Commit Graph

16 Commits

Author SHA1 Message Date
Daniel Lezcano 1727339590 clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE
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: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2017-06-14 11:58:45 +02:00
Thomas Gleixner a5a1d1c291 clocksource: Use a plain u64 instead of cycle_t
There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
2016-12-25 11:04:12 +01:00
Daniel Lezcano 177cf6e52b clocksources: Switch back to the clksrc table
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: Daniel Lezcano <daniel.lezcano@linaro.org>

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

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

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

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

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

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

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

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

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

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

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

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

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

For bcm2835:
Acked-by: Eric Anholt <eric@anholt.net>
2016-06-28 10:19:35 +02:00
Daniel Lezcano 979d7f28ff clocksource/drivers/vt8500: Convert init function to return error
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: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-06-28 10:19:33 +02:00
Thomas Gleixner 1f16f116b0 Merge branches 'clockevents/4.4-fixes' and 'clockevents/4.5-fixes' of http://git.linaro.org/people/daniel.lezcano/linux into timers/urgent
Pull in fixes from Daniel Lezcano:

 - Fix the vt8500 timer leading to a system lock up when dealing with too
   small delta (Roman Volkov)

 - Select the CLKSRC_MMIO when the fsl_ftm_timer is enabled with COMPILE_TEST
   (Daniel Lezcano)

 - Prevent to compile timers using the 'iomem' API when the architecture has
   not HAS_IOMEM set (Richard Weinberger)
2016-01-12 11:01:12 +01:00
Roman Volkov f9eccf2461 clocksource/drivers/vt8500: Increase the minimum delta
The vt8500 clocksource driver declares itself as capable to handle the
minimum delay of 4 cycles by passing the value into
clockevents_config_and_register(). The vt8500_timer_set_next_event()
requires the passed cycles value to be at least 16. The impact is that
userspace hangs in nanosleep() calls with small delay intervals.

This problem is reproducible in Linux 4.2 starting from:
c6eb3f70d4 ('hrtimer: Get rid of hrtimer softirq')

From Russell King, more detailed explanation:

"It's a speciality of the StrongARM/PXA hardware. It takes a certain
number of OSCR cycles for the value written to hit the compare registers.
So, if a very small delta is written (eg, the compare register is written
with a value of OSCR + 1), the OSCR will have incremented past this value
before it hits the underlying hardware. The result is, that you end up
waiting a very long time for the OSCR to wrap before the event fires.

So, we introduce a check in set_next_event() to detect this and return
-ETIME if the calculated delta is too small, which causes the generic
clockevents code to retry after adding the min_delta specified in
clockevents_config_and_register() to the current time value.

min_delta must be sufficient that we don't re-trip the -ETIME check - if
we do, we will return -ETIME, forward the next event time, try to set it,
return -ETIME again, and basically lock the system up. So, min_delta
must be larger than the check inside set_next_event(). A factor of two
was chosen to ensure that this situation would never occur.

The PXA code worked on PXA systems for years, and I'd suggest no one
changes this mechanism without access to a wide range of PXA systems,
otherwise they're risking breakage."

Cc: stable@vger.kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Alexey Charkov <alchark@gmail.com>
Signed-off-by: Roman Volkov <rvolkov@v1ros.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-01-11 22:49:07 +01:00
Daniel Lezcano 351bb99b71 clocksource/drivers/vt8500: Remove unneeded header
Remove the <asm/time.h> header inclusion which is pointless.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-12-15 09:41:40 +01:00
Viresh Kumar 214bc755b6 clockevents/drivers/vt8500: Migrate to new 'set-state' interface
Migrate vt8500 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: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2015-08-10 11:40:51 +02:00
Michael Opdenacker 39039eb31c clocksource: vt8500: Remove deprecated IRQF_DISABLED
This patch removes the use of the IRQF_DISABLED flag.

It's a NOOP since 2.6.35 and it will be removed one day.

[dlezcano] : slightly changed the changelog

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2013-12-11 11:40:28 +01:00
Uwe Kleine-König 326e31eebe clocksource: Put nodes passed to CLOCKSOURCE_OF_DECLARE callbacks centrally
Instead of letting each driver call of_node_put do it centrally in the
loop that also calls the CLOCKSOURCE_OF_DECLARE callbacks. This is less
prone to error and also moves getting and putting the references into the
same function.

Consequently all respective of_node_put calls in drivers are removed.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: David Brown <davidb@codeaurora.org>
2013-10-02 11:42:48 +02:00
Arnd Bergmann 3d5a965823 clocksource: make CLOCKSOURCE_OF_DECLARE type safe
This ensures that a function pointer passed into CLOCKSOURCE_OF_DECLARE
takes the same arguments that we use for calling that function later.

Also fix the extraneous semicolon at end of the CLOCKSOURCE_OF_DECLARE
definition.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
2013-03-28 12:01:06 +01:00
Rob Herring effbfdd7ba clocksource: pass DT node pointer to init functions
In cases where we have multiple nodes of the same type, we may need the
node pointer to know which node was matched. Passing the node pointer
also keeps the init function from having to match the node a 2nd time.

Update bcm2835, vt8500, and tegra20 init functions for the new function
prototype. Further tegra20 clean-ups are in follow-up commit.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Tested-by: Michal Simek <michal.simek@xilinx.com>
2013-03-11 08:42:07 -05:00
Olof Johansson 2ea0dde765 Merge branch 'vt8500/timer' into next/cleanup
* vt8500/timer:
  timer: vt8500: Convert vt8500 to use CLKSRC_OF

Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-15 10:57:24 -08:00
Tony Prisk 41d16512eb timer: vt8500: Convert vt8500 to use CLKSRC_OF
This patch converts arch-vt8500 to make use of CLKSRC_OF. Doing so
removes the need for include/linux/vt8500_timer.h as vt8500_timer_init
no longer needs to be visible outside vt8500_timer.c

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-15 10:56:24 -08:00
Olof Johansson 175dbc1eea Move arch-vt8500/timer.c to drivers/clocksource/vt8500-timer.c
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Merge tag 'vt8500/timer' of git://server.prisktech.co.nz/git/linuxwmt into next/cleanup

From Tony Prisk:
Move arch-vt8500/timer.c to drivers/clocksource/vt8500-timer.c

* tag 'vt8500/timer' of git://server.prisktech.co.nz/git/linuxwmt:
  timer: vt8500: Move timer code to drivers/clocksource

Signed-off-by: Olof Johansson <olof@lixom.net>
2013-01-14 14:13:48 -08:00
Tony Prisk ff7ec345f0 timer: vt8500: Move timer code to drivers/clocksource
This patch moves arch-vt8500/timer.c into drivers/clocksource and
updates the necessary Kconfig/Makefile options.

Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
2013-01-14 17:58:21 +13:00