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+extern void __udelay(unsigned long usecs);
+extern void __const_udelay(unsigned long);
+
+#define MAX_UDELAY_MS 2
+
+#define udelay(n) \
+ (__builtin_constant_p(n) ? \
+ ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \
+ __const_udelay((n) * ((2199023U*HZ)>>11))) : \
+ __udelay(n))
+
+#endif /* defined(_ARM_DELAY_H) */
+