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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM74 *5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche6 */7#include <linux/ethtool.h>8#include <linux/signal.h>9#include <linux/slab.h>10#include <linux/module.h>11#include <linux/netdevice.h>12#include <linux/usb.h>13 14#include <linux/can.h>15#include <linux/can/dev.h>16#include <linux/can/error.h>17 18MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");19MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");20MODULE_LICENSE("GPL v2");21 22/* Control-Values for CPC_Control() Command Subject Selection */23#define CONTR_CAN_MESSAGE 0x0424#define CONTR_CAN_STATE 0x0C25#define CONTR_BUS_ERROR 0x1C26 27/* Control Command Actions */28#define CONTR_CONT_OFF 029#define CONTR_CONT_ON 130#define CONTR_ONCE 231 32/* Messages from CPC to PC */33#define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */34#define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */35#define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */36#define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */37#define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */38#define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */39#define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */40#define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */41#define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */42#define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */43#define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */44 45/* Messages from the PC to the CPC interface */46#define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */47#define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */48#define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */49#define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */50#define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */51#define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */52#define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */53#define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */54 55#define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */56#define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */57#define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */58 59#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */60 61#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */62 63/* Overrun types */64#define CPC_OVR_EVENT_CAN 0x0165#define CPC_OVR_EVENT_CANSTATE 0x0266#define CPC_OVR_EVENT_BUSERROR 0x0467 68/*69 * If the CAN controller lost a message we indicate it with the highest bit70 * set in the count field.71 */72#define CPC_OVR_HW 0x8073 74/* Size of the "struct ems_cpc_msg" without the union */75#define CPC_MSG_HEADER_LEN 1176#define CPC_CAN_MSG_MIN_SIZE 577 78/* Define these values to match your devices */79#define USB_CPCUSB_VENDOR_ID 0x12D680 81#define USB_CPCUSB_ARM7_PRODUCT_ID 0x044482 83/* Mode register NXP LPC2119/SJA1000 CAN Controller */84#define SJA1000_MOD_NORMAL 0x0085#define SJA1000_MOD_RM 0x0186 87/* ECC register NXP LPC2119/SJA1000 CAN Controller */88#define SJA1000_ECC_SEG 0x1F89#define SJA1000_ECC_DIR 0x2090#define SJA1000_ECC_ERR 0x0691#define SJA1000_ECC_BIT 0x0092#define SJA1000_ECC_FORM 0x4093#define SJA1000_ECC_STUFF 0x8094#define SJA1000_ECC_MASK 0xc095 96/* Status register content */97#define SJA1000_SR_BS 0x8098#define SJA1000_SR_ES 0x4099 100#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA101 102/*103 * The device actually uses a 16MHz clock to generate the CAN clock104 * but it expects SJA1000 bit settings based on 8MHz (is internally105 * converted).106 */107#define EMS_USB_ARM7_CLOCK 8000000108 109#define CPC_TX_QUEUE_TRIGGER_LOW 25110#define CPC_TX_QUEUE_TRIGGER_HIGH 35111 112/*113 * CAN-Message representation in a CPC_MSG. Message object type is114 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or115 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.116 */117struct cpc_can_msg {118 __le32 id;119 u8 length;120 u8 msg[8];121};122 123/* Representation of the CAN parameters for the SJA1000 controller */124struct cpc_sja1000_params {125 u8 mode;126 u8 acc_code0;127 u8 acc_code1;128 u8 acc_code2;129 u8 acc_code3;130 u8 acc_mask0;131 u8 acc_mask1;132 u8 acc_mask2;133 u8 acc_mask3;134 u8 btr0;135 u8 btr1;136 u8 outp_contr;137};138 139/* CAN params message representation */140struct cpc_can_params {141 u8 cc_type;142 143 /* Will support M16C CAN controller in the future */144 union {145 struct cpc_sja1000_params sja1000;146 } cc_params;147};148 149/* Structure for confirmed message handling */150struct cpc_confirm {151 u8 error; /* error code */152};153 154/* Structure for overrun conditions */155struct cpc_overrun {156 u8 event;157 u8 count;158};159 160/* SJA1000 CAN errors (compatible to NXP LPC2119) */161struct cpc_sja1000_can_error {162 u8 ecc;163 u8 rxerr;164 u8 txerr;165};166 167/* structure for CAN error conditions */168struct cpc_can_error {169 u8 ecode;170 171 struct {172 u8 cc_type;173 174 /* Other controllers may also provide error code capture regs */175 union {176 struct cpc_sja1000_can_error sja1000;177 } regs;178 } cc;179};180 181/*182 * Structure containing RX/TX error counter. This structure is used to request183 * the values of the CAN controllers TX and RX error counter.184 */185struct cpc_can_err_counter {186 u8 rx;187 u8 tx;188};189 190/* Main message type used between library and application */191struct __packed ems_cpc_msg {192 u8 type; /* type of message */193 u8 length; /* length of data within union 'msg' */194 u8 msgid; /* confirmation handle */195 __le32 ts_sec; /* timestamp in seconds */196 __le32 ts_nsec; /* timestamp in nano seconds */197 198 union __packed {199 u8 generic[64];200 struct cpc_can_msg can_msg;201 struct cpc_can_params can_params;202 struct cpc_confirm confirmation;203 struct cpc_overrun overrun;204 struct cpc_can_error error;205 struct cpc_can_err_counter err_counter;206 u8 can_state;207 } msg;208};209 210/*211 * Table of devices that work with this driver212 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.213 */214static struct usb_device_id ems_usb_table[] = {215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},216 {} /* Terminating entry */217};218 219MODULE_DEVICE_TABLE(usb, ems_usb_table);220 221#define RX_BUFFER_SIZE 64222#define CPC_HEADER_SIZE 4223#define INTR_IN_BUFFER_SIZE 4224 225#define MAX_RX_URBS 10226#define MAX_TX_URBS 10227 228struct ems_usb;229 230struct ems_tx_urb_context {231 struct ems_usb *dev;232 233 u32 echo_index;234};235 236struct ems_usb {237 struct can_priv can; /* must be the first member */238 239 struct sk_buff *echo_skb[MAX_TX_URBS];240 241 struct usb_device *udev;242 struct net_device *netdev;243 244 atomic_t active_tx_urbs;245 struct usb_anchor tx_submitted;246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];247 248 struct usb_anchor rx_submitted;249 250 struct urb *intr_urb;251 252 u8 *tx_msg_buffer;253 254 u8 *intr_in_buffer;255 unsigned int free_slots; /* remember number of available slots */256 257 struct ems_cpc_msg active_params; /* active controller parameters */258 void *rxbuf[MAX_RX_URBS];259 dma_addr_t rxbuf_dma[MAX_RX_URBS];260};261 262static void ems_usb_read_interrupt_callback(struct urb *urb)263{264 struct ems_usb *dev = urb->context;265 struct net_device *netdev = dev->netdev;266 int err;267 268 if (!netif_device_present(netdev))269 return;270 271 switch (urb->status) {272 case 0:273 dev->free_slots = dev->intr_in_buffer[1];274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&275 netif_queue_stopped(netdev))276 netif_wake_queue(netdev);277 break;278 279 case -ECONNRESET: /* unlink */280 case -ENOENT:281 case -EPIPE:282 case -EPROTO:283 case -ESHUTDOWN:284 return;285 286 default:287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);288 break;289 }290 291 err = usb_submit_urb(urb, GFP_ATOMIC);292 293 if (err == -ENODEV)294 netif_device_detach(netdev);295 else if (err)296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);297}298 299static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)300{301 struct can_frame *cf;302 struct sk_buff *skb;303 int i;304 struct net_device_stats *stats = &dev->netdev->stats;305 306 skb = alloc_can_skb(dev->netdev, &cf);307 if (skb == NULL)308 return;309 310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);312 313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)315 cf->can_id |= CAN_EFF_FLAG;316 317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {319 cf->can_id |= CAN_RTR_FLAG;320 } else {321 for (i = 0; i < cf->len; i++)322 cf->data[i] = msg->msg.can_msg.msg[i];323 324 stats->rx_bytes += cf->len;325 }326 stats->rx_packets++;327 328 netif_rx(skb);329}330 331static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)332{333 struct can_frame *cf;334 struct sk_buff *skb;335 struct net_device_stats *stats = &dev->netdev->stats;336 337 skb = alloc_can_err_skb(dev->netdev, &cf);338 if (skb == NULL)339 return;340 341 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {342 u8 state = msg->msg.can_state;343 344 if (state & SJA1000_SR_BS) {345 dev->can.state = CAN_STATE_BUS_OFF;346 cf->can_id |= CAN_ERR_BUSOFF;347 348 dev->can.can_stats.bus_off++;349 can_bus_off(dev->netdev);350 } else if (state & SJA1000_SR_ES) {351 dev->can.state = CAN_STATE_ERROR_WARNING;352 dev->can.can_stats.error_warning++;353 } else {354 dev->can.state = CAN_STATE_ERROR_ACTIVE;355 dev->can.can_stats.error_passive++;356 }357 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {358 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;359 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;360 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;361 362 /* bus error interrupt */363 dev->can.can_stats.bus_error++;364 stats->rx_errors++;365 366 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;367 368 switch (ecc & SJA1000_ECC_MASK) {369 case SJA1000_ECC_BIT:370 cf->data[2] |= CAN_ERR_PROT_BIT;371 break;372 case SJA1000_ECC_FORM:373 cf->data[2] |= CAN_ERR_PROT_FORM;374 break;375 case SJA1000_ECC_STUFF:376 cf->data[2] |= CAN_ERR_PROT_STUFF;377 break;378 default:379 cf->data[3] = ecc & SJA1000_ECC_SEG;380 break;381 }382 383 /* Error occurred during transmission? */384 if ((ecc & SJA1000_ECC_DIR) == 0)385 cf->data[2] |= CAN_ERR_PROT_TX;386 387 if (dev->can.state == CAN_STATE_ERROR_WARNING ||388 dev->can.state == CAN_STATE_ERROR_PASSIVE) {389 cf->can_id |= CAN_ERR_CRTL;390 cf->data[1] = (txerr > rxerr) ?391 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;392 }393 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {394 cf->can_id |= CAN_ERR_CRTL;395 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;396 397 stats->rx_over_errors++;398 stats->rx_errors++;399 }400 401 netif_rx(skb);402}403 404/*405 * callback for bulk IN urb406 */407static void ems_usb_read_bulk_callback(struct urb *urb)408{409 struct ems_usb *dev = urb->context;410 struct net_device *netdev;411 int retval;412 413 netdev = dev->netdev;414 415 if (!netif_device_present(netdev))416 return;417 418 switch (urb->status) {419 case 0: /* success */420 break;421 422 case -ENOENT:423 return;424 425 default:426 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);427 goto resubmit_urb;428 }429 430 if (urb->actual_length > CPC_HEADER_SIZE) {431 struct ems_cpc_msg *msg;432 u8 *ibuf = urb->transfer_buffer;433 u8 msg_count, start;434 435 msg_count = ibuf[0] & ~0x80;436 437 start = CPC_HEADER_SIZE;438 439 while (msg_count) {440 msg = (struct ems_cpc_msg *)&ibuf[start];441 442 switch (msg->type) {443 case CPC_MSG_TYPE_CAN_STATE:444 /* Process CAN state changes */445 ems_usb_rx_err(dev, msg);446 break;447 448 case CPC_MSG_TYPE_CAN_FRAME:449 case CPC_MSG_TYPE_EXT_CAN_FRAME:450 case CPC_MSG_TYPE_RTR_FRAME:451 case CPC_MSG_TYPE_EXT_RTR_FRAME:452 ems_usb_rx_can_msg(dev, msg);453 break;454 455 case CPC_MSG_TYPE_CAN_FRAME_ERROR:456 /* Process errorframe */457 ems_usb_rx_err(dev, msg);458 break;459 460 case CPC_MSG_TYPE_OVERRUN:461 /* Message lost while receiving */462 ems_usb_rx_err(dev, msg);463 break;464 }465 466 start += CPC_MSG_HEADER_LEN + msg->length;467 msg_count--;468 469 if (start > urb->transfer_buffer_length) {470 netdev_err(netdev, "format error\n");471 break;472 }473 }474 }475 476resubmit_urb:477 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),478 urb->transfer_buffer, RX_BUFFER_SIZE,479 ems_usb_read_bulk_callback, dev);480 481 retval = usb_submit_urb(urb, GFP_ATOMIC);482 483 if (retval == -ENODEV)484 netif_device_detach(netdev);485 else if (retval)486 netdev_err(netdev,487 "failed resubmitting read bulk urb: %d\n", retval);488}489 490/*491 * callback for bulk IN urb492 */493static void ems_usb_write_bulk_callback(struct urb *urb)494{495 struct ems_tx_urb_context *context = urb->context;496 struct ems_usb *dev;497 struct net_device *netdev;498 499 BUG_ON(!context);500 501 dev = context->dev;502 netdev = dev->netdev;503 504 /* free up our allocated buffer */505 usb_free_coherent(urb->dev, urb->transfer_buffer_length,506 urb->transfer_buffer, urb->transfer_dma);507 508 atomic_dec(&dev->active_tx_urbs);509 510 if (!netif_device_present(netdev))511 return;512 513 if (urb->status)514 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);515 516 netif_trans_update(netdev);517 518 /* transmission complete interrupt */519 netdev->stats.tx_packets++;520 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,521 NULL);522 523 /* Release context */524 context->echo_index = MAX_TX_URBS;525 526}527 528/*529 * Send the given CPC command synchronously530 */531static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)532{533 int actual_length;534 535 /* Copy payload */536 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,537 msg->length + CPC_MSG_HEADER_LEN);538 539 /* Clear header */540 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);541 542 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),543 &dev->tx_msg_buffer[0],544 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,545 &actual_length, 1000);546}547 548/*549 * Change CAN controllers' mode register550 */551static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)552{553 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;554 555 return ems_usb_command_msg(dev, &dev->active_params);556}557 558/*559 * Send a CPC_Control command to change behaviour when interface receives a CAN560 * message, bus error or CAN state changed notifications.561 */562static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)563{564 struct ems_cpc_msg cmd;565 566 cmd.type = CPC_CMD_TYPE_CONTROL;567 cmd.length = CPC_MSG_HEADER_LEN + 1;568 569 cmd.msgid = 0;570 571 cmd.msg.generic[0] = val;572 573 return ems_usb_command_msg(dev, &cmd);574}575 576/*577 * Start interface578 */579static int ems_usb_start(struct ems_usb *dev)580{581 struct net_device *netdev = dev->netdev;582 int err, i;583 584 dev->intr_in_buffer[0] = 0;585 dev->free_slots = 50; /* initial size */586 587 for (i = 0; i < MAX_RX_URBS; i++) {588 struct urb *urb = NULL;589 u8 *buf = NULL;590 dma_addr_t buf_dma;591 592 /* create a URB, and a buffer for it */593 urb = usb_alloc_urb(0, GFP_KERNEL);594 if (!urb) {595 err = -ENOMEM;596 break;597 }598 599 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,600 &buf_dma);601 if (!buf) {602 netdev_err(netdev, "No memory left for USB buffer\n");603 usb_free_urb(urb);604 err = -ENOMEM;605 break;606 }607 608 urb->transfer_dma = buf_dma;609 610 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),611 buf, RX_BUFFER_SIZE,612 ems_usb_read_bulk_callback, dev);613 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;614 usb_anchor_urb(urb, &dev->rx_submitted);615 616 err = usb_submit_urb(urb, GFP_KERNEL);617 if (err) {618 usb_unanchor_urb(urb);619 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,620 urb->transfer_dma);621 usb_free_urb(urb);622 break;623 }624 625 dev->rxbuf[i] = buf;626 dev->rxbuf_dma[i] = buf_dma;627 628 /* Drop reference, USB core will take care of freeing it */629 usb_free_urb(urb);630 }631 632 /* Did we submit any URBs */633 if (i == 0) {634 netdev_warn(netdev, "couldn't setup read URBs\n");635 return err;636 }637 638 /* Warn if we've couldn't transmit all the URBs */639 if (i < MAX_RX_URBS)640 netdev_warn(netdev, "rx performance may be slow\n");641 642 /* Setup and start interrupt URB */643 usb_fill_int_urb(dev->intr_urb, dev->udev,644 usb_rcvintpipe(dev->udev, 1),645 dev->intr_in_buffer,646 INTR_IN_BUFFER_SIZE,647 ems_usb_read_interrupt_callback, dev, 1);648 649 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);650 if (err) {651 netdev_warn(netdev, "intr URB submit failed: %d\n", err);652 653 return err;654 }655 656 /* CPC-USB will transfer received message to host */657 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);658 if (err)659 goto failed;660 661 /* CPC-USB will transfer CAN state changes to host */662 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);663 if (err)664 goto failed;665 666 /* CPC-USB will transfer bus errors to host */667 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);668 if (err)669 goto failed;670 671 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);672 if (err)673 goto failed;674 675 dev->can.state = CAN_STATE_ERROR_ACTIVE;676 677 return 0;678 679failed:680 netdev_warn(netdev, "couldn't submit control: %d\n", err);681 682 return err;683}684 685static void unlink_all_urbs(struct ems_usb *dev)686{687 int i;688 689 usb_unlink_urb(dev->intr_urb);690 691 usb_kill_anchored_urbs(&dev->rx_submitted);692 693 for (i = 0; i < MAX_RX_URBS; ++i)694 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,695 dev->rxbuf[i], dev->rxbuf_dma[i]);696 697 usb_kill_anchored_urbs(&dev->tx_submitted);698 atomic_set(&dev->active_tx_urbs, 0);699 700 for (i = 0; i < MAX_TX_URBS; i++)701 dev->tx_contexts[i].echo_index = MAX_TX_URBS;702}703 704static int ems_usb_open(struct net_device *netdev)705{706 struct ems_usb *dev = netdev_priv(netdev);707 int err;708 709 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);710 if (err)711 return err;712 713 /* common open */714 err = open_candev(netdev);715 if (err)716 return err;717 718 /* finally start device */719 err = ems_usb_start(dev);720 if (err) {721 if (err == -ENODEV)722 netif_device_detach(dev->netdev);723 724 netdev_warn(netdev, "couldn't start device: %d\n", err);725 726 close_candev(netdev);727 728 return err;729 }730 731 732 netif_start_queue(netdev);733 734 return 0;735}736 737static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)738{739 struct ems_usb *dev = netdev_priv(netdev);740 struct ems_tx_urb_context *context = NULL;741 struct net_device_stats *stats = &netdev->stats;742 struct can_frame *cf = (struct can_frame *)skb->data;743 struct ems_cpc_msg *msg;744 struct urb *urb;745 u8 *buf;746 int i, err;747 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN748 + sizeof(struct cpc_can_msg);749 750 if (can_dev_dropped_skb(netdev, skb))751 return NETDEV_TX_OK;752 753 /* create a URB, and a buffer for it, and copy the data to the URB */754 urb = usb_alloc_urb(0, GFP_ATOMIC);755 if (!urb)756 goto nomem;757 758 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);759 if (!buf) {760 netdev_err(netdev, "No memory left for USB buffer\n");761 usb_free_urb(urb);762 goto nomem;763 }764 765 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];766 767 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);768 msg->msg.can_msg.length = cf->len;769 770 if (cf->can_id & CAN_RTR_FLAG) {771 msg->type = cf->can_id & CAN_EFF_FLAG ?772 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;773 774 msg->length = CPC_CAN_MSG_MIN_SIZE;775 } else {776 msg->type = cf->can_id & CAN_EFF_FLAG ?777 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;778 779 for (i = 0; i < cf->len; i++)780 msg->msg.can_msg.msg[i] = cf->data[i];781 782 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;783 }784 785 for (i = 0; i < MAX_TX_URBS; i++) {786 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {787 context = &dev->tx_contexts[i];788 break;789 }790 }791 792 /*793 * May never happen! When this happens we'd more URBs in flight as794 * allowed (MAX_TX_URBS).795 */796 if (!context) {797 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);798 usb_free_urb(urb);799 800 netdev_warn(netdev, "couldn't find free context\n");801 802 return NETDEV_TX_BUSY;803 }804 805 context->dev = dev;806 context->echo_index = i;807 808 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,809 size, ems_usb_write_bulk_callback, context);810 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;811 usb_anchor_urb(urb, &dev->tx_submitted);812 813 can_put_echo_skb(skb, netdev, context->echo_index, 0);814 815 atomic_inc(&dev->active_tx_urbs);816 817 err = usb_submit_urb(urb, GFP_ATOMIC);818 if (unlikely(err)) {819 can_free_echo_skb(netdev, context->echo_index, NULL);820 821 usb_unanchor_urb(urb);822 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);823 824 atomic_dec(&dev->active_tx_urbs);825 826 if (err == -ENODEV) {827 netif_device_detach(netdev);828 } else {829 netdev_warn(netdev, "failed tx_urb %d\n", err);830 831 stats->tx_dropped++;832 }833 } else {834 netif_trans_update(netdev);835 836 /* Slow down tx path */837 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||838 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {839 netif_stop_queue(netdev);840 }841 }842 843 /*844 * Release our reference to this URB, the USB core will eventually free845 * it entirely.846 */847 usb_free_urb(urb);848 849 return NETDEV_TX_OK;850 851nomem:852 dev_kfree_skb(skb);853 stats->tx_dropped++;854 855 return NETDEV_TX_OK;856}857 858static int ems_usb_close(struct net_device *netdev)859{860 struct ems_usb *dev = netdev_priv(netdev);861 862 /* Stop polling */863 unlink_all_urbs(dev);864 865 netif_stop_queue(netdev);866 867 /* Set CAN controller to reset mode */868 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))869 netdev_warn(netdev, "couldn't stop device");870 871 close_candev(netdev);872 873 return 0;874}875 876static const struct net_device_ops ems_usb_netdev_ops = {877 .ndo_open = ems_usb_open,878 .ndo_stop = ems_usb_close,879 .ndo_start_xmit = ems_usb_start_xmit,880 .ndo_change_mtu = can_change_mtu,881};882 883static const struct ethtool_ops ems_usb_ethtool_ops = {884 .get_ts_info = ethtool_op_get_ts_info,885};886 887static const struct can_bittiming_const ems_usb_bittiming_const = {888 .name = KBUILD_MODNAME,889 .tseg1_min = 1,890 .tseg1_max = 16,891 .tseg2_min = 1,892 .tseg2_max = 8,893 .sjw_max = 4,894 .brp_min = 1,895 .brp_max = 64,896 .brp_inc = 1,897};898 899static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)900{901 struct ems_usb *dev = netdev_priv(netdev);902 903 switch (mode) {904 case CAN_MODE_START:905 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))906 netdev_warn(netdev, "couldn't start device");907 908 if (netif_queue_stopped(netdev))909 netif_wake_queue(netdev);910 break;911 912 default:913 return -EOPNOTSUPP;914 }915 916 return 0;917}918 919static int ems_usb_set_bittiming(struct net_device *netdev)920{921 struct ems_usb *dev = netdev_priv(netdev);922 struct can_bittiming *bt = &dev->can.bittiming;923 u8 btr0, btr1;924 925 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);926 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |927 (((bt->phase_seg2 - 1) & 0x7) << 4);928 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)929 btr1 |= 0x80;930 931 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);932 933 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;934 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;935 936 return ems_usb_command_msg(dev, &dev->active_params);937}938 939static void init_params_sja1000(struct ems_cpc_msg *msg)940{941 struct cpc_sja1000_params *sja1000 =942 &msg->msg.can_params.cc_params.sja1000;943 944 msg->type = CPC_CMD_TYPE_CAN_PARAMS;945 msg->length = sizeof(struct cpc_can_params);946 msg->msgid = 0;947 948 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;949 950 /* Acceptance filter open */951 sja1000->acc_code0 = 0x00;952 sja1000->acc_code1 = 0x00;953 sja1000->acc_code2 = 0x00;954 sja1000->acc_code3 = 0x00;955 956 /* Acceptance filter open */957 sja1000->acc_mask0 = 0xFF;958 sja1000->acc_mask1 = 0xFF;959 sja1000->acc_mask2 = 0xFF;960 sja1000->acc_mask3 = 0xFF;961 962 sja1000->btr0 = 0;963 sja1000->btr1 = 0;964 965 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;966 sja1000->mode = SJA1000_MOD_RM;967}968 969/*970 * probe function for new CPC-USB devices971 */972static int ems_usb_probe(struct usb_interface *intf,973 const struct usb_device_id *id)974{975 struct net_device *netdev;976 struct ems_usb *dev;977 int i, err = -ENOMEM;978 979 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);980 if (!netdev) {981 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");982 return -ENOMEM;983 }984 985 dev = netdev_priv(netdev);986 987 dev->udev = interface_to_usbdev(intf);988 dev->netdev = netdev;989 990 dev->can.state = CAN_STATE_STOPPED;991 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;992 dev->can.bittiming_const = &ems_usb_bittiming_const;993 dev->can.do_set_bittiming = ems_usb_set_bittiming;994 dev->can.do_set_mode = ems_usb_set_mode;995 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;996 997 netdev->netdev_ops = &ems_usb_netdev_ops;998 netdev->ethtool_ops = &ems_usb_ethtool_ops;999 1000 netdev->flags |= IFF_ECHO; /* we support local echo */1001 1002 init_usb_anchor(&dev->rx_submitted);1003 1004 init_usb_anchor(&dev->tx_submitted);1005 atomic_set(&dev->active_tx_urbs, 0);1006 1007 for (i = 0; i < MAX_TX_URBS; i++)1008 dev->tx_contexts[i].echo_index = MAX_TX_URBS;1009 1010 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);1011 if (!dev->intr_urb)1012 goto cleanup_candev;1013 1014 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);1015 if (!dev->intr_in_buffer)1016 goto cleanup_intr_urb;1017 1018 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +1019 sizeof(struct ems_cpc_msg), GFP_KERNEL);1020 if (!dev->tx_msg_buffer)1021 goto cleanup_intr_in_buffer;1022 1023 usb_set_intfdata(intf, dev);1024 1025 SET_NETDEV_DEV(netdev, &intf->dev);1026 1027 init_params_sja1000(&dev->active_params);1028 1029 err = ems_usb_command_msg(dev, &dev->active_params);1030 if (err) {1031 netdev_err(netdev, "couldn't initialize controller: %d\n", err);1032 goto cleanup_tx_msg_buffer;1033 }1034 1035 err = register_candev(netdev);1036 if (err) {1037 netdev_err(netdev, "couldn't register CAN device: %d\n", err);1038 goto cleanup_tx_msg_buffer;1039 }1040 1041 return 0;1042 1043cleanup_tx_msg_buffer:1044 kfree(dev->tx_msg_buffer);1045 1046cleanup_intr_in_buffer:1047 kfree(dev->intr_in_buffer);1048 1049cleanup_intr_urb:1050 usb_free_urb(dev->intr_urb);1051 1052cleanup_candev:1053 free_candev(netdev);1054 1055 return err;1056}1057 1058/*1059 * called by the usb core when the device is removed from the system1060 */1061static void ems_usb_disconnect(struct usb_interface *intf)1062{1063 struct ems_usb *dev = usb_get_intfdata(intf);1064 1065 usb_set_intfdata(intf, NULL);1066 1067 if (dev) {1068 unregister_netdev(dev->netdev);1069 1070 unlink_all_urbs(dev);1071 1072 usb_free_urb(dev->intr_urb);1073 1074 kfree(dev->intr_in_buffer);1075 kfree(dev->tx_msg_buffer);1076 1077 free_candev(dev->netdev);1078 }1079}1080 1081/* usb specific object needed to register this driver with the usb subsystem */1082static struct usb_driver ems_usb_driver = {1083 .name = KBUILD_MODNAME,1084 .probe = ems_usb_probe,1085 .disconnect = ems_usb_disconnect,1086 .id_table = ems_usb_table,1087};1088 1089module_usb_driver(ems_usb_driver);1090