2 * CAN driver for PEAK System USB adapters
3 * Derived from the PCAN project file driver/src/pcan_usb_core.c
5 * Copyright (C) 2003-2010 PEAK System-Technik GmbH
6 * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com>
8 * Many thanks to Klaus Hitschler <klaus.hitschler@gmx.de>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published
12 * by the Free Software Foundation; version 2 of the License.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 #include <linux/init.h>
20 #include <linux/signal.h>
21 #include <linux/slab.h>
22 #include <linux/module.h>
23 #include <linux/netdevice.h>
24 #include <linux/usb.h>
26 #include <linux/can.h>
27 #include <linux/can/dev.h>
28 #include <linux/can/error.h>
30 #include "pcan_usb_core.h"
32 MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
33 MODULE_DESCRIPTION("CAN driver for PEAK-System USB adapters");
34 MODULE_LICENSE("GPL v2");
36 /* Table of devices that work with this driver */
37 static struct usb_device_id peak_usb_table[] = {
38 {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USB_PRODUCT_ID)},
39 {USB_DEVICE(PCAN_USB_VENDOR_ID, PCAN_USBPRO_PRODUCT_ID)},
40 {} /* Terminating entry */
43 MODULE_DEVICE_TABLE(usb, peak_usb_table);
45 /* List of supported PCAN-USB adapters (NULL terminated list) */
46 static struct peak_usb_adapter *peak_usb_adapters_list[] = {
56 void pcan_dump_mem(char *prompt, void *p, int l)
58 pr_info("%s dumping %s (%d bytes):\n",
59 PCAN_USB_DRIVER_NAME, prompt ? prompt : "memory", l);
60 print_hex_dump(KERN_INFO, PCAN_USB_DRIVER_NAME " ", DUMP_PREFIX_NONE,
61 DUMP_WIDTH, 1, p, l, false);
65 * initialize a time_ref object with usb adapter own settings
67 void peak_usb_init_time_ref(struct peak_time_ref *time_ref,
68 struct peak_usb_adapter *adapter)
71 memset(time_ref, 0, sizeof(struct peak_time_ref));
72 time_ref->adapter = adapter;
76 static void peak_usb_add_us(struct timeval *tv, u32 delta_us)
78 /* number of s. to add to final time */
79 u32 delta_s = delta_us / 1000000;
81 delta_us -= delta_s * 1000000;
83 tv->tv_usec += delta_us;
84 if (tv->tv_usec >= 1000000) {
85 tv->tv_usec -= 1000000;
88 tv->tv_sec += delta_s;
92 * sometimes, another now may be more recent than current one...
94 void peak_usb_update_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
96 time_ref->ts_dev_2 = ts_now;
98 /* should wait at least two passes before computing */
99 if (time_ref->tv_host.tv_sec > 0) {
100 u32 delta_ts = time_ref->ts_dev_2 - time_ref->ts_dev_1;
102 if (time_ref->ts_dev_2 < time_ref->ts_dev_1)
103 delta_ts &= (1 << time_ref->adapter->ts_used_bits) - 1;
105 time_ref->ts_total += delta_ts;
110 * register device timestamp as now
112 void peak_usb_set_ts_now(struct peak_time_ref *time_ref, u32 ts_now)
114 if (time_ref->tv_host_0.tv_sec == 0) {
115 /* use monotonic clock to correctly compute further deltas */
116 time_ref->tv_host_0 = ktime_to_timeval(ktime_get());
117 time_ref->tv_host.tv_sec = 0;
120 * delta_us should not be >= 2^32 => delta_s should be < 4294
121 * handle 32-bits wrapping here: if count of s. reaches 4200,
122 * reset counters and change time base
124 if (time_ref->tv_host.tv_sec != 0) {
125 u32 delta_s = time_ref->tv_host.tv_sec
126 - time_ref->tv_host_0.tv_sec;
127 if (delta_s > 4200) {
128 time_ref->tv_host_0 = time_ref->tv_host;
129 time_ref->ts_total = 0;
133 time_ref->tv_host = ktime_to_timeval(ktime_get());
134 time_ref->tick_count++;
137 time_ref->ts_dev_1 = time_ref->ts_dev_2;
138 peak_usb_update_ts_now(time_ref, ts_now);
142 * compute timeval according to current ts and time_ref data
144 void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts,
147 /* protect from getting timeval before setting now */
148 if (time_ref->tv_host.tv_sec > 0) {
151 delta_us = ts - time_ref->ts_dev_2;
152 if (ts < time_ref->ts_dev_2)
153 delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1;
155 delta_us += time_ref->ts_total;
157 delta_us *= time_ref->adapter->us_per_ts_scale;
158 delta_us >>= time_ref->adapter->us_per_ts_shift;
160 *tv = time_ref->tv_host_0;
161 peak_usb_add_us(tv, (u32)delta_us);
163 *tv = ktime_to_timeval(ktime_get());
168 * callback for bulk Rx urb
170 static void peak_usb_read_bulk_callback(struct urb *urb)
172 struct peak_usb_device *dev = urb->context;
173 struct net_device *netdev;
176 netdev = dev->netdev;
178 if (!netif_device_present(netdev))
181 /* check reception status */
182 switch (urb->status) {
196 "Rx urb aborted (%d)\n", urb->status);
200 /* protect from any incoming empty msgs */
201 if ((urb->actual_length > 0) && (dev->adapter->dev_decode_buf)) {
202 /* handle these kinds of msgs only if _start callback called */
203 if (dev->state & PCAN_USB_STATE_STARTED) {
204 err = dev->adapter->dev_decode_buf(dev, urb);
206 pcan_dump_mem("received usb message",
207 urb->transfer_buffer,
208 urb->transfer_buffer_length);
213 usb_fill_bulk_urb(urb, dev->udev,
214 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
215 urb->transfer_buffer, dev->adapter->rx_buffer_size,
216 peak_usb_read_bulk_callback, dev);
218 usb_anchor_urb(urb, &dev->rx_submitted);
219 err = usb_submit_urb(urb, GFP_ATOMIC);
223 usb_unanchor_urb(urb);
226 netif_device_detach(netdev);
228 netdev_err(netdev, "failed resubmitting read bulk urb: %d\n",
233 * callback for bulk Tx urb
235 static void peak_usb_write_bulk_callback(struct urb *urb)
237 struct peak_tx_urb_context *context = urb->context;
238 struct peak_usb_device *dev;
239 struct net_device *netdev;
244 netdev = dev->netdev;
246 atomic_dec(&dev->active_tx_urbs);
248 if (!netif_device_present(netdev))
251 /* check tx status */
252 switch (urb->status) {
254 /* transmission complete */
255 netdev->stats.tx_packets++;
256 netdev->stats.tx_bytes += context->dlc;
258 /* prevent tx timeout */
259 netdev->trans_start = jiffies;
264 netdev_err(netdev, "Tx urb aborted (%d)\n",
274 /* should always release echo skb and corresponding context */
275 can_get_echo_skb(netdev, context->echo_index);
276 context->echo_index = PCAN_USB_MAX_TX_URBS;
278 /* do wakeup tx queue in case of success only */
280 netif_wake_queue(netdev);
284 * called by netdev to send one skb on the CAN interface.
286 static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
287 struct net_device *netdev)
289 struct peak_usb_device *dev = netdev_priv(netdev);
290 struct peak_tx_urb_context *context = NULL;
291 struct net_device_stats *stats = &netdev->stats;
292 struct can_frame *cf = (struct can_frame *)skb->data;
296 size_t size = dev->adapter->tx_buffer_size;
298 if (can_dropped_invalid_skb(netdev, skb))
301 for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
302 if (dev->tx_contexts[i].echo_index == PCAN_USB_MAX_TX_URBS) {
303 context = dev->tx_contexts + i;
308 /* should not occur except during restart */
309 return NETDEV_TX_BUSY;
313 obuf = urb->transfer_buffer;
315 err = dev->adapter->dev_encode_msg(dev, skb, obuf, &size);
318 netdev_err(netdev, "packet dropped\n");
324 context->echo_index = i;
325 context->dlc = cf->can_dlc;
327 usb_anchor_urb(urb, &dev->tx_submitted);
329 can_put_echo_skb(skb, netdev, context->echo_index);
331 atomic_inc(&dev->active_tx_urbs);
333 err = usb_submit_urb(urb, GFP_ATOMIC);
335 can_free_echo_skb(netdev, context->echo_index);
337 usb_unanchor_urb(urb);
339 /* this context is not used in fact */
340 context->echo_index = PCAN_USB_MAX_TX_URBS;
342 atomic_dec(&dev->active_tx_urbs);
346 netif_device_detach(netdev);
349 netdev_warn(netdev, "tx urb submitting failed err=%d\n",
352 /* cable unplugged */
356 netdev->trans_start = jiffies;
358 /* slow down tx path */
359 if (atomic_read(&dev->active_tx_urbs) >= PCAN_USB_MAX_TX_URBS)
360 netif_stop_queue(netdev);
367 * start the CAN interface.
368 * Rx and Tx urbs are allocated here. Rx urbs are submitted here.
370 static int peak_usb_start(struct peak_usb_device *dev)
372 struct net_device *netdev = dev->netdev;
375 for (i = 0; i < PCAN_USB_MAX_RX_URBS; i++) {
379 /* create a URB, and a buffer for it, to receive usb messages */
380 urb = usb_alloc_urb(0, GFP_KERNEL);
382 netdev_err(netdev, "No memory left for URBs\n");
387 buf = kmalloc(dev->adapter->rx_buffer_size, GFP_KERNEL);
394 usb_fill_bulk_urb(urb, dev->udev,
395 usb_rcvbulkpipe(dev->udev, dev->ep_msg_in),
396 buf, dev->adapter->rx_buffer_size,
397 peak_usb_read_bulk_callback, dev);
399 /* ask last usb_free_urb() to also kfree() transfer_buffer */
400 urb->transfer_flags |= URB_FREE_BUFFER;
401 usb_anchor_urb(urb, &dev->rx_submitted);
403 err = usb_submit_urb(urb, GFP_KERNEL);
406 netif_device_detach(dev->netdev);
408 usb_unanchor_urb(urb);
414 /* drop reference, USB core will take care of freeing it */
418 /* did we submit any URBs? Warn if we was not able to submit all urbs */
419 if (i < PCAN_USB_MAX_RX_URBS) {
421 netdev_err(netdev, "couldn't setup any rx URB\n");
425 netdev_warn(netdev, "rx performance may be slow\n");
428 /* pre-alloc tx buffers and corresponding urbs */
429 for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
430 struct peak_tx_urb_context *context;
434 /* create a URB and a buffer for it, to transmit usb messages */
435 urb = usb_alloc_urb(0, GFP_KERNEL);
437 netdev_err(netdev, "No memory left for URBs\n");
442 buf = kmalloc(dev->adapter->tx_buffer_size, GFP_KERNEL);
449 context = dev->tx_contexts + i;
453 usb_fill_bulk_urb(urb, dev->udev,
454 usb_sndbulkpipe(dev->udev, dev->ep_msg_out),
455 buf, dev->adapter->tx_buffer_size,
456 peak_usb_write_bulk_callback, context);
458 /* ask last usb_free_urb() to also kfree() transfer_buffer */
459 urb->transfer_flags |= URB_FREE_BUFFER;
462 /* warn if we were not able to allocate enough tx contexts */
463 if (i < PCAN_USB_MAX_TX_URBS) {
465 netdev_err(netdev, "couldn't setup any tx URB\n");
469 netdev_warn(netdev, "tx performance may be slow\n");
472 if (dev->adapter->dev_start) {
473 err = dev->adapter->dev_start(dev);
478 dev->state |= PCAN_USB_STATE_STARTED;
480 /* can set bus on now */
481 if (dev->adapter->dev_set_bus) {
482 err = dev->adapter->dev_set_bus(dev, 1);
487 dev->can.state = CAN_STATE_ERROR_ACTIVE;
493 netif_device_detach(dev->netdev);
495 netdev_warn(netdev, "couldn't submit control: %d\n", err);
497 for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
498 usb_free_urb(dev->tx_contexts[i].urb);
499 dev->tx_contexts[i].urb = NULL;
502 usb_kill_anchored_urbs(&dev->rx_submitted);
508 * called by netdev to open the corresponding CAN interface.
510 static int peak_usb_ndo_open(struct net_device *netdev)
512 struct peak_usb_device *dev = netdev_priv(netdev);
516 err = open_candev(netdev);
520 /* finally start device */
521 err = peak_usb_start(dev);
523 netdev_err(netdev, "couldn't start device: %d\n", err);
524 close_candev(netdev);
528 netif_start_queue(netdev);
534 * unlink in-flight Rx and Tx urbs and free their memory.
536 static void peak_usb_unlink_all_urbs(struct peak_usb_device *dev)
540 /* free all Rx (submitted) urbs */
541 usb_kill_anchored_urbs(&dev->rx_submitted);
543 /* free unsubmitted Tx urbs first */
544 for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++) {
545 struct urb *urb = dev->tx_contexts[i].urb;
548 dev->tx_contexts[i].echo_index != PCAN_USB_MAX_TX_URBS) {
550 * this urb is already released or always submitted,
551 * let usb core free by itself
557 dev->tx_contexts[i].urb = NULL;
560 /* then free all submitted Tx urbs */
561 usb_kill_anchored_urbs(&dev->tx_submitted);
562 atomic_set(&dev->active_tx_urbs, 0);
566 * called by netdev to close the corresponding CAN interface.
568 static int peak_usb_ndo_stop(struct net_device *netdev)
570 struct peak_usb_device *dev = netdev_priv(netdev);
572 dev->state &= ~PCAN_USB_STATE_STARTED;
573 netif_stop_queue(netdev);
575 /* unlink all pending urbs and free used memory */
576 peak_usb_unlink_all_urbs(dev);
578 if (dev->adapter->dev_stop)
579 dev->adapter->dev_stop(dev);
581 close_candev(netdev);
583 dev->can.state = CAN_STATE_STOPPED;
585 /* can set bus off now */
586 if (dev->adapter->dev_set_bus) {
587 int err = dev->adapter->dev_set_bus(dev, 0);
596 * handle end of waiting for the device to reset
598 void peak_usb_restart_complete(struct peak_usb_device *dev)
600 /* finally MUST update can state */
601 dev->can.state = CAN_STATE_ERROR_ACTIVE;
603 /* netdev queue can be awaken now */
604 netif_wake_queue(dev->netdev);
607 void peak_usb_async_complete(struct urb *urb)
609 kfree(urb->transfer_buffer);
614 * device (auto-)restart mechanism runs in a timer context =>
615 * MUST handle restart with asynchronous usb transfers
617 static int peak_usb_restart(struct peak_usb_device *dev)
624 * if device doesn't define any asynchronous restart handler, simply
625 * wake the netdev queue up
627 if (!dev->adapter->dev_restart_async) {
628 peak_usb_restart_complete(dev);
632 /* first allocate a urb to handle the asynchronous steps */
633 urb = usb_alloc_urb(0, GFP_ATOMIC);
635 netdev_err(dev->netdev, "no memory left for urb\n");
639 /* also allocate enough space for the commands to send */
640 buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_ATOMIC);
646 /* call the device specific handler for the restart */
647 err = dev->adapter->dev_restart_async(dev, urb, buf);
658 * candev callback used to change CAN mode.
659 * Warning: this is called from a timer context!
661 static int peak_usb_set_mode(struct net_device *netdev, enum can_mode mode)
663 struct peak_usb_device *dev = netdev_priv(netdev);
668 err = peak_usb_restart(dev);
670 netdev_err(netdev, "couldn't start device (err %d)\n",
682 * candev callback used to set device bitrate.
684 static int peak_usb_set_bittiming(struct net_device *netdev)
686 struct peak_usb_device *dev = netdev_priv(netdev);
687 struct can_bittiming *bt = &dev->can.bittiming;
689 if (dev->adapter->dev_set_bittiming) {
690 int err = dev->adapter->dev_set_bittiming(dev, bt);
693 netdev_info(netdev, "couldn't set bitrate (err %d)\n",
701 static const struct net_device_ops peak_usb_netdev_ops = {
702 .ndo_open = peak_usb_ndo_open,
703 .ndo_stop = peak_usb_ndo_stop,
704 .ndo_start_xmit = peak_usb_ndo_start_xmit,
708 * create one device which is attached to CAN controller #ctrl_idx of the
711 static int peak_usb_create_dev(struct peak_usb_adapter *peak_usb_adapter,
712 struct usb_interface *intf, int ctrl_idx)
714 struct usb_device *usb_dev = interface_to_usbdev(intf);
715 int sizeof_candev = peak_usb_adapter->sizeof_dev_private;
716 struct peak_usb_device *dev;
717 struct net_device *netdev;
721 if (sizeof_candev < sizeof(struct peak_usb_device))
722 sizeof_candev = sizeof(struct peak_usb_device);
724 netdev = alloc_candev(sizeof_candev, PCAN_USB_MAX_TX_URBS);
726 dev_err(&intf->dev, "%s: couldn't alloc candev\n",
727 PCAN_USB_DRIVER_NAME);
731 dev = netdev_priv(netdev);
733 /* allocate a buffer large enough to send commands */
734 dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
737 goto lbl_set_intf_data;
741 dev->netdev = netdev;
742 dev->adapter = peak_usb_adapter;
743 dev->ctrl_idx = ctrl_idx;
744 dev->state = PCAN_USB_STATE_CONNECTED;
746 dev->ep_msg_in = peak_usb_adapter->ep_msg_in;
747 dev->ep_msg_out = peak_usb_adapter->ep_msg_out[ctrl_idx];
749 dev->can.clock = peak_usb_adapter->clock;
750 dev->can.bittiming_const = &peak_usb_adapter->bittiming_const;
751 dev->can.do_set_bittiming = peak_usb_set_bittiming;
752 dev->can.do_set_mode = peak_usb_set_mode;
753 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
754 CAN_CTRLMODE_LISTENONLY;
756 netdev->netdev_ops = &peak_usb_netdev_ops;
758 netdev->flags |= IFF_ECHO; /* we support local echo */
760 init_usb_anchor(&dev->rx_submitted);
762 init_usb_anchor(&dev->tx_submitted);
763 atomic_set(&dev->active_tx_urbs, 0);
765 for (i = 0; i < PCAN_USB_MAX_TX_URBS; i++)
766 dev->tx_contexts[i].echo_index = PCAN_USB_MAX_TX_URBS;
768 dev->prev_siblings = usb_get_intfdata(intf);
769 usb_set_intfdata(intf, dev);
771 SET_NETDEV_DEV(netdev, &intf->dev);
773 err = register_candev(netdev);
775 dev_err(&intf->dev, "couldn't register CAN device: %d\n", err);
776 goto lbl_free_cmd_buf;
779 if (dev->prev_siblings)
780 (dev->prev_siblings)->next_siblings = dev;
782 /* keep hw revision into the netdevice */
783 tmp16 = le16_to_cpu(usb_dev->descriptor.bcdDevice);
784 dev->device_rev = tmp16 >> 8;
786 if (dev->adapter->dev_init) {
787 err = dev->adapter->dev_init(dev);
789 goto lbl_free_cmd_buf;
793 if (dev->adapter->dev_set_bus) {
794 err = dev->adapter->dev_set_bus(dev, 0);
796 goto lbl_free_cmd_buf;
799 /* get device number early */
800 if (dev->adapter->dev_get_device_id)
801 dev->adapter->dev_get_device_id(dev, &dev->device_number);
803 netdev_info(netdev, "attached to %s channel %u (device %u)\n",
804 peak_usb_adapter->name, ctrl_idx, dev->device_number);
812 usb_set_intfdata(intf, dev->prev_siblings);
819 * called by the usb core when the device is unplugged from the system
821 static void peak_usb_disconnect(struct usb_interface *intf)
823 struct peak_usb_device *dev;
825 /* unregister as many netdev devices as siblings */
826 for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
827 struct net_device *netdev = dev->netdev;
830 dev->state &= ~PCAN_USB_STATE_CONNECTED;
831 strncpy(name, netdev->name, IFNAMSIZ);
833 unregister_netdev(netdev);
837 dev->next_siblings = NULL;
838 if (dev->adapter->dev_free)
839 dev->adapter->dev_free(dev);
841 dev_info(&intf->dev, "%s removed\n", name);
844 usb_set_intfdata(intf, NULL);
848 * probe function for new PEAK-System devices
850 static int peak_usb_probe(struct usb_interface *intf,
851 const struct usb_device_id *id)
853 struct usb_device *usb_dev = interface_to_usbdev(intf);
854 struct peak_usb_adapter *peak_usb_adapter, **pp;
855 int i, err = -ENOMEM;
857 usb_dev = interface_to_usbdev(intf);
859 /* get corresponding PCAN-USB adapter */
860 for (pp = peak_usb_adapters_list; *pp; pp++)
861 if ((*pp)->device_id == usb_dev->descriptor.idProduct)
864 peak_usb_adapter = *pp;
865 if (!peak_usb_adapter) {
866 /* should never come except device_id bad usage in this file */
867 pr_err("%s: didn't find device id. 0x%x in devices list\n",
868 PCAN_USB_DRIVER_NAME, usb_dev->descriptor.idProduct);
872 /* got corresponding adapter: check if it handles current interface */
873 if (peak_usb_adapter->intf_probe) {
874 err = peak_usb_adapter->intf_probe(intf);
879 for (i = 0; i < peak_usb_adapter->ctrl_count; i++) {
880 err = peak_usb_create_dev(peak_usb_adapter, intf, i);
882 /* deregister already created devices */
883 peak_usb_disconnect(intf);
891 /* usb specific object needed to register this driver with the usb subsystem */
892 static struct usb_driver peak_usb_driver = {
893 .name = PCAN_USB_DRIVER_NAME,
894 .disconnect = peak_usb_disconnect,
895 .probe = peak_usb_probe,
896 .id_table = peak_usb_table,
899 static int __init peak_usb_init(void)
903 /* register this driver with the USB subsystem */
904 err = usb_register(&peak_usb_driver);
906 pr_err("%s: usb_register failed (err %d)\n",
907 PCAN_USB_DRIVER_NAME, err);
912 static int peak_usb_do_device_exit(struct device *d, void *arg)
914 struct usb_interface *intf = to_usb_interface(d);
915 struct peak_usb_device *dev;
917 /* stop as many netdev devices as siblings */
918 for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
919 struct net_device *netdev = dev->netdev;
921 if (netif_device_present(netdev))
922 if (dev->adapter->dev_exit)
923 dev->adapter->dev_exit(dev);
929 static void __exit peak_usb_exit(void)
933 /* last chance do send any synchronous commands here */
934 err = driver_for_each_device(&peak_usb_driver.drvwrap.driver, NULL,
935 NULL, peak_usb_do_device_exit);
937 pr_err("%s: failed to stop all can devices (err %d)\n",
938 PCAN_USB_DRIVER_NAME, err);
940 /* deregister this driver with the USB subsystem */
941 usb_deregister(&peak_usb_driver);
943 pr_info("%s: PCAN-USB interfaces driver unloaded\n",
944 PCAN_USB_DRIVER_NAME);
947 module_init(peak_usb_init);
948 module_exit(peak_usb_exit);