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/signal.h> 8 #include <linux/slab.h> 9 #include <linux/module.h> 10 #include <linux/netdevice.h> 11 #include <linux/usb.h> 12 13 #include <linux/can.h> 14 #include <linux/can/dev.h> 15 #include <linux/can/error.h> 16 17 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 18 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 19 MODULE_LICENSE("GPL v2"); 20 21 /* Control-Values for CPC_Control() Command Subject Selection */ 22 #define CONTR_CAN_MESSAGE 0x04 23 #define CONTR_CAN_STATE 0x0C 24 #define CONTR_BUS_ERROR 0x1C 25 26 /* Control Command Actions */ 27 #define CONTR_CONT_OFF 0 28 #define CONTR_CONT_ON 1 29 #define CONTR_ONCE 2 30 31 /* Messages from CPC to PC */ 32 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */ 33 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */ 34 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */ 35 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */ 36 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */ 37 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */ 38 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */ 39 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */ 40 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */ 41 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */ 42 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */ 43 44 /* Messages from the PC to the CPC interface */ 45 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */ 46 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */ 47 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */ 48 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */ 49 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */ 50 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */ 51 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */ 52 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */ 53 54 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */ 55 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */ 56 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */ 57 58 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 59 60 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 61 62 /* Overrun types */ 63 #define CPC_OVR_EVENT_CAN 0x01 64 #define CPC_OVR_EVENT_CANSTATE 0x02 65 #define CPC_OVR_EVENT_BUSERROR 0x04 66 67 /* 68 * If the CAN controller lost a message we indicate it with the highest bit 69 * set in the count field. 70 */ 71 #define CPC_OVR_HW 0x80 72 73 /* Size of the "struct ems_cpc_msg" without the union */ 74 #define CPC_MSG_HEADER_LEN 11 75 #define CPC_CAN_MSG_MIN_SIZE 5 76 77 /* Define these values to match your devices */ 78 #define USB_CPCUSB_VENDOR_ID 0x12D6 79 80 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 81 82 /* Mode register NXP LPC2119/SJA1000 CAN Controller */ 83 #define SJA1000_MOD_NORMAL 0x00 84 #define SJA1000_MOD_RM 0x01 85 86 /* ECC register NXP LPC2119/SJA1000 CAN Controller */ 87 #define SJA1000_ECC_SEG 0x1F 88 #define SJA1000_ECC_DIR 0x20 89 #define SJA1000_ECC_ERR 0x06 90 #define SJA1000_ECC_BIT 0x00 91 #define SJA1000_ECC_FORM 0x40 92 #define SJA1000_ECC_STUFF 0x80 93 #define SJA1000_ECC_MASK 0xc0 94 95 /* Status register content */ 96 #define SJA1000_SR_BS 0x80 97 #define SJA1000_SR_ES 0x40 98 99 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 100 101 /* 102 * The device actually uses a 16MHz clock to generate the CAN clock 103 * but it expects SJA1000 bit settings based on 8MHz (is internally 104 * converted). 105 */ 106 #define EMS_USB_ARM7_CLOCK 8000000 107 108 #define CPC_TX_QUEUE_TRIGGER_LOW 25 109 #define CPC_TX_QUEUE_TRIGGER_HIGH 35 110 111 /* 112 * CAN-Message representation in a CPC_MSG. Message object type is 113 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or 114 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME. 115 */ 116 struct cpc_can_msg { 117 __le32 id; 118 u8 length; 119 u8 msg[8]; 120 }; 121 122 /* Representation of the CAN parameters for the SJA1000 controller */ 123 struct cpc_sja1000_params { 124 u8 mode; 125 u8 acc_code0; 126 u8 acc_code1; 127 u8 acc_code2; 128 u8 acc_code3; 129 u8 acc_mask0; 130 u8 acc_mask1; 131 u8 acc_mask2; 132 u8 acc_mask3; 133 u8 btr0; 134 u8 btr1; 135 u8 outp_contr; 136 }; 137 138 /* CAN params message representation */ 139 struct cpc_can_params { 140 u8 cc_type; 141 142 /* Will support M16C CAN controller in the future */ 143 union { 144 struct cpc_sja1000_params sja1000; 145 } cc_params; 146 }; 147 148 /* Structure for confirmed message handling */ 149 struct cpc_confirm { 150 u8 error; /* error code */ 151 }; 152 153 /* Structure for overrun conditions */ 154 struct cpc_overrun { 155 u8 event; 156 u8 count; 157 }; 158 159 /* SJA1000 CAN errors (compatible to NXP LPC2119) */ 160 struct cpc_sja1000_can_error { 161 u8 ecc; 162 u8 rxerr; 163 u8 txerr; 164 }; 165 166 /* structure for CAN error conditions */ 167 struct cpc_can_error { 168 u8 ecode; 169 170 struct { 171 u8 cc_type; 172 173 /* Other controllers may also provide error code capture regs */ 174 union { 175 struct cpc_sja1000_can_error sja1000; 176 } regs; 177 } cc; 178 }; 179 180 /* 181 * Structure containing RX/TX error counter. This structure is used to request 182 * the values of the CAN controllers TX and RX error counter. 183 */ 184 struct cpc_can_err_counter { 185 u8 rx; 186 u8 tx; 187 }; 188 189 /* Main message type used between library and application */ 190 struct __packed ems_cpc_msg { 191 u8 type; /* type of message */ 192 u8 length; /* length of data within union 'msg' */ 193 u8 msgid; /* confirmation handle */ 194 __le32 ts_sec; /* timestamp in seconds */ 195 __le32 ts_nsec; /* timestamp in nano seconds */ 196 197 union { 198 u8 generic[64]; 199 struct cpc_can_msg can_msg; 200 struct cpc_can_params can_params; 201 struct cpc_confirm confirmation; 202 struct cpc_overrun overrun; 203 struct cpc_can_error error; 204 struct cpc_can_err_counter err_counter; 205 u8 can_state; 206 } msg; 207 }; 208 209 /* 210 * Table of devices that work with this driver 211 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 212 */ 213 static struct usb_device_id ems_usb_table[] = { 214 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 215 {} /* Terminating entry */ 216 }; 217 218 MODULE_DEVICE_TABLE(usb, ems_usb_table); 219 220 #define RX_BUFFER_SIZE 64 221 #define CPC_HEADER_SIZE 4 222 #define INTR_IN_BUFFER_SIZE 4 223 224 #define MAX_RX_URBS 10 225 #define MAX_TX_URBS 10 226 227 struct ems_usb; 228 229 struct ems_tx_urb_context { 230 struct ems_usb *dev; 231 232 u32 echo_index; 233 u8 dlc; 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 }; 259 260 static void ems_usb_read_interrupt_callback(struct urb *urb) 261 { 262 struct ems_usb *dev = urb->context; 263 struct net_device *netdev = dev->netdev; 264 int err; 265 266 if (!netif_device_present(netdev)) 267 return; 268 269 switch (urb->status) { 270 case 0: 271 dev->free_slots = dev->intr_in_buffer[1]; 272 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH && 273 netif_queue_stopped(netdev)) 274 netif_wake_queue(netdev); 275 break; 276 277 case -ECONNRESET: /* unlink */ 278 case -ENOENT: 279 case -EPIPE: 280 case -EPROTO: 281 case -ESHUTDOWN: 282 return; 283 284 default: 285 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 286 break; 287 } 288 289 err = usb_submit_urb(urb, GFP_ATOMIC); 290 291 if (err == -ENODEV) 292 netif_device_detach(netdev); 293 else if (err) 294 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 295 } 296 297 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 298 { 299 struct can_frame *cf; 300 struct sk_buff *skb; 301 int i; 302 struct net_device_stats *stats = &dev->netdev->stats; 303 304 skb = alloc_can_skb(dev->netdev, &cf); 305 if (skb == NULL) 306 return; 307 308 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 309 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF); 310 311 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 312 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 313 cf->can_id |= CAN_EFF_FLAG; 314 315 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 316 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 317 cf->can_id |= CAN_RTR_FLAG; 318 } else { 319 for (i = 0; i < cf->len; i++) 320 cf->data[i] = msg->msg.can_msg.msg[i]; 321 } 322 323 stats->rx_packets++; 324 stats->rx_bytes += cf->len; 325 netif_rx(skb); 326 } 327 328 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 329 { 330 struct can_frame *cf; 331 struct sk_buff *skb; 332 struct net_device_stats *stats = &dev->netdev->stats; 333 334 skb = alloc_can_err_skb(dev->netdev, &cf); 335 if (skb == NULL) 336 return; 337 338 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 339 u8 state = msg->msg.can_state; 340 341 if (state & SJA1000_SR_BS) { 342 dev->can.state = CAN_STATE_BUS_OFF; 343 cf->can_id |= CAN_ERR_BUSOFF; 344 345 dev->can.can_stats.bus_off++; 346 can_bus_off(dev->netdev); 347 } else if (state & SJA1000_SR_ES) { 348 dev->can.state = CAN_STATE_ERROR_WARNING; 349 dev->can.can_stats.error_warning++; 350 } else { 351 dev->can.state = CAN_STATE_ERROR_ACTIVE; 352 dev->can.can_stats.error_passive++; 353 } 354 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 355 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 356 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 357 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 358 359 /* bus error interrupt */ 360 dev->can.can_stats.bus_error++; 361 stats->rx_errors++; 362 363 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 364 365 switch (ecc & SJA1000_ECC_MASK) { 366 case SJA1000_ECC_BIT: 367 cf->data[2] |= CAN_ERR_PROT_BIT; 368 break; 369 case SJA1000_ECC_FORM: 370 cf->data[2] |= CAN_ERR_PROT_FORM; 371 break; 372 case SJA1000_ECC_STUFF: 373 cf->data[2] |= CAN_ERR_PROT_STUFF; 374 break; 375 default: 376 cf->data[3] = ecc & SJA1000_ECC_SEG; 377 break; 378 } 379 380 /* Error occurred during transmission? */ 381 if ((ecc & SJA1000_ECC_DIR) == 0) 382 cf->data[2] |= CAN_ERR_PROT_TX; 383 384 if (dev->can.state == CAN_STATE_ERROR_WARNING || 385 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 386 cf->can_id |= CAN_ERR_CRTL; 387 cf->data[1] = (txerr > rxerr) ? 388 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 389 } 390 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 391 cf->can_id |= CAN_ERR_CRTL; 392 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 393 394 stats->rx_over_errors++; 395 stats->rx_errors++; 396 } 397 398 stats->rx_packets++; 399 stats->rx_bytes += cf->len; 400 netif_rx(skb); 401 } 402 403 /* 404 * callback for bulk IN urb 405 */ 406 static void ems_usb_read_bulk_callback(struct urb *urb) 407 { 408 struct ems_usb *dev = urb->context; 409 struct net_device *netdev; 410 int retval; 411 412 netdev = dev->netdev; 413 414 if (!netif_device_present(netdev)) 415 return; 416 417 switch (urb->status) { 418 case 0: /* success */ 419 break; 420 421 case -ENOENT: 422 return; 423 424 default: 425 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 426 goto resubmit_urb; 427 } 428 429 if (urb->actual_length > CPC_HEADER_SIZE) { 430 struct ems_cpc_msg *msg; 431 u8 *ibuf = urb->transfer_buffer; 432 u8 msg_count, start; 433 434 msg_count = ibuf[0] & ~0x80; 435 436 start = CPC_HEADER_SIZE; 437 438 while (msg_count) { 439 msg = (struct ems_cpc_msg *)&ibuf[start]; 440 441 switch (msg->type) { 442 case CPC_MSG_TYPE_CAN_STATE: 443 /* Process CAN state changes */ 444 ems_usb_rx_err(dev, msg); 445 break; 446 447 case CPC_MSG_TYPE_CAN_FRAME: 448 case CPC_MSG_TYPE_EXT_CAN_FRAME: 449 case CPC_MSG_TYPE_RTR_FRAME: 450 case CPC_MSG_TYPE_EXT_RTR_FRAME: 451 ems_usb_rx_can_msg(dev, msg); 452 break; 453 454 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 455 /* Process errorframe */ 456 ems_usb_rx_err(dev, msg); 457 break; 458 459 case CPC_MSG_TYPE_OVERRUN: 460 /* Message lost while receiving */ 461 ems_usb_rx_err(dev, msg); 462 break; 463 } 464 465 start += CPC_MSG_HEADER_LEN + msg->length; 466 msg_count--; 467 468 if (start > urb->transfer_buffer_length) { 469 netdev_err(netdev, "format error\n"); 470 break; 471 } 472 } 473 } 474 475 resubmit_urb: 476 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 477 urb->transfer_buffer, RX_BUFFER_SIZE, 478 ems_usb_read_bulk_callback, dev); 479 480 retval = usb_submit_urb(urb, GFP_ATOMIC); 481 482 if (retval == -ENODEV) 483 netif_device_detach(netdev); 484 else if (retval) 485 netdev_err(netdev, 486 "failed resubmitting read bulk urb: %d\n", retval); 487 } 488 489 /* 490 * callback for bulk IN urb 491 */ 492 static void ems_usb_write_bulk_callback(struct urb *urb) 493 { 494 struct ems_tx_urb_context *context = urb->context; 495 struct ems_usb *dev; 496 struct net_device *netdev; 497 498 BUG_ON(!context); 499 500 dev = context->dev; 501 netdev = dev->netdev; 502 503 /* free up our allocated buffer */ 504 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 505 urb->transfer_buffer, urb->transfer_dma); 506 507 atomic_dec(&dev->active_tx_urbs); 508 509 if (!netif_device_present(netdev)) 510 return; 511 512 if (urb->status) 513 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 514 515 netif_trans_update(netdev); 516 517 /* transmission complete interrupt */ 518 netdev->stats.tx_packets++; 519 netdev->stats.tx_bytes += context->dlc; 520 521 can_get_echo_skb(netdev, context->echo_index, NULL); 522 523 /* Release context */ 524 context->echo_index = MAX_TX_URBS; 525 526 } 527 528 /* 529 * Send the given CPC command synchronously 530 */ 531 static 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 */ 551 static 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 */ 562 static 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 */ 579 static 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; 590 591 /* create a URB, and a buffer for it */ 592 urb = usb_alloc_urb(0, GFP_KERNEL); 593 if (!urb) { 594 err = -ENOMEM; 595 break; 596 } 597 598 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 599 &urb->transfer_dma); 600 if (!buf) { 601 netdev_err(netdev, "No memory left for USB buffer\n"); 602 usb_free_urb(urb); 603 err = -ENOMEM; 604 break; 605 } 606 607 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 608 buf, RX_BUFFER_SIZE, 609 ems_usb_read_bulk_callback, dev); 610 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 611 usb_anchor_urb(urb, &dev->rx_submitted); 612 613 err = usb_submit_urb(urb, GFP_KERNEL); 614 if (err) { 615 usb_unanchor_urb(urb); 616 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 617 urb->transfer_dma); 618 usb_free_urb(urb); 619 break; 620 } 621 622 /* Drop reference, USB core will take care of freeing it */ 623 usb_free_urb(urb); 624 } 625 626 /* Did we submit any URBs */ 627 if (i == 0) { 628 netdev_warn(netdev, "couldn't setup read URBs\n"); 629 return err; 630 } 631 632 /* Warn if we've couldn't transmit all the URBs */ 633 if (i < MAX_RX_URBS) 634 netdev_warn(netdev, "rx performance may be slow\n"); 635 636 /* Setup and start interrupt URB */ 637 usb_fill_int_urb(dev->intr_urb, dev->udev, 638 usb_rcvintpipe(dev->udev, 1), 639 dev->intr_in_buffer, 640 INTR_IN_BUFFER_SIZE, 641 ems_usb_read_interrupt_callback, dev, 1); 642 643 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 644 if (err) { 645 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 646 647 return err; 648 } 649 650 /* CPC-USB will transfer received message to host */ 651 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 652 if (err) 653 goto failed; 654 655 /* CPC-USB will transfer CAN state changes to host */ 656 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 657 if (err) 658 goto failed; 659 660 /* CPC-USB will transfer bus errors to host */ 661 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 662 if (err) 663 goto failed; 664 665 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 666 if (err) 667 goto failed; 668 669 dev->can.state = CAN_STATE_ERROR_ACTIVE; 670 671 return 0; 672 673 failed: 674 netdev_warn(netdev, "couldn't submit control: %d\n", err); 675 676 return err; 677 } 678 679 static void unlink_all_urbs(struct ems_usb *dev) 680 { 681 int i; 682 683 usb_unlink_urb(dev->intr_urb); 684 685 usb_kill_anchored_urbs(&dev->rx_submitted); 686 687 usb_kill_anchored_urbs(&dev->tx_submitted); 688 atomic_set(&dev->active_tx_urbs, 0); 689 690 for (i = 0; i < MAX_TX_URBS; i++) 691 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 692 } 693 694 static int ems_usb_open(struct net_device *netdev) 695 { 696 struct ems_usb *dev = netdev_priv(netdev); 697 int err; 698 699 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 700 if (err) 701 return err; 702 703 /* common open */ 704 err = open_candev(netdev); 705 if (err) 706 return err; 707 708 /* finally start device */ 709 err = ems_usb_start(dev); 710 if (err) { 711 if (err == -ENODEV) 712 netif_device_detach(dev->netdev); 713 714 netdev_warn(netdev, "couldn't start device: %d\n", err); 715 716 close_candev(netdev); 717 718 return err; 719 } 720 721 722 netif_start_queue(netdev); 723 724 return 0; 725 } 726 727 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 728 { 729 struct ems_usb *dev = netdev_priv(netdev); 730 struct ems_tx_urb_context *context = NULL; 731 struct net_device_stats *stats = &netdev->stats; 732 struct can_frame *cf = (struct can_frame *)skb->data; 733 struct ems_cpc_msg *msg; 734 struct urb *urb; 735 u8 *buf; 736 int i, err; 737 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 738 + sizeof(struct cpc_can_msg); 739 740 if (can_dropped_invalid_skb(netdev, skb)) 741 return NETDEV_TX_OK; 742 743 /* create a URB, and a buffer for it, and copy the data to the URB */ 744 urb = usb_alloc_urb(0, GFP_ATOMIC); 745 if (!urb) 746 goto nomem; 747 748 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 749 if (!buf) { 750 netdev_err(netdev, "No memory left for USB buffer\n"); 751 usb_free_urb(urb); 752 goto nomem; 753 } 754 755 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 756 757 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 758 msg->msg.can_msg.length = cf->len; 759 760 if (cf->can_id & CAN_RTR_FLAG) { 761 msg->type = cf->can_id & CAN_EFF_FLAG ? 762 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 763 764 msg->length = CPC_CAN_MSG_MIN_SIZE; 765 } else { 766 msg->type = cf->can_id & CAN_EFF_FLAG ? 767 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 768 769 for (i = 0; i < cf->len; i++) 770 msg->msg.can_msg.msg[i] = cf->data[i]; 771 772 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 773 } 774 775 for (i = 0; i < MAX_TX_URBS; i++) { 776 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 777 context = &dev->tx_contexts[i]; 778 break; 779 } 780 } 781 782 /* 783 * May never happen! When this happens we'd more URBs in flight as 784 * allowed (MAX_TX_URBS). 785 */ 786 if (!context) { 787 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 788 usb_free_urb(urb); 789 790 netdev_warn(netdev, "couldn't find free context\n"); 791 792 return NETDEV_TX_BUSY; 793 } 794 795 context->dev = dev; 796 context->echo_index = i; 797 context->dlc = cf->len; 798 799 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 800 size, ems_usb_write_bulk_callback, context); 801 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 802 usb_anchor_urb(urb, &dev->tx_submitted); 803 804 can_put_echo_skb(skb, netdev, context->echo_index, 0); 805 806 atomic_inc(&dev->active_tx_urbs); 807 808 err = usb_submit_urb(urb, GFP_ATOMIC); 809 if (unlikely(err)) { 810 can_free_echo_skb(netdev, context->echo_index, NULL); 811 812 usb_unanchor_urb(urb); 813 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 814 dev_kfree_skb(skb); 815 816 atomic_dec(&dev->active_tx_urbs); 817 818 if (err == -ENODEV) { 819 netif_device_detach(netdev); 820 } else { 821 netdev_warn(netdev, "failed tx_urb %d\n", err); 822 823 stats->tx_dropped++; 824 } 825 } else { 826 netif_trans_update(netdev); 827 828 /* Slow down tx path */ 829 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 830 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 831 netif_stop_queue(netdev); 832 } 833 } 834 835 /* 836 * Release our reference to this URB, the USB core will eventually free 837 * it entirely. 838 */ 839 usb_free_urb(urb); 840 841 return NETDEV_TX_OK; 842 843 nomem: 844 dev_kfree_skb(skb); 845 stats->tx_dropped++; 846 847 return NETDEV_TX_OK; 848 } 849 850 static int ems_usb_close(struct net_device *netdev) 851 { 852 struct ems_usb *dev = netdev_priv(netdev); 853 854 /* Stop polling */ 855 unlink_all_urbs(dev); 856 857 netif_stop_queue(netdev); 858 859 /* Set CAN controller to reset mode */ 860 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 861 netdev_warn(netdev, "couldn't stop device"); 862 863 close_candev(netdev); 864 865 return 0; 866 } 867 868 static const struct net_device_ops ems_usb_netdev_ops = { 869 .ndo_open = ems_usb_open, 870 .ndo_stop = ems_usb_close, 871 .ndo_start_xmit = ems_usb_start_xmit, 872 .ndo_change_mtu = can_change_mtu, 873 }; 874 875 static const struct can_bittiming_const ems_usb_bittiming_const = { 876 .name = "ems_usb", 877 .tseg1_min = 1, 878 .tseg1_max = 16, 879 .tseg2_min = 1, 880 .tseg2_max = 8, 881 .sjw_max = 4, 882 .brp_min = 1, 883 .brp_max = 64, 884 .brp_inc = 1, 885 }; 886 887 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 888 { 889 struct ems_usb *dev = netdev_priv(netdev); 890 891 switch (mode) { 892 case CAN_MODE_START: 893 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 894 netdev_warn(netdev, "couldn't start device"); 895 896 if (netif_queue_stopped(netdev)) 897 netif_wake_queue(netdev); 898 break; 899 900 default: 901 return -EOPNOTSUPP; 902 } 903 904 return 0; 905 } 906 907 static int ems_usb_set_bittiming(struct net_device *netdev) 908 { 909 struct ems_usb *dev = netdev_priv(netdev); 910 struct can_bittiming *bt = &dev->can.bittiming; 911 u8 btr0, btr1; 912 913 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 914 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 915 (((bt->phase_seg2 - 1) & 0x7) << 4); 916 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 917 btr1 |= 0x80; 918 919 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 920 921 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 922 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 923 924 return ems_usb_command_msg(dev, &dev->active_params); 925 } 926 927 static void init_params_sja1000(struct ems_cpc_msg *msg) 928 { 929 struct cpc_sja1000_params *sja1000 = 930 &msg->msg.can_params.cc_params.sja1000; 931 932 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 933 msg->length = sizeof(struct cpc_can_params); 934 msg->msgid = 0; 935 936 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 937 938 /* Acceptance filter open */ 939 sja1000->acc_code0 = 0x00; 940 sja1000->acc_code1 = 0x00; 941 sja1000->acc_code2 = 0x00; 942 sja1000->acc_code3 = 0x00; 943 944 /* Acceptance filter open */ 945 sja1000->acc_mask0 = 0xFF; 946 sja1000->acc_mask1 = 0xFF; 947 sja1000->acc_mask2 = 0xFF; 948 sja1000->acc_mask3 = 0xFF; 949 950 sja1000->btr0 = 0; 951 sja1000->btr1 = 0; 952 953 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 954 sja1000->mode = SJA1000_MOD_RM; 955 } 956 957 /* 958 * probe function for new CPC-USB devices 959 */ 960 static int ems_usb_probe(struct usb_interface *intf, 961 const struct usb_device_id *id) 962 { 963 struct net_device *netdev; 964 struct ems_usb *dev; 965 int i, err = -ENOMEM; 966 967 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 968 if (!netdev) { 969 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 970 return -ENOMEM; 971 } 972 973 dev = netdev_priv(netdev); 974 975 dev->udev = interface_to_usbdev(intf); 976 dev->netdev = netdev; 977 978 dev->can.state = CAN_STATE_STOPPED; 979 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 980 dev->can.bittiming_const = &ems_usb_bittiming_const; 981 dev->can.do_set_bittiming = ems_usb_set_bittiming; 982 dev->can.do_set_mode = ems_usb_set_mode; 983 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 984 985 netdev->netdev_ops = &ems_usb_netdev_ops; 986 987 netdev->flags |= IFF_ECHO; /* we support local echo */ 988 989 init_usb_anchor(&dev->rx_submitted); 990 991 init_usb_anchor(&dev->tx_submitted); 992 atomic_set(&dev->active_tx_urbs, 0); 993 994 for (i = 0; i < MAX_TX_URBS; i++) 995 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 996 997 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 998 if (!dev->intr_urb) 999 goto cleanup_candev; 1000 1001 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1002 if (!dev->intr_in_buffer) 1003 goto cleanup_intr_urb; 1004 1005 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1006 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1007 if (!dev->tx_msg_buffer) 1008 goto cleanup_intr_in_buffer; 1009 1010 usb_set_intfdata(intf, dev); 1011 1012 SET_NETDEV_DEV(netdev, &intf->dev); 1013 1014 init_params_sja1000(&dev->active_params); 1015 1016 err = ems_usb_command_msg(dev, &dev->active_params); 1017 if (err) { 1018 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1019 goto cleanup_tx_msg_buffer; 1020 } 1021 1022 err = register_candev(netdev); 1023 if (err) { 1024 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1025 goto cleanup_tx_msg_buffer; 1026 } 1027 1028 return 0; 1029 1030 cleanup_tx_msg_buffer: 1031 kfree(dev->tx_msg_buffer); 1032 1033 cleanup_intr_in_buffer: 1034 kfree(dev->intr_in_buffer); 1035 1036 cleanup_intr_urb: 1037 usb_free_urb(dev->intr_urb); 1038 1039 cleanup_candev: 1040 free_candev(netdev); 1041 1042 return err; 1043 } 1044 1045 /* 1046 * called by the usb core when the device is removed from the system 1047 */ 1048 static void ems_usb_disconnect(struct usb_interface *intf) 1049 { 1050 struct ems_usb *dev = usb_get_intfdata(intf); 1051 1052 usb_set_intfdata(intf, NULL); 1053 1054 if (dev) { 1055 unregister_netdev(dev->netdev); 1056 free_candev(dev->netdev); 1057 1058 unlink_all_urbs(dev); 1059 1060 usb_free_urb(dev->intr_urb); 1061 1062 kfree(dev->intr_in_buffer); 1063 kfree(dev->tx_msg_buffer); 1064 } 1065 } 1066 1067 /* usb specific object needed to register this driver with the usb subsystem */ 1068 static struct usb_driver ems_usb_driver = { 1069 .name = "ems_usb", 1070 .probe = ems_usb_probe, 1071 .disconnect = ems_usb_disconnect, 1072 .id_table = ems_usb_table, 1073 }; 1074 1075 module_usb_driver(ems_usb_driver); 1076