ser-gigaset.c

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		return 0;
	}
	dev_set_drvdata(&cs->hw.ser->dev.dev, cs);

	tasklet_init(&cs->write_tasklet,
	             &gigaset_modem_fill, (unsigned long) cs);
	return 1;
}

/*
 * set modem control lines
 * Parameters:
 *	card state structure
 *	modem control line state ([TIOCM_DTR]|[TIOCM_RTS])
 * Called by "gigaset_start" and "gigaset_enterconfigmode" in common.c
 * and by "if_lock" and "if_termios" in interface.c
 */
static int gigaset_set_modem_ctrl(struct cardstate *cs, unsigned old_state, unsigned new_state)
{
	struct tty_struct *tty = cs->hw.ser->tty;
	unsigned int set, clear;

	if (!tty || !tty->driver || !tty->driver->tiocmset)
		return -EFAULT;
	set = new_state & ~old_state;
	clear = old_state & ~new_state;
	if (!set && !clear)
		return 0;
	gig_dbg(DEBUG_IF, "tiocmset set %x clear %x", set, clear);
	return tty->driver->tiocmset(tty, NULL, set, clear);
}

static int gigaset_baud_rate(struct cardstate *cs, unsigned cflag)
{
	return -EINVAL;
}

static int gigaset_set_line_ctrl(struct cardstate *cs, unsigned cflag)
{
	return -EINVAL;
}

static const struct gigaset_ops ops = {
	gigaset_write_cmd,
	gigaset_write_room,
	gigaset_chars_in_buffer,
	gigaset_brkchars,
	gigaset_init_bchannel,
	gigaset_close_bchannel,
	gigaset_initbcshw,
	gigaset_freebcshw,
	gigaset_reinitbcshw,
	gigaset_initcshw,
	gigaset_freecshw,
	gigaset_set_modem_ctrl,
	gigaset_baud_rate,
	gigaset_set_line_ctrl,
	gigaset_m10x_send_skb,	/* asyncdata.c */
	gigaset_m10x_input,	/* asyncdata.c */
};


/* Line Discipline Interface */
/* ========================= */

/* helper functions for cardstate refcounting */
static struct cardstate *cs_get(struct tty_struct *tty)
{
	struct cardstate *cs = tty->disc_data;

	if (!cs || !cs->hw.ser) {
		gig_dbg(DEBUG_ANY, "%s: no cardstate", __func__);
		return NULL;
	}
	atomic_inc(&cs->hw.ser->refcnt);
	return cs;
}

static void cs_put(struct cardstate *cs)
{
	if (atomic_dec_and_test(&cs->hw.ser->refcnt))
		mutex_unlock(&cs->hw.ser->dead_mutex);
}

/*
 * Called by the tty driver when the line discipline is pushed onto the tty.
 * Called in process context.
 */
static int
gigaset_tty_open(struct tty_struct *tty)
{
	struct cardstate *cs;

	gig_dbg(DEBUG_INIT, "Starting HLL for Gigaset M101");

	info(DRIVER_AUTHOR);
	info(DRIVER_DESC);

	if (!driver) {
		err("%s: no driver structure", __func__);
		return -ENODEV;
	}

	/* allocate memory for our device state and intialize it */
	if (!(cs = gigaset_initcs(driver, 1, 1, 0, cidmode,
				  GIGASET_MODULENAME)))
		goto error;

	cs->dev = &cs->hw.ser->dev.dev;
	cs->hw.ser->tty = tty;
	mutex_init(&cs->hw.ser->dead_mutex);
	atomic_set(&cs->hw.ser->refcnt, 1);

	tty->disc_data = cs;

	/* OK.. Initialization of the datastructures and the HW is done.. Now
	 * startup system and notify the LL that we are ready to run
	 */
	if (startmode == SM_LOCKED)
		atomic_set(&cs->mstate, MS_LOCKED);
	if (!gigaset_start(cs)) {
		tasklet_kill(&cs->write_tasklet);
		goto error;
	}

	gig_dbg(DEBUG_INIT, "Startup of HLL done");
	mutex_lock(&cs->hw.ser->dead_mutex);
	return 0;

error:
	gig_dbg(DEBUG_INIT, "Startup of HLL failed");
	tty->disc_data = NULL;
	gigaset_freecs(cs);
	return -ENODEV;
}

/*
 * Called by the tty driver when the line discipline is removed.
 * Called from process context.
 */
static void
gigaset_tty_close(struct tty_struct *tty)
{
	struct cardstate *cs = tty->disc_data;

	gig_dbg(DEBUG_INIT, "Stopping HLL for Gigaset M101");

	if (!cs) {
		gig_dbg(DEBUG_INIT, "%s: no cardstate", __func__);
		return;
	}

	/* prevent other callers from entering ldisc methods */
	tty->disc_data = NULL;

	if (!cs->hw.ser)
		err("%s: no hw cardstate", __func__);
	else {
		/* wait for running methods to finish */
		if (!atomic_dec_and_test(&cs->hw.ser->refcnt))
			mutex_lock(&cs->hw.ser->dead_mutex);
	}

	/* stop operations */
	gigaset_stop(cs);
	tasklet_kill(&cs->write_tasklet);
	flush_send_queue(cs);
	cs->dev = NULL;
	gigaset_freecs(cs);

	gig_dbg(DEBUG_INIT, "Shutdown of HLL done");
}

/*
 * Called by the tty driver when the tty line is hung up.
 * Wait for I/O to driver to complete and unregister ISDN device.
 * This is already done by the close routine, so just call that.
 * Called from process context.
 */
static int gigaset_tty_hangup(struct tty_struct *tty)
{
	gigaset_tty_close(tty);
	return 0;
}

/*
 * Read on the tty.
 * Unused, received data goes only to the Gigaset driver.
 */
static ssize_t
gigaset_tty_read(struct tty_struct *tty, struct file *file,
		 unsigned char __user *buf, size_t count)
{
	return -EAGAIN;
}

/*
 * Write on the tty.
 * Unused, transmit data comes only from the Gigaset driver.
 */
static ssize_t
gigaset_tty_write(struct tty_struct *tty, struct file *file,
		  const unsigned char *buf, size_t count)
{
	return -EAGAIN;
}

/*
 * Ioctl on the tty.
 * Called in process context only.
 * May be re-entered by multiple ioctl calling threads.
 */
static int
gigaset_tty_ioctl(struct tty_struct *tty, struct file *file,
		  unsigned int cmd, unsigned long arg)
{
	struct cardstate *cs = cs_get(tty);
	int rc, val;
	int __user *p = (int __user *)arg;

	if (!cs)
		return -ENXIO;

	switch (cmd) {
	case TCGETS:
	case TCGETA:
		/* pass through to underlying serial device */
		rc = n_tty_ioctl(tty, file, cmd, arg);
		break;

	case TCFLSH:
		/* flush our buffers and the serial port's buffer */
		switch (arg) {
		case TCIFLUSH:
			/* no own input buffer to flush */
			break;
		case TCIOFLUSH:
		case TCOFLUSH:
			flush_send_queue(cs);
			break;
		}
		/* flush the serial port's buffer */
		rc = n_tty_ioctl(tty, file, cmd, arg);
		break;

	case FIONREAD:
		/* unused, always return zero */
		val = 0;
		rc = put_user(val, p);
		break;

	default:
		rc = -ENOIOCTLCMD;
	}

	cs_put(cs);
	return rc;
}

/*
 * Poll on the tty.
 * Unused, always return zero.
 */
static unsigned int
gigaset_tty_poll(struct tty_struct *tty, struct file *file, poll_table *wait)
{
	return 0;
}

/*
 * Called by the tty driver when a block of data has been received.
 * Will not be re-entered while running but other ldisc functions
 * may be called in parallel.
 * Can be called from hard interrupt level as well as soft interrupt
 * level or mainline.
 * Parameters:
 *	tty	tty structure
 *	buf	buffer containing received characters
 *	cflags	buffer containing error flags for received characters (ignored)
 *	count	number of received characters
 */
static void
gigaset_tty_receive(struct tty_struct *tty, const unsigned char *buf,
		    char *cflags, int count)
{
	struct cardstate *cs = cs_get(tty);
	unsigned tail, head, n;
	struct inbuf_t *inbuf;

	if (!cs)
		return;
	if (!(inbuf = cs->inbuf)) {
		dev_err(cs->dev, "%s: no inbuf\n", __func__);
		cs_put(cs);
		return;
	}

	tail = atomic_read(&inbuf->tail);
	head = atomic_read(&inbuf->head);
	gig_dbg(DEBUG_INTR, "buffer state: %u -> %u, receive %u bytes",
		head, tail, count);

	if (head <= tail) {
		/* possible buffer wraparound */
		n = min_t(unsigned, count, RBUFSIZE - tail);
		memcpy(inbuf->data + tail, buf, n);
		tail = (tail + n) % RBUFSIZE;
		buf += n;
		count -= n;
	}

	if (count > 0) {
		/* tail < head and some data left */
		n = head - tail - 1;
		if (count > n) {
			dev_err(cs->dev,
				"inbuf overflow, discarding %d bytes\n",
				count - n);
			count = n;
		}
		memcpy(inbuf->data + tail, buf, count);
		tail += count;
	}

	gig_dbg(DEBUG_INTR, "setting tail to %u", tail);
	atomic_set(&inbuf->tail, tail);

	/* Everything was received .. Push data into handler */
	gig_dbg(DEBUG_INTR, "%s-->BH", __func__);
	gigaset_schedule_event(cs);
	cs_put(cs);
}

/*
 * Called by the tty driver when there's room for more data to send.
 */
static void
gigaset_tty_wakeup(struct tty_struct *tty)
{
	struct cardstate *cs = cs_get(tty);

	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
	if (!cs)
		return;
	tasklet_schedule(&cs->write_tasklet);
	cs_put(cs);
}

static struct tty_ldisc gigaset_ldisc = {
	.owner		= THIS_MODULE,
	.magic		= TTY_LDISC_MAGIC,
	.name		= "ser_gigaset",
	.open		= gigaset_tty_open,
	.close		= gigaset_tty_close,
	.hangup		= gigaset_tty_hangup,
	.read		= gigaset_tty_read,
	.write		= gigaset_tty_write,
	.ioctl		= gigaset_tty_ioctl,
	.poll		= gigaset_tty_poll,
	.receive_buf	= gigaset_tty_receive,
	.write_wakeup	= gigaset_tty_wakeup,
};


/* Initialization / Shutdown */
/* ========================= */

static int __init ser_gigaset_init(void)
{
	int rc;

	gig_dbg(DEBUG_INIT, "%s", __func__);
	if ((rc = platform_driver_register(&device_driver)) != 0) {
		err("error %d registering platform driver", rc);
		return rc;
	}

	/* allocate memory for our driver state and intialize it */
	if (!(driver = gigaset_initdriver(GIGASET_MINOR, GIGASET_MINORS,
					  GIGASET_MODULENAME, GIGASET_DEVNAME,
					  &ops, THIS_MODULE)))
		goto error;

	if ((rc = tty_register_ldisc(N_GIGASET_M101, &gigaset_ldisc)) != 0) {
		err("error %d registering line discipline", rc);
		goto error;
	}

	return 0;

error:
	if (driver) {
		gigaset_freedriver(driver);
		driver = NULL;
	}
	platform_driver_unregister(&device_driver);
	return rc;
}

static void __exit ser_gigaset_exit(void)
{
	int rc;

	gig_dbg(DEBUG_INIT, "%s", __func__);

	if (driver) {
		gigaset_freedriver(driver);
		driver = NULL;
	}

	if ((rc = tty_unregister_ldisc(N_GIGASET_M101)) != 0)
		err("error %d unregistering line discipline", rc);

	platform_driver_unregister(&device_driver);
}

module_init(ser_gigaset_init);
module_exit(ser_gigaset_exit);