can: gs_usb: Added support for the GS_USB CAN devices
The Geschwister Schneider Family of devices are galvanically isolated USB2.0 to
CAN2.0A/B adapters. Currently two form factors are available, a tethered dongle
in a rugged enclosure, and mini-pci-e card.
Signed-off-by: Maximilian Schneider <max@schneidersoft.net>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index 0b918eb..a77db919 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -13,6 +13,14 @@
This driver supports the CAN-USB/2 interface
from esd electronic system design gmbh (http://www.esd.eu).
+config CAN_GS_USB
+ tristate "Geschwister Schneider UG interfaces"
+ ---help---
+ This driver supports the Geschwister Schneider USB/CAN devices.
+ If unsure choose N,
+ choose Y for built in support,
+ M to compile as module (module will be named: gs_usb).
+
config CAN_KVASER_USB
tristate "Kvaser CAN/USB interface"
---help---
diff --git a/drivers/net/can/usb/Makefile b/drivers/net/can/usb/Makefile
index becef46..7b9a393 100644
--- a/drivers/net/can/usb/Makefile
+++ b/drivers/net/can/usb/Makefile
@@ -4,6 +4,7 @@
obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o
obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o
+obj-$(CONFIG_CAN_GS_USB) += gs_usb.o
obj-$(CONFIG_CAN_KVASER_USB) += kvaser_usb.o
obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/
obj-$(CONFIG_CAN_8DEV_USB) += usb_8dev.o
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
new file mode 100644
index 0000000..c9f1f99
--- /dev/null
+++ b/drivers/net/can/usb/gs_usb.c
@@ -0,0 +1,971 @@
+/* CAN driver for Geschwister Schneider USB/CAN devices.
+ *
+ * Copyright (C) 2013 Geschwister Schneider Technologie-,
+ * Entwicklungs- und Vertriebs UG (Haftungsbeschränkt).
+ *
+ * Many thanks to all socketcan devs!
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/usb.h>
+
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+
+/* Device specific constants */
+#define USB_GSUSB_1_VENDOR_ID 0x1d50
+#define USB_GSUSB_1_PRODUCT_ID 0x606f
+
+#define GSUSB_ENDPOINT_IN 1
+#define GSUSB_ENDPOINT_OUT 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
+};
+
+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
+};
+
+/* data types passed between host and device */
+struct gs_host_config {
+ u32 byte_order;
+} __packed;
+/* All data exchanged between host and device is exchanged in host byte order,
+ * thanks to the struct gs_host_config byte_order member, which is sent first
+ * to indicate the desired byte order.
+ */
+
+struct gs_device_config {
+ u8 reserved1;
+ u8 reserved2;
+ u8 reserved3;
+ u8 icount;
+ u32 sw_version;
+ u32 hw_version;
+} __packed;
+
+#define GS_CAN_MODE_NORMAL 0
+#define GS_CAN_MODE_LISTEN_ONLY (1<<0)
+#define GS_CAN_MODE_LOOP_BACK (1<<1)
+#define GS_CAN_MODE_TRIPLE_SAMPLE (1<<2)
+#define GS_CAN_MODE_ONE_SHOT (1<<3)
+
+struct gs_device_mode {
+ u32 mode;
+ u32 flags;
+} __packed;
+
+struct gs_device_state {
+ u32 state;
+ u32 rxerr;
+ u32 txerr;
+} __packed;
+
+struct gs_device_bittiming {
+ u32 prop_seg;
+ u32 phase_seg1;
+ u32 phase_seg2;
+ u32 sjw;
+ u32 brp;
+} __packed;
+
+#define GS_CAN_FEATURE_LISTEN_ONLY (1<<0)
+#define GS_CAN_FEATURE_LOOP_BACK (1<<1)
+#define GS_CAN_FEATURE_TRIPLE_SAMPLE (1<<2)
+#define GS_CAN_FEATURE_ONE_SHOT (1<<3)
+
+struct gs_device_bt_const {
+ u32 feature;
+ u32 fclk_can;
+ u32 tseg1_min;
+ u32 tseg1_max;
+ u32 tseg2_min;
+ u32 tseg2_max;
+ u32 sjw_max;
+ u32 brp_min;
+ u32 brp_max;
+ u32 brp_inc;
+} __packed;
+
+#define GS_CAN_FLAG_OVERFLOW 1
+
+struct gs_host_frame {
+ u32 echo_id;
+ u32 can_id;
+
+ u8 can_dlc;
+ u8 channel;
+ u8 flags;
+ u8 reserved;
+
+ u8 data[8];
+} __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 2 interfaces. The future may vary.
+ */
+#define GS_MAX_INTF 2
+
+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;
+ unsigned int channel; /* channel number */
+
+ /* This lock prevents a race condition between xmit and recieve. */
+ 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;
+ atomic_t active_channels;
+ struct usb_device *udev;
+};
+
+/* '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_usb *gsusb, struct gs_can *gsdev)
+{
+ struct gs_device_mode *dm;
+ struct usb_interface *intf = gsdev->iface;
+ int rc;
+
+ dm = kzalloc(sizeof(*dm), GFP_KERNEL);
+ if (!dm)
+ return -ENOMEM;
+
+ dm->mode = GS_CAN_MODE_RESET;
+
+ rc = usb_control_msg(interface_to_usbdev(intf),
+ usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+ GS_USB_BREQ_MODE,
+ USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+ gsdev->channel,
+ 0,
+ dm,
+ sizeof(*dm),
+ 1000);
+
+ return rc;
+}
+
+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_recieve_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 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 resubmit_urb;
+
+ dev = usbcan->canch[hf->channel];
+
+ netdev = dev->netdev;
+ stats = &netdev->stats;
+
+ if (!netif_device_present(netdev))
+ return;
+
+ if (hf->echo_id == -1) { /* normal rx */
+ skb = alloc_can_skb(dev->netdev, &cf);
+ if (!skb)
+ return;
+
+ cf->can_id = hf->can_id;
+
+ cf->can_dlc = get_can_dlc(hf->can_dlc);
+ memcpy(cf->data, hf->data, 8);
+
+ /* ERROR frames tell us information about the controller */
+ if (hf->can_id & CAN_ERR_FLAG)
+ gs_update_state(dev, cf);
+
+ 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 %d\n",
+ hf->echo_id);
+ goto resubmit_urb;
+ }
+
+ netdev->stats.tx_packets++;
+ netdev->stats.tx_bytes += hf->can_dlc;
+
+ txc = gs_get_tx_context(dev, hf->echo_id);
+
+ /* bad devices send bad echo_ids. */
+ if (!txc) {
+ netdev_err(netdev,
+ "Unexpected unused echo id %d\n",
+ hf->echo_id);
+ goto resubmit_urb;
+ }
+
+ can_get_echo_skb(netdev, hf->echo_id);
+
+ gs_free_tx_context(txc);
+
+ netif_wake_queue(netdev);
+ }
+
+ if (hf->flags & GS_CAN_FLAG_OVERFLOW) {
+ skb = alloc_can_err_skb(netdev, &cf);
+ if (!skb)
+ goto resubmit_urb;
+
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->can_dlc = CAN_ERR_DLC;
+ cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+ stats->rx_over_errors++;
+ stats->rx_errors++;
+ netif_rx(skb);
+ }
+
+ resubmit_urb:
+ usb_fill_bulk_urb(urb,
+ usbcan->udev,
+ usb_rcvbulkpipe(usbcan->udev, GSUSB_ENDPOINT_IN),
+ hf,
+ sizeof(struct gs_host_frame),
+ gs_usb_recieve_bulk_callback,
+ usbcan
+ );
+
+ rc = usb_submit_urb(urb, GFP_ATOMIC);
+
+ /* USB failure take down all interfaces */
+ if (rc == -ENODEV) {
+ 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 usb_interface *intf = dev->iface;
+ int rc;
+ struct gs_device_bittiming *dbt;
+
+ dbt = kmalloc(sizeof(*dbt), GFP_KERNEL);
+ if (!dbt)
+ return -ENOMEM;
+
+ dbt->prop_seg = bt->prop_seg;
+ dbt->phase_seg1 = bt->phase_seg1;
+ dbt->phase_seg2 = bt->phase_seg2;
+ dbt->sjw = bt->sjw;
+ dbt->brp = bt->brp;
+
+ /* request bit timings */
+ rc = usb_control_msg(interface_to_usbdev(intf),
+ usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+ GS_USB_BREQ_BITTIMING,
+ USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+ dev->channel,
+ 0,
+ dbt,
+ sizeof(*dbt),
+ 1000);
+
+ kfree(dbt);
+
+ if (rc < 0)
+ dev_err(netdev->dev.parent, "Couldn't set bittimings (err=%d)",
+ rc);
+
+ return rc;
+}
+
+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 %d\n", txc->echo_id);
+
+ usb_free_coherent(urb->dev,
+ urb->transfer_buffer_length,
+ urb->transfer_buffer,
+ urb->transfer_dma);
+
+ atomic_dec(&dev->active_tx_urbs);
+
+ if (!netif_device_present(netdev))
+ return;
+
+ if (netif_queue_stopped(netdev))
+ netif_wake_queue(netdev);
+}
+
+static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+ struct gs_can *dev = netdev_priv(netdev);
+ struct net_device_stats *stats = &dev->netdev->stats;
+ struct urb *urb;
+ struct gs_host_frame *hf;
+ struct can_frame *cf;
+ int rc;
+ unsigned int idx;
+ struct gs_tx_context *txc;
+
+ if (can_dropped_invalid_skb(netdev, skb))
+ return NETDEV_TX_OK;
+
+ /* find an empty context to keep track of transmission */
+ txc = gs_alloc_tx_context(dev);
+ if (!txc)
+ return NETDEV_TX_BUSY;
+
+ /* create a URB, and a buffer for it */
+ urb = usb_alloc_urb(0, GFP_ATOMIC);
+ if (!urb) {
+ netdev_err(netdev, "No memory left for URB\n");
+ goto nomem_urb;
+ }
+
+ hf = usb_alloc_coherent(dev->udev, sizeof(*hf), GFP_ATOMIC,
+ &urb->transfer_dma);
+ if (!hf) {
+ netdev_err(netdev, "No memory left for USB buffer\n");
+ goto nomem_hf;
+ }
+
+ idx = txc->echo_id;
+
+ if (idx >= GS_MAX_TX_URBS) {
+ netdev_err(netdev, "Invalid tx context %d\n", idx);
+ goto badidx;
+ }
+
+ hf->echo_id = idx;
+ hf->channel = dev->channel;
+
+ cf = (struct can_frame *)skb->data;
+
+ hf->can_id = cf->can_id;
+ hf->can_dlc = cf->can_dlc;
+ memcpy(hf->data, cf->data, cf->can_dlc);
+
+ usb_fill_bulk_urb(urb, dev->udev,
+ usb_sndbulkpipe(dev->udev, GSUSB_ENDPOINT_OUT),
+ hf,
+ sizeof(*hf),
+ gs_usb_xmit_callback,
+ txc);
+
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+ usb_anchor_urb(urb, &dev->tx_submitted);
+
+ can_put_echo_skb(skb, netdev, idx);
+
+ atomic_inc(&dev->active_tx_urbs);
+
+ rc = usb_submit_urb(urb, GFP_ATOMIC);
+ if (unlikely(rc)) { /* usb send failed */
+ atomic_dec(&dev->active_tx_urbs);
+
+ can_free_echo_skb(netdev, idx);
+ gs_free_tx_context(txc);
+
+ usb_unanchor_urb(urb);
+ usb_free_coherent(dev->udev,
+ sizeof(*hf),
+ hf,
+ urb->transfer_dma);
+
+
+ if (rc == -ENODEV) {
+ netif_device_detach(netdev);
+ } else {
+ netdev_err(netdev, "usb_submit failed (err=%d)\n", rc);
+ stats->tx_dropped++;
+ }
+ } else {
+ /* Slow down tx path */
+ if (atomic_read(&dev->active_tx_urbs) >= GS_MAX_TX_URBS)
+ netif_stop_queue(netdev);
+ }
+
+ /* let usb core take care of this urb */
+ usb_free_urb(urb);
+
+ return NETDEV_TX_OK;
+
+ badidx:
+ usb_free_coherent(dev->udev,
+ sizeof(*hf),
+ hf,
+ urb->transfer_dma);
+ nomem_hf:
+ usb_free_urb(urb);
+
+ nomem_urb:
+ gs_free_tx_context(txc);
+ dev_kfree_skb(skb);
+ stats->tx_dropped++;
+ return NETDEV_TX_OK;
+}
+
+static int gs_can_open(struct net_device *netdev)
+{
+ struct gs_can *dev = netdev_priv(netdev);
+ struct gs_usb *parent = dev->parent;
+ int rc, i;
+ struct gs_device_mode *dm;
+ u32 ctrlmode;
+
+ rc = open_candev(netdev);
+ if (rc)
+ return rc;
+
+ if (atomic_add_return(1, &parent->active_channels) == 1) {
+ for (i = 0; i < GS_MAX_RX_URBS; i++) {
+ struct urb *urb;
+ u8 *buf;
+
+ /* alloc rx urb */
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb) {
+ netdev_err(netdev,
+ "No memory left for URB\n");
+ return -ENOMEM;
+ }
+
+ /* alloc rx buffer */
+ buf = usb_alloc_coherent(dev->udev,
+ sizeof(struct gs_host_frame),
+ GFP_KERNEL,
+ &urb->transfer_dma);
+ if (!buf) {
+ netdev_err(netdev,
+ "No memory left for USB buffer\n");
+ usb_free_urb(urb);
+ return -ENOMEM;
+ }
+
+ /* fill, anchor, and submit rx urb */
+ usb_fill_bulk_urb(urb,
+ dev->udev,
+ usb_rcvbulkpipe(dev->udev,
+ GSUSB_ENDPOINT_IN),
+ buf,
+ sizeof(struct gs_host_frame),
+ gs_usb_recieve_bulk_callback,
+ parent);
+ urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+ 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);
+
+ usb_unanchor_urb(urb);
+ break;
+ }
+
+ /* Drop reference,
+ * USB core will take care of freeing it
+ */
+ usb_free_urb(urb);
+ }
+ }
+
+ dm = kmalloc(sizeof(*dm), GFP_KERNEL);
+ if (!dm)
+ return -ENOMEM;
+
+ /* flags */
+ ctrlmode = dev->can.ctrlmode;
+ dm->flags = 0;
+
+ if (ctrlmode & CAN_CTRLMODE_LOOPBACK)
+ dm->flags |= GS_CAN_MODE_LOOP_BACK;
+ else if (ctrlmode & CAN_CTRLMODE_LISTENONLY)
+ dm->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)
+ dm->flags |= GS_CAN_MODE_ONE_SHOT;
+
+ if (ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+ dm->flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
+
+ /* finally start device */
+ dm->mode = GS_CAN_MODE_START;
+ rc = usb_control_msg(interface_to_usbdev(dev->iface),
+ usb_sndctrlpipe(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);
+
+ if (rc < 0) {
+ netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
+ kfree(dm);
+ return rc;
+ }
+
+ kfree(dm);
+
+ dev->can.state = CAN_STATE_ERROR_ACTIVE;
+
+ if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
+ netif_start_queue(netdev);
+
+ return 0;
+}
+
+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 */
+ if (atomic_dec_and_test(&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);
+
+ /* reset the device */
+ rc = gs_cmd_reset(parent, 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 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,
+};
+
+static struct gs_can *gs_make_candev(unsigned int channel, struct usb_interface *intf)
+{
+ struct gs_can *dev;
+ struct net_device *netdev;
+ int rc;
+ struct gs_device_bt_const *bt_const;
+
+ bt_const = kmalloc(sizeof(*bt_const), GFP_KERNEL);
+ if (!bt_const)
+ return ERR_PTR(-ENOMEM);
+
+ /* fetch bit timing constants */
+ rc = usb_control_msg(interface_to_usbdev(intf),
+ usb_rcvctrlpipe(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);
+
+ if (rc < 0) {
+ dev_err(&intf->dev,
+ "Couldn't get bit timing const for channel (err=%d)\n",
+ rc);
+ kfree(bt_const);
+ 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");
+ kfree(bt_const);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ dev = netdev_priv(netdev);
+
+ netdev->netdev_ops = &gs_usb_netdev_ops;
+
+ netdev->flags |= IFF_ECHO; /* we support full roundtrip echo */
+
+ /* dev settup */
+ strcpy(dev->bt_const.name, "gs_usb");
+ dev->bt_const.tseg1_min = bt_const->tseg1_min;
+ dev->bt_const.tseg1_max = bt_const->tseg1_max;
+ dev->bt_const.tseg2_min = bt_const->tseg2_min;
+ dev->bt_const.tseg2_max = bt_const->tseg2_max;
+ dev->bt_const.sjw_max = bt_const->sjw_max;
+ dev->bt_const.brp_min = bt_const->brp_min;
+ dev->bt_const.brp_max = bt_const->brp_max;
+ dev->bt_const.brp_inc = 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 settup */
+ dev->can.state = CAN_STATE_STOPPED;
+ dev->can.clock.freq = bt_const->fclk_can;
+ dev->can.bittiming_const = &dev->bt_const;
+ dev->can.do_set_bittiming = gs_usb_set_bittiming;
+
+ dev->can.ctrlmode_supported = 0;
+
+ if (bt_const->feature & GS_CAN_FEATURE_LISTEN_ONLY)
+ dev->can.ctrlmode_supported |= CAN_CTRLMODE_LISTENONLY;
+
+ if (bt_const->feature & GS_CAN_FEATURE_LOOP_BACK)
+ dev->can.ctrlmode_supported |= CAN_CTRLMODE_LOOPBACK;
+
+ if (bt_const->feature & GS_CAN_FEATURE_TRIPLE_SAMPLE)
+ dev->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
+
+ if (bt_const->feature & GS_CAN_FEATURE_ONE_SHOT)
+ dev->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
+
+ kfree(bt_const);
+
+ SET_NETDEV_DEV(netdev, &intf->dev);
+
+ rc = register_candev(dev->netdev);
+ if (rc) {
+ free_candev(dev->netdev);
+ dev_err(&intf->dev, "Couldn't register candev (err=%d)\n", rc);
+ return ERR_PTR(rc);
+ }
+
+ return dev;
+}
+
+static void gs_destroy_candev(struct gs_can *dev)
+{
+ unregister_candev(dev->netdev);
+ free_candev(dev->netdev);
+ kfree(dev);
+ usb_kill_anchored_urbs(&dev->tx_submitted);
+}
+
+static int gs_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+ struct gs_usb *dev;
+ int rc = -ENOMEM;
+ unsigned int icount, i;
+ struct gs_host_config *hconf;
+ struct gs_device_config *dconf;
+
+ hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
+ if (!hconf)
+ return -ENOMEM;
+
+ hconf->byte_order = 0x0000beef;
+
+ /* send host config */
+ rc = usb_control_msg(interface_to_usbdev(intf),
+ usb_sndctrlpipe(interface_to_usbdev(intf), 0),
+ GS_USB_BREQ_HOST_FORMAT,
+ USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+ 1,
+ intf->altsetting[0].desc.bInterfaceNumber,
+ hconf,
+ sizeof(*hconf),
+ 1000);
+
+ kfree(hconf);
+
+ if (rc < 0) {
+ dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
+ rc);
+ return rc;
+ }
+
+ dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
+ if (!dconf)
+ return -ENOMEM;
+
+ /* read device config */
+ rc = usb_control_msg(interface_to_usbdev(intf),
+ usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
+ GS_USB_BREQ_DEVICE_CONFIG,
+ USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
+ 1,
+ intf->altsetting[0].desc.bInterfaceNumber,
+ dconf,
+ sizeof(*dconf),
+ 1000);
+ if (rc < 0) {
+ dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
+ rc);
+
+ kfree(dconf);
+
+ return rc;
+ }
+
+ icount = dconf->icount+1;
+
+ kfree(dconf);
+
+ dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
+
+ if (icount > GS_MAX_INTF) {
+ dev_err(&intf->dev,
+ "Driver cannot handle more that %d CAN interfaces\n",
+ GS_MAX_INTF);
+ return -EINVAL;
+ }
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ init_usb_anchor(&dev->rx_submitted);
+
+ atomic_set(&dev->active_channels, 0);
+
+ usb_set_intfdata(intf, dev);
+ dev->udev = interface_to_usbdev(intf);
+
+ for (i = 0; i < icount; i++) {
+ dev->canch[i] = gs_make_candev(i, intf);
+ if (IS_ERR_OR_NULL(dev->canch[i])) {
+ /* on failure destroy previously created candevs */
+ icount = i;
+ for (i = 0; i < icount; i++) {
+ gs_destroy_candev(dev->canch[i]);
+ dev->canch[i] = NULL;
+ }
+ kfree(dev);
+ return rc;
+ }
+ dev->canch[i]->parent = dev;
+ }
+
+ return 0;
+}
+
+static void gs_usb_disconnect(struct usb_interface *intf)
+{
+ unsigned i;
+ struct gs_usb *dev = usb_get_intfdata(intf);
+ usb_set_intfdata(intf, NULL);
+
+ if (!dev) {
+ dev_err(&intf->dev, "Disconnect (nodata)\n");
+ return;
+ }
+
+ for (i = 0; i < GS_MAX_INTF; i++) {
+ struct gs_can *can = dev->canch[i];
+
+ if (!can)
+ continue;
+
+ gs_destroy_candev(can);
+ }
+
+ usb_kill_anchored_urbs(&dev->rx_submitted);
+}
+
+static const struct usb_device_id gs_usb_table[] = {
+ {USB_DEVICE(USB_GSUSB_1_VENDOR_ID, USB_GSUSB_1_PRODUCT_ID)},
+ {} /* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, gs_usb_table);
+
+static struct usb_driver gs_usb_driver = {
+ .name = "gs_usb",
+ .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.");
+MODULE_LICENSE("GPL v2");