ems_usb.c revision 09da6c5f60ad2e2018366e47192a9ddbccfb3ac5
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/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> 25 26#include <linux/can.h> 27#include <linux/can/dev.h> 28#include <linux/can/error.h> 29 30MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 31MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 32MODULE_LICENSE("GPL v2"); 33 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 38 39/* Control Command Actions */ 40#define CONTR_CONT_OFF 0 41#define CONTR_CONT_ON 1 42#define CONTR_ONCE 2 43 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 */ 56 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 */ 66 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 */ 70 71#define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 72 73#define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 74 75/* Overrun types */ 76#define CPC_OVR_EVENT_CAN 0x01 77#define CPC_OVR_EVENT_CANSTATE 0x02 78#define CPC_OVR_EVENT_BUSERROR 0x04 79 80/* 81 * If the CAN controller lost a message we indicate it with the highest bit 82 * set in the count field. 83 */ 84#define CPC_OVR_HW 0x80 85 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 89 90/* Define these values to match your devices */ 91#define USB_CPCUSB_VENDOR_ID 0x12D6 92 93#define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 94 95/* Mode register NXP LPC2119/SJA1000 CAN Controller */ 96#define SJA1000_MOD_NORMAL 0x00 97#define SJA1000_MOD_RM 0x01 98 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 107 108/* Status register content */ 109#define SJA1000_SR_BS 0x80 110#define SJA1000_SR_ES 0x40 111 112#define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 113 114/* 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 117 * converted). 118 */ 119#define EMS_USB_ARM7_CLOCK 8000000 120 121/* 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. 125 */ 126struct cpc_can_msg { 127 u32 id; 128 u8 length; 129 u8 msg[8]; 130}; 131 132/* Representation of the CAN parameters for the SJA1000 controller */ 133struct cpc_sja1000_params { 134 u8 mode; 135 u8 acc_code0; 136 u8 acc_code1; 137 u8 acc_code2; 138 u8 acc_code3; 139 u8 acc_mask0; 140 u8 acc_mask1; 141 u8 acc_mask2; 142 u8 acc_mask3; 143 u8 btr0; 144 u8 btr1; 145 u8 outp_contr; 146}; 147 148/* CAN params message representation */ 149struct cpc_can_params { 150 u8 cc_type; 151 152 /* Will support M16C CAN controller in the future */ 153 union { 154 struct cpc_sja1000_params sja1000; 155 } cc_params; 156}; 157 158/* Structure for confirmed message handling */ 159struct cpc_confirm { 160 u8 error; /* error code */ 161}; 162 163/* Structure for overrun conditions */ 164struct cpc_overrun { 165 u8 event; 166 u8 count; 167}; 168 169/* SJA1000 CAN errors (compatible to NXP LPC2119) */ 170struct cpc_sja1000_can_error { 171 u8 ecc; 172 u8 rxerr; 173 u8 txerr; 174}; 175 176/* structure for CAN error conditions */ 177struct cpc_can_error { 178 u8 ecode; 179 180 struct { 181 u8 cc_type; 182 183 /* Other controllers may also provide error code capture regs */ 184 union { 185 struct cpc_sja1000_can_error sja1000; 186 } regs; 187 } cc; 188}; 189 190/* 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. 193 */ 194struct cpc_can_err_counter { 195 u8 rx; 196 u8 tx; 197}; 198 199/* Main message type used between library and application */ 200struct __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 */ 206 207 union { 208 u8 generic[64]; 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; 215 u8 can_state; 216 } msg; 217}; 218 219/* 220 * Table of devices that work with this driver 221 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 222 */ 223static struct usb_device_id ems_usb_table[] = { 224 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 225 {} /* Terminating entry */ 226}; 227 228MODULE_DEVICE_TABLE(usb, ems_usb_table); 229 230#define RX_BUFFER_SIZE 64 231#define CPC_HEADER_SIZE 4 232#define INTR_IN_BUFFER_SIZE 4 233 234#define MAX_RX_URBS 10 235#define MAX_TX_URBS 10 236 237struct ems_usb; 238 239struct ems_tx_urb_context { 240 struct ems_usb *dev; 241 242 u32 echo_index; 243 u8 dlc; 244}; 245 246struct ems_usb { 247 struct can_priv can; /* must be the first member */ 248 249 struct sk_buff *echo_skb[MAX_TX_URBS]; 250 251 struct usb_device *udev; 252 struct net_device *netdev; 253 254 atomic_t active_tx_urbs; 255 struct usb_anchor tx_submitted; 256 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 257 258 struct usb_anchor rx_submitted; 259 260 struct urb *intr_urb; 261 262 u8 *tx_msg_buffer; 263 264 u8 *intr_in_buffer; 265 unsigned int free_slots; /* remember number of available slots */ 266 267 struct ems_cpc_msg active_params; /* active controller parameters */ 268}; 269 270static void ems_usb_read_interrupt_callback(struct urb *urb) 271{ 272 struct ems_usb *dev = urb->context; 273 struct net_device *netdev = dev->netdev; 274 int err; 275 276 if (!netif_device_present(netdev)) 277 return; 278 279 switch (urb->status) { 280 case 0: 281 dev->free_slots = dev->intr_in_buffer[1]; 282 break; 283 284 case -ECONNRESET: /* unlink */ 285 case -ENOENT: 286 case -ESHUTDOWN: 287 return; 288 289 default: 290 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 291 break; 292 } 293 294 err = usb_submit_urb(urb, GFP_ATOMIC); 295 296 if (err == -ENODEV) 297 netif_device_detach(netdev); 298 else if (err) 299 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 300} 301 302static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 303{ 304 struct can_frame *cf; 305 struct sk_buff *skb; 306 int i; 307 struct net_device_stats *stats = &dev->netdev->stats; 308 309 skb = alloc_can_skb(dev->netdev, &cf); 310 if (skb == NULL) 311 return; 312 313 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 314 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 315 316 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 317 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 318 cf->can_id |= CAN_EFF_FLAG; 319 320 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 321 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 322 cf->can_id |= CAN_RTR_FLAG; 323 } else { 324 for (i = 0; i < cf->can_dlc; i++) 325 cf->data[i] = msg->msg.can_msg.msg[i]; 326 } 327 328 netif_rx(skb); 329 330 stats->rx_packets++; 331 stats->rx_bytes += cf->can_dlc; 332} 333 334static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 335{ 336 struct can_frame *cf; 337 struct sk_buff *skb; 338 struct net_device_stats *stats = &dev->netdev->stats; 339 340 skb = alloc_can_err_skb(dev->netdev, &cf); 341 if (skb == NULL) 342 return; 343 344 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 345 u8 state = msg->msg.can_state; 346 347 if (state & SJA1000_SR_BS) { 348 dev->can.state = CAN_STATE_BUS_OFF; 349 cf->can_id |= CAN_ERR_BUSOFF; 350 351 can_bus_off(dev->netdev); 352 } else if (state & SJA1000_SR_ES) { 353 dev->can.state = CAN_STATE_ERROR_WARNING; 354 dev->can.can_stats.error_warning++; 355 } else { 356 dev->can.state = CAN_STATE_ERROR_ACTIVE; 357 dev->can.can_stats.error_passive++; 358 } 359 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 360 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 361 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 362 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 363 364 /* bus error interrupt */ 365 dev->can.can_stats.bus_error++; 366 stats->rx_errors++; 367 368 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 369 370 switch (ecc & SJA1000_ECC_MASK) { 371 case SJA1000_ECC_BIT: 372 cf->data[2] |= CAN_ERR_PROT_BIT; 373 break; 374 case SJA1000_ECC_FORM: 375 cf->data[2] |= CAN_ERR_PROT_FORM; 376 break; 377 case SJA1000_ECC_STUFF: 378 cf->data[2] |= CAN_ERR_PROT_STUFF; 379 break; 380 default: 381 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 382 cf->data[3] = ecc & SJA1000_ECC_SEG; 383 break; 384 } 385 386 /* Error occurred during transmission? */ 387 if ((ecc & SJA1000_ECC_DIR) == 0) 388 cf->data[2] |= CAN_ERR_PROT_TX; 389 390 if (dev->can.state == CAN_STATE_ERROR_WARNING || 391 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 392 cf->data[1] = (txerr > rxerr) ? 393 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 394 } 395 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 396 cf->can_id |= CAN_ERR_CRTL; 397 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 398 399 stats->rx_over_errors++; 400 stats->rx_errors++; 401 } 402 403 netif_rx(skb); 404 405 stats->rx_packets++; 406 stats->rx_bytes += cf->can_dlc; 407} 408 409/* 410 * callback for bulk IN urb 411 */ 412static void ems_usb_read_bulk_callback(struct urb *urb) 413{ 414 struct ems_usb *dev = urb->context; 415 struct net_device *netdev; 416 int retval; 417 418 netdev = dev->netdev; 419 420 if (!netif_device_present(netdev)) 421 return; 422 423 switch (urb->status) { 424 case 0: /* success */ 425 break; 426 427 case -ENOENT: 428 return; 429 430 default: 431 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 432 goto resubmit_urb; 433 } 434 435 if (urb->actual_length > CPC_HEADER_SIZE) { 436 struct ems_cpc_msg *msg; 437 u8 *ibuf = urb->transfer_buffer; 438 u8 msg_count, again, start; 439 440 msg_count = ibuf[0] & ~0x80; 441 again = ibuf[0] & 0x80; 442 443 start = CPC_HEADER_SIZE; 444 445 while (msg_count) { 446 msg = (struct ems_cpc_msg *)&ibuf[start]; 447 448 switch (msg->type) { 449 case CPC_MSG_TYPE_CAN_STATE: 450 /* Process CAN state changes */ 451 ems_usb_rx_err(dev, msg); 452 break; 453 454 case CPC_MSG_TYPE_CAN_FRAME: 455 case CPC_MSG_TYPE_EXT_CAN_FRAME: 456 case CPC_MSG_TYPE_RTR_FRAME: 457 case CPC_MSG_TYPE_EXT_RTR_FRAME: 458 ems_usb_rx_can_msg(dev, msg); 459 break; 460 461 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 462 /* Process errorframe */ 463 ems_usb_rx_err(dev, msg); 464 break; 465 466 case CPC_MSG_TYPE_OVERRUN: 467 /* Message lost while receiving */ 468 ems_usb_rx_err(dev, msg); 469 break; 470 } 471 472 start += CPC_MSG_HEADER_LEN + msg->length; 473 msg_count--; 474 475 if (start > urb->transfer_buffer_length) { 476 netdev_err(netdev, "format error\n"); 477 break; 478 } 479 } 480 } 481 482resubmit_urb: 483 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 484 urb->transfer_buffer, RX_BUFFER_SIZE, 485 ems_usb_read_bulk_callback, dev); 486 487 retval = usb_submit_urb(urb, GFP_ATOMIC); 488 489 if (retval == -ENODEV) 490 netif_device_detach(netdev); 491 else if (retval) 492 netdev_err(netdev, 493 "failed resubmitting read bulk urb: %d\n", retval); 494} 495 496/* 497 * callback for bulk IN urb 498 */ 499static void ems_usb_write_bulk_callback(struct urb *urb) 500{ 501 struct ems_tx_urb_context *context = urb->context; 502 struct ems_usb *dev; 503 struct net_device *netdev; 504 505 BUG_ON(!context); 506 507 dev = context->dev; 508 netdev = dev->netdev; 509 510 /* free up our allocated buffer */ 511 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 512 urb->transfer_buffer, urb->transfer_dma); 513 514 atomic_dec(&dev->active_tx_urbs); 515 516 if (!netif_device_present(netdev)) 517 return; 518 519 if (urb->status) 520 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 521 522 netdev->trans_start = jiffies; 523 524 /* transmission complete interrupt */ 525 netdev->stats.tx_packets++; 526 netdev->stats.tx_bytes += context->dlc; 527 528 can_get_echo_skb(netdev, context->echo_index); 529 530 /* Release context */ 531 context->echo_index = MAX_TX_URBS; 532 533 if (netif_queue_stopped(netdev)) 534 netif_wake_queue(netdev); 535} 536 537/* 538 * Send the given CPC command synchronously 539 */ 540static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 541{ 542 int actual_length; 543 544 /* Copy payload */ 545 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 546 msg->length + CPC_MSG_HEADER_LEN); 547 548 /* Clear header */ 549 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 550 551 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 552 &dev->tx_msg_buffer[0], 553 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 554 &actual_length, 1000); 555} 556 557/* 558 * Change CAN controllers' mode register 559 */ 560static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 561{ 562 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 563 564 return ems_usb_command_msg(dev, &dev->active_params); 565} 566 567/* 568 * Send a CPC_Control command to change behaviour when interface receives a CAN 569 * message, bus error or CAN state changed notifications. 570 */ 571static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 572{ 573 struct ems_cpc_msg cmd; 574 575 cmd.type = CPC_CMD_TYPE_CONTROL; 576 cmd.length = CPC_MSG_HEADER_LEN + 1; 577 578 cmd.msgid = 0; 579 580 cmd.msg.generic[0] = val; 581 582 return ems_usb_command_msg(dev, &cmd); 583} 584 585/* 586 * Start interface 587 */ 588static int ems_usb_start(struct ems_usb *dev) 589{ 590 struct net_device *netdev = dev->netdev; 591 int err, i; 592 593 dev->intr_in_buffer[0] = 0; 594 dev->free_slots = 15; /* initial size */ 595 596 for (i = 0; i < MAX_RX_URBS; i++) { 597 struct urb *urb = NULL; 598 u8 *buf = NULL; 599 600 /* create a URB, and a buffer for it */ 601 urb = usb_alloc_urb(0, GFP_KERNEL); 602 if (!urb) { 603 netdev_err(netdev, "No memory left for URBs\n"); 604 err = -ENOMEM; 605 break; 606 } 607 608 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 609 &urb->transfer_dma); 610 if (!buf) { 611 netdev_err(netdev, "No memory left for USB buffer\n"); 612 usb_free_urb(urb); 613 err = -ENOMEM; 614 break; 615 } 616 617 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 618 buf, RX_BUFFER_SIZE, 619 ems_usb_read_bulk_callback, dev); 620 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 621 usb_anchor_urb(urb, &dev->rx_submitted); 622 623 err = usb_submit_urb(urb, GFP_KERNEL); 624 if (err) { 625 usb_unanchor_urb(urb); 626 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 627 urb->transfer_dma); 628 break; 629 } 630 631 /* Drop reference, USB core will take care of freeing it */ 632 usb_free_urb(urb); 633 } 634 635 /* Did we submit any URBs */ 636 if (i == 0) { 637 netdev_warn(netdev, "couldn't setup read URBs\n"); 638 return err; 639 } 640 641 /* Warn if we've couldn't transmit all the URBs */ 642 if (i < MAX_RX_URBS) 643 netdev_warn(netdev, "rx performance may be slow\n"); 644 645 /* Setup and start interrupt URB */ 646 usb_fill_int_urb(dev->intr_urb, dev->udev, 647 usb_rcvintpipe(dev->udev, 1), 648 dev->intr_in_buffer, 649 INTR_IN_BUFFER_SIZE, 650 ems_usb_read_interrupt_callback, dev, 1); 651 652 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 653 if (err) { 654 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 655 656 return err; 657 } 658 659 /* CPC-USB will transfer received message to host */ 660 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 661 if (err) 662 goto failed; 663 664 /* CPC-USB will transfer CAN state changes to host */ 665 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 666 if (err) 667 goto failed; 668 669 /* CPC-USB will transfer bus errors to host */ 670 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 671 if (err) 672 goto failed; 673 674 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 675 if (err) 676 goto failed; 677 678 dev->can.state = CAN_STATE_ERROR_ACTIVE; 679 680 return 0; 681 682failed: 683 netdev_warn(netdev, "couldn't submit control: %d\n", err); 684 685 return err; 686} 687 688static void unlink_all_urbs(struct ems_usb *dev) 689{ 690 int i; 691 692 usb_unlink_urb(dev->intr_urb); 693 694 usb_kill_anchored_urbs(&dev->rx_submitted); 695 696 usb_kill_anchored_urbs(&dev->tx_submitted); 697 atomic_set(&dev->active_tx_urbs, 0); 698 699 for (i = 0; i < MAX_TX_URBS; i++) 700 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 701} 702 703static int ems_usb_open(struct net_device *netdev) 704{ 705 struct ems_usb *dev = netdev_priv(netdev); 706 int err; 707 708 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 709 if (err) 710 return err; 711 712 /* common open */ 713 err = open_candev(netdev); 714 if (err) 715 return err; 716 717 /* finally start device */ 718 err = ems_usb_start(dev); 719 if (err) { 720 if (err == -ENODEV) 721 netif_device_detach(dev->netdev); 722 723 netdev_warn(netdev, "couldn't start device: %d\n", err); 724 725 close_candev(netdev); 726 727 return err; 728 } 729 730 731 netif_start_queue(netdev); 732 733 return 0; 734} 735 736static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 737{ 738 struct ems_usb *dev = netdev_priv(netdev); 739 struct ems_tx_urb_context *context = NULL; 740 struct net_device_stats *stats = &netdev->stats; 741 struct can_frame *cf = (struct can_frame *)skb->data; 742 struct ems_cpc_msg *msg; 743 struct urb *urb; 744 u8 *buf; 745 int i, err; 746 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 747 + sizeof(struct cpc_can_msg); 748 749 if (can_dropped_invalid_skb(netdev, skb)) 750 return NETDEV_TX_OK; 751 752 /* create a URB, and a buffer for it, and copy the data to the URB */ 753 urb = usb_alloc_urb(0, GFP_ATOMIC); 754 if (!urb) { 755 netdev_err(netdev, "No memory left for URBs\n"); 756 goto nomem; 757 } 758 759 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 760 if (!buf) { 761 netdev_err(netdev, "No memory left for USB buffer\n"); 762 usb_free_urb(urb); 763 goto nomem; 764 } 765 766 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 767 768 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 769 msg->msg.can_msg.length = cf->can_dlc; 770 771 if (cf->can_id & CAN_RTR_FLAG) { 772 msg->type = cf->can_id & CAN_EFF_FLAG ? 773 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 774 775 msg->length = CPC_CAN_MSG_MIN_SIZE; 776 } else { 777 msg->type = cf->can_id & CAN_EFF_FLAG ? 778 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 779 780 for (i = 0; i < cf->can_dlc; i++) 781 msg->msg.can_msg.msg[i] = cf->data[i]; 782 783 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 784 } 785 786 /* Respect byte order */ 787 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id); 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_unanchor_urb(urb); 802 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 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 < 5) { 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}; 887 888static const struct can_bittiming_const ems_usb_bittiming_const = { 889 .name = "ems_usb", 890 .tseg1_min = 1, 891 .tseg1_max = 16, 892 .tseg2_min = 1, 893 .tseg2_max = 8, 894 .sjw_max = 4, 895 .brp_min = 1, 896 .brp_max = 64, 897 .brp_inc = 1, 898}; 899 900static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 901{ 902 struct ems_usb *dev = netdev_priv(netdev); 903 904 switch (mode) { 905 case CAN_MODE_START: 906 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 907 netdev_warn(netdev, "couldn't start device"); 908 909 if (netif_queue_stopped(netdev)) 910 netif_wake_queue(netdev); 911 break; 912 913 default: 914 return -EOPNOTSUPP; 915 } 916 917 return 0; 918} 919 920static int ems_usb_set_bittiming(struct net_device *netdev) 921{ 922 struct ems_usb *dev = netdev_priv(netdev); 923 struct can_bittiming *bt = &dev->can.bittiming; 924 u8 btr0, btr1; 925 926 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 927 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 928 (((bt->phase_seg2 - 1) & 0x7) << 4); 929 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 930 btr1 |= 0x80; 931 932 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 933 934 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 935 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 936 937 return ems_usb_command_msg(dev, &dev->active_params); 938} 939 940static void init_params_sja1000(struct ems_cpc_msg *msg) 941{ 942 struct cpc_sja1000_params *sja1000 = 943 &msg->msg.can_params.cc_params.sja1000; 944 945 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 946 msg->length = sizeof(struct cpc_can_params); 947 msg->msgid = 0; 948 949 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 950 951 /* Acceptance filter open */ 952 sja1000->acc_code0 = 0x00; 953 sja1000->acc_code1 = 0x00; 954 sja1000->acc_code2 = 0x00; 955 sja1000->acc_code3 = 0x00; 956 957 /* Acceptance filter open */ 958 sja1000->acc_mask0 = 0xFF; 959 sja1000->acc_mask1 = 0xFF; 960 sja1000->acc_mask2 = 0xFF; 961 sja1000->acc_mask3 = 0xFF; 962 963 sja1000->btr0 = 0; 964 sja1000->btr1 = 0; 965 966 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 967 sja1000->mode = SJA1000_MOD_RM; 968} 969 970/* 971 * probe function for new CPC-USB devices 972 */ 973static int ems_usb_probe(struct usb_interface *intf, 974 const struct usb_device_id *id) 975{ 976 struct net_device *netdev; 977 struct ems_usb *dev; 978 int i, err = -ENOMEM; 979 980 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 981 if (!netdev) { 982 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 983 return -ENOMEM; 984 } 985 986 dev = netdev_priv(netdev); 987 988 dev->udev = interface_to_usbdev(intf); 989 dev->netdev = netdev; 990 991 dev->can.state = CAN_STATE_STOPPED; 992 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 993 dev->can.bittiming_const = &ems_usb_bittiming_const; 994 dev->can.do_set_bittiming = ems_usb_set_bittiming; 995 dev->can.do_set_mode = ems_usb_set_mode; 996 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 997 998 netdev->netdev_ops = &ems_usb_netdev_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 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1013 goto cleanup_candev; 1014 } 1015 1016 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1017 if (!dev->intr_in_buffer) 1018 goto cleanup_intr_urb; 1019 1020 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1021 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1022 if (!dev->tx_msg_buffer) { 1023 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n"); 1024 goto cleanup_intr_in_buffer; 1025 } 1026 1027 usb_set_intfdata(intf, dev); 1028 1029 SET_NETDEV_DEV(netdev, &intf->dev); 1030 1031 init_params_sja1000(&dev->active_params); 1032 1033 err = ems_usb_command_msg(dev, &dev->active_params); 1034 if (err) { 1035 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1036 goto cleanup_tx_msg_buffer; 1037 } 1038 1039 err = register_candev(netdev); 1040 if (err) { 1041 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1042 goto cleanup_tx_msg_buffer; 1043 } 1044 1045 return 0; 1046 1047cleanup_tx_msg_buffer: 1048 kfree(dev->tx_msg_buffer); 1049 1050cleanup_intr_in_buffer: 1051 kfree(dev->intr_in_buffer); 1052 1053cleanup_intr_urb: 1054 usb_free_urb(dev->intr_urb); 1055 1056cleanup_candev: 1057 free_candev(netdev); 1058 1059 return err; 1060} 1061 1062/* 1063 * called by the usb core when the device is removed from the system 1064 */ 1065static void ems_usb_disconnect(struct usb_interface *intf) 1066{ 1067 struct ems_usb *dev = usb_get_intfdata(intf); 1068 1069 usb_set_intfdata(intf, NULL); 1070 1071 if (dev) { 1072 unregister_netdev(dev->netdev); 1073 free_candev(dev->netdev); 1074 1075 unlink_all_urbs(dev); 1076 1077 usb_free_urb(dev->intr_urb); 1078 1079 kfree(dev->intr_in_buffer); 1080 } 1081} 1082 1083/* usb specific object needed to register this driver with the usb subsystem */ 1084static struct usb_driver ems_usb_driver = { 1085 .name = "ems_usb", 1086 .probe = ems_usb_probe, 1087 .disconnect = ems_usb_disconnect, 1088 .id_table = ems_usb_table, 1089}; 1090 1091module_usb_driver(ems_usb_driver); 1092