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[3] = ecc & SJA1000_ECC_SEG; 381 break; 382 } 383 384 /* Error occurred during transmission? */ 385 if ((ecc & SJA1000_ECC_DIR) == 0) 386 cf->data[2] |= CAN_ERR_PROT_TX; 387 388 if (dev->can.state == CAN_STATE_ERROR_WARNING || 389 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 390 cf->data[1] = (txerr > rxerr) ? 391 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 392 } 393 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 394 cf->can_id |= CAN_ERR_CRTL; 395 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 396 397 stats->rx_over_errors++; 398 stats->rx_errors++; 399 } 400 401 stats->rx_packets++; 402 stats->rx_bytes += cf->can_dlc; 403 netif_rx(skb); 404 } 405 406 /* 407 * callback for bulk IN urb 408 */ 409 static void ems_usb_read_bulk_callback(struct urb *urb) 410 { 411 struct ems_usb *dev = urb->context; 412 struct net_device *netdev; 413 int retval; 414 415 netdev = dev->netdev; 416 417 if (!netif_device_present(netdev)) 418 return; 419 420 switch (urb->status) { 421 case 0: /* success */ 422 break; 423 424 case -ENOENT: 425 return; 426 427 default: 428 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 429 goto resubmit_urb; 430 } 431 432 if (urb->actual_length > CPC_HEADER_SIZE) { 433 struct ems_cpc_msg *msg; 434 u8 *ibuf = urb->transfer_buffer; 435 u8 msg_count, start; 436 437 msg_count = ibuf[0] & ~0x80; 438 439 start = CPC_HEADER_SIZE; 440 441 while (msg_count) { 442 msg = (struct ems_cpc_msg *)&ibuf[start]; 443 444 switch (msg->type) { 445 case CPC_MSG_TYPE_CAN_STATE: 446 /* Process CAN state changes */ 447 ems_usb_rx_err(dev, msg); 448 break; 449 450 case CPC_MSG_TYPE_CAN_FRAME: 451 case CPC_MSG_TYPE_EXT_CAN_FRAME: 452 case CPC_MSG_TYPE_RTR_FRAME: 453 case CPC_MSG_TYPE_EXT_RTR_FRAME: 454 ems_usb_rx_can_msg(dev, msg); 455 break; 456 457 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 458 /* Process errorframe */ 459 ems_usb_rx_err(dev, msg); 460 break; 461 462 case CPC_MSG_TYPE_OVERRUN: 463 /* Message lost while receiving */ 464 ems_usb_rx_err(dev, msg); 465 break; 466 } 467 468 start += CPC_MSG_HEADER_LEN + msg->length; 469 msg_count--; 470 471 if (start > urb->transfer_buffer_length) { 472 netdev_err(netdev, "format error\n"); 473 break; 474 } 475 } 476 } 477 478 resubmit_urb: 479 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 480 urb->transfer_buffer, RX_BUFFER_SIZE, 481 ems_usb_read_bulk_callback, dev); 482 483 retval = usb_submit_urb(urb, GFP_ATOMIC); 484 485 if (retval == -ENODEV) 486 netif_device_detach(netdev); 487 else if (retval) 488 netdev_err(netdev, 489 "failed resubmitting read bulk urb: %d\n", retval); 490 } 491 492 /* 493 * callback for bulk IN urb 494 */ 495 static void ems_usb_write_bulk_callback(struct urb *urb) 496 { 497 struct ems_tx_urb_context *context = urb->context; 498 struct ems_usb *dev; 499 struct net_device *netdev; 500 501 BUG_ON(!context); 502 503 dev = context->dev; 504 netdev = dev->netdev; 505 506 /* free up our allocated buffer */ 507 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 508 urb->transfer_buffer, urb->transfer_dma); 509 510 atomic_dec(&dev->active_tx_urbs); 511 512 if (!netif_device_present(netdev)) 513 return; 514 515 if (urb->status) 516 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 517 518 netdev->trans_start = jiffies; 519 520 /* transmission complete interrupt */ 521 netdev->stats.tx_packets++; 522 netdev->stats.tx_bytes += context->dlc; 523 524 can_get_echo_skb(netdev, context->echo_index); 525 526 /* Release context */ 527 context->echo_index = MAX_TX_URBS; 528 529 if (netif_queue_stopped(netdev)) 530 netif_wake_queue(netdev); 531 } 532 533 /* 534 * Send the given CPC command synchronously 535 */ 536 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 537 { 538 int actual_length; 539 540 /* Copy payload */ 541 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 542 msg->length + CPC_MSG_HEADER_LEN); 543 544 /* Clear header */ 545 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 546 547 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 548 &dev->tx_msg_buffer[0], 549 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 550 &actual_length, 1000); 551 } 552 553 /* 554 * Change CAN controllers' mode register 555 */ 556 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 557 { 558 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 559 560 return ems_usb_command_msg(dev, &dev->active_params); 561 } 562 563 /* 564 * Send a CPC_Control command to change behaviour when interface receives a CAN 565 * message, bus error or CAN state changed notifications. 566 */ 567 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 568 { 569 struct ems_cpc_msg cmd; 570 571 cmd.type = CPC_CMD_TYPE_CONTROL; 572 cmd.length = CPC_MSG_HEADER_LEN + 1; 573 574 cmd.msgid = 0; 575 576 cmd.msg.generic[0] = val; 577 578 return ems_usb_command_msg(dev, &cmd); 579 } 580 581 /* 582 * Start interface 583 */ 584 static int ems_usb_start(struct ems_usb *dev) 585 { 586 struct net_device *netdev = dev->netdev; 587 int err, i; 588 589 dev->intr_in_buffer[0] = 0; 590 dev->free_slots = 15; /* initial size */ 591 592 for (i = 0; i < MAX_RX_URBS; i++) { 593 struct urb *urb = NULL; 594 u8 *buf = NULL; 595 596 /* create a URB, and a buffer for it */ 597 urb = usb_alloc_urb(0, GFP_KERNEL); 598 if (!urb) { 599 netdev_err(netdev, "No memory left for URBs\n"); 600 err = -ENOMEM; 601 break; 602 } 603 604 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 605 &urb->transfer_dma); 606 if (!buf) { 607 netdev_err(netdev, "No memory left for USB buffer\n"); 608 usb_free_urb(urb); 609 err = -ENOMEM; 610 break; 611 } 612 613 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 614 buf, RX_BUFFER_SIZE, 615 ems_usb_read_bulk_callback, dev); 616 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 617 usb_anchor_urb(urb, &dev->rx_submitted); 618 619 err = usb_submit_urb(urb, GFP_KERNEL); 620 if (err) { 621 usb_unanchor_urb(urb); 622 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 623 urb->transfer_dma); 624 usb_free_urb(urb); 625 break; 626 } 627 628 /* Drop reference, USB core will take care of freeing it */ 629 usb_free_urb(urb); 630 } 631 632 /* Did we submit any URBs */ 633 if (i == 0) { 634 netdev_warn(netdev, "couldn't setup read URBs\n"); 635 return err; 636 } 637 638 /* Warn if we've couldn't transmit all the URBs */ 639 if (i < MAX_RX_URBS) 640 netdev_warn(netdev, "rx performance may be slow\n"); 641 642 /* Setup and start interrupt URB */ 643 usb_fill_int_urb(dev->intr_urb, dev->udev, 644 usb_rcvintpipe(dev->udev, 1), 645 dev->intr_in_buffer, 646 INTR_IN_BUFFER_SIZE, 647 ems_usb_read_interrupt_callback, dev, 1); 648 649 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 650 if (err) { 651 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 652 653 return err; 654 } 655 656 /* CPC-USB will transfer received message to host */ 657 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 658 if (err) 659 goto failed; 660 661 /* CPC-USB will transfer CAN state changes to host */ 662 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 663 if (err) 664 goto failed; 665 666 /* CPC-USB will transfer bus errors to host */ 667 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 668 if (err) 669 goto failed; 670 671 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 672 if (err) 673 goto failed; 674 675 dev->can.state = CAN_STATE_ERROR_ACTIVE; 676 677 return 0; 678 679 failed: 680 netdev_warn(netdev, "couldn't submit control: %d\n", err); 681 682 return err; 683 } 684 685 static void unlink_all_urbs(struct ems_usb *dev) 686 { 687 int i; 688 689 usb_unlink_urb(dev->intr_urb); 690 691 usb_kill_anchored_urbs(&dev->rx_submitted); 692 693 usb_kill_anchored_urbs(&dev->tx_submitted); 694 atomic_set(&dev->active_tx_urbs, 0); 695 696 for (i = 0; i < MAX_TX_URBS; i++) 697 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 698 } 699 700 static int ems_usb_open(struct net_device *netdev) 701 { 702 struct ems_usb *dev = netdev_priv(netdev); 703 int err; 704 705 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 706 if (err) 707 return err; 708 709 /* common open */ 710 err = open_candev(netdev); 711 if (err) 712 return err; 713 714 /* finally start device */ 715 err = ems_usb_start(dev); 716 if (err) { 717 if (err == -ENODEV) 718 netif_device_detach(dev->netdev); 719 720 netdev_warn(netdev, "couldn't start device: %d\n", err); 721 722 close_candev(netdev); 723 724 return err; 725 } 726 727 728 netif_start_queue(netdev); 729 730 return 0; 731 } 732 733 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 734 { 735 struct ems_usb *dev = netdev_priv(netdev); 736 struct ems_tx_urb_context *context = NULL; 737 struct net_device_stats *stats = &netdev->stats; 738 struct can_frame *cf = (struct can_frame *)skb->data; 739 struct ems_cpc_msg *msg; 740 struct urb *urb; 741 u8 *buf; 742 int i, err; 743 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 744 + sizeof(struct cpc_can_msg); 745 746 if (can_dropped_invalid_skb(netdev, skb)) 747 return NETDEV_TX_OK; 748 749 /* create a URB, and a buffer for it, and copy the data to the URB */ 750 urb = usb_alloc_urb(0, GFP_ATOMIC); 751 if (!urb) { 752 netdev_err(netdev, "No memory left for URBs\n"); 753 goto nomem; 754 } 755 756 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 757 if (!buf) { 758 netdev_err(netdev, "No memory left for USB buffer\n"); 759 usb_free_urb(urb); 760 goto nomem; 761 } 762 763 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 764 765 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 766 msg->msg.can_msg.length = cf->can_dlc; 767 768 if (cf->can_id & CAN_RTR_FLAG) { 769 msg->type = cf->can_id & CAN_EFF_FLAG ? 770 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 771 772 msg->length = CPC_CAN_MSG_MIN_SIZE; 773 } else { 774 msg->type = cf->can_id & CAN_EFF_FLAG ? 775 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 776 777 for (i = 0; i < cf->can_dlc; i++) 778 msg->msg.can_msg.msg[i] = cf->data[i]; 779 780 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 781 } 782 783 for (i = 0; i < MAX_TX_URBS; i++) { 784 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 785 context = &dev->tx_contexts[i]; 786 break; 787 } 788 } 789 790 /* 791 * May never happen! When this happens we'd more URBs in flight as 792 * allowed (MAX_TX_URBS). 793 */ 794 if (!context) { 795 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 796 usb_free_urb(urb); 797 798 netdev_warn(netdev, "couldn't find free context\n"); 799 800 return NETDEV_TX_BUSY; 801 } 802 803 context->dev = dev; 804 context->echo_index = i; 805 context->dlc = cf->can_dlc; 806 807 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 808 size, ems_usb_write_bulk_callback, context); 809 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 810 usb_anchor_urb(urb, &dev->tx_submitted); 811 812 can_put_echo_skb(skb, netdev, context->echo_index); 813 814 atomic_inc(&dev->active_tx_urbs); 815 816 err = usb_submit_urb(urb, GFP_ATOMIC); 817 if (unlikely(err)) { 818 can_free_echo_skb(netdev, context->echo_index); 819 820 usb_unanchor_urb(urb); 821 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 822 dev_kfree_skb(skb); 823 824 atomic_dec(&dev->active_tx_urbs); 825 826 if (err == -ENODEV) { 827 netif_device_detach(netdev); 828 } else { 829 netdev_warn(netdev, "failed tx_urb %d\n", err); 830 831 stats->tx_dropped++; 832 } 833 } else { 834 netdev->trans_start = jiffies; 835 836 /* Slow down tx path */ 837 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 838 dev->free_slots < 5) { 839 netif_stop_queue(netdev); 840 } 841 } 842 843 /* 844 * Release our reference to this URB, the USB core will eventually free 845 * it entirely. 846 */ 847 usb_free_urb(urb); 848 849 return NETDEV_TX_OK; 850 851 nomem: 852 dev_kfree_skb(skb); 853 stats->tx_dropped++; 854 855 return NETDEV_TX_OK; 856 } 857 858 static int ems_usb_close(struct net_device *netdev) 859 { 860 struct ems_usb *dev = netdev_priv(netdev); 861 862 /* Stop polling */ 863 unlink_all_urbs(dev); 864 865 netif_stop_queue(netdev); 866 867 /* Set CAN controller to reset mode */ 868 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 869 netdev_warn(netdev, "couldn't stop device"); 870 871 close_candev(netdev); 872 873 return 0; 874 } 875 876 static const struct net_device_ops ems_usb_netdev_ops = { 877 .ndo_open = ems_usb_open, 878 .ndo_stop = ems_usb_close, 879 .ndo_start_xmit = ems_usb_start_xmit, 880 .ndo_change_mtu = can_change_mtu, 881 }; 882 883 static const struct can_bittiming_const ems_usb_bittiming_const = { 884 .name = "ems_usb", 885 .tseg1_min = 1, 886 .tseg1_max = 16, 887 .tseg2_min = 1, 888 .tseg2_max = 8, 889 .sjw_max = 4, 890 .brp_min = 1, 891 .brp_max = 64, 892 .brp_inc = 1, 893 }; 894 895 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 896 { 897 struct ems_usb *dev = netdev_priv(netdev); 898 899 switch (mode) { 900 case CAN_MODE_START: 901 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 902 netdev_warn(netdev, "couldn't start device"); 903 904 if (netif_queue_stopped(netdev)) 905 netif_wake_queue(netdev); 906 break; 907 908 default: 909 return -EOPNOTSUPP; 910 } 911 912 return 0; 913 } 914 915 static int ems_usb_set_bittiming(struct net_device *netdev) 916 { 917 struct ems_usb *dev = netdev_priv(netdev); 918 struct can_bittiming *bt = &dev->can.bittiming; 919 u8 btr0, btr1; 920 921 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 922 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 923 (((bt->phase_seg2 - 1) & 0x7) << 4); 924 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 925 btr1 |= 0x80; 926 927 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 928 929 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 930 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 931 932 return ems_usb_command_msg(dev, &dev->active_params); 933 } 934 935 static void init_params_sja1000(struct ems_cpc_msg *msg) 936 { 937 struct cpc_sja1000_params *sja1000 = 938 &msg->msg.can_params.cc_params.sja1000; 939 940 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 941 msg->length = sizeof(struct cpc_can_params); 942 msg->msgid = 0; 943 944 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 945 946 /* Acceptance filter open */ 947 sja1000->acc_code0 = 0x00; 948 sja1000->acc_code1 = 0x00; 949 sja1000->acc_code2 = 0x00; 950 sja1000->acc_code3 = 0x00; 951 952 /* Acceptance filter open */ 953 sja1000->acc_mask0 = 0xFF; 954 sja1000->acc_mask1 = 0xFF; 955 sja1000->acc_mask2 = 0xFF; 956 sja1000->acc_mask3 = 0xFF; 957 958 sja1000->btr0 = 0; 959 sja1000->btr1 = 0; 960 961 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 962 sja1000->mode = SJA1000_MOD_RM; 963 } 964 965 /* 966 * probe function for new CPC-USB devices 967 */ 968 static int ems_usb_probe(struct usb_interface *intf, 969 const struct usb_device_id *id) 970 { 971 struct net_device *netdev; 972 struct ems_usb *dev; 973 int i, err = -ENOMEM; 974 975 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 976 if (!netdev) { 977 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 978 return -ENOMEM; 979 } 980 981 dev = netdev_priv(netdev); 982 983 dev->udev = interface_to_usbdev(intf); 984 dev->netdev = netdev; 985 986 dev->can.state = CAN_STATE_STOPPED; 987 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 988 dev->can.bittiming_const = &ems_usb_bittiming_const; 989 dev->can.do_set_bittiming = ems_usb_set_bittiming; 990 dev->can.do_set_mode = ems_usb_set_mode; 991 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 992 993 netdev->netdev_ops = &ems_usb_netdev_ops; 994 995 netdev->flags |= IFF_ECHO; /* we support local echo */ 996 997 init_usb_anchor(&dev->rx_submitted); 998 999 init_usb_anchor(&dev->tx_submitted); 1000 atomic_set(&dev->active_tx_urbs, 0); 1001 1002 for (i = 0; i < MAX_TX_URBS; i++) 1003 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1004 1005 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1006 if (!dev->intr_urb) { 1007 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1008 goto cleanup_candev; 1009 } 1010 1011 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1012 if (!dev->intr_in_buffer) 1013 goto cleanup_intr_urb; 1014 1015 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1016 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1017 if (!dev->tx_msg_buffer) 1018 goto cleanup_intr_in_buffer; 1019 1020 usb_set_intfdata(intf, dev); 1021 1022 SET_NETDEV_DEV(netdev, &intf->dev); 1023 1024 init_params_sja1000(&dev->active_params); 1025 1026 err = ems_usb_command_msg(dev, &dev->active_params); 1027 if (err) { 1028 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1029 goto cleanup_tx_msg_buffer; 1030 } 1031 1032 err = register_candev(netdev); 1033 if (err) { 1034 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1035 goto cleanup_tx_msg_buffer; 1036 } 1037 1038 return 0; 1039 1040 cleanup_tx_msg_buffer: 1041 kfree(dev->tx_msg_buffer); 1042 1043 cleanup_intr_in_buffer: 1044 kfree(dev->intr_in_buffer); 1045 1046 cleanup_intr_urb: 1047 usb_free_urb(dev->intr_urb); 1048 1049 cleanup_candev: 1050 free_candev(netdev); 1051 1052 return err; 1053 } 1054 1055 /* 1056 * called by the usb core when the device is removed from the system 1057 */ 1058 static void ems_usb_disconnect(struct usb_interface *intf) 1059 { 1060 struct ems_usb *dev = usb_get_intfdata(intf); 1061 1062 usb_set_intfdata(intf, NULL); 1063 1064 if (dev) { 1065 unregister_netdev(dev->netdev); 1066 free_candev(dev->netdev); 1067 1068 unlink_all_urbs(dev); 1069 1070 usb_free_urb(dev->intr_urb); 1071 1072 kfree(dev->intr_in_buffer); 1073 } 1074 } 1075 1076 /* usb specific object needed to register this driver with the usb subsystem */ 1077 static struct usb_driver ems_usb_driver = { 1078 .name = "ems_usb", 1079 .probe = ems_usb_probe, 1080 .disconnect = ems_usb_disconnect, 1081 .id_table = ems_usb_table, 1082 }; 1083 1084 module_usb_driver(ems_usb_driver); 1085