drivers/net/wan/c101.c - pub/scm/linux/kernel/git/peterz/queue - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Moxa C101 synchronous serial card driver for Linux
  *
  * Copyright (C) 2000-2003 Krzysztof Halasa <khc@pm.waw.pl>
  *
  * For information see <https://www.kernel.org/pub/linux/utils/net/hdlc/>
  *
  * Sources of information:
  *    Hitachi HD64570 SCA User's Manual
  *    Moxa C101 User's Manual
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/capability.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/netdevice.h>
 #include <linux/hdlc.h>
 #include <linux/delay.h>
 #include <asm/io.h>

 #include "hd64570.h"

 static const char *version = "Moxa C101 driver version: 1.15";
 static const char *devname = "C101";

 #undef DEBUG_PKT
 #define DEBUG_RINGS

 #define C101_PAGE 0x1D00
 #define C101_DTR 0x1E00
 #define C101_SCA 0x1F00
 #define C101_WINDOW_SIZE 0x2000
 #define C101_MAPPED_RAM_SIZE 0x4000

 #define RAM_SIZE (256 * 1024)
 #define TX_RING_BUFFERS 10
 #define RX_RING_BUFFERS ((RAM_SIZE - C101_WINDOW_SIZE) /		\
 			 (sizeof(pkt_desc) + HDLC_MAX_MRU) - TX_RING_BUFFERS)

 #define CLOCK_BASE 9830400	/* 9.8304 MHz */
 #define PAGE0_ALWAYS_MAPPED

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

 typedef struct card_s {
 	struct net_device *dev;
 	spinlock_t lock;	/* TX lock */
 	u8 __iomem *win0base;	/* ISA window base address */
 	u32 phy_winbase;	/* ISA physical base address */
 	sync_serial_settings settings;
 	int rxpart;		/* partial frame received, next frame invalid*/
 	unsigned short encoding;
 	unsigned short parity;
 	u16 rx_ring_buffers;	/* number of buffers in a ring */
 	u16 tx_ring_buffers;
 	u16 buff_offset;	/* offset of first buffer of first channel */
 	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 irq;			/* IRQ (3-15) */
 	u8 page;

 	struct card_s *next_card;
 } card_t;

 typedef card_t port_t;

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

 #define sca_in(reg, card)	   readb((card)->win0base + C101_SCA + (reg))
 #define sca_out(value, reg, card)  writeb(value, (card)->win0base + C101_SCA + (reg))
 #define sca_inw(reg, card)	   readw((card)->win0base + C101_SCA + (reg))

 /* EDA address register must be set in EDAL, EDAH order - 8 bit ISA bus */
 #define sca_outw(value, reg, card) do { \
 	writeb(value & 0xFF, (card)->win0base + C101_SCA + (reg)); \
 	writeb((value >> 8) & 0xFF, (card)->win0base + C101_SCA + (reg + 1));\
 } while (0)

 #define port_to_card(port)	   (port)
 #define log_node(port)		   (0)
 #define phy_node(port)		   (0)
 #define winsize(card)		   (C101_WINDOW_SIZE)
 #define win0base(card)		   ((card)->win0base)
 #define winbase(card)		   ((card)->win0base + 0x2000)
 #define get_port(card, port)	   (card)
 static void sca_msci_intr(port_t *port);

 static inline u8 sca_get_page(card_t *card)
 {
 	return card->page;
 }

 static inline void openwin(card_t *card, u8 page)
 {
 	card->page = page;
 	writeb(page, card->win0base + C101_PAGE);
 }

 #include "hd64570.c"

 static inline void set_carrier(port_t *port)
 {
 	if (!(sca_in(MSCI1_OFFSET + ST3, port) & ST3_DCD))
 		netif_carrier_on(port_to_dev(port));
 	else
 		netif_carrier_off(port_to_dev(port));
 }

 static void sca_msci_intr(port_t *port)
 {
 	u8 stat = sca_in(MSCI0_OFFSET + ST1, port); /* read MSCI ST1 status */

 	/* Reset MSCI TX underrun and CDCD (ignored) status bit */
 	sca_out(stat & (ST1_UDRN | ST1_CDCD), MSCI0_OFFSET + ST1, port);

 	if (stat & ST1_UDRN) {
 		/* TX Underrun error detected */
 		port_to_dev(port)->stats.tx_errors++;
 		port_to_dev(port)->stats.tx_fifo_errors++;
 	}

 	stat = sca_in(MSCI1_OFFSET + ST1, port); /* read MSCI1 ST1 status */
 	/* Reset MSCI CDCD status bit - uses ch#2 DCD input */
 	sca_out(stat & ST1_CDCD, MSCI1_OFFSET + ST1, port);

 	if (stat & ST1_CDCD)
 		set_carrier(port);
 }

 static void c101_set_iface(port_t *port)
 {
 	u8 rxs = port->rxs & CLK_BRG_MASK;
 	u8 txs = port->txs & CLK_BRG_MASK;

 	switch (port->settings.clock_type) {
 	case CLOCK_INT:
 		rxs |= CLK_BRG_RX; /* TX clock */
 		txs |= CLK_RXCLK_TX; /* BRG output */
 		break;

 	case CLOCK_TXINT:
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_BRG_TX; /* BRG output */
 		break;

 	case CLOCK_TXFROMRX:
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_RXCLK_TX; /* RX clock */
 		break;

 	default:	/* EXTernal clock */
 		rxs |= CLK_LINE_RX; /* RXC input */
 		txs |= CLK_LINE_TX; /* TXC input */
 	}

 	port->rxs = rxs;
 	port->txs = txs;
 	sca_out(rxs, MSCI1_OFFSET + RXS, port);
 	sca_out(txs, MSCI1_OFFSET + TXS, port);
 	sca_set_port(port);
 }

 static int c101_open(struct net_device *dev)
 {
 	port_t *port = dev_to_port(dev);
 	int result;

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

 	writeb(1, port->win0base + C101_DTR);
 	sca_out(0, MSCI1_OFFSET + CTL, port); /* RTS uses ch#2 output */
 	sca_open(dev);
 	/* DCD is connected to port 2 !@#$%^& - disable MSCI0 CDCD interrupt */
 	sca_out(IE1_UDRN, MSCI0_OFFSET + IE1, port);
 	sca_out(IE0_TXINT, MSCI0_OFFSET + IE0, port);

 	set_carrier(port);

 	/* enable MSCI1 CDCD interrupt */
 	sca_out(IE1_CDCD, MSCI1_OFFSET + IE1, port);
 	sca_out(IE0_RXINTA, MSCI1_OFFSET + IE0, port);
 	sca_out(0x48, IER0, port); /* TXINT #0 and RXINT #1 */
 	c101_set_iface(port);
 	return 0;
 }

 static int c101_close(struct net_device *dev)
 {
 	port_t *port = dev_to_port(dev);

 	sca_close(dev);
 	writeb(0, port->win0base + C101_DTR);
 	sca_out(CTL_NORTS, MSCI1_OFFSET + CTL, port);
 	hdlc_close(dev);
 	return 0;
 }

 static int c101_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
 			       void __user *data, int cmd)
 {
 #ifdef DEBUG_RINGS
 	port_t *port = dev_to_port(dev);

 	if (cmd == SIOCDEVPRIVATE) {
 		sca_dump_rings(dev);
 		printk(KERN_DEBUG "MSCI1: ST: %02x %02x %02x %02x\n",
 		       sca_in(MSCI1_OFFSET + ST0, port),
 		       sca_in(MSCI1_OFFSET + ST1, port),
 		       sca_in(MSCI1_OFFSET + ST2, port),
 		       sca_in(MSCI1_OFFSET + ST3, port));
 		return 0;
 	}
 #endif

 	return -EOPNOTSUPP;
 }

 static int c101_ioctl(struct net_device *dev, struct if_settings *ifs)
 {
 	const size_t size = sizeof(sync_serial_settings);
 	sync_serial_settings new_line;
 	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
 	port_t *port = dev_to_port(dev);

 	switch (ifs->type) {
 	case IF_GET_IFACE:
 		ifs->type = IF_IFACE_SYNC_SERIAL;
 		if (ifs->size < size) {
 			ifs->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 */
 		c101_set_iface(port);
 		return 0;

 	default:
 		return hdlc_ioctl(dev, ifs);
 	}
 }

 static void c101_destroy_card(card_t *card)
 {
 	readb(card->win0base + C101_PAGE); /* Resets SCA? */

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

 	if (card->win0base) {
 		iounmap(card->win0base);
 		release_mem_region(card->phy_winbase, C101_MAPPED_RAM_SIZE);
 	}

 	free_netdev(card->dev);

 	kfree(card);
 }

 static const struct net_device_ops c101_ops = {
 	.ndo_open       = c101_open,
 	.ndo_stop       = c101_close,
 	.ndo_start_xmit = hdlc_start_xmit,
 	.ndo_siocwandev = c101_ioctl,
 	.ndo_siocdevprivate = c101_siocdevprivate,
 };

 static int __init c101_run(unsigned long irq, unsigned long winbase)
 {
 	struct net_device *dev;
 	hdlc_device *hdlc;
 	card_t *card;
 	int result;

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

 	if (winbase < 0xC0000 || winbase > 0xDFFFF || (winbase & 0x3FFF) != 0) {
 		pr_err("invalid RAM value\n");
 		return -ENODEV;
 	}

 	card = kzalloc(sizeof(card_t), GFP_KERNEL);
 	if (!card)
 		return -ENOBUFS;

 	card->dev = alloc_hdlcdev(card);
 	if (!card->dev) {
 		pr_err("unable to allocate memory\n");
 		kfree(card);
 		return -ENOBUFS;
 	}

 	if (request_irq(irq, sca_intr, 0, devname, card)) {
 		pr_err("could not allocate IRQ\n");
 		c101_destroy_card(card);
 		return -EBUSY;
 	}
 	card->irq = irq;

 	if (!request_mem_region(winbase, C101_MAPPED_RAM_SIZE, devname)) {
 		pr_err("could not request RAM window\n");
 		c101_destroy_card(card);
 		return -EBUSY;
 	}
 	card->phy_winbase = winbase;
 	card->win0base = ioremap(winbase, C101_MAPPED_RAM_SIZE);
 	if (!card->win0base) {
 		pr_err("could not map I/O address\n");
 		c101_destroy_card(card);
 		return -EFAULT;
 	}

 	card->tx_ring_buffers = TX_RING_BUFFERS;
 	card->rx_ring_buffers = RX_RING_BUFFERS;
 	card->buff_offset = C101_WINDOW_SIZE; /* Bytes 1D00-1FFF reserved */

 	readb(card->win0base + C101_PAGE); /* Resets SCA? */
 	udelay(100);
 	writeb(0, card->win0base + C101_PAGE);
 	writeb(0, card->win0base + C101_DTR); /* Power-up for RAM? */

 	sca_init(card, 0);

 	dev = port_to_dev(card);
 	hdlc = dev_to_hdlc(dev);

 	spin_lock_init(&card->lock);
 	dev->irq = irq;
 	dev->mem_start = winbase;
 	dev->mem_end = winbase + C101_MAPPED_RAM_SIZE - 1;
 	dev->tx_queue_len = 50;
 	dev->netdev_ops = &c101_ops;
 	hdlc->attach = sca_attach;
 	hdlc->xmit = sca_xmit;
 	card->settings.clock_type = CLOCK_EXT;

 	result = register_hdlc_device(dev);
 	if (result) {
 		pr_warn("unable to register hdlc device\n");
 		c101_destroy_card(card);
 		return result;
 	}

 	sca_init_port(card); /* Set up C101 memory */
 	set_carrier(card);

 	netdev_info(dev, "Moxa C101 on IRQ%u, using %u TX + %u RX packets rings\n",
 		    card->irq, card->tx_ring_buffers, card->rx_ring_buffers);

 	*new_card = card;
 	new_card = &card->next_card;
 	return 0;
 }

 static int __init c101_init(void)
 {
 	if (!hw) {
 #ifdef MODULE
 		pr_info("no card initialized\n");
 #endif
 		return -EINVAL;	/* no parameters specified, abort */
 	}

 	pr_info("%s\n", version);

 	do {
 		unsigned long irq, ram;

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

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

 		if (*hw == ':' || *hw == '\x0')
 			c101_run(irq, ram);

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

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

 static void __exit c101_cleanup(void)
 {
 	card_t *card = first_card;

 	while (card) {
 		card_t *ptr = card;

 		card = card->next_card;
 		unregister_hdlc_device(port_to_dev(ptr));
 		c101_destroy_card(ptr);
 	}
 }

 module_init(c101_init);
 module_exit(c101_cleanup);

 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 MODULE_DESCRIPTION("Moxa C101 serial port driver");
 MODULE_LICENSE("GPL v2");
 module_param(hw, charp, 0444);
 MODULE_PARM_DESC(hw, "irq,ram:irq,...");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Moxa C101 synchronous serial card driver for Linux
	*
	* Copyright (C) 2000-2003 Krzysztof Halasa <khc@pm.waw.pl>
	*
	* For information see <https://www.kernel.org/pub/linux/utils/net/hdlc/>
	*
	* Sources of information:
	* Hitachi HD64570 SCA User's Manual
	* Moxa C101 User's Manual
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/capability.h>
	#include <linux/slab.h>
	#include <linux/types.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/netdevice.h>
	#include <linux/hdlc.h>
	#include <linux/delay.h>
	#include <asm/io.h>

	#include "hd64570.h"

	static const char *version = "Moxa C101 driver version: 1.15";
	static const char *devname = "C101";

	#undef DEBUG_PKT
	#define DEBUG_RINGS

	#define C101_PAGE 0x1D00
	#define C101_DTR 0x1E00
	#define C101_SCA 0x1F00
	#define C101_WINDOW_SIZE 0x2000
	#define C101_MAPPED_RAM_SIZE 0x4000

	#define RAM_SIZE (256 * 1024)
	#define TX_RING_BUFFERS 10
	#define RX_RING_BUFFERS ((RAM_SIZE - C101_WINDOW_SIZE) / \
	(sizeof(pkt_desc) + HDLC_MAX_MRU) - TX_RING_BUFFERS)

	#define CLOCK_BASE 9830400 /* 9.8304 MHz */
	#define PAGE0_ALWAYS_MAPPED

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

	typedef struct card_s {
	struct net_device *dev;
	spinlock_t lock; /* TX lock */
	u8 __iomem win0base; / ISA window base address */
	u32 phy_winbase; /* ISA physical base address */
	sync_serial_settings settings;
	int rxpart; /* partial frame received, next frame invalid*/
	unsigned short encoding;
	unsigned short parity;
	u16 rx_ring_buffers; /* number of buffers in a ring */
	u16 tx_ring_buffers;
	u16 buff_offset; /* offset of first buffer of first channel */
	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 irq; /* IRQ (3-15) */
	u8 page;

	struct card_s *next_card;
	} card_t;

	typedef card_t port_t;

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

	#define sca_in(reg, card) readb((card)->win0base + C101_SCA + (reg))
	#define sca_out(value, reg, card) writeb(value, (card)->win0base + C101_SCA + (reg))
	#define sca_inw(reg, card) readw((card)->win0base + C101_SCA + (reg))

	/* EDA address register must be set in EDAL, EDAH order - 8 bit ISA bus */
	#define sca_outw(value, reg, card) do { \
	writeb(value & 0xFF, (card)->win0base + C101_SCA + (reg)); \
	writeb((value >> 8) & 0xFF, (card)->win0base + C101_SCA + (reg + 1));\
	} while (0)

	#define port_to_card(port) (port)
	#define log_node(port) (0)
	#define phy_node(port) (0)
	#define winsize(card) (C101_WINDOW_SIZE)
	#define win0base(card) ((card)->win0base)
	#define winbase(card) ((card)->win0base + 0x2000)
	#define get_port(card, port) (card)
	static void sca_msci_intr(port_t *port);

	static inline u8 sca_get_page(card_t *card)
	{
	return card->page;
	}

	static inline void openwin(card_t *card, u8 page)
	{
	card->page = page;
	writeb(page, card->win0base + C101_PAGE);
	}

	#include "hd64570.c"

	static inline void set_carrier(port_t *port)
	{
	if (!(sca_in(MSCI1_OFFSET + ST3, port) & ST3_DCD))
	netif_carrier_on(port_to_dev(port));
	else
	netif_carrier_off(port_to_dev(port));
	}

	static void sca_msci_intr(port_t *port)
	{
	u8 stat = sca_in(MSCI0_OFFSET + ST1, port); /* read MSCI ST1 status */

	/* Reset MSCI TX underrun and CDCD (ignored) status bit */
	sca_out(stat & (ST1_UDRN \| ST1_CDCD), MSCI0_OFFSET + ST1, port);

	if (stat & ST1_UDRN) {
	/* TX Underrun error detected */
	port_to_dev(port)->stats.tx_errors++;
	port_to_dev(port)->stats.tx_fifo_errors++;
	}

	stat = sca_in(MSCI1_OFFSET + ST1, port); /* read MSCI1 ST1 status */
	/* Reset MSCI CDCD status bit - uses ch#2 DCD input */
	sca_out(stat & ST1_CDCD, MSCI1_OFFSET + ST1, port);

	if (stat & ST1_CDCD)
	set_carrier(port);
	}

	static void c101_set_iface(port_t *port)
	{
	u8 rxs = port->rxs & CLK_BRG_MASK;
	u8 txs = port->txs & CLK_BRG_MASK;

	switch (port->settings.clock_type) {
	case CLOCK_INT:
	rxs \|= CLK_BRG_RX; /* TX clock */
	txs \|= CLK_RXCLK_TX; /* BRG output */
	break;

	case CLOCK_TXINT:
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_BRG_TX; /* BRG output */
	break;

	case CLOCK_TXFROMRX:
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_RXCLK_TX; /* RX clock */
	break;

	default: /* EXTernal clock */
	rxs \|= CLK_LINE_RX; /* RXC input */
	txs \|= CLK_LINE_TX; /* TXC input */
	}

	port->rxs = rxs;
	port->txs = txs;
	sca_out(rxs, MSCI1_OFFSET + RXS, port);
	sca_out(txs, MSCI1_OFFSET + TXS, port);
	sca_set_port(port);
	}

	static int c101_open(struct net_device *dev)
	{
	port_t *port = dev_to_port(dev);
	int result;

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

	writeb(1, port->win0base + C101_DTR);
	sca_out(0, MSCI1_OFFSET + CTL, port); /* RTS uses ch#2 output */
	sca_open(dev);
	/* DCD is connected to port 2 !@#$%^& - disable MSCI0 CDCD interrupt */
	sca_out(IE1_UDRN, MSCI0_OFFSET + IE1, port);
	sca_out(IE0_TXINT, MSCI0_OFFSET + IE0, port);

	set_carrier(port);

	/* enable MSCI1 CDCD interrupt */
	sca_out(IE1_CDCD, MSCI1_OFFSET + IE1, port);
	sca_out(IE0_RXINTA, MSCI1_OFFSET + IE0, port);
	sca_out(0x48, IER0, port); /* TXINT #0 and RXINT #1 */
	c101_set_iface(port);
	return 0;
	}

	static int c101_close(struct net_device *dev)
	{
	port_t *port = dev_to_port(dev);

	sca_close(dev);
	writeb(0, port->win0base + C101_DTR);
	sca_out(CTL_NORTS, MSCI1_OFFSET + CTL, port);
	hdlc_close(dev);
	return 0;
	}

	static int c101_siocdevprivate(struct net_device dev, struct ifreq ifr,
	void __user *data, int cmd)
	{
	#ifdef DEBUG_RINGS
	port_t *port = dev_to_port(dev);

	if (cmd == SIOCDEVPRIVATE) {
	sca_dump_rings(dev);
	printk(KERN_DEBUG "MSCI1: ST: %02x %02x %02x %02x\n",
	sca_in(MSCI1_OFFSET + ST0, port),
	sca_in(MSCI1_OFFSET + ST1, port),
	sca_in(MSCI1_OFFSET + ST2, port),
	sca_in(MSCI1_OFFSET + ST3, port));
	return 0;
	}
	#endif

	return -EOPNOTSUPP;
	}

	static int c101_ioctl(struct net_device dev, struct if_settings ifs)
	{
	const size_t size = sizeof(sync_serial_settings);
	sync_serial_settings new_line;
	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
	port_t *port = dev_to_port(dev);

	switch (ifs->type) {
	case IF_GET_IFACE:
	ifs->type = IF_IFACE_SYNC_SERIAL;
	if (ifs->size < size) {
	ifs->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 */
	c101_set_iface(port);
	return 0;

	default:
	return hdlc_ioctl(dev, ifs);
	}
	}

	static void c101_destroy_card(card_t *card)
	{
	readb(card->win0base + C101_PAGE); /* Resets SCA? */

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

	if (card->win0base) {
	iounmap(card->win0base);
	release_mem_region(card->phy_winbase, C101_MAPPED_RAM_SIZE);
	}

	free_netdev(card->dev);

	kfree(card);
	}

	static const struct net_device_ops c101_ops = {
	.ndo_open = c101_open,
	.ndo_stop = c101_close,
	.ndo_start_xmit = hdlc_start_xmit,
	.ndo_siocwandev = c101_ioctl,
	.ndo_siocdevprivate = c101_siocdevprivate,
	};

	static int __init c101_run(unsigned long irq, unsigned long winbase)
	{
	struct net_device *dev;
	hdlc_device *hdlc;
	card_t *card;
	int result;

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

	if (winbase < 0xC0000 \|\| winbase > 0xDFFFF \|\| (winbase & 0x3FFF) != 0) {
	pr_err("invalid RAM value\n");
	return -ENODEV;
	}

	card = kzalloc(sizeof(card_t), GFP_KERNEL);
	if (!card)
	return -ENOBUFS;

	card->dev = alloc_hdlcdev(card);
	if (!card->dev) {
	pr_err("unable to allocate memory\n");
	kfree(card);
	return -ENOBUFS;
	}

	if (request_irq(irq, sca_intr, 0, devname, card)) {
	pr_err("could not allocate IRQ\n");
	c101_destroy_card(card);
	return -EBUSY;
	}
	card->irq = irq;

	if (!request_mem_region(winbase, C101_MAPPED_RAM_SIZE, devname)) {
	pr_err("could not request RAM window\n");
	c101_destroy_card(card);
	return -EBUSY;
	}
	card->phy_winbase = winbase;
	card->win0base = ioremap(winbase, C101_MAPPED_RAM_SIZE);
	if (!card->win0base) {
	pr_err("could not map I/O address\n");
	c101_destroy_card(card);
	return -EFAULT;
	}

	card->tx_ring_buffers = TX_RING_BUFFERS;
	card->rx_ring_buffers = RX_RING_BUFFERS;
	card->buff_offset = C101_WINDOW_SIZE; /* Bytes 1D00-1FFF reserved */

	readb(card->win0base + C101_PAGE); /* Resets SCA? */
	udelay(100);
	writeb(0, card->win0base + C101_PAGE);
	writeb(0, card->win0base + C101_DTR); /* Power-up for RAM? */

	sca_init(card, 0);

	dev = port_to_dev(card);
	hdlc = dev_to_hdlc(dev);

	spin_lock_init(&card->lock);
	dev->irq = irq;
	dev->mem_start = winbase;
	dev->mem_end = winbase + C101_MAPPED_RAM_SIZE - 1;
	dev->tx_queue_len = 50;
	dev->netdev_ops = &c101_ops;
	hdlc->attach = sca_attach;
	hdlc->xmit = sca_xmit;
	card->settings.clock_type = CLOCK_EXT;

	result = register_hdlc_device(dev);
	if (result) {
	pr_warn("unable to register hdlc device\n");
	c101_destroy_card(card);
	return result;
	}

	sca_init_port(card); /* Set up C101 memory */
	set_carrier(card);

	netdev_info(dev, "Moxa C101 on IRQ%u, using %u TX + %u RX packets rings\n",
	card->irq, card->tx_ring_buffers, card->rx_ring_buffers);

	*new_card = card;
	new_card = &card->next_card;
	return 0;
	}

	static int __init c101_init(void)
	{
	if (!hw) {
	#ifdef MODULE
	pr_info("no card initialized\n");
	#endif
	return -EINVAL; /* no parameters specified, abort */
	}

	pr_info("%s\n", version);

	do {
	unsigned long irq, ram;

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

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

	if (hw == ':' \|\| hw == '\x0')
	c101_run(irq, ram);

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

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

	static void __exit c101_cleanup(void)
	{
	card_t *card = first_card;

	while (card) {
	card_t *ptr = card;

	card = card->next_card;
	unregister_hdlc_device(port_to_dev(ptr));
	c101_destroy_card(ptr);
	}
	}

	module_init(c101_init);
	module_exit(c101_cleanup);

	MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
	MODULE_DESCRIPTION("Moxa C101 serial port driver");
	MODULE_LICENSE("GPL v2");
	module_param(hw, charp, 0444);
	MODULE_PARM_DESC(hw, "irq,ram:irq,...");