usbserial.c

USB接口转换成RS232接口驱动程序

/*
 * USB Serial Converter driver
 *
 * Copyright (C) 1999, 2000 Greg Kroah-Hartman ([e-mail])
 * Copyright (c) 2000 Peter Berger ([e-mail])
 * Copyright (c) 2000 Al Borchers ([e-mail])
 *
 *	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 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
 *
 * 2001_02_05 gkh
 *	Fixed buffer overflows bug with the generic serial driver.  Thanks to
 *	Todd Squires <[e-mail]> 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_data
 *
 * (08/28/2000) gkh
 *	Added port_lock to port structure.
 *	Added locks for SMP safeness to generic driver
 *	Fixed the ability to open a generic device's port more than once.
 *
 * (07/23/2000) gkh
 *	Added bulk_out_endpointAddress to port structure.
 *
 * (07/19/2000) gkh, pberger, and borchers
 *	Modifications to allow usb-serial drivers to be modules.
 *
 * (07/03/2000) gkh
 *	Added more debugging to serial_ioctl call
 * 
 * (06/25/2000) gkh
 *	Changed generic_write_bulk_callback to not call wake_up_interruptible
 *	directly, but to have port_softint do it at a safer time.
 *
 * (06/23/2000) gkh
 *	Cleaned up debugging statements in a quest to find UHCI timeout bug.
 *
 * (05/22/2000) gkh
 *	Changed the makefile, enabling the big CONFIG_USB_SERIAL_SOMTHING to be 
 *	removed from the individual device source files.
 *
 * (05/03/2000) gkh
 *	Added the Digi Acceleport driver from Al Borchers and Peter Berger.
 * 
 * (05/02/2000) gkh
 *	Changed devfs and tty register code to work properly now. This was based on
 *	the ACM driver changes by Vojtech Pavlik.
 *
 * (04/27/2000) Ryan VanderBijl
 * 	Put calls to *_paranoia_checks into one function.
 * 
 * (04/23/2000) gkh
 *	Fixed bug that Randy Dunlap found for Generic devices with no bulk out ports.
 *	Moved when the startup code printed out the devices that are supported.
 *
 * (04/19/2000) gkh
 *	Added driver for ZyXEL omni.net lcd plus ISDN TA
 *	Made startup info message specify which drivers were compiled in.
 *
 * (04/03/2000) gkh
 *	Changed the probe process to remove the module unload races.
 *	Changed where the tty layer gets initialized to have devfs work nicer.
 *	Added initial devfs support.
 *
 * (03/26/2000) gkh
 *	Split driver up into device specific pieces.
 * 
 * (03/19/2000) gkh
 *	Fixed oops that could happen when device was removed while a program
 *	was talking to the device.
 *	Removed the static urbs and now all urbs are created and destroyed
 *	dynamically.
 *	Reworked the internal interface. Now everything is based on the 
 *	usb_serial_port structure instead of the larger usb_serial structure.
 *	This fixes the bug that a multiport device could not have more than
 *	one port open at one time.
 *
 * (03/17/2000) gkh
 *	Added config option for debugging messages.
 *	Added patch for keyspan pda from Brian Warner.
 *
 * (03/06/2000) gkh
 *	Added the keyspan pda code from Brian Warner <[e-mail]>
 *	Moved a bunch of the port specific stuff into its own structure. This
 *	is in anticipation of the true multiport devices (there's a bug if you
 *	try to access more than one port of any multiport device right now)
 *
 * (02/21/2000) gkh
 *	Made it so that any serial devices only have to specify which functions
 *	they want to overload from the generic function calls (great, 
 *	inheritance in C, in a driver, just what I wanted...)
 *	Added support for set_termios and ioctl function calls. No drivers take
 *	advantage of this yet.
 *	Removed the #ifdef MODULE, now there is no module specific code.
 *	Cleaned up a few comments in usb-serial.h that were wrong (thanks again
 *	to Miles Lott).
 *	Small fix to get_free_serial.
 *
 * (02/14/2000) gkh
 *	Removed the Belkin and Peracom functionality from the driver due to
 *	the lack of support from the vendor, and me not wanting people to 
 *	accidenatly buy the device, expecting it to work with Linux.
 *	Added read_bulk_callback and write_bulk_callback to the type structure
 *	for the needs of the FTDI and WhiteHEAT driver.
 *	Changed all reverences to FTDI to FTDI_SIO at the request of Bill
 *	Ryder.
 *	Changed the output urb size back to the max endpoint size to make
 *	the ftdi_sio driver have it easier, and due to the fact that it didn't
 *	really increase the speed any.
 *
 * (02/11/2000) gkh
 *	Added VISOR_FUNCTION_CONSOLE to the visor startup function. This was a
 *	patch from Miles Lott ([e-mail]).
 *	Fixed bug with not restoring the minor range that a device grabs, if
 *	the startup function fails (thanks Miles for finding this).
 *
 * (02/05/2000) gkh
 *	Added initial framework for the Keyspan PDA serial converter so that
 *	Brian Warner has a place to put his code.
 *	Made the ezusb specific functions generic enough that different
 *	devices can use them (whiteheat and keyspan_pda both need them).
 *	Split out a whole bunch of structure and other stuff to a seperate
 *	usb-serial.h file.
 *	Made the Visor connection messages a little more understandable, now
 *	that Miles Lott ([e-mail]) has gotten the Generic channel to
 *	work. Also made them always show up in the log file.
 * 
 * (01/25/2000) gkh
 *	Added initial framework for FTDI serial converter so that Bill Ryder
 *	has a place to put his code.
 *	Added the vendor specific info from Handspring. Now we can print out
 *	informational debug messages as well as understand what is happening.
 *
 * (01/23/2000) gkh
 *	Fixed problem of crash when trying to open a port that didn't have a
 *	device assigned to it. Made the minor node finding a little smarter,
 *	now it looks to find a continous space for the new device.
 *
 * (01/21/2000) gkh
 *	Fixed bug in visor_startup with patch from Miles Lott ([e-mail])
 *	Fixed get_serial_by_minor which was all messed up for multi port 
 *	devices. Fixed multi port problem for generic devices. Now the number
 *	of ports is determined by the number of bulk out endpoints for the
 *	generic device.
 *
 * (01/19/2000) gkh
 *	Removed lots of cruft that was around from the old (pre urb) driver 
 *	interface.
 *	Made the serial_table dynamic. This should save lots of memory when
 *	the number of minor nodes goes up to 256.
 *	Added initial support for devices that have more than one port. 
 *	Added more debugging comments for the Visor, and added a needed 
 *	set_configuration call.
 *
 * (01/17/2000) gkh
 *	Fixed the WhiteHEAT firmware (my processing tool had a bug)
 *	and added new debug loader firmware for it.
 *	Removed the put_char function as it isn't really needed.
 *	Added visor startup commands as found by the Win98 dump.
 * 
 * (01/13/2000) gkh
 *	Fixed the vendor id for the generic driver to the one I meant it to be.
 *
 * (01/12/2000) gkh
 *	Forget the version numbering...that's pretty useless...
 *	Made the driver able to be compiled so that the user can select which
 *	converter they want to use. This allows people who only want the Visor
 *	support to not pay the memory size price of the WhiteHEAT.
 *	Fixed bug where the generic driver (idVendor=0000 and idProduct=0000)
 *	grabbed the root hub. Not good.
 * 
 * version 0.4.0 (01/10/2000) gkh
 *	Added whiteheat.h containing the firmware for the ConnectTech WhiteHEAT
 *	device. Added startup function to allow firmware to be downloaded to
 *	a device if it needs to be.
 *	Added firmware download logic to the WhiteHEAT device.
 *	Started to add #defines to split up the different drivers for potential
 *	configuration option.
 *	
 * version 0.3.1 (12/30/99) gkh
 *      Fixed problems with urb for bulk out.
 *      Added initial support for multiple sets of endpoints. This enables
 *      the Handspring Visor to be attached successfully. Only the first
 *      bulk in / bulk out endpoint pair is being used right now.
 *
 * version 0.3.0 (12/27/99) gkh
 *	Added initial support for the Handspring Visor based on a patch from
 *	Miles Lott ([e-mail])
 *	Cleaned up the code a bunch and converted over to using urbs only.
 *
 * version 0.2.3 (12/21/99) gkh
 *	Added initial support for the Connect Tech WhiteHEAT converter.
 *	Incremented the number of ports in expectation of getting the
 *	WhiteHEAT to work properly (4 ports per connection).
 *	Added notification on insertion and removal of what port the
 *	device is/was connected to (and what kind of device it was).
 *
 * version 0.2.2 (12/16/99) gkh
 *	Changed major number to the new allocated number. We're legal now!
 *
 * version 0.2.1 (12/14/99) gkh
 *	Fixed bug that happens when device node is opened when there isn't a
 *	device attached to it. Thanks to [e-mail] for noticing this.
 *
 * version 0.2.0 (11/10/99) gkh
 *	Split up internals to make it easier to add different types of serial 
 *	converters to the code.
 *	Added a "generic" driver that gets it's vendor and product id
 *	from when the module is loaded. Thanks to David E. Nelson ([e-mail])
 *	for the idea and sample code (from the usb scanner driver.)
 *	Cleared up any licensing questions by releasing it under the GNU GPL.
 *
 * version 0.1.2 (10/25/99) gkh
 * 	Fixed bug in detecting device.
 *
 * version 0.1.1 (10/05/99) gkh
 * 	Changed the major number to not conflict with anything else.
 *
 * version 0.1 (09/28/99) gkh
 * 	Can recognize the two different devices and start up a read from
 *	device when asked to. Writes also work. No control signals yet, this
 *	all is vendor specific data (i.e. no spec), also no control for
 *	different baud rates or other bit settings.
 *	Currently we are using the same devid as the acm driver. This needs
 *	to change.
 * 
 */
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/smp_lock.h>

#ifdef USB_SERIAL_DEBUG
#define DEBUG
#else
#undef DEBUG
#endif
#include <linux/usb.h>

/* Module information */
MODULE_AUTHOR("Greg Kroah-Hartman, [e-mail], http://www.kroah.com/linux-usb/");
MODULE_DESCRIPTION("USB Serial Driver");

#include "usb-serial.h"

#define MAX(a, b) (((a) > (b)) ? (a) : (b))
/* function prototypes for a "generic" type serial converter (no flow control, not all endpoints needed) */

/* need to always compile these in, as some of the other devices use these functions as their own. */

/* if a driver does not provide a function pointer, the generic function will be called. */
static int    generic_open(struct usb_serial_port *port, struct file *filp);
static void   generic_close(struct usb_serial_port *port, struct file *filp);
static int    generic_write(struct usb_serial_port *port, int from_user, const unsigned char *buf, int count);
static int    generic_write_room(struct usb_serial_port *port);
static int    generic_chars_in_buffer(struct usb_serial_port *port);
static void   generic_read_bulk_callback(struct urb *urb);
static void   generic_write_bulk_callback(struct urb *urb);

#ifdef CONFIG_USB_SERIAL_GENERIC
static void   generic_shutdown(struct usb_serial *serial);
static __u16  vendor = 0x05f9;
static __u16  product = 0xffff;
MODULE_PARM(vendor, "i");
MODULE_PARM_DESC(vendor, "User specified USB idVendor");

MODULE_PARM(product, "i");
MODULE_PARM_DESC(product, "User specified USB idProduct");

static struct usb_device_id           generic_device_ids[2];  /* Initially all zeroes. */

/* All of the device info needed for the Generic Serial Converter */
static struct usb_serial_device_type  generic_device =
{
name:
  "Generic",
  id_table : generic_device_ids,
  needs_interrupt_in : DONT_CARE, /* don't have to have an interrupt in endpoint */
  needs_bulk_in : DONT_CARE,      /* don't have to have a bulk in endpoint */
  needs_bulk_out : DONT_CARE,     /* don't have to have a bulk out endpoint */
  num_interrupt_in : NUM_DONT_CARE,
  num_bulk_in : NUM_DONT_CARE,
  num_bulk_out : NUM_DONT_CARE,
  num_ports : 1,
  shutdown : generic_shutdown,
};
#endif

/* local function prototypes */
static int                            serial_open(struct tty_struct *tty, struct file *filp);
static void                           serial_close(struct tty_struct *tty, struct file *filp);
static int                            serial_write(struct tty_struct   *tty, int                 from_user,
                                                   const unsigned char *buf, int                 count);
static int                            serial_write_room(struct tty_struct *tty);
static int                            serial_chars_in_buffer(struct tty_struct *tty);
static void                           serial_throttle(struct tty_struct *tty);
static void                           serial_unthrottle(struct tty_struct *tty);
static int                            serial_ioctl(struct tty_struct *tty, struct file       *file, unsigned int      cmd,
                                                   unsigned long     arg);
static void                           serial_set_termios(struct tty_struct *tty, struct termios *old);

static void                           *usb_serial_probe(struct usb_device           *dev, unsigned int                ifnum,
                                                        const struct usb_device_id  *id);
static void                           usb_serial_disconnect(struct usb_device *dev, void *ptr);

static struct usb_driver              usb_serial_driver =
{
name:
  "serial",
  probe : usb_serial_probe,
  disconnect : usb_serial_disconnect,
  id_table : NULL,                /* check all devices */
};

/* There is no MODULE_DEVICE_TABLE for usbserial.c.  Instead
   the MODULE_DEVICE_TABLE declarations in each serial driver