Blame view

kernel/linux-rt-4.4.41/arch/blackfin/include/asm/delay.h 917 Bytes
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
  /*
   * delay.h - delay functions
   *
   * Copyright (c) 2004-2007 Analog Devices Inc.
   *
   * Licensed under the GPL-2 or later.
   */
  
  #ifndef __ASM_DELAY_H__
  #define __ASM_DELAY_H__
  
  #include <mach/anomaly.h>
  
  static inline void __delay(unsigned long loops)
  {
  __asm__ __volatile__ (
  			"LSETUP(1f, 1f) LC0 = %0;"
  			"1: NOP;"
  			:
  			: "a" (loops)
  			: "LT0", "LB0", "LC0"
  		);
  }
  
  #include <linux/param.h>	/* needed for HZ */
  
  /*
   * close approximation borrowed from m68knommu to avoid 64-bit math
   */
  
  #define	HZSCALE		(268435456 / (1000000/HZ))
  
  static inline unsigned long __to_delay(unsigned long scale)
  {
  	extern unsigned long loops_per_jiffy;
  	return (((scale * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6;
  }
  
  static inline void udelay(unsigned long usecs)
  {
  	__delay(__to_delay(usecs));
  }
  
  static inline void ndelay(unsigned long nsecs)
  {
  	__delay(__to_delay(1) * nsecs / 1000);
  }
  
  #define ndelay ndelay
  
  #endif