pcxx.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,385 行 · 第 1/4 页

/*
 *  linux/drivers/char/pcxx.c
 * 
 *  Written by Troy De Jongh, November, 1994
 *
 *  Copyright (C) 1994,1995 Troy De Jongh
 *  This software may be used and distributed according to the terms 
 *  of the GNU General Public License.
 *
 *  This driver is for the DigiBoard PC/Xe and PC/Xi line of products.
 *
 *  This driver does NOT support DigiBoard's fastcook FEP option and
 *  does not support the transparent print (i.e. digiprint) option.
 *
 * This Driver is currently maintained by Christoph Lameter ([e-mail])
 *
 * Please contact digi for support issues at [e-mail].
 * Some more information can be found at
 * http://lameter.com/digi.
 *
 *  1.5.2 Fall 1995 Bug fixes by David Nugent
 *  1.5.3 March 9, 1996 Christoph Lameter: Fixed 115.2K Support. Memory
 *		allocation harmonized with 1.3.X Series.
 *  1.5.4 March 30, 1996 Christoph Lameter: Fixup for 1.3.81. Use init_bh
 *		instead of direct assignment to kernel arrays.
 *  1.5.5 April 5, 1996 Major device numbers corrected.
 *              Mike McLagan<[e-mail]>: Add setup
 *              variable handling, instead of using the old pcxxconfig.h
 *  1.5.6 April 16, 1996 Christoph Lameter: Pointer cleanup, macro cleanup.
 *		Call out devices changed to /dev/cudxx.
 *  1.5.7 July 22, 1996 Martin Mares: CLOCAL fix, pcxe_table clearing.
 *		David Nugent: Bug in pcxe_open.
 *		Brian J. Murrell: Modem Control fixes, Majors correctly assigned
 *  1.6.1 April 6, 1997 Bernhard Kaindl: fixed virtual memory access for 2.1
 *              i386-kernels and use on other archtitectures, Allowing use
 *              as module, added module parameters, added switch to enable
 *              verbose messages to assist user during card configuration.
 *              Currently only tested on a PC/Xi card, but should work on Xe
 *              and Xeve also.
 *  1.6.2 August, 7, 2000: Arnaldo Carvalho de Melo <[e-mail]>
 *  		get rid of panics, release previously allocated resources
 *  1.6.3 August, 23, 2000: Arnaldo Carvalho de Melo <[e-mail]>
 *  		cleaned up wrt verify_area.
 *              Christoph Lameter: Update documentation, email addresses
 *              and URLs. Remove some obsolete code.
 *
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/delay.h>
#include <linux/serial.h>
#include <linux/tty_driver.h>
#include <linux/slab.h>
#include <linux/init.h>

#ifndef MODULE
#include <linux/ctype.h> /* We only need it for parsing the "digi="-line */
#endif

#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <asm/semaphore.h>

#define VERSION 	"1.6.3"

#include "digi.h"
#include "fep.h"
#include "pcxx.h"
#include "digi_fep.h"
#include "digi_bios.h"

/*
 * Define one default setting if no digi= config line is used.
 * Default is altpin = disabled, 16 ports, I/O 200h, Memory 0D0000h
 */
static struct board_info boards[MAX_DIGI_BOARDS] = { {
/* Board is enabled       */	ENABLED,
/* Type is auto-detected  */	0,
/* altping is disabled    */    DISABLED,
/* number of ports = 16   */	16,
/* io address is 0x200    */	0x200,
/* card memory at 0xd0000 */	0xd0000,
/* first minor device no. */	0
} };
 
static int verbose = 0;
static int debug   = 0;

#ifdef MODULE
/* Variables for insmod */
static int io[]           = {0, 0, 0, 0};
static int membase[]      = {0, 0, 0, 0};
static int memsize[]      = {0, 0, 0, 0};
static int altpin[]       = {0, 0, 0, 0};
static int numports[]     = {0, 0, 0, 0};

MODULE_AUTHOR("Bernhard Kaindl");
MODULE_DESCRIPTION("Digiboard PC/X{i,e,eve} driver");
MODULE_LICENSE("GPL");
MODULE_PARM(verbose,     "i");
MODULE_PARM(debug,       "i");
MODULE_PARM(io,          "1-4i");
MODULE_PARM(membase,     "1-4i");
MODULE_PARM(memsize,     "1-4i");
MODULE_PARM(altpin,      "1-4i");
MODULE_PARM(numports,    "1-4i");

#endif /* MODULE */

static int numcards = 1;
static int nbdevs = 0;
 
static struct channel    *digi_channels;
 
int pcxx_ncook=sizeof(pcxx_cook);
int pcxx_nbios=sizeof(pcxx_bios);

#define pcxxassert(x, msg)  if(!(x)) pcxx_error(__LINE__, msg)

#define FEPTIMEOUT 200000  
#define SERIAL_TYPE_NORMAL	1
#define PCXE_EVENT_HANGUP   1

static struct tty_driver *pcxe_driver;

static struct timer_list pcxx_timer;

static void pcxxpoll(unsigned long dummy);
static void fepcmd(struct channel *, int, int, int, int, int);
static void pcxe_put_char(struct tty_struct *, unsigned char);
static void pcxe_flush_chars(struct tty_struct *);
static void pcxx_error(int, char *);
static void pcxe_close(struct tty_struct *, struct file *);
static int pcxe_ioctl(struct tty_struct *, struct file *, unsigned int, unsigned long);
static void pcxe_set_termios(struct tty_struct *, struct termios *);
static int pcxe_write(struct tty_struct *, int, const unsigned char *, int);
static int pcxe_write_room(struct tty_struct *);
static int pcxe_chars_in_buffer(struct tty_struct *);
static void pcxe_flush_buffer(struct tty_struct *);
static void doevent(int);
static void receive_data(struct channel *);
static void pcxxparam(struct tty_struct *, struct channel *ch);
static void do_softint(void *);
static inline void pcxe_sched_event(struct channel *, int);
static void pcxe_start(struct tty_struct *);
static void pcxe_stop(struct tty_struct *);
static void pcxe_throttle(struct tty_struct *);
static void pcxe_unthrottle(struct tty_struct *);
static void digi_send_break(struct channel *ch, int msec);
static void shutdown(struct channel *);
static void setup_empty_event(struct tty_struct *tty, struct channel *ch);
static inline void memwinon(struct board_info *b, unsigned int win);
static inline void memwinoff(struct board_info *b, unsigned int win);
static inline void globalwinon(struct channel *ch);
static inline void rxwinon(struct channel *ch);
static inline void txwinon(struct channel *ch);
static inline void memoff(struct channel *ch);
static inline void assertgwinon(struct channel *ch);
static inline void assertmemoff(struct channel *ch);
static int pcxe_tiocmget(struct tty_struct *tty, struct file *file);
static int pcxe_tiocmset(struct tty_struct *tty, struct file *file,
			 unsigned int set, unsigned int clear);

#define TZ_BUFSZ 4096

/* function definitions */

/*****************************************************************************/

static void cleanup_board_resources(void)
{
	int crd, i;
	struct board_info *bd;
	struct channel *ch;

        for(crd = 0; crd < numcards; crd++) {
                bd = &boards[crd];
		ch = digi_channels + bd->first_minor;

		if (bd->region)
			release_region(bd->port, 4);

		for(i = 0; i < bd->numports; i++, ch++)
			if (ch->tmp_buf)
				kfree(ch->tmp_buf);
	}
}

static void __exit pcxe_cleanup(void)
{

	unsigned long	flags;
	int e1;

	printk(KERN_NOTICE "Unloading PC/Xx version %s\n", VERSION);

	save_flags(flags);
	cli();
	del_timer_sync(&pcxx_timer);

	if ((e1 = tty_unregister_driver(pcxe_driver)))
		printk("SERIAL: failed to unregister serial driver (%d)\n", e1);

	put_tty_driver(pcxe_driver);
	cleanup_board_resources();
	kfree(digi_channels);
	restore_flags(flags);
}

static inline struct channel *chan(register struct tty_struct *tty)
{
	if (tty) {
		register struct channel *ch=(struct channel *)tty->driver_data;
		if (ch >= digi_channels && ch < digi_channels+nbdevs) {
			if (ch->magic==PCXX_MAGIC)
				return ch;
		}
	}
	return NULL;
}

/* These inline routines are to turn board memory on and off */
static inline void memwinon(struct board_info *b, unsigned int win)
{
	if(b->type == PCXEVE)
		outb_p(FEPWIN|win, b->port+1);
	else
		outb_p(inb(b->port)|FEPMEM, b->port);
}

static inline void memwinoff(struct board_info *b, unsigned int win)
{
	outb_p(inb(b->port)&~FEPMEM, b->port);
	if(b->type == PCXEVE)
		outb_p(0, b->port + 1);
}

static inline void globalwinon(struct channel *ch)
{
	if(ch->board->type == PCXEVE)
		outb_p(FEPWIN, ch->board->port+1);
	else
		outb_p(FEPMEM, ch->board->port);
}

static inline void rxwinon(struct channel *ch)
{
	if(ch->rxwin == 0)
		outb_p(FEPMEM, ch->board->port);
	else 
		outb_p(ch->rxwin, ch->board->port+1);
}

static inline void txwinon(struct channel *ch)
{
	if(ch->txwin == 0)
		outb_p(FEPMEM, ch->board->port);
	else
		outb_p(ch->txwin, ch->board->port+1);
}

static inline void memoff(struct channel *ch)
{
	outb_p(0, ch->board->port);
	if(ch->board->type == PCXEVE)
		outb_p(0, ch->board->port+1);
}

static inline void assertgwinon(struct channel *ch)
{
	if(ch->board->type != PCXEVE)
		pcxxassert(inb(ch->board->port) & FEPMEM, "Global memory off");
}

static inline void assertmemoff(struct channel *ch)
{
	if(ch->board->type != PCXEVE)
		pcxxassert(!(inb(ch->board->port) & FEPMEM), "Memory on");
}

static inline void pcxe_sched_event(struct channel *info, int event)
{
	info->event |= 1 << event;
	schedule_work(&info->tqueue);
}

static void pcxx_error(int line, char *msg)
{
	printk("pcxx_error (DigiBoard): line=%d %s\n", line, msg);
}

static int pcxx_waitcarrier(struct tty_struct *tty,struct file *filp,struct channel *info)
{
	DECLARE_WAITQUEUE(wait, current);
	int	retval = 0;
	int	do_clocal = 0;

	if (tty->termios->c_cflag & CLOCAL)
		do_clocal = 1;

	/*
	 * Block waiting for the carrier detect and the line to become free
	 */

	retval = 0;
	add_wait_queue(&info->open_wait, &wait);
	info->count--;
	info->blocked_open++;

	for (;;) {
		cli();
		globalwinon(info);
		info->omodem |= DTR|RTS;
		fepcmd(info, SETMODEM, DTR|RTS, 0, 10, 1);
		memoff(info);
		sti();
		set_current_state(TASK_INTERRUPTIBLE);
		if(tty_hung_up_p(filp) || (info->asyncflags & ASYNC_INITIALIZED) == 0) {
			if(info->asyncflags & ASYNC_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;	
			break;
		}
		if ((info->asyncflags & ASYNC_CLOSING) == 0 &&
			(do_clocal || (info->imodem & info->dcd)))
			break;
		if(signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&info->open_wait, &wait);

	if(!tty_hung_up_p(filp))
		info->count++;
	info->blocked_open--;

	return retval;
}	


int pcxe_open(struct tty_struct *tty, struct file * filp)
{
	volatile struct board_chan *bc;
	struct channel *ch;
	unsigned long flags;
	int line;
	int boardnum;
	int retval;

	line = tty->index;

	if(line < 0 || line >= nbdevs) {
		printk("line out of range in pcxe_open\n");
		tty->driver_data = NULL;
		return(-ENODEV);
	}

	for(boardnum=0;boardnum<numcards;boardnum++)
		if ((line >= boards[boardnum].first_minor) && 
			(line < boards[boardnum].first_minor + boards[boardnum].numports))
		break;

	if(boardnum >= numcards || boards[boardnum].status == DISABLED ||
		(line - boards[boardnum].first_minor) >= boards[boardnum].numports) {
		tty->driver_data = NULL;   /* Mark this device as 'down' */
		return(-ENODEV);
	}

	ch = digi_channels+line;

	if(ch->brdchan == 0) {
		tty->driver_data = NULL;
		return(-ENODEV);
	}

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if(ch->asyncflags & ASYNC_CLOSING) {
		interruptible_sleep_on(&ch->close_wait);
		if(ch->asyncflags & ASYNC_HUP_NOTIFY)
			return -EAGAIN;
		else
			return -ERESTARTSYS;
	}

	save_flags(flags);
	cli();
	ch->count++;
	tty->driver_data = ch;
	ch->tty = tty;

	if ((ch->asyncflags & ASYNC_INITIALIZED) == 0) {
		unsigned int head;

		globalwinon(ch);
		ch->statusflags = 0;
		bc=ch->brdchan;
		ch->imodem = bc->mstat;
		head = bc->rin;
		bc->rout = head;
		ch->tty = tty;
		pcxxparam(tty,ch);
		ch->imodem = bc->mstat;
		bc->idata = 1;
		ch->omodem = DTR|RTS;
		fepcmd(ch, SETMODEM, DTR|RTS, 0, 10, 1);
		memoff(ch);
		ch->asyncflags |= ASYNC_INITIALIZED;
	}
	restore_flags(flags);

	if(ch->asyncflags & ASYNC_CLOSING) {
		interruptible_sleep_on(&ch->close_wait);
		if(ch->asyncflags & ASYNC_HUP_NOTIFY)
			return -EAGAIN;
		else
			return -ERESTARTSYS;
	}

	if (!(filp->f_flags & O_NONBLOCK)) {
		/* this has to be set in order for the "block until
		 * CD" code to work correctly.  i'm not sure under
		 * what circumstances asyncflags should be set to
		 * ASYNC_NORMAL_ACTIVE though
		 * [e-mail]
		 */
		ch->asyncflags |= ASYNC_NORMAL_ACTIVE;
		if ((retval = pcxx_waitcarrier(tty, filp, ch)) != 0)
			return retval;
	}
	ch->asyncflags |= ASYNC_NORMAL_ACTIVE;
 	
	return 0;
} 

static void shutdown(struct channel *info)
{
	unsigned long flags;
	volatile struct board_chan *bc;
	struct tty_struct *tty;

	if (!(info->asyncflags & ASYNC_INITIALIZED)) 
		return;

	save_flags(flags);
	cli();
	globalwinon(info);

	bc = info->brdchan;
	if(bc)
		bc->idata = 0;

	tty = info->tty;

	/*
	 * If we're a modem control device and HUPCL is on, drop RTS & DTR.
	 */
	if(tty->termios->c_cflag & HUPCL) {
		info->omodem &= ~(RTS|DTR);
		fepcmd(info, SETMODEM, 0, DTR|RTS, 10, 1);
	}

	memoff(info);
	info->asyncflags &= ~ASYNC_INITIALIZED;
	restore_flags(flags);
}


static void pcxe_close(struct tty_struct * tty, struct file * filp)
{
	struct channel *info;

	if ((info=chan(tty))!=NULL) {
		unsigned long flags;
		save_flags(flags);
		cli();

		if(tty_hung_up_p(filp)) {
			/* flag that somebody is done with this module */
			restore_flags(flags);
			return;
		}
		/* this check is in serial.c, it won't hurt to do it here too */
		if ((tty->count == 1) && (info->count != 1)) {
			/*
			 * Uh, oh.  tty->count is 1, which means that the tty
			 * structure will be freed.  Info->count should always
			 * be one in these conditions.  If it's greater than
			 * one, we've got real problems, since it means the
			 * serial port won't be shutdown.
			 */
			printk("pcxe_close: bad serial port count; tty->count is 1, info->count is %d\n", info->count);
			info->count = 1;
		}
		if (info->count-- > 1) {
			restore_flags(flags);
			return;
		}
		if (info->count < 0) {
			info->count = 0;
		}

		info->asyncflags |= ASYNC_CLOSING;
	
		tty->closing = 1;
		if(info->asyncflags & ASYNC_INITIALIZED) {
			setup_empty_event(tty,info);		
			tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */
		}
	
		if(tty->driver->flush_buffer)
			tty->driver->flush_buffer(tty);
		tty_ldisc_flush(tty);
		shutdown(info);
		tty->closing = 0;
		info->event = 0;
		info->tty = NULL;
		if(info->blocked_open) {
			if(info->close_delay) {
				current->state = TASK_INTERRUPTIBLE;
				schedule_timeout(info->close_delay);
			}
			wake_up_interruptible(&info->open_wait);
		}
		info->asyncflags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
		wake_up_interruptible(&info->close_wait);
		restore_flags(flags);
	}
}


void pcxe_hangup(struct tty_struct *tty)
{
	struct channel *ch;

	if ((ch=chan(tty))!=NULL) {
		unsigned long flags;

		save_flags(flags);
		cli();
		shutdown(ch);
		ch->event = 0;
		ch->count = 0;
		ch->tty = NULL;
		ch->asyncflags &= ~ASYNC_NORMAL_ACTIVE;
		wake_up_interruptible(&ch->open_wait);
		restore_flags(flags);
	}
}



static int pcxe_write(struct tty_struct * tty, int from_user, const unsigned char *buf, int count)
{
	struct channel *ch;
	volatile struct board_chan *bc;
	int total, remain, size, stlen;
	unsigned int head, tail;
	unsigned long flags;
	/* printk("Entering pcxe_write()\n"); */

	if ((ch=chan(tty))==NULL)
		return 0;

	bc = ch->brdchan;
	size = ch->txbufsize;

	if (from_user) {

		down(&ch->tmp_buf_sem);
		save_flags(flags);
		cli();
		globalwinon(ch);
		head = bc->tin & (size - 1);
		/* It seems to be necessary to make sure that the value is stable here somehow
		   This is a rather odd pice of code here. */