ems_usb.c revision aabdfd6adb804d0aaba0188ade0f1afe42a52e31
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 int open_time; 249 250 struct sk_buff *echo_skb[MAX_TX_URBS]; 251 252 struct usb_device *udev; 253 struct net_device *netdev; 254 255 atomic_t active_tx_urbs; 256 struct usb_anchor tx_submitted; 257 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 258 259 struct usb_anchor rx_submitted; 260 261 struct urb *intr_urb; 262 263 u8 *tx_msg_buffer; 264 265 u8 *intr_in_buffer; 266 unsigned int free_slots; /* remember number of available slots */ 267 268 struct ems_cpc_msg active_params; /* active controller parameters */ 269}; 270 271static void ems_usb_read_interrupt_callback(struct urb *urb) 272{ 273 struct ems_usb *dev = urb->context; 274 struct net_device *netdev = dev->netdev; 275 int err; 276 277 if (!netif_device_present(netdev)) 278 return; 279 280 switch (urb->status) { 281 case 0: 282 dev->free_slots = dev->intr_in_buffer[1]; 283 break; 284 285 case -ECONNRESET: /* unlink */ 286 case -ENOENT: 287 case -ESHUTDOWN: 288 return; 289 290 default: 291 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 292 break; 293 } 294 295 err = usb_submit_urb(urb, GFP_ATOMIC); 296 297 if (err == -ENODEV) 298 netif_device_detach(netdev); 299 else if (err) 300 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 301} 302 303static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 304{ 305 struct can_frame *cf; 306 struct sk_buff *skb; 307 int i; 308 struct net_device_stats *stats = &dev->netdev->stats; 309 310 skb = alloc_can_skb(dev->netdev, &cf); 311 if (skb == NULL) 312 return; 313 314 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 315 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 316 317 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 319 cf->can_id |= CAN_EFF_FLAG; 320 321 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 322 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 323 cf->can_id |= CAN_RTR_FLAG; 324 } else { 325 for (i = 0; i < cf->can_dlc; i++) 326 cf->data[i] = msg->msg.can_msg.msg[i]; 327 } 328 329 netif_rx(skb); 330 331 stats->rx_packets++; 332 stats->rx_bytes += cf->can_dlc; 333} 334 335static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 336{ 337 struct can_frame *cf; 338 struct sk_buff *skb; 339 struct net_device_stats *stats = &dev->netdev->stats; 340 341 skb = alloc_can_err_skb(dev->netdev, &cf); 342 if (skb == NULL) 343 return; 344 345 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 346 u8 state = msg->msg.can_state; 347 348 if (state & SJA1000_SR_BS) { 349 dev->can.state = CAN_STATE_BUS_OFF; 350 cf->can_id |= CAN_ERR_BUSOFF; 351 352 can_bus_off(dev->netdev); 353 } else if (state & SJA1000_SR_ES) { 354 dev->can.state = CAN_STATE_ERROR_WARNING; 355 dev->can.can_stats.error_warning++; 356 } else { 357 dev->can.state = CAN_STATE_ERROR_ACTIVE; 358 dev->can.can_stats.error_passive++; 359 } 360 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 361 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 362 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 363 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 364 365 /* bus error interrupt */ 366 dev->can.can_stats.bus_error++; 367 stats->rx_errors++; 368 369 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 370 371 switch (ecc & SJA1000_ECC_MASK) { 372 case SJA1000_ECC_BIT: 373 cf->data[2] |= CAN_ERR_PROT_BIT; 374 break; 375 case SJA1000_ECC_FORM: 376 cf->data[2] |= CAN_ERR_PROT_FORM; 377 break; 378 case SJA1000_ECC_STUFF: 379 cf->data[2] |= CAN_ERR_PROT_STUFF; 380 break; 381 default: 382 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 383 cf->data[3] = ecc & SJA1000_ECC_SEG; 384 break; 385 } 386 387 /* Error occurred during transmission? */ 388 if ((ecc & SJA1000_ECC_DIR) == 0) 389 cf->data[2] |= CAN_ERR_PROT_TX; 390 391 if (dev->can.state == CAN_STATE_ERROR_WARNING || 392 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 393 cf->data[1] = (txerr > rxerr) ? 394 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 395 } 396 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 397 cf->can_id |= CAN_ERR_CRTL; 398 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 399 400 stats->rx_over_errors++; 401 stats->rx_errors++; 402 } 403 404 netif_rx(skb); 405 406 stats->rx_packets++; 407 stats->rx_bytes += cf->can_dlc; 408} 409 410/* 411 * callback for bulk IN urb 412 */ 413static void ems_usb_read_bulk_callback(struct urb *urb) 414{ 415 struct ems_usb *dev = urb->context; 416 struct net_device *netdev; 417 int retval; 418 419 netdev = dev->netdev; 420 421 if (!netif_device_present(netdev)) 422 return; 423 424 switch (urb->status) { 425 case 0: /* success */ 426 break; 427 428 case -ENOENT: 429 return; 430 431 default: 432 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 433 goto resubmit_urb; 434 } 435 436 if (urb->actual_length > CPC_HEADER_SIZE) { 437 struct ems_cpc_msg *msg; 438 u8 *ibuf = urb->transfer_buffer; 439 u8 msg_count, again, start; 440 441 msg_count = ibuf[0] & ~0x80; 442 again = ibuf[0] & 0x80; 443 444 start = CPC_HEADER_SIZE; 445 446 while (msg_count) { 447 msg = (struct ems_cpc_msg *)&ibuf[start]; 448 449 switch (msg->type) { 450 case CPC_MSG_TYPE_CAN_STATE: 451 /* Process CAN state changes */ 452 ems_usb_rx_err(dev, msg); 453 break; 454 455 case CPC_MSG_TYPE_CAN_FRAME: 456 case CPC_MSG_TYPE_EXT_CAN_FRAME: 457 case CPC_MSG_TYPE_RTR_FRAME: 458 case CPC_MSG_TYPE_EXT_RTR_FRAME: 459 ems_usb_rx_can_msg(dev, msg); 460 break; 461 462 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 463 /* Process errorframe */ 464 ems_usb_rx_err(dev, msg); 465 break; 466 467 case CPC_MSG_TYPE_OVERRUN: 468 /* Message lost while receiving */ 469 ems_usb_rx_err(dev, msg); 470 break; 471 } 472 473 start += CPC_MSG_HEADER_LEN + msg->length; 474 msg_count--; 475 476 if (start > urb->transfer_buffer_length) { 477 netdev_err(netdev, "format error\n"); 478 break; 479 } 480 } 481 } 482 483resubmit_urb: 484 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 485 urb->transfer_buffer, RX_BUFFER_SIZE, 486 ems_usb_read_bulk_callback, dev); 487 488 retval = usb_submit_urb(urb, GFP_ATOMIC); 489 490 if (retval == -ENODEV) 491 netif_device_detach(netdev); 492 else if (retval) 493 netdev_err(netdev, 494 "failed resubmitting read bulk urb: %d\n", retval); 495} 496 497/* 498 * callback for bulk IN urb 499 */ 500static void ems_usb_write_bulk_callback(struct urb *urb) 501{ 502 struct ems_tx_urb_context *context = urb->context; 503 struct ems_usb *dev; 504 struct net_device *netdev; 505 506 BUG_ON(!context); 507 508 dev = context->dev; 509 netdev = dev->netdev; 510 511 /* free up our allocated buffer */ 512 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 513 urb->transfer_buffer, urb->transfer_dma); 514 515 atomic_dec(&dev->active_tx_urbs); 516 517 if (!netif_device_present(netdev)) 518 return; 519 520 if (urb->status) 521 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 522 523 netdev->trans_start = jiffies; 524 525 /* transmission complete interrupt */ 526 netdev->stats.tx_packets++; 527 netdev->stats.tx_bytes += context->dlc; 528 529 can_get_echo_skb(netdev, context->echo_index); 530 531 /* Release context */ 532 context->echo_index = MAX_TX_URBS; 533 534 if (netif_queue_stopped(netdev)) 535 netif_wake_queue(netdev); 536} 537 538/* 539 * Send the given CPC command synchronously 540 */ 541static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 542{ 543 int actual_length; 544 545 /* Copy payload */ 546 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 547 msg->length + CPC_MSG_HEADER_LEN); 548 549 /* Clear header */ 550 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 551 552 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 553 &dev->tx_msg_buffer[0], 554 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 555 &actual_length, 1000); 556} 557 558/* 559 * Change CAN controllers' mode register 560 */ 561static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 562{ 563 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 564 565 return ems_usb_command_msg(dev, &dev->active_params); 566} 567 568/* 569 * Send a CPC_Control command to change behaviour when interface receives a CAN 570 * message, bus error or CAN state changed notifications. 571 */ 572static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 573{ 574 struct ems_cpc_msg cmd; 575 576 cmd.type = CPC_CMD_TYPE_CONTROL; 577 cmd.length = CPC_MSG_HEADER_LEN + 1; 578 579 cmd.msgid = 0; 580 581 cmd.msg.generic[0] = val; 582 583 return ems_usb_command_msg(dev, &cmd); 584} 585 586/* 587 * Start interface 588 */ 589static int ems_usb_start(struct ems_usb *dev) 590{ 591 struct net_device *netdev = dev->netdev; 592 int err, i; 593 594 dev->intr_in_buffer[0] = 0; 595 dev->free_slots = 15; /* initial size */ 596 597 for (i = 0; i < MAX_RX_URBS; i++) { 598 struct urb *urb = NULL; 599 u8 *buf = NULL; 600 601 /* create a URB, and a buffer for it */ 602 urb = usb_alloc_urb(0, GFP_KERNEL); 603 if (!urb) { 604 netdev_err(netdev, "No memory left for URBs\n"); 605 err = -ENOMEM; 606 break; 607 } 608 609 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 610 &urb->transfer_dma); 611 if (!buf) { 612 netdev_err(netdev, "No memory left for USB buffer\n"); 613 usb_free_urb(urb); 614 err = -ENOMEM; 615 break; 616 } 617 618 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 619 buf, RX_BUFFER_SIZE, 620 ems_usb_read_bulk_callback, dev); 621 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 622 usb_anchor_urb(urb, &dev->rx_submitted); 623 624 err = usb_submit_urb(urb, GFP_KERNEL); 625 if (err) { 626 usb_unanchor_urb(urb); 627 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 628 urb->transfer_dma); 629 break; 630 } 631 632 /* Drop reference, USB core will take care of freeing it */ 633 usb_free_urb(urb); 634 } 635 636 /* Did we submit any URBs */ 637 if (i == 0) { 638 netdev_warn(netdev, "couldn't setup read URBs\n"); 639 return err; 640 } 641 642 /* Warn if we've couldn't transmit all the URBs */ 643 if (i < MAX_RX_URBS) 644 netdev_warn(netdev, "rx performance may be slow\n"); 645 646 /* Setup and start interrupt URB */ 647 usb_fill_int_urb(dev->intr_urb, dev->udev, 648 usb_rcvintpipe(dev->udev, 1), 649 dev->intr_in_buffer, 650 INTR_IN_BUFFER_SIZE, 651 ems_usb_read_interrupt_callback, dev, 1); 652 653 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 654 if (err) { 655 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 656 657 return err; 658 } 659 660 /* CPC-USB will transfer received message to host */ 661 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 662 if (err) 663 goto failed; 664 665 /* CPC-USB will transfer CAN state changes to host */ 666 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 667 if (err) 668 goto failed; 669 670 /* CPC-USB will transfer bus errors to host */ 671 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 672 if (err) 673 goto failed; 674 675 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 676 if (err) 677 goto failed; 678 679 dev->can.state = CAN_STATE_ERROR_ACTIVE; 680 681 return 0; 682 683failed: 684 netdev_warn(netdev, "couldn't submit control: %d\n", err); 685 686 return err; 687} 688 689static void unlink_all_urbs(struct ems_usb *dev) 690{ 691 int i; 692 693 usb_unlink_urb(dev->intr_urb); 694 695 usb_kill_anchored_urbs(&dev->rx_submitted); 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 dev->open_time = jiffies; 732 733 netif_start_queue(netdev); 734 735 return 0; 736} 737 738static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 739{ 740 struct ems_usb *dev = netdev_priv(netdev); 741 struct ems_tx_urb_context *context = NULL; 742 struct net_device_stats *stats = &netdev->stats; 743 struct can_frame *cf = (struct can_frame *)skb->data; 744 struct ems_cpc_msg *msg; 745 struct urb *urb; 746 u8 *buf; 747 int i, err; 748 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 749 + sizeof(struct cpc_can_msg); 750 751 if (can_dropped_invalid_skb(netdev, skb)) 752 return NETDEV_TX_OK; 753 754 /* create a URB, and a buffer for it, and copy the data to the URB */ 755 urb = usb_alloc_urb(0, GFP_ATOMIC); 756 if (!urb) { 757 netdev_err(netdev, "No memory left for URBs\n"); 758 goto nomem; 759 } 760 761 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 762 if (!buf) { 763 netdev_err(netdev, "No memory left for USB buffer\n"); 764 usb_free_urb(urb); 765 goto nomem; 766 } 767 768 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 769 770 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 771 msg->msg.can_msg.length = cf->can_dlc; 772 773 if (cf->can_id & CAN_RTR_FLAG) { 774 msg->type = cf->can_id & CAN_EFF_FLAG ? 775 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 776 777 msg->length = CPC_CAN_MSG_MIN_SIZE; 778 } else { 779 msg->type = cf->can_id & CAN_EFF_FLAG ? 780 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 781 782 for (i = 0; i < cf->can_dlc; i++) 783 msg->msg.can_msg.msg[i] = cf->data[i]; 784 785 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 786 } 787 788 /* Respect byte order */ 789 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id); 790 791 for (i = 0; i < MAX_TX_URBS; i++) { 792 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 793 context = &dev->tx_contexts[i]; 794 break; 795 } 796 } 797 798 /* 799 * May never happen! When this happens we'd more URBs in flight as 800 * allowed (MAX_TX_URBS). 801 */ 802 if (!context) { 803 usb_unanchor_urb(urb); 804 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 805 806 netdev_warn(netdev, "couldn't find free context\n"); 807 808 return NETDEV_TX_BUSY; 809 } 810 811 context->dev = dev; 812 context->echo_index = i; 813 context->dlc = cf->can_dlc; 814 815 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 816 size, ems_usb_write_bulk_callback, context); 817 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 818 usb_anchor_urb(urb, &dev->tx_submitted); 819 820 can_put_echo_skb(skb, netdev, context->echo_index); 821 822 atomic_inc(&dev->active_tx_urbs); 823 824 err = usb_submit_urb(urb, GFP_ATOMIC); 825 if (unlikely(err)) { 826 can_free_echo_skb(netdev, context->echo_index); 827 828 usb_unanchor_urb(urb); 829 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 830 dev_kfree_skb(skb); 831 832 atomic_dec(&dev->active_tx_urbs); 833 834 if (err == -ENODEV) { 835 netif_device_detach(netdev); 836 } else { 837 netdev_warn(netdev, "failed tx_urb %d\n", err); 838 839 stats->tx_dropped++; 840 } 841 } else { 842 netdev->trans_start = jiffies; 843 844 /* Slow down tx path */ 845 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 846 dev->free_slots < 5) { 847 netif_stop_queue(netdev); 848 } 849 } 850 851 /* 852 * Release our reference to this URB, the USB core will eventually free 853 * it entirely. 854 */ 855 usb_free_urb(urb); 856 857 return NETDEV_TX_OK; 858 859nomem: 860 dev_kfree_skb(skb); 861 stats->tx_dropped++; 862 863 return NETDEV_TX_OK; 864} 865 866static int ems_usb_close(struct net_device *netdev) 867{ 868 struct ems_usb *dev = netdev_priv(netdev); 869 870 /* Stop polling */ 871 unlink_all_urbs(dev); 872 873 netif_stop_queue(netdev); 874 875 /* Set CAN controller to reset mode */ 876 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 877 netdev_warn(netdev, "couldn't stop device"); 878 879 close_candev(netdev); 880 881 dev->open_time = 0; 882 883 return 0; 884} 885 886static const struct net_device_ops ems_usb_netdev_ops = { 887 .ndo_open = ems_usb_open, 888 .ndo_stop = ems_usb_close, 889 .ndo_start_xmit = ems_usb_start_xmit, 890}; 891 892static 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 if (!dev->open_time) 909 return -EINVAL; 910 911 switch (mode) { 912 case CAN_MODE_START: 913 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 914 netdev_warn(netdev, "couldn't start device"); 915 916 if (netif_queue_stopped(netdev)) 917 netif_wake_queue(netdev); 918 break; 919 920 default: 921 return -EOPNOTSUPP; 922 } 923 924 return 0; 925} 926 927static int ems_usb_set_bittiming(struct net_device *netdev) 928{ 929 struct ems_usb *dev = netdev_priv(netdev); 930 struct can_bittiming *bt = &dev->can.bittiming; 931 u8 btr0, btr1; 932 933 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 934 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 935 (((bt->phase_seg2 - 1) & 0x7) << 4); 936 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 937 btr1 |= 0x80; 938 939 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 940 941 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 942 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 943 944 return ems_usb_command_msg(dev, &dev->active_params); 945} 946 947static void init_params_sja1000(struct ems_cpc_msg *msg) 948{ 949 struct cpc_sja1000_params *sja1000 = 950 &msg->msg.can_params.cc_params.sja1000; 951 952 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 953 msg->length = sizeof(struct cpc_can_params); 954 msg->msgid = 0; 955 956 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 957 958 /* Acceptance filter open */ 959 sja1000->acc_code0 = 0x00; 960 sja1000->acc_code1 = 0x00; 961 sja1000->acc_code2 = 0x00; 962 sja1000->acc_code3 = 0x00; 963 964 /* Acceptance filter open */ 965 sja1000->acc_mask0 = 0xFF; 966 sja1000->acc_mask1 = 0xFF; 967 sja1000->acc_mask2 = 0xFF; 968 sja1000->acc_mask3 = 0xFF; 969 970 sja1000->btr0 = 0; 971 sja1000->btr1 = 0; 972 973 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 974 sja1000->mode = SJA1000_MOD_RM; 975} 976 977/* 978 * probe function for new CPC-USB devices 979 */ 980static int ems_usb_probe(struct usb_interface *intf, 981 const struct usb_device_id *id) 982{ 983 struct net_device *netdev; 984 struct ems_usb *dev; 985 int i, err = -ENOMEM; 986 987 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 988 if (!netdev) { 989 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 990 return -ENOMEM; 991 } 992 993 dev = netdev_priv(netdev); 994 995 dev->udev = interface_to_usbdev(intf); 996 dev->netdev = netdev; 997 998 dev->can.state = CAN_STATE_STOPPED; 999 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1000 dev->can.bittiming_const = &ems_usb_bittiming_const; 1001 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1002 dev->can.do_set_mode = ems_usb_set_mode; 1003 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1004 1005 netdev->netdev_ops = &ems_usb_netdev_ops; 1006 1007 netdev->flags |= IFF_ECHO; /* we support local echo */ 1008 1009 init_usb_anchor(&dev->rx_submitted); 1010 1011 init_usb_anchor(&dev->tx_submitted); 1012 atomic_set(&dev->active_tx_urbs, 0); 1013 1014 for (i = 0; i < MAX_TX_URBS; i++) 1015 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1016 1017 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1018 if (!dev->intr_urb) { 1019 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1020 goto cleanup_candev; 1021 } 1022 1023 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1024 if (!dev->intr_in_buffer) { 1025 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n"); 1026 goto cleanup_intr_urb; 1027 } 1028 1029 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1030 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1031 if (!dev->tx_msg_buffer) { 1032 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n"); 1033 goto cleanup_intr_in_buffer; 1034 } 1035 1036 usb_set_intfdata(intf, dev); 1037 1038 SET_NETDEV_DEV(netdev, &intf->dev); 1039 1040 init_params_sja1000(&dev->active_params); 1041 1042 err = ems_usb_command_msg(dev, &dev->active_params); 1043 if (err) { 1044 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1045 goto cleanup_tx_msg_buffer; 1046 } 1047 1048 err = register_candev(netdev); 1049 if (err) { 1050 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1051 goto cleanup_tx_msg_buffer; 1052 } 1053 1054 return 0; 1055 1056cleanup_tx_msg_buffer: 1057 kfree(dev->tx_msg_buffer); 1058 1059cleanup_intr_in_buffer: 1060 kfree(dev->intr_in_buffer); 1061 1062cleanup_intr_urb: 1063 usb_free_urb(dev->intr_urb); 1064 1065cleanup_candev: 1066 free_candev(netdev); 1067 1068 return err; 1069} 1070 1071/* 1072 * called by the usb core when the device is removed from the system 1073 */ 1074static void ems_usb_disconnect(struct usb_interface *intf) 1075{ 1076 struct ems_usb *dev = usb_get_intfdata(intf); 1077 1078 usb_set_intfdata(intf, NULL); 1079 1080 if (dev) { 1081 unregister_netdev(dev->netdev); 1082 free_candev(dev->netdev); 1083 1084 unlink_all_urbs(dev); 1085 1086 usb_free_urb(dev->intr_urb); 1087 1088 kfree(dev->intr_in_buffer); 1089 } 1090} 1091 1092/* usb specific object needed to register this driver with the usb subsystem */ 1093static struct usb_driver ems_usb_driver = { 1094 .name = "ems_usb", 1095 .probe = ems_usb_probe, 1096 .disconnect = ems_usb_disconnect, 1097 .id_table = ems_usb_table, 1098}; 1099 1100module_usb_driver(ems_usb_driver); 1101