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