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 }; 234 235 struct ems_usb { 236 struct can_priv can; /* must be the first member */ 237 238 struct sk_buff *echo_skb[MAX_TX_URBS]; 239 240 struct usb_device *udev; 241 struct net_device *netdev; 242 243 atomic_t active_tx_urbs; 244 struct usb_anchor tx_submitted; 245 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 246 247 struct usb_anchor rx_submitted; 248 249 struct urb *intr_urb; 250 251 u8 *tx_msg_buffer; 252 253 u8 *intr_in_buffer; 254 unsigned int free_slots; /* remember number of available slots */ 255 256 struct ems_cpc_msg active_params; /* active controller parameters */ 257 void *rxbuf[MAX_RX_URBS]; 258 dma_addr_t rxbuf_dma[MAX_RX_URBS]; 259 }; 260 261 static void ems_usb_read_interrupt_callback(struct urb *urb) 262 { 263 struct ems_usb *dev = urb->context; 264 struct net_device *netdev = dev->netdev; 265 int err; 266 267 if (!netif_device_present(netdev)) 268 return; 269 270 switch (urb->status) { 271 case 0: 272 dev->free_slots = dev->intr_in_buffer[1]; 273 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH && 274 netif_queue_stopped(netdev)) 275 netif_wake_queue(netdev); 276 break; 277 278 case -ECONNRESET: /* unlink */ 279 case -ENOENT: 280 case -EPIPE: 281 case -EPROTO: 282 case -ESHUTDOWN: 283 return; 284 285 default: 286 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status); 287 break; 288 } 289 290 err = usb_submit_urb(urb, GFP_ATOMIC); 291 292 if (err == -ENODEV) 293 netif_device_detach(netdev); 294 else if (err) 295 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err); 296 } 297 298 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 299 { 300 struct can_frame *cf; 301 struct sk_buff *skb; 302 int i; 303 struct net_device_stats *stats = &dev->netdev->stats; 304 305 skb = alloc_can_skb(dev->netdev, &cf); 306 if (skb == NULL) 307 return; 308 309 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 310 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF); 311 312 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 313 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 314 cf->can_id |= CAN_EFF_FLAG; 315 316 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 317 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 318 cf->can_id |= CAN_RTR_FLAG; 319 } else { 320 for (i = 0; i < cf->len; i++) 321 cf->data[i] = msg->msg.can_msg.msg[i]; 322 323 stats->rx_bytes += cf->len; 324 } 325 stats->rx_packets++; 326 327 netif_rx(skb); 328 } 329 330 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 331 { 332 struct can_frame *cf; 333 struct sk_buff *skb; 334 struct net_device_stats *stats = &dev->netdev->stats; 335 336 skb = alloc_can_err_skb(dev->netdev, &cf); 337 if (skb == NULL) 338 return; 339 340 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 341 u8 state = msg->msg.can_state; 342 343 if (state & SJA1000_SR_BS) { 344 dev->can.state = CAN_STATE_BUS_OFF; 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 stats->rx_errors++; 364 365 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 /* Error occurred during transmission? */ 383 if ((ecc & SJA1000_ECC_DIR) == 0) 384 cf->data[2] |= CAN_ERR_PROT_TX; 385 386 if (dev->can.state == CAN_STATE_ERROR_WARNING || 387 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 388 cf->can_id |= CAN_ERR_CRTL; 389 cf->data[1] = (txerr > rxerr) ? 390 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 391 } 392 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 393 cf->can_id |= CAN_ERR_CRTL; 394 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 395 396 stats->rx_over_errors++; 397 stats->rx_errors++; 398 } 399 400 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 += can_get_echo_skb(netdev, context->echo_index, 520 NULL); 521 522 /* Release context */ 523 context->echo_index = MAX_TX_URBS; 524 525 } 526 527 /* 528 * Send the given CPC command synchronously 529 */ 530 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 531 { 532 int actual_length; 533 534 /* Copy payload */ 535 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 536 msg->length + CPC_MSG_HEADER_LEN); 537 538 /* Clear header */ 539 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 540 541 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 542 &dev->tx_msg_buffer[0], 543 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 544 &actual_length, 1000); 545 } 546 547 /* 548 * Change CAN controllers' mode register 549 */ 550 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 551 { 552 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 553 554 return ems_usb_command_msg(dev, &dev->active_params); 555 } 556 557 /* 558 * Send a CPC_Control command to change behaviour when interface receives a CAN 559 * message, bus error or CAN state changed notifications. 560 */ 561 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 562 { 563 struct ems_cpc_msg cmd; 564 565 cmd.type = CPC_CMD_TYPE_CONTROL; 566 cmd.length = CPC_MSG_HEADER_LEN + 1; 567 568 cmd.msgid = 0; 569 570 cmd.msg.generic[0] = val; 571 572 return ems_usb_command_msg(dev, &cmd); 573 } 574 575 /* 576 * Start interface 577 */ 578 static int ems_usb_start(struct ems_usb *dev) 579 { 580 struct net_device *netdev = dev->netdev; 581 int err, i; 582 583 dev->intr_in_buffer[0] = 0; 584 dev->free_slots = 50; /* initial size */ 585 586 for (i = 0; i < MAX_RX_URBS; i++) { 587 struct urb *urb = NULL; 588 u8 *buf = NULL; 589 dma_addr_t buf_dma; 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 &buf_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 urb->transfer_dma = buf_dma; 608 609 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 610 buf, RX_BUFFER_SIZE, 611 ems_usb_read_bulk_callback, dev); 612 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 613 usb_anchor_urb(urb, &dev->rx_submitted); 614 615 err = usb_submit_urb(urb, GFP_KERNEL); 616 if (err) { 617 usb_unanchor_urb(urb); 618 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 619 urb->transfer_dma); 620 usb_free_urb(urb); 621 break; 622 } 623 624 dev->rxbuf[i] = buf; 625 dev->rxbuf_dma[i] = buf_dma; 626 627 /* Drop reference, USB core will take care of freeing it */ 628 usb_free_urb(urb); 629 } 630 631 /* Did we submit any URBs */ 632 if (i == 0) { 633 netdev_warn(netdev, "couldn't setup read URBs\n"); 634 return err; 635 } 636 637 /* Warn if we've couldn't transmit all the URBs */ 638 if (i < MAX_RX_URBS) 639 netdev_warn(netdev, "rx performance may be slow\n"); 640 641 /* Setup and start interrupt URB */ 642 usb_fill_int_urb(dev->intr_urb, dev->udev, 643 usb_rcvintpipe(dev->udev, 1), 644 dev->intr_in_buffer, 645 INTR_IN_BUFFER_SIZE, 646 ems_usb_read_interrupt_callback, dev, 1); 647 648 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 649 if (err) { 650 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 651 652 return err; 653 } 654 655 /* CPC-USB will transfer received message to host */ 656 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 657 if (err) 658 goto failed; 659 660 /* CPC-USB will transfer CAN state changes to host */ 661 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 662 if (err) 663 goto failed; 664 665 /* CPC-USB will transfer bus errors to host */ 666 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 667 if (err) 668 goto failed; 669 670 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 671 if (err) 672 goto failed; 673 674 dev->can.state = CAN_STATE_ERROR_ACTIVE; 675 676 return 0; 677 678 failed: 679 netdev_warn(netdev, "couldn't submit control: %d\n", err); 680 681 return err; 682 } 683 684 static void unlink_all_urbs(struct ems_usb *dev) 685 { 686 int i; 687 688 usb_unlink_urb(dev->intr_urb); 689 690 usb_kill_anchored_urbs(&dev->rx_submitted); 691 692 for (i = 0; i < MAX_RX_URBS; ++i) 693 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 694 dev->rxbuf[i], dev->rxbuf_dma[i]); 695 696 usb_kill_anchored_urbs(&dev->tx_submitted); 697 atomic_set(&dev->active_tx_urbs, 0); 698 699 for (i = 0; i < MAX_TX_URBS; i++) 700 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 701 } 702 703 static int ems_usb_open(struct net_device *netdev) 704 { 705 struct ems_usb *dev = netdev_priv(netdev); 706 int err; 707 708 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 709 if (err) 710 return err; 711 712 /* common open */ 713 err = open_candev(netdev); 714 if (err) 715 return err; 716 717 /* finally start device */ 718 err = ems_usb_start(dev); 719 if (err) { 720 if (err == -ENODEV) 721 netif_device_detach(dev->netdev); 722 723 netdev_warn(netdev, "couldn't start device: %d\n", err); 724 725 close_candev(netdev); 726 727 return err; 728 } 729 730 731 netif_start_queue(netdev); 732 733 return 0; 734 } 735 736 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 737 { 738 struct ems_usb *dev = netdev_priv(netdev); 739 struct ems_tx_urb_context *context = NULL; 740 struct net_device_stats *stats = &netdev->stats; 741 struct can_frame *cf = (struct can_frame *)skb->data; 742 struct ems_cpc_msg *msg; 743 struct urb *urb; 744 u8 *buf; 745 int i, err; 746 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 747 + sizeof(struct cpc_can_msg); 748 749 if (can_dropped_invalid_skb(netdev, skb)) 750 return NETDEV_TX_OK; 751 752 /* create a URB, and a buffer for it, and copy the data to the URB */ 753 urb = usb_alloc_urb(0, GFP_ATOMIC); 754 if (!urb) 755 goto nomem; 756 757 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 758 if (!buf) { 759 netdev_err(netdev, "No memory left for USB buffer\n"); 760 usb_free_urb(urb); 761 goto nomem; 762 } 763 764 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 765 766 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 767 msg->msg.can_msg.length = cf->len; 768 769 if (cf->can_id & CAN_RTR_FLAG) { 770 msg->type = cf->can_id & CAN_EFF_FLAG ? 771 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 772 773 msg->length = CPC_CAN_MSG_MIN_SIZE; 774 } else { 775 msg->type = cf->can_id & CAN_EFF_FLAG ? 776 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 777 778 for (i = 0; i < cf->len; i++) 779 msg->msg.can_msg.msg[i] = cf->data[i]; 780 781 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 782 } 783 784 for (i = 0; i < MAX_TX_URBS; i++) { 785 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 786 context = &dev->tx_contexts[i]; 787 break; 788 } 789 } 790 791 /* 792 * May never happen! When this happens we'd more URBs in flight as 793 * allowed (MAX_TX_URBS). 794 */ 795 if (!context) { 796 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 797 usb_free_urb(urb); 798 799 netdev_warn(netdev, "couldn't find free context\n"); 800 801 return NETDEV_TX_BUSY; 802 } 803 804 context->dev = dev; 805 context->echo_index = i; 806 807 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 808 size, ems_usb_write_bulk_callback, context); 809 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 810 usb_anchor_urb(urb, &dev->tx_submitted); 811 812 can_put_echo_skb(skb, netdev, context->echo_index, 0); 813 814 atomic_inc(&dev->active_tx_urbs); 815 816 err = usb_submit_urb(urb, GFP_ATOMIC); 817 if (unlikely(err)) { 818 can_free_echo_skb(netdev, context->echo_index, NULL); 819 820 usb_unanchor_urb(urb); 821 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 822 dev_kfree_skb(skb); 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; 850 851 nomem: 852 dev_kfree_skb(skb); 853 stats->tx_dropped++; 854 855 return NETDEV_TX_OK; 856 } 857 858 static 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 } 875 876 static 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 }; 882 883 static const struct can_bittiming_const ems_usb_bittiming_const = { 884 .name = "ems_usb", 885 .tseg1_min = 1, 886 .tseg1_max = 16, 887 .tseg2_min = 1, 888 .tseg2_max = 8, 889 .sjw_max = 4, 890 .brp_min = 1, 891 .brp_max = 64, 892 .brp_inc = 1, 893 }; 894 895 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 896 { 897 struct ems_usb *dev = netdev_priv(netdev); 898 899 switch (mode) { 900 case CAN_MODE_START: 901 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 902 netdev_warn(netdev, "couldn't start device"); 903 904 if (netif_queue_stopped(netdev)) 905 netif_wake_queue(netdev); 906 break; 907 908 default: 909 return -EOPNOTSUPP; 910 } 911 912 return 0; 913 } 914 915 static int ems_usb_set_bittiming(struct net_device *netdev) 916 { 917 struct ems_usb *dev = netdev_priv(netdev); 918 struct can_bittiming *bt = &dev->can.bittiming; 919 u8 btr0, btr1; 920 921 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 922 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 923 (((bt->phase_seg2 - 1) & 0x7) << 4); 924 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 925 btr1 |= 0x80; 926 927 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 928 929 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 930 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 931 932 return ems_usb_command_msg(dev, &dev->active_params); 933 } 934 935 static void init_params_sja1000(struct ems_cpc_msg *msg) 936 { 937 struct cpc_sja1000_params *sja1000 = 938 &msg->msg.can_params.cc_params.sja1000; 939 940 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 941 msg->length = sizeof(struct cpc_can_params); 942 msg->msgid = 0; 943 944 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 945 946 /* Acceptance filter open */ 947 sja1000->acc_code0 = 0x00; 948 sja1000->acc_code1 = 0x00; 949 sja1000->acc_code2 = 0x00; 950 sja1000->acc_code3 = 0x00; 951 952 /* Acceptance filter open */ 953 sja1000->acc_mask0 = 0xFF; 954 sja1000->acc_mask1 = 0xFF; 955 sja1000->acc_mask2 = 0xFF; 956 sja1000->acc_mask3 = 0xFF; 957 958 sja1000->btr0 = 0; 959 sja1000->btr1 = 0; 960 961 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 962 sja1000->mode = SJA1000_MOD_RM; 963 } 964 965 /* 966 * probe function for new CPC-USB devices 967 */ 968 static int ems_usb_probe(struct usb_interface *intf, 969 const struct usb_device_id *id) 970 { 971 struct net_device *netdev; 972 struct ems_usb *dev; 973 int i, err = -ENOMEM; 974 975 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 976 if (!netdev) { 977 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 978 return -ENOMEM; 979 } 980 981 dev = netdev_priv(netdev); 982 983 dev->udev = interface_to_usbdev(intf); 984 dev->netdev = netdev; 985 986 dev->can.state = CAN_STATE_STOPPED; 987 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 988 dev->can.bittiming_const = &ems_usb_bittiming_const; 989 dev->can.do_set_bittiming = ems_usb_set_bittiming; 990 dev->can.do_set_mode = ems_usb_set_mode; 991 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 992 993 netdev->netdev_ops = &ems_usb_netdev_ops; 994 995 netdev->flags |= IFF_ECHO; /* we support local echo */ 996 997 init_usb_anchor(&dev->rx_submitted); 998 999 init_usb_anchor(&dev->tx_submitted); 1000 atomic_set(&dev->active_tx_urbs, 0); 1001 1002 for (i = 0; i < MAX_TX_URBS; i++) 1003 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1004 1005 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1006 if (!dev->intr_urb) 1007 goto cleanup_candev; 1008 1009 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1010 if (!dev->intr_in_buffer) 1011 goto cleanup_intr_urb; 1012 1013 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1014 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1015 if (!dev->tx_msg_buffer) 1016 goto cleanup_intr_in_buffer; 1017 1018 usb_set_intfdata(intf, dev); 1019 1020 SET_NETDEV_DEV(netdev, &intf->dev); 1021 1022 init_params_sja1000(&dev->active_params); 1023 1024 err = ems_usb_command_msg(dev, &dev->active_params); 1025 if (err) { 1026 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1027 goto cleanup_tx_msg_buffer; 1028 } 1029 1030 err = register_candev(netdev); 1031 if (err) { 1032 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1033 goto cleanup_tx_msg_buffer; 1034 } 1035 1036 return 0; 1037 1038 cleanup_tx_msg_buffer: 1039 kfree(dev->tx_msg_buffer); 1040 1041 cleanup_intr_in_buffer: 1042 kfree(dev->intr_in_buffer); 1043 1044 cleanup_intr_urb: 1045 usb_free_urb(dev->intr_urb); 1046 1047 cleanup_candev: 1048 free_candev(netdev); 1049 1050 return err; 1051 } 1052 1053 /* 1054 * called by the usb core when the device is removed from the system 1055 */ 1056 static void ems_usb_disconnect(struct usb_interface *intf) 1057 { 1058 struct ems_usb *dev = usb_get_intfdata(intf); 1059 1060 usb_set_intfdata(intf, NULL); 1061 1062 if (dev) { 1063 unregister_netdev(dev->netdev); 1064 1065 unlink_all_urbs(dev); 1066 1067 usb_free_urb(dev->intr_urb); 1068 1069 kfree(dev->intr_in_buffer); 1070 kfree(dev->tx_msg_buffer); 1071 1072 free_candev(dev->netdev); 1073 } 1074 } 1075 1076 /* usb specific object needed to register this driver with the usb subsystem */ 1077 static struct usb_driver ems_usb_driver = { 1078 .name = "ems_usb", 1079 .probe = ems_usb_probe, 1080 .disconnect = ems_usb_disconnect, 1081 .id_table = ems_usb_table, 1082 }; 1083 1084 module_usb_driver(ems_usb_driver); 1085