1 /* 2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7 3 * 4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; version 2 of the License. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 #include <linux/signal.h> 20 #include <linux/slab.h> 21 #include <linux/module.h> 22 #include <linux/netdevice.h> 23 #include <linux/usb.h> 24 25 #include <linux/can.h> 26 #include <linux/can/dev.h> 27 #include <linux/can/error.h> 28 29 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 30 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 31 MODULE_LICENSE("GPL v2"); 32 33 /* Control-Values for CPC_Control() Command Subject Selection */ 34 #define CONTR_CAN_MESSAGE 0x04 35 #define CONTR_CAN_STATE 0x0C 36 #define CONTR_BUS_ERROR 0x1C 37 38 /* Control Command Actions */ 39 #define CONTR_CONT_OFF 0 40 #define CONTR_CONT_ON 1 41 #define CONTR_ONCE 2 42 43 /* Messages from CPC to PC */ 44 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */ 45 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */ 46 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */ 47 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */ 48 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */ 49 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */ 50 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */ 51 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */ 52 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */ 53 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */ 54 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */ 55 56 /* Messages from the PC to the CPC interface */ 57 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */ 58 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */ 59 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */ 60 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */ 61 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */ 62 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */ 63 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */ 64 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */ 65 66 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */ 67 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */ 68 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */ 69 70 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 71 72 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 73 74 /* Overrun types */ 75 #define CPC_OVR_EVENT_CAN 0x01 76 #define CPC_OVR_EVENT_CANSTATE 0x02 77 #define CPC_OVR_EVENT_BUSERROR 0x04 78 79 /* 80 * If the CAN controller lost a message we indicate it with the highest bit 81 * set in the count field. 82 */ 83 #define CPC_OVR_HW 0x80 84 85 /* Size of the "struct ems_cpc_msg" without the union */ 86 #define CPC_MSG_HEADER_LEN 11 87 #define CPC_CAN_MSG_MIN_SIZE 5 88 89 /* Define these values to match your devices */ 90 #define USB_CPCUSB_VENDOR_ID 0x12D6 91 92 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 93 94 /* Mode register NXP LPC2119/SJA1000 CAN Controller */ 95 #define SJA1000_MOD_NORMAL 0x00 96 #define SJA1000_MOD_RM 0x01 97 98 /* ECC register NXP LPC2119/SJA1000 CAN Controller */ 99 #define SJA1000_ECC_SEG 0x1F 100 #define SJA1000_ECC_DIR 0x20 101 #define SJA1000_ECC_ERR 0x06 102 #define SJA1000_ECC_BIT 0x00 103 #define SJA1000_ECC_FORM 0x40 104 #define SJA1000_ECC_STUFF 0x80 105 #define SJA1000_ECC_MASK 0xc0 106 107 /* Status register content */ 108 #define SJA1000_SR_BS 0x80 109 #define SJA1000_SR_ES 0x40 110 111 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 112 113 /* 114 * The device actually uses a 16MHz clock to generate the CAN clock 115 * but it expects SJA1000 bit settings based on 8MHz (is internally 116 * converted). 117 */ 118 #define EMS_USB_ARM7_CLOCK 8000000 119 120 /* 121 * CAN-Message representation in a CPC_MSG. Message object type is 122 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or 123 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME. 124 */ 125 struct cpc_can_msg { 126 __le32 id; 127 u8 length; 128 u8 msg[8]; 129 }; 130 131 /* Representation of the CAN parameters for the SJA1000 controller */ 132 struct cpc_sja1000_params { 133 u8 mode; 134 u8 acc_code0; 135 u8 acc_code1; 136 u8 acc_code2; 137 u8 acc_code3; 138 u8 acc_mask0; 139 u8 acc_mask1; 140 u8 acc_mask2; 141 u8 acc_mask3; 142 u8 btr0; 143 u8 btr1; 144 u8 outp_contr; 145 }; 146 147 /* CAN params message representation */ 148 struct cpc_can_params { 149 u8 cc_type; 150 151 /* Will support M16C CAN controller in the future */ 152 union { 153 struct cpc_sja1000_params sja1000; 154 } cc_params; 155 }; 156 157 /* Structure for confirmed message handling */ 158 struct cpc_confirm { 159 u8 error; /* error code */ 160 }; 161 162 /* Structure for overrun conditions */ 163 struct cpc_overrun { 164 u8 event; 165 u8 count; 166 }; 167 168 /* SJA1000 CAN errors (compatible to NXP LPC2119) */ 169 struct cpc_sja1000_can_error { 170 u8 ecc; 171 u8 rxerr; 172 u8 txerr; 173 }; 174 175 /* structure for CAN error conditions */ 176 struct cpc_can_error { 177 u8 ecode; 178 179 struct { 180 u8 cc_type; 181 182 /* Other controllers may also provide error code capture regs */ 183 union { 184 struct cpc_sja1000_can_error sja1000; 185 } regs; 186 } cc; 187 }; 188 189 /* 190 * Structure containing RX/TX error counter. This structure is used to request 191 * the values of the CAN controllers TX and RX error counter. 192 */ 193 struct cpc_can_err_counter { 194 u8 rx; 195 u8 tx; 196 }; 197 198 /* Main message type used between library and application */ 199 struct __packed ems_cpc_msg { 200 u8 type; /* type of message */ 201 u8 length; /* length of data within union 'msg' */ 202 u8 msgid; /* confirmation handle */ 203 __le32 ts_sec; /* timestamp in seconds */ 204 __le32 ts_nsec; /* timestamp in nano seconds */ 205 206 union { 207 u8 generic[64]; 208 struct cpc_can_msg can_msg; 209 struct cpc_can_params can_params; 210 struct cpc_confirm confirmation; 211 struct cpc_overrun overrun; 212 struct cpc_can_error error; 213 struct cpc_can_err_counter err_counter; 214 u8 can_state; 215 } msg; 216 }; 217 218 /* 219 * Table of devices that work with this driver 220 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 221 */ 222 static struct usb_device_id ems_usb_table[] = { 223 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 224 {} /* Terminating entry */ 225 }; 226 227 MODULE_DEVICE_TABLE(usb, ems_usb_table); 228 229 #define RX_BUFFER_SIZE 64 230 #define CPC_HEADER_SIZE 4 231 #define INTR_IN_BUFFER_SIZE 4 232 233 #define MAX_RX_URBS 10 234 #define MAX_TX_URBS 10 235 236 struct ems_usb; 237 238 struct ems_tx_urb_context { 239 struct ems_usb *dev; 240 241 u32 echo_index; 242 u8 dlc; 243 }; 244 245 struct ems_usb { 246 struct can_priv can; /* must be the first member */ 247 248 struct sk_buff *echo_skb[MAX_TX_URBS]; 249 250 struct usb_device *udev; 251 struct net_device *netdev; 252 253 atomic_t active_tx_urbs; 254 struct usb_anchor tx_submitted; 255 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 256 257 struct usb_anchor rx_submitted; 258 259 struct urb *intr_urb; 260 261 u8 *tx_msg_buffer; 262 263 u8 *intr_in_buffer; 264 unsigned int free_slots; /* remember number of available slots */ 265 266 struct ems_cpc_msg active_params; /* active controller parameters */ 267 }; 268 269 static void ems_usb_read_interrupt_callback(struct urb *urb) 270 { 271 struct ems_usb *dev = urb->context; 272 struct net_device *netdev = dev->netdev; 273 int err; 274 275 if (!netif_device_present(netdev)) 276 return; 277 278 switch (urb->status) { 279 case 0: 280 dev->free_slots = dev->intr_in_buffer[1]; 281 break; 282 283 case -ECONNRESET: /* unlink */ 284 case -ENOENT: 285 case -ESHUTDOWN: 286 return; 287 288 default: 289 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 290 break; 291 } 292 293 err = usb_submit_urb(urb, GFP_ATOMIC); 294 295 if (err == -ENODEV) 296 netif_device_detach(netdev); 297 else if (err) 298 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 299 } 300 301 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 302 { 303 struct can_frame *cf; 304 struct sk_buff *skb; 305 int i; 306 struct net_device_stats *stats = &dev->netdev->stats; 307 308 skb = alloc_can_skb(dev->netdev, &cf); 309 if (skb == NULL) 310 return; 311 312 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 313 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 314 315 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 316 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 317 cf->can_id |= CAN_EFF_FLAG; 318 319 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 320 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 321 cf->can_id |= CAN_RTR_FLAG; 322 } else { 323 for (i = 0; i < cf->can_dlc; i++) 324 cf->data[i] = msg->msg.can_msg.msg[i]; 325 } 326 327 stats->rx_packets++; 328 stats->rx_bytes += cf->can_dlc; 329 netif_rx(skb); 330 } 331 332 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 333 { 334 struct can_frame *cf; 335 struct sk_buff *skb; 336 struct net_device_stats *stats = &dev->netdev->stats; 337 338 skb = alloc_can_err_skb(dev->netdev, &cf); 339 if (skb == NULL) 340 return; 341 342 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 343 u8 state = msg->msg.can_state; 344 345 if (state & SJA1000_SR_BS) { 346 dev->can.state = CAN_STATE_BUS_OFF; 347 cf->can_id |= CAN_ERR_BUSOFF; 348 349 dev->can.can_stats.bus_off++; 350 can_bus_off(dev->netdev); 351 } else if (state & SJA1000_SR_ES) { 352 dev->can.state = CAN_STATE_ERROR_WARNING; 353 dev->can.can_stats.error_warning++; 354 } else { 355 dev->can.state = CAN_STATE_ERROR_ACTIVE; 356 dev->can.can_stats.error_passive++; 357 } 358 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 359 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 360 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 361 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 362 363 /* bus error interrupt */ 364 dev->can.can_stats.bus_error++; 365 stats->rx_errors++; 366 367 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 368 369 switch (ecc & SJA1000_ECC_MASK) { 370 case SJA1000_ECC_BIT: 371 cf->data[2] |= CAN_ERR_PROT_BIT; 372 break; 373 case SJA1000_ECC_FORM: 374 cf->data[2] |= CAN_ERR_PROT_FORM; 375 break; 376 case SJA1000_ECC_STUFF: 377 cf->data[2] |= CAN_ERR_PROT_STUFF; 378 break; 379 default: 380 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 381 cf->data[3] = ecc & SJA1000_ECC_SEG; 382 break; 383 } 384 385 /* Error occurred during transmission? */ 386 if ((ecc & SJA1000_ECC_DIR) == 0) 387 cf->data[2] |= CAN_ERR_PROT_TX; 388 389 if (dev->can.state == CAN_STATE_ERROR_WARNING || 390 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 391 cf->data[1] = (txerr > rxerr) ? 392 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 393 } 394 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 395 cf->can_id |= CAN_ERR_CRTL; 396 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 397 398 stats->rx_over_errors++; 399 stats->rx_errors++; 400 } 401 402 stats->rx_packets++; 403 stats->rx_bytes += cf->can_dlc; 404 netif_rx(skb); 405 } 406 407 /* 408 * callback for bulk IN urb 409 */ 410 static void ems_usb_read_bulk_callback(struct urb *urb) 411 { 412 struct ems_usb *dev = urb->context; 413 struct net_device *netdev; 414 int retval; 415 416 netdev = dev->netdev; 417 418 if (!netif_device_present(netdev)) 419 return; 420 421 switch (urb->status) { 422 case 0: /* success */ 423 break; 424 425 case -ENOENT: 426 return; 427 428 default: 429 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 430 goto resubmit_urb; 431 } 432 433 if (urb->actual_length > CPC_HEADER_SIZE) { 434 struct ems_cpc_msg *msg; 435 u8 *ibuf = urb->transfer_buffer; 436 u8 msg_count, start; 437 438 msg_count = ibuf[0] & ~0x80; 439 440 start = CPC_HEADER_SIZE; 441 442 while (msg_count) { 443 msg = (struct ems_cpc_msg *)&ibuf[start]; 444 445 switch (msg->type) { 446 case CPC_MSG_TYPE_CAN_STATE: 447 /* Process CAN state changes */ 448 ems_usb_rx_err(dev, msg); 449 break; 450 451 case CPC_MSG_TYPE_CAN_FRAME: 452 case CPC_MSG_TYPE_EXT_CAN_FRAME: 453 case CPC_MSG_TYPE_RTR_FRAME: 454 case CPC_MSG_TYPE_EXT_RTR_FRAME: 455 ems_usb_rx_can_msg(dev, msg); 456 break; 457 458 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 459 /* Process errorframe */ 460 ems_usb_rx_err(dev, msg); 461 break; 462 463 case CPC_MSG_TYPE_OVERRUN: 464 /* Message lost while receiving */ 465 ems_usb_rx_err(dev, msg); 466 break; 467 } 468 469 start += CPC_MSG_HEADER_LEN + msg->length; 470 msg_count--; 471 472 if (start > urb->transfer_buffer_length) { 473 netdev_err(netdev, "format error\n"); 474 break; 475 } 476 } 477 } 478 479 resubmit_urb: 480 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 481 urb->transfer_buffer, RX_BUFFER_SIZE, 482 ems_usb_read_bulk_callback, dev); 483 484 retval = usb_submit_urb(urb, GFP_ATOMIC); 485 486 if (retval == -ENODEV) 487 netif_device_detach(netdev); 488 else if (retval) 489 netdev_err(netdev, 490 "failed resubmitting read bulk urb: %d\n", retval); 491 } 492 493 /* 494 * callback for bulk IN urb 495 */ 496 static void ems_usb_write_bulk_callback(struct urb *urb) 497 { 498 struct ems_tx_urb_context *context = urb->context; 499 struct ems_usb *dev; 500 struct net_device *netdev; 501 502 BUG_ON(!context); 503 504 dev = context->dev; 505 netdev = dev->netdev; 506 507 /* free up our allocated buffer */ 508 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 509 urb->transfer_buffer, urb->transfer_dma); 510 511 atomic_dec(&dev->active_tx_urbs); 512 513 if (!netif_device_present(netdev)) 514 return; 515 516 if (urb->status) 517 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 518 519 netdev->trans_start = jiffies; 520 521 /* transmission complete interrupt */ 522 netdev->stats.tx_packets++; 523 netdev->stats.tx_bytes += context->dlc; 524 525 can_get_echo_skb(netdev, context->echo_index); 526 527 /* Release context */ 528 context->echo_index = MAX_TX_URBS; 529 530 if (netif_queue_stopped(netdev)) 531 netif_wake_queue(netdev); 532 } 533 534 /* 535 * Send the given CPC command synchronously 536 */ 537 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 538 { 539 int actual_length; 540 541 /* Copy payload */ 542 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 543 msg->length + CPC_MSG_HEADER_LEN); 544 545 /* Clear header */ 546 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 547 548 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 549 &dev->tx_msg_buffer[0], 550 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 551 &actual_length, 1000); 552 } 553 554 /* 555 * Change CAN controllers' mode register 556 */ 557 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 558 { 559 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 560 561 return ems_usb_command_msg(dev, &dev->active_params); 562 } 563 564 /* 565 * Send a CPC_Control command to change behaviour when interface receives a CAN 566 * message, bus error or CAN state changed notifications. 567 */ 568 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 569 { 570 struct ems_cpc_msg cmd; 571 572 cmd.type = CPC_CMD_TYPE_CONTROL; 573 cmd.length = CPC_MSG_HEADER_LEN + 1; 574 575 cmd.msgid = 0; 576 577 cmd.msg.generic[0] = val; 578 579 return ems_usb_command_msg(dev, &cmd); 580 } 581 582 /* 583 * Start interface 584 */ 585 static int ems_usb_start(struct ems_usb *dev) 586 { 587 struct net_device *netdev = dev->netdev; 588 int err, i; 589 590 dev->intr_in_buffer[0] = 0; 591 dev->free_slots = 15; /* initial size */ 592 593 for (i = 0; i < MAX_RX_URBS; i++) { 594 struct urb *urb = NULL; 595 u8 *buf = NULL; 596 597 /* create a URB, and a buffer for it */ 598 urb = usb_alloc_urb(0, GFP_KERNEL); 599 if (!urb) { 600 netdev_err(netdev, "No memory left for URBs\n"); 601 err = -ENOMEM; 602 break; 603 } 604 605 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 606 &urb->transfer_dma); 607 if (!buf) { 608 netdev_err(netdev, "No memory left for USB buffer\n"); 609 usb_free_urb(urb); 610 err = -ENOMEM; 611 break; 612 } 613 614 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 615 buf, RX_BUFFER_SIZE, 616 ems_usb_read_bulk_callback, dev); 617 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 618 usb_anchor_urb(urb, &dev->rx_submitted); 619 620 err = usb_submit_urb(urb, GFP_KERNEL); 621 if (err) { 622 usb_unanchor_urb(urb); 623 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 624 urb->transfer_dma); 625 usb_free_urb(urb); 626 break; 627 } 628 629 /* Drop reference, USB core will take care of freeing it */ 630 usb_free_urb(urb); 631 } 632 633 /* Did we submit any URBs */ 634 if (i == 0) { 635 netdev_warn(netdev, "couldn't setup read URBs\n"); 636 return err; 637 } 638 639 /* Warn if we've couldn't transmit all the URBs */ 640 if (i < MAX_RX_URBS) 641 netdev_warn(netdev, "rx performance may be slow\n"); 642 643 /* Setup and start interrupt URB */ 644 usb_fill_int_urb(dev->intr_urb, dev->udev, 645 usb_rcvintpipe(dev->udev, 1), 646 dev->intr_in_buffer, 647 INTR_IN_BUFFER_SIZE, 648 ems_usb_read_interrupt_callback, dev, 1); 649 650 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 651 if (err) { 652 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 653 654 return err; 655 } 656 657 /* CPC-USB will transfer received message to host */ 658 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 659 if (err) 660 goto failed; 661 662 /* CPC-USB will transfer CAN state changes to host */ 663 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 664 if (err) 665 goto failed; 666 667 /* CPC-USB will transfer bus errors to host */ 668 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 669 if (err) 670 goto failed; 671 672 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 673 if (err) 674 goto failed; 675 676 dev->can.state = CAN_STATE_ERROR_ACTIVE; 677 678 return 0; 679 680 failed: 681 netdev_warn(netdev, "couldn't submit control: %d\n", err); 682 683 return err; 684 } 685 686 static void unlink_all_urbs(struct ems_usb *dev) 687 { 688 int i; 689 690 usb_unlink_urb(dev->intr_urb); 691 692 usb_kill_anchored_urbs(&dev->rx_submitted); 693 694 usb_kill_anchored_urbs(&dev->tx_submitted); 695 atomic_set(&dev->active_tx_urbs, 0); 696 697 for (i = 0; i < MAX_TX_URBS; i++) 698 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 699 } 700 701 static int ems_usb_open(struct net_device *netdev) 702 { 703 struct ems_usb *dev = netdev_priv(netdev); 704 int err; 705 706 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 707 if (err) 708 return err; 709 710 /* common open */ 711 err = open_candev(netdev); 712 if (err) 713 return err; 714 715 /* finally start device */ 716 err = ems_usb_start(dev); 717 if (err) { 718 if (err == -ENODEV) 719 netif_device_detach(dev->netdev); 720 721 netdev_warn(netdev, "couldn't start device: %d\n", err); 722 723 close_candev(netdev); 724 725 return err; 726 } 727 728 729 netif_start_queue(netdev); 730 731 return 0; 732 } 733 734 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 735 { 736 struct ems_usb *dev = netdev_priv(netdev); 737 struct ems_tx_urb_context *context = NULL; 738 struct net_device_stats *stats = &netdev->stats; 739 struct can_frame *cf = (struct can_frame *)skb->data; 740 struct ems_cpc_msg *msg; 741 struct urb *urb; 742 u8 *buf; 743 int i, err; 744 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 745 + sizeof(struct cpc_can_msg); 746 747 if (can_dropped_invalid_skb(netdev, skb)) 748 return NETDEV_TX_OK; 749 750 /* create a URB, and a buffer for it, and copy the data to the URB */ 751 urb = usb_alloc_urb(0, GFP_ATOMIC); 752 if (!urb) { 753 netdev_err(netdev, "No memory left for URBs\n"); 754 goto nomem; 755 } 756 757 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 758 if (!buf) { 759 netdev_err(netdev, "No memory left for USB buffer\n"); 760 usb_free_urb(urb); 761 goto nomem; 762 } 763 764 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 765 766 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 767 msg->msg.can_msg.length = cf->can_dlc; 768 769 if (cf->can_id & CAN_RTR_FLAG) { 770 msg->type = cf->can_id & CAN_EFF_FLAG ? 771 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 772 773 msg->length = CPC_CAN_MSG_MIN_SIZE; 774 } else { 775 msg->type = cf->can_id & CAN_EFF_FLAG ? 776 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 777 778 for (i = 0; i < cf->can_dlc; i++) 779 msg->msg.can_msg.msg[i] = cf->data[i]; 780 781 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 782 } 783 784 for (i = 0; i < MAX_TX_URBS; i++) { 785 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 786 context = &dev->tx_contexts[i]; 787 break; 788 } 789 } 790 791 /* 792 * May never happen! When this happens we'd more URBs in flight as 793 * allowed (MAX_TX_URBS). 794 */ 795 if (!context) { 796 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 797 usb_free_urb(urb); 798 799 netdev_warn(netdev, "couldn't find free context\n"); 800 801 return NETDEV_TX_BUSY; 802 } 803 804 context->dev = dev; 805 context->echo_index = i; 806 context->dlc = cf->can_dlc; 807 808 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 809 size, ems_usb_write_bulk_callback, context); 810 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 811 usb_anchor_urb(urb, &dev->tx_submitted); 812 813 can_put_echo_skb(skb, netdev, context->echo_index); 814 815 atomic_inc(&dev->active_tx_urbs); 816 817 err = usb_submit_urb(urb, GFP_ATOMIC); 818 if (unlikely(err)) { 819 can_free_echo_skb(netdev, context->echo_index); 820 821 usb_unanchor_urb(urb); 822 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 823 dev_kfree_skb(skb); 824 825 atomic_dec(&dev->active_tx_urbs); 826 827 if (err == -ENODEV) { 828 netif_device_detach(netdev); 829 } else { 830 netdev_warn(netdev, "failed tx_urb %d\n", err); 831 832 stats->tx_dropped++; 833 } 834 } else { 835 netdev->trans_start = jiffies; 836 837 /* Slow down tx path */ 838 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 839 dev->free_slots < 5) { 840 netif_stop_queue(netdev); 841 } 842 } 843 844 /* 845 * Release our reference to this URB, the USB core will eventually free 846 * it entirely. 847 */ 848 usb_free_urb(urb); 849 850 return NETDEV_TX_OK; 851 852 nomem: 853 dev_kfree_skb(skb); 854 stats->tx_dropped++; 855 856 return NETDEV_TX_OK; 857 } 858 859 static int ems_usb_close(struct net_device *netdev) 860 { 861 struct ems_usb *dev = netdev_priv(netdev); 862 863 /* Stop polling */ 864 unlink_all_urbs(dev); 865 866 netif_stop_queue(netdev); 867 868 /* Set CAN controller to reset mode */ 869 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 870 netdev_warn(netdev, "couldn't stop device"); 871 872 close_candev(netdev); 873 874 return 0; 875 } 876 877 static const struct net_device_ops ems_usb_netdev_ops = { 878 .ndo_open = ems_usb_open, 879 .ndo_stop = ems_usb_close, 880 .ndo_start_xmit = ems_usb_start_xmit, 881 .ndo_change_mtu = can_change_mtu, 882 }; 883 884 static const struct can_bittiming_const ems_usb_bittiming_const = { 885 .name = "ems_usb", 886 .tseg1_min = 1, 887 .tseg1_max = 16, 888 .tseg2_min = 1, 889 .tseg2_max = 8, 890 .sjw_max = 4, 891 .brp_min = 1, 892 .brp_max = 64, 893 .brp_inc = 1, 894 }; 895 896 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 897 { 898 struct ems_usb *dev = netdev_priv(netdev); 899 900 switch (mode) { 901 case CAN_MODE_START: 902 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 903 netdev_warn(netdev, "couldn't start device"); 904 905 if (netif_queue_stopped(netdev)) 906 netif_wake_queue(netdev); 907 break; 908 909 default: 910 return -EOPNOTSUPP; 911 } 912 913 return 0; 914 } 915 916 static int ems_usb_set_bittiming(struct net_device *netdev) 917 { 918 struct ems_usb *dev = netdev_priv(netdev); 919 struct can_bittiming *bt = &dev->can.bittiming; 920 u8 btr0, btr1; 921 922 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 923 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 924 (((bt->phase_seg2 - 1) & 0x7) << 4); 925 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 926 btr1 |= 0x80; 927 928 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 929 930 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 931 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 932 933 return ems_usb_command_msg(dev, &dev->active_params); 934 } 935 936 static void init_params_sja1000(struct ems_cpc_msg *msg) 937 { 938 struct cpc_sja1000_params *sja1000 = 939 &msg->msg.can_params.cc_params.sja1000; 940 941 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 942 msg->length = sizeof(struct cpc_can_params); 943 msg->msgid = 0; 944 945 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 946 947 /* Acceptance filter open */ 948 sja1000->acc_code0 = 0x00; 949 sja1000->acc_code1 = 0x00; 950 sja1000->acc_code2 = 0x00; 951 sja1000->acc_code3 = 0x00; 952 953 /* Acceptance filter open */ 954 sja1000->acc_mask0 = 0xFF; 955 sja1000->acc_mask1 = 0xFF; 956 sja1000->acc_mask2 = 0xFF; 957 sja1000->acc_mask3 = 0xFF; 958 959 sja1000->btr0 = 0; 960 sja1000->btr1 = 0; 961 962 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 963 sja1000->mode = SJA1000_MOD_RM; 964 } 965 966 /* 967 * probe function for new CPC-USB devices 968 */ 969 static int ems_usb_probe(struct usb_interface *intf, 970 const struct usb_device_id *id) 971 { 972 struct net_device *netdev; 973 struct ems_usb *dev; 974 int i, err = -ENOMEM; 975 976 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 977 if (!netdev) { 978 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 979 return -ENOMEM; 980 } 981 982 dev = netdev_priv(netdev); 983 984 dev->udev = interface_to_usbdev(intf); 985 dev->netdev = netdev; 986 987 dev->can.state = CAN_STATE_STOPPED; 988 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 989 dev->can.bittiming_const = &ems_usb_bittiming_const; 990 dev->can.do_set_bittiming = ems_usb_set_bittiming; 991 dev->can.do_set_mode = ems_usb_set_mode; 992 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 993 994 netdev->netdev_ops = &ems_usb_netdev_ops; 995 996 netdev->flags |= IFF_ECHO; /* we support local echo */ 997 998 init_usb_anchor(&dev->rx_submitted); 999 1000 init_usb_anchor(&dev->tx_submitted); 1001 atomic_set(&dev->active_tx_urbs, 0); 1002 1003 for (i = 0; i < MAX_TX_URBS; i++) 1004 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1005 1006 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1007 if (!dev->intr_urb) { 1008 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1009 goto cleanup_candev; 1010 } 1011 1012 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1013 if (!dev->intr_in_buffer) 1014 goto cleanup_intr_urb; 1015 1016 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1017 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1018 if (!dev->tx_msg_buffer) 1019 goto cleanup_intr_in_buffer; 1020 1021 usb_set_intfdata(intf, dev); 1022 1023 SET_NETDEV_DEV(netdev, &intf->dev); 1024 1025 init_params_sja1000(&dev->active_params); 1026 1027 err = ems_usb_command_msg(dev, &dev->active_params); 1028 if (err) { 1029 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1030 goto cleanup_tx_msg_buffer; 1031 } 1032 1033 err = register_candev(netdev); 1034 if (err) { 1035 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1036 goto cleanup_tx_msg_buffer; 1037 } 1038 1039 return 0; 1040 1041 cleanup_tx_msg_buffer: 1042 kfree(dev->tx_msg_buffer); 1043 1044 cleanup_intr_in_buffer: 1045 kfree(dev->intr_in_buffer); 1046 1047 cleanup_intr_urb: 1048 usb_free_urb(dev->intr_urb); 1049 1050 cleanup_candev: 1051 free_candev(netdev); 1052 1053 return err; 1054 } 1055 1056 /* 1057 * called by the usb core when the device is removed from the system 1058 */ 1059 static void ems_usb_disconnect(struct usb_interface *intf) 1060 { 1061 struct ems_usb *dev = usb_get_intfdata(intf); 1062 1063 usb_set_intfdata(intf, NULL); 1064 1065 if (dev) { 1066 unregister_netdev(dev->netdev); 1067 free_candev(dev->netdev); 1068 1069 unlink_all_urbs(dev); 1070 1071 usb_free_urb(dev->intr_urb); 1072 1073 kfree(dev->intr_in_buffer); 1074 } 1075 } 1076 1077 /* usb specific object needed to register this driver with the usb subsystem */ 1078 static struct usb_driver ems_usb_driver = { 1079 .name = "ems_usb", 1080 .probe = ems_usb_probe, 1081 .disconnect = ems_usb_disconnect, 1082 .id_table = ems_usb_table, 1083 }; 1084 1085 module_usb_driver(ems_usb_driver); 1086