linux/drivers/net/can/usb/ucan.c
Marc Kleine-Budde 9420e1d495 can: dev: can_get_echo_skb(): extend to return can frame length
In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_get_echo_skb() to return
that value. Convert all users of this function, too.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-01-14 08:43:43 +01:00

1607 lines
41 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Driver for Theobroma Systems UCAN devices, Protocol Version 3
*
* Copyright (C) 2018 Theobroma Systems Design und Consulting GmbH
*
*
* General Description:
*
* The USB Device uses three Endpoints:
*
* CONTROL Endpoint: Is used the setup the device (start, stop,
* info, configure).
*
* IN Endpoint: The device sends CAN Frame Messages and Device
* Information using the IN endpoint.
*
* OUT Endpoint: The driver sends configuration requests, and CAN
* Frames on the out endpoint.
*
* Error Handling:
*
* If error reporting is turned on the device encodes error into CAN
* error frames (see uapi/linux/can/error.h) and sends it using the
* IN Endpoint. The driver updates statistics and forward it.
*/
#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/signal.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/usb.h>
#define UCAN_DRIVER_NAME "ucan"
#define UCAN_MAX_RX_URBS 8
/* the CAN controller needs a while to enable/disable the bus */
#define UCAN_USB_CTL_PIPE_TIMEOUT 1000
/* this driver currently supports protocol version 3 only */
#define UCAN_PROTOCOL_VERSION_MIN 3
#define UCAN_PROTOCOL_VERSION_MAX 3
/* UCAN Message Definitions
* ------------------------
*
* ucan_message_out_t and ucan_message_in_t define the messages
* transmitted on the OUT and IN endpoint.
*
* Multibyte fields are transmitted with little endianness
*
* INTR Endpoint: a single uint32_t storing the current space in the fifo
*
* OUT Endpoint: single message of type ucan_message_out_t is
* transmitted on the out endpoint
*
* IN Endpoint: multiple messages ucan_message_in_t concateted in
* the following way:
*
* m[n].len <=> the length if message n(including the header in bytes)
* m[n] is is aligned to a 4 byte boundary, hence
* offset(m[0]) := 0;
* offset(m[n+1]) := offset(m[n]) + (m[n].len + 3) & 3
*
* this implies that
* offset(m[n]) % 4 <=> 0
*/
/* Device Global Commands */
enum {
UCAN_DEVICE_GET_FW_STRING = 0,
};
/* UCAN Commands */
enum {
/* start the can transceiver - val defines the operation mode */
UCAN_COMMAND_START = 0,
/* cancel pending transmissions and stop the can transceiver */
UCAN_COMMAND_STOP = 1,
/* send can transceiver into low-power sleep mode */
UCAN_COMMAND_SLEEP = 2,
/* wake up can transceiver from low-power sleep mode */
UCAN_COMMAND_WAKEUP = 3,
/* reset the can transceiver */
UCAN_COMMAND_RESET = 4,
/* get piece of info from the can transceiver - subcmd defines what
* piece
*/
UCAN_COMMAND_GET = 5,
/* clear or disable hardware filter - subcmd defines which of the two */
UCAN_COMMAND_FILTER = 6,
/* Setup bittiming */
UCAN_COMMAND_SET_BITTIMING = 7,
/* recover from bus-off state */
UCAN_COMMAND_RESTART = 8,
};
/* UCAN_COMMAND_START and UCAN_COMMAND_GET_INFO operation modes (bitmap).
* Undefined bits must be set to 0.
*/
enum {
UCAN_MODE_LOOPBACK = BIT(0),
UCAN_MODE_SILENT = BIT(1),
UCAN_MODE_3_SAMPLES = BIT(2),
UCAN_MODE_ONE_SHOT = BIT(3),
UCAN_MODE_BERR_REPORT = BIT(4),
};
/* UCAN_COMMAND_GET subcommands */
enum {
UCAN_COMMAND_GET_INFO = 0,
UCAN_COMMAND_GET_PROTOCOL_VERSION = 1,
};
/* UCAN_COMMAND_FILTER subcommands */
enum {
UCAN_FILTER_CLEAR = 0,
UCAN_FILTER_DISABLE = 1,
UCAN_FILTER_ENABLE = 2,
};
/* OUT endpoint message types */
enum {
UCAN_OUT_TX = 2, /* transmit a CAN frame */
};
/* IN endpoint message types */
enum {
UCAN_IN_TX_COMPLETE = 1, /* CAN frame transmission completed */
UCAN_IN_RX = 2, /* CAN frame received */
};
struct ucan_ctl_cmd_start {
__le16 mode; /* OR-ing any of UCAN_MODE_* */
} __packed;
struct ucan_ctl_cmd_set_bittiming {
__le32 tq; /* Time quanta (TQ) in nanoseconds */
__le16 brp; /* TQ Prescaler */
__le16 sample_point; /* Samplepoint on tenth percent */
u8 prop_seg; /* Propagation segment in TQs */
u8 phase_seg1; /* Phase buffer segment 1 in TQs */
u8 phase_seg2; /* Phase buffer segment 2 in TQs */
u8 sjw; /* Synchronisation jump width in TQs */
} __packed;
struct ucan_ctl_cmd_device_info {
__le32 freq; /* Clock Frequency for tq generation */
u8 tx_fifo; /* Size of the transmission fifo */
u8 sjw_max; /* can_bittiming fields... */
u8 tseg1_min;
u8 tseg1_max;
u8 tseg2_min;
u8 tseg2_max;
__le16 brp_inc;
__le32 brp_min;
__le32 brp_max; /* ...can_bittiming fields */
__le16 ctrlmodes; /* supported control modes */
__le16 hwfilter; /* Number of HW filter banks */
__le16 rxmboxes; /* Number of receive Mailboxes */
} __packed;
struct ucan_ctl_cmd_get_protocol_version {
__le32 version;
} __packed;
union ucan_ctl_payload {
/* Setup Bittiming
* bmRequest == UCAN_COMMAND_START
*/
struct ucan_ctl_cmd_start cmd_start;
/* Setup Bittiming
* bmRequest == UCAN_COMMAND_SET_BITTIMING
*/
struct ucan_ctl_cmd_set_bittiming cmd_set_bittiming;
/* Get Device Information
* bmRequest == UCAN_COMMAND_GET; wValue = UCAN_COMMAND_GET_INFO
*/
struct ucan_ctl_cmd_device_info cmd_get_device_info;
/* Get Protocol Version
* bmRequest == UCAN_COMMAND_GET;
* wValue = UCAN_COMMAND_GET_PROTOCOL_VERSION
*/
struct ucan_ctl_cmd_get_protocol_version cmd_get_protocol_version;
u8 raw[128];
} __packed;
enum {
UCAN_TX_COMPLETE_SUCCESS = BIT(0),
};
/* Transmission Complete within ucan_message_in */
struct ucan_tx_complete_entry_t {
u8 echo_index;
u8 flags;
} __packed __aligned(0x2);
/* CAN Data message format within ucan_message_in/out */
struct ucan_can_msg {
/* note DLC is computed by
* msg.len - sizeof (msg.len)
* - sizeof (msg.type)
* - sizeof (msg.can_msg.id)
*/
__le32 id;
union {
u8 data[CAN_MAX_DLEN]; /* Data of CAN frames */
u8 dlc; /* RTR dlc */
};
} __packed;
/* OUT Endpoint, outbound messages */
struct ucan_message_out {
__le16 len; /* Length of the content include header */
u8 type; /* UCAN_OUT_TX and friends */
u8 subtype; /* command sub type */
union {
/* Transmit CAN frame
* (type == UCAN_TX) && ((msg.can_msg.id & CAN_RTR_FLAG) == 0)
* subtype stores the echo id
*/
struct ucan_can_msg can_msg;
} msg;
} __packed __aligned(0x4);
/* IN Endpoint, inbound messages */
struct ucan_message_in {
__le16 len; /* Length of the content include header */
u8 type; /* UCAN_IN_RX and friends */
u8 subtype; /* command sub type */
union {
/* CAN Frame received
* (type == UCAN_IN_RX)
* && ((msg.can_msg.id & CAN_RTR_FLAG) == 0)
*/
struct ucan_can_msg can_msg;
/* CAN transmission complete
* (type == UCAN_IN_TX_COMPLETE)
*/
struct ucan_tx_complete_entry_t can_tx_complete_msg[0];
} __aligned(0x4) msg;
} __packed;
/* Macros to calculate message lengths */
#define UCAN_OUT_HDR_SIZE offsetof(struct ucan_message_out, msg)
#define UCAN_IN_HDR_SIZE offsetof(struct ucan_message_in, msg)
#define UCAN_IN_LEN(member) (UCAN_OUT_HDR_SIZE + sizeof(member))
struct ucan_priv;
/* Context Information for transmission URBs */
struct ucan_urb_context {
struct ucan_priv *up;
u8 dlc;
bool allocated;
};
/* Information reported by the USB device */
struct ucan_device_info {
struct can_bittiming_const bittiming_const;
u8 tx_fifo;
};
/* Driver private data */
struct ucan_priv {
/* must be the first member */
struct can_priv can;
/* linux USB device structures */
struct usb_device *udev;
struct usb_interface *intf;
struct net_device *netdev;
/* lock for can->echo_skb (used around
* can_put/get/free_echo_skb
*/
spinlock_t echo_skb_lock;
/* usb device information information */
u8 intf_index;
u8 in_ep_addr;
u8 out_ep_addr;
u16 in_ep_size;
/* transmission and reception buffers */
struct usb_anchor rx_urbs;
struct usb_anchor tx_urbs;
union ucan_ctl_payload *ctl_msg_buffer;
struct ucan_device_info device_info;
/* transmission control information and locks */
spinlock_t context_lock;
unsigned int available_tx_urbs;
struct ucan_urb_context *context_array;
};
static u8 ucan_can_cc_dlc2len(struct ucan_can_msg *msg, u16 len)
{
if (le32_to_cpu(msg->id) & CAN_RTR_FLAG)
return can_cc_dlc2len(msg->dlc);
else
return can_cc_dlc2len(len - (UCAN_IN_HDR_SIZE + sizeof(msg->id)));
}
static void ucan_release_context_array(struct ucan_priv *up)
{
if (!up->context_array)
return;
/* lock is not needed because, driver is currently opening or closing */
up->available_tx_urbs = 0;
kfree(up->context_array);
up->context_array = NULL;
}
static int ucan_alloc_context_array(struct ucan_priv *up)
{
int i;
/* release contexts if any */
ucan_release_context_array(up);
up->context_array = kcalloc(up->device_info.tx_fifo,
sizeof(*up->context_array),
GFP_KERNEL);
if (!up->context_array) {
netdev_err(up->netdev,
"Not enough memory to allocate tx contexts\n");
return -ENOMEM;
}
for (i = 0; i < up->device_info.tx_fifo; i++) {
up->context_array[i].allocated = false;
up->context_array[i].up = up;
}
/* lock is not needed because, driver is currently opening */
up->available_tx_urbs = up->device_info.tx_fifo;
return 0;
}
static struct ucan_urb_context *ucan_alloc_context(struct ucan_priv *up)
{
int i;
unsigned long flags;
struct ucan_urb_context *ret = NULL;
if (WARN_ON_ONCE(!up->context_array))
return NULL;
/* execute context operation atomically */
spin_lock_irqsave(&up->context_lock, flags);
for (i = 0; i < up->device_info.tx_fifo; i++) {
if (!up->context_array[i].allocated) {
/* update context */
ret = &up->context_array[i];
up->context_array[i].allocated = true;
/* stop queue if necessary */
up->available_tx_urbs--;
if (!up->available_tx_urbs)
netif_stop_queue(up->netdev);
break;
}
}
spin_unlock_irqrestore(&up->context_lock, flags);
return ret;
}
static bool ucan_release_context(struct ucan_priv *up,
struct ucan_urb_context *ctx)
{
unsigned long flags;
bool ret = false;
if (WARN_ON_ONCE(!up->context_array))
return false;
/* execute context operation atomically */
spin_lock_irqsave(&up->context_lock, flags);
/* context was not allocated, maybe the device sent garbage */
if (ctx->allocated) {
ctx->allocated = false;
/* check if the queue needs to be woken */
if (!up->available_tx_urbs)
netif_wake_queue(up->netdev);
up->available_tx_urbs++;
ret = true;
}
spin_unlock_irqrestore(&up->context_lock, flags);
return ret;
}
static int ucan_ctrl_command_out(struct ucan_priv *up,
u8 cmd, u16 subcmd, u16 datalen)
{
return usb_control_msg(up->udev,
usb_sndctrlpipe(up->udev, 0),
cmd,
USB_DIR_OUT | USB_TYPE_VENDOR |
USB_RECIP_INTERFACE,
subcmd,
up->intf_index,
up->ctl_msg_buffer,
datalen,
UCAN_USB_CTL_PIPE_TIMEOUT);
}
static int ucan_device_request_in(struct ucan_priv *up,
u8 cmd, u16 subcmd, u16 datalen)
{
return usb_control_msg(up->udev,
usb_rcvctrlpipe(up->udev, 0),
cmd,
USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
subcmd,
0,
up->ctl_msg_buffer,
datalen,
UCAN_USB_CTL_PIPE_TIMEOUT);
}
/* Parse the device information structure reported by the device and
* setup private variables accordingly
*/
static void ucan_parse_device_info(struct ucan_priv *up,
struct ucan_ctl_cmd_device_info *device_info)
{
struct can_bittiming_const *bittiming =
&up->device_info.bittiming_const;
u16 ctrlmodes;
/* store the data */
up->can.clock.freq = le32_to_cpu(device_info->freq);
up->device_info.tx_fifo = device_info->tx_fifo;
strcpy(bittiming->name, "ucan");
bittiming->tseg1_min = device_info->tseg1_min;
bittiming->tseg1_max = device_info->tseg1_max;
bittiming->tseg2_min = device_info->tseg2_min;
bittiming->tseg2_max = device_info->tseg2_max;
bittiming->sjw_max = device_info->sjw_max;
bittiming->brp_min = le32_to_cpu(device_info->brp_min);
bittiming->brp_max = le32_to_cpu(device_info->brp_max);
bittiming->brp_inc = le16_to_cpu(device_info->brp_inc);
ctrlmodes = le16_to_cpu(device_info->ctrlmodes);
up->can.ctrlmode_supported = 0;
if (ctrlmodes & UCAN_MODE_LOOPBACK)
up->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
if (ctrlmodes & UCAN_MODE_SILENT)
up->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
if (ctrlmodes & UCAN_MODE_3_SAMPLES)
up->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
if (ctrlmodes & UCAN_MODE_ONE_SHOT)
up->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
if (ctrlmodes & UCAN_MODE_BERR_REPORT)
up->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
}
/* Handle a CAN error frame that we have received from the device.
* Returns true if the can state has changed.
*/
static bool ucan_handle_error_frame(struct ucan_priv *up,
struct ucan_message_in *m,
canid_t canid)
{
enum can_state new_state = up->can.state;
struct net_device_stats *net_stats = &up->netdev->stats;
struct can_device_stats *can_stats = &up->can.can_stats;
if (canid & CAN_ERR_LOSTARB)
can_stats->arbitration_lost++;
if (canid & CAN_ERR_BUSERROR)
can_stats->bus_error++;
if (canid & CAN_ERR_ACK)
net_stats->tx_errors++;
if (canid & CAN_ERR_BUSOFF)
new_state = CAN_STATE_BUS_OFF;
/* controller problems, details in data[1] */
if (canid & CAN_ERR_CRTL) {
u8 d1 = m->msg.can_msg.data[1];
if (d1 & CAN_ERR_CRTL_RX_OVERFLOW)
net_stats->rx_over_errors++;
/* controller state bits: if multiple are set the worst wins */
if (d1 & CAN_ERR_CRTL_ACTIVE)
new_state = CAN_STATE_ERROR_ACTIVE;
if (d1 & (CAN_ERR_CRTL_RX_WARNING | CAN_ERR_CRTL_TX_WARNING))
new_state = CAN_STATE_ERROR_WARNING;
if (d1 & (CAN_ERR_CRTL_RX_PASSIVE | CAN_ERR_CRTL_TX_PASSIVE))
new_state = CAN_STATE_ERROR_PASSIVE;
}
/* protocol error, details in data[2] */
if (canid & CAN_ERR_PROT) {
u8 d2 = m->msg.can_msg.data[2];
if (d2 & CAN_ERR_PROT_TX)
net_stats->tx_errors++;
else
net_stats->rx_errors++;
}
/* no state change - we are done */
if (up->can.state == new_state)
return false;
/* we switched into a better state */
if (up->can.state > new_state) {
up->can.state = new_state;
return true;
}
/* we switched into a worse state */
up->can.state = new_state;
switch (new_state) {
case CAN_STATE_BUS_OFF:
can_stats->bus_off++;
can_bus_off(up->netdev);
break;
case CAN_STATE_ERROR_PASSIVE:
can_stats->error_passive++;
break;
case CAN_STATE_ERROR_WARNING:
can_stats->error_warning++;
break;
default:
break;
}
return true;
}
/* Callback on reception of a can frame via the IN endpoint
*
* This function allocates an skb and transferres it to the Linux
* network stack
*/
static void ucan_rx_can_msg(struct ucan_priv *up, struct ucan_message_in *m)
{
int len;
canid_t canid;
struct can_frame *cf;
struct sk_buff *skb;
struct net_device_stats *stats = &up->netdev->stats;
/* get the contents of the length field */
len = le16_to_cpu(m->len);
/* check sanity */
if (len < UCAN_IN_HDR_SIZE + sizeof(m->msg.can_msg.id)) {
netdev_warn(up->netdev, "invalid input message len: %d\n", len);
return;
}
/* handle error frames */
canid = le32_to_cpu(m->msg.can_msg.id);
if (canid & CAN_ERR_FLAG) {
bool busstate_changed = ucan_handle_error_frame(up, m, canid);
/* if berr-reporting is off only state changes get through */
if (!(up->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
!busstate_changed)
return;
} else {
canid_t canid_mask;
/* compute the mask for canid */
canid_mask = CAN_RTR_FLAG;
if (canid & CAN_EFF_FLAG)
canid_mask |= CAN_EFF_MASK | CAN_EFF_FLAG;
else
canid_mask |= CAN_SFF_MASK;
if (canid & ~canid_mask)
netdev_warn(up->netdev,
"unexpected bits set (canid %x, mask %x)",
canid, canid_mask);
canid &= canid_mask;
}
/* allocate skb */
skb = alloc_can_skb(up->netdev, &cf);
if (!skb)
return;
/* fill the can frame */
cf->can_id = canid;
/* compute DLC taking RTR_FLAG into account */
cf->len = ucan_can_cc_dlc2len(&m->msg.can_msg, len);
/* copy the payload of non RTR frames */
if (!(cf->can_id & CAN_RTR_FLAG) || (cf->can_id & CAN_ERR_FLAG))
memcpy(cf->data, m->msg.can_msg.data, cf->len);
/* don't count error frames as real packets */
stats->rx_packets++;
stats->rx_bytes += cf->len;
/* pass it to Linux */
netif_rx(skb);
}
/* callback indicating completed transmission */
static void ucan_tx_complete_msg(struct ucan_priv *up,
struct ucan_message_in *m)
{
unsigned long flags;
u16 count, i;
u8 echo_index, dlc;
u16 len = le16_to_cpu(m->len);
struct ucan_urb_context *context;
if (len < UCAN_IN_HDR_SIZE || (len % 2 != 0)) {
netdev_err(up->netdev, "invalid tx complete length\n");
return;
}
count = (len - UCAN_IN_HDR_SIZE) / 2;
for (i = 0; i < count; i++) {
/* we did not submit such echo ids */
echo_index = m->msg.can_tx_complete_msg[i].echo_index;
if (echo_index >= up->device_info.tx_fifo) {
up->netdev->stats.tx_errors++;
netdev_err(up->netdev,
"invalid echo_index %d received\n",
echo_index);
continue;
}
/* gather information from the context */
context = &up->context_array[echo_index];
dlc = READ_ONCE(context->dlc);
/* Release context and restart queue if necessary.
* Also check if the context was allocated
*/
if (!ucan_release_context(up, context))
continue;
spin_lock_irqsave(&up->echo_skb_lock, flags);
if (m->msg.can_tx_complete_msg[i].flags &
UCAN_TX_COMPLETE_SUCCESS) {
/* update statistics */
up->netdev->stats.tx_packets++;
up->netdev->stats.tx_bytes += dlc;
can_get_echo_skb(up->netdev, echo_index, NULL);
} else {
up->netdev->stats.tx_dropped++;
can_free_echo_skb(up->netdev, echo_index);
}
spin_unlock_irqrestore(&up->echo_skb_lock, flags);
}
}
/* callback on reception of a USB message */
static void ucan_read_bulk_callback(struct urb *urb)
{
int ret;
int pos;
struct ucan_priv *up = urb->context;
struct net_device *netdev = up->netdev;
struct ucan_message_in *m;
/* the device is not up and the driver should not receive any
* data on the bulk in pipe
*/
if (WARN_ON(!up->context_array)) {
usb_free_coherent(up->udev,
up->in_ep_size,
urb->transfer_buffer,
urb->transfer_dma);
return;
}
/* check URB status */
switch (urb->status) {
case 0:
break;
case -ENOENT:
case -EPIPE:
case -EPROTO:
case -ESHUTDOWN:
case -ETIME:
/* urb is not resubmitted -> free dma data */
usb_free_coherent(up->udev,
up->in_ep_size,
urb->transfer_buffer,
urb->transfer_dma);
netdev_dbg(up->netdev, "not resubmitting urb; status: %d\n",
urb->status);
return;
default:
goto resubmit;
}
/* sanity check */
if (!netif_device_present(netdev))
return;
/* iterate over input */
pos = 0;
while (pos < urb->actual_length) {
int len;
/* check sanity (length of header) */
if ((urb->actual_length - pos) < UCAN_IN_HDR_SIZE) {
netdev_warn(up->netdev,
"invalid message (short; no hdr; l:%d)\n",
urb->actual_length);
goto resubmit;
}
/* setup the message address */
m = (struct ucan_message_in *)
((u8 *)urb->transfer_buffer + pos);
len = le16_to_cpu(m->len);
/* check sanity (length of content) */
if (urb->actual_length - pos < len) {
netdev_warn(up->netdev,
"invalid message (short; no data; l:%d)\n",
urb->actual_length);
print_hex_dump(KERN_WARNING,
"raw data: ",
DUMP_PREFIX_ADDRESS,
16,
1,
urb->transfer_buffer,
urb->actual_length,
true);
goto resubmit;
}
switch (m->type) {
case UCAN_IN_RX:
ucan_rx_can_msg(up, m);
break;
case UCAN_IN_TX_COMPLETE:
ucan_tx_complete_msg(up, m);
break;
default:
netdev_warn(up->netdev,
"invalid message (type; t:%d)\n",
m->type);
break;
}
/* proceed to next message */
pos += len;
/* align to 4 byte boundary */
pos = round_up(pos, 4);
}
resubmit:
/* resubmit urb when done */
usb_fill_bulk_urb(urb, up->udev,
usb_rcvbulkpipe(up->udev,
up->in_ep_addr),
urb->transfer_buffer,
up->in_ep_size,
ucan_read_bulk_callback,
up);
usb_anchor_urb(urb, &up->rx_urbs);
ret = usb_submit_urb(urb, GFP_ATOMIC);
if (ret < 0) {
netdev_err(up->netdev,
"failed resubmitting read bulk urb: %d\n",
ret);
usb_unanchor_urb(urb);
usb_free_coherent(up->udev,
up->in_ep_size,
urb->transfer_buffer,
urb->transfer_dma);
if (ret == -ENODEV)
netif_device_detach(netdev);
}
}
/* callback after transmission of a USB message */
static void ucan_write_bulk_callback(struct urb *urb)
{
unsigned long flags;
struct ucan_priv *up;
struct ucan_urb_context *context = urb->context;
/* get the urb context */
if (WARN_ON_ONCE(!context))
return;
/* free up our allocated buffer */
usb_free_coherent(urb->dev,
sizeof(struct ucan_message_out),
urb->transfer_buffer,
urb->transfer_dma);
up = context->up;
if (WARN_ON_ONCE(!up))
return;
/* sanity check */
if (!netif_device_present(up->netdev))
return;
/* transmission failed (USB - the device will not send a TX complete) */
if (urb->status) {
netdev_warn(up->netdev,
"failed to transmit USB message to device: %d\n",
urb->status);
/* update counters an cleanup */
spin_lock_irqsave(&up->echo_skb_lock, flags);
can_free_echo_skb(up->netdev, context - up->context_array);
spin_unlock_irqrestore(&up->echo_skb_lock, flags);
up->netdev->stats.tx_dropped++;
/* release context and restart the queue if necessary */
if (!ucan_release_context(up, context))
netdev_err(up->netdev,
"urb failed, failed to release context\n");
}
}
static void ucan_cleanup_rx_urbs(struct ucan_priv *up, struct urb **urbs)
{
int i;
for (i = 0; i < UCAN_MAX_RX_URBS; i++) {
if (urbs[i]) {
usb_unanchor_urb(urbs[i]);
usb_free_coherent(up->udev,
up->in_ep_size,
urbs[i]->transfer_buffer,
urbs[i]->transfer_dma);
usb_free_urb(urbs[i]);
}
}
memset(urbs, 0, sizeof(*urbs) * UCAN_MAX_RX_URBS);
}
static int ucan_prepare_and_anchor_rx_urbs(struct ucan_priv *up,
struct urb **urbs)
{
int i;
memset(urbs, 0, sizeof(*urbs) * UCAN_MAX_RX_URBS);
for (i = 0; i < UCAN_MAX_RX_URBS; i++) {
void *buf;
urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
if (!urbs[i])
goto err;
buf = usb_alloc_coherent(up->udev,
up->in_ep_size,
GFP_KERNEL, &urbs[i]->transfer_dma);
if (!buf) {
/* cleanup this urb */
usb_free_urb(urbs[i]);
urbs[i] = NULL;
goto err;
}
usb_fill_bulk_urb(urbs[i], up->udev,
usb_rcvbulkpipe(up->udev,
up->in_ep_addr),
buf,
up->in_ep_size,
ucan_read_bulk_callback,
up);
urbs[i]->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
usb_anchor_urb(urbs[i], &up->rx_urbs);
}
return 0;
err:
/* cleanup other unsubmitted urbs */
ucan_cleanup_rx_urbs(up, urbs);
return -ENOMEM;
}
/* Submits rx urbs with the semantic: Either submit all, or cleanup
* everything. I case of errors submitted urbs are killed and all urbs in
* the array are freed. I case of no errors every entry in the urb
* array is set to NULL.
*/
static int ucan_submit_rx_urbs(struct ucan_priv *up, struct urb **urbs)
{
int i, ret;
/* Iterate over all urbs to submit. On success remove the urb
* from the list.
*/
for (i = 0; i < UCAN_MAX_RX_URBS; i++) {
ret = usb_submit_urb(urbs[i], GFP_KERNEL);
if (ret) {
netdev_err(up->netdev,
"could not submit urb; code: %d\n",
ret);
goto err;
}
/* Anchor URB and drop reference, USB core will take
* care of freeing it
*/
usb_free_urb(urbs[i]);
urbs[i] = NULL;
}
return 0;
err:
/* Cleanup unsubmitted urbs */
ucan_cleanup_rx_urbs(up, urbs);
/* Kill urbs that are already submitted */
usb_kill_anchored_urbs(&up->rx_urbs);
return ret;
}
/* Open the network device */
static int ucan_open(struct net_device *netdev)
{
int ret, ret_cleanup;
u16 ctrlmode;
struct urb *urbs[UCAN_MAX_RX_URBS];
struct ucan_priv *up = netdev_priv(netdev);
ret = ucan_alloc_context_array(up);
if (ret)
return ret;
/* Allocate and prepare IN URBS - allocated and anchored
* urbs are stored in urbs[] for clean
*/
ret = ucan_prepare_and_anchor_rx_urbs(up, urbs);
if (ret)
goto err_contexts;
/* Check the control mode */
ctrlmode = 0;
if (up->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
ctrlmode |= UCAN_MODE_LOOPBACK;
if (up->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
ctrlmode |= UCAN_MODE_SILENT;
if (up->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
ctrlmode |= UCAN_MODE_3_SAMPLES;
if (up->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
ctrlmode |= UCAN_MODE_ONE_SHOT;
/* Enable this in any case - filtering is down within the
* receive path
*/
ctrlmode |= UCAN_MODE_BERR_REPORT;
up->ctl_msg_buffer->cmd_start.mode = cpu_to_le16(ctrlmode);
/* Driver is ready to receive data - start the USB device */
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_START, 0, 2);
if (ret < 0) {
netdev_err(up->netdev,
"could not start device, code: %d\n",
ret);
goto err_reset;
}
/* Call CAN layer open */
ret = open_candev(netdev);
if (ret)
goto err_stop;
/* Driver is ready to receive data. Submit RX URBS */
ret = ucan_submit_rx_urbs(up, urbs);
if (ret)
goto err_stop;
up->can.state = CAN_STATE_ERROR_ACTIVE;
/* Start the network queue */
netif_start_queue(netdev);
return 0;
err_stop:
/* The device have started already stop it */
ret_cleanup = ucan_ctrl_command_out(up, UCAN_COMMAND_STOP, 0, 0);
if (ret_cleanup < 0)
netdev_err(up->netdev,
"could not stop device, code: %d\n",
ret_cleanup);
err_reset:
/* The device might have received data, reset it for
* consistent state
*/
ret_cleanup = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0);
if (ret_cleanup < 0)
netdev_err(up->netdev,
"could not reset device, code: %d\n",
ret_cleanup);
/* clean up unsubmitted urbs */
ucan_cleanup_rx_urbs(up, urbs);
err_contexts:
ucan_release_context_array(up);
return ret;
}
static struct urb *ucan_prepare_tx_urb(struct ucan_priv *up,
struct ucan_urb_context *context,
struct can_frame *cf,
u8 echo_index)
{
int mlen;
struct urb *urb;
struct ucan_message_out *m;
/* create a URB, and a buffer for it, and copy the data to the URB */
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
netdev_err(up->netdev, "no memory left for URBs\n");
return NULL;
}
m = usb_alloc_coherent(up->udev,
sizeof(struct ucan_message_out),
GFP_ATOMIC,
&urb->transfer_dma);
if (!m) {
netdev_err(up->netdev, "no memory left for USB buffer\n");
usb_free_urb(urb);
return NULL;
}
/* build the USB message */
m->type = UCAN_OUT_TX;
m->msg.can_msg.id = cpu_to_le32(cf->can_id);
if (cf->can_id & CAN_RTR_FLAG) {
mlen = UCAN_OUT_HDR_SIZE +
offsetof(struct ucan_can_msg, dlc) +
sizeof(m->msg.can_msg.dlc);
m->msg.can_msg.dlc = cf->len;
} else {
mlen = UCAN_OUT_HDR_SIZE +
sizeof(m->msg.can_msg.id) + cf->len;
memcpy(m->msg.can_msg.data, cf->data, cf->len);
}
m->len = cpu_to_le16(mlen);
context->dlc = cf->len;
m->subtype = echo_index;
/* build the urb */
usb_fill_bulk_urb(urb, up->udev,
usb_sndbulkpipe(up->udev,
up->out_ep_addr),
m, mlen, ucan_write_bulk_callback, context);
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
return urb;
}
static void ucan_clean_up_tx_urb(struct ucan_priv *up, struct urb *urb)
{
usb_free_coherent(up->udev, sizeof(struct ucan_message_out),
urb->transfer_buffer, urb->transfer_dma);
usb_free_urb(urb);
}
/* callback when Linux needs to send a can frame */
static netdev_tx_t ucan_start_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
unsigned long flags;
int ret;
u8 echo_index;
struct urb *urb;
struct ucan_urb_context *context;
struct ucan_priv *up = netdev_priv(netdev);
struct can_frame *cf = (struct can_frame *)skb->data;
/* check skb */
if (can_dropped_invalid_skb(netdev, skb))
return NETDEV_TX_OK;
/* allocate a context and slow down tx path, if fifo state is low */
context = ucan_alloc_context(up);
echo_index = context - up->context_array;
if (WARN_ON_ONCE(!context))
return NETDEV_TX_BUSY;
/* prepare urb for transmission */
urb = ucan_prepare_tx_urb(up, context, cf, echo_index);
if (!urb)
goto drop;
/* put the skb on can loopback stack */
spin_lock_irqsave(&up->echo_skb_lock, flags);
can_put_echo_skb(skb, up->netdev, echo_index, 0);
spin_unlock_irqrestore(&up->echo_skb_lock, flags);
/* transmit it */
usb_anchor_urb(urb, &up->tx_urbs);
ret = usb_submit_urb(urb, GFP_ATOMIC);
/* cleanup urb */
if (ret) {
/* on error, clean up */
usb_unanchor_urb(urb);
ucan_clean_up_tx_urb(up, urb);
if (!ucan_release_context(up, context))
netdev_err(up->netdev,
"xmit err: failed to release context\n");
/* remove the skb from the echo stack - this also
* frees the skb
*/
spin_lock_irqsave(&up->echo_skb_lock, flags);
can_free_echo_skb(up->netdev, echo_index);
spin_unlock_irqrestore(&up->echo_skb_lock, flags);
if (ret == -ENODEV) {
netif_device_detach(up->netdev);
} else {
netdev_warn(up->netdev,
"xmit err: failed to submit urb %d\n",
ret);
up->netdev->stats.tx_dropped++;
}
return NETDEV_TX_OK;
}
netif_trans_update(netdev);
/* release ref, as we do not need the urb anymore */
usb_free_urb(urb);
return NETDEV_TX_OK;
drop:
if (!ucan_release_context(up, context))
netdev_err(up->netdev,
"xmit drop: failed to release context\n");
dev_kfree_skb(skb);
up->netdev->stats.tx_dropped++;
return NETDEV_TX_OK;
}
/* Device goes down
*
* Clean up used resources
*/
static int ucan_close(struct net_device *netdev)
{
int ret;
struct ucan_priv *up = netdev_priv(netdev);
up->can.state = CAN_STATE_STOPPED;
/* stop sending data */
usb_kill_anchored_urbs(&up->tx_urbs);
/* stop receiving data */
usb_kill_anchored_urbs(&up->rx_urbs);
/* stop and reset can device */
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_STOP, 0, 0);
if (ret < 0)
netdev_err(up->netdev,
"could not stop device, code: %d\n",
ret);
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0);
if (ret < 0)
netdev_err(up->netdev,
"could not reset device, code: %d\n",
ret);
netif_stop_queue(netdev);
ucan_release_context_array(up);
close_candev(up->netdev);
return 0;
}
/* CAN driver callbacks */
static const struct net_device_ops ucan_netdev_ops = {
.ndo_open = ucan_open,
.ndo_stop = ucan_close,
.ndo_start_xmit = ucan_start_xmit,
.ndo_change_mtu = can_change_mtu,
};
/* Request to set bittiming
*
* This function generates an USB set bittiming message and transmits
* it to the device
*/
static int ucan_set_bittiming(struct net_device *netdev)
{
int ret;
struct ucan_priv *up = netdev_priv(netdev);
struct ucan_ctl_cmd_set_bittiming *cmd_set_bittiming;
cmd_set_bittiming = &up->ctl_msg_buffer->cmd_set_bittiming;
cmd_set_bittiming->tq = cpu_to_le32(up->can.bittiming.tq);
cmd_set_bittiming->brp = cpu_to_le16(up->can.bittiming.brp);
cmd_set_bittiming->sample_point =
cpu_to_le16(up->can.bittiming.sample_point);
cmd_set_bittiming->prop_seg = up->can.bittiming.prop_seg;
cmd_set_bittiming->phase_seg1 = up->can.bittiming.phase_seg1;
cmd_set_bittiming->phase_seg2 = up->can.bittiming.phase_seg2;
cmd_set_bittiming->sjw = up->can.bittiming.sjw;
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_SET_BITTIMING, 0,
sizeof(*cmd_set_bittiming));
return (ret < 0) ? ret : 0;
}
/* Restart the device to get it out of BUS-OFF state.
* Called when the user runs "ip link set can1 type can restart".
*/
static int ucan_set_mode(struct net_device *netdev, enum can_mode mode)
{
int ret;
unsigned long flags;
struct ucan_priv *up = netdev_priv(netdev);
switch (mode) {
case CAN_MODE_START:
netdev_dbg(up->netdev, "restarting device\n");
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESTART, 0, 0);
up->can.state = CAN_STATE_ERROR_ACTIVE;
/* check if queue can be restarted,
* up->available_tx_urbs must be protected by the
* lock
*/
spin_lock_irqsave(&up->context_lock, flags);
if (up->available_tx_urbs > 0)
netif_wake_queue(up->netdev);
spin_unlock_irqrestore(&up->context_lock, flags);
return ret;
default:
return -EOPNOTSUPP;
}
}
/* Probe the device, reset it and gather general device information */
static int ucan_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
int ret;
int i;
u32 protocol_version;
struct usb_device *udev;
struct net_device *netdev;
struct usb_host_interface *iface_desc;
struct ucan_priv *up;
struct usb_endpoint_descriptor *ep;
u16 in_ep_size;
u16 out_ep_size;
u8 in_ep_addr;
u8 out_ep_addr;
union ucan_ctl_payload *ctl_msg_buffer;
char firmware_str[sizeof(union ucan_ctl_payload) + 1];
udev = interface_to_usbdev(intf);
/* Stage 1 - Interface Parsing
* ---------------------------
*
* Identifie the device USB interface descriptor and its
* endpoints. Probing is aborted on errors.
*/
/* check if the interface is sane */
iface_desc = intf->cur_altsetting;
if (!iface_desc)
return -ENODEV;
dev_info(&udev->dev,
"%s: probing device on interface #%d\n",
UCAN_DRIVER_NAME,
iface_desc->desc.bInterfaceNumber);
/* interface sanity check */
if (iface_desc->desc.bNumEndpoints != 2) {
dev_err(&udev->dev,
"%s: invalid EP count (%d)",
UCAN_DRIVER_NAME, iface_desc->desc.bNumEndpoints);
goto err_firmware_needs_update;
}
/* check interface endpoints */
in_ep_addr = 0;
out_ep_addr = 0;
in_ep_size = 0;
out_ep_size = 0;
for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
ep = &iface_desc->endpoint[i].desc;
if (((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) != 0) &&
((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
USB_ENDPOINT_XFER_BULK)) {
/* In Endpoint */
in_ep_addr = ep->bEndpointAddress;
in_ep_addr &= USB_ENDPOINT_NUMBER_MASK;
in_ep_size = le16_to_cpu(ep->wMaxPacketSize);
} else if (((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) ==
0) &&
((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
USB_ENDPOINT_XFER_BULK)) {
/* Out Endpoint */
out_ep_addr = ep->bEndpointAddress;
out_ep_addr &= USB_ENDPOINT_NUMBER_MASK;
out_ep_size = le16_to_cpu(ep->wMaxPacketSize);
}
}
/* check if interface is sane */
if (!in_ep_addr || !out_ep_addr) {
dev_err(&udev->dev, "%s: invalid endpoint configuration\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
if (in_ep_size < sizeof(struct ucan_message_in)) {
dev_err(&udev->dev, "%s: invalid in_ep MaxPacketSize\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
if (out_ep_size < sizeof(struct ucan_message_out)) {
dev_err(&udev->dev, "%s: invalid out_ep MaxPacketSize\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
/* Stage 2 - Device Identification
* -------------------------------
*
* The device interface seems to be a ucan device. Do further
* compatibility checks. On error probing is aborted, on
* success this stage leaves the ctl_msg_buffer with the
* reported contents of a GET_INFO command (supported
* bittimings, tx_fifo depth). This information is used in
* Stage 3 for the final driver initialisation.
*/
/* Prepare Memory for control transferes */
ctl_msg_buffer = devm_kzalloc(&udev->dev,
sizeof(union ucan_ctl_payload),
GFP_KERNEL);
if (!ctl_msg_buffer) {
dev_err(&udev->dev,
"%s: failed to allocate control pipe memory\n",
UCAN_DRIVER_NAME);
return -ENOMEM;
}
/* get protocol version
*
* note: ucan_ctrl_command_* wrappers cannot be used yet
* because `up` is initialised in Stage 3
*/
ret = usb_control_msg(udev,
usb_rcvctrlpipe(udev, 0),
UCAN_COMMAND_GET,
USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_INTERFACE,
UCAN_COMMAND_GET_PROTOCOL_VERSION,
iface_desc->desc.bInterfaceNumber,
ctl_msg_buffer,
sizeof(union ucan_ctl_payload),
UCAN_USB_CTL_PIPE_TIMEOUT);
/* older firmware version do not support this command - those
* are not supported by this drive
*/
if (ret != 4) {
dev_err(&udev->dev,
"%s: could not read protocol version, ret=%d\n",
UCAN_DRIVER_NAME, ret);
if (ret >= 0)
ret = -EINVAL;
goto err_firmware_needs_update;
}
/* this driver currently supports protocol version 3 only */
protocol_version =
le32_to_cpu(ctl_msg_buffer->cmd_get_protocol_version.version);
if (protocol_version < UCAN_PROTOCOL_VERSION_MIN ||
protocol_version > UCAN_PROTOCOL_VERSION_MAX) {
dev_err(&udev->dev,
"%s: device protocol version %d is not supported\n",
UCAN_DRIVER_NAME, protocol_version);
goto err_firmware_needs_update;
}
/* request the device information and store it in ctl_msg_buffer
*
* note: ucan_ctrl_command_* wrappers cannot be used yet
* because `up` is initialised in Stage 3
*/
ret = usb_control_msg(udev,
usb_rcvctrlpipe(udev, 0),
UCAN_COMMAND_GET,
USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_INTERFACE,
UCAN_COMMAND_GET_INFO,
iface_desc->desc.bInterfaceNumber,
ctl_msg_buffer,
sizeof(ctl_msg_buffer->cmd_get_device_info),
UCAN_USB_CTL_PIPE_TIMEOUT);
if (ret < 0) {
dev_err(&udev->dev, "%s: failed to retrieve device info\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
if (ret < sizeof(ctl_msg_buffer->cmd_get_device_info)) {
dev_err(&udev->dev, "%s: device reported invalid device info\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
if (ctl_msg_buffer->cmd_get_device_info.tx_fifo == 0) {
dev_err(&udev->dev,
"%s: device reported invalid tx-fifo size\n",
UCAN_DRIVER_NAME);
goto err_firmware_needs_update;
}
/* Stage 3 - Driver Initialisation
* -------------------------------
*
* Register device to Linux, prepare private structures and
* reset the device.
*/
/* allocate driver resources */
netdev = alloc_candev(sizeof(struct ucan_priv),
ctl_msg_buffer->cmd_get_device_info.tx_fifo);
if (!netdev) {
dev_err(&udev->dev,
"%s: cannot allocate candev\n", UCAN_DRIVER_NAME);
return -ENOMEM;
}
up = netdev_priv(netdev);
/* initialize data */
up->udev = udev;
up->intf = intf;
up->netdev = netdev;
up->intf_index = iface_desc->desc.bInterfaceNumber;
up->in_ep_addr = in_ep_addr;
up->out_ep_addr = out_ep_addr;
up->in_ep_size = in_ep_size;
up->ctl_msg_buffer = ctl_msg_buffer;
up->context_array = NULL;
up->available_tx_urbs = 0;
up->can.state = CAN_STATE_STOPPED;
up->can.bittiming_const = &up->device_info.bittiming_const;
up->can.do_set_bittiming = ucan_set_bittiming;
up->can.do_set_mode = &ucan_set_mode;
spin_lock_init(&up->context_lock);
spin_lock_init(&up->echo_skb_lock);
netdev->netdev_ops = &ucan_netdev_ops;
usb_set_intfdata(intf, up);
SET_NETDEV_DEV(netdev, &intf->dev);
/* parse device information
* the data retrieved in Stage 2 is still available in
* up->ctl_msg_buffer
*/
ucan_parse_device_info(up, &ctl_msg_buffer->cmd_get_device_info);
/* just print some device information - if available */
ret = ucan_device_request_in(up, UCAN_DEVICE_GET_FW_STRING, 0,
sizeof(union ucan_ctl_payload));
if (ret > 0) {
/* copy string while ensuring zero terminiation */
strncpy(firmware_str, up->ctl_msg_buffer->raw,
sizeof(union ucan_ctl_payload));
firmware_str[sizeof(union ucan_ctl_payload)] = '\0';
} else {
strcpy(firmware_str, "unknown");
}
/* device is compatible, reset it */
ret = ucan_ctrl_command_out(up, UCAN_COMMAND_RESET, 0, 0);
if (ret < 0)
goto err_free_candev;
init_usb_anchor(&up->rx_urbs);
init_usb_anchor(&up->tx_urbs);
up->can.state = CAN_STATE_STOPPED;
/* register the device */
ret = register_candev(netdev);
if (ret)
goto err_free_candev;
/* initialisation complete, log device info */
netdev_info(up->netdev, "registered device\n");
netdev_info(up->netdev, "firmware string: %s\n", firmware_str);
/* success */
return 0;
err_free_candev:
free_candev(netdev);
return ret;
err_firmware_needs_update:
dev_err(&udev->dev,
"%s: probe failed; try to update the device firmware\n",
UCAN_DRIVER_NAME);
return -ENODEV;
}
/* disconnect the device */
static void ucan_disconnect(struct usb_interface *intf)
{
struct ucan_priv *up = usb_get_intfdata(intf);
usb_set_intfdata(intf, NULL);
if (up) {
unregister_netdev(up->netdev);
free_candev(up->netdev);
}
}
static struct usb_device_id ucan_table[] = {
/* Mule (soldered onto compute modules) */
{USB_DEVICE_INTERFACE_NUMBER(0x2294, 0x425a, 0)},
/* Seal (standalone USB stick) */
{USB_DEVICE_INTERFACE_NUMBER(0x2294, 0x425b, 0)},
{} /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, ucan_table);
/* driver callbacks */
static struct usb_driver ucan_driver = {
.name = UCAN_DRIVER_NAME,
.probe = ucan_probe,
.disconnect = ucan_disconnect,
.id_table = ucan_table,
};
module_usb_driver(ucan_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Martin Elshuber <martin.elshuber@theobroma-systems.com>");
MODULE_AUTHOR("Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>");
MODULE_DESCRIPTION("Driver for Theobroma Systems UCAN devices");