linux/drivers/clocksource
Nicolai Stange c3c0a20df9 clocksource: sh_tmu: Compute rate before registration again
With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.

Currently, sh_tmu violates this requirement in that it registers its
clockevent device with a dummy rate and sets its final rate through
clockevents_config() called from its ->set_state_oneshot() and
->set_state_periodic() functions respectively.

This patch moves the setting of the clockevent device's rate to its
registration.

Note that there has been some back and forth regarding this question with
respect to the clocksource also provided by this driver:
  commit 66f49121ff ("clocksource: sh_tmu: compute mult and shift before
                        registration")
moves the rate determination from the clocksource's ->enable() function to
before its registration. OTOH, the later
  commit 0aeac458d9 ("clocksource: sh_tmu: __clocksource_updatefreq_hz()
                        update")
basically reverts this, saying
  "Without this patch the old code uses clocksource_register() together
   with a hack that assumes a never changing clock rate."

However, I checked all current sh_tmu users in arch/sh as well as in
arch/arm/mach-shmobile carefully and right now, none of them changes any
rate in any clock tree relevant to sh_tmu after their respective
time_init(). Since all sh_tmu instances are created after time_init(), none
of them should ever observe any clock rate changes.

What's more, both, a clocksource as well as a clockevent device, can
immediately get selected for use at their registration and thus, enabled
at this point already. So it's probably safer to assume a "never changing
clock rate" here.

- Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device:
  it's a property of the underlying clock which is in turn specific to
  the sh_tmu_device.
- Determine the ->rate value in sh_tmu_setup() at device probing rather
  than at first usage.
- Set the clockevent device's rate at its registration.
- Although not strictly necessary for the upcoming clockevent core changes,
  set the clocksource's rate at its registration for consistency.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-03-23 12:14:01 -07:00
..
acpi_pm.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
arc_timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
arm_arch_timer.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
arm_global_timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
armv7m_systick.c clocksource/drivers/armv7m_systick: Add the COMPILE_TEST option 2016-06-28 10:22:05 +02:00
asm9260_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
bcm2835_timer.c clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap 2016-11-22 09:22:59 +01:00
bcm_kona_timer.c clocksource/drivers/kona: Fix get_counter() error handling 2016-08-17 13:08:31 +02:00
cadence_ttc_timer.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
clkevt-probe.c clockevents: Add a clkevt-of mechanism like clksrc-of 2017-02-07 20:58:30 +01:00
clksrc_st_lpc.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
clksrc-dbx500-prcmu.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
clksrc-probe.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
clps711x-timer.c ARM: SoC driver updates for v4.8 2016-08-01 18:36:01 -04:00
cs5535-clockevt.c clockevents/drivers/cs5535: Migrate to new 'set-state' interface 2015-08-06 12:16:42 +02:00
dummy_timer.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
dw_apb_timer_of.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
dw_apb_timer.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
em_sti.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
exynos_mct.c clocksource/exynos_mct: Clear interrupt when cpu is shut down 2017-01-17 10:08:38 +01:00
fsl_ftm_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
h8300_timer8.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
h8300_timer16.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
h8300_tpu.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
i8253.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
jcore-pit.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
Kconfig clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101 2017-02-08 00:14:04 +01:00
Makefile clocksource/drivers/ostm: Add renesas-ostm timer driver 2017-02-07 20:58:30 +01:00
meson6_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
metag_generic.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
mips-gic-timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
mmio.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
moxart_timer.c clocksource/drivers/moxart: Plug memory and mapping leaks 2016-12-19 11:19:57 +01:00
mps2-timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
mtk_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
mxs_timer.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
nomadik-mtu.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
numachip.c x86/numachip: Fix timer build conflict 2015-09-23 05:39:20 +02:00
pxa_timer.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
qcom-timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
renesas-ostm.c clocksource/drivers/ostm: Add renesas-ostm timer driver 2017-02-07 20:58:30 +01:00
rockchip_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
samsung_pwm_timer.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
scx200_hrt.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
sh_cmt.c clocksource: sh_cmt: Compute rate before registration again 2017-03-23 12:14:00 -07:00
sh_mtu2.c clocksource/drivers/sh_mtu2: Fix multiple shutdown call issue 2015-10-28 15:22:56 +01:00
sh_tmu.c clocksource: sh_tmu: Compute rate before registration again 2017-03-23 12:14:01 -07:00
sun4i_timer.c clocksource/drivers/sun4i: Clear interrupts after stopping timer in probe function 2016-08-26 15:56:01 +02:00
tango_xtal.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
tcb_clksrc.c Revert "clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock" 2017-03-11 22:03:34 +01:00
tegra20_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
time-armada-370-xp.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
time-efm32.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
time-lpc32xx.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
time-orion.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
time-pistachio.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-atlas7.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
timer-atmel-pit.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-atmel-st.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-digicolor.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
timer-gemini.c clocksource/drivers/gemini: Add driver for the Cortina Gemini 2017-02-07 20:58:30 +01:00
timer-imx-gpt.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
timer-integrator-ap.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
timer-keystone.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
timer-nps.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-oxnas-rps.c clocksource/drivers/oxnas: Add OX820 compatible 2016-09-12 07:28:46 +02:00
timer-prima2.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-sp804.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
timer-sp.h ARM: 8366/1: move Dual-Timer SP804 driver to drivers/clocksource 2015-06-02 09:58:18 +01:00
timer-stm32.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
timer-sun5i.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-ti-32k.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timer-u300.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
versatile.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
vf_pit_timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00
vt8500_timer.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
zevio-timer.c clocksources: Switch back to the clksrc table 2016-06-28 10:19:35 +02:00