Update AT91SAM9/CAP9 PIT driver to use generic time and clockevent
infrastructure:
- Clocksource gives sub-microsecond timestamp precision, assuming
memory is clocked at over 16 MHz. It's less than a 32 bit counter,
unless it's is also generating IRQs.
- Clockevent device supports periodic mode only; no oneshot
support from this hardware. No IRQs generated unless it's the
active clocksource.
Later, another timer (probably from a TC module) can provide a oneshot
clockevent device to get NO_HZ and High-Res-Timer behavior.
This also updates the timekeeping to use the actual master clock rate
on the system, instead of compile-time <asm/arch/timex.h> constants
matching what Atmel's EK boards use. (Product boards may well differ!)
Plus cleanup: rename "*_timer*" symbols to "*_pit*" (there are other
timers, but only one PIT); shorter lines; remove needless CPP stuff;
make several symbols static; etc.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
move update_process_times() out from under xtime_lock.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add IRQF_IRQPOLL for each timer interrupt.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix an overrun in the AT91SAM9 gettimeoffset() function. This causes
the time value returned by gettimeofday() to jump "backwards".
Original patch from Michel Benoit.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that Linux includes support for the Atmel AT91SAM9260 and
AT91SAM9261 processors in addition to the original Atmel AT91RM9200
(with support for more AT91 processors pending), the "mach-at91rm9200"
and "arch-at91rm9200" directories should be renamed to indicate their
more generic nature.
The following git commands should be run BEFORE applying this patch:
git-mv arch/arm/mach-at91rm9200 arch/arm/mach-at91
git-mv include/asm-arm/arch-at91rm9200 include/asm-arm/arch-at91
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King