drivers/net/can/usb/ems_usb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
   4  *
   5  * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
   6  */
   7 #include <linux/ethtool.h>
   8 #include <linux/signal.h>
   9 #include <linux/slab.h>
  10 #include <linux/module.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/usb.h>
  13
  14 #include <linux/can.h>
  15 #include <linux/can/dev.h>
  16 #include <linux/can/error.h>
  17
  18 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
  19 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
  20 MODULE_LICENSE("GPL v2");
  21
  22 /* Control-Values for CPC_Control() Command Subject Selection */
  23 #define CONTR_CAN_MESSAGE 0x04
  24 #define CONTR_CAN_STATE   0x0C
  25 #define CONTR_BUS_ERROR   0x1C
  26
  27 /* Control Command Actions */
  28 #define CONTR_CONT_OFF 0
  29 #define CONTR_CONT_ON  1
  30 #define CONTR_ONCE     2
  31
  32 /* Messages from CPC to PC */
  33 #define CPC_MSG_TYPE_CAN_FRAME       1  /* CAN data frame */
  34 #define CPC_MSG_TYPE_RTR_FRAME       8  /* CAN remote frame */
  35 #define CPC_MSG_TYPE_CAN_PARAMS      12 /* Actual CAN parameters */
  36 #define CPC_MSG_TYPE_CAN_STATE       14 /* CAN state message */
  37 #define CPC_MSG_TYPE_EXT_CAN_FRAME   16 /* Extended CAN data frame */
  38 #define CPC_MSG_TYPE_EXT_RTR_FRAME   17 /* Extended remote frame */
  39 #define CPC_MSG_TYPE_CONTROL         19 /* change interface behavior */
  40 #define CPC_MSG_TYPE_CONFIRM         20 /* command processed confirmation */
  41 #define CPC_MSG_TYPE_OVERRUN         21 /* overrun events */
  42 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
  43 #define CPC_MSG_TYPE_ERR_COUNTER     25 /* RX/TX error counter */
  44
  45 /* Messages from the PC to the CPC interface  */
  46 #define CPC_CMD_TYPE_CAN_FRAME     1   /* CAN data frame */
  47 #define CPC_CMD_TYPE_CONTROL       3   /* control of interface behavior */
  48 #define CPC_CMD_TYPE_CAN_PARAMS    6   /* set CAN parameters */
  49 #define CPC_CMD_TYPE_RTR_FRAME     13  /* CAN remote frame */
  50 #define CPC_CMD_TYPE_CAN_STATE     14  /* CAN state message */
  51 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15  /* Extended CAN data frame */
  52 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16  /* Extended CAN remote frame */
  53 #define CPC_CMD_TYPE_CAN_EXIT      200 /* exit the CAN */
  54
  55 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
  56 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8  /* clear CPC_MSG queue */
  57 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
  58
  59 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
  60
  61 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
  62
  63 /* Overrun types */
  64 #define CPC_OVR_EVENT_CAN       0x01
  65 #define CPC_OVR_EVENT_CANSTATE  0x02
  66 #define CPC_OVR_EVENT_BUSERROR  0x04
  67
  68 /*
  69  * If the CAN controller lost a message we indicate it with the highest bit
  70  * set in the count field.
  71  */
  72 #define CPC_OVR_HW 0x80
  73
  74 /* Size of the "struct ems_cpc_msg" without the union */
  75 #define CPC_MSG_HEADER_LEN   11
  76 #define CPC_CAN_MSG_MIN_SIZE 5
  77
  78 /* Define these values to match your devices */
  79 #define USB_CPCUSB_VENDOR_ID 0x12D6
  80
  81 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
  82
  83 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
  84 #define SJA1000_MOD_NORMAL 0x00
  85 #define SJA1000_MOD_RM     0x01
  86
  87 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
  88 #define SJA1000_ECC_SEG   0x1F
  89 #define SJA1000_ECC_DIR   0x20
  90 #define SJA1000_ECC_ERR   0x06
  91 #define SJA1000_ECC_BIT   0x00
  92 #define SJA1000_ECC_FORM  0x40
  93 #define SJA1000_ECC_STUFF 0x80
  94 #define SJA1000_ECC_MASK  0xc0
  95
  96 /* Status register content */
  97 #define SJA1000_SR_BS 0x80
  98 #define SJA1000_SR_ES 0x40
  99
 100 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
 101
 102 /*
 103  * The device actually uses a 16MHz clock to generate the CAN clock
 104  * but it expects SJA1000 bit settings based on 8MHz (is internally
 105  * converted).
 106  */
 107 #define EMS_USB_ARM7_CLOCK 8000000
 108
 109 #define CPC_TX_QUEUE_TRIGGER_LOW        25
 110 #define CPC_TX_QUEUE_TRIGGER_HIGH       35
 111
 112 /*
 113  * CAN-Message representation in a CPC_MSG. Message object type is
 114  * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
 115  * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
 116  */
 117 struct cpc_can_msg {
 118         __le32 id;
 119         u8 length;
 120         u8 msg[8];
 121 };
 122
 123 /* Representation of the CAN parameters for the SJA1000 controller */
 124 struct cpc_sja1000_params {
 125         u8 mode;
 126         u8 acc_code0;
 127         u8 acc_code1;
 128         u8 acc_code2;
 129         u8 acc_code3;
 130         u8 acc_mask0;
 131         u8 acc_mask1;
 132         u8 acc_mask2;
 133         u8 acc_mask3;
 134         u8 btr0;
 135         u8 btr1;
 136         u8 outp_contr;
 137 };
 138
 139 /* CAN params message representation */
 140 struct cpc_can_params {
 141         u8 cc_type;
 142
 143         /* Will support M16C CAN controller in the future */
 144         union {
 145                 struct cpc_sja1000_params sja1000;
 146         } cc_params;
 147 };
 148
 149 /* Structure for confirmed message handling */
 150 struct cpc_confirm {
 151         u8 error; /* error code */
 152 };
 153
 154 /* Structure for overrun conditions */
 155 struct cpc_overrun {
 156         u8 event;
 157         u8 count;
 158 };
 159
 160 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
 161 struct cpc_sja1000_can_error {
 162         u8 ecc;
 163         u8 rxerr;
 164         u8 txerr;
 165 };
 166
 167 /* structure for CAN error conditions */
 168 struct cpc_can_error {
 169         u8 ecode;
 170
 171         struct {
 172                 u8 cc_type;
 173
 174                 /* Other controllers may also provide error code capture regs */
 175                 union {
 176                         struct cpc_sja1000_can_error sja1000;
 177                 } regs;
 178         } cc;
 179 };
 180
 181 /*
 182  * Structure containing RX/TX error counter. This structure is used to request
 183  * the values of the CAN controllers TX and RX error counter.
 184  */
 185 struct cpc_can_err_counter {
 186         u8 rx;
 187         u8 tx;
 188 };
 189
 190 /* Main message type used between library and application */
 191 struct __packed ems_cpc_msg {
 192         u8 type;        /* type of message */
 193         u8 length;      /* length of data within union 'msg' */
 194         u8 msgid;       /* confirmation handle */
 195         __le32 ts_sec;  /* timestamp in seconds */
 196         __le32 ts_nsec; /* timestamp in nano seconds */
 197
 198         union __packed {
 199                 u8 generic[64];
 200                 struct cpc_can_msg can_msg;
 201                 struct cpc_can_params can_params;
 202                 struct cpc_confirm confirmation;
 203                 struct cpc_overrun overrun;
 204                 struct cpc_can_error error;
 205                 struct cpc_can_err_counter err_counter;
 206                 u8 can_state;
 207         } msg;
 208 };
 209
 210 /*
 211  * Table of devices that work with this driver
 212  * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
 213  */
 214 static struct usb_device_id ems_usb_table[] = {
 215         {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
 216         {} /* Terminating entry */
 217 };
 218
 219 MODULE_DEVICE_TABLE(usb, ems_usb_table);
 220
 221 #define RX_BUFFER_SIZE      64
 222 #define CPC_HEADER_SIZE     4
 223 #define INTR_IN_BUFFER_SIZE 4
 224
 225 #define MAX_RX_URBS 10
 226 #define MAX_TX_URBS 10
 227
 228 struct ems_usb;
 229
 230 struct ems_tx_urb_context {
 231         struct ems_usb *dev;
 232
 233         u32 echo_index;
 234 };
 235
 236 struct ems_usb {
 237         struct can_priv can; /* must be the first member */
 238
 239         struct sk_buff *echo_skb[MAX_TX_URBS];
 240
 241         struct usb_device *udev;
 242         struct net_device *netdev;
 243
 244         atomic_t active_tx_urbs;
 245         struct usb_anchor tx_submitted;
 246         struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
 247
 248         struct usb_anchor rx_submitted;
 249
 250         struct urb *intr_urb;
 251
 252         u8 *tx_msg_buffer;
 253
 254         u8 *intr_in_buffer;
 255         unsigned int free_slots; /* remember number of available slots */
 256
 257         struct ems_cpc_msg active_params; /* active controller parameters */
 258         void *rxbuf[MAX_RX_URBS];
 259         dma_addr_t rxbuf_dma[MAX_RX_URBS];
 260 };
 261
 262 static void ems_usb_read_interrupt_callback(struct urb *urb)
 263 {
 264         struct ems_usb *dev = urb->context;
 265         struct net_device *netdev = dev->netdev;
 266         int err;
 267
 268         if (!netif_device_present(netdev))
 269                 return;
 270
 271         switch (urb->status) {
 272         case 0:
 273                 dev->free_slots = dev->intr_in_buffer[1];
 274                 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
 275                     netif_queue_stopped(netdev))
 276                         netif_wake_queue(netdev);
 277                 break;
 278
 279         case -ECONNRESET: /* unlink */
 280         case -ENOENT:
 281         case -EPIPE:
 282         case -EPROTO:
 283         case -ESHUTDOWN:
 284                 return;
 285
 286         default:
 287                 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
 288                 break;
 289         }
 290
 291         err = usb_submit_urb(urb, GFP_ATOMIC);
 292
 293         if (err == -ENODEV)
 294                 netif_device_detach(netdev);
 295         else if (err)
 296                 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
 297 }
 298
 299 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 300 {
 301         struct can_frame *cf;
 302         struct sk_buff *skb;
 303         int i;
 304         struct net_device_stats *stats = &dev->netdev->stats;
 305
 306         skb = alloc_can_skb(dev->netdev, &cf);
 307         if (skb == NULL)
 308                 return;
 309
 310         cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
 311         cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);
 312
 313         if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
 314             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
 315                 cf->can_id |= CAN_EFF_FLAG;
 316
 317         if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
 318             msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
 319                 cf->can_id |= CAN_RTR_FLAG;
 320         } else {
 321                 for (i = 0; i < cf->len; i++)
 322                         cf->data[i] = msg->msg.can_msg.msg[i];
 323
 324                 stats->rx_bytes += cf->len;
 325         }
 326         stats->rx_packets++;
 327
 328         netif_rx(skb);
 329 }
 330
 331 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
 332 {
 333         struct can_frame *cf;
 334         struct sk_buff *skb;
 335         struct net_device_stats *stats = &dev->netdev->stats;
 336
 337         skb = alloc_can_err_skb(dev->netdev, &cf);
 338         if (skb == NULL)
 339                 return;
 340
 341         if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
 342                 u8 state = msg->msg.can_state;
 343
 344                 if (state & SJA1000_SR_BS) {
 345                         dev->can.state = CAN_STATE_BUS_OFF;
 346                         cf->can_id |= CAN_ERR_BUSOFF;
 347
 348                         dev->can.can_stats.bus_off++;
 349                         can_bus_off(dev->netdev);
 350                 } else if (state & SJA1000_SR_ES) {
 351                         dev->can.state = CAN_STATE_ERROR_WARNING;
 352                         dev->can.can_stats.error_warning++;
 353                 } else {
 354                         dev->can.state = CAN_STATE_ERROR_ACTIVE;
 355                         dev->can.can_stats.error_passive++;
 356                 }
 357         } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
 358                 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
 359                 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
 360                 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
 361
 362                 /* bus error interrupt */
 363                 dev->can.can_stats.bus_error++;
 364                 stats->rx_errors++;
 365
 366                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 367
 368                 switch (ecc & SJA1000_ECC_MASK) {
 369                 case SJA1000_ECC_BIT:
 370                         cf->data[2] |= CAN_ERR_PROT_BIT;
 371                         break;
 372                 case SJA1000_ECC_FORM:
 373                         cf->data[2] |= CAN_ERR_PROT_FORM;
 374                         break;
 375                 case SJA1000_ECC_STUFF:
 376                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 377                         break;
 378                 default:
 379                         cf->data[3] = ecc & SJA1000_ECC_SEG;
 380                         break;
 381                 }
 382
 383                 /* Error occurred during transmission? */
 384                 if ((ecc & SJA1000_ECC_DIR) == 0)
 385                         cf->data[2] |= CAN_ERR_PROT_TX;
 386
 387                 if (dev->can.state == CAN_STATE_ERROR_WARNING ||
 388                     dev->can.state == CAN_STATE_ERROR_PASSIVE) {
 389                         cf->can_id |= CAN_ERR_CRTL;
 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         netif_rx(skb);
 402 }
 403
 404 /*
 405  * callback for bulk IN urb
 406  */
 407 static void ems_usb_read_bulk_callback(struct urb *urb)
 408 {
 409         struct ems_usb *dev = urb->context;
 410         struct net_device *netdev;
 411         int retval;
 412
 413         netdev = dev->netdev;
 414
 415         if (!netif_device_present(netdev))
 416                 return;
 417
 418         switch (urb->status) {
 419         case 0: /* success */
 420                 break;
 421
 422         case -ENOENT:
 423                 return;
 424
 425         default:
 426                 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
 427                 goto resubmit_urb;
 428         }
 429
 430         if (urb->actual_length > CPC_HEADER_SIZE) {
 431                 struct ems_cpc_msg *msg;
 432                 u8 *ibuf = urb->transfer_buffer;
 433                 u8 msg_count, start;
 434
 435                 msg_count = ibuf[0] & ~0x80;
 436
 437                 start = CPC_HEADER_SIZE;
 438
 439                 while (msg_count) {
 440                         msg = (struct ems_cpc_msg *)&ibuf[start];
 441
 442                         switch (msg->type) {
 443                         case CPC_MSG_TYPE_CAN_STATE:
 444                                 /* Process CAN state changes */
 445                                 ems_usb_rx_err(dev, msg);
 446                                 break;
 447
 448                         case CPC_MSG_TYPE_CAN_FRAME:
 449                         case CPC_MSG_TYPE_EXT_CAN_FRAME:
 450                         case CPC_MSG_TYPE_RTR_FRAME:
 451                         case CPC_MSG_TYPE_EXT_RTR_FRAME:
 452                                 ems_usb_rx_can_msg(dev, msg);
 453                                 break;
 454
 455                         case CPC_MSG_TYPE_CAN_FRAME_ERROR:
 456                                 /* Process errorframe */
 457                                 ems_usb_rx_err(dev, msg);
 458                                 break;
 459
 460                         case CPC_MSG_TYPE_OVERRUN:
 461                                 /* Message lost while receiving */
 462                                 ems_usb_rx_err(dev, msg);
 463                                 break;
 464                         }
 465
 466                         start += CPC_MSG_HEADER_LEN + msg->length;
 467                         msg_count--;
 468
 469                         if (start > urb->transfer_buffer_length) {
 470                                 netdev_err(netdev, "format error\n");
 471                                 break;
 472                         }
 473                 }
 474         }
 475
 476 resubmit_urb:
 477         usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 478                           urb->transfer_buffer, RX_BUFFER_SIZE,
 479                           ems_usb_read_bulk_callback, dev);
 480
 481         retval = usb_submit_urb(urb, GFP_ATOMIC);
 482
 483         if (retval == -ENODEV)
 484                 netif_device_detach(netdev);
 485         else if (retval)
 486                 netdev_err(netdev,
 487                            "failed resubmitting read bulk urb: %d\n", retval);
 488 }
 489
 490 /*
 491  * callback for bulk IN urb
 492  */
 493 static void ems_usb_write_bulk_callback(struct urb *urb)
 494 {
 495         struct ems_tx_urb_context *context = urb->context;
 496         struct ems_usb *dev;
 497         struct net_device *netdev;
 498
 499         BUG_ON(!context);
 500
 501         dev = context->dev;
 502         netdev = dev->netdev;
 503
 504         /* free up our allocated buffer */
 505         usb_free_coherent(urb->dev, urb->transfer_buffer_length,
 506                           urb->transfer_buffer, urb->transfer_dma);
 507
 508         atomic_dec(&dev->active_tx_urbs);
 509
 510         if (!netif_device_present(netdev))
 511                 return;
 512
 513         if (urb->status)
 514                 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
 515
 516         netif_trans_update(netdev);
 517
 518         /* transmission complete interrupt */
 519         netdev->stats.tx_packets++;
 520         netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,
 521                                                    NULL);
 522
 523         /* Release context */
 524         context->echo_index = MAX_TX_URBS;
 525
 526 }
 527
 528 /*
 529  * Send the given CPC command synchronously
 530  */
 531 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
 532 {
 533         int actual_length;
 534
 535         /* Copy payload */
 536         memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
 537                msg->length + CPC_MSG_HEADER_LEN);
 538
 539         /* Clear header */
 540         memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
 541
 542         return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
 543                             &dev->tx_msg_buffer[0],
 544                             msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
 545                             &actual_length, 1000);
 546 }
 547
 548 /*
 549  * Change CAN controllers' mode register
 550  */
 551 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
 552 {
 553         dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
 554
 555         return ems_usb_command_msg(dev, &dev->active_params);
 556 }
 557
 558 /*
 559  * Send a CPC_Control command to change behaviour when interface receives a CAN
 560  * message, bus error or CAN state changed notifications.
 561  */
 562 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
 563 {
 564         struct ems_cpc_msg cmd;
 565
 566         cmd.type = CPC_CMD_TYPE_CONTROL;
 567         cmd.length = CPC_MSG_HEADER_LEN + 1;
 568
 569         cmd.msgid = 0;
 570
 571         cmd.msg.generic[0] = val;
 572
 573         return ems_usb_command_msg(dev, &cmd);
 574 }
 575
 576 /*
 577  * Start interface
 578  */
 579 static int ems_usb_start(struct ems_usb *dev)
 580 {
 581         struct net_device *netdev = dev->netdev;
 582         int err, i;
 583
 584         dev->intr_in_buffer[0] = 0;
 585         dev->free_slots = 50; /* initial size */
 586
 587         for (i = 0; i < MAX_RX_URBS; i++) {
 588                 struct urb *urb = NULL;
 589                 u8 *buf = NULL;
 590                 dma_addr_t buf_dma;
 591
 592                 /* create a URB, and a buffer for it */
 593                 urb = usb_alloc_urb(0, GFP_KERNEL);
 594                 if (!urb) {
 595                         err = -ENOMEM;
 596                         break;
 597                 }
 598
 599                 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
 600                                          &buf_dma);
 601                 if (!buf) {
 602                         netdev_err(netdev, "No memory left for USB buffer\n");
 603                         usb_free_urb(urb);
 604                         err = -ENOMEM;
 605                         break;
 606                 }
 607
 608                 urb->transfer_dma = buf_dma;
 609
 610                 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
 611                                   buf, RX_BUFFER_SIZE,
 612                                   ems_usb_read_bulk_callback, dev);
 613                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 614                 usb_anchor_urb(urb, &dev->rx_submitted);
 615
 616                 err = usb_submit_urb(urb, GFP_KERNEL);
 617                 if (err) {
 618                         usb_unanchor_urb(urb);
 619                         usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
 620                                           urb->transfer_dma);
 621                         usb_free_urb(urb);
 622                         break;
 623                 }
 624
 625                 dev->rxbuf[i] = buf;
 626                 dev->rxbuf_dma[i] = buf_dma;
 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         for (i = 0; i < MAX_RX_URBS; ++i)
 694                 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
 695                                   dev->rxbuf[i], dev->rxbuf_dma[i]);
 696
 697         usb_kill_anchored_urbs(&dev->tx_submitted);
 698         atomic_set(&dev->active_tx_urbs, 0);
 699
 700         for (i = 0; i < MAX_TX_URBS; i++)
 701                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
 702 }
 703
 704 static int ems_usb_open(struct net_device *netdev)
 705 {
 706         struct ems_usb *dev = netdev_priv(netdev);
 707         int err;
 708
 709         err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
 710         if (err)
 711                 return err;
 712
 713         /* common open */
 714         err = open_candev(netdev);
 715         if (err)
 716                 return err;
 717
 718         /* finally start device */
 719         err = ems_usb_start(dev);
 720         if (err) {
 721                 if (err == -ENODEV)
 722                         netif_device_detach(dev->netdev);
 723
 724                 netdev_warn(netdev, "couldn't start device: %d\n", err);
 725
 726                 close_candev(netdev);
 727
 728                 return err;
 729         }
 730
 731
 732         netif_start_queue(netdev);
 733
 734         return 0;
 735 }
 736
 737 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 738 {
 739         struct ems_usb *dev = netdev_priv(netdev);
 740         struct ems_tx_urb_context *context = NULL;
 741         struct net_device_stats *stats = &netdev->stats;
 742         struct can_frame *cf = (struct can_frame *)skb->data;
 743         struct ems_cpc_msg *msg;
 744         struct urb *urb;
 745         u8 *buf;
 746         int i, err;
 747         size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
 748                         + sizeof(struct cpc_can_msg);
 749
 750         if (can_dev_dropped_skb(netdev, skb))
 751                 return NETDEV_TX_OK;
 752
 753         /* create a URB, and a buffer for it, and copy the data to the URB */
 754         urb = usb_alloc_urb(0, GFP_ATOMIC);
 755         if (!urb)
 756                 goto nomem;
 757
 758         buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
 759         if (!buf) {
 760                 netdev_err(netdev, "No memory left for USB buffer\n");
 761                 usb_free_urb(urb);
 762                 goto nomem;
 763         }
 764
 765         msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
 766
 767         msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
 768         msg->msg.can_msg.length = cf->len;
 769
 770         if (cf->can_id & CAN_RTR_FLAG) {
 771                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 772                         CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
 773
 774                 msg->length = CPC_CAN_MSG_MIN_SIZE;
 775         } else {
 776                 msg->type = cf->can_id & CAN_EFF_FLAG ?
 777                         CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
 778
 779                 for (i = 0; i < cf->len; i++)
 780                         msg->msg.can_msg.msg[i] = cf->data[i];
 781
 782                 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
 783         }
 784
 785         for (i = 0; i < MAX_TX_URBS; i++) {
 786                 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
 787                         context = &dev->tx_contexts[i];
 788                         break;
 789                 }
 790         }
 791
 792         /*
 793          * May never happen! When this happens we'd more URBs in flight as
 794          * allowed (MAX_TX_URBS).
 795          */
 796         if (!context) {
 797                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 798                 usb_free_urb(urb);
 799
 800                 netdev_warn(netdev, "couldn't find free context\n");
 801
 802                 return NETDEV_TX_BUSY;
 803         }
 804
 805         context->dev = dev;
 806         context->echo_index = i;
 807
 808         usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
 809                           size, ems_usb_write_bulk_callback, context);
 810         urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 811         usb_anchor_urb(urb, &dev->tx_submitted);
 812
 813         can_put_echo_skb(skb, netdev, context->echo_index, 0);
 814
 815         atomic_inc(&dev->active_tx_urbs);
 816
 817         err = usb_submit_urb(urb, GFP_ATOMIC);
 818         if (unlikely(err)) {
 819                 can_free_echo_skb(netdev, context->echo_index, NULL);
 820
 821                 usb_unanchor_urb(urb);
 822                 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
 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                 netif_trans_update(netdev);
 835
 836                 /* Slow down tx path */
 837                 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
 838                     dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
 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 ethtool_ops ems_usb_ethtool_ops = {
 884         .get_ts_info = ethtool_op_get_ts_info,
 885 };
 886
 887 static const struct can_bittiming_const ems_usb_bittiming_const = {
 888         .name = KBUILD_MODNAME,
 889         .tseg1_min = 1,
 890         .tseg1_max = 16,
 891         .tseg2_min = 1,
 892         .tseg2_max = 8,
 893         .sjw_max = 4,
 894         .brp_min = 1,
 895         .brp_max = 64,
 896         .brp_inc = 1,
 897 };
 898
 899 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
 900 {
 901         struct ems_usb *dev = netdev_priv(netdev);
 902
 903         switch (mode) {
 904         case CAN_MODE_START:
 905                 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
 906                         netdev_warn(netdev, "couldn't start device");
 907
 908                 if (netif_queue_stopped(netdev))
 909                         netif_wake_queue(netdev);
 910                 break;
 911
 912         default:
 913                 return -EOPNOTSUPP;
 914         }
 915
 916         return 0;
 917 }
 918
 919 static int ems_usb_set_bittiming(struct net_device *netdev)
 920 {
 921         struct ems_usb *dev = netdev_priv(netdev);
 922         struct can_bittiming *bt = &dev->can.bittiming;
 923         u8 btr0, btr1;
 924
 925         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 926         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 927                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 928         if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 929                 btr1 |= 0x80;
 930
 931         netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 932
 933         dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
 934         dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
 935
 936         return ems_usb_command_msg(dev, &dev->active_params);
 937 }
 938
 939 static void init_params_sja1000(struct ems_cpc_msg *msg)
 940 {
 941         struct cpc_sja1000_params *sja1000 =
 942                 &msg->msg.can_params.cc_params.sja1000;
 943
 944         msg->type = CPC_CMD_TYPE_CAN_PARAMS;
 945         msg->length = sizeof(struct cpc_can_params);
 946         msg->msgid = 0;
 947
 948         msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
 949
 950         /* Acceptance filter open */
 951         sja1000->acc_code0 = 0x00;
 952         sja1000->acc_code1 = 0x00;
 953         sja1000->acc_code2 = 0x00;
 954         sja1000->acc_code3 = 0x00;
 955
 956         /* Acceptance filter open */
 957         sja1000->acc_mask0 = 0xFF;
 958         sja1000->acc_mask1 = 0xFF;
 959         sja1000->acc_mask2 = 0xFF;
 960         sja1000->acc_mask3 = 0xFF;
 961
 962         sja1000->btr0 = 0;
 963         sja1000->btr1 = 0;
 964
 965         sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
 966         sja1000->mode = SJA1000_MOD_RM;
 967 }
 968
 969 /*
 970  * probe function for new CPC-USB devices
 971  */
 972 static int ems_usb_probe(struct usb_interface *intf,
 973                          const struct usb_device_id *id)
 974 {
 975         struct net_device *netdev;
 976         struct ems_usb *dev;
 977         int i, err = -ENOMEM;
 978
 979         netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
 980         if (!netdev) {
 981                 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
 982                 return -ENOMEM;
 983         }
 984
 985         dev = netdev_priv(netdev);
 986
 987         dev->udev = interface_to_usbdev(intf);
 988         dev->netdev = netdev;
 989
 990         dev->can.state = CAN_STATE_STOPPED;
 991         dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
 992         dev->can.bittiming_const = &ems_usb_bittiming_const;
 993         dev->can.do_set_bittiming = ems_usb_set_bittiming;
 994         dev->can.do_set_mode = ems_usb_set_mode;
 995         dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 996
 997         netdev->netdev_ops = &ems_usb_netdev_ops;
 998         netdev->ethtool_ops = &ems_usb_ethtool_ops;
 999
1000         netdev->flags |= IFF_ECHO; /* we support local echo */
1001
1002         init_usb_anchor(&dev->rx_submitted);
1003
1004         init_usb_anchor(&dev->tx_submitted);
1005         atomic_set(&dev->active_tx_urbs, 0);
1006
1007         for (i = 0; i < MAX_TX_URBS; i++)
1008                 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1009
1010         dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1011         if (!dev->intr_urb)
1012                 goto cleanup_candev;
1013
1014         dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1015         if (!dev->intr_in_buffer)
1016                 goto cleanup_intr_urb;
1017
1018         dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1019                                      sizeof(struct ems_cpc_msg), GFP_KERNEL);
1020         if (!dev->tx_msg_buffer)
1021                 goto cleanup_intr_in_buffer;
1022
1023         usb_set_intfdata(intf, dev);
1024
1025         SET_NETDEV_DEV(netdev, &intf->dev);
1026
1027         init_params_sja1000(&dev->active_params);
1028
1029         err = ems_usb_command_msg(dev, &dev->active_params);
1030         if (err) {
1031                 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1032                 goto cleanup_tx_msg_buffer;
1033         }
1034
1035         err = register_candev(netdev);
1036         if (err) {
1037                 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1038                 goto cleanup_tx_msg_buffer;
1039         }
1040
1041         return 0;
1042
1043 cleanup_tx_msg_buffer:
1044         kfree(dev->tx_msg_buffer);
1045
1046 cleanup_intr_in_buffer:
1047         kfree(dev->intr_in_buffer);
1048
1049 cleanup_intr_urb:
1050         usb_free_urb(dev->intr_urb);
1051
1052 cleanup_candev:
1053         free_candev(netdev);
1054
1055         return err;
1056 }
1057
1058 /*
1059  * called by the usb core when the device is removed from the system
1060  */
1061 static void ems_usb_disconnect(struct usb_interface *intf)
1062 {
1063         struct ems_usb *dev = usb_get_intfdata(intf);
1064
1065         usb_set_intfdata(intf, NULL);
1066
1067         if (dev) {
1068                 unregister_netdev(dev->netdev);
1069
1070                 unlink_all_urbs(dev);
1071
1072                 usb_free_urb(dev->intr_urb);
1073
1074                 kfree(dev->intr_in_buffer);
1075                 kfree(dev->tx_msg_buffer);
1076
1077                 free_candev(dev->netdev);
1078         }
1079 }
1080
1081 /* usb specific object needed to register this driver with the usb subsystem */
1082 static struct usb_driver ems_usb_driver = {
1083         .name = KBUILD_MODNAME,
1084         .probe = ems_usb_probe,
1085         .disconnect = ems_usb_disconnect,
1086         .id_table = ems_usb_table,
1087 };
1088
1089 module_usb_driver(ems_usb_driver);