1 #include <linux/kernel.h>
2 #include <linux/errno.h>
3 #include <linux/init.h>
4 #include <linux/slab.h>
5 #include <linux/module.h>
6 #include <linux/kref.h>
7 #include <linux/uaccess.h>
9 #include <linux/mutex.h>
10 #include <linux/netdevice.h>
11 #include <linux/version.h>
12 #include <linux/kthread.h>
13 #include <linux/freezer.h>
15 #include <linux/can.h>
16 #include <linux/can/dev.h>
17 #include <linux/can/error.h>
20 #define USBCAN_VENDOR_SET_CANBTR (9)
21 #define USBCAN_VENDOR_GET_BITTIMING_CONST (10)
22 // lpc17xx debug - end
24 #define CTU_USBCAN_VENDOR_ID 0x1669
25 #define CTU_USBCAN_PRODUCT_ID 0x1011
27 #define USBCAN_TOT_RX_URBS 8
28 #define USBCAN_TOT_TX_URBS 8
30 #define USBCAN_TRANSFER_SIZE 16
31 #define USBCAN_BITTIMING_SIZE 16
32 #define USBCAN_BITTIMING_CONST_SIZE 36
34 #define CAN_MSG_LENGTH 8
36 #define MSG_RTR (1<<0)
37 #define MSG_OVR (1<<1)
38 #define MSG_EXT (1<<2)
39 #define MSG_LOCAL (1<<3)
41 #define USBCAN_DATA_OK (1)
42 #define USBCAN_TX_PENDING (2)
43 #define USBCAN_BITTIMING_CONST_SET (3)
46 MODULE_LICENSE("GPL");
48 /* table of devices that work with this driver */
49 static struct usb_device_id ctu_usbcan_table [] = {
50 { USB_DEVICE(CTU_USBCAN_VENDOR_ID, CTU_USBCAN_PRODUCT_ID) },
51 { } /* Terminating entry */
53 MODULE_DEVICE_TABLE(usb, ctu_usbcan_table);
56 static struct usb_driver ctu_usbcan_driver;
57 struct ctu_usbcan_usb;
60 struct usbcan_message {
62 struct ctu_usbcan_usb *dev;
63 u8 msg[USBCAN_TRANSFER_SIZE];
66 struct list_head list_node;
69 Structure of byte array msg in struct usbcan_message that represents CAN message (little endian):
70 msg[0] - reserved (1 byte)
71 msg[1] - length (1 byte)
72 msg[2:3] - flags (2 bytes)
73 msg[4:7] - id (4 bytes)
74 msg[8:15] - data (8 bytes)
78 /* Structure to hold all of our device specific stuff */
79 struct ctu_usbcan_usb {
81 struct can_priv can; /* must be the first member */
83 struct can_bittiming_const cbc;
86 struct usb_device *udev; /* the usb device for this device */
87 struct net_device *netdev;
89 u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
90 u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
92 struct mutex io_mutex; /* synchronize I/O with disconnect */
94 struct list_head rx_pend_list; /* URBs waiting for data receive */
95 struct list_head rx_ready_list; /* URBs with valid received data */
96 struct list_head tx_idle_list; /* URBs prepared to hold Tx messages */
97 struct list_head tx_pend_list; /* URBs holding Tx messages in progress */
98 struct list_head tx_ready_list; /* URBs with yet confirmed Tx messages */
100 spinlock_t list_lock; /* list lock */
101 struct task_struct *comthread; /* usb communication kernel thread */
102 wait_queue_head_t queue;
109 static void usbcan_usb_message_move_list(struct ctu_usbcan_usb *dev,
110 struct usbcan_message *m, struct list_head *head)
113 spin_lock_irqsave(&dev->list_lock, flags);
114 list_del(&m->list_node);
115 list_add_tail(&m->list_node, head);
116 spin_unlock_irqrestore(&dev->list_lock, flags);
120 static int get_bittiming_constants(struct ctu_usbcan_usb *dev)
127 usbbuf = kzalloc(sizeof(u8)*USBCAN_BITTIMING_CONST_SIZE, GFP_KERNEL);
130 err("Error allocating receive buffer for bittiming constants\n");
134 retval = usb_control_msg(dev->udev,
135 usb_rcvctrlpipe(dev->udev, 0),
136 USBCAN_VENDOR_GET_BITTIMING_CONST,
138 cpu_to_le16(0), cpu_to_le16(0),
139 usbbuf, USBCAN_BITTIMING_CONST_SIZE,
147 dev->can_clock = le32_to_cpu(*(ptr++));
148 dev->cbc.tseg1_min = le32_to_cpu(*(ptr++));
149 dev->cbc.tseg1_max = le32_to_cpu(*(ptr++));
150 dev->cbc.tseg2_min = le32_to_cpu(*(ptr++));
151 dev->cbc.tseg2_max = le32_to_cpu(*(ptr++));
152 dev->cbc.sjw_max = le32_to_cpu(*(ptr++));
153 dev->cbc.brp_min = le32_to_cpu(*(ptr++));
154 dev->cbc.brp_max = le32_to_cpu(*(ptr++));
155 dev->cbc.brp_inc = le32_to_cpu(*(ptr));
157 set_bit(USBCAN_BITTIMING_CONST_SET,&dev->flags);
170 static int ctu_usbcan_set_mode(struct net_device *netdev, enum can_mode mode)
173 printk("SET MODE\n");
178 static int ctu_usbcan_set_bittiming(struct net_device *netdev)
180 struct ctu_usbcan_usb *dev = netdev_priv(netdev);
181 struct can_bittiming *bt = &dev->can.bittiming;
191 usbbuf = kzalloc(sizeof(u8)*USBCAN_BITTIMING_SIZE, GFP_KERNEL);
194 err("Error allocating transmit buffer for set bittiming\n");
200 *(ptr++)=cpu_to_le32(bt->brp); // baudrate prescaler
201 *(ptr++)=cpu_to_le32(bt->sjw); // sjw
202 *(ptr++)=cpu_to_le32(bt->prop_seg + bt->phase_seg1); // TSEG1
203 *(ptr)=cpu_to_le32(bt->phase_seg2); // TSEG2
206 retval = usb_control_msg(dev->udev,
207 usb_sndctrlpipe(dev->udev, 0),
208 USBCAN_VENDOR_SET_CANBTR,
210 cpu_to_le16(0), cpu_to_le16(0),
211 usbbuf, USBCAN_BITTIMING_SIZE,
217 printk("BITRATE %d, BRP: %d, SJW: %d, TSEG1: %d, TSEG2: %d \n", bt->bitrate, bt->brp, bt->sjw,\
218 (bt->prop_seg + bt->phase_seg1), bt->phase_seg2);
222 err("Could not set bittiming\n");
229 static void ctu_usbcan_tx_callback(struct urb *urb){
231 struct usbcan_message *m = urb->context;
232 struct net_device_stats *stats = &m->dev->netdev->stats;
234 if (!netif_device_present(m->dev->netdev))
237 if (urb->status != 0){
238 err("TX callback: error");
244 printk("TX callback: URB successfully transmitted\n");
247 stats->tx_bytes += m->dlc;
250 can_get_echo_skb(m->dev->netdev, m->echo_index);
252 set_bit(USBCAN_DATA_OK,&m->dev->flags);
253 usbcan_usb_message_move_list(m->dev, m, &m->dev->tx_ready_list);
254 wake_up_process(m->dev->comthread);
258 static void ctu_usbcan_rx_callback(struct urb *urb)
261 struct usbcan_message *m = urb->context;
263 if (!netif_device_present(m->dev->netdev))
267 if(urb->status != 0){
268 err("RX callback: error");
274 printk("RX callback: URB successfully received\n");
276 set_bit(USBCAN_DATA_OK,&m->dev->flags);
277 usbcan_usb_message_move_list(m->dev, m, &m->dev->rx_ready_list);
278 wake_up_process(m->dev->comthread);
282 static netdev_tx_t ctu_usbcan_start_xmit(struct sk_buff *skb, struct net_device *netdev)
284 struct ctu_usbcan_usb *dev = netdev_priv(netdev);
285 struct can_frame *cf = (struct can_frame *)skb->data;
286 struct usbcan_message *m;
291 if(list_empty(&dev->tx_idle_list))
294 m = list_first_entry(&dev->tx_idle_list, typeof(*m), list_node);
299 if(len > CAN_MSG_LENGTH)
300 len = CAN_MSG_LENGTH;
302 if (cf->can_id & CAN_RTR_FLAG)
305 if (cf->can_id & CAN_EFF_FLAG)
309 *(u8 *)(m->msg+1)=len & 0xFF;
310 *(u16 *)(m->msg+2)=cpu_to_le16(flags);
311 *(u32 *)(m->msg+4)=cpu_to_le32(cf->can_id & CAN_ERR_MASK);
313 for(ptr=m->msg+8, i=0; i < len; ptr++,i++)
314 *ptr= cf->data[i] & 0xFF;
316 for(; i < 8; ptr++,i++)
322 usbcan_usb_message_move_list(dev, m, &dev->tx_pend_list);
324 can_put_echo_skb(skb, netdev, m->echo_index);
327 retval = usb_submit_urb(m->u, GFP_ATOMIC);
329 err("Error submitting URB: %d", retval);
330 usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
341 static void usbcan_kthread_free_urbs(struct ctu_usbcan_usb *dev)
343 while(!list_empty(&dev->rx_pend_list)) {
344 struct usbcan_message *m;
345 m = list_first_entry(&dev->rx_pend_list, typeof(*m), list_node);
347 usbcan_usb_message_move_list(dev, m, &dev->rx_ready_list);
350 while(!list_empty(&dev->tx_pend_list)) {
351 struct usbcan_message *m;
352 m = list_first_entry(&dev->tx_pend_list, typeof(*m), list_node);
354 usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
357 while(!list_empty(&dev->rx_ready_list)) {
358 struct usbcan_message *m;
359 m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
360 list_del(&m->list_node);
365 while(!list_empty(&dev->tx_ready_list)) {
366 struct usbcan_message *m;
367 m = list_first_entry(&dev->tx_ready_list, typeof(*m), list_node);
368 list_del(&m->list_node);
373 while(!list_empty(&dev->tx_idle_list)) {
374 struct usbcan_message *m;
375 m = list_first_entry(&dev->tx_idle_list, typeof(*m), list_node);
376 list_del(&m->list_node);
383 void usbcan_kthread_write_handler(struct ctu_usbcan_usb *dev, struct usbcan_message *m)
386 usbcan_usb_message_move_list(dev, m, &dev->tx_idle_list);
390 void usbcan_kthread_read_handler(struct ctu_usbcan_usb *dev, struct usbcan_message *m)
393 struct can_frame *cf;
398 struct net_device_stats *stats = &m->dev->netdev->stats;
401 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,32)
402 skb = alloc_can_skb(m->dev->netdev, &cf);
404 skb = netdev_alloc_skb(m->dev->netdev, sizeof(struct can_frame));
405 skb->protocol = htons(ETH_P_CAN);
406 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
409 skb = alloc_can_skb(m->dev->netdev, &cf);
412 err("RX: error alloc skb\n");
417 printk("RX: URB successfully received\n");
419 len=*(u8 *)(m->msg+1);
420 if(len > CAN_MSG_LENGTH) len = CAN_MSG_LENGTH;
422 flags = le16_to_cpu(*(u16 *)(m->msg+2));
423 cf->can_id = le32_to_cpu((*(u32 *)(m->msg+4)));
426 cf->can_id |= CAN_RTR_FLAG;
429 cf->can_id |= CAN_EFF_FLAG;
433 for(ptr=m->msg+8,i=0; i < len; ptr++,i++) {
441 stats->rx_bytes += cf->can_dlc;
443 /* Renewing RX urb */
445 usbcan_usb_message_move_list(dev, m, &dev->rx_pend_list);
446 retval = usb_submit_urb (m->u, GFP_KERNEL);
448 err("URB error %d\n", retval);
455 static int usbcan_sleep_thread(struct ctu_usbcan_usb *dev)
459 /* Wait until a signal arrives or we are woken up */
462 set_current_state(TASK_INTERRUPTIBLE);
463 if (signal_pending(current)) {
468 kthread_should_stop() ||
469 test_bit(USBCAN_DATA_OK,&dev->flags)
474 __set_current_state(TASK_RUNNING);
478 int usbcan_kthread(void *data)
481 struct ctu_usbcan_usb *dev=(struct ctu_usbcan_usb *) data;
485 struct usbcan_message *m;
488 printk("CTU USBCAN: kthread running\n");
490 INIT_LIST_HEAD(&dev->rx_pend_list);
491 INIT_LIST_HEAD(&dev->rx_ready_list);
492 INIT_LIST_HEAD(&dev->tx_idle_list);
493 INIT_LIST_HEAD(&dev->tx_pend_list);
494 INIT_LIST_HEAD(&dev->tx_ready_list);
496 /* Prepare receive urbs */
497 for (i=0;i<USBCAN_TOT_RX_URBS;i++){
499 u = usb_alloc_urb(0, GFP_KERNEL);
500 m = kzalloc(sizeof(struct usbcan_message), GFP_KERNEL);
503 err("Error allocating usb receive urb");
509 err("Error allocating receive usbcan_message");
515 usb_fill_bulk_urb(u, dev->udev,
516 usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr),
517 m->msg, USBCAN_TRANSFER_SIZE, ctu_usbcan_rx_callback, m);
520 list_add_tail(&m->list_node, &dev->rx_ready_list);
523 /* Prepare transmit urbs */
524 for (i=0;i<USBCAN_TOT_TX_URBS;i++){
526 u = usb_alloc_urb(0, GFP_ATOMIC);
527 m = kzalloc(sizeof(struct usbcan_message), GFP_ATOMIC);
530 err("Error allocating usb transmit urb");
536 err("Error allocating transmit usbcan_message");
545 usb_fill_bulk_urb(u, dev->udev,
546 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
547 m->msg, USBCAN_TRANSFER_SIZE, ctu_usbcan_tx_callback, m);
549 list_add_tail(&m->list_node, &dev->tx_idle_list);
553 for (i=0;i<USBCAN_TOT_RX_URBS;i++){
555 m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
556 usbcan_usb_message_move_list(dev, m, &dev->rx_pend_list);
558 retval=usb_submit_urb(m->u, GFP_KERNEL);
560 err("Error submitting URB: %d", retval);
566 /* an endless loop in which we are doing our work */
571 /* We need to do a memory barrier here to be sure that
572 the flags are visible on all CPUs. */
576 if (!kthread_should_stop() && (usbcan_sleep_thread(dev)<0)){
579 /* We need to do a memory barrier here to be sure that the flags are visible on all CPUs. */
582 if (kthread_should_stop()){
588 clear_bit(USBCAN_DATA_OK,&dev->flags);
591 while(!list_empty(&dev->rx_ready_list)) {
592 struct usbcan_message *m;
593 m = list_first_entry(&dev->rx_ready_list, typeof(*m), list_node);
594 usbcan_kthread_read_handler(dev, m);
597 while(!list_empty(&dev->tx_ready_list)) {
598 struct usbcan_message *m;
599 m = list_first_entry(&dev->tx_ready_list, typeof(*m), list_node);
600 usbcan_kthread_write_handler(dev, m);
607 usbcan_kthread_free_urbs(dev);
608 printk("CTU USBCAN: usbcan thread finished\n");
614 static int ctu_usbcan_open(struct net_device *netdev)
618 struct ctu_usbcan_usb *dev = netdev_priv(netdev);
621 err = open_candev(netdev);
625 /* start kernel thread */
626 dev->comthread = kthread_run(usbcan_kthread, (void *)dev, "usbcan_1");
631 static int ctu_usbcan_close(struct net_device *netdev)
634 struct ctu_usbcan_usb *dev = netdev_priv(netdev);
635 kthread_stop(dev->comthread);
637 close_candev(netdev);
642 static const struct net_device_ops ctu_usbcan_netdev_ops = {
643 .ndo_open = ctu_usbcan_open,
644 .ndo_stop = ctu_usbcan_close,
645 .ndo_start_xmit = ctu_usbcan_start_xmit,
649 static int ctu_usbcan_probe(struct usb_interface *intf,
650 const struct usb_device_id *id)
652 struct net_device *netdev;
653 struct ctu_usbcan_usb *dev;
654 struct usb_host_interface *iface_desc;
655 struct usb_endpoint_descriptor *endpoint;
659 printk(KERN_INFO "CTU USBCAN device now attached\n");
662 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,32)
663 netdev = alloc_candev(sizeof(struct ctu_usbcan_usb), USBCAN_TOT_TX_URBS);
665 netdev = alloc_candev(sizeof(struct ctu_usbcan_usb));
668 netdev = alloc_candev(sizeof(struct ctu_usbcan_usb), USBCAN_TOT_TX_URBS);
671 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,33)
672 dev_err(&intf->dev, "Couldn't alloc candev\n");
674 dev_err(netdev->dev.parent, "Couldn't alloc candev\n");
679 dev = netdev_priv(netdev);
681 dev->udev = interface_to_usbdev(intf);
682 dev->netdev = netdev;
685 netdev->netdev_ops = &ctu_usbcan_netdev_ops;
686 netdev->flags |= IFF_ECHO;
688 /* set up the endpoint information */
689 /* use only the first bulk-in and bulk-out endpoints */
690 iface_desc = intf->cur_altsetting;
691 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
692 endpoint = &iface_desc->endpoint[i].desc;
694 if (!dev->bulk_in_endpointAddr &&
695 usb_endpoint_is_bulk_in(endpoint)) {
696 /* we found a bulk in endpoint */
697 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
700 if (!dev->bulk_out_endpointAddr &&
701 usb_endpoint_is_bulk_out(endpoint)) {
702 /* we found a bulk out endpoint */
703 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
706 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
707 err("Could not find both bulk-in and bulk-out endpoints");
712 usb_set_intfdata(intf, dev);
713 SET_NETDEV_DEV(netdev, &intf->dev);
715 if (get_bittiming_constants(dev)){
716 err("Could not get bittiming constants\n");
720 dev->can.clock.freq = dev->can_clock;
721 dev->can.bittiming_const = &dev->cbc;
722 dev->can.do_set_bittiming = ctu_usbcan_set_bittiming;
723 dev->can.do_set_mode = ctu_usbcan_set_mode;
726 err = register_candev(netdev);
728 dev_err(netdev->dev.parent,
729 "couldn't register CAN device: %d\n", err);
737 /* called by the usb core when the device is removed from the system */
738 static void ctu_usbcan_disconnect(struct usb_interface *intf)
741 struct ctu_usbcan_usb *dev = usb_get_intfdata(intf);
743 printk(KERN_INFO "CTU USBCAN device now disconnected\n");
745 usb_set_intfdata(intf, NULL);
748 if(test_bit(USBCAN_BITTIMING_CONST_SET,&dev->flags))
749 unregister_netdev(dev->netdev);
751 free_candev(dev->netdev);
752 clear_bit(USBCAN_BITTIMING_CONST_SET,&dev->flags);
757 /* usb specific object needed to register this driver with the usb subsystem */
758 static struct usb_driver ctu_usbcan_driver = {
759 .name = "ctu_usbcan",
760 .id_table = ctu_usbcan_table,
761 .probe = ctu_usbcan_probe,
762 .disconnect = ctu_usbcan_disconnect,
765 static int __init ctu_usbcan_init(void)
769 printk(KERN_INFO "CTU USBCAN kernel driver loaded\n");
771 /* register this driver with the USB subsystem */
772 result = usb_register(&ctu_usbcan_driver);
774 err("usb_register failed. Error number %d", result);
779 static void __exit ctu_usbcan_exit(void)
781 printk(KERN_INFO "CTU USBCAN kernel driver unloaded\n");
783 /* deregister this driver with the USB subsystem */
784 usb_deregister(&ctu_usbcan_driver);
787 module_init(ctu_usbcan_init);
788 module_exit(ctu_usbcan_exit);