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<table class="head">
<tr>
<td class="head-ltitle">GPIOLED(4)</td>
<td class="head-vol">Device Drivers Manual</td>
<td class="head-rtitle">GPIOLED(4)</td>
</tr>
</table>
<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<p class="Pp"><code class="Nm">gpioled</code> — <span class="Nd">GPIO LED
generic device driver</span></p>
</section>
<section class="Sh">
<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1>
<p class="Pp">To compile this driver into the kernel, place the following lines
in your kernel configuration file:</p>
<div class="Bd Pp Bd-indent"><code class="Cd">device gpio</code>
<br/>
<code class="Cd">device gpioled</code></div>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">The <code class="Nm">gpioled</code> driver provides glue to attach
a <a class="Xr">led(4)</a> compatible device to a GPIO pin. Each LED in the
system has a <span class="Pa">name</span> which is used to export a device
as <span class="Pa">/dev/led/<name></span>. The GPIO pin can then be
controlled by writing to this device as described in
<a class="Xr">led(4)</a>.</p>
<p class="Pp">On a <a class="Xr">device.hints(5)</a> based system, like
<code class="Li">MIPS</code>, these values are configurable for
<code class="Nm">gpioled</code>:</p>
<dl class="Bl-tag">
<dt id="hint.gpioled._d.at"><var class="Va">hint.gpioled.%d.at</var></dt>
<dd>The gpiobus you are attaching to. Normally assigned to gpiobus0.</dd>
<dt id="hint.gpioled._d.name"><var class="Va">hint.gpioled.%d.name</var></dt>
<dd>Arbitrary name of device in <span class="Pa">/dev/led/</span> to create
for <a class="Xr">led(4)</a>.</dd>
<dt id="hint.gpioled._d.pins"><var class="Va">hint.gpioled.%d.pins</var></dt>
<dd>Which pin on the GPIO interface to map to this instance. Please note that
this mask should only ever have one bit set (any other bits - i.e., pins -
will be ignored).</dd>
<dt id="hint.gpioled._d.invert"><var class="Va">hint.gpioled.%d.invert</var></dt>
<dd>Use pin inversion. If set to 1, the pin will be set to 0 to light the LED,
and 1 to clear it.</dd>
<dt id="hint.gpioled._d.invmode"><var class="Va">hint.gpioled.%d.invmode</var></dt>
<dd>Whether or not to use hardware support when pin inversion is requested.
Must be one of:
<dl class="Bl-tag">
<dt id="auto"><var class="Va">auto</var></dt>
<dd>Use hardware pin inversion if available, else fallback to software pin
inversion. This is the default.</dd>
<dt id="hw"><var class="Va">hw</var></dt>
<dd>Use hardware pin inversion.</dd>
<dt id="sw"><var class="Va">sw</var></dt>
<dd>Use software pin inversion.</dd>
</dl>
</dd>
<dt id="hint.gpioled._d.state"><var class="Va">hint.gpioled.%d.state</var></dt>
<dd>The initial state of the LED when the driver takes control over it. If set
to 1 or 0, the LED will be on or off correspondingly. If set to -1, the
LED will be kept in its original state.</dd>
</dl>
<p class="Pp">On a <a class="Xr">FDT(4)</a> based system, like
<code class="Li">ARM</code>, the DTS part for a
<code class="Nm">gpioled</code> device usually looks like:</p>
<div class="Bd Pp Li">
<pre>gpio: gpio {
gpio-controller;
...
led0 {
compatible = "gpioled";
gpios = <&gpio 16 2 0>; /* GPIO pin 16. */
name = "ok";
};
led1 {
compatible = "gpioled";
gpios = <&gpio 17 2 0>; /* GPIO pin 17. */
name = "user-led1";
};
};</pre>
</div>
<p class="Pp">Optionally, you can choose to combine all the LEDs under a single
“gpio-leds” compatible node:</p>
<div class="Bd Pp Li">
<pre>simplebus0 {
...
leds {
compatible = "gpio-leds";
led0 {
gpios = <&gpio 16 2 0>;
name = "ok"
};
led1 {
gpios = <&gpio 17 2 0>;
name = "user-led1"
};
};
};</pre>
</div>
<p class="Pp">Both methods are equally supported and it is possible to have the
LEDs defined with any sort of mix between the methods. The only restriction
is that a GPIO pin cannot be mapped by two different (gpio)leds.</p>
<p class="Pp">For more details about the <var class="Va">gpios</var> property,
please consult
<span class="Pa">/usr/src/sys/dts/bindings-gpio.txt</span>.</p>
<p class="Pp">The property <var class="Va">name</var> is the arbitrary name of
the device in <span class="Pa">/dev/led/</span> to create for
<a class="Xr">led(4)</a>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE
ALSO</a></h1>
<p class="Pp"><a class="Xr">fdt(4)</a>, <a class="Xr">gpio(4)</a>,
<a class="Xr">gpioiic(4)</a>, <a class="Xr">led(4)</a></p>
</section>
<section class="Sh">
<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1>
<p class="Pp">The <code class="Nm">gpioled</code> manual page first appeared in
<span class="Ux">FreeBSD 10.1</span>.</p>
</section>
<section class="Sh">
<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1>
<p class="Pp">This manual page was written by <span class="An">Luiz Otavio O
Souza</span>.</p>
</section>
</div>
<table class="foot">
<tr>
<td class="foot-date">May 23, 2019</td>
<td class="foot-os">FreeBSD 15.0</td>
</tr>
</table>
|
