/*
 * (MPSAFE)
 *
 * Copyright (C) 2003,2004
 *      Hidetoshi Shimokawa. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *
 *      This product includes software developed by Hidetoshi Shimokawa.
 *
 * 4. Neither the name of the author 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.
 * 
 * $FreeBSD: src/sys/dev/dcons/dcons_os.c,v 1.4 2004/10/24 12:41:04 simokawa Exp $
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/consio.h>
#include <sys/tty.h>
#include <sys/ttydefaults.h>    /* for TTYDEF_* */
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/ucred.h>
#include <sys/bus.h>

#include "dcons.h"
#include "dcons_os.h"

#include <ddb/ddb.h>
#include <sys/reboot.h>

#include <sys/sysctl.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>

#include "opt_ddb.h"
#include "opt_comconsole.h"
#include "opt_dcons.h"

#ifndef DCONS_POLL_HZ
#define DCONS_POLL_HZ   100
#endif

#ifndef DCONS_BUF_SIZE
#define DCONS_BUF_SIZE (16*1024)
#endif

#ifndef DCONS_FORCE_CONSOLE
#define DCONS_FORCE_CONSOLE     0       /* Mostly for FreeBSD-4/DragonFly */
#endif

#ifndef DCONS_FORCE_GDB
#define DCONS_FORCE_GDB 1
#endif

static d_open_t         dcons_open;
static d_close_t        dcons_close;
static d_ioctl_t        dcons_ioctl;

static struct dev_ops dcons_ops = {
        { "dcons", 0, D_TTY },
        .d_open =       dcons_open,
        .d_close =      dcons_close,
        .d_read =       ttyread,
        .d_write =      ttywrite,
        .d_ioctl =      dcons_ioctl,
        .d_kqfilter =   ttykqfilter,
        .d_revoke =     ttyrevoke
};

#ifndef KLD_MODULE
static char bssbuf[DCONS_BUF_SIZE];     /* buf in bss */
#endif

/* global data */
static struct dcons_global dg;
struct dcons_global *dcons_conf;
static int poll_hz = DCONS_POLL_HZ;

static struct dcons_softc sc[DCONS_NPORT];

SYSCTL_NODE(_kern, OID_AUTO, dcons, CTLFLAG_RD, 0, "Dumb Console");
SYSCTL_INT(_kern_dcons, OID_AUTO, poll_hz, CTLFLAG_RW, &poll_hz, 0,
                                "dcons polling rate");

static int drv_init = 0;
static struct callout dcons_callout;
struct dcons_buf *dcons_buf;            /* for local dconschat */

#define DEV     cdev_t
#define THREAD  d_thread_t

static void     dcons_tty_start(struct tty *);
static int      dcons_tty_param(struct tty *, struct termios *);
static void     dcons_timeout(void *);
static int      dcons_drv_init(int);

static cn_probe_t       dcons_cnprobe;
static cn_init_t        dcons_cninit;
static cn_init_fini_t   dcons_cninit_fini;
static cn_getc_t        dcons_cngetc;
static cn_checkc_t      dcons_cncheckc;
static cn_putc_t        dcons_cnputc;

CONS_DRIVER(dcons, dcons_cnprobe, dcons_cninit, dcons_cninit_fini,
            NULL, dcons_cngetc, dcons_cncheckc, dcons_cnputc, NULL, NULL);

#if defined(DDB) && defined(ALT_BREAK_TO_DEBUGGER)
static int
dcons_check_break(struct dcons_softc *dc, int c)
{
        if (c < 0)
                return (c);

        switch (dc->brk_state) {
        case STATE1:
                if (c == KEY_TILDE)
                        dc->brk_state = STATE2;
                else
                        dc->brk_state = STATE0;
                break;
        case STATE2:
                dc->brk_state = STATE0;
                if (c == KEY_CTRLB) {
#if DCONS_FORCE_GDB
                        if (dc->flags & DC_GDB)
                                boothowto |= RB_GDB;
#endif
                        breakpoint();
                }
        }
        if (c == KEY_CR)
                dc->brk_state = STATE1;
        return (c);
}
#else
#define dcons_check_break(dc, c)        (c)
#endif

static int
dcons_os_checkc(struct dcons_softc *dc)
{
        int c;

        if (dg.dma_tag != NULL)
                bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTREAD);
  
        c = dcons_check_break(dc, dcons_checkc(dc));

        if (dg.dma_tag != NULL)
                bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREREAD);

        return (c);
}

static int
dcons_os_getc(struct dcons_softc *dc)
{
        int c;

        while ((c = dcons_os_checkc(dc)) == -1);

        return (c & 0xff);
} 

static void
dcons_os_putc(struct dcons_softc *dc, int c)
{
        if (dg.dma_tag != NULL)
                bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTWRITE);

        dcons_putc(dc, c);

        if (dg.dma_tag != NULL)
                bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREWRITE);
}
static int
dcons_open(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct tty *tp;
        int unit, error;

        unit = minor(dev);
        if (unit != 0)
                return (ENXIO);

        tp = ttymalloc(&dev->si_tty);
        lwkt_gettoken(&tp->t_token);
        tp->t_oproc = dcons_tty_start;
        tp->t_param = dcons_tty_param;
        tp->t_stop = nottystop;
        tp->t_dev = dev;

        error = 0;

        if ((tp->t_state & TS_ISOPEN) == 0) {
                tp->t_state |= TS_CARR_ON;
                ttychars(tp);
                tp->t_iflag = TTYDEF_IFLAG;
                tp->t_oflag = TTYDEF_OFLAG;
                tp->t_cflag = TTYDEF_CFLAG|CLOCAL;
                tp->t_lflag = TTYDEF_LFLAG;
                tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
                ttsetwater(tp);
        } else if ((tp->t_state & TS_XCLUDE) &&
                   caps_priv_check(ap->a_cred, SYSCAP_RESTRICTEDROOT))
        {
                lwkt_reltoken(&tp->t_token);

                return (EBUSY);
        }

        error = (*linesw[tp->t_line].l_open)(dev, tp);
        lwkt_reltoken(&tp->t_token);

        return (error);
}

static int
dcons_close(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        int     unit;
        struct  tty *tp;

        unit = minor(dev);
        if (unit != 0)
                return (ENXIO);

        tp = dev->si_tty;
        lwkt_gettoken(&tp->t_token);
        if (tp->t_state & TS_ISOPEN) {
                (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
                ttyclose(tp);
        }
        lwkt_reltoken(&tp->t_token);

        return (0);
}

static int
dcons_ioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        int     unit;
        struct  tty *tp;
        int     error;

        unit = minor(dev);
        if (unit != 0)
                return (ENXIO);

        tp = dev->si_tty;
        lwkt_gettoken(&tp->t_token);
        error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data, ap->a_fflag, ap->a_cred);
        if (error != ENOIOCTL) {
                lwkt_reltoken(&tp->t_token);
                return (error);
        }

        error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
        if (error != ENOIOCTL) {
                lwkt_reltoken(&tp->t_token);
                return (error);
        }

        lwkt_reltoken(&tp->t_token);
        return (ENOTTY);
}

static int
dcons_tty_param(struct tty *tp, struct termios *t)
{
        lwkt_gettoken(&tp->t_token);
        tp->t_ispeed = t->c_ispeed;
        tp->t_ospeed = t->c_ospeed;
        tp->t_cflag = t->c_cflag;
        lwkt_reltoken(&tp->t_token);
        return 0;
}

static void
dcons_tty_start(struct tty *tp)
{
        struct dcons_softc *dc;

        lwkt_gettoken(&tp->t_token);
        dc = (struct dcons_softc *)tp->t_dev->si_drv1;
        if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
                ttwwakeup(tp);
                lwkt_reltoken(&tp->t_token);
                return;
        }

        tp->t_state |= TS_BUSY;
        while (tp->t_outq.c_cc != 0)
                dcons_os_putc(dc, clist_getc(&tp->t_outq));
        tp->t_state &= ~TS_BUSY;

        ttwwakeup(tp);
        lwkt_reltoken(&tp->t_token);
}

static void
dcons_timeout(void *dummy __unused)
{
        struct tty *tp;
        struct dcons_softc *dc;
        int i, c, polltime;

        for (i = 0; i < DCONS_NPORT; i ++) {
                dc = &sc[i];
                tp = ((DEV)dc->dev)->si_tty;
                lwkt_gettoken(&tp->t_token);
                while ((c = dcons_os_checkc(dc)) != -1) {
                        if (tp->t_state & TS_ISOPEN)
                                (*linesw[tp->t_line].l_rint)(c, tp);
                }
                lwkt_reltoken(&tp->t_token);
        }
        polltime = hz / poll_hz;
        if (polltime < 1)
                polltime = 1;
        callout_reset(&dcons_callout, polltime, dcons_timeout, NULL);
}

static void
dcons_cnprobe(struct consdev *cp)
{
        cp->cn_probegood = 1;
#if DCONS_FORCE_CONSOLE
        cp->cn_pri = CN_REMOTE;
#else
        cp->cn_pri = CN_NORMAL;
#endif
}

static void
dcons_cninit(struct consdev *cp)
{
        dcons_drv_init(0);
#ifdef CONS_NODEV
        cp->cn_arg
#else
        cp->cn_private
#endif
                = (void *)&sc[DCONS_CON]; /* share port0 with unit0 */
}

static void
dcons_cninit_fini(struct consdev *cp)
{
        cp->cn_dev = make_dev(&dcons_ops, DCONS_CON,
                              UID_ROOT, GID_WHEEL, 0600, "dcons");
}

#ifdef CONS_NODEV
static int
dcons_cngetc(struct consdev *cp)
{
        struct dcons_softc *dc = (struct dcons_softc *)cp->cn_arg;
        return (dcons_os_getc(dc));
}
static int
dcons_cncheckc(struct consdev *cp)
{
        struct dcons_softc *dc = (struct dcons_softc *)cp->cn_arg;
        return (dcons_os_checkc(dc));
}
static void
dcons_cnputc(struct consdev *cp, int c)
{
        struct dcons_softc *dc = (struct dcons_softc *)cp->cn_arg;
        dcons_os_putc(dc, c);
}
#else
static int
dcons_cngetc(void *private)
{
        struct dcons_softc *dc = (struct dcons_softc *)private;
        return (dcons_os_getc(dc));
}
static int
dcons_cncheckc(void *private)
{
        struct dcons_softc *dc = (struct dcons_softc *)private;
        return (dcons_os_checkc(dc));
}
static void
dcons_cnputc(void *private, int c)
{
        struct dcons_softc *dc = (struct dcons_softc *)private;
        dcons_os_putc(dc, c);
}
#endif

static int
dcons_drv_init(int stage)
{
        if (drv_init)
                return(drv_init);

        drv_init = -1;

        bzero(&dg, sizeof(dg));
        dcons_conf = &dg;
        dg.cdev = &dcons_consdev;
        dg.buf = NULL;
        dg.size = DCONS_BUF_SIZE;

        if (dg.buf != NULL)
                goto ok;

#ifndef KLD_MODULE
        if (stage == 0) { /* XXX or cold */
                /*
                 * DCONS_FORCE_CONSOLE == 1 and statically linked.
                 * called from cninit(). can't use contigmalloc yet .
                 */
                dg.buf = (struct dcons_buf *) bssbuf;
                dcons_init(dg.buf, dg.size, sc);
        } else
#endif
        {
                /*
                 * DCONS_FORCE_CONSOLE == 0 or kernel module case.
                 * if the module is loaded after boot,
                 * bssbuf could be non-continuous.
                 */ 
                dg.buf = (struct dcons_buf *) contigmalloc(dg.size,
                        M_DEVBUF, 0, 0x10000, 0xffffffff, PAGE_SIZE, 0ul);
                dcons_init(dg.buf, dg.size, sc);
        }

ok:
        dcons_buf = dg.buf;

#if defined(DDB) && DCONS_FORCE_GDB
        if (gdb_tab == NULL) {
                gdb_tab = &dcons_consdev;
                dcons_consdev.cn_gdbprivate = &sc[DCONS_GDB];
        }
#endif
        drv_init = 1;

        return 0;
}

static int
dcons_attach_port(int port, char *name, int flags)
{
        struct dcons_softc *dc;
        struct tty *tp;
        DEV dev;

        dc = &sc[port];
        dc->flags = flags;
        dev = make_dev(&dcons_ops, port, UID_ROOT, GID_WHEEL, 0600,
                       "%s", name);
        dc->dev = (void *)dev;
        dev->si_drv1 = (void *)dc;

        tp = ttymalloc(&dev->si_tty);
        tp->t_oproc = dcons_tty_start;
        tp->t_param = dcons_tty_param;
        tp->t_stop = nottystop;
        tp->t_dev = dc->dev;

        return(0);
}

static int
dcons_attach(void)
{
        int polltime;

        dcons_attach_port(DCONS_CON, "dcons", 0);
        dcons_attach_port(DCONS_GDB, "dgdb", DC_GDB);
        callout_init_mp(&dcons_callout);
        polltime = hz / poll_hz;
        if (polltime < 1)
                polltime = 1;
        callout_reset(&dcons_callout, polltime, dcons_timeout, NULL);
        return(0);
}

static int
dcons_detach(int port)
{
        struct  tty *tp;
        struct dcons_softc *dc;

        dc = &sc[port];

        tp = ((DEV)dc->dev)->si_tty;
        lwkt_gettoken(&tp->t_token);

        if (tp->t_state & TS_ISOPEN) {
                kprintf("dcons: still opened\n");
                (*linesw[tp->t_line].l_close)(tp, 0);
                ttyclose(tp);
        }
        /* XXX
         * must wait until all device are closed.
         */
#ifdef __DragonFly__
        tsleep((void *)dc, 0, "dcodtc", hz/4);
#else
        tsleep((void *)dc, PWAIT, "dcodtc", hz/4);
#endif
        lwkt_reltoken(&tp->t_token);
        destroy_dev(dc->dev);

        return(0);
}


/* cnXXX works only for FreeBSD-5 */
static int
dcons_modevent(module_t mode, int type, void *data)
{
        int err = 0, ret;

        switch (type) {
        case MOD_LOAD:
                ret = dcons_drv_init(1);
                dcons_attach();
#if 0 /* XXX __FreeBSD_version >= 500000 */
                if (ret == 0) {
                        dcons_cnprobe(&dcons_consdev);
                        dcons_cninit(&dcons_consdev);
                        cnadd(&dcons_consdev);
                }
#endif
                break;
        case MOD_UNLOAD:
                kprintf("dcons: unload\n");
                callout_stop(&dcons_callout);
#if defined(DDB) && DCONS_FORCE_GDB
#ifdef CONS_NODEV
                gdb_arg = NULL;
#else
                if (gdb_tab == &dcons_consdev)
                        gdb_tab = NULL;
#endif
#endif
#if 0 /* XXX __FreeBSD_version >= 500000 */
                cnremove(&dcons_consdev);
#endif
                dcons_detach(DCONS_CON);
                dcons_detach(DCONS_GDB);
                dg.buf->magic = 0;

                contigfree(dg.buf, DCONS_BUF_SIZE, M_DEVBUF);

                break;
        case MOD_SHUTDOWN:
                dg.buf->magic = 0;
                break;
        default:
                err = EOPNOTSUPP;
                break;
        }
        return(err);
}

DEV_MODULE(dcons, dcons_modevent, NULL);
MODULE_VERSION(dcons, DCONS_VERSION);