1/* 2 * CAN driver for "8 devices" USB2CAN converter 3 * 4 * Copyright (C) 2012 Bernd Krumboeck (krumboeck@universalnet.at) 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; version 2 of the License. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License along 16 * with this program. 17 * 18 * This driver is inspired by the 3.2.0 version of drivers/net/can/usb/ems_usb.c 19 * and drivers/net/can/usb/esd_usb2.c 20 * 21 * Many thanks to Gerhard Bertelsmann (info@gerhard-bertelsmann.de) 22 * for testing and fixing this driver. Also many thanks to "8 devices", 23 * who were very cooperative and answered my questions. 24 */ 25 26#include <linux/signal.h> 27#include <linux/slab.h> 28#include <linux/module.h> 29#include <linux/netdevice.h> 30#include <linux/usb.h> 31 32#include <linux/can.h> 33#include <linux/can/dev.h> 34#include <linux/can/error.h> 35#include <linux/can/led.h> 36 37/* driver constants */ 38#define MAX_RX_URBS 20 39#define MAX_TX_URBS 20 40#define RX_BUFFER_SIZE 64 41 42/* vendor and product id */ 43#define USB_8DEV_VENDOR_ID 0x0483 44#define USB_8DEV_PRODUCT_ID 0x1234 45 46/* endpoints */ 47enum usb_8dev_endpoint { 48 USB_8DEV_ENDP_DATA_RX = 1, 49 USB_8DEV_ENDP_DATA_TX, 50 USB_8DEV_ENDP_CMD_RX, 51 USB_8DEV_ENDP_CMD_TX 52}; 53 54/* device CAN clock */ 55#define USB_8DEV_ABP_CLOCK 32000000 56 57/* setup flags */ 58#define USB_8DEV_SILENT 0x01 59#define USB_8DEV_LOOPBACK 0x02 60#define USB_8DEV_DISABLE_AUTO_RESTRANS 0x04 61#define USB_8DEV_STATUS_FRAME 0x08 62 63/* commands */ 64enum usb_8dev_cmd { 65 USB_8DEV_RESET = 1, 66 USB_8DEV_OPEN, 67 USB_8DEV_CLOSE, 68 USB_8DEV_SET_SPEED, 69 USB_8DEV_SET_MASK_FILTER, 70 USB_8DEV_GET_STATUS, 71 USB_8DEV_GET_STATISTICS, 72 USB_8DEV_GET_SERIAL, 73 USB_8DEV_GET_SOFTW_VER, 74 USB_8DEV_GET_HARDW_VER, 75 USB_8DEV_RESET_TIMESTAMP, 76 USB_8DEV_GET_SOFTW_HARDW_VER 77}; 78 79/* command options */ 80#define USB_8DEV_BAUD_MANUAL 0x09 81#define USB_8DEV_CMD_START 0x11 82#define USB_8DEV_CMD_END 0x22 83 84#define USB_8DEV_CMD_SUCCESS 0 85#define USB_8DEV_CMD_ERROR 255 86 87#define USB_8DEV_CMD_TIMEOUT 1000 88 89/* frames */ 90#define USB_8DEV_DATA_START 0x55 91#define USB_8DEV_DATA_END 0xAA 92 93#define USB_8DEV_TYPE_CAN_FRAME 0 94#define USB_8DEV_TYPE_ERROR_FRAME 3 95 96#define USB_8DEV_EXTID 0x01 97#define USB_8DEV_RTR 0x02 98#define USB_8DEV_ERR_FLAG 0x04 99 100/* status */ 101#define USB_8DEV_STATUSMSG_OK 0x00 /* Normal condition. */ 102#define USB_8DEV_STATUSMSG_OVERRUN 0x01 /* Overrun occured when sending */ 103#define USB_8DEV_STATUSMSG_BUSLIGHT 0x02 /* Error counter has reached 96 */ 104#define USB_8DEV_STATUSMSG_BUSHEAVY 0x03 /* Error count. has reached 128 */ 105#define USB_8DEV_STATUSMSG_BUSOFF 0x04 /* Device is in BUSOFF */ 106#define USB_8DEV_STATUSMSG_STUFF 0x20 /* Stuff Error */ 107#define USB_8DEV_STATUSMSG_FORM 0x21 /* Form Error */ 108#define USB_8DEV_STATUSMSG_ACK 0x23 /* Ack Error */ 109#define USB_8DEV_STATUSMSG_BIT0 0x24 /* Bit1 Error */ 110#define USB_8DEV_STATUSMSG_BIT1 0x25 /* Bit0 Error */ 111#define USB_8DEV_STATUSMSG_CRC 0x27 /* CRC Error */ 112 113#define USB_8DEV_RP_MASK 0x7F /* Mask for Receive Error Bit */ 114 115 116/* table of devices that work with this driver */ 117static const struct usb_device_id usb_8dev_table[] = { 118 { USB_DEVICE(USB_8DEV_VENDOR_ID, USB_8DEV_PRODUCT_ID) }, 119 { } /* Terminating entry */ 120}; 121 122MODULE_DEVICE_TABLE(usb, usb_8dev_table); 123 124struct usb_8dev_tx_urb_context { 125 struct usb_8dev_priv *priv; 126 127 u32 echo_index; 128 u8 dlc; 129}; 130 131/* Structure to hold all of our device specific stuff */ 132struct usb_8dev_priv { 133 struct can_priv can; /* must be the first member */ 134 135 struct sk_buff *echo_skb[MAX_TX_URBS]; 136 137 struct usb_device *udev; 138 struct net_device *netdev; 139 140 atomic_t active_tx_urbs; 141 struct usb_anchor tx_submitted; 142 struct usb_8dev_tx_urb_context tx_contexts[MAX_TX_URBS]; 143 144 struct usb_anchor rx_submitted; 145 146 struct can_berr_counter bec; 147 148 u8 *cmd_msg_buffer; 149 150 struct mutex usb_8dev_cmd_lock; 151 152}; 153 154/* tx frame */ 155struct __packed usb_8dev_tx_msg { 156 u8 begin; 157 u8 flags; /* RTR and EXT_ID flag */ 158 __be32 id; /* upper 3 bits not used */ 159 u8 dlc; /* data length code 0-8 bytes */ 160 u8 data[8]; /* 64-bit data */ 161 u8 end; 162}; 163 164/* rx frame */ 165struct __packed usb_8dev_rx_msg { 166 u8 begin; 167 u8 type; /* frame type */ 168 u8 flags; /* RTR and EXT_ID flag */ 169 __be32 id; /* upper 3 bits not used */ 170 u8 dlc; /* data length code 0-8 bytes */ 171 u8 data[8]; /* 64-bit data */ 172 __be32 timestamp; /* 32-bit timestamp */ 173 u8 end; 174}; 175 176/* command frame */ 177struct __packed usb_8dev_cmd_msg { 178 u8 begin; 179 u8 channel; /* unkown - always 0 */ 180 u8 command; /* command to execute */ 181 u8 opt1; /* optional parameter / return value */ 182 u8 opt2; /* optional parameter 2 */ 183 u8 data[10]; /* optional parameter and data */ 184 u8 end; 185}; 186 187static int usb_8dev_send_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size) 188{ 189 int actual_length; 190 191 return usb_bulk_msg(priv->udev, 192 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_TX), 193 msg, size, &actual_length, USB_8DEV_CMD_TIMEOUT); 194} 195 196static int usb_8dev_wait_cmd_msg(struct usb_8dev_priv *priv, u8 *msg, int size, 197 int *actual_length) 198{ 199 return usb_bulk_msg(priv->udev, 200 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_CMD_RX), 201 msg, size, actual_length, USB_8DEV_CMD_TIMEOUT); 202} 203 204/* Send command to device and receive result. 205 * Command was successful when opt1 = 0. 206 */ 207static int usb_8dev_send_cmd(struct usb_8dev_priv *priv, 208 struct usb_8dev_cmd_msg *out, 209 struct usb_8dev_cmd_msg *in) 210{ 211 int err; 212 int num_bytes_read; 213 struct net_device *netdev; 214 215 netdev = priv->netdev; 216 217 out->begin = USB_8DEV_CMD_START; 218 out->end = USB_8DEV_CMD_END; 219 220 mutex_lock(&priv->usb_8dev_cmd_lock); 221 222 memcpy(priv->cmd_msg_buffer, out, 223 sizeof(struct usb_8dev_cmd_msg)); 224 225 err = usb_8dev_send_cmd_msg(priv, priv->cmd_msg_buffer, 226 sizeof(struct usb_8dev_cmd_msg)); 227 if (err < 0) { 228 netdev_err(netdev, "sending command message failed\n"); 229 goto failed; 230 } 231 232 err = usb_8dev_wait_cmd_msg(priv, priv->cmd_msg_buffer, 233 sizeof(struct usb_8dev_cmd_msg), 234 &num_bytes_read); 235 if (err < 0) { 236 netdev_err(netdev, "no command message answer\n"); 237 goto failed; 238 } 239 240 memcpy(in, priv->cmd_msg_buffer, sizeof(struct usb_8dev_cmd_msg)); 241 242 if (in->begin != USB_8DEV_CMD_START || in->end != USB_8DEV_CMD_END || 243 num_bytes_read != 16 || in->opt1 != 0) 244 err = -EPROTO; 245 246failed: 247 mutex_unlock(&priv->usb_8dev_cmd_lock); 248 return err; 249} 250 251/* Send open command to device */ 252static int usb_8dev_cmd_open(struct usb_8dev_priv *priv) 253{ 254 struct can_bittiming *bt = &priv->can.bittiming; 255 struct usb_8dev_cmd_msg outmsg; 256 struct usb_8dev_cmd_msg inmsg; 257 u32 ctrlmode = priv->can.ctrlmode; 258 u32 flags = USB_8DEV_STATUS_FRAME; 259 __be32 beflags; 260 __be16 bebrp; 261 262 memset(&outmsg, 0, sizeof(outmsg)); 263 outmsg.command = USB_8DEV_OPEN; 264 outmsg.opt1 = USB_8DEV_BAUD_MANUAL; 265 outmsg.data[0] = bt->prop_seg + bt->phase_seg1; 266 outmsg.data[1] = bt->phase_seg2; 267 outmsg.data[2] = bt->sjw; 268 269 /* BRP */ 270 bebrp = cpu_to_be16((u16)bt->brp); 271 memcpy(&outmsg.data[3], &bebrp, sizeof(bebrp)); 272 273 /* flags */ 274 if (ctrlmode & CAN_CTRLMODE_LOOPBACK) 275 flags |= USB_8DEV_LOOPBACK; 276 if (ctrlmode & CAN_CTRLMODE_LISTENONLY) 277 flags |= USB_8DEV_SILENT; 278 if (ctrlmode & CAN_CTRLMODE_ONE_SHOT) 279 flags |= USB_8DEV_DISABLE_AUTO_RESTRANS; 280 281 beflags = cpu_to_be32(flags); 282 memcpy(&outmsg.data[5], &beflags, sizeof(beflags)); 283 284 return usb_8dev_send_cmd(priv, &outmsg, &inmsg); 285} 286 287/* Send close command to device */ 288static int usb_8dev_cmd_close(struct usb_8dev_priv *priv) 289{ 290 struct usb_8dev_cmd_msg inmsg; 291 struct usb_8dev_cmd_msg outmsg = { 292 .channel = 0, 293 .command = USB_8DEV_CLOSE, 294 .opt1 = 0, 295 .opt2 = 0 296 }; 297 298 return usb_8dev_send_cmd(priv, &outmsg, &inmsg); 299} 300 301/* Get firmware and hardware version */ 302static int usb_8dev_cmd_version(struct usb_8dev_priv *priv, u32 *res) 303{ 304 struct usb_8dev_cmd_msg inmsg; 305 struct usb_8dev_cmd_msg outmsg = { 306 .channel = 0, 307 .command = USB_8DEV_GET_SOFTW_HARDW_VER, 308 .opt1 = 0, 309 .opt2 = 0 310 }; 311 312 int err = usb_8dev_send_cmd(priv, &outmsg, &inmsg); 313 if (err) 314 return err; 315 316 *res = be32_to_cpup((__be32 *)inmsg.data); 317 318 return err; 319} 320 321/* Set network device mode 322 * 323 * Maybe we should leave this function empty, because the device 324 * set mode variable with open command. 325 */ 326static int usb_8dev_set_mode(struct net_device *netdev, enum can_mode mode) 327{ 328 struct usb_8dev_priv *priv = netdev_priv(netdev); 329 int err = 0; 330 331 switch (mode) { 332 case CAN_MODE_START: 333 err = usb_8dev_cmd_open(priv); 334 if (err) 335 netdev_warn(netdev, "couldn't start device"); 336 break; 337 338 default: 339 return -EOPNOTSUPP; 340 } 341 342 return err; 343} 344 345/* Read error/status frames */ 346static void usb_8dev_rx_err_msg(struct usb_8dev_priv *priv, 347 struct usb_8dev_rx_msg *msg) 348{ 349 struct can_frame *cf; 350 struct sk_buff *skb; 351 struct net_device_stats *stats = &priv->netdev->stats; 352 353 /* Error message: 354 * byte 0: Status 355 * byte 1: bit 7: Receive Passive 356 * byte 1: bit 0-6: Receive Error Counter 357 * byte 2: Transmit Error Counter 358 * byte 3: Always 0 (maybe reserved for future use) 359 */ 360 361 u8 state = msg->data[0]; 362 u8 rxerr = msg->data[1] & USB_8DEV_RP_MASK; 363 u8 txerr = msg->data[2]; 364 int rx_errors = 0; 365 int tx_errors = 0; 366 367 skb = alloc_can_err_skb(priv->netdev, &cf); 368 if (!skb) 369 return; 370 371 switch (state) { 372 case USB_8DEV_STATUSMSG_OK: 373 priv->can.state = CAN_STATE_ERROR_ACTIVE; 374 cf->can_id |= CAN_ERR_PROT; 375 cf->data[2] = CAN_ERR_PROT_ACTIVE; 376 break; 377 case USB_8DEV_STATUSMSG_BUSOFF: 378 priv->can.state = CAN_STATE_BUS_OFF; 379 cf->can_id |= CAN_ERR_BUSOFF; 380 priv->can.can_stats.bus_off++; 381 can_bus_off(priv->netdev); 382 break; 383 case USB_8DEV_STATUSMSG_OVERRUN: 384 case USB_8DEV_STATUSMSG_BUSLIGHT: 385 case USB_8DEV_STATUSMSG_BUSHEAVY: 386 cf->can_id |= CAN_ERR_CRTL; 387 break; 388 default: 389 priv->can.state = CAN_STATE_ERROR_WARNING; 390 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 391 priv->can.can_stats.bus_error++; 392 break; 393 } 394 395 switch (state) { 396 case USB_8DEV_STATUSMSG_OK: 397 case USB_8DEV_STATUSMSG_BUSOFF: 398 break; 399 case USB_8DEV_STATUSMSG_ACK: 400 cf->can_id |= CAN_ERR_ACK; 401 tx_errors = 1; 402 break; 403 case USB_8DEV_STATUSMSG_CRC: 404 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 405 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ | 406 CAN_ERR_PROT_LOC_CRC_DEL; 407 rx_errors = 1; 408 break; 409 case USB_8DEV_STATUSMSG_BIT0: 410 cf->data[2] |= CAN_ERR_PROT_BIT0; 411 tx_errors = 1; 412 break; 413 case USB_8DEV_STATUSMSG_BIT1: 414 cf->data[2] |= CAN_ERR_PROT_BIT1; 415 tx_errors = 1; 416 break; 417 case USB_8DEV_STATUSMSG_FORM: 418 cf->data[2] |= CAN_ERR_PROT_FORM; 419 rx_errors = 1; 420 break; 421 case USB_8DEV_STATUSMSG_STUFF: 422 cf->data[2] |= CAN_ERR_PROT_STUFF; 423 rx_errors = 1; 424 break; 425 case USB_8DEV_STATUSMSG_OVERRUN: 426 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 427 stats->rx_over_errors++; 428 rx_errors = 1; 429 break; 430 case USB_8DEV_STATUSMSG_BUSLIGHT: 431 priv->can.state = CAN_STATE_ERROR_WARNING; 432 cf->data[1] = (txerr > rxerr) ? 433 CAN_ERR_CRTL_TX_WARNING : 434 CAN_ERR_CRTL_RX_WARNING; 435 priv->can.can_stats.error_warning++; 436 break; 437 case USB_8DEV_STATUSMSG_BUSHEAVY: 438 priv->can.state = CAN_STATE_ERROR_PASSIVE; 439 cf->data[1] = (txerr > rxerr) ? 440 CAN_ERR_CRTL_TX_PASSIVE : 441 CAN_ERR_CRTL_RX_PASSIVE; 442 priv->can.can_stats.error_passive++; 443 break; 444 default: 445 netdev_warn(priv->netdev, 446 "Unknown status/error message (%d)\n", state); 447 break; 448 } 449 450 if (tx_errors) { 451 cf->data[2] |= CAN_ERR_PROT_TX; 452 stats->tx_errors++; 453 } 454 455 if (rx_errors) 456 stats->rx_errors++; 457 458 cf->data[6] = txerr; 459 cf->data[7] = rxerr; 460 461 priv->bec.txerr = txerr; 462 priv->bec.rxerr = rxerr; 463 464 netif_rx(skb); 465 466 stats->rx_packets++; 467 stats->rx_bytes += cf->can_dlc; 468} 469 470/* Read data and status frames */ 471static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv, 472 struct usb_8dev_rx_msg *msg) 473{ 474 struct can_frame *cf; 475 struct sk_buff *skb; 476 struct net_device_stats *stats = &priv->netdev->stats; 477 478 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME && 479 msg->flags == USB_8DEV_ERR_FLAG) { 480 usb_8dev_rx_err_msg(priv, msg); 481 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) { 482 skb = alloc_can_skb(priv->netdev, &cf); 483 if (!skb) 484 return; 485 486 cf->can_id = be32_to_cpu(msg->id); 487 cf->can_dlc = get_can_dlc(msg->dlc & 0xF); 488 489 if (msg->flags & USB_8DEV_EXTID) 490 cf->can_id |= CAN_EFF_FLAG; 491 492 if (msg->flags & USB_8DEV_RTR) 493 cf->can_id |= CAN_RTR_FLAG; 494 else 495 memcpy(cf->data, msg->data, cf->can_dlc); 496 497 netif_rx(skb); 498 499 stats->rx_packets++; 500 stats->rx_bytes += cf->can_dlc; 501 502 can_led_event(priv->netdev, CAN_LED_EVENT_RX); 503 } else { 504 netdev_warn(priv->netdev, "frame type %d unknown", 505 msg->type); 506 } 507 508} 509 510/* Callback for reading data from device 511 * 512 * Check urb status, call read function and resubmit urb read operation. 513 */ 514static void usb_8dev_read_bulk_callback(struct urb *urb) 515{ 516 struct usb_8dev_priv *priv = urb->context; 517 struct net_device *netdev; 518 int retval; 519 int pos = 0; 520 521 netdev = priv->netdev; 522 523 if (!netif_device_present(netdev)) 524 return; 525 526 switch (urb->status) { 527 case 0: /* success */ 528 break; 529 530 case -ENOENT: 531 case -ESHUTDOWN: 532 return; 533 534 default: 535 netdev_info(netdev, "Rx URB aborted (%d)\n", 536 urb->status); 537 goto resubmit_urb; 538 } 539 540 while (pos < urb->actual_length) { 541 struct usb_8dev_rx_msg *msg; 542 543 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) { 544 netdev_err(priv->netdev, "format error\n"); 545 break; 546 } 547 548 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos); 549 usb_8dev_rx_can_msg(priv, msg); 550 551 pos += sizeof(struct usb_8dev_rx_msg); 552 } 553 554resubmit_urb: 555 usb_fill_bulk_urb(urb, priv->udev, 556 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX), 557 urb->transfer_buffer, RX_BUFFER_SIZE, 558 usb_8dev_read_bulk_callback, priv); 559 560 retval = usb_submit_urb(urb, GFP_ATOMIC); 561 562 if (retval == -ENODEV) 563 netif_device_detach(netdev); 564 else if (retval) 565 netdev_err(netdev, 566 "failed resubmitting read bulk urb: %d\n", retval); 567} 568 569/* Callback handler for write operations 570 * 571 * Free allocated buffers, check transmit status and 572 * calculate statistic. 573 */ 574static void usb_8dev_write_bulk_callback(struct urb *urb) 575{ 576 struct usb_8dev_tx_urb_context *context = urb->context; 577 struct usb_8dev_priv *priv; 578 struct net_device *netdev; 579 580 BUG_ON(!context); 581 582 priv = context->priv; 583 netdev = priv->netdev; 584 585 /* free up our allocated buffer */ 586 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 587 urb->transfer_buffer, urb->transfer_dma); 588 589 atomic_dec(&priv->active_tx_urbs); 590 591 if (!netif_device_present(netdev)) 592 return; 593 594 if (urb->status) 595 netdev_info(netdev, "Tx URB aborted (%d)\n", 596 urb->status); 597 598 netdev->stats.tx_packets++; 599 netdev->stats.tx_bytes += context->dlc; 600 601 can_get_echo_skb(netdev, context->echo_index); 602 603 can_led_event(netdev, CAN_LED_EVENT_TX); 604 605 /* Release context */ 606 context->echo_index = MAX_TX_URBS; 607 608 netif_wake_queue(netdev); 609} 610 611/* Send data to device */ 612static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb, 613 struct net_device *netdev) 614{ 615 struct usb_8dev_priv *priv = netdev_priv(netdev); 616 struct net_device_stats *stats = &netdev->stats; 617 struct can_frame *cf = (struct can_frame *) skb->data; 618 struct usb_8dev_tx_msg *msg; 619 struct urb *urb; 620 struct usb_8dev_tx_urb_context *context = NULL; 621 u8 *buf; 622 int i, err; 623 size_t size = sizeof(struct usb_8dev_tx_msg); 624 625 if (can_dropped_invalid_skb(netdev, skb)) 626 return NETDEV_TX_OK; 627 628 /* create a URB, and a buffer for it, and copy the data to the URB */ 629 urb = usb_alloc_urb(0, GFP_ATOMIC); 630 if (!urb) { 631 netdev_err(netdev, "No memory left for URBs\n"); 632 goto nomem; 633 } 634 635 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC, 636 &urb->transfer_dma); 637 if (!buf) { 638 netdev_err(netdev, "No memory left for USB buffer\n"); 639 goto nomembuf; 640 } 641 642 memset(buf, 0, size); 643 644 msg = (struct usb_8dev_tx_msg *)buf; 645 msg->begin = USB_8DEV_DATA_START; 646 msg->flags = 0x00; 647 648 if (cf->can_id & CAN_RTR_FLAG) 649 msg->flags |= USB_8DEV_RTR; 650 651 if (cf->can_id & CAN_EFF_FLAG) 652 msg->flags |= USB_8DEV_EXTID; 653 654 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK); 655 msg->dlc = cf->can_dlc; 656 memcpy(msg->data, cf->data, cf->can_dlc); 657 msg->end = USB_8DEV_DATA_END; 658 659 for (i = 0; i < MAX_TX_URBS; i++) { 660 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) { 661 context = &priv->tx_contexts[i]; 662 break; 663 } 664 } 665 666 /* May never happen! When this happens we'd more URBs in flight as 667 * allowed (MAX_TX_URBS). 668 */ 669 if (!context) 670 goto nofreecontext; 671 672 context->priv = priv; 673 context->echo_index = i; 674 context->dlc = cf->can_dlc; 675 676 usb_fill_bulk_urb(urb, priv->udev, 677 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX), 678 buf, size, usb_8dev_write_bulk_callback, context); 679 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 680 usb_anchor_urb(urb, &priv->tx_submitted); 681 682 can_put_echo_skb(skb, netdev, context->echo_index); 683 684 atomic_inc(&priv->active_tx_urbs); 685 686 err = usb_submit_urb(urb, GFP_ATOMIC); 687 if (unlikely(err)) 688 goto failed; 689 else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS) 690 /* Slow down tx path */ 691 netif_stop_queue(netdev); 692 693 /* Release our reference to this URB, the USB core will eventually free 694 * it entirely. 695 */ 696 usb_free_urb(urb); 697 698 return NETDEV_TX_OK; 699 700nofreecontext: 701 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma); 702 usb_free_urb(urb); 703 704 netdev_warn(netdev, "couldn't find free context"); 705 706 return NETDEV_TX_BUSY; 707 708failed: 709 can_free_echo_skb(netdev, context->echo_index); 710 711 usb_unanchor_urb(urb); 712 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma); 713 714 atomic_dec(&priv->active_tx_urbs); 715 716 if (err == -ENODEV) 717 netif_device_detach(netdev); 718 else 719 netdev_warn(netdev, "failed tx_urb %d\n", err); 720 721nomembuf: 722 usb_free_urb(urb); 723 724nomem: 725 dev_kfree_skb(skb); 726 stats->tx_dropped++; 727 728 return NETDEV_TX_OK; 729} 730 731static int usb_8dev_get_berr_counter(const struct net_device *netdev, 732 struct can_berr_counter *bec) 733{ 734 struct usb_8dev_priv *priv = netdev_priv(netdev); 735 736 bec->txerr = priv->bec.txerr; 737 bec->rxerr = priv->bec.rxerr; 738 739 return 0; 740} 741 742/* Start USB device */ 743static int usb_8dev_start(struct usb_8dev_priv *priv) 744{ 745 struct net_device *netdev = priv->netdev; 746 int err, i; 747 748 for (i = 0; i < MAX_RX_URBS; i++) { 749 struct urb *urb = NULL; 750 u8 *buf; 751 752 /* create a URB, and a buffer for it */ 753 urb = usb_alloc_urb(0, GFP_KERNEL); 754 if (!urb) { 755 netdev_err(netdev, "No memory left for URBs\n"); 756 err = -ENOMEM; 757 break; 758 } 759 760 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL, 761 &urb->transfer_dma); 762 if (!buf) { 763 netdev_err(netdev, "No memory left for USB buffer\n"); 764 usb_free_urb(urb); 765 err = -ENOMEM; 766 break; 767 } 768 769 usb_fill_bulk_urb(urb, priv->udev, 770 usb_rcvbulkpipe(priv->udev, 771 USB_8DEV_ENDP_DATA_RX), 772 buf, RX_BUFFER_SIZE, 773 usb_8dev_read_bulk_callback, priv); 774 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 775 usb_anchor_urb(urb, &priv->rx_submitted); 776 777 err = usb_submit_urb(urb, GFP_KERNEL); 778 if (err) { 779 usb_unanchor_urb(urb); 780 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf, 781 urb->transfer_dma); 782 usb_free_urb(urb); 783 break; 784 } 785 786 /* Drop reference, USB core will take care of freeing it */ 787 usb_free_urb(urb); 788 } 789 790 /* Did we submit any URBs */ 791 if (i == 0) { 792 netdev_warn(netdev, "couldn't setup read URBs\n"); 793 return err; 794 } 795 796 /* Warn if we've couldn't transmit all the URBs */ 797 if (i < MAX_RX_URBS) 798 netdev_warn(netdev, "rx performance may be slow\n"); 799 800 err = usb_8dev_cmd_open(priv); 801 if (err) 802 goto failed; 803 804 priv->can.state = CAN_STATE_ERROR_ACTIVE; 805 806 return 0; 807 808failed: 809 if (err == -ENODEV) 810 netif_device_detach(priv->netdev); 811 812 netdev_warn(netdev, "couldn't submit control: %d\n", err); 813 814 return err; 815} 816 817/* Open USB device */ 818static int usb_8dev_open(struct net_device *netdev) 819{ 820 struct usb_8dev_priv *priv = netdev_priv(netdev); 821 int err; 822 823 /* common open */ 824 err = open_candev(netdev); 825 if (err) 826 return err; 827 828 can_led_event(netdev, CAN_LED_EVENT_OPEN); 829 830 /* finally start device */ 831 err = usb_8dev_start(priv); 832 if (err) { 833 if (err == -ENODEV) 834 netif_device_detach(priv->netdev); 835 836 netdev_warn(netdev, "couldn't start device: %d\n", 837 err); 838 839 close_candev(netdev); 840 841 return err; 842 } 843 844 netif_start_queue(netdev); 845 846 return 0; 847} 848 849static void unlink_all_urbs(struct usb_8dev_priv *priv) 850{ 851 int i; 852 853 usb_kill_anchored_urbs(&priv->rx_submitted); 854 855 usb_kill_anchored_urbs(&priv->tx_submitted); 856 atomic_set(&priv->active_tx_urbs, 0); 857 858 for (i = 0; i < MAX_TX_URBS; i++) 859 priv->tx_contexts[i].echo_index = MAX_TX_URBS; 860} 861 862/* Close USB device */ 863static int usb_8dev_close(struct net_device *netdev) 864{ 865 struct usb_8dev_priv *priv = netdev_priv(netdev); 866 int err = 0; 867 868 /* Send CLOSE command to CAN controller */ 869 err = usb_8dev_cmd_close(priv); 870 if (err) 871 netdev_warn(netdev, "couldn't stop device"); 872 873 priv->can.state = CAN_STATE_STOPPED; 874 875 netif_stop_queue(netdev); 876 877 /* Stop polling */ 878 unlink_all_urbs(priv); 879 880 close_candev(netdev); 881 882 can_led_event(netdev, CAN_LED_EVENT_STOP); 883 884 return err; 885} 886 887static const struct net_device_ops usb_8dev_netdev_ops = { 888 .ndo_open = usb_8dev_open, 889 .ndo_stop = usb_8dev_close, 890 .ndo_start_xmit = usb_8dev_start_xmit, 891 .ndo_change_mtu = can_change_mtu, 892}; 893 894static const struct can_bittiming_const usb_8dev_bittiming_const = { 895 .name = "usb_8dev", 896 .tseg1_min = 1, 897 .tseg1_max = 16, 898 .tseg2_min = 1, 899 .tseg2_max = 8, 900 .sjw_max = 4, 901 .brp_min = 1, 902 .brp_max = 1024, 903 .brp_inc = 1, 904}; 905 906/* Probe USB device 907 * 908 * Check device and firmware. 909 * Set supported modes and bittiming constants. 910 * Allocate some memory. 911 */ 912static int usb_8dev_probe(struct usb_interface *intf, 913 const struct usb_device_id *id) 914{ 915 struct net_device *netdev; 916 struct usb_8dev_priv *priv; 917 int i, err = -ENOMEM; 918 u32 version; 919 char buf[18]; 920 struct usb_device *usbdev = interface_to_usbdev(intf); 921 922 /* product id looks strange, better we also check iProduct string */ 923 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf, 924 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) { 925 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n"); 926 return -ENODEV; 927 } 928 929 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS); 930 if (!netdev) { 931 dev_err(&intf->dev, "Couldn't alloc candev\n"); 932 return -ENOMEM; 933 } 934 935 priv = netdev_priv(netdev); 936 937 priv->udev = usbdev; 938 priv->netdev = netdev; 939 940 priv->can.state = CAN_STATE_STOPPED; 941 priv->can.clock.freq = USB_8DEV_ABP_CLOCK; 942 priv->can.bittiming_const = &usb_8dev_bittiming_const; 943 priv->can.do_set_mode = usb_8dev_set_mode; 944 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter; 945 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | 946 CAN_CTRLMODE_LISTENONLY | 947 CAN_CTRLMODE_ONE_SHOT; 948 949 netdev->netdev_ops = &usb_8dev_netdev_ops; 950 951 netdev->flags |= IFF_ECHO; /* we support local echo */ 952 953 init_usb_anchor(&priv->rx_submitted); 954 955 init_usb_anchor(&priv->tx_submitted); 956 atomic_set(&priv->active_tx_urbs, 0); 957 958 for (i = 0; i < MAX_TX_URBS; i++) 959 priv->tx_contexts[i].echo_index = MAX_TX_URBS; 960 961 priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg), 962 GFP_KERNEL); 963 if (!priv->cmd_msg_buffer) 964 goto cleanup_candev; 965 966 usb_set_intfdata(intf, priv); 967 968 SET_NETDEV_DEV(netdev, &intf->dev); 969 970 mutex_init(&priv->usb_8dev_cmd_lock); 971 972 err = register_candev(netdev); 973 if (err) { 974 netdev_err(netdev, 975 "couldn't register CAN device: %d\n", err); 976 goto cleanup_cmd_msg_buffer; 977 } 978 979 err = usb_8dev_cmd_version(priv, &version); 980 if (err) { 981 netdev_err(netdev, "can't get firmware version\n"); 982 goto cleanup_unregister_candev; 983 } else { 984 netdev_info(netdev, 985 "firmware: %d.%d, hardware: %d.%d\n", 986 (version>>24) & 0xff, (version>>16) & 0xff, 987 (version>>8) & 0xff, version & 0xff); 988 } 989 990 devm_can_led_init(netdev); 991 992 return 0; 993 994cleanup_unregister_candev: 995 unregister_netdev(priv->netdev); 996 997cleanup_cmd_msg_buffer: 998 kfree(priv->cmd_msg_buffer); 999 1000cleanup_candev: 1001 free_candev(netdev); 1002 1003 return err; 1004 1005} 1006 1007/* Called by the usb core when driver is unloaded or device is removed */ 1008static void usb_8dev_disconnect(struct usb_interface *intf) 1009{ 1010 struct usb_8dev_priv *priv = usb_get_intfdata(intf); 1011 1012 usb_set_intfdata(intf, NULL); 1013 1014 if (priv) { 1015 netdev_info(priv->netdev, "device disconnected\n"); 1016 1017 unregister_netdev(priv->netdev); 1018 free_candev(priv->netdev); 1019 1020 unlink_all_urbs(priv); 1021 } 1022 1023} 1024 1025static struct usb_driver usb_8dev_driver = { 1026 .name = "usb_8dev", 1027 .probe = usb_8dev_probe, 1028 .disconnect = usb_8dev_disconnect, 1029 .id_table = usb_8dev_table, 1030}; 1031 1032module_usb_driver(usb_8dev_driver); 1033 1034MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>"); 1035MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces"); 1036MODULE_LICENSE("GPL v2"); 1037