예제 #1
0
파일: c_can.c 프로젝트: Flipkart/linux
static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
				    struct net_device *dev)
{
	struct can_frame *frame = (struct can_frame *)skb->data;
	struct c_can_priv *priv = netdev_priv(dev);
	u32 idx, obj;

	if (can_dropped_invalid_skb(dev, skb))
		return NETDEV_TX_OK;
	/*
	 * This is not a FIFO. C/D_CAN sends out the buffers
	 * prioritized. The lowest buffer number wins.
	 */
	idx = fls(atomic_read(&priv->tx_active));
	obj = idx + C_CAN_MSG_OBJ_TX_FIRST;

	/* If this is the last buffer, stop the xmit queue */
	if (idx == C_CAN_MSG_OBJ_TX_NUM - 1)
		netif_stop_queue(dev);
	/*
	 * Store the message in the interface so we can call
	 * can_put_echo_skb(). We must do this before we enable
	 * transmit as we might race against do_tx().
	 */
	c_can_setup_tx_object(dev, IF_TX, frame, idx);
	priv->dlc[idx] = frame->can_dlc;
	can_put_echo_skb(skb, dev, idx);

	/* Update the active bits */
	atomic_add((1 << idx), &priv->tx_active);
	/* Start transmission */
	c_can_object_put(dev, IF_TX, obj, IF_COMM_TX);

	return NETDEV_TX_OK;
}
예제 #2
0
파일: c_can.c 프로젝트: 03199618/linux
static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
					struct net_device *dev)
{
	u32 msg_obj_no;
	struct c_can_priv *priv = netdev_priv(dev);
	struct can_frame *frame = (struct can_frame *)skb->data;

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

	msg_obj_no = get_tx_next_msg_obj(priv);

	/* prepare message object for transmission */
	c_can_write_msg_object(dev, 0, frame, msg_obj_no);
	can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);

	/*
	 * we have to stop the queue in case of a wrap around or
	 * if the next TX message object is still in use
	 */
	priv->tx_next++;
	if (c_can_is_next_tx_obj_busy(priv, get_tx_next_msg_obj(priv)) ||
			(priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0)
		netif_stop_queue(dev);

	return NETDEV_TX_OK;
}
예제 #3
0
/*
 * ti_hecc_xmit: HECC Transmit
 *
 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the
 * priority of the mailbox for tranmission is dependent upon priority setting
 * field in mailbox registers. The mailbox with highest value in priority field
 * is transmitted first. Only when two mailboxes have the same value in
 * priority field the highest numbered mailbox is transmitted first.
 *
 * To utilize the HECC priority feature as described above we start with the
 * highest numbered mailbox with highest priority level and move on to the next
 * mailbox with the same priority level and so on. Once we loop through all the
 * transmit mailboxes we choose the next priority level (lower) and so on
 * until we reach the lowest priority level on the lowest numbered mailbox
 * when we stop transmission until all mailboxes are transmitted and then
 * restart at highest numbered mailbox with highest priority.
 *
 * Two counters (head and tail) are used to track the next mailbox to transmit
 * and to track the echo buffer for already transmitted mailbox. The queue
 * is stopped when all the mailboxes are busy or when there is a priority
 * value roll-over happens.
 */
static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	struct ti_hecc_priv *priv = netdev_priv(ndev);
	struct can_frame *cf = (struct can_frame *)skb->data;
	u32 mbxno, mbx_mask, data;
	unsigned long flags;

	if (can_dropped_invalid_skb(ndev, skb))
		return NETDEV_TX_OK;

	mbxno = get_tx_head_mb(priv);
	mbx_mask = BIT(mbxno);
	spin_lock_irqsave(&priv->mbx_lock, flags);
	if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) {
		spin_unlock_irqrestore(&priv->mbx_lock, flags);
		netif_stop_queue(ndev);
		netdev_err(priv->ndev,
			"BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n",
			priv->tx_head, priv->tx_tail);
		return NETDEV_TX_BUSY;
	}
	spin_unlock_irqrestore(&priv->mbx_lock, flags);

	/* Prepare mailbox for transmission */
	data = cf->can_dlc | (get_tx_head_prio(priv) << 8);
	if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */
		data |= HECC_CANMCF_RTR;
	hecc_write_mbx(priv, mbxno, HECC_CANMCF, data);

	if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
		data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE;
	else /* Standard frame format */
		data = (cf->can_id & CAN_SFF_MASK) << 18;
	hecc_write_mbx(priv, mbxno, HECC_CANMID, data);
	hecc_write_mbx(priv, mbxno, HECC_CANMDL,
		be32_to_cpu(*(u32 *)(cf->data)));
	if (cf->can_dlc > 4)
		hecc_write_mbx(priv, mbxno, HECC_CANMDH,
			be32_to_cpu(*(u32 *)(cf->data + 4)));
	else
		*(u32 *)(cf->data + 4) = 0;
	can_put_echo_skb(skb, ndev, mbxno);

	spin_lock_irqsave(&priv->mbx_lock, flags);
	--priv->tx_head;
	if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) ||
		(priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) {
		netif_stop_queue(ndev);
	}
	hecc_set_bit(priv, HECC_CANME, mbx_mask);
	spin_unlock_irqrestore(&priv->mbx_lock, flags);

	hecc_clear_bit(priv, HECC_CANMD, mbx_mask);
	hecc_set_bit(priv, HECC_CANMIM, mbx_mask);
	hecc_write(priv, HECC_CANTRS, mbx_mask);

	return NETDEV_TX_OK;
}
예제 #4
0
static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct can_frame *frame = (struct can_frame *)skb->data;
	struct mscan_priv *priv = netdev_priv(dev);
	struct mscan_regs __iomem *regs = priv->reg_base;
	int i, rtr, buf_id;
	u32 can_id;

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

	out_8(&regs->cantier, 0);

	i = ~priv->tx_active & MSCAN_TXE;
	buf_id = ffs(i) - 1;
	switch (hweight8(i)) {
	case 0:
		netif_stop_queue(dev);
		netdev_err(dev, "Tx Ring full when queue awake!\n");
		return NETDEV_TX_BUSY;
	case 1:
		/*
		 * if buf_id < 3, then current frame will be send out of order,
		 * since buffer with lower id have higher priority (hell..)
		 */
		netif_stop_queue(dev);
	case 2:
		if (buf_id < priv->prev_buf_id) {
			priv->cur_pri++;
			if (priv->cur_pri == 0xff) {
				set_bit(F_TX_WAIT_ALL, &priv->flags);
				netif_stop_queue(dev);
			}
		}
		set_bit(F_TX_PROGRESS, &priv->flags);
		break;
	}
	priv->prev_buf_id = buf_id;
	out_8(&regs->cantbsel, i);

	rtr = frame->can_id & CAN_RTR_FLAG;

	/* RTR is always the lowest bit of interest, then IDs follow */
	if (frame->can_id & CAN_EFF_FLAG) {
		can_id = (frame->can_id & CAN_EFF_MASK)
			 << (MSCAN_EFF_RTR_SHIFT + 1);
		if (rtr)
			can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
		out_be16(&regs->tx.idr3_2, can_id);

		can_id >>= 16;
		/* EFF_FLAGS are between the IDs :( */
		can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
			 | MSCAN_EFF_FLAGS;
	} else {
예제 #5
0
static int vcan_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct can_frame *cf = (struct can_frame *)skb->data;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
	struct net_device_stats *stats = &dev->stats;
#else
	struct net_device_stats *stats = netdev_priv(dev);
#endif
	int loop;

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

	stats->tx_packets++;
	stats->tx_bytes += cf->can_dlc;

	/* set flag whether this packet has to be looped back */
	loop = skb->pkt_type == PACKET_LOOPBACK;

	if (!echo) {
		/* no echo handling available inside this driver */

		if (loop) {
			/*
			 * only count the packets here, because the
			 * CAN core already did the echo for us
			 */
			stats->rx_packets++;
			stats->rx_bytes += cf->can_dlc;
		}
		kfree_skb(skb);
		return NETDEV_TX_OK;
	}

	/* perform standard echo handling for CAN network interfaces */

	if (loop) {
		struct sock *srcsk = skb->sk;

		skb = skb_share_check(skb, GFP_ATOMIC);
		if (!skb)
			return NETDEV_TX_OK;

		/* receive with packet counting */
		skb->sk = srcsk;
		vcan_rx(skb, dev);
	} else {
		/* no looped packets => no counting */
		kfree_skb(skb);
	}
	return NETDEV_TX_OK;
}
예제 #6
0
static netdev_tx_t netdev_start_xmit(struct sk_buff *skb,
			struct net_device *dev)
#endif
{
	struct softing_priv *priv = netdev_priv(dev);
	struct softing *card = priv->card;
	int ret;
	int bhlock;
	u8 *ptr;
	u8 cmd;
	unsigned int fifo_wr;
	struct can_frame msg;

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

	if (in_interrupt()) {
		bhlock = 0;
		spin_lock(&card->spin);
	} else {
		bhlock = 1;
		spin_lock_bh(&card->spin);
	}
	ret = NETDEV_TX_BUSY;
	if (!card->fw.up)
		goto xmit_done;
	if (card->tx.pending >= TXMAX)
		goto xmit_done;
	if (priv->tx.pending >= TX_ECHO_SKB_MAX)
		goto xmit_done;
	fifo_wr = card->dpram.tx->wr;
	if (fifo_wr == card->dpram.tx->rd)
		/*fifo full */
		goto xmit_done;
	memcpy(&msg, skb->data, sizeof(msg));
	ptr = &card->dpram.tx->fifo[fifo_wr][0];
	cmd = CMD_TX;
	if (msg.can_id & CAN_RTR_FLAG)
		cmd |= CMD_RTR;
	if (msg.can_id & CAN_EFF_FLAG)
		cmd |= CMD_XTD;
	if (priv->index)
		cmd |= CMD_BUS2;
	*ptr++ = cmd;
	*ptr++ = msg.can_dlc;
	*ptr++ = (msg.can_id >> 0);
	*ptr++ = (msg.can_id >> 8);
	if (msg.can_id & CAN_EFF_FLAG) {
		*ptr++ = (msg.can_id >> 16);
		*ptr++ = (msg.can_id >> 24);
	} else {
예제 #7
0
static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
	struct net_device_stats *stats = &dev->stats;
	int loop;

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

	stats->tx_packets++;
	stats->tx_bytes += cfd->len;

	/* set flag whether this packet has to be looped back */
	loop = skb->pkt_type == PACKET_LOOPBACK;

	if (!echo) {
		/* no echo handling available inside this driver */

		if (loop) {
			/*
			 * only count the packets here, because the
			 * CAN core already did the echo for us
			 */
			stats->rx_packets++;
			stats->rx_bytes += cfd->len;
		}
		consume_skb(skb);
		return NETDEV_TX_OK;
	}

	/* perform standard echo handling for CAN network interfaces */

	if (loop) {

		skb = can_create_echo_skb(skb);
		if (!skb)
			return NETDEV_TX_OK;

		/* receive with packet counting */
		vcan_rx(skb, dev);
	} else {
		/* no looped packets => no counting */
		consume_skb(skb);
	}
	return NETDEV_TX_OK;
}
/* 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 {
예제 #9
0
static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct cc770_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf = (struct can_frame *)skb->data;
	unsigned int mo = obj2msgobj(CC770_OBJ_TX);
	u8 dlc, rtr;
	u32 id;
	int i;

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

	if ((cc770_read_reg(priv,
			    msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
		netdev_err(dev, "TX register is still occupied!\n");
		return NETDEV_TX_BUSY;
	}

	netif_stop_queue(dev);

	dlc = cf->can_dlc;
	id = cf->can_id;
	if (cf->can_id & CAN_RTR_FLAG)
		rtr = 0;
	else
		rtr = MSGCFG_DIR;
	cc770_write_reg(priv, msgobj[mo].ctrl1,
			RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
	cc770_write_reg(priv, msgobj[mo].ctrl0,
			MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
	if (id & CAN_EFF_FLAG) {
		id &= CAN_EFF_MASK;
		cc770_write_reg(priv, msgobj[mo].config,
				(dlc << 4) | rtr | MSGCFG_XTD);
		cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
		cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
		cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
		cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
	} else {
예제 #10
0
파일: vxcan.c 프로젝트: Lyude/linux
static netdev_tx_t vxcan_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct vxcan_priv *priv = netdev_priv(dev);
	struct net_device *peer;
	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
	struct net_device_stats *peerstats, *srcstats = &dev->stats;

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

	rcu_read_lock();
	peer = rcu_dereference(priv->peer);
	if (unlikely(!peer)) {
		kfree_skb(skb);
		dev->stats.tx_dropped++;
		goto out_unlock;
	}

	skb = can_create_echo_skb(skb);
	if (!skb)
		goto out_unlock;

	/* reset CAN GW hop counter */
	skb->csum_start = 0;
	skb->pkt_type   = PACKET_BROADCAST;
	skb->dev        = peer;
	skb->ip_summed  = CHECKSUM_UNNECESSARY;

	if (netif_rx_ni(skb) == NET_RX_SUCCESS) {
		srcstats->tx_packets++;
		srcstats->tx_bytes += cfd->len;
		peerstats = &peer->stats;
		peerstats->rx_packets++;
		peerstats->rx_bytes += cfd->len;
	}

out_unlock:
	rcu_read_unlock();
	return NETDEV_TX_OK;
}
예제 #11
0
/* Send close command to device */
static int usb_8dev_cmd_close(struct usb_8dev_priv *priv)
{
	struct usb_8dev_cmd_msg inmsg;
	struct usb_8dev_cmd_msg outmsg = {
		.channel = 0,
		.command = USB_8DEV_CLOSE,
		.opt1 = 0,
		.opt2 = 0
	};

	return usb_8dev_send_cmd(priv, &outmsg, &inmsg);
}

/* Get firmware and hardware version */
static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res)
{
	struct usb_8dev_cmd_msg	inmsg;
	struct usb_8dev_cmd_msg	outmsg = {
		.channel = 0,
		.command = USB_8DEV_GET_SOFTW_HARDW_VER,
		.opt1 = 0,
		.opt2 = 0
	};

	int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg);
	if (err)
		return err;

	*res = be32_to_cpup((__be32 *)inmsg.data);

	return err;
}

/* Set network device mode
 *
 * Maybe we should leave this function empty, because the device
 * set mode variable with open command.
 */
static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode)
{
	struct usb_8dev_priv *priv = netdev_priv(netdev);
	int err = 0;

	switch (mode) {
	case CAN_MODE_START:
		err = usb_8dev_cmd_open(priv);
		if (err)
			netdev_warn(netdev, "couldn't start device");
		break;

	default:
		return -EOPNOTSUPP;
	}

	return err;
}

/* Read error/status frames */
static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv,
				struct usb_8dev_rx_msg *msg)
{
	struct can_frame *cf;
	struct sk_buff *skb;
	struct net_device_stats *stats = &priv->netdev->stats;

	/* Error message:
	 * byte 0: Status
	 * byte 1: bit   7: Receive Passive
	 * byte 1: bit 0-6: Receive Error Counter
	 * byte 2: Transmit Error Counter
	 * byte 3: Always 0 (maybe reserved for future use)
	 */

	u8 state = msg->data[0];
	u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK;
	u8 txerr = msg->data[2];
	int rx_errors = 0;
	int tx_errors = 0;

	skb = alloc_can_err_skb(priv->netdev, &cf);
	if (!skb)
		return;

	switch (state) {
	case USB_8DEV_STATUSMSG_OK:
		priv->can.state = CAN_STATE_ERROR_ACTIVE;
		cf->can_id |= CAN_ERR_PROT;
		cf->data[2] = CAN_ERR_PROT_ACTIVE;
		break;
	case USB_8DEV_STATUSMSG_BUSOFF:
		priv->can.state = CAN_STATE_BUS_OFF;
		cf->can_id |= CAN_ERR_BUSOFF;
		can_bus_off(priv->netdev);
		break;
	case USB_8DEV_STATUSMSG_OVERRUN:
	case USB_8DEV_STATUSMSG_BUSLIGHT:
	case USB_8DEV_STATUSMSG_BUSHEAVY:
		cf->can_id |= CAN_ERR_CRTL;
		break;
	default:
		priv->can.state = CAN_STATE_ERROR_WARNING;
		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
		priv->can.can_stats.bus_error++;
		break;
	}

	switch (state) {
	case USB_8DEV_STATUSMSG_OK:
	case USB_8DEV_STATUSMSG_BUSOFF:
		break;
	case USB_8DEV_STATUSMSG_ACK:
		cf->can_id |= CAN_ERR_ACK;
		tx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_CRC:
		cf->data[2] |= CAN_ERR_PROT_UNSPEC;
		cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ |
			       CAN_ERR_PROT_LOC_CRC_DEL;
		rx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_BIT0:
		cf->data[2] |= CAN_ERR_PROT_BIT0;
		tx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_BIT1:
		cf->data[2] |= CAN_ERR_PROT_BIT1;
		tx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_FORM:
		cf->data[2] |= CAN_ERR_PROT_FORM;
		rx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_STUFF:
		cf->data[2] |= CAN_ERR_PROT_STUFF;
		rx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_OVERRUN:
		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
		stats->rx_over_errors++;
		rx_errors = 1;
		break;
	case USB_8DEV_STATUSMSG_BUSLIGHT:
		priv->can.state = CAN_STATE_ERROR_WARNING;
		cf->data[1] = (txerr > rxerr) ?
			CAN_ERR_CRTL_TX_WARNING :
			CAN_ERR_CRTL_RX_WARNING;
		priv->can.can_stats.error_warning++;
		break;
	case USB_8DEV_STATUSMSG_BUSHEAVY:
		priv->can.state = CAN_STATE_ERROR_PASSIVE;
		cf->data[1] = (txerr > rxerr) ?
			CAN_ERR_CRTL_TX_PASSIVE :
			CAN_ERR_CRTL_RX_PASSIVE;
		priv->can.can_stats.error_passive++;
		break;
	default:
		netdev_warn(priv->netdev,
			    "Unknown status/error message (%d)\n", state);
		break;
	}

	if (tx_errors) {
		cf->data[2] |= CAN_ERR_PROT_TX;
		stats->tx_errors++;
	}

	if (rx_errors)
		stats->rx_errors++;

	cf->data[6] = txerr;
	cf->data[7] = rxerr;

	priv->bec.txerr = txerr;
	priv->bec.rxerr = rxerr;

	netif_rx(skb);

	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;
}

/* Read data and status frames */
static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv,
				struct usb_8dev_rx_msg *msg)
{
	struct can_frame *cf;
	struct sk_buff *skb;
	struct net_device_stats *stats = &priv->netdev->stats;

	if (msg->type == USB_8DEV_TYPE_ERROR_FRAME &&
		   msg->flags == USB_8DEV_ERR_FLAG) {
		usb_8dev_rx_err_msg(priv, msg);
	} else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) {
		skb = alloc_can_skb(priv->netdev, &cf);
		if (!skb)
			return;

		cf->can_id = be32_to_cpu(msg->id);
		cf->can_dlc = get_can_dlc(msg->dlc & 0xF);

		if (msg->flags & USB_8DEV_EXTID)
			cf->can_id |= CAN_EFF_FLAG;

		if (msg->flags & USB_8DEV_RTR)
			cf->can_id |= CAN_RTR_FLAG;
		else
			memcpy(cf->data, msg->data, cf->can_dlc);

		netif_rx(skb);

		stats->rx_packets++;
		stats->rx_bytes += cf->can_dlc;

		can_led_event(priv->netdev, CAN_LED_EVENT_RX);
	} else {
		netdev_warn(priv->netdev, "frame type %d unknown",
			 msg->type);
	}

}

/* Callback for reading data from device
 *
 * Check urb status, call read function and resubmit urb read operation.
 */
static void usb_8dev_read_bulk_callback(struct urb *urb)
{
	struct usb_8dev_priv *priv = urb->context;
	struct net_device *netdev;
	int retval;
	int pos = 0;

	netdev = priv->netdev;

	if (!netif_device_present(netdev))
		return;

	switch (urb->status) {
	case 0: /* success */
		break;

	case -ENOENT:
	case -ESHUTDOWN:
		return;

	default:
		netdev_info(netdev, "Rx URB aborted (%d)\n",
			 urb->status);
		goto resubmit_urb;
	}

	while (pos < urb->actual_length) {
		struct usb_8dev_rx_msg *msg;

		if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) {
			netdev_err(priv->netdev, "format error\n");
			break;
		}

		msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos);
		usb_8dev_rx_can_msg(priv, msg);

		pos += sizeof(struct usb_8dev_rx_msg);
	}

resubmit_urb:
	usb_fill_bulk_urb(urb, priv->udev,
			  usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX),
			  urb->transfer_buffer, RX_BUFFER_SIZE,
			  usb_8dev_read_bulk_callback, priv);

	retval = usb_submit_urb(urb, GFP_ATOMIC);

	if (retval == -ENODEV)
		netif_device_detach(netdev);
	else if (retval)
		netdev_err(netdev,
			"failed resubmitting read bulk urb: %d\n", retval);
}

/* Callback handler for write operations
 *
 * Free allocated buffers, check transmit status and
 * calculate statistic.
 */
static void usb_8dev_write_bulk_callback(struct urb *urb)
{
	struct usb_8dev_tx_urb_context *context = urb->context;
	struct usb_8dev_priv *priv;
	struct net_device *netdev;

	BUG_ON(!context);

	priv = context->priv;
	netdev = priv->netdev;

	/* free up our allocated buffer */
	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
			  urb->transfer_buffer, urb->transfer_dma);

	atomic_dec(&priv->active_tx_urbs);

	if (!netif_device_present(netdev))
		return;

	if (urb->status)
		netdev_info(netdev, "Tx URB aborted (%d)\n",
			 urb->status);

	netdev->stats.tx_packets++;
	netdev->stats.tx_bytes += context->dlc;

	can_get_echo_skb(netdev, context->echo_index);

	can_led_event(netdev, CAN_LED_EVENT_TX);

	/* Release context */
	context->echo_index = MAX_TX_URBS;

	netif_wake_queue(netdev);
}

/* Send data to device */
static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
				      struct net_device *netdev)
{
	struct usb_8dev_priv *priv = netdev_priv(netdev);
	struct net_device_stats *stats = &netdev->stats;
	struct can_frame *cf = (struct can_frame *) skb->data;
	struct usb_8dev_tx_msg *msg;
	struct urb *urb;
	struct usb_8dev_tx_urb_context *context = NULL;
	u8 *buf;
	int i, err;
	size_t size = sizeof(struct usb_8dev_tx_msg);

	if (can_dropped_invalid_skb(netdev, skb))
		return NETDEV_TX_OK;

	/* create a URB, and a buffer for it, and copy the data to the URB */
	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		netdev_err(netdev, "No memory left for URBs\n");
		goto nomem;
	}

	buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC,
				 &urb->transfer_dma);
	if (!buf) {
		netdev_err(netdev, "No memory left for USB buffer\n");
		goto nomembuf;
	}

	memset(buf, 0, size);

	msg = (struct usb_8dev_tx_msg *)buf;
	msg->begin = USB_8DEV_DATA_START;
	msg->flags = 0x00;

	if (cf->can_id & CAN_RTR_FLAG)
		msg->flags |= USB_8DEV_RTR;

	if (cf->can_id & CAN_EFF_FLAG)
		msg->flags |= USB_8DEV_EXTID;

	msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK);
	msg->dlc = cf->can_dlc;
	memcpy(msg->data, cf->data, cf->can_dlc);
	msg->end = USB_8DEV_DATA_END;

	for (i = 0; i < MAX_TX_URBS; i++) {
		if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
			context = &priv->tx_contexts[i];
			break;
		}
	}

	/* May never happen! When this happens we'd more URBs in flight as
	 * allowed (MAX_TX_URBS).
	 */
	if (!context)
		goto nofreecontext;

	context->priv = priv;
	context->echo_index = i;
	context->dlc = cf->can_dlc;

	usb_fill_bulk_urb(urb, priv->udev,
			  usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX),
			  buf, size, usb_8dev_write_bulk_callback, context);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	usb_anchor_urb(urb, &priv->tx_submitted);

	can_put_echo_skb(skb, netdev, context->echo_index);

	atomic_inc(&priv->active_tx_urbs);

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (unlikely(err))
		goto failed;
	else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
		/* Slow down tx path */
		netif_stop_queue(netdev);

	/* Release our reference to this URB, the USB core will eventually free
	 * it entirely.
	 */
	usb_free_urb(urb);

	return NETDEV_TX_OK;

nofreecontext:
	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);
	usb_free_urb(urb);

	netdev_warn(netdev, "couldn't find free context");

	return NETDEV_TX_BUSY;

failed:
	can_free_echo_skb(netdev, context->echo_index);

	usb_unanchor_urb(urb);
	usb_free_coherent(priv->udev, size, buf, urb->transfer_dma);

	atomic_dec(&priv->active_tx_urbs);

	if (err == -ENODEV)
		netif_device_detach(netdev);
	else
		netdev_warn(netdev, "failed tx_urb %d\n", err);

nomembuf:
	usb_free_urb(urb);

nomem:
	dev_kfree_skb(skb);
	stats->tx_dropped++;

	return NETDEV_TX_OK;
}

static int usb_8dev_get_berr_counter(const struct net_device *netdev,
				     struct can_berr_counter *bec)
{
	struct usb_8dev_priv *priv = netdev_priv(netdev);

	bec->txerr = priv->bec.txerr;
	bec->rxerr = priv->bec.rxerr;

	return 0;
}

/* Start USB device */
static int usb_8dev_start(struct usb_8dev_priv *priv)
{
	struct net_device *netdev = priv->netdev;
	int err, i;

	for (i = 0; i < MAX_RX_URBS; i++) {
		struct urb *urb = NULL;
		u8 *buf;

		/* create a URB, and a buffer for it */
		urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!urb) {
			netdev_err(netdev, "No memory left for URBs\n");
			err = -ENOMEM;
			break;
		}

		buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL,
					 &urb->transfer_dma);
		if (!buf) {
			netdev_err(netdev, "No memory left for USB buffer\n");
			usb_free_urb(urb);
			err = -ENOMEM;
			break;
		}

		usb_fill_bulk_urb(urb, priv->udev,
				  usb_rcvbulkpipe(priv->udev,
						  USB_8DEV_ENDP_DATA_RX),
				  buf, RX_BUFFER_SIZE,
				  usb_8dev_read_bulk_callback, priv);
		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
		usb_anchor_urb(urb, &priv->rx_submitted);

		err = usb_submit_urb(urb, GFP_KERNEL);
		if (err) {
			usb_unanchor_urb(urb);
			usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf,
					  urb->transfer_dma);
			usb_free_urb(urb);
			break;
		}

		/* Drop reference, USB core will take care of freeing it */
		usb_free_urb(urb);
	}

	/* Did we submit any URBs */
	if (i == 0) {
		netdev_warn(netdev, "couldn't setup read URBs\n");
		return err;
	}

	/* Warn if we've couldn't transmit all the URBs */
	if (i < MAX_RX_URBS)
		netdev_warn(netdev, "rx performance may be slow\n");

	err = usb_8dev_cmd_open(priv);
	if (err)
		goto failed;

	priv->can.state = CAN_STATE_ERROR_ACTIVE;

	return 0;

failed:
	if (err == -ENODEV)
		netif_device_detach(priv->netdev);

	netdev_warn(netdev, "couldn't submit control: %d\n", err);

	return err;
}

/* Open USB device */
static int usb_8dev_open(struct net_device *netdev)
{
	struct usb_8dev_priv *priv = netdev_priv(netdev);
	int err;

	/* common open */
	err = open_candev(netdev);
	if (err)
		return err;

	can_led_event(netdev, CAN_LED_EVENT_OPEN);

	/* finally start device */
	err = usb_8dev_start(priv);
	if (err) {
		if (err == -ENODEV)
			netif_device_detach(priv->netdev);

		netdev_warn(netdev, "couldn't start device: %d\n",
			 err);

		close_candev(netdev);

		return err;
	}

	netif_start_queue(netdev);

	return 0;
}

static void unlink_all_urbs(struct usb_8dev_priv *priv)
{
	int i;

	usb_kill_anchored_urbs(&priv->rx_submitted);

	usb_kill_anchored_urbs(&priv->tx_submitted);
	atomic_set(&priv->active_tx_urbs, 0);

	for (i = 0; i < MAX_TX_URBS; i++)
		priv->tx_contexts[i].echo_index = MAX_TX_URBS;
}

/* Close USB device */
static int usb_8dev_close(struct net_device *netdev)
{
	struct usb_8dev_priv *priv = netdev_priv(netdev);
	int err = 0;

	/* Send CLOSE command to CAN controller */
	err = usb_8dev_cmd_close(priv);
	if (err)
		netdev_warn(netdev, "couldn't stop device");

	priv->can.state = CAN_STATE_STOPPED;

	netif_stop_queue(netdev);

	/* Stop polling */
	unlink_all_urbs(priv);

	close_candev(netdev);

	can_led_event(netdev, CAN_LED_EVENT_STOP);

	return err;
}

static const struct net_device_ops usb_8dev_netdev_ops = {
	.ndo_open = usb_8dev_open,
	.ndo_stop = usb_8dev_close,
	.ndo_start_xmit = usb_8dev_start_xmit,
	.ndo_change_mtu = can_change_mtu,
};

static const struct can_bittiming_const usb_8dev_bittiming_const = {
	.name = "usb_8dev",
	.tseg1_min = 1,
	.tseg1_max = 16,
	.tseg2_min = 1,
	.tseg2_max = 8,
	.sjw_max = 4,
	.brp_min = 1,
	.brp_max = 1024,
	.brp_inc = 1,
};

/* Probe USB device
 *
 * Check device and firmware.
 * Set supported modes and bittiming constants.
 * Allocate some memory.
 */
static int usb_8dev_probe(struct usb_interface *intf,
			 const struct usb_device_id *id)
{
	struct net_device *netdev;
	struct usb_8dev_priv *priv;
	int i, err = -ENOMEM;
	u32 version;
	char buf[18];
	struct usb_device *usbdev = interface_to_usbdev(intf);

	/* product id looks strange, better we also check iProduct string */
	if (usb_string(usbdev, usbdev->descriptor.iProduct, buf,
		       sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) {
		dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n");
		return -ENODEV;
	}

	netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS);
	if (!netdev) {
		dev_err(&intf->dev, "Couldn't alloc candev\n");
		return -ENOMEM;
	}

	priv = netdev_priv(netdev);

	priv->udev = usbdev;
	priv->netdev = netdev;

	priv->can.state = CAN_STATE_STOPPED;
	priv->can.clock.freq = USB_8DEV_ABP_CLOCK;
	priv->can.bittiming_const = &usb_8dev_bittiming_const;
	priv->can.do_set_mode = usb_8dev_set_mode;
	priv->can.do_get_berr_counter = usb_8dev_get_berr_counter;
	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
				      CAN_CTRLMODE_LISTENONLY |
				      CAN_CTRLMODE_ONE_SHOT;

	netdev->netdev_ops = &usb_8dev_netdev_ops;

	netdev->flags |= IFF_ECHO; /* we support local echo */

	init_usb_anchor(&priv->rx_submitted);

	init_usb_anchor(&priv->tx_submitted);
	atomic_set(&priv->active_tx_urbs, 0);

	for (i = 0; i < MAX_TX_URBS; i++)
		priv->tx_contexts[i].echo_index = MAX_TX_URBS;

	priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg),
				      GFP_KERNEL);
	if (!priv->cmd_msg_buffer)
		goto cleanup_candev;

	usb_set_intfdata(intf, priv);

	SET_NETDEV_DEV(netdev, &intf->dev);

	mutex_init(&priv->usb_8dev_cmd_lock);

	err = register_candev(netdev);
	if (err) {
		netdev_err(netdev,
			"couldn't register CAN device: %d\n", err);
		goto cleanup_cmd_msg_buffer;
	}

	err = usb_8dev_cmd_version(priv, &version);
	if (err) {
		netdev_err(netdev, "can't get firmware version\n");
		goto cleanup_unregister_candev;
	} else {
		netdev_info(netdev,
			 "firmware: %d.%d, hardware: %d.%d\n",
			 (version>>24) & 0xff, (version>>16) & 0xff,
			 (version>>8) & 0xff, version & 0xff);
	}

	devm_can_led_init(netdev);

	return 0;

cleanup_unregister_candev:
	unregister_netdev(priv->netdev);

cleanup_cmd_msg_buffer:
	kfree(priv->cmd_msg_buffer);

cleanup_candev:
	free_candev(netdev);

	return err;

}

/* Called by the usb core when driver is unloaded or device is removed */
static void usb_8dev_disconnect(struct usb_interface *intf)
{
	struct usb_8dev_priv *priv = usb_get_intfdata(intf);

	usb_set_intfdata(intf, NULL);

	if (priv) {
		netdev_info(priv->netdev, "device disconnected\n");

		unregister_netdev(priv->netdev);
		free_candev(priv->netdev);

		unlink_all_urbs(priv);
	}

}

static struct usb_driver usb_8dev_driver = {
	.name =		"usb_8dev",
	.probe =	usb_8dev_probe,
	.disconnect =	usb_8dev_disconnect,
	.id_table =	usb_8dev_table,
};

module_usb_driver(usb_8dev_driver);

MODULE_AUTHOR("Bernd Krumboeck <*****@*****.**>");
MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces");
MODULE_LICENSE("GPL v2");
예제 #12
0
파일: gs_usb.c 프로젝트: harlanstars/linux
static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
				     struct net_device *netdev)
{
	struct gs_can *dev = netdev_priv(netdev);
	struct net_device_stats *stats = &dev->netdev->stats;
	struct urb *urb;
	struct gs_host_frame *hf;
	struct can_frame *cf;
	int rc;
	unsigned int idx;
	struct gs_tx_context *txc;

	if (can_dropped_invalid_skb(netdev, skb))
		return NETDEV_TX_OK;

	/* find an empty context to keep track of transmission */
	txc = gs_alloc_tx_context(dev);
	if (!txc)
		return NETDEV_TX_BUSY;

	/* create a URB, and a buffer for it */
	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb)
		goto nomem_urb;

	hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
				&urb->transfer_dma);
	if (!hf) {
		netdev_err(netdev, "No memory left for USB buffer\n");
		goto nomem_hf;
	}

	idx = txc->echo_id;

	if (idx >= GS_MAX_TX_URBS) {
		netdev_err(netdev, "Invalid tx context %d\n", idx);
		goto badidx;
	}

	hf->echo_id = idx;
	hf->channel = dev->channel;

	cf = (struct can_frame *)skb->data;

	hf->can_id = cf->can_id;
	hf->can_dlc = cf->can_dlc;
	memcpy(hf->data, cf->data, cf->can_dlc);

	usb_fill_bulk_urb(urb, dev->udev,
			  usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
			  hf,
			  sizeof(*hf),
			  gs_usb_xmit_callback,
			  txc);

	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	usb_anchor_urb(urb, &dev->tx_submitted);

	can_put_echo_skb(skb, netdev, idx);

	atomic_inc(&dev->active_tx_urbs);

	rc = usb_submit_urb(urb, GFP_ATOMIC);
	if (unlikely(rc)) {			/* usb send failed */
		atomic_dec(&dev->active_tx_urbs);

		can_free_echo_skb(netdev, idx);
		gs_free_tx_context(txc);

		usb_unanchor_urb(urb);
		usb_free_coherent(dev->udev,
				  sizeof(*hf),
				  hf,
				  urb->transfer_dma);

		if (rc == -ENODEV) {
			netif_device_detach(netdev);
		} else {
			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
			stats->tx_dropped++;
		}
	} else {
		/* Slow down tx path */
		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
			netif_stop_queue(netdev);
	}

	/* let usb core take care of this urb */
	usb_free_urb(urb);

	return NETDEV_TX_OK;

 badidx:
	usb_free_coherent(dev->udev,
			  sizeof(*hf),
			  hf,
			  urb->transfer_dma);
 nomem_hf:
	usb_free_urb(urb);

 nomem_urb:
	gs_free_tx_context(txc);
	dev_kfree_skb(skb);
	stats->tx_dropped++;
	return NETDEV_TX_OK;
}
예제 #13
0
static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
	struct ems_usb *dev = netdev_priv(netdev);
	struct ems_tx_urb_context *context = NULL;
	struct net_device_stats *stats = &netdev->stats;
	struct can_frame *cf = (struct can_frame *)skb->data;
	struct ems_cpc_msg *msg;
	struct urb *urb;
	u8 *buf;
	int i, err;
	size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
			+ sizeof(struct cpc_can_msg);

	if (can_dropped_invalid_skb(netdev, skb))
		return NETDEV_TX_OK;

	/* create a URB, and a buffer for it, and copy the data to the URB */
	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		netdev_err(netdev, "No memory left for URBs\n");
		goto nomem;
	}

	buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
	if (!buf) {
		netdev_err(netdev, "No memory left for USB buffer\n");
		usb_free_urb(urb);
		goto nomem;
	}

	msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];

	msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
	msg->msg.can_msg.length = cf->can_dlc;

	if (cf->can_id & CAN_RTR_FLAG) {
		msg->type = cf->can_id & CAN_EFF_FLAG ?
			CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;

		msg->length = CPC_CAN_MSG_MIN_SIZE;
	} else {
		msg->type = cf->can_id & CAN_EFF_FLAG ?
			CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;

		for (i = 0; i < cf->can_dlc; i++)
			msg->msg.can_msg.msg[i] = cf->data[i];

		msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
	}

	/* Respect byte order */
	msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id);

	for (i = 0; i < MAX_TX_URBS; i++) {
		if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
			context = &dev->tx_contexts[i];
			break;
		}
	}

	/*
	 * May never happen! When this happens we'd more URBs in flight as
	 * allowed (MAX_TX_URBS).
	 */
	if (!context) {
		usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
		usb_free_urb(urb);

		netdev_warn(netdev, "couldn't find free context\n");

		return NETDEV_TX_BUSY;
	}

	context->dev = dev;
	context->echo_index = i;
	context->dlc = cf->can_dlc;

	usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
			  size, ems_usb_write_bulk_callback, context);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	usb_anchor_urb(urb, &dev->tx_submitted);

	can_put_echo_skb(skb, netdev, context->echo_index);

	atomic_inc(&dev->active_tx_urbs);

	err = usb_submit_urb(urb, GFP_ATOMIC);
	if (unlikely(err)) {
		can_free_echo_skb(netdev, context->echo_index);

		usb_unanchor_urb(urb);
		usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
		dev_kfree_skb(skb);

		atomic_dec(&dev->active_tx_urbs);

		if (err == -ENODEV) {
			netif_device_detach(netdev);
		} else {
			netdev_warn(netdev, "failed tx_urb %d\n", err);

			stats->tx_dropped++;
		}
	} else {
		netdev->trans_start = jiffies;

		/* Slow down tx path */
		if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
		    dev->free_slots < 5) {
			netif_stop_queue(netdev);
		}
	}

	/*
	 * Release our reference to this URB, the USB core will eventually free
	 * it entirely.
	 */
	usb_free_urb(urb);

	return NETDEV_TX_OK;

nomem:
	dev_kfree_skb(skb);
	stats->tx_dropped++;

	return NETDEV_TX_OK;
}
예제 #14
0
static netdev_tx_t sam4e_netdev_start_xmit(
		struct sk_buff *skb, struct net_device *netdev)
{
	struct sam4e_req *req;
	struct usb_device *udev;
	struct sam4e_usb_handle *sam4e_usb_hnd = netdev_priv(netdev);
	struct sam4e_usb *dev = sam4e_usb_hnd->sam4e_dev;
	struct net_device_stats *stats = &netdev->stats;
	int result;
	struct can_frame *cf = (struct can_frame *)skb->data;
	struct urb *urb;
	size_t size = sizeof(struct sam4e_req) +
			sizeof(struct sam4e_can_full_write);
	struct sam4e_can_full_write *cfw;

	if (can_dropped_invalid_skb(netdev, skb)) {
		pr_err("Dropping invalid can frame");
		return NETDEV_TX_OK;
	}

	udev = dev->udev;
	urb = usb_alloc_urb(0, GFP_ATOMIC);
	if (!urb) {
		pr_err("No memory left for URBs\n");
		goto nomem;
	}

	req = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC,
			&urb->transfer_dma);
	if (!req) {
		pr_err("No memory left for USB buffer\n");
		usb_free_urb(urb);
		goto nomem;
	}

	/* Fill message data */
	cfw = (struct sam4e_can_full_write *)&req->data;
	req->cmd = CMD_CAN_FULL_WRITE;
	req->len = sizeof(struct sam4e_req) +
			sizeof(struct sam4e_can_full_write);
	req->seq = atomic_inc_return(&dev->msg_seq);
	cfw->can = sam4e_usb_hnd->owner_netdev_index;
	cfw->mailbox = 0;
	cfw->prio = 0;
	cfw->mid = cf->can_id;
	cfw->dlc = cf->can_dlc;
	memcpy(cfw->data, cf->data, 8);

	LOGNI(">%x %2d [%d] send frame [%d] %x %d %x %x %x %x %x %x %x %x\n",
			req->cmd, req->len, req->seq,
			atomic_read(&dev->active_tx_urbs), cfw->mid,
			cfw->dlc, cfw->data[0], cfw->data[1], cfw->data[2],
			cfw->data[3], cfw->data[4], cfw->data[5],
			cfw->data[6], cfw->data[7]);

	usb_fill_bulk_urb(urb, dev->udev,
			usb_sndbulkpipe(dev->udev, BULK_OUT_EP), req,
			size, sam4e_usb_write_bulk_callback, netdev);
	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
	usb_anchor_urb(urb, &dev->tx_submitted);
	atomic_inc(&dev->active_tx_urbs);

	result = usb_submit_urb(urb, GFP_ATOMIC);
	if (unlikely(result)) {
		usb_unanchor_urb(urb);
		usb_free_coherent(dev->udev, size, req, urb->transfer_dma);
		dev_kfree_skb(skb);

		atomic_dec(&dev->active_tx_urbs);
		if (result == -ENODEV) {
			netif_device_detach(netdev);
		} else {
			pr_err("failed tx_urb %d\n", result);
			stats->tx_dropped++;
		}
	} else {
		/* Put on hold tx path */
		if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS) {
			LOGNI("Too many outstanding requests (%d). Stop queue",
					atomic_read(&dev->active_tx_urbs));
			atomic_inc(&dev->netif_queue_stop);
			if (dev->netdev1)
				netif_stop_queue(dev->netdev1);
			if (dev->netdev2)
				netif_stop_queue(dev->netdev2);
		}
	}
	dev_kfree_skb(skb);
	usb_free_urb(urb);
	return NETDEV_TX_OK;

nomem:
	dev_kfree_skb(skb);
	stats->tx_dropped++;

	return NETDEV_TX_OK;
}