Add hotplug(4) man page, with help from jmc@.

2 files changed, 106 insertions, 2 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index a7c6a1b6d26..c25b83916ef 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.264 2004/05/23 18:44:08 grange Exp $
+#	$OpenBSD: Makefile,v 1.265 2004/05/30 08:35:19 grange Exp $
 
 MAN=	aac.4 ac97.4 acphy.4 addcom.4 adv.4 aha.4 ahb.4 ahc.4 \
 	aic.4 amdpm.4 ami.4 amphy.4 an.4 aria.4 ast.4 atalk.4 \
@@ -11,7 +11,7 @@ MAN=	aac.4 ac97.4 acphy.4 addcom.4 adv.4 aha.4 ahb.4 ahc.4 \
 	emu.4 enc.4 ep.4 esa.4 esis.4 eso.4 ess.4 exphy.4 \
 	faith.4 fd.4 fdc.4 fms.4 fpa.4 fxp.4 gdt.4 gem.4 gif.4 \
 	gpr.4 gre.4 gscsio.4 gtp.4 hifn.4 hil.4 hilid.4 hilkbd.4 hilms.4 \
-	hme.4 hsq.4 icmp.4 icmp6.4 icsphy.4 idp.4 ifmedia.4 \
+	hme.4 hotplug.4 hsq.4 icmp.4 icmp6.4 icsphy.4 idp.4 ifmedia.4 \
 	iha.4 iic.4 inet.4 inet6.4 inphy.4 iop.4 iophy.4 ioprbs.4 \
 	iopsp.4 ip.4 ip6.4 ipcomp.4 ipsec.4 isa.4 isapnp.4 \
 	ises.4 iso.4 isp.4 it.4 ksyms.4 kue.4 lc.4 lge.4 lkm.4 \
diff --git a/share/man/man4/hotplug.4 b/share/man/man4/hotplug.4
new file mode 100644
index 00000000000..abf8b82c877
--- /dev/null
+++ b/share/man/man4/hotplug.4
@@ -0,0 +1,104 @@
+.\"	$OpenBSD: hotplug.4,v 1.1 2004/05/30 08:35:19 grange Exp $
+.\"
+.\" Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd March 30, 2004
+.Dt HOTPLUG 4
+.Os
+.Sh NAME
+.Nm hotplug
+.Nd devices hot plugging
+.Sh SYNOPSIS
+.Cd "pseudo-device hotplug 1"
+.Pp
+.Fd #include <sys/types.h>
+.Fd #include <sys/device.h>
+.Fd #include <sys/hotplug.h>
+.Sh DESCRIPTION
+The
+.Nm
+pseudo-device passes device attachment and detachment events to
+userland.
+When a device attaches or detaches, the corresponding event is queued.
+The events can then be obtained from the queue through the
+.Xr read 2
+call on the
+.Pa /dev/hotplug
+device file.
+Once an event has been read, it's deleted from the queue.
+The event queue has a limited size and if it's full all new events will be
+dropped.
+Each event is described with the following structure declared in the
+.Aq Pa sys/hotplug.h
+header file:
+.Bd -literal -offset indent
+struct hotplug_event {
+	int		he_type;	/* event type		*/
+	enum devclass	he_devclass;	/* device class		*/
+	char		he_devname[16];	/* device name		*/
+};
+
+.Ed
+The
+.Va he_type
+field describes the event type and can be either
+.Dv HOTPLUG_DEVAT
+for device attachment or
+.Dv HOTPLUG_DEVDT
+for detachment.
+The
+.Va he_devclass
+field describes the device class.
+All device classes can be found in the
+.Aq Pa sys/device.h
+header file:
+.Bd -literal -offset indent
+enum devclass {
+	DV_DULL,	/* generic, no special info */
+	DV_CPU,		/* CPU (carries resource utilization) */
+	DV_DISK,	/* disk drive (label, etc) */
+	DV_IFNET,	/* network interface */
+	DV_TAPE,	/* tape device */
+	DV_TTY		/* serial line interface */
+};
+
+.Ed
+The
+.Va he_devname
+is a device name including unit number, e.g.\&
+.Pa sd1 .
+.Pp
+Only one structure can be read per call.
+If there are no events in the queue, the
+.Xr read 2
+call will block until an event appears.
+.Sh DIAGNOSTICS
+.Bl -diag
+.It "hotplug: event lost, queue full"
+New events will be dropped until pending events aren't read.
+.El
+.Sh SEE ALSO
+.Xr read 2 ,
+.Xr hotplugd 8
+.Sh HISTORY
+The
+.Nm
+device first appeared in
+.Ox 3.6 .
+.Sh AUTHORS
+The
+.Nm
+driver was written by
+.An Alexander Yurchenko Aq grange@openbsd.org .