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[3] = CAN_ERR_PROT_LOC_CRC_SEQ; 405 rx_errors = 1; 406 break; 407 case USB_8DEV_STATUSMSG_BIT0: 408 cf->data[2] |= CAN_ERR_PROT_BIT0; 409 tx_errors = 1; 410 break; 411 case USB_8DEV_STATUSMSG_BIT1: 412 cf->data[2] |= CAN_ERR_PROT_BIT1; 413 tx_errors = 1; 414 break; 415 case USB_8DEV_STATUSMSG_FORM: 416 cf->data[2] |= CAN_ERR_PROT_FORM; 417 rx_errors = 1; 418 break; 419 case USB_8DEV_STATUSMSG_STUFF: 420 cf->data[2] |= CAN_ERR_PROT_STUFF; 421 rx_errors = 1; 422 break; 423 case USB_8DEV_STATUSMSG_OVERRUN: 424 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 425 stats->rx_over_errors++; 426 rx_errors = 1; 427 break; 428 case USB_8DEV_STATUSMSG_BUSLIGHT: 429 priv->can.state = CAN_STATE_ERROR_WARNING; 430 cf->data[1] = (txerr > rxerr) ? 431 CAN_ERR_CRTL_TX_WARNING : 432 CAN_ERR_CRTL_RX_WARNING; 433 priv->can.can_stats.error_warning++; 434 break; 435 case USB_8DEV_STATUSMSG_BUSHEAVY: 436 priv->can.state = CAN_STATE_ERROR_PASSIVE; 437 cf->data[1] = (txerr > rxerr) ? 438 CAN_ERR_CRTL_TX_PASSIVE : 439 CAN_ERR_CRTL_RX_PASSIVE; 440 priv->can.can_stats.error_passive++; 441 break; 442 default: 443 netdev_warn(priv->netdev, 444 "Unknown status/error message (%d)\n", state); 445 break; 446 } 447 448 if (tx_errors) { 449 cf->data[2] |= CAN_ERR_PROT_TX; 450 stats->tx_errors++; 451 } 452 453 if (rx_errors) 454 stats->rx_errors++; 455 456 cf->data[6] = txerr; 457 cf->data[7] = rxerr; 458 459 priv->bec.txerr = txerr; 460 priv->bec.rxerr = rxerr; 461 462 stats->rx_packets++; 463 stats->rx_bytes += cf->can_dlc; 464 netif_rx(skb); 465} 466 467/* Read data and status frames */ 468static void usb_8dev_rx_can_msg(struct usb_8dev_priv *priv, 469 struct usb_8dev_rx_msg *msg) 470{ 471 struct can_frame *cf; 472 struct sk_buff *skb; 473 struct net_device_stats *stats = &priv->netdev->stats; 474 475 if (msg->type == USB_8DEV_TYPE_ERROR_FRAME && 476 msg->flags == USB_8DEV_ERR_FLAG) { 477 usb_8dev_rx_err_msg(priv, msg); 478 } else if (msg->type == USB_8DEV_TYPE_CAN_FRAME) { 479 skb = alloc_can_skb(priv->netdev, &cf); 480 if (!skb) 481 return; 482 483 cf->can_id = be32_to_cpu(msg->id); 484 cf->can_dlc = get_can_dlc(msg->dlc & 0xF); 485 486 if (msg->flags & USB_8DEV_EXTID) 487 cf->can_id |= CAN_EFF_FLAG; 488 489 if (msg->flags & USB_8DEV_RTR) 490 cf->can_id |= CAN_RTR_FLAG; 491 else 492 memcpy(cf->data, msg->data, cf->can_dlc); 493 494 stats->rx_packets++; 495 stats->rx_bytes += cf->can_dlc; 496 netif_rx(skb); 497 498 can_led_event(priv->netdev, CAN_LED_EVENT_RX); 499 } else { 500 netdev_warn(priv->netdev, "frame type %d unknown", 501 msg->type); 502 } 503 504} 505 506/* Callback for reading data from device 507 * 508 * Check urb status, call read function and resubmit urb read operation. 509 */ 510static void usb_8dev_read_bulk_callback(struct urb *urb) 511{ 512 struct usb_8dev_priv *priv = urb->context; 513 struct net_device *netdev; 514 int retval; 515 int pos = 0; 516 517 netdev = priv->netdev; 518 519 if (!netif_device_present(netdev)) 520 return; 521 522 switch (urb->status) { 523 case 0: /* success */ 524 break; 525 526 case -ENOENT: 527 case -ESHUTDOWN: 528 return; 529 530 default: 531 netdev_info(netdev, "Rx URB aborted (%d)\n", 532 urb->status); 533 goto resubmit_urb; 534 } 535 536 while (pos < urb->actual_length) { 537 struct usb_8dev_rx_msg *msg; 538 539 if (pos + sizeof(struct usb_8dev_rx_msg) > urb->actual_length) { 540 netdev_err(priv->netdev, "format error\n"); 541 break; 542 } 543 544 msg = (struct usb_8dev_rx_msg *)(urb->transfer_buffer + pos); 545 usb_8dev_rx_can_msg(priv, msg); 546 547 pos += sizeof(struct usb_8dev_rx_msg); 548 } 549 550resubmit_urb: 551 usb_fill_bulk_urb(urb, priv->udev, 552 usb_rcvbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_RX), 553 urb->transfer_buffer, RX_BUFFER_SIZE, 554 usb_8dev_read_bulk_callback, priv); 555 556 retval = usb_submit_urb(urb, GFP_ATOMIC); 557 558 if (retval == -ENODEV) 559 netif_device_detach(netdev); 560 else if (retval) 561 netdev_err(netdev, 562 "failed resubmitting read bulk urb: %d\n", retval); 563} 564 565/* Callback handler for write operations 566 * 567 * Free allocated buffers, check transmit status and 568 * calculate statistic. 569 */ 570static void usb_8dev_write_bulk_callback(struct urb *urb) 571{ 572 struct usb_8dev_tx_urb_context *context = urb->context; 573 struct usb_8dev_priv *priv; 574 struct net_device *netdev; 575 576 BUG_ON(!context); 577 578 priv = context->priv; 579 netdev = priv->netdev; 580 581 /* free up our allocated buffer */ 582 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 583 urb->transfer_buffer, urb->transfer_dma); 584 585 atomic_dec(&priv->active_tx_urbs); 586 587 if (!netif_device_present(netdev)) 588 return; 589 590 if (urb->status) 591 netdev_info(netdev, "Tx URB aborted (%d)\n", 592 urb->status); 593 594 netdev->stats.tx_packets++; 595 netdev->stats.tx_bytes += context->dlc; 596 597 can_get_echo_skb(netdev, context->echo_index); 598 599 can_led_event(netdev, CAN_LED_EVENT_TX); 600 601 /* Release context */ 602 context->echo_index = MAX_TX_URBS; 603 604 netif_wake_queue(netdev); 605} 606 607/* Send data to device */ 608static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb, 609 struct net_device *netdev) 610{ 611 struct usb_8dev_priv *priv = netdev_priv(netdev); 612 struct net_device_stats *stats = &netdev->stats; 613 struct can_frame *cf = (struct can_frame *) skb->data; 614 struct usb_8dev_tx_msg *msg; 615 struct urb *urb; 616 struct usb_8dev_tx_urb_context *context = NULL; 617 u8 *buf; 618 int i, err; 619 size_t size = sizeof(struct usb_8dev_tx_msg); 620 621 if (can_dropped_invalid_skb(netdev, skb)) 622 return NETDEV_TX_OK; 623 624 /* create a URB, and a buffer for it, and copy the data to the URB */ 625 urb = usb_alloc_urb(0, GFP_ATOMIC); 626 if (!urb) { 627 netdev_err(netdev, "No memory left for URBs\n"); 628 goto nomem; 629 } 630 631 buf = usb_alloc_coherent(priv->udev, size, GFP_ATOMIC, 632 &urb->transfer_dma); 633 if (!buf) { 634 netdev_err(netdev, "No memory left for USB buffer\n"); 635 goto nomembuf; 636 } 637 638 memset(buf, 0, size); 639 640 msg = (struct usb_8dev_tx_msg *)buf; 641 msg->begin = USB_8DEV_DATA_START; 642 msg->flags = 0x00; 643 644 if (cf->can_id & CAN_RTR_FLAG) 645 msg->flags |= USB_8DEV_RTR; 646 647 if (cf->can_id & CAN_EFF_FLAG) 648 msg->flags |= USB_8DEV_EXTID; 649 650 msg->id = cpu_to_be32(cf->can_id & CAN_ERR_MASK); 651 msg->dlc = cf->can_dlc; 652 memcpy(msg->data, cf->data, cf->can_dlc); 653 msg->end = USB_8DEV_DATA_END; 654 655 for (i = 0; i < MAX_TX_URBS; i++) { 656 if (priv->tx_contexts[i].echo_index == MAX_TX_URBS) { 657 context = &priv->tx_contexts[i]; 658 break; 659 } 660 } 661 662 /* May never happen! When this happens we'd more URBs in flight as 663 * allowed (MAX_TX_URBS). 664 */ 665 if (!context) 666 goto nofreecontext; 667 668 context->priv = priv; 669 context->echo_index = i; 670 context->dlc = cf->can_dlc; 671 672 usb_fill_bulk_urb(urb, priv->udev, 673 usb_sndbulkpipe(priv->udev, USB_8DEV_ENDP_DATA_TX), 674 buf, size, usb_8dev_write_bulk_callback, context); 675 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 676 usb_anchor_urb(urb, &priv->tx_submitted); 677 678 can_put_echo_skb(skb, netdev, context->echo_index); 679 680 atomic_inc(&priv->active_tx_urbs); 681 682 err = usb_submit_urb(urb, GFP_ATOMIC); 683 if (unlikely(err)) 684 goto failed; 685 else if (atomic_read(&priv->active_tx_urbs) >= MAX_TX_URBS) 686 /* Slow down tx path */ 687 netif_stop_queue(netdev); 688 689 /* Release our reference to this URB, the USB core will eventually free 690 * it entirely. 691 */ 692 usb_free_urb(urb); 693 694 return NETDEV_TX_OK; 695 696nofreecontext: 697 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma); 698 usb_free_urb(urb); 699 700 netdev_warn(netdev, "couldn't find free context"); 701 702 return NETDEV_TX_BUSY; 703 704failed: 705 can_free_echo_skb(netdev, context->echo_index); 706 707 usb_unanchor_urb(urb); 708 usb_free_coherent(priv->udev, size, buf, urb->transfer_dma); 709 710 atomic_dec(&priv->active_tx_urbs); 711 712 if (err == -ENODEV) 713 netif_device_detach(netdev); 714 else 715 netdev_warn(netdev, "failed tx_urb %d\n", err); 716 717nomembuf: 718 usb_free_urb(urb); 719 720nomem: 721 dev_kfree_skb(skb); 722 stats->tx_dropped++; 723 724 return NETDEV_TX_OK; 725} 726 727static int usb_8dev_get_berr_counter(const struct net_device *netdev, 728 struct can_berr_counter *bec) 729{ 730 struct usb_8dev_priv *priv = netdev_priv(netdev); 731 732 bec->txerr = priv->bec.txerr; 733 bec->rxerr = priv->bec.rxerr; 734 735 return 0; 736} 737 738/* Start USB device */ 739static int usb_8dev_start(struct usb_8dev_priv *priv) 740{ 741 struct net_device *netdev = priv->netdev; 742 int err, i; 743 744 for (i = 0; i < MAX_RX_URBS; i++) { 745 struct urb *urb = NULL; 746 u8 *buf; 747 748 /* create a URB, and a buffer for it */ 749 urb = usb_alloc_urb(0, GFP_KERNEL); 750 if (!urb) { 751 netdev_err(netdev, "No memory left for URBs\n"); 752 err = -ENOMEM; 753 break; 754 } 755 756 buf = usb_alloc_coherent(priv->udev, RX_BUFFER_SIZE, GFP_KERNEL, 757 &urb->transfer_dma); 758 if (!buf) { 759 netdev_err(netdev, "No memory left for USB buffer\n"); 760 usb_free_urb(urb); 761 err = -ENOMEM; 762 break; 763 } 764 765 usb_fill_bulk_urb(urb, priv->udev, 766 usb_rcvbulkpipe(priv->udev, 767 USB_8DEV_ENDP_DATA_RX), 768 buf, RX_BUFFER_SIZE, 769 usb_8dev_read_bulk_callback, priv); 770 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 771 usb_anchor_urb(urb, &priv->rx_submitted); 772 773 err = usb_submit_urb(urb, GFP_KERNEL); 774 if (err) { 775 usb_unanchor_urb(urb); 776 usb_free_coherent(priv->udev, RX_BUFFER_SIZE, buf, 777 urb->transfer_dma); 778 usb_free_urb(urb); 779 break; 780 } 781 782 /* Drop reference, USB core will take care of freeing it */ 783 usb_free_urb(urb); 784 } 785 786 /* Did we submit any URBs */ 787 if (i == 0) { 788 netdev_warn(netdev, "couldn't setup read URBs\n"); 789 return err; 790 } 791 792 /* Warn if we've couldn't transmit all the URBs */ 793 if (i < MAX_RX_URBS) 794 netdev_warn(netdev, "rx performance may be slow\n"); 795 796 err = usb_8dev_cmd_open(priv); 797 if (err) 798 goto failed; 799 800 priv->can.state = CAN_STATE_ERROR_ACTIVE; 801 802 return 0; 803 804failed: 805 if (err == -ENODEV) 806 netif_device_detach(priv->netdev); 807 808 netdev_warn(netdev, "couldn't submit control: %d\n", err); 809 810 return err; 811} 812 813/* Open USB device */ 814static int usb_8dev_open(struct net_device *netdev) 815{ 816 struct usb_8dev_priv *priv = netdev_priv(netdev); 817 int err; 818 819 /* common open */ 820 err = open_candev(netdev); 821 if (err) 822 return err; 823 824 can_led_event(netdev, CAN_LED_EVENT_OPEN); 825 826 /* finally start device */ 827 err = usb_8dev_start(priv); 828 if (err) { 829 if (err == -ENODEV) 830 netif_device_detach(priv->netdev); 831 832 netdev_warn(netdev, "couldn't start device: %d\n", 833 err); 834 835 close_candev(netdev); 836 837 return err; 838 } 839 840 netif_start_queue(netdev); 841 842 return 0; 843} 844 845static void unlink_all_urbs(struct usb_8dev_priv *priv) 846{ 847 int i; 848 849 usb_kill_anchored_urbs(&priv->rx_submitted); 850 851 usb_kill_anchored_urbs(&priv->tx_submitted); 852 atomic_set(&priv->active_tx_urbs, 0); 853 854 for (i = 0; i < MAX_TX_URBS; i++) 855 priv->tx_contexts[i].echo_index = MAX_TX_URBS; 856} 857 858/* Close USB device */ 859static int usb_8dev_close(struct net_device *netdev) 860{ 861 struct usb_8dev_priv *priv = netdev_priv(netdev); 862 int err = 0; 863 864 /* Send CLOSE command to CAN controller */ 865 err = usb_8dev_cmd_close(priv); 866 if (err) 867 netdev_warn(netdev, "couldn't stop device"); 868 869 priv->can.state = CAN_STATE_STOPPED; 870 871 netif_stop_queue(netdev); 872 873 /* Stop polling */ 874 unlink_all_urbs(priv); 875 876 close_candev(netdev); 877 878 can_led_event(netdev, CAN_LED_EVENT_STOP); 879 880 return err; 881} 882 883static const struct net_device_ops usb_8dev_netdev_ops = { 884 .ndo_open = usb_8dev_open, 885 .ndo_stop = usb_8dev_close, 886 .ndo_start_xmit = usb_8dev_start_xmit, 887 .ndo_change_mtu = can_change_mtu, 888}; 889 890static const struct can_bittiming_const usb_8dev_bittiming_const = { 891 .name = "usb_8dev", 892 .tseg1_min = 1, 893 .tseg1_max = 16, 894 .tseg2_min = 1, 895 .tseg2_max = 8, 896 .sjw_max = 4, 897 .brp_min = 1, 898 .brp_max = 1024, 899 .brp_inc = 1, 900}; 901 902/* Probe USB device 903 * 904 * Check device and firmware. 905 * Set supported modes and bittiming constants. 906 * Allocate some memory. 907 */ 908static int usb_8dev_probe(struct usb_interface *intf, 909 const struct usb_device_id *id) 910{ 911 struct net_device *netdev; 912 struct usb_8dev_priv *priv; 913 int i, err = -ENOMEM; 914 u32 version; 915 char buf[18]; 916 struct usb_device *usbdev = interface_to_usbdev(intf); 917 918 /* product id looks strange, better we also check iProduct string */ 919 if (usb_string(usbdev, usbdev->descriptor.iProduct, buf, 920 sizeof(buf)) > 0 && strcmp(buf, "USB2CAN converter")) { 921 dev_info(&usbdev->dev, "ignoring: not an USB2CAN converter\n"); 922 return -ENODEV; 923 } 924 925 netdev = alloc_candev(sizeof(struct usb_8dev_priv), MAX_TX_URBS); 926 if (!netdev) { 927 dev_err(&intf->dev, "Couldn't alloc candev\n"); 928 return -ENOMEM; 929 } 930 931 priv = netdev_priv(netdev); 932 933 priv->udev = usbdev; 934 priv->netdev = netdev; 935 936 priv->can.state = CAN_STATE_STOPPED; 937 priv->can.clock.freq = USB_8DEV_ABP_CLOCK; 938 priv->can.bittiming_const = &usb_8dev_bittiming_const; 939 priv->can.do_set_mode = usb_8dev_set_mode; 940 priv->can.do_get_berr_counter = usb_8dev_get_berr_counter; 941 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK | 942 CAN_CTRLMODE_LISTENONLY | 943 CAN_CTRLMODE_ONE_SHOT; 944 945 netdev->netdev_ops = &usb_8dev_netdev_ops; 946 947 netdev->flags |= IFF_ECHO; /* we support local echo */ 948 949 init_usb_anchor(&priv->rx_submitted); 950 951 init_usb_anchor(&priv->tx_submitted); 952 atomic_set(&priv->active_tx_urbs, 0); 953 954 for (i = 0; i < MAX_TX_URBS; i++) 955 priv->tx_contexts[i].echo_index = MAX_TX_URBS; 956 957 priv->cmd_msg_buffer = kzalloc(sizeof(struct usb_8dev_cmd_msg), 958 GFP_KERNEL); 959 if (!priv->cmd_msg_buffer) 960 goto cleanup_candev; 961 962 usb_set_intfdata(intf, priv); 963 964 SET_NETDEV_DEV(netdev, &intf->dev); 965 966 mutex_init(&priv->usb_8dev_cmd_lock); 967 968 err = register_candev(netdev); 969 if (err) { 970 netdev_err(netdev, 971 "couldn't register CAN device: %d\n", err); 972 goto cleanup_cmd_msg_buffer; 973 } 974 975 err = usb_8dev_cmd_version(priv, &version); 976 if (err) { 977 netdev_err(netdev, "can't get firmware version\n"); 978 goto cleanup_unregister_candev; 979 } else { 980 netdev_info(netdev, 981 "firmware: %d.%d, hardware: %d.%d\n", 982 (version>>24) & 0xff, (version>>16) & 0xff, 983 (version>>8) & 0xff, version & 0xff); 984 } 985 986 devm_can_led_init(netdev); 987 988 return 0; 989 990cleanup_unregister_candev: 991 unregister_netdev(priv->netdev); 992 993cleanup_cmd_msg_buffer: 994 kfree(priv->cmd_msg_buffer); 995 996cleanup_candev: 997 free_candev(netdev); 998 999 return err; 1000 1001} 1002 1003/* Called by the usb core when driver is unloaded or device is removed */ 1004static void usb_8dev_disconnect(struct usb_interface *intf) 1005{ 1006 struct usb_8dev_priv *priv = usb_get_intfdata(intf); 1007 1008 usb_set_intfdata(intf, NULL); 1009 1010 if (priv) { 1011 netdev_info(priv->netdev, "device disconnected\n"); 1012 1013 unregister_netdev(priv->netdev); 1014 free_candev(priv->netdev); 1015 1016 unlink_all_urbs(priv); 1017 } 1018 1019} 1020 1021static struct usb_driver usb_8dev_driver = { 1022 .name = "usb_8dev", 1023 .probe = usb_8dev_probe, 1024 .disconnect = usb_8dev_disconnect, 1025 .id_table = usb_8dev_table, 1026}; 1027 1028module_usb_driver(usb_8dev_driver); 1029 1030MODULE_AUTHOR("Bernd Krumboeck <krumboeck@universalnet.at>"); 1031MODULE_DESCRIPTION("CAN driver for 8 devices USB2CAN interfaces"); 1032MODULE_LICENSE("GPL v2"); 1033