ftdi_sio.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

/*
 * USB FTDI SIO driver
 *
 * 	Copyright (C) 1999 - 2001
 * 	    Greg Kroah-Hartman ([e-mail])
 *          Bill Ryder ([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.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 * See http://ftdi-usb-sio.sourceforge.net for upto date testing info
 *     and extra documentation
 * 
 * (04/Nov/2001) Bill Ryder
 *     Fixed bug in read_bulk_callback where incorrect urb buffer was used.
 *     cleaned up write offset calculation
 *     added write_room since default values can be incorrect for sio
 *     changed write_bulk_callback to use same queue_task as other drivers
 *       (the previous version caused panics)
 *     Removed port iteration code since the device only has one I/O port and it 
 *       was wrong anyway.
 * 
 * (31/May/2001) gkh
 *	switched from using spinlock to a semaphore, which fixes lots of problems.
 *
 * (23/May/2001)   Bill Ryder
 *     Added runtime debug patch (thanx Tyson D Sawyer).
 *     Cleaned up comments for 8U232
 *     Added parity, framing and overrun error handling
 *     Added receive break handling.
 * 
 * (04/08/2001) gb
 *	Identify version on module load.
 *       
 * (18/March/2001) Bill Ryder
 *     (Not released)
 *     Added send break handling. (requires kernel patch too)
 *     Fixed 8U232AM hardware RTS/CTS etc status reporting.
 *     Added flipbuf fix copied from generic device
 * 
 * (12/3/2000) Bill Ryder
 *     Added support for 8U232AM device.
 *     Moved PID and VIDs into header file only.
 *     Turned on low-latency for the tty (device will do high baudrates)
 *     Added shutdown routine to close files when device removed.
 *     More debug and error message cleanups.
 *     
 *
 * (11/13/2000) Bill Ryder
 *     Added spinlock protected open code and close code.
 *     Multiple opens work (sort of - see webpage mentioned above).
 *     Cleaned up comments. Removed multiple PID/VID definitions.
 *     Factorised cts/dtr code
 *     Made use of __FUNCTION__ in dbg's
 *      
 * (11/01/2000) Adam J. Richter
 *	usb_device_id table support
 * 
 * (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
 *
 * (07/19/2000) gkh
 *	Added module_init and module_exit functions to handle the fact that this
 *	driver is a loadable module now.
 *
 * (04/04/2000) Bill Ryder 
 *      Fixed bugs in TCGET/TCSET ioctls (by removing them - they are 
 *        handled elsewhere in the tty io driver chain).
 *
 * (03/30/2000) Bill Ryder 
 *      Implemented lots of ioctls
 * 	Fixed a race condition in write
 * 	Changed some dbg's to errs
 *
 * (03/26/2000) gkh
 * 	Split driver up into device specific pieces.
 *
 */

/* Bill Ryder - [e-mail] - wrote the FTDI_SIO implementation */
/* Thanx to FTDI for so kindly providing details of the protocol required */
/*   to talk to the device */
/* Thanx to gkh and the rest of the usb dev group for all code I have assimilated :-) */


#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/usb.h>
#ifdef CONFIG_USB_SERIAL_DEBUG
	static int debug = 1;
#else
	static int debug;
#endif

#include "usb-serial.h"
#include "ftdi_sio.h"


/*
 * Version Information
 */
#define DRIVER_VERSION "v1.2.0"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <[e-mail]>, Bill Ryder <[e-mail]>"
#define DRIVER_DESC "USB FTDI RS232 Converters Driver"

static __devinitdata struct usb_device_id id_table_sio [] = {
	{ USB_DEVICE(FTDI_VID, FTDI_SIO_PID) },
	{ }						/* Terminating entry */
};

/* THe 8U232AM has the same API as the sio except for:
   - it can support MUCH higher baudrates (921600 at 48MHz/230400 
     at 12MHz so .. it's baudrate setting codes are different 
   - it has a two byte status code.
   - it returns characters very 16ms (the FTDI does it every 40ms)
  */

   
static __devinitdata struct usb_device_id id_table_8U232AM [] = {
	{ USB_DEVICE(FTDI_VID, FTDI_8U232AM_PID) },
	{ }						/* Terminating entry */
};


static __devinitdata struct usb_device_id id_table_combined [] = {
	{ USB_DEVICE(FTDI_VID, FTDI_SIO_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_8U232AM_PID) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);


struct ftdi_private {
	ftdi_type_t ftdi_type;
	__u16 last_set_data_urb_value ; /* the last data state set - needed for doing a break */
        int write_offset;
};
/* function prototypes for a FTDI serial converter */
static int  ftdi_sio_startup		(struct usb_serial *serial);
static int  ftdi_8U232AM_startup	(struct usb_serial *serial);
static void ftdi_sio_shutdown		(struct usb_serial *serial);
static int  ftdi_sio_open		(struct usb_serial_port *port, struct file *filp);
static void ftdi_sio_close		(struct usb_serial_port *port, struct file *filp);
static int  ftdi_sio_write		(struct usb_serial_port *port, int from_user, const unsigned char *buf, int count);
static int  ftdi_sio_write_room		(struct usb_serial_port *port);
static void ftdi_sio_write_bulk_callback (struct urb *urb);
static void ftdi_sio_read_bulk_callback	(struct urb *urb);
static void ftdi_sio_set_termios	(struct usb_serial_port *port, struct termios * old);
static int  ftdi_sio_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
static void ftdi_sio_break_ctl		(struct usb_serial_port *port, int break_state );

/* Should rename most ftdi_sio's to ftdi_ now since there are two devices 
   which share common code */ 

static struct usb_serial_device_type ftdi_sio_device = {
	name:			"FTDI SIO",
	id_table:		id_table_sio,
	needs_interrupt_in:	MUST_HAVE_NOT,
	needs_bulk_in:		MUST_HAVE,
	needs_bulk_out:		MUST_HAVE,
	num_interrupt_in:	0,
	num_bulk_in:		1,
	num_bulk_out:		1,
	num_ports:		1,
	open:			ftdi_sio_open,
	close:			ftdi_sio_close,
	write:			ftdi_sio_write,
	write_room:		ftdi_sio_write_room,
	read_bulk_callback:	ftdi_sio_read_bulk_callback,
	write_bulk_callback:	ftdi_sio_write_bulk_callback,
	ioctl:			ftdi_sio_ioctl,
	set_termios:		ftdi_sio_set_termios,
	break_ctl:		ftdi_sio_break_ctl,
	startup:		ftdi_sio_startup,
        shutdown:               ftdi_sio_shutdown,
};

static struct usb_serial_device_type ftdi_8U232AM_device = {
	name:			"FTDI 8U232AM",
	id_table:		id_table_8U232AM,
	needs_interrupt_in:	DONT_CARE,
	needs_bulk_in:		MUST_HAVE,
	needs_bulk_out:		MUST_HAVE,
	num_interrupt_in:	0,
	num_bulk_in:		1,
	num_bulk_out:		1,
	num_ports:		1,
	open:			ftdi_sio_open,
	close:			ftdi_sio_close,
	write:			ftdi_sio_write,
	write_room:		ftdi_sio_write_room,
	read_bulk_callback:	ftdi_sio_read_bulk_callback,
	write_bulk_callback:	ftdi_sio_write_bulk_callback,
	ioctl:			ftdi_sio_ioctl,
	set_termios:		ftdi_sio_set_termios,
	break_ctl:		ftdi_sio_break_ctl,
	startup:		ftdi_8U232AM_startup,
        shutdown:               ftdi_sio_shutdown,
};


/*
 * ***************************************************************************
 * FTDI SIO Serial Converter specific driver functions
 * ***************************************************************************
 */

#define WDR_TIMEOUT (HZ * 5 ) /* default urb timeout */

/* utility functions to set and unset dtr and rts */
#define HIGH 1
#define LOW 0
static int set_rts(struct usb_device *dev, 
		   unsigned int pipe,
		   int high_or_low)
{
	static char buf[1];
	unsigned ftdi_high_or_low = (high_or_low? FTDI_SIO_SET_RTS_HIGH : 
				FTDI_SIO_SET_RTS_LOW);
	return(usb_control_msg(dev, pipe,
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST, 
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE,
			       ftdi_high_or_low, 0, 
			       buf, 0, WDR_TIMEOUT));
}
static int set_dtr(struct usb_device *dev, 
		   unsigned int pipe,
		   int high_or_low)
{
	static char buf[1];
	unsigned ftdi_high_or_low = (high_or_low? FTDI_SIO_SET_DTR_HIGH : 
				FTDI_SIO_SET_DTR_LOW);
	return(usb_control_msg(dev, pipe,
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST, 
			       FTDI_SIO_SET_MODEM_CTRL_REQUEST_TYPE,
			       ftdi_high_or_low, 0, 
			       buf, 0, WDR_TIMEOUT));
}



static int ftdi_sio_startup (struct usb_serial *serial)
{
	struct ftdi_private *priv;
	
	
	priv = serial->port->private = kmalloc(sizeof(struct ftdi_private), GFP_KERNEL);
	if (!priv){
		err(__FUNCTION__"- kmalloc(%Zd) failed.", sizeof(struct ftdi_private));
		return -ENOMEM;
	}

	priv->ftdi_type = sio;
	priv->write_offset = 1;
	
	return (0);
}


static int ftdi_8U232AM_startup (struct usb_serial *serial)
{
	struct ftdi_private *priv;
 

	priv = serial->port->private = kmalloc(sizeof(struct ftdi_private), GFP_KERNEL);
	if (!priv){
		err(__FUNCTION__"- kmalloc(%Zd) failed.", sizeof(struct ftdi_private));
		return -ENOMEM;
	}

	priv->ftdi_type = F8U232AM;
	priv->write_offset = 0;
	
	return (0);
}

static void ftdi_sio_shutdown (struct usb_serial *serial)
{
	
	dbg (__FUNCTION__);


	/* stop reads and writes on all ports */
	while (serial->port[0].open_count > 0) {
	        ftdi_sio_close (&serial->port[0], NULL);
	}
	if (serial->port[0].private){
		kfree(serial->port[0].private);
		serial->port[0].private = NULL;
	}
}



static int  ftdi_sio_open (struct usb_serial_port *port, struct file *filp)
{ /* ftdi_sio_open */
	struct termios tmp_termios;
	struct usb_serial *serial = port->serial;
	int result = 0;
	char buf[1]; /* Needed for the usb_control_msg I think */

	dbg(__FUNCTION__);

	down (&port->sem);
	
	MOD_INC_USE_COUNT;
	++port->open_count;

	if (!port->active){
		port->active = 1;

		/* This will push the characters through immediately rather 
		   than queue a task to deliver them */
		port->tty->low_latency = 1;

		/* No error checking for this (will get errors later anyway) */
		/* See ftdi_sio.h for description of what is reset */