/*
* cdc-acm.c
*
* Copyright (c) 1999 Armin Fuerst <fuerst@in.tum.de>
* Copyright (c) 1999 Pavel Machek <pavel@suse.cz>
* Copyright (c) 1999 Johannes Erdfelt <johannes@erdfelt.com>
* Copyright (c) 2000 Vojtech Pavlik <vojtech@suse.cz>
* Copyright (c) 2004 Oliver Neukum <oliver@neukum.name>
* Copyright (c) 2005 David Kubicek <dave@awk.cz>
*
* USB Abstract Control Model driver for USB modems and ISDN adapters
*
* Sponsored by SuSE
*
* ChangeLog:
* v0.9 - thorough cleaning, URBification, almost a rewrite
* v0.10 - some more cleanups
* v0.11 - fixed flow control, read error doesn't stop reads
* v0.12 - added TIOCM ioctls, added break handling, made struct acm kmalloced
* v0.13 - added termios, added hangup
* v0.14 - sized down struct acm
* v0.15 - fixed flow control again - characters could be lost
* v0.16 - added code for modems with swapped data and control interfaces
* v0.17 - added new style probing
* v0.18 - fixed new style probing for devices with more configurations
* v0.19 - fixed CLOCAL handling (thanks to Richard Shih-Ping Chan)
* v0.20 - switched to probing on interface (rather than device) class
* v0.21 - revert to probing on device for devices with multiple configs
* v0.22 - probe only the control interface. if usbcore doesn't choose the
* config we want, sysadmin changes bConfigurationValue in sysfs.
* v0.23 - use softirq for rx processing, as needed by tty layer
* v0.24 - change probe method to evaluate CDC union descriptor
* v0.25 - downstream tasks paralelized to maximize throughput
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#undef DEBUG
#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/smp_lock.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/list.h>
#include "cdc-acm.h"
/*
* Version Information
*/
#define DRIVER_VERSION "v0.25"
#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
#define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
static struct usb_driver acm_driver;
static struct tty_driver *acm_tty_driver;
static struct acm *acm_table[ACM_TTY_MINORS];
static DEFINE_MUTEX(open_mutex);
#define ACM_READY(acm) (acm && acm->dev && acm->used)
/*
* Functions for ACM control messages.
*/
static int acm_ctrl_msg(struct acm *acm, int request, int value, void *buf, int len)
{
int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
request, USB_RT_ACM, value,
acm->control->altsetting[0].desc.bInterfaceNumber,
buf, len, 5000);
dbg("acm_control_msg: rq: 0x%02x val: %#x len: %#x result: %d", request, value, len, retval);
return retval < 0 ? retval : 0;
}
/* devices aren't required to support these requests.
* the cdc acm descriptor tells whether they do...
*/
#define acm_set_control(acm, control) \
acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
#define acm_set_line(acm, line) \
acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
#define acm_send_break(acm, ms) \
acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
/*
* Write buffer management.
* All of these assume proper locks taken by the caller.
*/
static int acm_wb_alloc(struct acm *acm)
{
int i, wbn;
struct acm_wb *wb;
wbn = acm->write_current;
i = 0;
for (;;) {
wb = &acm->wb[wbn];
if (!wb->use) {
wb->use = 1;
return wbn;
}
wbn = (wbn + 1) % ACM_NW;
if (++i >= ACM_NW)
return -1;
}
}
static void acm_wb_free(struct acm *acm, int wbn)
{
acm->wb[wbn].use = 0;
}
static int acm_wb_is_avail(struct acm *acm)
{
int i, n;