When a cpu goes to a deep idle state where its local timer is shutdown, it
notifies the time frame work to use the broadcast timer instead.

Unfortunately, the broadcast device could wake up any CPU, including an idle one
which is not concerned by the wake up at all.

This implies, in the worst case, an idle CPU will wake up to send an IPI to
another idle cpu.

This patch fixes this for ARM platforms using timer-sp, by setting
CLOCK_EVT_FEAT_DYNIRQ feature.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Nothing about the sched_clock implementation in the ARM port is
specific to the architecture. Generalize the code so that other
architectures can use it by selecting GENERIC_SCHED_CLOCK.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
[jstultz: Merge minor collisions with other patches in my tree]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Move the integrator-cp timer init to timer-sp.c and use CLKSRC_OF. There is
no reason to use the aliases, so drop them from the init code.

The integrator-cp timers are mistakenly called sp804 timers in the dts, but
in fact they are not sp804 dual timers, but single timers with the same
programming model. Fix the dts to reflect this.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

This adds CLKSRC_OF based init for sp804 timer. The clock initialization is
refactored to support retrieving the clock(s) from the DT.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

The SP804 driver statically initialises the cpumask of the clock event
device to be cpu_all_mask, which is derived from the compile-time
constant NR_CPUS. This breaks SMP_ON_UP systems where the interrupt
controller handling the sp804 doesn't have the irq_set_affinity callback
on the irq_chip, because the common timer code fails to identify the
device as cpu-local and ends up treating it as a broadcast device
instead.

This patch fixes the problem by using cpu_possible_mask at runtime,
which will correctly represent the possible CPUs when SMP_ON_UP is being
used.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add a sched_clock support for the sp804 timer. The clocksource timer
can optionally initialize itself as sched_clock timer.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>

This removes the hardcoded shift value and lets the clockevent core
come up with suitable mult and div factors. Tested on the
Integrator/CP.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows platforms to specify the rate of the SP804 clockevent via
the clk subsystem.  While ARM boards clock these at 1MHz, BCMRing also
has SP804 timers but are clocked at different rates.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows platforms to specify the clcokevent name upon registration.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows platforms to specify the rate of the SP804 clocksource via
the clk subsystem.  While ARM boards clock these at 1MHz, BCMRing also
has SP804 timers but are clocked at different rates.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This allows platforms to specify the clocksource name upon
registration, which is necessary should they wish to register more
than one sp804 clocksource.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert SP804, MXC, Nomadik and Orion 32-bit down-counting clocksources
to generic mmio clocksource infrastructure.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Alessandro Rubini <rubini@unipv.it>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Acked-by: NNicolas Pitre <nico@fluxnic.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

From: Rob Herring <rob.herring@smooth-stone.com>

The timer-sp h/w used on versatile platforms can also be used for other
platforms, so move it to a common location.
Signed-off-by: NRob Herring <rob.herring@smooth-stone.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Realview/Versatile copied the Integrator timer code, including the
calculations for ensuring that the reload value fits into the 16-bit
counter.  However, these platforms have a 32-bit counter which is
clocked at a slower rate.

The result is that the preprocessor conditions are never triggered:
TICKS_PER_uSEC = 1, mSEC_10 = 10000, which is 0x2710 - less than
0x10000.

So, remove the unnecessary complexity, reducing the TIMER_RELOAD
calculation to just:

	TICKS_PER_uSEC * mSEC_10
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>