drivers/net/can/usb/ems_usb.c

   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/signal.h>
  20 #include <linux/slab.h>
  21 #include <linux/module.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/usb.h>
  24
  25 #include <linux/can.h>
  26 #include <linux/can/dev.h>
  27 #include <linux/can/error.h>
  28
  29 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
  30 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
  31 MODULE_LICENSE("GPL v2");
  32
  33 /* Control-Values for CPC_Control() Command Subject Selection */
  34 #define CONTR_CAN_MESSAGE 0x04
  35 #define CONTR_CAN_STATE   0x0C
  36 #define CONTR_BUS_ERROR   0x1C
  37
  38 /* Control Command Actions */
  39 #define CONTR_CONT_OFF 0
  40 #define CONTR_CONT_ON  1
  41 #define CONTR_ONCE     2
  42
  43 /* Messages from CPC to PC */
  44 #define CPC_MSG_TYPE_CAN_FRAME       1  /* CAN data frame */
  45 #define CPC_MSG_TYPE_RTR_FRAME       8  /* CAN remote frame */
  46 #define CPC_MSG_TYPE_CAN_PARAMS      12 /* Actual CAN parameters */
  47 #define CPC_MSG_TYPE_CAN_STATE       14 /* CAN state message */
  48 #define CPC_MSG_TYPE_EXT_CAN_FRAME   16 /* Extended CAN data frame */
  49 #define CPC_MSG_TYPE_EXT_RTR_FRAME   17 /* Extended remote frame */
  50 #define CPC_MSG_TYPE_CONTROL         19 /* change interface behavior */
  51 #define CPC_MSG_TYPE_CONFIRM         20 /* command processed confirmation */
  52 #define CPC_MSG_TYPE_OVERRUN         21 /* overrun events */
  53 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
  54 #define CPC_MSG_TYPE_ERR_COUNTER     25 /* RX/TX error counter */
  55
  56 /* Messages from the PC to the CPC interface  */
  57 #define CPC_CMD_TYPE_CAN_FRAME     1   /* CAN data frame */
  58 #define CPC_CMD_TYPE_CONTROL       3   /* control of interface behavior */
  59 #define CPC_CMD_TYPE_CAN_PARAMS    6   /* set CAN parameters */
  60 #define CPC_CMD_TYPE_RTR_FRAME     13  /* CAN remote frame */
  61 #define CPC_CMD_TYPE_CAN_STATE     14  /* CAN state message */
  62 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15  /* Extended CAN data frame */
  63 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16  /* Extended CAN remote frame */
  64 #define CPC_CMD_TYPE_CAN_EXIT      200 /* exit the CAN */
  65
  66 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
  67 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8  /* clear CPC_MSG queue */
  68 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
  69
  70 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
  71
  72 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
  73
  74 /* Overrun types */
  75 #define CPC_OVR_EVENT_CAN       0x01
  76 #define CPC_OVR_EVENT_CANSTATE  0x02
  77 #define CPC_OVR_EVENT_BUSERROR  0x04
  78
  79 /*
  80  * If the CAN controller lost a message we indicate it with the highest bit
  81  * set in the count field.
  82  */
  83 #define CPC_OVR_HW 0x80
  84
  85 /* Size of the "struct ems_cpc_msg" without the union */
  86 #define CPC_MSG_HEADER_LEN   11
  87 #define CPC_CAN_MSG_MIN_SIZE 5
  88
  89 /* Define these values to match your devices */
  90 #define USB_CPCUSB_VENDOR_ID 0x12D6
  91
  92 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
  93
  94 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
  95 #define SJA1000_MOD_NORMAL 0x00
  96 #define SJA1000_MOD_RM     0x01
  97
  98 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
  99 #define SJA1000_ECC_SEG   0x1F
 100 #define SJA1000_ECC_DIR   0x20
 101 #define SJA1000_ECC_ERR   0x06
 102 #define SJA1000_ECC_BIT   0x00
 103 #define SJA1000_ECC_FORM  0x40
 104 #define SJA1000_ECC_STUFF 0x80
 105 #define SJA1000_ECC_MASK  0xc0
 106
 107 /* Status register content */
 108 #define SJA1000_SR_BS 0x80
 109 #define SJA1000_SR_ES 0x40
 110
 111 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
 112
 113 /*
 114  * The device actually uses a 16MHz clock to generate the CAN clock
 115  * but it expects SJA1000 bit settings based on 8MHz (is internally
 116  * converted).
 117  */
 118 #define EMS_USB_ARM7_CLOCK 8000000
 119
 120 #define CPC_TX_QUEUE_TRIGGER_LOW        25
 121 #define CPC_TX_QUEUE_TRIGGER_HIGH       35
 122
 123 /*
 124  * CAN-Message representation in a CPC_MSG. Message object type is
 125  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
 126  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
 127  */
 128 struct cpc_can_msg {
 129         u32 id;
 130         u8 length;
 131         u8 msg[8];
 132 };
 133
 134 /* Representation of the CAN parameters for the SJA1000 controller */
 135 struct cpc_sja1000_params {
 136         u8 mode;
 137         u8 acc_code0;
 138         u8 acc_code1;
 139         u8 acc_code2;
 140         u8 acc_code3;
 141         u8 acc_mask0;
 142         u8 acc_mask1;
 143         u8 acc_mask2;
 144         u8 acc_mask3;
 145         u8 btr0;
 146         u8 btr1;
 147         u8 outp_contr;
 148 };
 149
 150 /* CAN params message representation */
 151 struct cpc_can_params {
 152         u8 cc_type;
 153
 154         /* Will support M16C CAN controller in the future */
 155         union {
 156                 struct cpc_sja1000_params sja1000;
 157         } cc_params;
 158 };
 159
 160 /* Structure for confirmed message handling */
 161 struct cpc_confirm {
 162         u8 error; /* error code */
 163 };
 164
 165 /* Structure for overrun conditions */
 166 struct cpc_overrun {
 167         u8 event;
 168         u8 count;
 169 };
 170
 171 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
 172 struct cpc_sja1000_can_error {
 173         u8 ecc;
 174         u8 rxerr;
 175         u8 txerr;
 176 };
 177
 178 /* structure for CAN error conditions */
 179 struct cpc_can_error {
 180         u8 ecode;
 181
 182         struct {
 183                 u8 cc_type;
 184
 185                 /* Other controllers may also provide error code capture regs */
 186                 union {
 187                         struct cpc_sja1000_can_error sja1000;
 188                 } regs;
 189         } cc;
 190 };
 191
 192 /*
 193  * Structure containing RX/TX error counter. This structure is used to request
 194  * the values of the CAN controllers TX and RX error counter.
 195  */
 196 struct cpc_can_err_counter {
 197         u8 rx;
 198         u8 tx;
 199 };
 200
 201 /* Main message type used between library and application */
 202 struct __packed ems_cpc_msg {
 203         u8 type;        /* type of message */
 204         u8 length;      /* length of data within union 'msg' */
 205         u8 msgid;       /* confirmation handle */
 206         u32 ts_sec;     /* timestamp in seconds */
 207         u32 ts_nsec;    /* timestamp in nano seconds */
 208
 209         union {
 210                 u8 generic[64];
 211                 struct cpc_can_msg can_msg;
 212                 struct cpc_can_params can_params;
 213                 struct cpc_confirm confirmation;
 214                 struct cpc_overrun overrun;
 215                 struct cpc_can_error error;
 216                 struct cpc_can_err_counter err_counter;
 217                 u8 can_state;
 218         } msg;
 219 };
 220
 221 /*
 222  * Table of devices that work with this driver
 223  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
 224  */
 225 static struct usb_device_id ems_usb_table[] = {
 226         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
 227         {} /* Terminating entry */
 228 };
 229
 230 MODULE_DEVICE_TABLE(usb, ems_usb_table);
 231
 232 #define RX_BUFFER_SIZE      64
 233 #define CPC_HEADER_SIZE     4
 234 #define INTR_IN_BUFFER_SIZE 4
 235
 236 #define MAX_RX_URBS 10
 237 #define MAX_TX_URBS 10
 238
 239 struct ems_usb;
 240
 241 struct ems_tx_urb_context {
 242         struct ems_usb *dev;
 243
 244         u32 echo_index;
 245         u8 dlc;
 246 };
 247
 248 struct ems_usb {
 249         struct can_priv can; /* must be the first member */
 250
 251         struct sk_buff *echo_skb[MAX_TX_URBS];
 252
 253         struct usb_device *udev;
 254         struct net_device *netdev;
 255
 256         atomic_t active_tx_urbs;
 257         struct usb_anchor tx_submitted;
 258         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
 259
 260         struct usb_anchor rx_submitted;
 261
 262         struct urb *intr_urb;
 263
 264         u8 *tx_msg_buffer;
 265
 266         u8 *intr_in_buffer;
 267         unsigned int free_slots; /* remember number of available slots */
 268
 269         struct ems_cpc_msg active_params; /* active controller parameters */
 270 };
 271
 272 static void ems_usb_read_interrupt_callback(struct urb *urb)
 273 {
 274         struct ems_usb *dev = urb->context;
 275         struct net_device *netdev = dev->netdev;
 276         int err;
 277
 278         if (!netif_device_present(netdev))
 279                 return;
 280
 281         switch (urb->status) {
 282         case 0:
 283                 dev->free_slots = dev->intr_in_buffer[1];
 284                 if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){
 285                         if (netif_queue_stopped(netdev)){
 286                                 netif_wake_queue(netdev);
 287                         }
 288                 }
 289                 break;
 290
 291         case -ECONNRESET: /* unlink */
 292         case -ENOENT:
 293         case -ESHUTDOWN:
 294                 return;
 295
 296         default:
 297                 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
 298                 break;
 299         }
 300
 301         err = usb_submit_urb(urb, GFP_ATOMIC);
 302
 303         if (err == -ENODEV)
 304                 netif_device_detach(netdev);
 305         else if (err)
 306                 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
 307 }
 308
 309 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 310 {
 311         struct can_frame *cf;
 312         struct sk_buff *skb;
 313         int i;
 314         struct net_device_stats *stats = &dev->netdev->stats;
 315
 316         skb = alloc_can_skb(dev->netdev, &cf);
 317         if (skb == NULL)
 318                 return;
 319
 320         cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
 321         cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
 322
 323         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
 324             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
 325                 cf->can_id |= CAN_EFF_FLAG;
 326
 327         if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
 328             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
 329                 cf->can_id |= CAN_RTR_FLAG;
 330         } else {
 331                 for (i = 0; i < cf->can_dlc; i++)
 332                         cf->data[i] = msg->msg.can_msg.msg[i];
 333         }
 334
 335         netif_rx(skb);
 336
 337         stats->rx_packets++;
 338         stats->rx_bytes += cf->can_dlc;
 339 }
 340
 341 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 342 {
 343         struct can_frame *cf;
 344         struct sk_buff *skb;
 345         struct net_device_stats *stats = &dev->netdev->stats;
 346
 347         skb = alloc_can_err_skb(dev->netdev, &cf);
 348         if (skb == NULL)
 349                 return;
 350
 351         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
 352                 u8 state = msg->msg.can_state;
 353
 354                 if (state & SJA1000_SR_BS) {
 355                         dev->can.state = CAN_STATE_BUS_OFF;
 356                         cf->can_id |= CAN_ERR_BUSOFF;
 357
 358                         can_bus_off(dev->netdev);
 359                 } else if (state & SJA1000_SR_ES) {
 360                         dev->can.state = CAN_STATE_ERROR_WARNING;
 361                         dev->can.can_stats.error_warning++;
 362                 } else {
 363                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 364                         dev->can.can_stats.error_passive++;
 365                 }
 366         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
 367                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
 368                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
 369                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
 370
 371                 /* bus error interrupt */
 372                 dev->can.can_stats.bus_error++;
 373                 stats->rx_errors++;
 374
 375                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 376
 377                 switch (ecc & SJA1000_ECC_MASK) {
 378                 case SJA1000_ECC_BIT:
 379                         cf->data[2] |= CAN_ERR_PROT_BIT;
 380                         break;
 381                 case SJA1000_ECC_FORM:
 382                         cf->data[2] |= CAN_ERR_PROT_FORM;
 383                         break;
 384                 case SJA1000_ECC_STUFF:
 385                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 386                         break;
 387                 default:
 388                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 389                         cf->data[3] = ecc & SJA1000_ECC_SEG;
 390                         break;
 391                 }
 392
 393                 /* Error occurred during transmission? */
 394                 if ((ecc & SJA1000_ECC_DIR) == 0)
 395                         cf->data[2] |= CAN_ERR_PROT_TX;
 396
 397                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
 398                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
 399                         cf->data[1] = (txerr > rxerr) ?
 400                             CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
 401                 }
 402         } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
 403                 cf->can_id |= CAN_ERR_CRTL;
 404                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 405
 406                 stats->rx_over_errors++;
 407                 stats->rx_errors++;
 408         }
 409
 410         netif_rx(skb);
 411
 412         stats->rx_packets++;
 413         stats->rx_bytes += cf->can_dlc;
 414 }
 415
 416 /*
 417  * callback for bulk IN urb
 418  */
 419 static void ems_usb_read_bulk_callback(struct urb *urb)
 420 {
 421         struct ems_usb *dev = urb->context;
 422         struct net_device *netdev;
 423         int retval;
 424
 425         netdev = dev->netdev;
 426
 427         if (!netif_device_present(netdev))
 428                 return;
 429
 430         switch (urb->status) {
 431         case 0: /* success */
 432                 break;
 433
 434         case -ENOENT:
 435                 return;
 436
 437         default:
 438                 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
 439                 goto resubmit_urb;
 440         }
 441
 442         if (urb->actual_length > CPC_HEADER_SIZE) {
 443                 struct ems_cpc_msg *msg;
 444                 u8 *ibuf = urb->transfer_buffer;
 445                 u8 msg_count, again, start;
 446
 447                 msg_count = ibuf[0] & ~0x80;
 448                 again = ibuf[0] & 0x80;
 449
 450                 start = CPC_HEADER_SIZE;
 451
 452                 while (msg_count) {
 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->transfer_buffer_length) {
 483                                 netdev_err(netdev, "format error\n");
 484                                 break;
 485                         }
 486                 }
 487         }
 488
 489 resubmit_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         retval = usb_submit_urb(urb, GFP_ATOMIC);
 495
 496         if (retval == -ENODEV)
 497                 netif_device_detach(netdev);
 498         else if (retval)
 499                 netdev_err(netdev,
 500                            "failed resubmitting read bulk urb: %d\n", retval);
 501 }
 502
 503 /*
 504  * callback for bulk IN urb
 505  */
 506 static void ems_usb_write_bulk_callback(struct urb *urb)
 507 {
 508         struct ems_tx_urb_context *context = urb->context;
 509         struct ems_usb *dev;
 510         struct net_device *netdev;
 511
 512         BUG_ON(!context);
 513
 514         dev = context->dev;
 515         netdev = dev->netdev;
 516
 517         /* free up our allocated buffer */
 518         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 519                           urb->transfer_buffer, urb->transfer_dma);
 520
 521         atomic_dec(&dev->active_tx_urbs);
 522
 523         if (!netif_device_present(netdev))
 524                 return;
 525
 526         if (urb->status)
 527                 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 528
 529         netdev->trans_start = jiffies;
 530
 531         /* transmission complete interrupt */
 532         netdev->stats.tx_packets++;
 533         netdev->stats.tx_bytes += context->dlc;
 534
 535         can_get_echo_skb(netdev, context->echo_index);
 536
 537         /* Release context */
 538         context->echo_index = MAX_TX_URBS;
 539
 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 = 50; /* 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                         netdev_err(netdev, "No memory left for URBs\n");
 609                         err = -ENOMEM;
 610                         break;
 611                 }
 612
 613                 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 614                                          &urb->transfer_dma);
 615                 if (!buf) {
 616                         netdev_err(netdev, "No memory left for USB buffer\n");
 617                         usb_free_urb(urb);
 618                         err = -ENOMEM;
 619                         break;
 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                         usb_free_urb(urb);
 634                         break;
 635                 }
 636
 637                 /* Drop reference, USB core will take care of freeing it */
 638                 usb_free_urb(urb);
 639         }
 640
 641         /* Did we submit any URBs */
 642         if (i == 0) {
 643                 netdev_warn(netdev, "couldn't setup read URBs\n");
 644                 return err;
 645         }
 646
 647         /* Warn if we've couldn't transmit all the URBs */
 648         if (i < MAX_RX_URBS)
 649                 netdev_warn(netdev, "rx performance may be slow\n");
 650
 651         /* Setup and start interrupt URB */
 652         usb_fill_int_urb(dev->intr_urb, dev->udev,
 653                          usb_rcvintpipe(dev->udev, 1),
 654                          dev->intr_in_buffer,
 655                          INTR_IN_BUFFER_SIZE,
 656                          ems_usb_read_interrupt_callback, dev, 1);
 657
 658         err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
 659         if (err) {
 660                 netdev_warn(netdev, "intr URB submit failed: %d\n", 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         netdev_warn(netdev, "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                 netdev_warn(netdev, "couldn't start device: %d\n", err);
 730
 731                 close_candev(netdev);
 732
 733                 return err;
 734         }
 735
 736
 737         netif_start_queue(netdev);
 738
 739         return 0;
 740 }
 741
 742 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 743 {
 744         struct ems_usb *dev = netdev_priv(netdev);
 745         struct ems_tx_urb_context *context = NULL;
 746         struct net_device_stats *stats = &netdev->stats;
 747         struct can_frame *cf = (struct can_frame *)skb->data;
 748         struct ems_cpc_msg *msg;
 749         struct urb *urb;
 750         u8 *buf;
 751         int i, err;
 752         size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
 753                         + sizeof(struct cpc_can_msg);
 754
 755         if (can_dropped_invalid_skb(netdev, skb))
 756                 return NETDEV_TX_OK;
 757
 758         /* create a URB, and a buffer for it, and copy the data to the URB */
 759         urb = usb_alloc_urb(0, GFP_ATOMIC);
 760         if (!urb) {
 761                 netdev_err(netdev, "No memory left for URBs\n");
 762                 goto nomem;
 763         }
 764
 765         buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
 766         if (!buf) {
 767                 netdev_err(netdev, "No memory left for USB buffer\n");
 768                 usb_free_urb(urb);
 769                 goto nomem;
 770         }
 771
 772         msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
 773
 774         msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
 775         msg->msg.can_msg.length = cf->can_dlc;
 776
 777         if (cf->can_id & CAN_RTR_FLAG) {
 778                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 779                         CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
 780
 781                 msg->length = CPC_CAN_MSG_MIN_SIZE;
 782         } else {
 783                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 784                         CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
 785
 786                 for (i = 0; i < cf->can_dlc; i++)
 787                         msg->msg.can_msg.msg[i] = cf->data[i];
 788
 789                 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
 790         }
 791
 792         /* Respect byte order */
 793         msg->msg.can_msg.id = cpu_to_le32(msg->msg.can_msg.id);
 794
 795         for (i = 0; i < MAX_TX_URBS; i++) {
 796                 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
 797                         context = &dev->tx_contexts[i];
 798                         break;
 799                 }
 800         }
 801
 802         /*
 803          * May never happen! When this happens we'd more URBs in flight as
 804          * allowed (MAX_TX_URBS).
 805          */
 806         if (!context) {
 807                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 808                 usb_free_urb(urb);
 809
 810                 netdev_warn(netdev, "couldn't find free context\n");
 811
 812                 return NETDEV_TX_BUSY;
 813         }
 814
 815         context->dev = dev;
 816         context->echo_index = i;
 817         context->dlc = cf->can_dlc;
 818
 819         usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 820                           size, ems_usb_write_bulk_callback, context);
 821         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 822         usb_anchor_urb(urb, &dev->tx_submitted);
 823
 824         can_put_echo_skb(skb, netdev, context->echo_index);
 825
 826         atomic_inc(&dev->active_tx_urbs);
 827
 828         err = usb_submit_urb(urb, GFP_ATOMIC);
 829         if (unlikely(err)) {
 830                 can_free_echo_skb(netdev, context->echo_index);
 831
 832                 usb_unanchor_urb(urb);
 833                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 834                 dev_kfree_skb(skb);
 835
 836                 atomic_dec(&dev->active_tx_urbs);
 837
 838                 if (err == -ENODEV) {
 839                         netif_device_detach(netdev);
 840                 } else {
 841                         netdev_warn(netdev, "failed tx_urb %d\n", err);
 842
 843                         stats->tx_dropped++;
 844                 }
 845         } else {
 846                 netdev->trans_start = jiffies;
 847
 848                 /* Slow down tx path */
 849                 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
 850                     dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
 851                         netif_stop_queue(netdev);
 852                 }
 853         }
 854
 855         /*
 856          * Release our reference to this URB, the USB core will eventually free
 857          * it entirely.
 858          */
 859         usb_free_urb(urb);
 860
 861         return NETDEV_TX_OK;
 862
 863 nomem:
 864         dev_kfree_skb(skb);
 865         stats->tx_dropped++;
 866
 867         return NETDEV_TX_OK;
 868 }
 869
 870 static int ems_usb_close(struct net_device *netdev)
 871 {
 872         struct ems_usb *dev = netdev_priv(netdev);
 873
 874         /* Stop polling */
 875         unlink_all_urbs(dev);
 876
 877         netif_stop_queue(netdev);
 878
 879         /* Set CAN controller to reset mode */
 880         if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
 881                 netdev_warn(netdev, "couldn't stop device");
 882
 883         close_candev(netdev);
 884
 885         return 0;
 886 }
 887
 888 static const struct net_device_ops ems_usb_netdev_ops = {
 889         .ndo_open = ems_usb_open,
 890         .ndo_stop = ems_usb_close,
 891         .ndo_start_xmit = ems_usb_start_xmit,
 892         .ndo_change_mtu = can_change_mtu,
 893 };
 894
 895 static const struct can_bittiming_const ems_usb_bittiming_const = {
 896         .name = "ems_usb",
 897         .tseg1_min = 1,
 898         .tseg1_max = 16,
 899         .tseg2_min = 1,
 900         .tseg2_max = 8,
 901         .sjw_max = 4,
 902         .brp_min = 1,
 903         .brp_max = 64,
 904         .brp_inc = 1,
 905 };
 906
 907 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 908 {
 909         struct ems_usb *dev = netdev_priv(netdev);
 910
 911         switch (mode) {
 912         case CAN_MODE_START:
 913                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
 914                         netdev_warn(netdev, "couldn't start device");
 915
 916                 if (netif_queue_stopped(netdev))
 917                         netif_wake_queue(netdev);
 918                 break;
 919
 920         default:
 921                 return -EOPNOTSUPP;
 922         }
 923
 924         return 0;
 925 }
 926
 927 static int ems_usb_set_bittiming(struct net_device *netdev)
 928 {
 929         struct ems_usb *dev = netdev_priv(netdev);
 930         struct can_bittiming *bt = &dev->can.bittiming;
 931         u8 btr0, btr1;
 932
 933         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 934         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 935                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 936         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 937                 btr1 |= 0x80;
 938
 939         netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 940
 941         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
 942         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
 943
 944         return ems_usb_command_msg(dev, &dev->active_params);
 945 }
 946
 947 static void init_params_sja1000(struct ems_cpc_msg *msg)
 948 {
 949         struct cpc_sja1000_params *sja1000 =
 950                 &msg->msg.can_params.cc_params.sja1000;
 951
 952         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
 953         msg->length = sizeof(struct cpc_can_params);
 954         msg->msgid = 0;
 955
 956         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
 957
 958         /* Acceptance filter open */
 959         sja1000->acc_code0 = 0x00;
 960         sja1000->acc_code1 = 0x00;
 961         sja1000->acc_code2 = 0x00;
 962         sja1000->acc_code3 = 0x00;
 963
 964         /* Acceptance filter open */
 965         sja1000->acc_mask0 = 0xFF;
 966         sja1000->acc_mask1 = 0xFF;
 967         sja1000->acc_mask2 = 0xFF;
 968         sja1000->acc_mask3 = 0xFF;
 969
 970         sja1000->btr0 = 0;
 971         sja1000->btr1 = 0;
 972
 973         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
 974         sja1000->mode = SJA1000_MOD_RM;
 975 }
 976
 977 /*
 978  * probe function for new CPC-USB devices
 979  */
 980 static int ems_usb_probe(struct usb_interface *intf,
 981                          const struct usb_device_id *id)
 982 {
 983         struct net_device *netdev;
 984         struct ems_usb *dev;
 985         int i, err = -ENOMEM;
 986
 987         netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
 988         if (!netdev) {
 989                 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
 990                 return -ENOMEM;
 991         }
 992
 993         dev = netdev_priv(netdev);
 994
 995         dev->udev = interface_to_usbdev(intf);
 996         dev->netdev = netdev;
 997
 998         dev->can.state = CAN_STATE_STOPPED;
 999         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1000         dev->can.bittiming_const = &ems_usb_bittiming_const;
1001         dev->can.do_set_bittiming = ems_usb_set_bittiming;
1002         dev->can.do_set_mode = ems_usb_set_mode;
1003         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1004
1005         netdev->netdev_ops = &ems_usb_netdev_ops;
1006
1007         netdev->flags |= IFF_ECHO; /* we support local echo */
1008
1009         init_usb_anchor(&dev->rx_submitted);
1010
1011         init_usb_anchor(&dev->tx_submitted);
1012         atomic_set(&dev->active_tx_urbs, 0);
1013
1014         for (i = 0; i < MAX_TX_URBS; i++)
1015                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1016
1017         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1018         if (!dev->intr_urb) {
1019                 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1020                 goto cleanup_candev;
1021         }
1022
1023         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1024         if (!dev->intr_in_buffer)
1025                 goto cleanup_intr_urb;
1026
1027         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1028                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1029         if (!dev->tx_msg_buffer)
1030                 goto cleanup_intr_in_buffer;
1031
1032         usb_set_intfdata(intf, dev);
1033
1034         SET_NETDEV_DEV(netdev, &intf->dev);
1035
1036         init_params_sja1000(&dev->active_params);
1037
1038         err = ems_usb_command_msg(dev, &dev->active_params);
1039         if (err) {
1040                 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1041                 goto cleanup_tx_msg_buffer;
1042         }
1043
1044         err = register_candev(netdev);
1045         if (err) {
1046                 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1047                 goto cleanup_tx_msg_buffer;
1048         }
1049
1050         return 0;
1051
1052 cleanup_tx_msg_buffer:
1053         kfree(dev->tx_msg_buffer);
1054
1055 cleanup_intr_in_buffer:
1056         kfree(dev->intr_in_buffer);
1057
1058 cleanup_intr_urb:
1059         usb_free_urb(dev->intr_urb);
1060
1061 cleanup_candev:
1062         free_candev(netdev);
1063
1064         return err;
1065 }
1066
1067 /*
1068  * called by the usb core when the device is removed from the system
1069  */
1070 static void ems_usb_disconnect(struct usb_interface *intf)
1071 {
1072         struct ems_usb *dev = usb_get_intfdata(intf);
1073
1074         usb_set_intfdata(intf, NULL);
1075
1076         if (dev) {
1077                 unregister_netdev(dev->netdev);
1078                 free_candev(dev->netdev);
1079
1080                 unlink_all_urbs(dev);
1081
1082                 usb_free_urb(dev->intr_urb);
1083
1084                 kfree(dev->intr_in_buffer);
1085         }
1086 }
1087
1088 /* usb specific object needed to register this driver with the usb subsystem */
1089 static struct usb_driver ems_usb_driver = {
1090         .name = "ems_usb",
1091         .probe = ems_usb_probe,
1092         .disconnect = ems_usb_disconnect,
1093         .id_table = ems_usb_table,
1094 };
1095
1096 module_usb_driver(ems_usb_driver);