pcxx.c

powerpc内核mpc8241linux系统下char驱动程序

		if(tty->ldisc.num != ldiscs[N_TTY].num) {
			if(tty->ldisc.close)
				(tty->ldisc.close)(tty);
			tty->ldisc = ldiscs[N_TTY];
			tty->termios->c_line = N_TTY;
			if(tty->ldisc.open)
				(tty->ldisc.open)(tty);
		}
#endif
		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_CALLOUT_ACTIVE|ASYNC_CLOSING);
		wake_up_interruptible(&info->close_wait);
		MOD_DEC_USE_COUNT;
		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|ASYNC_CALLOUT_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) {

		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. */
		do
		{ tail = bc->tout;
		} while (tail != bc->tout);
		
		tail &= (size - 1);
		stlen = (head >= tail) ? (size - (head - tail) - 1) : (tail - head - 1);
		count = MIN(stlen, count);
		if (count) {
			if (verify_area(VERIFY_READ, (char*)buf, count))
				count=0;
			else copy_from_user(ch->tmp_buf, buf, count);
		}
		buf = ch->tmp_buf;
		memoff(ch);
		restore_flags(flags);
	}

	/*
	 * All data is now local
	 */

	total = 0;
	save_flags(flags);
	cli();
	globalwinon(ch);
	head = bc->tin & (size - 1);
	tail = bc->tout;
	if (tail != bc->tout)
		tail = bc->tout;
	tail &= (size - 1);
	if (head >= tail) {
		remain = size - (head - tail) - 1;
		stlen = size - head;
	}
	else {
		remain = tail - head - 1;
		stlen = remain;
	}
	count = MIN(remain, count);

	txwinon(ch);
	while (count > 0) {
		stlen = MIN(count, stlen);
		memcpy(ch->txptr + head, buf, stlen);
		buf += stlen;
		count -= stlen;
		total += stlen;
		head += stlen;
		if (head >= size) {
			head = 0;
			stlen = tail;
		}
	}
	ch->statusflags |= TXBUSY;
	globalwinon(ch);
	bc->tin = head;
	if ((ch->statusflags & LOWWAIT) == 0) {
		ch->statusflags |= LOWWAIT;
		bc->ilow = 1;
	}
	memoff(ch);
	restore_flags(flags);

	return(total);
}


static void pcxe_put_char(struct tty_struct *tty, unsigned char c)
{
	pcxe_write(tty, 0, &c, 1);
	return;
}


static int pcxe_write_room(struct tty_struct *tty)
{
	struct channel *ch;
	int remain;

	remain = 0;
	if ((ch=chan(tty))!=NULL) {
		volatile struct board_chan *bc;
		unsigned int head, tail;
		unsigned long flags;

		save_flags(flags);
		cli();
		globalwinon(ch);

		bc = ch->brdchan;
		head = bc->tin & (ch->txbufsize - 1);
		tail = bc->tout;
		if (tail != bc->tout)
			tail = bc->tout;
		tail &= (ch->txbufsize - 1);

		if((remain = tail - head - 1) < 0 )
			remain += ch->txbufsize;

		if (remain && (ch->statusflags & LOWWAIT) == 0) {
			ch->statusflags |= LOWWAIT;
			bc->ilow = 1;
		}
		memoff(ch);
		restore_flags(flags);
	}

	return remain;
}


static int pcxe_chars_in_buffer(struct tty_struct *tty)
{
	int chars;
	unsigned int ctail, head, tail;
	int remain;
	unsigned long flags;
	struct channel *ch;
	volatile struct board_chan *bc;

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

	save_flags(flags);
	cli();
	globalwinon(ch);

	bc = ch->brdchan;
	tail = bc->tout;
	head = bc->tin;
	ctail = ch->mailbox->cout;
	if(tail == head && ch->mailbox->cin == ctail && bc->tbusy == 0)
		chars = 0;
	else {
		head = bc->tin & (ch->txbufsize - 1);
		tail &= (ch->txbufsize - 1);
		if((remain = tail - head - 1) < 0 )
			remain += ch->txbufsize;

		chars = (int)(ch->txbufsize - remain);

		/* 
		 * Make it possible to wakeup anything waiting for output
		 * in tty_ioctl.c, etc.
		 */
		if(!(ch->statusflags & EMPTYWAIT))
			setup_empty_event(tty,ch);
	}

	memoff(ch);
	restore_flags(flags);

	return(chars);
}


static void pcxe_flush_buffer(struct tty_struct *tty)
{
	unsigned int tail;
	volatile struct board_chan *bc;
	struct channel *ch;
	unsigned long flags;

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

	save_flags(flags);
	cli();

	globalwinon(ch);
	bc = ch->brdchan;
	tail = bc->tout;
	fepcmd(ch, STOUT, (unsigned) tail, 0, 0, 0);

	memoff(ch);
	restore_flags(flags);

	wake_up_interruptible(&tty->write_wait);
	if((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && tty->ldisc.write_wakeup)
		(tty->ldisc.write_wakeup)(tty);
}

static void pcxe_flush_chars(struct tty_struct *tty)
{
	struct channel * ch;

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

		save_flags(flags);
		cli();
		if ((ch->statusflags & TXBUSY) && !(ch->statusflags & EMPTYWAIT))
			setup_empty_event(tty,ch);
		restore_flags(flags);
	}
}

#ifndef MODULE

/*
 * Driver setup function when linked into the kernel to optionally parse multible
 * "digi="-lines and initialize the driver at boot time. No probing.
 */
__initfunc(void pcxx_setup(char *str, int *ints))
{

	struct board_info board;
	int               i, j, last;
	char              *temp, *t2;
	unsigned          len;

	numcards=0;

	memset(&board, 0, sizeof(board));

	for(last=0,i=1;i<=ints[0];i++)
		switch(i)
		{
			case 1:
				board.status = ints[i];
				last = i;
				break;

			case 2:
				board.type = ints[i];
				last = i;
				break;

			case 3:
				board.altpin = ints[i];
				last = i;
				break;

			case 4:
				board.numports = ints[i];
				last = i;
				break;

			case 5:
				board.port = ints[i];
				last = i;
				break;

			case 6:
				board.membase = ints[i];
				last = i;
				break;

			default:
				printk("PC/Xx: Too many integer parms\n");
				return;
		}

	while (str && *str) 
	{
		/* find the next comma or terminator */
		temp = str;
		while (*temp && (*temp != ','))
			temp++;

		if (!*temp)
			temp = NULL;
		else
			*temp++ = 0;

		i = last + 1;

		switch(i)
		{
			case 1:
				len = strlen(str);
				if (strncmp("Disable", str, len) == 0) 
					board.status = 0;
				else
					if (strncmp("Enable", str, len) == 0)
						board.status = 1;
					else
					{
						printk("PC/Xx: Invalid status %s\n", str);
						return;
					}
				last = i;
				break;

			case 2:
				for(j=0;j<PCXX_NUM_TYPES;j++)
					if (strcmp(board_desc[j], str) == 0)
						break;

				if (i<PCXX_NUM_TYPES) 
					board.type = j;
				else
				{
					printk("PC/Xx: Invalid board name: %s\n", str);
					return;
				}
				last = i;
				break;

			case 3:
				len = strlen(str);
				if (strncmp("Disable", str, len) == 0) 
					board.altpin = 0;
				else
					if (strncmp("Enable", str, len) == 0)
						board.altpin = 1;
					else
					{
						printk("PC/Xx: Invalid altpin %s\n", str);
						return;
					}
				last = i;
				break;

			case 4:
				t2 = str;
				while (isdigit(*t2))
					t2++;

				if (*t2)
				{
					printk("PC/Xx: Invalid port count %s\n", str);
					return;
				}

				board.numports = simple_strtoul(str, NULL, 0);
				last = i;
				break;

			case 5:
				t2 = str;
				while (isxdigit(*t2))
					t2++;

				if (*t2)
				{
					printk("PC/Xx: Invalid io port address %s\n", str);
					return;
				}

				board.port = simple_strtoul(str, NULL, 16);
				last = i;
				break;

			case 6:
				t2 = str;
				while (isxdigit(*t2))
					t2++;

				if (*t2)
				{
					printk("PC/Xx: Invalid memory base %s\n", str);
					return;
				}

				board.membase = simple_strtoul(str, NULL, 16);
				last = i;
				break;

			default:
				printk("PC/Xx: Too many string parms\n");
				return;
		}
		str = temp;
	}

	if (last < 6)  
	{
		printk("PC/Xx: Insufficient parms specified\n");
		return;
	}
 
        /* I should REALLY validate the stuff here */

	memcpy(&boards[numcards],&board, sizeof(board));
	printk("PC/Xx: Added board %i, %s %s %i ports at 0x%4.4X base 0x%6.6X\n", 
		numcards, board_desc[board.type], board_mem[board.type], 
		board.numports, board.port, (unsigned int) board.membase);

	/* keep track of my initial minor number */
        if (numcards)
		boards[numcards].first_minor = boards[numcards-1].first_minor + boards[numcards-1].numports;
	else
		boards[numcards].first_minor = 0;

	/* yeha!  string parameter was successful! */
	numcards++;
}
#endif

/*
 * function to initialize the driver with the given parameters, which are either
 * the default values from this file or the parameters given at boot.
 */
__initfunc(int pcxe_init(void))
{
	ulong memory_seg=0, memory_size=0;
	int lowwater, enabled_cards=0, i, crd, shrinkmem=0, topwin = 0xff00L, botwin=0x100L;
	unchar *fepos, *memaddr, *bios, v;
	volatile struct global_data *gd;
	volatile struct board_chan *bc;
	struct board_info *bd;
	struct channel *ch;

	printk(KERN_NOTICE "Digiboard PC/X{i,e,eve} driver v%s\n", VERSION);

#ifdef MODULE
	for (i = 0; i < 4; i++) {
		if (io[i]) {
			numcards = 0;
			break;
		}
	}
	if (numcards == 0) {
		int first_minor = 0;

		for (i = 0; i < 4; i++) {
			if (io[i] == 0) {
				boards[i].port    = 0;
				boards[i].status  = DISABLED;
			}
			else {
				boards[i].port         = (ushort)io[i];
				boards[i].status       = ENABLED;
				boards[i].first_minor  = first_minor;
				numcards=i+1;
			}
			if (membase[i])
				boards[i].membase = (ulong)membase[i];
			else
				boards[i].membase = 0xD0000;

			if (memsize[i])
				boards[i].memsize = (ulong)(memsize[i] * 1024);
			else
				boards[i].memsize = 0;

			if (altpin[i])
				boards[i].altpin  = ON;
			else
				boards[i].altpin  = OFF;

			if (numports[i])
				boards[i].numports  = (ushort)numports[i];
			else
				boards[i].numports  = 16;

			first_minor += boards[i].numports;
		}
	}
#endif

	if (numcards <= 0)
	{
		printk("PC/Xx: No cards configured, driver not active.\n");
		return -EIO;
	}
#if 1
	if (debug)
	    for (i = 0; i < numcards; i++) {
		    printk("Card %d:status=%d, port=0x%x, membase=0x%lx, memsize=0x%lx, altpin=%d, numports=%d, first_minor=%d\n",
			    i+1,
			    boards[i].status,
			    boards[i].port,
			    boards[i].membase,
			    boards[i].memsize,
			    boards[i].altpin,
			    boards[i].numports,
			    boards[i].first_minor);
	    }
#endif

	for (i=0;i<numcards;i++)
		nbdevs += boards[i].numports;

	if (nbdevs <= 0)
	{
		printk("PC/Xx: No devices activated, driver not active.\n");
		return -EIO;
	}

	/*
	 * this turns out to be more memory efficient, as there are no 
	 * unused spaces.
	 */
	digi_channels = kmalloc(sizeof(struct channel) * nbdevs, GFP_KERNEL);
	if (!digi_channels)
		panic("Unable to allocate digi_channel struct");
	memset(digi_channels, 0, sizeof(struct channel) * nbdevs);

	pcxe_table =  kmalloc(sizeof(struct tty_struct *) * nbdevs, GFP_KERNEL);
	if (!pcxe_table)
		panic("Unable to allocate pcxe_table struct");
	memset(pcxe_table, 0, sizeof(struct tty_struct *) * nbdevs);

	pcxe_termios = kmalloc(sizeof(struct termios *) * nbdevs, GFP_KERNEL);
	if (!pcxe_termios)
		panic("Unable to allocate pcxe_termios struct");
	memset(pcxe_termios,0,sizeof(struct termios *)*nbdevs);

	pcxe_termios_locked = kmalloc(sizeof(struct termios *) * nbdevs, GFP_KERNEL);
	if (!pcxe_termios_locked)
		panic("Unable to allocate pcxe_termios_locked struct");
	memset(pcxe_termios_locked,0,sizeof(struct termios *)*nbdevs);

	init_bh(DIGI_BH,do_pcxe_bh);
	enable_bh(DIGI_BH);

	timer_table[DIGI_TIMER].fn = pcxxpoll;
	timer_table[DIGI_TIMER].expires = 0;

	memset(&pcxe_driver, 0, sizeof(struct tty_driver));
	pcxe_driver.magic = TTY_DRIVER_MAGIC;
	pcxe_driver.name = "ttyD";
	pcxe_driver.major = DIGI_MAJOR; 
	pcxe_driver.minor_start = 0;

	pcxe_driver.num = nbdevs;

	pcxe_driver.type = TTY_DRIVER_TYPE_SERIAL;
	pcxe_driver.subtype = SERIAL_TYPE_NORMAL;
	pcxe_driver.init_termios = tty_std_termios;
	pcxe_driver.init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL;
	pcxe_driver.flags = TTY_DRIVER_REAL_RAW;
	pcxe_driver.refcount = &pcxe_refcount;

	pcxe_driver.table = pcxe_table;
	pcxe_driver.termios = pcxe_termios;
	pcxe_driver.termios_locked = pcxe_termios_locked;

	pcxe_driver.open = pcxe_open;
	pcxe_driver.close = pcxe_close;
	pcxe_driver.write = pcxe_write;
	pcxe_driver.put_char = pcxe_put_char;
	pcxe_driver.flush_chars = pcxe_flush_chars;
	pcxe_driver.write_room = pcxe_write_room;
	pcxe_driver.chars_in_buffer = pcxe_chars_in_buffer;
	pcxe_driver.flush_buffer = pcxe_flush_buffer;
	pcxe_driver.ioctl = pcxe_ioctl;
	pcxe_driver.throttle = pcxe_throttle;
	pcxe_driver.unthrottle = pcxe_unthrottle;
	pcxe_driver.set_termios = pcxe_set_termios;
	pcxe_driver.stop = pcxe_stop;
	pcxe_driver.start = pcxe_start;
	pcxe_driver.hangup = pcxe_hangup;

	pcxe_callout = pcxe_driver;
	pcxe_callout.name = "cud";
	pcxe_callout.major = DIGICU_MAJOR;
	pcxe_callout.subtype = SERIAL_TYPE_CALLOUT;
	pcxe_callout.init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;

	for(crd=0; crd < numcards; crd++) {