Each AMD Geode MFGPT timer interrupt output is paired with another
timer; esentially the interrupt goes if either timer fires. This
is okay, but the handlers need to be aware of this. Make sure in
the timer tick handler that our timer really did expire.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We *really* don't want to be reading MFGPTx_SETUP and writing back those
values. What we want to be doing is clearing CMP1 and CMP2 unconditionally;
otherwise, we have races where CMP1 and/or CMP2 fire after we've read
MFGPTx_SETUP. They can also fire between when we've written ~CNTEN to
the register, and when the new register values get copied to the timer's
version of the register. By clearing both fields, we're okay.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There isn't much value to always detecting the MFGPT timers on
Geode platforms; detection is only needed when something wants
to use the timers. Move the detection code so that it gets
called the first time a timer is allocated.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We need to be called from elsewhere, and this gets some #ifdefs out
of the .c file.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Drop F_AVAIL and the 'flags' field, replacing with an 'avail' bit. This
looks more understandable to me.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We had planned to use the 'owner' field for allowing re-allocation of
MFGPTs; however, doing it by module owner name isn't flexible enough. So,
drop this for now. If it turns out that we need timers in modules, we'll
need to come up with a scheme that matches the write-once fields of the
MFGPTx_SETUP register, and drops ponies from the sky.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The GEODE MFGPT code assumed that 32kHz was 32000 Hz while the boards
run on a 32.768 kHz digital watch crystal. In practise, it will not
change the timer's frequency as the skew was only 2.4%, but it
should provide more accurate intervals.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
- uninline timer functions; the compiler knows better than we do
whether or not to inline these.
- mfgpt_start_timer() had an unused 'clock' argument, drop it.
From both Jordan and myself.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The new "mfgptfix" boot command line option may be usd to fix MFGPT
timers on AMD Geode platforms when the BIOS has incorrectly applied
a workaround. TinyBIOS version 0.98 is known to be affected, 0.99
fixes the problem by letting the user disable the workaround.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When we set the MFGPT timer tick, there is a chance that we'll
immediately assert an event. If for some reason the IRQ routing
for this clock has been setup for some other purpose, then we
could end up firing an interrupt into the SMM handler or worse.
This rearranges the timer tick init function to initalize the handler
before we set up the MFGPT clock to make sure that even if we get
an event, it will go to the handler.
Furthermore, in the handler we need to make sure that we clear the
event, even if the timer isn't running.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Arnd Hannemann <hannemann@i4.informatik.rwth-aachen.de>
Add support for an MFGPT clock event device; this allows us to use MFGPTs as
the basis for high-resolution timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds support for Multi-Function General Purpose Timers. It detects the
available timers during southbridge init, and provides an API for allocating
and setting the timers. They're higher resolution than the standard PIT, so
the MFGPTs come in handy for quite a few things.
Note that we never clobber the timers that the BIOS might have opted to use;
we just check for unused timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
