Hi Andy,
Le mer. 27 juin 2018 à 19:18, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> a écrit :
On Wed, Jun 27, 2018 at 2:48 PM, Paul Cercueil <paul@xxxxxxxxxxxxxxx>
wrote:
Hi Linus,
Here's a set of (rather RFC) patches, to implement
pinctrl_gpio_get_direction(). I did that, because my gpio-ingenic
driver
calls pinctrl_gpio_set_direction() within its gpio_chip's
.set_direction
callback, but there was no corresponding function to implement the
.get_direction callback. If that's not the right way to do it,
please
advise.
If not merging the whole series, patch [3/5] is a real fix that
should
go through.
Note that it doesn't make checkpatch.pl happy, I wasn't sure
whether I
should try to comply to checkpatch.pl or match the coding style in
the
pinctrl subsystem, I chose the latter.
I dunno what Linus would going to say about this, but I would like to
see a schematics for this piece of IP.
ftp://ftp.ingenic.com/SOC/JZ4780/JZ4780_pm.pdf
Even if GPIO and pin muxing has only one set of buffers to indicate
input or output (same registers in use) it's a GPIO driver business to
get direction from GPIO part of IP.
If I follow that logic it's also a GPIO driver business to set the
direction
of a GPIO, right? Truth is the pinctrl subsystem takes care of that. So
why
have "set direction" and no "get direction"?
Looking into the existing code I would rather say that
pinctrl-ingenic.c should incorporate gpio-ingenic.c as they are
(partially) sharing same registers.
To ->get_direction() implementation it's pretty straight forward, just
read necessary registers in the gpio-ingenic.c directly. No need to
have pin control or pin muxing to be involved.
Sure, it'd be pretty straightforward to do it from the GPIO driver, but
I'd
still like to hear Linus' point of view about this.
As for merging pinctrl-ingenic.c and gpio-ingenic.c... I wouldn't
disagree more,
even if they share registers, they belong to different subsystems.
Besides,
your platform might need the pinctrl driver but not the GPIO one, or
you might
want to provide the GPIO driver as a loadable module, etc.
Regards,
-Paul
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