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 18MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 19MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 20MODULE_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 */ 117struct 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 */ 124struct 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 */ 140struct 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 */ 150struct cpc_confirm { 151 u8 error; /* error code */ 152}; 153 154/* Structure for overrun conditions */ 155struct cpc_overrun { 156 u8 event; 157 u8 count; 158}; 159 160/* SJA1000 CAN errors (compatible to NXP LPC2119) */ 161struct cpc_sja1000_can_error { 162 u8 ecc; 163 u8 rxerr; 164 u8 txerr; 165}; 166 167/* structure for CAN error conditions */ 168struct 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 */ 185struct cpc_can_err_counter { 186 u8 rx; 187 u8 tx; 188}; 189 190/* Main message type used between library and application */ 191struct __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 */ 214static struct usb_device_id ems_usb_table[] = { 215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 216 {} /* Terminating entry */ 217}; 218 219MODULE_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 228struct ems_usb; 229 230struct ems_tx_urb_context { 231 struct ems_usb *dev; 232 233 u32 echo_index; 234}; 235 236struct 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 262static 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 299static 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 331static 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 if (skb == NULL) 339 return; 340 341 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 342 u8 state = msg->msg.can_state; 343 344 if (state & SJA1000_SR_BS) { 345 dev->can.state = CAN_STATE_BUS_OFF; 346 cf->can_id |= CAN_ERR_BUSOFF; 347 348 dev->can.can_stats.bus_off++; 349 can_bus_off(dev->netdev); 350 } else if (state & SJA1000_SR_ES) { 351 dev->can.state = CAN_STATE_ERROR_WARNING; 352 dev->can.can_stats.error_warning++; 353 } else { 354 dev->can.state = CAN_STATE_ERROR_ACTIVE; 355 dev->can.can_stats.error_passive++; 356 } 357 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 358 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 359 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 360 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 361 362 /* bus error interrupt */ 363 dev->can.can_stats.bus_error++; 364 stats->rx_errors++; 365 366 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 367 368 switch (ecc & SJA1000_ECC_MASK) { 369 case SJA1000_ECC_BIT: 370 cf->data[2] |= CAN_ERR_PROT_BIT; 371 break; 372 case SJA1000_ECC_FORM: 373 cf->data[2] |= CAN_ERR_PROT_FORM; 374 break; 375 case SJA1000_ECC_STUFF: 376 cf->data[2] |= CAN_ERR_PROT_STUFF; 377 break; 378 default: 379 cf->data[3] = ecc & SJA1000_ECC_SEG; 380 break; 381 } 382 383 /* Error occurred during transmission? */ 384 if ((ecc & SJA1000_ECC_DIR) == 0) 385 cf->data[2] |= CAN_ERR_PROT_TX; 386 387 if (dev->can.state == CAN_STATE_ERROR_WARNING || 388 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 389 cf->can_id |= CAN_ERR_CRTL; 390 cf->data[1] = (txerr > rxerr) ? 391 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 392 } 393 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 394 cf->can_id |= CAN_ERR_CRTL; 395 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 396 397 stats->rx_over_errors++; 398 stats->rx_errors++; 399 } 400 401 netif_rx(skb); 402} 403 404/* 405 * callback for bulk IN urb 406 */ 407static void ems_usb_read_bulk_callback(struct urb *urb) 408{ 409 struct ems_usb *dev = urb->context; 410 struct net_device *netdev; 411 int retval; 412 413 netdev = dev->netdev; 414 415 if (!netif_device_present(netdev)) 416 return; 417 418 switch (urb->status) { 419 case 0: /* success */ 420 break; 421 422 case -ENOENT: 423 return; 424 425 default: 426 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 427 goto resubmit_urb; 428 } 429 430 if (urb->actual_length > CPC_HEADER_SIZE) { 431 struct ems_cpc_msg *msg; 432 u8 *ibuf = urb->transfer_buffer; 433 u8 msg_count, start; 434 435 msg_count = ibuf[0] & ~0x80; 436 437 start = CPC_HEADER_SIZE; 438 439 while (msg_count) { 440 msg = (struct ems_cpc_msg *)&ibuf[start]; 441 442 switch (msg->type) { 443 case CPC_MSG_TYPE_CAN_STATE: 444 /* Process CAN state changes */ 445 ems_usb_rx_err(dev, msg); 446 break; 447 448 case CPC_MSG_TYPE_CAN_FRAME: 449 case CPC_MSG_TYPE_EXT_CAN_FRAME: 450 case CPC_MSG_TYPE_RTR_FRAME: 451 case CPC_MSG_TYPE_EXT_RTR_FRAME: 452 ems_usb_rx_can_msg(dev, msg); 453 break; 454 455 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 456 /* Process errorframe */ 457 ems_usb_rx_err(dev, msg); 458 break; 459 460 case CPC_MSG_TYPE_OVERRUN: 461 /* Message lost while receiving */ 462 ems_usb_rx_err(dev, msg); 463 break; 464 } 465 466 start += CPC_MSG_HEADER_LEN + msg->length; 467 msg_count--; 468 469 if (start > urb->transfer_buffer_length) { 470 netdev_err(netdev, "format error\n"); 471 break; 472 } 473 } 474 } 475 476resubmit_urb: 477 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 478 urb->transfer_buffer, RX_BUFFER_SIZE, 479 ems_usb_read_bulk_callback, dev); 480 481 retval = usb_submit_urb(urb, GFP_ATOMIC); 482 483 if (retval == -ENODEV) 484 netif_device_detach(netdev); 485 else if (retval) 486 netdev_err(netdev, 487 "failed resubmitting read bulk urb: %d\n", retval); 488} 489 490/* 491 * callback for bulk IN urb 492 */ 493static void ems_usb_write_bulk_callback(struct urb *urb) 494{ 495 struct ems_tx_urb_context *context = urb->context; 496 struct ems_usb *dev; 497 struct net_device *netdev; 498 499 BUG_ON(!context); 500 501 dev = context->dev; 502 netdev = dev->netdev; 503 504 /* free up our allocated buffer */ 505 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 506 urb->transfer_buffer, urb->transfer_dma); 507 508 atomic_dec(&dev->active_tx_urbs); 509 510 if (!netif_device_present(netdev)) 511 return; 512 513 if (urb->status) 514 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 515 516 netif_trans_update(netdev); 517 518 /* transmission complete interrupt */ 519 netdev->stats.tx_packets++; 520 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index, 521 NULL); 522 523 /* Release context */ 524 context->echo_index = MAX_TX_URBS; 525 526} 527 528/* 529 * Send the given CPC command synchronously 530 */ 531static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 532{ 533 int actual_length; 534 535 /* Copy payload */ 536 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 537 msg->length + CPC_MSG_HEADER_LEN); 538 539 /* Clear header */ 540 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 541 542 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 543 &dev->tx_msg_buffer[0], 544 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 545 &actual_length, 1000); 546} 547 548/* 549 * Change CAN controllers' mode register 550 */ 551static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 552{ 553 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 554 555 return ems_usb_command_msg(dev, &dev->active_params); 556} 557 558/* 559 * Send a CPC_Control command to change behaviour when interface receives a CAN 560 * message, bus error or CAN state changed notifications. 561 */ 562static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 563{ 564 struct ems_cpc_msg cmd; 565 566 cmd.type = CPC_CMD_TYPE_CONTROL; 567 cmd.length = CPC_MSG_HEADER_LEN + 1; 568 569 cmd.msgid = 0; 570 571 cmd.msg.generic[0] = val; 572 573 return ems_usb_command_msg(dev, &cmd); 574} 575 576/* 577 * Start interface 578 */ 579static int ems_usb_start(struct ems_usb *dev) 580{ 581 struct net_device *netdev = dev->netdev; 582 int err, i; 583 584 dev->intr_in_buffer[0] = 0; 585 dev->free_slots = 50; /* initial size */ 586 587 for (i = 0; i < MAX_RX_URBS; i++) { 588 struct urb *urb = NULL; 589 u8 *buf = NULL; 590 dma_addr_t buf_dma; 591 592 /* create a URB, and a buffer for it */ 593 urb = usb_alloc_urb(0, GFP_KERNEL); 594 if (!urb) { 595 err = -ENOMEM; 596 break; 597 } 598 599 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 600 &buf_dma); 601 if (!buf) { 602 netdev_err(netdev, "No memory left for USB buffer\n"); 603 usb_free_urb(urb); 604 err = -ENOMEM; 605 break; 606 } 607 608 urb->transfer_dma = buf_dma; 609 610 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 611 buf, RX_BUFFER_SIZE, 612 ems_usb_read_bulk_callback, dev); 613 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 614 usb_anchor_urb(urb, &dev->rx_submitted); 615 616 err = usb_submit_urb(urb, GFP_KERNEL); 617 if (err) { 618 usb_unanchor_urb(urb); 619 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 620 urb->transfer_dma); 621 usb_free_urb(urb); 622 break; 623 } 624 625 dev->rxbuf[i] = buf; 626 dev->rxbuf_dma[i] = buf_dma; 627 628 /* Drop reference, USB core will take care of freeing it */ 629 usb_free_urb(urb); 630 } 631 632 /* Did we submit any URBs */ 633 if (i == 0) { 634 netdev_warn(netdev, "couldn't setup read URBs\n"); 635 return err; 636 } 637 638 /* Warn if we've couldn't transmit all the URBs */ 639 if (i < MAX_RX_URBS) 640 netdev_warn(netdev, "rx performance may be slow\n"); 641 642 /* Setup and start interrupt URB */ 643 usb_fill_int_urb(dev->intr_urb, dev->udev, 644 usb_rcvintpipe(dev->udev, 1), 645 dev->intr_in_buffer, 646 INTR_IN_BUFFER_SIZE, 647 ems_usb_read_interrupt_callback, dev, 1); 648 649 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 650 if (err) { 651 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 652 653 return err; 654 } 655 656 /* CPC-USB will transfer received message to host */ 657 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 658 if (err) 659 goto failed; 660 661 /* CPC-USB will transfer CAN state changes to host */ 662 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 663 if (err) 664 goto failed; 665 666 /* CPC-USB will transfer bus errors to host */ 667 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 668 if (err) 669 goto failed; 670 671 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 672 if (err) 673 goto failed; 674 675 dev->can.state = CAN_STATE_ERROR_ACTIVE; 676 677 return 0; 678 679failed: 680 netdev_warn(netdev, "couldn't submit control: %d\n", err); 681 682 return err; 683} 684 685static void unlink_all_urbs(struct ems_usb *dev) 686{ 687 int i; 688 689 usb_unlink_urb(dev->intr_urb); 690 691 usb_kill_anchored_urbs(&dev->rx_submitted); 692 693 for (i = 0; i < MAX_RX_URBS; ++i) 694 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 695 dev->rxbuf[i], dev->rxbuf_dma[i]); 696 697 usb_kill_anchored_urbs(&dev->tx_submitted); 698 atomic_set(&dev->active_tx_urbs, 0); 699 700 for (i = 0; i < MAX_TX_URBS; i++) 701 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 702} 703 704static int ems_usb_open(struct net_device *netdev) 705{ 706 struct ems_usb *dev = netdev_priv(netdev); 707 int err; 708 709 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 710 if (err) 711 return err; 712 713 /* common open */ 714 err = open_candev(netdev); 715 if (err) 716 return err; 717 718 /* finally start device */ 719 err = ems_usb_start(dev); 720 if (err) { 721 if (err == -ENODEV) 722 netif_device_detach(dev->netdev); 723 724 netdev_warn(netdev, "couldn't start device: %d\n", err); 725 726 close_candev(netdev); 727 728 return err; 729 } 730 731 732 netif_start_queue(netdev); 733 734 return 0; 735} 736 737static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 738{ 739 struct ems_usb *dev = netdev_priv(netdev); 740 struct ems_tx_urb_context *context = NULL; 741 struct net_device_stats *stats = &netdev->stats; 742 struct can_frame *cf = (struct can_frame *)skb->data; 743 struct ems_cpc_msg *msg; 744 struct urb *urb; 745 u8 *buf; 746 int i, err; 747 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 748 + sizeof(struct cpc_can_msg); 749 750 if (can_dev_dropped_skb(netdev, skb)) 751 return NETDEV_TX_OK; 752 753 /* create a URB, and a buffer for it, and copy the data to the URB */ 754 urb = usb_alloc_urb(0, GFP_ATOMIC); 755 if (!urb) 756 goto nomem; 757 758 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 759 if (!buf) { 760 netdev_err(netdev, "No memory left for USB buffer\n"); 761 usb_free_urb(urb); 762 goto nomem; 763 } 764 765 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 766 767 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 768 msg->msg.can_msg.length = cf->len; 769 770 if (cf->can_id & CAN_RTR_FLAG) { 771 msg->type = cf->can_id & CAN_EFF_FLAG ? 772 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 773 774 msg->length = CPC_CAN_MSG_MIN_SIZE; 775 } else { 776 msg->type = cf->can_id & CAN_EFF_FLAG ? 777 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 778 779 for (i = 0; i < cf->len; i++) 780 msg->msg.can_msg.msg[i] = cf->data[i]; 781 782 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 783 } 784 785 for (i = 0; i < MAX_TX_URBS; i++) { 786 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 787 context = &dev->tx_contexts[i]; 788 break; 789 } 790 } 791 792 /* 793 * May never happen! When this happens we'd more URBs in flight as 794 * allowed (MAX_TX_URBS). 795 */ 796 if (!context) { 797 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 798 usb_free_urb(urb); 799 800 netdev_warn(netdev, "couldn't find free context\n"); 801 802 return NETDEV_TX_BUSY; 803 } 804 805 context->dev = dev; 806 context->echo_index = i; 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, 0); 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, NULL); 820 821 usb_unanchor_urb(urb); 822 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 823 824 atomic_dec(&dev->active_tx_urbs); 825 826 if (err == -ENODEV) { 827 netif_device_detach(netdev); 828 } else { 829 netdev_warn(netdev, "failed tx_urb %d\n", err); 830 831 stats->tx_dropped++; 832 } 833 } else { 834 netif_trans_update(netdev); 835 836 /* Slow down tx path */ 837 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 838 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 839 netif_stop_queue(netdev); 840 } 841 } 842 843 /* 844 * Release our reference to this URB, the USB core will eventually free 845 * it entirely. 846 */ 847 usb_free_urb(urb); 848 849 return NETDEV_TX_OK; 850 851nomem: 852 dev_kfree_skb(skb); 853 stats->tx_dropped++; 854 855 return NETDEV_TX_OK; 856} 857 858static int ems_usb_close(struct net_device *netdev) 859{ 860 struct ems_usb *dev = netdev_priv(netdev); 861 862 /* Stop polling */ 863 unlink_all_urbs(dev); 864 865 netif_stop_queue(netdev); 866 867 /* Set CAN controller to reset mode */ 868 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 869 netdev_warn(netdev, "couldn't stop device"); 870 871 close_candev(netdev); 872 873 return 0; 874} 875 876static const struct net_device_ops ems_usb_netdev_ops = { 877 .ndo_open = ems_usb_open, 878 .ndo_stop = ems_usb_close, 879 .ndo_start_xmit = ems_usb_start_xmit, 880 .ndo_change_mtu = can_change_mtu, 881}; 882 883static const struct ethtool_ops ems_usb_ethtool_ops = { 884 .get_ts_info = ethtool_op_get_ts_info, 885}; 886 887static const struct can_bittiming_const ems_usb_bittiming_const = { 888 .name = KBUILD_MODNAME, 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 899static 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 919static 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 939static 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 */ 972static 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 netdev->ethtool_ops = &ems_usb_ethtool_ops; 999 1000 netdev->flags |= IFF_ECHO; /* we support local echo */ 1001 1002 init_usb_anchor(&dev->rx_submitted); 1003 1004 init_usb_anchor(&dev->tx_submitted); 1005 atomic_set(&dev->active_tx_urbs, 0); 1006 1007 for (i = 0; i < MAX_TX_URBS; i++) 1008 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1009 1010 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1011 if (!dev->intr_urb) 1012 goto cleanup_candev; 1013 1014 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1015 if (!dev->intr_in_buffer) 1016 goto cleanup_intr_urb; 1017 1018 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1019 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1020 if (!dev->tx_msg_buffer) 1021 goto cleanup_intr_in_buffer; 1022 1023 usb_set_intfdata(intf, dev); 1024 1025 SET_NETDEV_DEV(netdev, &intf->dev); 1026 1027 init_params_sja1000(&dev->active_params); 1028 1029 err = ems_usb_command_msg(dev, &dev->active_params); 1030 if (err) { 1031 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1032 goto cleanup_tx_msg_buffer; 1033 } 1034 1035 err = register_candev(netdev); 1036 if (err) { 1037 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1038 goto cleanup_tx_msg_buffer; 1039 } 1040 1041 return 0; 1042 1043cleanup_tx_msg_buffer: 1044 kfree(dev->tx_msg_buffer); 1045 1046cleanup_intr_in_buffer: 1047 kfree(dev->intr_in_buffer); 1048 1049cleanup_intr_urb: 1050 usb_free_urb(dev->intr_urb); 1051 1052cleanup_candev: 1053 free_candev(netdev); 1054 1055 return err; 1056} 1057 1058/* 1059 * called by the usb core when the device is removed from the system 1060 */ 1061static void ems_usb_disconnect(struct usb_interface *intf) 1062{ 1063 struct ems_usb *dev = usb_get_intfdata(intf); 1064 1065 usb_set_intfdata(intf, NULL); 1066 1067 if (dev) { 1068 unregister_netdev(dev->netdev); 1069 1070 unlink_all_urbs(dev); 1071 1072 usb_free_urb(dev->intr_urb); 1073 1074 kfree(dev->intr_in_buffer); 1075 kfree(dev->tx_msg_buffer); 1076 1077 free_candev(dev->netdev); 1078 } 1079} 1080 1081/* usb specific object needed to register this driver with the usb subsystem */ 1082static struct usb_driver ems_usb_driver = { 1083 .name = KBUILD_MODNAME, 1084 .probe = ems_usb_probe, 1085 .disconnect = ems_usb_disconnect, 1086 .id_table = ems_usb_table, 1087}; 1088 1089module_usb_driver(ems_usb_driver); 1090