linux/drivers/usb/serial/usb_debug.c
Johan Hovold 80fa92c133 USB: usb_debug: use the generic kfifo-based write implementation
Use the generic kfifo-based write implementation rather than allowing up
to 4000 8 byte urbs in the host stack queues.

Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:34 -07:00

112 lines
2.5 KiB
C

/*
* USB Debug cable driver
*
* Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.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.
*/
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#define USB_DEBUG_MAX_PACKET_SIZE 8
#define USB_DEBUG_BRK_SIZE 8
static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = {
0x00,
0xff,
0x01,
0xfe,
0x00,
0xfe,
0x01,
0xff,
};
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x0525, 0x127a) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
static struct usb_driver debug_driver = {
.name = "debug",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static int usb_debug_open(struct tty_struct *tty, struct usb_serial_port *port)
{
port->bulk_out_size = USB_DEBUG_MAX_PACKET_SIZE;
return usb_serial_generic_open(tty, port);
}
/* This HW really does not support a serial break, so one will be
* emulated when ever the break state is set to true.
*/
static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
if (!break_state)
return;
usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
}
static void usb_debug_read_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
USB_DEBUG_BRK_SIZE) == 0) {
usb_serial_handle_break(port);
usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
return;
}
usb_serial_generic_read_bulk_callback(urb);
}
static struct usb_serial_driver debug_device = {
.driver = {
.owner = THIS_MODULE,
.name = "debug",
},
.id_table = id_table,
.num_ports = 1,
.open = usb_debug_open,
.break_ctl = usb_debug_break_ctl,
.read_bulk_callback = usb_debug_read_bulk_callback,
};
static int __init debug_init(void)
{
int retval;
retval = usb_serial_register(&debug_device);
if (retval)
return retval;
retval = usb_register(&debug_driver);
if (retval)
usb_serial_deregister(&debug_device);
return retval;
}
static void __exit debug_exit(void)
{
usb_deregister(&debug_driver);
usb_serial_deregister(&debug_device);
}
module_init(debug_init);
module_exit(debug_exit);
MODULE_LICENSE("GPL");