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