[PATCH 0/7] add support for clocksource/clockevent DT selection
From: Claudiu Beznea
Date: Tue Sep 10 2019 - 09:48:00 EST
Hi,
This series adds support to permit the selection of clocksource/clockevent
via DT.
In [1] I proposed a solution other than the one in this series, with parsing DT
bindings and at probe time and passing it to timer specific probe function.
Looking forward though the clocksource/clockevent drivers implementation and
taking into account the response at [2] I sticked the implementation to
timer-of specific library.
The implementation in this series is using timer-of specific library to parse
the DT bindings related to timers functions: clocksource or clockevent.
With this implementation a timer's driver registers for probing an array of
objects of type struct timer_of. In flags member of struct timer_of object it
has to be passed the following new flags (related to how the driver will behave)
as follows:
- TIMER_OF_TYPE_CS: timer could work only as clocksource at a time
- TIMER_OF_TYPE_CE: timer could work only as clockevent at a time
- TIMER_OF_TYPE_CE_AND_CE: timer could work at a time as both, clocksource and
clockevent.
The timer registration macro (for probing) now gets a new argument which should
be an array of struct timer_of objects:
TIMER_OF_DECLARE(name, compat, handler, to)
CLOCKSOURCE_OF_DECLARE(name, compat, handler, to)
In case driver could work to feed only the clocksource subsystem or only the
clockevent subsystem the struct timer_of array passed to TIMER_OF_DECLARE()/
CLOCKSOURCE_OF_DECLARE() should contain 2 entries: one to be filled if probed
timer works as clocksource device, one to be filled if probed timer works as
clockevent device.
For such a case, the minimal format of struct timer_of array is as follows:
struct timer_of to[] = {
{ .flags = TIMER_OF_TYPE_CS }
{ .flags = TIMER_OF_TYPE_CE }
{ /* sentinel. */
};
If timer could work as both, clocksource and clockevent at the same time,
the struct timer_of array should look as follows:
struct timer_of to[] = {
{ .flags = TIMER_OF_TYPE_CE_AND_CS }
{ /* sentinel. */
};
And in device tree there should be added chosen bindings as follows:
chosen {
linux,clocksource {
timer = <&timer1>
};
linux,clockevent {
timer = <&timer2>;
}
};
timer1: t1@123 {
compatible = "timerx-compatible";
/* the rest of DT bindings here */
};
timer2: t1@234 {
compatible = "timerx-compatible";
/* the rest of DT bindings here */
};
At probing time (timer_probe()), timer_of_init() will check the DT bindings
and try to match with one of the entries in struct timer_of array passed at
probe. The used entry will be considered used if the timers' device_node
pointer is set. If no matching b/w DT and what has been passed for probe
via struct timer_of array then probe should fail.
The patches in this series are organized as follows:
1/7 - avoid calling timer_of_init() for every CPU since it should not be needed
2/7 - changes timer registration macro by adding a new argument (pointer to
struct timer_of)
3/7 - use BIT() macro
4/7 - add clocksource/clockevent selection documentation [3]
5/7 - implement support described above
6/7 - remove an unnecessary line
7/7 - implement this support for integrator-ap timer
I implemented this support for timer published at [4].
Thank you,
Claudiu Beznea
[1] https://lore.kernel.org/lkml/34574b0f-7d09-eb92-ea62-4199c293b0e7@xxxxxxxxxxxxx/
[2] https://lore.kernel.org/lkml/1ebaa306-8a7f-fd58-56e0-a61b767357f7@xxxxxxxxxx/
[3] https://lore.kernel.org/lkml/20171213185313.20017-1-alexandre.belloni@xxxxxxxxxxxxxxxxxx/
[4] https://lore.kernel.org/lkml/1552580772-8499-1-git-send-email-claudiu.beznea@xxxxxxxxxxxxx/
Alexandre Belloni (2):
dt-bindings: chosen: Add clocksource and clockevent selection
clocksource/drivers/integrator-ap: parse the chosen node
Claudiu Beznea (5):
clocksource/drivers/c-sky: request timer_of_init only for probing CPU
clocksource: change timer registration macros
clocksource/timer_of: use BIT() macro
clocksource/drivers/timer-of: add support support for timer's
functionalities
drivers/clocksource/timer-of: keep declaration on one line
Documentation/devicetree/bindings/chosen.txt | 20 +++++
arch/arm/kernel/smp_twd.c | 10 ++-
arch/arm/mach-davinci/time.c | 2 +-
arch/microblaze/kernel/timer.c | 2 +-
arch/mips/ralink/cevt-rt3352.c | 2 +-
arch/nios2/kernel/time.c | 2 +-
drivers/clocksource/Kconfig | 1 +
drivers/clocksource/arc_timer.c | 6 +-
drivers/clocksource/arm_arch_timer.c | 6 +-
drivers/clocksource/arm_global_timer.c | 2 +-
drivers/clocksource/armv7m_systick.c | 2 +-
drivers/clocksource/asm9260_timer.c | 2 +-
drivers/clocksource/bcm2835_timer.c | 2 +-
drivers/clocksource/bcm_kona_timer.c | 4 +-
drivers/clocksource/clksrc-dbx500-prcmu.c | 2 +-
drivers/clocksource/clksrc_st_lpc.c | 2 +-
drivers/clocksource/clps711x-timer.c | 2 +-
drivers/clocksource/dw_apb_timer_of.c | 9 ++-
drivers/clocksource/exynos_mct.c | 4 +-
drivers/clocksource/h8300_timer16.c | 2 +-
drivers/clocksource/h8300_timer8.c | 2 +-
drivers/clocksource/h8300_tpu.c | 2 +-
drivers/clocksource/jcore-pit.c | 2 +-
drivers/clocksource/mips-gic-timer.c | 2 +-
drivers/clocksource/mps2-timer.c | 2 +-
drivers/clocksource/mxs_timer.c | 2 +-
drivers/clocksource/nomadik-mtu.c | 2 +-
drivers/clocksource/renesas-ostm.c | 2 +-
drivers/clocksource/samsung_pwm_timer.c | 12 ++-
drivers/clocksource/timer-armada-370-xp.c | 6 +-
drivers/clocksource/timer-atcpit100.c | 74 +++++++++---------
drivers/clocksource/timer-atlas7.c | 3 +-
drivers/clocksource/timer-atmel-pit.c | 2 +-
drivers/clocksource/timer-atmel-st.c | 2 +-
drivers/clocksource/timer-atmel-tcb.c | 2 +-
drivers/clocksource/timer-cadence-ttc.c | 2 +-
drivers/clocksource/timer-davinci.c | 3 +-
drivers/clocksource/timer-digicolor.c | 2 +-
drivers/clocksource/timer-efm32.c | 4 +-
drivers/clocksource/timer-fsl-ftm.c | 2 +-
drivers/clocksource/timer-fttmr010.c | 10 +--
drivers/clocksource/timer-gx6605s.c | 58 +++++++-------
drivers/clocksource/timer-imx-gpt.c | 24 +++---
drivers/clocksource/timer-imx-sysctr.c | 61 +++++++--------
drivers/clocksource/timer-imx-tpm.c | 69 ++++++++---------
drivers/clocksource/timer-integrator-ap.c | 21 +++++-
drivers/clocksource/timer-ixp4xx.c | 2 +-
drivers/clocksource/timer-keystone.c | 2 +-
drivers/clocksource/timer-lpc32xx.c | 2 +-
drivers/clocksource/timer-mediatek.c | 108 +++++++++++++++------------
drivers/clocksource/timer-meson6.c | 2 +-
drivers/clocksource/timer-milbeaut.c | 59 ++++++++-------
drivers/clocksource/timer-mp-csky.c | 52 ++++++-------
drivers/clocksource/timer-npcm7xx.c | 87 +++++++++++----------
drivers/clocksource/timer-nps.c | 6 +-
drivers/clocksource/timer-of.c | 91 +++++++++++++++++++++-
drivers/clocksource/timer-of.h | 36 +++++++--
drivers/clocksource/timer-orion.c | 2 +-
drivers/clocksource/timer-owl.c | 6 +-
drivers/clocksource/timer-oxnas-rps.c | 4 +-
drivers/clocksource/timer-pistachio.c | 2 +-
drivers/clocksource/timer-prima2.c | 2 +-
drivers/clocksource/timer-probe.c | 17 ++++-
drivers/clocksource/timer-pxa.c | 2 +-
drivers/clocksource/timer-qcom.c | 4 +-
drivers/clocksource/timer-rda.c | 66 ++++++++--------
drivers/clocksource/timer-riscv.c | 2 +-
drivers/clocksource/timer-rockchip.c | 4 +-
drivers/clocksource/timer-sp804.c | 4 +-
drivers/clocksource/timer-sprd.c | 75 +++++++++----------
drivers/clocksource/timer-stm32.c | 39 +++++-----
drivers/clocksource/timer-sun4i.c | 78 +++++++++----------
drivers/clocksource/timer-sun5i.c | 4 +-
drivers/clocksource/timer-tango-xtal.c | 2 +-
drivers/clocksource/timer-tegra.c | 31 ++++----
drivers/clocksource/timer-ti-32k.c | 2 +-
drivers/clocksource/timer-u300.c | 2 +-
drivers/clocksource/timer-versatile.c | 4 +-
drivers/clocksource/timer-vf-pit.c | 2 +-
drivers/clocksource/timer-vt8500.c | 2 +-
drivers/clocksource/timer-zevio.c | 2 +-
include/linux/clocksource.h | 30 +++++++-
82 files changed, 748 insertions(+), 544 deletions(-)
--
2.7.4