drivers/net/wan/n2.c - maze/linux - Git at Google

 /*
  * SDL Inc. RISCom/N2 synchronous serial card driver for Linux
  *
  * Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
  *
  * 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.
  *
  * For information see <http://www.kernel.org/pub/linux/utils/net/hdlc/>
  *
  * Note: integrated CSU/DSU/DDS are not supported by this driver
  *
  * Sources of information:
  *    Hitachi HD64570 SCA User's Manual
  *    SDL Inc. PPP/HDLC/CISCO driver
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/capability.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/in.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/moduleparam.h>
 #include <linux/netdevice.h>
 #include <linux/hdlc.h>
 #include <asm/io.h>
 #include "hd64570.h"


 static const char* version = "SDL RISCom/N2 driver version: 1.15";
 static const char* devname = "RISCom/N2";

 #undef DEBUG_PKT
 #define DEBUG_RINGS

 #define USE_WINDOWSIZE 16384
 #define USE_BUS16BITS 1
 #define CLOCK_BASE 9830400	/* 9.8304 MHz */
 #define MAX_PAGES      16	/* 16 RAM pages at max */
 #define MAX_RAM_SIZE 0x80000	/* 512 KB */
 #if MAX_RAM_SIZE > MAX_PAGES * USE_WINDOWSIZE
 #undef MAX_RAM_SIZE
 #define MAX_RAM_SIZE (MAX_PAGES * USE_WINDOWSIZE)
 #endif
 #define N2_IOPORTS 0x10
 #define NEED_DETECT_RAM
 #define NEED_SCA_MSCI_INTR
 #define MAX_TX_BUFFERS 10

 static char *hw;	/* pointer to hw=xxx command line string */

 /* RISCom/N2 Board Registers */

 /* PC Control Register */
 #define N2_PCR 0
 #define PCR_RUNSCA 1     /* Run 64570 */
 #define PCR_VPM    2     /* Enable VPM - needed if using RAM above 1 MB */
 #define PCR_ENWIN  4     /* Open window */
 #define PCR_BUS16  8     /* 16-bit bus */


 /* Memory Base Address Register */
 #define N2_BAR 2


 /* Page Scan Register  */
 #define N2_PSR 4
 #define WIN16K       0x00
 #define WIN32K       0x20
 #define WIN64K       0x40
 #define PSR_WINBITS  0x60
 #define PSR_DMAEN    0x80
 #define PSR_PAGEBITS 0x0F


 /* Modem Control Reg */
 #define N2_MCR 6
 #define CLOCK_OUT_PORT1 0x80
 #define CLOCK_OUT_PORT0 0x40
 #define TX422_PORT1     0x20
 #define TX422_PORT0     0x10
 #define DSR_PORT1       0x08
 #define DSR_PORT0       0x04
 #define DTR_PORT1       0x02
 #define DTR_PORT0       0x01


 typedef struct port_s {
 	struct net_device *dev;
 	struct card_s *card;
 	spinlock_t lock;	/* TX lock */
 	sync_serial_settings settings;
 	int valid;		/* port enabled */
 	int rxpart;		/* partial frame received, next frame invalid*/
 	unsigned short encoding;
 	unsigned short parity;
 	u16 rxin;		/* rx ring buffer 'in' pointer */
 	u16 txin;		/* tx ring buffer 'in' and 'last' pointers */
 	u16 txlast;
 	u8 rxs, txs, tmc;	/* SCA registers */
 	u8 phy_node;		/* physical port # - 0 or 1 */
 	u8 log_node;		/* logical port # */
 }port_t;


 typedef struct card_s {
 	u8 __iomem *winbase;		/* ISA window base address */
 	u32 phy_winbase;	/* ISA physical base address */
 	u32 ram_size;		/* number of bytes */
 	u16 io;			/* IO Base address */
 	u16 buff_offset;	/* offset of first buffer of first channel */
 	u16 rx_ring_buffers;	/* number of buffers in a ring */
 	u16 tx_ring_buffers;
 	u8 irq;			/* IRQ (3-15) */

 	port_t ports[2];
 	struct card_s *next_card;
 }card_t;


 static card_t *first_card;
 static card_t **new_card = &first_card;


 #define sca_reg(reg, card) (0x8000 | (card)->io | \
 			    ((reg) & 0x0F) | (((reg) & 0xF0) << 6))
 #define sca_in(reg, card)		inb(sca_reg(reg, card))
 #define sca_out(value, reg, card)	outb(value, sca_reg(reg, card))
 #define sca_inw(reg, card)		inw(sca_reg(reg, card))
 #define sca_outw(value, reg, card)	outw(value, sca_reg(reg, card))

 #define port_to_card(port)		((port)->card)
 #define log_node(port)			((port)->log_node)
 #define phy_node(port)			((port)->phy_node)
 #define winsize(card)			(USE_WINDOWSIZE)
 #define winbase(card)      	     	((card)->winbase)
 #define get_port(card, port)		((card)->ports[port].valid ? \
 					 &(card)->ports[port] : NULL)


 static __inline__ u8 sca_get_page(card_t *card)
 {
 	return inb(card->io + N2_PSR) & PSR_PAGEBITS;
 }


 static __inline__ void openwin(card_t *card, u8 page)
 {
 	u8 psr = inb(card->io + N2_PSR);
 	outb((psr & ~PSR_PAGEBITS) | page, card->io + N2_PSR);
 }


 #include "hd64570.c"


 static void n2_set_iface(port_t *port)
 {
 	card_t *card = port->card;
 	int io = card->io;
 	u8 mcr = inb(io + N2_MCR);
 	u8 msci = get_msci(port);
 	u8 rxs = port->rxs & CLK_BRG_MASK;
 	u8 txs = port->txs & CLK_BRG_MASK;

 	switch(port->settings.clock_type) {
 	case CLOCK_INT:
 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 		rxs |= CLK_BRG_RX; /* BRG output */
 		txs |= CLK_RXCLK_TX; /* RX clock */
 		break;

 	case CLOCK_TXINT:
 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_BRG_TX; /* BRG output */
 		break;

 	case CLOCK_TXFROMRX:
 		mcr |= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_RXCLK_TX; /* RX clock */
 		break;

 	default:		/* Clock EXTernal */
 		mcr &= port->phy_node ? ~CLOCK_OUT_PORT1 : ~CLOCK_OUT_PORT0;
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_LINE_TX; /* TXC input */
 	}

 	outb(mcr, io + N2_MCR);
 	port->rxs = rxs;
 	port->txs = txs;
 	sca_out(rxs, msci + RXS, card);
 	sca_out(txs, msci + TXS, card);
 	sca_set_port(port);
 }


 static int n2_open(struct net_device *dev)
 {
 	port_t *port = dev_to_port(dev);
 	int io = port->card->io;
 	u8 mcr = inb(io + N2_MCR) | (port->phy_node ? TX422_PORT1:TX422_PORT0);
 	int result;

 	result = hdlc_open(dev);
 	if (result)
 		return result;

 	mcr &= port->phy_node ? ~DTR_PORT1 : ~DTR_PORT0; /* set DTR ON */
 	outb(mcr, io + N2_MCR);

 	outb(inb(io + N2_PCR) | PCR_ENWIN, io + N2_PCR); /* open window */
 	outb(inb(io + N2_PSR) | PSR_DMAEN, io + N2_PSR); /* enable dma */
 	sca_open(dev);
 	n2_set_iface(port);
 	return 0;
 }


 static int n2_close(struct net_device *dev)
 {
 	port_t *port = dev_to_port(dev);
 	int io = port->card->io;
 	u8 mcr = inb(io+N2_MCR) | (port->phy_node ? TX422_PORT1 : TX422_PORT0);

 	sca_close(dev);
 	mcr |= port->phy_node ? DTR_PORT1 : DTR_PORT0; /* set DTR OFF */
 	outb(mcr, io + N2_MCR);
 	hdlc_close(dev);
 	return 0;
 }


 static int n2_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
 	const size_t size = sizeof(sync_serial_settings);
 	sync_serial_settings new_line;
 	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
 	port_t *port = dev_to_port(dev);

 #ifdef DEBUG_RINGS
 	if (cmd == SIOCDEVPRIVATE) {
 		sca_dump_rings(dev);
 		return 0;
 	}
 #endif
 	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;
 		}
 		if (copy_to_user(line, &port->settings, size))
 			return -EFAULT;
 		return 0;

 	case IF_IFACE_SYNC_SERIAL:
 		if(!capable(CAP_NET_ADMIN))
 			return -EPERM;

 		if (copy_from_user(&new_line, line, size))
 			return -EFAULT;

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

 		if (new_line.loopback != 0 && new_line.loopback != 1)
 			return -EINVAL;

 		memcpy(&port->settings, &new_line, size); /* Update settings */
 		n2_set_iface(port);
 		return 0;

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


 static void n2_destroy_card(card_t *card)
 {
 	int cnt;

 	for (cnt = 0; cnt < 2; cnt++)
 		if (card->ports[cnt].card) {
 			struct net_device *dev = port_to_dev(&card->ports[cnt]);
 			unregister_hdlc_device(dev);
 		}

 	if (card->irq)
 		free_irq(card->irq, card);

 	if (card->winbase) {
 		iounmap(card->winbase);
 		release_mem_region(card->phy_winbase, USE_WINDOWSIZE);
 	}

 	if (card->io)
 		release_region(card->io, N2_IOPORTS);
 	if (card->ports[0].dev)
 		free_netdev(card->ports[0].dev);
 	if (card->ports[1].dev)
 		free_netdev(card->ports[1].dev);
 	kfree(card);
 }

 static const struct net_device_ops n2_ops = {
 	.ndo_open       = n2_open,
 	.ndo_stop       = n2_close,
 	.ndo_change_mtu = hdlc_change_mtu,
 	.ndo_start_xmit = hdlc_start_xmit,
 	.ndo_do_ioctl   = n2_ioctl,
 };

 static int __init n2_run(unsigned long io, unsigned long irq,
 			 unsigned long winbase, long valid0, long valid1)
 {
 	card_t *card;
 	u8 cnt, pcr;
 	int i;

 	if (io < 0x200 || io > 0x3FF || (io % N2_IOPORTS) != 0) {
 		printk(KERN_ERR "n2: invalid I/O port value\n");
 		return -ENODEV;
 	}

 	if (irq < 3 || irq > 15 || irq == 6) /* FIXME */ {
 		printk(KERN_ERR "n2: invalid IRQ value\n");
 		return -ENODEV;
 	}

 	if (winbase < 0xA0000 || winbase > 0xFFFFF || (winbase & 0xFFF) != 0) {
 		printk(KERN_ERR "n2: invalid RAM value\n");
 		return -ENODEV;
 	}

 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
 	if (card == NULL) {
 		printk(KERN_ERR "n2: unable to allocate memory\n");
 		return -ENOBUFS;
 	}

 	card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
 	card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
 	if (!card->ports[0].dev || !card->ports[1].dev) {
 		printk(KERN_ERR "n2: unable to allocate memory\n");
 		n2_destroy_card(card);
 		return -ENOMEM;
 	}

 	if (!request_region(io, N2_IOPORTS, devname)) {
 		printk(KERN_ERR "n2: I/O port region in use\n");
 		n2_destroy_card(card);
 		return -EBUSY;
 	}
 	card->io = io;

 	if (request_irq(irq, &sca_intr, 0, devname, card)) {
 		printk(KERN_ERR "n2: could not allocate IRQ\n");
 		n2_destroy_card(card);
 		return(-EBUSY);
 	}
 	card->irq = irq;

 	if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
 		printk(KERN_ERR "n2: could not request RAM window\n");
 		n2_destroy_card(card);
 		return(-EBUSY);
 	}
 	card->phy_winbase = winbase;
 	card->winbase = ioremap(winbase, USE_WINDOWSIZE);
 	if (!card->winbase) {
 		printk(KERN_ERR "n2: ioremap() failed\n");
 		n2_destroy_card(card);
 		return -EFAULT;
 	}

 	outb(0, io + N2_PCR);
 	outb(winbase >> 12, io + N2_BAR);

 	switch (USE_WINDOWSIZE) {
 	case 16384:
 		outb(WIN16K, io + N2_PSR);
 		break;

 	case 32768:
 		outb(WIN32K, io + N2_PSR);
 		break;

 	case 65536:
 		outb(WIN64K, io + N2_PSR);
 		break;

 	default:
 		printk(KERN_ERR "n2: invalid window size\n");
 		n2_destroy_card(card);
 		return -ENODEV;
 	}

 	pcr = PCR_ENWIN | PCR_VPM | (USE_BUS16BITS ? PCR_BUS16 : 0);
 	outb(pcr, io + N2_PCR);

 	card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);

 	/* number of TX + RX buffers for one port */
 	i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
 						   HDLC_MAX_MRU));

 	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
 	card->rx_ring_buffers = i - card->tx_ring_buffers;

 	card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
 		(card->tx_ring_buffers + card->rx_ring_buffers);

 	printk(KERN_INFO "n2: RISCom/N2 %u KB RAM, IRQ%u, "
 	       "using %u TX + %u RX packets rings\n", card->ram_size / 1024,
 	       card->irq, card->tx_ring_buffers, card->rx_ring_buffers);

 	if (card->tx_ring_buffers < 1) {
 		printk(KERN_ERR "n2: RAM test failed\n");
 		n2_destroy_card(card);
 		return -EIO;
 	}

 	pcr |= PCR_RUNSCA;		/* run SCA */
 	outb(pcr, io + N2_PCR);
 	outb(0, io + N2_MCR);

 	sca_init(card, 0);
 	for (cnt = 0; cnt < 2; cnt++) {
 		port_t *port = &card->ports[cnt];
 		struct net_device *dev = port_to_dev(port);
 		hdlc_device *hdlc = dev_to_hdlc(dev);

 		if ((cnt == 0 && !valid0) || (cnt == 1 && !valid1))
 			continue;

 		port->phy_node = cnt;
 		port->valid = 1;

 		if ((cnt == 1) && valid0)
 			port->log_node = 1;

 		spin_lock_init(&port->lock);
 		dev->irq = irq;
 		dev->mem_start = winbase;
 		dev->mem_end = winbase + USE_WINDOWSIZE - 1;
 		dev->tx_queue_len = 50;
 		dev->netdev_ops = &n2_ops;
 		hdlc->attach = sca_attach;
 		hdlc->xmit = sca_xmit;
 		port->settings.clock_type = CLOCK_EXT;
 		port->card = card;

 		if (register_hdlc_device(dev)) {
 			printk(KERN_WARNING "n2: unable to register hdlc "
 			       "device\n");
 			port->card = NULL;
 			n2_destroy_card(card);
 			return -ENOBUFS;
 		}
 		sca_init_port(port); /* Set up SCA memory */

 		printk(KERN_INFO "%s: RISCom/N2 node %d\n",
 		       dev->name, port->phy_node);
 	}

 	*new_card = card;
 	new_card = &card->next_card;

 	return 0;
 }


 static int __init n2_init(void)
 {
 	if (hw==NULL) {
 #ifdef MODULE
 		printk(KERN_INFO "n2: no card initialized\n");
 #endif
 		return -EINVAL;	/* no parameters specified, abort */
 	}

 	printk(KERN_INFO "%s\n", version);

 	do {
 		unsigned long io, irq, ram;
 		long valid[2] = { 0, 0 }; /* Default = both ports disabled */

 		io = simple_strtoul(hw, &hw, 0);

 		if (*hw++ != ',')
 			break;
 		irq = simple_strtoul(hw, &hw, 0);

 		if (*hw++ != ',')
 			break;
 		ram = simple_strtoul(hw, &hw, 0);

 		if (*hw++ != ',')
 			break;
 		while(1) {
 			if (*hw == '0' && !valid[0])
 				valid[0] = 1; /* Port 0 enabled */
 			else if (*hw == '1' && !valid[1])
 				valid[1] = 1; /* Port 1 enabled */
 			else
 				break;
 			hw++;
 		}

 		if (!valid[0] && !valid[1])
 			break;	/* at least one port must be used */

 		if (*hw == ':' || *hw == '\x0')
 			n2_run(io, irq, ram, valid[0], valid[1]);

 		if (*hw == '\x0')
 			return first_card ? 0 : -EINVAL;
 	}while(*hw++ == ':');

 	printk(KERN_ERR "n2: invalid hardware parameters\n");
 	return first_card ? 0 : -EINVAL;
 }


 static void __exit n2_cleanup(void)
 {
 	card_t *card = first_card;

 	while (card) {
 		card_t *ptr = card;
 		card = card->next_card;
 		n2_destroy_card(ptr);
 	}
 }


 module_init(n2_init);
 module_exit(n2_cleanup);

 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 MODULE_DESCRIPTION("RISCom/N2 serial port driver");
 MODULE_LICENSE("GPL v2");
 module_param(hw, charp, 0444);
 MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");
	/*
	* SDL Inc. RISCom/N2 synchronous serial card driver for Linux
	*
	* Copyright (C) 1998-2003 Krzysztof Halasa <khc@pm.waw.pl>
	*
	* 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.
	*
	* For information see <http://www.kernel.org/pub/linux/utils/net/hdlc/>
	*
	* Note: integrated CSU/DSU/DDS are not supported by this driver
	*
	* Sources of information:
	* Hitachi HD64570 SCA User's Manual
	* SDL Inc. PPP/HDLC/CISCO driver
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/capability.h>
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/fcntl.h>
	#include <linux/in.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/ioport.h>
	#include <linux/moduleparam.h>
	#include <linux/netdevice.h>
	#include <linux/hdlc.h>
	#include <asm/io.h>
	#include "hd64570.h"


	static const char* version = "SDL RISCom/N2 driver version: 1.15";
	static const char* devname = "RISCom/N2";

	#undef DEBUG_PKT
	#define DEBUG_RINGS

	#define USE_WINDOWSIZE 16384
	#define USE_BUS16BITS 1
	#define CLOCK_BASE 9830400 /* 9.8304 MHz */
	#define MAX_PAGES 16 /* 16 RAM pages at max */
	#define MAX_RAM_SIZE 0x80000 /* 512 KB */
	#if MAX_RAM_SIZE > MAX_PAGES * USE_WINDOWSIZE
	#undef MAX_RAM_SIZE
	#define MAX_RAM_SIZE (MAX_PAGES * USE_WINDOWSIZE)
	#endif
	#define N2_IOPORTS 0x10
	#define NEED_DETECT_RAM
	#define NEED_SCA_MSCI_INTR
	#define MAX_TX_BUFFERS 10

	static char hw; / pointer to hw=xxx command line string */

	/* RISCom/N2 Board Registers */

	/* PC Control Register */
	#define N2_PCR 0
	#define PCR_RUNSCA 1 /* Run 64570 */
	#define PCR_VPM 2 /* Enable VPM - needed if using RAM above 1 MB */
	#define PCR_ENWIN 4 /* Open window */
	#define PCR_BUS16 8 /* 16-bit bus */


	/* Memory Base Address Register */
	#define N2_BAR 2


	/* Page Scan Register */
	#define N2_PSR 4
	#define WIN16K 0x00
	#define WIN32K 0x20
	#define WIN64K 0x40
	#define PSR_WINBITS 0x60
	#define PSR_DMAEN 0x80
	#define PSR_PAGEBITS 0x0F


	/* Modem Control Reg */
	#define N2_MCR 6
	#define CLOCK_OUT_PORT1 0x80
	#define CLOCK_OUT_PORT0 0x40
	#define TX422_PORT1 0x20
	#define TX422_PORT0 0x10
	#define DSR_PORT1 0x08
	#define DSR_PORT0 0x04
	#define DTR_PORT1 0x02
	#define DTR_PORT0 0x01


	typedef struct port_s {
	struct net_device *dev;
	struct card_s *card;
	spinlock_t lock; /* TX lock */
	sync_serial_settings settings;
	int valid; /* port enabled */
	int rxpart; /* partial frame received, next frame invalid*/
	unsigned short encoding;
	unsigned short parity;
	u16 rxin; /* rx ring buffer 'in' pointer */
	u16 txin; /* tx ring buffer 'in' and 'last' pointers */
	u16 txlast;
	u8 rxs, txs, tmc; /* SCA registers */
	u8 phy_node; /* physical port # - 0 or 1 */
	u8 log_node; /* logical port # */
	}port_t;



	typedef struct card_s {
	u8 __iomem winbase; / ISA window base address */
	u32 phy_winbase; /* ISA physical base address */
	u32 ram_size; /* number of bytes */
	u16 io; /* IO Base address */
	u16 buff_offset; /* offset of first buffer of first channel */
	u16 rx_ring_buffers; /* number of buffers in a ring */
	u16 tx_ring_buffers;
	u8 irq; /* IRQ (3-15) */

	port_t ports[2];
	struct card_s *next_card;
	}card_t;


	static card_t *first_card;
	static card_t **new_card = &first_card;


	#define sca_reg(reg, card) (0x8000 \| (card)->io \| \
	((reg) & 0x0F) \| (((reg) & 0xF0) << 6))
	#define sca_in(reg, card) inb(sca_reg(reg, card))
	#define sca_out(value, reg, card) outb(value, sca_reg(reg, card))
	#define sca_inw(reg, card) inw(sca_reg(reg, card))
	#define sca_outw(value, reg, card) outw(value, sca_reg(reg, card))

	#define port_to_card(port) ((port)->card)
	#define log_node(port) ((port)->log_node)
	#define phy_node(port) ((port)->phy_node)
	#define winsize(card) (USE_WINDOWSIZE)
	#define winbase(card) ((card)->winbase)
	#define get_port(card, port) ((card)->ports[port].valid ? \
	&(card)->ports[port] : NULL)


	static __inline__ u8 sca_get_page(card_t *card)
	{
	return inb(card->io + N2_PSR) & PSR_PAGEBITS;
	}


	static __inline__ void openwin(card_t *card, u8 page)
	{
	u8 psr = inb(card->io + N2_PSR);
	outb((psr & ~PSR_PAGEBITS) \| page, card->io + N2_PSR);
	}


	#include "hd64570.c"


	static void n2_set_iface(port_t *port)
	{
	card_t *card = port->card;
	int io = card->io;
	u8 mcr = inb(io + N2_MCR);
	u8 msci = get_msci(port);
	u8 rxs = port->rxs & CLK_BRG_MASK;
	u8 txs = port->txs & CLK_BRG_MASK;

	switch(port->settings.clock_type) {
	case CLOCK_INT:
	mcr \|= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
	rxs \|= CLK_BRG_RX; /* BRG output */
	txs \|= CLK_RXCLK_TX; /* RX clock */
	break;

	case CLOCK_TXINT:
	mcr \|= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_BRG_TX; /* BRG output */
	break;

	case CLOCK_TXFROMRX:
	mcr \|= port->phy_node ? CLOCK_OUT_PORT1 : CLOCK_OUT_PORT0;
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_RXCLK_TX; /* RX clock */
	break;

	default: /* Clock EXTernal */
	mcr &= port->phy_node ? ~CLOCK_OUT_PORT1 : ~CLOCK_OUT_PORT0;
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_LINE_TX; /* TXC input */
	}

	outb(mcr, io + N2_MCR);
	port->rxs = rxs;
	port->txs = txs;
	sca_out(rxs, msci + RXS, card);
	sca_out(txs, msci + TXS, card);
	sca_set_port(port);
	}



	static int n2_open(struct net_device *dev)
	{
	port_t *port = dev_to_port(dev);
	int io = port->card->io;
	u8 mcr = inb(io + N2_MCR) \| (port->phy_node ? TX422_PORT1:TX422_PORT0);
	int result;

	result = hdlc_open(dev);
	if (result)
	return result;

	mcr &= port->phy_node ? ~DTR_PORT1 : ~DTR_PORT0; /* set DTR ON */
	outb(mcr, io + N2_MCR);

	outb(inb(io + N2_PCR) \| PCR_ENWIN, io + N2_PCR); /* open window */
	outb(inb(io + N2_PSR) \| PSR_DMAEN, io + N2_PSR); /* enable dma */
	sca_open(dev);
	n2_set_iface(port);
	return 0;
	}



	static int n2_close(struct net_device *dev)
	{
	port_t *port = dev_to_port(dev);
	int io = port->card->io;
	u8 mcr = inb(io+N2_MCR) \| (port->phy_node ? TX422_PORT1 : TX422_PORT0);

	sca_close(dev);
	mcr \|= port->phy_node ? DTR_PORT1 : DTR_PORT0; /* set DTR OFF */
	outb(mcr, io + N2_MCR);
	hdlc_close(dev);
	return 0;
	}



	static int n2_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
	{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings new_line;
	sync_serial_settings __user *line = ifr->ifr_settings.ifs_ifsu.sync;
	port_t *port = dev_to_port(dev);

	#ifdef DEBUG_RINGS
	if (cmd == SIOCDEVPRIVATE) {
	sca_dump_rings(dev);
	return 0;
	}
	#endif
	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;
	}
	if (copy_to_user(line, &port->settings, size))
	return -EFAULT;
	return 0;

	case IF_IFACE_SYNC_SERIAL:
	if(!capable(CAP_NET_ADMIN))
	return -EPERM;

	if (copy_from_user(&new_line, line, size))
	return -EFAULT;

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

	if (new_line.loopback != 0 && new_line.loopback != 1)
	return -EINVAL;

	memcpy(&port->settings, &new_line, size); /* Update settings */
	n2_set_iface(port);
	return 0;

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



	static void n2_destroy_card(card_t *card)
	{
	int cnt;

	for (cnt = 0; cnt < 2; cnt++)
	if (card->ports[cnt].card) {
	struct net_device *dev = port_to_dev(&card->ports[cnt]);
	unregister_hdlc_device(dev);
	}

	if (card->irq)
	free_irq(card->irq, card);

	if (card->winbase) {
	iounmap(card->winbase);
	release_mem_region(card->phy_winbase, USE_WINDOWSIZE);
	}

	if (card->io)
	release_region(card->io, N2_IOPORTS);
	if (card->ports[0].dev)
	free_netdev(card->ports[0].dev);
	if (card->ports[1].dev)
	free_netdev(card->ports[1].dev);
	kfree(card);
	}

	static const struct net_device_ops n2_ops = {
	.ndo_open = n2_open,
	.ndo_stop = n2_close,
	.ndo_change_mtu = hdlc_change_mtu,
	.ndo_start_xmit = hdlc_start_xmit,
	.ndo_do_ioctl = n2_ioctl,
	};

	static int __init n2_run(unsigned long io, unsigned long irq,
	unsigned long winbase, long valid0, long valid1)
	{
	card_t *card;
	u8 cnt, pcr;
	int i;

	if (io < 0x200 \|\| io > 0x3FF \|\| (io % N2_IOPORTS) != 0) {
	printk(KERN_ERR "n2: invalid I/O port value\n");
	return -ENODEV;
	}

	if (irq < 3 \|\| irq > 15 \|\| irq == 6) /* FIXME */ {
	printk(KERN_ERR "n2: invalid IRQ value\n");
	return -ENODEV;
	}

	if (winbase < 0xA0000 \|\| winbase > 0xFFFFF \|\| (winbase & 0xFFF) != 0) {
	printk(KERN_ERR "n2: invalid RAM value\n");
	return -ENODEV;
	}

	card = kzalloc(sizeof(card_t), GFP_KERNEL);
	if (card == NULL) {
	printk(KERN_ERR "n2: unable to allocate memory\n");
	return -ENOBUFS;
	}

	card->ports[0].dev = alloc_hdlcdev(&card->ports[0]);
	card->ports[1].dev = alloc_hdlcdev(&card->ports[1]);
	if (!card->ports[0].dev \|\| !card->ports[1].dev) {
	printk(KERN_ERR "n2: unable to allocate memory\n");
	n2_destroy_card(card);
	return -ENOMEM;
	}

	if (!request_region(io, N2_IOPORTS, devname)) {
	printk(KERN_ERR "n2: I/O port region in use\n");
	n2_destroy_card(card);
	return -EBUSY;
	}
	card->io = io;

	if (request_irq(irq, &sca_intr, 0, devname, card)) {
	printk(KERN_ERR "n2: could not allocate IRQ\n");
	n2_destroy_card(card);
	return(-EBUSY);
	}
	card->irq = irq;

	if (!request_mem_region(winbase, USE_WINDOWSIZE, devname)) {
	printk(KERN_ERR "n2: could not request RAM window\n");
	n2_destroy_card(card);
	return(-EBUSY);
	}
	card->phy_winbase = winbase;
	card->winbase = ioremap(winbase, USE_WINDOWSIZE);
	if (!card->winbase) {
	printk(KERN_ERR "n2: ioremap() failed\n");
	n2_destroy_card(card);
	return -EFAULT;
	}

	outb(0, io + N2_PCR);
	outb(winbase >> 12, io + N2_BAR);

	switch (USE_WINDOWSIZE) {
	case 16384:
	outb(WIN16K, io + N2_PSR);
	break;

	case 32768:
	outb(WIN32K, io + N2_PSR);
	break;

	case 65536:
	outb(WIN64K, io + N2_PSR);
	break;

	default:
	printk(KERN_ERR "n2: invalid window size\n");
	n2_destroy_card(card);
	return -ENODEV;
	}

	pcr = PCR_ENWIN \| PCR_VPM \| (USE_BUS16BITS ? PCR_BUS16 : 0);
	outb(pcr, io + N2_PCR);

	card->ram_size = sca_detect_ram(card, card->winbase, MAX_RAM_SIZE);

	/* number of TX + RX buffers for one port */
	i = card->ram_size / ((valid0 + valid1) * (sizeof(pkt_desc) +
	HDLC_MAX_MRU));

	card->tx_ring_buffers = min(i / 2, MAX_TX_BUFFERS);
	card->rx_ring_buffers = i - card->tx_ring_buffers;

	card->buff_offset = (valid0 + valid1) * sizeof(pkt_desc) *
	(card->tx_ring_buffers + card->rx_ring_buffers);

	printk(KERN_INFO "n2: RISCom/N2 %u KB RAM, IRQ%u, "
	"using %u TX + %u RX packets rings\n", card->ram_size / 1024,
	card->irq, card->tx_ring_buffers, card->rx_ring_buffers);

	if (card->tx_ring_buffers < 1) {
	printk(KERN_ERR "n2: RAM test failed\n");
	n2_destroy_card(card);
	return -EIO;
	}

	pcr \|= PCR_RUNSCA; /* run SCA */
	outb(pcr, io + N2_PCR);
	outb(0, io + N2_MCR);

	sca_init(card, 0);
	for (cnt = 0; cnt < 2; cnt++) {
	port_t *port = &card->ports[cnt];
	struct net_device *dev = port_to_dev(port);
	hdlc_device *hdlc = dev_to_hdlc(dev);

	if ((cnt == 0 && !valid0) \|\| (cnt == 1 && !valid1))
	continue;

	port->phy_node = cnt;
	port->valid = 1;

	if ((cnt == 1) && valid0)
	port->log_node = 1;

	spin_lock_init(&port->lock);
	dev->irq = irq;
	dev->mem_start = winbase;
	dev->mem_end = winbase + USE_WINDOWSIZE - 1;
	dev->tx_queue_len = 50;
	dev->netdev_ops = &n2_ops;
	hdlc->attach = sca_attach;
	hdlc->xmit = sca_xmit;
	port->settings.clock_type = CLOCK_EXT;
	port->card = card;

	if (register_hdlc_device(dev)) {
	printk(KERN_WARNING "n2: unable to register hdlc "
	"device\n");
	port->card = NULL;
	n2_destroy_card(card);
	return -ENOBUFS;
	}
	sca_init_port(port); /* Set up SCA memory */

	printk(KERN_INFO "%s: RISCom/N2 node %d\n",
	dev->name, port->phy_node);
	}

	*new_card = card;
	new_card = &card->next_card;

	return 0;
	}



	static int __init n2_init(void)
	{
	if (hw==NULL) {
	#ifdef MODULE
	printk(KERN_INFO "n2: no card initialized\n");
	#endif
	return -EINVAL; /* no parameters specified, abort */
	}

	printk(KERN_INFO "%s\n", version);

	do {
	unsigned long io, irq, ram;
	long valid[2] = { 0, 0 }; /* Default = both ports disabled */

	io = simple_strtoul(hw, &hw, 0);

	if (*hw++ != ',')
	break;
	irq = simple_strtoul(hw, &hw, 0);

	if (*hw++ != ',')
	break;
	ram = simple_strtoul(hw, &hw, 0);

	if (*hw++ != ',')
	break;
	while(1) {
	if (*hw == '0' && !valid[0])
	valid[0] = 1; /* Port 0 enabled */
	else if (*hw == '1' && !valid[1])
	valid[1] = 1; /* Port 1 enabled */
	else
	break;
	hw++;
	}

	if (!valid[0] && !valid[1])
	break; /* at least one port must be used */

	if (hw == ':' \|\| hw == '\x0')
	n2_run(io, irq, ram, valid[0], valid[1]);

	if (*hw == '\x0')
	return first_card ? 0 : -EINVAL;
	}while(*hw++ == ':');

	printk(KERN_ERR "n2: invalid hardware parameters\n");
	return first_card ? 0 : -EINVAL;
	}


	static void __exit n2_cleanup(void)
	{
	card_t *card = first_card;

	while (card) {
	card_t *ptr = card;
	card = card->next_card;
	n2_destroy_card(ptr);
	}
	}


	module_init(n2_init);
	module_exit(n2_cleanup);

	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	MODULE_DESCRIPTION("RISCom/N2 serial port driver");
	MODULE_LICENSE("GPL v2");
	module_param(hw, charp, 0444);
	MODULE_PARM_DESC(hw, "io,irq,ram,ports:io,irq,...");