path: root/drivers/usb/serial/usb-serial.c

/*
 * USB Serial Converter driver
 *
 * Copyright (C) 1999 - 2005 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2000 Peter Berger (pberger@brimson.com)
 * Copyright (C) 2000 Al Borchers (borchers@steinerpoint.com)
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 *
 * This driver was originally based on the ACM driver by Armin Fuerst (which was
 * based on a driver by Brad Keryan)
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include "pl2303.h"

/*
 * Version Information
 */
#define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com, http://www.kroah.com/linux/"
#define DRIVER_DESC "USB Serial Driver core"

static void port_free(struct usb_serial_port *port);

/* Driver structure we register with the USB core */
static struct usb_driver usb_serial_driver = {
	.name =		"usbserial",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.no_dynamic_id = 	1,
};

/* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
   the MODULE_DEVICE_TABLE declarations in each serial driver
   cause the "hotplug" program to pull in whatever module is necessary
   via modprobe, and modprobe will load usbserial because the serial
   drivers depend on it.
*/

static int debug;
static struct usb_serial *serial_table[SERIAL_TTY_MINORS];	/* initially all NULL */
static LIST_HEAD(usb_serial_driver_list);

struct usb_serial *usb_serial_get_by_index(unsigned index)
{
	struct usb_serial *serial = serial_table[index];

	if (serial)
		kref_get(&serial->kref);
	return serial;
}

static struct usb_serial *get_free_serial (struct usb_serial *serial, int num_ports, unsigned int *minor)
{
	unsigned int i, j;
	int good_spot;

	dbg("%s %d", __FUNCTION__, num_ports);

	*minor = 0;
	for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
		if (serial_table[i])
			continue;

		good_spot = 1;
		for (j = 1; j <= num_ports-1; ++j)
			if ((i+j >= SERIAL_TTY_MINORS) || (serial_table[i+j])) {
				good_spot = 0;
				i += j;
				break;
			}
		if (good_spot == 0)
			continue;

		*minor = i;
		dbg("%s - minor base = %d", __FUNCTION__, *minor);
		for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i)
			serial_table[i] = serial;
		return serial;
	}
	return NULL;
}

static void return_serial(struct usb_serial *serial)
{
	int i;

	dbg("%s", __FUNCTION__);

	if (serial == NULL)
		return;

	for (i = 0; i < serial->num_ports; ++i) {
		serial_table[serial->minor +