Hi Paul,
在 2020/7/18 下午11:44, Paul Cercueil 写道:
Hi Zhou,
Le sam. 18 juil. 2020 à 21:42, Zhou Yanjie <zhouyanjie@xxxxxxxxxxxxxx>
a écrit :
Hello Paul and Daniel,
在 2020/7/18 下午9:12, Paul Cercueil 写道:
Hi Daniel,
Le ven. 17 juil. 2020 à 10:02, Daniel Lezcano
<daniel.lezcano@xxxxxxxxxx> a écrit :
On 17/07/2020 08:13, Zhou Yanjie wrote:
Hi Daniel,
在 2020/7/17 下午12:20, Daniel Lezcano 写道:
On 10/07/2020 19:02, 周琰杰 (Zhou Yanjie) wrote:
X1000 and SoCs after X1000 (such as X1500 and X1830) had a
separate
OST, it no longer belongs to TCU. This driver will register both a
clocksource and a sched_clock to the system.
Tested-by: 周正 (Zhou Zheng) <sernia.zhou@xxxxxxxxxxx>
Co-developed-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>
Signed-off-by: 漆鹏振 (Qi Pengzhen) <aric.pzqi@xxxxxxxxxxx>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
Reviewed-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
Notes:
v1->v2:
Fix compile warnings.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
v2->v3:
No change.
v3->v4:
1.Rename "ost" to "sysost"
1.Remove unrelated changes.
2.Remove ost_clock_parent enum.
3.Remove ost->percpu_timer_channel/ost->global_timer_channel.
4.Set up independent .recalc_rate/.set_rate for percpu/global
timer.
5.No longer call functions in variable declarations.
v4->v5:
Use "of_io_request_and_map()" instead "of_iomap()".
Suggested-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
v5->v6:
No change.
drivers/clocksource/Kconfig | 11 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/ingenic-sysost.c | 539
+++++++++++++++++++++++++++++++++++
3 files changed, 551 insertions(+)
create mode 100644 drivers/clocksource/ingenic-sysost.c
diff --git a/drivers/clocksource/Kconfig
b/drivers/clocksource/Kconfig
index 91418381fcd4..1bca8b8fb30f 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -696,6 +696,17 @@ config INGENIC_TIMER
help
Support for the timer/counter unit of the Ingenic JZ SoCs.
+config INGENIC_SYSOST
+ bool "Clocksource/timer using the SYSOST in Ingenic X SoCs"
We usually use silent options and let the platform's Kconfig
enable it.
We show up the option only when COMPILE_TEST is enabled.
Is there a reason to do it differently?
Do you mean
bool "Clocksource/timer using the SYSOST in Ingenic X SoCs"
or
default MACH_INGENIC ?
Both, no default here.
eg.
bool "Clocksource/timer using the SYSOST in Ingenic X SoCs" if
COMPILE_TEST
and
in arch/mips/Kconfig in the config MACH_INGENIC section :
...
select INGENIC_SYSOST
...
Disagreed. That's not how we do things on MIPS. Selecting
MACH_INGENIC means "this kernel will support Ingenic SoCs", but not
that it will only support these. Hence the depends on MIPS /
default MACH_INGENIC.
As for the select INGENIC_SYSOST, this driver only applies to a few
SoCs, I certainly don't want it to be force-enabled. I don't even
wait it to be force-enabled on X1000, since it is optional there too.
Cheers,
-Paul
If we still need to keep the "default MACH_INGENIC", then Daniel can
directly apply the v6 version.
If we need to use the silent options, maybe we can enable them
separately according to
MACH_JZ4740/MACH_JZ4770/MACH_JZ4780/MACH_X1000/MACH_X1830.
In fact, I think X1000 and X1830 need to enable this driver in most
cases, because the current test has found that use TCU to provide
clocksource and clockevent will cause data loss/error when
transmitting data through spi or ethernet. And these errors no longer
appear after using OST.
This is likely because the clock is too fast, try to reduce it by a
factor 2 or 4, it should behave better.
Yes, it is indeed because the clock is too fast, especially the TCU only
has 16-bit, which makes this problem more serious. I even reduced the
timing clock to the lowest possible 23kHz (divided by 1024). The problem
has been alleviated, but it cannot completely solved, and finally there
is no problem after opening the OST.
If it turns out OST is really needed, then it should be selected from
MACH_X1000/X1830, not MACH_INGENIC.
Sure, I will do it in v8.
Thanks and best regards!
Cheers,
-Paul
Thanks and best regards!
This driver has some origins from "INGENIC_TIMER" driver and
"INGENIC_OST" driver.
Early Ingenic processors used TCU (timer/counter unit, has 6 or 8
generic timer channels) to provide clocksource and clockevent
(both with
only 16bit precision). This part of the processor can only use
"INGENIC_TIMER" driver.
Later processors provide an independent 32bit or 64bit timer channel
(still under TCU, known as ost channel, this channel can not
generate
interrupt) to provid higher precision clocksource. The "INGENIC_OST"
driver is for this channel. These processors can use "INGENIC_TIMER"
driver, but using "INGENIC_OST" driver to provide higher precision
clocksource would be a better choice (clockevent still needs to be
provided by generic timer channel of TCU, and still 16bit
precision).
And the recent processors provide a SYSOST components, it is
independent
from TCU, including a 64bit timer channel for clocksource and a
32bit
timer channel for clockevent. Although these processors can also use
"INGENIC_TIMER" driver, but the better choice is completely
independent
use of "INGENIC_SYSOST" driver to provide higher precision
clocksource
and clockevent.
Ok, the rating should do the job then.
Thanks for the explanation.
You may have already noticed that this independent SYSOST
component is
like an upgraded and streamlined TCU, which only retains one generic
timer channel that can generate interrupts, upgrade it from 16bit to
32bit, and then retain the 64bit ost channel. so the driver code and
Kconfig code of this patch is largely referenced
"INGENIC_TIMER" driver and "INGENIC_OST" driver.
Thanks and best regards!
+ default MACH_INGENIC
+ depends on MIPS || COMPILE_TEST
+ depends on COMMON_CLK
+ select MFD_SYSCON
+ select TIMER_OF
+ select IRQ_DOMAIN
+ help
+ Support for the SYSOST of the Ingenic X Series SoCs.
+
[ ... ]
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