yam.c

linux-2.4.29操作系统的源码

	case 1200:
		return add_mcs(bits_1200, bitrate);
	default:
		return add_mcs(bits_9600, bitrate);
	}
}

/*
 * download bitstream to FPGA
 * data is contained in bits[] array in yam1200.h resp. yam9600.h
 */

static int fpga_download(int iobase, int bitrate)
{
	int i, rc;
	unsigned char *pbits;

	pbits = get_mcs(bitrate);
	if (pbits == NULL)
		return -1;

	fpga_reset(iobase);
	for (i = 0; i < YAM_FPGA_SIZE; i++) {
		if (fpga_write(iobase, pbits[i])) {
			printk(KERN_ERR "yam: error in write cycle\n");
			return -1;			/* write... */
		}
	}

	fpga_write(iobase, 0xFF);
	rc = inb(MSR(iobase));		/* check DONE signal */

	/* Needed for some hardwares */
	delay(50);

	return (rc & MSR_DSR) ? 0 : -1;
}


/************************************************************************
* Serial port init 
************************************************************************/

static void yam_set_uart(struct net_device *dev)
{
	struct yam_port *yp = (struct yam_port *) dev->priv;
	int divisor = 115200 / yp->baudrate;

	outb(0, IER(dev->base_addr));
	outb(LCR_DLAB | LCR_BIT8, LCR(dev->base_addr));
	outb(divisor, DLL(dev->base_addr));
	outb(0, DLM(dev->base_addr));
	outb(LCR_BIT8, LCR(dev->base_addr));
	outb(PTT_OFF, MCR(dev->base_addr));
	outb(0x00, FCR(dev->base_addr));

	/* Flush pending irq */

	inb(RBR(dev->base_addr));
	inb(MSR(dev->base_addr));

	/* Enable rx irq */

	outb(ENABLE_RTXINT, IER(dev->base_addr));
}


/* --------------------------------------------------------------------- */

enum uart {
	c_uart_unknown, c_uart_8250,
	c_uart_16450, c_uart_16550, c_uart_16550A
};

static const char *uart_str[] =
{"unknown", "8250", "16450", "16550", "16550A"};

static enum uart yam_check_uart(unsigned int iobase)
{
	unsigned char b1, b2, b3;
	enum uart u;
	enum uart uart_tab[] =
	{c_uart_16450, c_uart_unknown, c_uart_16550, c_uart_16550A};

	b1 = inb(MCR(iobase));
	outb(b1 | 0x10, MCR(iobase));	/* loopback mode */
	b2 = inb(MSR(iobase));
	outb(0x1a, MCR(iobase));
	b3 = inb(MSR(iobase)) & 0xf0;
	outb(b1, MCR(iobase));		/* restore old values */
	outb(b2, MSR(iobase));
	if (b3 != 0x90)
		return c_uart_unknown;
	inb(RBR(iobase));
	inb(RBR(iobase));
	outb(0x01, FCR(iobase));	/* enable FIFOs */
	u = uart_tab[(inb(IIR(iobase)) >> 6) & 3];
	if (u == c_uart_16450) {
		outb(0x5a, SCR(iobase));
		b1 = inb(SCR(iobase));
		outb(0xa5, SCR(iobase));
		b2 = inb(SCR(iobase));
		if ((b1 != 0x5a) || (b2 != 0xa5))
			u = c_uart_8250;
	}
	return u;
}

/******************************************************************************
* Rx Section
******************************************************************************/
static inline void yam_rx_flag(struct net_device *dev, struct yam_port *yp)
{
	if (yp->dcd && yp->rx_len >= 3 && yp->rx_len < YAM_MAX_FRAME) {
		int pkt_len = yp->rx_len - 2 + 1;	/* -CRC + kiss */
		struct sk_buff *skb;

		if ((yp->rx_crch & yp->rx_crcl) != 0xFF) {
			/* Bad crc */
		} else {
			if (!(skb = dev_alloc_skb(pkt_len))) {
				printk(KERN_WARNING "%s: memory squeeze, dropping packet\n", dev->name);
				++yp->stats.rx_dropped;
			} else {
				unsigned char *cp;
				skb->dev = dev;
				cp = skb_put(skb, pkt_len);
				*cp++ = 0;		/* KISS kludge */
				memcpy(cp, yp->rx_buf, pkt_len - 1);
				skb->protocol = htons(ETH_P_AX25);
				skb->mac.raw = skb->data;
				netif_rx(skb);
				++yp->stats.rx_packets;
			}
		}
	}
	yp->rx_len = 0;
	yp->rx_crcl = 0x21;
	yp->rx_crch = 0xf3;
}

static inline void yam_rx_byte(struct net_device *dev, struct yam_port *yp, unsigned char rxb)
{
	if (yp->rx_len < YAM_MAX_FRAME) {
		unsigned char c = yp->rx_crcl;
		yp->rx_crcl = (chktabl[c] ^ yp->rx_crch);
		yp->rx_crch = (chktabh[c] ^ rxb);
		yp->rx_buf[yp->rx_len++] = rxb;
	}
}

/********************************************************************************
* TX Section
********************************************************************************/

static void ptt_on(struct net_device *dev)
{
	outb(PTT_ON, MCR(dev->base_addr));
}

static void ptt_off(struct net_device *dev)
{
	outb(PTT_OFF, MCR(dev->base_addr));
}

static int yam_send_packet(struct sk_buff *skb, struct net_device *dev)
{
	struct yam_port *yp = dev->priv;

	skb_queue_tail(&yp->send_queue, skb);
	dev->trans_start = jiffies;
	return 0;
}

static void yam_start_tx(struct net_device *dev, struct yam_port *yp)
{
	if ((yp->tx_state == TX_TAIL) || (yp->txd == 0))
		yp->tx_count = 1;
	else
		yp->tx_count = (yp->bitrate * yp->txd) / 8000;
	yp->tx_state = TX_HEAD;
	ptt_on(dev);
}

static unsigned short random_seed;

static inline unsigned short random_num(void)
{
	random_seed = 28629 * random_seed + 157;
	return random_seed;
}

static void yam_arbitrate(struct net_device *dev)
{
	struct yam_port *yp = dev->priv;

	if (!yp || yp->magic != YAM_MAGIC
		|| yp->tx_state != TX_OFF || skb_queue_empty(&yp->send_queue)) {
		return;
	}
	/* tx_state is TX_OFF and there is data to send */

	if (yp->dupmode) {
		/* Full duplex mode, don't wait */
		yam_start_tx(dev, yp);
		return;
	}
	if (yp->dcd) {
		/* DCD on, wait slotime ... */
		yp->slotcnt = yp->slot / 10;
		return;
	}
	/* Is slottime passed ? */
	if ((--yp->slotcnt) > 0)
		return;

	yp->slotcnt = yp->slot / 10;

	/* is random > persist ? */
	if ((random_num() % 256) > yp->pers)
		return;

	yam_start_tx(dev, yp);
}

static void yam_dotimer(unsigned long dummy)
{
	int i;

	for (i = 0; i < NR_PORTS; i++) {
		struct net_device *dev = &yam_ports[i].dev;
		if (netif_running(dev))
			yam_arbitrate(dev);
	}
	yam_timer.expires = jiffies + HZ / 100;
	add_timer(&yam_timer);
}

static void yam_tx_byte(struct net_device *dev, struct yam_port *yp)
{
	struct sk_buff *skb;
	unsigned char b, temp;

	switch (yp->tx_state) {
	case TX_OFF:
		break;
	case TX_HEAD:
		if (--yp->tx_count <= 0) {
			if (!(skb = skb_dequeue(&yp->send_queue))) {
				ptt_off(dev);
				yp->tx_state = TX_OFF;
				break;
			}
			yp->tx_state = TX_DATA;
			if (skb->data[0] != 0) {
/*                              do_kiss_params(s, skb->data, skb->len); */
				dev_kfree_skb_any(skb);
				break;
			}
			yp->tx_len = skb->len - 1;	/* strip KISS byte */
			if (yp->tx_len >= YAM_MAX_FRAME || yp->tx_len < 2) {
        			dev_kfree_skb_any(skb);
				break;
			}
			memcpy(yp->tx_buf, skb->data + 1, yp->tx_len);
			dev_kfree_skb_any(skb);
			yp->tx_count = 0;
			yp->tx_crcl = 0x21;
			yp->tx_crch = 0xf3;
			yp->tx_state = TX_DATA;
		}
		break;
	case TX_DATA:
		b = yp->tx_buf[yp->tx_count++];
		outb(b, THR(dev->base_addr));
		temp = yp->tx_crcl;
		yp->tx_crcl = chktabl[temp] ^ yp->tx_crch;
		yp->tx_crch = chktabh[temp] ^ b;
		if (yp->tx_count >= yp->tx_len) {
			yp->tx_state = TX_CRC1;
		}
		break;
	case TX_CRC1:
		yp->tx_crch = chktabl[yp->tx_crcl] ^ yp->tx_crch;
		yp->tx_crcl = chktabh[yp->tx_crcl] ^ chktabl[yp->tx_crch] ^ 0xff;
		outb(yp->tx_crcl, THR(dev->base_addr));
		yp->tx_state = TX_CRC2;
		break;
	case TX_CRC2:
		outb(chktabh[yp->tx_crch] ^ 0xFF, THR(dev->base_addr));
		if (skb_queue_empty(&yp->send_queue)) {
			yp->tx_count = (yp->bitrate * yp->txtail) / 8000;
			if (yp->dupmode == 2)
				yp->tx_count += (yp->bitrate * yp->holdd) / 8;
			if (yp->tx_count == 0)
				yp->tx_count = 1;
			yp->tx_state = TX_TAIL;
		} else {
			yp->tx_count = 1;
			yp->tx_state = TX_HEAD;
		}
		++yp->stats.tx_packets;
		break;
	case TX_TAIL:
		if (--yp->tx_count <= 0) {
			yp->tx_state = TX_OFF;
			ptt_off(dev);
		}
		break;
	}
}

/***********************************************************************************
* ISR routine
************************************************************************************/

static void yam_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct net_device *dev;
	struct yam_port *yp;
	unsigned char iir;
	int counter = 100;
	int i;

	sti();

	for (i = 0; i < NR_PORTS; i++) {
		yp = &yam_ports[i];
		dev = &yp->dev;

		if (!netif_running(dev))
			continue;

		while ((iir = IIR_MASK & inb(IIR(dev->base_addr))) != IIR_NOPEND) {
			unsigned char msr = inb(MSR(dev->base_addr));
			unsigned char lsr = inb(LSR(dev->base_addr));
			unsigned char rxb;

			if (lsr & LSR_OE)
				++yp->stats.rx_fifo_errors;

			yp->dcd = (msr & RX_DCD) ? 1 : 0;

			if (--counter <= 0) {
				printk(KERN_ERR "%s: too many irq iir=%d\n", dev->name, iir);
				return;
			}
			if (msr & TX_RDY) {
				++yp->nb_mdint;
				yam_tx_byte(dev, yp);
			}
			if (lsr & LSR_RXC) {
				++yp->nb_rxint;
				rxb = inb(RBR(dev->base_addr));
				if (msr & RX_FLAG)
					yam_rx_flag(dev, yp);
				else
					yam_rx_byte(dev, yp, rxb);
			}
		}
	}
}

static int yam_net_get_info(char *buffer, char **start, off_t offset, int length)
{
	int len = 0;
	int i;
	off_t pos = 0;
	off_t begin = 0;

	cli();

	for (i = 0; i < NR_PORTS; i++) {
		if (yam_ports[i].iobase == 0 || yam_ports[i].irq == 0)
			continue;
		len += sprintf(buffer + len, "Device yam%d\n", i);
		len += sprintf(buffer + len, "  Up       %d\n", netif_running(&yam_ports[i].dev));
		len += sprintf(buffer + len, "  Speed    %u\n", yam_ports[i].bitrate);
		len += sprintf(buffer + len, "  IoBase   0x%x\n", yam_ports[i].iobase);
		len += sprintf(buffer + len, "  BaudRate %u\n", yam_ports[i].baudrate);
		len += sprintf(buffer + len, "  IRQ      %u\n", yam_ports[i].irq);
		len += sprintf(buffer + len, "  TxState  %u\n", yam_ports[i].tx_state);
		len += sprintf(buffer + len, "  Duplex   %u\n", yam_ports[i].dupmode);
		len += sprintf(buffer + len, "  HoldDly  %u\n", yam_ports[i].holdd);
		len += sprintf(buffer + len, "  TxDelay  %u\n", yam_ports[i].txd);
		len += sprintf(buffer + len, "  TxTail   %u\n", yam_ports[i].txtail);
		len += sprintf(buffer + len, "  SlotTime %u\n", yam_ports[i].slot);
		len += sprintf(buffer + len, "  Persist  %u\n", yam_ports[i].pers);
		len += sprintf(buffer + len, "  TxFrames %lu\n", yam_ports[i].stats.tx_packets);
		len += sprintf(buffer + len, "  RxFrames %lu\n", yam_ports[i].stats.rx_packets);
		len += sprintf(buffer + len, "  TxInt    %u\n", yam_ports[i].nb_mdint);
		len += sprintf(buffer + len, "  RxInt    %u\n", yam_ports[i].nb_rxint);
		len += sprintf(buffer + len, "  RxOver   %lu\n", yam_ports[i].stats.rx_fifo_errors);
		len += sprintf(buffer + len, "\n");

		pos = begin + len;

		if (pos < offset) {
			len = 0;