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 -EPIPE: 292 case -EPROTO: 293 case -ESHUTDOWN: 294 return; 295 296 default: 297 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 298 break; 299 } 300 301 err = usb_submit_urb(urb, GFP_ATOMIC); 302 303 if (err == -ENODEV) 304 netif_device_detach(netdev); 305 else if (err) 306 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 307 } 308 309 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 310 { 311 struct can_frame *cf; 312 struct sk_buff *skb; 313 int i; 314 struct net_device_stats *stats = &dev->netdev->stats; 315 316 skb = alloc_can_skb(dev->netdev, &cf); 317 if (skb == NULL) 318 return; 319 320 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 321 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 322 323 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 325 cf->can_id |= CAN_EFF_FLAG; 326 327 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 328 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 329 cf->can_id |= CAN_RTR_FLAG; 330 } else { 331 for (i = 0; i < cf->can_dlc; i++) 332 cf->data[i] = msg->msg.can_msg.msg[i]; 333 } 334 335 stats->rx_packets++; 336 stats->rx_bytes += cf->can_dlc; 337 netif_rx(skb); 338 } 339 340 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 341 { 342 struct can_frame *cf; 343 struct sk_buff *skb; 344 struct net_device_stats *stats = &dev->netdev->stats; 345 346 skb = alloc_can_err_skb(dev->netdev, &cf); 347 if (skb == NULL) 348 return; 349 350 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 351 u8 state = msg->msg.can_state; 352 353 if (state & SJA1000_SR_BS) { 354 dev->can.state = CAN_STATE_BUS_OFF; 355 cf->can_id |= CAN_ERR_BUSOFF; 356 357 dev->can.can_stats.bus_off++; 358 can_bus_off(dev->netdev); 359 } else if (state & SJA1000_SR_ES) { 360 dev->can.state = CAN_STATE_ERROR_WARNING; 361 dev->can.can_stats.error_warning++; 362 } else { 363 dev->can.state = CAN_STATE_ERROR_ACTIVE; 364 dev->can.can_stats.error_passive++; 365 } 366 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 367 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 368 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 369 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 370 371 /* bus error interrupt */ 372 dev->can.can_stats.bus_error++; 373 stats->rx_errors++; 374 375 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 376 377 switch (ecc & SJA1000_ECC_MASK) { 378 case SJA1000_ECC_BIT: 379 cf->data[2] |= CAN_ERR_PROT_BIT; 380 break; 381 case SJA1000_ECC_FORM: 382 cf->data[2] |= CAN_ERR_PROT_FORM; 383 break; 384 case SJA1000_ECC_STUFF: 385 cf->data[2] |= CAN_ERR_PROT_STUFF; 386 break; 387 default: 388 cf->data[3] = ecc & SJA1000_ECC_SEG; 389 break; 390 } 391 392 /* Error occurred during transmission? */ 393 if ((ecc & SJA1000_ECC_DIR) == 0) 394 cf->data[2] |= CAN_ERR_PROT_TX; 395 396 if (dev->can.state == CAN_STATE_ERROR_WARNING || 397 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 398 cf->data[1] = (txerr > rxerr) ? 399 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 400 } 401 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 402 cf->can_id |= CAN_ERR_CRTL; 403 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 404 405 stats->rx_over_errors++; 406 stats->rx_errors++; 407 } 408 409 stats->rx_packets++; 410 stats->rx_bytes += cf->can_dlc; 411 netif_rx(skb); 412 } 413 414 /* 415 * callback for bulk IN urb 416 */ 417 static void ems_usb_read_bulk_callback(struct urb *urb) 418 { 419 struct ems_usb *dev = urb->context; 420 struct net_device *netdev; 421 int retval; 422 423 netdev = dev->netdev; 424 425 if (!netif_device_present(netdev)) 426 return; 427 428 switch (urb->status) { 429 case 0: /* success */ 430 break; 431 432 case -ENOENT: 433 return; 434 435 default: 436 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 437 goto resubmit_urb; 438 } 439 440 if (urb->actual_length > CPC_HEADER_SIZE) { 441 struct ems_cpc_msg *msg; 442 u8 *ibuf = urb->transfer_buffer; 443 u8 msg_count, start; 444 445 msg_count = ibuf[0] & ~0x80; 446 447 start = CPC_HEADER_SIZE; 448 449 while (msg_count) { 450 msg = (struct ems_cpc_msg *)&ibuf[start]; 451 452 switch (msg->type) { 453 case CPC_MSG_TYPE_CAN_STATE: 454 /* Process CAN state changes */ 455 ems_usb_rx_err(dev, msg); 456 break; 457 458 case CPC_MSG_TYPE_CAN_FRAME: 459 case CPC_MSG_TYPE_EXT_CAN_FRAME: 460 case CPC_MSG_TYPE_RTR_FRAME: 461 case CPC_MSG_TYPE_EXT_RTR_FRAME: 462 ems_usb_rx_can_msg(dev, msg); 463 break; 464 465 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 466 /* Process errorframe */ 467 ems_usb_rx_err(dev, msg); 468 break; 469 470 case CPC_MSG_TYPE_OVERRUN: 471 /* Message lost while receiving */ 472 ems_usb_rx_err(dev, msg); 473 break; 474 } 475 476 start += CPC_MSG_HEADER_LEN + msg->length; 477 msg_count--; 478 479 if (start > urb->transfer_buffer_length) { 480 netdev_err(netdev, "format error\n"); 481 break; 482 } 483 } 484 } 485 486 resubmit_urb: 487 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 488 urb->transfer_buffer, RX_BUFFER_SIZE, 489 ems_usb_read_bulk_callback, dev); 490 491 retval = usb_submit_urb(urb, GFP_ATOMIC); 492 493 if (retval == -ENODEV) 494 netif_device_detach(netdev); 495 else if (retval) 496 netdev_err(netdev, 497 "failed resubmitting read bulk urb: %d\n", retval); 498 } 499 500 /* 501 * callback for bulk IN urb 502 */ 503 static void ems_usb_write_bulk_callback(struct urb *urb) 504 { 505 struct ems_tx_urb_context *context = urb->context; 506 struct ems_usb *dev; 507 struct net_device *netdev; 508 509 BUG_ON(!context); 510 511 dev = context->dev; 512 netdev = dev->netdev; 513 514 /* free up our allocated buffer */ 515 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 516 urb->transfer_buffer, urb->transfer_dma); 517 518 atomic_dec(&dev->active_tx_urbs); 519 520 if (!netif_device_present(netdev)) 521 return; 522 523 if (urb->status) 524 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 525 526 netif_trans_update(netdev); 527 528 /* transmission complete interrupt */ 529 netdev->stats.tx_packets++; 530 netdev->stats.tx_bytes += context->dlc; 531 532 can_get_echo_skb(netdev, context->echo_index); 533 534 /* Release context */ 535 context->echo_index = MAX_TX_URBS; 536 537 } 538 539 /* 540 * Send the given CPC command synchronously 541 */ 542 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 543 { 544 int actual_length; 545 546 /* Copy payload */ 547 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 548 msg->length + CPC_MSG_HEADER_LEN); 549 550 /* Clear header */ 551 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 552 553 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 554 &dev->tx_msg_buffer[0], 555 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 556 &actual_length, 1000); 557 } 558 559 /* 560 * Change CAN controllers' mode register 561 */ 562 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 563 { 564 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 565 566 return ems_usb_command_msg(dev, &dev->active_params); 567 } 568 569 /* 570 * Send a CPC_Control command to change behaviour when interface receives a CAN 571 * message, bus error or CAN state changed notifications. 572 */ 573 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 574 { 575 struct ems_cpc_msg cmd; 576 577 cmd.type = CPC_CMD_TYPE_CONTROL; 578 cmd.length = CPC_MSG_HEADER_LEN + 1; 579 580 cmd.msgid = 0; 581 582 cmd.msg.generic[0] = val; 583 584 return ems_usb_command_msg(dev, &cmd); 585 } 586 587 /* 588 * Start interface 589 */ 590 static int ems_usb_start(struct ems_usb *dev) 591 { 592 struct net_device *netdev = dev->netdev; 593 int err, i; 594 595 dev->intr_in_buffer[0] = 0; 596 dev->free_slots = 50; /* initial size */ 597 598 for (i = 0; i < MAX_RX_URBS; i++) { 599 struct urb *urb = NULL; 600 u8 *buf = NULL; 601 602 /* create a URB, and a buffer for it */ 603 urb = usb_alloc_urb(0, GFP_KERNEL); 604 if (!urb) { 605 err = -ENOMEM; 606 break; 607 } 608 609 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 610 &urb->transfer_dma); 611 if (!buf) { 612 netdev_err(netdev, "No memory left for USB buffer\n"); 613 usb_free_urb(urb); 614 err = -ENOMEM; 615 break; 616 } 617 618 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 619 buf, RX_BUFFER_SIZE, 620 ems_usb_read_bulk_callback, dev); 621 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 622 usb_anchor_urb(urb, &dev->rx_submitted); 623 624 err = usb_submit_urb(urb, GFP_KERNEL); 625 if (err) { 626 usb_unanchor_urb(urb); 627 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 628 urb->transfer_dma); 629 usb_free_urb(urb); 630 break; 631 } 632 633 /* Drop reference, USB core will take care of freeing it */ 634 usb_free_urb(urb); 635 } 636 637 /* Did we submit any URBs */ 638 if (i == 0) { 639 netdev_warn(netdev, "couldn't setup read URBs\n"); 640 return err; 641 } 642 643 /* Warn if we've couldn't transmit all the URBs */ 644 if (i < MAX_RX_URBS) 645 netdev_warn(netdev, "rx performance may be slow\n"); 646 647 /* Setup and start interrupt URB */ 648 usb_fill_int_urb(dev->intr_urb, dev->udev, 649 usb_rcvintpipe(dev->udev, 1), 650 dev->intr_in_buffer, 651 INTR_IN_BUFFER_SIZE, 652 ems_usb_read_interrupt_callback, dev, 1); 653 654 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 655 if (err) { 656 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 657 658 return err; 659 } 660 661 /* CPC-USB will transfer received message to host */ 662 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 663 if (err) 664 goto failed; 665 666 /* CPC-USB will transfer CAN state changes to host */ 667 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 668 if (err) 669 goto failed; 670 671 /* CPC-USB will transfer bus errors to host */ 672 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 673 if (err) 674 goto failed; 675 676 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 677 if (err) 678 goto failed; 679 680 dev->can.state = CAN_STATE_ERROR_ACTIVE; 681 682 return 0; 683 684 failed: 685 netdev_warn(netdev, "couldn't submit control: %d\n", err); 686 687 return err; 688 } 689 690 static void unlink_all_urbs(struct ems_usb *dev) 691 { 692 int i; 693 694 usb_unlink_urb(dev->intr_urb); 695 696 usb_kill_anchored_urbs(&dev->rx_submitted); 697 698 usb_kill_anchored_urbs(&dev->tx_submitted); 699 atomic_set(&dev->active_tx_urbs, 0); 700 701 for (i = 0; i < MAX_TX_URBS; i++) 702 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 703 } 704 705 static int ems_usb_open(struct net_device *netdev) 706 { 707 struct ems_usb *dev = netdev_priv(netdev); 708 int err; 709 710 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 711 if (err) 712 return err; 713 714 /* common open */ 715 err = open_candev(netdev); 716 if (err) 717 return err; 718 719 /* finally start device */ 720 err = ems_usb_start(dev); 721 if (err) { 722 if (err == -ENODEV) 723 netif_device_detach(dev->netdev); 724 725 netdev_warn(netdev, "couldn't start device: %d\n", err); 726 727 close_candev(netdev); 728 729 return err; 730 } 731 732 733 netif_start_queue(netdev); 734 735 return 0; 736 } 737 738 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 739 { 740 struct ems_usb *dev = netdev_priv(netdev); 741 struct ems_tx_urb_context *context = NULL; 742 struct net_device_stats *stats = &netdev->stats; 743 struct can_frame *cf = (struct can_frame *)skb->data; 744 struct ems_cpc_msg *msg; 745 struct urb *urb; 746 u8 *buf; 747 int i, err; 748 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 749 + sizeof(struct cpc_can_msg); 750 751 if (can_dropped_invalid_skb(netdev, skb)) 752 return NETDEV_TX_OK; 753 754 /* create a URB, and a buffer for it, and copy the data to the URB */ 755 urb = usb_alloc_urb(0, GFP_ATOMIC); 756 if (!urb) 757 goto nomem; 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 = cpu_to_le32(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 for (i = 0; i < MAX_TX_URBS; i++) { 787 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 788 context = &dev->tx_contexts[i]; 789 break; 790 } 791 } 792 793 /* 794 * May never happen! When this happens we'd more URBs in flight as 795 * allowed (MAX_TX_URBS). 796 */ 797 if (!context) { 798 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 799 usb_free_urb(urb); 800 801 netdev_warn(netdev, "couldn't find free context\n"); 802 803 return NETDEV_TX_BUSY; 804 } 805 806 context->dev = dev; 807 context->echo_index = i; 808 context->dlc = cf->can_dlc; 809 810 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 811 size, ems_usb_write_bulk_callback, context); 812 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 813 usb_anchor_urb(urb, &dev->tx_submitted); 814 815 can_put_echo_skb(skb, netdev, context->echo_index); 816 817 atomic_inc(&dev->active_tx_urbs); 818 819 err = usb_submit_urb(urb, GFP_ATOMIC); 820 if (unlikely(err)) { 821 can_free_echo_skb(netdev, context->echo_index); 822 823 usb_unanchor_urb(urb); 824 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 825 dev_kfree_skb(skb); 826 827 atomic_dec(&dev->active_tx_urbs); 828 829 if (err == -ENODEV) { 830 netif_device_detach(netdev); 831 } else { 832 netdev_warn(netdev, "failed tx_urb %d\n", err); 833 834 stats->tx_dropped++; 835 } 836 } else { 837 netif_trans_update(netdev); 838 839 /* Slow down tx path */ 840 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 841 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 842 netif_stop_queue(netdev); 843 } 844 } 845 846 /* 847 * Release our reference to this URB, the USB core will eventually free 848 * it entirely. 849 */ 850 usb_free_urb(urb); 851 852 return NETDEV_TX_OK; 853 854 nomem: 855 dev_kfree_skb(skb); 856 stats->tx_dropped++; 857 858 return NETDEV_TX_OK; 859 } 860 861 static int ems_usb_close(struct net_device *netdev) 862 { 863 struct ems_usb *dev = netdev_priv(netdev); 864 865 /* Stop polling */ 866 unlink_all_urbs(dev); 867 868 netif_stop_queue(netdev); 869 870 /* Set CAN controller to reset mode */ 871 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 872 netdev_warn(netdev, "couldn't stop device"); 873 874 close_candev(netdev); 875 876 return 0; 877 } 878 879 static const struct net_device_ops ems_usb_netdev_ops = { 880 .ndo_open = ems_usb_open, 881 .ndo_stop = ems_usb_close, 882 .ndo_start_xmit = ems_usb_start_xmit, 883 .ndo_change_mtu = can_change_mtu, 884 }; 885 886 static const struct can_bittiming_const ems_usb_bittiming_const = { 887 .name = "ems_usb", 888 .tseg1_min = 1, 889 .tseg1_max = 16, 890 .tseg2_min = 1, 891 .tseg2_max = 8, 892 .sjw_max = 4, 893 .brp_min = 1, 894 .brp_max = 64, 895 .brp_inc = 1, 896 }; 897 898 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 899 { 900 struct ems_usb *dev = netdev_priv(netdev); 901 902 switch (mode) { 903 case CAN_MODE_START: 904 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 905 netdev_warn(netdev, "couldn't start device"); 906 907 if (netif_queue_stopped(netdev)) 908 netif_wake_queue(netdev); 909 break; 910 911 default: 912 return -EOPNOTSUPP; 913 } 914 915 return 0; 916 } 917 918 static int ems_usb_set_bittiming(struct net_device *netdev) 919 { 920 struct ems_usb *dev = netdev_priv(netdev); 921 struct can_bittiming *bt = &dev->can.bittiming; 922 u8 btr0, btr1; 923 924 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 925 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 926 (((bt->phase_seg2 - 1) & 0x7) << 4); 927 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 928 btr1 |= 0x80; 929 930 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 931 932 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 933 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 934 935 return ems_usb_command_msg(dev, &dev->active_params); 936 } 937 938 static void init_params_sja1000(struct ems_cpc_msg *msg) 939 { 940 struct cpc_sja1000_params *sja1000 = 941 &msg->msg.can_params.cc_params.sja1000; 942 943 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 944 msg->length = sizeof(struct cpc_can_params); 945 msg->msgid = 0; 946 947 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 948 949 /* Acceptance filter open */ 950 sja1000->acc_code0 = 0x00; 951 sja1000->acc_code1 = 0x00; 952 sja1000->acc_code2 = 0x00; 953 sja1000->acc_code3 = 0x00; 954 955 /* Acceptance filter open */ 956 sja1000->acc_mask0 = 0xFF; 957 sja1000->acc_mask1 = 0xFF; 958 sja1000->acc_mask2 = 0xFF; 959 sja1000->acc_mask3 = 0xFF; 960 961 sja1000->btr0 = 0; 962 sja1000->btr1 = 0; 963 964 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 965 sja1000->mode = SJA1000_MOD_RM; 966 } 967 968 /* 969 * probe function for new CPC-USB devices 970 */ 971 static int ems_usb_probe(struct usb_interface *intf, 972 const struct usb_device_id *id) 973 { 974 struct net_device *netdev; 975 struct ems_usb *dev; 976 int i, err = -ENOMEM; 977 978 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 979 if (!netdev) { 980 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 981 return -ENOMEM; 982 } 983 984 dev = netdev_priv(netdev); 985 986 dev->udev = interface_to_usbdev(intf); 987 dev->netdev = netdev; 988 989 dev->can.state = CAN_STATE_STOPPED; 990 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 991 dev->can.bittiming_const = &ems_usb_bittiming_const; 992 dev->can.do_set_bittiming = ems_usb_set_bittiming; 993 dev->can.do_set_mode = ems_usb_set_mode; 994 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 995 996 netdev->netdev_ops = &ems_usb_netdev_ops; 997 998 netdev->flags |= IFF_ECHO; /* we support local echo */ 999 1000 init_usb_anchor(&dev->rx_submitted); 1001 1002 init_usb_anchor(&dev->tx_submitted); 1003 atomic_set(&dev->active_tx_urbs, 0); 1004 1005 for (i = 0; i < MAX_TX_URBS; i++) 1006 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1007 1008 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1009 if (!dev->intr_urb) 1010 goto cleanup_candev; 1011 1012 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1013 if (!dev->intr_in_buffer) 1014 goto cleanup_intr_urb; 1015 1016 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1017 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1018 if (!dev->tx_msg_buffer) 1019 goto cleanup_intr_in_buffer; 1020 1021 usb_set_intfdata(intf, dev); 1022 1023 SET_NETDEV_DEV(netdev, &intf->dev); 1024 1025 init_params_sja1000(&dev->active_params); 1026 1027 err = ems_usb_command_msg(dev, &dev->active_params); 1028 if (err) { 1029 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1030 goto cleanup_tx_msg_buffer; 1031 } 1032 1033 err = register_candev(netdev); 1034 if (err) { 1035 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1036 goto cleanup_tx_msg_buffer; 1037 } 1038 1039 return 0; 1040 1041 cleanup_tx_msg_buffer: 1042 kfree(dev->tx_msg_buffer); 1043 1044 cleanup_intr_in_buffer: 1045 kfree(dev->intr_in_buffer); 1046 1047 cleanup_intr_urb: 1048 usb_free_urb(dev->intr_urb); 1049 1050 cleanup_candev: 1051 free_candev(netdev); 1052 1053 return err; 1054 } 1055 1056 /* 1057 * called by the usb core when the device is removed from the system 1058 */ 1059 static void ems_usb_disconnect(struct usb_interface *intf) 1060 { 1061 struct ems_usb *dev = usb_get_intfdata(intf); 1062 1063 usb_set_intfdata(intf, NULL); 1064 1065 if (dev) { 1066 unregister_netdev(dev->netdev); 1067 free_candev(dev->netdev); 1068 1069 unlink_all_urbs(dev); 1070 1071 usb_free_urb(dev->intr_urb); 1072 1073 kfree(dev->intr_in_buffer); 1074 } 1075 } 1076 1077 /* usb specific object needed to register this driver with the usb subsystem */ 1078 static struct usb_driver ems_usb_driver = { 1079 .name = "ems_usb", 1080 .probe = ems_usb_probe, 1081 .disconnect = ems_usb_disconnect, 1082 .id_table = ems_usb_table, 1083 }; 1084 1085 module_usb_driver(ems_usb_driver); 1086