unicore32 additional architecture files: low-level lib: misc

This patch implements the rest low-level libraries.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 52 insertions, 0 deletions

diff --git a/arch/unicore32/include/asm/delay.h b/arch/unicore32/include/asm/delay.h
new file mode 100644
index 000000000000..164ae61cd6f7
--- /dev/null
+++ b/arch/unicore32/include/asm/delay.h
@@ -0,0 +1,52 @@
+/*
+ * linux/arch/unicore32/include/asm/delay.h
+ *
+ * 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.
+ *
+ * Delay routines, using a pre-computed "loops_per_second" value.
+ */
+#ifndef __UNICORE_DELAY_H__
+#define __UNICORE_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 /* __UNICORE_DELAY_H__ */
+