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/signal.h>
20 #include <linux/slab.h>
21 #include <linux/module.h>
22 #include <linux/netdevice.h>
23 #include <linux/usb.h>
25 #include <linux/can.h>
26 #include <linux/can/dev.h>
27 #include <linux/can/error.h>
29 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
30 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
31 MODULE_LICENSE("GPL v2");
33 /* Control-Values for CPC_Control() Command Subject Selection */
34 #define CONTR_CAN_MESSAGE 0x04
35 #define CONTR_CAN_STATE 0x0C
36 #define CONTR_BUS_ERROR 0x1C
38 /* Control Command Actions */
39 #define CONTR_CONT_OFF 0
40 #define CONTR_CONT_ON 1
43 /* Messages from CPC to PC */
44 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
45 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
46 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
47 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
48 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
49 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
50 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
51 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
52 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
53 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
54 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
56 /* Messages from the PC to the CPC interface */
57 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
58 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
59 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
60 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
61 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
62 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
63 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
64 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
66 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
67 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
68 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
70 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
72 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
75 #define CPC_OVR_EVENT_CAN 0x01
76 #define CPC_OVR_EVENT_CANSTATE 0x02
77 #define CPC_OVR_EVENT_BUSERROR 0x04
80 * If the CAN controller lost a message we indicate it with the highest bit
81 * set in the count field.
83 #define CPC_OVR_HW 0x80
85 /* Size of the "struct ems_cpc_msg" without the union */
86 #define CPC_MSG_HEADER_LEN 11
87 #define CPC_CAN_MSG_MIN_SIZE 5
89 /* Define these values to match your devices */
90 #define USB_CPCUSB_VENDOR_ID 0x12D6
92 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
94 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
95 #define SJA1000_MOD_NORMAL 0x00
96 #define SJA1000_MOD_RM 0x01
98 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
99 #define SJA1000_ECC_SEG 0x1F
100 #define SJA1000_ECC_DIR 0x20
101 #define SJA1000_ECC_ERR 0x06
102 #define SJA1000_ECC_BIT 0x00
103 #define SJA1000_ECC_FORM 0x40
104 #define SJA1000_ECC_STUFF 0x80
105 #define SJA1000_ECC_MASK 0xc0
107 /* Status register content */
108 #define SJA1000_SR_BS 0x80
109 #define SJA1000_SR_ES 0x40
111 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
114 * The device actually uses a 16MHz clock to generate the CAN clock
115 * but it expects SJA1000 bit settings based on 8MHz (is internally
118 #define EMS_USB_ARM7_CLOCK 8000000
120 #define CPC_TX_QUEUE_TRIGGER_LOW 25
121 #define CPC_TX_QUEUE_TRIGGER_HIGH 35
124 * CAN-Message representation in a CPC_MSG. Message object type is
125 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
126 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
134 /* Representation of the CAN parameters for the SJA1000 controller */
135 struct cpc_sja1000_params {
150 /* CAN params message representation */
151 struct cpc_can_params {
154 /* Will support M16C CAN controller in the future */
156 struct cpc_sja1000_params sja1000;
160 /* Structure for confirmed message handling */
162 u8 error; /* error code */
165 /* Structure for overrun conditions */
171 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
172 struct cpc_sja1000_can_error {
178 /* structure for CAN error conditions */
179 struct cpc_can_error {
185 /* Other controllers may also provide error code capture regs */
187 struct cpc_sja1000_can_error sja1000;
193 * Structure containing RX/TX error counter. This structure is used to request
194 * the values of the CAN controllers TX and RX error counter.
196 struct cpc_can_err_counter {
201 /* Main message type used between library and application */
202 struct __packed ems_cpc_msg {
203 u8 type; /* type of message */
204 u8 length; /* length of data within union 'msg' */
205 u8 msgid; /* confirmation handle */
206 __le32 ts_sec; /* timestamp in seconds */
207 __le32 ts_nsec; /* timestamp in nano seconds */
211 struct cpc_can_msg can_msg;
212 struct cpc_can_params can_params;
213 struct cpc_confirm confirmation;
214 struct cpc_overrun overrun;
215 struct cpc_can_error error;
216 struct cpc_can_err_counter err_counter;
222 * Table of devices that work with this driver
223 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
225 static struct usb_device_id ems_usb_table[] = {
226 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
227 {} /* Terminating entry */
230 MODULE_DEVICE_TABLE(usb, ems_usb_table);
232 #define RX_BUFFER_SIZE 64
233 #define CPC_HEADER_SIZE 4
234 #define INTR_IN_BUFFER_SIZE 4
236 #define MAX_RX_URBS 10
237 #define MAX_TX_URBS 10
241 struct ems_tx_urb_context {
249 struct can_priv can; /* must be the first member */
251 struct sk_buff *echo_skb[MAX_TX_URBS];
253 struct usb_device *udev;
254 struct net_device *netdev;
256 atomic_t active_tx_urbs;
257 struct usb_anchor tx_submitted;
258 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
260 struct usb_anchor rx_submitted;
262 struct urb *intr_urb;
267 unsigned int free_slots; /* remember number of available slots */
269 struct ems_cpc_msg active_params; /* active controller parameters */
270 void *rxbuf[MAX_RX_URBS];
271 dma_addr_t rxbuf_dma[MAX_RX_URBS];
274 static void ems_usb_read_interrupt_callback(struct urb *urb)
276 struct ems_usb *dev = urb->context;
277 struct net_device *netdev = dev->netdev;
280 if (!netif_device_present(netdev))
283 switch (urb->status) {
285 dev->free_slots = dev->intr_in_buffer[1];
286 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
287 netif_queue_stopped(netdev))
288 netif_wake_queue(netdev);
291 case -ECONNRESET: /* unlink */
299 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
303 err = usb_submit_urb(urb, GFP_ATOMIC);
306 netif_device_detach(netdev);
308 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
311 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
313 struct can_frame *cf;
316 struct net_device_stats *stats = &dev->netdev->stats;
318 skb = alloc_can_skb(dev->netdev, &cf);
322 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
323 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
325 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
326 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
327 cf->can_id |= CAN_EFF_FLAG;
329 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
330 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
331 cf->can_id |= CAN_RTR_FLAG;
333 for (i = 0; i < cf->can_dlc; i++)
334 cf->data[i] = msg->msg.can_msg.msg[i];
338 stats->rx_bytes += cf->can_dlc;
342 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
344 struct can_frame *cf;
346 struct net_device_stats *stats = &dev->netdev->stats;
348 skb = alloc_can_err_skb(dev->netdev, &cf);
352 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
353 u8 state = msg->msg.can_state;
355 if (state & SJA1000_SR_BS) {
356 dev->can.state = CAN_STATE_BUS_OFF;
357 cf->can_id |= CAN_ERR_BUSOFF;
359 dev->can.can_stats.bus_off++;
360 can_bus_off(dev->netdev);
361 } else if (state & SJA1000_SR_ES) {
362 dev->can.state = CAN_STATE_ERROR_WARNING;
363 dev->can.can_stats.error_warning++;
365 dev->can.state = CAN_STATE_ERROR_ACTIVE;
366 dev->can.can_stats.error_passive++;
368 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
369 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
370 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
371 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
373 /* bus error interrupt */
374 dev->can.can_stats.bus_error++;
377 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
379 switch (ecc & SJA1000_ECC_MASK) {
380 case SJA1000_ECC_BIT:
381 cf->data[2] |= CAN_ERR_PROT_BIT;
383 case SJA1000_ECC_FORM:
384 cf->data[2] |= CAN_ERR_PROT_FORM;
386 case SJA1000_ECC_STUFF:
387 cf->data[2] |= CAN_ERR_PROT_STUFF;
390 cf->data[3] = ecc & SJA1000_ECC_SEG;
394 /* Error occurred during transmission? */
395 if ((ecc & SJA1000_ECC_DIR) == 0)
396 cf->data[2] |= CAN_ERR_PROT_TX;
398 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
399 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
400 cf->data[1] = (txerr > rxerr) ?
401 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
403 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
404 cf->can_id |= CAN_ERR_CRTL;
405 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
407 stats->rx_over_errors++;
412 stats->rx_bytes += cf->can_dlc;
417 * callback for bulk IN urb
419 static void ems_usb_read_bulk_callback(struct urb *urb)
421 struct ems_usb *dev = urb->context;
422 struct net_device *netdev;
425 netdev = dev->netdev;
427 if (!netif_device_present(netdev))
430 switch (urb->status) {
431 case 0: /* success */
438 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
442 if (urb->actual_length > CPC_HEADER_SIZE) {
443 struct ems_cpc_msg *msg;
444 u8 *ibuf = urb->transfer_buffer;
447 msg_count = 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 netdev_err(netdev, "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);
499 "failed resubmitting read bulk urb: %d\n", retval);
503 * callback for bulk IN urb
505 static void ems_usb_write_bulk_callback(struct urb *urb)
507 struct ems_tx_urb_context *context = urb->context;
509 struct net_device *netdev;
514 netdev = dev->netdev;
516 /* free up our allocated buffer */
517 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
518 urb->transfer_buffer, urb->transfer_dma);
520 atomic_dec(&dev->active_tx_urbs);
522 if (!netif_device_present(netdev))
526 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
528 netif_trans_update(netdev);
530 /* transmission complete interrupt */
531 netdev->stats.tx_packets++;
532 netdev->stats.tx_bytes += context->dlc;
534 can_get_echo_skb(netdev, context->echo_index);
536 /* Release context */
537 context->echo_index = MAX_TX_URBS;
542 * Send the given CPC command synchronously
544 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
549 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
550 msg->length + CPC_MSG_HEADER_LEN);
553 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
555 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
556 &dev->tx_msg_buffer[0],
557 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
558 &actual_length, 1000);
562 * Change CAN controllers' mode register
564 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
566 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
568 return ems_usb_command_msg(dev, &dev->active_params);
572 * Send a CPC_Control command to change behaviour when interface receives a CAN
573 * message, bus error or CAN state changed notifications.
575 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
577 struct ems_cpc_msg cmd;
579 cmd.type = CPC_CMD_TYPE_CONTROL;
580 cmd.length = CPC_MSG_HEADER_LEN + 1;
584 cmd.msg.generic[0] = val;
586 return ems_usb_command_msg(dev, &cmd);
592 static int ems_usb_start(struct ems_usb *dev)
594 struct net_device *netdev = dev->netdev;
597 dev->intr_in_buffer[0] = 0;
598 dev->free_slots = 50; /* initial size */
600 for (i = 0; i < MAX_RX_URBS; i++) {
601 struct urb *urb = NULL;
605 /* create a URB, and a buffer for it */
606 urb = usb_alloc_urb(0, GFP_KERNEL);
612 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
615 netdev_err(netdev, "No memory left for USB buffer\n");
621 urb->transfer_dma = buf_dma;
623 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
625 ems_usb_read_bulk_callback, dev);
626 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
627 usb_anchor_urb(urb, &dev->rx_submitted);
629 err = usb_submit_urb(urb, GFP_KERNEL);
631 usb_unanchor_urb(urb);
632 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
639 dev->rxbuf_dma[i] = buf_dma;
641 /* Drop reference, USB core will take care of freeing it */
645 /* Did we submit any URBs */
647 netdev_warn(netdev, "couldn't setup read URBs\n");
651 /* Warn if we've couldn't transmit all the URBs */
653 netdev_warn(netdev, "rx performance may be slow\n");
655 /* Setup and start interrupt URB */
656 usb_fill_int_urb(dev->intr_urb, dev->udev,
657 usb_rcvintpipe(dev->udev, 1),
660 ems_usb_read_interrupt_callback, dev, 1);
662 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
664 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
669 /* CPC-USB will transfer received message to host */
670 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
674 /* CPC-USB will transfer CAN state changes to host */
675 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
679 /* CPC-USB will transfer bus errors to host */
680 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
684 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
688 dev->can.state = CAN_STATE_ERROR_ACTIVE;
693 netdev_warn(netdev, "couldn't submit control: %d\n", err);
698 static void unlink_all_urbs(struct ems_usb *dev)
702 usb_unlink_urb(dev->intr_urb);
704 usb_kill_anchored_urbs(&dev->rx_submitted);
706 for (i = 0; i < MAX_RX_URBS; ++i)
707 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
708 dev->rxbuf[i], dev->rxbuf_dma[i]);
710 usb_kill_anchored_urbs(&dev->tx_submitted);
711 atomic_set(&dev->active_tx_urbs, 0);
713 for (i = 0; i < MAX_TX_URBS; i++)
714 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
717 static int ems_usb_open(struct net_device *netdev)
719 struct ems_usb *dev = netdev_priv(netdev);
722 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
727 err = open_candev(netdev);
731 /* finally start device */
732 err = ems_usb_start(dev);
735 netif_device_detach(dev->netdev);
737 netdev_warn(netdev, "couldn't start device: %d\n", err);
739 close_candev(netdev);
745 netif_start_queue(netdev);
750 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
752 struct ems_usb *dev = netdev_priv(netdev);
753 struct ems_tx_urb_context *context = NULL;
754 struct net_device_stats *stats = &netdev->stats;
755 struct can_frame *cf = (struct can_frame *)skb->data;
756 struct ems_cpc_msg *msg;
760 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
761 + sizeof(struct cpc_can_msg);
763 if (can_dropped_invalid_skb(netdev, skb))
766 /* create a URB, and a buffer for it, and copy the data to the URB */
767 urb = usb_alloc_urb(0, GFP_ATOMIC);
771 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
773 netdev_err(netdev, "No memory left for USB buffer\n");
778 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
780 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
781 msg->msg.can_msg.length = cf->can_dlc;
783 if (cf->can_id & CAN_RTR_FLAG) {
784 msg->type = cf->can_id & CAN_EFF_FLAG ?
785 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
787 msg->length = CPC_CAN_MSG_MIN_SIZE;
789 msg->type = cf->can_id & CAN_EFF_FLAG ?
790 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
792 for (i = 0; i < cf->can_dlc; i++)
793 msg->msg.can_msg.msg[i] = cf->data[i];
795 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
798 for (i = 0; i < MAX_TX_URBS; i++) {
799 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
800 context = &dev->tx_contexts[i];
806 * May never happen! When this happens we'd more URBs in flight as
807 * allowed (MAX_TX_URBS).
810 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
813 netdev_warn(netdev, "couldn't find free context\n");
815 return NETDEV_TX_BUSY;
819 context->echo_index = i;
820 context->dlc = cf->can_dlc;
822 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
823 size, ems_usb_write_bulk_callback, context);
824 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
825 usb_anchor_urb(urb, &dev->tx_submitted);
827 can_put_echo_skb(skb, netdev, context->echo_index);
829 atomic_inc(&dev->active_tx_urbs);
831 err = usb_submit_urb(urb, GFP_ATOMIC);
833 can_free_echo_skb(netdev, context->echo_index);
835 usb_unanchor_urb(urb);
836 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
838 atomic_dec(&dev->active_tx_urbs);
840 if (err == -ENODEV) {
841 netif_device_detach(netdev);
843 netdev_warn(netdev, "failed tx_urb %d\n", err);
848 netif_trans_update(netdev);
850 /* Slow down tx path */
851 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
852 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
853 netif_stop_queue(netdev);
858 * Release our reference to this URB, the USB core will eventually free
872 static int ems_usb_close(struct net_device *netdev)
874 struct ems_usb *dev = netdev_priv(netdev);
877 unlink_all_urbs(dev);
879 netif_stop_queue(netdev);
881 /* Set CAN controller to reset mode */
882 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
883 netdev_warn(netdev, "couldn't stop device");
885 close_candev(netdev);
890 static const struct net_device_ops ems_usb_netdev_ops = {
891 .ndo_open = ems_usb_open,
892 .ndo_stop = ems_usb_close,
893 .ndo_start_xmit = ems_usb_start_xmit,
894 .ndo_change_mtu = can_change_mtu,
897 static const struct can_bittiming_const ems_usb_bittiming_const = {
909 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
911 struct ems_usb *dev = netdev_priv(netdev);
915 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
916 netdev_warn(netdev, "couldn't start device");
918 if (netif_queue_stopped(netdev))
919 netif_wake_queue(netdev);
929 static int ems_usb_set_bittiming(struct net_device *netdev)
931 struct ems_usb *dev = netdev_priv(netdev);
932 struct can_bittiming *bt = &dev->can.bittiming;
935 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
936 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
937 (((bt->phase_seg2 - 1) & 0x7) << 4);
938 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
941 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
943 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
944 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
946 return ems_usb_command_msg(dev, &dev->active_params);
949 static void init_params_sja1000(struct ems_cpc_msg *msg)
951 struct cpc_sja1000_params *sja1000 =
952 &msg->msg.can_params.cc_params.sja1000;
954 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
955 msg->length = sizeof(struct cpc_can_params);
958 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
960 /* Acceptance filter open */
961 sja1000->acc_code0 = 0x00;
962 sja1000->acc_code1 = 0x00;
963 sja1000->acc_code2 = 0x00;
964 sja1000->acc_code3 = 0x00;
966 /* Acceptance filter open */
967 sja1000->acc_mask0 = 0xFF;
968 sja1000->acc_mask1 = 0xFF;
969 sja1000->acc_mask2 = 0xFF;
970 sja1000->acc_mask3 = 0xFF;
975 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
976 sja1000->mode = SJA1000_MOD_RM;
980 * probe function for new CPC-USB devices
982 static int ems_usb_probe(struct usb_interface *intf,
983 const struct usb_device_id *id)
985 struct net_device *netdev;
987 int i, err = -ENOMEM;
989 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
991 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
995 dev = netdev_priv(netdev);
997 dev->udev = interface_to_usbdev(intf);
998 dev->netdev = netdev;
1000 dev->can.state = CAN_STATE_STOPPED;
1001 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1002 dev->can.bittiming_const = &ems_usb_bittiming_const;
1003 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1004 dev->can.do_set_mode = ems_usb_set_mode;
1005 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1007 netdev->netdev_ops = &ems_usb_netdev_ops;
1009 netdev->flags |= IFF_ECHO; /* we support local echo */
1011 init_usb_anchor(&dev->rx_submitted);
1013 init_usb_anchor(&dev->tx_submitted);
1014 atomic_set(&dev->active_tx_urbs, 0);
1016 for (i = 0; i < MAX_TX_URBS; i++)
1017 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1019 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1021 goto cleanup_candev;
1023 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1024 if (!dev->intr_in_buffer)
1025 goto cleanup_intr_urb;
1027 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1028 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1029 if (!dev->tx_msg_buffer)
1030 goto cleanup_intr_in_buffer;
1032 usb_set_intfdata(intf, dev);
1034 SET_NETDEV_DEV(netdev, &intf->dev);
1036 init_params_sja1000(&dev->active_params);
1038 err = ems_usb_command_msg(dev, &dev->active_params);
1040 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1041 goto cleanup_tx_msg_buffer;
1044 err = register_candev(netdev);
1046 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1047 goto cleanup_tx_msg_buffer;
1052 cleanup_tx_msg_buffer:
1053 kfree(dev->tx_msg_buffer);
1055 cleanup_intr_in_buffer:
1056 kfree(dev->intr_in_buffer);
1059 usb_free_urb(dev->intr_urb);
1062 free_candev(netdev);
1068 * called by the usb core when the device is removed from the system
1070 static void ems_usb_disconnect(struct usb_interface *intf)
1072 struct ems_usb *dev = usb_get_intfdata(intf);
1074 usb_set_intfdata(intf, NULL);
1077 unregister_netdev(dev->netdev);
1079 unlink_all_urbs(dev);
1081 usb_free_urb(dev->intr_urb);
1083 kfree(dev->intr_in_buffer);
1084 kfree(dev->tx_msg_buffer);
1086 free_candev(dev->netdev);
1090 /* usb specific object needed to register this driver with the usb subsystem */
1091 static struct usb_driver ems_usb_driver = {
1093 .probe = ems_usb_probe,
1094 .disconnect = ems_usb_disconnect,
1095 .id_table = ems_usb_table,
1098 module_usb_driver(ems_usb_driver);