ftdi_sio.c

ep9315平台下USB驱动的源码

/*
 * USB FTDI SIO driver
 *
 * 	Copyright (C) 1999 - 2001
 * 	    Greg Kroah-Hartman ([e-mail])
 *          Bill Ryder ([e-mail])
 *	Copyright (C) 2002
 *	    Kuba Ober ([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
 *
 * (23/Feb/2003) Bill Ryder
 *      Added matrix orb device vid/pids from Wayne Wylupski
 *
 * (19/Feb/2003) Ian Abbott
 *      For TIOCSSERIAL, set alt_speed to 0 when ASYNC_SPD_MASK value has
 *      changed to something other than ASYNC_SPD_HI, ASYNC_SPD_VHI,
 *      ASYNC_SPD_SHI or ASYNC_SPD_WARP.  Also, unless ASYNC_SPD_CUST is in
 *      force, don't bother changing baud rate when custom_divisor has changed.
 *
 * (18/Feb/2003) Ian Abbott
 *      Fixed TIOCMGET handling to include state of DTR and RTS, the state
 *      of which are now saved by set_dtr() and set_rts().
 *      Fixed improper storage class for buf in set_dtr() and set_rts().
 *      Added FT232BM chip type and support for its extra baud rates (compared
 *      to FT8U232AM).
 *      Took account of special case divisor values for highest baud rates of
 *      FT8U232AM and FT232BM.
 *      For TIOCSSERIAL, forced alt_speed to 0 when ASYNC_SPD_CUST kludge used,
 *      as previous alt_speed setting is now stale.
 *      Moved startup code common between the startup routines for the
 *      different chip types into a common subroutine.
 *
 * (17/Feb/2003) Bill Ryder
 *      Added write urb buffer pool on a per device basis
 *      Added more checking for open file on callbacks (fixed OOPS)
 *      Added CrystalFontz 632 and 634 PIDs 
 *         (thanx to CrystalFontz for the sample devices - they flushed out
 *           some driver bugs)
 *      Minor debugging message changes
 *      Added throttle, unthrottle and chars_in_buffer functions
 *      Fixed FTDI_SIO (the original device) bug
 *      Fixed some shutdown handling
 *      
 * 
 * 
 * 
 * (07/Jun/2002) Kuba Ober
 *	Changed FTDI_SIO_BASE_BAUD_TO_DIVISOR macro into ftdi_baud_to_divisor
 *	function. It was getting too complex.
 *	Fix the divisor calculation logic which was setting divisor of 0.125
 *	instead of 0.5 for fractional parts of divisor equal to 5/8, 6/8, 7/8.
 *	Also make it bump up the divisor to next integer in case of 7/8 - it's
 *	a better approximation.
 *
 * (25/Jul/2002) Bill Ryder inserted Dmitri's TIOCMIWAIT patch
 *      Not tested by me but it doesn't break anything I use.
 * 
 * (04/Jan/2002) Kuba Ober
 *	Implemented 38400 baudrate kludge, where it can be substituted with other
 *	  values. That's the only way to set custom baudrates.
 *	Implemented TIOCSSERIAL, TIOCGSERIAL ioctl's so that setserial is happy.
 *	FIXME: both baudrate things should eventually go to usbserial.c as other
 *	  devices may need that functionality too. Actually, it can probably be
 *	  merged in serial.c somehow - too many drivers repeat this code over
 *	  and over.
 *	Fixed baudrate forgetfulness - open() used to reset baudrate to 9600 every time.
 *	Divisors for baudrates are calculated by a macro.
 *	Small code cleanups. Ugly whitespace changes for Plato's sake only ;-].
 *
 * (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/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/serial.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 "v1.3.2"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <[e-mail]>, Bill Ryder <[e-mail]>, Kuba Ober <[e-mail]>"
#define DRIVER_DESC "USB FTDI Serial Converters Driver"

static 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; up to:
 *   o 921600 for RS232 and 2000000 for RS422/485 at 48MHz
 *   o 230400 at 12MHz
 *   so .. 8U232AM's baudrate setting codes are different
 * - it has a two byte status code.
 * - it returns characters every 16ms (the FTDI does it every 40ms)
 *
 * the bcdDevice value is used to differentiate FT232BM and FT245BM from
 * the earlier FT8U232AM and FT8U232BM.  For now, include all known VID/PID
 * combinations in both tables.
 * FIXME: perhaps bcdDevice can also identify 12MHz devices, but I don't know
 * if those ever went into mass production. [Ian Abbott]
 */


static struct usb_device_id id_table_8U232AM [] = {
	{ USB_DEVICE_VER(FTDI_VID, FTDI_8U232AM_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_NF_RIC_VID, FTDI_NF_RIC_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_VID, FTDI_XF_634_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_VID, FTDI_XF_632_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_0_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_1_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_2_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_3_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_4_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_5_PID, 0, 0x3ff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_6_PID, 0, 0x3ff) },
	{ }						/* Terminating entry */
};


static struct usb_device_id id_table_FT232BM [] = {
	{ USB_DEVICE_VER(FTDI_VID, FTDI_8U232AM_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_NF_RIC_VID, FTDI_NF_RIC_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_VID, FTDI_XF_634_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_VID, FTDI_XF_632_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_0_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_1_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_2_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_3_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_4_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_5_PID, 0x400, 0xffff) },
	{ USB_DEVICE_VER(FTDI_MTXORB_VID, FTDI_MTXORB_6_PID, 0x400, 0xffff) },

	{ }						/* 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) },
	{ USB_DEVICE(FTDI_VID, FTDI_XF_634_PID) },
	{ USB_DEVICE(FTDI_VID, FTDI_XF_632_PID) },
	{ USB_DEVICE(FTDI_NF_RIC_VID, FTDI_NF_RIC_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_0_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_1_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_2_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_3_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_4_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_5_PID) },
	{ USB_DEVICE(FTDI_MTXORB_VID, FTDI_MTXORB_6_PID) },	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table_combined);


/* constants which set the number of write urb buffers */
#define NUM_URBS			32
/* Don't be tempted to increase this buffer to > 64 ! I tried it and it doesn't work */
#define URB_TRANSFER_BUFFER_SIZE	64 /* the device's max packet size */


struct ftdi_private {
	ftdi_chip_type_t chip_type;
				/* type of the device, either SIO or FT8U232AM */
	int baud_base;		/* baud base clock for divisor setting */
	int custom_divisor;	/* custom_divisor kludge, this is for baud_base (different from what goes to the chip!) */
	__u16 last_set_data_urb_value ;
				/* the last data state set - needed for doing a break */
        int write_offset;       /* This is the offset in the usb data block to write the serial data - 
				 * it is different between devices
				 */
	int flags;		/* some ASYNC_xxxx flags are supported */
	unsigned long last_dtr_rts;	/* saved modem control outputs */
        wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
 	char prev_status, diff_status;        /* Used for TIOCMIWAIT */

	struct urb	*write_urb_pool[NUM_URBS];
	spinlock_t	write_urb_pool_lock;

};

/* Used for TIOCMIWAIT */
#define FTDI_STATUS_B0_MASK	(FTDI_RS0_CTS | FTDI_RS0_DSR | FTDI_RS0_RI | FTDI_RS0_RLSD)
#define FTDI_STATUS_B1_MASK	(FTDI_RS_BI)
/* End TIOCMIWAIT */

#define FTDI_IMPL_ASYNC_FLAGS = ( ASYNC_SPD_HI | ASYNC_SPD_VHI \
 ASYNC_SPD_CUST | ASYNC_SPD_SHI | ASYNC_SPD_WARP )

/* 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 int  ftdi_FT232BM_startup	(struct usb_serial *serial);
static void ftdi_shutdown		(struct usb_serial *serial);
static int  ftdi_open			(struct usb_serial_port *port, struct file *filp);
static void ftdi_close			(struct usb_serial_port *port, struct file *filp);
static int  ftdi_write			(struct usb_serial_port *port, int from_user, const unsigned char *buf, int count);
static int  ftdi_write_room		(struct usb_serial_port *port);
static int  ftdi_chars_in_buffer	(struct usb_serial_port *port);
static void ftdi_write_bulk_callback	(struct urb *urb);
static void ftdi_read_bulk_callback	(struct urb *urb);
static void ftdi_set_termios		(struct usb_serial_port *port, struct termios * old);
static int  ftdi_ioctl			(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
static void ftdi_break_ctl		(struct usb_serial_port *port, int break_state );
static void ftdi_throttle		(struct usb_serial_port *port);
static void ftdi_unthrottle		(struct usb_serial_port *port);

static unsigned short int ftdi_232am_baud_base_to_divisor (int baud, int base);
static unsigned short int ftdi_232am_baud_to_divisor (int baud);
static __u32 ftdi_232bm_baud_base_to_divisor (int baud, int base);
static __u32 ftdi_232bm_baud_to_divisor (int baud);

static struct usb_serial_device_type ftdi_SIO_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI SIO",
	.id_table =		id_table_sio,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_SIO_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_8U232AM_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI 8U232AM Compatible",
	.id_table =		id_table_8U232AM,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_8U232AM_startup,
	.shutdown =		ftdi_shutdown,
};

static struct usb_serial_device_type ftdi_FT232BM_device = {
	.owner =		THIS_MODULE,
	.name =			"FTDI FT232BM Compatible",
	.id_table =		id_table_FT232BM,
	.num_interrupt_in =	0,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			ftdi_open,
	.close =		ftdi_close,
	.throttle =		ftdi_throttle,
	.unthrottle =		ftdi_unthrottle,
	.write =		ftdi_write,
	.write_room =		ftdi_write_room,
	.chars_in_buffer =	ftdi_chars_in_buffer,
	.read_bulk_callback =	ftdi_read_bulk_callback,
	.write_bulk_callback =	ftdi_write_bulk_callback,
	.ioctl =		ftdi_ioctl,
	.set_termios =		ftdi_set_termios,
	.break_ctl =		ftdi_break_ctl,
	.startup =		ftdi_FT232BM_startup,
	.shutdown =		ftdi_shutdown,
};



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

/* High and low are for DTR, RTS etc etc */
#define HIGH 1
#define LOW 0

/*
 * ***************************************************************************
 * Utlity functions
 * ***************************************************************************
 */

static unsigned short int ftdi_232am_baud_base_to_divisor(int baud, int base)
{
	unsigned short int divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	if ((divisor3 & 0x7) == 7) divisor3 ++; // round x.7/8 up to x+1
	divisor = divisor3 >> 3;
	divisor3 &= 0x7;
	if (divisor3 == 1) divisor |= 0xc000; else // 0.125
	if (divisor3 >= 4) divisor |= 0x4000; else // 0.5
	if (divisor3 != 0) divisor |= 0x8000;      // 0.25
	if (divisor == 1) divisor = 0;	/* special case for maximum baud rate */
	return divisor;
}

static unsigned short int ftdi_232am_baud_to_divisor(int baud)
{
	 return(ftdi_232am_baud_base_to_divisor(baud, 48000000));
}

static __u32 ftdi_232bm_baud_base_to_divisor(int baud, int base)
{
	static const unsigned char divfrac[8] = { 0, 3, 2, 4, 1, 5, 6, 7 };
	__u32 divisor;
	int divisor3 = base / 2 / baud; // divisor shifted 3 bits to the left
	divisor = divisor3 >> 3;
	divisor |= (__u32)divfrac[divisor3 & 0x7] << 14;
	/* Deal with special cases for highest baud rates. */
	if (divisor == 1) divisor = 0; else	// 1.0