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/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 #define CPC_TX_QUEUE_TRIGGER_LOW        25
 122 #define CPC_TX_QUEUE_TRIGGER_HIGH       35
 123
 124 /*
 125  * CAN-Message representation in a CPC_MSG. Message object type is
 126  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
 127  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
 128  */
 129 struct cpc_can_msg {
 130         u32 id;
 131         u8 length;
 132         u8 msg[8];
 133 };
 134
 135 /* Representation of the CAN parameters for the SJA1000 controller */
 136 struct cpc_sja1000_params {
 137         u8 mode;
 138         u8 acc_code0;
 139         u8 acc_code1;
 140         u8 acc_code2;
 141         u8 acc_code3;
 142         u8 acc_mask0;
 143         u8 acc_mask1;
 144         u8 acc_mask2;
 145         u8 acc_mask3;
 146         u8 btr0;
 147         u8 btr1;
 148         u8 outp_contr;
 149 };
 150
 151 /* CAN params message representation */
 152 struct cpc_can_params {
 153         u8 cc_type;
 154
 155         /* Will support M16C CAN controller in the future */
 156         union {
 157                 struct cpc_sja1000_params sja1000;
 158         } cc_params;
 159 };
 160
 161 /* Structure for confirmed message handling */
 162 struct cpc_confirm {
 163         u8 error; /* error code */
 164 };
 165
 166 /* Structure for overrun conditions */
 167 struct cpc_overrun {
 168         u8 event;
 169         u8 count;
 170 };
 171
 172 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
 173 struct cpc_sja1000_can_error {
 174         u8 ecc;
 175         u8 rxerr;
 176         u8 txerr;
 177 };
 178
 179 /* structure for CAN error conditions */
 180 struct cpc_can_error {
 181         u8 ecode;
 182
 183         struct {
 184                 u8 cc_type;
 185
 186                 /* Other controllers may also provide error code capture regs */
 187                 union {
 188                         struct cpc_sja1000_can_error sja1000;
 189                 } regs;
 190         } cc;
 191 };
 192
 193 /*
 194  * Structure containing RX/TX error counter. This structure is used to request
 195  * the values of the CAN controllers TX and RX error counter.
 196  */
 197 struct cpc_can_err_counter {
 198         u8 rx;
 199         u8 tx;
 200 };
 201
 202 /* Main message type used between library and application */
 203 struct __packed ems_cpc_msg {
 204         u8 type;        /* type of message */
 205         u8 length;      /* length of data within union 'msg' */
 206         u8 msgid;       /* confirmation handle */
 207         u32 ts_sec;     /* timestamp in seconds */
 208         u32 ts_nsec;    /* timestamp in nano seconds */
 209
 210         union {
 211                 u8 generic[64];
 212                 struct cpc_can_msg can_msg;
 213                 struct cpc_can_params can_params;
 214                 struct cpc_confirm confirmation;
 215                 struct cpc_overrun overrun;
 216                 struct cpc_can_error error;
 217                 struct cpc_can_err_counter err_counter;
 218                 u8 can_state;
 219         } msg;
 220 };
 221
 222 /*
 223  * Table of devices that work with this driver
 224  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
 225  */
 226 static struct usb_device_id ems_usb_table[] = {
 227         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
 228         {} /* Terminating entry */
 229 };
 230
 231 MODULE_DEVICE_TABLE(usb, ems_usb_table);
 232
 233 #define RX_BUFFER_SIZE      64
 234 #define CPC_HEADER_SIZE     4
 235 #define INTR_IN_BUFFER_SIZE 4
 236
 237 #define MAX_RX_URBS 10
 238 #define MAX_TX_URBS 10
 239
 240 struct ems_usb;
 241
 242 struct ems_tx_urb_context {
 243         struct ems_usb *dev;
 244
 245         u32 echo_index;
 246         u8 dlc;
 247 };
 248
 249 struct ems_usb {
 250         struct can_priv can; /* must be the first member */
 251
 252         struct sk_buff *echo_skb[MAX_TX_URBS];
 253
 254         struct usb_device *udev;
 255         struct net_device *netdev;
 256
 257         atomic_t active_tx_urbs;
 258         struct usb_anchor tx_submitted;
 259         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
 260
 261         struct usb_anchor rx_submitted;
 262
 263         struct urb *intr_urb;
 264
 265         u8 *tx_msg_buffer;
 266
 267         u8 *intr_in_buffer;
 268         unsigned int free_slots; /* remember number of available slots */
 269
 270         struct ems_cpc_msg active_params; /* active controller parameters */
 271 };
 272
 273 static void ems_usb_read_interrupt_callback(struct urb *urb)
 274 {
 275         struct ems_usb *dev = urb->context;
 276         struct net_device *netdev = dev->netdev;
 277         int err;
 278
 279         if (!netif_device_present(netdev))
 280                 return;
 281
 282         switch (urb->status) {
 283         case 0:
 284                 dev->free_slots = dev->intr_in_buffer[1];
 285                 if(dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH){
 286                         if (netif_queue_stopped(netdev)){
 287                                 netif_wake_queue(netdev);
 288                         }
 289                 }
 290                 break;
 291
 292         case -ECONNRESET: /* unlink */
 293         case -ENOENT:
 294         case -ESHUTDOWN:
 295                 return;
 296
 297         default:
 298                 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
 299                 break;
 300         }
 301
 302         err = usb_submit_urb(urb, GFP_ATOMIC);
 303
 304         if (err == -ENODEV)
 305                 netif_device_detach(netdev);
 306         else if (err)
 307                 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
 308 }
 309
 310 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 311 {
 312         struct can_frame *cf;
 313         struct sk_buff *skb;
 314         int i;
 315         struct net_device_stats *stats = &dev->netdev->stats;
 316
 317         skb = alloc_can_skb(dev->netdev, &cf);
 318         if (skb == NULL)
 319                 return;
 320
 321         cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
 322         cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
 323
 324         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
 325             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
 326                 cf->can_id |= CAN_EFF_FLAG;
 327
 328         if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
 329             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
 330                 cf->can_id |= CAN_RTR_FLAG;
 331         } else {
 332                 for (i = 0; i < cf->can_dlc; i++)
 333                         cf->data[i] = msg->msg.can_msg.msg[i];
 334         }
 335
 336         netif_rx(skb);
 337
 338         stats->rx_packets++;
 339         stats->rx_bytes += cf->can_dlc;
 340 }
 341
 342 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 343 {
 344         struct can_frame *cf;
 345         struct sk_buff *skb;
 346         struct net_device_stats *stats = &dev->netdev->stats;
 347
 348         skb = alloc_can_err_skb(dev->netdev, &cf);
 349         if (skb == NULL)
 350                 return;
 351
 352         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
 353                 u8 state = msg->msg.can_state;
 354
 355                 if (state & SJA1000_SR_BS) {
 356                         dev->can.state = CAN_STATE_BUS_OFF;
 357                         cf->can_id |= CAN_ERR_BUSOFF;
 358
 359                         can_bus_off(dev->netdev);
 360                 } else if (state & SJA1000_SR_ES) {
 361                         dev->can.state = CAN_STATE_ERROR_WARNING;
 362                         dev->can.can_stats.error_warning++;
 363                 } else {
 364                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 365                         dev->can.can_stats.error_passive++;
 366                 }
 367         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
 368                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
 369                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
 370                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
 371
 372                 /* bus error interrupt */
 373                 dev->can.can_stats.bus_error++;
 374                 stats->rx_errors++;
 375
 376                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 377
 378                 switch (ecc & SJA1000_ECC_MASK) {
 379                 case SJA1000_ECC_BIT:
 380                         cf->data[2] |= CAN_ERR_PROT_BIT;
 381                         break;
 382                 case SJA1000_ECC_FORM:
 383                         cf->data[2] |= CAN_ERR_PROT_FORM;
 384                         break;
 385                 case SJA1000_ECC_STUFF:
 386                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 387                         break;
 388                 default:
 389                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 390                         cf->data[3] = ecc & SJA1000_ECC_SEG;
 391                         break;
 392                 }
 393
 394                 /* Error occurred during transmission? */
 395                 if ((ecc & SJA1000_ECC_DIR) == 0)
 396                         cf->data[2] |= CAN_ERR_PROT_TX;
 397
 398                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
 399                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
 400                         cf->data[1] = (txerr > rxerr) ?
 401                             CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
 402                 }
 403         } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
 404                 cf->can_id |= CAN_ERR_CRTL;
 405                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 406
 407                 stats->rx_over_errors++;
 408                 stats->rx_errors++;
 409         }
 410
 411         netif_rx(skb);
 412
 413         stats->rx_packets++;
 414         stats->rx_bytes += cf->can_dlc;
 415 }
 416
 417 /*
 418  * callback for bulk IN urb
 419  */
 420 static void ems_usb_read_bulk_callback(struct urb *urb)
 421 {
 422         struct ems_usb *dev = urb->context;
 423         struct net_device *netdev;
 424         int retval;
 425
 426         netdev = dev->netdev;
 427
 428         if (!netif_device_present(netdev))
 429                 return;
 430
 431         switch (urb->status) {
 432         case 0: /* success */
 433                 break;
 434
 435         case -ENOENT:
 436                 return;
 437
 438         default:
 439                 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
 440                 goto resubmit_urb;
 441         }
 442
 443         if (urb->actual_length > CPC_HEADER_SIZE) {
 444                 struct ems_cpc_msg *msg;
 445                 u8 *ibuf = urb->transfer_buffer;
 446                 u8 msg_count, again, start;
 447
 448                 msg_count = ibuf[0] & ~0x80;
 449                 again = ibuf[0] & 0x80;
 450
 451                 start = CPC_HEADER_SIZE;
 452
 453                 while (msg_count) {
 454                         msg = (struct ems_cpc_msg *)&ibuf[start];
 455
 456                         switch (msg->type) {
 457                         case CPC_MSG_TYPE_CAN_STATE:
 458                                 /* Process CAN state changes */
 459                                 ems_usb_rx_err(dev, msg);
 460                                 break;
 461
 462                         case CPC_MSG_TYPE_CAN_FRAME:
 463                         case CPC_MSG_TYPE_EXT_CAN_FRAME:
 464                         case CPC_MSG_TYPE_RTR_FRAME:
 465                         case CPC_MSG_TYPE_EXT_RTR_FRAME:
 466                                 ems_usb_rx_can_msg(dev, msg);
 467                                 break;
 468
 469                         case CPC_MSG_TYPE_CAN_FRAME_ERROR:
 470                                 /* Process errorframe */
 471                                 ems_usb_rx_err(dev, msg);
 472                                 break;
 473
 474                         case CPC_MSG_TYPE_OVERRUN:
 475                                 /* Message lost while receiving */
 476                                 ems_usb_rx_err(dev, msg);
 477                                 break;
 478                         }
 479
 480                         start += CPC_MSG_HEADER_LEN + msg->length;
 481                         msg_count--;
 482
 483                         if (start > urb->transfer_buffer_length) {
 484                                 netdev_err(netdev, "format error\n");
 485                                 break;
 486                         }
 487                 }
 488         }
 489
 490 resubmit_urb:
 491         usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 492                           urb->transfer_buffer, RX_BUFFER_SIZE,
 493                           ems_usb_read_bulk_callback, dev);
 494
 495         retval = usb_submit_urb(urb, GFP_ATOMIC);
 496
 497         if (retval == -ENODEV)
 498                 netif_device_detach(netdev);
 499         else if (retval)
 500                 netdev_err(netdev,
 501                            "failed resubmitting read bulk urb: %d\n", retval);
 502 }
 503
 504 /*
 505  * callback for bulk IN urb
 506  */
 507 static void ems_usb_write_bulk_callback(struct urb *urb)
 508 {
 509         struct ems_tx_urb_context *context = urb->context;
 510         struct ems_usb *dev;
 511         struct net_device *netdev;
 512
 513         BUG_ON(!context);
 514
 515         dev = context->dev;
 516         netdev = dev->netdev;
 517
 518         /* free up our allocated buffer */
 519         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 520                           urb->transfer_buffer, urb->transfer_dma);
 521
 522         atomic_dec(&dev->active_tx_urbs);
 523
 524         if (!netif_device_present(netdev))
 525                 return;
 526
 527         if (urb->status)
 528                 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 529
 530         netdev->trans_start = jiffies;
 531
 532         /* transmission complete interrupt */
 533         netdev->stats.tx_packets++;
 534         netdev->stats.tx_bytes += context->dlc;
 535
 536         can_get_echo_skb(netdev, context->echo_index);
 537
 538         /* Release context */
 539         context->echo_index = MAX_TX_URBS;
 540
 541 }
 542
 543 /*
 544  * Send the given CPC command synchronously
 545  */
 546 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 547 {
 548         int actual_length;
 549
 550         /* Copy payload */
 551         memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
 552                msg->length + CPC_MSG_HEADER_LEN);
 553
 554         /* Clear header */
 555         memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
 556
 557         return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
 558                             &dev->tx_msg_buffer[0],
 559                             msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
 560                             &actual_length, 1000);
 561 }
 562
 563 /*
 564  * Change CAN controllers' mode register
 565  */
 566 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
 567 {
 568         dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
 569
 570         return ems_usb_command_msg(dev, &dev->active_params);
 571 }
 572
 573 /*
 574  * Send a CPC_Control command to change behaviour when interface receives a CAN
 575  * message, bus error or CAN state changed notifications.
 576  */
 577 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
 578 {
 579         struct ems_cpc_msg cmd;
 580
 581         cmd.type = CPC_CMD_TYPE_CONTROL;
 582         cmd.length = CPC_MSG_HEADER_LEN + 1;
 583
 584         cmd.msgid = 0;
 585
 586         cmd.msg.generic[0] = val;
 587
 588         return ems_usb_command_msg(dev, &cmd);
 589 }
 590
 591 /*
 592  * Start interface
 593  */
 594 static int ems_usb_start(struct ems_usb *dev)
 595 {
 596         struct net_device *netdev = dev->netdev;
 597         int err, i;
 598
 599         dev->intr_in_buffer[0] = 0;
 600         dev->free_slots = 50; /* initial size */
 601
 602         for (i = 0; i < MAX_RX_URBS; i++) {
 603                 struct urb *urb = NULL;
 604                 u8 *buf = NULL;
 605
 606                 /* create a URB, and a buffer for it */
 607                 urb = usb_alloc_urb(0, GFP_KERNEL);
 608                 if (!urb) {
 609                         netdev_err(netdev, "No memory left for URBs\n");
 610                         err = -ENOMEM;
 611                         break;
 612                 }
 613
 614                 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 615                                          &urb->transfer_dma);
 616                 if (!buf) {
 617                         netdev_err(netdev, "No memory left for USB buffer\n");
 618                         usb_free_urb(urb);
 619                         err = -ENOMEM;
 620                         break;
 621                 }
 622
 623                 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 624                                   buf, RX_BUFFER_SIZE,
 625                                   ems_usb_read_bulk_callback, dev);
 626                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 627                 usb_anchor_urb(urb, &dev->rx_submitted);
 628
 629                 err = usb_submit_urb(urb, GFP_KERNEL);
 630                 if (err) {
 631                         usb_unanchor_urb(urb);
 632                         usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 633                                           urb->transfer_dma);
 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_unanchor_urb(urb);
 808                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 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 };
 893
 894 static const struct can_bittiming_const ems_usb_bittiming_const = {
 895         .name = "ems_usb",
 896         .tseg1_min = 1,
 897         .tseg1_max = 16,
 898         .tseg2_min = 1,
 899         .tseg2_max = 8,
 900         .sjw_max = 4,
 901         .brp_min = 1,
 902         .brp_max = 64,
 903         .brp_inc = 1,
 904 };
 905
 906 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 907 {
 908         struct ems_usb *dev = netdev_priv(netdev);
 909
 910         switch (mode) {
 911         case CAN_MODE_START:
 912                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
 913                         netdev_warn(netdev, "couldn't start device");
 914
 915                 if (netif_queue_stopped(netdev))
 916                         netif_wake_queue(netdev);
 917                 break;
 918
 919         default:
 920                 return -EOPNOTSUPP;
 921         }
 922
 923         return 0;
 924 }
 925
 926 static int ems_usb_set_bittiming(struct net_device *netdev)
 927 {
 928         struct ems_usb *dev = netdev_priv(netdev);
 929         struct can_bittiming *bt = &dev->can.bittiming;
 930         u8 btr0, btr1;
 931
 932         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 933         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 934                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 935         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 936                 btr1 |= 0x80;
 937
 938         netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 939
 940         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
 941         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
 942
 943         return ems_usb_command_msg(dev, &dev->active_params);
 944 }
 945
 946 static void init_params_sja1000(struct ems_cpc_msg *msg)
 947 {
 948         struct cpc_sja1000_params *sja1000 =
 949                 &msg->msg.can_params.cc_params.sja1000;
 950
 951         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
 952         msg->length = sizeof(struct cpc_can_params);
 953         msg->msgid = 0;
 954
 955         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
 956
 957         /* Acceptance filter open */
 958         sja1000->acc_code0 = 0x00;
 959         sja1000->acc_code1 = 0x00;
 960         sja1000->acc_code2 = 0x00;
 961         sja1000->acc_code3 = 0x00;
 962
 963         /* Acceptance filter open */
 964         sja1000->acc_mask0 = 0xFF;
 965         sja1000->acc_mask1 = 0xFF;
 966         sja1000->acc_mask2 = 0xFF;
 967         sja1000->acc_mask3 = 0xFF;
 968
 969         sja1000->btr0 = 0;
 970         sja1000->btr1 = 0;
 971
 972         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
 973         sja1000->mode = SJA1000_MOD_RM;
 974 }
 975
 976 /*
 977  * probe function for new CPC-USB devices
 978  */
 979 static int ems_usb_probe(struct usb_interface *intf,
 980                          const struct usb_device_id *id)
 981 {
 982         struct net_device *netdev;
 983         struct ems_usb *dev;
 984         int i, err = -ENOMEM;
 985
 986         netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
 987         if (!netdev) {
 988                 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
 989                 return -ENOMEM;
 990         }
 991
 992         dev = netdev_priv(netdev);
 993
 994         dev->udev = interface_to_usbdev(intf);
 995         dev->netdev = netdev;
 996
 997         dev->can.state = CAN_STATE_STOPPED;
 998         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
 999         dev->can.bittiming_const = &ems_usb_bittiming_const;
1000         dev->can.do_set_bittiming = ems_usb_set_bittiming;
1001         dev->can.do_set_mode = ems_usb_set_mode;
1002         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1003
1004         netdev->netdev_ops = &ems_usb_netdev_ops;
1005
1006         netdev->flags |= IFF_ECHO; /* we support local echo */
1007
1008         init_usb_anchor(&dev->rx_submitted);
1009
1010         init_usb_anchor(&dev->tx_submitted);
1011         atomic_set(&dev->active_tx_urbs, 0);
1012
1013         for (i = 0; i < MAX_TX_URBS; i++)
1014                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1015
1016         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1017         if (!dev->intr_urb) {
1018                 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1019                 goto cleanup_candev;
1020         }
1021
1022         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1023         if (!dev->intr_in_buffer)
1024                 goto cleanup_intr_urb;
1025
1026         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1027                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1028         if (!dev->tx_msg_buffer)
1029                 goto cleanup_intr_in_buffer;
1030
1031         usb_set_intfdata(intf, dev);
1032
1033         SET_NETDEV_DEV(netdev, &intf->dev);
1034
1035         init_params_sja1000(&dev->active_params);
1036
1037         err = ems_usb_command_msg(dev, &dev->active_params);
1038         if (err) {
1039                 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1040                 goto cleanup_tx_msg_buffer;
1041         }
1042
1043         err = register_candev(netdev);
1044         if (err) {
1045                 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1046                 goto cleanup_tx_msg_buffer;
1047         }
1048
1049         return 0;
1050
1051 cleanup_tx_msg_buffer:
1052         kfree(dev->tx_msg_buffer);
1053
1054 cleanup_intr_in_buffer:
1055         kfree(dev->intr_in_buffer);
1056
1057 cleanup_intr_urb:
1058         usb_free_urb(dev->intr_urb);
1059
1060 cleanup_candev:
1061         free_candev(netdev);
1062
1063         return err;
1064 }
1065
1066 /*
1067  * called by the usb core when the device is removed from the system
1068  */
1069 static void ems_usb_disconnect(struct usb_interface *intf)
1070 {
1071         struct ems_usb *dev = usb_get_intfdata(intf);
1072
1073         usb_set_intfdata(intf, NULL);
1074
1075         if (dev) {
1076                 unregister_netdev(dev->netdev);
1077                 free_candev(dev->netdev);
1078
1079                 unlink_all_urbs(dev);
1080
1081                 usb_free_urb(dev->intr_urb);
1082
1083                 kfree(dev->intr_in_buffer);
1084         }
1085 }
1086
1087 /* usb specific object needed to register this driver with the usb subsystem */
1088 static struct usb_driver ems_usb_driver = {
1089         .name = "ems_usb",
1090         .probe = ems_usb_probe,
1091         .disconnect = ems_usb_disconnect,
1092         .id_table = ems_usb_table,
1093 };
1094
1095 module_usb_driver(ems_usb_driver);