drivers/usb/serial/usb_wwan.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
   USB Driver layer for GSM modems

   Copyright (C) 2005  Matthias Urlichs <smurf@smurf.noris.de>

   Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>

   History: see the git log.

   Work sponsored by: Sigos GmbH, Germany <info@sigos.de>

   This driver exists because the "normal" serial driver doesn't work too well
   with GSM modems. Issues:
   - data loss -- one single Receive URB is not nearly enough
   - controlling the baud rate doesn't make sense
 */

 #define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
 #define DRIVER_DESC "USB Driver for GSM modems"

 #include <linux/kernel.h>
 #include <linux/jiffies.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/bitops.h>
 #include <linux/uaccess.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
 #include <linux/serial.h>
 #include "usb-wwan.h"

 /*
  * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
  * in CDC ACM.
  */
 static int usb_wwan_send_setup(struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
 	struct usb_wwan_port_private *portdata;
 	int val = 0;
 	int ifnum;
 	int res;

 	portdata = usb_get_serial_port_data(port);

 	if (portdata->dtr_state)
 		val |= 0x01;
 	if (portdata->rts_state)
 		val |= 0x02;

 	ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;

 	res = usb_autopm_get_interface(serial->interface);
 	if (res)
 		return res;

 	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 				0x22, 0x21, val, ifnum, NULL, 0,
 				USB_CTRL_SET_TIMEOUT);

 	usb_autopm_put_interface(port->serial->interface);

 	return res;
 }

 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
 {
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata;

 	intfdata = usb_get_serial_data(port->serial);

 	if (!intfdata->use_send_setup)
 		return;

 	portdata = usb_get_serial_port_data(port);
 	/* FIXME: locking */
 	portdata->rts_state = on;
 	portdata->dtr_state = on;

 	usb_wwan_send_setup(port);
 }
 EXPORT_SYMBOL(usb_wwan_dtr_rts);

 int usb_wwan_tiocmget(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	unsigned int value;
 	struct usb_wwan_port_private *portdata;

 	portdata = usb_get_serial_port_data(port);

 	value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
 	    ((portdata->dtr_state) ? TIOCM_DTR : 0) |
 	    ((portdata->cts_state) ? TIOCM_CTS : 0) |
 	    ((portdata->dsr_state) ? TIOCM_DSR : 0) |
 	    ((portdata->dcd_state) ? TIOCM_CAR : 0) |
 	    ((portdata->ri_state) ? TIOCM_RNG : 0);

 	return value;
 }
 EXPORT_SYMBOL(usb_wwan_tiocmget);

 int usb_wwan_tiocmset(struct tty_struct *tty,
 		      unsigned int set, unsigned int clear)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata;

 	portdata = usb_get_serial_port_data(port);
 	intfdata = usb_get_serial_data(port->serial);

 	if (!intfdata->use_send_setup)
 		return -EINVAL;

 	/* FIXME: what locks portdata fields ? */
 	if (set & TIOCM_RTS)
 		portdata->rts_state = 1;
 	if (set & TIOCM_DTR)
 		portdata->dtr_state = 1;

 	if (clear & TIOCM_RTS)
 		portdata->rts_state = 0;
 	if (clear & TIOCM_DTR)
 		portdata->dtr_state = 0;
 	return usb_wwan_send_setup(port);
 }
 EXPORT_SYMBOL(usb_wwan_tiocmset);

 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
 		   const unsigned char *buf, int count)
 {
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata;
 	int i;
 	int left, todo;
 	struct urb *this_urb = NULL;	/* spurious */
 	int err;
 	unsigned long flags;

 	portdata = usb_get_serial_port_data(port);
 	intfdata = usb_get_serial_data(port->serial);

 	dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);

 	i = 0;
 	left = count;
 	for (i = 0; left > 0 && i < N_OUT_URB; i++) {
 		todo = left;
 		if (todo > OUT_BUFLEN)
 			todo = OUT_BUFLEN;

 		this_urb = portdata->out_urbs[i];
 		if (test_and_set_bit(i, &portdata->out_busy)) {
 			if (time_before(jiffies,
 					portdata->tx_start_time[i] + 10 * HZ))
 				continue;
 			usb_unlink_urb(this_urb);
 			continue;
 		}
 		dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
 			usb_pipeendpoint(this_urb->pipe), i);

 		err = usb_autopm_get_interface_async(port->serial->interface);
 		if (err < 0) {
 			clear_bit(i, &portdata->out_busy);
 			break;
 		}

 		/* send the data */
 		memcpy(this_urb->transfer_buffer, buf, todo);
 		this_urb->transfer_buffer_length = todo;

 		spin_lock_irqsave(&intfdata->susp_lock, flags);
 		if (intfdata->suspended) {
 			usb_anchor_urb(this_urb, &portdata->delayed);
 			spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 		} else {
 			intfdata->in_flight++;
 			spin_unlock_irqrestore(&intfdata->susp_lock, flags);
 			err = usb_submit_urb(this_urb, GFP_ATOMIC);
 			if (err) {
 				dev_err(&port->dev,
 					"%s: submit urb %d failed: %d\n",
 					__func__, i, err);
 				clear_bit(i, &portdata->out_busy);
 				spin_lock_irqsave(&intfdata->susp_lock, flags);
 				intfdata->in_flight--;
 				spin_unlock_irqrestore(&intfdata->susp_lock,
 						       flags);
 				usb_autopm_put_interface_async(port->serial->interface);
 				break;
 			}
 		}

 		portdata->tx_start_time[i] = jiffies;
 		buf += todo;
 		left -= todo;
 	}

 	count -= left;
 	dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
 	return count;
 }
 EXPORT_SYMBOL(usb_wwan_write);

 static void usb_wwan_indat_callback(struct urb *urb)
 {
 	int err;
 	int endpoint;
 	struct usb_serial_port *port;
 	struct device *dev;
 	unsigned char *data = urb->transfer_buffer;
 	int status = urb->status;

 	endpoint = usb_pipeendpoint(urb->pipe);
 	port = urb->context;
 	dev = &port->dev;

 	if (status) {
 		dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
 			__func__, status, endpoint);

 		/* don't resubmit on fatal errors */
 		if (status == -ESHUTDOWN || status == -ENOENT)
 			return;
 	} else {
 		if (urb->actual_length) {
 			tty_insert_flip_string(&port->port, data,
 					urb->actual_length);
 			tty_flip_buffer_push(&port->port);
 		} else
 			dev_dbg(dev, "%s: empty read urb received\n", __func__);
 	}
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err) {
 		if (err != -EPERM && err != -ENODEV) {
 			dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
 				__func__, err);
 			/* busy also in error unless we are killed */
 			usb_mark_last_busy(port->serial->dev);
 		}
 	} else {
 		usb_mark_last_busy(port->serial->dev);
 	}
 }

 static void usb_wwan_outdat_callback(struct urb *urb)
 {
 	struct usb_serial_port *port;
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata;
 	unsigned long flags;
 	int i;

 	port = urb->context;
 	intfdata = usb_get_serial_data(port->serial);

 	usb_serial_port_softint(port);
 	usb_autopm_put_interface_async(port->serial->interface);
 	portdata = usb_get_serial_port_data(port);
 	spin_lock_irqsave(&intfdata->susp_lock, flags);
 	intfdata->in_flight--;
 	spin_unlock_irqrestore(&intfdata->susp_lock, flags);

 	for (i = 0; i < N_OUT_URB; ++i) {
 		if (portdata->out_urbs[i] == urb) {
 			smp_mb__before_atomic();
 			clear_bit(i, &portdata->out_busy);
 			break;
 		}
 	}
 }

 unsigned int usb_wwan_write_room(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct usb_wwan_port_private *portdata;
 	int i;
 	unsigned int data_len = 0;
 	struct urb *this_urb;

 	portdata = usb_get_serial_port_data(port);

 	for (i = 0; i < N_OUT_URB; i++) {
 		this_urb = portdata->out_urbs[i];
 		if (this_urb && !test_bit(i, &portdata->out_busy))
 			data_len += OUT_BUFLEN;
 	}

 	dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 	return data_len;
 }
 EXPORT_SYMBOL(usb_wwan_write_room);

 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct usb_wwan_port_private *portdata;
 	int i;
 	unsigned int data_len = 0;
 	struct urb *this_urb;

 	portdata = usb_get_serial_port_data(port);

 	for (i = 0; i < N_OUT_URB; i++) {
 		this_urb = portdata->out_urbs[i];
 		/* FIXME: This locking is insufficient as this_urb may
 		   go unused during the test */
 		if (this_urb && test_bit(i, &portdata->out_busy))
 			data_len += this_urb->transfer_buffer_length;
 	}
 	dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
 	return data_len;
 }
 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);

 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata;
 	struct usb_serial *serial = port->serial;
 	int i, err;
 	struct urb *urb;

 	portdata = usb_get_serial_port_data(port);
 	intfdata = usb_get_serial_data(serial);

 	if (port->interrupt_in_urb) {
 		err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 		if (err) {
 			dev_err(&port->dev, "%s: submit int urb failed: %d\n",
 				__func__, err);
 		}
 	}

 	/* Start reading from the IN endpoint */
 	for (i = 0; i < N_IN_URB; i++) {
 		urb = portdata->in_urbs[i];
 		if (!urb)
 			continue;
 		err = usb_submit_urb(urb, GFP_KERNEL);
 		if (err) {
 			dev_err(&port->dev,
 				"%s: submit read urb %d failed: %d\n",
 				__func__, i, err);
 		}
 	}

 	spin_lock_irq(&intfdata->susp_lock);
 	if (++intfdata->open_ports == 1)
 		serial->interface->needs_remote_wakeup = 1;
 	spin_unlock_irq(&intfdata->susp_lock);
 	/* this balances a get in the generic USB serial code */
 	usb_autopm_put_interface(serial->interface);

 	return 0;
 }
 EXPORT_SYMBOL(usb_wwan_open);

 static void unbusy_queued_urb(struct urb *urb,
 					struct usb_wwan_port_private *portdata)
 {
 	int i;

 	for (i = 0; i < N_OUT_URB; i++) {
 		if (urb == portdata->out_urbs[i]) {
 			clear_bit(i, &portdata->out_busy);
 			break;
 		}
 	}
 }

 void usb_wwan_close(struct usb_serial_port *port)
 {
 	int i;
 	struct usb_serial *serial = port->serial;
 	struct usb_wwan_port_private *portdata;
 	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 	struct urb *urb;

 	portdata = usb_get_serial_port_data(port);

 	/*
 	 * Need to take susp_lock to make sure port is not already being
 	 * resumed, but no need to hold it due to initialized
 	 */
 	spin_lock_irq(&intfdata->susp_lock);
 	if (--intfdata->open_ports == 0)
 		serial->interface->needs_remote_wakeup = 0;
 	spin_unlock_irq(&intfdata->susp_lock);

 	for (;;) {
 		urb = usb_get_from_anchor(&portdata->delayed);
 		if (!urb)
 			break;
 		unbusy_queued_urb(urb, portdata);
 		usb_autopm_put_interface_async(serial->interface);
 	}

 	for (i = 0; i < N_IN_URB; i++)
 		usb_kill_urb(portdata->in_urbs[i]);
 	for (i = 0; i < N_OUT_URB; i++)
 		usb_kill_urb(portdata->out_urbs[i]);
 	usb_kill_urb(port->interrupt_in_urb);

 	usb_autopm_get_interface_no_resume(serial->interface);
 }
 EXPORT_SYMBOL(usb_wwan_close);

 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
 				      int endpoint,
 				      int dir, void *ctx, char *buf, int len,
 				      void (*callback) (struct urb *))
 {
 	struct usb_serial *serial = port->serial;
 	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 	struct urb *urb;

 	urb = usb_alloc_urb(0, GFP_KERNEL);	/* No ISO */
 	if (!urb)
 		return NULL;

 	usb_fill_bulk_urb(urb, serial->dev,
 			  usb_sndbulkpipe(serial->dev, endpoint) | dir,
 			  buf, len, callback, ctx);

 	if (intfdata->use_zlp && dir == USB_DIR_OUT)
 		urb->transfer_flags |= URB_ZERO_PACKET;

 	return urb;
 }

 int usb_wwan_port_probe(struct usb_serial_port *port)
 {
 	struct usb_wwan_port_private *portdata;
 	struct urb *urb;
 	u8 *buffer;
 	int i;

 	if (!port->bulk_in_size || !port->bulk_out_size)
 		return -ENODEV;

 	portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
 	if (!portdata)
 		return -ENOMEM;

 	init_usb_anchor(&portdata->delayed);

 	for (i = 0; i < N_IN_URB; i++) {
 		buffer = (u8 *)__get_free_page(GFP_KERNEL);
 		if (!buffer)
 			goto bail_out_error;
 		portdata->in_buffer[i] = buffer;

 		urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
 						USB_DIR_IN, port,
 						buffer, IN_BUFLEN,
 						usb_wwan_indat_callback);
 		portdata->in_urbs[i] = urb;
 	}

 	for (i = 0; i < N_OUT_URB; i++) {
 		buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
 		if (!buffer)
 			goto bail_out_error2;
 		portdata->out_buffer[i] = buffer;

 		urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
 						USB_DIR_OUT, port,
 						buffer, OUT_BUFLEN,
 						usb_wwan_outdat_callback);
 		portdata->out_urbs[i] = urb;
 	}

 	usb_set_serial_port_data(port, portdata);

 	return 0;

 bail_out_error2:
 	for (i = 0; i < N_OUT_URB; i++) {
 		usb_free_urb(portdata->out_urbs[i]);
 		kfree(portdata->out_buffer[i]);
 	}
 bail_out_error:
 	for (i = 0; i < N_IN_URB; i++) {
 		usb_free_urb(portdata->in_urbs[i]);
 		free_page((unsigned long)portdata->in_buffer[i]);
 	}
 	kfree(portdata);

 	return -ENOMEM;
 }
 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);

 void usb_wwan_port_remove(struct usb_serial_port *port)
 {
 	int i;
 	struct usb_wwan_port_private *portdata;

 	portdata = usb_get_serial_port_data(port);
 	usb_set_serial_port_data(port, NULL);

 	for (i = 0; i < N_IN_URB; i++) {
 		usb_free_urb(portdata->in_urbs[i]);
 		free_page((unsigned long)portdata->in_buffer[i]);
 	}
 	for (i = 0; i < N_OUT_URB; i++) {
 		usb_free_urb(portdata->out_urbs[i]);
 		kfree(portdata->out_buffer[i]);
 	}

 	kfree(portdata);
 }
 EXPORT_SYMBOL(usb_wwan_port_remove);

 #ifdef CONFIG_PM
 static void stop_urbs(struct usb_serial *serial)
 {
 	int i, j;
 	struct usb_serial_port *port;
 	struct usb_wwan_port_private *portdata;

 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		portdata = usb_get_serial_port_data(port);
 		if (!portdata)
 			continue;
 		for (j = 0; j < N_IN_URB; j++)
 			usb_kill_urb(portdata->in_urbs[j]);
 		for (j = 0; j < N_OUT_URB; j++)
 			usb_kill_urb(portdata->out_urbs[j]);
 		usb_kill_urb(port->interrupt_in_urb);
 	}
 }

 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
 {
 	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);

 	spin_lock_irq(&intfdata->susp_lock);
 	if (PMSG_IS_AUTO(message)) {
 		if (intfdata->in_flight) {
 			spin_unlock_irq(&intfdata->susp_lock);
 			return -EBUSY;
 		}
 	}
 	intfdata->suspended = 1;
 	spin_unlock_irq(&intfdata->susp_lock);

 	stop_urbs(serial);

 	return 0;
 }
 EXPORT_SYMBOL(usb_wwan_suspend);

 /* Caller must hold susp_lock. */
 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
 {
 	struct usb_serial *serial = port->serial;
 	struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
 	struct usb_wwan_port_private *portdata;
 	struct urb *urb;
 	int err_count = 0;
 	int err;

 	portdata = usb_get_serial_port_data(port);

 	for (;;) {
 		urb = usb_get_from_anchor(&portdata->delayed);
 		if (!urb)
 			break;

 		err = usb_submit_urb(urb, GFP_ATOMIC);
 		if (err) {
 			dev_err(&port->dev, "%s: submit urb failed: %d\n",
 					__func__, err);
 			err_count++;
 			unbusy_queued_urb(urb, portdata);
 			usb_autopm_put_interface_async(serial->interface);
 			continue;
 		}
 		data->in_flight++;
 	}

 	if (err_count)
 		return -EIO;

 	return 0;
 }

 int usb_wwan_resume(struct usb_serial *serial)
 {
 	int i, j;
 	struct usb_serial_port *port;
 	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
 	struct usb_wwan_port_private *portdata;
 	struct urb *urb;
 	int err;
 	int err_count = 0;

 	spin_lock_irq(&intfdata->susp_lock);
 	for (i = 0; i < serial->num_ports; i++) {
 		port = serial->port[i];

 		if (!tty_port_initialized(&port->port))
 			continue;

 		portdata = usb_get_serial_port_data(port);

 		if (port->interrupt_in_urb) {
 			err = usb_submit_urb(port->interrupt_in_urb,
 					GFP_ATOMIC);
 			if (err) {
 				dev_err(&port->dev,
 					"%s: submit int urb failed: %d\n",
 					__func__, err);
 				err_count++;
 			}
 		}

 		err = usb_wwan_submit_delayed_urbs(port);
 		if (err)
 			err_count++;

 		for (j = 0; j < N_IN_URB; j++) {
 			urb = portdata->in_urbs[j];
 			err = usb_submit_urb(urb, GFP_ATOMIC);
 			if (err < 0) {
 				dev_err(&port->dev,
 					"%s: submit read urb %d failed: %d\n",
 					__func__, i, err);
 				err_count++;
 			}
 		}
 	}
 	intfdata->suspended = 0;
 	spin_unlock_irq(&intfdata->susp_lock);

 	if (err_count)
 		return -EIO;

 	return 0;
 }
 EXPORT_SYMBOL(usb_wwan_resume);
 #endif

 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	USB Driver layer for GSM modems

	Copyright (C) 2005 Matthias Urlichs <smurf@smurf.noris.de>

	Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>

	History: see the git log.

	Work sponsored by: Sigos GmbH, Germany <info@sigos.de>

	This driver exists because the "normal" serial driver doesn't work too well
	with GSM modems. Issues:
	- data loss -- one single Receive URB is not nearly enough
	- controlling the baud rate doesn't make sense
	*/

	#define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
	#define DRIVER_DESC "USB Driver for GSM modems"

	#include <linux/kernel.h>
	#include <linux/jiffies.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/tty.h>
	#include <linux/tty_flip.h>
	#include <linux/module.h>
	#include <linux/bitops.h>
	#include <linux/uaccess.h>
	#include <linux/usb.h>
	#include <linux/usb/serial.h>
	#include <linux/serial.h>
	#include "usb-wwan.h"

	/*
	* Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
	* in CDC ACM.
	*/
	static int usb_wwan_send_setup(struct usb_serial_port *port)
	{
	struct usb_serial *serial = port->serial;
	struct usb_wwan_port_private *portdata;
	int val = 0;
	int ifnum;
	int res;

	portdata = usb_get_serial_port_data(port);

	if (portdata->dtr_state)
	val \|= 0x01;
	if (portdata->rts_state)
	val \|= 0x02;

	ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;

	res = usb_autopm_get_interface(serial->interface);
	if (res)
	return res;

	res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
	0x22, 0x21, val, ifnum, NULL, 0,
	USB_CTRL_SET_TIMEOUT);

	usb_autopm_put_interface(port->serial->interface);

	return res;
	}

	void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
	{
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata;

	intfdata = usb_get_serial_data(port->serial);

	if (!intfdata->use_send_setup)
	return;

	portdata = usb_get_serial_port_data(port);
	/* FIXME: locking */
	portdata->rts_state = on;
	portdata->dtr_state = on;

	usb_wwan_send_setup(port);
	}
	EXPORT_SYMBOL(usb_wwan_dtr_rts);

	int usb_wwan_tiocmget(struct tty_struct *tty)
	{
	struct usb_serial_port *port = tty->driver_data;
	unsigned int value;
	struct usb_wwan_port_private *portdata;

	portdata = usb_get_serial_port_data(port);

	value = ((portdata->rts_state) ? TIOCM_RTS : 0) \|
	((portdata->dtr_state) ? TIOCM_DTR : 0) \|
	((portdata->cts_state) ? TIOCM_CTS : 0) \|
	((portdata->dsr_state) ? TIOCM_DSR : 0) \|
	((portdata->dcd_state) ? TIOCM_CAR : 0) \|
	((portdata->ri_state) ? TIOCM_RNG : 0);

	return value;
	}
	EXPORT_SYMBOL(usb_wwan_tiocmget);

	int usb_wwan_tiocmset(struct tty_struct *tty,
	unsigned int set, unsigned int clear)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata;

	portdata = usb_get_serial_port_data(port);
	intfdata = usb_get_serial_data(port->serial);

	if (!intfdata->use_send_setup)
	return -EINVAL;

	/* FIXME: what locks portdata fields ? */
	if (set & TIOCM_RTS)
	portdata->rts_state = 1;
	if (set & TIOCM_DTR)
	portdata->dtr_state = 1;

	if (clear & TIOCM_RTS)
	portdata->rts_state = 0;
	if (clear & TIOCM_DTR)
	portdata->dtr_state = 0;
	return usb_wwan_send_setup(port);
	}
	EXPORT_SYMBOL(usb_wwan_tiocmset);

	int usb_wwan_write(struct tty_struct tty, struct usb_serial_port port,
	const unsigned char *buf, int count)
	{
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata;
	int i;
	int left, todo;
	struct urb this_urb = NULL; / spurious */
	int err;
	unsigned long flags;

	portdata = usb_get_serial_port_data(port);
	intfdata = usb_get_serial_data(port->serial);

	dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);

	i = 0;
	left = count;
	for (i = 0; left > 0 && i < N_OUT_URB; i++) {
	todo = left;
	if (todo > OUT_BUFLEN)
	todo = OUT_BUFLEN;

	this_urb = portdata->out_urbs[i];
	if (test_and_set_bit(i, &portdata->out_busy)) {
	if (time_before(jiffies,
	portdata->tx_start_time[i] + 10 * HZ))
	continue;
	usb_unlink_urb(this_urb);
	continue;
	}
	dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
	usb_pipeendpoint(this_urb->pipe), i);

	err = usb_autopm_get_interface_async(port->serial->interface);
	if (err < 0) {
	clear_bit(i, &portdata->out_busy);
	break;
	}

	/* send the data */
	memcpy(this_urb->transfer_buffer, buf, todo);
	this_urb->transfer_buffer_length = todo;

	spin_lock_irqsave(&intfdata->susp_lock, flags);
	if (intfdata->suspended) {
	usb_anchor_urb(this_urb, &portdata->delayed);
	spin_unlock_irqrestore(&intfdata->susp_lock, flags);
	} else {
	intfdata->in_flight++;
	spin_unlock_irqrestore(&intfdata->susp_lock, flags);
	err = usb_submit_urb(this_urb, GFP_ATOMIC);
	if (err) {
	dev_err(&port->dev,
	"%s: submit urb %d failed: %d\n",
	__func__, i, err);
	clear_bit(i, &portdata->out_busy);
	spin_lock_irqsave(&intfdata->susp_lock, flags);
	intfdata->in_flight--;
	spin_unlock_irqrestore(&intfdata->susp_lock,
	flags);
	usb_autopm_put_interface_async(port->serial->interface);
	break;
	}
	}

	portdata->tx_start_time[i] = jiffies;
	buf += todo;
	left -= todo;
	}

	count -= left;
	dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
	return count;
	}
	EXPORT_SYMBOL(usb_wwan_write);

	static void usb_wwan_indat_callback(struct urb *urb)
	{
	int err;
	int endpoint;
	struct usb_serial_port *port;
	struct device *dev;
	unsigned char *data = urb->transfer_buffer;
	int status = urb->status;

	endpoint = usb_pipeendpoint(urb->pipe);
	port = urb->context;
	dev = &port->dev;

	if (status) {
	dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
	__func__, status, endpoint);

	/* don't resubmit on fatal errors */
	if (status == -ESHUTDOWN \|\| status == -ENOENT)
	return;
	} else {
	if (urb->actual_length) {
	tty_insert_flip_string(&port->port, data,
	urb->actual_length);
	tty_flip_buffer_push(&port->port);
	} else
	dev_dbg(dev, "%s: empty read urb received\n", __func__);
	}
	/* Resubmit urb so we continue receiving */
	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err) {
	if (err != -EPERM && err != -ENODEV) {
	dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
	__func__, err);
	/* busy also in error unless we are killed */
	usb_mark_last_busy(port->serial->dev);
	}
	} else {
	usb_mark_last_busy(port->serial->dev);
	}
	}

	static void usb_wwan_outdat_callback(struct urb *urb)
	{
	struct usb_serial_port *port;
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata;
	unsigned long flags;
	int i;

	port = urb->context;
	intfdata = usb_get_serial_data(port->serial);

	usb_serial_port_softint(port);
	usb_autopm_put_interface_async(port->serial->interface);
	portdata = usb_get_serial_port_data(port);
	spin_lock_irqsave(&intfdata->susp_lock, flags);
	intfdata->in_flight--;
	spin_unlock_irqrestore(&intfdata->susp_lock, flags);

	for (i = 0; i < N_OUT_URB; ++i) {
	if (portdata->out_urbs[i] == urb) {
	smp_mb__before_atomic();
	clear_bit(i, &portdata->out_busy);
	break;
	}
	}
	}

	unsigned int usb_wwan_write_room(struct tty_struct *tty)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_wwan_port_private *portdata;
	int i;
	unsigned int data_len = 0;
	struct urb *this_urb;

	portdata = usb_get_serial_port_data(port);

	for (i = 0; i < N_OUT_URB; i++) {
	this_urb = portdata->out_urbs[i];
	if (this_urb && !test_bit(i, &portdata->out_busy))
	data_len += OUT_BUFLEN;
	}

	dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
	return data_len;
	}
	EXPORT_SYMBOL(usb_wwan_write_room);

	unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_wwan_port_private *portdata;
	int i;
	unsigned int data_len = 0;
	struct urb *this_urb;

	portdata = usb_get_serial_port_data(port);

	for (i = 0; i < N_OUT_URB; i++) {
	this_urb = portdata->out_urbs[i];
	/* FIXME: This locking is insufficient as this_urb may
	go unused during the test */
	if (this_urb && test_bit(i, &portdata->out_busy))
	data_len += this_urb->transfer_buffer_length;
	}
	dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
	return data_len;
	}
	EXPORT_SYMBOL(usb_wwan_chars_in_buffer);

	int usb_wwan_open(struct tty_struct tty, struct usb_serial_port port)
	{
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata;
	struct usb_serial *serial = port->serial;
	int i, err;
	struct urb *urb;

	portdata = usb_get_serial_port_data(port);
	intfdata = usb_get_serial_data(serial);

	if (port->interrupt_in_urb) {
	err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	if (err) {
	dev_err(&port->dev, "%s: submit int urb failed: %d\n",
	__func__, err);
	}
	}

	/* Start reading from the IN endpoint */
	for (i = 0; i < N_IN_URB; i++) {
	urb = portdata->in_urbs[i];
	if (!urb)
	continue;
	err = usb_submit_urb(urb, GFP_KERNEL);
	if (err) {
	dev_err(&port->dev,
	"%s: submit read urb %d failed: %d\n",
	__func__, i, err);
	}
	}

	spin_lock_irq(&intfdata->susp_lock);
	if (++intfdata->open_ports == 1)
	serial->interface->needs_remote_wakeup = 1;
	spin_unlock_irq(&intfdata->susp_lock);
	/* this balances a get in the generic USB serial code */
	usb_autopm_put_interface(serial->interface);

	return 0;
	}
	EXPORT_SYMBOL(usb_wwan_open);

	static void unbusy_queued_urb(struct urb *urb,
	struct usb_wwan_port_private *portdata)
	{
	int i;

	for (i = 0; i < N_OUT_URB; i++) {
	if (urb == portdata->out_urbs[i]) {
	clear_bit(i, &portdata->out_busy);
	break;
	}
	}
	}

	void usb_wwan_close(struct usb_serial_port *port)
	{
	int i;
	struct usb_serial *serial = port->serial;
	struct usb_wwan_port_private *portdata;
	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
	struct urb *urb;

	portdata = usb_get_serial_port_data(port);

	/*
	* Need to take susp_lock to make sure port is not already being
	* resumed, but no need to hold it due to initialized
	*/
	spin_lock_irq(&intfdata->susp_lock);
	if (--intfdata->open_ports == 0)
	serial->interface->needs_remote_wakeup = 0;
	spin_unlock_irq(&intfdata->susp_lock);

	for (;;) {
	urb = usb_get_from_anchor(&portdata->delayed);
	if (!urb)
	break;
	unbusy_queued_urb(urb, portdata);
	usb_autopm_put_interface_async(serial->interface);
	}

	for (i = 0; i < N_IN_URB; i++)
	usb_kill_urb(portdata->in_urbs[i]);
	for (i = 0; i < N_OUT_URB; i++)
	usb_kill_urb(portdata->out_urbs[i]);
	usb_kill_urb(port->interrupt_in_urb);

	usb_autopm_get_interface_no_resume(serial->interface);
	}
	EXPORT_SYMBOL(usb_wwan_close);

	static struct urb usb_wwan_setup_urb(struct usb_serial_port port,
	int endpoint,
	int dir, void ctx, char buf, int len,
	void (callback) (struct urb ))
	{
	struct usb_serial *serial = port->serial;
	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
	struct urb *urb;

	urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
	if (!urb)
	return NULL;

	usb_fill_bulk_urb(urb, serial->dev,
	usb_sndbulkpipe(serial->dev, endpoint) \| dir,
	buf, len, callback, ctx);

	if (intfdata->use_zlp && dir == USB_DIR_OUT)
	urb->transfer_flags \|= URB_ZERO_PACKET;

	return urb;
	}

	int usb_wwan_port_probe(struct usb_serial_port *port)
	{
	struct usb_wwan_port_private *portdata;
	struct urb *urb;
	u8 *buffer;
	int i;

	if (!port->bulk_in_size \|\| !port->bulk_out_size)
	return -ENODEV;

	portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
	if (!portdata)
	return -ENOMEM;

	init_usb_anchor(&portdata->delayed);

	for (i = 0; i < N_IN_URB; i++) {
	buffer = (u8 *)__get_free_page(GFP_KERNEL);
	if (!buffer)
	goto bail_out_error;
	portdata->in_buffer[i] = buffer;

	urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
	USB_DIR_IN, port,
	buffer, IN_BUFLEN,
	usb_wwan_indat_callback);
	portdata->in_urbs[i] = urb;
	}

	for (i = 0; i < N_OUT_URB; i++) {
	buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
	if (!buffer)
	goto bail_out_error2;
	portdata->out_buffer[i] = buffer;

	urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
	USB_DIR_OUT, port,
	buffer, OUT_BUFLEN,
	usb_wwan_outdat_callback);
	portdata->out_urbs[i] = urb;
	}

	usb_set_serial_port_data(port, portdata);

	return 0;

	bail_out_error2:
	for (i = 0; i < N_OUT_URB; i++) {
	usb_free_urb(portdata->out_urbs[i]);
	kfree(portdata->out_buffer[i]);
	}
	bail_out_error:
	for (i = 0; i < N_IN_URB; i++) {
	usb_free_urb(portdata->in_urbs[i]);
	free_page((unsigned long)portdata->in_buffer[i]);
	}
	kfree(portdata);

	return -ENOMEM;
	}
	EXPORT_SYMBOL_GPL(usb_wwan_port_probe);

	void usb_wwan_port_remove(struct usb_serial_port *port)
	{
	int i;
	struct usb_wwan_port_private *portdata;

	portdata = usb_get_serial_port_data(port);
	usb_set_serial_port_data(port, NULL);

	for (i = 0; i < N_IN_URB; i++) {
	usb_free_urb(portdata->in_urbs[i]);
	free_page((unsigned long)portdata->in_buffer[i]);
	}
	for (i = 0; i < N_OUT_URB; i++) {
	usb_free_urb(portdata->out_urbs[i]);
	kfree(portdata->out_buffer[i]);
	}

	kfree(portdata);
	}
	EXPORT_SYMBOL(usb_wwan_port_remove);

	#ifdef CONFIG_PM
	static void stop_urbs(struct usb_serial *serial)
	{
	int i, j;
	struct usb_serial_port *port;
	struct usb_wwan_port_private *portdata;

	for (i = 0; i < serial->num_ports; ++i) {
	port = serial->port[i];
	portdata = usb_get_serial_port_data(port);
	if (!portdata)
	continue;
	for (j = 0; j < N_IN_URB; j++)
	usb_kill_urb(portdata->in_urbs[j]);
	for (j = 0; j < N_OUT_URB; j++)
	usb_kill_urb(portdata->out_urbs[j]);
	usb_kill_urb(port->interrupt_in_urb);
	}
	}

	int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
	{
	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);

	spin_lock_irq(&intfdata->susp_lock);
	if (PMSG_IS_AUTO(message)) {
	if (intfdata->in_flight) {
	spin_unlock_irq(&intfdata->susp_lock);
	return -EBUSY;
	}
	}
	intfdata->suspended = 1;
	spin_unlock_irq(&intfdata->susp_lock);

	stop_urbs(serial);

	return 0;
	}
	EXPORT_SYMBOL(usb_wwan_suspend);

	/* Caller must hold susp_lock. */
	static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
	{
	struct usb_serial *serial = port->serial;
	struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
	struct usb_wwan_port_private *portdata;
	struct urb *urb;
	int err_count = 0;
	int err;

	portdata = usb_get_serial_port_data(port);

	for (;;) {
	urb = usb_get_from_anchor(&portdata->delayed);
	if (!urb)
	break;

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err) {
	dev_err(&port->dev, "%s: submit urb failed: %d\n",
	__func__, err);
	err_count++;
	unbusy_queued_urb(urb, portdata);
	usb_autopm_put_interface_async(serial->interface);
	continue;
	}
	data->in_flight++;
	}

	if (err_count)
	return -EIO;

	return 0;
	}

	int usb_wwan_resume(struct usb_serial *serial)
	{
	int i, j;
	struct usb_serial_port *port;
	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
	struct usb_wwan_port_private *portdata;
	struct urb *urb;
	int err;
	int err_count = 0;

	spin_lock_irq(&intfdata->susp_lock);
	for (i = 0; i < serial->num_ports; i++) {
	port = serial->port[i];

	if (!tty_port_initialized(&port->port))
	continue;

	portdata = usb_get_serial_port_data(port);

	if (port->interrupt_in_urb) {
	err = usb_submit_urb(port->interrupt_in_urb,
	GFP_ATOMIC);
	if (err) {
	dev_err(&port->dev,
	"%s: submit int urb failed: %d\n",
	__func__, err);
	err_count++;
	}
	}

	err = usb_wwan_submit_delayed_urbs(port);
	if (err)
	err_count++;

	for (j = 0; j < N_IN_URB; j++) {
	urb = portdata->in_urbs[j];
	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (err < 0) {
	dev_err(&port->dev,
	"%s: submit read urb %d failed: %d\n",
	__func__, i, err);
	err_count++;
	}
	}
	}
	intfdata->suspended = 0;
	spin_unlock_irq(&intfdata->susp_lock);

	if (err_count)
	return -EIO;

	return 0;
	}
	EXPORT_SYMBOL(usb_wwan_resume);
	#endif

	MODULE_AUTHOR(DRIVER_AUTHOR);
	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_LICENSE("GPL v2");