original_kernel/arch/c6x/include/asm/delay.h

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/*
* Port on Texas Instruments TMS320C6x architecture
*
* Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
*
* 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.
*/
#ifndef _ASM_C6X_DELAY_H
#define _ASM_C6X_DELAY_H
#include <linux/kernel.h>
extern unsigned int ticks_per_ns_scaled;
static inline void __delay(unsigned long loops)
{
uint32_t tmp;
/* 6 cycles per loop */
asm volatile (" mv .s1 %0,%1\n"
"0: [%1] b .s1 0b\n"
" add .l1 -6,%0,%0\n"
" cmplt .l1 1,%0,%1\n"
" nop 3\n"
: "+a"(loops), "=A"(tmp));
}
static inline void _c6x_tickdelay(unsigned int x)
{
uint32_t cnt, endcnt;
asm volatile (" mvc .s2 TSCL,%0\n"
" add .s2x %0,%1,%2\n"
" || mvk .l2 1,B0\n"
"0: [B0] b .s2 0b\n"
" mvc .s2 TSCL,%0\n"
" sub .s2 %0,%2,%0\n"
" cmpgt .l2 0,%0,B0\n"
" nop 2\n"
: "=b"(cnt), "+a"(x), "=b"(endcnt) : : "B0");
}
/* use scaled math to avoid slow division */
#define C6X_NDELAY_SCALE 10
static inline void _ndelay(unsigned int n)
{
_c6x_tickdelay((ticks_per_ns_scaled * n) >> C6X_NDELAY_SCALE);
}
static inline void _udelay(unsigned int n)
{
while (n >= 10) {
_ndelay(10000);
n -= 10;
}
while (n-- > 0)
_ndelay(1000);
}
#define udelay(x) _udelay((unsigned int)(x))
#define ndelay(x) _ndelay((unsigned int)(x))
#endif /* _ASM_C6X_DELAY_H */