2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
31 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
32 MODULE_LICENSE("GPL v2");
34 /* Control-Values for CPC_Control() Command Subject Selection */
35 #define CONTR_CAN_MESSAGE 0x04
36 #define CONTR_CAN_STATE 0x0C
37 #define CONTR_BUS_ERROR 0x1C
39 /* Control Command Actions */
40 #define CONTR_CONT_OFF 0
41 #define CONTR_CONT_ON 1
44 /* Messages from CPC to PC */
45 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
46 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
47 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
48 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
49 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
50 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
51 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
52 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
53 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
54 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
55 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
57 /* Messages from the PC to the CPC interface */
58 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
59 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
60 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
61 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
62 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
63 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
64 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
65 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
67 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
68 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
69 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
71 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
73 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
76 #define CPC_OVR_EVENT_CAN 0x01
77 #define CPC_OVR_EVENT_CANSTATE 0x02
78 #define CPC_OVR_EVENT_BUSERROR 0x04
81 * If the CAN controller lost a message we indicate it with the highest bit
82 * set in the count field.
84 #define CPC_OVR_HW 0x80
86 /* Size of the "struct ems_cpc_msg" without the union */
87 #define CPC_MSG_HEADER_LEN 11
88 #define CPC_CAN_MSG_MIN_SIZE 5
90 /* Define these values to match your devices */
91 #define USB_CPCUSB_VENDOR_ID 0x12D6
93 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
95 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
96 #define SJA1000_MOD_NORMAL 0x00
97 #define SJA1000_MOD_RM 0x01
99 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
100 #define SJA1000_ECC_SEG 0x1F
101 #define SJA1000_ECC_DIR 0x20
102 #define SJA1000_ECC_ERR 0x06
103 #define SJA1000_ECC_BIT 0x00
104 #define SJA1000_ECC_FORM 0x40
105 #define SJA1000_ECC_STUFF 0x80
106 #define SJA1000_ECC_MASK 0xc0
108 /* Status register content */
109 #define SJA1000_SR_BS 0x80
110 #define SJA1000_SR_ES 0x40
112 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
115 * The device actually uses a 16MHz clock to generate the CAN clock
116 * but it expects SJA1000 bit settings based on 8MHz (is internally
119 #define EMS_USB_ARM7_CLOCK 8000000
122 * CAN-Message representation in a CPC_MSG. Message object type is
123 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
124 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
132 /* Representation of the CAN parameters for the SJA1000 controller */
133 struct cpc_sja1000_params {
148 /* CAN params message representation */
149 struct cpc_can_params {
152 /* Will support M16C CAN controller in the future */
154 struct cpc_sja1000_params sja1000;
158 /* Structure for confirmed message handling */
160 u8 error; /* error code */
163 /* Structure for overrun conditions */
169 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
170 struct cpc_sja1000_can_error {
176 /* structure for CAN error conditions */
177 struct cpc_can_error {
183 /* Other controllers may also provide error code capture regs */
185 struct cpc_sja1000_can_error sja1000;
191 * Structure containing RX/TX error counter. This structure is used to request
192 * the values of the CAN controllers TX and RX error counter.
194 struct cpc_can_err_counter {
199 /* Main message type used between library and application */
200 struct __attribute__ ((packed)) ems_cpc_msg {
201 u8 type; /* type of message */
202 u8 length; /* length of data within union 'msg' */
203 u8 msgid; /* confirmation handle */
204 u32 ts_sec; /* timestamp in seconds */
205 u32 ts_nsec; /* timestamp in nano seconds */
209 struct cpc_can_msg can_msg;
210 struct cpc_can_params can_params;
211 struct cpc_confirm confirmation;
212 struct cpc_overrun overrun;
213 struct cpc_can_error error;
214 struct cpc_can_err_counter err_counter;
220 * Table of devices that work with this driver
221 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
223 static struct usb_device_id ems_usb_table[] = {
224 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
225 {} /* Terminating entry */
228 MODULE_DEVICE_TABLE(usb, ems_usb_table);
230 #define RX_BUFFER_SIZE 64
231 #define CPC_HEADER_SIZE 4
232 #define INTR_IN_BUFFER_SIZE 4
234 #define MAX_RX_URBS 10
235 #define MAX_TX_URBS 10
239 struct ems_tx_urb_context {
247 struct can_priv can; /* must be the first member */
250 struct sk_buff *echo_skb[MAX_TX_URBS];
252 struct usb_device *udev;
253 struct net_device *netdev;
255 atomic_t active_tx_urbs;
256 struct usb_anchor tx_submitted;
257 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
259 struct usb_anchor rx_submitted;
261 struct urb *intr_urb;
266 unsigned int free_slots; /* remember number of available slots */
268 struct ems_cpc_msg active_params; /* active controller parameters */
271 static void ems_usb_read_interrupt_callback(struct urb *urb)
273 struct ems_usb *dev = urb->context;
274 struct net_device *netdev = dev->netdev;
277 if (!netif_device_present(netdev))
280 switch (urb->status) {
282 dev->free_slots = dev->intr_in_buffer[1];
285 case -ECONNRESET: /* unlink */
291 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n",
296 err = usb_submit_urb(urb, GFP_ATOMIC);
299 netif_device_detach(netdev);
301 dev_err(netdev->dev.parent,
302 "failed resubmitting intr urb: %d\n", err);
307 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
309 struct can_frame *cf;
312 struct net_device_stats *stats = &dev->netdev->stats;
314 skb = alloc_can_skb(dev->netdev, &cf);
318 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
319 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
321 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
322 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
323 cf->can_id |= CAN_EFF_FLAG;
325 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
326 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
327 cf->can_id |= CAN_RTR_FLAG;
329 for (i = 0; i < cf->can_dlc; i++)
330 cf->data[i] = msg->msg.can_msg.msg[i];
336 stats->rx_bytes += cf->can_dlc;
339 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
341 struct can_frame *cf;
343 struct net_device_stats *stats = &dev->netdev->stats;
345 skb = alloc_can_err_skb(dev->netdev, &cf);
349 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
350 u8 state = msg->msg.can_state;
352 if (state & SJA1000_SR_BS) {
353 dev->can.state = CAN_STATE_BUS_OFF;
354 cf->can_id |= CAN_ERR_BUSOFF;
356 can_bus_off(dev->netdev);
357 } else if (state & SJA1000_SR_ES) {
358 dev->can.state = CAN_STATE_ERROR_WARNING;
359 dev->can.can_stats.error_warning++;
361 dev->can.state = CAN_STATE_ERROR_ACTIVE;
362 dev->can.can_stats.error_passive++;
364 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
365 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
366 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
367 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
369 /* bus error interrupt */
370 dev->can.can_stats.bus_error++;
373 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
375 switch (ecc & SJA1000_ECC_MASK) {
376 case SJA1000_ECC_BIT:
377 cf->data[2] |= CAN_ERR_PROT_BIT;
379 case SJA1000_ECC_FORM:
380 cf->data[2] |= CAN_ERR_PROT_FORM;
382 case SJA1000_ECC_STUFF:
383 cf->data[2] |= CAN_ERR_PROT_STUFF;
386 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
387 cf->data[3] = ecc & SJA1000_ECC_SEG;
391 /* Error occured during transmission? */
392 if ((ecc & SJA1000_ECC_DIR) == 0)
393 cf->data[2] |= CAN_ERR_PROT_TX;
395 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
396 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
397 cf->data[1] = (txerr > rxerr) ?
398 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
400 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
401 cf->can_id |= CAN_ERR_CRTL;
402 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
404 stats->rx_over_errors++;
411 stats->rx_bytes += cf->can_dlc;
415 * callback for bulk IN urb
417 static void ems_usb_read_bulk_callback(struct urb *urb)
419 struct ems_usb *dev = urb->context;
420 struct net_device *netdev;
423 netdev = dev->netdev;
425 if (!netif_device_present(netdev))
428 switch (urb->status) {
429 case 0: /* success */
436 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n",
441 if (urb->actual_length > CPC_HEADER_SIZE) {
442 struct ems_cpc_msg *msg;
443 u8 *ibuf = urb->transfer_buffer;
444 u8 msg_count, again, start;
446 msg_count = ibuf[0] & ~0x80;
447 again = ibuf[0] & 0x80;
449 start = CPC_HEADER_SIZE;
452 msg = (struct ems_cpc_msg *)&ibuf[start];
455 case CPC_MSG_TYPE_CAN_STATE:
456 /* Process CAN state changes */
457 ems_usb_rx_err(dev, msg);
460 case CPC_MSG_TYPE_CAN_FRAME:
461 case CPC_MSG_TYPE_EXT_CAN_FRAME:
462 case CPC_MSG_TYPE_RTR_FRAME:
463 case CPC_MSG_TYPE_EXT_RTR_FRAME:
464 ems_usb_rx_can_msg(dev, msg);
467 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
468 /* Process errorframe */
469 ems_usb_rx_err(dev, msg);
472 case CPC_MSG_TYPE_OVERRUN:
473 /* Message lost while receiving */
474 ems_usb_rx_err(dev, msg);
478 start += CPC_MSG_HEADER_LEN + msg->length;
481 if (start > urb->transfer_buffer_length) {
482 dev_err(netdev->dev.parent, "format error\n");
489 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
490 urb->transfer_buffer, RX_BUFFER_SIZE,
491 ems_usb_read_bulk_callback, dev);
493 retval = usb_submit_urb(urb, GFP_ATOMIC);
495 if (retval == -ENODEV)
496 netif_device_detach(netdev);
498 dev_err(netdev->dev.parent,
499 "failed resubmitting read bulk urb: %d\n", retval);
505 * callback for bulk IN urb
507 static void ems_usb_write_bulk_callback(struct urb *urb)
509 struct ems_tx_urb_context *context = urb->context;
511 struct net_device *netdev;
516 netdev = dev->netdev;
518 /* free up our allocated buffer */
519 usb_buffer_free(urb->dev, urb->transfer_buffer_length,
520 urb->transfer_buffer, urb->transfer_dma);
522 atomic_dec(&dev->active_tx_urbs);
524 if (!netif_device_present(netdev))
528 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
531 netdev->trans_start = jiffies;
533 /* transmission complete interrupt */
534 netdev->stats.tx_packets++;
535 netdev->stats.tx_bytes += context->dlc;
537 can_get_echo_skb(netdev, context->echo_index);
539 /* Release context */
540 context->echo_index = MAX_TX_URBS;
542 if (netif_queue_stopped(netdev))
543 netif_wake_queue(netdev);
547 * Send the given CPC command synchronously
549 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
554 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
555 msg->length + CPC_MSG_HEADER_LEN);
558 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
560 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
561 &dev->tx_msg_buffer[0],
562 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
563 &actual_length, 1000);
567 * Change CAN controllers' mode register
569 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
571 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
573 return ems_usb_command_msg(dev, &dev->active_params);
577 * Send a CPC_Control command to change behaviour when interface receives a CAN
578 * message, bus error or CAN state changed notifications.
580 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
582 struct ems_cpc_msg cmd;
584 cmd.type = CPC_CMD_TYPE_CONTROL;
585 cmd.length = CPC_MSG_HEADER_LEN + 1;
589 cmd.msg.generic[0] = val;
591 return ems_usb_command_msg(dev, &cmd);
597 static int ems_usb_start(struct ems_usb *dev)
599 struct net_device *netdev = dev->netdev;
602 dev->intr_in_buffer[0] = 0;
603 dev->free_slots = 15; /* initial size */
605 for (i = 0; i < MAX_RX_URBS; i++) {
606 struct urb *urb = NULL;
609 /* create a URB, and a buffer for it */
610 urb = usb_alloc_urb(0, GFP_KERNEL);
612 dev_err(netdev->dev.parent,
613 "No memory left for URBs\n");
617 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
620 dev_err(netdev->dev.parent,
621 "No memory left for USB buffer\n");
626 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
628 ems_usb_read_bulk_callback, dev);
629 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
630 usb_anchor_urb(urb, &dev->rx_submitted);
632 err = usb_submit_urb(urb, GFP_KERNEL);
635 netif_device_detach(dev->netdev);
637 usb_unanchor_urb(urb);
638 usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf,
643 /* Drop reference, USB core will take care of freeing it */
647 /* Did we submit any URBs */
649 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n");
653 /* Warn if we've couldn't transmit all the URBs */
655 dev_warn(netdev->dev.parent, "rx performance may be slow\n");
657 /* Setup and start interrupt URB */
658 usb_fill_int_urb(dev->intr_urb, dev->udev,
659 usb_rcvintpipe(dev->udev, 1),
662 ems_usb_read_interrupt_callback, dev, 1);
664 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
667 netif_device_detach(dev->netdev);
669 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n",
675 /* CPC-USB will transfer received message to host */
676 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
680 /* CPC-USB will transfer CAN state changes to host */
681 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
685 /* CPC-USB will transfer bus errors to host */
686 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
690 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
694 dev->can.state = CAN_STATE_ERROR_ACTIVE;
700 netif_device_detach(dev->netdev);
702 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err);
707 static void unlink_all_urbs(struct ems_usb *dev)
711 usb_unlink_urb(dev->intr_urb);
713 usb_kill_anchored_urbs(&dev->rx_submitted);
715 usb_kill_anchored_urbs(&dev->tx_submitted);
716 atomic_set(&dev->active_tx_urbs, 0);
718 for (i = 0; i < MAX_TX_URBS; i++)
719 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
722 static int ems_usb_open(struct net_device *netdev)
724 struct ems_usb *dev = netdev_priv(netdev);
727 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
732 err = open_candev(netdev);
736 /* finally start device */
737 err = ems_usb_start(dev);
740 netif_device_detach(dev->netdev);
742 dev_warn(netdev->dev.parent, "couldn't start device: %d\n",
745 close_candev(netdev);
750 dev->open_time = jiffies;
752 netif_start_queue(netdev);
757 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
759 struct ems_usb *dev = netdev_priv(netdev);
760 struct ems_tx_urb_context *context = NULL;
761 struct net_device_stats *stats = &netdev->stats;
762 struct can_frame *cf = (struct can_frame *)skb->data;
763 struct ems_cpc_msg *msg;
767 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
768 + sizeof(struct cpc_can_msg);
770 if (can_dropped_invalid_skb(netdev, skb))
773 /* create a URB, and a buffer for it, and copy the data to the URB */
774 urb = usb_alloc_urb(0, GFP_ATOMIC);
776 dev_err(netdev->dev.parent, "No memory left for URBs\n");
780 buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
782 dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
787 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
789 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
790 msg->msg.can_msg.length = cf->can_dlc;
792 if (cf->can_id & CAN_RTR_FLAG) {
793 msg->type = cf->can_id & CAN_EFF_FLAG ?
794 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
796 msg->length = CPC_CAN_MSG_MIN_SIZE;
798 msg->type = cf->can_id & CAN_EFF_FLAG ?
799 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
801 for (i = 0; i < cf->can_dlc; i++)
802 msg->msg.can_msg.msg[i] = cf->data[i];
804 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
807 /* Respect byte order */
808 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id);
810 for (i = 0; i < MAX_TX_URBS; i++) {
811 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
812 context = &dev->tx_contexts[i];
818 * May never happen! When this happens we'd more URBs in flight as
819 * allowed (MAX_TX_URBS).
822 usb_unanchor_urb(urb);
823 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
825 dev_warn(netdev->dev.parent, "couldn't find free context\n");
827 return NETDEV_TX_BUSY;
831 context->echo_index = i;
832 context->dlc = cf->can_dlc;
834 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
835 size, ems_usb_write_bulk_callback, context);
836 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
837 usb_anchor_urb(urb, &dev->tx_submitted);
839 can_put_echo_skb(skb, netdev, context->echo_index);
841 atomic_inc(&dev->active_tx_urbs);
843 err = usb_submit_urb(urb, GFP_ATOMIC);
845 can_free_echo_skb(netdev, context->echo_index);
847 usb_unanchor_urb(urb);
848 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
851 atomic_dec(&dev->active_tx_urbs);
853 if (err == -ENODEV) {
854 netif_device_detach(netdev);
856 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
861 netdev->trans_start = jiffies;
863 /* Slow down tx path */
864 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
865 dev->free_slots < 5) {
866 netif_stop_queue(netdev);
871 * Release our reference to this URB, the USB core will eventually free
885 static int ems_usb_close(struct net_device *netdev)
887 struct ems_usb *dev = netdev_priv(netdev);
890 unlink_all_urbs(dev);
892 netif_stop_queue(netdev);
894 /* Set CAN controller to reset mode */
895 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
896 dev_warn(netdev->dev.parent, "couldn't stop device");
898 close_candev(netdev);
905 static const struct net_device_ops ems_usb_netdev_ops = {
906 .ndo_open = ems_usb_open,
907 .ndo_stop = ems_usb_close,
908 .ndo_start_xmit = ems_usb_start_xmit,
911 static struct can_bittiming_const ems_usb_bittiming_const = {
923 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
925 struct ems_usb *dev = netdev_priv(netdev);
932 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
933 dev_warn(netdev->dev.parent, "couldn't start device");
935 if (netif_queue_stopped(netdev))
936 netif_wake_queue(netdev);
946 static int ems_usb_set_bittiming(struct net_device *netdev)
948 struct ems_usb *dev = netdev_priv(netdev);
949 struct can_bittiming *bt = &dev->can.bittiming;
952 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
953 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
954 (((bt->phase_seg2 - 1) & 0x7) << 4);
955 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
958 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
961 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
962 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
964 return ems_usb_command_msg(dev, &dev->active_params);
967 static void init_params_sja1000(struct ems_cpc_msg *msg)
969 struct cpc_sja1000_params *sja1000 =
970 &msg->msg.can_params.cc_params.sja1000;
972 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
973 msg->length = sizeof(struct cpc_can_params);
976 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
978 /* Acceptance filter open */
979 sja1000->acc_code0 = 0x00;
980 sja1000->acc_code1 = 0x00;
981 sja1000->acc_code2 = 0x00;
982 sja1000->acc_code3 = 0x00;
984 /* Acceptance filter open */
985 sja1000->acc_mask0 = 0xFF;
986 sja1000->acc_mask1 = 0xFF;
987 sja1000->acc_mask2 = 0xFF;
988 sja1000->acc_mask3 = 0xFF;
993 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
994 sja1000->mode = SJA1000_MOD_RM;
998 * probe function for new CPC-USB devices
1000 static int ems_usb_probe(struct usb_interface *intf,
1001 const struct usb_device_id *id)
1003 struct net_device *netdev;
1004 struct ems_usb *dev;
1005 int i, err = -ENOMEM;
1007 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1009 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
1013 dev = netdev_priv(netdev);
1015 dev->udev = interface_to_usbdev(intf);
1016 dev->netdev = netdev;
1018 dev->can.state = CAN_STATE_STOPPED;
1019 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1020 dev->can.bittiming_const = &ems_usb_bittiming_const;
1021 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1022 dev->can.do_set_mode = ems_usb_set_mode;
1023 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1025 netdev->netdev_ops = &ems_usb_netdev_ops;
1027 netdev->flags |= IFF_ECHO; /* we support local echo */
1029 init_usb_anchor(&dev->rx_submitted);
1031 init_usb_anchor(&dev->tx_submitted);
1032 atomic_set(&dev->active_tx_urbs, 0);
1034 for (i = 0; i < MAX_TX_URBS; i++)
1035 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1037 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1038 if (!dev->intr_urb) {
1039 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1040 goto cleanup_candev;
1043 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1044 if (!dev->intr_in_buffer) {
1045 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n");
1046 goto cleanup_intr_urb;
1049 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1050 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1051 if (!dev->tx_msg_buffer) {
1052 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n");
1053 goto cleanup_intr_in_buffer;
1056 usb_set_intfdata(intf, dev);
1058 SET_NETDEV_DEV(netdev, &intf->dev);
1060 init_params_sja1000(&dev->active_params);
1062 err = ems_usb_command_msg(dev, &dev->active_params);
1064 dev_err(netdev->dev.parent,
1065 "couldn't initialize controller: %d\n", err);
1066 goto cleanup_tx_msg_buffer;
1069 err = register_candev(netdev);
1071 dev_err(netdev->dev.parent,
1072 "couldn't register CAN device: %d\n", err);
1073 goto cleanup_tx_msg_buffer;
1078 cleanup_tx_msg_buffer:
1079 kfree(dev->tx_msg_buffer);
1081 cleanup_intr_in_buffer:
1082 kfree(dev->intr_in_buffer);
1085 usb_free_urb(dev->intr_urb);
1088 free_candev(netdev);
1094 * called by the usb core when the device is removed from the system
1096 static void ems_usb_disconnect(struct usb_interface *intf)
1098 struct ems_usb *dev = usb_get_intfdata(intf);
1100 usb_set_intfdata(intf, NULL);
1103 unregister_netdev(dev->netdev);
1104 free_candev(dev->netdev);
1106 unlink_all_urbs(dev);
1108 usb_free_urb(dev->intr_urb);
1110 kfree(dev->intr_in_buffer);
1114 /* usb specific object needed to register this driver with the usb subsystem */
1115 static struct usb_driver ems_usb_driver = {
1117 .probe = ems_usb_probe,
1118 .disconnect = ems_usb_disconnect,
1119 .id_table = ems_usb_table,
1122 static int __init ems_usb_init(void)
1126 printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1128 /* register this driver with the USB subsystem */
1129 err = usb_register(&ems_usb_driver);
1132 err("usb_register failed. Error number %d\n", err);
1139 static void __exit ems_usb_exit(void)
1141 /* deregister this driver with the USB subsystem */
1142 usb_deregister(&ems_usb_driver);
1145 module_init(ems_usb_init);
1146 module_exit(ems_usb_exit);