1/* 2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7 3 * 4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche 5 * 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. 9 * 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. 14 * 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. 18 */ 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> 24 25#include <linux/can.h> 26#include <linux/can/dev.h> 27#include <linux/can/error.h> 28 29MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 30MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 31MODULE_LICENSE("GPL v2"); 32 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 37 38/* Control Command Actions */ 39#define CONTR_CONT_OFF 0 40#define CONTR_CONT_ON 1 41#define CONTR_ONCE 2 42 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 */ 55 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 */ 65 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 */ 69 70#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 71 72#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 73 74/* Overrun types */ 75#define CPC_OVR_EVENT_CAN 0x01 76#define CPC_OVR_EVENT_CANSTATE 0x02 77#define CPC_OVR_EVENT_BUSERROR 0x04 78 79/* 80 * If the CAN controller lost a message we indicate it with the highest bit 81 * set in the count field. 82 */ 83#define CPC_OVR_HW 0x80 84 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 88 89/* Define these values to match your devices */ 90#define USB_CPCUSB_VENDOR_ID 0x12D6 91 92#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 93 94/* Mode register NXP LPC2119/SJA1000 CAN Controller */ 95#define SJA1000_MOD_NORMAL 0x00 96#define SJA1000_MOD_RM 0x01 97 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 106 107/* Status register content */ 108#define SJA1000_SR_BS 0x80 109#define SJA1000_SR_ES 0x40 110 111#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 112 113/* 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 116 * converted). 117 */ 118#define EMS_USB_ARM7_CLOCK 8000000 119 120#define CPC_TX_QUEUE_TRIGGER_LOW 25 121#define CPC_TX_QUEUE_TRIGGER_HIGH 35 122 123/* 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. 127 */ 128struct cpc_can_msg { 129 __le32 id; 130 u8 length; 131 u8 msg[8]; 132}; 133 134/* Representation of the CAN parameters for the SJA1000 controller */ 135struct cpc_sja1000_params { 136 u8 mode; 137 u8 acc_code0; 138 u8 acc_code1; 139 u8 acc_code2; 140 u8 acc_code3; 141 u8 acc_mask0; 142 u8 acc_mask1; 143 u8 acc_mask2; 144 u8 acc_mask3; 145 u8 btr0; 146 u8 btr1; 147 u8 outp_contr; 148}; 149 150/* CAN params message representation */ 151struct cpc_can_params { 152 u8 cc_type; 153 154 /* Will support M16C CAN controller in the future */ 155 union { 156 struct cpc_sja1000_params sja1000; 157 } cc_params; 158}; 159 160/* Structure for confirmed message handling */ 161struct cpc_confirm { 162 u8 error; /* error code */ 163}; 164 165/* Structure for overrun conditions */ 166struct cpc_overrun { 167 u8 event; 168 u8 count; 169}; 170 171/* SJA1000 CAN errors (compatible to NXP LPC2119) */ 172struct cpc_sja1000_can_error { 173 u8 ecc; 174 u8 rxerr; 175 u8 txerr; 176}; 177 178/* structure for CAN error conditions */ 179struct cpc_can_error { 180 u8 ecode; 181 182 struct { 183 u8 cc_type; 184 185 /* Other controllers may also provide error code capture regs */ 186 union { 187 struct cpc_sja1000_can_error sja1000; 188 } regs; 189 } cc; 190}; 191 192/* 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. 195 */ 196struct cpc_can_err_counter { 197 u8 rx; 198 u8 tx; 199}; 200 201/* Main message type used between library and application */ 202struct __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 */ 208 209 union { 210 u8 generic[64]; 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; 217 u8 can_state; 218 } msg; 219}; 220 221/* 222 * Table of devices that work with this driver 223 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 224 */ 225static struct usb_device_id ems_usb_table[] = { 226 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 227 {} /* Terminating entry */ 228}; 229 230MODULE_DEVICE_TABLE(usb, ems_usb_table); 231 232#define RX_BUFFER_SIZE 64 233#define CPC_HEADER_SIZE 4 234#define INTR_IN_BUFFER_SIZE 4 235 236#define MAX_RX_URBS 10 237#define MAX_TX_URBS 10 238 239struct ems_usb; 240 241struct ems_tx_urb_context { 242 struct ems_usb *dev; 243 244 u32 echo_index; 245 u8 dlc; 246}; 247 248struct ems_usb { 249 struct can_priv can; /* must be the first member */ 250 251 struct sk_buff *echo_skb[MAX_TX_URBS]; 252 253 struct usb_device *udev; 254 struct net_device *netdev; 255 256 atomic_t active_tx_urbs; 257 struct usb_anchor tx_submitted; 258 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 259 260 struct usb_anchor rx_submitted; 261 262 struct urb *intr_urb; 263 264 u8 *tx_msg_buffer; 265 266 u8 *intr_in_buffer; 267 unsigned int free_slots; /* remember number of available slots */ 268 269 struct ems_cpc_msg active_params; /* active controller parameters */ 270}; 271 272static void ems_usb_read_interrupt_callback(struct urb *urb) 273{ 274 struct ems_usb *dev = urb->context; 275 struct net_device *netdev = dev->netdev; 276 int err; 277 278 if (!netif_device_present(netdev)) 279 return; 280 281 switch (urb->status) { 282 case 0: 283 dev->free_slots = dev->intr_in_buffer[1]; 284 if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){ 285 if (netif_queue_stopped(netdev)){ 286 netif_wake_queue(netdev); 287 } 288 } 289 break; 290 291 case -ECONNRESET: /* unlink */ 292 case -ENOENT: 293 case -ESHUTDOWN: 294 return; 295 296 default: 297 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 298 break; 299 } 300 301 err = usb_submit_urb(urb, GFP_ATOMIC); 302 303 if (err == -ENODEV) 304 netif_device_detach(netdev); 305 else if (err) 306 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 307} 308 309static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 310{ 311 struct can_frame *cf; 312 struct sk_buff *skb; 313 int i; 314 struct net_device_stats *stats = &dev->netdev->stats; 315 316 skb = alloc_can_skb(dev->netdev, &cf); 317 if (skb == NULL) 318 return; 319 320 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 321 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 322 323 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 325 cf->can_id |= CAN_EFF_FLAG; 326 327 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 329 cf->can_id |= CAN_RTR_FLAG; 330 } else { 331 for (i = 0; i < cf->can_dlc; i++) 332 cf->data[i] = msg->msg.can_msg.msg[i]; 333 } 334 335 netif_rx(skb); 336 337 stats->rx_packets++; 338 stats->rx_bytes += cf->can_dlc; 339} 340 341static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 342{ 343 struct can_frame *cf; 344 struct sk_buff *skb; 345 struct net_device_stats *stats = &dev->netdev->stats; 346 347 skb = alloc_can_err_skb(dev->netdev, &cf); 348 if (skb == NULL) 349 return; 350 351 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 352 u8 state = msg->msg.can_state; 353 354 if (state & SJA1000_SR_BS) { 355 dev->can.state = CAN_STATE_BUS_OFF; 356 cf->can_id |= CAN_ERR_BUSOFF; 357 358 dev->can.can_stats.bus_off++; 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++; 363 } else { 364 dev->can.state = CAN_STATE_ERROR_ACTIVE; 365 dev->can.can_stats.error_passive++; 366 } 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; 371 372 /* bus error interrupt */ 373 dev->can.can_stats.bus_error++; 374 stats->rx_errors++; 375 376 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 377 378 switch (ecc & SJA1000_ECC_MASK) { 379 case SJA1000_ECC_BIT: 380 cf->data[2] |= CAN_ERR_PROT_BIT; 381 break; 382 case SJA1000_ECC_FORM: 383 cf->data[2] |= CAN_ERR_PROT_FORM; 384 break; 385 case SJA1000_ECC_STUFF: 386 cf->data[2] |= CAN_ERR_PROT_STUFF; 387 break; 388 default: 389 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 390 cf->data[3] = ecc & SJA1000_ECC_SEG; 391 break; 392 } 393 394 /* Error occurred during transmission? */ 395 if ((ecc & SJA1000_ECC_DIR) == 0) 396 cf->data[2] |= CAN_ERR_PROT_TX; 397 398 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; 402 } 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; 406 407 stats->rx_over_errors++; 408 stats->rx_errors++; 409 } 410 411 netif_rx(skb); 412 413 stats->rx_packets++; 414 stats->rx_bytes += cf->can_dlc; 415} 416 417/* 418 * callback for bulk IN urb 419 */ 420static void ems_usb_read_bulk_callback(struct urb *urb) 421{ 422 struct ems_usb *dev = urb->context; 423 struct net_device *netdev; 424 int retval; 425 426 netdev = dev->netdev; 427 428 if (!netif_device_present(netdev)) 429 return; 430 431 switch (urb->status) { 432 case 0: /* success */ 433 break; 434 435 case -ENOENT: 436 return; 437 438 default: 439 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 440 goto resubmit_urb; 441 } 442 443 if (urb->actual_length > CPC_HEADER_SIZE) { 444 struct ems_cpc_msg *msg; 445 u8 *ibuf = urb->transfer_buffer; 446 u8 msg_count, start; 447 448 msg_count = ibuf[0] & ~0x80; 449 450 start = CPC_HEADER_SIZE; 451 452 while (msg_count) { 453 msg = (struct ems_cpc_msg *)&ibuf[start]; 454 455 switch (msg->type) { 456 case CPC_MSG_TYPE_CAN_STATE: 457 /* Process CAN state changes */ 458 ems_usb_rx_err(dev, msg); 459 break; 460 461 case CPC_MSG_TYPE_CAN_FRAME: 462 case CPC_MSG_TYPE_EXT_CAN_FRAME: 463 case CPC_MSG_TYPE_RTR_FRAME: 464 case CPC_MSG_TYPE_EXT_RTR_FRAME: 465 ems_usb_rx_can_msg(dev, msg); 466 break; 467 468 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 469 /* Process errorframe */ 470 ems_usb_rx_err(dev, msg); 471 break; 472 473 case CPC_MSG_TYPE_OVERRUN: 474 /* Message lost while receiving */ 475 ems_usb_rx_err(dev, msg); 476 break; 477 } 478 479 start += CPC_MSG_HEADER_LEN + msg->length; 480 msg_count--; 481 482 if (start > urb->transfer_buffer_length) { 483 netdev_err(netdev, "format error\n"); 484 break; 485 } 486 } 487 } 488 489resubmit_urb: 490 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 491 urb->transfer_buffer, RX_BUFFER_SIZE, 492 ems_usb_read_bulk_callback, dev); 493 494 retval = usb_submit_urb(urb, GFP_ATOMIC); 495 496 if (retval == -ENODEV) 497 netif_device_detach(netdev); 498 else if (retval) 499 netdev_err(netdev, 500 "failed resubmitting read bulk urb: %d\n", retval); 501} 502 503/* 504 * callback for bulk IN urb 505 */ 506static void ems_usb_write_bulk_callback(struct urb *urb) 507{ 508 struct ems_tx_urb_context *context = urb->context; 509 struct ems_usb *dev; 510 struct net_device *netdev; 511 512 BUG_ON(!context); 513 514 dev = context->dev; 515 netdev = dev->netdev; 516 517 /* free up our allocated buffer */ 518 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 519 urb->transfer_buffer, urb->transfer_dma); 520 521 atomic_dec(&dev->active_tx_urbs); 522 523 if (!netif_device_present(netdev)) 524 return; 525 526 if (urb->status) 527 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 528 529 netdev->trans_start = jiffies; 530 531 /* transmission complete interrupt */ 532 netdev->stats.tx_packets++; 533 netdev->stats.tx_bytes += context->dlc; 534 535 can_get_echo_skb(netdev, context->echo_index); 536 537 /* Release context */ 538 context->echo_index = MAX_TX_URBS; 539 540} 541 542/* 543 * Send the given CPC command synchronously 544 */ 545static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 546{ 547 int actual_length; 548 549 /* Copy payload */ 550 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 551 msg->length + CPC_MSG_HEADER_LEN); 552 553 /* Clear header */ 554 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 555 556 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 557 &dev->tx_msg_buffer[0], 558 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 559 &actual_length, 1000); 560} 561 562/* 563 * Change CAN controllers' mode register 564 */ 565static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 566{ 567 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 568 569 return ems_usb_command_msg(dev, &dev->active_params); 570} 571 572/* 573 * Send a CPC_Control command to change behaviour when interface receives a CAN 574 * message, bus error or CAN state changed notifications. 575 */ 576static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 577{ 578 struct ems_cpc_msg cmd; 579 580 cmd.type = CPC_CMD_TYPE_CONTROL; 581 cmd.length = CPC_MSG_HEADER_LEN + 1; 582 583 cmd.msgid = 0; 584 585 cmd.msg.generic[0] = val; 586 587 return ems_usb_command_msg(dev, &cmd); 588} 589 590/* 591 * Start interface 592 */ 593static int ems_usb_start(struct ems_usb *dev) 594{ 595 struct net_device *netdev = dev->netdev; 596 int err, i; 597 598 dev->intr_in_buffer[0] = 0; 599 dev->free_slots = 50; /* initial size */ 600 601 for (i = 0; i < MAX_RX_URBS; i++) { 602 struct urb *urb = NULL; 603 u8 *buf = NULL; 604 605 /* create a URB, and a buffer for it */ 606 urb = usb_alloc_urb(0, GFP_KERNEL); 607 if (!urb) { 608 netdev_err(netdev, "No memory left for URBs\n"); 609 err = -ENOMEM; 610 break; 611 } 612 613 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 614 &urb->transfer_dma); 615 if (!buf) { 616 netdev_err(netdev, "No memory left for USB buffer\n"); 617 usb_free_urb(urb); 618 err = -ENOMEM; 619 break; 620 } 621 622 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 623 buf, RX_BUFFER_SIZE, 624 ems_usb_read_bulk_callback, dev); 625 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 626 usb_anchor_urb(urb, &dev->rx_submitted); 627 628 err = usb_submit_urb(urb, GFP_KERNEL); 629 if (err) { 630 usb_unanchor_urb(urb); 631 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 632 urb->transfer_dma); 633 usb_free_urb(urb); 634 break; 635 } 636 637 /* Drop reference, USB core will take care of freeing it */ 638 usb_free_urb(urb); 639 } 640 641 /* Did we submit any URBs */ 642 if (i == 0) { 643 netdev_warn(netdev, "couldn't setup read URBs\n"); 644 return err; 645 } 646 647 /* Warn if we've couldn't transmit all the URBs */ 648 if (i < MAX_RX_URBS) 649 netdev_warn(netdev, "rx performance may be slow\n"); 650 651 /* Setup and start interrupt URB */ 652 usb_fill_int_urb(dev->intr_urb, dev->udev, 653 usb_rcvintpipe(dev->udev, 1), 654 dev->intr_in_buffer, 655 INTR_IN_BUFFER_SIZE, 656 ems_usb_read_interrupt_callback, dev, 1); 657 658 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 659 if (err) { 660 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 661 662 return err; 663 } 664 665 /* CPC-USB will transfer received message to host */ 666 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 667 if (err) 668 goto failed; 669 670 /* CPC-USB will transfer CAN state changes to host */ 671 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 672 if (err) 673 goto failed; 674 675 /* CPC-USB will transfer bus errors to host */ 676 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 677 if (err) 678 goto failed; 679 680 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 681 if (err) 682 goto failed; 683 684 dev->can.state = CAN_STATE_ERROR_ACTIVE; 685 686 return 0; 687 688failed: 689 netdev_warn(netdev, "couldn't submit control: %d\n", err); 690 691 return err; 692} 693 694static void unlink_all_urbs(struct ems_usb *dev) 695{ 696 int i; 697 698 usb_unlink_urb(dev->intr_urb); 699 700 usb_kill_anchored_urbs(&dev->rx_submitted); 701 702 usb_kill_anchored_urbs(&dev->tx_submitted); 703 atomic_set(&dev->active_tx_urbs, 0); 704 705 for (i = 0; i < MAX_TX_URBS; i++) 706 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 707} 708 709static int ems_usb_open(struct net_device *netdev) 710{ 711 struct ems_usb *dev = netdev_priv(netdev); 712 int err; 713 714 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 715 if (err) 716 return err; 717 718 /* common open */ 719 err = open_candev(netdev); 720 if (err) 721 return err; 722 723 /* finally start device */ 724 err = ems_usb_start(dev); 725 if (err) { 726 if (err == -ENODEV) 727 netif_device_detach(dev->netdev); 728 729 netdev_warn(netdev, "couldn't start device: %d\n", err); 730 731 close_candev(netdev); 732 733 return err; 734 } 735 736 737 netif_start_queue(netdev); 738 739 return 0; 740} 741 742static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 743{ 744 struct ems_usb *dev = netdev_priv(netdev); 745 struct ems_tx_urb_context *context = NULL; 746 struct net_device_stats *stats = &netdev->stats; 747 struct can_frame *cf = (struct can_frame *)skb->data; 748 struct ems_cpc_msg *msg; 749 struct urb *urb; 750 u8 *buf; 751 int i, err; 752 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 753 + sizeof(struct cpc_can_msg); 754 755 if (can_dropped_invalid_skb(netdev, skb)) 756 return NETDEV_TX_OK; 757 758 /* create a URB, and a buffer for it, and copy the data to the URB */ 759 urb = usb_alloc_urb(0, GFP_ATOMIC); 760 if (!urb) { 761 netdev_err(netdev, "No memory left for URBs\n"); 762 goto nomem; 763 } 764 765 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 766 if (!buf) { 767 netdev_err(netdev, "No memory left for USB buffer\n"); 768 usb_free_urb(urb); 769 goto nomem; 770 } 771 772 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 773 774 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 775 msg->msg.can_msg.length = cf->can_dlc; 776 777 if (cf->can_id & CAN_RTR_FLAG) { 778 msg->type = cf->can_id & CAN_EFF_FLAG ? 779 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 780 781 msg->length = CPC_CAN_MSG_MIN_SIZE; 782 } else { 783 msg->type = cf->can_id & CAN_EFF_FLAG ? 784 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 785 786 for (i = 0; i < cf->can_dlc; i++) 787 msg->msg.can_msg.msg[i] = cf->data[i]; 788 789 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 790 } 791 792 for (i = 0; i < MAX_TX_URBS; i++) { 793 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 794 context = &dev->tx_contexts[i]; 795 break; 796 } 797 } 798 799 /* 800 * May never happen! When this happens we'd more URBs in flight as 801 * allowed (MAX_TX_URBS). 802 */ 803 if (!context) { 804 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 805 usb_free_urb(urb); 806 807 netdev_warn(netdev, "couldn't find free context\n"); 808 809 return NETDEV_TX_BUSY; 810 } 811 812 context->dev = dev; 813 context->echo_index = i; 814 context->dlc = cf->can_dlc; 815 816 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 817 size, ems_usb_write_bulk_callback, context); 818 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 819 usb_anchor_urb(urb, &dev->tx_submitted); 820 821 can_put_echo_skb(skb, netdev, context->echo_index); 822 823 atomic_inc(&dev->active_tx_urbs); 824 825 err = usb_submit_urb(urb, GFP_ATOMIC); 826 if (unlikely(err)) { 827 can_free_echo_skb(netdev, context->echo_index); 828 829 usb_unanchor_urb(urb); 830 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 831 dev_kfree_skb(skb); 832 833 atomic_dec(&dev->active_tx_urbs); 834 835 if (err == -ENODEV) { 836 netif_device_detach(netdev); 837 } else { 838 netdev_warn(netdev, "failed tx_urb %d\n", err); 839 840 stats->tx_dropped++; 841 } 842 } else { 843 netdev->trans_start = jiffies; 844 845 /* Slow down tx path */ 846 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 847 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 848 netif_stop_queue(netdev); 849 } 850 } 851 852 /* 853 * Release our reference to this URB, the USB core will eventually free 854 * it entirely. 855 */ 856 usb_free_urb(urb); 857 858 return NETDEV_TX_OK; 859 860nomem: 861 dev_kfree_skb(skb); 862 stats->tx_dropped++; 863 864 return NETDEV_TX_OK; 865} 866 867static int ems_usb_close(struct net_device *netdev) 868{ 869 struct ems_usb *dev = netdev_priv(netdev); 870 871 /* Stop polling */ 872 unlink_all_urbs(dev); 873 874 netif_stop_queue(netdev); 875 876 /* Set CAN controller to reset mode */ 877 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 878 netdev_warn(netdev, "couldn't stop device"); 879 880 close_candev(netdev); 881 882 return 0; 883} 884 885static const struct net_device_ops ems_usb_netdev_ops = { 886 .ndo_open = ems_usb_open, 887 .ndo_stop = ems_usb_close, 888 .ndo_start_xmit = ems_usb_start_xmit, 889 .ndo_change_mtu = can_change_mtu, 890}; 891 892static const struct can_bittiming_const ems_usb_bittiming_const = { 893 .name = "ems_usb", 894 .tseg1_min = 1, 895 .tseg1_max = 16, 896 .tseg2_min = 1, 897 .tseg2_max = 8, 898 .sjw_max = 4, 899 .brp_min = 1, 900 .brp_max = 64, 901 .brp_inc = 1, 902}; 903 904static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 905{ 906 struct ems_usb *dev = netdev_priv(netdev); 907 908 switch (mode) { 909 case CAN_MODE_START: 910 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 911 netdev_warn(netdev, "couldn't start device"); 912 913 if (netif_queue_stopped(netdev)) 914 netif_wake_queue(netdev); 915 break; 916 917 default: 918 return -EOPNOTSUPP; 919 } 920 921 return 0; 922} 923 924static int ems_usb_set_bittiming(struct net_device *netdev) 925{ 926 struct ems_usb *dev = netdev_priv(netdev); 927 struct can_bittiming *bt = &dev->can.bittiming; 928 u8 btr0, btr1; 929 930 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 931 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 932 (((bt->phase_seg2 - 1) & 0x7) << 4); 933 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 934 btr1 |= 0x80; 935 936 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 937 938 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 939 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 940 941 return ems_usb_command_msg(dev, &dev->active_params); 942} 943 944static void init_params_sja1000(struct ems_cpc_msg *msg) 945{ 946 struct cpc_sja1000_params *sja1000 = 947 &msg->msg.can_params.cc_params.sja1000; 948 949 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 950 msg->length = sizeof(struct cpc_can_params); 951 msg->msgid = 0; 952 953 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 954 955 /* Acceptance filter open */ 956 sja1000->acc_code0 = 0x00; 957 sja1000->acc_code1 = 0x00; 958 sja1000->acc_code2 = 0x00; 959 sja1000->acc_code3 = 0x00; 960 961 /* Acceptance filter open */ 962 sja1000->acc_mask0 = 0xFF; 963 sja1000->acc_mask1 = 0xFF; 964 sja1000->acc_mask2 = 0xFF; 965 sja1000->acc_mask3 = 0xFF; 966 967 sja1000->btr0 = 0; 968 sja1000->btr1 = 0; 969 970 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 971 sja1000->mode = SJA1000_MOD_RM; 972} 973 974/* 975 * probe function for new CPC-USB devices 976 */ 977static int ems_usb_probe(struct usb_interface *intf, 978 const struct usb_device_id *id) 979{ 980 struct net_device *netdev; 981 struct ems_usb *dev; 982 int i, err = -ENOMEM; 983 984 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 985 if (!netdev) { 986 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 987 return -ENOMEM; 988 } 989 990 dev = netdev_priv(netdev); 991 992 dev->udev = interface_to_usbdev(intf); 993 dev->netdev = netdev; 994 995 dev->can.state = CAN_STATE_STOPPED; 996 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 997 dev->can.bittiming_const = &ems_usb_bittiming_const; 998 dev->can.do_set_bittiming = ems_usb_set_bittiming; 999 dev->can.do_set_mode = ems_usb_set_mode; 1000 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1001 1002 netdev->netdev_ops = &ems_usb_netdev_ops; 1003 1004 netdev->flags |= IFF_ECHO; /* we support local echo */ 1005 1006 init_usb_anchor(&dev->rx_submitted); 1007 1008 init_usb_anchor(&dev->tx_submitted); 1009 atomic_set(&dev->active_tx_urbs, 0); 1010 1011 for (i = 0; i < MAX_TX_URBS; i++) 1012 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1013 1014 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1015 if (!dev->intr_urb) { 1016 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1017 goto cleanup_candev; 1018 } 1019 1020 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1021 if (!dev->intr_in_buffer) 1022 goto cleanup_intr_urb; 1023 1024 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1025 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1026 if (!dev->tx_msg_buffer) 1027 goto cleanup_intr_in_buffer; 1028 1029 usb_set_intfdata(intf, dev); 1030 1031 SET_NETDEV_DEV(netdev, &intf->dev); 1032 1033 init_params_sja1000(&dev->active_params); 1034 1035 err = ems_usb_command_msg(dev, &dev->active_params); 1036 if (err) { 1037 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1038 goto cleanup_tx_msg_buffer; 1039 } 1040 1041 err = register_candev(netdev); 1042 if (err) { 1043 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1044 goto cleanup_tx_msg_buffer; 1045 } 1046 1047 return 0; 1048 1049cleanup_tx_msg_buffer: 1050 kfree(dev->tx_msg_buffer); 1051 1052cleanup_intr_in_buffer: 1053 kfree(dev->intr_in_buffer); 1054 1055cleanup_intr_urb: 1056 usb_free_urb(dev->intr_urb); 1057 1058cleanup_candev: 1059 free_candev(netdev); 1060 1061 return err; 1062} 1063 1064/* 1065 * called by the usb core when the device is removed from the system 1066 */ 1067static void ems_usb_disconnect(struct usb_interface *intf) 1068{ 1069 struct ems_usb *dev = usb_get_intfdata(intf); 1070 1071 usb_set_intfdata(intf, NULL); 1072 1073 if (dev) { 1074 unregister_netdev(dev->netdev); 1075 free_candev(dev->netdev); 1076 1077 unlink_all_urbs(dev); 1078 1079 usb_free_urb(dev->intr_urb); 1080 1081 kfree(dev->intr_in_buffer); 1082 } 1083} 1084 1085/* usb specific object needed to register this driver with the usb subsystem */ 1086static struct usb_driver ems_usb_driver = { 1087 .name = "ems_usb", 1088 .probe = ems_usb_probe, 1089 .disconnect = ems_usb_disconnect, 1090 .id_table = ems_usb_table, 1091}; 1092 1093module_usb_driver(ems_usb_driver); 1094