pc300_tty.c

linux-2.6.15.6

	if (!tty || !tty->driver_data ) {
	   	CPC_TTY_DBG("hdlcX-tty: no TTY to chars in buffer\n");	
		return -ENODEV; 
	}

	cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

	if (set & TIOCM_RTS)
		cpc_tty_signal_on(cpc_tty->pc300dev, CTL_RTS);
	if (set & TIOCM_DTR)
		cpc_tty_signal_on(cpc_tty->pc300dev, CTL_DTR);

	if (clear & TIOCM_RTS)
		cpc_tty_signal_off(cpc_tty->pc300dev, CTL_RTS);
	if (clear & TIOCM_DTR)
		cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);

	return 0;
}

static int pc300_tiocmget(struct tty_struct *tty, struct file *file)
{
	unsigned int result;
	unsigned char status;
	unsigned long flags;
	st_cpc_tty_area  *cpc_tty = (st_cpc_tty_area *) tty->driver_data;
	pc300dev_t *pc300dev = cpc_tty->pc300dev;
	pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
	pc300_t *card = (pc300_t *) pc300chan->card;
	int ch = pc300chan->channel;

	cpc_tty = (st_cpc_tty_area *) tty->driver_data;

	CPC_TTY_DBG("%s-tty: tiocmget\n",
		((struct net_device*)(pc300dev->hdlc))->name);

	CPC_TTY_LOCK(card, flags);
	status = cpc_readb(card->hw.scabase+M_REG(CTL,ch));
	CPC_TTY_UNLOCK(card,flags);

	result = ((status & CTL_DTR) ? TIOCM_DTR : 0) |
		 ((status & CTL_RTS) ? TIOCM_RTS : 0);

	return result;
}

/*
 * PC300 TTY Flush Buffer routine
 *
 * This routine resets the transmission buffer 
 */
static void cpc_tty_flush_buffer(struct tty_struct *tty)
{ 
	st_cpc_tty_area    *cpc_tty; 
	
	if (!tty || !tty->driver_data ) {
	   	CPC_TTY_DBG("hdlcX-tty: no TTY to flush buffer\n");	
		return; 
	}

	cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

	if ((cpc_tty->tty != tty) ||  (cpc_tty->state != CPC_TTY_ST_OPEN)) { 
		CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
		return; 
	}

	CPC_TTY_DBG("%s: call wake_up_interruptible\n",cpc_tty->name);

	tty_wakeup(tty);	
	return; 
} 

/*
 * PC300 TTY Hangup routine
 *
 * This routine is called by the tty driver to hangup the interface 
 * o clear DTR signal
 */

static void cpc_tty_hangup(struct tty_struct *tty)
{ 
	st_cpc_tty_area    *cpc_tty; 
	int res;

	if (!tty || !tty->driver_data ) {
		CPC_TTY_DBG("hdlcX-tty: no TTY to hangup\n");	
		return ; 
	}

	cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

	if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
		CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
		return ;
	}
	if (!serial_drv.refcount && cpc_tty_unreg_flag) {
		cpc_tty_unreg_flag = 0;
		CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
		if ((res=tty_unregister_driver(&serial_drv))) { 
			CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
							cpc_tty->name,res);
		}
	}
	cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
}

/*
 * PC300 TTY RX work routine
 * This routine treats RX work
 * o verify read buffer
 * o call the line disc. read
 * o free memory
 */
static void cpc_tty_rx_work(void * data)
{
	unsigned long port;
	int i, j;
	st_cpc_tty_area *cpc_tty; 
	volatile st_cpc_rx_buf *buf;
	char flags=0,flg_rx=1; 
	struct tty_ldisc *ld;

	if (cpc_tty_cnt == 0) return;

	
	for (i=0; (i < 4) && flg_rx ; i++) {
		flg_rx = 0;
		port = (unsigned long)data;
		for (j=0; j < CPC_TTY_NPORTS; j++) {
			cpc_tty = &cpc_tty_area[port];
		
			if ((buf=cpc_tty->buf_rx.first) != 0) {
				if (cpc_tty->tty) {
					ld = tty_ldisc_ref(cpc_tty->tty);
					if (ld) {
						if (ld->receive_buf) {
							CPC_TTY_DBG("%s: call line disc. receive_buf\n",cpc_tty->name);
							ld->receive_buf(cpc_tty->tty, (char *)(buf->data), &flags, buf->size);
						}
						tty_ldisc_deref(ld);
					}
				}	
				cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
				kfree(buf);
				buf = cpc_tty->buf_rx.first;
				flg_rx = 1;
			}
			if (++port == CPC_TTY_NPORTS) port = 0;
		}
	}
} 

/*
 * PC300 TTY RX work routine
 *
 * This routine treats RX interrupt. 
 * o read all frames in card
 * o verify the frame size
 * o read the frame in rx buffer
 */
static void cpc_tty_rx_disc_frame(pc300ch_t *pc300chan)
{
	volatile pcsca_bd_t __iomem * ptdescr; 
	volatile unsigned char status; 
	pc300_t *card = (pc300_t *)pc300chan->card; 
	int ch = pc300chan->channel; 

	/* dma buf read */ 
	ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
				RX_BD_ADDR(ch, pc300chan->rx_first_bd)); 
	while (pc300chan->rx_first_bd != pc300chan->rx_last_bd) { 
		status = cpc_readb(&ptdescr->status); 
		cpc_writeb(&ptdescr->status, 0); 
		cpc_writeb(&ptdescr->len, 0); 
		pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) & 
					(N_DMA_RX_BUF - 1); 
		if (status & DST_EOM) { 
			break; /* end of message */
		}
		ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + cpc_readl(&ptdescr->next)); 
	}
}

void cpc_tty_receive(pc300dev_t *pc300dev)
{
	st_cpc_tty_area *cpc_tty; 
	pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan; 
	pc300_t *card = (pc300_t *)pc300chan->card; 
	int ch = pc300chan->channel; 
	volatile pcsca_bd_t  __iomem * ptdescr; 
	struct net_device_stats *stats = hdlc_stats(pc300dev->dev);
	int rx_len, rx_aux; 
	volatile unsigned char status; 
	unsigned short first_bd = pc300chan->rx_first_bd;
	st_cpc_rx_buf *new = NULL;
	unsigned char dsr_rx;

	if (pc300dev->cpc_tty == NULL) { 
		return; 
	}

	dsr_rx = cpc_readb(card->hw.scabase + DSR_RX(ch));

	cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty; 

	while (1) { 
		rx_len = 0;
		ptdescr = (pcsca_bd_t  __iomem *)(card->hw.rambase + RX_BD_ADDR(ch, first_bd));
		while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
			rx_len += cpc_readw(&ptdescr->len);
			first_bd = (first_bd + 1) & (N_DMA_RX_BUF - 1);
			if (status & DST_EOM) {
				break;
			}
			ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase+cpc_readl(&ptdescr->next));
		}
			
		if (!rx_len) { 
			if (dsr_rx & DSR_BOF) {
				/* update EDA */ 
				cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch), 
						RX_BD_ADDR(ch, pc300chan->rx_last_bd)); 
			}
			kfree(new);
			return; 
		}
		
		if (rx_len > CPC_TTY_MAX_MTU) { 
			/* Free RX descriptors */ 
			CPC_TTY_DBG("%s: frame size is invalid.\n",cpc_tty->name);
			stats->rx_errors++; 
			stats->rx_frame_errors++; 
			cpc_tty_rx_disc_frame(pc300chan);
			continue;
		} 
		
		new = (st_cpc_rx_buf *)kmalloc(rx_len + sizeof(st_cpc_rx_buf), GFP_ATOMIC);
		if (new == 0) {
			cpc_tty_rx_disc_frame(pc300chan);
			continue;
		}
		
		/* dma buf read */ 
		ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
				RX_BD_ADDR(ch, pc300chan->rx_first_bd)); 

		rx_len = 0;	/* counter frame size */
		
		while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
			rx_aux = cpc_readw(&ptdescr->len);
			if ((status & (DST_OVR | DST_CRC | DST_RBIT |  DST_SHRT | DST_ABT))
				|| (rx_aux > BD_DEF_LEN)) {
				CPC_TTY_DBG("%s: reception error\n", cpc_tty->name);
				stats->rx_errors++; 
				if (status & DST_OVR) { 
					stats->rx_fifo_errors++; 
				}
				if (status & DST_CRC) { 
					stats->rx_crc_errors++; 
				}
				if ((status & (DST_RBIT | DST_SHRT | DST_ABT)) ||
					(rx_aux > BD_DEF_LEN))	{ 
					stats->rx_frame_errors++; 
				} 
				/* discard remainig descriptors used by the bad frame */ 
				CPC_TTY_DBG("%s: reception error - discard descriptors",
						cpc_tty->name);
				cpc_tty_rx_disc_frame(pc300chan);
				rx_len = 0;
				kfree(new);
				new = NULL;
				break; /* read next frame - while(1) */
			}

			if (cpc_tty->state != CPC_TTY_ST_OPEN) {
				/* Free RX descriptors */ 
				cpc_tty_rx_disc_frame(pc300chan);
				stats->rx_dropped++; 
				rx_len = 0; 
				kfree(new);
				new = NULL;
				break; /* read next frame - while(1) */
			}

			/* read the segment of the frame */
			if (rx_aux != 0) {
				memcpy_fromio((new->data + rx_len), 
					(void __iomem *)(card->hw.rambase + 
					 cpc_readl(&ptdescr->ptbuf)), rx_aux);
				rx_len += rx_aux; 
			}
			cpc_writeb(&ptdescr->status,0); 
			cpc_writeb(&ptdescr->len, 0); 
			pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) & 
					(N_DMA_RX_BUF -1); 
			if (status & DST_EOM)break;
			
			ptdescr = (pcsca_bd_t __iomem *) (card->hw.rambase + 
					cpc_readl(&ptdescr->next)); 
		}
		/* update pointer */ 
		pc300chan->rx_last_bd = (pc300chan->rx_first_bd - 1) & 
					(N_DMA_RX_BUF - 1) ; 
		if (!(dsr_rx & DSR_BOF)) {
			/* update EDA */ 
			cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch), 
					RX_BD_ADDR(ch, pc300chan->rx_last_bd)); 
		}
		if (rx_len != 0) { 
			stats->rx_bytes += rx_len; 
		
			if (pc300dev->trace_on) { 
				cpc_tty_trace(pc300dev, new->data,rx_len, 'R'); 
			} 
			new->size = rx_len;
			new->next = NULL;
			if (cpc_tty->buf_rx.first == 0) {
				cpc_tty->buf_rx.first = new;
				cpc_tty->buf_rx.last = new;
			} else {
				cpc_tty->buf_rx.last->next = new;
				cpc_tty->buf_rx.last = new;
			}
			schedule_work(&(cpc_tty->tty_rx_work));
			stats->rx_packets++;
		}
	} 
} 

/*
 * PC300 TTY TX work routine
 * 
 * This routine treats TX interrupt. 
 * o if need call line discipline wakeup
 * o call wake_up_interruptible
 */
static void cpc_tty_tx_work(void *data)
{
	st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *) data; 
	struct tty_struct *tty; 

	CPC_TTY_DBG("%s: cpc_tty_tx_work init\n",cpc_tty->name);
	
	if ((tty = cpc_tty->tty) == 0) { 
		CPC_TTY_DBG("%s: the interface is not opened\n",cpc_tty->name);
		return; 
	}
	tty_wakeup(tty);
}

/*
 * PC300 TTY send to card routine
 * 
 * This routine send data to card. 
 * o clear descriptors
 * o write data to DMA buffers
 * o start the transmission
 */
static int cpc_tty_send_to_card(pc300dev_t *dev,void* buf, int len)
{
	pc300ch_t *chan = (pc300ch_t *)dev->chan; 
	pc300_t *card = (pc300_t *)chan->card; 
	int ch = chan->channel; 
	struct net_device_stats *stats = hdlc_stats(dev->dev);
	unsigned long flags; 
	volatile pcsca_bd_t __iomem *ptdescr; 
	int i, nchar;
	int tosend = len;
	int nbuf = ((len - 1)/BD_DEF_LEN) + 1;
	unsigned char *pdata=buf;

	CPC_TTY_DBG("%s:cpc_tty_send_to_cars len=%i", 
			(st_cpc_tty_area *)dev->cpc_tty->name,len);	

	if (nbuf >= card->chan[ch].nfree_tx_bd) {
		return 1;
	}
	
	/* write buffer to DMA buffers */ 
	CPC_TTY_DBG("%s: call dma_buf_write\n",
			(st_cpc_tty_area *)dev->cpc_tty->name);	
	for (i = 0 ; i < nbuf ; i++) {
		ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
			TX_BD_ADDR(ch, card->chan[ch].tx_next_bd));
		nchar = (BD_DEF_LEN > tosend) ? tosend : BD_DEF_LEN;
		if (cpc_readb(&ptdescr->status) & DST_OSB) {
			memcpy_toio((void __iomem *)(card->hw.rambase + 
				cpc_readl(&ptdescr->ptbuf)), 
				&pdata[len - tosend], 
				nchar);
			card->chan[ch].nfree_tx_bd--;
			if ((i + 1) == nbuf) {
				/* This must be the last BD to be used */
				cpc_writeb(&ptdescr->status, DST_EOM);
			} else {
				cpc_writeb(&ptdescr->status, 0);
			}
			cpc_writew(&ptdescr->len, nchar);
		} else {
			CPC_TTY_DBG("%s: error in dma_buf_write\n",
					(st_cpc_tty_area *)dev->cpc_tty->name);	
			stats->tx_dropped++;
			return 1; 
		}
		tosend -= nchar;
		card->chan[ch].tx_next_bd = 
			(card->chan[ch].tx_next_bd + 1) & (N_DMA_TX_BUF - 1);
	}

	if (dev->trace_on) { 
		cpc_tty_trace(dev, buf, len,'T'); 
	}

	/* start transmission */ 
	CPC_TTY_DBG("%s: start transmission\n",
		(st_cpc_tty_area *)dev->cpc_tty->name);	
	
	CPC_TTY_LOCK(card, flags); 
	cpc_writeb(card->hw.scabase + DTX_REG(EDAL, ch), 
			TX_BD_ADDR(ch, chan->tx_next_bd)); 
	cpc_writeb(card->hw.scabase + M_REG(CMD, ch), CMD_TX_ENA); 
	cpc_writeb(card->hw.scabase + DSR_TX(ch), DSR_DE); 

	if (card->hw.type == PC300_TE) { 
		cpc_writeb(card->hw.falcbase + card->hw.cpld_reg2, 
			cpc_readb(card->hw.falcbase + card->hw.cpld_reg2) |
			(CPLD_REG2_FALC_LED1 << (2 * ch))); 
	}
	CPC_TTY_UNLOCK(card, flags); 
	return 0; 
} 

/*
 *	PC300 TTY trace routine
 *
 *  This routine send trace of connection to application. 
 *  o clear descriptors
 *  o write data to DMA buffers
 *  o start the transmission
 */

static void cpc_tty_trace(pc300dev_t *dev, char* buf, int len, char rxtx)
{
	struct sk_buff *skb; 

	if ((skb = dev_alloc_skb(10 + len)) == NULL) { 
		/* out of memory */ 
		CPC_TTY_DBG("%s: tty_trace - out of memory\n", dev->dev->name);
		return; 
	}

	skb_put (skb, 10 + len); 
	skb->dev = dev->dev; 
	skb->protocol = htons(ETH_P_CUST); 
	skb->mac.raw = skb->data; 
	skb->pkt_type = PACKET_HOST; 
	skb->len = 10 + len; 

	memcpy(skb->data,dev->dev->name,5);
	skb->data[5] = '['; 
	skb->data[6] = rxtx; 
	skb->data[7] = ']'; 
	skb->data[8] = ':'; 
	skb->data[9] = ' '; 
	memcpy(&skb->data[10], buf, len); 
	netif_rx(skb); 
} 	

/*
 *	PC300 TTY unregister service routine
 *
 *	This routine unregister one interface. 
 */
void cpc_tty_unregister_service(pc300dev_t *pc300dev)
{
	st_cpc_tty_area *cpc_tty; 
	ulong flags;
	int res;

	if ((cpc_tty= (st_cpc_tty_area *) pc300dev->cpc_tty) == 0) { 
		CPC_TTY_DBG("%s: interface is not TTY\n", pc300dev->dev->name);
		return; 
	}
	CPC_TTY_DBG("%s: cpc_tty_unregister_service", cpc_tty->name);

	if (cpc_tty->pc300dev != pc300dev) { 
		CPC_TTY_DBG("%s: invalid tty ptr=%s\n", 
		pc300dev->dev->name, cpc_tty->name);
		return; 
	}

	if (--cpc_tty_cnt == 0) { 
		if (serial_drv.refcount) {
			CPC_TTY_DBG("%s: unregister is not possible, refcount=%d",
							cpc_tty->name, serial_drv.refcount);
			cpc_tty_cnt++;
			cpc_tty_unreg_flag = 1;
			return;
		} else { 
			CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
			if ((res=tty_unregister_driver(&serial_drv))) { 
				CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
								cpc_tty->name,res);
			}
		}
	}
	CPC_TTY_LOCK(pc300dev->chan->card,flags);
	cpc_tty->tty = NULL; 
	CPC_TTY_UNLOCK(pc300dev->chan->card, flags);
	cpc_tty->tty_minor = 0; 
	cpc_tty->state = CPC_TTY_ST_IDLE; 
} 

/*
 * PC300 TTY trigger poll routine
 * This routine is called by pc300driver to treats Tx interrupt. 
 */
void cpc_tty_trigger_poll(pc300dev_t *pc300dev)
{
	st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty; 
	if (!cpc_tty) {
		return;
	}
	schedule_work(&(cpc_tty->tty_tx_work)); 
} 

/*
 * PC300 TTY reset var routine
 * This routine is called by pc300driver to init the TTY area. 
 */

void cpc_tty_reset_var(void)
{
	int i ; 

	CPC_TTY_DBG("hdlcX-tty: reset variables\n");
	/* reset  the tty_driver structure - serial_drv */ 
	memset(&serial_drv, 0, sizeof(struct tty_driver));
	for (i=0; i < CPC_TTY_NPORTS; i++){
		memset(&cpc_tty_area[i],0, sizeof(st_cpc_tty_area)); 
	}
}