diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2009-06-17 02:31:12 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-17 06:47:27 +0400 |
| commit | 08604bd9935dc98fb62ef61d5b7baa7ccc10f8c2 (patch) | |
| tree | 2d0d451d78024bfbb4961a9ba94902abdc5f17e4 /include/linux/timex.h | |
| parent | 03347e2592078a90df818670fddf97a33eec70fb (diff) | |
| download | linux-08604bd9935dc98fb62ef61d5b7baa7ccc10f8c2.tar.xz | |
time: move PIT_TICK_RATE to linux/timex.h
PIT_TICK_RATE is currently defined in four architectures, but in three
different places. While linux/timex.h is not the perfect place for it, it
is still a reasonable replacement for those drivers that traditionally use
asm/timex.h to get CLOCK_TICK_RATE and expect it to be the PIT frequency.
Note that for Alpha, the actual value changed from 1193182UL to 1193180UL.
This is unlikely to make a difference, and probably can only improve
accuracy. There was a discussion on the correct value of CLOCK_TICK_RATE
a few years ago, after which every existing instance was getting changed
to 1193182. According to the specification, it should be
1193181.818181...
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/timex.h')
| -rw-r--r-- | include/linux/timex.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h index 9910e3bd5b31..e6967d10d9e5 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -280,6 +280,9 @@ extern int do_adjtimex(struct timex *); int read_current_timer(unsigned long *timer_val); +/* The clock frequency of the i8253/i8254 PIT */ +#define PIT_TICK_RATE 1193182ul + #endif /* KERNEL */ #endif /* LINUX_TIMEX_H */ |