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 stats->rx_packets++; 336 stats->rx_bytes += cf->can_dlc; 337 netif_rx(skb); 338} 339 340static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 341{ 342 struct can_frame *cf; 343 struct sk_buff *skb; 344 struct net_device_stats *stats = &dev->netdev->stats; 345 346 skb = alloc_can_err_skb(dev->netdev, &cf); 347 if (skb == NULL) 348 return; 349 350 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 351 u8 state = msg->msg.can_state; 352 353 if (state & SJA1000_SR_BS) { 354 dev->can.state = CAN_STATE_BUS_OFF; 355 cf->can_id |= CAN_ERR_BUSOFF; 356 357 dev->can.can_stats.bus_off++; 358 can_bus_off(dev->netdev); 359 } else if (state & SJA1000_SR_ES) { 360 dev->can.state = CAN_STATE_ERROR_WARNING; 361 dev->can.can_stats.error_warning++; 362 } else { 363 dev->can.state = CAN_STATE_ERROR_ACTIVE; 364 dev->can.can_stats.error_passive++; 365 } 366 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 367 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 368 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 369 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 370 371 /* bus error interrupt */ 372 dev->can.can_stats.bus_error++; 373 stats->rx_errors++; 374 375 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 376 377 switch (ecc & SJA1000_ECC_MASK) { 378 case SJA1000_ECC_BIT: 379 cf->data[2] |= CAN_ERR_PROT_BIT; 380 break; 381 case SJA1000_ECC_FORM: 382 cf->data[2] |= CAN_ERR_PROT_FORM; 383 break; 384 case SJA1000_ECC_STUFF: 385 cf->data[2] |= CAN_ERR_PROT_STUFF; 386 break; 387 default: 388 cf->data[3] = ecc & SJA1000_ECC_SEG; 389 break; 390 } 391 392 /* Error occurred during transmission? */ 393 if ((ecc & SJA1000_ECC_DIR) == 0) 394 cf->data[2] |= CAN_ERR_PROT_TX; 395 396 if (dev->can.state == CAN_STATE_ERROR_WARNING || 397 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 398 cf->data[1] = (txerr > rxerr) ? 399 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 400 } 401 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 402 cf->can_id |= CAN_ERR_CRTL; 403 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 404 405 stats->rx_over_errors++; 406 stats->rx_errors++; 407 } 408 409 stats->rx_packets++; 410 stats->rx_bytes += cf->can_dlc; 411 netif_rx(skb); 412} 413 414/* 415 * callback for bulk IN urb 416 */ 417static void ems_usb_read_bulk_callback(struct urb *urb) 418{ 419 struct ems_usb *dev = urb->context; 420 struct net_device *netdev; 421 int retval; 422 423 netdev = dev->netdev; 424 425 if (!netif_device_present(netdev)) 426 return; 427 428 switch (urb->status) { 429 case 0: /* success */ 430 break; 431 432 case -ENOENT: 433 return; 434 435 default: 436 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 437 goto resubmit_urb; 438 } 439 440 if (urb->actual_length > CPC_HEADER_SIZE) { 441 struct ems_cpc_msg *msg; 442 u8 *ibuf = urb->transfer_buffer; 443 u8 msg_count, start; 444 445 msg_count = ibuf[0] & ~0x80; 446 447 start = CPC_HEADER_SIZE; 448 449 while (msg_count) { 450 msg = (struct ems_cpc_msg *)&ibuf[start]; 451 452 switch (msg->type) { 453 case CPC_MSG_TYPE_CAN_STATE: 454 /* Process CAN state changes */ 455 ems_usb_rx_err(dev, msg); 456 break; 457 458 case CPC_MSG_TYPE_CAN_FRAME: 459 case CPC_MSG_TYPE_EXT_CAN_FRAME: 460 case CPC_MSG_TYPE_RTR_FRAME: 461 case CPC_MSG_TYPE_EXT_RTR_FRAME: 462 ems_usb_rx_can_msg(dev, msg); 463 break; 464 465 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 466 /* Process errorframe */ 467 ems_usb_rx_err(dev, msg); 468 break; 469 470 case CPC_MSG_TYPE_OVERRUN: 471 /* Message lost while receiving */ 472 ems_usb_rx_err(dev, msg); 473 break; 474 } 475 476 start += CPC_MSG_HEADER_LEN + msg->length; 477 msg_count--; 478 479 if (start > urb->transfer_buffer_length) { 480 netdev_err(netdev, "format error\n"); 481 break; 482 } 483 } 484 } 485 486resubmit_urb: 487 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 488 urb->transfer_buffer, RX_BUFFER_SIZE, 489 ems_usb_read_bulk_callback, dev); 490 491 retval = usb_submit_urb(urb, GFP_ATOMIC); 492 493 if (retval == -ENODEV) 494 netif_device_detach(netdev); 495 else if (retval) 496 netdev_err(netdev, 497 "failed resubmitting read bulk urb: %d\n", retval); 498} 499 500/* 501 * callback for bulk IN urb 502 */ 503static void ems_usb_write_bulk_callback(struct urb *urb) 504{ 505 struct ems_tx_urb_context *context = urb->context; 506 struct ems_usb *dev; 507 struct net_device *netdev; 508 509 BUG_ON(!context); 510 511 dev = context->dev; 512 netdev = dev->netdev; 513 514 /* free up our allocated buffer */ 515 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 516 urb->transfer_buffer, urb->transfer_dma); 517 518 atomic_dec(&dev->active_tx_urbs); 519 520 if (!netif_device_present(netdev)) 521 return; 522 523 if (urb->status) 524 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 525 526 netdev->trans_start = jiffies; 527 528 /* transmission complete interrupt */ 529 netdev->stats.tx_packets++; 530 netdev->stats.tx_bytes += context->dlc; 531 532 can_get_echo_skb(netdev, context->echo_index); 533 534 /* Release context */ 535 context->echo_index = MAX_TX_URBS; 536 537} 538 539/* 540 * Send the given CPC command synchronously 541 */ 542static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 543{ 544 int actual_length; 545 546 /* Copy payload */ 547 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 548 msg->length + CPC_MSG_HEADER_LEN); 549 550 /* Clear header */ 551 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 552 553 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 554 &dev->tx_msg_buffer[0], 555 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 556 &actual_length, 1000); 557} 558 559/* 560 * Change CAN controllers' mode register 561 */ 562static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 563{ 564 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 565 566 return ems_usb_command_msg(dev, &dev->active_params); 567} 568 569/* 570 * Send a CPC_Control command to change behaviour when interface receives a CAN 571 * message, bus error or CAN state changed notifications. 572 */ 573static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 574{ 575 struct ems_cpc_msg cmd; 576 577 cmd.type = CPC_CMD_TYPE_CONTROL; 578 cmd.length = CPC_MSG_HEADER_LEN + 1; 579 580 cmd.msgid = 0; 581 582 cmd.msg.generic[0] = val; 583 584 return ems_usb_command_msg(dev, &cmd); 585} 586 587/* 588 * Start interface 589 */ 590static int ems_usb_start(struct ems_usb *dev) 591{ 592 struct net_device *netdev = dev->netdev; 593 int err, i; 594 595 dev->intr_in_buffer[0] = 0; 596 dev->free_slots = 50; /* initial size */ 597 598 for (i = 0; i < MAX_RX_URBS; i++) { 599 struct urb *urb = NULL; 600 u8 *buf = NULL; 601 602 /* create a URB, and a buffer for it */ 603 urb = usb_alloc_urb(0, GFP_KERNEL); 604 if (!urb) { 605 netdev_err(netdev, "No memory left for URBs\n"); 606 err = -ENOMEM; 607 break; 608 } 609 610 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 611 &urb->transfer_dma); 612 if (!buf) { 613 netdev_err(netdev, "No memory left for USB buffer\n"); 614 usb_free_urb(urb); 615 err = -ENOMEM; 616 break; 617 } 618 619 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 620 buf, RX_BUFFER_SIZE, 621 ems_usb_read_bulk_callback, dev); 622 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 623 usb_anchor_urb(urb, &dev->rx_submitted); 624 625 err = usb_submit_urb(urb, GFP_KERNEL); 626 if (err) { 627 usb_unanchor_urb(urb); 628 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 629 urb->transfer_dma); 630 usb_free_urb(urb); 631 break; 632 } 633 634 /* Drop reference, USB core will take care of freeing it */ 635 usb_free_urb(urb); 636 } 637 638 /* Did we submit any URBs */ 639 if (i == 0) { 640 netdev_warn(netdev, "couldn't setup read URBs\n"); 641 return err; 642 } 643 644 /* Warn if we've couldn't transmit all the URBs */ 645 if (i < MAX_RX_URBS) 646 netdev_warn(netdev, "rx performance may be slow\n"); 647 648 /* Setup and start interrupt URB */ 649 usb_fill_int_urb(dev->intr_urb, dev->udev, 650 usb_rcvintpipe(dev->udev, 1), 651 dev->intr_in_buffer, 652 INTR_IN_BUFFER_SIZE, 653 ems_usb_read_interrupt_callback, dev, 1); 654 655 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 656 if (err) { 657 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 658 659 return err; 660 } 661 662 /* CPC-USB will transfer received message to host */ 663 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 664 if (err) 665 goto failed; 666 667 /* CPC-USB will transfer CAN state changes to host */ 668 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 669 if (err) 670 goto failed; 671 672 /* CPC-USB will transfer bus errors to host */ 673 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 674 if (err) 675 goto failed; 676 677 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 678 if (err) 679 goto failed; 680 681 dev->can.state = CAN_STATE_ERROR_ACTIVE; 682 683 return 0; 684 685failed: 686 netdev_warn(netdev, "couldn't submit control: %d\n", err); 687 688 return err; 689} 690 691static void unlink_all_urbs(struct ems_usb *dev) 692{ 693 int i; 694 695 usb_unlink_urb(dev->intr_urb); 696 697 usb_kill_anchored_urbs(&dev->rx_submitted); 698 699 usb_kill_anchored_urbs(&dev->tx_submitted); 700 atomic_set(&dev->active_tx_urbs, 0); 701 702 for (i = 0; i < MAX_TX_URBS; i++) 703 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 704} 705 706static int ems_usb_open(struct net_device *netdev) 707{ 708 struct ems_usb *dev = netdev_priv(netdev); 709 int err; 710 711 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 712 if (err) 713 return err; 714 715 /* common open */ 716 err = open_candev(netdev); 717 if (err) 718 return err; 719 720 /* finally start device */ 721 err = ems_usb_start(dev); 722 if (err) { 723 if (err == -ENODEV) 724 netif_device_detach(dev->netdev); 725 726 netdev_warn(netdev, "couldn't start device: %d\n", err); 727 728 close_candev(netdev); 729 730 return err; 731 } 732 733 734 netif_start_queue(netdev); 735 736 return 0; 737} 738 739static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 740{ 741 struct ems_usb *dev = netdev_priv(netdev); 742 struct ems_tx_urb_context *context = NULL; 743 struct net_device_stats *stats = &netdev->stats; 744 struct can_frame *cf = (struct can_frame *)skb->data; 745 struct ems_cpc_msg *msg; 746 struct urb *urb; 747 u8 *buf; 748 int i, err; 749 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 750 + sizeof(struct cpc_can_msg); 751 752 if (can_dropped_invalid_skb(netdev, skb)) 753 return NETDEV_TX_OK; 754 755 /* create a URB, and a buffer for it, and copy the data to the URB */ 756 urb = usb_alloc_urb(0, GFP_ATOMIC); 757 if (!urb) { 758 netdev_err(netdev, "No memory left for URBs\n"); 759 goto nomem; 760 } 761 762 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 763 if (!buf) { 764 netdev_err(netdev, "No memory left for USB buffer\n"); 765 usb_free_urb(urb); 766 goto nomem; 767 } 768 769 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 770 771 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 772 msg->msg.can_msg.length = cf->can_dlc; 773 774 if (cf->can_id & CAN_RTR_FLAG) { 775 msg->type = cf->can_id & CAN_EFF_FLAG ? 776 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 777 778 msg->length = CPC_CAN_MSG_MIN_SIZE; 779 } else { 780 msg->type = cf->can_id & CAN_EFF_FLAG ? 781 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 782 783 for (i = 0; i < cf->can_dlc; i++) 784 msg->msg.can_msg.msg[i] = cf->data[i]; 785 786 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 787 } 788 789 for (i = 0; i < MAX_TX_URBS; i++) { 790 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 791 context = &dev->tx_contexts[i]; 792 break; 793 } 794 } 795 796 /* 797 * May never happen! When this happens we'd more URBs in flight as 798 * allowed (MAX_TX_URBS). 799 */ 800 if (!context) { 801 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 802 usb_free_urb(urb); 803 804 netdev_warn(netdev, "couldn't find free context\n"); 805 806 return NETDEV_TX_BUSY; 807 } 808 809 context->dev = dev; 810 context->echo_index = i; 811 context->dlc = cf->can_dlc; 812 813 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 814 size, ems_usb_write_bulk_callback, context); 815 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 816 usb_anchor_urb(urb, &dev->tx_submitted); 817 818 can_put_echo_skb(skb, netdev, context->echo_index); 819 820 atomic_inc(&dev->active_tx_urbs); 821 822 err = usb_submit_urb(urb, GFP_ATOMIC); 823 if (unlikely(err)) { 824 can_free_echo_skb(netdev, context->echo_index); 825 826 usb_unanchor_urb(urb); 827 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 828 dev_kfree_skb(skb); 829 830 atomic_dec(&dev->active_tx_urbs); 831 832 if (err == -ENODEV) { 833 netif_device_detach(netdev); 834 } else { 835 netdev_warn(netdev, "failed tx_urb %d\n", err); 836 837 stats->tx_dropped++; 838 } 839 } else { 840 netdev->trans_start = jiffies; 841 842 /* Slow down tx path */ 843 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 844 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 845 netif_stop_queue(netdev); 846 } 847 } 848 849 /* 850 * Release our reference to this URB, the USB core will eventually free 851 * it entirely. 852 */ 853 usb_free_urb(urb); 854 855 return NETDEV_TX_OK; 856 857nomem: 858 dev_kfree_skb(skb); 859 stats->tx_dropped++; 860 861 return NETDEV_TX_OK; 862} 863 864static int ems_usb_close(struct net_device *netdev) 865{ 866 struct ems_usb *dev = netdev_priv(netdev); 867 868 /* Stop polling */ 869 unlink_all_urbs(dev); 870 871 netif_stop_queue(netdev); 872 873 /* Set CAN controller to reset mode */ 874 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 875 netdev_warn(netdev, "couldn't stop device"); 876 877 close_candev(netdev); 878 879 return 0; 880} 881 882static const struct net_device_ops ems_usb_netdev_ops = { 883 .ndo_open = ems_usb_open, 884 .ndo_stop = ems_usb_close, 885 .ndo_start_xmit = ems_usb_start_xmit, 886 .ndo_change_mtu = can_change_mtu, 887}; 888 889static const struct can_bittiming_const ems_usb_bittiming_const = { 890 .name = "ems_usb", 891 .tseg1_min = 1, 892 .tseg1_max = 16, 893 .tseg2_min = 1, 894 .tseg2_max = 8, 895 .sjw_max = 4, 896 .brp_min = 1, 897 .brp_max = 64, 898 .brp_inc = 1, 899}; 900 901static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 902{ 903 struct ems_usb *dev = netdev_priv(netdev); 904 905 switch (mode) { 906 case CAN_MODE_START: 907 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 908 netdev_warn(netdev, "couldn't start device"); 909 910 if (netif_queue_stopped(netdev)) 911 netif_wake_queue(netdev); 912 break; 913 914 default: 915 return -EOPNOTSUPP; 916 } 917 918 return 0; 919} 920 921static int ems_usb_set_bittiming(struct net_device *netdev) 922{ 923 struct ems_usb *dev = netdev_priv(netdev); 924 struct can_bittiming *bt = &dev->can.bittiming; 925 u8 btr0, btr1; 926 927 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 928 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 929 (((bt->phase_seg2 - 1) & 0x7) << 4); 930 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 931 btr1 |= 0x80; 932 933 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 934 935 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 936 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 937 938 return ems_usb_command_msg(dev, &dev->active_params); 939} 940 941static void init_params_sja1000(struct ems_cpc_msg *msg) 942{ 943 struct cpc_sja1000_params *sja1000 = 944 &msg->msg.can_params.cc_params.sja1000; 945 946 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 947 msg->length = sizeof(struct cpc_can_params); 948 msg->msgid = 0; 949 950 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 951 952 /* Acceptance filter open */ 953 sja1000->acc_code0 = 0x00; 954 sja1000->acc_code1 = 0x00; 955 sja1000->acc_code2 = 0x00; 956 sja1000->acc_code3 = 0x00; 957 958 /* Acceptance filter open */ 959 sja1000->acc_mask0 = 0xFF; 960 sja1000->acc_mask1 = 0xFF; 961 sja1000->acc_mask2 = 0xFF; 962 sja1000->acc_mask3 = 0xFF; 963 964 sja1000->btr0 = 0; 965 sja1000->btr1 = 0; 966 967 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 968 sja1000->mode = SJA1000_MOD_RM; 969} 970 971/* 972 * probe function for new CPC-USB devices 973 */ 974static int ems_usb_probe(struct usb_interface *intf, 975 const struct usb_device_id *id) 976{ 977 struct net_device *netdev; 978 struct ems_usb *dev; 979 int i, err = -ENOMEM; 980 981 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 982 if (!netdev) { 983 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 984 return -ENOMEM; 985 } 986 987 dev = netdev_priv(netdev); 988 989 dev->udev = interface_to_usbdev(intf); 990 dev->netdev = netdev; 991 992 dev->can.state = CAN_STATE_STOPPED; 993 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 994 dev->can.bittiming_const = &ems_usb_bittiming_const; 995 dev->can.do_set_bittiming = ems_usb_set_bittiming; 996 dev->can.do_set_mode = ems_usb_set_mode; 997 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 998 999 netdev->netdev_ops = &ems_usb_netdev_ops; 1000 1001 netdev->flags |= IFF_ECHO; /* we support local echo */ 1002 1003 init_usb_anchor(&dev->rx_submitted); 1004 1005 init_usb_anchor(&dev->tx_submitted); 1006 atomic_set(&dev->active_tx_urbs, 0); 1007 1008 for (i = 0; i < MAX_TX_URBS; i++) 1009 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1010 1011 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1012 if (!dev->intr_urb) { 1013 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1014 goto cleanup_candev; 1015 } 1016 1017 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1018 if (!dev->intr_in_buffer) 1019 goto cleanup_intr_urb; 1020 1021 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1022 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1023 if (!dev->tx_msg_buffer) 1024 goto cleanup_intr_in_buffer; 1025 1026 usb_set_intfdata(intf, dev); 1027 1028 SET_NETDEV_DEV(netdev, &intf->dev); 1029 1030 init_params_sja1000(&dev->active_params); 1031 1032 err = ems_usb_command_msg(dev, &dev->active_params); 1033 if (err) { 1034 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1035 goto cleanup_tx_msg_buffer; 1036 } 1037 1038 err = register_candev(netdev); 1039 if (err) { 1040 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1041 goto cleanup_tx_msg_buffer; 1042 } 1043 1044 return 0; 1045 1046cleanup_tx_msg_buffer: 1047 kfree(dev->tx_msg_buffer); 1048 1049cleanup_intr_in_buffer: 1050 kfree(dev->intr_in_buffer); 1051 1052cleanup_intr_urb: 1053 usb_free_urb(dev->intr_urb); 1054 1055cleanup_candev: 1056 free_candev(netdev); 1057 1058 return err; 1059} 1060 1061/* 1062 * called by the usb core when the device is removed from the system 1063 */ 1064static void ems_usb_disconnect(struct usb_interface *intf) 1065{ 1066 struct ems_usb *dev = usb_get_intfdata(intf); 1067 1068 usb_set_intfdata(intf, NULL); 1069 1070 if (dev) { 1071 unregister_netdev(dev->netdev); 1072 free_candev(dev->netdev); 1073 1074 unlink_all_urbs(dev); 1075 1076 usb_free_urb(dev->intr_urb); 1077 1078 kfree(dev->intr_in_buffer); 1079 } 1080} 1081 1082/* usb specific object needed to register this driver with the usb subsystem */ 1083static struct usb_driver ems_usb_driver = { 1084 .name = "ems_usb", 1085 .probe = ems_usb_probe, 1086 .disconnect = ems_usb_disconnect, 1087 .id_table = ems_usb_table, 1088}; 1089 1090module_usb_driver(ems_usb_driver); 1091