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 /*
 121  * CAN-Message representation in a CPC_MSG. Message object type is
 122  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
 123  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
 124  */
 125 struct cpc_can_msg {
 126         __le32 id;
 127         u8 length;
 128         u8 msg[8];
 129 };
 130
 131 /* Representation of the CAN parameters for the SJA1000 controller */
 132 struct cpc_sja1000_params {
 133         u8 mode;
 134         u8 acc_code0;
 135         u8 acc_code1;
 136         u8 acc_code2;
 137         u8 acc_code3;
 138         u8 acc_mask0;
 139         u8 acc_mask1;
 140         u8 acc_mask2;
 141         u8 acc_mask3;
 142         u8 btr0;
 143         u8 btr1;
 144         u8 outp_contr;
 145 };
 146
 147 /* CAN params message representation */
 148 struct cpc_can_params {
 149         u8 cc_type;
 150
 151         /* Will support M16C CAN controller in the future */
 152         union {
 153                 struct cpc_sja1000_params sja1000;
 154         } cc_params;
 155 };
 156
 157 /* Structure for confirmed message handling */
 158 struct cpc_confirm {
 159         u8 error; /* error code */
 160 };
 161
 162 /* Structure for overrun conditions */
 163 struct cpc_overrun {
 164         u8 event;
 165         u8 count;
 166 };
 167
 168 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
 169 struct cpc_sja1000_can_error {
 170         u8 ecc;
 171         u8 rxerr;
 172         u8 txerr;
 173 };
 174
 175 /* structure for CAN error conditions */
 176 struct cpc_can_error {
 177         u8 ecode;
 178
 179         struct {
 180                 u8 cc_type;
 181
 182                 /* Other controllers may also provide error code capture regs */
 183                 union {
 184                         struct cpc_sja1000_can_error sja1000;
 185                 } regs;
 186         } cc;
 187 };
 188
 189 /*
 190  * Structure containing RX/TX error counter. This structure is used to request
 191  * the values of the CAN controllers TX and RX error counter.
 192  */
 193 struct cpc_can_err_counter {
 194         u8 rx;
 195         u8 tx;
 196 };
 197
 198 /* Main message type used between library and application */
 199 struct __packed ems_cpc_msg {
 200         u8 type;        /* type of message */
 201         u8 length;      /* length of data within union 'msg' */
 202         u8 msgid;       /* confirmation handle */
 203         __le32 ts_sec;  /* timestamp in seconds */
 204         __le32 ts_nsec; /* timestamp in nano seconds */
 205
 206         union {
 207                 u8 generic[64];
 208                 struct cpc_can_msg can_msg;
 209                 struct cpc_can_params can_params;
 210                 struct cpc_confirm confirmation;
 211                 struct cpc_overrun overrun;
 212                 struct cpc_can_error error;
 213                 struct cpc_can_err_counter err_counter;
 214                 u8 can_state;
 215         } msg;
 216 };
 217
 218 /*
 219  * Table of devices that work with this driver
 220  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
 221  */
 222 static struct usb_device_id ems_usb_table[] = {
 223         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
 224         {} /* Terminating entry */
 225 };
 226
 227 MODULE_DEVICE_TABLE(usb, ems_usb_table);
 228
 229 #define RX_BUFFER_SIZE      64
 230 #define CPC_HEADER_SIZE     4
 231 #define INTR_IN_BUFFER_SIZE 4
 232
 233 #define MAX_RX_URBS 10
 234 #define MAX_TX_URBS 10
 235
 236 struct ems_usb;
 237
 238 struct ems_tx_urb_context {
 239         struct ems_usb *dev;
 240
 241         u32 echo_index;
 242         u8 dlc;
 243 };
 244
 245 struct ems_usb {
 246         struct can_priv can; /* must be the first member */
 247
 248         struct sk_buff *echo_skb[MAX_TX_URBS];
 249
 250         struct usb_device *udev;
 251         struct net_device *netdev;
 252
 253         atomic_t active_tx_urbs;
 254         struct usb_anchor tx_submitted;
 255         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
 256
 257         struct usb_anchor rx_submitted;
 258
 259         struct urb *intr_urb;
 260
 261         u8 *tx_msg_buffer;
 262
 263         u8 *intr_in_buffer;
 264         unsigned int free_slots; /* remember number of available slots */
 265
 266         struct ems_cpc_msg active_params; /* active controller parameters */
 267 };
 268
 269 static void ems_usb_read_interrupt_callback(struct urb *urb)
 270 {
 271         struct ems_usb *dev = urb->context;
 272         struct net_device *netdev = dev->netdev;
 273         int err;
 274
 275         if (!netif_device_present(netdev))
 276                 return;
 277
 278         switch (urb->status) {
 279         case 0:
 280                 dev->free_slots = dev->intr_in_buffer[1];
 281                 break;
 282
 283         case -ECONNRESET: /* unlink */
 284         case -ENOENT:
 285         case -ESHUTDOWN:
 286                 return;
 287
 288         default:
 289                 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
 290                 break;
 291         }
 292
 293         err = usb_submit_urb(urb, GFP_ATOMIC);
 294
 295         if (err == -ENODEV)
 296                 netif_device_detach(netdev);
 297         else if (err)
 298                 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
 299 }
 300
 301 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 302 {
 303         struct can_frame *cf;
 304         struct sk_buff *skb;
 305         int i;
 306         struct net_device_stats *stats = &dev->netdev->stats;
 307
 308         skb = alloc_can_skb(dev->netdev, &cf);
 309         if (skb == NULL)
 310                 return;
 311
 312         cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
 313         cf->can_dlc = get_can_dlc(msg->msg.can_msg.length & 0xF);
 314
 315         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
 316             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
 317                 cf->can_id |= CAN_EFF_FLAG;
 318
 319         if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
 320             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
 321                 cf->can_id |= CAN_RTR_FLAG;
 322         } else {
 323                 for (i = 0; i < cf->can_dlc; i++)
 324                         cf->data[i] = msg->msg.can_msg.msg[i];
 325         }
 326
 327         stats->rx_packets++;
 328         stats->rx_bytes += cf->can_dlc;
 329         netif_rx(skb);
 330 }
 331
 332 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 333 {
 334         struct can_frame *cf;
 335         struct sk_buff *skb;
 336         struct net_device_stats *stats = &dev->netdev->stats;
 337
 338         skb = alloc_can_err_skb(dev->netdev, &cf);
 339         if (skb == NULL)
 340                 return;
 341
 342         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
 343                 u8 state = msg->msg.can_state;
 344
 345                 if (state & SJA1000_SR_BS) {
 346                         dev->can.state = CAN_STATE_BUS_OFF;
 347                         cf->can_id |= CAN_ERR_BUSOFF;
 348
 349                         dev->can.can_stats.bus_off++;
 350                         can_bus_off(dev->netdev);
 351                 } else if (state & SJA1000_SR_ES) {
 352                         dev->can.state = CAN_STATE_ERROR_WARNING;
 353                         dev->can.can_stats.error_warning++;
 354                 } else {
 355                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 356                         dev->can.can_stats.error_passive++;
 357                 }
 358         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
 359                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
 360                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
 361                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
 362
 363                 /* bus error interrupt */
 364                 dev->can.can_stats.bus_error++;
 365                 stats->rx_errors++;
 366
 367                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 368
 369                 switch (ecc & SJA1000_ECC_MASK) {
 370                 case SJA1000_ECC_BIT:
 371                         cf->data[2] |= CAN_ERR_PROT_BIT;
 372                         break;
 373                 case SJA1000_ECC_FORM:
 374                         cf->data[2] |= CAN_ERR_PROT_FORM;
 375                         break;
 376                 case SJA1000_ECC_STUFF:
 377                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 378                         break;
 379                 default:
 380                         cf->data[3] = ecc & SJA1000_ECC_SEG;
 381                         break;
 382                 }
 383
 384                 /* Error occurred during transmission? */
 385                 if ((ecc & SJA1000_ECC_DIR) == 0)
 386                         cf->data[2] |= CAN_ERR_PROT_TX;
 387
 388                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
 389                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
 390                         cf->data[1] = (txerr > rxerr) ?
 391                             CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
 392                 }
 393         } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
 394                 cf->can_id |= CAN_ERR_CRTL;
 395                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 396
 397                 stats->rx_over_errors++;
 398                 stats->rx_errors++;
 399         }
 400
 401         stats->rx_packets++;
 402         stats->rx_bytes += cf->can_dlc;
 403         netif_rx(skb);
 404 }
 405
 406 /*
 407  * callback for bulk IN urb
 408  */
 409 static void ems_usb_read_bulk_callback(struct urb *urb)
 410 {
 411         struct ems_usb *dev = urb->context;
 412         struct net_device *netdev;
 413         int retval;
 414
 415         netdev = dev->netdev;
 416
 417         if (!netif_device_present(netdev))
 418                 return;
 419
 420         switch (urb->status) {
 421         case 0: /* success */
 422                 break;
 423
 424         case -ENOENT:
 425                 return;
 426
 427         default:
 428                 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
 429                 goto resubmit_urb;
 430         }
 431
 432         if (urb->actual_length > CPC_HEADER_SIZE) {
 433                 struct ems_cpc_msg *msg;
 434                 u8 *ibuf = urb->transfer_buffer;
 435                 u8 msg_count, start;
 436
 437                 msg_count = ibuf[0] & ~0x80;
 438
 439                 start = CPC_HEADER_SIZE;
 440
 441                 while (msg_count) {
 442                         msg = (struct ems_cpc_msg *)&ibuf[start];
 443
 444                         switch (msg->type) {
 445                         case CPC_MSG_TYPE_CAN_STATE:
 446                                 /* Process CAN state changes */
 447                                 ems_usb_rx_err(dev, msg);
 448                                 break;
 449
 450                         case CPC_MSG_TYPE_CAN_FRAME:
 451                         case CPC_MSG_TYPE_EXT_CAN_FRAME:
 452                         case CPC_MSG_TYPE_RTR_FRAME:
 453                         case CPC_MSG_TYPE_EXT_RTR_FRAME:
 454                                 ems_usb_rx_can_msg(dev, msg);
 455                                 break;
 456
 457                         case CPC_MSG_TYPE_CAN_FRAME_ERROR:
 458                                 /* Process errorframe */
 459                                 ems_usb_rx_err(dev, msg);
 460                                 break;
 461
 462                         case CPC_MSG_TYPE_OVERRUN:
 463                                 /* Message lost while receiving */
 464                                 ems_usb_rx_err(dev, msg);
 465                                 break;
 466                         }
 467
 468                         start += CPC_MSG_HEADER_LEN + msg->length;
 469                         msg_count--;
 470
 471                         if (start > urb->transfer_buffer_length) {
 472                                 netdev_err(netdev, "format error\n");
 473                                 break;
 474                         }
 475                 }
 476         }
 477
 478 resubmit_urb:
 479         usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 480                           urb->transfer_buffer, RX_BUFFER_SIZE,
 481                           ems_usb_read_bulk_callback, dev);
 482
 483         retval = usb_submit_urb(urb, GFP_ATOMIC);
 484
 485         if (retval == -ENODEV)
 486                 netif_device_detach(netdev);
 487         else if (retval)
 488                 netdev_err(netdev,
 489                            "failed resubmitting read bulk urb: %d\n", retval);
 490 }
 491
 492 /*
 493  * callback for bulk IN urb
 494  */
 495 static void ems_usb_write_bulk_callback(struct urb *urb)
 496 {
 497         struct ems_tx_urb_context *context = urb->context;
 498         struct ems_usb *dev;
 499         struct net_device *netdev;
 500
 501         BUG_ON(!context);
 502
 503         dev = context->dev;
 504         netdev = dev->netdev;
 505
 506         /* free up our allocated buffer */
 507         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 508                           urb->transfer_buffer, urb->transfer_dma);
 509
 510         atomic_dec(&dev->active_tx_urbs);
 511
 512         if (!netif_device_present(netdev))
 513                 return;
 514
 515         if (urb->status)
 516                 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 517
 518         netdev->trans_start = jiffies;
 519
 520         /* transmission complete interrupt */
 521         netdev->stats.tx_packets++;
 522         netdev->stats.tx_bytes += context->dlc;
 523
 524         can_get_echo_skb(netdev, context->echo_index);
 525
 526         /* Release context */
 527         context->echo_index = MAX_TX_URBS;
 528
 529         if (netif_queue_stopped(netdev))
 530                 netif_wake_queue(netdev);
 531 }
 532
 533 /*
 534  * Send the given CPC command synchronously
 535  */
 536 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 537 {
 538         int actual_length;
 539
 540         /* Copy payload */
 541         memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
 542                msg->length + CPC_MSG_HEADER_LEN);
 543
 544         /* Clear header */
 545         memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
 546
 547         return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
 548                             &dev->tx_msg_buffer[0],
 549                             msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
 550                             &actual_length, 1000);
 551 }
 552
 553 /*
 554  * Change CAN controllers' mode register
 555  */
 556 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
 557 {
 558         dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
 559
 560         return ems_usb_command_msg(dev, &dev->active_params);
 561 }
 562
 563 /*
 564  * Send a CPC_Control command to change behaviour when interface receives a CAN
 565  * message, bus error or CAN state changed notifications.
 566  */
 567 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
 568 {
 569         struct ems_cpc_msg cmd;
 570
 571         cmd.type = CPC_CMD_TYPE_CONTROL;
 572         cmd.length = CPC_MSG_HEADER_LEN + 1;
 573
 574         cmd.msgid = 0;
 575
 576         cmd.msg.generic[0] = val;
 577
 578         return ems_usb_command_msg(dev, &cmd);
 579 }
 580
 581 /*
 582  * Start interface
 583  */
 584 static int ems_usb_start(struct ems_usb *dev)
 585 {
 586         struct net_device *netdev = dev->netdev;
 587         int err, i;
 588
 589         dev->intr_in_buffer[0] = 0;
 590         dev->free_slots = 15; /* initial size */
 591
 592         for (i = 0; i < MAX_RX_URBS; i++) {
 593                 struct urb *urb = NULL;
 594                 u8 *buf = NULL;
 595
 596                 /* create a URB, and a buffer for it */
 597                 urb = usb_alloc_urb(0, GFP_KERNEL);
 598                 if (!urb) {
 599                         netdev_err(netdev, "No memory left for URBs\n");
 600                         err = -ENOMEM;
 601                         break;
 602                 }
 603
 604                 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 605                                          &urb->transfer_dma);
 606                 if (!buf) {
 607                         netdev_err(netdev, "No memory left for USB buffer\n");
 608                         usb_free_urb(urb);
 609                         err = -ENOMEM;
 610                         break;
 611                 }
 612
 613                 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 614                                   buf, RX_BUFFER_SIZE,
 615                                   ems_usb_read_bulk_callback, dev);
 616                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 617                 usb_anchor_urb(urb, &dev->rx_submitted);
 618
 619                 err = usb_submit_urb(urb, GFP_KERNEL);
 620                 if (err) {
 621                         usb_unanchor_urb(urb);
 622                         usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 623                                           urb->transfer_dma);
 624                         usb_free_urb(urb);
 625                         break;
 626                 }
 627
 628                 /* Drop reference, USB core will take care of freeing it */
 629                 usb_free_urb(urb);
 630         }
 631
 632         /* Did we submit any URBs */
 633         if (i == 0) {
 634                 netdev_warn(netdev, "couldn't setup read URBs\n");
 635                 return err;
 636         }
 637
 638         /* Warn if we've couldn't transmit all the URBs */
 639         if (i < MAX_RX_URBS)
 640                 netdev_warn(netdev, "rx performance may be slow\n");
 641
 642         /* Setup and start interrupt URB */
 643         usb_fill_int_urb(dev->intr_urb, dev->udev,
 644                          usb_rcvintpipe(dev->udev, 1),
 645                          dev->intr_in_buffer,
 646                          INTR_IN_BUFFER_SIZE,
 647                          ems_usb_read_interrupt_callback, dev, 1);
 648
 649         err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
 650         if (err) {
 651                 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
 652
 653                 return err;
 654         }
 655
 656         /* CPC-USB will transfer received message to host */
 657         err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
 658         if (err)
 659                 goto failed;
 660
 661         /* CPC-USB will transfer CAN state changes to host */
 662         err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
 663         if (err)
 664                 goto failed;
 665
 666         /* CPC-USB will transfer bus errors to host */
 667         err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
 668         if (err)
 669                 goto failed;
 670
 671         err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
 672         if (err)
 673                 goto failed;
 674
 675         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 676
 677         return 0;
 678
 679 failed:
 680         netdev_warn(netdev, "couldn't submit control: %d\n", err);
 681
 682         return err;
 683 }
 684
 685 static void unlink_all_urbs(struct ems_usb *dev)
 686 {
 687         int i;
 688
 689         usb_unlink_urb(dev->intr_urb);
 690
 691         usb_kill_anchored_urbs(&dev->rx_submitted);
 692
 693         usb_kill_anchored_urbs(&dev->tx_submitted);
 694         atomic_set(&dev->active_tx_urbs, 0);
 695
 696         for (i = 0; i < MAX_TX_URBS; i++)
 697                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
 698 }
 699
 700 static int ems_usb_open(struct net_device *netdev)
 701 {
 702         struct ems_usb *dev = netdev_priv(netdev);
 703         int err;
 704
 705         err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
 706         if (err)
 707                 return err;
 708
 709         /* common open */
 710         err = open_candev(netdev);
 711         if (err)
 712                 return err;
 713
 714         /* finally start device */
 715         err = ems_usb_start(dev);
 716         if (err) {
 717                 if (err == -ENODEV)
 718                         netif_device_detach(dev->netdev);
 719
 720                 netdev_warn(netdev, "couldn't start device: %d\n", err);
 721
 722                 close_candev(netdev);
 723
 724                 return err;
 725         }
 726
 727
 728         netif_start_queue(netdev);
 729
 730         return 0;
 731 }
 732
 733 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 734 {
 735         struct ems_usb *dev = netdev_priv(netdev);
 736         struct ems_tx_urb_context *context = NULL;
 737         struct net_device_stats *stats = &netdev->stats;
 738         struct can_frame *cf = (struct can_frame *)skb->data;
 739         struct ems_cpc_msg *msg;
 740         struct urb *urb;
 741         u8 *buf;
 742         int i, err;
 743         size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
 744                         + sizeof(struct cpc_can_msg);
 745
 746         if (can_dropped_invalid_skb(netdev, skb))
 747                 return NETDEV_TX_OK;
 748
 749         /* create a URB, and a buffer for it, and copy the data to the URB */
 750         urb = usb_alloc_urb(0, GFP_ATOMIC);
 751         if (!urb) {
 752                 netdev_err(netdev, "No memory left for URBs\n");
 753                 goto nomem;
 754         }
 755
 756         buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
 757         if (!buf) {
 758                 netdev_err(netdev, "No memory left for USB buffer\n");
 759                 usb_free_urb(urb);
 760                 goto nomem;
 761         }
 762
 763         msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
 764
 765         msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
 766         msg->msg.can_msg.length = cf->can_dlc;
 767
 768         if (cf->can_id & CAN_RTR_FLAG) {
 769                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 770                         CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
 771
 772                 msg->length = CPC_CAN_MSG_MIN_SIZE;
 773         } else {
 774                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 775                         CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
 776
 777                 for (i = 0; i < cf->can_dlc; i++)
 778                         msg->msg.can_msg.msg[i] = cf->data[i];
 779
 780                 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
 781         }
 782
 783         for (i = 0; i < MAX_TX_URBS; i++) {
 784                 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
 785                         context = &dev->tx_contexts[i];
 786                         break;
 787                 }
 788         }
 789
 790         /*
 791          * May never happen! When this happens we'd more URBs in flight as
 792          * allowed (MAX_TX_URBS).
 793          */
 794         if (!context) {
 795                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 796                 usb_free_urb(urb);
 797
 798                 netdev_warn(netdev, "couldn't find free context\n");
 799
 800                 return NETDEV_TX_BUSY;
 801         }
 802
 803         context->dev = dev;
 804         context->echo_index = i;
 805         context->dlc = cf->can_dlc;
 806
 807         usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 808                           size, ems_usb_write_bulk_callback, context);
 809         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 810         usb_anchor_urb(urb, &dev->tx_submitted);
 811
 812         can_put_echo_skb(skb, netdev, context->echo_index);
 813
 814         atomic_inc(&dev->active_tx_urbs);
 815
 816         err = usb_submit_urb(urb, GFP_ATOMIC);
 817         if (unlikely(err)) {
 818                 can_free_echo_skb(netdev, context->echo_index);
 819
 820                 usb_unanchor_urb(urb);
 821                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 822                 dev_kfree_skb(skb);
 823
 824                 atomic_dec(&dev->active_tx_urbs);
 825
 826                 if (err == -ENODEV) {
 827                         netif_device_detach(netdev);
 828                 } else {
 829                         netdev_warn(netdev, "failed tx_urb %d\n", err);
 830
 831                         stats->tx_dropped++;
 832                 }
 833         } else {
 834                 netdev->trans_start = jiffies;
 835
 836                 /* Slow down tx path */
 837                 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
 838                     dev->free_slots < 5) {
 839                         netif_stop_queue(netdev);
 840                 }
 841         }
 842
 843         /*
 844          * Release our reference to this URB, the USB core will eventually free
 845          * it entirely.
 846          */
 847         usb_free_urb(urb);
 848
 849         return NETDEV_TX_OK;
 850
 851 nomem:
 852         dev_kfree_skb(skb);
 853         stats->tx_dropped++;
 854
 855         return NETDEV_TX_OK;
 856 }
 857
 858 static int ems_usb_close(struct net_device *netdev)
 859 {
 860         struct ems_usb *dev = netdev_priv(netdev);
 861
 862         /* Stop polling */
 863         unlink_all_urbs(dev);
 864
 865         netif_stop_queue(netdev);
 866
 867         /* Set CAN controller to reset mode */
 868         if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
 869                 netdev_warn(netdev, "couldn't stop device");
 870
 871         close_candev(netdev);
 872
 873         return 0;
 874 }
 875
 876 static const struct net_device_ops ems_usb_netdev_ops = {
 877         .ndo_open = ems_usb_open,
 878         .ndo_stop = ems_usb_close,
 879         .ndo_start_xmit = ems_usb_start_xmit,
 880         .ndo_change_mtu = can_change_mtu,
 881 };
 882
 883 static const struct can_bittiming_const ems_usb_bittiming_const = {
 884         .name = "ems_usb",
 885         .tseg1_min = 1,
 886         .tseg1_max = 16,
 887         .tseg2_min = 1,
 888         .tseg2_max = 8,
 889         .sjw_max = 4,
 890         .brp_min = 1,
 891         .brp_max = 64,
 892         .brp_inc = 1,
 893 };
 894
 895 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 896 {
 897         struct ems_usb *dev = netdev_priv(netdev);
 898
 899         switch (mode) {
 900         case CAN_MODE_START:
 901                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
 902                         netdev_warn(netdev, "couldn't start device");
 903
 904                 if (netif_queue_stopped(netdev))
 905                         netif_wake_queue(netdev);
 906                 break;
 907
 908         default:
 909                 return -EOPNOTSUPP;
 910         }
 911
 912         return 0;
 913 }
 914
 915 static int ems_usb_set_bittiming(struct net_device *netdev)
 916 {
 917         struct ems_usb *dev = netdev_priv(netdev);
 918         struct can_bittiming *bt = &dev->can.bittiming;
 919         u8 btr0, btr1;
 920
 921         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 922         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 923                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 924         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 925                 btr1 |= 0x80;
 926
 927         netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 928
 929         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
 930         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
 931
 932         return ems_usb_command_msg(dev, &dev->active_params);
 933 }
 934
 935 static void init_params_sja1000(struct ems_cpc_msg *msg)
 936 {
 937         struct cpc_sja1000_params *sja1000 =
 938                 &msg->msg.can_params.cc_params.sja1000;
 939
 940         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
 941         msg->length = sizeof(struct cpc_can_params);
 942         msg->msgid = 0;
 943
 944         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
 945
 946         /* Acceptance filter open */
 947         sja1000->acc_code0 = 0x00;
 948         sja1000->acc_code1 = 0x00;
 949         sja1000->acc_code2 = 0x00;
 950         sja1000->acc_code3 = 0x00;
 951
 952         /* Acceptance filter open */
 953         sja1000->acc_mask0 = 0xFF;
 954         sja1000->acc_mask1 = 0xFF;
 955         sja1000->acc_mask2 = 0xFF;
 956         sja1000->acc_mask3 = 0xFF;
 957
 958         sja1000->btr0 = 0;
 959         sja1000->btr1 = 0;
 960
 961         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
 962         sja1000->mode = SJA1000_MOD_RM;
 963 }
 964
 965 /*
 966  * probe function for new CPC-USB devices
 967  */
 968 static int ems_usb_probe(struct usb_interface *intf,
 969                          const struct usb_device_id *id)
 970 {
 971         struct net_device *netdev;
 972         struct ems_usb *dev;
 973         int i, err = -ENOMEM;
 974
 975         netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
 976         if (!netdev) {
 977                 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
 978                 return -ENOMEM;
 979         }
 980
 981         dev = netdev_priv(netdev);
 982
 983         dev->udev = interface_to_usbdev(intf);
 984         dev->netdev = netdev;
 985
 986         dev->can.state = CAN_STATE_STOPPED;
 987         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
 988         dev->can.bittiming_const = &ems_usb_bittiming_const;
 989         dev->can.do_set_bittiming = ems_usb_set_bittiming;
 990         dev->can.do_set_mode = ems_usb_set_mode;
 991         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 992
 993         netdev->netdev_ops = &ems_usb_netdev_ops;
 994
 995         netdev->flags |= IFF_ECHO; /* we support local echo */
 996
 997         init_usb_anchor(&dev->rx_submitted);
 998
 999         init_usb_anchor(&dev->tx_submitted);
1000         atomic_set(&dev->active_tx_urbs, 0);
1001
1002         for (i = 0; i < MAX_TX_URBS; i++)
1003                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1004
1005         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1006         if (!dev->intr_urb) {
1007                 dev_err(&intf->dev, "Couldn't alloc intr URB\n");
1008                 goto cleanup_candev;
1009         }
1010
1011         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1012         if (!dev->intr_in_buffer)
1013                 goto cleanup_intr_urb;
1014
1015         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1016                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1017         if (!dev->tx_msg_buffer)
1018                 goto cleanup_intr_in_buffer;
1019
1020         usb_set_intfdata(intf, dev);
1021
1022         SET_NETDEV_DEV(netdev, &intf->dev);
1023
1024         init_params_sja1000(&dev->active_params);
1025
1026         err = ems_usb_command_msg(dev, &dev->active_params);
1027         if (err) {
1028                 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1029                 goto cleanup_tx_msg_buffer;
1030         }
1031
1032         err = register_candev(netdev);
1033         if (err) {
1034                 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1035                 goto cleanup_tx_msg_buffer;
1036         }
1037
1038         return 0;
1039
1040 cleanup_tx_msg_buffer:
1041         kfree(dev->tx_msg_buffer);
1042
1043 cleanup_intr_in_buffer:
1044         kfree(dev->intr_in_buffer);
1045
1046 cleanup_intr_urb:
1047         usb_free_urb(dev->intr_urb);
1048
1049 cleanup_candev:
1050         free_candev(netdev);
1051
1052         return err;
1053 }
1054
1055 /*
1056  * called by the usb core when the device is removed from the system
1057  */
1058 static void ems_usb_disconnect(struct usb_interface *intf)
1059 {
1060         struct ems_usb *dev = usb_get_intfdata(intf);
1061
1062         usb_set_intfdata(intf, NULL);
1063
1064         if (dev) {
1065                 unregister_netdev(dev->netdev);
1066                 free_candev(dev->netdev);
1067
1068                 unlink_all_urbs(dev);
1069
1070                 usb_free_urb(dev->intr_urb);
1071
1072                 kfree(dev->intr_in_buffer);
1073         }
1074 }
1075
1076 /* usb specific object needed to register this driver with the usb subsystem */
1077 static struct usb_driver ems_usb_driver = {
1078         .name = "ems_usb",
1079         .probe = ems_usb_probe,
1080         .disconnect = ems_usb_disconnect,
1081         .id_table = ems_usb_table,
1082 };
1083
1084 module_usb_driver(ems_usb_driver);