ip2main.c

来自「LINUX 2.6.17.4的源码」· C语言 代码 · 共 1,945 行 · 第 1/5 页

		i2ServiceBoard( pB );
		if( pB->i2eUsingIrq ) {
//			Re-enable his interrupts
			iiEnableMailIrq(pB);
		}
	}
}


/******************************************************************************/
/* Function:   ip2_interrupt(int irq, void *dev_id, struct pt_regs * regs)    */
/* Parameters: irq - interrupt number                                         */
/*             pointer to optional device ID structure                        */
/*             pointer to register structure                                  */
/* Returns:    Nothing                                                        */
/*                                                                            */
/* Description:                                                               */
/*                                                                            */
/*	Our task here is simply to identify each board which needs servicing. */
/*	If we are queuing then, queue it to be serviced, and disable its irq  */
/*	mask otherwise process the board directly.                            */
/*                                                                            */
/*	We could queue by IRQ but that just complicates things on both ends   */
/*	with very little gain in performance (how many instructions does      */
/*	it take to iterate on the immediate queue).                           */
/*                                                                            */
/*                                                                            */
/******************************************************************************/
static irqreturn_t
ip2_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
	int i;
	i2eBordStrPtr  pB;
	int handled = 0;

	ip2trace (ITRC_NO_PORT, ITRC_INTR, 99, 1, irq );

	/* Service just the boards on the list using this irq */
	for( i = 0; i < i2nBoards; ++i ) {
		pB = i2BoardPtrTable[i];

//		Only process those boards which match our IRQ.
//			IRQ = 0 for polled boards, we won't poll "IRQ" boards

		if ( pB && (pB->i2eUsingIrq == irq) ) {
			handled = 1;
#ifdef USE_IQI

		    if (NO_MAIL_HERE != ( pB->i2eStartMail = iiGetMail(pB))) {
//			Disable his interrupt (will be enabled when serviced)
//			This is mostly to protect from reentrancy.
			iiDisableMailIrq(pB);

//			Park the board on the immediate queue for processing.
			schedule_work(&pB->tqueue_interrupt);

//			Make sure the immediate queue is flagged to fire.
		    }
#else
//		We are using immediate servicing here.  This sucks and can
//		cause all sorts of havoc with ppp and others.  The failsafe
//		check on iiSendPendingMail could also throw a hairball.
			i2ServiceBoard( pB );
#endif /* USE_IQI */
		}
	}

	++irq_counter;

	ip2trace (ITRC_NO_PORT, ITRC_INTR, ITRC_RETURN, 0 );
	return IRQ_RETVAL(handled);
}

/******************************************************************************/
/* Function:   ip2_poll(unsigned long arg)                                    */
/* Parameters: ?                                                              */
/* Returns:    Nothing                                                        */
/*                                                                            */
/* Description:                                                               */
/* This function calls the library routine i2ServiceBoard for each board in   */
/* the board table. This is used instead of the interrupt routine when polled */
/* mode is specified.                                                         */
/******************************************************************************/
static void
ip2_poll(unsigned long arg)
{
	ip2trace (ITRC_NO_PORT, ITRC_INTR, 100, 0 );

	TimerOn = 0; // it's the truth but not checked in service

	// Just polled boards, IRQ = 0 will hit all non-interrupt boards.
	// It will NOT poll boards handled by hard interrupts.
	// The issue of queued BH interrups is handled in ip2_interrupt().
	ip2_interrupt(0, NULL, NULL);

	PollTimer.expires = POLL_TIMEOUT;
	add_timer( &PollTimer );
	TimerOn = 1;

	ip2trace (ITRC_NO_PORT, ITRC_INTR, ITRC_RETURN, 0 );
}

static void do_input(void *p)
{
	i2ChanStrPtr pCh = p;
	unsigned long flags;

	ip2trace(CHANN, ITRC_INPUT, 21, 0 );

	// Data input
	if ( pCh->pTTY != NULL ) {
		READ_LOCK_IRQSAVE(&pCh->Ibuf_spinlock,flags)
		if (!pCh->throttled && (pCh->Ibuf_stuff != pCh->Ibuf_strip)) {
			READ_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags)
			i2Input( pCh );
		} else
			READ_UNLOCK_IRQRESTORE(&pCh->Ibuf_spinlock,flags)
	} else {
		ip2trace(CHANN, ITRC_INPUT, 22, 0 );

		i2InputFlush( pCh );
	}
}

// code duplicated from n_tty (ldisc)
static inline void  isig(int sig, struct tty_struct *tty, int flush)
{
	if (tty->pgrp > 0)
		kill_pg(tty->pgrp, sig, 1);
	if (flush || !L_NOFLSH(tty)) {
		if ( tty->ldisc.flush_buffer )  
			tty->ldisc.flush_buffer(tty);
		i2InputFlush( tty->driver_data );
	}
}

static void do_status(void *p)
{
	i2ChanStrPtr pCh = p;
	int status;

	status =  i2GetStatus( pCh, (I2_BRK|I2_PAR|I2_FRA|I2_OVR) );

	ip2trace (CHANN, ITRC_STATUS, 21, 1, status );

	if (pCh->pTTY && (status & (I2_BRK|I2_PAR|I2_FRA|I2_OVR)) ) {
		if ( (status & I2_BRK) ) {
			// code duplicated from n_tty (ldisc)
			if (I_IGNBRK(pCh->pTTY))
				goto skip_this;
			if (I_BRKINT(pCh->pTTY)) {
				isig(SIGINT, pCh->pTTY, 1);
				goto skip_this;
			}
			wake_up_interruptible(&pCh->pTTY->read_wait);
		}
#ifdef NEVER_HAPPENS_AS_SETUP_XXX
	// and can't work because we don't know the_char
	// as the_char is reported on a separate path
	// The intelligent board does this stuff as setup
	{
	char brkf = TTY_NORMAL;
	unsigned char brkc = '\0';
	unsigned char tmp;
		if ( (status & I2_BRK) ) {
			brkf = TTY_BREAK;
			brkc = '\0';
		} 
		else if (status & I2_PAR) {
			brkf = TTY_PARITY;
			brkc = the_char;
		} else if (status & I2_FRA) {
			brkf = TTY_FRAME;
			brkc = the_char;
		} else if (status & I2_OVR) {
			brkf = TTY_OVERRUN;
			brkc = the_char;
		}
		tmp = pCh->pTTY->real_raw;
		pCh->pTTY->real_raw = 0;
		pCh->pTTY->ldisc.receive_buf( pCh->pTTY, &brkc, &brkf, 1 );
		pCh->pTTY->real_raw = tmp;
	}
#endif /* NEVER_HAPPENS_AS_SETUP_XXX */
	}
skip_this:

	if ( status & (I2_DDCD | I2_DDSR | I2_DCTS | I2_DRI) ) {
		wake_up_interruptible(&pCh->delta_msr_wait);

		if ( (pCh->flags & ASYNC_CHECK_CD) && (status & I2_DDCD) ) {
			if ( status & I2_DCD ) {
				if ( pCh->wopen ) {
					wake_up_interruptible ( &pCh->open_wait );
				}
			} else {
				if (pCh->pTTY &&  (!(pCh->pTTY->termios->c_cflag & CLOCAL)) ) {
					tty_hangup( pCh->pTTY );
				}
			}
		}
	}

	ip2trace (CHANN, ITRC_STATUS, 26, 0 );
}

/******************************************************************************/
/* Device Open/Close/Ioctl Entry Point Section                                */
/******************************************************************************/

/******************************************************************************/
/* Function:   open_sanity_check()                                            */
/* Parameters: Pointer to tty structure                                       */
/*             Pointer to file structure                                      */
/* Returns:    Success or failure                                             */
/*                                                                            */
/* Description:                                                               */
/* Verifies the structure magic numbers and cross links.                      */
/******************************************************************************/
#ifdef IP2DEBUG_OPEN
static void 
open_sanity_check( i2ChanStrPtr pCh, i2eBordStrPtr pBrd )
{
	if ( pBrd->i2eValid != I2E_MAGIC ) {
		printk(KERN_ERR "IP2: invalid board structure\n" );
	} else if ( pBrd != pCh->pMyBord ) {
		printk(KERN_ERR "IP2: board structure pointer mismatch (%p)\n",
			 pCh->pMyBord );
	} else if ( pBrd->i2eChannelCnt < pCh->port_index ) {
		printk(KERN_ERR "IP2: bad device index (%d)\n", pCh->port_index );
	} else if (&((i2ChanStrPtr)pBrd->i2eChannelPtr)[pCh->port_index] != pCh) {
	} else {
		printk(KERN_INFO "IP2: all pointers check out!\n" );
	}
}
#endif


/******************************************************************************/
/* Function:   ip2_open()                                                     */
/* Parameters: Pointer to tty structure                                       */
/*             Pointer to file structure                                      */
/* Returns:    Success or failure                                             */
/*                                                                            */
/* Description: (MANDATORY)                                                   */
/* A successful device open has to run a gauntlet of checks before it         */
/* completes. After some sanity checking and pointer setup, the function      */
/* blocks until all conditions are satisfied. It then initialises the port to */
/* the default characteristics and returns.                                   */
/******************************************************************************/
static int
ip2_open( PTTY tty, struct file *pFile )
{
	wait_queue_t wait;
	int rc = 0;
	int do_clocal = 0;
	i2ChanStrPtr  pCh = DevTable[tty->index];

	ip2trace (tty->index, ITRC_OPEN, ITRC_ENTER, 0 );

	if ( pCh == NULL ) {
		return -ENODEV;
	}
	/* Setup pointer links in device and tty structures */
	pCh->pTTY = tty;
	tty->driver_data = pCh;

#ifdef IP2DEBUG_OPEN
	printk(KERN_DEBUG \
			"IP2:open(tty=%p,pFile=%p):dev=%s,ch=%d,idx=%d\n",
	       tty, pFile, tty->name, pCh->infl.hd.i2sChannel, pCh->port_index);
	open_sanity_check ( pCh, pCh->pMyBord );
#endif

	i2QueueCommands(PTYPE_INLINE, pCh, 100, 3, CMD_DTRUP,CMD_RTSUP,CMD_DCD_REP);
	pCh->dataSetOut |= (I2_DTR | I2_RTS);
	serviceOutgoingFifo( pCh->pMyBord );

	/* Block here until the port is ready (per serial and istallion) */
	/*
	 * 1. If the port is in the middle of closing wait for the completion
	 *    and then return the appropriate error.
	 */
	init_waitqueue_entry(&wait, current);
	add_wait_queue(&pCh->close_wait, &wait);
	set_current_state( TASK_INTERRUPTIBLE );

	if ( tty_hung_up_p(pFile) || ( pCh->flags & ASYNC_CLOSING )) {
		if ( pCh->flags & ASYNC_CLOSING ) {
			schedule();
		}
		if ( tty_hung_up_p(pFile) ) {
			set_current_state( TASK_RUNNING );
			remove_wait_queue(&pCh->close_wait, &wait);
			return( pCh->flags & ASYNC_HUP_NOTIFY ) ? -EAGAIN : -ERESTARTSYS;
		}
	}
	set_current_state( TASK_RUNNING );
	remove_wait_queue(&pCh->close_wait, &wait);

	/*
	 * 3. Handle a non-blocking open of a normal port.
	 */
	if ( (pFile->f_flags & O_NONBLOCK) || (tty->flags & (1<<TTY_IO_ERROR) )) {
		pCh->flags |= ASYNC_NORMAL_ACTIVE;
		goto noblock;
	}
	/*
	 * 4. Now loop waiting for the port to be free and carrier present
	 *    (if required).
	 */
	if ( tty->termios->c_cflag & CLOCAL )
		do_clocal = 1;

#ifdef IP2DEBUG_OPEN
	printk(KERN_DEBUG "OpenBlock: do_clocal = %d\n", do_clocal);
#endif

	++pCh->wopen;

	init_waitqueue_entry(&wait, current);
	add_wait_queue(&pCh->open_wait, &wait);

	for(;;) {
		i2QueueCommands(PTYPE_INLINE, pCh, 100, 2, CMD_DTRUP, CMD_RTSUP);
		pCh->dataSetOut |= (I2_DTR | I2_RTS);
		set_current_state( TASK_INTERRUPTIBLE );
		serviceOutgoingFifo( pCh->pMyBord );
		if ( tty_hung_up_p(pFile) ) {
			set_current_state( TASK_RUNNING );
			remove_wait_queue(&pCh->open_wait, &wait);
			return ( pCh->flags & ASYNC_HUP_NOTIFY ) ? -EBUSY : -ERESTARTSYS;
		}
		if (!(pCh->flags & ASYNC_CLOSING) && 
				(do_clocal || (pCh->dataSetIn & I2_DCD) )) {
			rc = 0;
			break;
		}

#ifdef IP2DEBUG_OPEN
		printk(KERN_DEBUG "ASYNC_CLOSING = %s\n",
			(pCh->flags & ASYNC_CLOSING)?"True":"False");
		printk(KERN_DEBUG "OpenBlock: waiting for CD or signal\n");
#endif
		ip2trace (CHANN, ITRC_OPEN, 3, 2, 0,
				(pCh->flags & ASYNC_CLOSING) );
		/* check for signal */
		if (signal_pending(current)) {
			rc = (( pCh->flags & ASYNC_HUP_NOTIFY ) ? -EAGAIN : -ERESTARTSYS);
			break;
		}
		schedule();
	}
	set_current_state( TASK_RUNNING );
	remove_wait_queue(&pCh->open_wait, &wait);

	--pCh->wopen; //why count?

	ip2trace (CHANN, ITRC_OPEN, 4, 0 );

	if (rc != 0 ) {
		return rc;
	}
	pCh->flags |= ASYNC_NORMAL_ACTIVE;

noblock:

	/* first open - Assign termios structure to port */
	if ( tty->count == 1 ) {
		i2QueueCommands(PTYPE_INLINE, pCh, 0, 2, CMD_CTSFL_DSAB, CMD_RTSFL_DSAB);
		/* Now we must send the termios settings to the loadware */
		set_params( pCh, NULL );
	}

	/*
	 * Now set any i2lib options. These may go away if the i2lib code ends
	 * up rolled into the mainline.
	 */
	pCh->channelOptions |= CO_NBLOCK_WRITE;

#ifdef IP2DEBUG_OPEN
	printk (KERN_DEBUG "IP2: open completed\n" );
#endif
	serviceOutgoingFifo( pCh->pMyBord );

	ip2trace (CHANN, ITRC_OPEN, ITRC_RETURN, 0 );

	return 0;
}