NetBSD/sys/arch/sparc/dev/event.c

172 lines
4.8 KiB
C

/* $NetBSD: event.c,v 1.3 1994/11/20 20:52:13 deraadt Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Lawrence Berkeley Laboratory.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)event.c 8.1 (Berkeley) 6/11/93
*/
/*
* Internal `Firm_event' interface for the keyboard and mouse drivers.
*/
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <machine/vuid_event.h>
#include <sparc/dev/event_var.h>
/*
* Initialize a firm_event queue.
*/
void
ev_init(ev)
register struct evvar *ev;
{
ev->ev_get = ev->ev_put = 0;
ev->ev_q = malloc((u_long)EV_QSIZE * sizeof(struct firm_event),
M_DEVBUF, M_WAITOK);
bzero((caddr_t)ev->ev_q, EV_QSIZE * sizeof(struct firm_event));
}
/*
* Tear down a firm_event queue.
*/
void
ev_fini(ev)
register struct evvar *ev;
{
free(ev->ev_q, M_DEVBUF);
}
/*
* User-level interface: read, select.
* (User cannot write an event queue.)
*/
int
ev_read(ev, uio, flags)
register struct evvar *ev;
struct uio *uio;
int flags;
{
int s, n, cnt, error;
/*
* Make sure we can return at least 1.
*/
if (uio->uio_resid < sizeof(struct firm_event))
return (EMSGSIZE); /* ??? */
s = splev();
while (ev->ev_get == ev->ev_put) {
if (flags & IO_NDELAY) {
splx(s);
return (EWOULDBLOCK);
}
ev->ev_wanted = 1;
error = tsleep((caddr_t)ev, PEVENT | PCATCH, "firm_event", 0);
if (error) {
splx(s);
return (error);
}
}
/*
* Move firm_events from tail end of queue (there is at least one
* there).
*/
if (ev->ev_put < ev->ev_get)
cnt = EV_QSIZE - ev->ev_get; /* events in [get..QSIZE) */
else
cnt = ev->ev_put - ev->ev_get; /* events in [get..put) */
splx(s);
n = howmany(uio->uio_resid, sizeof(struct firm_event));
if (cnt > n)
cnt = n;
error = uiomove((caddr_t)&ev->ev_q[ev->ev_get],
cnt * sizeof(struct firm_event), uio);
n -= cnt;
/*
* If we do not wrap to 0, used up all our space, or had an error,
* stop. Otherwise move from front of queue to put index, if there
* is anything there to move.
*/
if ((ev->ev_get = (ev->ev_get + cnt) % EV_QSIZE) != 0 ||
n == 0 || error || (cnt = ev->ev_put) == 0)
return (error);
if (cnt > n)
cnt = n;
error = uiomove((caddr_t)&ev->ev_q[0],
cnt * sizeof(struct firm_event), uio);
ev->ev_get = cnt;
return (error);
}
int
ev_select(ev, rw, p)
register struct evvar *ev;
int rw;
struct proc *p;
{
int s = splev();
switch (rw) {
case FREAD:
/* succeed if there is something to read */
if (ev->ev_get != ev->ev_put) {
splx(s);
return (1);
}
selrecord(p, &ev->ev_sel);
break;
case FWRITE:
return (1); /* always fails => never blocks */
}
splx(s);
return (0);
}