macserial.c

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/*
 * rs_wait_until_sent() --- wait until the transmitter is empty
 */
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
	struct mac_serial *info = (struct mac_serial *) tty->driver_data;
	unsigned long orig_jiffies, char_time;

	if (serial_paranoia_check(info, tty->device, "rs_wait_until_sent"))
		return;

/*	printk("rs_wait_until_sent, timeout:%d, tty_stopped:%d, tx_stopped:%d\n",
			timeout, tty->stopped, info->tx_stopped);
*/
	orig_jiffies = jiffies;
	/*
	 * Set the check interval to be 1/5 of the estimated time to
	 * send a single character, and make it at least 1.  The check
	 * interval should also be less than the timeout.
	 */
	if (info->timeout <= HZ/50) {
		printk("macserial: invalid info->timeout=%d\n", info->timeout);
		info->timeout = HZ/50+1;
	}

	char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
	char_time = char_time / 5;
	if (char_time > HZ) {
		printk("macserial: char_time %ld >HZ !!!\n", char_time);
		char_time = 1;
	} else if (char_time == 0)
		char_time = 1;
	if (timeout)
		char_time = MIN(char_time, timeout);
	while ((read_zsreg(info->zs_channel, 1) & ALL_SNT) == 0) {
		current->state = TASK_INTERRUPTIBLE;
		schedule_timeout(char_time);
		if (signal_pending(current))
			break;
		if (timeout && time_after(jiffies, orig_jiffies + timeout))
			break;
	}
	current->state = TASK_RUNNING;
}

/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
static void rs_hangup(struct tty_struct *tty)
{
	struct mac_serial * info = (struct mac_serial *)tty->driver_data;

	if (serial_paranoia_check(info, tty->device, "rs_hangup"))
		return;

	rs_flush_buffer(tty);
	shutdown(info);
	info->event = 0;
	info->count = 0;
	info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CALLOUT_ACTIVE);
	info->tty = 0;
	wake_up_interruptible(&info->open_wait);
}

/*
 * ------------------------------------------------------------
 * rs_open() and friends
 * ------------------------------------------------------------
 */
static int block_til_ready(struct tty_struct *tty, struct file * filp,
			   struct mac_serial *info)
{
	DECLARE_WAITQUEUE(wait,current);
	int		retval;
	int		do_clocal = 0;

	/*
	 * If the device is in the middle of being closed, then block
	 * until it's done, and then try again.
	 */
	if (info->flags & ZILOG_CLOSING) {
		interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
		return ((info->flags & ZILOG_HUP_NOTIFY) ?
			-EAGAIN : -ERESTARTSYS);
#else
		return -EAGAIN;
#endif
	}

	/*
	 * If this is a callout device, then just make sure the normal
	 * device isn't being used.
	 */
	if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
		if (info->flags & ZILOG_NORMAL_ACTIVE)
			return -EBUSY;
		if ((info->flags & ZILOG_CALLOUT_ACTIVE) &&
		    (info->flags & ZILOG_SESSION_LOCKOUT) &&
		    (info->session != current->session))
		    return -EBUSY;
		if ((info->flags & ZILOG_CALLOUT_ACTIVE) &&
		    (info->flags & ZILOG_PGRP_LOCKOUT) &&
		    (info->pgrp != current->pgrp))
		    return -EBUSY;
		info->flags |= ZILOG_CALLOUT_ACTIVE;
		return 0;
	}

	/*
	 * If non-blocking mode is set, or the port is not enabled,
	 * then make the check up front and then exit.
	 */
	if ((filp->f_flags & O_NONBLOCK) ||
	    (tty->flags & (1 << TTY_IO_ERROR))) {
		if (info->flags & ZILOG_CALLOUT_ACTIVE)
			return -EBUSY;
		info->flags |= ZILOG_NORMAL_ACTIVE;
		return 0;
	}

	if (info->flags & ZILOG_CALLOUT_ACTIVE) {
		if (info->normal_termios.c_cflag & CLOCAL)
			do_clocal = 1;
	} else {
		if (tty->termios->c_cflag & CLOCAL)
			do_clocal = 1;
	}

	/*
	 * Block waiting for the carrier detect and the line to become
	 * free (i.e., not in use by the callout).  While we are in
	 * this loop, info->count is dropped by one, so that
	 * rs_close() knows when to free things.  We restore it upon
	 * exit, either normal or abnormal.
	 */
	retval = 0;
	add_wait_queue(&info->open_wait, &wait);
	OPNDBG("block_til_ready before block: ttys%d, count = %d\n",
	       info->line, info->count);
	cli();
	if (!tty_hung_up_p(filp)) 
		info->count--;
	sti();
	info->blocked_open++;
	while (1) {
		cli();
		if (!(info->flags & ZILOG_CALLOUT_ACTIVE) &&
		    (tty->termios->c_cflag & CBAUD) &&
		    !info->is_irda)
			zs_rtsdtr(info, 1);
		sti();
		set_current_state(TASK_INTERRUPTIBLE);
		if (tty_hung_up_p(filp) ||
		    !(info->flags & ZILOG_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
			if (info->flags & ZILOG_HUP_NOTIFY)
				retval = -EAGAIN;
			else
				retval = -ERESTARTSYS;
#else
			retval = -EAGAIN;
#endif
			break;
		}
		if (!(info->flags & ZILOG_CALLOUT_ACTIVE) &&
		    !(info->flags & ZILOG_CLOSING) &&
		    (do_clocal || (read_zsreg(info->zs_channel, 0) & DCD)))
			break;
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		OPNDBG("block_til_ready blocking: ttys%d, count = %d\n",
		       info->line, info->count);
		schedule();
	}
	current->state = TASK_RUNNING;
	remove_wait_queue(&info->open_wait, &wait);
	if (!tty_hung_up_p(filp))
		info->count++;
	info->blocked_open--;
	OPNDBG("block_til_ready after blocking: ttys%d, count = %d\n",
	       info->line, info->count);
	if (retval)
		return retval;
	info->flags |= ZILOG_NORMAL_ACTIVE;
	return 0;
}

/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its ZILOG structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
static int rs_open(struct tty_struct *tty, struct file * filp)
{
	struct mac_serial	*info;
	int 			retval, line;
	unsigned long		page;

	MOD_INC_USE_COUNT;
	line = MINOR(tty->device) - tty->driver.minor_start;
	if ((line < 0) || (line >= zs_channels_found)) {
		MOD_DEC_USE_COUNT;
		return -ENODEV;
	}
	info = zs_soft + line;

#ifdef CONFIG_KGDB
	if (info->kgdb_channel) {
		MOD_DEC_USE_COUNT;
		return -ENODEV;
	}
#endif
	if (serial_paranoia_check(info, tty->device, "rs_open"))
		return -ENODEV;
	OPNDBG("rs_open %s%d, count = %d\n", tty->driver.name, info->line,
	       info->count);

	info->count++;
	tty->driver_data = info;
	info->tty = tty;

	if (!tmp_buf) {
		page = get_free_page(GFP_KERNEL);
		if (!page)
			return -ENOMEM;
		if (tmp_buf)
			free_page(page);
		else
			tmp_buf = (unsigned char *) page;
	}

	/*
	 * If the port is the middle of closing, bail out now
	 */
	if (tty_hung_up_p(filp) ||
	    (info->flags & ZILOG_CLOSING)) {
		if (info->flags & ZILOG_CLOSING)
			interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
		return ((info->flags & ZILOG_HUP_NOTIFY) ?
			-EAGAIN : -ERESTARTSYS);
#else
		return -EAGAIN;
#endif
	}

	/*
	 * Start up serial port
	 */

	retval = startup(info, 1);
	if (retval)
		return retval;

	retval = block_til_ready(tty, filp, info);
	if (retval) {
		OPNDBG("rs_open returning after block_til_ready with %d\n",
			retval);
		return retval;
	}

	if ((info->count == 1) && (info->flags & ZILOG_SPLIT_TERMIOS)) {
		if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
			*tty->termios = info->normal_termios;
		else 
			*tty->termios = info->callout_termios;
		change_speed(info, 0);
	}
#ifdef CONFIG_SERIAL_CONSOLE
	if (sercons.cflag && sercons.index == line) {
		tty->termios->c_cflag = sercons.cflag;
		sercons.cflag = 0;
		change_speed(info, 0);
	}
#endif

	info->session = current->session;
	info->pgrp = current->pgrp;

	OPNDBG("rs_open ttys%d successful...\n", info->line);
	return 0;
}

/* Finally, routines used to initialize the serial driver. */

static void show_serial_version(void)
{
	printk("PowerMac Z8530 serial driver version 2.0\n");
}

/*
 * Initialize one channel, both the mac_serial and mac_zschannel
 * structs.  We use the dev_node field of the mac_serial struct.
 */
static void
chan_init(struct mac_serial *zss, struct mac_zschannel *zs_chan,
	  struct mac_zschannel *zs_chan_a)
{
	struct device_node *ch = zss->dev_node;
	char *conn;
	int len;
	struct slot_names_prop {
		int	count;
		char	name[1];
	} *slots;

	zss->irq = ch->intrs[0].line;
	zss->has_dma = 0;
#if !defined(CONFIG_KGDB) && defined(SUPPORT_SERIAL_DMA)
	if (ch->n_addrs >= 3 && ch->n_intrs == 3)
		zss->has_dma = 1;
#endif
	zss->dma_initted = 0;

	zs_chan->control = (volatile unsigned char *)
		ioremap(ch->addrs[0].address, 0x1000);
	zs_chan->data = zs_chan->control + 0x10;
	spin_lock_init(&zs_chan->lock);
	zs_chan->parent = zss;
	zss->zs_channel = zs_chan;
	zss->zs_chan_a = zs_chan_a;

	/* setup misc varariables */
	zss->kgdb_channel = 0;
	zss->is_cobalt_modem = device_is_compatible(ch, "cobalt");

	/* XXX tested only with wallstreet PowerBook,
	   should do no harm anyway */
	conn = get_property(ch, "AAPL,connector", &len);
	zss->is_irda = conn && (strcmp(conn, "infrared") == 0);
	/* 1999 Powerbook G3 has slot-names property instead */
	slots = (struct slot_names_prop *)get_property(ch, "slot-names", &len);
	if (slots && slots->count > 0 && strcmp(slots->name, "IrDA") == 0)
		zss->is_irda = 1;

	if (zss->has_dma) {
		zss->dma_priv = NULL;
		/* it seems that the last two addresses are the
		   DMA controllers */
		zss->tx_dma = (volatile struct dbdma_regs *)
			ioremap(ch->addrs[ch->n_addrs - 2].address, 0x100);
		zss->rx = (volatile struct mac_dma *)
			ioremap(ch->addrs[ch->n_addrs - 1].address, 0x100);
		zss->tx_dma_irq = ch->intrs[1].line;
		zss->rx_dma_irq = ch->intrs[2].line;
		spin_lock_init(&zss->rx_dma_lock);
	}
}

/* Ask the PROM how many Z8530s we have and initialize their zs_channels */
static void
probe_sccs()
{
	struct device_node *dev, *ch;
	struct mac_serial **pp;
	int n, chip, nchan;
	struct mac_zschannel *zs_chan;
	int chan_a_index;

	n = 0;
	pp = &zs_chain;
	zs_chan = zs_channels;
	for (dev = find_devices("escc"); dev != 0; dev = dev->next) {
		nchan = 0;
		chip = n;
		if (n >= NUM_CHANNELS) {
			printk("Sorry, can't use %s: no more channels\n",
			       dev->full_name);
			continue;
		}
		chan_a_index = 0;
		for (ch = dev->child; ch != 0; ch = ch->sibling) {
			if (nchan >= 2) {
				printk(KERN_WARNING "SCC: Only 2 channels per "
					"chip are supported\n");
				break;
			}
			if (ch->n_addrs < 1 || (ch ->n_intrs < 1)) {
				printk("Can't use %s: %d addrs %d intrs\n",
				      ch->full_name, ch->n_addrs, ch->n_intrs);
				continue;
			}

			/* The channel with the higher address
			   will be the A side. */
			if (nchan > 0 &&
			    ch->addrs[0].address
			    > zs_soft[n-1].dev_node->addrs[0].address)
				chan_a_index = 1;

			/* minimal initialization for now */
			zs_soft[n].dev_node = ch;
			*pp = &zs_soft[n];
			pp = &zs_soft[n].zs_next;
			++nchan;
			++n;
		}
		if (nchan == 0)
			continue;

		/* set up A side */
		chan_init(&zs_soft[chip + chan_a_index], zs_chan, zs_chan);
		++zs_chan;

		/* set up B side, if it exists */
		if (nchan > 1)
			chan_init(&zs_soft[chip + 1 - chan_a_index],
				  zs_chan, zs_chan - 1);
		++zs_chan;
	}
	*pp = 0;

	zs_channels_found = n;
#ifdef CONFIG_PMAC_PBOOK
	if (n)
		pmu_register_sleep_notifier(&serial_sleep_notifier);
#endif /* CONFIG_PMAC_PBOOK */
}

/* rs_init inits the driver */
int macserial_init(void)
{
	int channel, i;
	unsigned long flags;
	struct mac_serial *info;

	/* Setup base handler, and timer table. */
	init_bh(MACSERIAL_BH, do_serial_bh);

	/* Find out how many Z8530 SCCs we have */
	if (zs_chain == 0)
		probe_sccs();

	/* XXX assume it's a powerbook if we have a via-pmu */
	is_powerbook = find_devices("via-pmu") != 0;

	/* Register the interrupt handler for each one */
	save_flags(flags); cli();
	for (i = 0; i < zs_channels_found; ++i) {
		if (zs_soft[i].has_dma) {
			if (request_irq(zs_soft[i].tx_dma_irq, rs_txdma_irq, 0,
					"SCC-txdma", &zs_soft[i]))
				printk(KERN_ERR "macserial: can't get irq %d\n",
				       zs_soft[i].tx_dma_irq);
			disable_irq(zs_soft[i].tx_dma_irq);
			if (request_irq(zs_soft[i].rx_dma_irq, rs_rxdma_irq, 0,
					"SCC-rxdma", &zs_soft[i]))
				printk(KERN_ERR "macserial: can't get irq %d\n",
				       zs_soft[i].rx_dma_irq);
			disable_irq(zs_soft[i].rx_dma_irq);
		}
		if (request_irq(zs_soft[i].irq, rs_interrupt, 0,
				"SCC", &zs_soft[i]))
			printk(KERN_ERR "macserial: can't get irq %d\n",
			       zs_soft[i].irq);
		disable_irq(zs_soft[i].irq);
	}
	restore_flags(flags);

	show_serial_version();

	/* Initialize the tty_driver structure */
	/* Not all of this is exactly right for us. */

	memset(&serial_driver, 0, sizeof(struct tty_driver));
	serial_driver.magic = TTY_DRIVER_MAGIC;
#ifdef CONFIG_DEVFS_FS
	serial_driver.name = "tts/%d";
#else
	serial_driver.name = "ttyS";
#endif /* CONFIG_DEVFS_FS */
	serial_driver.major = TTY_MAJOR;
	serial_driver.minor_start = 64;
	serial_driver.num = zs_channels_found;
	serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
	serial_driver.subtype = SERIAL_TYPE_NORMAL;
	serial_driver.init_termios = tty_std_termios;

	serial_driver.init_termios.c_cflag =
		B38400 | CS8 | CREAD | HUPCL | CLOCAL;
	serial_driver.flags = TTY_DRIVER_REAL_RAW;
	serial_driver.refcount = &serial_refcount;
	serial_driver.table = serial_table;
	serial_driver.termios = serial_termios;
	serial_driver.termios_locked = serial_termios_locked;

	serial_driver.open = rs_open;
	serial_driver.close = rs_close;
	serial_dr