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ems_usb.c
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linux-6.19.14/drivers/net/can/usb/ems_usb.c
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 18MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 19MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 20MODULE_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 */ 117struct 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 */ 124struct 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 */ 140struct 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 */ 150struct cpc_confirm { 151 u8 error; /* error code */ 152}; 153 154/* Structure for overrun conditions */ 155struct cpc_overrun { 156 u8 event; 157 u8 count; 158}; 159 160/* SJA1000 CAN errors (compatible to NXP LPC2119) */ 161struct cpc_sja1000_can_error { 162 u8 ecc; 163 u8 rxerr; 164 u8 txerr; 165}; 166 167/* structure for CAN error conditions */ 168struct 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 */ 185struct cpc_can_err_counter { 186 u8 rx; 187 u8 tx; 188}; 189 190/* Main message type used between library and application */ 191struct __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 */ 214static struct usb_device_id ems_usb_table[] = { 215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 216 {} /* Terminating entry */ 217}; 218 219MODULE_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 228struct ems_usb; 229 230struct ems_tx_urb_context { 231 struct ems_usb *dev; 232 233 u32 echo_index; 234}; 235 236struct 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 262static 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 299static 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 331static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 332{ 333 struct can_frame *cf; 334 struct sk_buff *skb; 335 struct net_device_stats *stats = &dev->netdev->stats; 336 337 skb = alloc_can_err_skb(dev->netdev, &cf); 338 339 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 340 u8 state = msg->msg.can_state; 341 342 if (state & SJA1000_SR_BS) { 343 dev->can.state = CAN_STATE_BUS_OFF; 344 if (skb) 345 cf->can_id |= CAN_ERR_BUSOFF; 346 347 dev->can.can_stats.bus_off++; 348 can_bus_off(dev->netdev); 349 } else if (state & SJA1000_SR_ES) { 350 dev->can.state = CAN_STATE_ERROR_WARNING; 351 dev->can.can_stats.error_warning++; 352 } else { 353 dev->can.state = CAN_STATE_ERROR_ACTIVE; 354 dev->can.can_stats.error_passive++; 355 } 356 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 357 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 358 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 359 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 360 361 /* bus error interrupt */ 362 dev->can.can_stats.bus_error++; 363 364 if (skb) { 365 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 366 367 switch (ecc & SJA1000_ECC_MASK) { 368 case SJA1000_ECC_BIT: 369 cf->data[2] |= CAN_ERR_PROT_BIT; 370 break; 371 case SJA1000_ECC_FORM: 372 cf->data[2] |= CAN_ERR_PROT_FORM; 373 break; 374 case SJA1000_ECC_STUFF: 375 cf->data[2] |= CAN_ERR_PROT_STUFF; 376 break; 377 default: 378 cf->data[3] = ecc & SJA1000_ECC_SEG; 379 break; 380 } 381 } 382 383 /* Error occurred during transmission? */ 384 if ((ecc & SJA1000_ECC_DIR) == 0) { 385 stats->tx_errors++; 386 if (skb) 387 cf->data[2] |= CAN_ERR_PROT_TX; 388 } else { 389 stats->rx_errors++; 390 } 391 392 if (skb && (dev->can.state == CAN_STATE_ERROR_WARNING || 393 dev->can.state == CAN_STATE_ERROR_PASSIVE)) { 394 cf->can_id |= CAN_ERR_CRTL; 395 cf->data[1] = (txerr > rxerr) ? 396 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE; 397 } 398 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) { 399 if (skb) { 400 cf->can_id |= CAN_ERR_CRTL; 401 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 402 } 403 404 stats->rx_over_errors++; 405 stats->rx_errors++; 406 } 407 408 if (skb) 409 netif_rx(skb); 410} 411 412/* 413 * callback for bulk IN urb 414 */ 415static void ems_usb_read_bulk_callback(struct urb *urb) 416{ 417 struct ems_usb *dev = urb->context; 418 struct net_device *netdev; 419 int retval; 420 421 netdev = dev->netdev; 422 423 if (!netif_device_present(netdev)) 424 return; 425 426 switch (urb->status) { 427 case 0: /* success */ 428 break; 429 430 case -ENOENT: 431 return; 432 433 default: 434 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status); 435 goto resubmit_urb; 436 } 437 438 if (urb->actual_length > CPC_HEADER_SIZE) { 439 struct ems_cpc_msg *msg; 440 u8 *ibuf = urb->transfer_buffer; 441 u8 msg_count, start; 442 443 msg_count = ibuf[0] & ~0x80; 444 445 start = CPC_HEADER_SIZE; 446 447 while (msg_count) { 448 if (start + CPC_MSG_HEADER_LEN > urb->actual_length) { 449 netdev_err(netdev, "format error\n"); 450 break; 451 } 452 453 msg = (struct ems_cpc_msg *)&ibuf[start]; 454 455 switch (msg->type) { 456 case CPC_MSG_TYPE_CAN_STATE: 457 /* Process CAN state changes */ 458 ems_usb_rx_err(dev, msg); 459 break; 460 461 case CPC_MSG_TYPE_CAN_FRAME: 462 case CPC_MSG_TYPE_EXT_CAN_FRAME: 463 case CPC_MSG_TYPE_RTR_FRAME: 464 case CPC_MSG_TYPE_EXT_RTR_FRAME: 465 ems_usb_rx_can_msg(dev, msg); 466 break; 467 468 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 469 /* Process errorframe */ 470 ems_usb_rx_err(dev, msg); 471 break; 472 473 case CPC_MSG_TYPE_OVERRUN: 474 /* Message lost while receiving */ 475 ems_usb_rx_err(dev, msg); 476 break; 477 } 478 479 start += CPC_MSG_HEADER_LEN + msg->length; 480 msg_count--; 481 482 if (start > urb->actual_length) { 483 netdev_err(netdev, "format error\n"); 484 break; 485 } 486 } 487 } 488 489resubmit_urb: 490 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 491 urb->transfer_buffer, RX_BUFFER_SIZE, 492 ems_usb_read_bulk_callback, dev); 493 494 usb_anchor_urb(urb, &dev->rx_submitted); 495 496 retval = usb_submit_urb(urb, GFP_ATOMIC); 497 if (!retval) 498 return; 499 500 usb_unanchor_urb(urb); 501 502 if (retval == -ENODEV) 503 netif_device_detach(netdev); 504 else 505 netdev_err(netdev, 506 "failed resubmitting read bulk urb: %d\n", retval); 507} 508 509/* 510 * callback for bulk IN urb 511 */ 512static void ems_usb_write_bulk_callback(struct urb *urb) 513{ 514 struct ems_tx_urb_context *context = urb->context; 515 struct ems_usb *dev; 516 struct net_device *netdev; 517 518 BUG_ON(!context); 519 520 dev = context->dev; 521 netdev = dev->netdev; 522 523 /* free up our allocated buffer */ 524 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 525 urb->transfer_buffer, urb->transfer_dma); 526 527 atomic_dec(&dev->active_tx_urbs); 528 529 if (!netif_device_present(netdev)) 530 return; 531 532 if (urb->status) 533 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status); 534 535 netif_trans_update(netdev); 536 537 /* transmission complete interrupt */ 538 netdev->stats.tx_packets++; 539 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index, 540 NULL); 541 542 /* Release context */ 543 context->echo_index = MAX_TX_URBS; 544 545} 546 547/* 548 * Send the given CPC command synchronously 549 */ 550static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 551{ 552 int actual_length; 553 554 /* Copy payload */ 555 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 556 msg->length + CPC_MSG_HEADER_LEN); 557 558 /* Clear header */ 559 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 560 561 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 562 &dev->tx_msg_buffer[0], 563 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 564 &actual_length, 1000); 565} 566 567/* 568 * Change CAN controllers' mode register 569 */ 570static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 571{ 572 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 573 574 return ems_usb_command_msg(dev, &dev->active_params); 575} 576 577/* 578 * Send a CPC_Control command to change behaviour when interface receives a CAN 579 * message, bus error or CAN state changed notifications. 580 */ 581static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 582{ 583 struct ems_cpc_msg cmd; 584 585 cmd.type = CPC_CMD_TYPE_CONTROL; 586 cmd.length = CPC_MSG_HEADER_LEN + 1; 587 588 cmd.msgid = 0; 589 590 cmd.msg.generic[0] = val; 591 592 return ems_usb_command_msg(dev, &cmd); 593} 594 595/* 596 * Start interface 597 */ 598static int ems_usb_start(struct ems_usb *dev) 599{ 600 struct net_device *netdev = dev->netdev; 601 int err, i; 602 603 dev->intr_in_buffer[0] = 0; 604 dev->free_slots = 50; /* initial size */ 605 606 for (i = 0; i < MAX_RX_URBS; i++) { 607 struct urb *urb = NULL; 608 u8 *buf = NULL; 609 dma_addr_t buf_dma; 610 611 /* create a URB, and a buffer for it */ 612 urb = usb_alloc_urb(0, GFP_KERNEL); 613 if (!urb) { 614 err = -ENOMEM; 615 break; 616 } 617 618 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 619 &buf_dma); 620 if (!buf) { 621 netdev_err(netdev, "No memory left for USB buffer\n"); 622 usb_free_urb(urb); 623 err = -ENOMEM; 624 break; 625 } 626 627 urb->transfer_dma = buf_dma; 628 629 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 630 buf, RX_BUFFER_SIZE, 631 ems_usb_read_bulk_callback, dev); 632 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 633 usb_anchor_urb(urb, &dev->rx_submitted); 634 635 err = usb_submit_urb(urb, GFP_KERNEL); 636 if (err) { 637 usb_unanchor_urb(urb); 638 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 639 urb->transfer_dma); 640 usb_free_urb(urb); 641 break; 642 } 643 644 dev->rxbuf[i] = buf; 645 dev->rxbuf_dma[i] = buf_dma; 646 647 /* Drop reference, USB core will take care of freeing it */ 648 usb_free_urb(urb); 649 } 650 651 /* Did we submit any URBs */ 652 if (i == 0) { 653 netdev_warn(netdev, "couldn't setup read URBs\n"); 654 return err; 655 } 656 657 /* Warn if we've couldn't transmit all the URBs */ 658 if (i < MAX_RX_URBS) 659 netdev_warn(netdev, "rx performance may be slow\n"); 660 661 /* Setup and start interrupt URB */ 662 usb_fill_int_urb(dev->intr_urb, dev->udev, 663 usb_rcvintpipe(dev->udev, 1), 664 dev->intr_in_buffer, 665 INTR_IN_BUFFER_SIZE, 666 ems_usb_read_interrupt_callback, dev, 1); 667 668 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 669 if (err) { 670 netdev_warn(netdev, "intr URB submit failed: %d\n", err); 671 672 return err; 673 } 674 675 /* CPC-USB will transfer received message to host */ 676 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 677 if (err) 678 goto failed; 679 680 /* CPC-USB will transfer CAN state changes to host */ 681 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 682 if (err) 683 goto failed; 684 685 /* CPC-USB will transfer bus errors to host */ 686 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 687 if (err) 688 goto failed; 689 690 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 691 if (err) 692 goto failed; 693 694 dev->can.state = CAN_STATE_ERROR_ACTIVE; 695 696 return 0; 697 698failed: 699 netdev_warn(netdev, "couldn't submit control: %d\n", err); 700 701 return err; 702} 703 704static void unlink_all_urbs(struct ems_usb *dev) 705{ 706 int i; 707 708 usb_unlink_urb(dev->intr_urb); 709 710 usb_kill_anchored_urbs(&dev->rx_submitted); 711 712 for (i = 0; i < MAX_RX_URBS; ++i) 713 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, 714 dev->rxbuf[i], dev->rxbuf_dma[i]); 715 716 usb_kill_anchored_urbs(&dev->tx_submitted); 717 atomic_set(&dev->active_tx_urbs, 0); 718 719 for (i = 0; i < MAX_TX_URBS; i++) 720 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 721} 722 723static int ems_usb_open(struct net_device *netdev) 724{ 725 struct ems_usb *dev = netdev_priv(netdev); 726 int err; 727 728 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 729 if (err) 730 return err; 731 732 /* common open */ 733 err = open_candev(netdev); 734 if (err) 735 return err; 736 737 /* finally start device */ 738 err = ems_usb_start(dev); 739 if (err) { 740 if (err == -ENODEV) 741 netif_device_detach(dev->netdev); 742 743 netdev_warn(netdev, "couldn't start device: %d\n", err); 744 745 close_candev(netdev); 746 747 return err; 748 } 749 750 751 netif_start_queue(netdev); 752 753 return 0; 754} 755 756static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 757{ 758 struct ems_usb *dev = netdev_priv(netdev); 759 struct ems_tx_urb_context *context = NULL; 760 struct net_device_stats *stats = &netdev->stats; 761 struct can_frame *cf = (struct can_frame *)skb->data; 762 struct ems_cpc_msg *msg; 763 struct urb *urb; 764 u8 *buf; 765 int i, err; 766 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 767 + sizeof(struct cpc_can_msg); 768 769 if (can_dev_dropped_skb(netdev, skb)) 770 return NETDEV_TX_OK; 771 772 /* create a URB, and a buffer for it, and copy the data to the URB */ 773 urb = usb_alloc_urb(0, GFP_ATOMIC); 774 if (!urb) 775 goto nomem; 776 777 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 778 if (!buf) { 779 netdev_err(netdev, "No memory left for USB buffer\n"); 780 usb_free_urb(urb); 781 goto nomem; 782 } 783 784 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 785 786 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK); 787 msg->msg.can_msg.length = cf->len; 788 789 if (cf->can_id & CAN_RTR_FLAG) { 790 msg->type = cf->can_id & CAN_EFF_FLAG ? 791 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 792 793 msg->length = CPC_CAN_MSG_MIN_SIZE; 794 } else { 795 msg->type = cf->can_id & CAN_EFF_FLAG ? 796 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 797 798 for (i = 0; i < cf->len; i++) 799 msg->msg.can_msg.msg[i] = cf->data[i]; 800 801 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len; 802 } 803 804 for (i = 0; i < MAX_TX_URBS; i++) { 805 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 806 context = &dev->tx_contexts[i]; 807 break; 808 } 809 } 810 811 /* 812 * May never happen! When this happens we'd more URBs in flight as 813 * allowed (MAX_TX_URBS). 814 */ 815 if (!context) { 816 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 817 usb_free_urb(urb); 818 819 netdev_warn(netdev, "couldn't find free context\n"); 820 821 return NETDEV_TX_BUSY; 822 } 823 824 context->dev = dev; 825 context->echo_index = i; 826 827 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 828 size, ems_usb_write_bulk_callback, context); 829 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 830 usb_anchor_urb(urb, &dev->tx_submitted); 831 832 can_put_echo_skb(skb, netdev, context->echo_index, 0); 833 834 atomic_inc(&dev->active_tx_urbs); 835 836 err = usb_submit_urb(urb, GFP_ATOMIC); 837 if (unlikely(err)) { 838 can_free_echo_skb(netdev, context->echo_index, NULL); 839 840 usb_unanchor_urb(urb); 841 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 842 843 atomic_dec(&dev->active_tx_urbs); 844 845 if (err == -ENODEV) { 846 netif_device_detach(netdev); 847 } else { 848 netdev_warn(netdev, "failed tx_urb %d\n", err); 849 850 stats->tx_dropped++; 851 } 852 } else { 853 netif_trans_update(netdev); 854 855 /* Slow down tx path */ 856 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 857 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) { 858 netif_stop_queue(netdev); 859 } 860 } 861 862 /* 863 * Release our reference to this URB, the USB core will eventually free 864 * it entirely. 865 */ 866 usb_free_urb(urb); 867 868 return NETDEV_TX_OK; 869 870nomem: 871 dev_kfree_skb(skb); 872 stats->tx_dropped++; 873 874 return NETDEV_TX_OK; 875} 876 877static int ems_usb_close(struct net_device *netdev) 878{ 879 struct ems_usb *dev = netdev_priv(netdev); 880 881 /* Stop polling */ 882 unlink_all_urbs(dev); 883 884 netif_stop_queue(netdev); 885 886 /* Set CAN controller to reset mode */ 887 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 888 netdev_warn(netdev, "couldn't stop device"); 889 890 close_candev(netdev); 891 892 return 0; 893} 894 895static const struct net_device_ops ems_usb_netdev_ops = { 896 .ndo_open = ems_usb_open, 897 .ndo_stop = ems_usb_close, 898 .ndo_start_xmit = ems_usb_start_xmit, 899}; 900 901static const struct ethtool_ops ems_usb_ethtool_ops = { 902 .get_ts_info = ethtool_op_get_ts_info, 903}; 904 905static const struct can_bittiming_const ems_usb_bittiming_const = { 906 .name = KBUILD_MODNAME, 907 .tseg1_min = 1, 908 .tseg1_max = 16, 909 .tseg2_min = 1, 910 .tseg2_max = 8, 911 .sjw_max = 4, 912 .brp_min = 1, 913 .brp_max = 64, 914 .brp_inc = 1, 915}; 916 917static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 918{ 919 struct ems_usb *dev = netdev_priv(netdev); 920 921 switch (mode) { 922 case CAN_MODE_START: 923 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 924 netdev_warn(netdev, "couldn't start device"); 925 926 if (netif_queue_stopped(netdev)) 927 netif_wake_queue(netdev); 928 break; 929 930 default: 931 return -EOPNOTSUPP; 932 } 933 934 return 0; 935} 936 937static int ems_usb_set_bittiming(struct net_device *netdev) 938{ 939 struct ems_usb *dev = netdev_priv(netdev); 940 struct can_bittiming *bt = &dev->can.bittiming; 941 u8 btr0, btr1; 942 943 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 944 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 945 (((bt->phase_seg2 - 1) & 0x7) << 4); 946 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 947 btr1 |= 0x80; 948 949 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 950 951 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 952 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 953 954 return ems_usb_command_msg(dev, &dev->active_params); 955} 956 957static void init_params_sja1000(struct ems_cpc_msg *msg) 958{ 959 struct cpc_sja1000_params *sja1000 = 960 &msg->msg.can_params.cc_params.sja1000; 961 962 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 963 msg->length = sizeof(struct cpc_can_params); 964 msg->msgid = 0; 965 966 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 967 968 /* Acceptance filter open */ 969 sja1000->acc_code0 = 0x00; 970 sja1000->acc_code1 = 0x00; 971 sja1000->acc_code2 = 0x00; 972 sja1000->acc_code3 = 0x00; 973 974 /* Acceptance filter open */ 975 sja1000->acc_mask0 = 0xFF; 976 sja1000->acc_mask1 = 0xFF; 977 sja1000->acc_mask2 = 0xFF; 978 sja1000->acc_mask3 = 0xFF; 979 980 sja1000->btr0 = 0; 981 sja1000->btr1 = 0; 982 983 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 984 sja1000->mode = SJA1000_MOD_RM; 985} 986 987/* 988 * probe function for new CPC-USB devices 989 */ 990static int ems_usb_probe(struct usb_interface *intf, 991 const struct usb_device_id *id) 992{ 993 struct net_device *netdev; 994 struct ems_usb *dev; 995 int i, err = -ENOMEM; 996 997 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 998 if (!netdev) { 999 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 1000 return -ENOMEM; 1001 } 1002 1003 dev = netdev_priv(netdev); 1004 1005 dev->udev = interface_to_usbdev(intf); 1006 dev->netdev = netdev; 1007 1008 dev->can.state = CAN_STATE_STOPPED; 1009 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1010 dev->can.bittiming_const = &ems_usb_bittiming_const; 1011 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1012 dev->can.do_set_mode = ems_usb_set_mode; 1013 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1014 1015 netdev->netdev_ops = &ems_usb_netdev_ops; 1016 netdev->ethtool_ops = &ems_usb_ethtool_ops; 1017 1018 netdev->flags |= IFF_ECHO; /* we support local echo */ 1019 1020 init_usb_anchor(&dev->rx_submitted); 1021 1022 init_usb_anchor(&dev->tx_submitted); 1023 atomic_set(&dev->active_tx_urbs, 0); 1024 1025 for (i = 0; i < MAX_TX_URBS; i++) 1026 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1027 1028 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1029 if (!dev->intr_urb) 1030 goto cleanup_candev; 1031 1032 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1033 if (!dev->intr_in_buffer) 1034 goto cleanup_intr_urb; 1035 1036 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE + 1037 sizeof(struct ems_cpc_msg), GFP_KERNEL); 1038 if (!dev->tx_msg_buffer) 1039 goto cleanup_intr_in_buffer; 1040 1041 usb_set_intfdata(intf, dev); 1042 1043 SET_NETDEV_DEV(netdev, &intf->dev); 1044 1045 init_params_sja1000(&dev->active_params); 1046 1047 err = ems_usb_command_msg(dev, &dev->active_params); 1048 if (err) { 1049 netdev_err(netdev, "couldn't initialize controller: %d\n", err); 1050 goto cleanup_tx_msg_buffer; 1051 } 1052 1053 err = register_candev(netdev); 1054 if (err) { 1055 netdev_err(netdev, "couldn't register CAN device: %d\n", err); 1056 goto cleanup_tx_msg_buffer; 1057 } 1058 1059 return 0; 1060 1061cleanup_tx_msg_buffer: 1062 kfree(dev->tx_msg_buffer); 1063 1064cleanup_intr_in_buffer: 1065 kfree(dev->intr_in_buffer); 1066 1067cleanup_intr_urb: 1068 usb_free_urb(dev->intr_urb); 1069 1070cleanup_candev: 1071 free_candev(netdev); 1072 1073 return err; 1074} 1075 1076/* 1077 * called by the usb core when the device is removed from the system 1078 */ 1079static void ems_usb_disconnect(struct usb_interface *intf) 1080{ 1081 struct ems_usb *dev = usb_get_intfdata(intf); 1082 1083 usb_set_intfdata(intf, NULL); 1084 1085 if (dev) { 1086 unregister_netdev(dev->netdev); 1087 1088 unlink_all_urbs(dev); 1089 1090 usb_free_urb(dev->intr_urb); 1091 1092 kfree(dev->intr_in_buffer); 1093 kfree(dev->tx_msg_buffer); 1094 1095 free_candev(dev->netdev); 1096 } 1097} 1098 1099/* usb specific object needed to register this driver with the usb subsystem */ 1100static struct usb_driver ems_usb_driver = { 1101 .name = KBUILD_MODNAME, 1102 .probe = ems_usb_probe, 1103 .disconnect = ems_usb_disconnect, 1104 .id_table = ems_usb_table, 1105}; 1106 1107module_usb_driver(ems_usb_driver);
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