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What is the right way to setup MIPS timer irq in 2.6.29?

To: linux-mips@linux-mips.org
Subject: What is the right way to setup MIPS timer irq in 2.6.29?
From: David Wuertele <dave+gmane@wuertele.com>
Date: Wed, 8 Apr 2009 16:57:33 +0000 (UTC)
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
User-agent: Loom/3.14 (http://gmane.org/)
Has the system timer paradigm changed between 2.6.18 and 2.6.29?
I'm trying to update my Broadcom-based embedded system to 2.6.29,
and I'm running into problems getting the system timer to run.
I'm looking for a clue about how to port forward my arch/mips/brcmstb/*
files, specifically I want to write a plat_time_init() function
that does for 2.6.29 what plat_timer_setup(struct irqaction *irq)
did for 2.6.18.

In 2.6.18, arch/mips/kernel/time.c defines a high-level ISR called
timer_interrupt (which does things like lock xtime_lock, call
mips_hpt_read() and do_timer(regs), and return IRQ_HANDLED). time.c
then defines a struct irqaction timer_irqaction and sets
timer_interrupt to be the .handler field.  Finally, time.c calls
plat_timer_setup(timer_irqaction), which is defined by the Broadcom
patches to call setup_irq(timer_irqaction).

In 2.6.29, arch/mips/kernel/time.c has a comment saying that the new
plat_time_init hook does not receive the irqaction pointer argument
anymore, because each "clock_event_device" should use its own struct
irqrequest.

I tried having the broadcom arch's plat_time_init() function create an
irqaction and call setup_irq(), but the timer_interrupt() function
that used to be in arch/mips/kernel/time.c doesn't exist anymore, and
I can't seem to find the replacement.

Is there a replacement for timer_interrupt()?  I thought that maybe
the hrtimer_interrupt() might be the one, but it requires something
called a struct clock_event_device.  When I looked at clock_event_device
it was very complex, and I get the feeling I'm barking up the wrong tree.

Can anyone offer pointers on how to call setup_irq() from plat_time_init()?

Thanks,
Dave


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