1 files changed, 72 insertions, 0 deletions
diff --git a/arch/microblaze/include/asm/delay.h b/arch/microblaze/include/asm/delay.h
new file mode 100644
index 0000000..05b7d39
--- /dev/null
+++ b/arch/microblaze/include/asm/delay.h
@@ -0,0 +1,72 @@
+/*
+ * include/asm-microblaze/delay.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Michal Simek
+ * Copyright (C) 2007 John Williams
+ * Copyright (C) 2006 Atmark Techno, Inc.
+ */
+
+#ifndef _ASM_MICROBLAZE_DELAY_H
+#define _ASM_MICROBLAZE_DELAY_H
+
+extern inline void __delay(unsigned long loops)
+{
+	asm volatile ("# __delay		\n\t"		\
+			"1: addi	%0, %0, -1\t\n"		\
+			"bneid	%0, 1b		\t\n"		\
+			"nop			\t\n"
+			: "=r" (loops)
+			: "0" (loops));
+}
+
+/*
+ * Note that 19 * 226 == 4294 ==~ 2^32 / 10^6, so
+ * loops = (4294 * usecs * loops_per_jiffy * HZ) / 2^32.
+ *
+ * The mul instruction gives us loops = (a * b) / 2^32.
+ * We choose a = usecs * 19 * HZ and b = loops_per_jiffy * 226
+ * because this lets us support a wide range of HZ and
+ * loops_per_jiffy values without either a or b overflowing 2^32.
+ * Thus we need usecs * HZ <= (2^32 - 1) / 19 = 226050910 and
+ * loops_per_jiffy <= (2^32 - 1) / 226 = 19004280
+ * (which corresponds to ~3800 bogomips at HZ = 100).
+ * -- paulus
+ */
+#define __MAX_UDELAY	(226050910UL/HZ)	/* maximum udelay argument */
+#define __MAX_NDELAY	(4294967295UL/HZ)	/* maximum ndelay argument */
+
+extern unsigned long loops_per_jiffy;
+
+extern inline void __udelay(unsigned int x)
+{
+
+	unsigned long long tmp =
+		(unsigned long long)x * (unsigned long long)loops_per_jiffy \
+			* 226LL;
+	unsigned loops = tmp >> 32;
+
+/*
+	__asm__("mulxuu %0,%1,%2" : "=r" (loops) :
+		"r" (x), "r" (loops_per_jiffy * 226));
+*/
+	__delay(loops);
+}
+
+extern void __bad_udelay(void);		/* deliberately undefined */
+extern void __bad_ndelay(void);		/* deliberately undefined */
+
+#define udelay(n) (__builtin_constant_p(n) ? \
+	((n) > __MAX_UDELAY ? __bad_udelay() : __udelay((n) * (19 * HZ))) : \
+	__udelay((n) * (19 * HZ)))
+
+#define ndelay(n) (__builtin_constant_p(n) ? \
+	((n) > __MAX_NDELAY ? __bad_ndelay() : __udelay((n) * HZ)) : \
+	__udelay((n) * HZ))
+
+#define muldiv(a, b, c)		(((a)*(b))/(c))
+
+#endif /* _ASM_MICROBLAZE_DELAY_H */