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 /*
 122  * CAN-Message representation in a CPC_MSG. Message object type is
 123  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
 124  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
 125  */
 126 struct cpc_can_msg {
 127         u32 id;
 128         u8 length;
 129         u8 msg[8];
 130 };
 131
 132 /* Representation of the CAN parameters for the SJA1000 controller */
 133 struct cpc_sja1000_params {
 134         u8 mode;
 135         u8 acc_code0;
 136         u8 acc_code1;
 137         u8 acc_code2;
 138         u8 acc_code3;
 139         u8 acc_mask0;
 140         u8 acc_mask1;
 141         u8 acc_mask2;
 142         u8 acc_mask3;
 143         u8 btr0;
 144         u8 btr1;
 145         u8 outp_contr;
 146 };
 147
 148 /* CAN params message representation */
 149 struct cpc_can_params {
 150         u8 cc_type;
 151
 152         /* Will support M16C CAN controller in the future */
 153         union {
 154                 struct cpc_sja1000_params sja1000;
 155         } cc_params;
 156 };
 157
 158 /* Structure for confirmed message handling */
 159 struct cpc_confirm {
 160         u8 error; /* error code */
 161 };
 162
 163 /* Structure for overrun conditions */
 164 struct cpc_overrun {
 165         u8 event;
 166         u8 count;
 167 };
 168
 169 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
 170 struct cpc_sja1000_can_error {
 171         u8 ecc;
 172         u8 rxerr;
 173         u8 txerr;
 174 };
 175
 176 /* structure for CAN error conditions */
 177 struct cpc_can_error {
 178         u8 ecode;
 179
 180         struct {
 181                 u8 cc_type;
 182
 183                 /* Other controllers may also provide error code capture regs */
 184                 union {
 185                         struct cpc_sja1000_can_error sja1000;
 186                 } regs;
 187         } cc;
 188 };
 189
 190 /*
 191  * Structure containing RX/TX error counter. This structure is used to request
 192  * the values of the CAN controllers TX and RX error counter.
 193  */
 194 struct cpc_can_err_counter {
 195         u8 rx;
 196         u8 tx;
 197 };
 198
 199 /* Main message type used between library and application */
 200 struct __attribute__ ((packed)) ems_cpc_msg {
 201         u8 type;        /* type of message */
 202         u8 length;      /* length of data within union 'msg' */
 203         u8 msgid;       /* confirmation handle */
 204         u32 ts_sec;     /* timestamp in seconds */
 205         u32 ts_nsec;    /* timestamp in nano seconds */
 206
 207         union {
 208                 u8 generic[64];
 209                 struct cpc_can_msg can_msg;
 210                 struct cpc_can_params can_params;
 211                 struct cpc_confirm confirmation;
 212                 struct cpc_overrun overrun;
 213                 struct cpc_can_error error;
 214                 struct cpc_can_err_counter err_counter;
 215                 u8 can_state;
 216         } msg;
 217 };
 218
 219 /*
 220  * Table of devices that work with this driver
 221  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
 222  */
 223 static struct usb_device_id ems_usb_table[] = {
 224         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
 225         {} /* Terminating entry */
 226 };
 227
 228 MODULE_DEVICE_TABLE(usb, ems_usb_table);
 229
 230 #define RX_BUFFER_SIZE      64
 231 #define CPC_HEADER_SIZE     4
 232 #define INTR_IN_BUFFER_SIZE 4
 233
 234 #define MAX_RX_URBS 10
 235 #define MAX_TX_URBS CAN_ECHO_SKB_MAX
 236
 237 struct ems_usb;
 238
 239 struct ems_tx_urb_context {
 240         struct ems_usb *dev;
 241
 242         u32 echo_index;
 243         u8 dlc;
 244 };
 245
 246 struct ems_usb {
 247         struct can_priv can; /* must be the first member */
 248         int open_time;
 249
 250         struct sk_buff *echo_skb[MAX_TX_URBS];
 251
 252         struct usb_device *udev;
 253         struct net_device *netdev;
 254
 255         atomic_t active_tx_urbs;
 256         struct usb_anchor tx_submitted;
 257         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
 258
 259         struct usb_anchor rx_submitted;
 260
 261         struct urb *intr_urb;
 262
 263         u8 *tx_msg_buffer;
 264
 265         u8 *intr_in_buffer;
 266         unsigned int free_slots; /* remember number of available slots */
 267
 268         struct ems_cpc_msg active_params; /* active controller parameters */
 269 };
 270
 271 static void ems_usb_read_interrupt_callback(struct urb *urb)
 272 {
 273         struct ems_usb *dev = urb->context;
 274         struct net_device *netdev = dev->netdev;
 275         int err;
 276
 277         if (!netif_device_present(netdev))
 278                 return;
 279
 280         switch (urb->status) {
 281         case 0:
 282                 dev->free_slots = dev->intr_in_buffer[1];
 283                 break;
 284
 285         case -ECONNRESET: /* unlink */
 286         case -ENOENT:
 287         case -ESHUTDOWN:
 288                 return;
 289
 290         default:
 291                 dev_info(netdev->dev.parent, "Rx interrupt aborted %d\n",
 292                          urb->status);
 293                 break;
 294         }
 295
 296         err = usb_submit_urb(urb, GFP_ATOMIC);
 297
 298         if (err == -ENODEV)
 299                 netif_device_detach(netdev);
 300         else if (err)
 301                 dev_err(netdev->dev.parent,
 302                         "failed resubmitting intr urb: %d\n", err);
 303
 304         return;
 305 }
 306
 307 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 308 {
 309         struct can_frame *cf;
 310         struct sk_buff *skb;
 311         int i;
 312         struct net_device_stats *stats = &dev->netdev->stats;
 313
 314         skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame));
 315         if (skb == NULL)
 316                 return;
 317
 318         skb->protocol = htons(ETH_P_CAN);
 319
 320         cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
 321
 322         cf->can_id = msg->msg.can_msg.id;
 323         cf->can_dlc = min_t(u8, msg->msg.can_msg.length, 8);
 324
 325         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME
 326             || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
 327                 cf->can_id |= CAN_EFF_FLAG;
 328
 329         if (msg->type == CPC_MSG_TYPE_RTR_FRAME
 330             || msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
 331                 cf->can_id |= CAN_RTR_FLAG;
 332         } else {
 333                 for (i = 0; i < cf->can_dlc; i++)
 334                         cf->data[i] = msg->msg.can_msg.msg[i];
 335         }
 336
 337         netif_rx(skb);
 338
 339         stats->rx_packets++;
 340         stats->rx_bytes += cf->can_dlc;
 341 }
 342
 343 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 344 {
 345         struct can_frame *cf;
 346         struct sk_buff *skb;
 347         struct net_device_stats *stats = &dev->netdev->stats;
 348
 349         skb = netdev_alloc_skb(dev->netdev, sizeof(struct can_frame));
 350         if (skb == NULL)
 351                 return;
 352
 353         skb->protocol = htons(ETH_P_CAN);
 354
 355         cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
 356         memset(cf, 0, sizeof(struct can_frame));
 357
 358         cf->can_id = CAN_ERR_FLAG;
 359         cf->can_dlc = CAN_ERR_DLC;
 360
 361         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
 362                 u8 state = msg->msg.can_state;
 363
 364                 if (state & SJA1000_SR_BS) {
 365                         dev->can.state = CAN_STATE_BUS_OFF;
 366                         cf->can_id |= CAN_ERR_BUSOFF;
 367
 368                         can_bus_off(dev->netdev);
 369                 } else if (state & SJA1000_SR_ES) {
 370                         dev->can.state = CAN_STATE_ERROR_WARNING;
 371                         dev->can.can_stats.error_warning++;
 372                 } else {
 373                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 374                         dev->can.can_stats.error_passive++;
 375                 }
 376         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
 377                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
 378                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
 379                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
 380
 381                 /* bus error interrupt */
 382                 dev->can.can_stats.bus_error++;
 383                 stats->rx_errors++;
 384
 385                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 386
 387                 switch (ecc & SJA1000_ECC_MASK) {
 388                 case SJA1000_ECC_BIT:
 389                         cf->data[2] |= CAN_ERR_PROT_BIT;
 390                         break;
 391                 case SJA1000_ECC_FORM:
 392                         cf->data[2] |= CAN_ERR_PROT_FORM;
 393                         break;
 394                 case SJA1000_ECC_STUFF:
 395                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 396                         break;
 397                 default:
 398                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 399                         cf->data[3] = ecc & SJA1000_ECC_SEG;
 400                         break;
 401                 }
 402
 403                 /* Error occured during transmission? */
 404                 if ((ecc & SJA1000_ECC_DIR) == 0)
 405                         cf->data[2] |= CAN_ERR_PROT_TX;
 406
 407                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
 408                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
 409                         cf->data[1] = (txerr > rxerr) ?
 410                             CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
 411                 }
 412         } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
 413                 cf->can_id |= CAN_ERR_CRTL;
 414                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 415
 416                 stats->rx_over_errors++;
 417                 stats->rx_errors++;
 418         }
 419
 420         netif_rx(skb);
 421
 422         stats->rx_packets++;
 423         stats->rx_bytes += cf->can_dlc;
 424 }
 425
 426 /*
 427  * callback for bulk IN urb
 428  */
 429 static void ems_usb_read_bulk_callback(struct urb *urb)
 430 {
 431         struct ems_usb *dev = urb->context;
 432         struct net_device *netdev;
 433         int retval;
 434
 435         netdev = dev->netdev;
 436
 437         if (!netif_device_present(netdev))
 438                 return;
 439
 440         switch (urb->status) {
 441         case 0: /* success */
 442                 break;
 443
 444         case -ENOENT:
 445                 return;
 446
 447         default:
 448                 dev_info(netdev->dev.parent, "Rx URB aborted (%d)\n",
 449                          urb->status);
 450                 goto resubmit_urb;
 451         }
 452
 453         if (urb->actual_length > CPC_HEADER_SIZE) {
 454                 struct ems_cpc_msg *msg;
 455                 u8 *ibuf = urb->transfer_buffer;
 456                 u8 msg_count, again, start;
 457
 458                 msg_count = ibuf[0] & ~0x80;
 459                 again = ibuf[0] & 0x80;
 460
 461                 start = CPC_HEADER_SIZE;
 462
 463                 while (msg_count) {
 464                         msg = (struct ems_cpc_msg *)&ibuf[start];
 465
 466                         switch (msg->type) {
 467                         case CPC_MSG_TYPE_CAN_STATE:
 468                                 /* Process CAN state changes */
 469                                 ems_usb_rx_err(dev, msg);
 470                                 break;
 471
 472                         case CPC_MSG_TYPE_CAN_FRAME:
 473                         case CPC_MSG_TYPE_EXT_CAN_FRAME:
 474                         case CPC_MSG_TYPE_RTR_FRAME:
 475                         case CPC_MSG_TYPE_EXT_RTR_FRAME:
 476                                 ems_usb_rx_can_msg(dev, msg);
 477                                 break;
 478
 479                         case CPC_MSG_TYPE_CAN_FRAME_ERROR:
 480                                 /* Process errorframe */
 481                                 ems_usb_rx_err(dev, msg);
 482                                 break;
 483
 484                         case CPC_MSG_TYPE_OVERRUN:
 485                                 /* Message lost while receiving */
 486                                 ems_usb_rx_err(dev, msg);
 487                                 break;
 488                         }
 489
 490                         start += CPC_MSG_HEADER_LEN + msg->length;
 491                         msg_count--;
 492
 493                         if (start > urb->transfer_buffer_length) {
 494                                 dev_err(netdev->dev.parent, "format error\n");
 495                                 break;
 496                         }
 497                 }
 498         }
 499
 500 resubmit_urb:
 501         usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 502                           urb->transfer_buffer, RX_BUFFER_SIZE,
 503                           ems_usb_read_bulk_callback, dev);
 504
 505         retval = usb_submit_urb(urb, GFP_ATOMIC);
 506
 507         if (retval == -ENODEV)
 508                 netif_device_detach(netdev);
 509         else if (retval)
 510                 dev_err(netdev->dev.parent,
 511                         "failed resubmitting read bulk urb: %d\n", retval);
 512
 513         return;
 514 }
 515
 516 /*
 517  * callback for bulk IN urb
 518  */
 519 static void ems_usb_write_bulk_callback(struct urb *urb)
 520 {
 521         struct ems_tx_urb_context *context = urb->context;
 522         struct ems_usb *dev;
 523         struct net_device *netdev;
 524
 525         BUG_ON(!context);
 526
 527         dev = context->dev;
 528         netdev = dev->netdev;
 529
 530         /* free up our allocated buffer */
 531         usb_buffer_free(urb->dev, urb->transfer_buffer_length,
 532                         urb->transfer_buffer, urb->transfer_dma);
 533
 534         atomic_dec(&dev->active_tx_urbs);
 535
 536         if (!netif_device_present(netdev))
 537                 return;
 538
 539         if (urb->status)
 540                 dev_info(netdev->dev.parent, "Tx URB aborted (%d)\n",
 541                          urb->status);
 542
 543         netdev->trans_start = jiffies;
 544
 545         /* transmission complete interrupt */
 546         netdev->stats.tx_packets++;
 547         netdev->stats.tx_bytes += context->dlc;
 548
 549         can_get_echo_skb(netdev, context->echo_index);
 550
 551         /* Release context */
 552         context->echo_index = MAX_TX_URBS;
 553
 554         if (netif_queue_stopped(netdev))
 555                 netif_wake_queue(netdev);
 556 }
 557
 558 /*
 559  * Send the given CPC command synchronously
 560  */
 561 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 562 {
 563         int actual_length;
 564
 565         /* Copy payload */
 566         memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
 567                msg->length + CPC_MSG_HEADER_LEN);
 568
 569         /* Clear header */
 570         memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
 571
 572         return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
 573                             &dev->tx_msg_buffer[0],
 574                             msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
 575                             &actual_length, 1000);
 576 }
 577
 578 /*
 579  * Change CAN controllers' mode register
 580  */
 581 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
 582 {
 583         dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
 584
 585         return ems_usb_command_msg(dev, &dev->active_params);
 586 }
 587
 588 /*
 589  * Send a CPC_Control command to change behaviour when interface receives a CAN
 590  * message, bus error or CAN state changed notifications.
 591  */
 592 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
 593 {
 594         struct ems_cpc_msg cmd;
 595
 596         cmd.type = CPC_CMD_TYPE_CONTROL;
 597         cmd.length = CPC_MSG_HEADER_LEN + 1;
 598
 599         cmd.msgid = 0;
 600
 601         cmd.msg.generic[0] = val;
 602
 603         return ems_usb_command_msg(dev, &cmd);
 604 }
 605
 606 /*
 607  * Start interface
 608  */
 609 static int ems_usb_start(struct ems_usb *dev)
 610 {
 611         struct net_device *netdev = dev->netdev;
 612         int err, i;
 613
 614         dev->intr_in_buffer[0] = 0;
 615         dev->free_slots = 15; /* initial size */
 616
 617         for (i = 0; i < MAX_RX_URBS; i++) {
 618                 struct urb *urb = NULL;
 619                 u8 *buf = NULL;
 620
 621                 /* create a URB, and a buffer for it */
 622                 urb = usb_alloc_urb(0, GFP_KERNEL);
 623                 if (!urb) {
 624                         dev_err(netdev->dev.parent,
 625                                 "No memory left for URBs\n");
 626                         return -ENOMEM;
 627                 }
 628
 629                 buf = usb_buffer_alloc(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 630                                        &urb->transfer_dma);
 631                 if (!buf) {
 632                         dev_err(netdev->dev.parent,
 633                                 "No memory left for USB buffer\n");
 634                         usb_free_urb(urb);
 635                         return -ENOMEM;
 636                 }
 637
 638                 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 639                                   buf, RX_BUFFER_SIZE,
 640                                   ems_usb_read_bulk_callback, dev);
 641                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 642                 usb_anchor_urb(urb, &dev->rx_submitted);
 643
 644                 err = usb_submit_urb(urb, GFP_KERNEL);
 645                 if (err) {
 646                         if (err == -ENODEV)
 647                                 netif_device_detach(dev->netdev);
 648
 649                         usb_unanchor_urb(urb);
 650                         usb_buffer_free(dev->udev, RX_BUFFER_SIZE, buf,
 651                                         urb->transfer_dma);
 652                         break;
 653                 }
 654
 655                 /* Drop reference, USB core will take care of freeing it */
 656                 usb_free_urb(urb);
 657         }
 658
 659         /* Did we submit any URBs */
 660         if (i == 0) {
 661                 dev_warn(netdev->dev.parent, "couldn't setup read URBs\n");
 662                 return err;
 663         }
 664
 665         /* Warn if we've couldn't transmit all the URBs */
 666         if (i < MAX_RX_URBS)
 667                 dev_warn(netdev->dev.parent, "rx performance may be slow\n");
 668
 669         /* Setup and start interrupt URB */
 670         usb_fill_int_urb(dev->intr_urb, dev->udev,
 671                          usb_rcvintpipe(dev->udev, 1),
 672                          dev->intr_in_buffer,
 673                          INTR_IN_BUFFER_SIZE,
 674                          ems_usb_read_interrupt_callback, dev, 1);
 675
 676         err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
 677         if (err) {
 678                 if (err == -ENODEV)
 679                         netif_device_detach(dev->netdev);
 680
 681                 dev_warn(netdev->dev.parent, "intr URB submit failed: %d\n",
 682                          err);
 683
 684                 return err;
 685         }
 686
 687         /* CPC-USB will transfer received message to host */
 688         err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
 689         if (err)
 690                 goto failed;
 691
 692         /* CPC-USB will transfer CAN state changes to host */
 693         err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
 694         if (err)
 695                 goto failed;
 696
 697         /* CPC-USB will transfer bus errors to host */
 698         err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
 699         if (err)
 700                 goto failed;
 701
 702         err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
 703         if (err)
 704                 goto failed;
 705
 706         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 707
 708         return 0;
 709
 710 failed:
 711         if (err == -ENODEV)
 712                 netif_device_detach(dev->netdev);
 713
 714         dev_warn(netdev->dev.parent, "couldn't submit control: %d\n", err);
 715
 716         return err;
 717 }
 718
 719 static void unlink_all_urbs(struct ems_usb *dev)
 720 {
 721         int i;
 722
 723         usb_unlink_urb(dev->intr_urb);
 724
 725         usb_kill_anchored_urbs(&dev->rx_submitted);
 726
 727         usb_kill_anchored_urbs(&dev->tx_submitted);
 728         atomic_set(&dev->active_tx_urbs, 0);
 729
 730         for (i = 0; i < MAX_TX_URBS; i++)
 731                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
 732 }
 733
 734 static int ems_usb_open(struct net_device *netdev)
 735 {
 736         struct ems_usb *dev = netdev_priv(netdev);
 737         int err;
 738
 739         err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
 740         if (err)
 741                 return err;
 742
 743         /* common open */
 744         err = open_candev(netdev);
 745         if (err)
 746                 return err;
 747
 748         /* finally start device */
 749         err = ems_usb_start(dev);
 750         if (err) {
 751                 if (err == -ENODEV)
 752                         netif_device_detach(dev->netdev);
 753
 754                 dev_warn(netdev->dev.parent, "couldn't start device: %d\n",
 755                          err);
 756
 757                 close_candev(netdev);
 758
 759                 return err;
 760         }
 761
 762         dev->open_time = jiffies;
 763
 764         netif_start_queue(netdev);
 765
 766         return 0;
 767 }
 768
 769 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 770 {
 771         struct ems_usb *dev = netdev_priv(netdev);
 772         struct ems_tx_urb_context *context = NULL;
 773         struct net_device_stats *stats = &netdev->stats;
 774         struct can_frame *cf = (struct can_frame *)skb->data;
 775         struct ems_cpc_msg *msg;
 776         struct urb *urb;
 777         u8 *buf;
 778         int i, err;
 779         size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
 780                         + sizeof(struct cpc_can_msg);
 781
 782         /* create a URB, and a buffer for it, and copy the data to the URB */
 783         urb = usb_alloc_urb(0, GFP_ATOMIC);
 784         if (!urb) {
 785                 dev_err(netdev->dev.parent, "No memory left for URBs\n");
 786                 goto nomem;
 787         }
 788
 789         buf = usb_buffer_alloc(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
 790         if (!buf) {
 791                 dev_err(netdev->dev.parent, "No memory left for USB buffer\n");
 792                 usb_free_urb(urb);
 793                 goto nomem;
 794         }
 795
 796         msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
 797
 798         msg->msg.can_msg.id = cf->can_id & CAN_ERR_MASK;
 799         msg->msg.can_msg.length = cf->can_dlc;
 800
 801         if (cf->can_id & CAN_RTR_FLAG) {
 802                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 803                         CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
 804
 805                 msg->length = CPC_CAN_MSG_MIN_SIZE;
 806         } else {
 807                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 808                         CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
 809
 810                 for (i = 0; i < cf->can_dlc; i++)
 811                         msg->msg.can_msg.msg[i] = cf->data[i];
 812
 813                 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->can_dlc;
 814         }
 815
 816         for (i = 0; i < MAX_TX_URBS; i++) {
 817                 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
 818                         context = &dev->tx_contexts[i];
 819                         break;
 820                 }
 821         }
 822
 823         /*
 824          * May never happen! When this happens we'd more URBs in flight as
 825          * allowed (MAX_TX_URBS).
 826          */
 827         if (!context) {
 828                 usb_unanchor_urb(urb);
 829                 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
 830
 831                 dev_warn(netdev->dev.parent, "couldn't find free context\n");
 832
 833                 return NETDEV_TX_BUSY;
 834         }
 835
 836         context->dev = dev;
 837         context->echo_index = i;
 838         context->dlc = cf->can_dlc;
 839
 840         usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 841                           size, ems_usb_write_bulk_callback, context);
 842         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 843         usb_anchor_urb(urb, &dev->tx_submitted);
 844
 845         can_put_echo_skb(skb, netdev, context->echo_index);
 846
 847         atomic_inc(&dev->active_tx_urbs);
 848
 849         err = usb_submit_urb(urb, GFP_ATOMIC);
 850         if (unlikely(err)) {
 851                 can_free_echo_skb(netdev, context->echo_index);
 852
 853                 usb_unanchor_urb(urb);
 854                 usb_buffer_free(dev->udev, size, buf, urb->transfer_dma);
 855                 dev_kfree_skb(skb);
 856
 857                 atomic_dec(&dev->active_tx_urbs);
 858
 859                 if (err == -ENODEV) {
 860                         netif_device_detach(netdev);
 861                 } else {
 862                         dev_warn(netdev->dev.parent, "failed tx_urb %d\n", err);
 863
 864                         stats->tx_dropped++;
 865                 }
 866         } else {
 867                 netdev->trans_start = jiffies;
 868
 869                 /* Slow down tx path */
 870                 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
 871                     dev->free_slots < 5) {
 872                         netif_stop_queue(netdev);
 873                 }
 874         }
 875
 876         /*
 877          * Release our reference to this URB, the USB core will eventually free
 878          * it entirely.
 879          */
 880         usb_free_urb(urb);
 881
 882         return NETDEV_TX_OK;
 883
 884 nomem:
 885         if (skb)
 886                 dev_kfree_skb(skb);
 887
 888         stats->tx_dropped++;
 889
 890         return NETDEV_TX_OK;
 891 }
 892
 893 static int ems_usb_close(struct net_device *netdev)
 894 {
 895         struct ems_usb *dev = netdev_priv(netdev);
 896
 897         /* Stop polling */
 898         unlink_all_urbs(dev);
 899
 900         netif_stop_queue(netdev);
 901
 902         /* Set CAN controller to reset mode */
 903         if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
 904                 dev_warn(netdev->dev.parent, "couldn't stop device");
 905
 906         close_candev(netdev);
 907
 908         dev->open_time = 0;
 909
 910         return 0;
 911 }
 912
 913 static const struct net_device_ops ems_usb_netdev_ops = {
 914         .ndo_open = ems_usb_open,
 915         .ndo_stop = ems_usb_close,
 916         .ndo_start_xmit = ems_usb_start_xmit,
 917 };
 918
 919 static struct can_bittiming_const ems_usb_bittiming_const = {
 920         .name = "ems_usb",
 921         .tseg1_min = 1,
 922         .tseg1_max = 16,
 923         .tseg2_min = 1,
 924         .tseg2_max = 8,
 925         .sjw_max = 4,
 926         .brp_min = 1,
 927         .brp_max = 64,
 928         .brp_inc = 1,
 929 };
 930
 931 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 932 {
 933         struct ems_usb *dev = netdev_priv(netdev);
 934
 935         if (!dev->open_time)
 936                 return -EINVAL;
 937
 938         switch (mode) {
 939         case CAN_MODE_START:
 940                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
 941                         dev_warn(netdev->dev.parent, "couldn't start device");
 942
 943                 if (netif_queue_stopped(netdev))
 944                         netif_wake_queue(netdev);
 945                 break;
 946
 947         default:
 948                 return -EOPNOTSUPP;
 949         }
 950
 951         return 0;
 952 }
 953
 954 static int ems_usb_set_bittiming(struct net_device *netdev)
 955 {
 956         struct ems_usb *dev = netdev_priv(netdev);
 957         struct can_bittiming *bt = &dev->can.bittiming;
 958         u8 btr0, btr1;
 959
 960         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 961         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 962                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 963         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 964                 btr1 |= 0x80;
 965
 966         dev_info(netdev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
 967                  btr0, btr1);
 968
 969         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
 970         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
 971
 972         return ems_usb_command_msg(dev, &dev->active_params);
 973 }
 974
 975 static void init_params_sja1000(struct ems_cpc_msg *msg)
 976 {
 977         struct cpc_sja1000_params *sja1000 =
 978                 &msg->msg.can_params.cc_params.sja1000;
 979
 980         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
 981         msg->length = sizeof(struct cpc_can_params);
 982         msg->msgid = 0;
 983
 984         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
 985
 986         /* Acceptance filter open */
 987         sja1000->acc_code0 = 0x00;
 988         sja1000->acc_code1 = 0x00;
 989         sja1000->acc_code2 = 0x00;
 990         sja1000->acc_code3 = 0x00;
 991
 992         /* Acceptance filter open */
 993         sja1000->acc_mask0 = 0xFF;
 994         sja1000->acc_mask1 = 0xFF;
 995         sja1000->acc_mask2 = 0xFF;
 996         sja1000->acc_mask3 = 0xFF;
 997
 998         sja1000->btr0 = 0;
 999         sja1000->btr1 = 0;
1000
1001         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
1002         sja1000->mode = SJA1000_MOD_RM;
1003 }
1004
1005 /*
1006  * probe function for new CPC-USB devices
1007  */
1008 static int ems_usb_probe(struct usb_interface *intf,
1009                          const struct usb_device_id *id)
1010 {
1011         struct net_device *netdev;
1012         struct ems_usb *dev;
1013         int i, err = -ENOMEM;
1014
1015         netdev = alloc_candev(sizeof(struct ems_usb));
1016         if (!netdev) {
1017                 dev_err(netdev->dev.parent, "Couldn't alloc candev\n");
1018                 return -ENOMEM;
1019         }
1020
1021         dev = netdev_priv(netdev);
1022
1023         dev->udev = interface_to_usbdev(intf);
1024         dev->netdev = netdev;
1025
1026         dev->can.state = CAN_STATE_STOPPED;
1027         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1028         dev->can.bittiming_const = &ems_usb_bittiming_const;
1029         dev->can.do_set_bittiming = ems_usb_set_bittiming;
1030         dev->can.do_set_mode = ems_usb_set_mode;
1031
1032         netdev->flags |= IFF_ECHO; /* we support local echo */
1033
1034         netdev->netdev_ops = &ems_usb_netdev_ops;
1035
1036         netdev->flags |= IFF_ECHO; /* we support local echo */
1037
1038         init_usb_anchor(&dev->rx_submitted);
1039
1040         init_usb_anchor(&dev->tx_submitted);
1041         atomic_set(&dev->active_tx_urbs, 0);
1042
1043         for (i = 0; i < MAX_TX_URBS; i++)
1044                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1045
1046         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1047         if (!dev->intr_urb) {
1048                 dev_err(netdev->dev.parent, "Couldn't alloc intr URB\n");
1049                 goto cleanup_candev;
1050         }
1051
1052         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1053         if (!dev->intr_in_buffer) {
1054                 dev_err(netdev->dev.parent, "Couldn't alloc Intr buffer\n");
1055                 goto cleanup_intr_urb;
1056         }
1057
1058         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1059                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1060         if (!dev->tx_msg_buffer) {
1061                 dev_err(netdev->dev.parent, "Couldn't alloc Tx buffer\n");
1062                 goto cleanup_intr_in_buffer;
1063         }
1064
1065         usb_set_intfdata(intf, dev);
1066
1067         SET_NETDEV_DEV(netdev, &intf->dev);
1068
1069         init_params_sja1000(&dev->active_params);
1070
1071         err = ems_usb_command_msg(dev, &dev->active_params);
1072         if (err) {
1073                 dev_err(netdev->dev.parent,
1074                         "couldn't initialize controller: %d\n", err);
1075                 goto cleanup_tx_msg_buffer;
1076         }
1077
1078         err = register_candev(netdev);
1079         if (err) {
1080                 dev_err(netdev->dev.parent,
1081                         "couldn't register CAN device: %d\n", err);
1082                 goto cleanup_tx_msg_buffer;
1083         }
1084
1085         return 0;
1086
1087 cleanup_tx_msg_buffer:
1088         kfree(dev->tx_msg_buffer);
1089
1090 cleanup_intr_in_buffer:
1091         kfree(dev->intr_in_buffer);
1092
1093 cleanup_intr_urb:
1094         usb_free_urb(dev->intr_urb);
1095
1096 cleanup_candev:
1097         free_candev(netdev);
1098
1099         return err;
1100 }
1101
1102 /*
1103  * called by the usb core when the device is removed from the system
1104  */
1105 static void ems_usb_disconnect(struct usb_interface *intf)
1106 {
1107         struct ems_usb *dev = usb_get_intfdata(intf);
1108
1109         usb_set_intfdata(intf, NULL);
1110
1111         if (dev) {
1112                 unregister_netdev(dev->netdev);
1113                 free_candev(dev->netdev);
1114
1115                 unlink_all_urbs(dev);
1116
1117                 usb_free_urb(dev->intr_urb);
1118
1119                 kfree(dev->intr_in_buffer);
1120         }
1121 }
1122
1123 /* usb specific object needed to register this driver with the usb subsystem */
1124 static struct usb_driver ems_usb_driver = {
1125         .name = "ems_usb",
1126         .probe = ems_usb_probe,
1127         .disconnect = ems_usb_disconnect,
1128         .id_table = ems_usb_table,
1129 };
1130
1131 static int __init ems_usb_init(void)
1132 {
1133         int err;
1134
1135         printk(KERN_INFO "CPC-USB kernel driver loaded\n");
1136
1137         /* register this driver with the USB subsystem */
1138         err = usb_register(&ems_usb_driver);
1139
1140         if (err) {
1141                 err("usb_register failed. Error number %d\n", err);
1142                 return err;
1143         }
1144
1145         return 0;
1146 }
1147
1148 static void __exit ems_usb_exit(void)
1149 {
1150         /* deregister this driver with the USB subsystem */
1151         usb_deregister(&ems_usb_driver);
1152 }
1153
1154 module_init(ems_usb_init);
1155 module_exit(ems_usb_exit);