linux/drivers/usb/serial/navman.c
Alan Cox 95da310e66 usb_serial: API all change
USB serial likes to use port->tty back pointers for the real work it does and
to do so without any actual locking. Unfortunately when you consider hangup
events, hangup/parallel reopen or even worse hangup followed by parallel close
events the tty->port and port->tty pointers are not guaranteed to be the same
as port->tty is the active tty while tty->port is the port the tty may or
may not still be attached to.

So rework the entire API to pass the tty struct. For console cases we need
to pass both for now. This shows up multiple drivers that immediately crash
with USB console some of which have been fixed in the process.

Longer term we need a proper tty as console abstraction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-22 13:03:22 -07:00

157 lines
3.6 KiB
C

/*
* Navman Serial USB driver
*
* Copyright (C) 2006 Greg Kroah-Hartman <gregkh@suse.de>
*
* 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.
*
* TODO:
* Add termios method that uses copy_hw but also kills all echo
* flags as the navman is rx only so cannot echo.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
static int debug;
static struct usb_device_id id_table [] = {
{ USB_DEVICE(0x0a99, 0x0001) }, /* Talon Technology device */
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
static struct usb_driver navman_driver = {
.name = "navman",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static void navman_read_int_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
struct tty_struct *tty;
int status = urb->status;
int result;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d",
__func__, status);
return;
default:
dbg("%s - nonzero urb status received: %d",
__func__, status);
goto exit;
}
usb_serial_debug_data(debug, &port->dev, __func__,
urb->actual_length, data);
tty = port->port.tty;
if (tty && urb->actual_length) {
tty_buffer_request_room(tty, urb->actual_length);
tty_insert_flip_string(tty, data, urb->actual_length);
tty_flip_buffer_push(tty);
}
exit:
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result)
dev_err(&urb->dev->dev,
"%s - Error %d submitting interrupt urb\n",
__func__, result);
}
static int navman_open(struct tty_struct *tty,
struct usb_serial_port *port, struct file *filp)
{
int result = 0;
dbg("%s - port %d", __func__, port->number);
if (port->interrupt_in_urb) {
dbg("%s - adding interrupt input for treo", __func__);
result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting interrupt urb, error %d\n",
__func__, result);
}
return result;
}
static void navman_close(struct tty_struct *tty,
struct usb_serial_port *port, struct file *filp)
{
dbg("%s - port %d", __func__, port->number);
usb_kill_urb(port->interrupt_in_urb);
}
static int navman_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
dbg("%s - port %d", __func__, port->number);
/*
* This device can't write any data, only read from the device
*/
return -EOPNOTSUPP;
}
static struct usb_serial_driver navman_device = {
.driver = {
.owner = THIS_MODULE,
.name = "navman",
},
.id_table = id_table,
.usb_driver = &navman_driver,
.num_ports = 1,
.open = navman_open,
.close = navman_close,
.write = navman_write,
.read_int_callback = navman_read_int_callback,
};
static int __init navman_init(void)
{
int retval;
retval = usb_serial_register(&navman_device);
if (retval)
return retval;
retval = usb_register(&navman_driver);
if (retval)
usb_serial_deregister(&navman_device);
return retval;
}
static void __exit navman_exit(void)
{
usb_deregister(&navman_driver);
usb_serial_deregister(&navman_device);
}
module_init(navman_init);
module_exit(navman_exit);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");