peak_pci.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * \file    drivers/net/can/sja1000/peak_pci.c
 * \brief   This file is originally from the Linux Kernel source-code and has
 *          been very slightly modified to integrate to QNX RTOS.
 *
 * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
 * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
 * Copyright (C) 2022 Deniz Eren <deniz.eren@outlook.com>
 *
 * Derived from the PCAN project file driver/src/pcan_pci.c:
 *
 * Copyright (C) 2001-2006  PEAK System-Technik GmbH
 *
 * Please also check the "SPDX-License-Identifier" documentation from the Linux
 * Kernel source code repository: github.com/torvalds/linux.git for further
 * details.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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/io.h>
#include <linux/can.h>
#include <linux/can/dev.h>

#include "sja1000.h"

MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCI family cards");
MODULE_LICENSE("GPL v2");

#define DRV_NAME  "peak_pci"

/* FPGA cards FW version registers */
#define PEAK_VER_REG1		0x40
#define PEAK_VER_REG2		0x44

struct peak_pciec_card;
struct peak_pci_chan {
	void __iomem *cfg_base;		/* Common for all channels */
	struct net_device *prev_dev;	/* Chain of network devices */
	u16 icr_mask;			/* Interrupt mask for fast ack */
	struct peak_pciec_card *pciec_card;	/* only for PCIeC LEDs */
};

#define PEAK_PCI_CAN_CLOCK	(16000000 / 2)

#define PEAK_PCI_CDR		(CDR_CBP | CDR_CLKOUT_MASK)
#define PEAK_PCI_OCR		OCR_TX0_PUSHPULL

/* Important PITA registers */
#define PITA_ICR		0x00	/* Interrupt control register */
#define PITA_GPIOICR		0x18	/* GPIO interface control register */
#define PITA_MISC		0x1C	/* Miscellaneous register */

#define PEAK_PCI_CFG_SIZE	0x1000	/* Size of the config PCI bar */
#define PEAK_PCI_CHAN_SIZE	0x0400	/* Size used by the channel */

#define PEAK_PCI_VENDOR_ID	0x001C	/* The PCI device and vendor IDs */
#define PEAK_PCI_DEVICE_ID	0x0001	/* for PCI/PCIe slot cards */
#define PEAK_PCIEC_DEVICE_ID	0x0002	/* for ExpressCard slot cards */
#define PEAK_PCIE_DEVICE_ID	0x0003	/* for nextgen PCIe slot cards */
#define PEAK_CPCI_DEVICE_ID	0x0004	/* for nextgen cPCI slot cards */
#define PEAK_MPCI_DEVICE_ID	0x0005	/* for nextgen miniPCI slot cards */
#define PEAK_PC_104P_DEVICE_ID	0x0006	/* PCAN-PC/104+ cards */
#define PEAK_PCI_104E_DEVICE_ID	0x0007	/* PCAN-PCI/104 Express cards */
#define PEAK_MPCIE_DEVICE_ID	0x0008	/* The miniPCIe slot cards */
#define PEAK_PCIE_OEM_ID	0x0009	/* PCAN-PCI Express OEM */
#define PEAK_PCIEC34_DEVICE_ID	0x000A	/* PCAN-PCI Express 34 (one channel) */

#define PEAK_PCI_CHAN_MAX	4

static const u16 peak_pci_icr_masks[PEAK_PCI_CHAN_MAX] = {
	0x02, 0x01, 0x40, 0x80
};

static const struct pci_device_id peak_pci_tbl[] = {
	{
		PEAK_PCI_VENDOR_ID, PEAK_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-PCI",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_PCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-PCI Express",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_MPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-miniPCI",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_MPCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-miniPCIe",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_PC_104P_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-PC/104-Plus Quad",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_PCI_104E_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-PCI/104-Express",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_CPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-cPCI",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_PCIE_OEM_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-Chip PCIe",
	},
#ifdef CONFIG_CAN_PEAK_PCIEC
	{
		PEAK_PCI_VENDOR_ID, PEAK_PCIEC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-ExpressCard",
	}, {
		PEAK_PCI_VENDOR_ID, PEAK_PCIEC34_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
		.driver_data = (kernel_ulong_t)"PCAN-ExpressCard 34",
	},
#endif
	{ /* sentinel */ }
};

MODULE_DEVICE_TABLE(pci, peak_pci_tbl);

#ifdef CONFIG_CAN_PEAK_PCIEC
/* PCAN-ExpressCard needs I2C bit-banging configuration option. */

/* GPIOICR byte access offsets */
#define PITA_GPOUT		0x18	/* GPx output value */
#define PITA_GPIN		0x19	/* GPx input value */
#define PITA_GPOEN		0x1A	/* configure GPx as output pin */

/* I2C GP bits */
#define PITA_GPIN_SCL		0x01	/* Serial Clock Line */
#define PITA_GPIN_SDA		0x04	/* Serial DAta line */

#define PCA9553_1_SLAVEADDR	(0xC4 >> 1)

/* PCA9553 LS0 fields values */
enum {
	PCA9553_LOW,
	PCA9553_HIGHZ,
	PCA9553_PWM0,
	PCA9553_PWM1
};

/* LEDs control */
#define PCA9553_ON		PCA9553_LOW
#define PCA9553_OFF		PCA9553_HIGHZ
#define PCA9553_SLOW		PCA9553_PWM0
#define PCA9553_FAST		PCA9553_PWM1

#define PCA9553_LED(c)		(1 << (c))
#define PCA9553_LED_STATE(s, c)	((s) << ((c) << 1))

#define PCA9553_LED_ON(c)	PCA9553_LED_STATE(PCA9553_ON, c)
#define PCA9553_LED_OFF(c)	PCA9553_LED_STATE(PCA9553_OFF, c)
#define PCA9553_LED_SLOW(c)	PCA9553_LED_STATE(PCA9553_SLOW, c)
#define PCA9553_LED_FAST(c)	PCA9553_LED_STATE(PCA9553_FAST, c)
#define PCA9553_LED_MASK(c)	PCA9553_LED_STATE(0x03, c)

#define PCA9553_LED_OFF_ALL	(PCA9553_LED_OFF(0) | PCA9553_LED_OFF(1))

#define PCA9553_LS0_INIT	0x40 /* initial value (!= from 0x00) */

struct peak_pciec_chan {
	struct net_device *netdev;
	unsigned long prev_rx_bytes;
	unsigned long prev_tx_bytes;
};

struct peak_pciec_card {
	void __iomem *cfg_base;		/* Common for all channels */
	void __iomem *reg_base;		/* first channel base address */
	u8 led_cache;			/* leds state cache */

	/* PCIExpressCard i2c data */
	struct i2c_algo_bit_data i2c_bit;
	struct i2c_adapter led_chip;
	struct delayed_work led_work;	/* led delayed work */
	int chan_count;
	struct peak_pciec_chan channel[PEAK_PCI_CHAN_MAX];
};

/* "normal" pci register write callback is overloaded for leds control */
static void peak_pci_write_reg(const struct sja1000_priv *priv,
			       int port, u8 val);

static inline void pita_set_scl_highz(struct peak_pciec_card *card)
{
	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SCL;

	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
}

static inline void pita_set_sda_highz(struct peak_pciec_card *card)
{
	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SDA;

	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
}

static void peak_pciec_init_pita_gpio(struct peak_pciec_card *card)
{
	/* raise SCL & SDA GPIOs to high-Z */
	pita_set_scl_highz(card);
	pita_set_sda_highz(card);
}

static void pita_setsda(void *data, int state)
{
	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
	u8 gp_out, gp_outen;

	/* set output sda always to 0 */
	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SDA;
	writeb(gp_out, card->cfg_base + PITA_GPOUT);

	/* control output sda with GPOEN */
	gp_outen = readb(card->cfg_base + PITA_GPOEN);
	if (state)
		gp_outen &= ~PITA_GPIN_SDA;
	else
		gp_outen |= PITA_GPIN_SDA;

	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
}

static void pita_setscl(void *data, int state)
{
	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
	u8 gp_out, gp_outen;

	/* set output scl always to 0 */
	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SCL;
	writeb(gp_out, card->cfg_base + PITA_GPOUT);

	/* control output scl with GPOEN */
	gp_outen = readb(card->cfg_base + PITA_GPOEN);
	if (state)
		gp_outen &= ~PITA_GPIN_SCL;
	else
		gp_outen |= PITA_GPIN_SCL;

	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
}

static int pita_getsda(void *data)
{
	struct peak_pciec_card *card = (struct peak_pciec_card *)data;

	/* set tristate */
	pita_set_sda_highz(card);

	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SDA) ? 1 : 0;
}

static int pita_getscl(void *data)
{
	struct peak_pciec_card *card = (struct peak_pciec_card *)data;

	/* set tristate */
	pita_set_scl_highz(card);

	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SCL) ? 1 : 0;
}

/* write commands to the LED chip though the I2C-bus of the PCAN-PCIeC */
static int peak_pciec_write_pca9553(struct peak_pciec_card *card,
				    u8 offset, u8 data)
{
	u8 buffer[2] = {
		offset,
		data
	};
	struct i2c_msg msg = {
		.addr = PCA9553_1_SLAVEADDR,
		.len = 2,
		.buf = buffer,
	};
	int ret;

	/* cache led mask */
	if (offset == 5 && data == card->led_cache)
		return 0;

	ret = i2c_transfer(&card->led_chip, &msg, 1);
	if (ret < 0)
		return ret;

	if (offset == 5)
		card->led_cache = data;

	return 0;
}

/* delayed work callback used to control the LEDs */
static void peak_pciec_led_work(struct work_struct *work)
{
	struct peak_pciec_card *card =
		container_of(work, struct peak_pciec_card, led_work.work);
	struct net_device *netdev;
	u8 new_led = card->led_cache;
	int i, up_count = 0;

	/* first check what is to do */
	for (i = 0; i < card->chan_count; i++) {
		/* default is: not configured */
		new_led &= ~PCA9553_LED_MASK(i);
		new_led |= PCA9553_LED_ON(i);

		netdev = card->channel[i].netdev;
		if (!netdev || !(netdev->flags & IFF_UP))
			continue;

		up_count++;

		/* no activity (but configured) */
		new_led &= ~PCA9553_LED_MASK(i);
		new_led |= PCA9553_LED_SLOW(i);

		/* if bytes counters changed, set fast blinking led */
		if (netdev->stats.rx_bytes != card->channel[i].prev_rx_bytes) {
			card->channel[i].prev_rx_bytes = netdev->stats.rx_bytes;
			new_led &= ~PCA9553_LED_MASK(i);
			new_led |= PCA9553_LED_FAST(i);
		}
		if (netdev->stats.tx_bytes != card->channel[i].prev_tx_bytes) {
			card->channel[i].prev_tx_bytes = netdev->stats.tx_bytes;
			new_led &= ~PCA9553_LED_MASK(i);
			new_led |= PCA9553_LED_FAST(i);
		}
	}

	/* check if LS0 settings changed, only update i2c if so */
	peak_pciec_write_pca9553(card, 5, new_led);

	/* restart timer (except if no more configured channels) */
	if (up_count)
		schedule_delayed_work(&card->led_work, HZ);
}

/* set LEDs blinking state */
static void peak_pciec_set_leds(struct peak_pciec_card *card, u8 led_mask, u8 s)
{
	u8 new_led = card->led_cache;
	int i;

	/* first check what is to do */
	for (i = 0; i < card->chan_count; i++)
		if (led_mask & PCA9553_LED(i)) {
			new_led &= ~PCA9553_LED_MASK(i);
			new_led |= PCA9553_LED_STATE(s, i);
		}

	/* check if LS0 settings changed, only update i2c if so */
	peak_pciec_write_pca9553(card, 5, new_led);
}

/* start one second delayed work to control LEDs */
static void peak_pciec_start_led_work(struct peak_pciec_card *card)
{
	schedule_delayed_work(&card->led_work, HZ);
}

/* stop LEDs delayed work */
static void peak_pciec_stop_led_work(struct peak_pciec_card *card)
{
	cancel_delayed_work_sync(&card->led_work);
}

/* initialize the PCA9553 4-bit I2C-bus LED chip */
static int peak_pciec_init_leds(struct peak_pciec_card *card)
{
	int err;

	/* prescaler for frequency 0: "SLOW" = 1 Hz = "44" */
	err = peak_pciec_write_pca9553(card, 1, 44 / 1);
	if (err)
		return err;

	/* duty cycle 0: 50% */
	err = peak_pciec_write_pca9553(card, 2, 0x80);
	if (err)
		return err;

	/* prescaler for frequency 1: "FAST" = 5 Hz */
	err = peak_pciec_write_pca9553(card, 3, 44 / 5);
	if (err)
		return err;

	/* duty cycle 1: 50% */
	err = peak_pciec_write_pca9553(card, 4, 0x80);
	if (err)
		return err;

	/* switch LEDs to initial state */
	return peak_pciec_write_pca9553(card, 5, PCA9553_LS0_INIT);
}

/* restore LEDs state to off peak_pciec_leds_exit */
static void peak_pciec_leds_exit(struct peak_pciec_card *card)
{
	/* switch LEDs to off */
	peak_pciec_write_pca9553(card, 5, PCA9553_LED_OFF_ALL);
}

/* normal write sja1000 register method overloaded to catch when controller
 * is started or stopped, to control leds
 */
static void peak_pciec_write_reg(const struct sja1000_priv *priv,
				 int port, u8 val)
{
	struct peak_pci_chan *chan = priv->priv;
	struct peak_pciec_card *card = chan->pciec_card;
	int c = (priv->reg_base - card->reg_base) / PEAK_PCI_CHAN_SIZE;

	/* sja1000 register changes control the leds state */
	if (port == SJA1000_MOD)
		switch (val) {
		case MOD_RM:
			/* Reset Mode: set led on */
			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_ON);
			break;
		case 0x00:
			/* Normal Mode: led slow blinking and start led timer */
			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_SLOW);
			peak_pciec_start_led_work(card);
			break;
		default:
			break;
		}

	/* call base function */
	peak_pci_write_reg(priv, port, val);
}

static const struct i2c_algo_bit_data peak_pciec_i2c_bit_ops = {
	.setsda	= pita_setsda,
	.setscl	= pita_setscl,
	.getsda	= pita_getsda,
	.getscl	= pita_getscl,
	.udelay	= 10,
	.timeout = HZ,
};

static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct peak_pci_chan *chan = priv->priv;
	struct peak_pciec_card *card;
	int err;

	/* copy i2c object address from 1st channel */
	if (chan->prev_dev) {
		struct sja1000_priv *prev_priv = netdev_priv(chan->prev_dev);
		struct peak_pci_chan *prev_chan = prev_priv->priv;

		card = prev_chan->pciec_card;
		if (!card)
			return -ENODEV;

	/* channel is the first one: do the init part */
	} else {
		/* create the bit banging I2C adapter structure */
		card = kzalloc(sizeof(*card), GFP_KERNEL);
		if (!card)
			return -ENOMEM;

		card->cfg_base = chan->cfg_base;
		card->reg_base = priv->reg_base;

		card->led_chip.owner = THIS_MODULE;
		card->led_chip.dev.parent = &pdev->dev;
		card->led_chip.algo_data = &card->i2c_bit;
		strncpy(card->led_chip.name, "peak_i2c",
			sizeof(card->led_chip.name));

		card->i2c_bit = peak_pciec_i2c_bit_ops;
		card->i2c_bit.udelay = 10;
		card->i2c_bit.timeout = HZ;
		card->i2c_bit.data = card;

		peak_pciec_init_pita_gpio(card);

		err = i2c_bit_add_bus(&card->led_chip);
		if (err) {
			dev_err(&pdev->dev, "i2c init failed\n");
			goto pciec_init_err_1;
		}

		err = peak_pciec_init_leds(card);
		if (err) {
			dev_err(&pdev->dev, "leds hardware init failed\n");
			goto pciec_init_err_2;
		}

		INIT_DELAYED_WORK(&card->led_work, peak_pciec_led_work);
		/* PCAN-ExpressCard needs its own callback for leds */
		priv->write_reg = peak_pciec_write_reg;
	}

	chan->pciec_card = card;
	card->channel[card->chan_count++].netdev = dev;

	return 0;

pciec_init_err_2:
	i2c_del_adapter(&card->led_chip);

pciec_init_err_1:
	peak_pciec_init_pita_gpio(card);
	kfree(card);

	return err;
}

static void peak_pciec_remove(struct peak_pciec_card *card)
{
	peak_pciec_stop_led_work(card);
	peak_pciec_leds_exit(card);
	i2c_del_adapter(&card->led_chip);
	peak_pciec_init_pita_gpio(card);
	kfree(card);
}

#else /* CONFIG_CAN_PEAK_PCIEC */

/* Placebo functions when PCAN-ExpressCard support is not selected */
static inline int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
{
	return -ENODEV;
}

static inline void peak_pciec_remove(struct peak_pciec_card *card)
{
}
#endif /* CONFIG_CAN_PEAK_PCIEC */

static u8 peak_pci_read_reg(const struct sja1000_priv *priv, int port)
{
	return readb(priv->reg_base + (port << 2));
}

static void peak_pci_write_reg(const struct sja1000_priv *priv,
			       int port, u8 val)
{
	writeb(val, priv->reg_base + (port << 2));
}

static void peak_pci_post_irq(const struct sja1000_priv *priv)
{
	struct peak_pci_chan *chan = priv->priv;
	u16 icr;

	/* Select and clear in PITA stored interrupt */
	icr = readw(chan->cfg_base + PITA_ICR);
	if (icr & chan->icr_mask)
		writew(chan->icr_mask, chan->cfg_base + PITA_ICR);
}

static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
	struct sja1000_priv *priv;
	struct peak_pci_chan *chan;
	struct net_device *dev, *prev_dev;
	void __iomem *cfg_base, *reg_base;
	u16 sub_sys_id, icr;
	int i, err, channels;
	char fw_str[14] = "";

	err = pci_enable_device(pdev);
	if (err)
		return err;

	err = pci_request_regions(pdev, DRV_NAME);
	if (err)
		goto failure_disable_pci;

	err = pci_read_config_word(pdev, 0x2e, &sub_sys_id);
	if (err)
		goto failure_release_regions;

	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
		pdev->vendor, pdev->device, sub_sys_id);

	err = pci_write_config_word(pdev, 0x44, 0);
	if (err)
		goto failure_release_regions;

	if (sub_sys_id >= 12)
		channels = 4;
	else if (sub_sys_id >= 10)
		channels = 3;
	else if (sub_sys_id >= 4)
		channels = 2;
	else
		channels = 1;

	cfg_base = pci_iomap(pdev, 0, PEAK_PCI_CFG_SIZE);
	if (!cfg_base) {
		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
		err = -ENOMEM;
		goto failure_release_regions;
	}

	reg_base = pci_iomap(pdev, 1, PEAK_PCI_CHAN_SIZE * channels);
	if (!reg_base) {
		dev_err(&pdev->dev, "failed to map PCI resource #1\n");
		err = -ENOMEM;
		goto failure_unmap_cfg_base;
	}

	/* Set GPIO control register */
	writew(0x0005, cfg_base + PITA_GPIOICR + 2);
	/* Enable all channels of this card */
	writeb(0x00, cfg_base + PITA_GPIOICR);
	/* Toggle reset */
	writeb(0x05, cfg_base + PITA_MISC + 3);
	usleep_range(5000, 6000);
	/* Leave parport mux mode */
	writeb(0x04, cfg_base + PITA_MISC + 3);

	/* FPGA equipped card if not 0 */
	if (readl(cfg_base + PEAK_VER_REG1)) {
		/* FPGA card: display version of the running firmware */
		u32 fw_ver = readl(cfg_base + PEAK_VER_REG2);

		snprintf(fw_str, sizeof(fw_str), " FW v%u.%u.%u",
			 (fw_ver >> 12) & 0xf,
			 (fw_ver >> 8) & 0xf,
			 (fw_ver >> 4) & 0xf);
	}

	/* Display commercial name (and, eventually, FW version) of the card */
	dev_info(&pdev->dev, "%ux CAN %s%s\n",
		 channels, (const char *)ent->driver_data, fw_str);

	icr = readw(cfg_base + PITA_ICR + 2);

	for (i = 0; i < channels; i++) {
		dev = alloc_sja1000dev(sizeof(struct peak_pci_chan));
		if (!dev) {
			err = -ENOMEM;
			goto failure_remove_channels;
		}

		priv = netdev_priv(dev);
		chan = priv->priv;

		chan->cfg_base = cfg_base;
		priv->reg_base = reg_base + i * PEAK_PCI_CHAN_SIZE;

		priv->read_reg = peak_pci_read_reg;
		priv->write_reg = peak_pci_write_reg;
		priv->post_irq = peak_pci_post_irq;

		priv->can.clock.freq = PEAK_PCI_CAN_CLOCK;
		priv->ocr = PEAK_PCI_OCR;
		priv->cdr = PEAK_PCI_CDR;
		/* Neither a slave nor a single device distributes the clock */
		if (channels == 1 || i > 0)
			priv->cdr |= CDR_CLK_OFF;

		/* Setup interrupt handling */
		priv->irq_flags = IRQF_SHARED;
		dev->irq = pdev->irq;

		chan->icr_mask = peak_pci_icr_masks[i];
		icr |= chan->icr_mask;

		SET_NETDEV_DEV(dev, &pdev->dev);
		dev->dev_id = i;

		/* Create chain of SJA1000 devices */
		chan->prev_dev = pci_get_drvdata(pdev);
		pci_set_drvdata(pdev, dev);

		/* PCAN-ExpressCard needs some additional i2c init.
		 * This must be done *before* register_sja1000dev() but
		 * *after* devices linkage
		 */
		if (pdev->device == PEAK_PCIEC_DEVICE_ID ||
		    pdev->device == PEAK_PCIEC34_DEVICE_ID) {
			err = peak_pciec_probe(pdev, dev);
			if (err) {
				dev_err(&pdev->dev,
					"failed to probe device (err %d)\n",
					err);
				goto failure_free_dev;
			}
		}

		err = register_sja1000dev(dev);
		if (err) {
			dev_err(&pdev->dev, "failed to register device\n");
			goto failure_free_dev;
		}

		dev_info(&pdev->dev,
			 "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
			 dev->name, priv->reg_base, chan->cfg_base, dev->irq);
	}

	/* Enable interrupts */
	writew(icr, cfg_base + PITA_ICR + 2);

	return 0;

failure_free_dev:
	pci_set_drvdata(pdev, chan->prev_dev);
	free_sja1000dev(dev);

failure_remove_channels:
	/* Disable interrupts */
	writew(0x0, cfg_base + PITA_ICR + 2);

	chan = NULL;
	for (dev = pci_get_drvdata(pdev); dev; dev = prev_dev) {
		priv = netdev_priv(dev);
		chan = priv->priv;
		prev_dev = chan->prev_dev;

		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
	}

	/* free any PCIeC resources too */
	if (chan && chan->pciec_card)
		peak_pciec_remove(chan->pciec_card);

	pci_iounmap(pdev, reg_base);

failure_unmap_cfg_base:
	pci_iounmap(pdev, cfg_base);

failure_release_regions:
	pci_release_regions(pdev);

failure_disable_pci:
	pci_disable_device(pdev);

	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
	 * the probe() function must return a negative errno in case of failure
	 * (err is unchanged if negative)
	 */
	return pcibios_err_to_errno(err);
}

static void peak_pci_remove(struct pci_dev *pdev)
{
	struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
	struct sja1000_priv *priv = netdev_priv(dev);
	struct peak_pci_chan *chan = priv->priv;
	void __iomem *cfg_base = chan->cfg_base;
	void __iomem *reg_base = priv->reg_base;

	/* Disable interrupts */
	writew(0x0, cfg_base + PITA_ICR + 2);

	/* Loop over all registered devices */
	while (1) {
		struct net_device *prev_dev = chan->prev_dev;

		dev_info(&pdev->dev, "removing device %s\n", dev->name);
		/* do that only for first channel */
		if (!prev_dev && chan->pciec_card)
			peak_pciec_remove(chan->pciec_card);
		unregister_sja1000dev(dev);
		free_sja1000dev(dev);
		dev = prev_dev;

		if (!dev)
			break;
		priv = netdev_priv(dev);
		chan = priv->priv;
	}

	pci_iounmap(pdev, reg_base);
	pci_iounmap(pdev, cfg_base);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
}

/*static */struct pci_driver peak_pci_driver = {
	.name = DRV_NAME,
	.id_table = peak_pci_tbl,
	.probe = peak_pci_probe,
	.remove = peak_pci_remove,
};

module_pci_driver(peak_pci_driver);