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authorArnd Bergmann <arnd@arndb.de>2009-06-16 15:31:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:47:27 -0700
commit08604bd9935dc98fb62ef61d5b7baa7ccc10f8c2 (patch)
tree2d0d451d78024bfbb4961a9ba94902abdc5f17e4 /include/linux/timex.h
parent03347e2592078a90df818670fddf97a33eec70fb (diff)
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op-kernel-dev-08604bd9935dc98fb62ef61d5b7baa7ccc10f8c2.tar.gz
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.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 9910e3b..e6967d1 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 */
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