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
121 #define CPC_TX_QUEUE_TRIGGER_LOW 25
122 #define CPC_TX_QUEUE_TRIGGER_HIGH 35
125 * CAN-Message representation in a CPC_MSG. Message object type is
126 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
127 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
135 /* Representation of the CAN parameters for the SJA1000 controller */
136 struct cpc_sja1000_params {
151 /* CAN params message representation */
152 struct cpc_can_params {
155 /* Will support M16C CAN controller in the future */
157 struct cpc_sja1000_params sja1000;
161 /* Structure for confirmed message handling */
163 u8 error; /* error code */
166 /* Structure for overrun conditions */
172 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
173 struct cpc_sja1000_can_error {
179 /* structure for CAN error conditions */
180 struct cpc_can_error {
186 /* Other controllers may also provide error code capture regs */
188 struct cpc_sja1000_can_error sja1000;
194 * Structure containing RX/TX error counter. This structure is used to request
195 * the values of the CAN controllers TX and RX error counter.
197 struct cpc_can_err_counter {
202 /* Main message type used between library and application */
203 struct __packed ems_cpc_msg {
204 u8 type; /* type of message */
205 u8 length; /* length of data within union 'msg' */
206 u8 msgid; /* confirmation handle */
207 u32 ts_sec; /* timestamp in seconds */
208 u32 ts_nsec; /* timestamp in nano seconds */
212 struct cpc_can_msg can_msg;
213 struct cpc_can_params can_params;
214 struct cpc_confirm confirmation;
215 struct cpc_overrun overrun;
216 struct cpc_can_error error;
217 struct cpc_can_err_counter err_counter;
223 * Table of devices that work with this driver
224 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
226 static struct usb_device_id ems_usb_table[] = {
227 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
228 {} /* Terminating entry */
231 MODULE_DEVICE_TABLE(usb, ems_usb_table);
233 #define RX_BUFFER_SIZE 64
234 #define CPC_HEADER_SIZE 4
235 #define INTR_IN_BUFFER_SIZE 4
237 #define MAX_RX_URBS 10
238 #define MAX_TX_URBS 10
242 struct ems_tx_urb_context {
250 struct can_priv can; /* must be the first member */
253 struct sk_buff *echo_skb[MAX_TX_URBS];
255 struct usb_device *udev;
256 struct net_device *netdev;
258 atomic_t active_tx_urbs;
259 struct usb_anchor tx_submitted;
260 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
262 struct usb_anchor rx_submitted;
264 struct urb *intr_urb;
269 unsigned int free_slots; /* remember number of available slots */
271 struct ems_cpc_msg active_params; /* active controller parameters */
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 if (netif_queue_stopped(netdev)){
288 netif_wake_queue(netdev);
293 case -ECONNRESET: /* unlink */
299 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n",
304 err = usb_submit_urb(urb, GFP_ATOMIC);
307 netif_device_detach(netdev);
309 dev_err(netdev->dev.parent,
310 "failed resubmitting intr urb: %d\n", err);
313 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
315 struct can_frame *cf;
318 struct net_device_stats *stats = &dev->netdev->stats;
320 skb = alloc_can_skb(dev->netdev, &cf);
324 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
325 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
327 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
329 cf->can_id |= CAN_EFF_FLAG;
331 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
332 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
333 cf->can_id |= CAN_RTR_FLAG;
335 for (i = 0; i < cf->can_dlc; i++)
336 cf->data[i] = msg->msg.can_msg.msg[i];
342 stats->rx_bytes += cf->can_dlc;
345 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
347 struct can_frame *cf;
349 struct net_device_stats *stats = &dev->netdev->stats;
351 skb = alloc_can_err_skb(dev->netdev, &cf);
355 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
356 u8 state = msg->msg.can_state;
358 if (state & SJA1000_SR_BS) {
359 dev->can.state = CAN_STATE_BUS_OFF;
360 cf->can_id |= CAN_ERR_BUSOFF;
362 can_bus_off(dev->netdev);
363 } else if (state & SJA1000_SR_ES) {
364 dev->can.state = CAN_STATE_ERROR_WARNING;
365 dev->can.can_stats.error_warning++;
367 dev->can.state = CAN_STATE_ERROR_ACTIVE;
368 dev->can.can_stats.error_passive++;
370 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
371 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
372 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
373 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
375 /* bus error interrupt */
376 dev->can.can_stats.bus_error++;
379 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
381 switch (ecc & SJA1000_ECC_MASK) {
382 case SJA1000_ECC_BIT:
383 cf->data[2] |= CAN_ERR_PROT_BIT;
385 case SJA1000_ECC_FORM:
386 cf->data[2] |= CAN_ERR_PROT_FORM;
388 case SJA1000_ECC_STUFF:
389 cf->data[2] |= CAN_ERR_PROT_STUFF;
392 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
393 cf->data[3] = ecc & SJA1000_ECC_SEG;
397 /* Error occurred during transmission? */
398 if ((ecc & SJA1000_ECC_DIR) == 0)
399 cf->data[2] |= CAN_ERR_PROT_TX;
401 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
402 dev->can.state == CAN_STATE_ERROR_PASSIVE) {
403 cf->data[1] = (txerr > rxerr) ?
404 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
406 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
407 cf->can_id |= CAN_ERR_CRTL;
408 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
410 stats->rx_over_errors++;
417 stats->rx_bytes += cf->can_dlc;
421 * callback for bulk IN urb
423 static void ems_usb_read_bulk_callback(struct urb *urb)
425 struct ems_usb *dev = urb->context;
426 struct net_device *netdev;
429 netdev = dev->netdev;
431 if (!netif_device_present(netdev))
434 switch (urb->status) {
435 case 0: /* success */
442 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n",
447 if (urb->actual_length > CPC_HEADER_SIZE) {
448 struct ems_cpc_msg *msg;
449 u8 *ibuf = urb->transfer_buffer;
450 u8 msg_count, again, start;
452 msg_count = ibuf[0] & ~0x80;
453 again = ibuf[0] & 0x80;
455 start = CPC_HEADER_SIZE;
458 msg = (struct ems_cpc_msg *)&ibuf[start];
461 case CPC_MSG_TYPE_CAN_STATE:
462 /* Process CAN state changes */
463 ems_usb_rx_err(dev, msg);
466 case CPC_MSG_TYPE_CAN_FRAME:
467 case CPC_MSG_TYPE_EXT_CAN_FRAME:
468 case CPC_MSG_TYPE_RTR_FRAME:
469 case CPC_MSG_TYPE_EXT_RTR_FRAME:
470 ems_usb_rx_can_msg(dev, msg);
473 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
474 /* Process errorframe */
475 ems_usb_rx_err(dev, msg);
478 case CPC_MSG_TYPE_OVERRUN:
479 /* Message lost while receiving */
480 ems_usb_rx_err(dev, msg);
484 start += CPC_MSG_HEADER_LEN + msg->length;
487 if (start > urb->transfer_buffer_length) {
488 dev_err(netdev->dev.parent, "format error\n");
495 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
496 urb->transfer_buffer, RX_BUFFER_SIZE,
497 ems_usb_read_bulk_callback, dev);
499 retval = usb_submit_urb(urb, GFP_ATOMIC);
501 if (retval == -ENODEV)
502 netif_device_detach(netdev);
504 dev_err(netdev->dev.parent,
505 "failed resubmitting read bulk urb: %d\n", retval);
509 * callback for bulk IN urb
511 static void ems_usb_write_bulk_callback(struct urb *urb)
513 struct ems_tx_urb_context *context = urb->context;
515 struct net_device *netdev;
520 netdev = dev->netdev;
522 /* free up our allocated buffer */
523 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
524 urb->transfer_buffer, urb->transfer_dma);
526 atomic_dec(&dev->active_tx_urbs);
528 if (!netif_device_present(netdev))
532 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
535 netdev->trans_start = jiffies;
537 /* transmission complete interrupt */
538 netdev->stats.tx_packets++;
539 netdev->stats.tx_bytes += context->dlc;
541 can_get_echo_skb(netdev, context->echo_index);
543 /* Release context */
544 context->echo_index = MAX_TX_URBS;
549 * Send the given CPC command synchronously
551 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
556 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
557 msg->length + CPC_MSG_HEADER_LEN);
560 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
562 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
563 &dev->tx_msg_buffer[0],
564 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
565 &actual_length, 1000);
569 * Change CAN controllers' mode register
571 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
573 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
575 return ems_usb_command_msg(dev, &dev->active_params);
579 * Send a CPC_Control command to change behaviour when interface receives a CAN
580 * message, bus error or CAN state changed notifications.
582 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
584 struct ems_cpc_msg cmd;
586 cmd.type = CPC_CMD_TYPE_CONTROL;
587 cmd.length = CPC_MSG_HEADER_LEN + 1;
591 cmd.msg.generic[0] = val;
593 return ems_usb_command_msg(dev, &cmd);
599 static int ems_usb_start(struct ems_usb *dev)
601 struct net_device *netdev = dev->netdev;
604 dev->intr_in_buffer[0] = 0;
605 dev->free_slots = 50; /* initial size */
607 for (i = 0; i < MAX_RX_URBS; i++) {
608 struct urb *urb = NULL;
611 /* create a URB, and a buffer for it */
612 urb = usb_alloc_urb(0, GFP_KERNEL);
614 dev_err(netdev->dev.parent,
615 "No memory left for URBs\n");
619 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
622 dev_err(netdev->dev.parent,
623 "No memory left for USB buffer\n");
628 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
630 ems_usb_read_bulk_callback, dev);
631 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
632 usb_anchor_urb(urb, &dev->rx_submitted);
634 err = usb_submit_urb(urb, GFP_KERNEL);
637 netif_device_detach(dev->netdev);
639 usb_unanchor_urb(urb);
640 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
645 /* Drop reference, USB core will take care of freeing it */
649 /* Did we submit any URBs */
651 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n");
655 /* Warn if we've couldn't transmit all the URBs */
657 dev_warn(netdev->dev.parent, "rx performance may be slow\n");
659 /* Setup and start interrupt URB */
660 usb_fill_int_urb(dev->intr_urb, dev->udev,
661 usb_rcvintpipe(dev->udev, 1),
664 ems_usb_read_interrupt_callback, dev, 1);
666 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
669 netif_device_detach(dev->netdev);
671 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n",
677 /* CPC-USB will transfer received message to host */
678 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
682 /* CPC-USB will transfer CAN state changes to host */
683 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
687 /* CPC-USB will transfer bus errors to host */
688 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
692 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
696 dev->can.state = CAN_STATE_ERROR_ACTIVE;
702 netif_device_detach(dev->netdev);
704 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err);
709 static void unlink_all_urbs(struct ems_usb *dev)
713 usb_unlink_urb(dev->intr_urb);
715 usb_kill_anchored_urbs(&dev->rx_submitted);
717 usb_kill_anchored_urbs(&dev->tx_submitted);
718 atomic_set(&dev->active_tx_urbs, 0);
720 for (i = 0; i < MAX_TX_URBS; i++)
721 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
724 static int ems_usb_open(struct net_device *netdev)
726 struct ems_usb *dev = netdev_priv(netdev);
729 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
734 err = open_candev(netdev);
738 /* finally start device */
739 err = ems_usb_start(dev);
742 netif_device_detach(dev->netdev);
744 dev_warn(netdev->dev.parent, "couldn't start device: %d\n",
747 close_candev(netdev);
752 dev->open_time = jiffies;
754 netif_start_queue(netdev);
759 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
761 struct ems_usb *dev = netdev_priv(netdev);
762 struct ems_tx_urb_context *context = NULL;
763 struct net_device_stats *stats = &netdev->stats;
764 struct can_frame *cf = (struct can_frame *)skb->data;
765 struct ems_cpc_msg *msg;
769 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
770 + sizeof(struct cpc_can_msg);
772 if (can_dropped_invalid_skb(netdev, skb))
775 /* create a URB, and a buffer for it, and copy the data to the URB */
776 urb = usb_alloc_urb(0, GFP_ATOMIC);
778 dev_err(netdev->dev.parent, "No memory left for URBs\n");
782 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
784 dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
789 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
791 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
792 msg->msg.can_msg.length = cf->can_dlc;
794 if (cf->can_id & CAN_RTR_FLAG) {
795 msg->type = cf->can_id & CAN_EFF_FLAG ?
796 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
798 msg->length = CPC_CAN_MSG_MIN_SIZE;
800 msg->type = cf->can_id & CAN_EFF_FLAG ?
801 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
803 for (i = 0; i < cf->can_dlc; i++)
804 msg->msg.can_msg.msg[i] = cf->data[i];
806 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
809 /* Respect byte order */
810 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id);
812 for (i = 0; i < MAX_TX_URBS; i++) {
813 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
814 context = &dev->tx_contexts[i];
820 * May never happen! When this happens we'd more URBs in flight as
821 * allowed (MAX_TX_URBS).
824 usb_unanchor_urb(urb);
825 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
827 dev_warn(netdev->dev.parent, "couldn't find free context\n");
829 return NETDEV_TX_BUSY;
833 context->echo_index = i;
834 context->dlc = cf->can_dlc;
836 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
837 size, ems_usb_write_bulk_callback, context);
838 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
839 usb_anchor_urb(urb, &dev->tx_submitted);
841 can_put_echo_skb(skb, netdev, context->echo_index);
843 atomic_inc(&dev->active_tx_urbs);
845 err = usb_submit_urb(urb, GFP_ATOMIC);
847 can_free_echo_skb(netdev, context->echo_index);
849 usb_unanchor_urb(urb);
850 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
853 atomic_dec(&dev->active_tx_urbs);
855 if (err == -ENODEV) {
856 netif_device_detach(netdev);
858 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
863 netdev->trans_start = jiffies;
865 /* Slow down tx path */
866 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
867 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
868 netif_stop_queue(netdev);
873 * Release our reference to this URB, the USB core will eventually free
887 static int ems_usb_close(struct net_device *netdev)
889 struct ems_usb *dev = netdev_priv(netdev);
892 unlink_all_urbs(dev);
894 netif_stop_queue(netdev);
896 /* Set CAN controller to reset mode */
897 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
898 dev_warn(netdev->dev.parent, "couldn't stop device");
900 close_candev(netdev);
907 static const struct net_device_ops ems_usb_netdev_ops = {
908 .ndo_open = ems_usb_open,
909 .ndo_stop = ems_usb_close,
910 .ndo_start_xmit = ems_usb_start_xmit,
913 static struct can_bittiming_const ems_usb_bittiming_const = {
925 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
927 struct ems_usb *dev = netdev_priv(netdev);
934 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
935 dev_warn(netdev->dev.parent, "couldn't start device");
937 if (netif_queue_stopped(netdev))
938 netif_wake_queue(netdev);
948 static int ems_usb_set_bittiming(struct net_device *netdev)
950 struct ems_usb *dev = netdev_priv(netdev);
951 struct can_bittiming *bt = &dev->can.bittiming;
954 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
955 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
956 (((bt->phase_seg2 - 1) & 0x7) << 4);
957 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
960 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
963 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
964 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
966 return ems_usb_command_msg(dev, &dev->active_params);
969 static void init_params_sja1000(struct ems_cpc_msg *msg)
971 struct cpc_sja1000_params *sja1000 =
972 &msg->msg.can_params.cc_params.sja1000;
974 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
975 msg->length = sizeof(struct cpc_can_params);
978 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
980 /* Acceptance filter open */
981 sja1000->acc_code0 = 0x00;
982 sja1000->acc_code1 = 0x00;
983 sja1000->acc_code2 = 0x00;
984 sja1000->acc_code3 = 0x00;
986 /* Acceptance filter open */
987 sja1000->acc_mask0 = 0xFF;
988 sja1000->acc_mask1 = 0xFF;
989 sja1000->acc_mask2 = 0xFF;
990 sja1000->acc_mask3 = 0xFF;
995 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
996 sja1000->mode = SJA1000_MOD_RM;
1000 * probe function for new CPC-USB devices
1002 static int ems_usb_probe(struct usb_interface *intf,
1003 const struct usb_device_id *id)
1005 struct net_device *netdev;
1006 struct ems_usb *dev;
1007 int i, err = -ENOMEM;
1009 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1011 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
1015 dev = netdev_priv(netdev);
1017 dev->udev = interface_to_usbdev(intf);
1018 dev->netdev = netdev;
1020 dev->can.state = CAN_STATE_STOPPED;
1021 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1022 dev->can.bittiming_const = &ems_usb_bittiming_const;
1023 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1024 dev->can.do_set_mode = ems_usb_set_mode;
1025 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1027 netdev->netdev_ops = &ems_usb_netdev_ops;
1029 netdev->flags |= IFF_ECHO; /* we support local echo */
1031 init_usb_anchor(&dev->rx_submitted);
1033 init_usb_anchor(&dev->tx_submitted);
1034 atomic_set(&dev->active_tx_urbs, 0);
1036 for (i = 0; i < MAX_TX_URBS; i++)
1037 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1039 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1040 if (!dev->intr_urb) {
1041 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1042 goto cleanup_candev;
1045 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1046 if (!dev->intr_in_buffer) {
1047 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n");
1048 goto cleanup_intr_urb;
1051 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1052 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1053 if (!dev->tx_msg_buffer) {
1054 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n");
1055 goto cleanup_intr_in_buffer;
1058 usb_set_intfdata(intf, dev);
1060 SET_NETDEV_DEV(netdev, &intf->dev);
1062 init_params_sja1000(&dev->active_params);
1064 err = ems_usb_command_msg(dev, &dev->active_params);
1066 dev_err(netdev->dev.parent,
1067 "couldn't initialize controller: %d\n", err);
1068 goto cleanup_tx_msg_buffer;
1071 err = register_candev(netdev);
1073 dev_err(netdev->dev.parent,
1074 "couldn't register CAN device: %d\n", err);
1075 goto cleanup_tx_msg_buffer;
1080 cleanup_tx_msg_buffer:
1081 kfree(dev->tx_msg_buffer);
1083 cleanup_intr_in_buffer:
1084 kfree(dev->intr_in_buffer);
1087 usb_free_urb(dev->intr_urb);
1090 free_candev(netdev);
1096 * called by the usb core when the device is removed from the system
1098 static void ems_usb_disconnect(struct usb_interface *intf)
1100 struct ems_usb *dev = usb_get_intfdata(intf);
1102 usb_set_intfdata(intf, NULL);
1105 unregister_netdev(dev->netdev);
1106 free_candev(dev->netdev);
1108 unlink_all_urbs(dev);
1110 usb_free_urb(dev->intr_urb);
1112 kfree(dev->intr_in_buffer);
1116 /* usb specific object needed to register this driver with the usb subsystem */
1117 static struct usb_driver ems_usb_driver = {
1119 .probe = ems_usb_probe,
1120 .disconnect = ems_usb_disconnect,
1121 .id_table = ems_usb_table,
1124 static int __init ems_usb_init(void)
1128 printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1130 /* register this driver with the USB subsystem */
1131 err = usb_register(&ems_usb_driver);
1134 err("usb_register failed. Error number %d\n", err);
1141 static void __exit ems_usb_exit(void)
1143 /* deregister this driver with the USB subsystem */
1144 usb_deregister(&ems_usb_driver);
1147 module_init(ems_usb_init);
1148 module_exit(ems_usb_exit);