// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
 *
 * Derived from the PCAN project file driver/src/pcan_pci.c:
 *
 * Copyright (C) 2001-2025 PEAK System-Technik GmbH
 * Author: Stéphane Grosjean <stephane.grosjean@hms-networks.com>
 */

#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/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <linux/can.h>
#include <linux/can/dev.h>

#include "sja1000.h"

MODULE_AUTHOR("Stéphane Grosjean <stephane.grosjean@hms-networks.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_obj(*card);
                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;
                strscpy(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);