1.\" Copyright (c) 2003 Sergey A. Osokin <osa@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd April 24, 2007 28.Dt LED 4 29.Os 30.Sh NAME 31.Nm led 32.Nd API for manipulating LED's, lamps and other annunciators 33.Sh SYNOPSIS 34.In dev/led/led.h 35.Pp 36.Fd "typedef void led_t(void *priv, int onoff);" 37.Ft struct cdev * 38.Fn led_create_state "led_t *func" "void *priv" "char const *name" "int state" 39.Ft struct cdev * 40.Fn led_create "led_t *func" "void *priv" "char const *name" 41.Ft void 42.Fn led_destroy "struct cdev *" 43.Sh DESCRIPTION 44The 45.Nm 46driver provides generic support for handling LEDs, lamps and other 47annunciators. 48.Pp 49The hardware driver must supply a function to turn the annunciator on and off 50and the device 51.Fa name 52of the annunciator relative to 53.Pa /dev/led/ . 54The 55.Fa priv 56argument is passed back to this on/off function and can be used however 57the hardware driver sees fit. 58.Pp 59The lamp can be controlled by opening and writing 60.Tn ASCII 61strings to the 62.Pa /dev/led/bla 63device. 64.Pp 65In the following, we will use this special notation to indicate the resulting 66output of the annunciator: 67.Pp 68.Bl -tag -width indent -offset indent -compact 69.It Ic * 70The annunciator is on for 1/10th second. 71.It Ic _ 72The annunciator is off for 1/10th second. 73.El 74.Pp 75State can be set directly, and since the change happens immediately, 76it is possible to flash the annunciator with very short periods and 77synchronize it with program events. 78It should be noted that there is a non-trivial overhead, so this may 79not be usable for benchmarking or measuring short intervals. 80.Pp 81.Bl -tag -width indent -offset indent -compact 82.It Ic 0 83Turn the annunciator off immediately. 84.It Ic 1 85Turn the annunciator on immediately. 86.El 87.Pp 88Flashing can be set with a given period. 89The pattern continues endlessly. 90.Pp 91.Bl -tag -width indent -offset indent -compact 92.It Ic f 93_* 94.It Ic f1 95_* 96.It Ic f2 97__** 98.It Ic f3 99___*** 100.It ... 101.It Ic f9 102_________********* 103.El 104.Pp 105Three high-level commands are available: 106.Bl -tag -width indent -offset indent 107.It Ic d%d 108Numbers. 109Each digit is blinked out at 1/10th second, zero as ten pulses. 110Between digits a one second pause and after the last 111digit a two second pause after which the sequence is repeated. 112.It Ic s%s 113String. 114This gives full control over the annunciator. 115Letters 116.Ql A 117.No ... 118.Ql J 119turn the annunciator on for from 1/10th to one full 120second. 121Letters 122.Ql a 123.No ... 124.Ql j 125turn the annunciator off for 1/10th 126to one full second. 127Letters 128.Ql u 129and 130.Ql U 131turn the annunciator off and on respectively when the next 132UTC second starts. 133Unless terminated with a 134.Ql \&. , 135the sequence is immediately repeated. 136.It Ic m%s 137Morse. 138.Pp 139.Bl -tag -width indent -offset indent -compact 140.It Ql \&. 141becomes 142.Ql _* 143.It Ql - 144becomes 145.Sq Li _*** 146.It Ql "\ " 147becomes 148.Sq Li __ 149.It Ql \en 150becomes 151.Sq Li ____ 152.El 153.El 154.Pp 155The sequence is repeated after a one second pause. 156.Sh FILES 157.Bl -tag -width ".Pa /dev/led/*" 158.It Pa /dev/led/* 159.El 160.Sh EXAMPLES 161A 162.Sq Li d12 163flashes the lamp 164.Pp 165.Dl *__________*_*______________________________ 166.Pp 167A 168.Sq Li sAaAbBa 169flashes 170.Pp 171.Dl *_*__**_ 172.Bd -literal 173/usr/bin/morse -l "Soekris rocks" > /dev/led/error 174.Ed 175.Sh SEE ALSO 176.Xr morse 6 177.Sh HISTORY 178The 179.Nm 180driver first appeared in 181.Fx 5.2 . 182.Sh AUTHORS 183.An -nosplit 184This software was written by 185.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org . 186.Pp 187This manual page was written by 188.An Sergey A. Osokin Aq Mt osa@FreeBSD.org 189and 190.An Poul-Henning Kamp Aq Mt phk@FreeBSD.org . 191