GPIO drivers under drivers/char/

GPIO drivers under drivers/char/

[Andy Shevchenko]

Hi!

Due to patch bomb from Jens, I noticed that we have two interesting drivers
(and a common library) under drivers/char/. Shouldn't we move them to
drivers/gpio/ to keep an eye on that (with the respective update of MAINTAINERS
if needed)? Also William might say something about this since those are old ISA
(?) related ones and (perhaps?) might utilise PC-104 code.

-- 
With Best Regards,
Andy Shevchenko

Re: GPIO drivers under drivers/char/

[Andy Shevchenko]

(Update William's email; btw, William, it seems MAINTAINERS need an update, or .mailcap)

On Fri, May 10, 2024 at 08:33:53PM +0300, Andy Shevchenko wrote:
> Hi!
> 
> Due to patch bomb from Jens, I noticed that we have two interesting drivers
> (and a common library) under drivers/char/. Shouldn't we move them to
> drivers/gpio/ to keep an eye on that (with the respective update of MAINTAINERS
> if needed)? Also William might say something about this since those are old ISA
> (?) related ones and (perhaps?) might utilise PC-104 code.

-- 
With Best Regards,
Andy Shevchenko

Re: GPIO drivers under drivers/char/

[William Breathitt Gray]

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On Fri, May 10, 2024 at 09:20:33PM +0300, Andy Shevchenko wrote:
> (Update William's email; btw, William, it seems MAINTAINERS need an update, or .mailcap)
> 
> On Fri, May 10, 2024 at 08:33:53PM +0300, Andy Shevchenko wrote:
> > Hi!
> > 
> > Due to patch bomb from Jens, I noticed that we have two interesting drivers
> > (and a common library) under drivers/char/. Shouldn't we move them to
> > drivers/gpio/ to keep an eye on that (with the respective update of MAINTAINERS
> > if needed)? Also William might say something about this since those are old ISA
> > (?) related ones and (perhaps?) might utilise PC-104 code.
> 
> -- 
> With Best Regards,
> Andy Shevchenko

Thank you for the forward; I'm updating MAINTAINERS to match my
kernel.org address from now on so that we don't have this problem again
in the future. :-)

Regarding the gpio char drivers, I take it you are referring to the
nsc_gpio used by scx200_gpio and pc8736x_gpio. I agree, these should be
moved to the GPIO subsystem so they're with the old GPIO drivers (and
ported to the standard GPIO interface we have there if they're not
already).

Taking a quick look, neither of these are PC-104 devices, but rather
appear to be part of the Super I/O chip. Regardless, the driver
interface can be the same since they're both performing ioport
operations over an ISA bus essentially. You can utilize
include/linux/isa.h and leverage the module_isa_driver() like what we do
in the gpio-mm driver.

William Breathitt Gray

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