text: // SPDX-License-Identifier: GPL-2.0-only
  /*
   * Copyright (C) 2008-2010
   *
   * - Kurt Van Dijck, EIA Electronics
   */
  
  #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_dropped_invalid_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->can_dlc;
  	*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->can_dlc);
  	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);
  	++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.can_dlc = CAN_ERR_DLC;
  		msg.data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
  		/*
  		 * service to all busses, we don't know which it was applicable
  		 * but only service busses 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.can_dlc = 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);
  		ptr += 4;
  		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.can_dlc = get_can_dlc(*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);
  		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;
  			can_get_echo_skb(netdev, priv->tx.echo_get);
  			++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;
  			++netdev->stats.tx_packets;
  			if (!(msg.can_id & CAN_RTR_FLAG))
  				netdev->stats.tx_bytes += msg.can_dlc;
  		} 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.can_dlc;
  			} 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 busses */
  			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 inter-operability
   */
  static int softing_netdev_open(struct net_device *ndev)
  {
  	int ret;
  
  	/* check or determine and set bittime */
  	ret = open_candev(ndev);
  	if (!ret)
  		ret = softing_startstop(ndev, 1);
  	return ret;
  }
  
  static int softing_netdev_stop(struct net_device *ndev)
  {
  	int ret;
  
  	netif_stop_queue(ndev);
  
  	/* softing cycle does close_candev() */
  	ret = softing_startstop(ndev, 0);
  	return ret;
  }
  
  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,
  	.ndo_change_mtu = can_change_mtu,
  };
  
  static const struct can_bittiming_const softing_btr_const = {
  	.name = "softing",
  	.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;
  	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 int 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);
  	return 0;
  }
  
  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(sizeof(*card), GFP_KERNEL);
  	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 = "softing",
  	},
  	.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");
  