root/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
// SPDX-License-Identifier: GPL-2.0
/* Parts of this driver are based on the following:
 *  - Kvaser linux leaf driver (version 4.78)
 *  - CAN driver for esd CAN-USB/2
 *  - Kvaser linux usbcanII driver (version 5.3)
 *
 * Copyright (C) 2002-2018 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>
 * Copyright (C) 2015 Valeo S.A.
 */

#include <linux/bitfield.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/gfp.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/units.h>
#include <linux/usb.h>
#include <linux/workqueue.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/netlink.h>

#include "kvaser_usb.h"

#define MAX_USBCAN_NET_DEVICES          2

/* Command header size */
#define CMD_HEADER_LEN                  2

/* Kvaser 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 (M16C CxSTRH register) */
#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)

/* Leaf/usbcan command 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_RESET_CHIP                  24
#define CMD_START_CHIP                  26
#define CMD_START_CHIP_REPLY            27
#define CMD_STOP_CHIP                   28
#define CMD_STOP_CHIP_REPLY             29

#define CMD_USBCAN_CLOCK_OVERFLOW_EVENT 33

#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_TX_ACKNOWLEDGE              50
#define CMD_CAN_ERROR_EVENT             51
#define CMD_FLUSH_QUEUE_REPLY           68
#define CMD_GET_CAPABILITIES_REQ        95
#define CMD_GET_CAPABILITIES_RESP       96
#define CMD_LED_ACTION_REQ              101
#define CMD_LED_ACTION_RESP             102

#define CMD_LEAF_LOG_MESSAGE            106

/* Leaf frequency options */
#define KVASER_USB_LEAF_SWOPTION_FREQ_MASK 0x60
#define KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK 0
#define KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK BIT(5)
#define KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK BIT(6)

#define KVASER_USB_LEAF_SWOPTION_EXT_CAP BIT(12)

/* 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)

/* Only Leaf-based devices can report M16C error factors,
 * thus define our own error status flags for USBCANII
 */
#define USBCAN_ERROR_STATE_NONE         0
#define USBCAN_ERROR_STATE_TX_ERROR     BIT(0)
#define USBCAN_ERROR_STATE_RX_ERROR     BIT(1)
#define USBCAN_ERROR_STATE_BUSERROR     BIT(2)

/* 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

/* Extended CAN identifier flag */
#define KVASER_EXTENDED_FRAME           BIT(31)

/* USBCanII timestamp */
#define KVASER_USB_USBCAN_CLK_OVERFLOW_MASK GENMASK(31, 16)
#define KVASER_USB_USBCAN_TIMESTAMP_FACTOR 10

struct kvaser_cmd_simple {
        u8 tid;
        u8 channel;
} __packed;

struct kvaser_cmd_cardinfo {
        u8 tid;
        u8 nchannels;
        __le32 serial_number;
        __le32 padding0;
        __le32 clock_resolution;
        __le32 mfgdate;
        __le32 ean[2];
        u8 hw_revision;
        union {
                struct {
                        u8 usb_hs_mode;
                } __packed leaf1;
                struct {
                        u8 padding;
                } __packed usbcan1;
        } __packed;
        __le16 padding1;
} __packed;

struct leaf_cmd_softinfo {
        u8 tid;
        u8 padding0;
        __le32 sw_options;
        __le32 fw_version;
        __le16 max_outstanding_tx;
        __le16 padding1[9];
} __packed;

struct usbcan_cmd_softinfo {
        u8 tid;
        u8 fw_name[5];
        __le16 max_outstanding_tx;
        u8 padding[6];
        __le32 fw_version;
        __le16 checksum;
        __le16 sw_options;
} __packed;

struct kvaser_cmd_busparams {
        u8 tid;
        u8 channel;
        struct kvaser_usb_busparams busparams;
} __packed;

/* The device has one LED per CAN channel
 * The LSB of action field controls the state:
 *   0 = ON
 *   1 = OFF
 * The remaining bits of action field is the LED index
 */
#define KVASER_USB_LEAF_LED_IDX_MASK GENMASK(31, 1)
#define KVASER_USB_LEAF_LED_YELLOW_CH0_IDX 2
struct kvaser_cmd_led_action_req {
        u8 tid;
        u8 action;
        __le16 duration_ms;
        u8 padding[24];
} __packed;

struct kvaser_cmd_tx_can {
        u8 channel;
        u8 tid;
        u8 data[14];
        union {
                struct {
                        u8 padding;
                        u8 flags;
                } __packed leaf;
                struct {
                        u8 flags;
                        u8 padding;
                } __packed usbcan;
        } __packed;
} __packed;

struct kvaser_cmd_rx_can_header {
        u8 channel;
        u8 flag;
} __packed;

struct leaf_cmd_rx_can {
        u8 channel;
        u8 flag;

        __le16 time[3];
        u8 data[14];
} __packed;

struct usbcan_cmd_rx_can {
        u8 channel;
        u8 flag;

        u8 data[14];
        __le16 time;
} __packed;

struct leaf_cmd_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 usbcan_cmd_chip_state_event {
        u8 tid;
        u8 channel;

        u8 tx_errors_count;
        u8 rx_errors_count;
        __le16 time;

        u8 status;
        u8 padding[3];
} __packed;

struct kvaser_cmd_tx_acknowledge_header {
        u8 channel;
        u8 tid;
} __packed;

struct leaf_cmd_tx_acknowledge {
        u8 channel;
        u8 tid;
        __le16 time[3];
        u8 padding[2];
} __packed;

struct usbcan_cmd_tx_acknowledge {
        u8 channel;
        u8 tid;
        __le16 time;
        u8 padding[2];
} __packed;

struct leaf_cmd_can_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 usbcan_cmd_can_error_event {
        u8 tid;
        u8 padding;
        u8 tx_errors_count_ch0;
        u8 rx_errors_count_ch0;
        u8 tx_errors_count_ch1;
        u8 rx_errors_count_ch1;
        u8 status_ch0;
        u8 status_ch1;
        __le16 time;
} __packed;

/* CMD_ERROR_EVENT error codes */
#define KVASER_USB_LEAF_ERROR_EVENT_TX_QUEUE_FULL 0x8
#define KVASER_USB_LEAF_ERROR_EVENT_PARAM 0x9

struct leaf_cmd_error_event {
        u8 tid;
        u8 error_code;
        __le16 timestamp[3];
        __le16 padding;
        __le16 info1;
        __le16 info2;
} __packed;

struct usbcan_cmd_error_event {
        u8 tid;
        u8 error_code;
        __le16 info1;
        __le16 info2;
        __le16 timestamp;
        __le16 padding;
} __packed;

struct usbcan_cmd_clk_overflow_event {
        u8 tid;
        u8 padding;
        __le32 time;
} __packed;

struct kvaser_cmd_ctrl_mode {
        u8 tid;
        u8 channel;
        u8 ctrl_mode;
        u8 padding[3];
} __packed;

struct kvaser_cmd_flush_queue {
        u8 tid;
        u8 channel;
        u8 flags;
        u8 padding[3];
} __packed;

struct leaf_cmd_log_message {
        u8 channel;
        u8 flags;
        __le16 time[3];
        u8 dlc;
        u8 time_offset;
        __le32 id;
        u8 data[8];
} __packed;

/* Sub commands for cap_req and cap_res */
#define KVASER_USB_LEAF_CAP_CMD_LISTEN_MODE 0x02
#define KVASER_USB_LEAF_CAP_CMD_ERR_REPORT 0x05
struct kvaser_cmd_cap_req {
        __le16 padding0;
        __le16 cap_cmd;
        __le16 padding1;
        __le16 channel;
} __packed;

/* Status codes for cap_res */
#define KVASER_USB_LEAF_CAP_STAT_OK 0x00
#define KVASER_USB_LEAF_CAP_STAT_NOT_IMPL 0x01
#define KVASER_USB_LEAF_CAP_STAT_UNAVAIL 0x02
struct kvaser_cmd_cap_res {
        __le16 padding;
        __le16 cap_cmd;
        __le16 status;
        __le32 mask;
        __le32 value;
} __packed;

struct kvaser_cmd {
        u8 len;
        u8 id;
        union   {
                struct kvaser_cmd_simple simple;
                struct kvaser_cmd_cardinfo cardinfo;
                struct kvaser_cmd_busparams busparams;

                struct kvaser_cmd_led_action_req led_action_req;

                struct kvaser_cmd_rx_can_header rx_can_header;
                struct kvaser_cmd_tx_acknowledge_header tx_acknowledge_header;

                union {
                        struct leaf_cmd_softinfo softinfo;
                        struct leaf_cmd_rx_can rx_can;
                        struct leaf_cmd_chip_state_event chip_state_event;
                        struct leaf_cmd_can_error_event can_error_event;
                        struct leaf_cmd_log_message log_message;
                        struct leaf_cmd_error_event error_event;
                        struct kvaser_cmd_cap_req cap_req;
                        struct kvaser_cmd_cap_res cap_res;
                        struct leaf_cmd_tx_acknowledge tx_ack;
                } __packed leaf;

                union {
                        struct usbcan_cmd_softinfo softinfo;
                        struct usbcan_cmd_rx_can rx_can;
                        struct usbcan_cmd_chip_state_event chip_state_event;
                        struct usbcan_cmd_can_error_event can_error_event;
                        struct usbcan_cmd_error_event error_event;
                        struct usbcan_cmd_tx_acknowledge tx_ack;
                        struct usbcan_cmd_clk_overflow_event clk_overflow_event;
                } __packed usbcan;

                struct kvaser_cmd_tx_can tx_can;
                struct kvaser_cmd_ctrl_mode ctrl_mode;
                struct kvaser_cmd_flush_queue flush_queue;
        } u;
} __packed;

#define CMD_SIZE_ANY 0xff
#define kvaser_fsize(field) sizeof_field(struct kvaser_cmd, field)

static const u8 kvaser_usb_leaf_cmd_sizes_leaf[] = {
        [CMD_START_CHIP_REPLY]          = kvaser_fsize(u.simple),
        [CMD_STOP_CHIP_REPLY]           = kvaser_fsize(u.simple),
        [CMD_GET_CARD_INFO_REPLY]       = kvaser_fsize(u.cardinfo),
        [CMD_TX_ACKNOWLEDGE]            = kvaser_fsize(u.leaf.tx_ack),
        [CMD_GET_SOFTWARE_INFO_REPLY]   = kvaser_fsize(u.leaf.softinfo),
        [CMD_RX_STD_MESSAGE]            = kvaser_fsize(u.leaf.rx_can),
        [CMD_RX_EXT_MESSAGE]            = kvaser_fsize(u.leaf.rx_can),
        [CMD_LEAF_LOG_MESSAGE]          = kvaser_fsize(u.leaf.log_message),
        [CMD_CHIP_STATE_EVENT]          = kvaser_fsize(u.leaf.chip_state_event),
        [CMD_CAN_ERROR_EVENT]           = kvaser_fsize(u.leaf.can_error_event),
        [CMD_GET_CAPABILITIES_RESP]     = kvaser_fsize(u.leaf.cap_res),
        [CMD_GET_BUS_PARAMS_REPLY]      = kvaser_fsize(u.busparams),
        [CMD_ERROR_EVENT]               = kvaser_fsize(u.leaf.error_event),
        /* ignored events: */
        [CMD_FLUSH_QUEUE_REPLY]         = CMD_SIZE_ANY,
        [CMD_LED_ACTION_RESP]           = CMD_SIZE_ANY,
};

static const u8 kvaser_usb_leaf_cmd_sizes_usbcan[] = {
        [CMD_START_CHIP_REPLY]          = kvaser_fsize(u.simple),
        [CMD_STOP_CHIP_REPLY]           = kvaser_fsize(u.simple),
        [CMD_GET_CARD_INFO_REPLY]       = kvaser_fsize(u.cardinfo),
        [CMD_TX_ACKNOWLEDGE]            = kvaser_fsize(u.usbcan.tx_ack),
        [CMD_GET_SOFTWARE_INFO_REPLY]   = kvaser_fsize(u.usbcan.softinfo),
        [CMD_RX_STD_MESSAGE]            = kvaser_fsize(u.usbcan.rx_can),
        [CMD_RX_EXT_MESSAGE]            = kvaser_fsize(u.usbcan.rx_can),
        [CMD_CHIP_STATE_EVENT]          = kvaser_fsize(u.usbcan.chip_state_event),
        [CMD_CAN_ERROR_EVENT]           = kvaser_fsize(u.usbcan.can_error_event),
        [CMD_ERROR_EVENT]               = kvaser_fsize(u.usbcan.error_event),
        [CMD_USBCAN_CLOCK_OVERFLOW_EVENT] = kvaser_fsize(u.usbcan.clk_overflow_event),
        /* ignored events: */
        [CMD_LED_ACTION_RESP]           = CMD_SIZE_ANY,
};

/* Summary of a kvaser error event, for a unified Leaf/Usbcan error
 * handling. Some discrepancies between the two families exist:
 *
 * - USBCAN firmware does not report M16C "error factors"
 * - USBCAN controllers has difficulties reporting if the raised error
 *   event is for ch0 or ch1. They leave such arbitration to the OS
 *   driver by letting it compare error counters with previous values
 *   and decide the error event's channel. Thus for USBCAN, the channel
 *   field is only advisory.
 */
struct kvaser_usb_err_summary {
        u8 channel, status, txerr, rxerr;
        union {
                struct {
                        u8 error_factor;
                } leaf;
                struct {
                        u8 other_ch_status;
                        u8 error_state;
                } usbcan;
        };
};

struct kvaser_usb_net_leaf_priv {
        struct kvaser_usb_net_priv *net;

        struct delayed_work chip_state_req_work;

        /* started but not reported as bus-on yet */
        bool joining_bus;
};

static const struct can_bittiming_const kvaser_usb_leaf_m16c_bittiming_const = {
        .name = "kvaser_usb_ucii",
        .tseg1_min = 4,
        .tseg1_max = 16,
        .tseg2_min = 2,
        .tseg2_max = 8,
        .sjw_max = 4,
        .brp_min = 1,
        .brp_max = 16,
        .brp_inc = 1,
};

static const struct can_bittiming_const kvaser_usb_leaf_m32c_bittiming_const = {
        .name = "kvaser_usb_leaf",
        .tseg1_min = 3,
        .tseg1_max = 16,
        .tseg2_min = 2,
        .tseg2_max = 8,
        .sjw_max = 4,
        .brp_min = 2,
        .brp_max = 128,
        .brp_inc = 2,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_usbcan_dev_cfg = {
        .clock = {
                .freq = 8 * MEGA /* Hz */,
        },
        .timestamp_freq = 1,
        .bittiming_const = &kvaser_usb_leaf_m16c_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_m32c_dev_cfg_16mhz = {
        .clock = {
                .freq = 16 * MEGA /* Hz */,
        },
        .timestamp_freq = 16,
        .bittiming_const = &kvaser_usb_leaf_m32c_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_m32c_dev_cfg_24mhz = {
        .clock = {
                .freq = 16 * MEGA /* Hz */,
        },
        .timestamp_freq = 24,
        .bittiming_const = &kvaser_usb_leaf_m32c_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_m32c_dev_cfg_32mhz = {
        .clock = {
                .freq = 16 * MEGA /* Hz */,
        },
        .timestamp_freq = 32,
        .bittiming_const = &kvaser_usb_leaf_m32c_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_imx_dev_cfg_16mhz = {
        .clock = {
                .freq = 16 * MEGA /* Hz */,
        },
        .timestamp_freq = 16,
        .bittiming_const = &kvaser_usb_flexc_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_imx_dev_cfg_24mhz = {
        .clock = {
                .freq = 24 * MEGA /* Hz */,
        },
        .timestamp_freq = 24,
        .bittiming_const = &kvaser_usb_flexc_bittiming_const,
};

static const struct kvaser_usb_dev_cfg kvaser_usb_leaf_imx_dev_cfg_32mhz = {
        .clock = {
                .freq = 32 * MEGA /* Hz */,
        },
        .timestamp_freq = 32,
        .bittiming_const = &kvaser_usb_flexc_bittiming_const,
};

static inline ktime_t kvaser_usb_usbcan_timestamp_to_ktime(const struct kvaser_usb *dev,
                                                           __le16 timestamp)
{
        u64 ticks = le16_to_cpu(timestamp) |
                    dev->card_data.usbcan_timestamp_msb;

        return kvaser_usb_ticks_to_ktime(dev->cfg, ticks * KVASER_USB_USBCAN_TIMESTAMP_FACTOR);
}

static int kvaser_usb_leaf_verify_size(const struct kvaser_usb *dev,
                                       const struct kvaser_cmd *cmd)
{
        /* buffer size >= cmd->len ensured by caller */
        u8 min_size = 0;

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                if (cmd->id < ARRAY_SIZE(kvaser_usb_leaf_cmd_sizes_leaf))
                        min_size = kvaser_usb_leaf_cmd_sizes_leaf[cmd->id];
                break;
        case KVASER_USBCAN:
                if (cmd->id < ARRAY_SIZE(kvaser_usb_leaf_cmd_sizes_usbcan))
                        min_size = kvaser_usb_leaf_cmd_sizes_usbcan[cmd->id];
                break;
        }

        if (min_size == CMD_SIZE_ANY)
                return 0;

        if (min_size) {
                min_size += CMD_HEADER_LEN;
                if (cmd->len >= min_size)
                        return 0;

                dev_err_ratelimited(&dev->intf->dev,
                                    "Received command %u too short (size %u, needed %u)",
                                    cmd->id, cmd->len, min_size);
                return -EIO;
        }

        dev_warn_ratelimited(&dev->intf->dev,
                             "Unhandled command (%d, size %d)\n",
                             cmd->id, cmd->len);
        return -EINVAL;
}

static void *
kvaser_usb_leaf_frame_to_cmd(const struct kvaser_usb_net_priv *priv,
                             const struct sk_buff *skb, int *cmd_len,
                             u16 transid)
{
        struct kvaser_usb *dev = priv->dev;
        struct kvaser_cmd *cmd;
        u8 *cmd_tx_can_flags = NULL;            /* GCC */
        struct can_frame *cf = (struct can_frame *)skb->data;

        cmd = kmalloc_obj(*cmd, GFP_ATOMIC);
        if (cmd) {
                cmd->u.tx_can.tid = transid & 0xff;
                cmd->len = *cmd_len = CMD_HEADER_LEN +
                                      sizeof(struct kvaser_cmd_tx_can);
                cmd->u.tx_can.channel = priv->channel;

                switch (dev->driver_info->family) {
                case KVASER_LEAF:
                        cmd_tx_can_flags = &cmd->u.tx_can.leaf.flags;
                        break;
                case KVASER_USBCAN:
                        cmd_tx_can_flags = &cmd->u.tx_can.usbcan.flags;
                        break;
                }

                *cmd_tx_can_flags = 0;

                if (cf->can_id & CAN_EFF_FLAG) {
                        cmd->id = CMD_TX_EXT_MESSAGE;
                        cmd->u.tx_can.data[0] = (cf->can_id >> 24) & 0x1f;
                        cmd->u.tx_can.data[1] = (cf->can_id >> 18) & 0x3f;
                        cmd->u.tx_can.data[2] = (cf->can_id >> 14) & 0x0f;
                        cmd->u.tx_can.data[3] = (cf->can_id >> 6) & 0xff;
                        cmd->u.tx_can.data[4] = cf->can_id & 0x3f;
                } else {
                        cmd->id = CMD_TX_STD_MESSAGE;
                        cmd->u.tx_can.data[0] = (cf->can_id >> 6) & 0x1f;
                        cmd->u.tx_can.data[1] = cf->can_id & 0x3f;
                }

                cmd->u.tx_can.data[5] = can_get_cc_dlc(cf, priv->can.ctrlmode);
                memcpy(&cmd->u.tx_can.data[6], cf->data, cf->len);

                if (cf->can_id & CAN_RTR_FLAG)
                        *cmd_tx_can_flags |= MSG_FLAG_REMOTE_FRAME;
        }
        return cmd;
}

static int kvaser_usb_leaf_wait_cmd(const struct kvaser_usb *dev, u8 id,
                                    struct kvaser_cmd *cmd)
{
        struct kvaser_cmd *tmp;
        void *buf;
        int actual_len;
        int err;
        int pos;
        unsigned long to = jiffies + msecs_to_jiffies(KVASER_USB_TIMEOUT);

        buf = kzalloc(KVASER_USB_RX_BUFFER_SIZE, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        do {
                err = kvaser_usb_recv_cmd(dev, buf, KVASER_USB_RX_BUFFER_SIZE,
                                          &actual_len);
                if (err < 0)
                        goto end;

                pos = 0;
                while (pos <= actual_len - CMD_HEADER_LEN) {
                        tmp = buf + pos;

                        /* Handle commands crossing the USB endpoint max packet
                         * size boundary. Check kvaser_usb_read_bulk_callback()
                         * for further details.
                         */
                        if (tmp->len == 0) {
                                pos = round_up(pos + 1,
                                               le16_to_cpu
                                                (dev->bulk_in->wMaxPacketSize));
                                continue;
                        }

                        if (tmp->len < CMD_HEADER_LEN ||
                            tmp->len > actual_len - pos) {
                                dev_err_ratelimited(&dev->intf->dev,
                                                    "Format error\n");
                                break;
                        }

                        if (tmp->id == id) {
                                if (tmp->len > sizeof(*cmd)) {
                                        dev_err_ratelimited(&dev->intf->dev,
                                                            "Received command %u too large (%u)\n",
                                                            tmp->id, tmp->len);
                                        err = -EIO;
                                        goto end;
                                }

                                memcpy(cmd, tmp, tmp->len);
                                goto end;
                        }

                        pos += tmp->len;
                }
        } while (time_before(jiffies, to));

        err = -EINVAL;

end:
        kfree(buf);

        if (err == 0)
                err = kvaser_usb_leaf_verify_size(dev, cmd);

        return err;
}

static int kvaser_usb_leaf_send_simple_cmd(const struct kvaser_usb *dev,
                                           u8 cmd_id, int channel)
{
        struct kvaser_cmd *cmd;
        int rc;

        cmd = kmalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = cmd_id;
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_simple);
        cmd->u.simple.channel = channel;
        cmd->u.simple.tid = 0xff;

        rc = kvaser_usb_send_cmd(dev, cmd, cmd->len);

        kfree(cmd);
        return rc;
}

static void kvaser_usb_leaf_get_software_info_leaf(struct kvaser_usb *dev,
                                                   const struct leaf_cmd_softinfo *softinfo)
{
        u32 fw_version;
        u32 sw_options = le32_to_cpu(softinfo->sw_options);

        fw_version = le32_to_cpu(softinfo->fw_version);
        dev->fw_version.major = FIELD_GET(KVASER_USB_SW_VERSION_MAJOR_MASK, fw_version);
        dev->fw_version.minor = FIELD_GET(KVASER_USB_SW_VERSION_MINOR_MASK, fw_version);
        dev->fw_version.build = FIELD_GET(KVASER_USB_SW_VERSION_BUILD_MASK, fw_version);
        dev->max_tx_urbs = le16_to_cpu(softinfo->max_outstanding_tx);

        if (sw_options & KVASER_USB_LEAF_SWOPTION_EXT_CAP)
                dev->card_data.capabilities |= KVASER_USB_CAP_EXT_CAP;

        if (dev->driver_info->quirks & KVASER_USB_QUIRK_IGNORE_CLK_FREQ) {
                /* Firmware expects bittiming parameters calculated for 16MHz
                 * clock, regardless of the actual clock
                 * Though, the reported freq is used for timestamps
                 */
                switch (sw_options & KVASER_USB_LEAF_SWOPTION_FREQ_MASK) {
                case KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_m32c_dev_cfg_16mhz;
                        break;
                case KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_m32c_dev_cfg_24mhz;
                        break;
                case KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_m32c_dev_cfg_32mhz;
                        break;
                }
        } else {
                switch (sw_options & KVASER_USB_LEAF_SWOPTION_FREQ_MASK) {
                case KVASER_USB_LEAF_SWOPTION_FREQ_16_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_imx_dev_cfg_16mhz;
                        break;
                case KVASER_USB_LEAF_SWOPTION_FREQ_24_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_imx_dev_cfg_24mhz;
                        break;
                case KVASER_USB_LEAF_SWOPTION_FREQ_32_MHZ_CLK:
                        dev->cfg = &kvaser_usb_leaf_imx_dev_cfg_32mhz;
                        break;
                }
        }
}

static int kvaser_usb_leaf_get_software_info_inner(struct kvaser_usb *dev)
{
        struct kvaser_cmd cmd;
        int err;
        u32 fw_version;

        err = kvaser_usb_leaf_send_simple_cmd(dev, CMD_GET_SOFTWARE_INFO, 0);
        if (err)
                return err;

        err = kvaser_usb_leaf_wait_cmd(dev, CMD_GET_SOFTWARE_INFO_REPLY, &cmd);
        if (err)
                return err;

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                kvaser_usb_leaf_get_software_info_leaf(dev, &cmd.u.leaf.softinfo);
                break;
        case KVASER_USBCAN:
                fw_version = le32_to_cpu(cmd.u.usbcan.softinfo.fw_version);
                dev->fw_version.major = FIELD_GET(KVASER_USB_SW_VERSION_MAJOR_MASK,
                                                  fw_version);
                dev->fw_version.minor = FIELD_GET(KVASER_USB_SW_VERSION_MINOR_MASK,
                                                  fw_version);
                dev->fw_version.build = FIELD_GET(KVASER_USB_SW_VERSION_BUILD_MASK,
                                                  fw_version);
                dev->max_tx_urbs =
                        le16_to_cpu(cmd.u.usbcan.softinfo.max_outstanding_tx);
                dev->cfg = &kvaser_usb_leaf_usbcan_dev_cfg;
                break;
        }

        return 0;
}

static int kvaser_usb_leaf_get_software_info(struct kvaser_usb *dev)
{
        int err;
        int retry = 3;

        /* On some x86 laptops, plugging a Kvaser device again after
         * an unplug makes the firmware always ignore the very first
         * command. For such a case, provide some room for retries
         * instead of completely exiting the driver.
         */
        do {
                err = kvaser_usb_leaf_get_software_info_inner(dev);
        } while (--retry && err == -ETIMEDOUT);

        return err;
}

static int kvaser_usb_leaf_get_card_info(struct kvaser_usb *dev)
{
        struct kvaser_cmd cmd;
        int err;

        err = kvaser_usb_leaf_send_simple_cmd(dev, CMD_GET_CARD_INFO, 0);
        if (err)
                return err;

        err = kvaser_usb_leaf_wait_cmd(dev, CMD_GET_CARD_INFO_REPLY, &cmd);
        if (err)
                return err;

        dev->nchannels = cmd.u.cardinfo.nchannels;
        if (dev->nchannels > KVASER_USB_MAX_NET_DEVICES ||
            (dev->driver_info->family == KVASER_USBCAN &&
             dev->nchannels > MAX_USBCAN_NET_DEVICES))
                return -EINVAL;
        dev->ean[1] = le32_to_cpu(cmd.u.cardinfo.ean[1]);
        dev->ean[0] = le32_to_cpu(cmd.u.cardinfo.ean[0]);
        dev->serial_number = le32_to_cpu(cmd.u.cardinfo.serial_number);
        dev->hw_revision = cmd.u.cardinfo.hw_revision;

        return 0;
}

static int kvaser_usb_leaf_get_single_capability(struct kvaser_usb *dev,
                                                 u16 cap_cmd_req, u16 *status)
{
        struct kvaser_usb_dev_card_data *card_data = &dev->card_data;
        struct kvaser_cmd *cmd;
        u32 value = 0;
        u32 mask = 0;
        u16 cap_cmd_res;
        int err;
        int i;

        cmd = kzalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = CMD_GET_CAPABILITIES_REQ;
        cmd->u.leaf.cap_req.cap_cmd = cpu_to_le16(cap_cmd_req);
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_cap_req);

        err = kvaser_usb_send_cmd(dev, cmd, cmd->len);
        if (err)
                goto end;

        err = kvaser_usb_leaf_wait_cmd(dev, CMD_GET_CAPABILITIES_RESP, cmd);
        if (err)
                goto end;

        *status = le16_to_cpu(cmd->u.leaf.cap_res.status);

        if (*status != KVASER_USB_LEAF_CAP_STAT_OK)
                goto end;

        cap_cmd_res = le16_to_cpu(cmd->u.leaf.cap_res.cap_cmd);
        switch (cap_cmd_res) {
        case KVASER_USB_LEAF_CAP_CMD_LISTEN_MODE:
        case KVASER_USB_LEAF_CAP_CMD_ERR_REPORT:
                value = le32_to_cpu(cmd->u.leaf.cap_res.value);
                mask = le32_to_cpu(cmd->u.leaf.cap_res.mask);
                break;
        default:
                dev_warn(&dev->intf->dev, "Unknown capability command %u\n",
                         cap_cmd_res);
                break;
        }

        for (i = 0; i < dev->nchannels; i++) {
                if (BIT(i) & (value & mask)) {
                        switch (cap_cmd_res) {
                        case KVASER_USB_LEAF_CAP_CMD_LISTEN_MODE:
                                card_data->ctrlmode_supported |=
                                                CAN_CTRLMODE_LISTENONLY;
                                break;
                        case KVASER_USB_LEAF_CAP_CMD_ERR_REPORT:
                                card_data->capabilities |=
                                                KVASER_USB_CAP_BERR_CAP;
                                break;
                        }
                }
        }

end:
        kfree(cmd);

        return err;
}

static int kvaser_usb_leaf_get_capabilities_leaf(struct kvaser_usb *dev)
{
        int err;
        u16 status;

        if (!(dev->card_data.capabilities & KVASER_USB_CAP_EXT_CAP)) {
                dev_info(&dev->intf->dev,
                         "No extended capability support. Upgrade device firmware.\n");
                return 0;
        }

        err = kvaser_usb_leaf_get_single_capability(dev,
                                                    KVASER_USB_LEAF_CAP_CMD_LISTEN_MODE,
                                                    &status);
        if (err)
                return err;
        if (status)
                dev_info(&dev->intf->dev,
                         "KVASER_USB_LEAF_CAP_CMD_LISTEN_MODE failed %u\n",
                         status);

        err = kvaser_usb_leaf_get_single_capability(dev,
                                                    KVASER_USB_LEAF_CAP_CMD_ERR_REPORT,
                                                    &status);
        if (err)
                return err;
        if (status)
                dev_info(&dev->intf->dev,
                         "KVASER_USB_LEAF_CAP_CMD_ERR_REPORT failed %u\n",
                         status);

        return 0;
}

static int kvaser_usb_leaf_set_led(struct kvaser_usb_net_priv *priv,
                                   enum kvaser_usb_led_state state,
                                   u16 duration_ms)
{
        struct kvaser_usb *dev = priv->dev;
        struct kvaser_cmd *cmd;
        int ret;

        cmd = kzalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = CMD_LED_ACTION_REQ;
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_led_action_req);
        cmd->u.led_action_req.tid = 0xff;

        cmd->u.led_action_req.duration_ms = cpu_to_le16(duration_ms);
        cmd->u.led_action_req.action = state |
                                       FIELD_PREP(KVASER_USB_LEAF_LED_IDX_MASK,
                                                  KVASER_USB_LEAF_LED_YELLOW_CH0_IDX +
                                                  priv->channel);

        ret = kvaser_usb_send_cmd(dev, cmd, cmd->len);
        kfree(cmd);

        return ret;
}

static int kvaser_usb_leaf_get_capabilities(struct kvaser_usb *dev)
{
        int err = 0;

        if (dev->driver_info->family == KVASER_LEAF)
                err = kvaser_usb_leaf_get_capabilities_leaf(dev);

        return err;
}

static void kvaser_usb_leaf_tx_acknowledge(const struct kvaser_usb *dev,
                                           const struct kvaser_cmd *cmd)
{
        struct net_device_stats *stats;
        struct kvaser_usb_tx_urb_context *context;
        struct kvaser_usb_net_priv *priv;
        unsigned long flags;
        u8 channel, tid;
        struct sk_buff *skb;
        ktime_t hwtstamp = 0;

        channel = cmd->u.tx_acknowledge_header.channel;
        tid = cmd->u.tx_acknowledge_header.tid;

        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "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 % dev->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) {
                struct sk_buff *err_skb;
                struct can_frame *cf;

                err_skb = alloc_can_err_skb(priv->netdev, &cf);
                if (err_skb) {
                        cf->can_id |= CAN_ERR_RESTARTED;

                        netif_rx(err_skb);
                } 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;
        }
        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                hwtstamp = kvaser_usb_timestamp48_to_ktime(dev->cfg, cmd->u.leaf.tx_ack.time);
                break;
        case KVASER_USBCAN:
                hwtstamp = kvaser_usb_usbcan_timestamp_to_ktime(dev, cmd->u.usbcan.tx_ack.time);
                break;
        }

        spin_lock_irqsave(&priv->tx_contexts_lock, flags);

        skb = priv->can.echo_skb[context->echo_index];
        if (skb)
                skb_hwtstamps(skb)->hwtstamp = hwtstamp;
        stats->tx_packets++;
        stats->tx_bytes += can_get_echo_skb(priv->netdev,
                                            context->echo_index, NULL);
        context->echo_index = dev->max_tx_urbs;
        --priv->active_tx_contexts;
        netif_wake_queue(priv->netdev);

        spin_unlock_irqrestore(&priv->tx_contexts_lock, flags);
}

static int kvaser_usb_leaf_simple_cmd_async(struct kvaser_usb_net_priv *priv,
                                            u8 cmd_id)
{
        struct kvaser_cmd *cmd;
        int err;

        cmd = kzalloc_obj(*cmd, GFP_ATOMIC);
        if (!cmd)
                return -ENOMEM;

        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_simple);
        cmd->id = cmd_id;
        cmd->u.simple.channel = priv->channel;

        err = kvaser_usb_send_cmd_async(priv, cmd, cmd->len);
        if (err)
                kfree(cmd);

        return err;
}

static void kvaser_usb_leaf_chip_state_req_work(struct work_struct *work)
{
        struct kvaser_usb_net_leaf_priv *leaf =
                container_of(work, struct kvaser_usb_net_leaf_priv,
                             chip_state_req_work.work);
        struct kvaser_usb_net_priv *priv = leaf->net;

        kvaser_usb_leaf_simple_cmd_async(priv, CMD_GET_CHIP_STATE);
}

static void
kvaser_usb_leaf_rx_error_update_can_state(struct kvaser_usb_net_priv *priv,
                                        const struct kvaser_usb_err_summary *es,
                                        struct can_frame *cf)
{
        struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
        struct kvaser_usb *dev = priv->dev;
        struct net_device_stats *stats = &priv->netdev->stats;
        enum can_state cur_state, new_state, tx_state, rx_state;

        netdev_dbg(priv->netdev, "Error status: 0x%02x\n", es->status);

        new_state = priv->can.state;
        cur_state = priv->can.state;

        if (es->status & (M16C_STATE_BUS_OFF | M16C_STATE_BUS_RESET)) {
                new_state = CAN_STATE_BUS_OFF;
        } else if (es->status & M16C_STATE_BUS_PASSIVE) {
                new_state = CAN_STATE_ERROR_PASSIVE;
        } else if ((es->status & M16C_STATE_BUS_ERROR) &&
                   cur_state >= CAN_STATE_BUS_OFF) {
                /* Guard against spurious error events after a busoff */
        } else if (es->txerr >= 128 || es->rxerr >= 128) {
                new_state = CAN_STATE_ERROR_PASSIVE;
        } else if (es->txerr >= 96 || es->rxerr >= 96) {
                new_state = CAN_STATE_ERROR_WARNING;
        } else {
                new_state = CAN_STATE_ERROR_ACTIVE;
        }

        /* 0bfd:0124 FW 4.18.778 was observed to send the initial
         * CMD_CHIP_STATE_EVENT after CMD_START_CHIP with M16C_STATE_BUS_OFF
         * bit set if the channel was bus-off when it was last stopped (even
         * across chip resets). This bit will clear shortly afterwards, without
         * triggering a second unsolicited chip state event.
         * Ignore this initial bus-off.
         */
        if (leaf->joining_bus) {
                if (new_state == CAN_STATE_BUS_OFF) {
                        netdev_dbg(priv->netdev, "ignoring bus-off during startup");
                        new_state = cur_state;
                } else {
                        leaf->joining_bus = false;
                }
        }

        if (new_state != cur_state) {
                tx_state = (es->txerr >= es->rxerr) ? new_state : 0;
                rx_state = (es->txerr <= es->rxerr) ? new_state : 0;

                can_change_state(priv->netdev, cf, tx_state, rx_state);
        }

        if (priv->can.restart_ms &&
            cur_state == CAN_STATE_BUS_OFF &&
            new_state < CAN_STATE_BUS_OFF)
                priv->can.can_stats.restarts++;

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                if (es->leaf.error_factor) {
                        priv->can.can_stats.bus_error++;
                        stats->rx_errors++;
                }
                break;
        case KVASER_USBCAN:
                if (es->usbcan.error_state & USBCAN_ERROR_STATE_TX_ERROR)
                        stats->tx_errors++;
                if (es->usbcan.error_state & USBCAN_ERROR_STATE_RX_ERROR)
                        stats->rx_errors++;
                if (es->usbcan.error_state & USBCAN_ERROR_STATE_BUSERROR)
                        priv->can.can_stats.bus_error++;
                break;
        }

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

static void kvaser_usb_leaf_rx_error(const struct kvaser_usb *dev,
                                     const struct kvaser_usb_err_summary *es)
{
        struct can_frame *cf = NULL;
        struct sk_buff *skb = NULL;
        struct net_device_stats *stats;
        struct kvaser_usb_net_priv *priv;
        struct kvaser_usb_net_leaf_priv *leaf;
        enum can_state old_state, new_state;

        if (es->channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "Invalid channel number (%d)\n", es->channel);
                return;
        }

        priv = dev->nets[es->channel];
        leaf = priv->sub_priv;
        stats = &priv->netdev->stats;

        /* Ignore e.g. state change to bus-off reported just after stopping */
        if (!netif_running(priv->netdev))
                return;

        old_state = priv->can.state;
        if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
                skb = alloc_can_err_skb(priv->netdev, &cf);
        kvaser_usb_leaf_rx_error_update_can_state(priv, es, cf);
        new_state = priv->can.state;

        /* If there are errors, request status updates periodically as we do
         * not get automatic notifications of improved state.
         * Also request updates if we saw a stale BUS_OFF during startup
         * (joining_bus).
         */
        if (new_state < CAN_STATE_BUS_OFF &&
            (es->rxerr || es->txerr || new_state == CAN_STATE_ERROR_PASSIVE ||
             leaf->joining_bus))
                schedule_delayed_work(&leaf->chip_state_req_work,
                                      msecs_to_jiffies(500));

        if (new_state != old_state) {
                if (es->status &
                    (M16C_STATE_BUS_OFF | M16C_STATE_BUS_RESET)) {
                        if (!priv->can.restart_ms)
                                kvaser_usb_leaf_simple_cmd_async(priv,
                                                                 CMD_STOP_CHIP);
                        netif_carrier_off(priv->netdev);
                }

                if (priv->can.restart_ms &&
                    old_state == CAN_STATE_BUS_OFF &&
                    new_state < CAN_STATE_BUS_OFF) {
                        if (cf)
                                cf->can_id |= CAN_ERR_RESTARTED;
                        netif_carrier_on(priv->netdev);
                }
        }

        if (!skb) {
                if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
                        stats->rx_dropped++;
                        netdev_warn(priv->netdev, "No memory left for err_skb\n");
                }
                return;
        }

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                if (es->leaf.error_factor) {
                        cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;

                        if (es->leaf.error_factor & M16C_EF_ACKE)
                                cf->data[3] = CAN_ERR_PROT_LOC_ACK;
                        if (es->leaf.error_factor & M16C_EF_CRCE)
                                cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
                        if (es->leaf.error_factor & M16C_EF_FORME)
                                cf->data[2] |= CAN_ERR_PROT_FORM;
                        if (es->leaf.error_factor & M16C_EF_STFE)
                                cf->data[2] |= CAN_ERR_PROT_STUFF;
                        if (es->leaf.error_factor & M16C_EF_BITE0)
                                cf->data[2] |= CAN_ERR_PROT_BIT0;
                        if (es->leaf.error_factor & M16C_EF_BITE1)
                                cf->data[2] |= CAN_ERR_PROT_BIT1;
                        if (es->leaf.error_factor & M16C_EF_TRE)
                                cf->data[2] |= CAN_ERR_PROT_TX;
                }
                break;
        case KVASER_USBCAN:
                if (es->usbcan.error_state & USBCAN_ERROR_STATE_BUSERROR)
                        cf->can_id |= CAN_ERR_BUSERROR;
                break;
        }

        if (new_state != CAN_STATE_BUS_OFF) {
                cf->can_id |= CAN_ERR_CNT;
                cf->data[6] = es->txerr;
                cf->data[7] = es->rxerr;
        }

        netif_rx(skb);
}

/* For USBCAN, report error to userspace if the channels's errors counter
 * has changed, or we're the only channel seeing a bus error state.
 */
static void
kvaser_usb_leaf_usbcan_conditionally_rx_error(const struct kvaser_usb *dev,
                                              struct kvaser_usb_err_summary *es)
{
        struct kvaser_usb_net_priv *priv;
        unsigned int channel;
        bool report_error;

        channel = es->channel;
        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "Invalid channel number (%d)\n", channel);
                return;
        }

        priv = dev->nets[channel];
        report_error = false;

        if (es->txerr != priv->bec.txerr) {
                es->usbcan.error_state |= USBCAN_ERROR_STATE_TX_ERROR;
                report_error = true;
        }
        if (es->rxerr != priv->bec.rxerr) {
                es->usbcan.error_state |= USBCAN_ERROR_STATE_RX_ERROR;
                report_error = true;
        }
        if ((es->status & M16C_STATE_BUS_ERROR) &&
            !(es->usbcan.other_ch_status & M16C_STATE_BUS_ERROR)) {
                es->usbcan.error_state |= USBCAN_ERROR_STATE_BUSERROR;
                report_error = true;
        }

        if (report_error)
                kvaser_usb_leaf_rx_error(dev, es);
}

static void kvaser_usb_leaf_usbcan_rx_error(const struct kvaser_usb *dev,
                                            const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_err_summary es = { };

        switch (cmd->id) {
        /* Sometimes errors are sent as unsolicited chip state events */
        case CMD_CHIP_STATE_EVENT:
                es.channel = cmd->u.usbcan.chip_state_event.channel;
                es.status = cmd->u.usbcan.chip_state_event.status;
                es.txerr = cmd->u.usbcan.chip_state_event.tx_errors_count;
                es.rxerr = cmd->u.usbcan.chip_state_event.rx_errors_count;
                kvaser_usb_leaf_usbcan_conditionally_rx_error(dev, &es);
                break;

        case CMD_CAN_ERROR_EVENT:
                es.channel = 0;
                es.status = cmd->u.usbcan.can_error_event.status_ch0;
                es.txerr = cmd->u.usbcan.can_error_event.tx_errors_count_ch0;
                es.rxerr = cmd->u.usbcan.can_error_event.rx_errors_count_ch0;
                es.usbcan.other_ch_status =
                        cmd->u.usbcan.can_error_event.status_ch1;
                kvaser_usb_leaf_usbcan_conditionally_rx_error(dev, &es);

                /* The USBCAN firmware supports up to 2 channels.
                 * Now that ch0 was checked, check if ch1 has any errors.
                 */
                if (dev->nchannels == MAX_USBCAN_NET_DEVICES) {
                        es.channel = 1;
                        es.status = cmd->u.usbcan.can_error_event.status_ch1;
                        es.txerr =
                                cmd->u.usbcan.can_error_event.tx_errors_count_ch1;
                        es.rxerr =
                                cmd->u.usbcan.can_error_event.rx_errors_count_ch1;
                        es.usbcan.other_ch_status =
                                cmd->u.usbcan.can_error_event.status_ch0;
                        kvaser_usb_leaf_usbcan_conditionally_rx_error(dev, &es);
                }
                break;

        default:
                dev_err(&dev->intf->dev, "Invalid cmd id (%d)\n", cmd->id);
        }
}

static void kvaser_usb_leaf_leaf_rx_error(const struct kvaser_usb *dev,
                                          const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_err_summary es = { };

        switch (cmd->id) {
        case CMD_CAN_ERROR_EVENT:
                es.channel = cmd->u.leaf.can_error_event.channel;
                es.status = cmd->u.leaf.can_error_event.status;
                es.txerr = cmd->u.leaf.can_error_event.tx_errors_count;
                es.rxerr = cmd->u.leaf.can_error_event.rx_errors_count;
                es.leaf.error_factor = cmd->u.leaf.can_error_event.error_factor;
                break;
        case CMD_LEAF_LOG_MESSAGE:
                es.channel = cmd->u.leaf.log_message.channel;
                es.status = cmd->u.leaf.log_message.data[0];
                es.txerr = cmd->u.leaf.log_message.data[2];
                es.rxerr = cmd->u.leaf.log_message.data[3];
                es.leaf.error_factor = cmd->u.leaf.log_message.data[1];
                break;
        case CMD_CHIP_STATE_EVENT:
                es.channel = cmd->u.leaf.chip_state_event.channel;
                es.status = cmd->u.leaf.chip_state_event.status;
                es.txerr = cmd->u.leaf.chip_state_event.tx_errors_count;
                es.rxerr = cmd->u.leaf.chip_state_event.rx_errors_count;
                es.leaf.error_factor = 0;
                break;
        default:
                dev_err(&dev->intf->dev, "Invalid cmd id (%d)\n", cmd->id);
                return;
        }

        kvaser_usb_leaf_rx_error(dev, &es);
}

static void kvaser_usb_leaf_rx_can_err(const struct kvaser_usb_net_priv *priv,
                                       const struct kvaser_cmd *cmd)
{
        if (cmd->u.rx_can_header.flag & (MSG_FLAG_ERROR_FRAME |
                                         MSG_FLAG_NERR)) {
                struct net_device_stats *stats = &priv->netdev->stats;

                netdev_err(priv->netdev, "Unknown error (flags: 0x%02x)\n",
                           cmd->u.rx_can_header.flag);

                stats->rx_errors++;
                return;
        }

        if (cmd->u.rx_can_header.flag & MSG_FLAG_OVERRUN)
                kvaser_usb_can_rx_over_error(priv->netdev);
}

static void kvaser_usb_leaf_rx_can_msg(const struct kvaser_usb *dev,
                                       const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_net_priv *priv;
        struct can_frame *cf;
        struct sk_buff *skb;
        struct net_device_stats *stats;
        u8 channel = cmd->u.rx_can_header.channel;
        const u8 *rx_data = NULL;       /* GCC */
        ktime_t hwtstamp = 0;

        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "Invalid channel number (%d)\n", channel);
                return;
        }

        priv = dev->nets[channel];
        stats = &priv->netdev->stats;

        if ((cmd->u.rx_can_header.flag & MSG_FLAG_ERROR_FRAME) &&
            (dev->driver_info->family == KVASER_LEAF &&
             cmd->id == CMD_LEAF_LOG_MESSAGE)) {
                kvaser_usb_leaf_leaf_rx_error(dev, cmd);
                return;
        } else if (cmd->u.rx_can_header.flag & (MSG_FLAG_ERROR_FRAME |
                                                MSG_FLAG_NERR |
                                                MSG_FLAG_OVERRUN)) {
                kvaser_usb_leaf_rx_can_err(priv, cmd);
                return;
        } else if (cmd->u.rx_can_header.flag & ~MSG_FLAG_REMOTE_FRAME) {
                netdev_warn(priv->netdev,
                            "Unhandled frame (flags: 0x%02x)\n",
                            cmd->u.rx_can_header.flag);
                return;
        }

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                rx_data = cmd->u.leaf.rx_can.data;
                hwtstamp = kvaser_usb_timestamp48_to_ktime(dev->cfg, cmd->u.leaf.rx_can.time);
                break;
        case KVASER_USBCAN:
                rx_data = cmd->u.usbcan.rx_can.data;
                hwtstamp = kvaser_usb_usbcan_timestamp_to_ktime(dev, cmd->u.usbcan.rx_can.time);
                break;
        }

        skb = alloc_can_skb(priv->netdev, &cf);
        if (!skb) {
                stats->rx_dropped++;
                return;
        }

        if (dev->driver_info->family == KVASER_LEAF && cmd->id ==
            CMD_LEAF_LOG_MESSAGE) {
                cf->can_id = le32_to_cpu(cmd->u.leaf.log_message.id);
                if (cf->can_id & KVASER_EXTENDED_FRAME)
                        cf->can_id &= CAN_EFF_MASK | CAN_EFF_FLAG;
                else
                        cf->can_id &= CAN_SFF_MASK;

                can_frame_set_cc_len(cf, cmd->u.leaf.log_message.dlc & 0xF, priv->can.ctrlmode);

                if (cmd->u.leaf.log_message.flags & MSG_FLAG_REMOTE_FRAME)
                        cf->can_id |= CAN_RTR_FLAG;
                else
                        memcpy(cf->data, &cmd->u.leaf.log_message.data,
                               cf->len);
        } else {
                cf->can_id = ((rx_data[0] & 0x1f) << 6) | (rx_data[1] & 0x3f);

                if (cmd->id == CMD_RX_EXT_MESSAGE) {
                        cf->can_id <<= 18;
                        cf->can_id |= ((rx_data[2] & 0x0f) << 14) |
                                      ((rx_data[3] & 0xff) << 6) |
                                      (rx_data[4] & 0x3f);
                        cf->can_id |= CAN_EFF_FLAG;
                }

                can_frame_set_cc_len(cf, rx_data[5] & 0xF, priv->can.ctrlmode);

                if (cmd->u.rx_can_header.flag & MSG_FLAG_REMOTE_FRAME)
                        cf->can_id |= CAN_RTR_FLAG;
                else
                        memcpy(cf->data, &rx_data[6], cf->len);
        }

        skb_hwtstamps(skb)->hwtstamp = hwtstamp;
        stats->rx_packets++;
        if (!(cf->can_id & CAN_RTR_FLAG))
                stats->rx_bytes += cf->len;
        netif_rx(skb);
}

static void kvaser_usb_leaf_error_event_parameter(const struct kvaser_usb *dev,
                                                  const struct kvaser_cmd *cmd)
{
        u16 info1 = 0;

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                info1 = le16_to_cpu(cmd->u.leaf.error_event.info1);
                break;
        case KVASER_USBCAN:
                info1 = le16_to_cpu(cmd->u.usbcan.error_event.info1);
                break;
        }

        /* info1 will contain the offending cmd_no */
        switch (info1) {
        case CMD_SET_CTRL_MODE:
                dev_warn(&dev->intf->dev,
                         "CMD_SET_CTRL_MODE error in parameter\n");
                break;

        case CMD_SET_BUS_PARAMS:
                dev_warn(&dev->intf->dev,
                         "CMD_SET_BUS_PARAMS error in parameter\n");
                break;

        default:
                dev_warn(&dev->intf->dev,
                         "Unhandled parameter error event cmd_no (%u)\n",
                         info1);
                break;
        }
}

static void kvaser_usb_leaf_error_event(const struct kvaser_usb *dev,
                                        const struct kvaser_cmd *cmd)
{
        u8 error_code = 0;

        switch (dev->driver_info->family) {
        case KVASER_LEAF:
                error_code = cmd->u.leaf.error_event.error_code;
                break;
        case KVASER_USBCAN:
                error_code = cmd->u.usbcan.error_event.error_code;
                break;
        }

        switch (error_code) {
        case KVASER_USB_LEAF_ERROR_EVENT_TX_QUEUE_FULL:
                /* Received additional CAN message, when firmware TX queue is
                 * already full. Something is wrong with the driver.
                 * This should never happen!
                 */
                dev_err(&dev->intf->dev,
                        "Received error event TX_QUEUE_FULL\n");
                break;
        case KVASER_USB_LEAF_ERROR_EVENT_PARAM:
                kvaser_usb_leaf_error_event_parameter(dev, cmd);
                break;

        default:
                dev_warn(&dev->intf->dev,
                         "Unhandled error event (%d)\n", error_code);
                break;
        }
}

static void kvaser_usb_leaf_start_chip_reply(const struct kvaser_usb *dev,
                                             const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_net_priv *priv;
        u8 channel = cmd->u.simple.channel;

        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "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_leaf_stop_chip_reply(const struct kvaser_usb *dev,
                                            const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_net_priv *priv;
        u8 channel = cmd->u.simple.channel;

        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "Invalid channel number (%d)\n", channel);
                return;
        }

        priv = dev->nets[channel];

        complete(&priv->stop_comp);
}

static void kvaser_usb_leaf_get_busparams_reply(const struct kvaser_usb *dev,
                                                const struct kvaser_cmd *cmd)
{
        struct kvaser_usb_net_priv *priv;
        u8 channel = cmd->u.busparams.channel;

        if (channel >= dev->nchannels) {
                dev_err(&dev->intf->dev,
                        "Invalid channel number (%d)\n", channel);
                return;
        }

        priv = dev->nets[channel];
        memcpy(&priv->busparams_nominal, &cmd->u.busparams.busparams,
               sizeof(priv->busparams_nominal));

        complete(&priv->get_busparams_comp);
}

static void kvaser_usb_leaf_handle_command(struct kvaser_usb *dev,
                                           const struct kvaser_cmd *cmd)
{
        if (kvaser_usb_leaf_verify_size(dev, cmd) < 0)
                return;

        switch (cmd->id) {
        case CMD_START_CHIP_REPLY:
                kvaser_usb_leaf_start_chip_reply(dev, cmd);
                break;

        case CMD_STOP_CHIP_REPLY:
                kvaser_usb_leaf_stop_chip_reply(dev, cmd);
                break;

        case CMD_RX_STD_MESSAGE:
        case CMD_RX_EXT_MESSAGE:
                kvaser_usb_leaf_rx_can_msg(dev, cmd);
                break;

        case CMD_LEAF_LOG_MESSAGE:
                if (dev->driver_info->family != KVASER_LEAF)
                        goto warn;
                kvaser_usb_leaf_rx_can_msg(dev, cmd);
                break;

        case CMD_CHIP_STATE_EVENT:
        case CMD_CAN_ERROR_EVENT:
                if (dev->driver_info->family == KVASER_LEAF)
                        kvaser_usb_leaf_leaf_rx_error(dev, cmd);
                else
                        kvaser_usb_leaf_usbcan_rx_error(dev, cmd);
                break;

        case CMD_TX_ACKNOWLEDGE:
                kvaser_usb_leaf_tx_acknowledge(dev, cmd);
                break;

        case CMD_ERROR_EVENT:
                kvaser_usb_leaf_error_event(dev, cmd);
                break;

        case CMD_GET_BUS_PARAMS_REPLY:
                kvaser_usb_leaf_get_busparams_reply(dev, cmd);
                break;

        case CMD_USBCAN_CLOCK_OVERFLOW_EVENT:
                if (dev->driver_info->family != KVASER_USBCAN)
                        goto warn;
                dev->card_data.usbcan_timestamp_msb =
                                        le32_to_cpu(cmd->u.usbcan.clk_overflow_event.time) &
                                        KVASER_USB_USBCAN_CLK_OVERFLOW_MASK;
                break;

        /* Ignored commands */
        case CMD_FLUSH_QUEUE_REPLY:
                if (dev->driver_info->family != KVASER_LEAF)
                        goto warn;
                break;
        case CMD_LED_ACTION_RESP:
                break;

        default:
warn:           dev_warn(&dev->intf->dev, "Unhandled command (%d)\n", cmd->id);
                break;
        }
}

static void kvaser_usb_leaf_read_bulk_callback(struct kvaser_usb *dev,
                                               void *buf, int len)
{
        struct kvaser_cmd *cmd;
        int pos = 0;

        while (pos <= len - CMD_HEADER_LEN) {
                cmd = buf + pos;

                /* The Kvaser firmware can only read and write commands that
                 * does not cross the USB's endpoint wMaxPacketSize boundary.
                 * If a follow-up command crosses such boundary, firmware puts
                 * a placeholder zero-length command in its place then aligns
                 * the real command to the next max packet size.
                 *
                 * Handle such cases or we're going to miss a significant
                 * number of events in case of a heavy rx load on the bus.
                 */
                if (cmd->len == 0) {
                        pos = round_up(pos + 1, le16_to_cpu
                                                (dev->bulk_in->wMaxPacketSize));
                        continue;
                }

                if (cmd->len < CMD_HEADER_LEN || cmd->len > len - pos) {
                        dev_err_ratelimited(&dev->intf->dev, "Format error\n");
                        break;
                }

                kvaser_usb_leaf_handle_command(dev, cmd);
                pos += cmd->len;
        }
}

static int kvaser_usb_leaf_set_opt_mode(const struct kvaser_usb_net_priv *priv)
{
        struct kvaser_cmd *cmd;
        int rc;

        cmd = kzalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = CMD_SET_CTRL_MODE;
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_ctrl_mode);
        cmd->u.ctrl_mode.tid = 0xff;
        cmd->u.ctrl_mode.channel = priv->channel;

        if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
                cmd->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_SILENT;
        else
                cmd->u.ctrl_mode.ctrl_mode = KVASER_CTRL_MODE_NORMAL;

        rc = kvaser_usb_send_cmd(priv->dev, cmd, cmd->len);

        kfree(cmd);
        return rc;
}

static int kvaser_usb_leaf_start_chip(struct kvaser_usb_net_priv *priv)
{
        struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
        int err;

        leaf->joining_bus = true;

        reinit_completion(&priv->start_comp);

        err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_START_CHIP,
                                              priv->channel);
        if (err)
                return err;

        if (!wait_for_completion_timeout(&priv->start_comp,
                                         msecs_to_jiffies(KVASER_USB_TIMEOUT)))
                return -ETIMEDOUT;

        return 0;
}

static int kvaser_usb_leaf_stop_chip(struct kvaser_usb_net_priv *priv)
{
        struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
        int err;

        reinit_completion(&priv->stop_comp);

        cancel_delayed_work(&leaf->chip_state_req_work);

        err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_STOP_CHIP,
                                              priv->channel);
        if (err)
                return err;

        if (!wait_for_completion_timeout(&priv->stop_comp,
                                         msecs_to_jiffies(KVASER_USB_TIMEOUT)))
                return -ETIMEDOUT;

        return 0;
}

static int kvaser_usb_leaf_reset_chip(struct kvaser_usb *dev, int channel)
{
        return kvaser_usb_leaf_send_simple_cmd(dev, CMD_RESET_CHIP, channel);
}

static int kvaser_usb_leaf_flush_queue(struct kvaser_usb_net_priv *priv)
{
        struct kvaser_cmd *cmd;
        int rc;

        cmd = kzalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = CMD_FLUSH_QUEUE;
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_flush_queue);
        cmd->u.flush_queue.channel = priv->channel;
        cmd->u.flush_queue.flags = 0x00;

        rc = kvaser_usb_send_cmd(priv->dev, cmd, cmd->len);

        kfree(cmd);
        return rc;
}

static int kvaser_usb_leaf_init_card(struct kvaser_usb *dev)
{
        struct kvaser_usb_dev_card_data *card_data = &dev->card_data;

        card_data->ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;

        return 0;
}

static int kvaser_usb_leaf_init_channel(struct kvaser_usb_net_priv *priv)
{
        struct kvaser_usb_net_leaf_priv *leaf;

        leaf = devm_kzalloc(&priv->dev->intf->dev, sizeof(*leaf), GFP_KERNEL);
        if (!leaf)
                return -ENOMEM;

        leaf->net = priv;
        INIT_DELAYED_WORK(&leaf->chip_state_req_work,
                          kvaser_usb_leaf_chip_state_req_work);

        priv->sub_priv = leaf;

        return 0;
}

static void kvaser_usb_leaf_remove_channel(struct kvaser_usb_net_priv *priv)
{
        struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;

        if (leaf)
                cancel_delayed_work_sync(&leaf->chip_state_req_work);
}

static int kvaser_usb_leaf_set_bittiming(const struct net_device *netdev,
                                         const struct kvaser_usb_busparams *busparams)
{
        struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
        struct kvaser_usb *dev = priv->dev;
        struct kvaser_cmd *cmd;
        int rc;

        cmd = kmalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        cmd->id = CMD_SET_BUS_PARAMS;
        cmd->len = CMD_HEADER_LEN + sizeof(struct kvaser_cmd_busparams);
        cmd->u.busparams.channel = priv->channel;
        cmd->u.busparams.tid = 0xff;
        memcpy(&cmd->u.busparams.busparams, busparams,
               sizeof(cmd->u.busparams.busparams));

        rc = kvaser_usb_send_cmd(dev, cmd, cmd->len);

        kfree(cmd);
        return rc;
}

static int kvaser_usb_leaf_get_busparams(struct kvaser_usb_net_priv *priv)
{
        int err;

        if (priv->dev->driver_info->family == KVASER_USBCAN)
                return -EOPNOTSUPP;

        reinit_completion(&priv->get_busparams_comp);

        err = kvaser_usb_leaf_send_simple_cmd(priv->dev, CMD_GET_BUS_PARAMS,
                                              priv->channel);
        if (err)
                return err;

        if (!wait_for_completion_timeout(&priv->get_busparams_comp,
                                         msecs_to_jiffies(KVASER_USB_TIMEOUT)))
                return -ETIMEDOUT;

        return 0;
}

static int kvaser_usb_leaf_set_mode(struct net_device *netdev,
                                    enum can_mode mode)
{
        struct kvaser_usb_net_priv *priv = netdev_priv(netdev);
        struct kvaser_usb_net_leaf_priv *leaf = priv->sub_priv;
        int err;

        switch (mode) {
        case CAN_MODE_START:
                kvaser_usb_unlink_tx_urbs(priv);

                leaf->joining_bus = true;

                err = kvaser_usb_leaf_simple_cmd_async(priv, CMD_START_CHIP);
                if (err)
                        return err;

                priv->can.state = CAN_STATE_ERROR_ACTIVE;
                break;
        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static int kvaser_usb_leaf_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 int kvaser_usb_leaf_setup_endpoints(struct kvaser_usb *dev)
{
        struct usb_host_interface *iface_desc;
        int ret;

        iface_desc = dev->intf->cur_altsetting;

        /* use first bulk endpoint for in and out */
        ret = usb_find_common_endpoints(iface_desc, &dev->bulk_in, &dev->bulk_out,
                                        NULL, NULL);
        if (ret)
                return -ENODEV;

        return 0;
}

const struct kvaser_usb_dev_ops kvaser_usb_leaf_dev_ops = {
        .dev_set_mode = kvaser_usb_leaf_set_mode,
        .dev_set_bittiming = kvaser_usb_leaf_set_bittiming,
        .dev_get_busparams = kvaser_usb_leaf_get_busparams,
        .dev_set_data_bittiming = NULL,
        .dev_get_data_busparams = NULL,
        .dev_get_berr_counter = kvaser_usb_leaf_get_berr_counter,
        .dev_setup_endpoints = kvaser_usb_leaf_setup_endpoints,
        .dev_init_card = kvaser_usb_leaf_init_card,
        .dev_init_channel = kvaser_usb_leaf_init_channel,
        .dev_remove_channel = kvaser_usb_leaf_remove_channel,
        .dev_get_software_info = kvaser_usb_leaf_get_software_info,
        .dev_get_software_details = NULL,
        .dev_get_card_info = kvaser_usb_leaf_get_card_info,
        .dev_get_capabilities = kvaser_usb_leaf_get_capabilities,
        .dev_set_led = kvaser_usb_leaf_set_led,
        .dev_set_opt_mode = kvaser_usb_leaf_set_opt_mode,
        .dev_start_chip = kvaser_usb_leaf_start_chip,
        .dev_stop_chip = kvaser_usb_leaf_stop_chip,
        .dev_reset_chip = kvaser_usb_leaf_reset_chip,
        .dev_flush_queue = kvaser_usb_leaf_flush_queue,
        .dev_read_bulk_callback = kvaser_usb_leaf_read_bulk_callback,
        .dev_frame_to_cmd = kvaser_usb_leaf_frame_to_cmd,
};