Re: [PATCH 12/18] gpio: add support for the sl28cpld GPIO controller

[Michael Walle]

Hi,


Am 2020-03-30 13:21, schrieb Bartosz Golaszewski:
> pt., 27 mar 2020 o 16:28 Michael Walle <michael@xxxxxxxx> napisaÅ(a):
> > Am 2020-03-27 11:20, schrieb Linus Walleij:
> > > On Thu, Mar 26, 2020 at 9:06 PM Michael Walle <michael@xxxxxxxx> wrote:
> > >> Am 2020-03-25 12:50, schrieb Bartosz Golaszewski:
> > >
> > >> > In that case maybe you should use the disable_locking option in
> > >> > regmap_config and provide your own callbacks that you can use in the
> > >> > irqchip code too?
> > >>
> > >> But how would that solve problem (1). And keep in mind, that the
> > >> reqmap_irqchip is actually used for the interrupt controller, which
> > >> is not this gpio controller.
> > >>
> > >> Ie. the interrupt controller of the sl28cpld uses the regmap_irqchip
> > >> and all interrupt phandles pointing to the interrupt controller will
> > >> reference the toplevel node. Any phandles pointing to the gpio
> > >> controller will reference the GPIO subnode.
> > >
> > > Ideally we would create something generic that has been on my
> > > mind for some time, like a generic GPIO regmap irqchip now that
> > > there are a few controllers like that.
> > >
> > > I don't know how feasible it is or how much work it would be. But
> > > as with GPIO_GENERIC (for MMIO) it would be helpful since we
> > > can then implement things like .set_multiple() and .get_multiple()
> > > for everyone.
> >
> > For starters, would that be a drivers/gpio/gpio-regmap.c or a
> > drivers/base/regmap/regmap-gpio.c? I would assume the first,
> > because the stuff in drivers/base/regmap operates on a given
> > regmap and we'd just be using one, correct? On the other hand
> > there is also the reqmap-irq.c. But as pointed out before, it
> > will add an interrupt controller to the regmap, not a device
> > so to speak.
> >
> > -michael
>
> This has been on my TODO list for so long, but I've never been able to
> find the time... I'd really appreciate any effort in that direction as
> I believe it would allow us to slowly port a big part of the GPIO
> expander drivers over to it and make large portions of our codebase
> generic.

I might have at least a first patch this week. So if you and Linus
Walleij might have some time to help review and comment on that, it
would be greatly appreciated.

-michael

> Best regards,
> Bartosz Golaszewski