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 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 } 324 325 stats->rx_packets++; 326 stats->rx_bytes += cf->len; 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 stats->rx_packets++; 401 stats->rx_bytes += cf->len; 402 netif_rx(skb); 403 } 404 405 /* 406 * callback for bulk IN urb 407 */ 408 static void ems_usb_read_bulk_callback(struct urb *urb) 409 { 410 struct ems_usb *dev = urb->context; 411 struct net_device *netdev; 412 int retval; 413 414 netdev = dev->netdev; 415 416 if (!netif_device_present(netdev)) 417 return; 418 419 switch (urb->status) { 420 case 0: /* success */ 421 break; 422 423 case -ENOENT: 424 return; 425 426 default: 427 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 428 goto resubmit_urb; 429 } 430 431 if (urb->actual_length > CPC_HEADER_SIZE) { 432 struct ems_cpc_msg *msg; 433 u8 *ibuf = urb->transfer_buffer; 434 u8 msg_count, start; 435 436 msg_count = ibuf[0] & ~0x80; 437 438 start = CPC_HEADER_SIZE; 439 440 while (msg_count) { 441 msg = (struct ems_cpc_msg *)&ibuf[start]; 442 443 switch (msg->type) { 444 case CPC_MSG_TYPE_CAN_STATE: 445 /* Process CAN state changes */ 446 ems_usb_rx_err(dev, msg); 447 break; 448 449 case CPC_MSG_TYPE_CAN_FRAME: 450 case CPC_MSG_TYPE_EXT_CAN_FRAME: 451 case CPC_MSG_TYPE_RTR_FRAME: 452 case CPC_MSG_TYPE_EXT_RTR_FRAME: 453 ems_usb_rx_can_msg(dev, msg); 454 break; 455 456 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 457 /* Process errorframe */ 458 ems_usb_rx_err(dev, msg); 459 break; 460 461 case CPC_MSG_TYPE_OVERRUN: 462 /* Message lost while receiving */ 463 ems_usb_rx_err(dev, msg); 464 break; 465 } 466 467 start += CPC_MSG_HEADER_LEN + msg->length; 468 msg_count--; 469 470 if (start > urb->transfer_buffer_length) { 471 netdev_err(netdev, "format error\n"); 472 break; 473 } 474 } 475 } 476 477 resubmit_urb: 478 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 479 urb->transfer_buffer, RX_BUFFER_SIZE, 480 ems_usb_read_bulk_callback, dev); 481 482 retval = usb_submit_urb(urb, GFP_ATOMIC); 483 484 if (retval == -ENODEV) 485 netif_device_detach(netdev); 486 else if (retval) 487 netdev_err(netdev, 488 "failed resubmitting read bulk urb: %d\n", retval); 489 } 490 491 /* 492 * callback for bulk IN urb 493 */ 494 static void ems_usb_write_bulk_callback(struct urb *urb) 495 { 496 struct ems_tx_urb_context *context = urb->context; 497 struct ems_usb *dev; 498 struct net_device *netdev; 499 500 BUG_ON(!context); 501 502 dev = context->dev; 503 netdev = dev->netdev; 504 505 /* free up our allocated buffer */ 506 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 507 urb->transfer_buffer, urb->transfer_dma); 508 509 atomic_dec(&dev->active_tx_urbs); 510 511 if (!netif_device_present(netdev)) 512 return; 513 514 if (urb->status) 515 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 516 517 netif_trans_update(netdev); 518 519 /* transmission complete interrupt */ 520 netdev->stats.tx_packets++; 521 netdev->stats.tx_bytes += context->dlc; 522 523 can_get_echo_skb(netdev, context->echo_index, NULL); 524 525 /* Release context */ 526 context->echo_index = MAX_TX_URBS; 527 528 } 529 530 /* 531 * Send the given CPC command synchronously 532 */ 533 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 534 { 535 int actual_length; 536 537 /* Copy payload */ 538 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 539 msg->length + CPC_MSG_HEADER_LEN); 540 541 /* Clear header */ 542 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 543 544 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 545 &dev->tx_msg_buffer[0], 546 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 547 &actual_length, 1000); 548 } 549 550 /* 551 * Change CAN controllers' mode register 552 */ 553 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 554 { 555 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 556 557 return ems_usb_command_msg(dev, &dev->active_params); 558 } 559 560 /* 561 * Send a CPC_Control command to change behaviour when interface receives a CAN 562 * message, bus error or CAN state changed notifications. 563 */ 564 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 565 { 566 struct ems_cpc_msg cmd; 567 568 cmd.type = CPC_CMD_TYPE_CONTROL; 569 cmd.length = CPC_MSG_HEADER_LEN + 1; 570 571 cmd.msgid = 0; 572 573 cmd.msg.generic[0] = val; 574 575 return ems_usb_command_msg(dev, &cmd); 576 } 577 578 /* 579 * Start interface 580 */ 581 static int ems_usb_start(struct ems_usb *dev) 582 { 583 struct net_device *netdev = dev->netdev; 584 int err, i; 585 586 dev->intr_in_buffer[0] = 0; 587 dev->free_slots = 50; /* initial size */ 588 589 for (i = 0; i < MAX_RX_URBS; i++) { 590 struct urb *urb = NULL; 591 u8 *buf = NULL; 592 dma_addr_t buf_dma; 593 594 /* create a URB, and a buffer for it */ 595 urb = usb_alloc_urb(0, GFP_KERNEL); 596 if (!urb) { 597 err = -ENOMEM; 598 break; 599 } 600 601 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 602 &buf_dma); 603 if (!buf) { 604 netdev_err(netdev, "No memory left for USB buffer\n"); 605 usb_free_urb(urb); 606 err = -ENOMEM; 607 break; 608 } 609 610 urb->transfer_dma = buf_dma; 611 612 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 613 buf, RX_BUFFER_SIZE, 614 ems_usb_read_bulk_callback, dev); 615 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 616 usb_anchor_urb(urb, &dev->rx_submitted); 617 618 err = usb_submit_urb(urb, GFP_KERNEL); 619 if (err) { 620 usb_unanchor_urb(urb); 621 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 622 urb->transfer_dma); 623 usb_free_urb(urb); 624 break; 625 } 626 627 dev->rxbuf[i] = buf; 628 dev->rxbuf_dma[i] = buf_dma; 629 630 /* Drop reference, USB core will take care of freeing it */ 631 usb_free_urb(urb); 632 } 633 634 /* Did we submit any URBs */ 635 if (i == 0) { 636 netdev_warn(netdev, "couldn't setup read URBs\n"); 637 return err; 638 } 639 640 /* Warn if we've couldn't transmit all the URBs */ 641 if (i < MAX_RX_URBS) 642 netdev_warn(netdev, "rx performance may be slow\n"); 643 644 /* Setup and start interrupt URB */ 645 usb_fill_int_urb(dev->intr_urb, dev->udev, 646 usb_rcvintpipe(dev->udev, 1), 647 dev->intr_in_buffer, 648 INTR_IN_BUFFER_SIZE, 649 ems_usb_read_interrupt_callback, dev, 1); 650 651 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 652 if (err) { 653 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 654 655 return err; 656 } 657 658 /* CPC-USB will transfer received message to host */ 659 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 660 if (err) 661 goto failed; 662 663 /* CPC-USB will transfer CAN state changes to host */ 664 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 665 if (err) 666 goto failed; 667 668 /* CPC-USB will transfer bus errors to host */ 669 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 670 if (err) 671 goto failed; 672 673 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 674 if (err) 675 goto failed; 676 677 dev->can.state = CAN_STATE_ERROR_ACTIVE; 678 679 return 0; 680 681 failed: 682 netdev_warn(netdev, "couldn't submit control: %d\n", err); 683 684 return err; 685 } 686 687 static void unlink_all_urbs(struct ems_usb *dev) 688 { 689 int i; 690 691 usb_unlink_urb(dev->intr_urb); 692 693 usb_kill_anchored_urbs(&dev->rx_submitted); 694 695 for (i = 0; i < MAX_RX_URBS; ++i) 696 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 697 dev->rxbuf[i], dev->rxbuf_dma[i]); 698 699 usb_kill_anchored_urbs(&dev->tx_submitted); 700 atomic_set(&dev->active_tx_urbs, 0); 701 702 for (i = 0; i < MAX_TX_URBS; i++) 703 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 704 } 705 706 static int ems_usb_open(struct net_device *netdev) 707 { 708 struct ems_usb *dev = netdev_priv(netdev); 709 int err; 710 711 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 712 if (err) 713 return err; 714 715 /* common open */ 716 err = open_candev(netdev); 717 if (err) 718 return err; 719 720 /* finally start device */ 721 err = ems_usb_start(dev); 722 if (err) { 723 if (err == -ENODEV) 724 netif_device_detach(dev->netdev); 725 726 netdev_warn(netdev, "couldn't start device: %d\n", err); 727 728 close_candev(netdev); 729 730 return err; 731 } 732 733 734 netif_start_queue(netdev); 735 736 return 0; 737 } 738 739 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 740 { 741 struct ems_usb *dev = netdev_priv(netdev); 742 struct ems_tx_urb_context *context = NULL; 743 struct net_device_stats *stats = &netdev->stats; 744 struct can_frame *cf = (struct can_frame *)skb->data; 745 struct ems_cpc_msg *msg; 746 struct urb *urb; 747 u8 *buf; 748 int i, err; 749 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 750 + sizeof(struct cpc_can_msg); 751 752 if (can_dropped_invalid_skb(netdev, skb)) 753 return NETDEV_TX_OK; 754 755 /* create a URB, and a buffer for it, and copy the data to the URB */ 756 urb = usb_alloc_urb(0, GFP_ATOMIC); 757 if (!urb) 758 goto nomem; 759 760 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 761 if (!buf) { 762 netdev_err(netdev, "No memory left for USB buffer\n"); 763 usb_free_urb(urb); 764 goto nomem; 765 } 766 767 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 768 769 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 770 msg->msg.can_msg.length = cf->len; 771 772 if (cf->can_id & CAN_RTR_FLAG) { 773 msg->type = cf->can_id & CAN_EFF_FLAG ? 774 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 775 776 msg->length = CPC_CAN_MSG_MIN_SIZE; 777 } else { 778 msg->type = cf->can_id & CAN_EFF_FLAG ? 779 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 780 781 for (i = 0; i < cf->len; i++) 782 msg->msg.can_msg.msg[i] = cf->data[i]; 783 784 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 785 } 786 787 for (i = 0; i < MAX_TX_URBS; i++) { 788 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 789 context = &dev->tx_contexts[i]; 790 break; 791 } 792 } 793 794 /* 795 * May never happen! When this happens we'd more URBs in flight as 796 * allowed (MAX_TX_URBS). 797 */ 798 if (!context) { 799 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 800 usb_free_urb(urb); 801 802 netdev_warn(netdev, "couldn't find free context\n"); 803 804 return NETDEV_TX_BUSY; 805 } 806 807 context->dev = dev; 808 context->echo_index = i; 809 context->dlc = cf->len; 810 811 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 812 size, ems_usb_write_bulk_callback, context); 813 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 814 usb_anchor_urb(urb, &dev->tx_submitted); 815 816 can_put_echo_skb(skb, netdev, context->echo_index, 0); 817 818 atomic_inc(&dev->active_tx_urbs); 819 820 err = usb_submit_urb(urb, GFP_ATOMIC); 821 if (unlikely(err)) { 822 can_free_echo_skb(netdev, context->echo_index, NULL); 823 824 usb_unanchor_urb(urb); 825 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 826 dev_kfree_skb(skb); 827 828 atomic_dec(&dev->active_tx_urbs); 829 830 if (err == -ENODEV) { 831 netif_device_detach(netdev); 832 } else { 833 netdev_warn(netdev, "failed tx_urb %d\n", err); 834 835 stats->tx_dropped++; 836 } 837 } else { 838 netif_trans_update(netdev); 839 840 /* Slow down tx path */ 841 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 842 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 843 netif_stop_queue(netdev); 844 } 845 } 846 847 /* 848 * Release our reference to this URB, the USB core will eventually free 849 * it entirely. 850 */ 851 usb_free_urb(urb); 852 853 return NETDEV_TX_OK; 854 855 nomem: 856 dev_kfree_skb(skb); 857 stats->tx_dropped++; 858 859 return NETDEV_TX_OK; 860 } 861 862 static int ems_usb_close(struct net_device *netdev) 863 { 864 struct ems_usb *dev = netdev_priv(netdev); 865 866 /* Stop polling */ 867 unlink_all_urbs(dev); 868 869 netif_stop_queue(netdev); 870 871 /* Set CAN controller to reset mode */ 872 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 873 netdev_warn(netdev, "couldn't stop device"); 874 875 close_candev(netdev); 876 877 return 0; 878 } 879 880 static const struct net_device_ops ems_usb_netdev_ops = { 881 .ndo_open = ems_usb_open, 882 .ndo_stop = ems_usb_close, 883 .ndo_start_xmit = ems_usb_start_xmit, 884 .ndo_change_mtu = can_change_mtu, 885 }; 886 887 static const struct can_bittiming_const ems_usb_bittiming_const = { 888 .name = "ems_usb", 889 .tseg1_min = 1, 890 .tseg1_max = 16, 891 .tseg2_min = 1, 892 .tseg2_max = 8, 893 .sjw_max = 4, 894 .brp_min = 1, 895 .brp_max = 64, 896 .brp_inc = 1, 897 }; 898 899 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 900 { 901 struct ems_usb *dev = netdev_priv(netdev); 902 903 switch (mode) { 904 case CAN_MODE_START: 905 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 906 netdev_warn(netdev, "couldn't start device"); 907 908 if (netif_queue_stopped(netdev)) 909 netif_wake_queue(netdev); 910 break; 911 912 default: 913 return -EOPNOTSUPP; 914 } 915 916 return 0; 917 } 918 919 static int ems_usb_set_bittiming(struct net_device *netdev) 920 { 921 struct ems_usb *dev = netdev_priv(netdev); 922 struct can_bittiming *bt = &dev->can.bittiming; 923 u8 btr0, btr1; 924 925 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 926 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 927 (((bt->phase_seg2 - 1) & 0x7) << 4); 928 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 929 btr1 |= 0x80; 930 931 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 932 933 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 934 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 935 936 return ems_usb_command_msg(dev, &dev->active_params); 937 } 938 939 static void init_params_sja1000(struct ems_cpc_msg *msg) 940 { 941 struct cpc_sja1000_params *sja1000 = 942 &msg->msg.can_params.cc_params.sja1000; 943 944 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 945 msg->length = sizeof(struct cpc_can_params); 946 msg->msgid = 0; 947 948 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 949 950 /* Acceptance filter open */ 951 sja1000->acc_code0 = 0x00; 952 sja1000->acc_code1 = 0x00; 953 sja1000->acc_code2 = 0x00; 954 sja1000->acc_code3 = 0x00; 955 956 /* Acceptance filter open */ 957 sja1000->acc_mask0 = 0xFF; 958 sja1000->acc_mask1 = 0xFF; 959 sja1000->acc_mask2 = 0xFF; 960 sja1000->acc_mask3 = 0xFF; 961 962 sja1000->btr0 = 0; 963 sja1000->btr1 = 0; 964 965 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 966 sja1000->mode = SJA1000_MOD_RM; 967 } 968 969 /* 970 * probe function for new CPC-USB devices 971 */ 972 static int ems_usb_probe(struct usb_interface *intf, 973 const struct usb_device_id *id) 974 { 975 struct net_device *netdev; 976 struct ems_usb *dev; 977 int i, err = -ENOMEM; 978 979 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 980 if (!netdev) { 981 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 982 return -ENOMEM; 983 } 984 985 dev = netdev_priv(netdev); 986 987 dev->udev = interface_to_usbdev(intf); 988 dev->netdev = netdev; 989 990 dev->can.state = CAN_STATE_STOPPED; 991 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 992 dev->can.bittiming_const = &ems_usb_bittiming_const; 993 dev->can.do_set_bittiming = ems_usb_set_bittiming; 994 dev->can.do_set_mode = ems_usb_set_mode; 995 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 996 997 netdev->netdev_ops = &ems_usb_netdev_ops; 998 999 netdev->flags |= IFF_ECHO; /* we support local echo */ 1000 1001 init_usb_anchor(&dev->rx_submitted); 1002 1003 init_usb_anchor(&dev->tx_submitted); 1004 atomic_set(&dev->active_tx_urbs, 0); 1005 1006 for (i = 0; i < MAX_TX_URBS; i++) 1007 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1008 1009 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1010 if (!dev->intr_urb) 1011 goto cleanup_candev; 1012 1013 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1014 if (!dev->intr_in_buffer) 1015 goto cleanup_intr_urb; 1016 1017 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1018 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1019 if (!dev->tx_msg_buffer) 1020 goto cleanup_intr_in_buffer; 1021 1022 usb_set_intfdata(intf, dev); 1023 1024 SET_NETDEV_DEV(netdev, &intf->dev); 1025 1026 init_params_sja1000(&dev->active_params); 1027 1028 err = ems_usb_command_msg(dev, &dev->active_params); 1029 if (err) { 1030 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1031 goto cleanup_tx_msg_buffer; 1032 } 1033 1034 err = register_candev(netdev); 1035 if (err) { 1036 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1037 goto cleanup_tx_msg_buffer; 1038 } 1039 1040 return 0; 1041 1042 cleanup_tx_msg_buffer: 1043 kfree(dev->tx_msg_buffer); 1044 1045 cleanup_intr_in_buffer: 1046 kfree(dev->intr_in_buffer); 1047 1048 cleanup_intr_urb: 1049 usb_free_urb(dev->intr_urb); 1050 1051 cleanup_candev: 1052 free_candev(netdev); 1053 1054 return err; 1055 } 1056 1057 /* 1058 * called by the usb core when the device is removed from the system 1059 */ 1060 static void ems_usb_disconnect(struct usb_interface *intf) 1061 { 1062 struct ems_usb *dev = usb_get_intfdata(intf); 1063 1064 usb_set_intfdata(intf, NULL); 1065 1066 if (dev) { 1067 unregister_netdev(dev->netdev); 1068 1069 unlink_all_urbs(dev); 1070 1071 usb_free_urb(dev->intr_urb); 1072 1073 kfree(dev->intr_in_buffer); 1074 kfree(dev->tx_msg_buffer); 1075 1076 free_candev(dev->netdev); 1077 } 1078 } 1079 1080 /* usb specific object needed to register this driver with the usb subsystem */ 1081 static struct usb_driver ems_usb_driver = { 1082 .name = "ems_usb", 1083 .probe = ems_usb_probe, 1084 .disconnect = ems_usb_disconnect, 1085 .id_table = ems_usb_table, 1086 }; 1087 1088 module_usb_driver(ems_usb_driver); 1089