can: kvaser_usb: Add support for Kvaser CAN/USB devices
authorOlivier Sobrie <olivier@sobrie.be>
Wed, 21 Nov 2012 07:11:13 +0000 (08:11 +0100)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Tue, 27 Nov 2012 08:49:31 +0000 (09:49 +0100)
This driver provides support for several Kvaser CAN/USB devices.
Such kind of devices supports up to three CAN network interfaces.

It has been tested with a Kvaser USB Leaf Light (one network interface)
connected to a pch_can interface.
The firmware version of the Kvaser device was 2.5.205.

List of Kvaser devices supported by the driver:
  - Kvaser Leaf Light
  - Kvaser Leaf Professional HS
  - Kvaser Leaf SemiPro HS
  - Kvaser Leaf Professional LS
  - Kvaser Leaf Professional SWC
  - Kvaser Leaf Professional LIN
  - Kvaser Leaf SemiPro LS
  - Kvaser Leaf SemiPro SWC
  - Kvaser Memorator II HS/HS
  - Kvaser USBcan Professional HS/HS
  - Kvaser Leaf Light GI
  - Kvaser Leaf Professional HS (OBD-II connector)
  - Kvaser Memorator Professional HS/LS
  - Kvaser Leaf Light "China"
  - Kvaser BlackBird SemiPro
  - Kvaser USBcan R

Signed-off-by: Daniel Berglund <db@kvaser.com>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
drivers/net/can/usb/Kconfig
drivers/net/can/usb/Makefile
drivers/net/can/usb/kvaser_usb.c [new file with mode: 0644]

index 0a6876841c20b62ab75f49e41b33ca6c45afbf12..a4e4bee35710fa3f71b1b597c98782765603c45f 100644 (file)
@@ -13,6 +13,35 @@ config CAN_ESD_USB2
           This driver supports the CAN-USB/2 interface
           from esd electronic system design gmbh (http://www.esd.eu).
 
+config CAN_KVASER_USB
+       tristate "Kvaser CAN/USB interface"
+       ---help---
+         This driver adds support for Kvaser CAN/USB devices like Kvaser
+         Leaf Light.
+
+         The driver gives support for the following devices:
+           - Kvaser Leaf Light
+           - Kvaser Leaf Professional HS
+           - Kvaser Leaf SemiPro HS
+           - Kvaser Leaf Professional LS
+           - Kvaser Leaf Professional SWC
+           - Kvaser Leaf Professional LIN
+           - Kvaser Leaf SemiPro LS
+           - Kvaser Leaf SemiPro SWC
+           - Kvaser Memorator II HS/HS
+           - Kvaser USBcan Professional HS/HS
+           - Kvaser Leaf Light GI
+           - Kvaser Leaf Professional HS (OBD-II connector)
+           - Kvaser Memorator Professional HS/LS
+           - Kvaser Leaf Light "China"
+           - Kvaser BlackBird SemiPro
+           - Kvaser USBcan R
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called kvaser_usb.
+
 config CAN_PEAK_USB
        tristate "PEAK PCAN-USB/USB Pro interfaces"
        ---help---
index da6d1d3b2969939758b6165c67ce3278a1e3e831..80a2ee41fd61726dc43b70724d20e6c63c9b8cac 100644 (file)
@@ -4,6 +4,7 @@
 
 obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
 obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
+obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
 obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
 
 ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/usb/kvaser_usb.c b/drivers/net/can/usb/kvaser_usb.c
new file mode 100644 (file)
index 0000000..5b58a4d
--- /dev/null
@@ -0,0 +1,1627 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * Parts of this driver are based on the following:
+ *  - Kvaser linux leaf driver (version 4.78)
+ *  - CAN driver for esd CAN-USB/2
+ *
+ * Copyright (C) 2002-2006 KVASER AB, Sweden. All rights reserved.
+ * Copyright (C) 2010 Matthias Fuchs <matthias.fuchs@esd.eu>, esd gmbh
+ * Copyright (C) 2012 Olivier Sobrie <olivier@sobrie.be>
+ */
+
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/usb.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+
+#define MAX_TX_URBS                    16
+#define MAX_RX_URBS                    4
+#define START_TIMEOUT                  1000 /* msecs */
+#define STOP_TIMEOUT                   1000 /* msecs */
+#define USB_SEND_TIMEOUT               1000 /* msecs */
+#define USB_RECV_TIMEOUT               1000 /* msecs */
+#define RX_BUFFER_SIZE                 3072
+#define CAN_USB_CLOCK                  8000000
+#define MAX_NET_DEVICES                        3
+
+/* Kvaser USB devices */
+#define KVASER_VENDOR_ID               0x0bfd
+#define USB_LEAF_DEVEL_PRODUCT_ID      10
+#define USB_LEAF_LITE_PRODUCT_ID       11
+#define USB_LEAF_PRO_PRODUCT_ID                12
+#define USB_LEAF_SPRO_PRODUCT_ID       14
+#define USB_LEAF_PRO_LS_PRODUCT_ID     15
+#define USB_LEAF_PRO_SWC_PRODUCT_ID    16
+#define USB_LEAF_PRO_LIN_PRODUCT_ID    17
+#define USB_LEAF_SPRO_LS_PRODUCT_ID    18
+#define USB_LEAF_SPRO_SWC_PRODUCT_ID   19
+#define USB_MEMO2_DEVEL_PRODUCT_ID     22
+#define USB_MEMO2_HSHS_PRODUCT_ID      23
+#define USB_UPRO_HSHS_PRODUCT_ID       24
+#define USB_LEAF_LITE_GI_PRODUCT_ID    25
+#define USB_LEAF_PRO_OBDII_PRODUCT_ID  26
+#define USB_MEMO2_HSLS_PRODUCT_ID      27
+#define USB_LEAF_LITE_CH_PRODUCT_ID    28
+#define USB_BLACKBIRD_SPRO_PRODUCT_ID  29
+#define USB_OEM_MERCURY_PRODUCT_ID     34
+#define USB_OEM_LEAF_PRODUCT_ID                35
+#define USB_CAN_R_PRODUCT_ID           39
+
+/* USB devices features */
+#define KVASER_HAS_SILENT_MODE         BIT(0)
+#define KVASER_HAS_TXRX_ERRORS         BIT(1)
+
+/* Message header size */
+#define MSG_HEADER_LEN                 2
+
+/* Can message flags */
+#define MSG_FLAG_ERROR_FRAME           BIT(0)
+#define MSG_FLAG_OVERRUN               BIT(1)
+#define MSG_FLAG_NERR                  BIT(2)
+#define MSG_FLAG_WAKEUP                        BIT(3)
+#define MSG_FLAG_REMOTE_FRAME          BIT(4)
+#define MSG_FLAG_RESERVED              BIT(5)
+#define MSG_FLAG_TX_ACK                        BIT(6)
+#define MSG_FLAG_TX_REQUEST            BIT(7)
+
+/* Can states */
+#define M16C_STATE_BUS_RESET           BIT(0)
+#define M16C_STATE_BUS_ERROR           BIT(4)
+#define M16C_STATE_BUS_PASSIVE         BIT(5)
+#define M16C_STATE_BUS_OFF             BIT(6)
+
+/* Can msg ids */
+#define CMD_RX_STD_MESSAGE             12
+#define CMD_TX_STD_MESSAGE             13
+#define CMD_RX_EXT_MESSAGE             14
+#define CMD_TX_EXT_MESSAGE             15
+#define CMD_SET_BUS_PARAMS             16
+#define CMD_GET_BUS_PARAMS             17
+#define CMD_GET_BUS_PARAMS_REPLY       18
+#define CMD_GET_CHIP_STATE             19
+#define CMD_CHIP_STATE_EVENT           20
+#define CMD_SET_CTRL_MODE              21
+#define CMD_GET_CTRL_MODE              22
+#define CMD_GET_CTRL_MODE_REPLY                23
+#define CMD_RESET_CHIP                 24
+#define CMD_RESET_CARD                 25
+#define CMD_START_CHIP                 26
+#define CMD_START_CHIP_REPLY           27
+#define CMD_STOP_CHIP                  28
+#define CMD_STOP_CHIP_REPLY            29
+#define CMD_GET_CARD_INFO2             32
+#define CMD_GET_CARD_INFO              34
+#define CMD_GET_CARD_INFO_REPLY                35
+#define CMD_GET_SOFTWARE_INFO          38
+#define CMD_GET_SOFTWARE_INFO_REPLY    39
+#define CMD_ERROR_EVENT                        45
+#define CMD_FLUSH_QUEUE                        48
+#define CMD_RESET_ERROR_COUNTER                49
+#define CMD_TX_ACKNOWLEDGE             50
+#define CMD_CAN_ERROR_EVENT            51
+#define CMD_USB_THROTTLE               77
+#define CMD_LOG_MESSAGE                        106
+
+/* error factors */
+#define M16C_EF_ACKE                   BIT(0)
+#define M16C_EF_CRCE                   BIT(1)
+#define M16C_EF_FORME                  BIT(2)
+#define M16C_EF_STFE                   BIT(3)
+#define M16C_EF_BITE0                  BIT(4)
+#define M16C_EF_BITE1                  BIT(5)
+#define M16C_EF_RCVE                   BIT(6)
+#define M16C_EF_TRE                    BIT(7)
+
+/* bittiming parameters */
+#define KVASER_USB_TSEG1_MIN           1
+#define KVASER_USB_TSEG1_MAX           16
+#define KVASER_USB_TSEG2_MIN           1
+#define KVASER_USB_TSEG2_MAX           8
+#define KVASER_USB_SJW_MAX             4
+#define KVASER_USB_BRP_MIN             1
+#define KVASER_USB_BRP_MAX             64
+#define KVASER_USB_BRP_INC             1
+
+/* ctrl modes */
+#define KVASER_CTRL_MODE_NORMAL                1
+#define KVASER_CTRL_MODE_SILENT                2
+#define KVASER_CTRL_MODE_SELFRECEPTION 3
+#define KVASER_CTRL_MODE_OFF           4
+
+struct kvaser_msg_simple {
+       u8 tid;
+       u8 channel;
+} __packed;
+
+struct kvaser_msg_cardinfo {
+       u8 tid;
+       u8 nchannels;
+       __le32 serial_number;
+       __le32 padding;
+       __le32 clock_resolution;
+       __le32 mfgdate;
+       u8 ean[8];
+       u8 hw_revision;
+       u8 usb_hs_mode;
+       __le16 padding2;
+} __packed;
+
+struct kvaser_msg_cardinfo2 {
+       u8 tid;
+       u8 channel;
+       u8 pcb_id[24];
+       __le32 oem_unlock_code;
+} __packed;
+
+struct kvaser_msg_softinfo {
+       u8 tid;
+       u8 channel;
+       __le32 sw_options;
+       __le32 fw_version;
+       __le16 max_outstanding_tx;
+       __le16 padding[9];
+} __packed;
+
+struct kvaser_msg_busparams {
+       u8 tid;
+       u8 channel;
+       __le32 bitrate;
+       u8 tseg1;
+       u8 tseg2;
+       u8 sjw;
+       u8 no_samp;
+} __packed;
+
+struct kvaser_msg_tx_can {
+       u8 channel;
+       u8 tid;
+       u8 msg[14];
+       u8 padding;
+       u8 flags;
+} __packed;
+
+struct kvaser_msg_rx_can {
+       u8 channel;
+       u8 flag;
+       __le16 time[3];
+       u8 msg[14];
+} __packed;
+
+struct kvaser_msg_chip_state_event {
+       u8 tid;
+       u8 channel;
+       __le16 time[3];
+       u8 tx_errors_count;
+       u8 rx_errors_count;
+       u8 status;
+       u8 padding[3];
+} __packed;
+
+struct kvaser_msg_tx_acknowledge {
+       u8 channel;
+       u8 tid;
+       __le16 time[3];
+       u8 flags;
+       u8 time_offset;
+} __packed;
+
+struct kvaser_msg_error_event {
+       u8 tid;
+       u8 flags;
+       __le16 time[3];
+       u8 channel;
+       u8 padding;
+       u8 tx_errors_count;
+       u8 rx_errors_count;
+       u8 status;
+       u8 error_factor;
+} __packed;
+
+struct kvaser_msg_ctrl_mode {
+       u8 tid;
+       u8 channel;
+       u8 ctrl_mode;
+       u8 padding[3];
+} __packed;
+
+struct kvaser_msg_flush_queue {
+       u8 tid;
+       u8 channel;
+       u8 flags;
+       u8 padding[3];
+} __packed;
+
+struct kvaser_msg_log_message {
+       u8 channel;
+       u8 flags;
+       __le16 time[3];
+       u8 dlc;
+       u8 time_offset;
+       __le32 id;
+       u8 data[8];
+} __packed;
+
+struct kvaser_msg {
+       u8 len;
+       u8 id;
+       union   {
+               struct kvaser_msg_simple simple;
+               struct kvaser_msg_cardinfo cardinfo;
+               struct kvaser_msg_cardinfo2 cardinfo2;
+               struct kvaser_msg_softinfo softinfo;
+               struct kvaser_msg_busparams busparams;
+               struct kvaser_msg_tx_can tx_can;
+               struct kvaser_msg_rx_can rx_can;
+               struct kvaser_msg_chip_state_event chip_state_event;
+               struct kvaser_msg_tx_acknowledge tx_acknowledge;
+               struct kvaser_msg_error_event error_event;
+               struct kvaser_msg_ctrl_mode ctrl_mode;
+               struct kvaser_msg_flush_queue flush_queue;
+               struct kvaser_msg_log_message log_message;
+       } u;
+} __packed;
+
+struct kvaser_usb_tx_urb_context {
+       struct kvaser_usb_net_priv *priv;
+       u32 echo_index;
+       int dlc;
+};
+
+struct kvaser_usb {
+       struct usb_device *udev;
+       struct kvaser_usb_net_priv *nets[MAX_NET_DEVICES];
+
+       struct usb_endpoint_descriptor *bulk_in, *bulk_out;
+       struct usb_anchor rx_submitted;
+
+       u32 fw_version;
+       unsigned int nchannels;
+
+       bool rxinitdone;
+       void *rxbuf[MAX_RX_URBS];
+       dma_addr_t rxbuf_dma[MAX_RX_URBS];
+};
+
+struct kvaser_usb_net_priv {
+       struct can_priv can;
+
+       atomic_t active_tx_urbs;
+       struct usb_anchor tx_submitted;
+       struct kvaser_usb_tx_urb_context tx_contexts[MAX_TX_URBS];
+
+       struct completion start_comp, stop_comp;
+
+       struct kvaser_usb *dev;
+       struct net_device *netdev;
+       int channel;
+
+       struct can_berr_counter bec;
+};
+
+static const struct usb_device_id kvaser_usb_table[] = {
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_DEVEL_PRODUCT_ID) },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_PRODUCT_ID) },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LS_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_SWC_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_LIN_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_LS_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_SPRO_SWC_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_DEVEL_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSHS_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_UPRO_HSHS_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_GI_PRODUCT_ID) },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_PRO_OBDII_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS |
+                              KVASER_HAS_SILENT_MODE },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_MEMO2_HSLS_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_LEAF_LITE_CH_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_BLACKBIRD_SPRO_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_MERCURY_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_OEM_LEAF_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { USB_DEVICE(KVASER_VENDOR_ID, USB_CAN_R_PRODUCT_ID),
+               .driver_info = KVASER_HAS_TXRX_ERRORS },
+       { }
+};
+MODULE_DEVICE_TABLE(usb, kvaser_usb_table);
+
+static inline int kvaser_usb_send_msg(const struct kvaser_usb *dev,
+                                     struct kvaser_msg *msg)
+{
+       int actual_len;
+
+       return usb_bulk_msg(dev->udev,
+                           usb_sndbulkpipe(dev->udev,
+                                       dev->bulk_out->bEndpointAddress),
+                           msg, msg->len, &actual_len,
+                           USB_SEND_TIMEOUT);
+}
+
+static int kvaser_usb_wait_msg(const struct kvaser_usb *dev, u8 id,
+                              struct kvaser_msg *msg)
+{
+       struct kvaser_msg *tmp;
+       void *buf;
+       int actual_len;
+       int err;
+       int pos = 0;
+
+       buf = kzalloc(RX_BUFFER_SIZE, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       err = usb_bulk_msg(dev->udev,
+                          usb_rcvbulkpipe(dev->udev,
+                                          dev->bulk_in->bEndpointAddress),
+                          buf, RX_BUFFER_SIZE, &actual_len,
+                          USB_RECV_TIMEOUT);
+       if (err < 0)
+               goto end;
+
+       while (pos <= actual_len - MSG_HEADER_LEN) {
+               tmp = buf + pos;
+
+               if (!tmp->len)
+                       break;
+
+               if (pos + tmp->len > actual_len) {
+                       dev_err(dev->udev->dev.parent, "Format error\n");
+                       break;
+               }
+
+               if (tmp->id == id) {
+                       memcpy(msg, tmp, tmp->len);
+                       goto end;
+               }
+
+               pos += tmp->len;
+       }
+
+       err = -EINVAL;
+
+end:
+       kfree(buf);
+
+       return err;
+}
+
+static int kvaser_usb_send_simple_msg(const struct kvaser_usb *dev,
+                                     u8 msg_id, int channel)
+{
+       struct kvaser_msg *msg;
+       int rc;
+
+       msg = kmalloc(sizeof(*msg), GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       msg->id = msg_id;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
+       msg->u.simple.channel = channel;
+       msg->u.simple.tid = 0xff;
+
+       rc = kvaser_usb_send_msg(dev, msg);
+
+       kfree(msg);
+       return rc;
+}
+
+static int kvaser_usb_get_software_info(struct kvaser_usb *dev)
+{
+       struct kvaser_msg msg;
+       int err;
+
+       err = kvaser_usb_send_simple_msg(dev, CMD_GET_SOFTWARE_INFO, 0);
+       if (err)
+               return err;
+
+       err = kvaser_usb_wait_msg(dev, CMD_GET_SOFTWARE_INFO_REPLY, &msg);
+       if (err)
+               return err;
+
+       dev->fw_version = le32_to_cpu(msg.u.softinfo.fw_version);
+
+       return 0;
+}
+
+static int kvaser_usb_get_card_info(struct kvaser_usb *dev)
+{
+       struct kvaser_msg msg;
+       int err;
+
+       err = kvaser_usb_send_simple_msg(dev, CMD_GET_CARD_INFO, 0);
+       if (err)
+               return err;
+
+       err = kvaser_usb_wait_msg(dev, CMD_GET_CARD_INFO_REPLY, &msg);
+       if (err)
+               return err;
+
+       dev->nchannels = msg.u.cardinfo.nchannels;
+
+       return 0;
+}
+
+static void kvaser_usb_tx_acknowledge(const struct kvaser_usb *dev,
+                                     const struct kvaser_msg *msg)
+{
+       struct net_device_stats *stats;
+       struct kvaser_usb_tx_urb_context *context;
+       struct kvaser_usb_net_priv *priv;
+       struct sk_buff *skb;
+       struct can_frame *cf;
+       u8 channel = msg->u.tx_acknowledge.channel;
+       u8 tid = msg->u.tx_acknowledge.tid;
+
+       if (channel >= dev->nchannels) {
+               dev_err(dev->udev->dev.parent,
+                       "Invalid channel number (%d)\n", channel);
+               return;
+       }
+
+       priv = dev->nets[channel];
+
+       if (!netif_device_present(priv->netdev))
+               return;
+
+       stats = &priv->netdev->stats;
+
+       context = &priv->tx_contexts[tid % MAX_TX_URBS];
+
+       /* Sometimes the state change doesn't come after a bus-off event */
+       if (priv->can.restart_ms &&
+           (priv->can.state >= CAN_STATE_BUS_OFF)) {
+               skb = alloc_can_err_skb(priv->netdev, &cf);
+               if (skb) {
+                       cf->can_id |= CAN_ERR_RESTARTED;
+                       netif_rx(skb);
+
+                       stats->rx_packets++;
+                       stats->rx_bytes += cf->can_dlc;
+               } else {
+                       netdev_err(priv->netdev,
+                                  "No memory left for err_skb\n");
+               }
+
+               priv->can.can_stats.restarts++;
+               netif_carrier_on(priv->netdev);
+
+               priv->can.state = CAN_STATE_ERROR_ACTIVE;
+       }
+
+       stats->tx_packets++;
+       stats->tx_bytes += context->dlc;
+       can_get_echo_skb(priv->netdev, context->echo_index);
+
+       context->echo_index = MAX_TX_URBS;
+       atomic_dec(&priv->active_tx_urbs);
+
+       netif_wake_queue(priv->netdev);
+}
+
+static void kvaser_usb_simple_msg_callback(struct urb *urb)
+{
+       struct net_device *netdev = urb->context;
+
+       kfree(urb->transfer_buffer);
+
+       if (urb->status)
+               netdev_warn(netdev, "urb status received: %d\n",
+                           urb->status);
+}
+
+static int kvaser_usb_simple_msg_async(struct kvaser_usb_net_priv *priv,
+                                      u8 msg_id)
+{
+       struct kvaser_usb *dev = priv->dev;
+       struct net_device *netdev = priv->netdev;
+       struct kvaser_msg *msg;
+       struct urb *urb;
+       void *buf;
+       int err;
+
+       urb = usb_alloc_urb(0, GFP_ATOMIC);
+       if (!urb) {
+               netdev_err(netdev, "No memory left for URBs\n");
+               return -ENOMEM;
+       }
+
+       buf = kmalloc(sizeof(struct kvaser_msg), GFP_ATOMIC);
+       if (!buf) {
+               netdev_err(netdev, "No memory left for USB buffer\n");
+               usb_free_urb(urb);
+               return -ENOMEM;
+       }
+
+       msg = (struct kvaser_msg *)buf;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_simple);
+       msg->id = msg_id;
+       msg->u.simple.channel = priv->channel;
+
+       usb_fill_bulk_urb(urb, dev->udev,
+                         usb_sndbulkpipe(dev->udev,
+                                         dev->bulk_out->bEndpointAddress),
+                         buf, msg->len,
+                         kvaser_usb_simple_msg_callback, priv);
+       usb_anchor_urb(urb, &priv->tx_submitted);
+
+       err = usb_submit_urb(urb, GFP_ATOMIC);
+       if (err) {
+               netdev_err(netdev, "Error transmitting URB\n");
+               usb_unanchor_urb(urb);
+               usb_free_urb(urb);
+               kfree(buf);
+               return err;
+       }
+
+       usb_free_urb(urb);
+
+       return 0;
+}
+
+static void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv)
+{
+       int i;
+
+       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;
+}
+
+static void kvaser_usb_rx_error(const struct kvaser_usb *dev,
+                               const struct kvaser_msg *msg)
+{
+       struct can_frame *cf;
+       struct sk_buff *skb;
+       struct net_device_stats *stats;
+       struct kvaser_usb_net_priv *priv;
+       unsigned int new_state;
+       u8 channel, status, txerr, rxerr, error_factor;
+
+       switch (msg->id) {
+       case CMD_CAN_ERROR_EVENT:
+               channel = msg->u.error_event.channel;
+               status =  msg->u.error_event.status;
+               txerr = msg->u.error_event.tx_errors_count;
+               rxerr = msg->u.error_event.rx_errors_count;
+               error_factor = msg->u.error_event.error_factor;
+               break;
+       case CMD_LOG_MESSAGE:
+               channel = msg->u.log_message.channel;
+               status = msg->u.log_message.data[0];
+               txerr = msg->u.log_message.data[2];
+               rxerr = msg->u.log_message.data[3];
+               error_factor = msg->u.log_message.data[1];
+               break;
+       case CMD_CHIP_STATE_EVENT:
+               channel = msg->u.chip_state_event.channel;
+               status =  msg->u.chip_state_event.status;
+               txerr = msg->u.chip_state_event.tx_errors_count;
+               rxerr = msg->u.chip_state_event.rx_errors_count;
+               error_factor = 0;
+               break;
+       default:
+               dev_err(dev->udev->dev.parent, "Invalid msg id (%d)\n",
+                       msg->id);
+               return;
+       }
+
+       if (channel >= dev->nchannels) {
+               dev_err(dev->udev->dev.parent,
+                       "Invalid channel number (%d)\n", channel);
+               return;
+       }
+
+       priv = dev->nets[channel];
+       stats = &priv->netdev->stats;
+
+       if (status & M16C_STATE_BUS_RESET) {
+               kvaser_usb_unlink_tx_urbs(priv);
+               return;
+       }
+
+       skb = alloc_can_err_skb(priv->netdev, &cf);
+       if (!skb) {
+               stats->rx_dropped++;
+               return;
+       }
+
+       new_state = priv->can.state;
+
+       netdev_dbg(priv->netdev, "Error status: 0x%02x\n", status);
+
+       if (status & M16C_STATE_BUS_OFF) {
+               cf->can_id |= CAN_ERR_BUSOFF;
+
+               priv->can.can_stats.bus_off++;
+               if (!priv->can.restart_ms)
+                       kvaser_usb_simple_msg_async(priv, CMD_STOP_CHIP);
+
+               netif_carrier_off(priv->netdev);
+
+               new_state = CAN_STATE_BUS_OFF;
+       } else if (status & M16C_STATE_BUS_PASSIVE) {
+               if (priv->can.state != CAN_STATE_ERROR_PASSIVE) {
+                       cf->can_id |= CAN_ERR_CRTL;
+
+                       if (txerr || rxerr)
+                               cf->data[1] = (txerr > rxerr)
+                                               ? CAN_ERR_CRTL_TX_PASSIVE
+                                               : CAN_ERR_CRTL_RX_PASSIVE;
+                       else
+                               cf->data[1] = CAN_ERR_CRTL_TX_PASSIVE |
+                                             CAN_ERR_CRTL_RX_PASSIVE;
+
+                       priv->can.can_stats.error_passive++;
+               }
+
+               new_state = CAN_STATE_ERROR_PASSIVE;
+       }
+
+       if (status == M16C_STATE_BUS_ERROR) {
+               if ((priv->can.state < CAN_STATE_ERROR_WARNING) &&
+                   ((txerr >= 96) || (rxerr >= 96))) {
+                       cf->can_id |= CAN_ERR_CRTL;
+                       cf->data[1] = (txerr > rxerr)
+                                       ? CAN_ERR_CRTL_TX_WARNING
+                                       : CAN_ERR_CRTL_RX_WARNING;
+
+                       priv->can.can_stats.error_warning++;
+                       new_state = CAN_STATE_ERROR_WARNING;
+               } else if (priv->can.state > CAN_STATE_ERROR_ACTIVE) {
+                       cf->can_id |= CAN_ERR_PROT;
+                       cf->data[2] = CAN_ERR_PROT_ACTIVE;
+
+                       new_state = CAN_STATE_ERROR_ACTIVE;
+               }
+       }
+
+       if (!status) {
+               cf->can_id |= CAN_ERR_PROT;
+               cf->data[2] = CAN_ERR_PROT_ACTIVE;
+
+               new_state = CAN_STATE_ERROR_ACTIVE;
+       }
+
+       if (priv->can.restart_ms &&
+           (priv->can.state >= CAN_STATE_BUS_OFF) &&
+           (new_state < CAN_STATE_BUS_OFF)) {
+               cf->can_id |= CAN_ERR_RESTARTED;
+               netif_carrier_on(priv->netdev);
+
+               priv->can.can_stats.restarts++;
+       }
+
+       if (error_factor) {
+               priv->can.can_stats.bus_error++;
+               stats->rx_errors++;
+
+               cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
+
+               if (error_factor & M16C_EF_ACKE)
+                       cf->data[3] |= (CAN_ERR_PROT_LOC_ACK);
+               if (error_factor & M16C_EF_CRCE)
+                       cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
+                                       CAN_ERR_PROT_LOC_CRC_DEL);
+               if (error_factor & M16C_EF_FORME)
+                       cf->data[2] |= CAN_ERR_PROT_FORM;
+               if (error_factor & M16C_EF_STFE)
+                       cf->data[2] |= CAN_ERR_PROT_STUFF;
+               if (error_factor & M16C_EF_BITE0)
+                       cf->data[2] |= CAN_ERR_PROT_BIT0;
+               if (error_factor & M16C_EF_BITE1)
+                       cf->data[2] |= CAN_ERR_PROT_BIT1;
+               if (error_factor & M16C_EF_TRE)
+                       cf->data[2] |= CAN_ERR_PROT_TX;
+       }
+
+       cf->data[6] = txerr;
+       cf->data[7] = rxerr;
+
+       priv->bec.txerr = txerr;
+       priv->bec.rxerr = rxerr;
+
+       priv->can.state = new_state;
+
+       netif_rx(skb);
+
+       stats->rx_packets++;
+       stats->rx_bytes += cf->can_dlc;
+}
+
+static void kvaser_usb_rx_can_err(const struct kvaser_usb_net_priv *priv,
+                                 const struct kvaser_msg *msg)
+{
+       struct can_frame *cf;
+       struct sk_buff *skb;
+       struct net_device_stats *stats = &priv->netdev->stats;
+
+       if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME |
+                                        MSG_FLAG_NERR)) {
+               netdev_err(priv->netdev, "Unknow error (flags: 0x%02x)\n",
+                          msg->u.rx_can.flag);
+
+               stats->rx_errors++;
+               return;
+       }
+
+       if (msg->u.rx_can.flag & MSG_FLAG_OVERRUN) {
+               skb = alloc_can_err_skb(priv->netdev, &cf);
+               if (!skb) {
+                       stats->rx_dropped++;
+                       return;
+               }
+
+               cf->can_id |= CAN_ERR_CRTL;
+               cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+
+               stats->rx_over_errors++;
+               stats->rx_errors++;
+
+               netif_rx(skb);
+
+               stats->rx_packets++;
+               stats->rx_bytes += cf->can_dlc;
+       }
+}
+
+static void kvaser_usb_rx_can_msg(const struct kvaser_usb *dev,
+                                 const struct kvaser_msg *msg)
+{
+       struct kvaser_usb_net_priv *priv;
+       struct can_frame *cf;
+       struct sk_buff *skb;
+       struct net_device_stats *stats;
+       u8 channel = msg->u.rx_can.channel;
+
+       if (channel >= dev->nchannels) {
+               dev_err(dev->udev->dev.parent,
+                       "Invalid channel number (%d)\n", channel);
+               return;
+       }
+
+       priv = dev->nets[channel];
+       stats = &priv->netdev->stats;
+
+       if (msg->u.rx_can.flag & (MSG_FLAG_ERROR_FRAME | MSG_FLAG_NERR |
+                                 MSG_FLAG_OVERRUN)) {
+               kvaser_usb_rx_can_err(priv, msg);
+               return;
+       } else if (msg->u.rx_can.flag & ~MSG_FLAG_REMOTE_FRAME) {
+               netdev_warn(priv->netdev,
+                           "Unhandled frame (flags: 0x%02x)",
+                           msg->u.rx_can.flag);
+               return;
+       }
+
+       skb = alloc_can_skb(priv->netdev, &cf);
+       if (!skb) {
+               stats->tx_dropped++;
+               return;
+       }
+
+       cf->can_id = ((msg->u.rx_can.msg[0] & 0x1f) << 6) |
+                    (msg->u.rx_can.msg[1] & 0x3f);
+       cf->can_dlc = get_can_dlc(msg->u.rx_can.msg[5]);
+
+       if (msg->id == CMD_RX_EXT_MESSAGE) {
+               cf->can_id <<= 18;
+               cf->can_id |= ((msg->u.rx_can.msg[2] & 0x0f) << 14) |
+                             ((msg->u.rx_can.msg[3] & 0xff) << 6) |
+                             (msg->u.rx_can.msg[4] & 0x3f);
+               cf->can_id |= CAN_EFF_FLAG;
+       }
+
+       if (msg->u.rx_can.flag & MSG_FLAG_REMOTE_FRAME)
+               cf->can_id |= CAN_RTR_FLAG;
+       else
+               memcpy(cf->data, &msg->u.rx_can.msg[6], cf->can_dlc);
+
+       netif_rx(skb);
+
+       stats->rx_packets++;
+       stats->rx_bytes += cf->can_dlc;
+}
+
+static void kvaser_usb_start_chip_reply(const struct kvaser_usb *dev,
+                                       const struct kvaser_msg *msg)
+{
+       struct kvaser_usb_net_priv *priv;
+       u8 channel = msg->u.simple.channel;
+
+       if (channel >= dev->nchannels) {
+               dev_err(dev->udev->dev.parent,
+                       "Invalid channel number (%d)\n", channel);
+               return;
+       }
+
+       priv = dev->nets[channel];
+
+       if (completion_done(&priv->start_comp) &&
+           netif_queue_stopped(priv->netdev)) {
+               netif_wake_queue(priv->netdev);
+       } else {
+               netif_start_queue(priv->netdev);
+               complete(&priv->start_comp);
+       }
+}
+
+static void kvaser_usb_stop_chip_reply(const struct kvaser_usb *dev,
+                                      const struct kvaser_msg *msg)
+{
+       struct kvaser_usb_net_priv *priv;
+       u8 channel = msg->u.simple.channel;
+
+       if (channel >= dev->nchannels) {
+               dev_err(dev->udev->dev.parent,
+                       "Invalid channel number (%d)\n", channel);
+               return;
+       }
+
+       priv = dev->nets[channel];
+
+       complete(&priv->stop_comp);
+}
+
+static void kvaser_usb_handle_message(const struct kvaser_usb *dev,
+                                     const struct kvaser_msg *msg)
+{
+       switch (msg->id) {
+       case CMD_START_CHIP_REPLY:
+               kvaser_usb_start_chip_reply(dev, msg);
+               break;
+
+       case CMD_STOP_CHIP_REPLY:
+               kvaser_usb_stop_chip_reply(dev, msg);
+               break;
+
+       case CMD_RX_STD_MESSAGE:
+       case CMD_RX_EXT_MESSAGE:
+               kvaser_usb_rx_can_msg(dev, msg);
+               break;
+
+       case CMD_CHIP_STATE_EVENT:
+       case CMD_CAN_ERROR_EVENT:
+               kvaser_usb_rx_error(dev, msg);
+               break;
+
+       case CMD_LOG_MESSAGE:
+               if (msg->u.log_message.flags & MSG_FLAG_ERROR_FRAME)
+                       kvaser_usb_rx_error(dev, msg);
+               break;
+
+       case CMD_TX_ACKNOWLEDGE:
+               kvaser_usb_tx_acknowledge(dev, msg);
+               break;
+
+       default:
+               dev_warn(dev->udev->dev.parent,
+                        "Unhandled message (%d)\n", msg->id);
+               break;
+       }
+}
+
+static void kvaser_usb_read_bulk_callback(struct urb *urb)
+{
+       struct kvaser_usb *dev = urb->context;
+       struct kvaser_msg *msg;
+       int pos = 0;
+       int err, i;
+
+       switch (urb->status) {
+       case 0:
+               break;
+       case -ENOENT:
+       case -ESHUTDOWN:
+               return;
+       default:
+               dev_info(dev->udev->dev.parent, "Rx URB aborted (%d)\n",
+                        urb->status);
+               goto resubmit_urb;
+       }
+
+       while (pos <= urb->actual_length - MSG_HEADER_LEN) {
+               msg = urb->transfer_buffer + pos;
+
+               if (!msg->len)
+                       break;
+
+               if (pos + msg->len > urb->actual_length) {
+                       dev_err(dev->udev->dev.parent, "Format error\n");
+                       break;
+               }
+
+               kvaser_usb_handle_message(dev, msg);
+
+               pos += msg->len;
+       }
+
+resubmit_urb:
+       usb_fill_bulk_urb(urb, dev->udev,
+                         usb_rcvbulkpipe(dev->udev,
+                                         dev->bulk_in->bEndpointAddress),
+                         urb->transfer_buffer, RX_BUFFER_SIZE,
+                         kvaser_usb_read_bulk_callback, dev);
+
+       err = usb_submit_urb(urb, GFP_ATOMIC);
+       if (err == -ENODEV) {
+               for (i = 0; i < dev->nchannels; i++) {
+                       if (!dev->nets[i])
+                               continue;
+
+                       netif_device_detach(dev->nets[i]->netdev);
+               }
+       } else if (err) {
+               dev_err(dev->udev->dev.parent,
+                       "Failed resubmitting read bulk urb: %d\n", err);
+       }
+
+       return;
+}
+
+static int kvaser_usb_setup_rx_urbs(struct kvaser_usb *dev)
+{
+       int i, err = 0;
+
+       if (dev->rxinitdone)
+               return 0;
+
+       for (i = 0; i < MAX_RX_URBS; i++) {
+               struct urb *urb = NULL;
+               u8 *buf = NULL;
+               dma_addr_t buf_dma;
+
+               urb = usb_alloc_urb(0, GFP_KERNEL);
+               if (!urb) {
+                       dev_warn(dev->udev->dev.parent,
+                                "No memory left for URBs\n");
+                       err = -ENOMEM;
+                       break;
+               }
+
+               buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE,
+                                        GFP_KERNEL, &buf_dma);
+               if (!buf) {
+                       dev_warn(dev->udev->dev.parent,
+                                "No memory left for USB buffer\n");
+                       usb_free_urb(urb);
+                       err = -ENOMEM;
+                       break;
+               }
+
+               usb_fill_bulk_urb(urb, dev->udev,
+                                 usb_rcvbulkpipe(dev->udev,
+                                         dev->bulk_in->bEndpointAddress),
+                                 buf, RX_BUFFER_SIZE,
+                                 kvaser_usb_read_bulk_callback,
+                                 dev);
+               urb->transfer_dma = buf_dma;
+               urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+               usb_anchor_urb(urb, &dev->rx_submitted);
+
+               err = usb_submit_urb(urb, GFP_KERNEL);
+               if (err) {
+                       usb_unanchor_urb(urb);
+                       usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
+                                         buf_dma);
+                       usb_free_urb(urb);
+                       break;
+               }
+
+               dev->rxbuf[i] = buf;
+               dev->rxbuf_dma[i] = buf_dma;
+
+               usb_free_urb(urb);
+       }
+
+       if (i == 0) {
+               dev_warn(dev->udev->dev.parent,
+                        "Cannot setup read URBs, error %d\n", err);
+               return err;
+       } else if (i < MAX_RX_URBS) {
+               dev_warn(dev->udev->dev.parent,
+                        "RX performances may be slow\n");
+       }
+
+       dev->rxinitdone = true;
+
+       return 0;
+}
+
+static int kvaser_usb_set_opt_mode(const struct kvaser_usb_net_priv *priv)
+{
+       struct kvaser_msg *msg;
+       int rc;
+
+       msg = kmalloc(sizeof(*msg), GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       msg->id = CMD_SET_CTRL_MODE;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_ctrl_mode);
+       msg->u.ctrl_mode.tid = 0xff;
+       msg->u.ctrl_mode.channel = priv->channel;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+               msg->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
+       else
+               msg->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;
+
+       rc = kvaser_usb_send_msg(priv->dev, msg);
+
+       kfree(msg);
+       return rc;
+}
+
+static int kvaser_usb_start_chip(struct kvaser_usb_net_priv *priv)
+{
+       int err;
+
+       init_completion(&priv->start_comp);
+
+       err = kvaser_usb_send_simple_msg(priv->dev, CMD_START_CHIP,
+                                        priv->channel);
+       if (err)
+               return err;
+
+       if (!wait_for_completion_timeout(&priv->start_comp,
+                                        msecs_to_jiffies(START_TIMEOUT)))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int kvaser_usb_open(struct net_device *netdev)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+       struct kvaser_usb *dev = priv->dev;
+       int err;
+
+       err = open_candev(netdev);
+       if (err)
+               return err;
+
+       err = kvaser_usb_setup_rx_urbs(dev);
+       if (err)
+               goto error;
+
+       err = kvaser_usb_set_opt_mode(priv);
+       if (err)
+               goto error;
+
+       err = kvaser_usb_start_chip(priv);
+       if (err) {
+               netdev_warn(netdev, "Cannot start device, error %d\n", err);
+               goto error;
+       }
+
+       priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+       return 0;
+
+error:
+       close_candev(netdev);
+       return err;
+}
+
+static void kvaser_usb_unlink_all_urbs(struct kvaser_usb *dev)
+{
+       int i;
+
+       usb_kill_anchored_urbs(&dev->rx_submitted);
+
+       for (i = 0; i < MAX_RX_URBS; i++)
+               usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
+                                 dev->rxbuf[i],
+                                 dev->rxbuf_dma[i]);
+
+       for (i = 0; i < MAX_NET_DEVICES; i++) {
+               struct kvaser_usb_net_priv *priv = dev->nets[i];
+
+               if (priv)
+                       kvaser_usb_unlink_tx_urbs(priv);
+       }
+}
+
+static int kvaser_usb_stop_chip(struct kvaser_usb_net_priv *priv)
+{
+       int err;
+
+       init_completion(&priv->stop_comp);
+
+       err = kvaser_usb_send_simple_msg(priv->dev, CMD_STOP_CHIP,
+                                        priv->channel);
+       if (err)
+               return err;
+
+       if (!wait_for_completion_timeout(&priv->stop_comp,
+                                        msecs_to_jiffies(STOP_TIMEOUT)))
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+static int kvaser_usb_flush_queue(struct kvaser_usb_net_priv *priv)
+{
+       struct kvaser_msg *msg;
+       int rc;
+
+       msg = kmalloc(sizeof(*msg), GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       msg->id = CMD_FLUSH_QUEUE;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_flush_queue);
+       msg->u.flush_queue.channel = priv->channel;
+       msg->u.flush_queue.flags = 0x00;
+
+       rc = kvaser_usb_send_msg(priv->dev, msg);
+
+       kfree(msg);
+       return rc;
+}
+
+static int kvaser_usb_close(struct net_device *netdev)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+       struct kvaser_usb *dev = priv->dev;
+       int err;
+
+       netif_stop_queue(netdev);
+
+       err = kvaser_usb_flush_queue(priv);
+       if (err)
+               netdev_warn(netdev, "Cannot flush queue, error %d\n", err);
+
+       if (kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, priv->channel))
+               netdev_warn(netdev, "Cannot reset card, error %d\n", err);
+
+       err = kvaser_usb_stop_chip(priv);
+       if (err)
+               netdev_warn(netdev, "Cannot stop device, error %d\n", err);
+
+       priv->can.state = CAN_STATE_STOPPED;
+       close_candev(priv->netdev);
+
+       return 0;
+}
+
+static void kvaser_usb_write_bulk_callback(struct urb *urb)
+{
+       struct kvaser_usb_tx_urb_context *context = urb->context;
+       struct kvaser_usb_net_priv *priv;
+       struct net_device *netdev;
+
+       if (WARN_ON(!context))
+               return;
+
+       priv = context->priv;
+       netdev = priv->netdev;
+
+       kfree(urb->transfer_buffer);
+
+       if (!netif_device_present(netdev))
+               return;
+
+       if (urb->status)
+               netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
+}
+
+static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
+                                        struct net_device *netdev)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+       struct kvaser_usb *dev = priv->dev;
+       struct net_device_stats *stats = &netdev->stats;
+       struct can_frame *cf = (struct can_frame *)skb->data;
+       struct kvaser_usb_tx_urb_context *context = NULL;
+       struct urb *urb;
+       void *buf;
+       struct kvaser_msg *msg;
+       int i, err;
+       int ret = NETDEV_TX_OK;
+
+       if (can_dropped_invalid_skb(netdev, skb))
+               return NETDEV_TX_OK;
+
+       urb = usb_alloc_urb(0, GFP_ATOMIC);
+       if (!urb) {
+               netdev_err(netdev, "No memory left for URBs\n");
+               stats->tx_dropped++;
+               goto nourbmem;
+       }
+
+       buf = kmalloc(sizeof(struct kvaser_msg), GFP_ATOMIC);
+       if (!buf) {
+               netdev_err(netdev, "No memory left for USB buffer\n");
+               stats->tx_dropped++;
+               goto nobufmem;
+       }
+
+       msg = buf;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_tx_can);
+       msg->u.tx_can.flags = 0;
+       msg->u.tx_can.channel = priv->channel;
+
+       if (cf->can_id & CAN_EFF_FLAG) {
+               msg->id = CMD_TX_EXT_MESSAGE;
+               msg->u.tx_can.msg[0] = (cf->can_id >> 24) & 0x1f;
+               msg->u.tx_can.msg[1] = (cf->can_id >> 18) & 0x3f;
+               msg->u.tx_can.msg[2] = (cf->can_id >> 14) & 0x0f;
+               msg->u.tx_can.msg[3] = (cf->can_id >> 6) & 0xff;
+               msg->u.tx_can.msg[4] = cf->can_id & 0x3f;
+       } else {
+               msg->id = CMD_TX_STD_MESSAGE;
+               msg->u.tx_can.msg[0] = (cf->can_id >> 6) & 0x1f;
+               msg->u.tx_can.msg[1] = cf->can_id & 0x3f;
+       }
+
+       msg->u.tx_can.msg[5] = cf->can_dlc;
+       memcpy(&msg->u.tx_can.msg[6], cf->data, cf->can_dlc);
+
+       if (cf->can_id & CAN_RTR_FLAG)
+               msg->u.tx_can.flags |= MSG_FLAG_REMOTE_FRAME;
+
+       for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++) {
+               if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) {
+                       context = &priv->tx_contexts[i];
+                       break;
+               }
+       }
+
+       if (!context) {
+               netdev_warn(netdev, "cannot find free context\n");
+               ret =  NETDEV_TX_BUSY;
+               goto releasebuf;
+       }
+
+       context->priv = priv;
+       context->echo_index = i;
+       context->dlc = cf->can_dlc;
+
+       msg->u.tx_can.tid = context->echo_index;
+
+       usb_fill_bulk_urb(urb, dev->udev,
+                         usb_sndbulkpipe(dev->udev,
+                                         dev->bulk_out->bEndpointAddress),
+                         buf, msg->len,
+                         kvaser_usb_write_bulk_callback, context);
+       usb_anchor_urb(urb, &priv->tx_submitted);
+
+       can_put_echo_skb(skb, netdev, context->echo_index);
+
+       atomic_inc(&priv->active_tx_urbs);
+
+       if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS)
+               netif_stop_queue(netdev);
+
+       err = usb_submit_urb(urb, GFP_ATOMIC);
+       if (unlikely(err)) {
+               can_free_echo_skb(netdev, context->echo_index);
+
+               skb = NULL; /* set to NULL to avoid double free in
+                            * dev_kfree_skb(skb) */
+
+               atomic_dec(&priv->active_tx_urbs);
+               usb_unanchor_urb(urb);
+
+               stats->tx_dropped++;
+
+               if (err == -ENODEV)
+                       netif_device_detach(netdev);
+               else
+                       netdev_warn(netdev, "Failed tx_urb %d\n", err);
+
+               goto releasebuf;
+       }
+
+       usb_free_urb(urb);
+
+       return NETDEV_TX_OK;
+
+releasebuf:
+       kfree(buf);
+nobufmem:
+       usb_free_urb(urb);
+nourbmem:
+       dev_kfree_skb(skb);
+       return ret;
+}
+
+static const struct net_device_ops kvaser_usb_netdev_ops = {
+       .ndo_open = kvaser_usb_open,
+       .ndo_stop = kvaser_usb_close,
+       .ndo_start_xmit = kvaser_usb_start_xmit,
+};
+
+static const struct can_bittiming_const kvaser_usb_bittiming_const = {
+       .name = "kvaser_usb",
+       .tseg1_min = KVASER_USB_TSEG1_MIN,
+       .tseg1_max = KVASER_USB_TSEG1_MAX,
+       .tseg2_min = KVASER_USB_TSEG2_MIN,
+       .tseg2_max = KVASER_USB_TSEG2_MAX,
+       .sjw_max = KVASER_USB_SJW_MAX,
+       .brp_min = KVASER_USB_BRP_MIN,
+       .brp_max = KVASER_USB_BRP_MAX,
+       .brp_inc = KVASER_USB_BRP_INC,
+};
+
+static int kvaser_usb_set_bittiming(struct net_device *netdev)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+       struct can_bittiming *bt = &priv->can.bittiming;
+       struct kvaser_usb *dev = priv->dev;
+       struct kvaser_msg *msg;
+       int rc;
+
+       msg = kmalloc(sizeof(*msg), GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       msg->id = CMD_SET_BUS_PARAMS;
+       msg->len = MSG_HEADER_LEN + sizeof(struct kvaser_msg_busparams);
+       msg->u.busparams.channel = priv->channel;
+       msg->u.busparams.tid = 0xff;
+       msg->u.busparams.bitrate = cpu_to_le32(bt->bitrate);
+       msg->u.busparams.sjw = bt->sjw;
+       msg->u.busparams.tseg1 = bt->prop_seg + bt->phase_seg1;
+       msg->u.busparams.tseg2 = bt->phase_seg2;
+
+       if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+               msg->u.busparams.no_samp = 3;
+       else
+               msg->u.busparams.no_samp = 1;
+
+       rc = kvaser_usb_send_msg(dev, msg);
+
+       kfree(msg);
+       return rc;
+}
+
+static int kvaser_usb_set_mode(struct net_device *netdev,
+                              enum can_mode mode)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+       int err;
+
+       switch (mode) {
+       case CAN_MODE_START:
+               err = kvaser_usb_simple_msg_async(priv, CMD_START_CHIP);
+               if (err)
+                       return err;
+               break;
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+static int kvaser_usb_get_berr_counter(const struct net_device *netdev,
+                                      struct can_berr_counter *bec)
+{
+       struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
+
+       *bec = priv->bec;
+
+       return 0;
+}
+
+static void kvaser_usb_remove_interfaces(struct kvaser_usb *dev)
+{
+       int i;
+
+       for (i = 0; i < dev->nchannels; i++) {
+               if (!dev->nets[i])
+                       continue;
+
+               unregister_netdev(dev->nets[i]->netdev);
+       }
+
+       kvaser_usb_unlink_all_urbs(dev);
+
+       for (i = 0; i < dev->nchannels; i++) {
+               if (!dev->nets[i])
+                       continue;
+
+               free_candev(dev->nets[i]->netdev);
+       }
+}
+
+static int kvaser_usb_init_one(struct usb_interface *intf,
+                              const struct usb_device_id *id, int channel)
+{
+       struct kvaser_usb *dev = usb_get_intfdata(intf);
+       struct net_device *netdev;
+       struct kvaser_usb_net_priv *priv;
+       int i, err;
+
+       netdev = alloc_candev(sizeof(*priv), MAX_TX_URBS);
+       if (!netdev) {
+               dev_err(&intf->dev, "Cannot alloc candev\n");
+               return -ENOMEM;
+       }
+
+       priv = netdev_priv(netdev);
+
+       init_completion(&priv->start_comp);
+       init_completion(&priv->stop_comp);
+
+       init_usb_anchor(&priv->tx_submitted);
+       atomic_set(&priv->active_tx_urbs, 0);
+
+       for (i = 0; i < ARRAY_SIZE(priv->tx_contexts); i++)
+               priv->tx_contexts[i].echo_index = MAX_TX_URBS;
+
+       priv->dev = dev;
+       priv->netdev = netdev;
+       priv->channel = channel;
+
+       priv->can.state = CAN_STATE_STOPPED;
+       priv->can.clock.freq = CAN_USB_CLOCK;
+       priv->can.bittiming_const = &kvaser_usb_bittiming_const;
+       priv->can.do_set_bittiming = kvaser_usb_set_bittiming;
+       priv->can.do_set_mode = kvaser_usb_set_mode;
+       if (id->driver_info & KVASER_HAS_TXRX_ERRORS)
+               priv->can.do_get_berr_counter = kvaser_usb_get_berr_counter;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
+       if (id->driver_info & KVASER_HAS_SILENT_MODE)
+               priv->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
+
+       netdev->flags |= IFF_ECHO;
+
+       netdev->netdev_ops = &kvaser_usb_netdev_ops;
+
+       SET_NETDEV_DEV(netdev, &intf->dev);
+
+       dev->nets[channel] = priv;
+
+       err = register_candev(netdev);
+       if (err) {
+               dev_err(&intf->dev, "Failed to register can device\n");
+               free_candev(netdev);
+               dev->nets[channel] = NULL;
+               return err;
+       }
+
+       netdev_dbg(netdev, "device registered\n");
+
+       return 0;
+}
+
+static void kvaser_usb_get_endpoints(const struct usb_interface *intf,
+                                    struct usb_endpoint_descriptor **in,
+                                    struct usb_endpoint_descriptor **out)
+{
+       const struct usb_host_interface *iface_desc;
+       struct usb_endpoint_descriptor *endpoint;
+       int i;
+
+       iface_desc = &intf->altsetting[0];
+
+       for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+               endpoint = &iface_desc->endpoint[i].desc;
+
+               if (usb_endpoint_is_bulk_in(endpoint))
+                       *in = endpoint;
+
+               if (usb_endpoint_is_bulk_out(endpoint))
+                       *out = endpoint;
+       }
+}
+
+static int kvaser_usb_probe(struct usb_interface *intf,
+                           const struct usb_device_id *id)
+{
+       struct kvaser_usb *dev;
+       int err = -ENOMEM;
+       int i;
+
+       dev = devm_kzalloc(&intf->dev, sizeof(*dev), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
+
+       kvaser_usb_get_endpoints(intf, &dev->bulk_in, &dev->bulk_out);
+       if (!dev->bulk_in || !dev->bulk_out) {
+               dev_err(&intf->dev, "Cannot get usb endpoint(s)");
+               return err;
+       }
+
+       dev->udev = interface_to_usbdev(intf);
+
+       init_usb_anchor(&dev->rx_submitted);
+
+       usb_set_intfdata(intf, dev);
+
+       for (i = 0; i < MAX_NET_DEVICES; i++)
+               kvaser_usb_send_simple_msg(dev, CMD_RESET_CHIP, i);
+
+       err = kvaser_usb_get_software_info(dev);
+       if (err) {
+               dev_err(&intf->dev,
+                       "Cannot get software infos, error %d\n", err);
+               return err;
+       }
+
+       err = kvaser_usb_get_card_info(dev);
+       if (err) {
+               dev_err(&intf->dev,
+                       "Cannot get card infos, error %d\n", err);
+               return err;
+       }
+
+       dev_dbg(&intf->dev, "Firmware version: %d.%d.%d\n",
+               ((dev->fw_version >> 24) & 0xff),
+               ((dev->fw_version >> 16) & 0xff),
+               (dev->fw_version & 0xffff));
+
+       for (i = 0; i < dev->nchannels; i++) {
+               err = kvaser_usb_init_one(intf, id, i);
+               if (err) {
+                       kvaser_usb_remove_interfaces(dev);
+                       return err;
+               }
+       }
+
+       return 0;
+}
+
+static void kvaser_usb_disconnect(struct usb_interface *intf)
+{
+       struct kvaser_usb *dev = usb_get_intfdata(intf);
+
+       usb_set_intfdata(intf, NULL);
+
+       if (!dev)
+               return;
+
+       kvaser_usb_remove_interfaces(dev);
+}
+
+static struct usb_driver kvaser_usb_driver = {
+       .name = "kvaser_usb",
+       .probe = kvaser_usb_probe,
+       .disconnect = kvaser_usb_disconnect,
+       .id_table = kvaser_usb_table,
+};
+
+module_usb_driver(kvaser_usb_driver);
+
+MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
+MODULE_DESCRIPTION("CAN driver for Kvaser CAN/USB devices");
+MODULE_LICENSE("GPL v2");