ems_usb.c revision 1c0b28b1ee90261a0a27194e6684dd2837785064
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 = alloc_can_skb(dev->netdev, &cf); 315 if (skb == NULL) 316 return; 317 318 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 319 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 320 321 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 322 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 323 cf->can_id |= CAN_EFF_FLAG; 324 325 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 326 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 327 cf->can_id |= CAN_RTR_FLAG; 328 } else { 329 for (i = 0; i < cf->can_dlc; i++) 330 cf->data[i] = msg->msg.can_msg.msg[i]; 331 } 332 333 netif_rx(skb); 334 335 stats->rx_packets++; 336 stats->rx_bytes += cf->can_dlc; 337} 338 339static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 340{ 341 struct can_frame *cf; 342 struct sk_buff *skb; 343 struct net_device_stats *stats = &dev->netdev->stats; 344 345 skb = alloc_can_err_skb(dev->netdev, &cf); 346 if (skb == NULL) 347 return; 348 349 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 350 u8 state = msg->msg.can_state; 351 352 if (state & SJA1000_SR_BS) { 353 dev->can.state = CAN_STATE_BUS_OFF; 354 cf->can_id |= CAN_ERR_BUSOFF; 355 356 can_bus_off(dev->netdev); 357 } else if (state & SJA1000_SR_ES) { 358 dev->can.state = CAN_STATE_ERROR_WARNING; 359 dev->can.can_stats.error_warning++; 360 } else { 361 dev->can.state = CAN_STATE_ERROR_ACTIVE; 362 dev->can.can_stats.error_passive++; 363 } 364 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 365 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 366 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 367 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 368 369 /* bus error interrupt */ 370 dev->can.can_stats.bus_error++; 371 stats->rx_errors++; 372 373 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 374 375 switch (ecc & SJA1000_ECC_MASK) { 376 case SJA1000_ECC_BIT: 377 cf->data[2] |= CAN_ERR_PROT_BIT; 378 break; 379 case SJA1000_ECC_FORM: 380 cf->data[2] |= CAN_ERR_PROT_FORM; 381 break; 382 case SJA1000_ECC_STUFF: 383 cf->data[2] |= CAN_ERR_PROT_STUFF; 384 break; 385 default: 386 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 387 cf->data[3] = ecc & SJA1000_ECC_SEG; 388 break; 389 } 390 391 /* Error occured during transmission? */ 392 if ((ecc & SJA1000_ECC_DIR) == 0) 393 cf->data[2] |= CAN_ERR_PROT_TX; 394 395 if (dev->can.state == CAN_STATE_ERROR_WARNING || 396 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 397 cf->data[1] = (txerr > rxerr) ? 398 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 399 } 400 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 401 cf->can_id |= CAN_ERR_CRTL; 402 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 403 404 stats->rx_over_errors++; 405 stats->rx_errors++; 406 } 407 408 netif_rx(skb); 409 410 stats->rx_packets++; 411 stats->rx_bytes += cf->can_dlc; 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 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n", 437 urb->status); 438 goto resubmit_urb; 439 } 440 441 if (urb->actual_length > CPC_HEADER_SIZE) { 442 struct ems_cpc_msg *msg; 443 u8 *ibuf = urb->transfer_buffer; 444 u8 msg_count, again, start; 445 446 msg_count = ibuf[0] & ~0x80; 447 again = ibuf[0] & 0x80; 448 449 start = CPC_HEADER_SIZE; 450 451 while (msg_count) { 452 msg = (struct ems_cpc_msg *)&ibuf[start]; 453 454 switch (msg->type) { 455 case CPC_MSG_TYPE_CAN_STATE: 456 /* Process CAN state changes */ 457 ems_usb_rx_err(dev, msg); 458 break; 459 460 case CPC_MSG_TYPE_CAN_FRAME: 461 case CPC_MSG_TYPE_EXT_CAN_FRAME: 462 case CPC_MSG_TYPE_RTR_FRAME: 463 case CPC_MSG_TYPE_EXT_RTR_FRAME: 464 ems_usb_rx_can_msg(dev, msg); 465 break; 466 467 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 468 /* Process errorframe */ 469 ems_usb_rx_err(dev, msg); 470 break; 471 472 case CPC_MSG_TYPE_OVERRUN: 473 /* Message lost while receiving */ 474 ems_usb_rx_err(dev, msg); 475 break; 476 } 477 478 start += CPC_MSG_HEADER_LEN + msg->length; 479 msg_count--; 480 481 if (start > urb->transfer_buffer_length) { 482 dev_err(netdev->dev.parent, "format error\n"); 483 break; 484 } 485 } 486 } 487 488resubmit_urb: 489 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 490 urb->transfer_buffer, RX_BUFFER_SIZE, 491 ems_usb_read_bulk_callback, dev); 492 493 retval = usb_submit_urb(urb, GFP_ATOMIC); 494 495 if (retval == -ENODEV) 496 netif_device_detach(netdev); 497 else if (retval) 498 dev_err(netdev->dev.parent, 499 "failed resubmitting read bulk urb: %d\n", retval); 500 501 return; 502} 503 504/* 505 * callback for bulk IN urb 506 */ 507static void ems_usb_write_bulk_callback(struct urb *urb) 508{ 509 struct ems_tx_urb_context *context = urb->context; 510 struct ems_usb *dev; 511 struct net_device *netdev; 512 513 BUG_ON(!context); 514 515 dev = context->dev; 516 netdev = dev->netdev; 517 518 /* free up our allocated buffer */ 519 usb_buffer_free(urb->dev, urb->transfer_buffer_length, 520 urb->transfer_buffer, urb->transfer_dma); 521 522 atomic_dec(&dev->active_tx_urbs); 523 524 if (!netif_device_present(netdev)) 525 return; 526 527 if (urb->status) 528 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n", 529 urb->status); 530 531 netdev->trans_start = jiffies; 532 533 /* transmission complete interrupt */ 534 netdev->stats.tx_packets++; 535 netdev->stats.tx_bytes += context->dlc; 536 537 can_get_echo_skb(netdev, context->echo_index); 538 539 /* Release context */ 540 context->echo_index = MAX_TX_URBS; 541 542 if (netif_queue_stopped(netdev)) 543 netif_wake_queue(netdev); 544} 545 546/* 547 * Send the given CPC command synchronously 548 */ 549static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 550{ 551 int actual_length; 552 553 /* Copy payload */ 554 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 555 msg->length + CPC_MSG_HEADER_LEN); 556 557 /* Clear header */ 558 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 559 560 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 561 &dev->tx_msg_buffer[0], 562 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 563 &actual_length, 1000); 564} 565 566/* 567 * Change CAN controllers' mode register 568 */ 569static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 570{ 571 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 572 573 return ems_usb_command_msg(dev, &dev->active_params); 574} 575 576/* 577 * Send a CPC_Control command to change behaviour when interface receives a CAN 578 * message, bus error or CAN state changed notifications. 579 */ 580static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 581{ 582 struct ems_cpc_msg cmd; 583 584 cmd.type = CPC_CMD_TYPE_CONTROL; 585 cmd.length = CPC_MSG_HEADER_LEN + 1; 586 587 cmd.msgid = 0; 588 589 cmd.msg.generic[0] = val; 590 591 return ems_usb_command_msg(dev, &cmd); 592} 593 594/* 595 * Start interface 596 */ 597static int ems_usb_start(struct ems_usb *dev) 598{ 599 struct net_device *netdev = dev->netdev; 600 int err, i; 601 602 dev->intr_in_buffer[0] = 0; 603 dev->free_slots = 15; /* initial size */ 604 605 for (i = 0; i < MAX_RX_URBS; i++) { 606 struct urb *urb = NULL; 607 u8 *buf = NULL; 608 609 /* create a URB, and a buffer for it */ 610 urb = usb_alloc_urb(0, GFP_KERNEL); 611 if (!urb) { 612 dev_err(netdev->dev.parent, 613 "No memory left for URBs\n"); 614 return -ENOMEM; 615 } 616 617 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 618 &urb->transfer_dma); 619 if (!buf) { 620 dev_err(netdev->dev.parent, 621 "No memory left for USB buffer\n"); 622 usb_free_urb(urb); 623 return -ENOMEM; 624 } 625 626 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 627 buf, RX_BUFFER_SIZE, 628 ems_usb_read_bulk_callback, dev); 629 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 630 usb_anchor_urb(urb, &dev->rx_submitted); 631 632 err = usb_submit_urb(urb, GFP_KERNEL); 633 if (err) { 634 if (err == -ENODEV) 635 netif_device_detach(dev->netdev); 636 637 usb_unanchor_urb(urb); 638 usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf, 639 urb->transfer_dma); 640 break; 641 } 642 643 /* Drop reference, USB core will take care of freeing it */ 644 usb_free_urb(urb); 645 } 646 647 /* Did we submit any URBs */ 648 if (i == 0) { 649 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n"); 650 return err; 651 } 652 653 /* Warn if we've couldn't transmit all the URBs */ 654 if (i < MAX_RX_URBS) 655 dev_warn(netdev->dev.parent, "rx performance may be slow\n"); 656 657 /* Setup and start interrupt URB */ 658 usb_fill_int_urb(dev->intr_urb, dev->udev, 659 usb_rcvintpipe(dev->udev, 1), 660 dev->intr_in_buffer, 661 INTR_IN_BUFFER_SIZE, 662 ems_usb_read_interrupt_callback, dev, 1); 663 664 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 665 if (err) { 666 if (err == -ENODEV) 667 netif_device_detach(dev->netdev); 668 669 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n", 670 err); 671 672 return err; 673 } 674 675 /* CPC-USB will transfer received message to host */ 676 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 677 if (err) 678 goto failed; 679 680 /* CPC-USB will transfer CAN state changes to host */ 681 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 682 if (err) 683 goto failed; 684 685 /* CPC-USB will transfer bus errors to host */ 686 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 687 if (err) 688 goto failed; 689 690 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 691 if (err) 692 goto failed; 693 694 dev->can.state = CAN_STATE_ERROR_ACTIVE; 695 696 return 0; 697 698failed: 699 if (err == -ENODEV) 700 netif_device_detach(dev->netdev); 701 702 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err); 703 704 return err; 705} 706 707static void unlink_all_urbs(struct ems_usb *dev) 708{ 709 int i; 710 711 usb_unlink_urb(dev->intr_urb); 712 713 usb_kill_anchored_urbs(&dev->rx_submitted); 714 715 usb_kill_anchored_urbs(&dev->tx_submitted); 716 atomic_set(&dev->active_tx_urbs, 0); 717 718 for (i = 0; i < MAX_TX_URBS; i++) 719 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 720} 721 722static int ems_usb_open(struct net_device *netdev) 723{ 724 struct ems_usb *dev = netdev_priv(netdev); 725 int err; 726 727 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 728 if (err) 729 return err; 730 731 /* common open */ 732 err = open_candev(netdev); 733 if (err) 734 return err; 735 736 /* finally start device */ 737 err = ems_usb_start(dev); 738 if (err) { 739 if (err == -ENODEV) 740 netif_device_detach(dev->netdev); 741 742 dev_warn(netdev->dev.parent, "couldn't start device: %d\n", 743 err); 744 745 close_candev(netdev); 746 747 return err; 748 } 749 750 dev->open_time = jiffies; 751 752 netif_start_queue(netdev); 753 754 return 0; 755} 756 757static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 758{ 759 struct ems_usb *dev = netdev_priv(netdev); 760 struct ems_tx_urb_context *context = NULL; 761 struct net_device_stats *stats = &netdev->stats; 762 struct can_frame *cf = (struct can_frame *)skb->data; 763 struct ems_cpc_msg *msg; 764 struct urb *urb; 765 u8 *buf; 766 int i, err; 767 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 768 + sizeof(struct cpc_can_msg); 769 770 if (can_dropped_invalid_skb(netdev, skb)) 771 return NETDEV_TX_OK; 772 773 /* create a URB, and a buffer for it, and copy the data to the URB */ 774 urb = usb_alloc_urb(0, GFP_ATOMIC); 775 if (!urb) { 776 dev_err(netdev->dev.parent, "No memory left for URBs\n"); 777 goto nomem; 778 } 779 780 buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 781 if (!buf) { 782 dev_err(netdev->dev.parent, "No memory left for USB buffer\n"); 783 usb_free_urb(urb); 784 goto nomem; 785 } 786 787 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 788 789 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 790 msg->msg.can_msg.length = cf->can_dlc; 791 792 if (cf->can_id & CAN_RTR_FLAG) { 793 msg->type = cf->can_id & CAN_EFF_FLAG ? 794 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 795 796 msg->length = CPC_CAN_MSG_MIN_SIZE; 797 } else { 798 msg->type = cf->can_id & CAN_EFF_FLAG ? 799 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 800 801 for (i = 0; i < cf->can_dlc; i++) 802 msg->msg.can_msg.msg[i] = cf->data[i]; 803 804 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 805 } 806 807 /* Respect byte order */ 808 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id); 809 810 for (i = 0; i < MAX_TX_URBS; i++) { 811 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 812 context = &dev->tx_contexts[i]; 813 break; 814 } 815 } 816 817 /* 818 * May never happen! When this happens we'd more URBs in flight as 819 * allowed (MAX_TX_URBS). 820 */ 821 if (!context) { 822 usb_unanchor_urb(urb); 823 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma); 824 825 dev_warn(netdev->dev.parent, "couldn't find free context\n"); 826 827 return NETDEV_TX_BUSY; 828 } 829 830 context->dev = dev; 831 context->echo_index = i; 832 context->dlc = cf->can_dlc; 833 834 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 835 size, ems_usb_write_bulk_callback, context); 836 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 837 usb_anchor_urb(urb, &dev->tx_submitted); 838 839 can_put_echo_skb(skb, netdev, context->echo_index); 840 841 atomic_inc(&dev->active_tx_urbs); 842 843 err = usb_submit_urb(urb, GFP_ATOMIC); 844 if (unlikely(err)) { 845 can_free_echo_skb(netdev, context->echo_index); 846 847 usb_unanchor_urb(urb); 848 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma); 849 dev_kfree_skb(skb); 850 851 atomic_dec(&dev->active_tx_urbs); 852 853 if (err == -ENODEV) { 854 netif_device_detach(netdev); 855 } else { 856 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err); 857 858 stats->tx_dropped++; 859 } 860 } else { 861 netdev->trans_start = jiffies; 862 863 /* Slow down tx path */ 864 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 865 dev->free_slots < 5) { 866 netif_stop_queue(netdev); 867 } 868 } 869 870 /* 871 * Release our reference to this URB, the USB core will eventually free 872 * it entirely. 873 */ 874 usb_free_urb(urb); 875 876 return NETDEV_TX_OK; 877 878nomem: 879 dev_kfree_skb(skb); 880 stats->tx_dropped++; 881 882 return NETDEV_TX_OK; 883} 884 885static int ems_usb_close(struct net_device *netdev) 886{ 887 struct ems_usb *dev = netdev_priv(netdev); 888 889 /* Stop polling */ 890 unlink_all_urbs(dev); 891 892 netif_stop_queue(netdev); 893 894 /* Set CAN controller to reset mode */ 895 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 896 dev_warn(netdev->dev.parent, "couldn't stop device"); 897 898 close_candev(netdev); 899 900 dev->open_time = 0; 901 902 return 0; 903} 904 905static const struct net_device_ops ems_usb_netdev_ops = { 906 .ndo_open = ems_usb_open, 907 .ndo_stop = ems_usb_close, 908 .ndo_start_xmit = ems_usb_start_xmit, 909}; 910 911static struct can_bittiming_const ems_usb_bittiming_const = { 912 .name = "ems_usb", 913 .tseg1_min = 1, 914 .tseg1_max = 16, 915 .tseg2_min = 1, 916 .tseg2_max = 8, 917 .sjw_max = 4, 918 .brp_min = 1, 919 .brp_max = 64, 920 .brp_inc = 1, 921}; 922 923static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 924{ 925 struct ems_usb *dev = netdev_priv(netdev); 926 927 if (!dev->open_time) 928 return -EINVAL; 929 930 switch (mode) { 931 case CAN_MODE_START: 932 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 933 dev_warn(netdev->dev.parent, "couldn't start device"); 934 935 if (netif_queue_stopped(netdev)) 936 netif_wake_queue(netdev); 937 break; 938 939 default: 940 return -EOPNOTSUPP; 941 } 942 943 return 0; 944} 945 946static int ems_usb_set_bittiming(struct net_device *netdev) 947{ 948 struct ems_usb *dev = netdev_priv(netdev); 949 struct can_bittiming *bt = &dev->can.bittiming; 950 u8 btr0, btr1; 951 952 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 953 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 954 (((bt->phase_seg2 - 1) & 0x7) << 4); 955 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 956 btr1 |= 0x80; 957 958 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n", 959 btr0, btr1); 960 961 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 962 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 963 964 return ems_usb_command_msg(dev, &dev->active_params); 965} 966 967static void init_params_sja1000(struct ems_cpc_msg *msg) 968{ 969 struct cpc_sja1000_params *sja1000 = 970 &msg->msg.can_params.cc_params.sja1000; 971 972 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 973 msg->length = sizeof(struct cpc_can_params); 974 msg->msgid = 0; 975 976 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 977 978 /* Acceptance filter open */ 979 sja1000->acc_code0 = 0x00; 980 sja1000->acc_code1 = 0x00; 981 sja1000->acc_code2 = 0x00; 982 sja1000->acc_code3 = 0x00; 983 984 /* Acceptance filter open */ 985 sja1000->acc_mask0 = 0xFF; 986 sja1000->acc_mask1 = 0xFF; 987 sja1000->acc_mask2 = 0xFF; 988 sja1000->acc_mask3 = 0xFF; 989 990 sja1000->btr0 = 0; 991 sja1000->btr1 = 0; 992 993 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 994 sja1000->mode = SJA1000_MOD_RM; 995} 996 997/* 998 * probe function for new CPC-USB devices 999 */ 1000static int ems_usb_probe(struct usb_interface *intf, 1001 const struct usb_device_id *id) 1002{ 1003 struct net_device *netdev; 1004 struct ems_usb *dev; 1005 int i, err = -ENOMEM; 1006 1007 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 1008 if (!netdev) { 1009 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 1010 return -ENOMEM; 1011 } 1012 1013 dev = netdev_priv(netdev); 1014 1015 dev->udev = interface_to_usbdev(intf); 1016 dev->netdev = netdev; 1017 1018 dev->can.state = CAN_STATE_STOPPED; 1019 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1020 dev->can.bittiming_const = &ems_usb_bittiming_const; 1021 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1022 dev->can.do_set_mode = ems_usb_set_mode; 1023 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1024 1025 netdev->netdev_ops = &ems_usb_netdev_ops; 1026 1027 netdev->flags |= IFF_ECHO; /* we support local echo */ 1028 1029 init_usb_anchor(&dev->rx_submitted); 1030 1031 init_usb_anchor(&dev->tx_submitted); 1032 atomic_set(&dev->active_tx_urbs, 0); 1033 1034 for (i = 0; i < MAX_TX_URBS; i++) 1035 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1036 1037 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1038 if (!dev->intr_urb) { 1039 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1040 goto cleanup_candev; 1041 } 1042 1043 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1044 if (!dev->intr_in_buffer) { 1045 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n"); 1046 goto cleanup_intr_urb; 1047 } 1048 1049 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1050 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1051 if (!dev->tx_msg_buffer) { 1052 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n"); 1053 goto cleanup_intr_in_buffer; 1054 } 1055 1056 usb_set_intfdata(intf, dev); 1057 1058 SET_NETDEV_DEV(netdev, &intf->dev); 1059 1060 init_params_sja1000(&dev->active_params); 1061 1062 err = ems_usb_command_msg(dev, &dev->active_params); 1063 if (err) { 1064 dev_err(netdev->dev.parent, 1065 "couldn't initialize controller: %d\n", err); 1066 goto cleanup_tx_msg_buffer; 1067 } 1068 1069 err = register_candev(netdev); 1070 if (err) { 1071 dev_err(netdev->dev.parent, 1072 "couldn't register CAN device: %d\n", err); 1073 goto cleanup_tx_msg_buffer; 1074 } 1075 1076 return 0; 1077 1078cleanup_tx_msg_buffer: 1079 kfree(dev->tx_msg_buffer); 1080 1081cleanup_intr_in_buffer: 1082 kfree(dev->intr_in_buffer); 1083 1084cleanup_intr_urb: 1085 usb_free_urb(dev->intr_urb); 1086 1087cleanup_candev: 1088 free_candev(netdev); 1089 1090 return err; 1091} 1092 1093/* 1094 * called by the usb core when the device is removed from the system 1095 */ 1096static void ems_usb_disconnect(struct usb_interface *intf) 1097{ 1098 struct ems_usb *dev = usb_get_intfdata(intf); 1099 1100 usb_set_intfdata(intf, NULL); 1101 1102 if (dev) { 1103 unregister_netdev(dev->netdev); 1104 free_candev(dev->netdev); 1105 1106 unlink_all_urbs(dev); 1107 1108 usb_free_urb(dev->intr_urb); 1109 1110 kfree(dev->intr_in_buffer); 1111 } 1112} 1113 1114/* usb specific object needed to register this driver with the usb subsystem */ 1115static struct usb_driver ems_usb_driver = { 1116 .name = "ems_usb", 1117 .probe = ems_usb_probe, 1118 .disconnect = ems_usb_disconnect, 1119 .id_table = ems_usb_table, 1120}; 1121 1122static int __init ems_usb_init(void) 1123{ 1124 int err; 1125 1126 printk(KERN_INFO "CPC-USB kernel driver loaded\n"); 1127 1128 /* register this driver with the USB subsystem */ 1129 err = usb_register(&ems_usb_driver); 1130 1131 if (err) { 1132 err("usb_register failed. Error number %d\n", err); 1133 return err; 1134 } 1135 1136 return 0; 1137} 1138 1139static void __exit ems_usb_exit(void) 1140{ 1141 /* deregister this driver with the USB subsystem */ 1142 usb_deregister(&ems_usb_driver); 1143} 1144 1145module_init(ems_usb_init); 1146module_exit(ems_usb_exit); 1147