1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7 4 * 5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche 6 */ 7 #include <linux/ethtool.h> 8 #include <linux/signal.h> 9 #include <linux/slab.h> 10 #include <linux/module.h> 11 #include <linux/netdevice.h> 12 #include <linux/usb.h> 13 14 #include <linux/can.h> 15 #include <linux/can/dev.h> 16 #include <linux/can/error.h> 17 18 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 19 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 20 MODULE_LICENSE("GPL v2"); 21 22 /* Control-Values for CPC_Control() Command Subject Selection */ 23 #define CONTR_CAN_MESSAGE 0x04 24 #define CONTR_CAN_STATE 0x0C 25 #define CONTR_BUS_ERROR 0x1C 26 27 /* Control Command Actions */ 28 #define CONTR_CONT_OFF 0 29 #define CONTR_CONT_ON 1 30 #define CONTR_ONCE 2 31 32 /* Messages from CPC to PC */ 33 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */ 34 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */ 35 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */ 36 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */ 37 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */ 38 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */ 39 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */ 40 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */ 41 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */ 42 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */ 43 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */ 44 45 /* Messages from the PC to the CPC interface */ 46 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */ 47 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */ 48 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */ 49 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */ 50 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */ 51 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */ 52 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */ 53 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */ 54 55 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */ 56 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */ 57 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */ 58 59 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 60 61 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 62 63 /* Overrun types */ 64 #define CPC_OVR_EVENT_CAN 0x01 65 #define CPC_OVR_EVENT_CANSTATE 0x02 66 #define CPC_OVR_EVENT_BUSERROR 0x04 67 68 /* 69 * If the CAN controller lost a message we indicate it with the highest bit 70 * set in the count field. 71 */ 72 #define CPC_OVR_HW 0x80 73 74 /* Size of the "struct ems_cpc_msg" without the union */ 75 #define CPC_MSG_HEADER_LEN 11 76 #define CPC_CAN_MSG_MIN_SIZE 5 77 78 /* Define these values to match your devices */ 79 #define USB_CPCUSB_VENDOR_ID 0x12D6 80 81 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 82 83 /* Mode register NXP LPC2119/SJA1000 CAN Controller */ 84 #define SJA1000_MOD_NORMAL 0x00 85 #define SJA1000_MOD_RM 0x01 86 87 /* ECC register NXP LPC2119/SJA1000 CAN Controller */ 88 #define SJA1000_ECC_SEG 0x1F 89 #define SJA1000_ECC_DIR 0x20 90 #define SJA1000_ECC_ERR 0x06 91 #define SJA1000_ECC_BIT 0x00 92 #define SJA1000_ECC_FORM 0x40 93 #define SJA1000_ECC_STUFF 0x80 94 #define SJA1000_ECC_MASK 0xc0 95 96 /* Status register content */ 97 #define SJA1000_SR_BS 0x80 98 #define SJA1000_SR_ES 0x40 99 100 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 101 102 /* 103 * The device actually uses a 16MHz clock to generate the CAN clock 104 * but it expects SJA1000 bit settings based on 8MHz (is internally 105 * converted). 106 */ 107 #define EMS_USB_ARM7_CLOCK 8000000 108 109 #define CPC_TX_QUEUE_TRIGGER_LOW 25 110 #define CPC_TX_QUEUE_TRIGGER_HIGH 35 111 112 /* 113 * CAN-Message representation in a CPC_MSG. Message object type is 114 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or 115 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME. 116 */ 117 struct cpc_can_msg { 118 __le32 id; 119 u8 length; 120 u8 msg[8]; 121 }; 122 123 /* Representation of the CAN parameters for the SJA1000 controller */ 124 struct cpc_sja1000_params { 125 u8 mode; 126 u8 acc_code0; 127 u8 acc_code1; 128 u8 acc_code2; 129 u8 acc_code3; 130 u8 acc_mask0; 131 u8 acc_mask1; 132 u8 acc_mask2; 133 u8 acc_mask3; 134 u8 btr0; 135 u8 btr1; 136 u8 outp_contr; 137 }; 138 139 /* CAN params message representation */ 140 struct cpc_can_params { 141 u8 cc_type; 142 143 /* Will support M16C CAN controller in the future */ 144 union { 145 struct cpc_sja1000_params sja1000; 146 } cc_params; 147 }; 148 149 /* Structure for confirmed message handling */ 150 struct cpc_confirm { 151 u8 error; /* error code */ 152 }; 153 154 /* Structure for overrun conditions */ 155 struct cpc_overrun { 156 u8 event; 157 u8 count; 158 }; 159 160 /* SJA1000 CAN errors (compatible to NXP LPC2119) */ 161 struct cpc_sja1000_can_error { 162 u8 ecc; 163 u8 rxerr; 164 u8 txerr; 165 }; 166 167 /* structure for CAN error conditions */ 168 struct cpc_can_error { 169 u8 ecode; 170 171 struct { 172 u8 cc_type; 173 174 /* Other controllers may also provide error code capture regs */ 175 union { 176 struct cpc_sja1000_can_error sja1000; 177 } regs; 178 } cc; 179 }; 180 181 /* 182 * Structure containing RX/TX error counter. This structure is used to request 183 * the values of the CAN controllers TX and RX error counter. 184 */ 185 struct cpc_can_err_counter { 186 u8 rx; 187 u8 tx; 188 }; 189 190 /* Main message type used between library and application */ 191 struct __packed ems_cpc_msg { 192 u8 type; /* type of message */ 193 u8 length; /* length of data within union 'msg' */ 194 u8 msgid; /* confirmation handle */ 195 __le32 ts_sec; /* timestamp in seconds */ 196 __le32 ts_nsec; /* timestamp in nano seconds */ 197 198 union __packed { 199 u8 generic[64]; 200 struct cpc_can_msg can_msg; 201 struct cpc_can_params can_params; 202 struct cpc_confirm confirmation; 203 struct cpc_overrun overrun; 204 struct cpc_can_error error; 205 struct cpc_can_err_counter err_counter; 206 u8 can_state; 207 } msg; 208 }; 209 210 /* 211 * Table of devices that work with this driver 212 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 213 */ 214 static struct usb_device_id ems_usb_table[] = { 215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 216 {} /* Terminating entry */ 217 }; 218 219 MODULE_DEVICE_TABLE(usb, ems_usb_table); 220 221 #define RX_BUFFER_SIZE 64 222 #define CPC_HEADER_SIZE 4 223 #define INTR_IN_BUFFER_SIZE 4 224 225 #define MAX_RX_URBS 10 226 #define MAX_TX_URBS 10 227 228 struct ems_usb; 229 230 struct ems_tx_urb_context { 231 struct ems_usb *dev; 232 233 u32 echo_index; 234 }; 235 236 struct ems_usb { 237 struct can_priv can; /* must be the first member */ 238 239 struct sk_buff *echo_skb[MAX_TX_URBS]; 240 241 struct usb_device *udev; 242 struct net_device *netdev; 243 244 atomic_t active_tx_urbs; 245 struct usb_anchor tx_submitted; 246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 247 248 struct usb_anchor rx_submitted; 249 250 struct urb *intr_urb; 251 252 u8 *tx_msg_buffer; 253 254 u8 *intr_in_buffer; 255 unsigned int free_slots; /* remember number of available slots */ 256 257 struct ems_cpc_msg active_params; /* active controller parameters */ 258 void *rxbuf[MAX_RX_URBS]; 259 dma_addr_t rxbuf_dma[MAX_RX_URBS]; 260 }; 261 262 static void ems_usb_read_interrupt_callback(struct urb *urb) 263 { 264 struct ems_usb *dev = urb->context; 265 struct net_device *netdev = dev->netdev; 266 int err; 267 268 if (!netif_device_present(netdev)) 269 return; 270 271 switch (urb->status) { 272 case 0: 273 dev->free_slots = dev->intr_in_buffer[1]; 274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH && 275 netif_queue_stopped(netdev)) 276 netif_wake_queue(netdev); 277 break; 278 279 case -ECONNRESET: /* unlink */ 280 case -ENOENT: 281 case -EPIPE: 282 case -EPROTO: 283 case -ESHUTDOWN: 284 return; 285 286 default: 287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 288 break; 289 } 290 291 err = usb_submit_urb(urb, GFP_ATOMIC); 292 293 if (err == -ENODEV) 294 netif_device_detach(netdev); 295 else if (err) 296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 297 } 298 299 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 300 { 301 struct can_frame *cf; 302 struct sk_buff *skb; 303 int i; 304 struct net_device_stats *stats = &dev->netdev->stats; 305 306 skb = alloc_can_skb(dev->netdev, &cf); 307 if (skb == NULL) 308 return; 309 310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF); 312 313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 315 cf->can_id |= CAN_EFF_FLAG; 316 317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 319 cf->can_id |= CAN_RTR_FLAG; 320 } else { 321 for (i = 0; i < cf->len; i++) 322 cf->data[i] = msg->msg.can_msg.msg[i]; 323 324 stats->rx_bytes += cf->len; 325 } 326 stats->rx_packets++; 327 328 netif_rx(skb); 329 } 330 331 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 332 { 333 struct can_frame *cf; 334 struct sk_buff *skb; 335 struct net_device_stats *stats = &dev->netdev->stats; 336 337 skb = alloc_can_err_skb(dev->netdev, &cf); 338 339 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 340 u8 state = msg->msg.can_state; 341 342 if (state & SJA1000_SR_BS) { 343 dev->can.state = CAN_STATE_BUS_OFF; 344 if (skb) 345 cf->can_id |= CAN_ERR_BUSOFF; 346 347 dev->can.can_stats.bus_off++; 348 can_bus_off(dev->netdev); 349 } else if (state & SJA1000_SR_ES) { 350 dev->can.state = CAN_STATE_ERROR_WARNING; 351 dev->can.can_stats.error_warning++; 352 } else { 353 dev->can.state = CAN_STATE_ERROR_ACTIVE; 354 dev->can.can_stats.error_passive++; 355 } 356 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 357 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 358 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 359 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 360 361 /* bus error interrupt */ 362 dev->can.can_stats.bus_error++; 363 364 if (skb) { 365 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 366 367 switch (ecc & SJA1000_ECC_MASK) { 368 case SJA1000_ECC_BIT: 369 cf->data[2] |= CAN_ERR_PROT_BIT; 370 break; 371 case SJA1000_ECC_FORM: 372 cf->data[2] |= CAN_ERR_PROT_FORM; 373 break; 374 case SJA1000_ECC_STUFF: 375 cf->data[2] |= CAN_ERR_PROT_STUFF; 376 break; 377 default: 378 cf->data[3] = ecc & SJA1000_ECC_SEG; 379 break; 380 } 381 } 382 383 /* Error occurred during transmission? */ 384 if ((ecc & SJA1000_ECC_DIR) == 0) { 385 stats->tx_errors++; 386 if (skb) 387 cf->data[2] |= CAN_ERR_PROT_TX; 388 } else { 389 stats->rx_errors++; 390 } 391 392 if (skb && (dev->can.state == CAN_STATE_ERROR_WARNING || 393 dev->can.state == CAN_STATE_ERROR_PASSIVE)) { 394 cf->can_id |= CAN_ERR_CRTL; 395 cf->data[1] = (txerr > rxerr) ? 396 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 397 } 398 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 399 if (skb) { 400 cf->can_id |= CAN_ERR_CRTL; 401 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 402 } 403 404 stats->rx_over_errors++; 405 stats->rx_errors++; 406 } 407 408 if (skb) 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 += can_get_echo_skb(netdev, context->echo_index, 529 NULL); 530 531 /* Release context */ 532 context->echo_index = MAX_TX_URBS; 533 534 } 535 536 /* 537 * Send the given CPC command synchronously 538 */ 539 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 540 { 541 int actual_length; 542 543 /* Copy payload */ 544 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 545 msg->length + CPC_MSG_HEADER_LEN); 546 547 /* Clear header */ 548 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 549 550 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 551 &dev->tx_msg_buffer[0], 552 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 553 &actual_length, 1000); 554 } 555 556 /* 557 * Change CAN controllers' mode register 558 */ 559 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 560 { 561 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 562 563 return ems_usb_command_msg(dev, &dev->active_params); 564 } 565 566 /* 567 * Send a CPC_Control command to change behaviour when interface receives a CAN 568 * message, bus error or CAN state changed notifications. 569 */ 570 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 571 { 572 struct ems_cpc_msg cmd; 573 574 cmd.type = CPC_CMD_TYPE_CONTROL; 575 cmd.length = CPC_MSG_HEADER_LEN + 1; 576 577 cmd.msgid = 0; 578 579 cmd.msg.generic[0] = val; 580 581 return ems_usb_command_msg(dev, &cmd); 582 } 583 584 /* 585 * Start interface 586 */ 587 static int ems_usb_start(struct ems_usb *dev) 588 { 589 struct net_device *netdev = dev->netdev; 590 int err, i; 591 592 dev->intr_in_buffer[0] = 0; 593 dev->free_slots = 50; /* initial size */ 594 595 for (i = 0; i < MAX_RX_URBS; i++) { 596 struct urb *urb = NULL; 597 u8 *buf = NULL; 598 dma_addr_t buf_dma; 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 &buf_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 urb->transfer_dma = buf_dma; 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 dev->rxbuf[i] = buf; 634 dev->rxbuf_dma[i] = buf_dma; 635 636 /* Drop reference, USB core will take care of freeing it */ 637 usb_free_urb(urb); 638 } 639 640 /* Did we submit any URBs */ 641 if (i == 0) { 642 netdev_warn(netdev, "couldn't setup read URBs\n"); 643 return err; 644 } 645 646 /* Warn if we've couldn't transmit all the URBs */ 647 if (i < MAX_RX_URBS) 648 netdev_warn(netdev, "rx performance may be slow\n"); 649 650 /* Setup and start interrupt URB */ 651 usb_fill_int_urb(dev->intr_urb, dev->udev, 652 usb_rcvintpipe(dev->udev, 1), 653 dev->intr_in_buffer, 654 INTR_IN_BUFFER_SIZE, 655 ems_usb_read_interrupt_callback, dev, 1); 656 657 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 658 if (err) { 659 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 660 661 return err; 662 } 663 664 /* CPC-USB will transfer received message to host */ 665 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 666 if (err) 667 goto failed; 668 669 /* CPC-USB will transfer CAN state changes to host */ 670 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 671 if (err) 672 goto failed; 673 674 /* CPC-USB will transfer bus errors to host */ 675 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 676 if (err) 677 goto failed; 678 679 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 680 if (err) 681 goto failed; 682 683 dev->can.state = CAN_STATE_ERROR_ACTIVE; 684 685 return 0; 686 687 failed: 688 netdev_warn(netdev, "couldn't submit control: %d\n", err); 689 690 return err; 691 } 692 693 static void unlink_all_urbs(struct ems_usb *dev) 694 { 695 int i; 696 697 usb_unlink_urb(dev->intr_urb); 698 699 usb_kill_anchored_urbs(&dev->rx_submitted); 700 701 for (i = 0; i < MAX_RX_URBS; ++i) 702 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 703 dev->rxbuf[i], dev->rxbuf_dma[i]); 704 705 usb_kill_anchored_urbs(&dev->tx_submitted); 706 atomic_set(&dev->active_tx_urbs, 0); 707 708 for (i = 0; i < MAX_TX_URBS; i++) 709 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 710 } 711 712 static int ems_usb_open(struct net_device *netdev) 713 { 714 struct ems_usb *dev = netdev_priv(netdev); 715 int err; 716 717 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 718 if (err) 719 return err; 720 721 /* common open */ 722 err = open_candev(netdev); 723 if (err) 724 return err; 725 726 /* finally start device */ 727 err = ems_usb_start(dev); 728 if (err) { 729 if (err == -ENODEV) 730 netif_device_detach(dev->netdev); 731 732 netdev_warn(netdev, "couldn't start device: %d\n", err); 733 734 close_candev(netdev); 735 736 return err; 737 } 738 739 740 netif_start_queue(netdev); 741 742 return 0; 743 } 744 745 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 746 { 747 struct ems_usb *dev = netdev_priv(netdev); 748 struct ems_tx_urb_context *context = NULL; 749 struct net_device_stats *stats = &netdev->stats; 750 struct can_frame *cf = (struct can_frame *)skb->data; 751 struct ems_cpc_msg *msg; 752 struct urb *urb; 753 u8 *buf; 754 int i, err; 755 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 756 + sizeof(struct cpc_can_msg); 757 758 if (can_dev_dropped_skb(netdev, skb)) 759 return NETDEV_TX_OK; 760 761 /* create a URB, and a buffer for it, and copy the data to the URB */ 762 urb = usb_alloc_urb(0, GFP_ATOMIC); 763 if (!urb) 764 goto nomem; 765 766 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 767 if (!buf) { 768 netdev_err(netdev, "No memory left for USB buffer\n"); 769 usb_free_urb(urb); 770 goto nomem; 771 } 772 773 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 774 775 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 776 msg->msg.can_msg.length = cf->len; 777 778 if (cf->can_id & CAN_RTR_FLAG) { 779 msg->type = cf->can_id & CAN_EFF_FLAG ? 780 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 781 782 msg->length = CPC_CAN_MSG_MIN_SIZE; 783 } else { 784 msg->type = cf->can_id & CAN_EFF_FLAG ? 785 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 786 787 for (i = 0; i < cf->len; i++) 788 msg->msg.can_msg.msg[i] = cf->data[i]; 789 790 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 791 } 792 793 for (i = 0; i < MAX_TX_URBS; i++) { 794 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 795 context = &dev->tx_contexts[i]; 796 break; 797 } 798 } 799 800 /* 801 * May never happen! When this happens we'd more URBs in flight as 802 * allowed (MAX_TX_URBS). 803 */ 804 if (!context) { 805 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 806 usb_free_urb(urb); 807 808 netdev_warn(netdev, "couldn't find free context\n"); 809 810 return NETDEV_TX_BUSY; 811 } 812 813 context->dev = dev; 814 context->echo_index = i; 815 816 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 817 size, ems_usb_write_bulk_callback, context); 818 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 819 usb_anchor_urb(urb, &dev->tx_submitted); 820 821 can_put_echo_skb(skb, netdev, context->echo_index, 0); 822 823 atomic_inc(&dev->active_tx_urbs); 824 825 err = usb_submit_urb(urb, GFP_ATOMIC); 826 if (unlikely(err)) { 827 can_free_echo_skb(netdev, context->echo_index, NULL); 828 829 usb_unanchor_urb(urb); 830 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 831 832 atomic_dec(&dev->active_tx_urbs); 833 834 if (err == -ENODEV) { 835 netif_device_detach(netdev); 836 } else { 837 netdev_warn(netdev, "failed tx_urb %d\n", err); 838 839 stats->tx_dropped++; 840 } 841 } else { 842 netif_trans_update(netdev); 843 844 /* Slow down tx path */ 845 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 846 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 847 netif_stop_queue(netdev); 848 } 849 } 850 851 /* 852 * Release our reference to this URB, the USB core will eventually free 853 * it entirely. 854 */ 855 usb_free_urb(urb); 856 857 return NETDEV_TX_OK; 858 859 nomem: 860 dev_kfree_skb(skb); 861 stats->tx_dropped++; 862 863 return NETDEV_TX_OK; 864 } 865 866 static int ems_usb_close(struct net_device *netdev) 867 { 868 struct ems_usb *dev = netdev_priv(netdev); 869 870 /* Stop polling */ 871 unlink_all_urbs(dev); 872 873 netif_stop_queue(netdev); 874 875 /* Set CAN controller to reset mode */ 876 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 877 netdev_warn(netdev, "couldn't stop device"); 878 879 close_candev(netdev); 880 881 return 0; 882 } 883 884 static const struct net_device_ops ems_usb_netdev_ops = { 885 .ndo_open = ems_usb_open, 886 .ndo_stop = ems_usb_close, 887 .ndo_start_xmit = ems_usb_start_xmit, 888 .ndo_change_mtu = can_change_mtu, 889 }; 890 891 static const struct ethtool_ops ems_usb_ethtool_ops = { 892 .get_ts_info = ethtool_op_get_ts_info, 893 }; 894 895 static const struct can_bittiming_const ems_usb_bittiming_const = { 896 .name = KBUILD_MODNAME, 897 .tseg1_min = 1, 898 .tseg1_max = 16, 899 .tseg2_min = 1, 900 .tseg2_max = 8, 901 .sjw_max = 4, 902 .brp_min = 1, 903 .brp_max = 64, 904 .brp_inc = 1, 905 }; 906 907 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 908 { 909 struct ems_usb *dev = netdev_priv(netdev); 910 911 switch (mode) { 912 case CAN_MODE_START: 913 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 914 netdev_warn(netdev, "couldn't start device"); 915 916 if (netif_queue_stopped(netdev)) 917 netif_wake_queue(netdev); 918 break; 919 920 default: 921 return -EOPNOTSUPP; 922 } 923 924 return 0; 925 } 926 927 static int ems_usb_set_bittiming(struct net_device *netdev) 928 { 929 struct ems_usb *dev = netdev_priv(netdev); 930 struct can_bittiming *bt = &dev->can.bittiming; 931 u8 btr0, btr1; 932 933 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 934 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 935 (((bt->phase_seg2 - 1) & 0x7) << 4); 936 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 937 btr1 |= 0x80; 938 939 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 940 941 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 942 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 943 944 return ems_usb_command_msg(dev, &dev->active_params); 945 } 946 947 static void init_params_sja1000(struct ems_cpc_msg *msg) 948 { 949 struct cpc_sja1000_params *sja1000 = 950 &msg->msg.can_params.cc_params.sja1000; 951 952 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 953 msg->length = sizeof(struct cpc_can_params); 954 msg->msgid = 0; 955 956 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 957 958 /* Acceptance filter open */ 959 sja1000->acc_code0 = 0x00; 960 sja1000->acc_code1 = 0x00; 961 sja1000->acc_code2 = 0x00; 962 sja1000->acc_code3 = 0x00; 963 964 /* Acceptance filter open */ 965 sja1000->acc_mask0 = 0xFF; 966 sja1000->acc_mask1 = 0xFF; 967 sja1000->acc_mask2 = 0xFF; 968 sja1000->acc_mask3 = 0xFF; 969 970 sja1000->btr0 = 0; 971 sja1000->btr1 = 0; 972 973 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 974 sja1000->mode = SJA1000_MOD_RM; 975 } 976 977 /* 978 * probe function for new CPC-USB devices 979 */ 980 static int ems_usb_probe(struct usb_interface *intf, 981 const struct usb_device_id *id) 982 { 983 struct net_device *netdev; 984 struct ems_usb *dev; 985 int i, err = -ENOMEM; 986 987 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 988 if (!netdev) { 989 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 990 return -ENOMEM; 991 } 992 993 dev = netdev_priv(netdev); 994 995 dev->udev = interface_to_usbdev(intf); 996 dev->netdev = netdev; 997 998 dev->can.state = CAN_STATE_STOPPED; 999 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1000 dev->can.bittiming_const = &ems_usb_bittiming_const; 1001 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1002 dev->can.do_set_mode = ems_usb_set_mode; 1003 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1004 1005 netdev->netdev_ops = &ems_usb_netdev_ops; 1006 netdev->ethtool_ops = &ems_usb_ethtool_ops; 1007 1008 netdev->flags |= IFF_ECHO; /* we support local echo */ 1009 1010 init_usb_anchor(&dev->rx_submitted); 1011 1012 init_usb_anchor(&dev->tx_submitted); 1013 atomic_set(&dev->active_tx_urbs, 0); 1014 1015 for (i = 0; i < MAX_TX_URBS; i++) 1016 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1017 1018 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1019 if (!dev->intr_urb) 1020 goto cleanup_candev; 1021 1022 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1023 if (!dev->intr_in_buffer) 1024 goto cleanup_intr_urb; 1025 1026 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1027 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1028 if (!dev->tx_msg_buffer) 1029 goto cleanup_intr_in_buffer; 1030 1031 usb_set_intfdata(intf, dev); 1032 1033 SET_NETDEV_DEV(netdev, &intf->dev); 1034 1035 init_params_sja1000(&dev->active_params); 1036 1037 err = ems_usb_command_msg(dev, &dev->active_params); 1038 if (err) { 1039 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1040 goto cleanup_tx_msg_buffer; 1041 } 1042 1043 err = register_candev(netdev); 1044 if (err) { 1045 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1046 goto cleanup_tx_msg_buffer; 1047 } 1048 1049 return 0; 1050 1051 cleanup_tx_msg_buffer: 1052 kfree(dev->tx_msg_buffer); 1053 1054 cleanup_intr_in_buffer: 1055 kfree(dev->intr_in_buffer); 1056 1057 cleanup_intr_urb: 1058 usb_free_urb(dev->intr_urb); 1059 1060 cleanup_candev: 1061 free_candev(netdev); 1062 1063 return err; 1064 } 1065 1066 /* 1067 * called by the usb core when the device is removed from the system 1068 */ 1069 static void ems_usb_disconnect(struct usb_interface *intf) 1070 { 1071 struct ems_usb *dev = usb_get_intfdata(intf); 1072 1073 usb_set_intfdata(intf, NULL); 1074 1075 if (dev) { 1076 unregister_netdev(dev->netdev); 1077 1078 unlink_all_urbs(dev); 1079 1080 usb_free_urb(dev->intr_urb); 1081 1082 kfree(dev->intr_in_buffer); 1083 kfree(dev->tx_msg_buffer); 1084 1085 free_candev(dev->netdev); 1086 } 1087 } 1088 1089 /* usb specific object needed to register this driver with the usb subsystem */ 1090 static struct usb_driver ems_usb_driver = { 1091 .name = KBUILD_MODNAME, 1092 .probe = ems_usb_probe, 1093 .disconnect = ems_usb_disconnect, 1094 .id_table = ems_usb_table, 1095 }; 1096 1097 module_usb_driver(ems_usb_driver); 1098