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 usb_anchor_urb(urb, &dev->rx_submitted); 490 491 retval = usb_submit_urb(urb, GFP_ATOMIC); 492 if (!retval) 493 return; 494 495 usb_unanchor_urb(urb); 496 497 if (retval == -ENODEV) 498 netif_device_detach(netdev); 499 else 500 netdev_err(netdev, 501 "failed resubmitting read bulk urb: %d\n", retval); 502 } 503 504 /* 505 * callback for bulk IN urb 506 */ 507 static void ems_usb_write_bulk_callback(struct urb *urb) 508 { 509 struct ems_tx_urb_context *context = urb->context; 510 struct ems_usb *dev; 511 struct net_device *netdev; 512 513 BUG_ON(!context); 514 515 dev = context->dev; 516 netdev = dev->netdev; 517 518 /* free up our allocated buffer */ 519 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 520 urb->transfer_buffer, urb->transfer_dma); 521 522 atomic_dec(&dev->active_tx_urbs); 523 524 if (!netif_device_present(netdev)) 525 return; 526 527 if (urb->status) 528 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 529 530 netif_trans_update(netdev); 531 532 /* transmission complete interrupt */ 533 netdev->stats.tx_packets++; 534 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index, 535 NULL); 536 537 /* Release context */ 538 context->echo_index = MAX_TX_URBS; 539 540 } 541 542 /* 543 * Send the given CPC command synchronously 544 */ 545 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 546 { 547 int actual_length; 548 549 /* Copy payload */ 550 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 551 msg->length + CPC_MSG_HEADER_LEN); 552 553 /* Clear header */ 554 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 555 556 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 557 &dev->tx_msg_buffer[0], 558 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 559 &actual_length, 1000); 560 } 561 562 /* 563 * Change CAN controllers' mode register 564 */ 565 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 566 { 567 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 568 569 return ems_usb_command_msg(dev, &dev->active_params); 570 } 571 572 /* 573 * Send a CPC_Control command to change behaviour when interface receives a CAN 574 * message, bus error or CAN state changed notifications. 575 */ 576 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 577 { 578 struct ems_cpc_msg cmd; 579 580 cmd.type = CPC_CMD_TYPE_CONTROL; 581 cmd.length = CPC_MSG_HEADER_LEN + 1; 582 583 cmd.msgid = 0; 584 585 cmd.msg.generic[0] = val; 586 587 return ems_usb_command_msg(dev, &cmd); 588 } 589 590 /* 591 * Start interface 592 */ 593 static int ems_usb_start(struct ems_usb *dev) 594 { 595 struct net_device *netdev = dev->netdev; 596 int err, i; 597 598 dev->intr_in_buffer[0] = 0; 599 dev->free_slots = 50; /* initial size */ 600 601 for (i = 0; i < MAX_RX_URBS; i++) { 602 struct urb *urb = NULL; 603 u8 *buf = NULL; 604 dma_addr_t buf_dma; 605 606 /* create a URB, and a buffer for it */ 607 urb = usb_alloc_urb(0, GFP_KERNEL); 608 if (!urb) { 609 err = -ENOMEM; 610 break; 611 } 612 613 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 614 &buf_dma); 615 if (!buf) { 616 netdev_err(netdev, "No memory left for USB buffer\n"); 617 usb_free_urb(urb); 618 err = -ENOMEM; 619 break; 620 } 621 622 urb->transfer_dma = buf_dma; 623 624 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 625 buf, RX_BUFFER_SIZE, 626 ems_usb_read_bulk_callback, dev); 627 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 628 usb_anchor_urb(urb, &dev->rx_submitted); 629 630 err = usb_submit_urb(urb, GFP_KERNEL); 631 if (err) { 632 usb_unanchor_urb(urb); 633 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 634 urb->transfer_dma); 635 usb_free_urb(urb); 636 break; 637 } 638 639 dev->rxbuf[i] = buf; 640 dev->rxbuf_dma[i] = buf_dma; 641 642 /* Drop reference, USB core will take care of freeing it */ 643 usb_free_urb(urb); 644 } 645 646 /* Did we submit any URBs */ 647 if (i == 0) { 648 netdev_warn(netdev, "couldn't setup read URBs\n"); 649 return err; 650 } 651 652 /* Warn if we've couldn't transmit all the URBs */ 653 if (i < MAX_RX_URBS) 654 netdev_warn(netdev, "rx performance may be slow\n"); 655 656 /* Setup and start interrupt URB */ 657 usb_fill_int_urb(dev->intr_urb, dev->udev, 658 usb_rcvintpipe(dev->udev, 1), 659 dev->intr_in_buffer, 660 INTR_IN_BUFFER_SIZE, 661 ems_usb_read_interrupt_callback, dev, 1); 662 663 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 664 if (err) { 665 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 666 667 return err; 668 } 669 670 /* CPC-USB will transfer received message to host */ 671 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 672 if (err) 673 goto failed; 674 675 /* CPC-USB will transfer CAN state changes to host */ 676 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 677 if (err) 678 goto failed; 679 680 /* CPC-USB will transfer bus errors to host */ 681 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 682 if (err) 683 goto failed; 684 685 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 686 if (err) 687 goto failed; 688 689 dev->can.state = CAN_STATE_ERROR_ACTIVE; 690 691 return 0; 692 693 failed: 694 netdev_warn(netdev, "couldn't submit control: %d\n", err); 695 696 return err; 697 } 698 699 static void unlink_all_urbs(struct ems_usb *dev) 700 { 701 int i; 702 703 usb_unlink_urb(dev->intr_urb); 704 705 usb_kill_anchored_urbs(&dev->rx_submitted); 706 707 for (i = 0; i < MAX_RX_URBS; ++i) 708 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 709 dev->rxbuf[i], dev->rxbuf_dma[i]); 710 711 usb_kill_anchored_urbs(&dev->tx_submitted); 712 atomic_set(&dev->active_tx_urbs, 0); 713 714 for (i = 0; i < MAX_TX_URBS; i++) 715 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 716 } 717 718 static int ems_usb_open(struct net_device *netdev) 719 { 720 struct ems_usb *dev = netdev_priv(netdev); 721 int err; 722 723 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 724 if (err) 725 return err; 726 727 /* common open */ 728 err = open_candev(netdev); 729 if (err) 730 return err; 731 732 /* finally start device */ 733 err = ems_usb_start(dev); 734 if (err) { 735 if (err == -ENODEV) 736 netif_device_detach(dev->netdev); 737 738 netdev_warn(netdev, "couldn't start device: %d\n", err); 739 740 close_candev(netdev); 741 742 return err; 743 } 744 745 746 netif_start_queue(netdev); 747 748 return 0; 749 } 750 751 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 752 { 753 struct ems_usb *dev = netdev_priv(netdev); 754 struct ems_tx_urb_context *context = NULL; 755 struct net_device_stats *stats = &netdev->stats; 756 struct can_frame *cf = (struct can_frame *)skb->data; 757 struct ems_cpc_msg *msg; 758 struct urb *urb; 759 u8 *buf; 760 int i, err; 761 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 762 + sizeof(struct cpc_can_msg); 763 764 if (can_dev_dropped_skb(netdev, skb)) 765 return NETDEV_TX_OK; 766 767 /* create a URB, and a buffer for it, and copy the data to the URB */ 768 urb = usb_alloc_urb(0, GFP_ATOMIC); 769 if (!urb) 770 goto nomem; 771 772 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 773 if (!buf) { 774 netdev_err(netdev, "No memory left for USB buffer\n"); 775 usb_free_urb(urb); 776 goto nomem; 777 } 778 779 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 780 781 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 782 msg->msg.can_msg.length = cf->len; 783 784 if (cf->can_id & CAN_RTR_FLAG) { 785 msg->type = cf->can_id & CAN_EFF_FLAG ? 786 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 787 788 msg->length = CPC_CAN_MSG_MIN_SIZE; 789 } else { 790 msg->type = cf->can_id & CAN_EFF_FLAG ? 791 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 792 793 for (i = 0; i < cf->len; i++) 794 msg->msg.can_msg.msg[i] = cf->data[i]; 795 796 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 797 } 798 799 for (i = 0; i < MAX_TX_URBS; i++) { 800 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 801 context = &dev->tx_contexts[i]; 802 break; 803 } 804 } 805 806 /* 807 * May never happen! When this happens we'd more URBs in flight as 808 * allowed (MAX_TX_URBS). 809 */ 810 if (!context) { 811 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 812 usb_free_urb(urb); 813 814 netdev_warn(netdev, "couldn't find free context\n"); 815 816 return NETDEV_TX_BUSY; 817 } 818 819 context->dev = dev; 820 context->echo_index = i; 821 822 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 823 size, ems_usb_write_bulk_callback, context); 824 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 825 usb_anchor_urb(urb, &dev->tx_submitted); 826 827 can_put_echo_skb(skb, netdev, context->echo_index, 0); 828 829 atomic_inc(&dev->active_tx_urbs); 830 831 err = usb_submit_urb(urb, GFP_ATOMIC); 832 if (unlikely(err)) { 833 can_free_echo_skb(netdev, context->echo_index, NULL); 834 835 usb_unanchor_urb(urb); 836 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 837 838 atomic_dec(&dev->active_tx_urbs); 839 840 if (err == -ENODEV) { 841 netif_device_detach(netdev); 842 } else { 843 netdev_warn(netdev, "failed tx_urb %d\n", err); 844 845 stats->tx_dropped++; 846 } 847 } else { 848 netif_trans_update(netdev); 849 850 /* Slow down tx path */ 851 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 852 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 853 netif_stop_queue(netdev); 854 } 855 } 856 857 /* 858 * Release our reference to this URB, the USB core will eventually free 859 * it entirely. 860 */ 861 usb_free_urb(urb); 862 863 return NETDEV_TX_OK; 864 865 nomem: 866 dev_kfree_skb(skb); 867 stats->tx_dropped++; 868 869 return NETDEV_TX_OK; 870 } 871 872 static int ems_usb_close(struct net_device *netdev) 873 { 874 struct ems_usb *dev = netdev_priv(netdev); 875 876 /* Stop polling */ 877 unlink_all_urbs(dev); 878 879 netif_stop_queue(netdev); 880 881 /* Set CAN controller to reset mode */ 882 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 883 netdev_warn(netdev, "couldn't stop device"); 884 885 close_candev(netdev); 886 887 return 0; 888 } 889 890 static const struct net_device_ops ems_usb_netdev_ops = { 891 .ndo_open = ems_usb_open, 892 .ndo_stop = ems_usb_close, 893 .ndo_start_xmit = ems_usb_start_xmit, 894 }; 895 896 static const struct ethtool_ops ems_usb_ethtool_ops = { 897 .get_ts_info = ethtool_op_get_ts_info, 898 }; 899 900 static const struct can_bittiming_const ems_usb_bittiming_const = { 901 .name = KBUILD_MODNAME, 902 .tseg1_min = 1, 903 .tseg1_max = 16, 904 .tseg2_min = 1, 905 .tseg2_max = 8, 906 .sjw_max = 4, 907 .brp_min = 1, 908 .brp_max = 64, 909 .brp_inc = 1, 910 }; 911 912 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 913 { 914 struct ems_usb *dev = netdev_priv(netdev); 915 916 switch (mode) { 917 case CAN_MODE_START: 918 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 919 netdev_warn(netdev, "couldn't start device"); 920 921 if (netif_queue_stopped(netdev)) 922 netif_wake_queue(netdev); 923 break; 924 925 default: 926 return -EOPNOTSUPP; 927 } 928 929 return 0; 930 } 931 932 static int ems_usb_set_bittiming(struct net_device *netdev) 933 { 934 struct ems_usb *dev = netdev_priv(netdev); 935 struct can_bittiming *bt = &dev->can.bittiming; 936 u8 btr0, btr1; 937 938 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 939 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 940 (((bt->phase_seg2 - 1) & 0x7) << 4); 941 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 942 btr1 |= 0x80; 943 944 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 945 946 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 947 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 948 949 return ems_usb_command_msg(dev, &dev->active_params); 950 } 951 952 static void init_params_sja1000(struct ems_cpc_msg *msg) 953 { 954 struct cpc_sja1000_params *sja1000 = 955 &msg->msg.can_params.cc_params.sja1000; 956 957 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 958 msg->length = sizeof(struct cpc_can_params); 959 msg->msgid = 0; 960 961 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 962 963 /* Acceptance filter open */ 964 sja1000->acc_code0 = 0x00; 965 sja1000->acc_code1 = 0x00; 966 sja1000->acc_code2 = 0x00; 967 sja1000->acc_code3 = 0x00; 968 969 /* Acceptance filter open */ 970 sja1000->acc_mask0 = 0xFF; 971 sja1000->acc_mask1 = 0xFF; 972 sja1000->acc_mask2 = 0xFF; 973 sja1000->acc_mask3 = 0xFF; 974 975 sja1000->btr0 = 0; 976 sja1000->btr1 = 0; 977 978 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 979 sja1000->mode = SJA1000_MOD_RM; 980 } 981 982 /* 983 * probe function for new CPC-USB devices 984 */ 985 static int ems_usb_probe(struct usb_interface *intf, 986 const struct usb_device_id *id) 987 { 988 struct net_device *netdev; 989 struct ems_usb *dev; 990 int i, err = -ENOMEM; 991 992 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 993 if (!netdev) { 994 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 995 return -ENOMEM; 996 } 997 998 dev = netdev_priv(netdev); 999 1000 dev->udev = interface_to_usbdev(intf); 1001 dev->netdev = netdev; 1002 1003 dev->can.state = CAN_STATE_STOPPED; 1004 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1005 dev->can.bittiming_const = &ems_usb_bittiming_const; 1006 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1007 dev->can.do_set_mode = ems_usb_set_mode; 1008 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1009 1010 netdev->netdev_ops = &ems_usb_netdev_ops; 1011 netdev->ethtool_ops = &ems_usb_ethtool_ops; 1012 1013 netdev->flags |= IFF_ECHO; /* we support local echo */ 1014 1015 init_usb_anchor(&dev->rx_submitted); 1016 1017 init_usb_anchor(&dev->tx_submitted); 1018 atomic_set(&dev->active_tx_urbs, 0); 1019 1020 for (i = 0; i < MAX_TX_URBS; i++) 1021 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1022 1023 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1024 if (!dev->intr_urb) 1025 goto cleanup_candev; 1026 1027 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1028 if (!dev->intr_in_buffer) 1029 goto cleanup_intr_urb; 1030 1031 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1032 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1033 if (!dev->tx_msg_buffer) 1034 goto cleanup_intr_in_buffer; 1035 1036 usb_set_intfdata(intf, dev); 1037 1038 SET_NETDEV_DEV(netdev, &intf->dev); 1039 1040 init_params_sja1000(&dev->active_params); 1041 1042 err = ems_usb_command_msg(dev, &dev->active_params); 1043 if (err) { 1044 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1045 goto cleanup_tx_msg_buffer; 1046 } 1047 1048 err = register_candev(netdev); 1049 if (err) { 1050 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1051 goto cleanup_tx_msg_buffer; 1052 } 1053 1054 return 0; 1055 1056 cleanup_tx_msg_buffer: 1057 kfree(dev->tx_msg_buffer); 1058 1059 cleanup_intr_in_buffer: 1060 kfree(dev->intr_in_buffer); 1061 1062 cleanup_intr_urb: 1063 usb_free_urb(dev->intr_urb); 1064 1065 cleanup_candev: 1066 free_candev(netdev); 1067 1068 return err; 1069 } 1070 1071 /* 1072 * called by the usb core when the device is removed from the system 1073 */ 1074 static void ems_usb_disconnect(struct usb_interface *intf) 1075 { 1076 struct ems_usb *dev = usb_get_intfdata(intf); 1077 1078 usb_set_intfdata(intf, NULL); 1079 1080 if (dev) { 1081 unregister_netdev(dev->netdev); 1082 1083 unlink_all_urbs(dev); 1084 1085 usb_free_urb(dev->intr_urb); 1086 1087 kfree(dev->intr_in_buffer); 1088 kfree(dev->tx_msg_buffer); 1089 1090 free_candev(dev->netdev); 1091 } 1092 } 1093 1094 /* usb specific object needed to register this driver with the usb subsystem */ 1095 static struct usb_driver ems_usb_driver = { 1096 .name = KBUILD_MODNAME, 1097 .probe = ems_usb_probe, 1098 .disconnect = ems_usb_disconnect, 1099 .id_table = ems_usb_table, 1100 }; 1101 1102 module_usb_driver(ems_usb_driver); 1103