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.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
.\"
.\" Copyright (c) 2020 Andriy Gapon <avg@FreeBSD.org>
.\"
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.\" modification, are permitted provided that the following conditions
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.\" $FreeBSD$
.\"
.Dd August 3, 2020
.Dt GPIOKEYS 4
.Os
.Sh NAME
.Nm gpiokeys
.Nd GPIO keys device driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "options FDT"
.Cd "device gpio"
.Cd "device gpiokeys"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
gpiokeys_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides a way to represent a set of general purpose inputs as a
.Xr keyboard 4
device.
At the moment the driver supports only
.Xr FDT 4
based systems.
The DTS determines what pins are mapped to buttons and what key codes are
generated for each virtual button.
manuUnsubmitted
Done
Inline Actions

This sounds weird to me, I think that s/FDT/DTS/ would sound better.

manu: This sounds weird to me, I think that s/FDT/DTS/ would sound better.
avgAuthorUnsubmitted
Done
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Okay.

avg: Okay.
The
.Xr keyboard 4
device can be used from userland to monitor for input changes.
.Pp
On an
.Xr FDT 4
based system
the DTS part for a
.Nm
device usually looks like:
bjkUnsubmitted
Done
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I expect mandoc -Tlint to complain about an argument to .Nm here.

bjk: I expect mandoc -Tlint to complain about an argument to .Nm here.
avgAuthorUnsubmitted
Done
Inline Actions

Actually, it didn't.
I'll fix this.

avg: Actually, it didn't. I'll fix this.
.Bd -literal
/ {
...
gpio_keys {
compatible = "gpio-keys";
btn1 {
label = "button1";
linux,code = <KEY_1>;
gpios = <&gpio 0 3 GPIO_ACTIVE_LOW>
};
btn2 {
label = "button2";
linux,code = <KEY_2>;
gpios = <&gpio 0 4 GPIO_ACTIVE_LOW>
};
};
};
.Ed
.Pp
For more details about the
.Va gpios
property, please consult
.Pa /usr/src/sys/dts/bindings-gpio.txt .
.Pp
manuUnsubmitted
Not Done
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Mhm, I didn't knew we still had this.
It's an old file that might not be accurate anymore and we don't import the dt-bindings files, maybe we should, I've been saying for a long time that they would be useful to reference in a manpage ...

manu: Mhm, I didn't knew we still had this. It's an old file that might not be accurate anymore and…
avgAuthorUnsubmitted
Done
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I took this from from gpioled(4).
If you can make a suggestion on how to improve this part, please do.
Maybe it is acceptable that this manual page will be improved later.
I did not have a hope of writing a perfect man page since I am very new to this driver and FDT and GPIO.
But I thought that having some page would be a good start and better than nothing.

avg: I took this from from gpioled(4). If you can make a suggestion on how to improve this part…
manuUnsubmitted
Not Done
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Yeah we can improve later, this is way better that what we currently have :)

manu: Yeah we can improve later, this is way better that what we currently have :)
avgAuthorUnsubmitted
Done
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BTW, that document seems to have a fairly accurate, if a bit vague, description of the gpios property\

avg: BTW, that document seems to have a fairly accurate, if a bit vague, description of the `gpios`…
The
.Nm
driver supports two properties for specifying a key code.
.Pp
The property
.Va freebsd,code
specifies a
.Fx
native scancode compatible with
.Xr kbdmap 5
keyboard maps.
.Pp
The property
.Va linux,code
specifies an evdev scancode.
That scancode is internally translated to a native scancode.
Note that not all evdev scancodes have corresponding native scancodes.
If a scancode cannot be translated, then a diagnostic message is printed
and the input is ignored.
.Pp
The property
.Va label
is a descriptive name of a button.
It is used for diagnostic messages only.
Its alternative spelling is
.Va name .
.Pp
The property
.Va autorepeat
determines whether autorepeat is enabled for a button.
.Pp
The property
.Va debounce-interval
defines debouncing interval time in milliseconds.
If not specified the interval defaults to 5.
.Sh SEE ALSO
.Xr fdt 4 ,
.Xr gpio 4 ,
.Xr keyboard 4 ,
.Xr kbdmap 5
.Sh HISTORY
The
.Nm
manual page first appeared in
.Fx 12.2 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Oleksandr Tymoshenko Aq Mt gonzo@FreeBSD.org .
This
manual page was written by
.An Andriy Gapon Aq Mt avg@FreeBSD.org .