synclink_cs.c

LINUX 2.6.17.4的源码

{
 	unsigned long flags;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("tx_abort(%s)\n", info->device_name);
			
	spin_lock_irqsave(&info->lock,flags);
	if (info->tx_active && info->tx_count &&
	    info->params.mode == MGSL_MODE_HDLC) {
		/* clear data count so FIFO is not filled on next IRQ.
		 * This results in underrun and abort transmission.
		 */
		info->tx_count = info->tx_put = info->tx_get = 0;
		info->tx_aborting = TRUE;
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

static int set_rxenable(MGSLPC_INFO * info, int enable)
{
 	unsigned long flags;
 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("set_rxenable(%s,%d)\n", info->device_name, enable);
			
	spin_lock_irqsave(&info->lock,flags);
	if (enable) {
		if (!info->rx_enabled)
			rx_start(info);
	} else {
		if (info->rx_enabled)
			rx_stop(info);
	}
	spin_unlock_irqrestore(&info->lock,flags);
	return 0;
}

/* wait for specified event to occur
 * 	
 * Arguments:	 	info	pointer to device instance data
 * 			mask	pointer to bitmask of events to wait for
 * Return Value:	0 	if successful and bit mask updated with
 *				of events triggerred,
 * 			otherwise error code
 */
static int wait_events(MGSLPC_INFO * info, int __user *mask_ptr)
{
 	unsigned long flags;
	int s;
	int rc=0;
	struct mgsl_icount cprev, cnow;
	int events;
	int mask;
	struct	_input_signal_events oldsigs, newsigs;
	DECLARE_WAITQUEUE(wait, current);

	COPY_FROM_USER(rc,&mask, mask_ptr, sizeof(int));
	if (rc)
		return  -EFAULT;
		 
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("wait_events(%s,%d)\n", info->device_name, mask);

	spin_lock_irqsave(&info->lock,flags);

	/* return immediately if state matches requested events */
	get_signals(info);
	s = info->serial_signals;
	events = mask &
		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
 		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
	if (events) {
		spin_unlock_irqrestore(&info->lock,flags);
		goto exit;
	}

	/* save current irq counts */
	cprev = info->icount;
	oldsigs = info->input_signal_events;
	
	if ((info->params.mode == MGSL_MODE_HDLC) &&
	    (mask & MgslEvent_ExitHuntMode))
		irq_enable(info, CHA, IRQ_EXITHUNT);
	
	set_current_state(TASK_INTERRUPTIBLE);
	add_wait_queue(&info->event_wait_q, &wait);
	
	spin_unlock_irqrestore(&info->lock,flags);
	
	
	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}
			
		/* get current irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		newsigs = info->input_signal_events;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
		    newsigs.dsr_down == oldsigs.dsr_down &&
		    newsigs.dcd_up   == oldsigs.dcd_up   &&
		    newsigs.dcd_down == oldsigs.dcd_down &&
		    newsigs.cts_up   == oldsigs.cts_up   &&
		    newsigs.cts_down == oldsigs.cts_down &&
		    newsigs.ri_up    == oldsigs.ri_up    &&
		    newsigs.ri_down  == oldsigs.ri_down  &&
		    cnow.exithunt    == cprev.exithunt   &&
		    cnow.rxidle      == cprev.rxidle) {
			rc = -EIO;
			break;
		}

		events = mask &
			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
		if (events)
			break;
		
		cprev = cnow;
		oldsigs = newsigs;
	}
	
	remove_wait_queue(&info->event_wait_q, &wait);
	set_current_state(TASK_RUNNING);

	if (mask & MgslEvent_ExitHuntMode) {
		spin_lock_irqsave(&info->lock,flags);
		if (!waitqueue_active(&info->event_wait_q))
			irq_disable(info, CHA, IRQ_EXITHUNT);
		spin_unlock_irqrestore(&info->lock,flags);
	}
exit:
	if (rc == 0)
		PUT_USER(rc, events, mask_ptr);
	return rc;
}

static int modem_input_wait(MGSLPC_INFO *info,int arg)
{
 	unsigned long flags;
	int rc;
	struct mgsl_icount cprev, cnow;
	DECLARE_WAITQUEUE(wait, current);

	/* save current irq counts */
	spin_lock_irqsave(&info->lock,flags);
	cprev = info->icount;
	add_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_INTERRUPTIBLE);
	spin_unlock_irqrestore(&info->lock,flags);

	for(;;) {
		schedule();
		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			break;
		}

		/* get new irq counts */
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		set_current_state(TASK_INTERRUPTIBLE);
		spin_unlock_irqrestore(&info->lock,flags);

		/* if no change, wait aborted for some reason */
		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
			rc = -EIO;
			break;
		}

		/* check for change in caller specified modem input */
		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
			rc = 0;
			break;
		}

		cprev = cnow;
	}
	remove_wait_queue(&info->status_event_wait_q, &wait);
	set_current_state(TASK_RUNNING);
	return rc;
}

/* return the state of the serial control and status signals
 */
static int tiocmget(struct tty_struct *tty, struct file *file)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned int result;
 	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
 	get_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	result = ((info->serial_signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
		((info->serial_signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
		((info->serial_signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
		((info->serial_signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
		((info->serial_signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
		((info->serial_signals & SerialSignal_CTS) ? TIOCM_CTS:0);

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):%s tiocmget() value=%08X\n",
			 __FILE__,__LINE__, info->device_name, result );
	return result;
}

/* set modem control signals (DTR/RTS)
 */
static int tiocmset(struct tty_struct *tty, struct file *file,
		    unsigned int set, unsigned int clear)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
 	unsigned long flags;

	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):%s tiocmset(%x,%x)\n",
			__FILE__,__LINE__,info->device_name, set, clear);

	if (set & TIOCM_RTS)
		info->serial_signals |= SerialSignal_RTS;
	if (set & TIOCM_DTR)
		info->serial_signals |= SerialSignal_DTR;
	if (clear & TIOCM_RTS)
		info->serial_signals &= ~SerialSignal_RTS;
	if (clear & TIOCM_DTR)
		info->serial_signals &= ~SerialSignal_DTR;

	spin_lock_irqsave(&info->lock,flags);
 	set_signals(info);
	spin_unlock_irqrestore(&info->lock,flags);

	return 0;
}

/* Set or clear transmit break condition
 *
 * Arguments:		tty		pointer to tty instance data
 *			break_state	-1=set break condition, 0=clear
 */
static void mgslpc_break(struct tty_struct *tty, int break_state)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_break(%s,%d)\n",
			 __FILE__,__LINE__, info->device_name, break_state);
			 
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_break"))
		return;

	spin_lock_irqsave(&info->lock,flags);
 	if (break_state == -1)
		set_reg_bits(info, CHA+DAFO, BIT6);
	else 
		clear_reg_bits(info, CHA+DAFO, BIT6);
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Service an IOCTL request
 * 	
 * Arguments:
 * 
 * 	tty	pointer to tty instance data
 * 	file	pointer to associated file object for device
 * 	cmd	IOCTL command code
 * 	arg	command argument/context
 * 	
 * Return Value:	0 if success, otherwise error code
 */
static int mgslpc_ioctl(struct tty_struct *tty, struct file * file,
			unsigned int cmd, unsigned long arg)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_ioctl %s cmd=%08X\n", __FILE__,__LINE__,
			info->device_name, cmd );
	
	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_ioctl"))
		return -ENODEV;

	if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
	    (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
		if (tty->flags & (1 << TTY_IO_ERROR))
		    return -EIO;
	}

	return ioctl_common(info, cmd, arg);
}

int ioctl_common(MGSLPC_INFO *info, unsigned int cmd, unsigned long arg)
{
	int error;
	struct mgsl_icount cnow;	/* kernel counter temps */
	struct serial_icounter_struct __user *p_cuser;	/* user space */
	void __user *argp = (void __user *)arg;
	unsigned long flags;
	
	switch (cmd) {
	case MGSL_IOCGPARAMS:
		return get_params(info, argp);
	case MGSL_IOCSPARAMS:
		return set_params(info, argp);
	case MGSL_IOCGTXIDLE:
		return get_txidle(info, argp);
	case MGSL_IOCSTXIDLE:
		return set_txidle(info, (int)arg);
	case MGSL_IOCGIF:
		return get_interface(info, argp);
	case MGSL_IOCSIF:
		return set_interface(info,(int)arg);
	case MGSL_IOCTXENABLE:
		return set_txenable(info,(int)arg);
	case MGSL_IOCRXENABLE:
		return set_rxenable(info,(int)arg);
	case MGSL_IOCTXABORT:
		return tx_abort(info);
	case MGSL_IOCGSTATS:
		return get_stats(info, argp);
	case MGSL_IOCWAITEVENT:
		return wait_events(info, argp);
	case TIOCMIWAIT:
		return modem_input_wait(info,(int)arg);
	case TIOCGICOUNT:
		spin_lock_irqsave(&info->lock,flags);
		cnow = info->icount;
		spin_unlock_irqrestore(&info->lock,flags);
		p_cuser = argp;
		PUT_USER(error,cnow.cts, &p_cuser->cts);
		if (error) return error;
		PUT_USER(error,cnow.dsr, &p_cuser->dsr);
		if (error) return error;
		PUT_USER(error,cnow.rng, &p_cuser->rng);
		if (error) return error;
		PUT_USER(error,cnow.dcd, &p_cuser->dcd);
		if (error) return error;
		PUT_USER(error,cnow.rx, &p_cuser->rx);
		if (error) return error;
		PUT_USER(error,cnow.tx, &p_cuser->tx);
		if (error) return error;
		PUT_USER(error,cnow.frame, &p_cuser->frame);
		if (error) return error;
		PUT_USER(error,cnow.overrun, &p_cuser->overrun);
		if (error) return error;
		PUT_USER(error,cnow.parity, &p_cuser->parity);
		if (error) return error;
		PUT_USER(error,cnow.brk, &p_cuser->brk);
		if (error) return error;
		PUT_USER(error,cnow.buf_overrun, &p_cuser->buf_overrun);
		if (error) return error;
		return 0;
	default:
		return -ENOIOCTLCMD;
	}
	return 0;
}

/* Set new termios settings
 * 	
 * Arguments:
 * 
 * 	tty		pointer to tty structure
 * 	termios		pointer to buffer to hold returned old termios
 */
static void mgslpc_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
	MGSLPC_INFO *info = (MGSLPC_INFO *)tty->driver_data;
	unsigned long flags;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_set_termios %s\n", __FILE__,__LINE__,
			tty->driver->name );
	
	/* just return if nothing has changed */
	if ((tty->termios->c_cflag == old_termios->c_cflag)
	    && (RELEVANT_IFLAG(tty->termios->c_iflag) 
		== RELEVANT_IFLAG(old_termios->c_iflag)))
	  return;

	mgslpc_change_params(info);

	/* Handle transition to B0 status */
	if (old_termios->c_cflag & CBAUD &&
	    !(tty->termios->c_cflag & CBAUD)) {
		info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
		spin_lock_irqsave(&info->lock,flags);
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
	
	/* Handle transition away from B0 status */
	if (!(old_termios->c_cflag & CBAUD) &&
	    tty->termios->c_cflag & CBAUD) {
		info->serial_signals |= SerialSignal_DTR;
 		if (!(tty->termios->c_cflag & CRTSCTS) || 
 		    !test_bit(TTY_THROTTLED, &tty->flags)) {
			info->serial_signals |= SerialSignal_RTS;
 		}
		spin_lock_irqsave(&info->lock,flags);
	 	set_signals(info);
		spin_unlock_irqrestore(&info->lock,flags);
	}
	
	/* Handle turning off CRTSCTS */
	if (old_termios->c_cflag & CRTSCTS &&
	    !(tty->termios->c_cflag & CRTSCTS)) {
		tty->hw_stopped = 0;
		tx_release(tty);
	}
}

static void mgslpc_close(struct tty_struct *tty, struct file * filp)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)tty->driver_data;

	if (mgslpc_paranoia_check(info, tty->name, "mgslpc_close"))
		return;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_close(%s) entry, count=%d\n",
			 __FILE__,__LINE__, info->device_name, info->count);
			 
	if (!info->count)
		return;

	if (tty_hung_up_p(filp))
		goto cleanup;
			
	if ((tty->count == 1) && (info->count != 1)) {
		/*
		 * tty->count is 1 and the tty structure will be freed.
		 * info->count should be one in this case.
		 * if it's not, correct it so that the port is shutdown.
		 */
		printk("mgslpc_close: bad refcount; tty->count is 1, "
		       "info->count is %d\n", info->count);
		info->count = 1;
	}
	
	info->count--;
	
	/* if at least one open remaining, leave hardware active */
	if (info->count)
		goto cleanup;
	
	info->flags |= ASYNC_CLOSING;
	
	/* set tty->closing to notify line discipline to 
	 * only process XON/XOFF characters. Only the N_TTY
	 * discipline appears to use this (ppp does not).
	 */
	tty->closing = 1;
	
	/* wait for transmit data to clear all layers */
	
	if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE) {
		if (debug_level >= DEBUG_LEVEL_INFO)
			printk("%s(%d):mgslpc_close(%s) calling tty_wait_until_sent\n",
				 __FILE__,__LINE__, info->device_name );
		tty_wait_until_sent(tty, info->closing_wait);
	}
		
 	if (info->flags & ASYNC_INITIALIZED)
 		mgslpc_wait_until_sent(tty, info->timeout);

	if (tty->driver->flush_buffer)
		tty->driver->flush_buffer(tty);

	ldisc_flush_buff