Commit | Line | Data |
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9a8fd558 CZ |
1 | /* |
2 | * include/asm-xtensa/delay.h | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (C) 2001 - 2005 Tensilica Inc. | |
9 | * | |
10 | */ | |
11 | ||
12 | #ifndef _XTENSA_DELAY_H | |
13 | #define _XTENSA_DELAY_H | |
14 | ||
8102f47a | 15 | #include <asm/timex.h> |
9a8fd558 CZ |
16 | #include <asm/param.h> |
17 | ||
18 | extern unsigned long loops_per_jiffy; | |
19 | ||
d99cf715 | 20 | static inline void __delay(unsigned long loops) |
9a8fd558 | 21 | { |
01e3b3cb MF |
22 | if (__builtin_constant_p(loops) && loops < 2) |
23 | __asm__ __volatile__ ("nop"); | |
24 | else if (loops >= 2) | |
25 | /* 2 cycles per loop. */ | |
26 | __asm__ __volatile__ ("1: addi %0, %0, -2; bgeui %0, 2, 1b" | |
27 | : "+r" (loops)); | |
9a8fd558 CZ |
28 | } |
29 | ||
58f60c22 MF |
30 | /* Undefined function to get compile-time error */ |
31 | void __bad_udelay(void); | |
9ed82c68 | 32 | void __bad_ndelay(void); |
9a8fd558 | 33 | |
58f60c22 | 34 | #define __MAX_UDELAY 30000 |
9ed82c68 | 35 | #define __MAX_NDELAY 30000 |
58f60c22 MF |
36 | |
37 | static inline void __udelay(unsigned long usecs) | |
9a8fd558 | 38 | { |
8102f47a | 39 | unsigned long start = get_ccount(); |
58f60c22 | 40 | unsigned long cycles = (usecs * (ccount_freq >> 15)) >> 5; |
9a8fd558 CZ |
41 | |
42 | /* Note: all variables are unsigned (can wrap around)! */ | |
8102f47a | 43 | while (((unsigned long)get_ccount()) - start < cycles) |
58f60c22 MF |
44 | cpu_relax(); |
45 | } | |
46 | ||
47 | static inline void udelay(unsigned long usec) | |
48 | { | |
49 | if (__builtin_constant_p(usec) && usec >= __MAX_UDELAY) | |
50 | __bad_udelay(); | |
51 | else | |
52 | __udelay(usec); | |
9a8fd558 CZ |
53 | } |
54 | ||
9ed82c68 MF |
55 | static inline void __ndelay(unsigned long nsec) |
56 | { | |
57 | /* | |
58 | * Inner shift makes sure multiplication doesn't overflow | |
59 | * for legitimate nsec values | |
60 | */ | |
61 | unsigned long cycles = (nsec * (ccount_freq >> 15)) >> 15; | |
62 | __delay(cycles); | |
63 | } | |
64 | ||
65 | #define ndelay(n) ndelay(n) | |
66 | ||
67 | static inline void ndelay(unsigned long nsec) | |
68 | { | |
69 | if (__builtin_constant_p(nsec) && nsec >= __MAX_NDELAY) | |
70 | __bad_ndelay(); | |
71 | else | |
72 | __ndelay(nsec); | |
73 | } | |
74 | ||
9a8fd558 | 75 | #endif |