The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.

It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.

On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.

So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.

The patch has not functional changes.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>

All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

For exynos_mct and samsung_pwm_timer:
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>

For arch/arc:
Acked-by: NVineet Gupta <vgupta@synopsys.com>

For mediatek driver:
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

For the Rockchip-part
Acked-by: NHeiko Stuebner <heiko@sntech.de>

For STi :
Acked-by: NPatrice Chotard <patrice.chotard@st.com>

For the mps2-timer.c and versatile.c changes:
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>

For the OXNAS part :
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>

For LPC32xx driver:
Acked-by: NSylvain Lemieux <slemieux.tyco@gmail.com>

For Broadcom Kona timer change:
Acked-by: NRay Jui <ray.jui@broadcom.com>

For Sun4i and Sun5i:
Acked-by: NChen-Yu Tsai <wens@csie.org>

For Meson6:
Acked-by: NCarlo Caione <carlo@caione.org>

For Keystone:
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>

For NPS:
Acked-by: NNoam Camus <noamca@mellanox.com>

For bcm2835:
Acked-by: NEric Anholt <eric@anholt.net>

The init functions do not return any error. They behave as the following:

 - panic, thus leading to a kernel crash while another timer may work and
   make the system boot up correctly

 or

 - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

Add __init attribute on a function that is only called from other __init
functions and that is not inlined, at least with gcc version 4.8.4 on an
x86 machine with allyesconfig.  Currently, the function is put in the
.text.unlikely segment.  Declaring it as __init will cause it to be put in
the .init.text and to disappear after initialization.

The result of objdump -x on the function before the change is as follows:

0000000000000000 l     F .text.unlikely 000000000000006f mtk_timer_setup.isra.4

And after the change it is as follows:

0000000000000000 l     F .init.text	000000000000006a mtk_timer_setup.isra.4

Done with the help of Coccinelle.  The semantic patch checks for local
static non-init functions that are called from an __init function and are
not called from any other function.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

Add error path to clear evt struct allocated by kzalloc() in the beginning of
function mtk_timer_init().
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NAlexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

1) Change pr_warn()s to pr_err()s. These messages are actually errors and not
   warnings.
2) Add missing \n.
3) Error message for kzalloc() failure is removed per suggestion by Joe Perches.
   There is generic stack_dump() for allocation issues.
Signed-off-by: NAlexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

It's a bit unclear what subsystem/driver emits some messages to dmesg in
the function mtk_init_timer(). Use pr_fmt to auto-prefix the messages
appropriately.
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NAlexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

When cpu is in deep idle, arch timer will stop counting. Setup GPT as
sched clock source so it can keep counting in idle.
Signed-off-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

After analysis done by Yingjoe Chen, the timer appears to have a pending
interrupt when it is enabled.

Fix this by acknowledging the pending interrupt when enabling the timer
interrupt.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: NYingjoe Chen <yingjoe.chen@mediatek.com>

Migrate mtk driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

We have two race conditions in the probe code which could lead to a null
pointer dereference in the interrupt handler.

The interrupt handler accesses the clockevent device, which may not yet be
registered.

First race condition happens when the interrupt handler gets registered before
the interrupts get disabled. The second race condition happens when the
interrupts get enabled, but the clockevent device is not yet registered.

Fix that by disabling the interrupts before we register the interrupt and enable
the interrupts after the clockevent device got registered.
Reported-by: NGongbae Park <yongbae2@gmail.com>
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

This patch adds a clock source and clock event for the timer found
on the Mediatek SoCs.

The Mediatek General Purpose Timer block provides five 32 bit timers and
one 64 bit timer.

Two 32 bit timers are used by this driver:
TIMER1: clock events supporting periodic and oneshot events
TIMER2: clock source configured as a free running counter

The General Purpose Timer block can be run with two clocks. A 13 MHz system
clock and the RTC clock running at 32 KHz. This implementation uses the system
clock with no clock source divider.

The interrupts are shared between the different timers and have to be read back
from a register. We just enable one interrupt for the clock event. The clock
event timer is used by all cores.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>