synclink.c

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static int __init synclink_init_one (struct pci_dev *dev,
				     const struct pci_device_id *ent);
static void __exit synclink_remove_one (struct pci_dev *dev);

static struct pci_device_id synclink_pci_tbl[] __devinitdata = {
	{ PCI_VENDOR_ID_MICROGATE, PCI_DEVICE_ID_MICROGATE_USC, PCI_ANY_ID, PCI_ANY_ID, },
	{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, synclink_pci_tbl);

static struct pci_driver synclink_pci_driver = {
	name:		"synclink",
	id_table:	synclink_pci_tbl,
	probe:		synclink_init_one,
	remove:		synclink_remove_one,
};

static struct tty_driver serial_driver, callout_driver;
static int serial_refcount;

/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256


static void mgsl_change_params(struct mgsl_struct *info);
static void mgsl_wait_until_sent(struct tty_struct *tty, int timeout);

static struct tty_struct *serial_table[MAX_TOTAL_DEVICES];
static struct termios *serial_termios[MAX_TOTAL_DEVICES];
static struct termios *serial_termios_locked[MAX_TOTAL_DEVICES];

#ifndef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))
#endif

/*
 * 1st function defined in .text section. Calling this function in
 * init_module() followed by a breakpoint allows a remote debugger
 * (gdb) to get the .text address for the add-symbol-file command.
 * This allows remote debugging of dynamically loadable modules.
 */
void* mgsl_get_text_ptr(void);
void* mgsl_get_text_ptr() {return mgsl_get_text_ptr;}

/*
 * tmp_buf is used as a temporary buffer by mgsl_write.  We need to
 * lock it in case the COPY_FROM_USER blocks while swapping in a page,
 * and some other program tries to do a serial write at the same time.
 * Since the lock will only come under contention when the system is
 * swapping and available memory is low, it makes sense to share one
 * buffer across all the serial ioports, since it significantly saves
 * memory if large numbers of serial ports are open.
 */
static unsigned char *tmp_buf;
static DECLARE_MUTEX(tmp_buf_sem);

static inline int mgsl_paranoia_check(struct mgsl_struct *info,
					kdev_t device, const char *routine)
{
#ifdef MGSL_PARANOIA_CHECK
	static const char *badmagic =
		"Warning: bad magic number for mgsl struct (%s) in %s\n";
	static const char *badinfo =
		"Warning: null mgsl_struct for (%s) in %s\n";

	if (!info) {
		printk(badinfo, kdevname(device), routine);
		return 1;
	}
	if (info->magic != MGSL_MAGIC) {
		printk(badmagic, kdevname(device), routine);
		return 1;
	}
#endif
	return 0;
}

/* mgsl_stop()		throttle (stop) transmitter
 * 	
 * Arguments:		tty	pointer to tty info structure
 * Return Value:	None
 */
static void mgsl_stop(struct tty_struct *tty)
{
	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
	unsigned long flags;
	
	if (mgsl_paranoia_check(info, tty->device, "mgsl_stop"))
		return;
	
	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk("mgsl_stop(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->irq_spinlock,flags);
	if (info->tx_enabled)
	 	usc_stop_transmitter(info);
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
	
}	/* end of mgsl_stop() */

/* mgsl_start()		release (start) transmitter
 * 	
 * Arguments:		tty	pointer to tty info structure
 * Return Value:	None
 */
static void mgsl_start(struct tty_struct *tty)
{
	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
	unsigned long flags;
	
	if (mgsl_paranoia_check(info, tty->device, "mgsl_start"))
		return;
	
	if ( debug_level >= DEBUG_LEVEL_INFO )
		printk("mgsl_start(%s)\n",info->device_name);	
		
	spin_lock_irqsave(&info->irq_spinlock,flags);
	if (!info->tx_enabled)
	 	usc_start_transmitter(info);
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
	
}	/* end of mgsl_start() */

/*
 * Bottom half work queue access functions
 */

/* mgsl_bh_action()	Return next bottom half action to perform.
 * Return Value:	BH action code or 0 if nothing to do.
 */
int mgsl_bh_action(struct mgsl_struct *info)
{
	unsigned long flags;
	int rc = 0;
	
	spin_lock_irqsave(&info->irq_spinlock,flags);

	if (info->pending_bh & BH_RECEIVE) {
		info->pending_bh &= ~BH_RECEIVE;
		rc = BH_RECEIVE;
	} else if (info->pending_bh & BH_TRANSMIT) {
		info->pending_bh &= ~BH_TRANSMIT;
		rc = BH_TRANSMIT;
	} else if (info->pending_bh & BH_STATUS) {
		info->pending_bh &= ~BH_STATUS;
		rc = BH_STATUS;
	}

	if (!rc) {
		/* Mark BH routine as complete */
		info->bh_running   = 0;
		info->bh_requested = 0;
	}
	
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
	
	return rc;
}

/*
 * 	Perform bottom half processing of work items queued by ISR.
 */
void mgsl_bh_handler(void* Context)
{
	struct mgsl_struct *info = (struct mgsl_struct*)Context;
	int action;

	if (!info)
		return;
		
	if ( debug_level >= DEBUG_LEVEL_BH )
		printk( "%s(%d):mgsl_bh_handler(%s) entry\n",
			__FILE__,__LINE__,info->device_name);
	
	info->bh_running = 1;

	while((action = mgsl_bh_action(info)) != 0) {
	
		/* Process work item */
		if ( debug_level >= DEBUG_LEVEL_BH )
			printk( "%s(%d):mgsl_bh_handler() work item action=%d\n",
				__FILE__,__LINE__,action);

		switch (action) {
		
		case BH_RECEIVE:
			mgsl_bh_receive(info);
			break;
		case BH_TRANSMIT:
			mgsl_bh_transmit(info);
			break;
		case BH_STATUS:
			mgsl_bh_status(info);
			break;
		default:
			/* unknown work item ID */
			printk("Unknown work item ID=%08X!\n", action);
			break;
		}
	}

	if ( debug_level >= DEBUG_LEVEL_BH )
		printk( "%s(%d):mgsl_bh_handler(%s) exit\n",
			__FILE__,__LINE__,info->device_name);
}

void mgsl_bh_receive(struct mgsl_struct *info)
{
	if ( debug_level >= DEBUG_LEVEL_BH )
		printk( "%s(%d):mgsl_bh_receive(%s)\n",
			__FILE__,__LINE__,info->device_name);
	
	while( mgsl_get_rx_frame(info) );
}

void mgsl_bh_transmit(struct mgsl_struct *info)
{
	struct tty_struct *tty = info->tty;
	unsigned long flags;
	
	if ( debug_level >= DEBUG_LEVEL_BH )
		printk( "%s(%d):mgsl_bh_transmit() entry on %s\n",
			__FILE__,__LINE__,info->device_name);

	if (tty) {
		if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
		    tty->ldisc.write_wakeup) {
			if ( debug_level >= DEBUG_LEVEL_BH )
				printk( "%s(%d):calling ldisc.write_wakeup on %s\n",
					__FILE__,__LINE__,info->device_name);
			(tty->ldisc.write_wakeup)(tty);
		}
		wake_up_interruptible(&tty->write_wait);
	}

	/* if transmitter idle and loopmode_send_done_requested
	 * then start echoing RxD to TxD
	 */
	spin_lock_irqsave(&info->irq_spinlock,flags);
 	if ( !info->tx_active && info->loopmode_send_done_requested )
 		usc_loopmode_send_done( info );
	spin_unlock_irqrestore(&info->irq_spinlock,flags);
}

void mgsl_bh_status(struct mgsl_struct *info)
{
	if ( debug_level >= DEBUG_LEVEL_BH )
		printk( "%s(%d):mgsl_bh_status() entry on %s\n",
			__FILE__,__LINE__,info->device_name);

	info->ri_chkcount = 0;
	info->dsr_chkcount = 0;
	info->dcd_chkcount = 0;
	info->cts_chkcount = 0;
}

/* mgsl_isr_receive_status()
 * 
 *	Service a receive status interrupt. The type of status
 *	interrupt is indicated by the state of the RCSR.
 *	This is only used for HDLC mode.
 *
 * Arguments:		info	pointer to device instance data
 * Return Value:	None
 */
void mgsl_isr_receive_status( struct mgsl_struct *info )
{
	u16 status = usc_InReg( info, RCSR );

	if ( debug_level >= DEBUG_LEVEL_ISR )	
		printk("%s(%d):mgsl_isr_receive_status status=%04X\n",
			__FILE__,__LINE__,status);
			
 	if ( (status & RXSTATUS_ABORT_RECEIVED) && 
		info->loopmode_insert_requested &&
 		usc_loopmode_active(info) )
 	{
		++info->icount.rxabort;
	 	info->loopmode_insert_requested = FALSE;
 
 		/* clear CMR:13 to start echoing RxD to TxD */
		info->cmr_value &= ~BIT13;
 		usc_OutReg(info, CMR, info->cmr_value);
 
		/* disable received abort irq (no longer required) */
	 	usc_OutReg(info, RICR,
 			(usc_InReg(info, RICR) & ~RXSTATUS_ABORT_RECEIVED));
 	}

	if (status & (RXSTATUS_EXITED_HUNT + RXSTATUS_IDLE_RECEIVED)) {
		if (status & RXSTATUS_EXITED_HUNT)
			info->icount.exithunt++;
		if (status & RXSTATUS_IDLE_RECEIVED)
			info->icount.rxidle++;
		wake_up_interruptible(&info->event_wait_q);
	}

	if (status & RXSTATUS_OVERRUN){
		info->icount.rxover++;
		usc_process_rxoverrun_sync( info );
	}

	usc_ClearIrqPendingBits( info, RECEIVE_STATUS );
	usc_UnlatchRxstatusBits( info, status );

}	/* end of mgsl_isr_receive_status() */

/* mgsl_isr_transmit_status()
 * 
 * 	Service a transmit status interrupt
 *	HDLC mode :end of transmit frame
 *	Async mode:all data is sent
 * 	transmit status is indicated by bits in the TCSR.
 * 
 * Arguments:		info	       pointer to device instance data
 * Return Value:	None
 */
void mgsl_isr_transmit_status( struct mgsl_struct *info )
{
	u16 status = usc_InReg( info, TCSR );

	if ( debug_level >= DEBUG_LEVEL_ISR )	
		printk("%s(%d):mgsl_isr_transmit_status status=%04X\n",
			__FILE__,__LINE__,status);
	
	usc_ClearIrqPendingBits( info, TRANSMIT_STATUS );
	usc_UnlatchTxstatusBits( info, status );
	
	if ( status & (TXSTATUS_UNDERRUN | TXSTATUS_ABORT_SENT) )
	{
		/* finished sending HDLC abort. This may leave	*/
		/* the TxFifo with data from the aborted frame	*/
		/* so purge the TxFifo. Also shutdown the DMA	*/
		/* channel in case there is data remaining in 	*/
		/* the DMA buffer				*/
 		usc_DmaCmd( info, DmaCmd_ResetTxChannel );
 		usc_RTCmd( info, RTCmd_PurgeTxFifo );
	}
 
	if ( status & TXSTATUS_EOF_SENT )
		info->icount.txok++;
	else if ( status & TXSTATUS_UNDERRUN )
		info->icount.txunder++;
	else if ( status & TXSTATUS_ABORT_SENT )
		info->icount.txabort++;
	else
		info->icount.txunder++;
			
	info->tx_active = 0;
	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
	del_timer(&info->tx_timer);	
	
	if ( info->drop_rts_on_tx_done ) {
		usc_get_serial_signals( info );
		if ( info->serial_signals & SerialSignal_RTS ) {
			info->serial_signals &= ~SerialSignal_RTS;
			usc_set_serial_signals( info );
		}
		info->drop_rts_on_tx_done = 0;
	}

#ifdef CONFIG_SYNCLINK_SYNCPPP	
	if (info->netcount)
		mgsl_sppp_tx_done(info);
	else 
#endif
	{
		if (info->tty->stopped || info->tty->hw_stopped) {
			usc_stop_transmitter(info);
			return;
		}
		info->pending_bh |= BH_TRANSMIT;
	}

}	/* end of mgsl_isr_transmit_status() */

/* mgsl_isr_io_pin()
 * 
 * 	Service an Input/Output pin interrupt. The type of
 * 	interrupt is indicated by bits in the MISR
 * 	
 * Arguments:		info	       pointer to device instance data
 * Return Value:	None
 */
void mgsl_isr_io_pin( struct mgsl_struct *info )
{
 	struct	mgsl_icount *icount;
	u16 status = usc_InReg( info, MISR );

	if ( debug_level >= DEBUG_LEVEL_ISR )	
		printk("%s(%d):mgsl_isr_io_pin status=%04X\n",
			__FILE__,__LINE__,status);
			
	usc_ClearIrqPendingBits( info, IO_PIN );
	usc_UnlatchIostatusBits( info, status );

	if (status & (MISCSTATUS_CTS_LATCHED | MISCSTATUS_DCD_LATCHED |
	              MISCSTATUS_DSR_LATCHED | MISCSTATUS_RI_LATCHED) ) {
		icount = &info->icount;
		/* update input line counters */
		if (status & MISCSTATUS_RI_LATCHED) {
			if ((info->ri_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
				usc_DisablestatusIrqs(info,SICR_RI);
			icount->rng++;
			if ( status & MISCSTATUS_RI )
				info->input_signal_events.ri_up++;	
			else
				info->input_signal_events.ri_down++;	
		}
		if (status & MISCSTATUS_DSR_LATCHED) {
			if ((info->dsr_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
				usc_DisablestatusIrqs(info,SICR_DSR);
			icount->dsr++;
			if ( status & MISCSTATUS_DSR )
				info->input_signal_events.dsr_up++;
			else
				info->input_signal_events.dsr_down++;
		}
		if (status & MISCSTATUS_DCD_LATCHED) {
			if ((info->dcd_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
				usc_DisablestatusIrqs(info,SICR_DCD);
			icount->dcd++;
			if (status & MISCSTATUS_DCD) {
				info->input_signal_events.dcd_up++;
#ifdef CONFIG_SYNCLINK_SYNCPPP	
				if (info->netcount)
					sppp_reopen(info->netdev);
#endif
			} else
				info->input_signal_events.dcd_down++;
#ifdef CONFIG_HARD_PPS
			if ((info->flags & ASYNC_HARDPPS_CD) &&
			    (status & MISCSTATUS_DCD_LATCHED))
				hardpps();
#endif
		}
		if (status & MISCSTATUS_CTS_LATCHED)
		{
			if ((info->cts_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
				usc_DisablestatusIrqs(info,SICR_CTS);
			icount->cts++;
			if ( status & MISCSTATUS_CTS )
				info->input_signal_events.cts_up++;