Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1470 insertions, 0 deletions

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
new file mode 100644
index 000000000..264a0f764
--- /dev/null
+++ b/drivers/net/can/usb/gs_usb.c
@@ -0,0 +1,1470 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* CAN driver for Geschwister Schneider USB/CAN devices
+ * and bytewerk.org candleLight USB CAN interfaces.
+ *
+ * Copyright (C) 2013-2016 Geschwister Schneider Technologie-,
+ * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
+ * Copyright (C) 2016 Hubert Denkmair
+ *
+ * Many thanks to all socketcan devs!
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clocksource.h>
+#include <linux/ethtool.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/signal.h>
+#include <linux/timecounter.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>
+
+/* Device specific constants */
+#define USB_GS_USB_1_VENDOR_ID 0x1d50
+#define USB_GS_USB_1_PRODUCT_ID 0x606f
+
+#define USB_CANDLELIGHT_VENDOR_ID 0x1209
+#define USB_CANDLELIGHT_PRODUCT_ID 0x2323
+
+#define USB_CES_CANEXT_FD_VENDOR_ID 0x1cd2
+#define USB_CES_CANEXT_FD_PRODUCT_ID 0x606f
+
+#define USB_ABE_CANDEBUGGER_FD_VENDOR_ID 0x16d0
+#define USB_ABE_CANDEBUGGER_FD_PRODUCT_ID 0x10b8
+
+#define GS_USB_ENDPOINT_IN 1
+#define GS_USB_ENDPOINT_OUT 2
+
+/* Timestamp 32 bit timer runs at 1 MHz (1 µs tick). Worker accounts
+ * for timer overflow (will be after ~71 minutes)
+ */
+#define GS_USB_TIMESTAMP_TIMER_HZ (1 * HZ_PER_MHZ)
+#define GS_USB_TIMESTAMP_WORK_DELAY_SEC 1800
+static_assert(GS_USB_TIMESTAMP_WORK_DELAY_SEC <
+	      CYCLECOUNTER_MASK(32) / GS_USB_TIMESTAMP_TIMER_HZ / 2);
+
+/* Device specific constants */
+enum gs_usb_breq {
+	GS_USB_BREQ_HOST_FORMAT = 0,
+	GS_USB_BREQ_BITTIMING,
+	GS_USB_BREQ_MODE,
+	GS_USB_BREQ_BERR,
+	GS_USB_BREQ_BT_CONST,
+	GS_USB_BREQ_DEVICE_CONFIG,
+	GS_USB_BREQ_TIMESTAMP,
+	GS_USB_BREQ_IDENTIFY,
+	GS_USB_BREQ_GET_USER_ID,
+	GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING = GS_USB_BREQ_GET_USER_ID,
+	GS_USB_BREQ_SET_USER_ID,
+	GS_USB_BREQ_DATA_BITTIMING,
+	GS_USB_BREQ_BT_CONST_EXT,
+	GS_USB_BREQ_SET_TERMINATION,
+	GS_USB_BREQ_GET_TERMINATION,
+};
+
+enum gs_can_mode {
+	/* reset a channel. turns it off */
+	GS_CAN_MODE_RESET = 0,
+	/* starts a channel */
+	GS_CAN_MODE_START
+};
+
+enum gs_can_state {
+	GS_CAN_STATE_ERROR_ACTIVE = 0,
+	GS_CAN_STATE_ERROR_WARNING,
+	GS_CAN_STATE_ERROR_PASSIVE,
+	GS_CAN_STATE_BUS_OFF,
+	GS_CAN_STATE_STOPPED,
+	GS_CAN_STATE_SLEEPING
+};
+
+enum gs_can_identify_mode {
+	GS_CAN_IDENTIFY_OFF = 0,
+	GS_CAN_IDENTIFY_ON
+};
+
+enum gs_can_termination_state {
+	GS_CAN_TERMINATION_STATE_OFF = 0,
+	GS_CAN_TERMINATION_STATE_ON
+};
+
+#define GS_USB_TERMINATION_DISABLED CAN_TERMINATION_DISABLED
+#define GS_USB_TERMINATION_ENABLED 120
+
+/* data types passed between host and device */
+
+/* The firmware on the original USB2CAN by Geschwister Schneider
+ * Technologie Entwicklungs- und Vertriebs UG exchanges all data
+ * between the host and the device in host byte order. This is done
+ * with the struct gs_host_config::byte_order member, which is sent
+ * first to indicate the desired byte order.
+ *
+ * The widely used open source firmware candleLight doesn't support
+ * this feature and exchanges the data in little endian byte order.
+ */
+struct gs_host_config {
+	__le32 byte_order;
+} __packed;
+
+struct gs_device_config {
+	u8 reserved1;
+	u8 reserved2;
+	u8 reserved3;
+	u8 icount;
+	__le32 sw_version;
+	__le32 hw_version;
+} __packed;
+
+#define GS_CAN_MODE_NORMAL 0
+#define GS_CAN_MODE_LISTEN_ONLY BIT(0)
+#define GS_CAN_MODE_LOOP_BACK BIT(1)
+#define GS_CAN_MODE_TRIPLE_SAMPLE BIT(2)
+#define GS_CAN_MODE_ONE_SHOT BIT(3)
+#define GS_CAN_MODE_HW_TIMESTAMP BIT(4)
+/* GS_CAN_FEATURE_IDENTIFY BIT(5) */
+/* GS_CAN_FEATURE_USER_ID BIT(6) */
+#define GS_CAN_MODE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
+#define GS_CAN_MODE_FD BIT(8)
+/* GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9) */
+/* GS_CAN_FEATURE_BT_CONST_EXT BIT(10) */
+/* GS_CAN_FEATURE_TERMINATION BIT(11) */
+
+struct gs_device_mode {
+	__le32 mode;
+	__le32 flags;
+} __packed;
+
+struct gs_device_state {
+	__le32 state;
+	__le32 rxerr;
+	__le32 txerr;
+} __packed;
+
+struct gs_device_bittiming {
+	__le32 prop_seg;
+	__le32 phase_seg1;
+	__le32 phase_seg2;
+	__le32 sjw;
+	__le32 brp;
+} __packed;
+
+struct gs_identify_mode {
+	__le32 mode;
+} __packed;
+
+struct gs_device_termination_state {
+	__le32 state;
+} __packed;
+
+#define GS_CAN_FEATURE_LISTEN_ONLY BIT(0)
+#define GS_CAN_FEATURE_LOOP_BACK BIT(1)
+#define GS_CAN_FEATURE_TRIPLE_SAMPLE BIT(2)
+#define GS_CAN_FEATURE_ONE_SHOT BIT(3)
+#define GS_CAN_FEATURE_HW_TIMESTAMP BIT(4)
+#define GS_CAN_FEATURE_IDENTIFY BIT(5)
+#define GS_CAN_FEATURE_USER_ID BIT(6)
+#define GS_CAN_FEATURE_PAD_PKTS_TO_MAX_PKT_SIZE BIT(7)
+#define GS_CAN_FEATURE_FD BIT(8)
+#define GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX BIT(9)
+#define GS_CAN_FEATURE_BT_CONST_EXT BIT(10)
+#define GS_CAN_FEATURE_TERMINATION BIT(11)
+#define GS_CAN_FEATURE_MASK GENMASK(11, 0)
+
+/* internal quirks - keep in GS_CAN_FEATURE space for now */
+
+/* CANtact Pro original firmware:
+ * BREQ DATA_BITTIMING overlaps with GET_USER_ID
+ */
+#define GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO BIT(31)
+
+struct gs_device_bt_const {
+	__le32 feature;
+	__le32 fclk_can;
+	__le32 tseg1_min;
+	__le32 tseg1_max;
+	__le32 tseg2_min;
+	__le32 tseg2_max;
+	__le32 sjw_max;
+	__le32 brp_min;
+	__le32 brp_max;
+	__le32 brp_inc;
+} __packed;
+
+struct gs_device_bt_const_extended {
+	__le32 feature;
+	__le32 fclk_can;
+	__le32 tseg1_min;
+	__le32 tseg1_max;
+	__le32 tseg2_min;
+	__le32 tseg2_max;
+	__le32 sjw_max;
+	__le32 brp_min;
+	__le32 brp_max;
+	__le32 brp_inc;
+
+	__le32 dtseg1_min;
+	__le32 dtseg1_max;
+	__le32 dtseg2_min;
+	__le32 dtseg2_max;
+	__le32 dsjw_max;
+	__le32 dbrp_min;
+	__le32 dbrp_max;
+	__le32 dbrp_inc;
+} __packed;
+
+#define GS_CAN_FLAG_OVERFLOW BIT(0)
+#define GS_CAN_FLAG_FD BIT(1)
+#define GS_CAN_FLAG_BRS BIT(2)
+#define GS_CAN_FLAG_ESI BIT(3)
+
+struct classic_can {
+	u8 data[8];
+} __packed;
+
+struct classic_can_ts {
+	u8 data[8];
+	__le32 timestamp_us;
+} __packed;
+
+struct classic_can_quirk {
+	u8 data[8];
+	u8 quirk;
+} __packed;
+
+struct canfd {
+	u8 data[64];
+} __packed;
+
+struct canfd_ts {
+	u8 data[64];
+	__le32 timestamp_us;
+} __packed;
+
+struct canfd_quirk {
+	u8 data[64];
+	u8 quirk;
+} __packed;
+
+struct gs_host_frame {
+	u32 echo_id;
+	__le32 can_id;
+
+	u8 can_dlc;
+	u8 channel;
+	u8 flags;
+	u8 reserved;
+
+	union {
+		DECLARE_FLEX_ARRAY(struct classic_can, classic_can);
+		DECLARE_FLEX_ARRAY(struct classic_can_ts, classic_can_ts);
+		DECLARE_FLEX_ARRAY(struct classic_can_quirk, classic_can_quirk);
+		DECLARE_FLEX_ARRAY(struct canfd, canfd);
+		DECLARE_FLEX_ARRAY(struct canfd_ts, canfd_ts);
+		DECLARE_FLEX_ARRAY(struct canfd_quirk, canfd_quirk);
+	};
+} __packed;
+/* The GS USB devices make use of the same flags and masks as in
+ * linux/can.h and linux/can/error.h, and no additional mapping is necessary.
+ */
+
+/* Only send a max of GS_MAX_TX_URBS frames per channel at a time. */
+#define GS_MAX_TX_URBS 10
+/* Only launch a max of GS_MAX_RX_URBS usb requests at a time. */
+#define GS_MAX_RX_URBS 30
+/* Maximum number of interfaces the driver supports per device.
+ * Current hardware only supports 3 interfaces. The future may vary.
+ */
+#define GS_MAX_INTF 3
+
+struct gs_tx_context {
+	struct gs_can *dev;
+	unsigned int echo_id;
+};
+
+struct gs_can {
+	struct can_priv can; /* must be the first member */
+
+	struct gs_usb *parent;
+
+	struct net_device *netdev;
+	struct usb_device *udev;
+	struct usb_interface *iface;
+
+	struct can_bittiming_const bt_const, data_bt_const;
+	unsigned int channel;	/* channel number */
+
+	/* time counter for hardware timestamps */
+	struct cyclecounter cc;
+	struct timecounter tc;
+	spinlock_t tc_lock; /* spinlock to guard access tc->cycle_last */
+	struct delayed_work timestamp;
+
+	u32 feature;
+	unsigned int hf_size_tx;
+
+	/* This lock prevents a race condition between xmit and receive. */
+	spinlock_t tx_ctx_lock;
+	struct gs_tx_context tx_context[GS_MAX_TX_URBS];
+
+	struct usb_anchor tx_submitted;
+	atomic_t active_tx_urbs;
+};
+
+/* usb interface struct */
+struct gs_usb {
+	struct gs_can *canch[GS_MAX_INTF];
+	struct usb_anchor rx_submitted;
+	struct usb_device *udev;
+	unsigned int hf_size_rx;
+	u8 active_channels;
+};
+
+/* 'allocate' a tx context.
+ * returns a valid tx context or NULL if there is no space.
+ */
+static struct gs_tx_context *gs_alloc_tx_context(struct gs_can *dev)
+{
+	int i = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->tx_ctx_lock, flags);
+
+	for (; i < GS_MAX_TX_URBS; i++) {
+		if (dev->tx_context[i].echo_id == GS_MAX_TX_URBS) {
+			dev->tx_context[i].echo_id = i;
+			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+			return &dev->tx_context[i];
+		}
+	}
+
+	spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+	return NULL;
+}
+
+/* releases a tx context
+ */
+static void gs_free_tx_context(struct gs_tx_context *txc)
+{
+	txc->echo_id = GS_MAX_TX_URBS;
+}
+
+/* Get a tx context by id.
+ */
+static struct gs_tx_context *gs_get_tx_context(struct gs_can *dev,
+					       unsigned int id)
+{
+	unsigned long flags;
+
+	if (id < GS_MAX_TX_URBS) {
+		spin_lock_irqsave(&dev->tx_ctx_lock, flags);
+		if (dev->tx_context[id].echo_id == id) {
+			spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+			return &dev->tx_context[id];
+		}
+		spin_unlock_irqrestore(&dev->tx_ctx_lock, flags);
+	}
+	return NULL;
+}
+
+static int gs_cmd_reset(struct gs_can *dev)
+{
+	struct gs_device_mode dm = {
+		.mode = GS_CAN_MODE_RESET,
+	};
+
+	return usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				    GS_USB_BREQ_MODE,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				    dev->channel, 0, &dm, sizeof(dm), 1000,
+				    GFP_KERNEL);
+}
+
+static inline int gs_usb_get_timestamp(const struct gs_can *dev,
+				       u32 *timestamp_p)
+{
+	__le32 timestamp;
+	int rc;
+
+	rc = usb_control_msg_recv(interface_to_usbdev(dev->iface), 0,
+				  GS_USB_BREQ_TIMESTAMP,
+				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  dev->channel, 0,
+				  &timestamp, sizeof(timestamp),
+				  USB_CTRL_GET_TIMEOUT,
+				  GFP_KERNEL);
+	if (rc)
+		return rc;
+
+	*timestamp_p = le32_to_cpu(timestamp);
+
+	return 0;
+}
+
+static u64 gs_usb_timestamp_read(const struct cyclecounter *cc) __must_hold(&dev->tc_lock)
+{
+	struct gs_can *dev = container_of(cc, struct gs_can, cc);
+	u32 timestamp = 0;
+	int err;
+
+	lockdep_assert_held(&dev->tc_lock);
+
+	/* drop lock for synchronous USB transfer */
+	spin_unlock_bh(&dev->tc_lock);
+	err = gs_usb_get_timestamp(dev, &timestamp);
+	spin_lock_bh(&dev->tc_lock);
+	if (err)
+		netdev_err(dev->netdev,
+			   "Error %d while reading timestamp. HW timestamps may be inaccurate.",
+			   err);
+
+	return timestamp;
+}
+
+static void gs_usb_timestamp_work(struct work_struct *work)
+{
+	struct delayed_work *delayed_work = to_delayed_work(work);
+	struct gs_can *dev;
+
+	dev = container_of(delayed_work, struct gs_can, timestamp);
+	spin_lock_bh(&dev->tc_lock);
+	timecounter_read(&dev->tc);
+	spin_unlock_bh(&dev->tc_lock);
+
+	schedule_delayed_work(&dev->timestamp,
+			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
+}
+
+static void gs_usb_skb_set_timestamp(struct gs_can *dev,
+				     struct sk_buff *skb, u32 timestamp)
+{
+	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
+	u64 ns;
+
+	spin_lock_bh(&dev->tc_lock);
+	ns = timecounter_cyc2time(&dev->tc, timestamp);
+	spin_unlock_bh(&dev->tc_lock);
+
+	hwtstamps->hwtstamp = ns_to_ktime(ns);
+}
+
+static void gs_usb_timestamp_init(struct gs_can *dev)
+{
+	struct cyclecounter *cc = &dev->cc;
+
+	cc->read = gs_usb_timestamp_read;
+	cc->mask = CYCLECOUNTER_MASK(32);
+	cc->shift = 32 - bits_per(NSEC_PER_SEC / GS_USB_TIMESTAMP_TIMER_HZ);
+	cc->mult = clocksource_hz2mult(GS_USB_TIMESTAMP_TIMER_HZ, cc->shift);
+
+	spin_lock_init(&dev->tc_lock);
+	spin_lock_bh(&dev->tc_lock);
+	timecounter_init(&dev->tc, &dev->cc, ktime_get_real_ns());
+	spin_unlock_bh(&dev->tc_lock);
+
+	INIT_DELAYED_WORK(&dev->timestamp, gs_usb_timestamp_work);
+	schedule_delayed_work(&dev->timestamp,
+			      GS_USB_TIMESTAMP_WORK_DELAY_SEC * HZ);
+}
+
+static void gs_usb_timestamp_stop(struct gs_can *dev)
+{
+	cancel_delayed_work_sync(&dev->timestamp);
+}
+
+static void gs_update_state(struct gs_can *dev, struct can_frame *cf)
+{
+	struct can_device_stats *can_stats = &dev->can.can_stats;
+
+	if (cf->can_id & CAN_ERR_RESTARTED) {
+		dev->can.state = CAN_STATE_ERROR_ACTIVE;
+		can_stats->restarts++;
+	} else if (cf->can_id & CAN_ERR_BUSOFF) {
+		dev->can.state = CAN_STATE_BUS_OFF;
+		can_stats->bus_off++;
+	} else if (cf->can_id & CAN_ERR_CRTL) {
+		if ((cf->data[1] & CAN_ERR_CRTL_TX_WARNING) ||
+		    (cf->data[1] & CAN_ERR_CRTL_RX_WARNING)) {
+			dev->can.state = CAN_STATE_ERROR_WARNING;
+			can_stats->error_warning++;
+		} else if ((cf->data[1] & CAN_ERR_CRTL_TX_PASSIVE) ||
+			   (cf->data[1] & CAN_ERR_CRTL_RX_PASSIVE)) {
+			dev->can.state = CAN_STATE_ERROR_PASSIVE;
+			can_stats->error_passive++;
+		} else {
+			dev->can.state = CAN_STATE_ERROR_ACTIVE;
+		}
+	}
+}
+
+static void gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb,
+				 const struct gs_host_frame *hf)
+{
+	u32 timestamp;
+
+	if (!(dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP))
+		return;
+
+	if (hf->flags & GS_CAN_FLAG_FD)
+		timestamp = le32_to_cpu(hf->canfd_ts->timestamp_us);
+	else
+		timestamp = le32_to_cpu(hf->classic_can_ts->timestamp_us);
+
+	gs_usb_skb_set_timestamp(dev, skb, timestamp);
+
+	return;
+}
+
+static void gs_usb_receive_bulk_callback(struct urb *urb)
+{
+	struct gs_usb *usbcan = urb->context;
+	struct gs_can *dev;
+	struct net_device *netdev;
+	int rc;
+	struct net_device_stats *stats;
+	struct gs_host_frame *hf = urb->transfer_buffer;
+	struct gs_tx_context *txc;
+	struct can_frame *cf;
+	struct canfd_frame *cfd;
+	struct sk_buff *skb;
+
+	BUG_ON(!usbcan);
+
+	switch (urb->status) {
+	case 0: /* success */
+		break;
+	case -ENOENT:
+	case -ESHUTDOWN:
+		return;
+	default:
+		/* do not resubmit aborted urbs. eg: when device goes down */
+		return;
+	}
+
+	/* device reports out of range channel id */
+	if (hf->channel >= GS_MAX_INTF)
+		goto device_detach;
+
+	dev = usbcan->canch[hf->channel];
+
+	netdev = dev->netdev;
+	stats = &netdev->stats;
+
+	if (!netif_device_present(netdev))
+		return;
+
+	if (hf->echo_id == -1) { /* normal rx */
+		if (hf->flags & GS_CAN_FLAG_FD) {
+			skb = alloc_canfd_skb(dev->netdev, &cfd);
+			if (!skb)
+				return;
+
+			cfd->can_id = le32_to_cpu(hf->can_id);
+			cfd->len = can_fd_dlc2len(hf->can_dlc);
+			if (hf->flags & GS_CAN_FLAG_BRS)
+				cfd->flags |= CANFD_BRS;
+			if (hf->flags & GS_CAN_FLAG_ESI)
+				cfd->flags |= CANFD_ESI;
+
+			memcpy(cfd->data, hf->canfd->data, cfd->len);
+		} else {
+			skb = alloc_can_skb(dev->netdev, &cf);
+			if (!skb)
+				return;
+
+			cf->can_id = le32_to_cpu(hf->can_id);
+			can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode);
+
+			memcpy(cf->data, hf->classic_can->data, 8);
+
+			/* ERROR frames tell us information about the controller */
+			if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG)
+				gs_update_state(dev, cf);
+		}
+
+		gs_usb_set_timestamp(dev, skb, hf);
+
+		netdev->stats.rx_packets++;
+		netdev->stats.rx_bytes += hf->can_dlc;
+
+		netif_rx(skb);
+	} else { /* echo_id == hf->echo_id */
+		if (hf->echo_id >= GS_MAX_TX_URBS) {
+			netdev_err(netdev,
+				   "Unexpected out of range echo id %u\n",
+				   hf->echo_id);
+			goto resubmit_urb;
+		}
+
+		txc = gs_get_tx_context(dev, hf->echo_id);
+
+		/* bad devices send bad echo_ids. */
+		if (!txc) {
+			netdev_err(netdev,
+				   "Unexpected unused echo id %u\n",
+				   hf->echo_id);
+			goto resubmit_urb;
+		}
+
+		skb = dev->can.echo_skb[hf->echo_id];
+		gs_usb_set_timestamp(dev, skb, hf);
+
+		netdev->stats.tx_packets++;
+		netdev->stats.tx_bytes += can_get_echo_skb(netdev, hf->echo_id,
+							   NULL);
+
+		gs_free_tx_context(txc);
+
+		atomic_dec(&dev->active_tx_urbs);
+
+		netif_wake_queue(netdev);
+	}
+
+	if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
+		stats->rx_over_errors++;
+		stats->rx_errors++;
+
+		skb = alloc_can_err_skb(netdev, &cf);
+		if (!skb)
+			goto resubmit_urb;
+
+		cf->can_id |= CAN_ERR_CRTL;
+		cf->len = CAN_ERR_DLC;
+		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+		netif_rx(skb);
+	}
+
+ resubmit_urb:
+	usb_fill_bulk_urb(urb, usbcan->udev,
+			  usb_rcvbulkpipe(usbcan->udev, GS_USB_ENDPOINT_IN),
+			  hf, dev->parent->hf_size_rx,
+			  gs_usb_receive_bulk_callback, usbcan);
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+
+	/* USB failure take down all interfaces */
+	if (rc == -ENODEV) {
+ device_detach:
+		for (rc = 0; rc < GS_MAX_INTF; rc++) {
+			if (usbcan->canch[rc])
+				netif_device_detach(usbcan->canch[rc]->netdev);
+		}
+	}
+}
+
+static int gs_usb_set_bittiming(struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct can_bittiming *bt = &dev->can.bittiming;
+	struct gs_device_bittiming dbt = {
+		.prop_seg = cpu_to_le32(bt->prop_seg),
+		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
+		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
+		.sjw = cpu_to_le32(bt->sjw),
+		.brp = cpu_to_le32(bt->brp),
+	};
+
+	/* request bit timings */
+	return usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				    GS_USB_BREQ_BITTIMING,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
+				    GFP_KERNEL);
+}
+
+static int gs_usb_set_data_bittiming(struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct can_bittiming *bt = &dev->can.data_bittiming;
+	struct gs_device_bittiming dbt = {
+		.prop_seg = cpu_to_le32(bt->prop_seg),
+		.phase_seg1 = cpu_to_le32(bt->phase_seg1),
+		.phase_seg2 = cpu_to_le32(bt->phase_seg2),
+		.sjw = cpu_to_le32(bt->sjw),
+		.brp = cpu_to_le32(bt->brp),
+	};
+	u8 request = GS_USB_BREQ_DATA_BITTIMING;
+
+	if (dev->feature & GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO)
+		request = GS_USB_BREQ_QUIRK_CANTACT_PRO_DATA_BITTIMING;
+
+	/* request data bit timings */
+	return usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				    request,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				    dev->channel, 0, &dbt, sizeof(dbt), 1000,
+				    GFP_KERNEL);
+}
+
+static void gs_usb_xmit_callback(struct urb *urb)
+{
+	struct gs_tx_context *txc = urb->context;
+	struct gs_can *dev = txc->dev;
+	struct net_device *netdev = dev->netdev;
+
+	if (urb->status)
+		netdev_info(netdev, "usb xmit fail %u\n", txc->echo_id);
+}
+
+static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
+				     struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct net_device_stats *stats = &dev->netdev->stats;
+	struct urb *urb;
+	struct gs_host_frame *hf;
+	struct can_frame *cf;
+	struct canfd_frame *cfd;
+	int rc;
+	unsigned int idx;
+	struct gs_tx_context *txc;
+
+	if (can_dev_dropped_skb(netdev, skb))
+		return NETDEV_TX_OK;
+
+	/* find an empty context to keep track of transmission */
+	txc = gs_alloc_tx_context(dev);
+	if (!txc)
+		return NETDEV_TX_BUSY;
+
+	/* create a URB, and a buffer for it */
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb)
+		goto nomem_urb;
+
+	hf = kmalloc(dev->hf_size_tx, GFP_ATOMIC);
+	if (!hf) {
+		netdev_err(netdev, "No memory left for USB buffer\n");
+		goto nomem_hf;
+	}
+
+	idx = txc->echo_id;
+
+	if (idx >= GS_MAX_TX_URBS) {
+		netdev_err(netdev, "Invalid tx context %u\n", idx);
+		goto badidx;
+	}
+
+	hf->echo_id = idx;
+	hf->channel = dev->channel;
+	hf->flags = 0;
+	hf->reserved = 0;
+
+	if (can_is_canfd_skb(skb)) {
+		cfd = (struct canfd_frame *)skb->data;
+
+		hf->can_id = cpu_to_le32(cfd->can_id);
+		hf->can_dlc = can_fd_len2dlc(cfd->len);
+		hf->flags |= GS_CAN_FLAG_FD;
+		if (cfd->flags & CANFD_BRS)
+			hf->flags |= GS_CAN_FLAG_BRS;
+		if (cfd->flags & CANFD_ESI)
+			hf->flags |= GS_CAN_FLAG_ESI;
+
+		memcpy(hf->canfd->data, cfd->data, cfd->len);
+	} else {
+		cf = (struct can_frame *)skb->data;
+
+		hf->can_id = cpu_to_le32(cf->can_id);
+		hf->can_dlc = can_get_cc_dlc(cf, dev->can.ctrlmode);
+
+		memcpy(hf->classic_can->data, cf->data, cf->len);
+	}
+
+	usb_fill_bulk_urb(urb, dev->udev,
+			  usb_sndbulkpipe(dev->udev, GS_USB_ENDPOINT_OUT),
+			  hf, dev->hf_size_tx,
+			  gs_usb_xmit_callback, txc);
+
+	urb->transfer_flags |= URB_FREE_BUFFER;
+	usb_anchor_urb(urb, &dev->tx_submitted);
+
+	can_put_echo_skb(skb, netdev, idx, 0);
+
+	atomic_inc(&dev->active_tx_urbs);
+
+	rc = usb_submit_urb(urb, GFP_ATOMIC);
+	if (unlikely(rc)) {			/* usb send failed */
+		atomic_dec(&dev->active_tx_urbs);
+
+		can_free_echo_skb(netdev, idx, NULL);
+		gs_free_tx_context(txc);
+
+		usb_unanchor_urb(urb);
+
+		if (rc == -ENODEV) {
+			netif_device_detach(netdev);
+		} else {
+			netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
+			stats->tx_dropped++;
+		}
+	} else {
+		/* Slow down tx path */
+		if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
+			netif_stop_queue(netdev);
+	}
+
+	/* let usb core take care of this urb */
+	usb_free_urb(urb);
+
+	return NETDEV_TX_OK;
+
+ badidx:
+	kfree(hf);
+ nomem_hf:
+	usb_free_urb(urb);
+
+ nomem_urb:
+	gs_free_tx_context(txc);
+	dev_kfree_skb(skb);
+	stats->tx_dropped++;
+	return NETDEV_TX_OK;
+}
+
+static int gs_can_open(struct net_device *netdev)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_usb *parent = dev->parent;
+	struct gs_device_mode dm = {
+		.mode = cpu_to_le32(GS_CAN_MODE_START),
+	};
+	struct gs_host_frame *hf;
+	struct urb *urb = NULL;
+	u32 ctrlmode;
+	u32 flags = 0;
+	int rc, i;
+
+	rc = open_candev(netdev);
+	if (rc)
+		return rc;
+
+	ctrlmode = dev->can.ctrlmode;
+	if (ctrlmode & CAN_CTRLMODE_FD) {
+		flags |= GS_CAN_MODE_FD;
+
+		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
+			dev->hf_size_tx = struct_size(hf, canfd_quirk, 1);
+		else
+			dev->hf_size_tx = struct_size(hf, canfd, 1);
+	} else {
+		if (dev->feature & GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX)
+			dev->hf_size_tx = struct_size(hf, classic_can_quirk, 1);
+		else
+			dev->hf_size_tx = struct_size(hf, classic_can, 1);
+	}
+
+	if (!parent->active_channels) {
+		for (i = 0; i < GS_MAX_RX_URBS; i++) {
+			u8 *buf;
+
+			/* alloc rx urb */
+			urb = usb_alloc_urb(0, GFP_KERNEL);
+			if (!urb) {
+				rc = -ENOMEM;
+				goto out_usb_kill_anchored_urbs;
+			}
+
+			/* alloc rx buffer */
+			buf = kmalloc(dev->parent->hf_size_rx,
+				      GFP_KERNEL);
+			if (!buf) {
+				netdev_err(netdev,
+					   "No memory left for USB buffer\n");
+				rc = -ENOMEM;
+				goto out_usb_free_urb;
+			}
+
+			/* fill, anchor, and submit rx urb */
+			usb_fill_bulk_urb(urb,
+					  dev->udev,
+					  usb_rcvbulkpipe(dev->udev,
+							  GS_USB_ENDPOINT_IN),
+					  buf,
+					  dev->parent->hf_size_rx,
+					  gs_usb_receive_bulk_callback, parent);
+			urb->transfer_flags |= URB_FREE_BUFFER;
+
+			usb_anchor_urb(urb, &parent->rx_submitted);
+
+			rc = usb_submit_urb(urb, GFP_KERNEL);
+			if (rc) {
+				if (rc == -ENODEV)
+					netif_device_detach(dev->netdev);
+
+				netdev_err(netdev,
+					   "usb_submit failed (err=%d)\n", rc);
+
+				goto out_usb_unanchor_urb;
+			}
+
+			/* Drop reference,
+			 * USB core will take care of freeing it
+			 */
+			usb_free_urb(urb);
+		}
+	}
+
+	/* flags */
+	if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		flags |= GS_CAN_MODE_LOOP_BACK;
+	else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		flags |= GS_CAN_MODE_LISTEN_ONLY;
+
+	/* Controller is not allowed to retry TX
+	 * this mode is unavailable on atmels uc3c hardware
+	 */
+	if (ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+		flags |= GS_CAN_MODE_ONE_SHOT;
+
+	if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+		flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
+
+	/* if hardware supports timestamps, enable it */
+	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+		flags |= GS_CAN_MODE_HW_TIMESTAMP;
+
+	/* start polling timestamp */
+	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+		gs_usb_timestamp_init(dev);
+
+	/* finally start device */
+	dev->can.state = CAN_STATE_ERROR_ACTIVE;
+	dm.flags = cpu_to_le32(flags);
+	rc = usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				  GS_USB_BREQ_MODE,
+				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  dev->channel, 0, &dm, sizeof(dm), 1000,
+				  GFP_KERNEL);
+	if (rc) {
+		netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
+		if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+			gs_usb_timestamp_stop(dev);
+		dev->can.state = CAN_STATE_STOPPED;
+
+		goto out_usb_kill_anchored_urbs;
+	}
+
+	parent->active_channels++;
+	if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
+		netif_start_queue(netdev);
+
+	return 0;
+
+out_usb_unanchor_urb:
+	usb_unanchor_urb(urb);
+out_usb_free_urb:
+	usb_free_urb(urb);
+out_usb_kill_anchored_urbs:
+	if (!parent->active_channels)
+		usb_kill_anchored_urbs(&dev->tx_submitted);
+
+	close_candev(netdev);
+
+	return rc;
+}
+
+static int gs_can_close(struct net_device *netdev)
+{
+	int rc;
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_usb *parent = dev->parent;
+
+	netif_stop_queue(netdev);
+
+	/* stop polling timestamp */
+	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+		gs_usb_timestamp_stop(dev);
+
+	/* Stop polling */
+	parent->active_channels--;
+	if (!parent->active_channels) {
+		usb_kill_anchored_urbs(&parent->rx_submitted);
+	}
+
+	/* Stop sending URBs */
+	usb_kill_anchored_urbs(&dev->tx_submitted);
+	atomic_set(&dev->active_tx_urbs, 0);
+
+	dev->can.state = CAN_STATE_STOPPED;
+
+	/* reset the device */
+	rc = gs_cmd_reset(dev);
+	if (rc < 0)
+		netdev_warn(netdev, "Couldn't shutdown device (err=%d)", rc);
+
+	/* reset tx contexts */
+	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
+		dev->tx_context[rc].dev = dev;
+		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
+	}
+
+	/* close the netdev */
+	close_candev(netdev);
+
+	return 0;
+}
+
+static int gs_can_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+	const struct gs_can *dev = netdev_priv(netdev);
+
+	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+		return can_eth_ioctl_hwts(netdev, ifr, cmd);
+
+	return -EOPNOTSUPP;
+}
+
+static const struct net_device_ops gs_usb_netdev_ops = {
+	.ndo_open = gs_can_open,
+	.ndo_stop = gs_can_close,
+	.ndo_start_xmit = gs_can_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
+	.ndo_eth_ioctl = gs_can_eth_ioctl,
+};
+
+static int gs_usb_set_identify(struct net_device *netdev, bool do_identify)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_identify_mode imode;
+
+	if (do_identify)
+		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_ON);
+	else
+		imode.mode = cpu_to_le32(GS_CAN_IDENTIFY_OFF);
+
+	return usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				    GS_USB_BREQ_IDENTIFY,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				    dev->channel, 0, &imode, sizeof(imode), 100,
+				    GFP_KERNEL);
+}
+
+/* blink LED's for finding the this interface */
+static int gs_usb_set_phys_id(struct net_device *netdev,
+			      enum ethtool_phys_id_state state)
+{
+	const struct gs_can *dev = netdev_priv(netdev);
+	int rc = 0;
+
+	if (!(dev->feature & GS_CAN_FEATURE_IDENTIFY))
+		return -EOPNOTSUPP;
+
+	switch (state) {
+	case ETHTOOL_ID_ACTIVE:
+		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_ON);
+		break;
+	case ETHTOOL_ID_INACTIVE:
+		rc = gs_usb_set_identify(netdev, GS_CAN_IDENTIFY_OFF);
+		break;
+	default:
+		break;
+	}
+
+	return rc;
+}
+
+static int gs_usb_get_ts_info(struct net_device *netdev,
+			      struct ethtool_ts_info *info)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+
+	/* report if device supports HW timestamps */
+	if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+		return can_ethtool_op_get_ts_info_hwts(netdev, info);
+
+	return ethtool_op_get_ts_info(netdev, info);
+}
+
+static const struct ethtool_ops gs_usb_ethtool_ops = {
+	.set_phys_id = gs_usb_set_phys_id,
+	.get_ts_info = gs_usb_get_ts_info,
+};
+
+static int gs_usb_get_termination(struct net_device *netdev, u16 *term)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_device_termination_state term_state;
+	int rc;
+
+	rc = usb_control_msg_recv(interface_to_usbdev(dev->iface), 0,
+				  GS_USB_BREQ_GET_TERMINATION,
+				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  dev->channel, 0,
+				  &term_state, sizeof(term_state), 1000,
+				  GFP_KERNEL);
+	if (rc)
+		return rc;
+
+	if (term_state.state == cpu_to_le32(GS_CAN_TERMINATION_STATE_ON))
+		*term = GS_USB_TERMINATION_ENABLED;
+	else
+		*term = GS_USB_TERMINATION_DISABLED;
+
+	return 0;
+}
+
+static int gs_usb_set_termination(struct net_device *netdev, u16 term)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_device_termination_state term_state;
+
+	if (term == GS_USB_TERMINATION_ENABLED)
+		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_ON);
+	else
+		term_state.state = cpu_to_le32(GS_CAN_TERMINATION_STATE_OFF);
+
+	return usb_control_msg_send(interface_to_usbdev(dev->iface), 0,
+				    GS_USB_BREQ_SET_TERMINATION,
+				    USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				    dev->channel, 0,
+				    &term_state, sizeof(term_state), 1000,
+				    GFP_KERNEL);
+}
+
+static const u16 gs_usb_termination_const[] = {
+	GS_USB_TERMINATION_DISABLED,
+	GS_USB_TERMINATION_ENABLED
+};
+
+static struct gs_can *gs_make_candev(unsigned int channel,
+				     struct usb_interface *intf,
+				     struct gs_device_config *dconf)
+{
+	struct gs_can *dev;
+	struct net_device *netdev;
+	int rc;
+	struct gs_device_bt_const_extended bt_const_extended;
+	struct gs_device_bt_const bt_const;
+	u32 feature;
+
+	/* fetch bit timing constants */
+	rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
+				  GS_USB_BREQ_BT_CONST,
+				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  channel, 0, &bt_const, sizeof(bt_const), 1000,
+				  GFP_KERNEL);
+
+	if (rc) {
+		dev_err(&intf->dev,
+			"Couldn't get bit timing const for channel %d (%pe)\n",
+			channel, ERR_PTR(rc));
+		return ERR_PTR(rc);
+	}
+
+	/* create netdev */
+	netdev = alloc_candev(sizeof(struct gs_can), GS_MAX_TX_URBS);
+	if (!netdev) {
+		dev_err(&intf->dev, "Couldn't allocate candev\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	dev = netdev_priv(netdev);
+
+	netdev->netdev_ops = &gs_usb_netdev_ops;
+	netdev->ethtool_ops = &gs_usb_ethtool_ops;
+
+	netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
+
+	/* dev setup */
+	strcpy(dev->bt_const.name, KBUILD_MODNAME);
+	dev->bt_const.tseg1_min = le32_to_cpu(bt_const.tseg1_min);
+	dev->bt_const.tseg1_max = le32_to_cpu(bt_const.tseg1_max);
+	dev->bt_const.tseg2_min = le32_to_cpu(bt_const.tseg2_min);
+	dev->bt_const.tseg2_max = le32_to_cpu(bt_const.tseg2_max);
+	dev->bt_const.sjw_max = le32_to_cpu(bt_const.sjw_max);
+	dev->bt_const.brp_min = le32_to_cpu(bt_const.brp_min);
+	dev->bt_const.brp_max = le32_to_cpu(bt_const.brp_max);
+	dev->bt_const.brp_inc = le32_to_cpu(bt_const.brp_inc);
+
+	dev->udev = interface_to_usbdev(intf);
+	dev->iface = intf;
+	dev->netdev = netdev;
+	dev->channel = channel;
+
+	init_usb_anchor(&dev->tx_submitted);
+	atomic_set(&dev->active_tx_urbs, 0);
+	spin_lock_init(&dev->tx_ctx_lock);
+	for (rc = 0; rc < GS_MAX_TX_URBS; rc++) {
+		dev->tx_context[rc].dev = dev;
+		dev->tx_context[rc].echo_id = GS_MAX_TX_URBS;
+	}
+
+	/* can setup */
+	dev->can.state = CAN_STATE_STOPPED;
+	dev->can.clock.freq = le32_to_cpu(bt_const.fclk_can);
+	dev->can.bittiming_const = &dev->bt_const;
+	dev->can.do_set_bittiming = gs_usb_set_bittiming;
+
+	dev->can.ctrlmode_supported = CAN_CTRLMODE_CC_LEN8_DLC;
+
+	feature = le32_to_cpu(bt_const.feature);
+	dev->feature = FIELD_GET(GS_CAN_FEATURE_MASK, feature);
+	if (feature & GS_CAN_FEATURE_LISTEN_ONLY)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
+
+	if (feature & GS_CAN_FEATURE_LOOP_BACK)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
+
+	if (feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
+
+	if (feature & GS_CAN_FEATURE_ONE_SHOT)
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
+
+	if (feature & GS_CAN_FEATURE_FD) {
+		dev->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
+		/* The data bit timing will be overwritten, if
+		 * GS_CAN_FEATURE_BT_CONST_EXT is set.
+		 */
+		dev->can.data_bittiming_const = &dev->bt_const;
+		dev->can.do_set_data_bittiming = gs_usb_set_data_bittiming;
+	}
+
+	if (feature & GS_CAN_FEATURE_TERMINATION) {
+		rc = gs_usb_get_termination(netdev, &dev->can.termination);
+		if (rc) {
+			dev->feature &= ~GS_CAN_FEATURE_TERMINATION;
+
+			dev_info(&intf->dev,
+				 "Disabling termination support for channel %d (%pe)\n",
+				 channel, ERR_PTR(rc));
+		} else {
+			dev->can.termination_const = gs_usb_termination_const;
+			dev->can.termination_const_cnt = ARRAY_SIZE(gs_usb_termination_const);
+			dev->can.do_set_termination = gs_usb_set_termination;
+		}
+	}
+
+	/* The CANtact Pro from LinkLayer Labs is based on the
+	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
+	 * erratum. However, the current firmware (version 2) doesn't
+	 * set the GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX bit. Set the
+	 * feature GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX to workaround
+	 * this issue.
+	 *
+	 * For the GS_USB_BREQ_DATA_BITTIMING USB control message the
+	 * CANtact Pro firmware uses a request value, which is already
+	 * used by the candleLight firmware for a different purpose
+	 * (GS_USB_BREQ_GET_USER_ID). Set the feature
+	 * GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO to workaround this
+	 * issue.
+	 */
+	if (dev->udev->descriptor.idVendor == cpu_to_le16(USB_GS_USB_1_VENDOR_ID) &&
+	    dev->udev->descriptor.idProduct == cpu_to_le16(USB_GS_USB_1_PRODUCT_ID) &&
+	    dev->udev->manufacturer && dev->udev->product &&
+	    !strcmp(dev->udev->manufacturer, "LinkLayer Labs") &&
+	    !strcmp(dev->udev->product, "CANtact Pro") &&
+	    (le32_to_cpu(dconf->sw_version) <= 2))
+		dev->feature |= GS_CAN_FEATURE_REQ_USB_QUIRK_LPC546XX |
+			GS_CAN_FEATURE_QUIRK_BREQ_CANTACT_PRO;
+
+	/* GS_CAN_FEATURE_IDENTIFY is only supported for sw_version > 1 */
+	if (!(le32_to_cpu(dconf->sw_version) > 1 &&
+	      feature & GS_CAN_FEATURE_IDENTIFY))
+		dev->feature &= ~GS_CAN_FEATURE_IDENTIFY;
+
+	/* fetch extended bit timing constants if device has feature
+	 * GS_CAN_FEATURE_FD and GS_CAN_FEATURE_BT_CONST_EXT
+	 */
+	if (feature & GS_CAN_FEATURE_FD &&
+	    feature & GS_CAN_FEATURE_BT_CONST_EXT) {
+		rc = usb_control_msg_recv(interface_to_usbdev(intf), 0,
+					  GS_USB_BREQ_BT_CONST_EXT,
+					  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+					  channel, 0, &bt_const_extended,
+					  sizeof(bt_const_extended),
+					  1000, GFP_KERNEL);
+		if (rc) {
+			dev_err(&intf->dev,
+				"Couldn't get extended bit timing const for channel %d (%pe)\n",
+				channel, ERR_PTR(rc));
+			goto out_free_candev;
+		}
+
+		strcpy(dev->data_bt_const.name, KBUILD_MODNAME);
+		dev->data_bt_const.tseg1_min = le32_to_cpu(bt_const_extended.dtseg1_min);
+		dev->data_bt_const.tseg1_max = le32_to_cpu(bt_const_extended.dtseg1_max);
+		dev->data_bt_const.tseg2_min = le32_to_cpu(bt_const_extended.dtseg2_min);
+		dev->data_bt_const.tseg2_max = le32_to_cpu(bt_const_extended.dtseg2_max);
+		dev->data_bt_const.sjw_max = le32_to_cpu(bt_const_extended.dsjw_max);
+		dev->data_bt_const.brp_min = le32_to_cpu(bt_const_extended.dbrp_min);
+		dev->data_bt_const.brp_max = le32_to_cpu(bt_const_extended.dbrp_max);
+		dev->data_bt_const.brp_inc = le32_to_cpu(bt_const_extended.dbrp_inc);
+
+		dev->can.data_bittiming_const = &dev->data_bt_const;
+	}
+
+	SET_NETDEV_DEV(netdev, &intf->dev);
+
+	rc = register_candev(dev->netdev);
+	if (rc) {
+		dev_err(&intf->dev,
+			"Couldn't register candev for channel %d (%pe)\n",
+			channel, ERR_PTR(rc));
+		goto out_free_candev;
+	}
+
+	return dev;
+
+ out_free_candev:
+	free_candev(dev->netdev);
+	return ERR_PTR(rc);
+}
+
+static void gs_destroy_candev(struct gs_can *dev)
+{
+	unregister_candev(dev->netdev);
+	usb_kill_anchored_urbs(&dev->tx_submitted);
+	free_candev(dev->netdev);
+}
+
+static int gs_usb_probe(struct usb_interface *intf,
+			const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct gs_host_frame *hf;
+	struct gs_usb *dev;
+	struct gs_host_config hconf = {
+		.byte_order = cpu_to_le32(0x0000beef),
+	};
+	struct gs_device_config dconf;
+	unsigned int icount, i;
+	int rc;
+
+	/* send host config */
+	rc = usb_control_msg_send(udev, 0,
+				  GS_USB_BREQ_HOST_FORMAT,
+				  USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  1, intf->cur_altsetting->desc.bInterfaceNumber,
+				  &hconf, sizeof(hconf), 1000,
+				  GFP_KERNEL);
+	if (rc) {
+		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n", rc);
+		return rc;
+	}
+
+	/* read device config */
+	rc = usb_control_msg_recv(udev, 0,
+				  GS_USB_BREQ_DEVICE_CONFIG,
+				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  1, intf->cur_altsetting->desc.bInterfaceNumber,
+				  &dconf, sizeof(dconf), 1000,
+				  GFP_KERNEL);
+	if (rc) {
+		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
+			rc);
+		return rc;
+	}
+
+	icount = dconf.icount + 1;
+	dev_info(&intf->dev, "Configuring for %u interfaces\n", icount);
+
+	if (icount > GS_MAX_INTF) {
+		dev_err(&intf->dev,
+			"Driver cannot handle more that %u CAN interfaces\n",
+			GS_MAX_INTF);
+		return -EINVAL;
+	}
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	init_usb_anchor(&dev->rx_submitted);
+
+	usb_set_intfdata(intf, dev);
+	dev->udev = udev;
+
+	for (i = 0; i < icount; i++) {
+		unsigned int hf_size_rx = 0;
+
+		dev->canch[i] = gs_make_candev(i, intf, &dconf);
+		if (IS_ERR_OR_NULL(dev->canch[i])) {
+			/* save error code to return later */
+			rc = PTR_ERR(dev->canch[i]);
+
+			/* on failure destroy previously created candevs */
+			icount = i;
+			for (i = 0; i < icount; i++)
+				gs_destroy_candev(dev->canch[i]);
+
+			usb_kill_anchored_urbs(&dev->rx_submitted);
+			kfree(dev);
+			return rc;
+		}
+		dev->canch[i]->parent = dev;
+
+		/* set RX packet size based on FD and if hardware
+                * timestamps are supported.
+		*/
+		if (dev->canch[i]->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
+			if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+				hf_size_rx = struct_size(hf, canfd_ts, 1);
+			else
+				hf_size_rx = struct_size(hf, canfd, 1);
+		} else {
+			if (dev->canch[i]->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
+				hf_size_rx = struct_size(hf, classic_can_ts, 1);
+			else
+				hf_size_rx = struct_size(hf, classic_can, 1);
+		}
+		dev->hf_size_rx = max(dev->hf_size_rx, hf_size_rx);
+	}
+
+	return 0;
+}
+
+static void gs_usb_disconnect(struct usb_interface *intf)
+{
+	struct gs_usb *dev = usb_get_intfdata(intf);
+	unsigned int i;
+
+	usb_set_intfdata(intf, NULL);
+
+	if (!dev) {
+		dev_err(&intf->dev, "Disconnect (nodata)\n");
+		return;
+	}
+
+	for (i = 0; i < GS_MAX_INTF; i++)
+		if (dev->canch[i])
+			gs_destroy_candev(dev->canch[i]);
+
+	usb_kill_anchored_urbs(&dev->rx_submitted);
+	kfree(dev);
+}
+
+static const struct usb_device_id gs_usb_table[] = {
+	{ USB_DEVICE_INTERFACE_NUMBER(USB_GS_USB_1_VENDOR_ID,
+				      USB_GS_USB_1_PRODUCT_ID, 0) },
+	{ USB_DEVICE_INTERFACE_NUMBER(USB_CANDLELIGHT_VENDOR_ID,
+				      USB_CANDLELIGHT_PRODUCT_ID, 0) },
+	{ USB_DEVICE_INTERFACE_NUMBER(USB_CES_CANEXT_FD_VENDOR_ID,
+				      USB_CES_CANEXT_FD_PRODUCT_ID, 0) },
+	{ USB_DEVICE_INTERFACE_NUMBER(USB_ABE_CANDEBUGGER_FD_VENDOR_ID,
+				      USB_ABE_CANDEBUGGER_FD_PRODUCT_ID, 0) },
+	{} /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, gs_usb_table);
+
+static struct usb_driver gs_usb_driver = {
+	.name = KBUILD_MODNAME,
+	.probe = gs_usb_probe,
+	.disconnect = gs_usb_disconnect,
+	.id_table = gs_usb_table,
+};
+
+module_usb_driver(gs_usb_driver);
+
+MODULE_AUTHOR("Maximilian Schneider <mws@schneidersoft.net>");
+MODULE_DESCRIPTION(
+"Socket CAN device driver for Geschwister Schneider Technologie-, "
+"Entwicklungs- und Vertriebs UG. USB2.0 to CAN interfaces\n"
+"and bytewerk.org candleLight USB CAN interfaces.");
+MODULE_LICENSE("GPL v2");