synclink_cs.c

LINUX 2.6.17.4的源码

		data   = read_reg(info, CHA + RXFIFO);
		status = read_reg(info, CHA + RXFIFO);
		fifo_count -= 2;

		icount->rx++;
		flag = TTY_NORMAL;

		// if no frameing/crc error then save data
		// BIT7:parity error
		// BIT6:framing error

		if (status & (BIT7 + BIT6)) {
			if (status & BIT7) 
				icount->parity++;
			else
				icount->frame++;

			/* discard char if tty control flags say so */
			if (status & info->ignore_status_mask)
				continue;
				
			status &= info->read_status_mask;

			if (status & BIT7)
				flag = TTY_PARITY;
			else if (status & BIT6)
				flag = TTY_FRAME;
		}
		work += tty_insert_flip_char(tty, data, flag);
	}
	issue_command(info, CHA, CMD_RXFIFO);

	if (debug_level >= DEBUG_LEVEL_ISR) {
		printk("%s(%d):rx_ready_async",
			__FILE__,__LINE__);
		printk("%s(%d):rx=%d brk=%d parity=%d frame=%d overrun=%d\n",
			__FILE__,__LINE__,icount->rx,icount->brk,
			icount->parity,icount->frame,icount->overrun);
	}
			
	if (work)
		tty_flip_buffer_push(tty);
}


static void tx_done(MGSLPC_INFO *info)
{
	if (!info->tx_active)
		return;
			
	info->tx_active = 0;
	info->tx_aborting = 0;

	if (info->params.mode == MGSL_MODE_ASYNC)
		return;

	info->tx_count = info->tx_put = info->tx_get = 0;
	del_timer(&info->tx_timer);	
	
	if (info->drop_rts_on_tx_done) {
		get_signals(info);
		if (info->serial_signals & SerialSignal_RTS) {
			info->serial_signals &= ~SerialSignal_RTS;
			set_signals(info);
		}
		info->drop_rts_on_tx_done = 0;
	}

#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlcdev_tx_done(info);
	else 
#endif
	{
		if (info->tty->stopped || info->tty->hw_stopped) {
			tx_stop(info);
			return;
		}
		info->pending_bh |= BH_TRANSMIT;
	}
}

static void tx_ready(MGSLPC_INFO *info)
{
	unsigned char fifo_count = 32;
	int c;

	if (debug_level >= DEBUG_LEVEL_ISR)
		printk("%s(%d):tx_ready(%s)\n", __FILE__,__LINE__,info->device_name);

	if (info->params.mode == MGSL_MODE_HDLC) {
		if (!info->tx_active)
			return;
	} else {
		if (info->tty->stopped || info->tty->hw_stopped) {
			tx_stop(info);
			return;
		}
		if (!info->tx_count)
			info->tx_active = 0;
	}

	if (!info->tx_count)
		return;

	while (info->tx_count && fifo_count) {
		c = min(2, min_t(int, fifo_count, min(info->tx_count, TXBUFSIZE - info->tx_get)));
		
		if (c == 1) {
			write_reg(info, CHA + TXFIFO, *(info->tx_buf + info->tx_get));
		} else {
			write_reg16(info, CHA + TXFIFO,
					  *((unsigned short*)(info->tx_buf + info->tx_get)));
		}
		info->tx_count -= c;
		info->tx_get = (info->tx_get + c) & (TXBUFSIZE - 1);
		fifo_count -= c;
	}

	if (info->params.mode == MGSL_MODE_ASYNC) {
		if (info->tx_count < WAKEUP_CHARS)
			info->pending_bh |= BH_TRANSMIT;
		issue_command(info, CHA, CMD_TXFIFO);
	} else {
		if (info->tx_count)
			issue_command(info, CHA, CMD_TXFIFO);
		else
			issue_command(info, CHA, CMD_TXFIFO + CMD_TXEOM);
	}
}

static void cts_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->cts_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		irq_disable(info, CHB, IRQ_CTS);
	info->icount.cts++;
	if (info->serial_signals & SerialSignal_CTS)
		info->input_signal_events.cts_up++;
	else
		info->input_signal_events.cts_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	if (info->flags & ASYNC_CTS_FLOW) {
		if (info->tty->hw_stopped) {
			if (info->serial_signals & SerialSignal_CTS) {
				if (debug_level >= DEBUG_LEVEL_ISR)
					printk("CTS tx start...");
				if (info->tty)
					info->tty->hw_stopped = 0;
				tx_start(info);
				info->pending_bh |= BH_TRANSMIT;
				return;
			}
		} else {
			if (!(info->serial_signals & SerialSignal_CTS)) {
				if (debug_level >= DEBUG_LEVEL_ISR)
					printk("CTS tx stop...");
				if (info->tty)
					info->tty->hw_stopped = 1;
				tx_stop(info);
			}
		}
	}
	info->pending_bh |= BH_STATUS;
}

static void dcd_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->dcd_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		irq_disable(info, CHB, IRQ_DCD);
	info->icount.dcd++;
	if (info->serial_signals & SerialSignal_DCD) {
		info->input_signal_events.dcd_up++;
	}
	else
		info->input_signal_events.dcd_down++;
#ifdef CONFIG_HDLC
	if (info->netcount)
		hdlc_set_carrier(info->serial_signals & SerialSignal_DCD, info->netdev);
#endif
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	if (info->flags & ASYNC_CHECK_CD) {
		if (debug_level >= DEBUG_LEVEL_ISR)
			printk("%s CD now %s...", info->device_name,
			       (info->serial_signals & SerialSignal_DCD) ? "on" : "off");
		if (info->serial_signals & SerialSignal_DCD)
			wake_up_interruptible(&info->open_wait);
		else {
			if (debug_level >= DEBUG_LEVEL_ISR)
				printk("doing serial hangup...");
			if (info->tty)
				tty_hangup(info->tty);
		}
	}
	info->pending_bh |= BH_STATUS;
}

static void dsr_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->dsr_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		port_irq_disable(info, PVR_DSR);
	info->icount.dsr++;
	if (info->serial_signals & SerialSignal_DSR)
		info->input_signal_events.dsr_up++;
	else
		info->input_signal_events.dsr_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

static void ri_change(MGSLPC_INFO *info)
{
	get_signals(info);
	if ((info->ri_chkcount)++ >= IO_PIN_SHUTDOWN_LIMIT)
		port_irq_disable(info, PVR_RI);
	info->icount.rng++;
	if (info->serial_signals & SerialSignal_RI)
		info->input_signal_events.ri_up++;
	else
		info->input_signal_events.ri_down++;
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;
}

/* Interrupt service routine entry point.
 * 	
 * Arguments:
 * 
 * irq     interrupt number that caused interrupt
 * dev_id  device ID supplied during interrupt registration
 * regs    interrupted processor context
 */
static irqreturn_t mgslpc_isr(int irq, void *dev_id, struct pt_regs * regs)
{
	MGSLPC_INFO * info = (MGSLPC_INFO *)dev_id;
	unsigned short isr;
	unsigned char gis, pis;
	int count=0;

	if (debug_level >= DEBUG_LEVEL_ISR)	
		printk("mgslpc_isr(%d) entry.\n", irq);
	if (!info)
		return IRQ_NONE;
		
	if (!(info->p_dev->_locked))
		return IRQ_HANDLED;

	spin_lock(&info->lock);

	while ((gis = read_reg(info, CHA + GIS))) {
		if (debug_level >= DEBUG_LEVEL_ISR)	
			printk("mgslpc_isr %s gis=%04X\n", info->device_name,gis);

		if ((gis & 0x70) || count > 1000) {
			printk("synclink_cs:hardware failed or ejected\n");
			break;
		}
		count++;

		if (gis & (BIT1 + BIT0)) {
			isr = read_reg16(info, CHB + ISR);
			if (isr & IRQ_DCD)
				dcd_change(info);
			if (isr & IRQ_CTS)
				cts_change(info);
		}
		if (gis & (BIT3 + BIT2))
		{
			isr = read_reg16(info, CHA + ISR);
			if (isr & IRQ_TIMER) {
				info->irq_occurred = 1;
				irq_disable(info, CHA, IRQ_TIMER);
			}

			/* receive IRQs */ 
			if (isr & IRQ_EXITHUNT) {
				info->icount.exithunt++;
				wake_up_interruptible(&info->event_wait_q);
			}
			if (isr & IRQ_BREAK_ON) {
				info->icount.brk++;
				if (info->flags & ASYNC_SAK)
					do_SAK(info->tty);
			}
			if (isr & IRQ_RXTIME) {
				issue_command(info, CHA, CMD_RXFIFO_READ);
			}
			if (isr & (IRQ_RXEOM + IRQ_RXFIFO)) {
				if (info->params.mode == MGSL_MODE_HDLC)
					rx_ready_hdlc(info, isr & IRQ_RXEOM); 
				else
					rx_ready_async(info, isr & IRQ_RXEOM);
			}

			/* transmit IRQs */ 
			if (isr & IRQ_UNDERRUN) {
				if (info->tx_aborting)
					info->icount.txabort++;
				else
					info->icount.txunder++;
				tx_done(info);
			}
			else if (isr & IRQ_ALLSENT) {
				info->icount.txok++;
				tx_done(info);
			}
			else if (isr & IRQ_TXFIFO)
				tx_ready(info);
		}
		if (gis & BIT7) {
			pis = read_reg(info, CHA + PIS);
			if (pis & BIT1)
				dsr_change(info);
			if (pis & BIT2)
				ri_change(info);
		}
	}
	
	/* Request bottom half processing if there's something 
	 * for it to do and the bh is not already running
	 */

	if (info->pending_bh && !info->bh_running && !info->bh_requested) {
		if ( debug_level >= DEBUG_LEVEL_ISR )	
			printk("%s(%d):%s queueing bh task.\n",
				__FILE__,__LINE__,info->device_name);
		schedule_work(&info->task);
		info->bh_requested = 1;
	}

	spin_unlock(&info->lock);
	
	if (debug_level >= DEBUG_LEVEL_ISR)	
		printk("%s(%d):mgslpc_isr(%d)exit.\n",
		       __FILE__,__LINE__,irq);

	return IRQ_HANDLED;
}

/* Initialize and start device.
 */
static int startup(MGSLPC_INFO * info)
{
	int retval = 0;
	
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):startup(%s)\n",__FILE__,__LINE__,info->device_name);
		
	if (info->flags & ASYNC_INITIALIZED)
		return 0;
	
	if (!info->tx_buf) {
		/* allocate a page of memory for a transmit buffer */
		info->tx_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
		if (!info->tx_buf) {
			printk(KERN_ERR"%s(%d):%s can't allocate transmit buffer\n",
				__FILE__,__LINE__,info->device_name);
			return -ENOMEM;
		}
	}

	info->pending_bh = 0;
	
	memset(&info->icount, 0, sizeof(info->icount));

	init_timer(&info->tx_timer);
	info->tx_timer.data = (unsigned long)info;
	info->tx_timer.function = tx_timeout;

	/* Allocate and claim adapter resources */
	retval = claim_resources(info);
	
	/* perform existance check and diagnostics */
	if ( !retval )
		retval = adapter_test(info);
		
	if ( retval ) {
  		if (capable(CAP_SYS_ADMIN) && info->tty)
			set_bit(TTY_IO_ERROR, &info->tty->flags);
		release_resources(info);
  		return retval;
  	}

	/* program hardware for current parameters */
	mgslpc_change_params(info);
	
	if (info->tty)
		clear_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags |= ASYNC_INITIALIZED;
	
	return 0;
}

/* Called by mgslpc_close() and mgslpc_hangup() to shutdown hardware
 */
static void shutdown(MGSLPC_INFO * info)
{
	unsigned long flags;
	
	if (!(info->flags & ASYNC_INITIALIZED))
		return;

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

	/* clear status wait queue because status changes */
	/* can't happen after shutting down the hardware */
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);

	del_timer(&info->tx_timer);	

	if (info->tx_buf) {
		free_page((unsigned long) info->tx_buf);
		info->tx_buf = NULL;
	}

	spin_lock_irqsave(&info->lock,flags);

	rx_stop(info);
	tx_stop(info);

	/* TODO:disable interrupts instead of reset to preserve signal states */
	reset_device(info);
	
 	if (!info->tty || info->tty->termios->c_cflag & HUPCL) {
 		info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
		set_signals(info);
	}
	
	spin_unlock_irqrestore(&info->lock,flags);

	release_resources(info);	
	
	if (info->tty)
		set_bit(TTY_IO_ERROR, &info->tty->flags);

	info->flags &= ~ASYNC_INITIALIZED;
}

static void mgslpc_program_hw(MGSLPC_INFO *info)
{
	unsigned long flags;

	spin_lock_irqsave(&info->lock,flags);
	
	rx_stop(info);
	tx_stop(info);
	info->tx_count = info->tx_put = info->tx_get = 0;
	
	if (info->params.mode == MGSL_MODE_HDLC || info->netcount)
		hdlc_mode(info);
	else
		async_mode(info);
		
	set_signals(info);
	
	info->dcd_chkcount = 0;
	info->cts_chkcount = 0;
	info->ri_chkcount = 0;
	info->dsr_chkcount = 0;

	irq_enable(info, CHB, IRQ_DCD | IRQ_CTS);
	port_irq_enable(info, (unsigned char) PVR_DSR | PVR_RI);
	get_signals(info);
		
	if (info->netcount || info->tty->termios->c_cflag & CREAD)
		rx_start(info);
		
	spin_unlock_irqrestore(&info->lock,flags);
}

/* Reconfigure adapter based on new parameters
 */
static void mgslpc_change_params(MGSLPC_INFO *info)
{
	unsigned cflag;
	int bits_per_char;

	if (!info->tty || !info->tty->termios)
		return;
		
	if (debug_level >= DEBUG_LEVEL_INFO)
		printk("%s(%d):mgslpc_change_params(%s)\n",
			 __FILE__,__LINE__, info->device_name );
			 
	cflag = info->tty->termios->c_cflag;