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->can_id |= CAN_ERR_CRTL; 399 cf->data[1] = (txerr > rxerr) ? 400 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 401 } 402 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 403 cf->can_id |= CAN_ERR_CRTL; 404 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 405 406 stats->rx_over_errors++; 407 stats->rx_errors++; 408 } 409 410 stats->rx_packets++; 411 stats->rx_bytes += cf->can_dlc; 412 netif_rx(skb); 413 } 414 415 /* 416 * callback for bulk IN urb 417 */ 418 static void ems_usb_read_bulk_callback(struct urb *urb) 419 { 420 struct ems_usb *dev = urb->context; 421 struct net_device *netdev; 422 int retval; 423 424 netdev = dev->netdev; 425 426 if (!netif_device_present(netdev)) 427 return; 428 429 switch (urb->status) { 430 case 0: /* success */ 431 break; 432 433 case -ENOENT: 434 return; 435 436 default: 437 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 438 goto resubmit_urb; 439 } 440 441 if (urb->actual_length > CPC_HEADER_SIZE) { 442 struct ems_cpc_msg *msg; 443 u8 *ibuf = urb->transfer_buffer; 444 u8 msg_count, start; 445 446 msg_count = ibuf[0] & ~0x80; 447 448 start = CPC_HEADER_SIZE; 449 450 while (msg_count) { 451 msg = (struct ems_cpc_msg *)&ibuf[start]; 452 453 switch (msg->type) { 454 case CPC_MSG_TYPE_CAN_STATE: 455 /* Process CAN state changes */ 456 ems_usb_rx_err(dev, msg); 457 break; 458 459 case CPC_MSG_TYPE_CAN_FRAME: 460 case CPC_MSG_TYPE_EXT_CAN_FRAME: 461 case CPC_MSG_TYPE_RTR_FRAME: 462 case CPC_MSG_TYPE_EXT_RTR_FRAME: 463 ems_usb_rx_can_msg(dev, msg); 464 break; 465 466 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 467 /* Process errorframe */ 468 ems_usb_rx_err(dev, msg); 469 break; 470 471 case CPC_MSG_TYPE_OVERRUN: 472 /* Message lost while receiving */ 473 ems_usb_rx_err(dev, msg); 474 break; 475 } 476 477 start += CPC_MSG_HEADER_LEN + msg->length; 478 msg_count--; 479 480 if (start > urb->transfer_buffer_length) { 481 netdev_err(netdev, "format error\n"); 482 break; 483 } 484 } 485 } 486 487 resubmit_urb: 488 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 489 urb->transfer_buffer, RX_BUFFER_SIZE, 490 ems_usb_read_bulk_callback, dev); 491 492 retval = usb_submit_urb(urb, GFP_ATOMIC); 493 494 if (retval == -ENODEV) 495 netif_device_detach(netdev); 496 else if (retval) 497 netdev_err(netdev, 498 "failed resubmitting read bulk urb: %d\n", retval); 499 } 500 501 /* 502 * callback for bulk IN urb 503 */ 504 static void ems_usb_write_bulk_callback(struct urb *urb) 505 { 506 struct ems_tx_urb_context *context = urb->context; 507 struct ems_usb *dev; 508 struct net_device *netdev; 509 510 BUG_ON(!context); 511 512 dev = context->dev; 513 netdev = dev->netdev; 514 515 /* free up our allocated buffer */ 516 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 517 urb->transfer_buffer, urb->transfer_dma); 518 519 atomic_dec(&dev->active_tx_urbs); 520 521 if (!netif_device_present(netdev)) 522 return; 523 524 if (urb->status) 525 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 526 527 netif_trans_update(netdev); 528 529 /* transmission complete interrupt */ 530 netdev->stats.tx_packets++; 531 netdev->stats.tx_bytes += context->dlc; 532 533 can_get_echo_skb(netdev, context->echo_index); 534 535 /* Release context */ 536 context->echo_index = MAX_TX_URBS; 537 538 } 539 540 /* 541 * Send the given CPC command synchronously 542 */ 543 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 544 { 545 int actual_length; 546 547 /* Copy payload */ 548 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 549 msg->length + CPC_MSG_HEADER_LEN); 550 551 /* Clear header */ 552 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 553 554 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 555 &dev->tx_msg_buffer[0], 556 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 557 &actual_length, 1000); 558 } 559 560 /* 561 * Change CAN controllers' mode register 562 */ 563 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 564 { 565 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 566 567 return ems_usb_command_msg(dev, &dev->active_params); 568 } 569 570 /* 571 * Send a CPC_Control command to change behaviour when interface receives a CAN 572 * message, bus error or CAN state changed notifications. 573 */ 574 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 575 { 576 struct ems_cpc_msg cmd; 577 578 cmd.type = CPC_CMD_TYPE_CONTROL; 579 cmd.length = CPC_MSG_HEADER_LEN + 1; 580 581 cmd.msgid = 0; 582 583 cmd.msg.generic[0] = val; 584 585 return ems_usb_command_msg(dev, &cmd); 586 } 587 588 /* 589 * Start interface 590 */ 591 static int ems_usb_start(struct ems_usb *dev) 592 { 593 struct net_device *netdev = dev->netdev; 594 int err, i; 595 596 dev->intr_in_buffer[0] = 0; 597 dev->free_slots = 50; /* initial size */ 598 599 for (i = 0; i < MAX_RX_URBS; i++) { 600 struct urb *urb = NULL; 601 u8 *buf = NULL; 602 603 /* create a URB, and a buffer for it */ 604 urb = usb_alloc_urb(0, GFP_KERNEL); 605 if (!urb) { 606 err = -ENOMEM; 607 break; 608 } 609 610 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 611 &urb->transfer_dma); 612 if (!buf) { 613 netdev_err(netdev, "No memory left for USB buffer\n"); 614 usb_free_urb(urb); 615 err = -ENOMEM; 616 break; 617 } 618 619 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 620 buf, RX_BUFFER_SIZE, 621 ems_usb_read_bulk_callback, dev); 622 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 623 usb_anchor_urb(urb, &dev->rx_submitted); 624 625 err = usb_submit_urb(urb, GFP_KERNEL); 626 if (err) { 627 usb_unanchor_urb(urb); 628 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 629 urb->transfer_dma); 630 usb_free_urb(urb); 631 break; 632 } 633 634 /* Drop reference, USB core will take care of freeing it */ 635 usb_free_urb(urb); 636 } 637 638 /* Did we submit any URBs */ 639 if (i == 0) { 640 netdev_warn(netdev, "couldn't setup read URBs\n"); 641 return err; 642 } 643 644 /* Warn if we've couldn't transmit all the URBs */ 645 if (i < MAX_RX_URBS) 646 netdev_warn(netdev, "rx performance may be slow\n"); 647 648 /* Setup and start interrupt URB */ 649 usb_fill_int_urb(dev->intr_urb, dev->udev, 650 usb_rcvintpipe(dev->udev, 1), 651 dev->intr_in_buffer, 652 INTR_IN_BUFFER_SIZE, 653 ems_usb_read_interrupt_callback, dev, 1); 654 655 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 656 if (err) { 657 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 658 659 return err; 660 } 661 662 /* CPC-USB will transfer received message to host */ 663 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 664 if (err) 665 goto failed; 666 667 /* CPC-USB will transfer CAN state changes to host */ 668 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 669 if (err) 670 goto failed; 671 672 /* CPC-USB will transfer bus errors to host */ 673 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 674 if (err) 675 goto failed; 676 677 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 678 if (err) 679 goto failed; 680 681 dev->can.state = CAN_STATE_ERROR_ACTIVE; 682 683 return 0; 684 685 failed: 686 netdev_warn(netdev, "couldn't submit control: %d\n", err); 687 688 return err; 689 } 690 691 static void unlink_all_urbs(struct ems_usb *dev) 692 { 693 int i; 694 695 usb_unlink_urb(dev->intr_urb); 696 697 usb_kill_anchored_urbs(&dev->rx_submitted); 698 699 usb_kill_anchored_urbs(&dev->tx_submitted); 700 atomic_set(&dev->active_tx_urbs, 0); 701 702 for (i = 0; i < MAX_TX_URBS; i++) 703 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 704 } 705 706 static int ems_usb_open(struct net_device *netdev) 707 { 708 struct ems_usb *dev = netdev_priv(netdev); 709 int err; 710 711 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 712 if (err) 713 return err; 714 715 /* common open */ 716 err = open_candev(netdev); 717 if (err) 718 return err; 719 720 /* finally start device */ 721 err = ems_usb_start(dev); 722 if (err) { 723 if (err == -ENODEV) 724 netif_device_detach(dev->netdev); 725 726 netdev_warn(netdev, "couldn't start device: %d\n", err); 727 728 close_candev(netdev); 729 730 return err; 731 } 732 733 734 netif_start_queue(netdev); 735 736 return 0; 737 } 738 739 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 740 { 741 struct ems_usb *dev = netdev_priv(netdev); 742 struct ems_tx_urb_context *context = NULL; 743 struct net_device_stats *stats = &netdev->stats; 744 struct can_frame *cf = (struct can_frame *)skb->data; 745 struct ems_cpc_msg *msg; 746 struct urb *urb; 747 u8 *buf; 748 int i, err; 749 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 750 + sizeof(struct cpc_can_msg); 751 752 if (can_dropped_invalid_skb(netdev, skb)) 753 return NETDEV_TX_OK; 754 755 /* create a URB, and a buffer for it, and copy the data to the URB */ 756 urb = usb_alloc_urb(0, GFP_ATOMIC); 757 if (!urb) 758 goto nomem; 759 760 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 761 if (!buf) { 762 netdev_err(netdev, "No memory left for USB buffer\n"); 763 usb_free_urb(urb); 764 goto nomem; 765 } 766 767 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 768 769 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 770 msg->msg.can_msg.length = cf->can_dlc; 771 772 if (cf->can_id & CAN_RTR_FLAG) { 773 msg->type = cf->can_id & CAN_EFF_FLAG ? 774 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 775 776 msg->length = CPC_CAN_MSG_MIN_SIZE; 777 } else { 778 msg->type = cf->can_id & CAN_EFF_FLAG ? 779 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 780 781 for (i = 0; i < cf->can_dlc; i++) 782 msg->msg.can_msg.msg[i] = cf->data[i]; 783 784 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 785 } 786 787 for (i = 0; i < MAX_TX_URBS; i++) { 788 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 789 context = &dev->tx_contexts[i]; 790 break; 791 } 792 } 793 794 /* 795 * May never happen! When this happens we'd more URBs in flight as 796 * allowed (MAX_TX_URBS). 797 */ 798 if (!context) { 799 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 800 usb_free_urb(urb); 801 802 netdev_warn(netdev, "couldn't find free context\n"); 803 804 return NETDEV_TX_BUSY; 805 } 806 807 context->dev = dev; 808 context->echo_index = i; 809 context->dlc = cf->can_dlc; 810 811 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 812 size, ems_usb_write_bulk_callback, context); 813 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 814 usb_anchor_urb(urb, &dev->tx_submitted); 815 816 can_put_echo_skb(skb, netdev, context->echo_index); 817 818 atomic_inc(&dev->active_tx_urbs); 819 820 err = usb_submit_urb(urb, GFP_ATOMIC); 821 if (unlikely(err)) { 822 can_free_echo_skb(netdev, context->echo_index); 823 824 usb_unanchor_urb(urb); 825 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 826 dev_kfree_skb(skb); 827 828 atomic_dec(&dev->active_tx_urbs); 829 830 if (err == -ENODEV) { 831 netif_device_detach(netdev); 832 } else { 833 netdev_warn(netdev, "failed tx_urb %d\n", err); 834 835 stats->tx_dropped++; 836 } 837 } else { 838 netif_trans_update(netdev); 839 840 /* Slow down tx path */ 841 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 842 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 843 netif_stop_queue(netdev); 844 } 845 } 846 847 /* 848 * Release our reference to this URB, the USB core will eventually free 849 * it entirely. 850 */ 851 usb_free_urb(urb); 852 853 return NETDEV_TX_OK; 854 855 nomem: 856 dev_kfree_skb(skb); 857 stats->tx_dropped++; 858 859 return NETDEV_TX_OK; 860 } 861 862 static int ems_usb_close(struct net_device *netdev) 863 { 864 struct ems_usb *dev = netdev_priv(netdev); 865 866 /* Stop polling */ 867 unlink_all_urbs(dev); 868 869 netif_stop_queue(netdev); 870 871 /* Set CAN controller to reset mode */ 872 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 873 netdev_warn(netdev, "couldn't stop device"); 874 875 close_candev(netdev); 876 877 return 0; 878 } 879 880 static const struct net_device_ops ems_usb_netdev_ops = { 881 .ndo_open = ems_usb_open, 882 .ndo_stop = ems_usb_close, 883 .ndo_start_xmit = ems_usb_start_xmit, 884 .ndo_change_mtu = can_change_mtu, 885 }; 886 887 static const struct can_bittiming_const ems_usb_bittiming_const = { 888 .name = "ems_usb", 889 .tseg1_min = 1, 890 .tseg1_max = 16, 891 .tseg2_min = 1, 892 .tseg2_max = 8, 893 .sjw_max = 4, 894 .brp_min = 1, 895 .brp_max = 64, 896 .brp_inc = 1, 897 }; 898 899 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 900 { 901 struct ems_usb *dev = netdev_priv(netdev); 902 903 switch (mode) { 904 case CAN_MODE_START: 905 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 906 netdev_warn(netdev, "couldn't start device"); 907 908 if (netif_queue_stopped(netdev)) 909 netif_wake_queue(netdev); 910 break; 911 912 default: 913 return -EOPNOTSUPP; 914 } 915 916 return 0; 917 } 918 919 static int ems_usb_set_bittiming(struct net_device *netdev) 920 { 921 struct ems_usb *dev = netdev_priv(netdev); 922 struct can_bittiming *bt = &dev->can.bittiming; 923 u8 btr0, btr1; 924 925 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 926 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 927 (((bt->phase_seg2 - 1) & 0x7) << 4); 928 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 929 btr1 |= 0x80; 930 931 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 932 933 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 934 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 935 936 return ems_usb_command_msg(dev, &dev->active_params); 937 } 938 939 static void init_params_sja1000(struct ems_cpc_msg *msg) 940 { 941 struct cpc_sja1000_params *sja1000 = 942 &msg->msg.can_params.cc_params.sja1000; 943 944 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 945 msg->length = sizeof(struct cpc_can_params); 946 msg->msgid = 0; 947 948 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 949 950 /* Acceptance filter open */ 951 sja1000->acc_code0 = 0x00; 952 sja1000->acc_code1 = 0x00; 953 sja1000->acc_code2 = 0x00; 954 sja1000->acc_code3 = 0x00; 955 956 /* Acceptance filter open */ 957 sja1000->acc_mask0 = 0xFF; 958 sja1000->acc_mask1 = 0xFF; 959 sja1000->acc_mask2 = 0xFF; 960 sja1000->acc_mask3 = 0xFF; 961 962 sja1000->btr0 = 0; 963 sja1000->btr1 = 0; 964 965 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 966 sja1000->mode = SJA1000_MOD_RM; 967 } 968 969 /* 970 * probe function for new CPC-USB devices 971 */ 972 static int ems_usb_probe(struct usb_interface *intf, 973 const struct usb_device_id *id) 974 { 975 struct net_device *netdev; 976 struct ems_usb *dev; 977 int i, err = -ENOMEM; 978 979 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 980 if (!netdev) { 981 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 982 return -ENOMEM; 983 } 984 985 dev = netdev_priv(netdev); 986 987 dev->udev = interface_to_usbdev(intf); 988 dev->netdev = netdev; 989 990 dev->can.state = CAN_STATE_STOPPED; 991 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 992 dev->can.bittiming_const = &ems_usb_bittiming_const; 993 dev->can.do_set_bittiming = ems_usb_set_bittiming; 994 dev->can.do_set_mode = ems_usb_set_mode; 995 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 996 997 netdev->netdev_ops = &ems_usb_netdev_ops; 998 999 netdev->flags |= IFF_ECHO; /* we support local echo */ 1000 1001 init_usb_anchor(&dev->rx_submitted); 1002 1003 init_usb_anchor(&dev->tx_submitted); 1004 atomic_set(&dev->active_tx_urbs, 0); 1005 1006 for (i = 0; i < MAX_TX_URBS; i++) 1007 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1008 1009 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1010 if (!dev->intr_urb) 1011 goto cleanup_candev; 1012 1013 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1014 if (!dev->intr_in_buffer) 1015 goto cleanup_intr_urb; 1016 1017 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1018 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1019 if (!dev->tx_msg_buffer) 1020 goto cleanup_intr_in_buffer; 1021 1022 usb_set_intfdata(intf, dev); 1023 1024 SET_NETDEV_DEV(netdev, &intf->dev); 1025 1026 init_params_sja1000(&dev->active_params); 1027 1028 err = ems_usb_command_msg(dev, &dev->active_params); 1029 if (err) { 1030 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1031 goto cleanup_tx_msg_buffer; 1032 } 1033 1034 err = register_candev(netdev); 1035 if (err) { 1036 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1037 goto cleanup_tx_msg_buffer; 1038 } 1039 1040 return 0; 1041 1042 cleanup_tx_msg_buffer: 1043 kfree(dev->tx_msg_buffer); 1044 1045 cleanup_intr_in_buffer: 1046 kfree(dev->intr_in_buffer); 1047 1048 cleanup_intr_urb: 1049 usb_free_urb(dev->intr_urb); 1050 1051 cleanup_candev: 1052 free_candev(netdev); 1053 1054 return err; 1055 } 1056 1057 /* 1058 * called by the usb core when the device is removed from the system 1059 */ 1060 static void ems_usb_disconnect(struct usb_interface *intf) 1061 { 1062 struct ems_usb *dev = usb_get_intfdata(intf); 1063 1064 usb_set_intfdata(intf, NULL); 1065 1066 if (dev) { 1067 unregister_netdev(dev->netdev); 1068 free_candev(dev->netdev); 1069 1070 unlink_all_urbs(dev); 1071 1072 usb_free_urb(dev->intr_urb); 1073 1074 kfree(dev->intr_in_buffer); 1075 } 1076 } 1077 1078 /* usb specific object needed to register this driver with the usb subsystem */ 1079 static struct usb_driver ems_usb_driver = { 1080 .name = "ems_usb", 1081 .probe = ems_usb_probe, 1082 .disconnect = ems_usb_disconnect, 1083 .id_table = ems_usb_table, 1084 }; 1085 1086 module_usb_driver(ems_usb_driver); 1087