tty.c

鼎力推荐！本程序是基于嵌入式LUNUX系统开发的源程序代码

}

/* ---- DLC callbacks ---- */
static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
{
	struct rfcomm_dev *dev = dlc->owner;
	struct tty_struct *tty;
       
	if (!dev || !(tty = dev->tty)) {
		kfree_skb(skb);
		return;
	}

	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);

	if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
		register int i;
		for (i = 0; i < skb->len; i++) {
			if (tty->flip.count >= TTY_FLIPBUF_SIZE)
				tty_flip_buffer_push(tty);

			tty_insert_flip_char(tty, skb->data[i], 0);
		}
		tty_flip_buffer_push(tty);
	} else
		tty->ldisc.receive_buf(tty, skb->data, NULL, skb->len);

	kfree_skb(skb);
}

static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
{
	struct rfcomm_dev *dev = dlc->owner;
	if (!dev)
		return;
	
	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);

	dev->err = err;
	wake_up_interruptible(&dev->wait);

	if (dlc->state == BT_CLOSED) {
		if (!dev->tty) {
			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
				rfcomm_dev_hold(dev);
				rfcomm_dev_del(dev);

				/* We have to drop DLC lock here, otherwise
				   rfcomm_dev_put() will dead lock if it's
				   the last reference. */
				rfcomm_dlc_unlock(dlc);
				rfcomm_dev_put(dev);
				rfcomm_dlc_lock(dlc);
			}
		} else 
			tty_hangup(dev->tty);
	}
}

static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
{
	struct rfcomm_dev *dev = dlc->owner;
	if (!dev)
		return;
	
	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);

	dev->modem_status = 
		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
}

/* ---- TTY functions ---- */
static void rfcomm_tty_wakeup(unsigned long arg)
{
	struct rfcomm_dev *dev = (void *) arg;
	struct tty_struct *tty = dev->tty;
	if (!tty)
		return;

	BT_DBG("dev %p tty %p", dev, tty);

	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
                (tty->ldisc.write_wakeup)(tty);

	wake_up_interruptible(&tty->write_wait);
#ifdef SERIAL_HAVE_POLL_WAIT
	wake_up_interruptible(&tty->poll_wait);
#endif
}

static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
{
	DECLARE_WAITQUEUE(wait, current);
	struct rfcomm_dev *dev;
	struct rfcomm_dlc *dlc;
	int err, id;

        id = tty->index;

	BT_DBG("tty %p id %d", tty, id);

	/* We don't leak this refcount. For reasons which are not entirely
	   clear, the TTY layer will call our ->close() method even if the
	   open fails. We decrease the refcount there, and decreasing it
	   here too would cause breakage. */
	dev = rfcomm_dev_get(id);
	if (!dev)
		return -ENODEV;

	BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst), dev->channel, dev->opened);

	if (dev->opened++ != 0)
		return 0;

	dlc = dev->dlc;

	/* Attach TTY and open DLC */

	rfcomm_dlc_lock(dlc);
	tty->driver_data = dev;
	dev->tty = tty;
	rfcomm_dlc_unlock(dlc);
	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);

	err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
	if (err < 0)
		return err;

	/* Wait for DLC to connect */
	add_wait_queue(&dev->wait, &wait);
	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (dlc->state == BT_CLOSED) {
			err = -dev->err;
			break;
		}

		if (dlc->state == BT_CONNECTED)
			break;

		if (signal_pending(current)) {
			err = -EINTR;
			break;
		}

		schedule();
	}
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&dev->wait, &wait);

	return err;
}

static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	if (!dev)
		return;

	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc, dev->opened);

	if (--dev->opened == 0) {
		/* Close DLC and dettach TTY */
		rfcomm_dlc_close(dev->dlc, 0);

		clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
		tasklet_kill(&dev->wakeup_task);

		rfcomm_dlc_lock(dev->dlc);
		tty->driver_data = NULL;
		dev->tty = NULL;
		rfcomm_dlc_unlock(dev->dlc);
	}

	rfcomm_dev_put(dev);
}

static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	struct rfcomm_dlc *dlc = dev->dlc;
	struct sk_buff *skb;
	int err = 0, sent = 0, size;

	BT_DBG("tty %p count %d", tty, count);

	while (count) {
		size = min_t(uint, count, dlc->mtu);

		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
		
		if (!skb)
			break;

		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);

		memcpy(skb_put(skb, size), buf + sent, size);

		if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
			kfree_skb(skb);
			break;
		}

		sent  += size;
		count -= size;
	}

	return sent ? sent : err;
}

static int rfcomm_tty_write_room(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	int room;

	BT_DBG("tty %p", tty);

	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
	if (room < 0)
		room = 0;
	return room;
}

static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
{
	BT_DBG("tty %p cmd 0x%02x", tty, cmd);

	switch (cmd) {
	case TCGETS:
		BT_DBG("TCGETS is not supported");
		return -ENOIOCTLCMD;

	case TCSETS:
		BT_DBG("TCSETS is not supported");
		return -ENOIOCTLCMD;

	case TIOCMIWAIT:
		BT_DBG("TIOCMIWAIT");
		break;

	case TIOCGICOUNT:
		BT_DBG("TIOCGICOUNT");
		break;

	case TIOCGSERIAL:
		BT_ERR("TIOCGSERIAL is not supported");
		return -ENOIOCTLCMD;

	case TIOCSSERIAL:
		BT_ERR("TIOCSSERIAL is not supported");
		return -ENOIOCTLCMD;

	case TIOCSERGSTRUCT:
		BT_ERR("TIOCSERGSTRUCT is not supported");
		return -ENOIOCTLCMD;

	case TIOCSERGETLSR:
		BT_ERR("TIOCSERGETLSR is not supported");
		return -ENOIOCTLCMD;

	case TIOCSERCONFIG:
		BT_ERR("TIOCSERCONFIG is not supported");
		return -ENOIOCTLCMD;

	default:
		return -ENOIOCTLCMD;	/* ioctls which we must ignore */

	}

	return -ENOIOCTLCMD;
}

#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))

static void rfcomm_tty_set_termios(struct tty_struct *tty, struct termios *old)
{
	BT_DBG("tty %p", tty);

	if ((tty->termios->c_cflag == old->c_cflag) &&
		(RELEVANT_IFLAG(tty->termios->c_iflag) == RELEVANT_IFLAG(old->c_iflag)))
		return;

	/* handle turning off CRTSCTS */
	if ((old->c_cflag & CRTSCTS) && !(tty->termios->c_cflag & CRTSCTS)) {
		BT_DBG("turning off CRTSCTS");
	}
}

static void rfcomm_tty_throttle(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;

	BT_DBG("tty %p dev %p", tty, dev);
	
	rfcomm_dlc_throttle(dev->dlc);
}

static void rfcomm_tty_unthrottle(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;

	BT_DBG("tty %p dev %p", tty, dev);
	
	rfcomm_dlc_unthrottle(dev->dlc);
}

static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	struct rfcomm_dlc *dlc = dev->dlc;

	BT_DBG("tty %p dev %p", tty, dev);

	if (skb_queue_len(&dlc->tx_queue))
		return dlc->mtu;

	return 0;
}

static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	if (!dev)
		return;

	BT_DBG("tty %p dev %p", tty, dev);

	skb_queue_purge(&dev->dlc->tx_queue);

	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
		tty->ldisc.write_wakeup(tty);
}

static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
{
	BT_DBG("tty %p ch %c", tty, ch);
}

static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
{
	BT_DBG("tty %p timeout %d", tty, timeout);
}

static void rfcomm_tty_hangup(struct tty_struct *tty)
{
	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
	if (!dev)
		return;

	BT_DBG("tty %p dev %p", tty, dev);

	rfcomm_tty_flush_buffer(tty);

	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
		rfcomm_dev_del(dev);
}

static int rfcomm_tty_read_proc(char *buf, char **start, off_t offset, int len, int *eof, void *unused)
{
	return 0;
}

static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
{
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;

	BT_DBG("tty %p dev %p", tty, dev);

 	return dev->modem_status;
}

static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
{
 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 	struct rfcomm_dlc *dlc = dev->dlc;
 	u8 v24_sig;

	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);

 	rfcomm_dlc_get_modem_status(dlc, &v24_sig);

 	if (set & TIOCM_DSR || set & TIOCM_DTR)
 		v24_sig |= RFCOMM_V24_RTC;
 	if (set & TIOCM_RTS || set & TIOCM_CTS)
 		v24_sig |= RFCOMM_V24_RTR;
 	if (set & TIOCM_RI)
 		v24_sig |= RFCOMM_V24_IC;
 	if (set & TIOCM_CD)
 		v24_sig |= RFCOMM_V24_DV;

 	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
 		v24_sig &= ~RFCOMM_V24_RTC;
 	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
 		v24_sig &= ~RFCOMM_V24_RTR;
 	if (clear & TIOCM_RI)
 		v24_sig &= ~RFCOMM_V24_IC;
 	if (clear & TIOCM_CD)
 		v24_sig &= ~RFCOMM_V24_DV;

 	rfcomm_dlc_set_modem_status(dlc, v24_sig);

 	return 0;
}

/* ---- TTY structure ---- */

static struct tty_operations rfcomm_ops = {
	.open			= rfcomm_tty_open,
	.close			= rfcomm_tty_close,
	.write			= rfcomm_tty_write,
	.write_room		= rfcomm_tty_write_room,
	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
	.flush_buffer		= rfcomm_tty_flush_buffer,
	.ioctl			= rfcomm_tty_ioctl,
	.throttle		= rfcomm_tty_throttle,
	.unthrottle		= rfcomm_tty_unthrottle,
	.set_termios		= rfcomm_tty_set_termios,
	.send_xchar		= rfcomm_tty_send_xchar,
	.hangup			= rfcomm_tty_hangup,
	.wait_until_sent	= rfcomm_tty_wait_until_sent,
	.read_proc		= rfcomm_tty_read_proc,
	.tiocmget		= rfcomm_tty_tiocmget,
	.tiocmset		= rfcomm_tty_tiocmset,
};

int rfcomm_init_ttys(void)
{
	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
	if (!rfcomm_tty_driver)
		return -1;

	rfcomm_tty_driver->owner	= THIS_MODULE;
	rfcomm_tty_driver->driver_name	= "rfcomm";
	rfcomm_tty_driver->devfs_name	= "bluetooth/rfcomm/";
	rfcomm_tty_driver->name		= "rfcomm";
	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
	rfcomm_tty_driver->init_termios	= tty_std_termios;
	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);

	if (tty_register_driver(rfcomm_tty_driver)) {
		BT_ERR("Can't register RFCOMM TTY driver");
		put_tty_driver(rfcomm_tty_driver);
		return -1;
	}

	BT_INFO("RFCOMM TTY layer initialized");

	return 0;
}

void rfcomm_cleanup_ttys(void)
{
	tty_unregister_driver(rfcomm_tty_driver);
	put_tty_driver(rfcomm_tty_driver);
}