Re: Extending wdt-gpio to be used on non-of (no DT) platforms

["Alexander Shiyan" <shc_work-JGs/UdohzUI@public.gmane.org>]

Sat, 29 Mar 2014 14:51:34 +0100 от Rafał Miłecki <zajec5@gmail.com>:
> 2014-03-29 14:33 GMT+01:00 Alexander Shiyan <shc_work@mail.ru>:
> > Sat, 29 Mar 2014 14:16:40 +0100 от Hauke Mehrtens <hauke@hauke-m.de>:
> >> The Huawei E970, the only device with a bcm47xx SoC which uses this gpio
> >> watchdog I know of, needs the gpio driver very early. It is not possible
> >> to deactivate the watchdogs, so it has to get trigged very early in the
> >
> > Why it cannot be deactivated?
> > The driver has been designed for ADM70x ICs, where watchdog is
> > deactivated by set GPIO to tristate.
> 
> I'm not sure how to achieve tri-state with Broadcom SoC. Our code is in:
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/bcma/driver_gpio.c
> 
> We have bcma_chipco_gpio_control that sets if GPIO is controlled by
> ChipCommon (part of the SoC, one of many cores).
> Maybe setting GPIO to be *not* controlled by ChipCommon will make it tri-state?
> 
> Any other ideas?

Usually this should be done by setup GPIO direction to input.

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