1 /* 2 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7 3 * 4 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche 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; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 #include <linux/init.h> 20 #include <linux/signal.h> 21 #include <linux/slab.h> 22 #include <linux/module.h> 23 #include <linux/netdevice.h> 24 #include <linux/usb.h> 25 26 #include <linux/can.h> 27 #include <linux/can/dev.h> 28 #include <linux/can/error.h> 29 30 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>"); 31 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces"); 32 MODULE_LICENSE("GPL v2"); 33 34 /* Control-Values for CPC_Control() Command Subject Selection */ 35 #define CONTR_CAN_MESSAGE 0x04 36 #define CONTR_CAN_STATE 0x0C 37 #define CONTR_BUS_ERROR 0x1C 38 39 /* Control Command Actions */ 40 #define CONTR_CONT_OFF 0 41 #define CONTR_CONT_ON 1 42 #define CONTR_ONCE 2 43 44 /* Messages from CPC to PC */ 45 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */ 46 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */ 47 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */ 48 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */ 49 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */ 50 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */ 51 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */ 52 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */ 53 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */ 54 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */ 55 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */ 56 57 /* Messages from the PC to the CPC interface */ 58 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */ 59 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */ 60 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */ 61 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */ 62 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */ 63 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */ 64 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */ 65 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */ 66 67 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */ 68 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */ 69 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */ 70 71 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */ 72 73 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */ 74 75 /* Overrun types */ 76 #define CPC_OVR_EVENT_CAN 0x01 77 #define CPC_OVR_EVENT_CANSTATE 0x02 78 #define CPC_OVR_EVENT_BUSERROR 0x04 79 80 /* 81 * If the CAN controller lost a message we indicate it with the highest bit 82 * set in the count field. 83 */ 84 #define CPC_OVR_HW 0x80 85 86 /* Size of the "struct ems_cpc_msg" without the union */ 87 #define CPC_MSG_HEADER_LEN 11 88 #define CPC_CAN_MSG_MIN_SIZE 5 89 90 /* Define these values to match your devices */ 91 #define USB_CPCUSB_VENDOR_ID 0x12D6 92 93 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444 94 95 /* Mode register NXP LPC2119/SJA1000 CAN Controller */ 96 #define SJA1000_MOD_NORMAL 0x00 97 #define SJA1000_MOD_RM 0x01 98 99 /* ECC register NXP LPC2119/SJA1000 CAN Controller */ 100 #define SJA1000_ECC_SEG 0x1F 101 #define SJA1000_ECC_DIR 0x20 102 #define SJA1000_ECC_ERR 0x06 103 #define SJA1000_ECC_BIT 0x00 104 #define SJA1000_ECC_FORM 0x40 105 #define SJA1000_ECC_STUFF 0x80 106 #define SJA1000_ECC_MASK 0xc0 107 108 /* Status register content */ 109 #define SJA1000_SR_BS 0x80 110 #define SJA1000_SR_ES 0x40 111 112 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA 113 114 /* 115 * The device actually uses a 16MHz clock to generate the CAN clock 116 * but it expects SJA1000 bit settings based on 8MHz (is internally 117 * converted). 118 */ 119 #define EMS_USB_ARM7_CLOCK 8000000 120 121 /* 122 * CAN-Message representation in a CPC_MSG. Message object type is 123 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or 124 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME. 125 */ 126 struct cpc_can_msg { 127 u32 id; 128 u8 length; 129 u8 msg[8]; 130 }; 131 132 /* Representation of the CAN parameters for the SJA1000 controller */ 133 struct cpc_sja1000_params { 134 u8 mode; 135 u8 acc_code0; 136 u8 acc_code1; 137 u8 acc_code2; 138 u8 acc_code3; 139 u8 acc_mask0; 140 u8 acc_mask1; 141 u8 acc_mask2; 142 u8 acc_mask3; 143 u8 btr0; 144 u8 btr1; 145 u8 outp_contr; 146 }; 147 148 /* CAN params message representation */ 149 struct cpc_can_params { 150 u8 cc_type; 151 152 /* Will support M16C CAN controller in the future */ 153 union { 154 struct cpc_sja1000_params sja1000; 155 } cc_params; 156 }; 157 158 /* Structure for confirmed message handling */ 159 struct cpc_confirm { 160 u8 error; /* error code */ 161 }; 162 163 /* Structure for overrun conditions */ 164 struct cpc_overrun { 165 u8 event; 166 u8 count; 167 }; 168 169 /* SJA1000 CAN errors (compatible to NXP LPC2119) */ 170 struct cpc_sja1000_can_error { 171 u8 ecc; 172 u8 rxerr; 173 u8 txerr; 174 }; 175 176 /* structure for CAN error conditions */ 177 struct cpc_can_error { 178 u8 ecode; 179 180 struct { 181 u8 cc_type; 182 183 /* Other controllers may also provide error code capture regs */ 184 union { 185 struct cpc_sja1000_can_error sja1000; 186 } regs; 187 } cc; 188 }; 189 190 /* 191 * Structure containing RX/TX error counter. This structure is used to request 192 * the values of the CAN controllers TX and RX error counter. 193 */ 194 struct cpc_can_err_counter { 195 u8 rx; 196 u8 tx; 197 }; 198 199 /* Main message type used between library and application */ 200 struct __packed ems_cpc_msg { 201 u8 type; /* type of message */ 202 u8 length; /* length of data within union 'msg' */ 203 u8 msgid; /* confirmation handle */ 204 u32 ts_sec; /* timestamp in seconds */ 205 u32 ts_nsec; /* timestamp in nano seconds */ 206 207 union { 208 u8 generic[64]; 209 struct cpc_can_msg can_msg; 210 struct cpc_can_params can_params; 211 struct cpc_confirm confirmation; 212 struct cpc_overrun overrun; 213 struct cpc_can_error error; 214 struct cpc_can_err_counter err_counter; 215 u8 can_state; 216 } msg; 217 }; 218 219 /* 220 * Table of devices that work with this driver 221 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet. 222 */ 223 static struct usb_device_id ems_usb_table[] = { 224 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)}, 225 {} /* Terminating entry */ 226 }; 227 228 MODULE_DEVICE_TABLE(usb, ems_usb_table); 229 230 #define RX_BUFFER_SIZE 64 231 #define CPC_HEADER_SIZE 4 232 #define INTR_IN_BUFFER_SIZE 4 233 234 #define MAX_RX_URBS 10 235 #define MAX_TX_URBS 10 236 237 struct ems_usb; 238 239 struct ems_tx_urb_context { 240 struct ems_usb *dev; 241 242 u32 echo_index; 243 u8 dlc; 244 }; 245 246 struct ems_usb { 247 struct can_priv can; /* must be the first member */ 248 int open_time; 249 250 struct sk_buff *echo_skb[MAX_TX_URBS]; 251 252 struct usb_device *udev; 253 struct net_device *netdev; 254 255 atomic_t active_tx_urbs; 256 struct usb_anchor tx_submitted; 257 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS]; 258 259 struct usb_anchor rx_submitted; 260 261 struct urb *intr_urb; 262 263 u8 *tx_msg_buffer; 264 265 u8 *intr_in_buffer; 266 unsigned int free_slots; /* remember number of available slots */ 267 268 struct ems_cpc_msg active_params; /* active controller parameters */ 269 }; 270 271 static void ems_usb_read_interrupt_callback(struct urb *urb) 272 { 273 struct ems_usb *dev = urb->context; 274 struct net_device *netdev = dev->netdev; 275 int err; 276 277 if (!netif_device_present(netdev)) 278 return; 279 280 switch (urb->status) { 281 case 0: 282 dev->free_slots = dev->intr_in_buffer[1]; 283 break; 284 285 case -ECONNRESET: /* unlink */ 286 case -ENOENT: 287 case -ESHUTDOWN: 288 return; 289 290 default: 291 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n", 292 urb->status); 293 break; 294 } 295 296 err = usb_submit_urb(urb, GFP_ATOMIC); 297 298 if (err == -ENODEV) 299 netif_device_detach(netdev); 300 else if (err) 301 dev_err(netdev->dev.parent, 302 "failed resubmitting intr urb: %d\n", err); 303 } 304 305 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 306 { 307 struct can_frame *cf; 308 struct sk_buff *skb; 309 int i; 310 struct net_device_stats *stats = &dev->netdev->stats; 311 312 skb = alloc_can_skb(dev->netdev, &cf); 313 if (skb == NULL) 314 return; 315 316 cf->can_id = le32_to_cpu(msg->msg.can_msg.id); 317 cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF); 318 319 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME || 320 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) 321 cf->can_id |= CAN_EFF_FLAG; 322 323 if (msg->type == CPC_MSG_TYPE_RTR_FRAME || 324 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) { 325 cf->can_id |= CAN_RTR_FLAG; 326 } else { 327 for (i = 0; i < cf->can_dlc; i++) 328 cf->data[i] = msg->msg.can_msg.msg[i]; 329 } 330 331 netif_rx(skb); 332 333 stats->rx_packets++; 334 stats->rx_bytes += cf->can_dlc; 335 } 336 337 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) 338 { 339 struct can_frame *cf; 340 struct sk_buff *skb; 341 struct net_device_stats *stats = &dev->netdev->stats; 342 343 skb = alloc_can_err_skb(dev->netdev, &cf); 344 if (skb == NULL) 345 return; 346 347 if (msg->type == CPC_MSG_TYPE_CAN_STATE) { 348 u8 state = msg->msg.can_state; 349 350 if (state & SJA1000_SR_BS) { 351 dev->can.state = CAN_STATE_BUS_OFF; 352 cf->can_id |= CAN_ERR_BUSOFF; 353 354 can_bus_off(dev->netdev); 355 } else if (state & SJA1000_SR_ES) { 356 dev->can.state = CAN_STATE_ERROR_WARNING; 357 dev->can.can_stats.error_warning++; 358 } else { 359 dev->can.state = CAN_STATE_ERROR_ACTIVE; 360 dev->can.can_stats.error_passive++; 361 } 362 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) { 363 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc; 364 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr; 365 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr; 366 367 /* bus error interrupt */ 368 dev->can.can_stats.bus_error++; 369 stats->rx_errors++; 370 371 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 372 373 switch (ecc & SJA1000_ECC_MASK) { 374 case SJA1000_ECC_BIT: 375 cf->data[2] |= CAN_ERR_PROT_BIT; 376 break; 377 case SJA1000_ECC_FORM: 378 cf->data[2] |= CAN_ERR_PROT_FORM; 379 break; 380 case SJA1000_ECC_STUFF: 381 cf->data[2] |= CAN_ERR_PROT_STUFF; 382 break; 383 default: 384 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 385 cf->data[3] = ecc & SJA1000_ECC_SEG; 386 break; 387 } 388 389 /* Error occurred during transmission? */ 390 if ((ecc & SJA1000_ECC_DIR) == 0) 391 cf->data[2] |= CAN_ERR_PROT_TX; 392 393 if (dev->can.state == CAN_STATE_ERROR_WARNING || 394 dev->can.state == CAN_STATE_ERROR_PASSIVE) { 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 cf->can_id |= CAN_ERR_CRTL; 400 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 401 402 stats->rx_over_errors++; 403 stats->rx_errors++; 404 } 405 406 netif_rx(skb); 407 408 stats->rx_packets++; 409 stats->rx_bytes += cf->can_dlc; 410 } 411 412 /* 413 * callback for bulk IN urb 414 */ 415 static 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 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n", 435 urb->status); 436 goto resubmit_urb; 437 } 438 439 if (urb->actual_length > CPC_HEADER_SIZE) { 440 struct ems_cpc_msg *msg; 441 u8 *ibuf = urb->transfer_buffer; 442 u8 msg_count, again, start; 443 444 msg_count = ibuf[0] & ~0x80; 445 again = ibuf[0] & 0x80; 446 447 start = CPC_HEADER_SIZE; 448 449 while (msg_count) { 450 msg = (struct ems_cpc_msg *)&ibuf[start]; 451 452 switch (msg->type) { 453 case CPC_MSG_TYPE_CAN_STATE: 454 /* Process CAN state changes */ 455 ems_usb_rx_err(dev, msg); 456 break; 457 458 case CPC_MSG_TYPE_CAN_FRAME: 459 case CPC_MSG_TYPE_EXT_CAN_FRAME: 460 case CPC_MSG_TYPE_RTR_FRAME: 461 case CPC_MSG_TYPE_EXT_RTR_FRAME: 462 ems_usb_rx_can_msg(dev, msg); 463 break; 464 465 case CPC_MSG_TYPE_CAN_FRAME_ERROR: 466 /* Process errorframe */ 467 ems_usb_rx_err(dev, msg); 468 break; 469 470 case CPC_MSG_TYPE_OVERRUN: 471 /* Message lost while receiving */ 472 ems_usb_rx_err(dev, msg); 473 break; 474 } 475 476 start += CPC_MSG_HEADER_LEN + msg->length; 477 msg_count--; 478 479 if (start > urb->transfer_buffer_length) { 480 dev_err(netdev->dev.parent, "format error\n"); 481 break; 482 } 483 } 484 } 485 486 resubmit_urb: 487 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 488 urb->transfer_buffer, RX_BUFFER_SIZE, 489 ems_usb_read_bulk_callback, dev); 490 491 retval = usb_submit_urb(urb, GFP_ATOMIC); 492 493 if (retval == -ENODEV) 494 netif_device_detach(netdev); 495 else if (retval) 496 dev_err(netdev->dev.parent, 497 "failed resubmitting read bulk urb: %d\n", retval); 498 } 499 500 /* 501 * callback for bulk IN urb 502 */ 503 static void ems_usb_write_bulk_callback(struct urb *urb) 504 { 505 struct ems_tx_urb_context *context = urb->context; 506 struct ems_usb *dev; 507 struct net_device *netdev; 508 509 BUG_ON(!context); 510 511 dev = context->dev; 512 netdev = dev->netdev; 513 514 /* free up our allocated buffer */ 515 usb_free_coherent(urb->dev, urb->transfer_buffer_length, 516 urb->transfer_buffer, urb->transfer_dma); 517 518 atomic_dec(&dev->active_tx_urbs); 519 520 if (!netif_device_present(netdev)) 521 return; 522 523 if (urb->status) 524 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n", 525 urb->status); 526 527 netdev->trans_start = jiffies; 528 529 /* transmission complete interrupt */ 530 netdev->stats.tx_packets++; 531 netdev->stats.tx_bytes += context->dlc; 532 533 can_get_echo_skb(netdev, context->echo_index); 534 535 /* Release context */ 536 context->echo_index = MAX_TX_URBS; 537 538 if (netif_queue_stopped(netdev)) 539 netif_wake_queue(netdev); 540 } 541 542 /* 543 * Send the given CPC command synchronously 544 */ 545 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg) 546 { 547 int actual_length; 548 549 /* Copy payload */ 550 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg, 551 msg->length + CPC_MSG_HEADER_LEN); 552 553 /* Clear header */ 554 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE); 555 556 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2), 557 &dev->tx_msg_buffer[0], 558 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE, 559 &actual_length, 1000); 560 } 561 562 /* 563 * Change CAN controllers' mode register 564 */ 565 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode) 566 { 567 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode; 568 569 return ems_usb_command_msg(dev, &dev->active_params); 570 } 571 572 /* 573 * Send a CPC_Control command to change behaviour when interface receives a CAN 574 * message, bus error or CAN state changed notifications. 575 */ 576 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val) 577 { 578 struct ems_cpc_msg cmd; 579 580 cmd.type = CPC_CMD_TYPE_CONTROL; 581 cmd.length = CPC_MSG_HEADER_LEN + 1; 582 583 cmd.msgid = 0; 584 585 cmd.msg.generic[0] = val; 586 587 return ems_usb_command_msg(dev, &cmd); 588 } 589 590 /* 591 * Start interface 592 */ 593 static int ems_usb_start(struct ems_usb *dev) 594 { 595 struct net_device *netdev = dev->netdev; 596 int err, i; 597 598 dev->intr_in_buffer[0] = 0; 599 dev->free_slots = 15; /* initial size */ 600 601 for (i = 0; i < MAX_RX_URBS; i++) { 602 struct urb *urb = NULL; 603 u8 *buf = NULL; 604 605 /* create a URB, and a buffer for it */ 606 urb = usb_alloc_urb(0, GFP_KERNEL); 607 if (!urb) { 608 dev_err(netdev->dev.parent, 609 "No memory left for URBs\n"); 610 return -ENOMEM; 611 } 612 613 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL, 614 &urb->transfer_dma); 615 if (!buf) { 616 dev_err(netdev->dev.parent, 617 "No memory left for USB buffer\n"); 618 usb_free_urb(urb); 619 return -ENOMEM; 620 } 621 622 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2), 623 buf, RX_BUFFER_SIZE, 624 ems_usb_read_bulk_callback, dev); 625 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 626 usb_anchor_urb(urb, &dev->rx_submitted); 627 628 err = usb_submit_urb(urb, GFP_KERNEL); 629 if (err) { 630 usb_unanchor_urb(urb); 631 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf, 632 urb->transfer_dma); 633 break; 634 } 635 636 /* Drop reference, USB core will take care of freeing it */ 637 usb_free_urb(urb); 638 } 639 640 /* Did we submit any URBs */ 641 if (i == 0) { 642 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n"); 643 return err; 644 } 645 646 /* Warn if we've couldn't transmit all the URBs */ 647 if (i < MAX_RX_URBS) 648 dev_warn(netdev->dev.parent, "rx performance may be slow\n"); 649 650 /* Setup and start interrupt URB */ 651 usb_fill_int_urb(dev->intr_urb, dev->udev, 652 usb_rcvintpipe(dev->udev, 1), 653 dev->intr_in_buffer, 654 INTR_IN_BUFFER_SIZE, 655 ems_usb_read_interrupt_callback, dev, 1); 656 657 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL); 658 if (err) { 659 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n", 660 err); 661 662 return err; 663 } 664 665 /* CPC-USB will transfer received message to host */ 666 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON); 667 if (err) 668 goto failed; 669 670 /* CPC-USB will transfer CAN state changes to host */ 671 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON); 672 if (err) 673 goto failed; 674 675 /* CPC-USB will transfer bus errors to host */ 676 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON); 677 if (err) 678 goto failed; 679 680 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL); 681 if (err) 682 goto failed; 683 684 dev->can.state = CAN_STATE_ERROR_ACTIVE; 685 686 return 0; 687 688 failed: 689 dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err); 690 691 return err; 692 } 693 694 static void unlink_all_urbs(struct ems_usb *dev) 695 { 696 int i; 697 698 usb_unlink_urb(dev->intr_urb); 699 700 usb_kill_anchored_urbs(&dev->rx_submitted); 701 702 usb_kill_anchored_urbs(&dev->tx_submitted); 703 atomic_set(&dev->active_tx_urbs, 0); 704 705 for (i = 0; i < MAX_TX_URBS; i++) 706 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 707 } 708 709 static int ems_usb_open(struct net_device *netdev) 710 { 711 struct ems_usb *dev = netdev_priv(netdev); 712 int err; 713 714 err = ems_usb_write_mode(dev, SJA1000_MOD_RM); 715 if (err) 716 return err; 717 718 /* common open */ 719 err = open_candev(netdev); 720 if (err) 721 return err; 722 723 /* finally start device */ 724 err = ems_usb_start(dev); 725 if (err) { 726 if (err == -ENODEV) 727 netif_device_detach(dev->netdev); 728 729 dev_warn(netdev->dev.parent, "couldn't start device: %d\n", 730 err); 731 732 close_candev(netdev); 733 734 return err; 735 } 736 737 dev->open_time = jiffies; 738 739 netif_start_queue(netdev); 740 741 return 0; 742 } 743 744 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev) 745 { 746 struct ems_usb *dev = netdev_priv(netdev); 747 struct ems_tx_urb_context *context = NULL; 748 struct net_device_stats *stats = &netdev->stats; 749 struct can_frame *cf = (struct can_frame *)skb->data; 750 struct ems_cpc_msg *msg; 751 struct urb *urb; 752 u8 *buf; 753 int i, err; 754 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN 755 + sizeof(struct cpc_can_msg); 756 757 if (can_dropped_invalid_skb(netdev, skb)) 758 return NETDEV_TX_OK; 759 760 /* create a URB, and a buffer for it, and copy the data to the URB */ 761 urb = usb_alloc_urb(0, GFP_ATOMIC); 762 if (!urb) { 763 dev_err(netdev->dev.parent, "No memory left for URBs\n"); 764 goto nomem; 765 } 766 767 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma); 768 if (!buf) { 769 dev_err(netdev->dev.parent, "No memory left for USB buffer\n"); 770 usb_free_urb(urb); 771 goto nomem; 772 } 773 774 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE]; 775 776 msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK; 777 msg->msg.can_msg.length = cf->can_dlc; 778 779 if (cf->can_id & CAN_RTR_FLAG) { 780 msg->type = cf->can_id & CAN_EFF_FLAG ? 781 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME; 782 783 msg->length = CPC_CAN_MSG_MIN_SIZE; 784 } else { 785 msg->type = cf->can_id & CAN_EFF_FLAG ? 786 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME; 787 788 for (i = 0; i < cf->can_dlc; i++) 789 msg->msg.can_msg.msg[i] = cf->data[i]; 790 791 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc; 792 } 793 794 /* Respect byte order */ 795 msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id); 796 797 for (i = 0; i < MAX_TX_URBS; i++) { 798 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) { 799 context = &dev->tx_contexts[i]; 800 break; 801 } 802 } 803 804 /* 805 * May never happen! When this happens we'd more URBs in flight as 806 * allowed (MAX_TX_URBS). 807 */ 808 if (!context) { 809 usb_unanchor_urb(urb); 810 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 811 812 dev_warn(netdev->dev.parent, "couldn't find free context\n"); 813 814 return NETDEV_TX_BUSY; 815 } 816 817 context->dev = dev; 818 context->echo_index = i; 819 context->dlc = cf->can_dlc; 820 821 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf, 822 size, ems_usb_write_bulk_callback, context); 823 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 824 usb_anchor_urb(urb, &dev->tx_submitted); 825 826 can_put_echo_skb(skb, netdev, context->echo_index); 827 828 atomic_inc(&dev->active_tx_urbs); 829 830 err = usb_submit_urb(urb, GFP_ATOMIC); 831 if (unlikely(err)) { 832 can_free_echo_skb(netdev, context->echo_index); 833 834 usb_unanchor_urb(urb); 835 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma); 836 dev_kfree_skb(skb); 837 838 atomic_dec(&dev->active_tx_urbs); 839 840 if (err == -ENODEV) { 841 netif_device_detach(netdev); 842 } else { 843 dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err); 844 845 stats->tx_dropped++; 846 } 847 } else { 848 netdev->trans_start = jiffies; 849 850 /* Slow down tx path */ 851 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS || 852 dev->free_slots < 5) { 853 netif_stop_queue(netdev); 854 } 855 } 856 857 /* 858 * Release our reference to this URB, the USB core will eventually free 859 * it entirely. 860 */ 861 usb_free_urb(urb); 862 863 return NETDEV_TX_OK; 864 865 nomem: 866 dev_kfree_skb(skb); 867 stats->tx_dropped++; 868 869 return NETDEV_TX_OK; 870 } 871 872 static int ems_usb_close(struct net_device *netdev) 873 { 874 struct ems_usb *dev = netdev_priv(netdev); 875 876 /* Stop polling */ 877 unlink_all_urbs(dev); 878 879 netif_stop_queue(netdev); 880 881 /* Set CAN controller to reset mode */ 882 if (ems_usb_write_mode(dev, SJA1000_MOD_RM)) 883 dev_warn(netdev->dev.parent, "couldn't stop device"); 884 885 close_candev(netdev); 886 887 dev->open_time = 0; 888 889 return 0; 890 } 891 892 static const struct net_device_ops ems_usb_netdev_ops = { 893 .ndo_open = ems_usb_open, 894 .ndo_stop = ems_usb_close, 895 .ndo_start_xmit = ems_usb_start_xmit, 896 }; 897 898 static struct can_bittiming_const ems_usb_bittiming_const = { 899 .name = "ems_usb", 900 .tseg1_min = 1, 901 .tseg1_max = 16, 902 .tseg2_min = 1, 903 .tseg2_max = 8, 904 .sjw_max = 4, 905 .brp_min = 1, 906 .brp_max = 64, 907 .brp_inc = 1, 908 }; 909 910 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode) 911 { 912 struct ems_usb *dev = netdev_priv(netdev); 913 914 if (!dev->open_time) 915 return -EINVAL; 916 917 switch (mode) { 918 case CAN_MODE_START: 919 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL)) 920 dev_warn(netdev->dev.parent, "couldn't start device"); 921 922 if (netif_queue_stopped(netdev)) 923 netif_wake_queue(netdev); 924 break; 925 926 default: 927 return -EOPNOTSUPP; 928 } 929 930 return 0; 931 } 932 933 static int ems_usb_set_bittiming(struct net_device *netdev) 934 { 935 struct ems_usb *dev = netdev_priv(netdev); 936 struct can_bittiming *bt = &dev->can.bittiming; 937 u8 btr0, btr1; 938 939 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 940 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 941 (((bt->phase_seg2 - 1) & 0x7) << 4); 942 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 943 btr1 |= 0x80; 944 945 dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n", 946 btr0, btr1); 947 948 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0; 949 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1; 950 951 return ems_usb_command_msg(dev, &dev->active_params); 952 } 953 954 static void init_params_sja1000(struct ems_cpc_msg *msg) 955 { 956 struct cpc_sja1000_params *sja1000 = 957 &msg->msg.can_params.cc_params.sja1000; 958 959 msg->type = CPC_CMD_TYPE_CAN_PARAMS; 960 msg->length = sizeof(struct cpc_can_params); 961 msg->msgid = 0; 962 963 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000; 964 965 /* Acceptance filter open */ 966 sja1000->acc_code0 = 0x00; 967 sja1000->acc_code1 = 0x00; 968 sja1000->acc_code2 = 0x00; 969 sja1000->acc_code3 = 0x00; 970 971 /* Acceptance filter open */ 972 sja1000->acc_mask0 = 0xFF; 973 sja1000->acc_mask1 = 0xFF; 974 sja1000->acc_mask2 = 0xFF; 975 sja1000->acc_mask3 = 0xFF; 976 977 sja1000->btr0 = 0; 978 sja1000->btr1 = 0; 979 980 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL; 981 sja1000->mode = SJA1000_MOD_RM; 982 } 983 984 /* 985 * probe function for new CPC-USB devices 986 */ 987 static int ems_usb_probe(struct usb_interface *intf, 988 const struct usb_device_id *id) 989 { 990 struct net_device *netdev; 991 struct ems_usb *dev; 992 int i, err = -ENOMEM; 993 994 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS); 995 if (!netdev) { 996 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n"); 997 return -ENOMEM; 998 } 999 1000 dev = netdev_priv(netdev); 1001 1002 dev->udev = interface_to_usbdev(intf); 1003 dev->netdev = netdev; 1004 1005 dev->can.state = CAN_STATE_STOPPED; 1006 dev->can.clock.freq = EMS_USB_ARM7_CLOCK; 1007 dev->can.bittiming_const = &ems_usb_bittiming_const; 1008 dev->can.do_set_bittiming = ems_usb_set_bittiming; 1009 dev->can.do_set_mode = ems_usb_set_mode; 1010 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 1011 1012 netdev->netdev_ops = &ems_usb_netdev_ops; 1013 1014 netdev->flags |= IFF_ECHO; /* we support local echo */ 1015 1016 init_usb_anchor(&dev->rx_submitted); 1017 1018 init_usb_anchor(&dev->tx_submitted); 1019 atomic_set(&dev->active_tx_urbs, 0); 1020 1021 for (i = 0; i < MAX_TX_URBS; i++) 1022 dev->tx_contexts[i].echo_index = MAX_TX_URBS; 1023 1024 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL); 1025 if (!dev->intr_urb) { 1026 dev_err(&intf->dev, "Couldn't alloc intr URB\n"); 1027 goto cleanup_candev; 1028 } 1029 1030 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL); 1031 if (!dev->intr_in_buffer) { 1032 dev_err(&intf->dev, "Couldn't alloc Intr buffer\n"); 1033 goto cleanup_intr_urb; 1034 } 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 dev_err(&intf->dev, "Couldn't alloc Tx buffer\n"); 1040 goto cleanup_intr_in_buffer; 1041 } 1042 1043 usb_set_intfdata(intf, dev); 1044 1045 SET_NETDEV_DEV(netdev, &intf->dev); 1046 1047 init_params_sja1000(&dev->active_params); 1048 1049 err = ems_usb_command_msg(dev, &dev->active_params); 1050 if (err) { 1051 dev_err(netdev->dev.parent, 1052 "couldn't initialize controller: %d\n", err); 1053 goto cleanup_tx_msg_buffer; 1054 } 1055 1056 err = register_candev(netdev); 1057 if (err) { 1058 dev_err(netdev->dev.parent, 1059 "couldn't register CAN device: %d\n", err); 1060 goto cleanup_tx_msg_buffer; 1061 } 1062 1063 return 0; 1064 1065 cleanup_tx_msg_buffer: 1066 kfree(dev->tx_msg_buffer); 1067 1068 cleanup_intr_in_buffer: 1069 kfree(dev->intr_in_buffer); 1070 1071 cleanup_intr_urb: 1072 usb_free_urb(dev->intr_urb); 1073 1074 cleanup_candev: 1075 free_candev(netdev); 1076 1077 return err; 1078 } 1079 1080 /* 1081 * called by the usb core when the device is removed from the system 1082 */ 1083 static void ems_usb_disconnect(struct usb_interface *intf) 1084 { 1085 struct ems_usb *dev = usb_get_intfdata(intf); 1086 1087 usb_set_intfdata(intf, NULL); 1088 1089 if (dev) { 1090 unregister_netdev(dev->netdev); 1091 free_candev(dev->netdev); 1092 1093 unlink_all_urbs(dev); 1094 1095 usb_free_urb(dev->intr_urb); 1096 1097 kfree(dev->intr_in_buffer); 1098 } 1099 } 1100 1101 /* usb specific object needed to register this driver with the usb subsystem */ 1102 static struct usb_driver ems_usb_driver = { 1103 .name = "ems_usb", 1104 .probe = ems_usb_probe, 1105 .disconnect = ems_usb_disconnect, 1106 .id_table = ems_usb_table, 1107 }; 1108 1109 module_usb_driver(ems_usb_driver); 1110