ems_usb.c revision a6e4bc5304033e434fabccabb230b8e9ff55d76f
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 __attribute__ ((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 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n", 292 urb->status); 293 break; 294 } 295 296 err = usb_submit_urb(urb, GFP_ATOMIC); 297 298 if (err == -ENODEV) 299 netif_device_detach(netdev); 300 else if (err) 301 dev_err(netdev->dev.parent, 302 "failed resubmitting intr urb: %d\n", err); 303 304 return; 305} 306 307static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 308{ 309 struct can_frame *cf; 310 struct sk_buff *skb; 311 int i; 312 struct net_device_stats *stats = &dev->netdev->stats; 313 314 skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame)); 315 if (skb == NULL) 316 return; 317 318 skb->protocol = htons(ETH_P_CAN); 319 320 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 321 322 cf->can_id = msg->msg.can_msg.id; 323 cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8); 324 325 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME 326 || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 327 cf->can_id |= CAN_EFF_FLAG; 328 329 if (msg->type == CPC_MSG_TYPE_RTR_FRAME 330 || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 331 cf->can_id |= CAN_RTR_FLAG; 332 } else { 333 for (i = 0; i < cf->can_dlc; i++) 334 cf->data[i] = msg->msg.can_msg.msg[i]; 335 } 336 337 netif_rx(skb); 338 339 stats->rx_packets++; 340 stats->rx_bytes += cf->can_dlc; 341} 342 343static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 344{ 345 struct can_frame *cf; 346 struct sk_buff *skb; 347 struct net_device_stats *stats = &dev->netdev->stats; 348 349 skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame)); 350 if (skb == NULL) 351 return; 352 353 skb->protocol = htons(ETH_P_CAN); 354 355 cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame)); 356 memset(cf, 0, sizeof(struct can_frame)); 357 358 cf->can_id = CAN_ERR_FLAG; 359 cf->can_dlc = CAN_ERR_DLC; 360 361 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 362 u8 state = msg->msg.can_state; 363 364 if (state & SJA1000_SR_BS) { 365 dev->can.state = CAN_STATE_BUS_OFF; 366 cf->can_id |= CAN_ERR_BUSOFF; 367 368 can_bus_off(dev->netdev); 369 } else if (state & SJA1000_SR_ES) { 370 dev->can.state = CAN_STATE_ERROR_WARNING; 371 dev->can.can_stats.error_warning++; 372 } else { 373 dev->can.state = CAN_STATE_ERROR_ACTIVE; 374 dev->can.can_stats.error_passive++; 375 } 376 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 377 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 378 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 379 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 380 381 /* bus error interrupt */ 382 dev->can.can_stats.bus_error++; 383 stats->rx_errors++; 384 385 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 386 387 switch (ecc & SJA1000_ECC_MASK) { 388 case SJA1000_ECC_BIT: 389 cf->data[2] |= CAN_ERR_PROT_BIT; 390 break; 391 case SJA1000_ECC_FORM: 392 cf->data[2] |= CAN_ERR_PROT_FORM; 393 break; 394 case SJA1000_ECC_STUFF: 395 cf->data[2] |= CAN_ERR_PROT_STUFF; 396 break; 397 default: 398 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 399 cf->data[3] = ecc & SJA1000_ECC_SEG; 400 break; 401 } 402 403 /* Error occured during transmission? */ 404 if ((ecc & SJA1000_ECC_DIR) == 0) 405 cf->data[2] |= CAN_ERR_PROT_TX; 406 407 if (dev->can.state == CAN_STATE_ERROR_WARNING || 408 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 409 cf->data[1] = (txerr > rxerr) ? 410 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 411 } 412 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 413 cf->can_id |= CAN_ERR_CRTL; 414 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 415 416 stats->rx_over_errors++; 417 stats->rx_errors++; 418 } 419 420 netif_rx(skb); 421 422 stats->rx_packets++; 423 stats->rx_bytes += cf->can_dlc; 424} 425 426/* 427 * callback for bulk IN urb 428 */ 429static void ems_usb_read_bulk_callback(struct urb *urb) 430{ 431 struct ems_usb *dev = urb->context; 432 struct net_device *netdev; 433 int retval; 434 435 netdev = dev->netdev; 436 437 if (!netif_device_present(netdev)) 438 return; 439 440 switch (urb->status) { 441 case 0: /* success */ 442 break; 443 444 case -ENOENT: 445 return; 446 447 default: 448 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n", 449 urb->status); 450 goto resubmit_urb; 451 } 452 453 if (urb->actual_length > CPC_HEADER_SIZE) { 454 struct ems_cpc_msg *msg; 455 u8 *ibuf = urb->transfer_buffer; 456 u8 msg_count, again, start; 457 458 msg_count = ibuf[0] & ~0x80; 459 again = ibuf[0] & 0x80; 460 461 start = CPC_HEADER_SIZE; 462 463 while (msg_count) { 464 msg = (struct ems_cpc_msg *)&ibuf[start]; 465 466 switch (msg->type) { 467 case CPC_MSG_TYPE_CAN_STATE: 468 /* Process CAN state changes */ 469 ems_usb_rx_err(dev, msg); 470 break; 471 472 case CPC_MSG_TYPE_CAN_FRAME: 473 case CPC_MSG_TYPE_EXT_CAN_FRAME: 474 case CPC_MSG_TYPE_RTR_FRAME: 475 case CPC_MSG_TYPE_EXT_RTR_FRAME: 476 ems_usb_rx_can_msg(dev, msg); 477 break; 478 479 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 480 /* Process errorframe */ 481 ems_usb_rx_err(dev, msg); 482 break; 483 484 case CPC_MSG_TYPE_OVERRUN: 485 /* Message lost while receiving */ 486 ems_usb_rx_err(dev, msg); 487 break; 488 } 489 490 start += CPC_MSG_HEADER_LEN + msg->length; 491 msg_count--; 492 493 if (start > urb->transfer_buffer_length) { 494 dev_err(netdev->dev.parent, "format error\n"); 495 break; 496 } 497 } 498 } 499 500resubmit_urb: 501 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 502 urb->transfer_buffer, RX_BUFFER_SIZE, 503 ems_usb_read_bulk_callback, dev); 504 505 retval = usb_submit_urb(urb, GFP_ATOMIC); 506 507 if (retval == -ENODEV) 508 netif_device_detach(netdev); 509 else if (retval) 510 dev_err(netdev->dev.parent, 511 "failed resubmitting read bulk urb: %d\n", retval); 512 513 return; 514} 515 516/* 517 * callback for bulk IN urb 518 */ 519static void ems_usb_write_bulk_callback(struct urb *urb) 520{ 521 struct ems_tx_urb_context *context = urb->context; 522 struct ems_usb *dev; 523 struct net_device *netdev; 524 525 BUG_ON(!context); 526 527 dev = context->dev; 528 netdev = dev->netdev; 529 530 /* free up our allocated buffer */ 531 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 532 urb->transfer_buffer, urb->transfer_dma); 533 534 atomic_dec(&dev->active_tx_urbs); 535 536 if (!netif_device_present(netdev)) 537 return; 538 539 if (urb->status) 540 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n", 541 urb->status); 542 543 netdev->trans_start = jiffies; 544 545 /* transmission complete interrupt */ 546 netdev->stats.tx_packets++; 547 netdev->stats.tx_bytes += context->dlc; 548 549 can_get_echo_skb(netdev, context->echo_index); 550 551 /* Release context */ 552 context->echo_index = MAX_TX_URBS; 553 554 if (netif_queue_stopped(netdev)) 555 netif_wake_queue(netdev); 556} 557 558/* 559 * Send the given CPC command synchronously 560 */ 561static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 562{ 563 int actual_length; 564 565 /* Copy payload */ 566 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 567 msg->length + CPC_MSG_HEADER_LEN); 568 569 /* Clear header */ 570 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 571 572 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 573 &dev->tx_msg_buffer[0], 574 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 575 &actual_length, 1000); 576} 577 578/* 579 * Change CAN controllers' mode register 580 */ 581static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 582{ 583 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 584 585 return ems_usb_command_msg(dev, &dev->active_params); 586} 587 588/* 589 * Send a CPC_Control command to change behaviour when interface receives a CAN 590 * message, bus error or CAN state changed notifications. 591 */ 592static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 593{ 594 struct ems_cpc_msg cmd; 595 596 cmd.type = CPC_CMD_TYPE_CONTROL; 597 cmd.length = CPC_MSG_HEADER_LEN + 1; 598 599 cmd.msgid = 0; 600 601 cmd.msg.generic[0] = val; 602 603 return ems_usb_command_msg(dev, &cmd); 604} 605 606/* 607 * Start interface 608 */ 609static int ems_usb_start(struct ems_usb *dev) 610{ 611 struct net_device *netdev = dev->netdev; 612 int err, i; 613 614 dev->intr_in_buffer[0] = 0; 615 dev->free_slots = 15; /* initial size */ 616 617 for (i = 0; i < MAX_RX_URBS; i++) { 618 struct urb *urb = NULL; 619 u8 *buf = NULL; 620 621 /* create a URB, and a buffer for it */ 622 urb = usb_alloc_urb(0, GFP_KERNEL); 623 if (!urb) { 624 dev_err(netdev->dev.parent, 625 "No memory left for URBs\n"); 626 return -ENOMEM; 627 } 628 629 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 630 &urb->transfer_dma); 631 if (!buf) { 632 dev_err(netdev->dev.parent, 633 "No memory left for USB buffer\n"); 634 usb_free_urb(urb); 635 return -ENOMEM; 636 } 637 638 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 639 buf, RX_BUFFER_SIZE, 640 ems_usb_read_bulk_callback, dev); 641 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 642 usb_anchor_urb(urb, &dev->rx_submitted); 643 644 err = usb_submit_urb(urb, GFP_KERNEL); 645 if (err) { 646 if (err == -ENODEV) 647 netif_device_detach(dev->netdev); 648 649 usb_unanchor_urb(urb); 650 usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf, 651 urb->transfer_dma); 652 break; 653 } 654 655 /* Drop reference, USB core will take care of freeing it */ 656 usb_free_urb(urb); 657 } 658 659 /* Did we submit any URBs */ 660 if (i == 0) { 661 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n"); 662 return err; 663 } 664 665 /* Warn if we've couldn't transmit all the URBs */ 666 if (i < MAX_RX_URBS) 667 dev_warn(netdev->dev.parent, "rx performance may be slow\n"); 668 669 /* Setup and start interrupt URB */ 670 usb_fill_int_urb(dev->intr_urb, dev->udev, 671 usb_rcvintpipe(dev->udev, 1), 672 dev->intr_in_buffer, 673 INTR_IN_BUFFER_SIZE, 674 ems_usb_read_interrupt_callback, dev, 1); 675 676 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 677 if (err) { 678 if (err == -ENODEV) 679 netif_device_detach(dev->netdev); 680 681 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n", 682 err); 683 684 return err; 685 } 686 687 /* CPC-USB will transfer received message to host */ 688 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 689 if (err) 690 goto failed; 691 692 /* CPC-USB will transfer CAN state changes to host */ 693 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 694 if (err) 695 goto failed; 696 697 /* CPC-USB will transfer bus errors to host */ 698 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 699 if (err) 700 goto failed; 701 702 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 703 if (err) 704 goto failed; 705 706 dev->can.state = CAN_STATE_ERROR_ACTIVE; 707 708 return 0; 709 710failed: 711 if (err == -ENODEV) 712 netif_device_detach(dev->netdev); 713 714 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err); 715 716 return err; 717} 718 719static void unlink_all_urbs(struct ems_usb *dev) 720{ 721 int i; 722 723 usb_unlink_urb(dev->intr_urb); 724 725 usb_kill_anchored_urbs(&dev->rx_submitted); 726 727 usb_kill_anchored_urbs(&dev->tx_submitted); 728 atomic_set(&dev->active_tx_urbs, 0); 729 730 for (i = 0; i < MAX_TX_URBS; i++) 731 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 732} 733 734static int ems_usb_open(struct net_device *netdev) 735{ 736 struct ems_usb *dev = netdev_priv(netdev); 737 int err; 738 739 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 740 if (err) 741 return err; 742 743 /* common open */ 744 err = open_candev(netdev); 745 if (err) 746 return err; 747 748 /* finally start device */ 749 err = ems_usb_start(dev); 750 if (err) { 751 if (err == -ENODEV) 752 netif_device_detach(dev->netdev); 753 754 dev_warn(netdev->dev.parent, "couldn't start device: %d\n", 755 err); 756 757 close_candev(netdev); 758 759 return err; 760 } 761 762 dev->open_time = jiffies; 763 764 netif_start_queue(netdev); 765 766 return 0; 767} 768 769static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 770{ 771 struct ems_usb *dev = netdev_priv(netdev); 772 struct ems_tx_urb_context *context = NULL; 773 struct net_device_stats *stats = &netdev->stats; 774 struct can_frame *cf = (struct can_frame *)skb->data; 775 struct ems_cpc_msg *msg; 776 struct urb *urb; 777 u8 *buf; 778 int i, err; 779 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 780 + sizeof(struct cpc_can_msg); 781 782 /* create a URB, and a buffer for it, and copy the data to the URB */ 783 urb = usb_alloc_urb(0, GFP_ATOMIC); 784 if (!urb) { 785 dev_err(netdev->dev.parent, "No memory left for URBs\n"); 786 goto nomem; 787 } 788 789 buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 790 if (!buf) { 791 dev_err(netdev->dev.parent, "No memory left for USB buffer\n"); 792 usb_free_urb(urb); 793 goto nomem; 794 } 795 796 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 797 798 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 799 msg->msg.can_msg.length = cf->can_dlc; 800 801 if (cf->can_id & CAN_RTR_FLAG) { 802 msg->type = cf->can_id & CAN_EFF_FLAG ? 803 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 804 805 msg->length = CPC_CAN_MSG_MIN_SIZE; 806 } else { 807 msg->type = cf->can_id & CAN_EFF_FLAG ? 808 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 809 810 for (i = 0; i < cf->can_dlc; i++) 811 msg->msg.can_msg.msg[i] = cf->data[i]; 812 813 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 814 } 815 816 for (i = 0; i < MAX_TX_URBS; i++) { 817 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 818 context = &dev->tx_contexts[i]; 819 break; 820 } 821 } 822 823 /* 824 * May never happen! When this happens we'd more URBs in flight as 825 * allowed (MAX_TX_URBS). 826 */ 827 if (!context) { 828 usb_unanchor_urb(urb); 829 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma); 830 831 dev_warn(netdev->dev.parent, "couldn't find free context\n"); 832 833 return NETDEV_TX_BUSY; 834 } 835 836 context->dev = dev; 837 context->echo_index = i; 838 context->dlc = cf->can_dlc; 839 840 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 841 size, ems_usb_write_bulk_callback, context); 842 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 843 usb_anchor_urb(urb, &dev->tx_submitted); 844 845 can_put_echo_skb(skb, netdev, context->echo_index); 846 847 atomic_inc(&dev->active_tx_urbs); 848 849 err = usb_submit_urb(urb, GFP_ATOMIC); 850 if (unlikely(err)) { 851 can_free_echo_skb(netdev, context->echo_index); 852 853 usb_unanchor_urb(urb); 854 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma); 855 dev_kfree_skb(skb); 856 857 atomic_dec(&dev->active_tx_urbs); 858 859 if (err == -ENODEV) { 860 netif_device_detach(netdev); 861 } else { 862 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err); 863 864 stats->tx_dropped++; 865 } 866 } else { 867 netdev->trans_start = jiffies; 868 869 /* Slow down tx path */ 870 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 871 dev->free_slots < 5) { 872 netif_stop_queue(netdev); 873 } 874 } 875 876 /* 877 * Release our reference to this URB, the USB core will eventually free 878 * it entirely. 879 */ 880 usb_free_urb(urb); 881 882 return NETDEV_TX_OK; 883 884nomem: 885 if (skb) 886 dev_kfree_skb(skb); 887 888 stats->tx_dropped++; 889 890 return NETDEV_TX_OK; 891} 892 893static int ems_usb_close(struct net_device *netdev) 894{ 895 struct ems_usb *dev = netdev_priv(netdev); 896 897 /* Stop polling */ 898 unlink_all_urbs(dev); 899 900 netif_stop_queue(netdev); 901 902 /* Set CAN controller to reset mode */ 903 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 904 dev_warn(netdev->dev.parent, "couldn't stop device"); 905 906 close_candev(netdev); 907 908 dev->open_time = 0; 909 910 return 0; 911} 912 913static const struct net_device_ops ems_usb_netdev_ops = { 914 .ndo_open = ems_usb_open, 915 .ndo_stop = ems_usb_close, 916 .ndo_start_xmit = ems_usb_start_xmit, 917}; 918 919static struct can_bittiming_const ems_usb_bittiming_const = { 920 .name = "ems_usb", 921 .tseg1_min = 1, 922 .tseg1_max = 16, 923 .tseg2_min = 1, 924 .tseg2_max = 8, 925 .sjw_max = 4, 926 .brp_min = 1, 927 .brp_max = 64, 928 .brp_inc = 1, 929}; 930 931static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 932{ 933 struct ems_usb *dev = netdev_priv(netdev); 934 935 if (!dev->open_time) 936 return -EINVAL; 937 938 switch (mode) { 939 case CAN_MODE_START: 940 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 941 dev_warn(netdev->dev.parent, "couldn't start device"); 942 943 if (netif_queue_stopped(netdev)) 944 netif_wake_queue(netdev); 945 break; 946 947 default: 948 return -EOPNOTSUPP; 949 } 950 951 return 0; 952} 953 954static int ems_usb_set_bittiming(struct net_device *netdev) 955{ 956 struct ems_usb *dev = netdev_priv(netdev); 957 struct can_bittiming *bt = &dev->can.bittiming; 958 u8 btr0, btr1; 959 960 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 961 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 962 (((bt->phase_seg2 - 1) & 0x7) << 4); 963 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 964 btr1 |= 0x80; 965 966 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n", 967 btr0, btr1); 968 969 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 970 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 971 972 return ems_usb_command_msg(dev, &dev->active_params); 973} 974 975static void init_params_sja1000(struct ems_cpc_msg *msg) 976{ 977 struct cpc_sja1000_params *sja1000 = 978 &msg->msg.can_params.cc_params.sja1000; 979 980 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 981 msg->length = sizeof(struct cpc_can_params); 982 msg->msgid = 0; 983 984 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 985 986 /* Acceptance filter open */ 987 sja1000->acc_code0 = 0x00; 988 sja1000->acc_code1 = 0x00; 989 sja1000->acc_code2 = 0x00; 990 sja1000->acc_code3 = 0x00; 991 992 /* Acceptance filter open */ 993 sja1000->acc_mask0 = 0xFF; 994 sja1000->acc_mask1 = 0xFF; 995 sja1000->acc_mask2 = 0xFF; 996 sja1000->acc_mask3 = 0xFF; 997 998 sja1000->btr0 = 0; 999 sja1000->btr1 = 0; 1000 1001 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 1002 sja1000->mode = SJA1000_MOD_RM; 1003} 1004 1005/* 1006 * probe function for new CPC-USB devices 1007 */ 1008static int ems_usb_probe(struct usb_interface *intf, 1009 const struct usb_device_id *id) 1010{ 1011 struct net_device *netdev; 1012 struct ems_usb *dev; 1013 int i, err = -ENOMEM; 1014 1015 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 1016 if (!netdev) { 1017 dev_err(netdev->dev.parent, "Couldn't alloc candev\n"); 1018 return -ENOMEM; 1019 } 1020 1021 dev = netdev_priv(netdev); 1022 1023 dev->udev = interface_to_usbdev(intf); 1024 dev->netdev = netdev; 1025 1026 dev->can.state = CAN_STATE_STOPPED; 1027 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1028 dev->can.bittiming_const = &ems_usb_bittiming_const; 1029 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1030 dev->can.do_set_mode = ems_usb_set_mode; 1031 1032 netdev->flags |= IFF_ECHO; /* we support local echo */ 1033 1034 netdev->netdev_ops = &ems_usb_netdev_ops; 1035 1036 netdev->flags |= IFF_ECHO; /* we support local echo */ 1037 1038 init_usb_anchor(&dev->rx_submitted); 1039 1040 init_usb_anchor(&dev->tx_submitted); 1041 atomic_set(&dev->active_tx_urbs, 0); 1042 1043 for (i = 0; i < MAX_TX_URBS; i++) 1044 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1045 1046 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1047 if (!dev->intr_urb) { 1048 dev_err(netdev->dev.parent, "Couldn't alloc intr URB\n"); 1049 goto cleanup_candev; 1050 } 1051 1052 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1053 if (!dev->intr_in_buffer) { 1054 dev_err(netdev->dev.parent, "Couldn't alloc Intr buffer\n"); 1055 goto cleanup_intr_urb; 1056 } 1057 1058 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1059 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1060 if (!dev->tx_msg_buffer) { 1061 dev_err(netdev->dev.parent, "Couldn't alloc Tx buffer\n"); 1062 goto cleanup_intr_in_buffer; 1063 } 1064 1065 usb_set_intfdata(intf, dev); 1066 1067 SET_NETDEV_DEV(netdev, &intf->dev); 1068 1069 init_params_sja1000(&dev->active_params); 1070 1071 err = ems_usb_command_msg(dev, &dev->active_params); 1072 if (err) { 1073 dev_err(netdev->dev.parent, 1074 "couldn't initialize controller: %d\n", err); 1075 goto cleanup_tx_msg_buffer; 1076 } 1077 1078 err = register_candev(netdev); 1079 if (err) { 1080 dev_err(netdev->dev.parent, 1081 "couldn't register CAN device: %d\n", err); 1082 goto cleanup_tx_msg_buffer; 1083 } 1084 1085 return 0; 1086 1087cleanup_tx_msg_buffer: 1088 kfree(dev->tx_msg_buffer); 1089 1090cleanup_intr_in_buffer: 1091 kfree(dev->intr_in_buffer); 1092 1093cleanup_intr_urb: 1094 usb_free_urb(dev->intr_urb); 1095 1096cleanup_candev: 1097 free_candev(netdev); 1098 1099 return err; 1100} 1101 1102/* 1103 * called by the usb core when the device is removed from the system 1104 */ 1105static void ems_usb_disconnect(struct usb_interface *intf) 1106{ 1107 struct ems_usb *dev = usb_get_intfdata(intf); 1108 1109 usb_set_intfdata(intf, NULL); 1110 1111 if (dev) { 1112 unregister_netdev(dev->netdev); 1113 free_candev(dev->netdev); 1114 1115 unlink_all_urbs(dev); 1116 1117 usb_free_urb(dev->intr_urb); 1118 1119 kfree(dev->intr_in_buffer); 1120 } 1121} 1122 1123/* usb specific object needed to register this driver with the usb subsystem */ 1124static struct usb_driver ems_usb_driver = { 1125 .name = "ems_usb", 1126 .probe = ems_usb_probe, 1127 .disconnect = ems_usb_disconnect, 1128 .id_table = ems_usb_table, 1129}; 1130 1131static int __init ems_usb_init(void) 1132{ 1133 int err; 1134 1135 printk(KERN_INFO "CPC-USB kernel driver loaded\n"); 1136 1137 /* register this driver with the USB subsystem */ 1138 err = usb_register(&ems_usb_driver); 1139 1140 if (err) { 1141 err("usb_register failed. Error number %d\n", err); 1142 return err; 1143 } 1144 1145 return 0; 1146} 1147 1148static void __exit ems_usb_exit(void) 1149{ 1150 /* deregister this driver with the USB subsystem */ 1151 usb_deregister(&ems_usb_driver); 1152} 1153 1154module_init(ems_usb_init); 1155module_exit(ems_usb_exit); 1156