linux-toradex.git/drivers/clocksource/sh_cmt.c, branch v4.9.37

clocksource/drivers/sh_cmt: Remove unneeded memset() in sh_cmt_setup()

2015-10-15T15:42:00+00:00

Memory for cmt struct is allocated by kzalloc() in sh_cmt_setup.

Signed-off-by: Alexey Klimov 
Signed-off-by: Daniel Lezcano

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-09-01T21:04:50+00:00

Pull timer updates from Thomas Gleixner:
 "Rather large, but nothing exiting:

   - new range check for settimeofday() to prevent that boot time
     becomes negative.
   - fix for file time rounding
   - a few simplifications of the hrtimer code
   - fix for the proc/timerlist code so the output of clock realtime
     timers is accurate
   - more y2038 work
   - tree wide conversion of clockevent drivers to the new callbacks"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
  hrtimer: Handle failure of tick_init_highres() gracefully
  hrtimer: Unconfuse switch_hrtimer_base() a bit
  hrtimer: Simplify get_target_base() by returning current base
  hrtimer: Drop return code of hrtimer_switch_to_hres()
  time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
  time: Introduce current_kernel_time64()
  time: Introduce struct itimerspec64
  time: Add the common weak version of update_persistent_clock()
  time: Always make sure wall_to_monotonic isn't positive
  time: Fix nanosecond file time rounding in timespec_trunc()
  timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
  cris/time: Migrate to new 'set-state' interface
  kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
  xtensa/time: Migrate to new 'set-state' interface
  unicore/time: Migrate to new 'set-state' interface
  um/time: Migrate to new 'set-state' interface
  sparc/time: Migrate to new 'set-state' interface
  sh/localtimer: Migrate to new 'set-state' interface
  score/time: Migrate to new 'set-state' interface
  s390/time: Migrate to new 'set-state' interface
  ...

clockevents/drivers/sh_cmt: Remove obsolete sh-cmt-48 platform_device_id entry

2015-08-10T09:40:54+00:00

Since the removal of the r8a7740 legacy SoC code in commit
44d88c754e57a6d9 ("ARM: shmobile: Remove legacy SoC code for R-Mobile
A1"), all former users of the "sh-cmt-48-gen2" platform device name are
only supported in generic DT-only ARM multi-platform builds.  The driver
doesn't need to match platform devices by name anymore, hence remove the
corresponding platform_device_id entry.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Daniel Lezcano 
Acked-by: Simon Horman

clockevents/drivers/sh_cmt: Migrate to new 'set-state' interface

2015-08-10T09:40:38+00:00

Migrate sh_cmt 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: Magnus Damm 
Cc: Laurent Pinchart 
Cc: Paul Mundt 
Signed-off-by: Viresh Kumar 
Signed-off-by: Daniel Lezcano 
Acked-by: Laurent Pinchart

clockevents/drivers/sh_cmt: Remove obsolete sh-cmt-48-gen2 platform_device_id entry

2015-08-10T09:40:25+00:00

Since commit 914d7d148411997c ("ARM: shmobile: r8a73a4: Remove legacy
code"), all former users of the "sh-cmt-48-gen2" platform device name
are only supported in generic DT-only ARM multi-platform builds.  The
driver doesn't need to match platform devices by name anymore, hence
remove the corresponding platform_device_id entry.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Daniel Lezcano 
Acked-by: Simon Horman

clockevents/drivers/sh_cmt: Remove obsolete sh-cmt-32-fast platform_device_id entry

2015-08-10T09:40:24+00:00

Since commit 59b89af1d5551c12 ("ARM: shmobile: sh7372: Remove Legacy C
SoC code"), there are no more users left of the "sh-cmt-32-fast"
platform device name. Hence remove the corresponding platform_device_id
entry from the driver.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Daniel Lezcano 
Acked-by: Simon Horman

clockevents/drivers/sh_cmt: Only perform clocksource suspend/resume if enabled

2015-08-08T08:50:08+00:00

Currently the sh_cmt clocksource timer is disabled or enabled
unconditionally on clocksource suspend resp. resume, even if a
better clocksource is present (e.g. arch_sys_counter) and the
sh_cmt clocksource is not enabled.

As sh_cmt is a syscore device when its timer is enabled, this
may lead to a genpd.prepared_count imbalance in the presence of
PM Domains, which may cause a lock-up during reboot after s2ram.

During suspend:
  - pm_genpd_prepare() is called for all non-syscore devices (incl.
    sh_cmt), increasing genpd.prepared_count for each device,
  - clocksource.suspend() is called for all clocksource devices,
  - sh_cmt_clocksource_suspend() calls sh_cmt_stop(), which is a no-op
    as the clocksource was not enabled.

During resume:
  - clocksource.resume() is called for all clocksource devices,
  - sh_cmt_clocksource_resume() calls sh_cmt_start(), which enables the
    clocksource timer, and turns sh_cmt into a syscore device,
  - pm_genpd_complete() is called for all non-syscore devices (excl.
    sh_cmt now!), decreasing genpd.prepared_count for each device but
    sh_cmt.

Now genpd.prepared_count of the PM Domain containing sh_cmt is
still 1 instead of zero.  On subsequent suspend/resume cycles,
sh_cmt is still a syscore device, hence it's skipped for
pm_genpd_{prepare,complete}(), keeping the imbalance of
genpd.prepared_count at 1.

During reboot:

  - platform_drv_shutdown() is called for any platform device that has
    a driver with a .shutdown() method (only rcar-dmac on R-Car Gen2),

  - platform_drv_shutdown() calls dev_pm_domain_detach(), which
    calls genpd_dev_pm_detach(),

  - genpd_dev_pm_detach() keeps calling pm_genpd_remove_device() until
    it doesn't return -EAGAIN[*],

  - If the device is part of the same PM Domain as sh_cmt,
    pm_genpd_remove_device() always fails with -EAGAIN due to
    genpd.prepared_count > 0.

  - Infinite loop in genpd_dev_pm_detach()[*].

[*] Commit 93af5e9354432828 ("PM / Domains: Avoid infinite loops in
    attach/detach code") already limited the number of loop iterations,
    avoiding the lock-up.

To fix this, only disable or enable the clocksource timer on
clocksource suspend resp. resume if the clocksource was enabled.

This was tested on r8a7791/koelsch with the CPG Clock Domain:

  - using arch_sys_counter as the clocksource, which is the default, and
    which showed the problem,

  - using sh_cmt as a clocksource ("echo ffca0000.timer > \
    /sys/devices/system/clocksource/clocksource0/current_clocksource"),
    which behaves the same as before.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Daniel Lezcano 
Acked-by: Laurent Pinchart 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1438875126-12596-2-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar

clocksource: Rename __clocksource_updatefreq_() to __clocksource_update_freq_()

2015-03-13T07:07:08+00:00

Ingo requested this function be renamed to improve readability,
so I've renamed __clocksource_updatefreq_scale() as well as the
__clocksource_updatefreq_hz/khz() functions to avoid
squishedtogethernames.

This touches some of the sh clocksources, which I've not tested.

The arch/arm/plat-omap change is just a comment change for
consistency.

Signed-off-by: John Stultz 
Cc: Daniel Lezcano 
Cc: Dave Jones 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Prarit Bhargava 
Cc: Richard Cochran 
Cc: Stephen Boyd 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1426133800-29329-13-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar

clocksource: sh_cmt: Add DT support

2014-07-04T13:46:17+00:00

Document DT bindings and parse them in the CMT driver.

Signed-off-by: Laurent Pinchart 
Tested-by: Simon Horman

clocksource: sh_cmt: Replace global spinlock with a per-device spinlock

2014-07-02T14:01:48+00:00

The global spinlock is used to protect the shared start/stop register.
Now that all CMT channels are handled by a single device instance, use a
per-device spinlock.

Signed-off-by: Laurent Pinchart 
Tested-by: Simon Horman