Hi Chris,
On Fri, Feb 10, 2017 at 8:46 PM, Chris Brandt <Chris.Brandt@xxxxxxxxxxx> wrote:
> On Friday, February 10, 2017, Geert Uytterhoeven wrote:
>> Alternatively, you can write a restart driver (cfr.
>> drivers/power/reset/rmobile-reset.c) that binds against a
>> "renesas,r7s72100-wdt" device node, but doesn't implement watchdog
>> functionality.
>> You're gonna need DT bindings anyway.
>
> I like that idea. That should take me no time at all.
> Thank you.
>
> Do you think I can still keep my 'weak function' idea in there??
>
>
> extern void __attribute__ ((weak)) prepare_for_restart(void)
> {
> /* override to do board specific stuff */
> }
>
> static int renesas_wdt_reset_handler(struct notifier_block *this,
> unsigned long mode, void *cmd)
> {
> pr_debug("%s %lu\n", __func__, mode);
>
> prepare_for_restart();
>
> /* set WDT for reset */
> . . .
>
> return NOTIFY_DONE;
> }
What do you want to use the board-specific function for?
Have a board-specific reset handler, or do some preparatory cleanup?
In case of the former, please write a separate driver that registers a
reset handler with a higher priority.
In case of the latter, please use register_reboot_notifier() in the driver
that needs it.
> Or...do you think I can just use the rmobile-reset.c driver and
> just add WDT to it?
>
> Honestly, the only thing different will be rmobile_reset_handler().
> I could make a rmobile_wdt_reset_handler() and I could just pass in
> a different notifier_block depending on the DT.
>
> What do you think?
Given the small amount of code to add to the existing driver, and the sheer
amount of boilerplate for writing a new driver, I'm inclined to say yes.
But in the end, it's up to the subsystem maintainer to decide.
> static const struct of_device_id rmobile_reset_of_match[] = {
> { .compatible = "renesas,sysc-rmobile", },
> { .compatible = "renesas,wdt-rmobile", },
renesas,r7s72100-wdt
> { /* sentinel */ }
> };
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
