projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 |