wanxl.c

linux-2.6.15.6

/*
 * wanXL serial card driver for Linux
 * host part
 *
 * Copyright (C) 2003 Krzysztof Halasa <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 *
 * Status:
 *   - Only DTE (external clock) support with NRZ and NRZI encodings
 *   - wanXL100 will require minor driver modifications, no access to hw
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/netdevice.h>
#include <linux/hdlc.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <asm/io.h>
#include <asm/delay.h>

#include "wanxl.h"

static const char* version = "wanXL serial card driver version: 0.48";

#define PLX_CTL_RESET   0x40000000 /* adapter reset */

#undef DEBUG_PKT
#undef DEBUG_PCI

/* MAILBOX #1 - PUTS COMMANDS */
#define MBX1_CMD_ABORTJ 0x85000000 /* Abort and Jump */
#ifdef __LITTLE_ENDIAN
#define MBX1_CMD_BSWAP  0x8C000001 /* little-endian Byte Swap Mode */
#else
#define MBX1_CMD_BSWAP  0x8C000000 /* big-endian Byte Swap Mode */
#endif

/* MAILBOX #2 - DRAM SIZE */
#define MBX2_MEMSZ_MASK 0xFFFF0000 /* PUTS Memory Size Register mask */


typedef struct {
	struct net_device *dev;
	struct card_t *card;
	spinlock_t lock;	/* for wanxl_xmit */
        int node;		/* physical port #0 - 3 */
	unsigned int clock_type;
	int tx_in, tx_out;
	struct sk_buff *tx_skbs[TX_BUFFERS];
}port_t;


typedef struct {
	desc_t rx_descs[RX_QUEUE_LENGTH];
	port_status_t port_status[4];
}card_status_t;


typedef struct card_t {
	int n_ports;		/* 1, 2 or 4 ports */
	u8 irq;

	u8 __iomem *plx;	/* PLX PCI9060 virtual base address */
	struct pci_dev *pdev;	/* for pci_name(pdev) */
	int rx_in;
	struct sk_buff *rx_skbs[RX_QUEUE_LENGTH];
	card_status_t *status;	/* shared between host and card */
	dma_addr_t status_address;
	port_t ports[0];	/* 1 - 4 port_t structures follow */
}card_t;



static inline port_t* dev_to_port(struct net_device *dev)
{
        return (port_t *)dev_to_hdlc(dev)->priv;
}


static inline port_status_t* get_status(port_t *port)
{
	return &port->card->status->port_status[port->node];
}


#ifdef DEBUG_PCI
static inline dma_addr_t pci_map_single_debug(struct pci_dev *pdev, void *ptr,
					      size_t size, int direction)
{
	dma_addr_t addr = pci_map_single(pdev, ptr, size, direction);
	if (addr + size > 0x100000000LL)
		printk(KERN_CRIT "wanXL %s: pci_map_single() returned memory"
		       " at 0x%LX!\n", pci_name(pdev),
		       (unsigned long long)addr);
	return addr;
}

#undef pci_map_single
#define pci_map_single pci_map_single_debug
#endif


/* Cable and/or personality module change interrupt service */
static inline void wanxl_cable_intr(port_t *port)
{
	u32 value = get_status(port)->cable;
	int valid = 1;
	const char *cable, *pm, *dte = "", *dsr = "", *dcd = "";

	switch(value & 0x7) {
	case STATUS_CABLE_V35: cable = "V.35"; break;
	case STATUS_CABLE_X21: cable = "X.21"; break;
	case STATUS_CABLE_V24: cable = "V.24"; break;
	case STATUS_CABLE_EIA530: cable = "EIA530"; break;
	case STATUS_CABLE_NONE: cable = "no"; break;
	default: cable = "invalid";
	}

	switch((value >> STATUS_CABLE_PM_SHIFT) & 0x7) {
	case STATUS_CABLE_V35: pm = "V.35"; break;
	case STATUS_CABLE_X21: pm = "X.21"; break;
	case STATUS_CABLE_V24: pm = "V.24"; break;
	case STATUS_CABLE_EIA530: pm = "EIA530"; break;
	case STATUS_CABLE_NONE: pm = "no personality"; valid = 0; break;
	default: pm = "invalid personality"; valid = 0;
	}

	if (valid) {
		if ((value & 7) == ((value >> STATUS_CABLE_PM_SHIFT) & 7)) {
			dsr = (value & STATUS_CABLE_DSR) ? ", DSR ON" :
				", DSR off";
			dcd = (value & STATUS_CABLE_DCD) ? ", carrier ON" :
				", carrier off";
		}
		dte = (value & STATUS_CABLE_DCE) ? " DCE" : " DTE";
	}
	printk(KERN_INFO "%s: %s%s module, %s cable%s%s\n",
	       port->dev->name, pm, dte, cable, dsr, dcd);

	hdlc_set_carrier(value & STATUS_CABLE_DCD, port->dev);
}



/* Transmit complete interrupt service */
static inline void wanxl_tx_intr(port_t *port)
{
	struct net_device *dev = port->dev;
	struct net_device_stats *stats = hdlc_stats(dev);
	while (1) {
                desc_t *desc = &get_status(port)->tx_descs[port->tx_in];
		struct sk_buff *skb = port->tx_skbs[port->tx_in];

		switch (desc->stat) {
		case PACKET_FULL:
		case PACKET_EMPTY:
			netif_wake_queue(dev);
			return;

		case PACKET_UNDERRUN:
			stats->tx_errors++;
			stats->tx_fifo_errors++;
			break;

		default:
			stats->tx_packets++;
			stats->tx_bytes += skb->len;
		}
                desc->stat = PACKET_EMPTY; /* Free descriptor */
		pci_unmap_single(port->card->pdev, desc->address, skb->len,
				 PCI_DMA_TODEVICE);
		dev_kfree_skb_irq(skb);
                port->tx_in = (port->tx_in + 1) % TX_BUFFERS;
        }
}



/* Receive complete interrupt service */
static inline void wanxl_rx_intr(card_t *card)
{
	desc_t *desc;
	while (desc = &card->status->rx_descs[card->rx_in],
	       desc->stat != PACKET_EMPTY) {
		if ((desc->stat & PACKET_PORT_MASK) > card->n_ports)
			printk(KERN_CRIT "wanXL %s: received packet for"
			       " nonexistent port\n", pci_name(card->pdev));
		else {
			struct sk_buff *skb = card->rx_skbs[card->rx_in];
			port_t *port = &card->ports[desc->stat &
						    PACKET_PORT_MASK];
			struct net_device *dev = port->dev;
			struct net_device_stats *stats = hdlc_stats(dev);

			if (!skb)
				stats->rx_dropped++;
			else {
				pci_unmap_single(card->pdev, desc->address,
						 BUFFER_LENGTH,
						 PCI_DMA_FROMDEVICE);
				skb_put(skb, desc->length);

#ifdef DEBUG_PKT
				printk(KERN_DEBUG "%s RX(%i):", dev->name,
				       skb->len);
				debug_frame(skb);
#endif
				stats->rx_packets++;
				stats->rx_bytes += skb->len;
				dev->last_rx = jiffies;
				skb->protocol = hdlc_type_trans(skb, dev);
				netif_rx(skb);
				skb = NULL;
			}

			if (!skb) {
				skb = dev_alloc_skb(BUFFER_LENGTH);
				desc->address = skb ?
					pci_map_single(card->pdev, skb->data,
						       BUFFER_LENGTH,
						       PCI_DMA_FROMDEVICE) : 0;
				card->rx_skbs[card->rx_in] = skb;
			}
		}
		desc->stat = PACKET_EMPTY; /* Free descriptor */
		card->rx_in = (card->rx_in + 1) % RX_QUEUE_LENGTH;
	}
}



static irqreturn_t wanxl_intr(int irq, void* dev_id, struct pt_regs *regs)
{
        card_t *card = dev_id;
        int i;
        u32 stat;
        int handled = 0;


        while((stat = readl(card->plx + PLX_DOORBELL_FROM_CARD)) != 0) {
                handled = 1;
		writel(stat, card->plx + PLX_DOORBELL_FROM_CARD);

                for (i = 0; i < card->n_ports; i++) {
			if (stat & (1 << (DOORBELL_FROM_CARD_TX_0 + i)))
				wanxl_tx_intr(&card->ports[i]);
			if (stat & (1 << (DOORBELL_FROM_CARD_CABLE_0 + i)))
				wanxl_cable_intr(&card->ports[i]);
		}
		if (stat & (1 << DOORBELL_FROM_CARD_RX))
			wanxl_rx_intr(card);
        }

        return IRQ_RETVAL(handled);
}



static int wanxl_xmit(struct sk_buff *skb, struct net_device *dev)
{
        port_t *port = dev_to_port(dev);
	desc_t *desc;

        spin_lock(&port->lock);

	desc = &get_status(port)->tx_descs[port->tx_out];
        if (desc->stat != PACKET_EMPTY) {
                /* should never happen - previous xmit should stop queue */
#ifdef DEBUG_PKT
                printk(KERN_DEBUG "%s: transmitter buffer full\n", dev->name);
#endif
		netif_stop_queue(dev);
		spin_unlock_irq(&port->lock);
		return 1;       /* request packet to be queued */
	}

#ifdef DEBUG_PKT
	printk(KERN_DEBUG "%s TX(%i):", dev->name, skb->len);
	debug_frame(skb);
#endif

	port->tx_skbs[port->tx_out] = skb;
	desc->address = pci_map_single(port->card->pdev, skb->data, skb->len,
				       PCI_DMA_TODEVICE);
	desc->length = skb->len;
	desc->stat = PACKET_FULL;
	writel(1 << (DOORBELL_TO_CARD_TX_0 + port->node),
	       port->card->plx + PLX_DOORBELL_TO_CARD);
	dev->trans_start = jiffies;

	port->tx_out = (port->tx_out + 1) % TX_BUFFERS;

	if (get_status(port)->tx_descs[port->tx_out].stat != PACKET_EMPTY) {
		netif_stop_queue(dev);
#ifdef DEBUG_PKT
		printk(KERN_DEBUG "%s: transmitter buffer full\n", dev->name);
#endif
	}

	spin_unlock(&port->lock);
	return 0;
}



static int wanxl_attach(struct net_device *dev, unsigned short encoding,
			unsigned short parity)
{
	port_t *port = dev_to_port(dev);

	if (encoding != ENCODING_NRZ &&
	    encoding != ENCODING_NRZI)
		return -EINVAL;

	if (parity != PARITY_NONE &&
	    parity != PARITY_CRC32_PR1_CCITT &&
	    parity != PARITY_CRC16_PR1_CCITT &&
	    parity != PARITY_CRC32_PR0_CCITT &&
	    parity != PARITY_CRC16_PR0_CCITT)
		return -EINVAL;

	get_status(port)->encoding = encoding;
	get_status(port)->parity = parity;
	return 0;
}



static int wanxl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings line;
	port_t *port = dev_to_port(dev);

	if (cmd != SIOCWANDEV)
		return hdlc_ioctl(dev, ifr, cmd);

	switch (ifr->ifr_settings.type) {
	case IF_GET_IFACE:
		ifr->ifr_settings.type = IF_IFACE_SYNC_SERIAL;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		line.clock_type = get_status(port)->clocking;
		line.clock_rate = 0;
		line.loopback = 0;

		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.sync, &line, size))
			return -EFAULT;
		return 0;

	case IF_IFACE_SYNC_SERIAL:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;
		if (dev->flags & IFF_UP)
			return -EBUSY;

		if (copy_from_user(&line, ifr->ifr_settings.ifs_ifsu.sync,
				   size))
			return -EFAULT;

		if (line.clock_type != CLOCK_EXT &&
		    line.clock_type != CLOCK_TXFROMRX)
			return -EINVAL; /* No such clock setting */

		if (line.loopback != 0)
			return -EINVAL;

		get_status(port)->clocking = line.clock_type;
		return 0;

	default:
		return hdlc_ioctl(dev, ifr, cmd);
        }
}



static int wanxl_open(struct net_device *dev)
{
	port_t *port = dev_to_port(dev);
	u8 __iomem *dbr = port->card->plx + PLX_DOORBELL_TO_CARD;
	unsigned long timeout;
	int i;

	if (get_status(port)->open) {
		printk(KERN_ERR "%s: port already open\n", dev->name);
		return -EIO;
	}
	if ((i = hdlc_open(dev)) != 0)
		return i;

	port->tx_in = port->tx_out = 0;
	for (i = 0; i < TX_BUFFERS; i++)
		get_status(port)->tx_descs[i].stat = PACKET_EMPTY;
	/* signal the card */
	writel(1 << (DOORBELL_TO_CARD_OPEN_0 + port->node), dbr);

	timeout = jiffies + HZ;
	do
		if (get_status(port)->open) {
			netif_start_queue(dev);
			return 0;
		}
	while (time_after(timeout, jiffies));

	printk(KERN_ERR "%s: unable to open port\n", dev->name);
	/* ask the card to close the port, should it be still alive */