Messages in this thread |  | | From | Alexey Charkov <> | | Date | Thu, 22 May 2025 11:45:33 +0400 | | Subject | Re: [PATCH v5 4/4] watchdog: Add support for VIA/WonderMedia SoC watchdog functionality |
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On Wed, May 21, 2025 at 9:24 PM Daniel Lezcano <daniel.lezcano@linaro.org> wrote: > > On Wed, May 21, 2025 at 05:00:12PM +0400, Alexey Charkov wrote: > > VIA/WonderMedia SoCs can use their system timer's first channel as a > > watchdog device which will reset the system if the clocksource counter > > matches the value given in its match register 0 and if the watchdog > > function is enabled. > > > > Since the watchdog function is tightly coupled to the timer itself, it > > is implemented as an auxiliary device of the timer device > > > > Signed-off-by: Alexey Charkov <alchark@gmail.com> > > --- > > MAINTAINERS | 1 + > > drivers/watchdog/Kconfig | 15 ++++++++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/vt8500-wdt.c | 88 +++++++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 105 insertions(+) > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 5362095240627f613638197fda275db6edc16cf7..97d1842625dbdf7fdca3556260662dab469ed091 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -3447,6 +3447,7 @@ F: drivers/tty/serial/vt8500_serial.c > > F: drivers/video/fbdev/vt8500lcdfb.* > > F: drivers/video/fbdev/wm8505fb* > > F: drivers/video/fbdev/wmt_ge_rops.* > > +F: drivers/watchdog/vt8500-wdt.c > > F: include/linux/vt8500-timer.h > > > > ARM/ZYNQ ARCHITECTURE > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > > index 0d8d37f712e8cfb4bf8156853baa13c23a57d6d9..2e59303306feba7e15a015c2fce25b1290dc4cbc 100644 > > --- a/drivers/watchdog/Kconfig > > +++ b/drivers/watchdog/Kconfig > > @@ -1115,6 +1115,21 @@ config SUNPLUS_WATCHDOG > > To compile this driver as a module, choose M here: the > > module will be called sunplus_wdt. > > > > +config VT8500_WATCHDOG > > + tristate "VIA/WonderMedia VT8500 watchdog support" > > + depends on ARCH_VT8500 || COMPILE_TEST > > + select WATCHDOG_CORE > > + select AUXILIARY_BUS > > + help > > + VIA/WonderMedia SoCs can use their system timer as a hardware > > + watchdog, as long as the first timer channel is free from other > > + uses and respective function is enabled in its registers. To > > + make use of it, say Y here and ensure that the device tree > > + lists at least two interrupts for the VT8500 timer device. > > + > > + To compile this driver as a module, choose M here. > > + The module will be called vt8500-wdt. > > Module is not supported by the timers. That will change in a very near > future but unloading won't be supported, you should consider tying the > wdt life cycle with the subsystem it is connected to.
But there's an auxiliary bus between the timer and this module, so it should be possible to boot a system with the timer initialized as usual, and then load the watchdog if/when needed. Which also saves a bit of space in the main kernel image.
Or am I missing anything here?
Best regards, Alexey
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