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 <socketcan/can.h>
27 #include <socketcan/can/dev.h>
28 #include <socketcan/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(ND2D(netdev), "Rx interrupt aborted %d\n",
296 err = usb_submit_urb(urb, GFP_ATOMIC);
299 netif_device_detach(netdev);
301 dev_err(ND2D(netdev),
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 = msg->msg.can_msg.id;
319 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length);
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];
335 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,32)
336 dev->netdev->last_rx = jiffies;
339 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 can_bus_off(dev->netdev);
360 } else if (state & SJA1000_SR_ES) {
361 dev->can.state = CAN_STATE_ERROR_WARNING;
362 dev->can.can_stats.error_warning++;
364 dev->can.state = CAN_STATE_ERROR_ACTIVE;
365 dev->can.can_stats.error_passive++;
367 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
368 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
369 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
370 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
372 /* bus error interrupt */
373 dev->can.can_stats.bus_error++;
376 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
378 switch (ecc & SJA1000_ECC_MASK) {
379 case SJA1000_ECC_BIT:
380 cf->data[2] |= CAN_ERR_PROT_BIT;
382 case SJA1000_ECC_FORM:
383 cf->data[2] |= CAN_ERR_PROT_FORM;
385 case SJA1000_ECC_STUFF:
386 cf->data[2] |= CAN_ERR_PROT_STUFF;
389 cf->data[2] |= CAN_ERR_PROT_UNSPEC;
390 cf->data[3] = ecc & SJA1000_ECC_SEG;
394 /* Error occured 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++;
413 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,32)
414 dev->netdev->last_rx = jiffies;
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(ND2D(netdev), "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(ND2D(netdev), "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(ND2D(netdev),
505 "failed resubmitting read bulk urb: %d\n", retval);
511 * callback for bulk IN urb
513 static void ems_usb_write_bulk_callback(struct urb *urb)
515 struct ems_tx_urb_context *context = urb->context;
517 struct net_device *netdev;
522 netdev = dev->netdev;
524 /* free up our allocated buffer */
525 usb_buffer_free(urb->dev, urb->transfer_buffer_length,
526 urb->transfer_buffer, urb->transfer_dma);
528 atomic_dec(&dev->active_tx_urbs);
530 if (!netif_device_present(netdev))
534 dev_info(ND2D(netdev), "Tx URB aborted (%d)\n",
537 netdev->trans_start = jiffies;
539 /* transmission complete interrupt */
540 netdev->stats.tx_packets++;
541 netdev->stats.tx_bytes += context->dlc;
543 can_get_echo_skb(netdev, context->echo_index);
545 /* Release context */
546 context->echo_index = MAX_TX_URBS;
548 if (netif_queue_stopped(netdev))
549 netif_wake_queue(netdev);
553 * Send the given CPC command synchronously
555 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
560 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
561 msg->length + CPC_MSG_HEADER_LEN);
564 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
566 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
567 &dev->tx_msg_buffer[0],
568 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
569 &actual_length, 1000);
573 * Change CAN controllers' mode register
575 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
577 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
579 return ems_usb_command_msg(dev, &dev->active_params);
583 * Send a CPC_Control command to change behaviour when interface receives a CAN
584 * message, bus error or CAN state changed notifications.
586 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
588 struct ems_cpc_msg cmd;
590 cmd.type = CPC_CMD_TYPE_CONTROL;
591 cmd.length = CPC_MSG_HEADER_LEN + 1;
595 cmd.msg.generic[0] = val;
597 return ems_usb_command_msg(dev, &cmd);
603 static int ems_usb_start(struct ems_usb *dev)
605 struct net_device *netdev = dev->netdev;
608 dev->intr_in_buffer[0] = 0;
609 dev->free_slots = 15; /* initial size */
611 for (i = 0; i < MAX_RX_URBS; i++) {
612 struct urb *urb = NULL;
615 /* create a URB, and a buffer for it */
616 urb = usb_alloc_urb(0, GFP_KERNEL);
618 dev_err(ND2D(netdev),
619 "No memory left for URBs\n");
623 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
626 dev_err(ND2D(netdev),
627 "No memory left for USB buffer\n");
632 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
634 ems_usb_read_bulk_callback, dev);
635 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
636 usb_anchor_urb(urb, &dev->rx_submitted);
638 err = usb_submit_urb(urb, GFP_KERNEL);
641 netif_device_detach(dev->netdev);
643 usb_unanchor_urb(urb);
644 usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf,
649 /* Drop reference, USB core will take care of freeing it */
653 /* Did we submit any URBs */
655 dev_warn(ND2D(netdev), "couldn't setup read URBs\n");
659 /* Warn if we've couldn't transmit all the URBs */
661 dev_warn(ND2D(netdev), "rx performance may be slow\n");
663 /* Setup and start interrupt URB */
664 usb_fill_int_urb(dev->intr_urb, dev->udev,
665 usb_rcvintpipe(dev->udev, 1),
668 ems_usb_read_interrupt_callback, dev, 1);
670 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
673 netif_device_detach(dev->netdev);
675 dev_warn(ND2D(netdev), "intr URB submit failed: %d\n",
681 /* CPC-USB will transfer received message to host */
682 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
686 /* CPC-USB will transfer CAN state changes to host */
687 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
691 /* CPC-USB will transfer bus errors to host */
692 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
696 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
700 dev->can.state = CAN_STATE_ERROR_ACTIVE;
706 netif_device_detach(dev->netdev);
708 dev_warn(ND2D(netdev), "couldn't submit control: %d\n", err);
713 static void unlink_all_urbs(struct ems_usb *dev)
717 usb_unlink_urb(dev->intr_urb);
719 usb_kill_anchored_urbs(&dev->rx_submitted);
721 usb_kill_anchored_urbs(&dev->tx_submitted);
722 atomic_set(&dev->active_tx_urbs, 0);
724 for (i = 0; i < MAX_TX_URBS; i++)
725 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
728 static int ems_usb_open(struct net_device *netdev)
730 struct ems_usb *dev = netdev_priv(netdev);
733 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
738 err = open_candev(netdev);
742 /* finally start device */
743 err = ems_usb_start(dev);
746 netif_device_detach(dev->netdev);
748 dev_warn(ND2D(netdev), "couldn't start device: %d\n",
751 close_candev(netdev);
756 dev->open_time = jiffies;
758 netif_start_queue(netdev);
763 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,32)
764 static int ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
766 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
769 struct ems_usb *dev = netdev_priv(netdev);
770 struct ems_tx_urb_context *context = NULL;
771 struct net_device_stats *stats = &netdev->stats;
772 struct can_frame *cf = (struct can_frame *)skb->data;
773 struct ems_cpc_msg *msg;
777 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
778 + sizeof(struct cpc_can_msg);
780 if (can_dropped_invalid_skb(netdev, skb))
783 /* create a URB, and a buffer for it, and copy the data to the URB */
784 urb = usb_alloc_urb(0, GFP_ATOMIC);
786 dev_err(ND2D(netdev), "No memory left for URBs\n");
790 buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
792 dev_err(ND2D(netdev), "No memory left for USB buffer\n");
797 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
799 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
800 msg->msg.can_msg.length = cf->can_dlc;
802 if (cf->can_id & CAN_RTR_FLAG) {
803 msg->type = cf->can_id & CAN_EFF_FLAG ?
804 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
806 msg->length = CPC_CAN_MSG_MIN_SIZE;
808 msg->type = cf->can_id & CAN_EFF_FLAG ?
809 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
811 for (i = 0; i < cf->can_dlc; i++)
812 msg->msg.can_msg.msg[i] = cf->data[i];
814 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
817 for (i = 0; i < MAX_TX_URBS; i++) {
818 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
819 context = &dev->tx_contexts[i];
825 * May never happen! When this happens we'd more URBs in flight as
826 * allowed (MAX_TX_URBS).
829 usb_unanchor_urb(urb);
830 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
832 dev_warn(ND2D(netdev), "couldn't find free context\n");
834 return NETDEV_TX_BUSY;
838 context->echo_index = i;
839 context->dlc = cf->can_dlc;
841 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
842 size, ems_usb_write_bulk_callback, context);
843 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
844 usb_anchor_urb(urb, &dev->tx_submitted);
846 can_put_echo_skb(skb, netdev, context->echo_index);
848 atomic_inc(&dev->active_tx_urbs);
850 err = usb_submit_urb(urb, GFP_ATOMIC);
852 can_free_echo_skb(netdev, context->echo_index);
854 usb_unanchor_urb(urb);
855 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
858 atomic_dec(&dev->active_tx_urbs);
860 if (err == -ENODEV) {
861 netif_device_detach(netdev);
863 dev_warn(ND2D(netdev), "failed tx_urb %d\n", err);
868 netdev->trans_start = jiffies;
870 /* Slow down tx path */
871 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
872 dev->free_slots < 5) {
873 netif_stop_queue(netdev);
878 * Release our reference to this URB, the USB core will eventually free
894 static int ems_usb_close(struct net_device *netdev)
896 struct ems_usb *dev = netdev_priv(netdev);
899 unlink_all_urbs(dev);
901 netif_stop_queue(netdev);
903 /* Set CAN controller to reset mode */
904 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
905 dev_warn(ND2D(netdev), "couldn't stop device");
907 close_candev(netdev);
914 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,28)
915 static const struct net_device_ops ems_usb_netdev_ops = {
916 .ndo_open = ems_usb_open,
917 .ndo_stop = ems_usb_close,
918 .ndo_start_xmit = ems_usb_start_xmit,
922 static struct can_bittiming_const ems_usb_bittiming_const = {
934 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
936 struct ems_usb *dev = netdev_priv(netdev);
943 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
944 dev_warn(ND2D(netdev), "couldn't start device");
946 if (netif_queue_stopped(netdev))
947 netif_wake_queue(netdev);
957 static int ems_usb_set_bittiming(struct net_device *netdev)
959 struct ems_usb *dev = netdev_priv(netdev);
960 struct can_bittiming *bt = &dev->can.bittiming;
963 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
964 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
965 (((bt->phase_seg2 - 1) & 0x7) << 4);
966 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
969 dev_info(ND2D(netdev), "setting BTR0=0x%02x BTR1=0x%02x\n",
972 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
973 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
975 return ems_usb_command_msg(dev, &dev->active_params);
978 static void init_params_sja1000(struct ems_cpc_msg *msg)
980 struct cpc_sja1000_params *sja1000 =
981 &msg->msg.can_params.cc_params.sja1000;
983 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
984 msg->length = sizeof(struct cpc_can_params);
987 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
989 /* Acceptance filter open */
990 sja1000->acc_code0 = 0x00;
991 sja1000->acc_code1 = 0x00;
992 sja1000->acc_code2 = 0x00;
993 sja1000->acc_code3 = 0x00;
995 /* Acceptance filter open */
996 sja1000->acc_mask0 = 0xFF;
997 sja1000->acc_mask1 = 0xFF;
998 sja1000->acc_mask2 = 0xFF;
999 sja1000->acc_mask3 = 0xFF;
1004 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
1005 sja1000->mode = SJA1000_MOD_RM;
1009 * probe function for new CPC-USB devices
1011 static int ems_usb_probe(struct usb_interface *intf,
1012 const struct usb_device_id *id)
1014 struct net_device *netdev;
1015 struct ems_usb *dev;
1016 int i, err = -ENOMEM;
1018 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
1020 dev_err(ND2D(netdev), "Couldn't alloc candev\n");
1024 dev = netdev_priv(netdev);
1026 dev->udev = interface_to_usbdev(intf);
1027 dev->netdev = netdev;
1029 dev->can.state = CAN_STATE_STOPPED;
1030 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1031 dev->can.bittiming_const = &ems_usb_bittiming_const;
1032 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1033 dev->can.do_set_mode = ems_usb_set_mode;
1035 netdev->flags |= IFF_ECHO; /* we support local echo */
1037 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,28)
1038 netdev->netdev_ops = &ems_usb_netdev_ops;
1040 netdev->open = ems_usb_open;
1041 netdev->stop = ems_usb_close;
1042 netdev->hard_start_xmit = ems_usb_start_xmit;
1045 netdev->flags |= IFF_ECHO; /* we support local echo */
1047 init_usb_anchor(&dev->rx_submitted);
1049 init_usb_anchor(&dev->tx_submitted);
1050 atomic_set(&dev->active_tx_urbs, 0);
1052 for (i = 0; i < MAX_TX_URBS; i++)
1053 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1055 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1056 if (!dev->intr_urb) {
1057 dev_err(ND2D(netdev), "Couldn't alloc intr URB\n");
1058 goto cleanup_candev;
1061 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1062 if (!dev->intr_in_buffer) {
1063 dev_err(netdev->dev.parent, "Couldn't alloc Intr buffer\n");
1064 goto cleanup_intr_urb;
1067 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1068 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1069 if (!dev->tx_msg_buffer) {
1070 dev_err(ND2D(netdev), "Couldn't alloc Tx buffer\n");
1071 goto cleanup_intr_in_buffer;
1074 usb_set_intfdata(intf, dev);
1076 SET_NETDEV_DEV(netdev, &intf->dev);
1078 init_params_sja1000(&dev->active_params);
1080 err = ems_usb_command_msg(dev, &dev->active_params);
1082 dev_err(netdev->dev.parent,
1083 "couldn't initialize controller: %d\n", err);
1084 goto cleanup_tx_msg_buffer;
1087 err = register_candev(netdev);
1089 dev_err(netdev->dev.parent,
1090 "couldn't register CAN device: %d\n", err);
1091 goto cleanup_tx_msg_buffer;
1096 cleanup_tx_msg_buffer:
1097 kfree(dev->tx_msg_buffer);
1099 cleanup_intr_in_buffer:
1100 kfree(dev->intr_in_buffer);
1103 usb_free_urb(dev->intr_urb);
1106 free_candev(netdev);
1112 * called by the usb core when the device is removed from the system
1114 static void ems_usb_disconnect(struct usb_interface *intf)
1116 struct ems_usb *dev = usb_get_intfdata(intf);
1118 usb_set_intfdata(intf, NULL);
1121 unregister_netdev(dev->netdev);
1122 free_candev(dev->netdev);
1124 unlink_all_urbs(dev);
1126 usb_free_urb(dev->intr_urb);
1128 kfree(dev->intr_in_buffer);
1132 /* usb specific object needed to register this driver with the usb subsystem */
1133 static struct usb_driver ems_usb_driver = {
1135 .probe = ems_usb_probe,
1136 .disconnect = ems_usb_disconnect,
1137 .id_table = ems_usb_table,
1140 static int __init ems_usb_init(void)
1144 printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1146 /* register this driver with the USB subsystem */
1147 err = usb_register(&ems_usb_driver);
1150 err("usb_register failed. Error number %d\n", err);
1157 static void __exit ems_usb_exit(void)
1159 /* deregister this driver with the USB subsystem */
1160 usb_deregister(&ems_usb_driver);
1163 module_init(ems_usb_init);
1164 module_exit(ems_usb_exit);