Messages in this thread | | | Date | Sat, 19 Dec 2020 12:18:42 -0800 | From | Drew Fustini <> | Subject | Re: [RFC PATCH] pinctrl: add helper to expose pinctrl state in debugfs |
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On Fri, Dec 18, 2020 at 06:00:49PM +0200, Andy Shevchenko wrote: > On Wed, Dec 16, 2020 at 12:42 AM Drew Fustini <drew@beagleboard.org> wrote: > > On Tue, Dec 15, 2020 at 09:39:18PM +0200, Andy Shevchenko wrote: > > > On Tue, Dec 15, 2020 at 9:36 PM Andy Shevchenko > > > <andy.shevchenko@gmail.com> wrote: > > > > On Mon, Dec 14, 2020 at 11:44 PM Drew Fustini <drew@beagleboard.org> wrote: > > > > > On Mon, Dec 14, 2020 at 07:55:12PM +0200, Andy Shevchenko wrote: > > > > > > ... > > > > > > > > With regards to parent directory, I did discover there is > > > > > debugfs_lookup(), so I can get the dentry for "pinctrl" and create new > > > > > subdirectory inside of it. This is the structure now: > > > > > > > > > > /sys/kernel/debug/pinctrl/pinctrl_state/ocp:P2_35_pinmux/state > > > > > /sys/kernel/debug/pinctrl/pinctrl_state/ocp:P2_34_pinmux/state > > > > > /sys/kernel/debug/pinctrl/pinctrl_state/ocp:P2_33_pinmux/state > > > > > /sys/kernel/debug/pinctrl/pinctrl_state/ocp:P2_32_pinmux/state > > > > > etc.. > > > > > > Missed part to comment. > > > > > > I was talking about > > > > > > /sys/kernel/debug/pinctrl/<$PINCTRL>/mux/<$PIN> (maybe folder, maybe node) > > > > Thanks for the example. > > > > What would the value be "<$PINCTRL>"? The name of the driver? > > The name of the device instance. This is already done in the pin control code.
Ah, so for the BeagleBone, that would be 44e10800.pinmux-pinctrl-single:
/sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/
> > > The "ocp:Px_yy_pinmux" directory name comes from dev_name(dev). Is that > > the name you were referencing in "<$PIN>"? > > No, the <$PIN> is an actual pin on this controller. However, I think > we probably don't need this, just supply it as tuple of the parameters > to be set: like > echo $PIN $STATE > .../<$PINCTRL>/mux or alike.
Do you mean not having a debugfs file for each pin, but instead just using the existing combined file?
/sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/pinmux-pins
There is one line in there for each pin in the pinctrl-single instance.
For example:
pin 105 (PIN105): ocp:P2_34_pinmux (GPIO UNCLAIMED) function pinmux_P2_34_default_pin group pinmux_P2_34_default_pin
So maybe one solution to changing pinctrl state could to:
echo "105 gpio_pu" > /sys/kernel/debug/pinctrl/44e10800.pinmux-pinctrl-single/pinmux-pins
I'll make an attempt at implementing that.
> > -- > With Best Regards, > Andy Shevchenko
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