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FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/amd64/compile/hs32/modules/usr/src/sys/modules/isci/@/dev/nmdm/nmdm.c |
/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/dev/nmdm/nmdm.c 193828 2009-06-09 13:33:03Z jhb $");
/*
* Pseudo-nulmodem driver
* Mighty handy for use with serial console in Vmware
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/poll.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/module.h>
#include <sys/serial.h>
#include <sys/signalvar.h>
#include <sys/malloc.h>
#include <sys/taskqueue.h>
MALLOC_DEFINE(M_NMDM, "nullmodem", "nullmodem data structures");
static tsw_inwakeup_t nmdm_outwakeup;
static tsw_outwakeup_t nmdm_inwakeup;
static tsw_param_t nmdm_param;
static tsw_modem_t nmdm_modem;
static struct ttydevsw nmdm_class = {
.tsw_flags = TF_NOPREFIX,
.tsw_inwakeup = nmdm_inwakeup,
.tsw_outwakeup = nmdm_outwakeup,
.tsw_param = nmdm_param,
.tsw_modem = nmdm_modem,
};
static void nmdm_task_tty(void *, int);
struct nmdmsoftc;
struct nmdmpart {
struct tty *np_tty;
int np_dcd;
struct task np_task;
struct nmdmpart *np_other;
struct nmdmsoftc *np_pair;
struct callout np_callout;
u_long np_quota;
u_long np_accumulator;
int np_rate;
int np_credits;
#define QS 8 /* Quota shift */
};
struct nmdmsoftc {
struct nmdmpart ns_part1;
struct nmdmpart ns_part2;
struct mtx ns_mtx;
};
static int nmdm_count = 0;
static struct nmdmsoftc *
nmdm_alloc(unsigned long unit)
{
struct nmdmsoftc *ns;
struct tty *tp;
atomic_add_int(&nmdm_count, 1);
ns = malloc(sizeof(*ns), M_NMDM, M_WAITOK|M_ZERO);
mtx_init(&ns->ns_mtx, "nmdm", NULL, MTX_DEF);
/* Hook the pairs together. */
ns->ns_part1.np_pair = ns;
ns->ns_part1.np_other = &ns->ns_part2;
TASK_INIT(&ns->ns_part1.np_task, 0, nmdm_task_tty, &ns->ns_part1);
callout_init_mtx(&ns->ns_part1.np_callout, &ns->ns_mtx, 0);
ns->ns_part2.np_pair = ns;
ns->ns_part2.np_other = &ns->ns_part1;
TASK_INIT(&ns->ns_part2.np_task, 0, nmdm_task_tty, &ns->ns_part2);
callout_init_mtx(&ns->ns_part2.np_callout, &ns->ns_mtx, 0);
/* Create device nodes. */
tp = ns->ns_part1.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part1,
&ns->ns_mtx);
tty_makedev(tp, NULL, "nmdm%luA", unit);
tp = ns->ns_part2.np_tty = tty_alloc_mutex(&nmdm_class, &ns->ns_part2,
&ns->ns_mtx);
tty_makedev(tp, NULL, "nmdm%luB", unit);
return (ns);
}
static void
nmdm_clone(void *arg, struct ucred *cred, char *name, int nameen,
struct cdev **dev)
{
unsigned long unit;
char *end;
struct nmdmsoftc *ns;
if (*dev != NULL)
return;
if (strncmp(name, "nmdm", 4) != 0)
return;
/* Device name must be "nmdm%lu%c", where %c is 'A' or 'B'. */
name += 4;
unit = strtoul(name, &end, 10);
if (unit == ULONG_MAX || name == end)
return;
if ((end[0] != 'A' && end[0] != 'B') || end[1] != '\0')
return;
/* XXX: pass privileges? */
ns = nmdm_alloc(unit);
if (end[0] == 'A')
*dev = ns->ns_part1.np_tty->t_dev;
else
*dev = ns->ns_part2.np_tty->t_dev;
}
static void
nmdm_timeout(void *arg)
{
struct nmdmpart *np = arg;
if (np->np_rate == 0)
return;
/*
* Do a simple Floyd-Steinberg dither here to avoid FP math.
* Wipe out unused quota from last tick.
*/
np->np_accumulator += np->np_credits;
np->np_quota = np->np_accumulator >> QS;
np->np_accumulator &= ((1 << QS) - 1);
taskqueue_enqueue(taskqueue_swi, &np->np_task);
callout_reset(&np->np_callout, np->np_rate, nmdm_timeout, np);
}
static void
nmdm_task_tty(void *arg, int pending __unused)
{
struct tty *tp, *otp;
struct nmdmpart *np = arg;
char c;
tp = np->np_tty;
tty_lock(tp);
otp = np->np_other->np_tty;
KASSERT(otp != NULL, ("NULL otp in nmdmstart"));
KASSERT(otp != tp, ("NULL otp == tp nmdmstart"));
if (np->np_other->np_dcd) {
if (!tty_opened(tp)) {
np->np_other->np_dcd = 0;
ttydisc_modem(otp, 0);
}
} else {
if (tty_opened(tp)) {
np->np_other->np_dcd = 1;
ttydisc_modem(otp, 1);
}
}
while (ttydisc_rint_poll(otp) > 0) {
if (np->np_rate && !np->np_quota)
break;
if (ttydisc_getc(tp, &c, 1) != 1)
break;
np->np_quota--;
ttydisc_rint(otp, c, 0);
}
ttydisc_rint_done(otp);
tty_unlock(tp);
}
static int
bits_per_char(struct termios *t)
{
int bits;
bits = 1; /* start bit */
switch (t->c_cflag & CSIZE) {
case CS5: bits += 5; break;
case CS6: bits += 6; break;
case CS7: bits += 7; break;
case CS8: bits += 8; break;
}
bits++; /* stop bit */
if (t->c_cflag & PARENB)
bits++;
if (t->c_cflag & CSTOPB)
bits++;
return (bits);
}
static int
nmdm_param(struct tty *tp, struct termios *t)
{
struct nmdmpart *np = tty_softc(tp);
struct tty *tp2;
int bpc, rate, speed, i;
tp2 = np->np_other->np_tty;
if (!((t->c_cflag | tp2->t_termios.c_cflag) & CDSR_OFLOW)) {
np->np_rate = 0;
np->np_other->np_rate = 0;
return (0);
}
/*
* DSRFLOW one either side enables rate-simulation for both
* directions.
* NB: the two directions may run at different rates.
*/
/* Find the larger of the number of bits transmitted */
bpc = imax(bits_per_char(t), bits_per_char(&tp2->t_termios));
for (i = 0; i < 2; i++) {
/* Use the slower of our receive and their transmit rate */
speed = imin(tp2->t_termios.c_ospeed, t->c_ispeed);
if (speed == 0) {
np->np_rate = 0;
np->np_other->np_rate = 0;
return (0);
}
speed <<= QS; /* [bit/sec, scaled] */
speed /= bpc; /* [char/sec, scaled] */
rate = (hz << QS) / speed; /* [hz per callout] */
if (rate == 0)
rate = 1;
speed *= rate;
speed /= hz; /* [(char/sec)/tick, scaled */
np->np_credits = speed;
np->np_rate = rate;
callout_reset(&np->np_callout, rate, nmdm_timeout, np);
/*
* swap pointers for second pass so the other end gets
* updated as well.
*/
np = np->np_other;
t = &tp2->t_termios;
tp2 = tp;
}
return (0);
}
static int
nmdm_modem(struct tty *tp, int sigon, int sigoff)
{
struct nmdmpart *np = tty_softc(tp);
int i = 0;
if (sigon || sigoff) {
if (sigon & SER_DTR)
np->np_other->np_dcd = 1;
if (sigoff & SER_DTR)
np->np_other->np_dcd = 0;
ttydisc_modem(np->np_other->np_tty, np->np_other->np_dcd);
return (0);
} else {
if (np->np_dcd)
i |= SER_DCD;
if (np->np_other->np_dcd)
i |= SER_DTR;
return (i);
}
}
static void
nmdm_inwakeup(struct tty *tp)
{
struct nmdmpart *np = tty_softc(tp);
/* We can receive again, so wake up the other side. */
taskqueue_enqueue(taskqueue_swi, &np->np_other->np_task);
}
static void
nmdm_outwakeup(struct tty *tp)
{
struct nmdmpart *np = tty_softc(tp);
/* We can transmit again, so wake up our side. */
taskqueue_enqueue(taskqueue_swi, &np->np_task);
}
/*
* Module handling
*/
static int
nmdm_modevent(module_t mod, int type, void *data)
{
static eventhandler_tag tag;
switch(type) {
case MOD_LOAD:
tag = EVENTHANDLER_REGISTER(dev_clone, nmdm_clone, 0, 1000);
if (tag == NULL)
return (ENOMEM);
break;
case MOD_SHUTDOWN:
break;
case MOD_UNLOAD:
if (nmdm_count != 0)
return (EBUSY);
EVENTHANDLER_DEREGISTER(dev_clone, tag);
break;
default:
return (EOPNOTSUPP);
}
return (0);
}
DEV_MODULE(nmdm, nmdm_modevent, NULL);