Blame view

kernel/linux-rt-4.4.41/arch/c6x/include/asm/delay.h 1.67 KB
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
  /*
   *  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
  "
  		      "0: [%1] b     .s1  0b
  "
  		      "        add   .l1  -6,%0,%0
  "
  		      "        cmplt .l1  1,%0,%1
  "
  		      "        nop   3
  "
  		      : "+a"(loops), "=A"(tmp));
  }
  
  static inline void _c6x_tickdelay(unsigned int x)
  {
  	uint32_t cnt, endcnt;
  
  	asm volatile ("        mvc   .s2   TSCL,%0
  "
  		      "        add   .s2x  %0,%1,%2
  "
  		      " ||     mvk   .l2   1,B0
  "
  		      "0: [B0] b     .s2   0b
  "
  		      "        mvc   .s2   TSCL,%0
  "
  		      "        sub   .s2   %0,%2,%0
  "
  		      "        cmpgt .l2   0,%0,B0
  "
  		      "        nop   2
  "
  		      : "=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 */