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

/*
 * USB Serial Converter driver
 *
 * Copyright (C) 1999 - 2004 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
 *
 * (12/10/2002) gkh
 *	Split the ports off into their own struct device, and added a
 *	usb-serial bus driver.
 *
 * (11/19/2002) gkh
 *	removed a few #ifdefs for the generic code and cleaned up the failure
 *	logic in initialization.
 *
 * (10/02/2002) gkh
 *	moved the console code to console.c and out of this file.
 *
 * (06/05/2002) gkh
 *	moved location of startup() call in serial_probe() until after all
 *	of the port information and endpoints are initialized.  This makes
 *	things easier for some drivers.
 *
 * (04/10/2002) gkh
 *	added serial_read_proc function which creates a
 *	/proc/tty/driver/usb-serial file.
 *
 * (03/27/2002) gkh
 *	Got USB serial console code working properly and merged into the main
 *	version of the tree.  Thanks to Randy Dunlap for the initial version
 *	of this code, and for pushing me to finish it up.
 *	The USB serial console works with any usb serial driver device.
 *
 * (03/21/2002) gkh
 *	Moved all manipulation of port->open_count into the core.  Now the
 *	individual driver's open and close functions are called only when the
 *	first open() and last close() is called.  Making the drivers a bit
 *	smaller and simpler.
 *	Fixed a bug if a driver didn't have the owner field set.
 *
 * (02/26/2002) gkh
 *	Moved all locking into the main serial_* functions, instead of having 
 *	the individual drivers have to grab the port semaphore.  This should
 *	reduce races.
 *	Reworked the MOD_INC logic a bit to always increment and decrement, even
 *	if the generic driver is being used.
 *
 * (10/10/2001) gkh
 *	usb_serial_disconnect() now sets the serial->dev pointer is to NULL to
 *	help prevent child drivers from accessing the device since it is now
 *	gone.
 *
 * (09/13/2001) gkh
 *	Moved generic driver initialize after we have registered with the USB
 *	core.  Thanks to Randy Dunlap for pointing this problem out.
 *
 * (07/03/2001) gkh
 *	Fixed module paramater size.  Thanks to John Brockmeyer for the pointer.
 *	Fixed vendor and product getting defined through the MODULE_PARM macro
 *	if the Generic driver wasn't compiled in.
 *	Fixed problem with generic_shutdown() not being called for drivers that
 *	don't have a shutdown() function.
 *
 * (06/06/2001) gkh
 *	added evil hack that is needed for the prolific pl2303 device due to the
 *	crazy way its endpoints are set up.
 *
 * (05/30/2001) gkh
 *	switched from using spinlock to a semaphore, which fixes lots of problems.
 *
 * (04/08/2001) gb
 *	Identify version on module load.
 *
 * 2001_02_05 gkh
 *	Fixed buffer overflows bug with the generic serial driver.  Thanks to
 *	Todd Squires <squirest@ct0.com> for fixing this.
 *
 * (01/10/2001) gkh
 *	Fixed bug where the generic serial adaptor grabbed _any_ device that was
 *	offered to it.
 *
 * (12/12/2000) gkh
 *	Removed MOD_INC and MOD_DEC from poll and disconnect functions, and
 *	moved them to the serial_open and serial_close functions.
 *	Also fixed bug with there not being a MOD_DEC for the generic driver
 *	(thanks to Gary Brubaker for finding this.)
 *
 * (11/29/2000) gkh
 *	Small NULL pointer initialization cleanup which saves a bit of disk image
 *
 * (11/01/2000) Adam J. Richter
 *	instead of using idVendor/idProduct pairs, usb serial drivers
 *	now identify their hardware interest with usb_device_id tables,
 *	which they usually have anyhow for use with MODULE_DEVICE_TABLE.
 *
 * (10/05/2000) gkh
 *	Fixed bug with urb->dev not being set properly, now that the usb
 *	core needs it.
 * 
 * (09/11/2000) gkh
 *	Removed DEBUG #ifdefs with call to usb_serial_debug_da