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 #define CPC_TX_QUEUE_TRIGGER_LOW 25 121 #define CPC_TX_QUEUE_TRIGGER_HIGH 35 122 123 /* 124 * CAN-Message representation in a CPC_MSG. Message object type is 125 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or 126 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME. 127 */ 128 struct cpc_can_msg { 129 __le32 id; 130 u8 length; 131 u8 msg[8]; 132 }; 133 134 /* Representation of the CAN parameters for the SJA1000 controller */ 135 struct cpc_sja1000_params { 136 u8 mode; 137 u8 acc_code0; 138 u8 acc_code1; 139 u8 acc_code2; 140 u8 acc_code3; 141 u8 acc_mask0; 142 u8 acc_mask1; 143 u8 acc_mask2; 144 u8 acc_mask3; 145 u8 btr0; 146 u8 btr1; 147 u8 outp_contr; 148 }; 149 150 /* CAN params message representation */ 151 struct cpc_can_params { 152 u8 cc_type; 153 154 /* Will support M16C CAN controller in the future */ 155 union { 156 struct cpc_sja1000_params sja1000; 157 } cc_params; 158 }; 159 160 /* Structure for confirmed message handling */ 161 struct cpc_confirm { 162 u8 error; /* error code */ 163 }; 164 165 /* Structure for overrun conditions */ 166 struct cpc_overrun { 167 u8 event; 168 u8 count; 169 }; 170 171 /* SJA1000 CAN errors (compatible to NXP LPC2119) */ 172 struct cpc_sja1000_can_error { 173 u8 ecc; 174 u8 rxerr; 175 u8 txerr; 176 }; 177 178 /* structure for CAN error conditions */ 179 struct cpc_can_error { 180 u8 ecode; 181 182 struct { 183 u8 cc_type; 184 185 /* Other controllers may also provide error code capture regs */ 186 union { 187 struct cpc_sja1000_can_error sja1000; 188 } regs; 189 } cc; 190 }; 191 192 /* 193 * Structure containing RX/TX error counter. This structure is used to request 194 * the values of the CAN controllers TX and RX error counter. 195 */ 196 struct cpc_can_err_counter { 197 u8 rx; 198 u8 tx; 199 }; 200 201 /* Main message type used between library and application */ 202 struct __packed ems_cpc_msg { 203 u8 type; /* type of message */ 204 u8 length; /* length of data within union 'msg' */ 205 u8 msgid; /* confirmation handle */ 206 __le32 ts_sec; /* timestamp in seconds */ 207 __le32 ts_nsec; /* timestamp in nano seconds */ 208 209 union { 210 u8 generic[64]; 211 struct cpc_can_msg can_msg; 212 struct cpc_can_params can_params; 213 struct cpc_confirm confirmation; 214 struct cpc_overrun overrun; 215 struct cpc_can_error error; 216 struct cpc_can_err_counter err_counter; 217 u8 can_state; 218 } msg; 219 }; 220 221 /* 222 * Table of devices that work with this driver 223 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 224 */ 225 static struct usb_device_id ems_usb_table[] = { 226 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 227 {} /* Terminating entry */ 228 }; 229 230 MODULE_DEVICE_TABLE(usb, ems_usb_table); 231 232 #define RX_BUFFER_SIZE 64 233 #define CPC_HEADER_SIZE 4 234 #define INTR_IN_BUFFER_SIZE 4 235 236 #define MAX_RX_URBS 10 237 #define MAX_TX_URBS 10 238 239 struct ems_usb; 240 241 struct ems_tx_urb_context { 242 struct ems_usb *dev; 243 244 u32 echo_index; 245 u8 dlc; 246 }; 247 248 struct ems_usb { 249 struct can_priv can; /* must be the first member */ 250 251 struct sk_buff *echo_skb[MAX_TX_URBS]; 252 253 struct usb_device *udev; 254 struct net_device *netdev; 255 256 atomic_t active_tx_urbs; 257 struct usb_anchor tx_submitted; 258 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 259 260 struct usb_anchor rx_submitted; 261 262 struct urb *intr_urb; 263 264 u8 *tx_msg_buffer; 265 266 u8 *intr_in_buffer; 267 unsigned int free_slots; /* remember number of available slots */ 268 269 struct ems_cpc_msg active_params; /* active controller parameters */ 270 }; 271 272 static void ems_usb_read_interrupt_callback(struct urb *urb) 273 { 274 struct ems_usb *dev = urb->context; 275 struct net_device *netdev = dev->netdev; 276 int err; 277 278 if (!netif_device_present(netdev)) 279 return; 280 281 switch (urb->status) { 282 case 0: 283 dev->free_slots = dev->intr_in_buffer[1]; 284 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH && 285 netif_queue_stopped(netdev)) 286 netif_wake_queue(netdev); 287 break; 288 289 case -ECONNRESET: /* unlink */ 290 case -ENOENT: 291 case -ESHUTDOWN: 292 return; 293 294 default: 295 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 296 break; 297 } 298 299 err = usb_submit_urb(urb, GFP_ATOMIC); 300 301 if (err == -ENODEV) 302 netif_device_detach(netdev); 303 else if (err) 304 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 305 } 306 307 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 308 { 309 struct can_frame *cf; 310 struct sk_buff *skb; 311 int i; 312 struct net_device_stats *stats = &dev->netdev->stats; 313 314 skb = alloc_can_skb(dev->netdev, &cf); 315 if (skb == NULL) 316 return; 317 318 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 319 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 320 321 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 322 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 323 cf->can_id |= CAN_EFF_FLAG; 324 325 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 326 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 327 cf->can_id |= CAN_RTR_FLAG; 328 } else { 329 for (i = 0; i < cf->can_dlc; i++) 330 cf->data[i] = msg->msg.can_msg.msg[i]; 331 } 332 333 stats->rx_packets++; 334 stats->rx_bytes += cf->can_dlc; 335 netif_rx(skb); 336 } 337 338 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 339 { 340 struct can_frame *cf; 341 struct sk_buff *skb; 342 struct net_device_stats *stats = &dev->netdev->stats; 343 344 skb = alloc_can_err_skb(dev->netdev, &cf); 345 if (skb == NULL) 346 return; 347 348 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 349 u8 state = msg->msg.can_state; 350 351 if (state & SJA1000_SR_BS) { 352 dev->can.state = CAN_STATE_BUS_OFF; 353 cf->can_id |= CAN_ERR_BUSOFF; 354 355 dev->can.can_stats.bus_off++; 356 can_bus_off(dev->netdev); 357 } else if (state & SJA1000_SR_ES) { 358 dev->can.state = CAN_STATE_ERROR_WARNING; 359 dev->can.can_stats.error_warning++; 360 } else { 361 dev->can.state = CAN_STATE_ERROR_ACTIVE; 362 dev->can.can_stats.error_passive++; 363 } 364 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 365 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 366 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 367 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 368 369 /* bus error interrupt */ 370 dev->can.can_stats.bus_error++; 371 stats->rx_errors++; 372 373 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 374 375 switch (ecc & SJA1000_ECC_MASK) { 376 case SJA1000_ECC_BIT: 377 cf->data[2] |= CAN_ERR_PROT_BIT; 378 break; 379 case SJA1000_ECC_FORM: 380 cf->data[2] |= CAN_ERR_PROT_FORM; 381 break; 382 case SJA1000_ECC_STUFF: 383 cf->data[2] |= CAN_ERR_PROT_STUFF; 384 break; 385 default: 386 cf->data[3] = ecc & SJA1000_ECC_SEG; 387 break; 388 } 389 390 /* Error occurred during transmission? */ 391 if ((ecc & SJA1000_ECC_DIR) == 0) 392 cf->data[2] |= CAN_ERR_PROT_TX; 393 394 if (dev->can.state == CAN_STATE_ERROR_WARNING || 395 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 396 cf->data[1] = (txerr > rxerr) ? 397 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 398 } 399 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 400 cf->can_id |= CAN_ERR_CRTL; 401 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 402 403 stats->rx_over_errors++; 404 stats->rx_errors++; 405 } 406 407 stats->rx_packets++; 408 stats->rx_bytes += cf->can_dlc; 409 netif_rx(skb); 410 } 411 412 /* 413 * callback for bulk IN urb 414 */ 415 static void ems_usb_read_bulk_callback(struct urb *urb) 416 { 417 struct ems_usb *dev = urb->context; 418 struct net_device *netdev; 419 int retval; 420 421 netdev = dev->netdev; 422 423 if (!netif_device_present(netdev)) 424 return; 425 426 switch (urb->status) { 427 case 0: /* success */ 428 break; 429 430 case -ENOENT: 431 return; 432 433 default: 434 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 435 goto resubmit_urb; 436 } 437 438 if (urb->actual_length > CPC_HEADER_SIZE) { 439 struct ems_cpc_msg *msg; 440 u8 *ibuf = urb->transfer_buffer; 441 u8 msg_count, start; 442 443 msg_count = ibuf[0] & ~0x80; 444 445 start = CPC_HEADER_SIZE; 446 447 while (msg_count) { 448 msg = (struct ems_cpc_msg *)&ibuf[start]; 449 450 switch (msg->type) { 451 case CPC_MSG_TYPE_CAN_STATE: 452 /* Process CAN state changes */ 453 ems_usb_rx_err(dev, msg); 454 break; 455 456 case CPC_MSG_TYPE_CAN_FRAME: 457 case CPC_MSG_TYPE_EXT_CAN_FRAME: 458 case CPC_MSG_TYPE_RTR_FRAME: 459 case CPC_MSG_TYPE_EXT_RTR_FRAME: 460 ems_usb_rx_can_msg(dev, msg); 461 break; 462 463 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 464 /* Process errorframe */ 465 ems_usb_rx_err(dev, msg); 466 break; 467 468 case CPC_MSG_TYPE_OVERRUN: 469 /* Message lost while receiving */ 470 ems_usb_rx_err(dev, msg); 471 break; 472 } 473 474 start += CPC_MSG_HEADER_LEN + msg->length; 475 msg_count--; 476 477 if (start > urb->transfer_buffer_length) { 478 netdev_err(netdev, "format error\n"); 479 break; 480 } 481 } 482 } 483 484 resubmit_urb: 485 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 486 urb->transfer_buffer, RX_BUFFER_SIZE, 487 ems_usb_read_bulk_callback, dev); 488 489 retval = usb_submit_urb(urb, GFP_ATOMIC); 490 491 if (retval == -ENODEV) 492 netif_device_detach(netdev); 493 else if (retval) 494 netdev_err(netdev, 495 "failed resubmitting read bulk urb: %d\n", retval); 496 } 497 498 /* 499 * callback for bulk IN urb 500 */ 501 static void ems_usb_write_bulk_callback(struct urb *urb) 502 { 503 struct ems_tx_urb_context *context = urb->context; 504 struct ems_usb *dev; 505 struct net_device *netdev; 506 507 BUG_ON(!context); 508 509 dev = context->dev; 510 netdev = dev->netdev; 511 512 /* free up our allocated buffer */ 513 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 514 urb->transfer_buffer, urb->transfer_dma); 515 516 atomic_dec(&dev->active_tx_urbs); 517 518 if (!netif_device_present(netdev)) 519 return; 520 521 if (urb->status) 522 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 523 524 netif_trans_update(netdev); 525 526 /* transmission complete interrupt */ 527 netdev->stats.tx_packets++; 528 netdev->stats.tx_bytes += context->dlc; 529 530 can_get_echo_skb(netdev, context->echo_index); 531 532 /* Release context */ 533 context->echo_index = MAX_TX_URBS; 534 535 } 536 537 /* 538 * Send the given CPC command synchronously 539 */ 540 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 541 { 542 int actual_length; 543 544 /* Copy payload */ 545 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 546 msg->length + CPC_MSG_HEADER_LEN); 547 548 /* Clear header */ 549 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 550 551 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 552 &dev->tx_msg_buffer[0], 553 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 554 &actual_length, 1000); 555 } 556 557 /* 558 * Change CAN controllers' mode register 559 */ 560 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 561 { 562 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 563 564 return ems_usb_command_msg(dev, &dev->active_params); 565 } 566 567 /* 568 * Send a CPC_Control command to change behaviour when interface receives a CAN 569 * message, bus error or CAN state changed notifications. 570 */ 571 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 572 { 573 struct ems_cpc_msg cmd; 574 575 cmd.type = CPC_CMD_TYPE_CONTROL; 576 cmd.length = CPC_MSG_HEADER_LEN + 1; 577 578 cmd.msgid = 0; 579 580 cmd.msg.generic[0] = val; 581 582 return ems_usb_command_msg(dev, &cmd); 583 } 584 585 /* 586 * Start interface 587 */ 588 static int ems_usb_start(struct ems_usb *dev) 589 { 590 struct net_device *netdev = dev->netdev; 591 int err, i; 592 593 dev->intr_in_buffer[0] = 0; 594 dev->free_slots = 50; /* initial size */ 595 596 for (i = 0; i < MAX_RX_URBS; i++) { 597 struct urb *urb = NULL; 598 u8 *buf = NULL; 599 600 /* create a URB, and a buffer for it */ 601 urb = usb_alloc_urb(0, GFP_KERNEL); 602 if (!urb) { 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 goto nomem; 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 netif_trans_update(netdev); 836 837 /* Slow down tx path */ 838 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 839 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 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 goto cleanup_candev; 1009 1010 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1011 if (!dev->intr_in_buffer) 1012 goto cleanup_intr_urb; 1013 1014 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1015 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1016 if (!dev->tx_msg_buffer) 1017 goto cleanup_intr_in_buffer; 1018 1019 usb_set_intfdata(intf, dev); 1020 1021 SET_NETDEV_DEV(netdev, &intf->dev); 1022 1023 init_params_sja1000(&dev->active_params); 1024 1025 err = ems_usb_command_msg(dev, &dev->active_params); 1026 if (err) { 1027 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1028 goto cleanup_tx_msg_buffer; 1029 } 1030 1031 err = register_candev(netdev); 1032 if (err) { 1033 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1034 goto cleanup_tx_msg_buffer; 1035 } 1036 1037 return 0; 1038 1039 cleanup_tx_msg_buffer: 1040 kfree(dev->tx_msg_buffer); 1041 1042 cleanup_intr_in_buffer: 1043 kfree(dev->intr_in_buffer); 1044 1045 cleanup_intr_urb: 1046 usb_free_urb(dev->intr_urb); 1047 1048 cleanup_candev: 1049 free_candev(netdev); 1050 1051 return err; 1052 } 1053 1054 /* 1055 * called by the usb core when the device is removed from the system 1056 */ 1057 static void ems_usb_disconnect(struct usb_interface *intf) 1058 { 1059 struct ems_usb *dev = usb_get_intfdata(intf); 1060 1061 usb_set_intfdata(intf, NULL); 1062 1063 if (dev) { 1064 unregister_netdev(dev->netdev); 1065 free_candev(dev->netdev); 1066 1067 unlink_all_urbs(dev); 1068 1069 usb_free_urb(dev->intr_urb); 1070 1071 kfree(dev->intr_in_buffer); 1072 } 1073 } 1074 1075 /* usb specific object needed to register this driver with the usb subsystem */ 1076 static struct usb_driver ems_usb_driver = { 1077 .name = "ems_usb", 1078 .probe = ems_usb_probe, 1079 .disconnect = ems_usb_disconnect, 1080 .id_table = ems_usb_table, 1081 }; 1082 1083 module_usb_driver(ems_usb_driver); 1084