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 static bool ems_usb_rx_msg_len_valid(struct ems_cpc_msg *msg) 413 { 414 size_t len = msg->length; 415 size_t can_len; 416 417 switch (msg->type) { 418 case CPC_MSG_TYPE_CAN_STATE: 419 return len >= sizeof(msg->msg.can_state); 420 421 case CPC_MSG_TYPE_CAN_FRAME: 422 case CPC_MSG_TYPE_EXT_CAN_FRAME: 423 case CPC_MSG_TYPE_RTR_FRAME: 424 case CPC_MSG_TYPE_EXT_RTR_FRAME: 425 if (len < CPC_CAN_MSG_MIN_SIZE) 426 return false; 427 428 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 429 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 430 return true; 431 432 can_len = can_cc_dlc2len(msg->msg.can_msg.length & 0xf); 433 return len >= CPC_CAN_MSG_MIN_SIZE + can_len; 434 435 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 436 return len >= sizeof(msg->msg.error); 437 438 case CPC_MSG_TYPE_OVERRUN: 439 return len >= sizeof(msg->msg.overrun); 440 441 default: 442 return true; 443 } 444 } 445 446 /* 447 * callback for bulk IN urb 448 */ 449 static void ems_usb_read_bulk_callback(struct urb *urb) 450 { 451 struct ems_usb *dev = urb->context; 452 struct net_device *netdev; 453 int retval; 454 455 netdev = dev->netdev; 456 457 if (!netif_device_present(netdev)) 458 return; 459 460 switch (urb->status) { 461 case 0: /* success */ 462 break; 463 464 case -ENOENT: 465 return; 466 467 default: 468 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 469 goto resubmit_urb; 470 } 471 472 if (urb->actual_length > CPC_HEADER_SIZE) { 473 struct ems_cpc_msg *msg; 474 u8 *ibuf = urb->transfer_buffer; 475 u8 msg_count, start; 476 477 msg_count = ibuf[0] & ~0x80; 478 479 start = CPC_HEADER_SIZE; 480 481 while (msg_count) { 482 if (start + CPC_MSG_HEADER_LEN > urb->actual_length) { 483 netdev_err(netdev, "format error\n"); 484 break; 485 } 486 487 msg = (struct ems_cpc_msg *)&ibuf[start]; 488 if (msg->length > 489 urb->actual_length - start - CPC_MSG_HEADER_LEN) { 490 netdev_err(netdev, "format error\n"); 491 break; 492 } 493 if (!ems_usb_rx_msg_len_valid(msg)) { 494 netdev_err(netdev, "format error\n"); 495 break; 496 } 497 498 switch (msg->type) { 499 case CPC_MSG_TYPE_CAN_STATE: 500 /* Process CAN state changes */ 501 ems_usb_rx_err(dev, msg); 502 break; 503 504 case CPC_MSG_TYPE_CAN_FRAME: 505 case CPC_MSG_TYPE_EXT_CAN_FRAME: 506 case CPC_MSG_TYPE_RTR_FRAME: 507 case CPC_MSG_TYPE_EXT_RTR_FRAME: 508 ems_usb_rx_can_msg(dev, msg); 509 break; 510 511 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 512 /* Process errorframe */ 513 ems_usb_rx_err(dev, msg); 514 break; 515 516 case CPC_MSG_TYPE_OVERRUN: 517 /* Message lost while receiving */ 518 ems_usb_rx_err(dev, msg); 519 break; 520 } 521 522 start += CPC_MSG_HEADER_LEN + msg->length; 523 msg_count--; 524 525 if (start > urb->actual_length) { 526 netdev_err(netdev, "format error\n"); 527 break; 528 } 529 } 530 } 531 532 resubmit_urb: 533 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 534 urb->transfer_buffer, RX_BUFFER_SIZE, 535 ems_usb_read_bulk_callback, dev); 536 537 usb_anchor_urb(urb, &dev->rx_submitted); 538 539 retval = usb_submit_urb(urb, GFP_ATOMIC); 540 if (!retval) 541 return; 542 543 usb_unanchor_urb(urb); 544 545 if (retval == -ENODEV) 546 netif_device_detach(netdev); 547 else 548 netdev_err(netdev, 549 "failed resubmitting read bulk urb: %d\n", retval); 550 } 551 552 /* 553 * callback for bulk IN urb 554 */ 555 static void ems_usb_write_bulk_callback(struct urb *urb) 556 { 557 struct ems_tx_urb_context *context = urb->context; 558 struct ems_usb *dev; 559 struct net_device *netdev; 560 561 BUG_ON(!context); 562 563 dev = context->dev; 564 netdev = dev->netdev; 565 566 /* free up our allocated buffer */ 567 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 568 urb->transfer_buffer, urb->transfer_dma); 569 570 atomic_dec(&dev->active_tx_urbs); 571 572 if (!netif_device_present(netdev)) 573 return; 574 575 if (urb->status) 576 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 577 578 netif_trans_update(netdev); 579 580 /* transmission complete interrupt */ 581 netdev->stats.tx_packets++; 582 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index, 583 NULL); 584 585 /* Release context */ 586 context->echo_index = MAX_TX_URBS; 587 588 } 589 590 /* 591 * Send the given CPC command synchronously 592 */ 593 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 594 { 595 int actual_length; 596 597 /* Copy payload */ 598 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 599 msg->length + CPC_MSG_HEADER_LEN); 600 601 /* Clear header */ 602 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 603 604 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 605 &dev->tx_msg_buffer[0], 606 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 607 &actual_length, 1000); 608 } 609 610 /* 611 * Change CAN controllers' mode register 612 */ 613 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 614 { 615 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 616 617 return ems_usb_command_msg(dev, &dev->active_params); 618 } 619 620 /* 621 * Send a CPC_Control command to change behaviour when interface receives a CAN 622 * message, bus error or CAN state changed notifications. 623 */ 624 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 625 { 626 struct ems_cpc_msg cmd; 627 628 cmd.type = CPC_CMD_TYPE_CONTROL; 629 cmd.length = CPC_MSG_HEADER_LEN + 1; 630 631 cmd.msgid = 0; 632 633 cmd.msg.generic[0] = val; 634 635 return ems_usb_command_msg(dev, &cmd); 636 } 637 638 /* 639 * Start interface 640 */ 641 static int ems_usb_start(struct ems_usb *dev) 642 { 643 struct net_device *netdev = dev->netdev; 644 int err, i; 645 646 dev->intr_in_buffer[0] = 0; 647 dev->free_slots = 50; /* initial size */ 648 649 for (i = 0; i < MAX_RX_URBS; i++) { 650 struct urb *urb = NULL; 651 u8 *buf = NULL; 652 dma_addr_t buf_dma; 653 654 /* create a URB, and a buffer for it */ 655 urb = usb_alloc_urb(0, GFP_KERNEL); 656 if (!urb) { 657 err = -ENOMEM; 658 break; 659 } 660 661 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 662 &buf_dma); 663 if (!buf) { 664 netdev_err(netdev, "No memory left for USB buffer\n"); 665 usb_free_urb(urb); 666 err = -ENOMEM; 667 break; 668 } 669 670 urb->transfer_dma = buf_dma; 671 672 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 673 buf, RX_BUFFER_SIZE, 674 ems_usb_read_bulk_callback, dev); 675 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 676 usb_anchor_urb(urb, &dev->rx_submitted); 677 678 err = usb_submit_urb(urb, GFP_KERNEL); 679 if (err) { 680 usb_unanchor_urb(urb); 681 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 682 urb->transfer_dma); 683 usb_free_urb(urb); 684 break; 685 } 686 687 dev->rxbuf[i] = buf; 688 dev->rxbuf_dma[i] = buf_dma; 689 690 /* Drop reference, USB core will take care of freeing it */ 691 usb_free_urb(urb); 692 } 693 694 /* Did we submit any URBs */ 695 if (i == 0) { 696 netdev_warn(netdev, "couldn't setup read URBs\n"); 697 return err; 698 } 699 700 /* Warn if we've couldn't transmit all the URBs */ 701 if (i < MAX_RX_URBS) 702 netdev_warn(netdev, "rx performance may be slow\n"); 703 704 /* Setup and start interrupt URB */ 705 usb_fill_int_urb(dev->intr_urb, dev->udev, 706 usb_rcvintpipe(dev->udev, 1), 707 dev->intr_in_buffer, 708 INTR_IN_BUFFER_SIZE, 709 ems_usb_read_interrupt_callback, dev, 1); 710 711 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 712 if (err) { 713 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 714 715 return err; 716 } 717 718 /* CPC-USB will transfer received message to host */ 719 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 720 if (err) 721 goto failed; 722 723 /* CPC-USB will transfer CAN state changes to host */ 724 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 725 if (err) 726 goto failed; 727 728 /* CPC-USB will transfer bus errors to host */ 729 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 730 if (err) 731 goto failed; 732 733 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 734 if (err) 735 goto failed; 736 737 dev->can.state = CAN_STATE_ERROR_ACTIVE; 738 739 return 0; 740 741 failed: 742 netdev_warn(netdev, "couldn't submit control: %d\n", err); 743 744 return err; 745 } 746 747 static void unlink_all_urbs(struct ems_usb *dev) 748 { 749 int i; 750 751 usb_unlink_urb(dev->intr_urb); 752 753 usb_kill_anchored_urbs(&dev->rx_submitted); 754 755 for (i = 0; i < MAX_RX_URBS; ++i) 756 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 757 dev->rxbuf[i], dev->rxbuf_dma[i]); 758 759 usb_kill_anchored_urbs(&dev->tx_submitted); 760 atomic_set(&dev->active_tx_urbs, 0); 761 762 for (i = 0; i < MAX_TX_URBS; i++) 763 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 764 } 765 766 static int ems_usb_open(struct net_device *netdev) 767 { 768 struct ems_usb *dev = netdev_priv(netdev); 769 int err; 770 771 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 772 if (err) 773 return err; 774 775 /* common open */ 776 err = open_candev(netdev); 777 if (err) 778 return err; 779 780 /* finally start device */ 781 err = ems_usb_start(dev); 782 if (err) { 783 if (err == -ENODEV) 784 netif_device_detach(dev->netdev); 785 786 netdev_warn(netdev, "couldn't start device: %d\n", err); 787 788 close_candev(netdev); 789 790 return err; 791 } 792 793 794 netif_start_queue(netdev); 795 796 return 0; 797 } 798 799 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 800 { 801 struct ems_usb *dev = netdev_priv(netdev); 802 struct ems_tx_urb_context *context = NULL; 803 struct net_device_stats *stats = &netdev->stats; 804 struct can_frame *cf = (struct can_frame *)skb->data; 805 struct ems_cpc_msg *msg; 806 struct urb *urb; 807 u8 *buf; 808 int i, err; 809 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 810 + sizeof(struct cpc_can_msg); 811 812 if (can_dev_dropped_skb(netdev, skb)) 813 return NETDEV_TX_OK; 814 815 /* create a URB, and a buffer for it, and copy the data to the URB */ 816 urb = usb_alloc_urb(0, GFP_ATOMIC); 817 if (!urb) 818 goto nomem; 819 820 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 821 if (!buf) { 822 netdev_err(netdev, "No memory left for USB buffer\n"); 823 usb_free_urb(urb); 824 goto nomem; 825 } 826 827 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 828 829 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 830 msg->msg.can_msg.length = cf->len; 831 832 if (cf->can_id & CAN_RTR_FLAG) { 833 msg->type = cf->can_id & CAN_EFF_FLAG ? 834 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 835 836 msg->length = CPC_CAN_MSG_MIN_SIZE; 837 } else { 838 msg->type = cf->can_id & CAN_EFF_FLAG ? 839 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 840 841 for (i = 0; i < cf->len; i++) 842 msg->msg.can_msg.msg[i] = cf->data[i]; 843 844 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 845 } 846 847 for (i = 0; i < MAX_TX_URBS; i++) { 848 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 849 context = &dev->tx_contexts[i]; 850 break; 851 } 852 } 853 854 /* 855 * May never happen! When this happens we'd more URBs in flight as 856 * allowed (MAX_TX_URBS). 857 */ 858 if (!context) { 859 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 860 usb_free_urb(urb); 861 862 netdev_warn(netdev, "couldn't find free context\n"); 863 864 return NETDEV_TX_BUSY; 865 } 866 867 context->dev = dev; 868 context->echo_index = i; 869 870 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 871 size, ems_usb_write_bulk_callback, context); 872 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 873 usb_anchor_urb(urb, &dev->tx_submitted); 874 875 can_put_echo_skb(skb, netdev, context->echo_index, 0); 876 877 atomic_inc(&dev->active_tx_urbs); 878 879 err = usb_submit_urb(urb, GFP_ATOMIC); 880 if (unlikely(err)) { 881 can_free_echo_skb(netdev, context->echo_index, NULL); 882 883 usb_unanchor_urb(urb); 884 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 885 886 atomic_dec(&dev->active_tx_urbs); 887 888 if (err == -ENODEV) { 889 netif_device_detach(netdev); 890 } else { 891 netdev_warn(netdev, "failed tx_urb %d\n", err); 892 893 stats->tx_dropped++; 894 } 895 } else { 896 netif_trans_update(netdev); 897 898 /* Slow down tx path */ 899 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 900 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 901 netif_stop_queue(netdev); 902 } 903 } 904 905 /* 906 * Release our reference to this URB, the USB core will eventually free 907 * it entirely. 908 */ 909 usb_free_urb(urb); 910 911 return NETDEV_TX_OK; 912 913 nomem: 914 dev_kfree_skb(skb); 915 stats->tx_dropped++; 916 917 return NETDEV_TX_OK; 918 } 919 920 static int ems_usb_close(struct net_device *netdev) 921 { 922 struct ems_usb *dev = netdev_priv(netdev); 923 924 /* Stop polling */ 925 unlink_all_urbs(dev); 926 927 netif_stop_queue(netdev); 928 929 /* Set CAN controller to reset mode */ 930 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 931 netdev_warn(netdev, "couldn't stop device"); 932 933 close_candev(netdev); 934 935 return 0; 936 } 937 938 static const struct net_device_ops ems_usb_netdev_ops = { 939 .ndo_open = ems_usb_open, 940 .ndo_stop = ems_usb_close, 941 .ndo_start_xmit = ems_usb_start_xmit, 942 }; 943 944 static const struct ethtool_ops ems_usb_ethtool_ops = { 945 .get_ts_info = ethtool_op_get_ts_info, 946 }; 947 948 static const struct can_bittiming_const ems_usb_bittiming_const = { 949 .name = KBUILD_MODNAME, 950 .tseg1_min = 1, 951 .tseg1_max = 16, 952 .tseg2_min = 1, 953 .tseg2_max = 8, 954 .sjw_max = 4, 955 .brp_min = 1, 956 .brp_max = 64, 957 .brp_inc = 1, 958 }; 959 960 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 961 { 962 struct ems_usb *dev = netdev_priv(netdev); 963 964 switch (mode) { 965 case CAN_MODE_START: 966 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 967 netdev_warn(netdev, "couldn't start device"); 968 969 if (netif_queue_stopped(netdev)) 970 netif_wake_queue(netdev); 971 break; 972 973 default: 974 return -EOPNOTSUPP; 975 } 976 977 return 0; 978 } 979 980 static int ems_usb_set_bittiming(struct net_device *netdev) 981 { 982 struct ems_usb *dev = netdev_priv(netdev); 983 struct can_bittiming *bt = &dev->can.bittiming; 984 u8 btr0, btr1; 985 986 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 987 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 988 (((bt->phase_seg2 - 1) & 0x7) << 4); 989 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 990 btr1 |= 0x80; 991 992 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 993 994 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 995 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 996 997 return ems_usb_command_msg(dev, &dev->active_params); 998 } 999 1000 static void init_params_sja1000(struct ems_cpc_msg *msg) 1001 { 1002 struct cpc_sja1000_params *sja1000 = 1003 &msg->msg.can_params.cc_params.sja1000; 1004 1005 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 1006 msg->length = sizeof(struct cpc_can_params); 1007 msg->msgid = 0; 1008 1009 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 1010 1011 /* Acceptance filter open */ 1012 sja1000->acc_code0 = 0x00; 1013 sja1000->acc_code1 = 0x00; 1014 sja1000->acc_code2 = 0x00; 1015 sja1000->acc_code3 = 0x00; 1016 1017 /* Acceptance filter open */ 1018 sja1000->acc_mask0 = 0xFF; 1019 sja1000->acc_mask1 = 0xFF; 1020 sja1000->acc_mask2 = 0xFF; 1021 sja1000->acc_mask3 = 0xFF; 1022 1023 sja1000->btr0 = 0; 1024 sja1000->btr1 = 0; 1025 1026 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 1027 sja1000->mode = SJA1000_MOD_RM; 1028 } 1029 1030 /* 1031 * probe function for new CPC-USB devices 1032 */ 1033 static int ems_usb_probe(struct usb_interface *intf, 1034 const struct usb_device_id *id) 1035 { 1036 struct net_device *netdev; 1037 struct ems_usb *dev; 1038 int i, err = -ENOMEM; 1039 1040 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 1041 if (!netdev) { 1042 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 1043 return -ENOMEM; 1044 } 1045 1046 dev = netdev_priv(netdev); 1047 1048 dev->udev = interface_to_usbdev(intf); 1049 dev->netdev = netdev; 1050 1051 dev->can.state = CAN_STATE_STOPPED; 1052 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1053 dev->can.bittiming_const = &ems_usb_bittiming_const; 1054 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1055 dev->can.do_set_mode = ems_usb_set_mode; 1056 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1057 1058 netdev->netdev_ops = &ems_usb_netdev_ops; 1059 netdev->ethtool_ops = &ems_usb_ethtool_ops; 1060 1061 netdev->flags |= IFF_ECHO; /* we support local echo */ 1062 1063 init_usb_anchor(&dev->rx_submitted); 1064 1065 init_usb_anchor(&dev->tx_submitted); 1066 atomic_set(&dev->active_tx_urbs, 0); 1067 1068 for (i = 0; i < MAX_TX_URBS; i++) 1069 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1070 1071 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1072 if (!dev->intr_urb) 1073 goto cleanup_candev; 1074 1075 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1076 if (!dev->intr_in_buffer) 1077 goto cleanup_intr_urb; 1078 1079 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1080 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1081 if (!dev->tx_msg_buffer) 1082 goto cleanup_intr_in_buffer; 1083 1084 usb_set_intfdata(intf, dev); 1085 1086 SET_NETDEV_DEV(netdev, &intf->dev); 1087 1088 init_params_sja1000(&dev->active_params); 1089 1090 err = ems_usb_command_msg(dev, &dev->active_params); 1091 if (err) { 1092 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1093 goto cleanup_tx_msg_buffer; 1094 } 1095 1096 err = register_candev(netdev); 1097 if (err) { 1098 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1099 goto cleanup_tx_msg_buffer; 1100 } 1101 1102 return 0; 1103 1104 cleanup_tx_msg_buffer: 1105 kfree(dev->tx_msg_buffer); 1106 1107 cleanup_intr_in_buffer: 1108 kfree(dev->intr_in_buffer); 1109 1110 cleanup_intr_urb: 1111 usb_free_urb(dev->intr_urb); 1112 1113 cleanup_candev: 1114 free_candev(netdev); 1115 1116 return err; 1117 } 1118 1119 /* 1120 * called by the usb core when the device is removed from the system 1121 */ 1122 static void ems_usb_disconnect(struct usb_interface *intf) 1123 { 1124 struct ems_usb *dev = usb_get_intfdata(intf); 1125 1126 usb_set_intfdata(intf, NULL); 1127 1128 if (dev) { 1129 unregister_netdev(dev->netdev); 1130 1131 unlink_all_urbs(dev); 1132 1133 usb_free_urb(dev->intr_urb); 1134 1135 kfree(dev->intr_in_buffer); 1136 kfree(dev->tx_msg_buffer); 1137 1138 free_candev(dev->netdev); 1139 } 1140 } 1141 1142 /* usb specific object needed to register this driver with the usb subsystem */ 1143 static struct usb_driver ems_usb_driver = { 1144 .name = KBUILD_MODNAME, 1145 .probe = ems_usb_probe, 1146 .disconnect = ems_usb_disconnect, 1147 .id_table = ems_usb_table, 1148 }; 1149 1150 module_usb_driver(ems_usb_driver); 1151