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 u32 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 u32 ts_sec; /* timestamp in seconds */ 204 u32 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 netif_rx(skb); 328 329 stats->rx_packets++; 330 stats->rx_bytes += cf->can_dlc; 331 } 332 333 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 334 { 335 struct can_frame *cf; 336 struct sk_buff *skb; 337 struct net_device_stats *stats = &dev->netdev->stats; 338 339 skb = alloc_can_err_skb(dev->netdev, &cf); 340 if (skb == NULL) 341 return; 342 343 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 344 u8 state = msg->msg.can_state; 345 346 if (state & SJA1000_SR_BS) { 347 dev->can.state = CAN_STATE_BUS_OFF; 348 cf->can_id |= CAN_ERR_BUSOFF; 349 350 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 netif_rx(skb); 403 404 stats->rx_packets++; 405 stats->rx_bytes += cf->can_dlc; 406 } 407 408 /* 409 * callback for bulk IN urb 410 */ 411 static void ems_usb_read_bulk_callback(struct urb *urb) 412 { 413 struct ems_usb *dev = urb->context; 414 struct net_device *netdev; 415 int retval; 416 417 netdev = dev->netdev; 418 419 if (!netif_device_present(netdev)) 420 return; 421 422 switch (urb->status) { 423 case 0: /* success */ 424 break; 425 426 case -ENOENT: 427 return; 428 429 default: 430 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 431 goto resubmit_urb; 432 } 433 434 if (urb->actual_length > CPC_HEADER_SIZE) { 435 struct ems_cpc_msg *msg; 436 u8 *ibuf = urb->transfer_buffer; 437 u8 msg_count, again, start; 438 439 msg_count = ibuf[0] & ~0x80; 440 again = ibuf[0] & 0x80; 441 442 start = CPC_HEADER_SIZE; 443 444 while (msg_count) { 445 msg = (struct ems_cpc_msg *)&ibuf[start]; 446 447 switch (msg->type) { 448 case CPC_MSG_TYPE_CAN_STATE: 449 /* Process CAN state changes */ 450 ems_usb_rx_err(dev, msg); 451 break; 452 453 case CPC_MSG_TYPE_CAN_FRAME: 454 case CPC_MSG_TYPE_EXT_CAN_FRAME: 455 case CPC_MSG_TYPE_RTR_FRAME: 456 case CPC_MSG_TYPE_EXT_RTR_FRAME: 457 ems_usb_rx_can_msg(dev, msg); 458 break; 459 460 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 461 /* Process errorframe */ 462 ems_usb_rx_err(dev, msg); 463 break; 464 465 case CPC_MSG_TYPE_OVERRUN: 466 /* Message lost while receiving */ 467 ems_usb_rx_err(dev, msg); 468 break; 469 } 470 471 start += CPC_MSG_HEADER_LEN + msg->length; 472 msg_count--; 473 474 if (start > urb->transfer_buffer_length) { 475 netdev_err(netdev, "format error\n"); 476 break; 477 } 478 } 479 } 480 481 resubmit_urb: 482 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 483 urb->transfer_buffer, RX_BUFFER_SIZE, 484 ems_usb_read_bulk_callback, dev); 485 486 retval = usb_submit_urb(urb, GFP_ATOMIC); 487 488 if (retval == -ENODEV) 489 netif_device_detach(netdev); 490 else if (retval) 491 netdev_err(netdev, 492 "failed resubmitting read bulk urb: %d\n", retval); 493 } 494 495 /* 496 * callback for bulk IN urb 497 */ 498 static void ems_usb_write_bulk_callback(struct urb *urb) 499 { 500 struct ems_tx_urb_context *context = urb->context; 501 struct ems_usb *dev; 502 struct net_device *netdev; 503 504 BUG_ON(!context); 505 506 dev = context->dev; 507 netdev = dev->netdev; 508 509 /* free up our allocated buffer */ 510 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 511 urb->transfer_buffer, urb->transfer_dma); 512 513 atomic_dec(&dev->active_tx_urbs); 514 515 if (!netif_device_present(netdev)) 516 return; 517 518 if (urb->status) 519 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 520 521 netdev->trans_start = jiffies; 522 523 /* transmission complete interrupt */ 524 netdev->stats.tx_packets++; 525 netdev->stats.tx_bytes += context->dlc; 526 527 can_get_echo_skb(netdev, context->echo_index); 528 529 /* Release context */ 530 context->echo_index = MAX_TX_URBS; 531 532 if (netif_queue_stopped(netdev)) 533 netif_wake_queue(netdev); 534 } 535 536 /* 537 * Send the given CPC command synchronously 538 */ 539 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 540 { 541 int actual_length; 542 543 /* Copy payload */ 544 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 545 msg->length + CPC_MSG_HEADER_LEN); 546 547 /* Clear header */ 548 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 549 550 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 551 &dev->tx_msg_buffer[0], 552 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 553 &actual_length, 1000); 554 } 555 556 /* 557 * Change CAN controllers' mode register 558 */ 559 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 560 { 561 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 562 563 return ems_usb_command_msg(dev, &dev->active_params); 564 } 565 566 /* 567 * Send a CPC_Control command to change behaviour when interface receives a CAN 568 * message, bus error or CAN state changed notifications. 569 */ 570 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 571 { 572 struct ems_cpc_msg cmd; 573 574 cmd.type = CPC_CMD_TYPE_CONTROL; 575 cmd.length = CPC_MSG_HEADER_LEN + 1; 576 577 cmd.msgid = 0; 578 579 cmd.msg.generic[0] = val; 580 581 return ems_usb_command_msg(dev, &cmd); 582 } 583 584 /* 585 * Start interface 586 */ 587 static int ems_usb_start(struct ems_usb *dev) 588 { 589 struct net_device *netdev = dev->netdev; 590 int err, i; 591 592 dev->intr_in_buffer[0] = 0; 593 dev->free_slots = 15; /* initial size */ 594 595 for (i = 0; i < MAX_RX_URBS; i++) { 596 struct urb *urb = NULL; 597 u8 *buf = NULL; 598 599 /* create a URB, and a buffer for it */ 600 urb = usb_alloc_urb(0, GFP_KERNEL); 601 if (!urb) { 602 netdev_err(netdev, "No memory left for URBs\n"); 603 err = -ENOMEM; 604 break; 605 } 606 607 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 608 &urb->transfer_dma); 609 if (!buf) { 610 netdev_err(netdev, "No memory left for USB buffer\n"); 611 usb_free_urb(urb); 612 err = -ENOMEM; 613 break; 614 } 615 616 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 617 buf, RX_BUFFER_SIZE, 618 ems_usb_read_bulk_callback, dev); 619 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 620 usb_anchor_urb(urb, &dev->rx_submitted); 621 622 err = usb_submit_urb(urb, GFP_KERNEL); 623 if (err) { 624 usb_unanchor_urb(urb); 625 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 626 urb->transfer_dma); 627 usb_free_urb(urb); 628 break; 629 } 630 631 /* Drop reference, USB core will take care of freeing it */ 632 usb_free_urb(urb); 633 } 634 635 /* Did we submit any URBs */ 636 if (i == 0) { 637 netdev_warn(netdev, "couldn't setup read URBs\n"); 638 return err; 639 } 640 641 /* Warn if we've couldn't transmit all the URBs */ 642 if (i < MAX_RX_URBS) 643 netdev_warn(netdev, "rx performance may be slow\n"); 644 645 /* Setup and start interrupt URB */ 646 usb_fill_int_urb(dev->intr_urb, dev->udev, 647 usb_rcvintpipe(dev->udev, 1), 648 dev->intr_in_buffer, 649 INTR_IN_BUFFER_SIZE, 650 ems_usb_read_interrupt_callback, dev, 1); 651 652 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 653 if (err) { 654 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 655 656 return err; 657 } 658 659 /* CPC-USB will transfer received message to host */ 660 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 661 if (err) 662 goto failed; 663 664 /* CPC-USB will transfer CAN state changes to host */ 665 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 666 if (err) 667 goto failed; 668 669 /* CPC-USB will transfer bus errors to host */ 670 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 671 if (err) 672 goto failed; 673 674 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 675 if (err) 676 goto failed; 677 678 dev->can.state = CAN_STATE_ERROR_ACTIVE; 679 680 return 0; 681 682 failed: 683 netdev_warn(netdev, "couldn't submit control: %d\n", err); 684 685 return err; 686 } 687 688 static void unlink_all_urbs(struct ems_usb *dev) 689 { 690 int i; 691 692 usb_unlink_urb(dev->intr_urb); 693 694 usb_kill_anchored_urbs(&dev->rx_submitted); 695 696 usb_kill_anchored_urbs(&dev->tx_submitted); 697 atomic_set(&dev->active_tx_urbs, 0); 698 699 for (i = 0; i < MAX_TX_URBS; i++) 700 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 701 } 702 703 static int ems_usb_open(struct net_device *netdev) 704 { 705 struct ems_usb *dev = netdev_priv(netdev); 706 int err; 707 708 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 709 if (err) 710 return err; 711 712 /* common open */ 713 err = open_candev(netdev); 714 if (err) 715 return err; 716 717 /* finally start device */ 718 err = ems_usb_start(dev); 719 if (err) { 720 if (err == -ENODEV) 721 netif_device_detach(dev->netdev); 722 723 netdev_warn(netdev, "couldn't start device: %d\n", err); 724 725 close_candev(netdev); 726 727 return err; 728 } 729 730 731 netif_start_queue(netdev); 732 733 return 0; 734 } 735 736 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 737 { 738 struct ems_usb *dev = netdev_priv(netdev); 739 struct ems_tx_urb_context *context = NULL; 740 struct net_device_stats *stats = &netdev->stats; 741 struct can_frame *cf = (struct can_frame *)skb->data; 742 struct ems_cpc_msg *msg; 743 struct urb *urb; 744 u8 *buf; 745 int i, err; 746 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 747 + sizeof(struct cpc_can_msg); 748 749 if (can_dropped_invalid_skb(netdev, skb)) 750 return NETDEV_TX_OK; 751 752 /* create a URB, and a buffer for it, and copy the data to the URB */ 753 urb = usb_alloc_urb(0, GFP_ATOMIC); 754 if (!urb) { 755 netdev_err(netdev, "No memory left for URBs\n"); 756 goto nomem; 757 } 758 759 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 760 if (!buf) { 761 netdev_err(netdev, "No memory left for USB buffer\n"); 762 usb_free_urb(urb); 763 goto nomem; 764 } 765 766 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 767 768 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 769 msg->msg.can_msg.length = cf->can_dlc; 770 771 if (cf->can_id & CAN_RTR_FLAG) { 772 msg->type = cf->can_id & CAN_EFF_FLAG ? 773 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 774 775 msg->length = CPC_CAN_MSG_MIN_SIZE; 776 } else { 777 msg->type = cf->can_id & CAN_EFF_FLAG ? 778 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 779 780 for (i = 0; i < cf->can_dlc; i++) 781 msg->msg.can_msg.msg[i] = cf->data[i]; 782 783 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 784 } 785 786 /* Respect byte order */ 787 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id); 788 789 for (i = 0; i < MAX_TX_URBS; i++) { 790 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 791 context = &dev->tx_contexts[i]; 792 break; 793 } 794 } 795 796 /* 797 * May never happen! When this happens we'd more URBs in flight as 798 * allowed (MAX_TX_URBS). 799 */ 800 if (!context) { 801 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 802 usb_free_urb(urb); 803 804 netdev_warn(netdev, "couldn't find free context\n"); 805 806 return NETDEV_TX_BUSY; 807 } 808 809 context->dev = dev; 810 context->echo_index = i; 811 context->dlc = cf->can_dlc; 812 813 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 814 size, ems_usb_write_bulk_callback, context); 815 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 816 usb_anchor_urb(urb, &dev->tx_submitted); 817 818 can_put_echo_skb(skb, netdev, context->echo_index); 819 820 atomic_inc(&dev->active_tx_urbs); 821 822 err = usb_submit_urb(urb, GFP_ATOMIC); 823 if (unlikely(err)) { 824 can_free_echo_skb(netdev, context->echo_index); 825 826 usb_unanchor_urb(urb); 827 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 828 dev_kfree_skb(skb); 829 830 atomic_dec(&dev->active_tx_urbs); 831 832 if (err == -ENODEV) { 833 netif_device_detach(netdev); 834 } else { 835 netdev_warn(netdev, "failed tx_urb %d\n", err); 836 837 stats->tx_dropped++; 838 } 839 } else { 840 netdev->trans_start = jiffies; 841 842 /* Slow down tx path */ 843 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 844 dev->free_slots < 5) { 845 netif_stop_queue(netdev); 846 } 847 } 848 849 /* 850 * Release our reference to this URB, the USB core will eventually free 851 * it entirely. 852 */ 853 usb_free_urb(urb); 854 855 return NETDEV_TX_OK; 856 857 nomem: 858 dev_kfree_skb(skb); 859 stats->tx_dropped++; 860 861 return NETDEV_TX_OK; 862 } 863 864 static int ems_usb_close(struct net_device *netdev) 865 { 866 struct ems_usb *dev = netdev_priv(netdev); 867 868 /* Stop polling */ 869 unlink_all_urbs(dev); 870 871 netif_stop_queue(netdev); 872 873 /* Set CAN controller to reset mode */ 874 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 875 netdev_warn(netdev, "couldn't stop device"); 876 877 close_candev(netdev); 878 879 return 0; 880 } 881 882 static const struct net_device_ops ems_usb_netdev_ops = { 883 .ndo_open = ems_usb_open, 884 .ndo_stop = ems_usb_close, 885 .ndo_start_xmit = ems_usb_start_xmit, 886 .ndo_change_mtu = can_change_mtu, 887 }; 888 889 static const struct can_bittiming_const ems_usb_bittiming_const = { 890 .name = "ems_usb", 891 .tseg1_min = 1, 892 .tseg1_max = 16, 893 .tseg2_min = 1, 894 .tseg2_max = 8, 895 .sjw_max = 4, 896 .brp_min = 1, 897 .brp_max = 64, 898 .brp_inc = 1, 899 }; 900 901 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 902 { 903 struct ems_usb *dev = netdev_priv(netdev); 904 905 switch (mode) { 906 case CAN_MODE_START: 907 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 908 netdev_warn(netdev, "couldn't start device"); 909 910 if (netif_queue_stopped(netdev)) 911 netif_wake_queue(netdev); 912 break; 913 914 default: 915 return -EOPNOTSUPP; 916 } 917 918 return 0; 919 } 920 921 static int ems_usb_set_bittiming(struct net_device *netdev) 922 { 923 struct ems_usb *dev = netdev_priv(netdev); 924 struct can_bittiming *bt = &dev->can.bittiming; 925 u8 btr0, btr1; 926 927 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 928 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 929 (((bt->phase_seg2 - 1) & 0x7) << 4); 930 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 931 btr1 |= 0x80; 932 933 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 934 935 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 936 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 937 938 return ems_usb_command_msg(dev, &dev->active_params); 939 } 940 941 static void init_params_sja1000(struct ems_cpc_msg *msg) 942 { 943 struct cpc_sja1000_params *sja1000 = 944 &msg->msg.can_params.cc_params.sja1000; 945 946 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 947 msg->length = sizeof(struct cpc_can_params); 948 msg->msgid = 0; 949 950 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 951 952 /* Acceptance filter open */ 953 sja1000->acc_code0 = 0x00; 954 sja1000->acc_code1 = 0x00; 955 sja1000->acc_code2 = 0x00; 956 sja1000->acc_code3 = 0x00; 957 958 /* Acceptance filter open */ 959 sja1000->acc_mask0 = 0xFF; 960 sja1000->acc_mask1 = 0xFF; 961 sja1000->acc_mask2 = 0xFF; 962 sja1000->acc_mask3 = 0xFF; 963 964 sja1000->btr0 = 0; 965 sja1000->btr1 = 0; 966 967 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 968 sja1000->mode = SJA1000_MOD_RM; 969 } 970 971 /* 972 * probe function for new CPC-USB devices 973 */ 974 static int ems_usb_probe(struct usb_interface *intf, 975 const struct usb_device_id *id) 976 { 977 struct net_device *netdev; 978 struct ems_usb *dev; 979 int i, err = -ENOMEM; 980 981 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 982 if (!netdev) { 983 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 984 return -ENOMEM; 985 } 986 987 dev = netdev_priv(netdev); 988 989 dev->udev = interface_to_usbdev(intf); 990 dev->netdev = netdev; 991 992 dev->can.state = CAN_STATE_STOPPED; 993 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 994 dev->can.bittiming_const = &ems_usb_bittiming_const; 995 dev->can.do_set_bittiming = ems_usb_set_bittiming; 996 dev->can.do_set_mode = ems_usb_set_mode; 997 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 998 999 netdev->netdev_ops = &ems_usb_netdev_ops; 1000 1001 netdev->flags |= IFF_ECHO; /* we support local echo */ 1002 1003 init_usb_anchor(&dev->rx_submitted); 1004 1005 init_usb_anchor(&dev->tx_submitted); 1006 atomic_set(&dev->active_tx_urbs, 0); 1007 1008 for (i = 0; i < MAX_TX_URBS; i++) 1009 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1010 1011 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1012 if (!dev->intr_urb) { 1013 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1014 goto cleanup_candev; 1015 } 1016 1017 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1018 if (!dev->intr_in_buffer) 1019 goto cleanup_intr_urb; 1020 1021 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1022 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1023 if (!dev->tx_msg_buffer) 1024 goto cleanup_intr_in_buffer; 1025 1026 usb_set_intfdata(intf, dev); 1027 1028 SET_NETDEV_DEV(netdev, &intf->dev); 1029 1030 init_params_sja1000(&dev->active_params); 1031 1032 err = ems_usb_command_msg(dev, &dev->active_params); 1033 if (err) { 1034 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1035 goto cleanup_tx_msg_buffer; 1036 } 1037 1038 err = register_candev(netdev); 1039 if (err) { 1040 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1041 goto cleanup_tx_msg_buffer; 1042 } 1043 1044 return 0; 1045 1046 cleanup_tx_msg_buffer: 1047 kfree(dev->tx_msg_buffer); 1048 1049 cleanup_intr_in_buffer: 1050 kfree(dev->intr_in_buffer); 1051 1052 cleanup_intr_urb: 1053 usb_free_urb(dev->intr_urb); 1054 1055 cleanup_candev: 1056 free_candev(netdev); 1057 1058 return err; 1059 } 1060 1061 /* 1062 * called by the usb core when the device is removed from the system 1063 */ 1064 static void ems_usb_disconnect(struct usb_interface *intf) 1065 { 1066 struct ems_usb *dev = usb_get_intfdata(intf); 1067 1068 usb_set_intfdata(intf, NULL); 1069 1070 if (dev) { 1071 unregister_netdev(dev->netdev); 1072 free_candev(dev->netdev); 1073 1074 unlink_all_urbs(dev); 1075 1076 usb_free_urb(dev->intr_urb); 1077 1078 kfree(dev->intr_in_buffer); 1079 } 1080 } 1081 1082 /* usb specific object needed to register this driver with the usb subsystem */ 1083 static struct usb_driver ems_usb_driver = { 1084 .name = "ems_usb", 1085 .probe = ems_usb_probe, 1086 .disconnect = ems_usb_disconnect, 1087 .id_table = ems_usb_table, 1088 }; 1089 1090 module_usb_driver(ems_usb_driver); 1091