// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2008-2010
 *
 * - Kurt Van Dijck, EIA Electronics
 */

#include <linux/ethtool.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <asm/io.h>

#include "softing.h"

#define TX_ECHO_SKB_MAX (((TXMAX+1)/2)-1)

/*
 * test is a specific CAN netdev
 * is online (ie. up 'n running, not sleeping, not busoff
 */
static inline int canif_is_active(struct net_device *netdev)
{
        struct can_priv *can = netdev_priv(netdev);

        if (!netif_running(netdev))
                return 0;
        return (can->state <= CAN_STATE_ERROR_PASSIVE);
}

/* reset DPRAM */
static inline void softing_set_reset_dpram(struct softing *card)
{
        if (card->pdat->generation >= 2) {
                spin_lock_bh(&card->spin);
                iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) & ~1,
                                &card->dpram[DPRAM_V2_RESET]);
                spin_unlock_bh(&card->spin);
        }
}

static inline void softing_clr_reset_dpram(struct softing *card)
{
        if (card->pdat->generation >= 2) {
                spin_lock_bh(&card->spin);
                iowrite8(ioread8(&card->dpram[DPRAM_V2_RESET]) | 1,
                                &card->dpram[DPRAM_V2_RESET]);
                spin_unlock_bh(&card->spin);
        }
}

/* trigger the tx queue-ing */
static netdev_tx_t softing_netdev_start_xmit(struct sk_buff *skb,
                struct net_device *dev)
{
        struct softing_priv *priv = netdev_priv(dev);
        struct softing *card = priv->card;
        int ret;
        uint8_t *ptr;
        uint8_t fifo_wr, fifo_rd;
        struct can_frame *cf = (struct can_frame *)skb->data;
        uint8_t buf[DPRAM_TX_SIZE];

        if (can_dev_dropped_skb(dev, skb))
                return NETDEV_TX_OK;

        spin_lock(&card->spin);

        ret = NETDEV_TX_BUSY;
        if (!card->fw.up ||
                        (card->tx.pending >= TXMAX) ||
                        (priv->tx.pending >= TX_ECHO_SKB_MAX))
                goto xmit_done;
        fifo_wr = ioread8(&card->dpram[DPRAM_TX_WR]);
        fifo_rd = ioread8(&card->dpram[DPRAM_TX_RD]);
        if (fifo_wr == fifo_rd)
                /* fifo full */
                goto xmit_done;
        memset(buf, 0, sizeof(buf));
        ptr = buf;
        *ptr = CMD_TX;
        if (cf->can_id & CAN_RTR_FLAG)
                *ptr |= CMD_RTR;
        if (cf->can_id & CAN_EFF_FLAG)
                *ptr |= CMD_XTD;
        if (priv->index)
                *ptr |= CMD_BUS2;
        ++ptr;
        *ptr++ = cf->len;
        *ptr++ = (cf->can_id >> 0);
        *ptr++ = (cf->can_id >> 8);
        if (cf->can_id & CAN_EFF_FLAG) {
                *ptr++ = (cf->can_id >> 16);
                *ptr++ = (cf->can_id >> 24);
        } else {
                /* increment 1, not 2 as you might think */
                ptr += 1;
        }
        if (!(cf->can_id & CAN_RTR_FLAG))
                memcpy(ptr, &cf->data[0], cf->len);
        memcpy_toio(&card->dpram[DPRAM_TX + DPRAM_TX_SIZE * fifo_wr],
                        buf, DPRAM_TX_SIZE);
        if (++fifo_wr >= DPRAM_TX_CNT)
                fifo_wr = 0;
        iowrite8(fifo_wr, &card->dpram[DPRAM_TX_WR]);
        card->tx.last_bus = priv->index;
        ++card->tx.pending;
        ++priv->tx.pending;
        can_put_echo_skb(skb, dev, priv->tx.echo_put, 0);
        ++priv->tx.echo_put;
        if (priv->tx.echo_put >= TX_ECHO_SKB_MAX)
                priv->tx.echo_put = 0;
        /* can_put_echo_skb() saves the skb, safe to return TX_OK */
        ret = NETDEV_TX_OK;
xmit_done:
        spin_unlock(&card->spin);
        if (card->tx.pending >= TXMAX) {
                int j;
                for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                        if (card->net[j])
                                netif_stop_queue(card->net[j]);
                }
        }
        if (ret != NETDEV_TX_OK)
                netif_stop_queue(dev);

        return ret;
}

/*
 * shortcut for skb delivery
 */
int softing_netdev_rx(struct net_device *netdev, const struct can_frame *msg,
                ktime_t ktime)
{
        struct sk_buff *skb;
        struct can_frame *cf;

        skb = alloc_can_skb(netdev, &cf);
        if (!skb)
                return -ENOMEM;
        memcpy(cf, msg, sizeof(*msg));
        skb->tstamp = ktime;
        return netif_rx(skb);
}

/*
 * softing_handle_1
 * pop 1 entry from the DPRAM queue, and process
 */
static int softing_handle_1(struct softing *card)
{
        struct net_device *netdev;
        struct softing_priv *priv;
        ktime_t ktime;
        struct can_frame msg;
        int cnt = 0, lost_msg;
        uint8_t fifo_rd, fifo_wr, cmd;
        uint8_t *ptr;
        uint32_t tmp_u32;
        uint8_t buf[DPRAM_RX_SIZE];

        memset(&msg, 0, sizeof(msg));
        /* test for lost msgs */
        lost_msg = ioread8(&card->dpram[DPRAM_RX_LOST]);
        if (lost_msg) {
                int j;
                /* reset condition */
                iowrite8(0, &card->dpram[DPRAM_RX_LOST]);
                /* prepare msg */
                msg.can_id = CAN_ERR_FLAG | CAN_ERR_CRTL;
                msg.len = CAN_ERR_DLC;
                msg.data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
                /*
                 * service to all buses, we don't know which it was applicable
                 * but only service buses that are online
                 */
                for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                        netdev = card->net[j];
                        if (!netdev)
                                continue;
                        if (!canif_is_active(netdev))
                                /* a dead bus has no overflows */
                                continue;
                        ++netdev->stats.rx_over_errors;
                        softing_netdev_rx(netdev, &msg, 0);
                }
                /* prepare for other use */
                memset(&msg, 0, sizeof(msg));
                ++cnt;
        }

        fifo_rd = ioread8(&card->dpram[DPRAM_RX_RD]);
        fifo_wr = ioread8(&card->dpram[DPRAM_RX_WR]);

        if (++fifo_rd >= DPRAM_RX_CNT)
                fifo_rd = 0;
        if (fifo_wr == fifo_rd)
                return cnt;

        memcpy_fromio(buf, &card->dpram[DPRAM_RX + DPRAM_RX_SIZE*fifo_rd],
                        DPRAM_RX_SIZE);
        mb();
        /* trigger dual port RAM */
        iowrite8(fifo_rd, &card->dpram[DPRAM_RX_RD]);

        ptr = buf;
        cmd = *ptr++;
        if (cmd == 0xff)
                /* not quite useful, probably the card has got out */
                return 0;
        netdev = card->net[0];
        if (cmd & CMD_BUS2)
                netdev = card->net[1];
        priv = netdev_priv(netdev);

        if (cmd & CMD_ERR) {
                uint8_t can_state, state;

                state = *ptr++;

                msg.can_id = CAN_ERR_FLAG;
                msg.len = CAN_ERR_DLC;

                if (state & SF_MASK_BUSOFF) {
                        can_state = CAN_STATE_BUS_OFF;
                        msg.can_id |= CAN_ERR_BUSOFF;
                        state = STATE_BUSOFF;
                } else if (state & SF_MASK_EPASSIVE) {
                        can_state = CAN_STATE_ERROR_PASSIVE;
                        msg.can_id |= CAN_ERR_CRTL;
                        msg.data[1] = CAN_ERR_CRTL_TX_PASSIVE;
                        state = STATE_EPASSIVE;
                } else {
                        can_state = CAN_STATE_ERROR_ACTIVE;
                        msg.can_id |= CAN_ERR_CRTL;
                        state = STATE_EACTIVE;
                }
                /* update DPRAM */
                iowrite8(state, &card->dpram[priv->index ?
                                DPRAM_INFO_BUSSTATE2 : DPRAM_INFO_BUSSTATE]);
                /* timestamp */
                tmp_u32 = le32_to_cpup((void *)ptr);
                ktime = softing_raw2ktime(card, tmp_u32);

                ++netdev->stats.rx_errors;
                /* update internal status */
                if (can_state != priv->can.state) {
                        priv->can.state = can_state;
                        if (can_state == CAN_STATE_ERROR_PASSIVE)
                                ++priv->can.can_stats.error_passive;
                        else if (can_state == CAN_STATE_BUS_OFF) {
                                /* this calls can_close_cleanup() */
                                ++priv->can.can_stats.bus_off;
                                can_bus_off(netdev);
                                netif_stop_queue(netdev);
                        }
                        /* trigger socketcan */
                        softing_netdev_rx(netdev, &msg, ktime);
                }

        } else {
                if (cmd & CMD_RTR)
                        msg.can_id |= CAN_RTR_FLAG;
                msg.len = can_cc_dlc2len(*ptr++);
                if (cmd & CMD_XTD) {
                        msg.can_id |= CAN_EFF_FLAG;
                        msg.can_id |= le32_to_cpup((void *)ptr);
                        ptr += 4;
                } else {
                        msg.can_id |= le16_to_cpup((void *)ptr);
                        ptr += 2;
                }
                /* timestamp */
                tmp_u32 = le32_to_cpup((void *)ptr);
                ptr += 4;
                ktime = softing_raw2ktime(card, tmp_u32);
                if (!(msg.can_id & CAN_RTR_FLAG))
                        memcpy(&msg.data[0], ptr, 8);
                /* update socket */
                if (cmd & CMD_ACK) {
                        /* acknowledge, was tx msg */
                        struct sk_buff *skb;
                        skb = priv->can.echo_skb[priv->tx.echo_get];
                        if (skb)
                                skb->tstamp = ktime;
                        ++netdev->stats.tx_packets;
                        netdev->stats.tx_bytes +=
                                can_get_echo_skb(netdev, priv->tx.echo_get,
                                                 NULL);
                        ++priv->tx.echo_get;
                        if (priv->tx.echo_get >= TX_ECHO_SKB_MAX)
                                priv->tx.echo_get = 0;
                        if (priv->tx.pending)
                                --priv->tx.pending;
                        if (card->tx.pending)
                                --card->tx.pending;
                } else {
                        int ret;

                        ret = softing_netdev_rx(netdev, &msg, ktime);
                        if (ret == NET_RX_SUCCESS) {
                                ++netdev->stats.rx_packets;
                                if (!(msg.can_id & CAN_RTR_FLAG))
                                        netdev->stats.rx_bytes += msg.len;
                        } else {
                                ++netdev->stats.rx_dropped;
                        }
                }
        }
        ++cnt;
        return cnt;
}

/*
 * real interrupt handler
 */
static irqreturn_t softing_irq_thread(int irq, void *dev_id)
{
        struct softing *card = (struct softing *)dev_id;
        struct net_device *netdev;
        struct softing_priv *priv;
        int j, offset, work_done;

        work_done = 0;
        spin_lock_bh(&card->spin);
        while (softing_handle_1(card) > 0) {
                ++card->irq.svc_count;
                ++work_done;
        }
        spin_unlock_bh(&card->spin);
        /* resume tx queue's */
        offset = card->tx.last_bus;
        for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                if (card->tx.pending >= TXMAX)
                        break;
                netdev = card->net[(j + offset + 1) % card->pdat->nbus];
                if (!netdev)
                        continue;
                priv = netdev_priv(netdev);
                if (!canif_is_active(netdev))
                        /* it makes no sense to wake dead buses */
                        continue;
                if (priv->tx.pending >= TX_ECHO_SKB_MAX)
                        continue;
                ++work_done;
                netif_wake_queue(netdev);
        }
        return work_done ? IRQ_HANDLED : IRQ_NONE;
}

/*
 * interrupt routines:
 * schedule the 'real interrupt handler'
 */
static irqreturn_t softing_irq_v2(int irq, void *dev_id)
{
        struct softing *card = (struct softing *)dev_id;
        uint8_t ir;

        ir = ioread8(&card->dpram[DPRAM_V2_IRQ_TOHOST]);
        iowrite8(0, &card->dpram[DPRAM_V2_IRQ_TOHOST]);
        return (1 == ir) ? IRQ_WAKE_THREAD : IRQ_NONE;
}

static irqreturn_t softing_irq_v1(int irq, void *dev_id)
{
        struct softing *card = (struct softing *)dev_id;
        uint8_t ir;

        ir = ioread8(&card->dpram[DPRAM_IRQ_TOHOST]);
        iowrite8(0, &card->dpram[DPRAM_IRQ_TOHOST]);
        return ir ? IRQ_WAKE_THREAD : IRQ_NONE;
}

/*
 * netdev/candev interoperability
 */
static int softing_netdev_open(struct net_device *ndev)
{
        int ret;

        /* check or determine and set bittime */
        ret = open_candev(ndev);
        if (ret)
                return ret;

        ret = softing_startstop(ndev, 1);
        if (ret < 0)
                close_candev(ndev);

        return ret;
}

static int softing_netdev_stop(struct net_device *ndev)
{
        netif_stop_queue(ndev);

        /* softing cycle does close_candev() */
        return softing_startstop(ndev, 0);
}

static int softing_candev_set_mode(struct net_device *ndev, enum can_mode mode)
{
        int ret;

        switch (mode) {
        case CAN_MODE_START:
                /* softing_startstop does close_candev() */
                ret = softing_startstop(ndev, 1);
                return ret;
        case CAN_MODE_STOP:
        case CAN_MODE_SLEEP:
                return -EOPNOTSUPP;
        }
        return 0;
}

/*
 * Softing device management helpers
 */
int softing_enable_irq(struct softing *card, int enable)
{
        int ret;

        if (!card->irq.nr) {
                return 0;
        } else if (card->irq.requested && !enable) {
                free_irq(card->irq.nr, card);
                card->irq.requested = 0;
        } else if (!card->irq.requested && enable) {
                ret = request_threaded_irq(card->irq.nr,
                                (card->pdat->generation >= 2) ?
                                        softing_irq_v2 : softing_irq_v1,
                                softing_irq_thread, IRQF_SHARED,
                                dev_name(&card->pdev->dev), card);
                if (ret) {
                        dev_alert(&card->pdev->dev,
                                        "request_threaded_irq(%u) failed\n",
                                        card->irq.nr);
                        return ret;
                }
                card->irq.requested = 1;
        }
        return 0;
}

static void softing_card_shutdown(struct softing *card)
{
        int fw_up = 0;

        if (mutex_lock_interruptible(&card->fw.lock)) {
                /* return -ERESTARTSYS */;
        }
        fw_up = card->fw.up;
        card->fw.up = 0;

        if (card->irq.requested && card->irq.nr) {
                free_irq(card->irq.nr, card);
                card->irq.requested = 0;
        }
        if (fw_up) {
                if (card->pdat->enable_irq)
                        card->pdat->enable_irq(card->pdev, 0);
                softing_set_reset_dpram(card);
                if (card->pdat->reset)
                        card->pdat->reset(card->pdev, 1);
        }
        mutex_unlock(&card->fw.lock);
}

static int softing_card_boot(struct softing *card)
{
        int ret, j;
        static const uint8_t stream[] = {
                0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, };
        unsigned char back[sizeof(stream)];

        if (mutex_lock_interruptible(&card->fw.lock))
                return -ERESTARTSYS;
        if (card->fw.up) {
                mutex_unlock(&card->fw.lock);
                return 0;
        }
        /* reset board */
        if (card->pdat->enable_irq)
                card->pdat->enable_irq(card->pdev, 1);
        /* boot card */
        softing_set_reset_dpram(card);
        if (card->pdat->reset)
                card->pdat->reset(card->pdev, 1);
        for (j = 0; (j + sizeof(stream)) < card->dpram_size;
                        j += sizeof(stream)) {

                memcpy_toio(&card->dpram[j], stream, sizeof(stream));
                /* flush IO cache */
                mb();
                memcpy_fromio(back, &card->dpram[j], sizeof(stream));

                if (!memcmp(back, stream, sizeof(stream)))
                        continue;
                /* memory is not equal */
                dev_alert(&card->pdev->dev, "dpram failed at 0x%04x\n", j);
                ret = -EIO;
                goto failed;
        }
        wmb();
        /* load boot firmware */
        ret = softing_load_fw(card->pdat->boot.fw, card, card->dpram,
                                card->dpram_size,
                                card->pdat->boot.offs - card->pdat->boot.addr);
        if (ret < 0)
                goto failed;
        /* load loader firmware */
        ret = softing_load_fw(card->pdat->load.fw, card, card->dpram,
                                card->dpram_size,
                                card->pdat->load.offs - card->pdat->load.addr);
        if (ret < 0)
                goto failed;

        if (card->pdat->reset)
                card->pdat->reset(card->pdev, 0);
        softing_clr_reset_dpram(card);
        ret = softing_bootloader_command(card, 0, "card boot");
        if (ret < 0)
                goto failed;
        ret = softing_load_app_fw(card->pdat->app.fw, card);
        if (ret < 0)
                goto failed;

        ret = softing_chip_poweron(card);
        if (ret < 0)
                goto failed;

        card->fw.up = 1;
        mutex_unlock(&card->fw.lock);
        return 0;
failed:
        card->fw.up = 0;
        if (card->pdat->enable_irq)
                card->pdat->enable_irq(card->pdev, 0);
        softing_set_reset_dpram(card);
        if (card->pdat->reset)
                card->pdat->reset(card->pdev, 1);
        mutex_unlock(&card->fw.lock);
        return ret;
}

/*
 * netdev sysfs
 */
static ssize_t show_chip(struct device *dev, struct device_attribute *attr,
                char *buf)
{
        struct net_device *ndev = to_net_dev(dev);
        struct softing_priv *priv = netdev2softing(ndev);

        return sprintf(buf, "%i\n", priv->chip);
}

static ssize_t show_output(struct device *dev, struct device_attribute *attr,
                char *buf)
{
        struct net_device *ndev = to_net_dev(dev);
        struct softing_priv *priv = netdev2softing(ndev);

        return sprintf(buf, "0x%02x\n", priv->output);
}

static ssize_t store_output(struct device *dev, struct device_attribute *attr,
                const char *buf, size_t count)
{
        struct net_device *ndev = to_net_dev(dev);
        struct softing_priv *priv = netdev2softing(ndev);
        struct softing *card = priv->card;
        unsigned long val;
        int ret;

        ret = kstrtoul(buf, 0, &val);
        if (ret < 0)
                return ret;
        val &= 0xFF;

        ret = mutex_lock_interruptible(&card->fw.lock);
        if (ret)
                return -ERESTARTSYS;
        if (netif_running(ndev)) {
                mutex_unlock(&card->fw.lock);
                return -EBUSY;
        }
        priv->output = val;
        mutex_unlock(&card->fw.lock);
        return count;
}

static const DEVICE_ATTR(chip, 0444, show_chip, NULL);
static const DEVICE_ATTR(output, 0644, show_output, store_output);

static const struct attribute *const netdev_sysfs_attrs[] = {
        &dev_attr_chip.attr,
        &dev_attr_output.attr,
        NULL,
};
static const struct attribute_group netdev_sysfs_group = {
        .name = NULL,
        .attrs = (struct attribute **)netdev_sysfs_attrs,
};

static const struct net_device_ops softing_netdev_ops = {
        .ndo_open = softing_netdev_open,
        .ndo_stop = softing_netdev_stop,
        .ndo_start_xmit = softing_netdev_start_xmit,
};

static const struct ethtool_ops softing_ethtool_ops = {
        .get_ts_info = ethtool_op_get_ts_info,
};

static const struct can_bittiming_const softing_btr_const = {
        .name = KBUILD_MODNAME,
        .tseg1_min = 1,
        .tseg1_max = 16,
        .tseg2_min = 1,
        .tseg2_max = 8,
        .sjw_max = 4, /* overruled */
        .brp_min = 1,
        .brp_max = 32, /* overruled */
        .brp_inc = 1,
};


static struct net_device *softing_netdev_create(struct softing *card,
                                                uint16_t chip_id)
{
        struct net_device *netdev;
        struct softing_priv *priv;

        netdev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
        if (!netdev) {
                dev_alert(&card->pdev->dev, "alloc_candev failed\n");
                return NULL;
        }
        priv = netdev_priv(netdev);
        priv->netdev = netdev;
        priv->card = card;
        memcpy(&priv->btr_const, &softing_btr_const, sizeof(priv->btr_const));
        priv->btr_const.brp_max = card->pdat->max_brp;
        priv->btr_const.sjw_max = card->pdat->max_sjw;
        priv->can.bittiming_const = &priv->btr_const;
        priv->can.clock.freq = 8000000;
        priv->chip = chip_id;
        priv->output = softing_default_output(netdev);
        SET_NETDEV_DEV(netdev, &card->pdev->dev);

        netdev->flags |= IFF_ECHO;
        netdev->netdev_ops = &softing_netdev_ops;
        netdev->ethtool_ops = &softing_ethtool_ops;
        priv->can.do_set_mode = softing_candev_set_mode;
        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;

        return netdev;
}

static int softing_netdev_register(struct net_device *netdev)
{
        int ret;

        ret = register_candev(netdev);
        if (ret) {
                dev_alert(&netdev->dev, "register failed\n");
                return ret;
        }
        if (sysfs_create_group(&netdev->dev.kobj, &netdev_sysfs_group) < 0)
                netdev_alert(netdev, "sysfs group failed\n");

        return 0;
}

static void softing_netdev_cleanup(struct net_device *netdev)
{
        sysfs_remove_group(&netdev->dev.kobj, &netdev_sysfs_group);
        unregister_candev(netdev);
        free_candev(netdev);
}

/*
 * sysfs for Platform device
 */
#define DEV_ATTR_RO(name, member) \
static ssize_t show_##name(struct device *dev, \
                struct device_attribute *attr, char *buf) \
{ \
        struct softing *card = dev_get_drvdata(dev); \
        return sprintf(buf, "%u\n", card->member); \
} \
static DEVICE_ATTR(name, 0444, show_##name, NULL)

#define DEV_ATTR_RO_STR(name, member) \
static ssize_t show_##name(struct device *dev, \
                struct device_attribute *attr, char *buf) \
{ \
        struct softing *card = dev_get_drvdata(dev); \
        return sprintf(buf, "%s\n", card->member); \
} \
static DEVICE_ATTR(name, 0444, show_##name, NULL)

DEV_ATTR_RO(serial, id.serial);
DEV_ATTR_RO_STR(firmware, pdat->app.fw);
DEV_ATTR_RO(firmware_version, id.fw_version);
DEV_ATTR_RO_STR(hardware, pdat->name);
DEV_ATTR_RO(hardware_version, id.hw_version);
DEV_ATTR_RO(license, id.license);

static struct attribute *softing_pdev_attrs[] = {
        &dev_attr_serial.attr,
        &dev_attr_firmware.attr,
        &dev_attr_firmware_version.attr,
        &dev_attr_hardware.attr,
        &dev_attr_hardware_version.attr,
        &dev_attr_license.attr,
        NULL,
};

static const struct attribute_group softing_pdev_group = {
        .name = NULL,
        .attrs = softing_pdev_attrs,
};

/*
 * platform driver
 */
static void softing_pdev_remove(struct platform_device *pdev)
{
        struct softing *card = platform_get_drvdata(pdev);
        int j;

        /* first, disable card*/
        softing_card_shutdown(card);

        for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                if (!card->net[j])
                        continue;
                softing_netdev_cleanup(card->net[j]);
                card->net[j] = NULL;
        }
        sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);

        iounmap(card->dpram);
        kfree(card);
}

static int softing_pdev_probe(struct platform_device *pdev)
{
        const struct softing_platform_data *pdat = dev_get_platdata(&pdev->dev);
        struct softing *card;
        struct net_device *netdev;
        struct softing_priv *priv;
        struct resource *pres;
        int ret;
        int j;

        if (!pdat) {
                dev_warn(&pdev->dev, "no platform data\n");
                return -EINVAL;
        }
        if (pdat->nbus > ARRAY_SIZE(card->net)) {
                dev_warn(&pdev->dev, "%u nets??\n", pdat->nbus);
                return -EINVAL;
        }

        card = kzalloc_obj(*card);
        if (!card)
                return -ENOMEM;
        card->pdat = pdat;
        card->pdev = pdev;
        platform_set_drvdata(pdev, card);
        mutex_init(&card->fw.lock);
        spin_lock_init(&card->spin);

        ret = -EINVAL;
        pres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!pres)
                goto platform_resource_failed;
        card->dpram_phys = pres->start;
        card->dpram_size = resource_size(pres);
        card->dpram = ioremap(card->dpram_phys, card->dpram_size);
        if (!card->dpram) {
                dev_alert(&card->pdev->dev, "dpram ioremap failed\n");
                goto ioremap_failed;
        }

        pres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (pres)
                card->irq.nr = pres->start;

        /* reset card */
        ret = softing_card_boot(card);
        if (ret < 0) {
                dev_alert(&pdev->dev, "failed to boot\n");
                goto boot_failed;
        }

        /* only now, the chip's are known */
        card->id.freq = card->pdat->freq;

        ret = sysfs_create_group(&pdev->dev.kobj, &softing_pdev_group);
        if (ret < 0) {
                dev_alert(&card->pdev->dev, "sysfs failed\n");
                goto sysfs_failed;
        }

        for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                card->net[j] = netdev =
                        softing_netdev_create(card, card->id.chip[j]);
                if (!netdev) {
                        dev_alert(&pdev->dev, "failed to make can[%i]", j);
                        ret = -ENOMEM;
                        goto netdev_failed;
                }
                netdev->dev_id = j;
                priv = netdev_priv(card->net[j]);
                priv->index = j;
                ret = softing_netdev_register(netdev);
                if (ret) {
                        free_candev(netdev);
                        card->net[j] = NULL;
                        dev_alert(&card->pdev->dev,
                                        "failed to register can[%i]\n", j);
                        goto netdev_failed;
                }
        }
        dev_info(&card->pdev->dev, "%s ready.\n", card->pdat->name);
        return 0;

netdev_failed:
        for (j = 0; j < ARRAY_SIZE(card->net); ++j) {
                if (!card->net[j])
                        continue;
                softing_netdev_cleanup(card->net[j]);
        }
        sysfs_remove_group(&pdev->dev.kobj, &softing_pdev_group);
sysfs_failed:
        softing_card_shutdown(card);
boot_failed:
        iounmap(card->dpram);
ioremap_failed:
platform_resource_failed:
        kfree(card);
        return ret;
}

static struct platform_driver softing_driver = {
        .driver = {
                .name = KBUILD_MODNAME,
        },
        .probe = softing_pdev_probe,
        .remove = softing_pdev_remove,
};

module_platform_driver(softing_driver);

MODULE_ALIAS("platform:softing");
MODULE_DESCRIPTION("Softing DPRAM CAN driver");
MODULE_AUTHOR("Kurt Van Dijck <kurt.van.dijck@eia.be>");
MODULE_LICENSE("GPL v2");