drivers/net/can/sja1000/ems_pci.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
  * Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
  * Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the version 2 of the GNU General Public License
  * as published by the Free Software Foundation
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/netdevice.h>
 #include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/can.h>
 #include <linux/can/dev.h>
 #include <linux/io.h>

 #include "sja1000.h"

 #define DRV_NAME  "ems_pci"

 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
 MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
 MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
 MODULE_LICENSE("GPL v2");

 #define EMS_PCI_V1_MAX_CHAN 2
 #define EMS_PCI_V2_MAX_CHAN 4
 #define EMS_PCI_MAX_CHAN    EMS_PCI_V2_MAX_CHAN

 struct ems_pci_card {
 	int version;
 	int channels;

 	struct pci_dev *pci_dev;
 	struct net_device *net_dev[EMS_PCI_MAX_CHAN];

 	void __iomem *conf_addr;
 	void __iomem *base_addr;
 };

 #define EMS_PCI_CAN_CLOCK (16000000 / 2)

 /*
  * Register definitions and descriptions are from LinCAN 0.3.3.
  *
  * PSB4610 PITA-2 bridge control registers
  */
 #define PITA2_ICR           0x00	/* Interrupt Control Register */
 #define PITA2_ICR_INT0      0x00000002	/* [RC] INT0 Active/Clear */
 #define PITA2_ICR_INT0_EN   0x00020000	/* [RW] Enable INT0 */

 #define PITA2_MISC          0x1c	/* Miscellaneous Register */
 #define PITA2_MISC_CONFIG   0x04000000	/* Multiplexed parallel interface */

 /*
  * Register definitions for the PLX 9030
  */
 #define PLX_ICSR            0x4c   /* Interrupt Control/Status register */
 #define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
 #define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
 #define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
 #define PLX_ICSR_ENA_CLR    (PLX_ICSR_LINTI1_ENA | PLX_ICSR_PCIINT_ENA | \
 			     PLX_ICSR_LINTI1_CLR)

 /*
  * The board configuration is probably following:
  * RX1 is connected to ground.
  * TX1 is not connected.
  * CLKO is not connected.
  * Setting the OCR register to 0xDA is a good idea.
  * This means normal output mode, push-pull and the correct polarity.
  */
 #define EMS_PCI_OCR         (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL)

 /*
  * In the CDR register, you should set CBP to 1.
  * You will probably also want to set the clock divider value to 7
  * (meaning direct oscillator output) because the second SJA1000 chip
  * is driven by the first one CLKOUT output.
  */
 #define EMS_PCI_CDR             (CDR_CBP | CDR_CLKOUT_MASK)

 #define EMS_PCI_V1_BASE_BAR     1
 #define EMS_PCI_V1_CONF_SIZE    4096 /* size of PITA control area */
 #define EMS_PCI_V2_BASE_BAR     2
 #define EMS_PCI_V2_CONF_SIZE    128 /* size of PLX control area */
 #define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
 #define EMS_PCI_CAN_CTRL_SIZE   0x200 /* memory size for each controller */

 #define EMS_PCI_BASE_SIZE  4096 /* size of controller area */

 static DEFINE_PCI_DEVICE_TABLE(ems_pci_tbl) = {
 	/* CPC-PCI v1 */
 	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
 	/* CPC-PCI v2 */
 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
 	/* CPC-104P v2 */
 	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
 	{0,}
 };
 MODULE_DEVICE_TABLE(pci, ems_pci_tbl);

 /*
  * Helper to read internal registers from card logic (not CAN)
  */
 static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
 {
 	return readb(card->base_addr + (port * 4));
 }

 static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
 {
 	return readb(priv->reg_base + (port * 4));
 }

 static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
 				 int port, u8 val)
 {
 	writeb(val, priv->reg_base + (port * 4));
 }

 static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
 {
 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;

 	/* reset int flag of pita */
 	writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
 	       card->conf_addr + PITA2_ICR);
 }

 static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
 {
 	return readb(priv->reg_base + port);
 }

 static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
 				 int port, u8 val)
 {
 	writeb(val, priv->reg_base + port);
 }

 static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
 {
 	struct ems_pci_card *card = (struct ems_pci_card *)priv->priv;

 	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
 }

 /*
  * Check if a CAN controller is present at the specified location
  * by trying to set 'em into the PeliCAN mode
  */
 static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
 {
 	unsigned char res;

 	/* Make sure SJA1000 is in reset mode */
 	priv->write_reg(priv, REG_MOD, 1);

 	priv->write_reg(priv, REG_CDR, CDR_PELICAN);

 	/* read reset-values */
 	res = priv->read_reg(priv, REG_CDR);

 	if (res == CDR_PELICAN)
 		return 1;

 	return 0;
 }

 static void ems_pci_del_card(struct pci_dev *pdev)
 {
 	struct ems_pci_card *card = pci_get_drvdata(pdev);
 	struct net_device *dev;
 	int i = 0;

 	for (i = 0; i < card->channels; i++) {
 		dev = card->net_dev[i];

 		if (!dev)
 			continue;

 		dev_info(&pdev->dev, "Removing %s.\n", dev->name);
 		unregister_sja1000dev(dev);
 		free_sja1000dev(dev);
 	}

 	if (card->base_addr != NULL)
 		pci_iounmap(card->pci_dev, card->base_addr);

 	if (card->conf_addr != NULL)
 		pci_iounmap(card->pci_dev, card->conf_addr);

 	kfree(card);

 	pci_disable_device(pdev);
 	pci_set_drvdata(pdev, NULL);
 }

 static void ems_pci_card_reset(struct ems_pci_card *card)
 {
 	/* Request board reset */
 	writeb(0, card->base_addr);
 }

 /*
  * Probe PCI device for EMS CAN signature and register each available
  * CAN channel to SJA1000 Socket-CAN subsystem.
  */
 static int __devinit ems_pci_add_card(struct pci_dev *pdev,
 					const struct pci_device_id *ent)
 {
 	struct sja1000_priv *priv;
 	struct net_device *dev;
 	struct ems_pci_card *card;
 	int max_chan, conf_size, base_bar;
 	int err, i;

 	/* Enabling PCI device */
 	if (pci_enable_device(pdev) < 0) {
 		dev_err(&pdev->dev, "Enabling PCI device failed\n");
 		return -ENODEV;
 	}

 	/* Allocating card structures to hold addresses, ... */
 	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
 	if (card == NULL) {
 		dev_err(&pdev->dev, "Unable to allocate memory\n");
 		pci_disable_device(pdev);
 		return -ENOMEM;
 	}

 	pci_set_drvdata(pdev, card);

 	card->pci_dev = pdev;

 	card->channels = 0;

 	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
 		card->version = 2; /* CPC-PCI v2 */
 		max_chan = EMS_PCI_V2_MAX_CHAN;
 		base_bar = EMS_PCI_V2_BASE_BAR;
 		conf_size = EMS_PCI_V2_CONF_SIZE;
 	} else {
 		card->version = 1; /* CPC-PCI v1 */
 		max_chan = EMS_PCI_V1_MAX_CHAN;
 		base_bar = EMS_PCI_V1_BASE_BAR;
 		conf_size = EMS_PCI_V1_CONF_SIZE;
 	}

 	/* Remap configuration space and controller memory area */
 	card->conf_addr = pci_iomap(pdev, 0, conf_size);
 	if (card->conf_addr == NULL) {
 		err = -ENOMEM;
 		goto failure_cleanup;
 	}

 	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
 	if (card->base_addr == NULL) {
 		err = -ENOMEM;
 		goto failure_cleanup;
 	}

 	if (card->version == 1) {
 		/* Configure PITA-2 parallel interface (enable MUX) */
 		writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);

 		/* Check for unique EMS CAN signature */
 		if (ems_pci_v1_readb(card, 0) != 0x55 ||
 		    ems_pci_v1_readb(card, 1) != 0xAA ||
 		    ems_pci_v1_readb(card, 2) != 0x01 ||
 		    ems_pci_v1_readb(card, 3) != 0xCB ||
 		    ems_pci_v1_readb(card, 4) != 0x11) {
 			dev_err(&pdev->dev,
 				"Not EMS Dr. Thomas Wuensche interface\n");
 			err = -ENODEV;
 			goto failure_cleanup;
 		}
 	}

 	ems_pci_card_reset(card);

 	/* Detect available channels */
 	for (i = 0; i < max_chan; i++) {
 		dev = alloc_sja1000dev(0);
 		if (dev == NULL) {
 			err = -ENOMEM;
 			goto failure_cleanup;
 		}

 		card->net_dev[i] = dev;
 		priv = netdev_priv(dev);
 		priv->priv = card;
 		priv->irq_flags = IRQF_SHARED;

 		dev->irq = pdev->irq;
 		priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
 					+ (i * EMS_PCI_CAN_CTRL_SIZE);
 		if (card->version == 1) {
 			priv->read_reg  = ems_pci_v1_read_reg;
 			priv->write_reg = ems_pci_v1_write_reg;
 			priv->post_irq  = ems_pci_v1_post_irq;
 		} else {
 			priv->read_reg  = ems_pci_v2_read_reg;
 			priv->write_reg = ems_pci_v2_write_reg;
 			priv->post_irq  = ems_pci_v2_post_irq;
 		}

 		/* Check if channel is present */
 		if (ems_pci_check_chan(priv)) {
 			priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
 			priv->ocr = EMS_PCI_OCR;
 			priv->cdr = EMS_PCI_CDR;

 			SET_NETDEV_DEV(dev, &pdev->dev);

 			if (card->version == 1)
 				/* reset int flag of pita */
 				writel(PITA2_ICR_INT0_EN | PITA2_ICR_INT0,
 				       card->conf_addr + PITA2_ICR);
 			else
 				/* enable IRQ in PLX 9030 */
 				writel(PLX_ICSR_ENA_CLR,
 				       card->conf_addr + PLX_ICSR);

 			/* Register SJA1000 device */
 			err = register_sja1000dev(dev);
 			if (err) {
 				dev_err(&pdev->dev, "Registering device failed "
 							"(err=%d)\n", err);
 				free_sja1000dev(dev);
 				goto failure_cleanup;
 			}

 			card->channels++;

 			dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
 					i + 1, priv->reg_base, dev->irq);
 		} else {
 			free_sja1000dev(dev);
 		}
 	}

 	return 0;

 failure_cleanup:
 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);

 	ems_pci_del_card(pdev);

 	return err;
 }

 static struct pci_driver ems_pci_driver = {
 	.name = DRV_NAME,
 	.id_table = ems_pci_tbl,
 	.probe = ems_pci_add_card,
 	.remove = ems_pci_del_card,
 };

 static int __init ems_pci_init(void)
 {
 	return pci_register_driver(&ems_pci_driver);
 }

 static void __exit ems_pci_exit(void)
 {
 	pci_unregister_driver(&ems_pci_driver);
 }

 module_init(ems_pci_init);
 module_exit(ems_pci_exit);
	/*
	* Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
	* Copyright (C) 2008 Markus Plessing <plessing@ems-wuensche.com>
	* Copyright (C) 2008 Sebastian Haas <haas@ems-wuensche.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the version 2 of the GNU General Public License
	* as published by the Free Software Foundation
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software Foundation,
	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/interrupt.h>
	#include <linux/netdevice.h>
	#include <linux/delay.h>
	#include <linux/pci.h>
	#include <linux/can.h>
	#include <linux/can/dev.h>
	#include <linux/io.h>

	#include "sja1000.h"

	#define DRV_NAME "ems_pci"

	MODULE_AUTHOR("Sebastian Haas <haas@ems-wuenche.com>");
	MODULE_DESCRIPTION("Socket-CAN driver for EMS CPC-PCI/PCIe/104P CAN cards");
	MODULE_SUPPORTED_DEVICE("EMS CPC-PCI/PCIe/104P CAN card");
	MODULE_LICENSE("GPL v2");

	#define EMS_PCI_V1_MAX_CHAN 2
	#define EMS_PCI_V2_MAX_CHAN 4
	#define EMS_PCI_MAX_CHAN EMS_PCI_V2_MAX_CHAN

	struct ems_pci_card {
	int version;
	int channels;

	struct pci_dev *pci_dev;
	struct net_device *net_dev[EMS_PCI_MAX_CHAN];

	void __iomem *conf_addr;
	void __iomem *base_addr;
	};

	#define EMS_PCI_CAN_CLOCK (16000000 / 2)

	/*
	* Register definitions and descriptions are from LinCAN 0.3.3.
	*
	* PSB4610 PITA-2 bridge control registers
	*/
	#define PITA2_ICR 0x00 /* Interrupt Control Register */
	#define PITA2_ICR_INT0 0x00000002 /* [RC] INT0 Active/Clear */
	#define PITA2_ICR_INT0_EN 0x00020000 /* [RW] Enable INT0 */

	#define PITA2_MISC 0x1c /* Miscellaneous Register */
	#define PITA2_MISC_CONFIG 0x04000000 /* Multiplexed parallel interface */

	/*
	* Register definitions for the PLX 9030
	*/
	#define PLX_ICSR 0x4c /* Interrupt Control/Status register */
	#define PLX_ICSR_LINTI1_ENA 0x0001 /* LINTi1 Enable */
	#define PLX_ICSR_PCIINT_ENA 0x0040 /* PCI Interrupt Enable */
	#define PLX_ICSR_LINTI1_CLR 0x0400 /* Local Edge Triggerable Interrupt Clear */
	#define PLX_ICSR_ENA_CLR (PLX_ICSR_LINTI1_ENA \| PLX_ICSR_PCIINT_ENA \| \
	PLX_ICSR_LINTI1_CLR)

	/*
	* The board configuration is probably following:
	* RX1 is connected to ground.
	* TX1 is not connected.
	* CLKO is not connected.
	* Setting the OCR register to 0xDA is a good idea.
	* This means normal output mode, push-pull and the correct polarity.
	*/
	#define EMS_PCI_OCR (OCR_TX0_PUSHPULL \| OCR_TX1_PUSHPULL)

	/*
	* In the CDR register, you should set CBP to 1.
	* You will probably also want to set the clock divider value to 7
	* (meaning direct oscillator output) because the second SJA1000 chip
	* is driven by the first one CLKOUT output.
	*/
	#define EMS_PCI_CDR (CDR_CBP \| CDR_CLKOUT_MASK)

	#define EMS_PCI_V1_BASE_BAR 1
	#define EMS_PCI_V1_CONF_SIZE 4096 /* size of PITA control area */
	#define EMS_PCI_V2_BASE_BAR 2
	#define EMS_PCI_V2_CONF_SIZE 128 /* size of PLX control area */
	#define EMS_PCI_CAN_BASE_OFFSET 0x400 /* offset where the controllers starts */
	#define EMS_PCI_CAN_CTRL_SIZE 0x200 /* memory size for each controller */

	#define EMS_PCI_BASE_SIZE 4096 /* size of controller area */

	static DEFINE_PCI_DEVICE_TABLE(ems_pci_tbl) = {
	/* CPC-PCI v1 */
	{PCI_VENDOR_ID_SIEMENS, 0x2104, PCI_ANY_ID, PCI_ANY_ID,},
	/* CPC-PCI v2 */
	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4000},
	/* CPC-104P v2 */
	{PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_PLX, 0x4002},
	{0,}
	};
	MODULE_DEVICE_TABLE(pci, ems_pci_tbl);

	/*
	* Helper to read internal registers from card logic (not CAN)
	*/
	static u8 ems_pci_v1_readb(struct ems_pci_card *card, unsigned int port)
	{
	return readb(card->base_addr + (port * 4));
	}

	static u8 ems_pci_v1_read_reg(const struct sja1000_priv *priv, int port)
	{
	return readb(priv->reg_base + (port * 4));
	}

	static void ems_pci_v1_write_reg(const struct sja1000_priv *priv,
	int port, u8 val)
	{
	writeb(val, priv->reg_base + (port * 4));
	}

	static void ems_pci_v1_post_irq(const struct sja1000_priv *priv)
	{
	struct ems_pci_card card = (struct ems_pci_card )priv->priv;

	/* reset int flag of pita */
	writel(PITA2_ICR_INT0_EN \| PITA2_ICR_INT0,
	card->conf_addr + PITA2_ICR);
	}

	static u8 ems_pci_v2_read_reg(const struct sja1000_priv *priv, int port)
	{
	return readb(priv->reg_base + port);
	}

	static void ems_pci_v2_write_reg(const struct sja1000_priv *priv,
	int port, u8 val)
	{
	writeb(val, priv->reg_base + port);
	}

	static void ems_pci_v2_post_irq(const struct sja1000_priv *priv)
	{
	struct ems_pci_card card = (struct ems_pci_card )priv->priv;

	writel(PLX_ICSR_ENA_CLR, card->conf_addr + PLX_ICSR);
	}

	/*
	* Check if a CAN controller is present at the specified location
	* by trying to set 'em into the PeliCAN mode
	*/
	static inline int ems_pci_check_chan(const struct sja1000_priv *priv)
	{
	unsigned char res;

	/* Make sure SJA1000 is in reset mode */
	priv->write_reg(priv, REG_MOD, 1);

	priv->write_reg(priv, REG_CDR, CDR_PELICAN);

	/* read reset-values */
	res = priv->read_reg(priv, REG_CDR);

	if (res == CDR_PELICAN)
	return 1;

	return 0;
	}

	static void ems_pci_del_card(struct pci_dev *pdev)
	{
	struct ems_pci_card *card = pci_get_drvdata(pdev);
	struct net_device *dev;
	int i = 0;

	for (i = 0; i < card->channels; i++) {
	dev = card->net_dev[i];

	if (!dev)
	continue;

	dev_info(&pdev->dev, "Removing %s.\n", dev->name);
	unregister_sja1000dev(dev);
	free_sja1000dev(dev);
	}

	if (card->base_addr != NULL)
	pci_iounmap(card->pci_dev, card->base_addr);

	if (card->conf_addr != NULL)
	pci_iounmap(card->pci_dev, card->conf_addr);

	kfree(card);

	pci_disable_device(pdev);
	pci_set_drvdata(pdev, NULL);
	}

	static void ems_pci_card_reset(struct ems_pci_card *card)
	{
	/* Request board reset */
	writeb(0, card->base_addr);
	}

	/*
	* Probe PCI device for EMS CAN signature and register each available
	* CAN channel to SJA1000 Socket-CAN subsystem.
	*/
	static int __devinit ems_pci_add_card(struct pci_dev *pdev,
	const struct pci_device_id *ent)
	{
	struct sja1000_priv *priv;
	struct net_device *dev;
	struct ems_pci_card *card;
	int max_chan, conf_size, base_bar;
	int err, i;

	/* Enabling PCI device */
	if (pci_enable_device(pdev) < 0) {
	dev_err(&pdev->dev, "Enabling PCI device failed\n");
	return -ENODEV;
	}

	/* Allocating card structures to hold addresses, ... */
	card = kzalloc(sizeof(struct ems_pci_card), GFP_KERNEL);
	if (card == NULL) {
	dev_err(&pdev->dev, "Unable to allocate memory\n");
	pci_disable_device(pdev);
	return -ENOMEM;
	}

	pci_set_drvdata(pdev, card);

	card->pci_dev = pdev;

	card->channels = 0;

	if (pdev->vendor == PCI_VENDOR_ID_PLX) {
	card->version = 2; /* CPC-PCI v2 */
	max_chan = EMS_PCI_V2_MAX_CHAN;
	base_bar = EMS_PCI_V2_BASE_BAR;
	conf_size = EMS_PCI_V2_CONF_SIZE;
	} else {
	card->version = 1; /* CPC-PCI v1 */
	max_chan = EMS_PCI_V1_MAX_CHAN;
	base_bar = EMS_PCI_V1_BASE_BAR;
	conf_size = EMS_PCI_V1_CONF_SIZE;
	}

	/* Remap configuration space and controller memory area */
	card->conf_addr = pci_iomap(pdev, 0, conf_size);
	if (card->conf_addr == NULL) {
	err = -ENOMEM;
	goto failure_cleanup;
	}

	card->base_addr = pci_iomap(pdev, base_bar, EMS_PCI_BASE_SIZE);
	if (card->base_addr == NULL) {
	err = -ENOMEM;
	goto failure_cleanup;
	}

	if (card->version == 1) {
	/* Configure PITA-2 parallel interface (enable MUX) */
	writel(PITA2_MISC_CONFIG, card->conf_addr + PITA2_MISC);

	/* Check for unique EMS CAN signature */
	if (ems_pci_v1_readb(card, 0) != 0x55 \|\|
	ems_pci_v1_readb(card, 1) != 0xAA \|\|
	ems_pci_v1_readb(card, 2) != 0x01 \|\|
	ems_pci_v1_readb(card, 3) != 0xCB \|\|
	ems_pci_v1_readb(card, 4) != 0x11) {
	dev_err(&pdev->dev,
	"Not EMS Dr. Thomas Wuensche interface\n");
	err = -ENODEV;
	goto failure_cleanup;
	}
	}

	ems_pci_card_reset(card);

	/* Detect available channels */
	for (i = 0; i < max_chan; i++) {
	dev = alloc_sja1000dev(0);
	if (dev == NULL) {
	err = -ENOMEM;
	goto failure_cleanup;
	}

	card->net_dev[i] = dev;
	priv = netdev_priv(dev);
	priv->priv = card;
	priv->irq_flags = IRQF_SHARED;

	dev->irq = pdev->irq;
	priv->reg_base = card->base_addr + EMS_PCI_CAN_BASE_OFFSET
	+ (i * EMS_PCI_CAN_CTRL_SIZE);
	if (card->version == 1) {
	priv->read_reg = ems_pci_v1_read_reg;
	priv->write_reg = ems_pci_v1_write_reg;
	priv->post_irq = ems_pci_v1_post_irq;
	} else {
	priv->read_reg = ems_pci_v2_read_reg;
	priv->write_reg = ems_pci_v2_write_reg;
	priv->post_irq = ems_pci_v2_post_irq;
	}

	/* Check if channel is present */
	if (ems_pci_check_chan(priv)) {
	priv->can.clock.freq = EMS_PCI_CAN_CLOCK;
	priv->ocr = EMS_PCI_OCR;
	priv->cdr = EMS_PCI_CDR;

	SET_NETDEV_DEV(dev, &pdev->dev);

	if (card->version == 1)
	/* reset int flag of pita */
	writel(PITA2_ICR_INT0_EN \| PITA2_ICR_INT0,
	card->conf_addr + PITA2_ICR);
	else
	/* enable IRQ in PLX 9030 */
	writel(PLX_ICSR_ENA_CLR,
	card->conf_addr + PLX_ICSR);

	/* Register SJA1000 device */
	err = register_sja1000dev(dev);
	if (err) {
	dev_err(&pdev->dev, "Registering device failed "
	"(err=%d)\n", err);
	free_sja1000dev(dev);
	goto failure_cleanup;
	}

	card->channels++;

	dev_info(&pdev->dev, "Channel #%d at 0x%p, irq %d\n",
	i + 1, priv->reg_base, dev->irq);
	} else {
	free_sja1000dev(dev);
	}
	}

	return 0;

	failure_cleanup:
	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);

	ems_pci_del_card(pdev);

	return err;
	}

	static struct pci_driver ems_pci_driver = {
	.name = DRV_NAME,
	.id_table = ems_pci_tbl,
	.probe = ems_pci_add_card,
	.remove = ems_pci_del_card,
	};

	static int __init ems_pci_init(void)
	{
	return pci_register_driver(&ems_pci_driver);
	}

	static void __exit ems_pci_exit(void)
	{
	pci_unregister_driver(&ems_pci_driver);
	}

	module_init(ems_pci_init);
	module_exit(ems_pci_exit);