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Commit bb478555 authored by Stephane Grosjean's avatar Stephane Grosjean Committed by Marc Kleine-Budde
Browse files

can: usb: PEAK-System Technik USB adapters driver core 



This patch adds the core of the peak_usb driver which handles PEAK-System
Technik PCAN USB adapters. It defines the parts which are common to the
PCAN-USB adapters: can network interfaces management, network-to/from-usb
data path interface, timestamps management...

Tested-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Acked-by: default avatarWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: default avatarStephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 2b61972b

drivers/net/can/usb/Kconfig

+6 −0
Original line number Original line Diff line number Diff line
@@ -13,4 +13,10 @@ config CAN_ESD_USB2 
          This driver supports the CAN-USB/2 interface

          This driver supports the CAN-USB/2 interface

          from esd electronic system design gmbh (http://www.esd.eu).

          from esd electronic system design gmbh (http://www.esd.eu).





config CAN_PEAK_USB

	tristate "PEAK PCAN-USB/USB Pro interfaces"

	---help---

	  This driver supports the PCAN-USB and PCAN-USB Pro adapters

	  from PEAK-System Technik (http://www.peak-system.com).



endmenu
 
endmenu

drivers/net/can/usb/Makefile

+1 −0
Original line number Original line Diff line number Diff line
@@ -4,5 +4,6 @@ 




obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o

obj-$(CONFIG_CAN_EMS_USB) += ems_usb.o

obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o

obj-$(CONFIG_CAN_ESD_USB2) += esd_usb2.o

obj-$(CONFIG_CAN_PEAK_USB) += peak_usb/





ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
 
ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG

drivers/net/can/usb/peak_usb/Makefile

0 → 100644
+2 −0
Original line number Original line Diff line number Diff line 
obj-$(CONFIG_CAN_PEAK_USB) += peak_usb.o

peak_usb-y = pcan_usb_core.o

drivers/net/can/usb/peak_usb/pcan_usb_core.c

0 → 100644
+951 −0
Original line number Original line Diff line number Diff line 
/*

 * CAN driver for PEAK System USB adapters

 * Derived from the PCAN project file driver/src/pcan_usb_core.c

 *

 * Copyright (C) 2003-2010 PEAK System-Technik GmbH

 * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>

 *

 * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>

 *

 * 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/slab.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>



#include "pcan_usb_core.h"



MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");

MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");

MODULE_LICENSE("GPL v2");



/* Table of devices that work with this driver */

static struct usb_device_id peak_usb_table[] = {

	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID)},

	{USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID)},

	{} /* Terminating entry */

};



MODULE_DEVICE_TABLE(usb, peak_usb_table);



/* List of supported PCAN-USB adapters (NULL terminated list) */

static struct peak_usb_adapter *peak_usb_adapters_list[] = {

	&pcan_usb,

	&pcan_usb_pro,

	NULL,

};



/*

 * dump memory

 */

#define DUMP_WIDTH	16

void dump_mem(char *prompt, void *p, int l)

{

	pr_info("%s dumping %s (%d bytes):\n",

		PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);

	print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,

		       DUMP_WIDTH, 1, p, l, false);

}



/*

 * initialize a time_ref object with usb adapter own settings

 */

void peak_usb_init_time_ref(struct peak_time_ref *time_ref,

			    struct peak_usb_adapter *adapter)

{

	if (time_ref) {

		memset(time_ref, 0, sizeof(struct peak_time_ref));

		time_ref->adapter = adapter;

	}

}



static void peak_usb_add_us(struct timeval *tv, u32 delta_us)

{

	/* number of s. to add to final time */

	u32 delta_s = delta_us / 1000000;



	delta_us -= delta_s * 1000000;



	tv->tv_usec += delta_us;

	if (tv->tv_usec >= 1000000) {

		tv->tv_usec -= 1000000;

		delta_s++;

	}

	tv->tv_sec += delta_s;

}



/*

 * sometimes, another now may be  more recent than current one...

 */

void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)

{

	time_ref->ts_dev_2 = ts_now;



	/* should wait at least two passes before computing */

	if (time_ref->tv_host.tv_sec > 0) {

		u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;



		if (time_ref->ts_dev_2 < time_ref->ts_dev_1)

			delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;



		time_ref->ts_total += delta_ts;

	}

}



/*

 * register device timestamp as now

 */

void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)

{

	if (time_ref->tv_host_0.tv_sec == 0) {

		/* use monotonic clock to correctly compute further deltas */

		time_ref->tv_host_0 = ktime_to_timeval(ktime_get());

		time_ref->tv_host.tv_sec = 0;

	} else {

		/*

		 * delta_us should not be >= 2^32 => delta_s should be < 4294

		 * handle 32-bits wrapping here: if count of s. reaches 4200,

		 * reset counters and change time base

		 */

		if (time_ref->tv_host.tv_sec != 0) {

			u32 delta_s = time_ref->tv_host.tv_sec

						- time_ref->tv_host_0.tv_sec;

			if (delta_s > 4200) {

				time_ref->tv_host_0 = time_ref->tv_host;

				time_ref->ts_total = 0;

			}

		}



		time_ref->tv_host = ktime_to_timeval(ktime_get());

		time_ref->tick_count++;

	}



	time_ref->ts_dev_1 = time_ref->ts_dev_2;

	peak_usb_update_ts_now(time_ref, ts_now);

}



/*

 * compute timeval according to current ts and time_ref data

 */

void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,

			struct timeval *tv)

{

	/* protect from getting timeval before setting now */

	if (time_ref->tv_host.tv_sec > 0) {

		u64 delta_us;



		delta_us = ts - time_ref->ts_dev_2;

		if (ts < time_ref->ts_dev_2)

			delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;



		delta_us += time_ref->ts_total;



		delta_us *= time_ref->adapter->us_per_ts_scale;

		delta_us >>= time_ref->adapter->us_per_ts_shift;



		*tv = time_ref->tv_host_0;

		peak_usb_add_us(tv, (u32)delta_us);

	} else {

		*tv = ktime_to_timeval(ktime_get());

	}

}



/*

 * callback for bulk Rx urb

 */

static void peak_usb_read_bulk_callback(struct urb *urb)

{

	struct peak_usb_device *dev = urb->context;

	struct net_device *netdev;

	int err;



	netdev = dev->netdev;



	if (!netif_device_present(netdev))

		return;



	/* check reception status */

	switch (urb->status) {

	case 0:

		/* success */

		break;



	case -EILSEQ:

	case -ENOENT:

	case -ECONNRESET:

	case -ESHUTDOWN:

		return;



	default:

		if (net_ratelimit())

			netdev_err(netdev,

				   "Rx urb aborted (%d)\n", urb->status);

		goto resubmit_urb;

	}



	/* protect from any incoming empty msgs */

	if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {

		/* handle these kinds of msgs only if _start callback called */

		if (dev->state & PCAN_USB_STATE_STARTED) {

			err = dev->adapter->dev_decode_buf(dev, urb);

			if (err)

				dump_mem("received usb message",

					urb->transfer_buffer,

					urb->transfer_buffer_length);

		}

	}



resubmit_urb:

	usb_fill_bulk_urb(urb, dev->udev,

		usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),

		urb->transfer_buffer, dev->adapter->rx_buffer_size,

		peak_usb_read_bulk_callback, dev);



	usb_anchor_urb(urb, &dev->rx_submitted);

	err = usb_submit_urb(urb, GFP_ATOMIC);

	if (!err)

		return;



	usb_unanchor_urb(urb);



	if (err == -ENODEV)

		netif_device_detach(netdev);

	else

		netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",

			   err);

}



/*

 * callback for bulk Tx urb

 */

static void peak_usb_write_bulk_callback(struct urb *urb)

{

	struct peak_tx_urb_context *context = urb->context;

	struct peak_usb_device *dev;

	struct net_device *netdev;



	BUG_ON(!context);



	dev = context->dev;

	netdev = dev->netdev;



	atomic_dec(&dev->active_tx_urbs);



	if (!netif_device_present(netdev))

		return;



	/* check tx status */

	switch (urb->status) {

	case 0:

		/* transmission complete */

		netdev->stats.tx_packets++;

		netdev->stats.tx_bytes += context->dlc;



		/* prevent tx timeout */

		netdev->trans_start = jiffies;

		break;



	default:

		if (net_ratelimit())

			netdev_err(netdev, "Tx urb aborted (%d)\n",

				   urb->status);

	case -EPROTO:

	case -ENOENT:

	case -ECONNRESET:

	case -ESHUTDOWN:



		break;

	}



	/* should always release echo skb and corresponding context */

	can_get_echo_skb(netdev, context->echo_index);

	context->echo_index = PCAN_USB_MAX_TX_URBS;



	/* do wakeup tx queue in case of success only */

	if (!urb->status)

		netif_wake_queue(netdev);

}



/*

 * called by netdev to send one skb on the CAN interface.

 */

static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,

					   struct net_device *netdev)

{

	struct peak_usb_device *dev = netdev_priv(netdev);

	struct peak_tx_urb_context *context = NULL;

	struct net_device_stats *stats = &netdev->stats;

	struct can_frame *cf = (struct can_frame *)skb->data;

	struct urb *urb;

	u8 *obuf;

	int i, err;

	size_t size = dev->adapter->tx_buffer_size;



	if (can_dropped_invalid_skb(netdev, skb))

		return NETDEV_TX_OK;



	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)

		if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {

			context = dev->tx_contexts + i;

			break;

		}



	if (!context) {

		/* should not occur except during restart */

		return NETDEV_TX_BUSY;

	}



	urb = context->urb;

	obuf = urb->transfer_buffer;



	err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);

	if (err) {

		if (net_ratelimit())

			netdev_err(netdev, "packet dropped\n");

		dev_kfree_skb(skb);

		stats->tx_dropped++;

		return NETDEV_TX_OK;

	}



	context->echo_index = i;

	context->dlc = cf->can_dlc;



	usb_anchor_urb(urb, &dev->tx_submitted);



	can_put_echo_skb(skb, netdev, context->echo_index);



	atomic_inc(&dev->active_tx_urbs);



	err = usb_submit_urb(urb, GFP_ATOMIC);

	if (err) {

		can_free_echo_skb(netdev, context->echo_index);



		usb_unanchor_urb(urb);



		/* this context is not used in fact */

		context->echo_index = PCAN_USB_MAX_TX_URBS;



		atomic_dec(&dev->active_tx_urbs);



		switch (err) {

		case -ENODEV:

			netif_device_detach(netdev);

			break;

		default:

			netdev_warn(netdev, "tx urb submitting failed err=%d\n",

				    err);

		case -ENOENT:

			/* cable unplugged */

			stats->tx_dropped++;

		}

	} else {

		netdev->trans_start = jiffies;



		/* slow down tx path */

		if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)

			netif_stop_queue(netdev);

	}



	return NETDEV_TX_OK;

}



/*

 * start the CAN interface.

 * Rx and Tx urbs are allocated here. Rx urbs are submitted here.

 */

static int peak_usb_start(struct peak_usb_device *dev)

{

	struct net_device *netdev = dev->netdev;

	int err, i;



	for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {

		struct urb *urb;

		u8 *buf;



		/* create a URB, and a buffer for it, to receive usb messages */

		urb = usb_alloc_urb(0, GFP_KERNEL);

		if (!urb) {

			netdev_err(netdev, "No memory left for URBs\n");

			err = -ENOMEM;

			break;

		}



		buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);

		if (!buf) {

			netdev_err(netdev, "No memory left for USB buffer\n");

			usb_free_urb(urb);

			err = -ENOMEM;

			break;

		}



		usb_fill_bulk_urb(urb, dev->udev,

			usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),

			buf, dev->adapter->rx_buffer_size,

			peak_usb_read_bulk_callback, dev);



		/* ask last usb_free_urb() to also kfree() transfer_buffer */

		urb->transfer_flags |= URB_FREE_BUFFER;

		usb_anchor_urb(urb, &dev->rx_submitted);



		err = usb_submit_urb(urb, GFP_KERNEL);

		if (err) {

			if (err == -ENODEV)

				netif_device_detach(dev->netdev);



			usb_unanchor_urb(urb);

			kfree(buf);

			usb_free_urb(urb);

			break;

		}



		/* drop reference, USB core will take care of freeing it */

		usb_free_urb(urb);

	}



	/* did we submit any URBs? Warn if we was not able to submit all urbs */

	if (i < PCAN_USB_MAX_RX_URBS) {

		if (i == 0) {

			netdev_err(netdev, "couldn't setup any rx URB\n");

			return err;

		}



		netdev_warn(netdev, "rx performance may be slow\n");

	}



	/* pre-alloc tx buffers and corresponding urbs */

	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {

		struct peak_tx_urb_context *context;

		struct urb *urb;

		u8 *buf;



		/* create a URB and a buffer for it, to transmit usb messages */

		urb = usb_alloc_urb(0, GFP_KERNEL);

		if (!urb) {

			netdev_err(netdev, "No memory left for URBs\n");

			err = -ENOMEM;

			break;

		}



		buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);

		if (!buf) {

			netdev_err(netdev, "No memory left for USB buffer\n");

			usb_free_urb(urb);

			err = -ENOMEM;

			break;

		}



		context = dev->tx_contexts + i;

		context->dev = dev;

		context->urb = urb;



		usb_fill_bulk_urb(urb, dev->udev,

			usb_sndbulkpipe(dev->udev, dev->ep_msg_out),

			buf, dev->adapter->tx_buffer_size,

			peak_usb_write_bulk_callback, context);



		/* ask last usb_free_urb() to also kfree() transfer_buffer */

		urb->transfer_flags |= URB_FREE_BUFFER;

	}



	/* warn if we were not able to allocate enough tx contexts */

	if (i < PCAN_USB_MAX_TX_URBS) {

		if (i == 0) {

			netdev_err(netdev, "couldn't setup any tx URB\n");

			return err;

		}



		netdev_warn(netdev, "tx performance may be slow\n");

	}



	if (dev->adapter->dev_start) {

		err = dev->adapter->dev_start(dev);

		if (err)

			goto failed;

	}



	dev->state |= PCAN_USB_STATE_STARTED;



	/* can set bus on now */

	if (dev->adapter->dev_set_bus) {

		err = dev->adapter->dev_set_bus(dev, 1);

		if (err)

			goto failed;

	}



	dev->can.state = CAN_STATE_ERROR_ACTIVE;



	return 0;



failed:

	if (err == -ENODEV)

		netif_device_detach(dev->netdev);



	netdev_warn(netdev, "couldn't submit control: %d\n", err);



	return err;

}



/*

 * called by netdev to open the corresponding CAN interface.

 */

static int peak_usb_ndo_open(struct net_device *netdev)

{

	struct peak_usb_device *dev = netdev_priv(netdev);

	int err;



	/* common open */

	err = open_candev(netdev);

	if (err)

		return err;



	/* finally start device */

	err = peak_usb_start(dev);

	if (err) {

		netdev_err(netdev, "couldn't start device: %d\n", err);

		close_candev(netdev);

		return err;

	}



	dev->open_time = jiffies;

	netif_start_queue(netdev);



	return 0;

}



/*

 * unlink in-flight Rx and Tx urbs and free their memory.

 */

static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)

{

	int i;



	/* free all Rx (submitted) urbs */

	usb_kill_anchored_urbs(&dev->rx_submitted);



	/* free unsubmitted Tx urbs first */

	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {

		struct urb *urb = dev->tx_contexts[i].urb;



		if (!urb ||

		    dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {

			/*

			 * this urb is already released or always submitted,

			 * let usb core free by itself

			 */

			continue;

		}



		usb_free_urb(urb);

		dev->tx_contexts[i].urb = NULL;

	}



	/* then free all submitted Tx urbs */

	usb_kill_anchored_urbs(&dev->tx_submitted);

	atomic_set(&dev->active_tx_urbs, 0);

}



/*

 * called by netdev to close the corresponding CAN interface.

 */

static int peak_usb_ndo_stop(struct net_device *netdev)

{

	struct peak_usb_device *dev = netdev_priv(netdev);



	dev->state &= ~PCAN_USB_STATE_STARTED;

	netif_stop_queue(netdev);



	/* unlink all pending urbs and free used memory */

	peak_usb_unlink_all_urbs(dev);



	if (dev->adapter->dev_stop)

		dev->adapter->dev_stop(dev);



	close_candev(netdev);



	dev->open_time = 0;

	dev->can.state = CAN_STATE_STOPPED;



	/* can set bus off now */

	if (dev->adapter->dev_set_bus) {

		int err = dev->adapter->dev_set_bus(dev, 0);

		if (err)

			return err;

	}



	return 0;

}



/*

 * handle end of waiting for the device to reset

 */

void peak_usb_restart_complete(struct peak_usb_device *dev)

{

	/* finally MUST update can state */

	dev->can.state = CAN_STATE_ERROR_ACTIVE;



	/* netdev queue can be awaken now */

	netif_wake_queue(dev->netdev);

}



void peak_usb_async_complete(struct urb *urb)

{

	kfree(urb->transfer_buffer);

	usb_free_urb(urb);

}



/*

 * device (auto-)restart mechanism runs in a timer context =>

 * MUST handle restart with asynchronous usb transfers

 */

static int peak_usb_restart(struct peak_usb_device *dev)

{

	struct urb *urb;

	int err;

	u8 *buf;



	/*

	 * if device doesn't define any asynchronous restart handler, simply

	 * wake the netdev queue up

	 */

	if (!dev->adapter->dev_restart_async) {

		peak_usb_restart_complete(dev);

		return 0;

	}



	/* first allocate a urb to handle the asynchronous steps */

	urb = usb_alloc_urb(0, GFP_ATOMIC);

	if (!urb) {

		netdev_err(dev->netdev, "no memory left for urb\n");

		return -ENOMEM;

	}



	/* also allocate enough space for the commands to send */

	buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);

	if (!buf) {

		netdev_err(dev->netdev, "no memory left for async cmd\n");

		usb_free_urb(urb);

		return -ENOMEM;

	}



	/* call the device specific handler for the restart */

	err = dev->adapter->dev_restart_async(dev, urb, buf);

	if (!err)

		return 0;



	kfree(buf);

	usb_free_urb(urb);



	return err;

}



/*

 * candev callback used to change CAN mode.

 * Warning: this is called from a timer context!

 */

static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)

{

	struct peak_usb_device *dev = netdev_priv(netdev);

	int err = 0;



	if (!dev->open_time)

		return -EINVAL;



	switch (mode) {

	case CAN_MODE_START:

		err = peak_usb_restart(dev);

		if (err)

			netdev_err(netdev, "couldn't start device (err %d)\n",

				   err);

		break;



	default:

		return -EOPNOTSUPP;

	}



	return err;

}



/*

 * candev callback used to set device bitrate.

 */

static int peak_usb_set_bittiming(struct net_device *netdev)

{

	struct peak_usb_device *dev = netdev_priv(netdev);

	struct can_bittiming *bt = &dev->can.bittiming;



	if (dev->adapter->dev_set_bittiming) {

		int err = dev->adapter->dev_set_bittiming(dev, bt);



		if (err)

			netdev_info(netdev, "couldn't set bitrate (err %d)\n",

				err);

		return err;

	}



	return 0;

}



static const struct net_device_ops peak_usb_netdev_ops = {

	.ndo_open = peak_usb_ndo_open,

	.ndo_stop = peak_usb_ndo_stop,

	.ndo_start_xmit = peak_usb_ndo_start_xmit,

};



/*

 * create one device which is attached to CAN controller #ctrl_idx of the

 * usb adapter.

 */

static int peak_usb_create_dev(struct peak_usb_adapter *peak_usb_adapter,

			       struct usb_interface *intf, int ctrl_idx)

{

	struct usb_device *usb_dev = interface_to_usbdev(intf);

	int sizeof_candev = peak_usb_adapter->sizeof_dev_private;

	struct peak_usb_device *dev;

	struct net_device *netdev;

	int i, err;

	u16 tmp16;



	if (sizeof_candev < sizeof(struct peak_usb_device))

		sizeof_candev = sizeof(struct peak_usb_device);



	netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);

	if (!netdev) {

		dev_err(&intf->dev, "%s: couldn't alloc candev\n",

			PCAN_USB_DRIVER_NAME);

		return -ENOMEM;

	}



	dev = netdev_priv(netdev);



	/* allocate a buffer large enough to send commands */

	dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);

	if (!dev->cmd_buf) {

		dev_err(&intf->dev, "%s: couldn't alloc cmd buffer\n",

			PCAN_USB_DRIVER_NAME);

		err = -ENOMEM;

		goto lbl_set_intf_data;

	}



	dev->udev = usb_dev;

	dev->netdev = netdev;

	dev->adapter = peak_usb_adapter;

	dev->ctrl_idx = ctrl_idx;

	dev->state = PCAN_USB_STATE_CONNECTED;



	dev->ep_msg_in = peak_usb_adapter->ep_msg_in;

	dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];



	dev->can.clock = peak_usb_adapter->clock;

	dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;

	dev->can.do_set_bittiming = peak_usb_set_bittiming;

	dev->can.do_set_mode = peak_usb_set_mode;

	dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |

				      CAN_CTRLMODE_LISTENONLY;



	netdev->netdev_ops = &peak_usb_netdev_ops;



	netdev->flags |= IFF_ECHO; /* we support local echo */



	init_usb_anchor(&dev->rx_submitted);



	init_usb_anchor(&dev->tx_submitted);

	atomic_set(&dev->active_tx_urbs, 0);



	for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)

		dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;



	dev->prev_siblings = usb_get_intfdata(intf);

	usb_set_intfdata(intf, dev);



	SET_NETDEV_DEV(netdev, &intf->dev);



	err = register_candev(netdev);

	if (err) {

		dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);

		goto lbl_free_cmd_buf;

	}



	if (dev->prev_siblings)

		(dev->prev_siblings)->next_siblings = dev;



	/* keep hw revision into the netdevice */

	tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);

	dev->device_rev = tmp16 >> 8;



	if (dev->adapter->dev_init) {

		err = dev->adapter->dev_init(dev);

		if (err)

			goto lbl_free_cmd_buf;

	}



	/* set bus off */

	if (dev->adapter->dev_set_bus) {

		err = dev->adapter->dev_set_bus(dev, 0);

		if (err)

			goto lbl_free_cmd_buf;

	}



	/* get device number early */

	if (dev->adapter->dev_get_device_id)

		dev->adapter->dev_get_device_id(dev, &dev->device_number);



	netdev_info(netdev, "attached to %s channel %u (device %u)\n",

			peak_usb_adapter->name, ctrl_idx, dev->device_number);



	return 0;



lbl_free_cmd_buf:

	kfree(dev->cmd_buf);



lbl_set_intf_data:

	usb_set_intfdata(intf, dev->prev_siblings);

	free_candev(netdev);



	return err;

}



/*

 * called by the usb core when the device is unplugged from the system

 */

static void peak_usb_disconnect(struct usb_interface *intf)

{

	struct peak_usb_device *dev;



	/* unregister as many netdev devices as siblings */

	for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {

		struct net_device *netdev = dev->netdev;

		char name[IFNAMSIZ];



		dev->state &= ~PCAN_USB_STATE_CONNECTED;

		strncpy(name, netdev->name, IFNAMSIZ);



		unregister_netdev(netdev);

		free_candev(netdev);



		kfree(dev->cmd_buf);

		dev->next_siblings = NULL;

		if (dev->adapter->dev_free)

			dev->adapter->dev_free(dev);



		dev_info(&intf->dev, "%s removed\n", name);

	}



	usb_set_intfdata(intf, NULL);

}



/*

 * probe function for new PEAK-System devices

 */

static int peak_usb_probe(struct usb_interface *intf,

			  const struct usb_device_id *id)

{

	struct usb_device *usb_dev = interface_to_usbdev(intf);

	struct peak_usb_adapter *peak_usb_adapter, **pp;

	int i, err = -ENOMEM;



	usb_dev = interface_to_usbdev(intf);



	/* get corresponding PCAN-USB adapter */

	for (pp = peak_usb_adapters_list; *pp; pp++)

		if ((*pp)->device_id == usb_dev->descriptor.idProduct)

			break;



	peak_usb_adapter = *pp;

	if (!peak_usb_adapter) {

		/* should never come except device_id bad usage in this file */

		pr_err("%s: didn't find device id. 0x%x in devices list\n",

			PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);

		return -ENODEV;

	}



	/* got corresponding adapter: check if it handles current interface */

	if (peak_usb_adapter->intf_probe) {

		err = peak_usb_adapter->intf_probe(intf);

		if (err)

			return err;

	}



	for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {

		err = peak_usb_create_dev(peak_usb_adapter, intf, i);

		if (err) {

			/* deregister already created devices */

			peak_usb_disconnect(intf);

			break;

		}

	}



	return err;

}



/* usb specific object needed to register this driver with the usb subsystem */

static struct usb_driver peak_usb_driver = {

	.name = PCAN_USB_DRIVER_NAME,

	.disconnect = peak_usb_disconnect,

	.probe = peak_usb_probe,

	.id_table = peak_usb_table,

};



static int __init peak_usb_init(void)

{

	int err;



	/* register this driver with the USB subsystem */

	err = usb_register(&peak_usb_driver);

	if (err)

		pr_err("%s: usb_register failed (err %d)\n",

			PCAN_USB_DRIVER_NAME, err);



	return err;

}



static int peak_usb_do_device_exit(struct device *d, void *arg)

{

	struct usb_interface *intf = to_usb_interface(d);

	struct peak_usb_device *dev;



	/* stop as many netdev devices as siblings */

	for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {

		struct net_device *netdev = dev->netdev;



		if (netif_device_present(netdev))

			if (dev->adapter->dev_exit)

				dev->adapter->dev_exit(dev);

	}



	return 0;

}



static void __exit peak_usb_exit(void)

{

	int err;



	/* last chance do send any synchronous commands here */

	err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,

				     NULL, peak_usb_do_device_exit);

	if (err)

		pr_err("%s: failed to stop all can devices (err %d)\n",

			PCAN_USB_DRIVER_NAME, err);



	/* deregister this driver with the USB subsystem */

	usb_deregister(&peak_usb_driver);



	pr_info("%s: PCAN-USB interfaces driver unloaded\n",

		PCAN_USB_DRIVER_NAME);

}



module_init(peak_usb_init);

module_exit(peak_usb_exit);