On Tue, Mar 07, 2023 at 02:43:54PM +0000, Biju Das wrote:
> Hi Linus Walleij,
>
> Thanks for the feedback.
>
> > Subject: Re: [PATCH v6 03/13] pinctrl: Add sysfs support
> >
> > On Mon, Mar 6, 2023 at 10:00 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> >
> > > Add a simple sysfs interface to the generic pinctrl framework for
> > > configuring pins for output disable operation.
> > >
> > > /sys/class/pinctrl/
> > > `-- output-disable/
> > > |-- configure (w/o) ask the kernel to configure a pin group
> > > for output disable operation.
> > >
> > > echo "<group-name function-name 0 1>" > configure
> > >
> > > The existing "pinmux-functions" debugfs file lists the pin functions
> > > registered for the pin controller. For example:
> > >
> > > function 0: usb0, groups = [ usb0 ]
> > > function 1: usb1, groups = [ usb1 ]
> > > function 2: gpt4-pins, groups = [ gpt4-pins ]
> > > function 3: scif0, groups = [ scif0 ]
> > > function 4: scif2, groups = [ scif2 ]
> > > function 5: spi1, groups = [ spi1 ]
> > >
> > > To configure gpt4-pins for output disable activation by user:
> > >
> > > echo "gpt4-pins gpt4-pins 0 1" > configure
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> >
> >
> > You have to run things like this by Greg K-H (adde on To)
> >
> > > +static struct class pinctrl_class = {
> > > + .name = "pinctrl",
> > > + .owner = THIS_MODULE,
> > > + .dev_groups = pinctrl_groups,
> > > +};
> >
> > Why are you adding a new device class?
> >
> > IIRC Greg don't like them, we should probably just deal with the devices
> > directly on the bus where they are, which also implies some topology search
> > etc which is a feature.
>
> I am ok for both,
>
> I thought adding new device class will be more generic and
> people can use simple sysfs[1] like pwm for output disable operation
> rather than the SoC specific operation[2].
>
> [1]
> /sys/class/pinctrl/output-disable/configure
That's fine, but you don't need a class for it, use configfs for
configuring things like this, that is what it is there for.
thanks,
greg k-h
