synclink_gt.c

linux 内核源代码

		info->rbuf_index = 0;
		free_rbufs(info, end, end);

		if (++end == info->rbuf_count)
			end = 0;

		/* if entire list searched then no frame available */
		if (end == start)
			break;
	}

	if (tty && chars)
		tty_flip_buffer_push(tty);
}

/*
 * return next bottom half action to perform
 */
static int bh_action(struct slgt_info *info)
{
	unsigned long flags;
	int rc;

	spin_lock_irqsave(&info->lock,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;
	} else {
		/* Mark BH routine as complete */
		info->bh_running   = 0;
		info->bh_requested = 0;
		rc = 0;
	}

	spin_unlock_irqrestore(&info->lock,flags);

	return rc;
}

/*
 * perform bottom half processing
 */
static void bh_handler(struct work_struct *work)
{
	struct slgt_info *info = container_of(work, struct slgt_info, task);
	int action;

	if (!info)
		return;
	info->bh_running = 1;

	while((action = bh_action(info))) {
		switch (action) {
		case BH_RECEIVE:
			DBGBH(("%s bh receive\n", info->device_name));
			switch(info->params.mode) {
			case MGSL_MODE_ASYNC:
				rx_async(info);
				break;
			case MGSL_MODE_HDLC:
				while(rx_get_frame(info));
				break;
			case MGSL_MODE_RAW:
			case MGSL_MODE_MONOSYNC:
			case MGSL_MODE_BISYNC:
				while(rx_get_buf(info));
				break;
			}
			/* restart receiver if rx DMA buffers exhausted */
			if (info->rx_restart)
				rx_start(info);
			break;
		case BH_TRANSMIT:
			bh_transmit(info);
			break;
		case BH_STATUS:
			DBGBH(("%s bh status\n", info->device_name));
			info->ri_chkcount = 0;
			info->dsr_chkcount = 0;
			info->dcd_chkcount = 0;
			info->cts_chkcount = 0;
			break;
		default:
			DBGBH(("%s unknown action\n", info->device_name));
			break;
		}
	}
	DBGBH(("%s bh_handler exit\n", info->device_name));
}

static void bh_transmit(struct slgt_info *info)
{
	struct tty_struct *tty = info->tty;

	DBGBH(("%s bh_transmit\n", info->device_name));
	if (tty)
		tty_wakeup(tty);
}

static void dsr_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_DSR);
		return;
	}
	info->icount.dsr++;
	if (info->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 cts_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_CTS);
		return;
	}
	info->icount.cts++;
	if (info->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);
	info->pending_bh |= BH_STATUS;

	if (info->flags & ASYNC_CTS_FLOW) {
		if (info->tty) {
			if (info->tty->hw_stopped) {
				if (info->signals & SerialSignal_CTS) {
		 			info->tty->hw_stopped = 0;
					info->pending_bh |= BH_TRANSMIT;
					return;
				}
			} else {
				if (!(info->signals & SerialSignal_CTS))
		 			info->tty->hw_stopped = 1;
			}
		}
	}
}

static void dcd_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_DCD);
		return;
	}
	info->icount.dcd++;
	if (info->signals & SerialSignal_DCD) {
		info->input_signal_events.dcd_up++;
	} else {
		info->input_signal_events.dcd_down++;
	}
#if SYNCLINK_GENERIC_HDLC
	if (info->netcount) {
		if (info->signals & SerialSignal_DCD)
			netif_carrier_on(info->netdev);
		else
			netif_carrier_off(info->netdev);
	}
#endif
	wake_up_interruptible(&info->status_event_wait_q);
	wake_up_interruptible(&info->event_wait_q);
	info->pending_bh |= BH_STATUS;

	if (info->flags & ASYNC_CHECK_CD) {
		if (info->signals & SerialSignal_DCD)
			wake_up_interruptible(&info->open_wait);
		else {
			if (info->tty)
				tty_hangup(info->tty);
		}
	}
}

static void ri_change(struct slgt_info *info)
{
	get_signals(info);
	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
		slgt_irq_off(info, IRQ_RI);
		return;
	}
	info->icount.dcd++;
	if (info->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;
}

static void isr_serial(struct slgt_info *info)
{
	unsigned short status = rd_reg16(info, SSR);

	DBGISR(("%s isr_serial status=%04X\n", info->device_name, status));

	wr_reg16(info, SSR, status); /* clear pending */

	info->irq_occurred = 1;

	if (info->params.mode == MGSL_MODE_ASYNC) {
		if (status & IRQ_TXIDLE) {
			if (info->tx_count)
				isr_txeom(info, status);
		}
		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
			info->icount.brk++;
			/* process break detection if tty control allows */
			if (info->tty) {
				if (!(status & info->ignore_status_mask)) {
					if (info->read_status_mask & MASK_BREAK) {
						tty_insert_flip_char(info->tty, 0, TTY_BREAK);
						if (info->flags & ASYNC_SAK)
							do_SAK(info->tty);
					}
				}
			}
		}
	} else {
		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
			isr_txeom(info, status);

		if (status & IRQ_RXIDLE) {
			if (status & RXIDLE)
				info->icount.rxidle++;
			else
				info->icount.exithunt++;
			wake_up_interruptible(&info->event_wait_q);
		}

		if (status & IRQ_RXOVER)
			rx_start(info);
	}

	if (status & IRQ_DSR)
		dsr_change(info);
	if (status & IRQ_CTS)
		cts_change(info);
	if (status & IRQ_DCD)
		dcd_change(info);
	if (status & IRQ_RI)
		ri_change(info);
}

static void isr_rdma(struct slgt_info *info)
{
	unsigned int status = rd_reg32(info, RDCSR);

	DBGISR(("%s isr_rdma status=%08x\n", info->device_name, status));

	/* RDCSR (rx DMA control/status)
	 *
	 * 31..07  reserved
	 * 06      save status byte to DMA buffer
	 * 05      error
	 * 04      eol (end of list)
	 * 03      eob (end of buffer)
	 * 02      IRQ enable
	 * 01      reset
	 * 00      enable
	 */
	wr_reg32(info, RDCSR, status);	/* clear pending */

	if (status & (BIT5 + BIT4)) {
		DBGISR(("%s isr_rdma rx_restart=1\n", info->device_name));
		info->rx_restart = 1;
	}
	info->pending_bh |= BH_RECEIVE;
}

static void isr_tdma(struct slgt_info *info)
{
	unsigned int status = rd_reg32(info, TDCSR);

	DBGISR(("%s isr_tdma status=%08x\n", info->device_name, status));

	/* TDCSR (tx DMA control/status)
	 *
	 * 31..06  reserved
	 * 05      error
	 * 04      eol (end of list)
	 * 03      eob (end of buffer)
	 * 02      IRQ enable
	 * 01      reset
	 * 00      enable
	 */
	wr_reg32(info, TDCSR, status);	/* clear pending */

	if (status & (BIT5 + BIT4 + BIT3)) {
		// another transmit buffer has completed
		// run bottom half to get more send data from user
		info->pending_bh |= BH_TRANSMIT;
	}
}

static void isr_txeom(struct slgt_info *info, unsigned short status)
{
	DBGISR(("%s txeom status=%04x\n", info->device_name, status));

	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
	tdma_reset(info);
	reset_tbufs(info);
	if (status & IRQ_TXUNDER) {
		unsigned short val = rd_reg16(info, TCR);
		wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
		wr_reg16(info, TCR, val); /* clear reset bit */
	}

	if (info->tx_active) {
		if (info->params.mode != MGSL_MODE_ASYNC) {
			if (status & IRQ_TXUNDER)
				info->icount.txunder++;
			else if (status & IRQ_TXIDLE)
				info->icount.txok++;
		}

		info->tx_active = 0;
		info->tx_count = 0;

		del_timer(&info->tx_timer);

		if (info->params.mode != MGSL_MODE_ASYNC && info->drop_rts_on_tx_done) {
			info->signals &= ~SerialSignal_RTS;
			info->drop_rts_on_tx_done = 0;
			set_signals(info);
		}

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

static void isr_gpio(struct slgt_info *info, unsigned int changed, unsigned int state)
{
	struct cond_wait *w, *prev;

	/* wake processes waiting for specific transitions */
	for (w = info->gpio_wait_q, prev = NULL ; w != NULL ; w = w->next) {
		if (w->data & changed) {
			w->data = state;
			wake_up_interruptible(&w->q);
			if (prev != NULL)
				prev->next = w->next;
			else
				info->gpio_wait_q = w->next;
		} else
			prev = w;
	}
}

/* interrupt service routine
 *
 * 	irq	interrupt number
 * 	dev_id	device ID supplied during interrupt registration
 */
static irqreturn_t slgt_interrupt(int irq, void *dev_id)
{
	struct slgt_info *info;
	unsigned int gsr;
	unsigned int i;

	DBGISR(("slgt_interrupt irq=%d entry\n", irq));

	info = dev_id;
	if (!info)
		return IRQ_NONE;

	spin_lock(&info->lock);

	while((gsr = rd_reg32(info, GSR) & 0xffffff00)) {
		DBGISR(("%s gsr=%08x\n", info->device_name, gsr));
		info->irq_occurred = 1;
		for(i=0; i < info->port_count ; i++) {
			if (info->port_array[i] == NULL)
				continue;
			if (gsr & (BIT8 << i))
				isr_serial(info->port_array[i]);
			if (gsr & (BIT16 << (i*2)))
				isr_rdma(info->port_array[i]);
			if (gsr & (BIT17 << (i*2)))
				isr_tdma(info->port_array[i]);
		}
	}

	if (info->gpio_present) {
		unsigned int state;
		unsigned int changed;
		while ((changed = rd_reg32(info, IOSR)) != 0) {
			DBGISR(("%s iosr=%08x\n", info->device_name, changed));
			/* read latched state of GPIO signals */
			state = rd_reg32(info, IOVR);
			/* clear pending GPIO interrupt bits */
			wr_reg32(info, IOSR, changed);
			for (i=0 ; i < info->port_count ; i++) {
				if (info->port_array[i] != NULL)
					isr_gpio(info->port_array[i], changed, state);
			}
		}
	}

	for(i=0; i < info->port_count ; i++) {
		struct slgt_info *port = info->port_array[i];

		if (port && (port->count || port->netcount) &&
		    port->pending_bh && !port->bh_running &&
		    !port->bh_requested) {
			DBGISR(("%s bh queued\n", port->device_name));
			schedule_work(&port->task);
			port->bh_requested = 1;
		}
	}

	spin_unlock(&info->lock);

	DBGISR(("slgt_interrupt irq=%d exit\n", irq));
	return IRQ_HANDLED;
}

static int startup(struct slgt_info *info)
{
	DBGINFO(("%s startup\n", info->device_name));

	if (info->flags & ASYNC_INITIALIZED)
		return 0;

	if (!info->tx_buf) {
		info->tx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
		if (!info->tx_buf) {
			DBGERR(("%s can't allocate tx buffer\n", info->device_name));
			return -ENOMEM;
		}
	}

	info->pending_bh = 0;

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

	/* program hardware for current parameters */
	change_params(info);

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

	info->flags |= ASYNC_INITIALIZED;

	return 0;
}

/*
 *