drivers/net/can/bfin_can.c

   1 /*
   2  * Blackfin On-Chip CAN Driver
   3  *
   4  * Copyright 2004-2009 Analog Devices Inc.
   5  *
   6  * Enter bugs at http://blackfin.uclinux.org/
   7  *
   8  * Licensed under the GPL-2 or later.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/bitops.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/errno.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/platform_device.h>
  20
  21 #include <linux/can/dev.h>
  22 #include <linux/can/error.h>
  23
  24 #include <asm/bfin_can.h>
  25 #include <asm/portmux.h>
  26
  27 #define DRV_NAME "bfin_can"
  28 #define BFIN_CAN_TIMEOUT 100
  29 #define TX_ECHO_SKB_MAX  1
  30
  31 /*
  32  * bfin can private data
  33  */
  34 struct bfin_can_priv {
  35         struct can_priv can;    /* must be the first member */
  36         struct net_device *dev;
  37         void __iomem *membase;
  38         int rx_irq;
  39         int tx_irq;
  40         int err_irq;
  41         unsigned short *pin_list;
  42 };
  43
  44 /*
  45  * bfin can timing parameters
  46  */
  47 static const struct can_bittiming_const bfin_can_bittiming_const = {
  48         .name = DRV_NAME,
  49         .tseg1_min = 1,
  50         .tseg1_max = 16,
  51         .tseg2_min = 1,
  52         .tseg2_max = 8,
  53         .sjw_max = 4,
  54         /*
  55          * Although the BRP field can be set to any value, it is recommended
  56          * that the value be greater than or equal to 4, as restrictions
  57          * apply to the bit timing configuration when BRP is less than 4.
  58          */
  59         .brp_min = 4,
  60         .brp_max = 1024,
  61         .brp_inc = 1,
  62 };
  63
  64 static int bfin_can_set_bittiming(struct net_device *dev)
  65 {
  66         struct bfin_can_priv *priv = netdev_priv(dev);
  67         struct bfin_can_regs __iomem *reg = priv->membase;
  68         struct can_bittiming *bt = &priv->can.bittiming;
  69         u16 clk, timing;
  70
  71         clk = bt->brp - 1;
  72         timing = ((bt->sjw - 1) << 8) | (bt->prop_seg + bt->phase_seg1 - 1) |
  73                 ((bt->phase_seg2 - 1) << 4);
  74
  75         /*
  76          * If the SAM bit is set, the input signal is oversampled three times
  77          * at the SCLK rate.
  78          */
  79         if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
  80                 timing |= SAM;
  81
  82         bfin_write(&reg->clock, clk);
  83         bfin_write(&reg->timing, timing);
  84
  85         netdev_info(dev, "setting CLOCK=0x%04x TIMING=0x%04x\n", clk, timing);
  86
  87         return 0;
  88 }
  89
  90 static void bfin_can_set_reset_mode(struct net_device *dev)
  91 {
  92         struct bfin_can_priv *priv = netdev_priv(dev);
  93         struct bfin_can_regs __iomem *reg = priv->membase;
  94         int timeout = BFIN_CAN_TIMEOUT;
  95         int i;
  96
  97         /* disable interrupts */
  98         bfin_write(&reg->mbim1, 0);
  99         bfin_write(&reg->mbim2, 0);
 100         bfin_write(&reg->gim, 0);
 101
 102         /* reset can and enter configuration mode */
 103         bfin_write(&reg->control, SRS | CCR);
 104         SSYNC();
 105         bfin_write(&reg->control, CCR);
 106         SSYNC();
 107         while (!(bfin_read(&reg->control) & CCA)) {
 108                 udelay(10);
 109                 if (--timeout == 0) {
 110                         netdev_err(dev, "fail to enter configuration mode\n");
 111                         BUG();
 112                 }
 113         }
 114
 115         /*
 116          * All mailbox configurations are marked as inactive
 117          * by writing to CAN Mailbox Configuration Registers 1 and 2
 118          * For all bits: 0 - Mailbox disabled, 1 - Mailbox enabled
 119          */
 120         bfin_write(&reg->mc1, 0);
 121         bfin_write(&reg->mc2, 0);
 122
 123         /* Set Mailbox Direction */
 124         bfin_write(&reg->md1, 0xFFFF);   /* mailbox 1-16 are RX */
 125         bfin_write(&reg->md2, 0);   /* mailbox 17-32 are TX */
 126
 127         /* RECEIVE_STD_CHL */
 128         for (i = 0; i < 2; i++) {
 129                 bfin_write(&reg->chl[RECEIVE_STD_CHL + i].id0, 0);
 130                 bfin_write(&reg->chl[RECEIVE_STD_CHL + i].id1, AME);
 131                 bfin_write(&reg->chl[RECEIVE_STD_CHL + i].dlc, 0);
 132                 bfin_write(&reg->msk[RECEIVE_STD_CHL + i].amh, 0x1FFF);
 133                 bfin_write(&reg->msk[RECEIVE_STD_CHL + i].aml, 0xFFFF);
 134         }
 135
 136         /* RECEIVE_EXT_CHL */
 137         for (i = 0; i < 2; i++) {
 138                 bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].id0, 0);
 139                 bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].id1, AME | IDE);
 140                 bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].dlc, 0);
 141                 bfin_write(&reg->msk[RECEIVE_EXT_CHL + i].amh, 0x1FFF);
 142                 bfin_write(&reg->msk[RECEIVE_EXT_CHL + i].aml, 0xFFFF);
 143         }
 144
 145         bfin_write(&reg->mc2, BIT(TRANSMIT_CHL - 16));
 146         bfin_write(&reg->mc1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
 147         SSYNC();
 148
 149         priv->can.state = CAN_STATE_STOPPED;
 150 }
 151
 152 static void bfin_can_set_normal_mode(struct net_device *dev)
 153 {
 154         struct bfin_can_priv *priv = netdev_priv(dev);
 155         struct bfin_can_regs __iomem *reg = priv->membase;
 156         int timeout = BFIN_CAN_TIMEOUT;
 157
 158         /*
 159          * leave configuration mode
 160          */
 161         bfin_write(&reg->control, bfin_read(&reg->control) & ~CCR);
 162
 163         while (bfin_read(&reg->status) & CCA) {
 164                 udelay(10);
 165                 if (--timeout == 0) {
 166                         netdev_err(dev, "fail to leave configuration mode\n");
 167                         BUG();
 168                 }
 169         }
 170
 171         /*
 172          * clear _All_  tx and rx interrupts
 173          */
 174         bfin_write(&reg->mbtif1, 0xFFFF);
 175         bfin_write(&reg->mbtif2, 0xFFFF);
 176         bfin_write(&reg->mbrif1, 0xFFFF);
 177         bfin_write(&reg->mbrif2, 0xFFFF);
 178
 179         /*
 180          * clear global interrupt status register
 181          */
 182         bfin_write(&reg->gis, 0x7FF); /* overwrites with '1' */
 183
 184         /*
 185          * Initialize Interrupts
 186          * - set bits in the mailbox interrupt mask register
 187          * - global interrupt mask
 188          */
 189         bfin_write(&reg->mbim1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
 190         bfin_write(&reg->mbim2, BIT(TRANSMIT_CHL - 16));
 191
 192         bfin_write(&reg->gim, EPIM | BOIM | RMLIM);
 193         SSYNC();
 194 }
 195
 196 static void bfin_can_start(struct net_device *dev)
 197 {
 198         struct bfin_can_priv *priv = netdev_priv(dev);
 199
 200         /* enter reset mode */
 201         if (priv->can.state != CAN_STATE_STOPPED)
 202                 bfin_can_set_reset_mode(dev);
 203
 204         /* leave reset mode */
 205         bfin_can_set_normal_mode(dev);
 206 }
 207
 208 static int bfin_can_set_mode(struct net_device *dev, enum can_mode mode)
 209 {
 210         switch (mode) {
 211         case CAN_MODE_START:
 212                 bfin_can_start(dev);
 213                 if (netif_queue_stopped(dev))
 214                         netif_wake_queue(dev);
 215                 break;
 216
 217         default:
 218                 return -EOPNOTSUPP;
 219         }
 220
 221         return 0;
 222 }
 223
 224 static int bfin_can_get_berr_counter(const struct net_device *dev,
 225                                      struct can_berr_counter *bec)
 226 {
 227         struct bfin_can_priv *priv = netdev_priv(dev);
 228         struct bfin_can_regs __iomem *reg = priv->membase;
 229
 230         u16 cec = bfin_read(&reg->cec);
 231
 232         bec->txerr = cec >> 8;
 233         bec->rxerr = cec;
 234
 235         return 0;
 236 }
 237
 238 static int bfin_can_start_xmit(struct sk_buff *skb, struct net_device *dev)
 239 {
 240         struct bfin_can_priv *priv = netdev_priv(dev);
 241         struct bfin_can_regs __iomem *reg = priv->membase;
 242         struct can_frame *cf = (struct can_frame *)skb->data;
 243         u8 dlc = cf->can_dlc;
 244         canid_t id = cf->can_id;
 245         u8 *data = cf->data;
 246         u16 val;
 247         int i;
 248
 249         if (can_dropped_invalid_skb(dev, skb))
 250                 return NETDEV_TX_OK;
 251
 252         netif_stop_queue(dev);
 253
 254         /* fill id */
 255         if (id & CAN_EFF_FLAG) {
 256                 bfin_write(&reg->chl[TRANSMIT_CHL].id0, id);
 257                 val = ((id & 0x1FFF0000) >> 16) | IDE;
 258         } else
 259                 val = (id << 2);
 260         if (id & CAN_RTR_FLAG)
 261                 val |= RTR;
 262         bfin_write(&reg->chl[TRANSMIT_CHL].id1, val | AME);
 263
 264         /* fill payload */
 265         for (i = 0; i < 8; i += 2) {
 266                 val = ((7 - i) < dlc ? (data[7 - i]) : 0) +
 267                         ((6 - i) < dlc ? (data[6 - i] << 8) : 0);
 268                 bfin_write(&reg->chl[TRANSMIT_CHL].data[i], val);
 269         }
 270
 271         /* fill data length code */
 272         bfin_write(&reg->chl[TRANSMIT_CHL].dlc, dlc);
 273
 274         can_put_echo_skb(skb, dev, 0);
 275
 276         /* set transmit request */
 277         bfin_write(&reg->trs2, BIT(TRANSMIT_CHL - 16));
 278
 279         return 0;
 280 }
 281
 282 static void bfin_can_rx(struct net_device *dev, u16 isrc)
 283 {
 284         struct bfin_can_priv *priv = netdev_priv(dev);
 285         struct net_device_stats *stats = &dev->stats;
 286         struct bfin_can_regs __iomem *reg = priv->membase;
 287         struct can_frame *cf;
 288         struct sk_buff *skb;
 289         int obj;
 290         int i;
 291         u16 val;
 292
 293         skb = alloc_can_skb(dev, &cf);
 294         if (skb == NULL)
 295                 return;
 296
 297         /* get id */
 298         if (isrc & BIT(RECEIVE_EXT_CHL)) {
 299                 /* extended frame format (EFF) */
 300                 cf->can_id = ((bfin_read(&reg->chl[RECEIVE_EXT_CHL].id1)
 301                              & 0x1FFF) << 16)
 302                              + bfin_read(&reg->chl[RECEIVE_EXT_CHL].id0);
 303                 cf->can_id |= CAN_EFF_FLAG;
 304                 obj = RECEIVE_EXT_CHL;
 305         } else {
 306                 /* standard frame format (SFF) */
 307                 cf->can_id = (bfin_read(&reg->chl[RECEIVE_STD_CHL].id1)
 308                              & 0x1ffc) >> 2;
 309                 obj = RECEIVE_STD_CHL;
 310         }
 311         if (bfin_read(&reg->chl[obj].id1) & RTR)
 312                 cf->can_id |= CAN_RTR_FLAG;
 313
 314         /* get data length code */
 315         cf->can_dlc = get_can_dlc(bfin_read(&reg->chl[obj].dlc) & 0xF);
 316
 317         /* get payload */
 318         for (i = 0; i < 8; i += 2) {
 319                 val = bfin_read(&reg->chl[obj].data[i]);
 320                 cf->data[7 - i] = (7 - i) < cf->can_dlc ? val : 0;
 321                 cf->data[6 - i] = (6 - i) < cf->can_dlc ? (val >> 8) : 0;
 322         }
 323
 324         netif_rx(skb);
 325
 326         stats->rx_packets++;
 327         stats->rx_bytes += cf->can_dlc;
 328 }
 329
 330 static int bfin_can_err(struct net_device *dev, u16 isrc, u16 status)
 331 {
 332         struct bfin_can_priv *priv = netdev_priv(dev);
 333         struct bfin_can_regs __iomem *reg = priv->membase;
 334         struct net_device_stats *stats = &dev->stats;
 335         struct can_frame *cf;
 336         struct sk_buff *skb;
 337         enum can_state state = priv->can.state;
 338
 339         skb = alloc_can_err_skb(dev, &cf);
 340         if (skb == NULL)
 341                 return -ENOMEM;
 342
 343         if (isrc & RMLIS) {
 344                 /* data overrun interrupt */
 345                 netdev_dbg(dev, "data overrun interrupt\n");
 346                 cf->can_id |= CAN_ERR_CRTL;
 347                 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 348                 stats->rx_over_errors++;
 349                 stats->rx_errors++;
 350         }
 351
 352         if (isrc & BOIS) {
 353                 netdev_dbg(dev, "bus-off mode interrupt\n");
 354                 state = CAN_STATE_BUS_OFF;
 355                 cf->can_id |= CAN_ERR_BUSOFF;
 356                 can_bus_off(dev);
 357         }
 358
 359         if (isrc & EPIS) {
 360                 /* error passive interrupt */
 361                 netdev_dbg(dev, "error passive interrupt\n");
 362                 state = CAN_STATE_ERROR_PASSIVE;
 363         }
 364
 365         if ((isrc & EWTIS) || (isrc & EWRIS)) {
 366                 netdev_dbg(dev, "Error Warning Transmit/Receive Interrupt\n");
 367                 state = CAN_STATE_ERROR_WARNING;
 368         }
 369
 370         if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
 371                                 state == CAN_STATE_ERROR_PASSIVE)) {
 372                 u16 cec = bfin_read(&reg->cec);
 373                 u8 rxerr = cec;
 374                 u8 txerr = cec >> 8;
 375
 376                 cf->can_id |= CAN_ERR_CRTL;
 377                 if (state == CAN_STATE_ERROR_WARNING) {
 378                         priv->can.can_stats.error_warning++;
 379                         cf->data[1] = (txerr > rxerr) ?
 380                                 CAN_ERR_CRTL_TX_WARNING :
 381                                 CAN_ERR_CRTL_RX_WARNING;
 382                 } else {
 383                         priv->can.can_stats.error_passive++;
 384                         cf->data[1] = (txerr > rxerr) ?
 385                                 CAN_ERR_CRTL_TX_PASSIVE :
 386                                 CAN_ERR_CRTL_RX_PASSIVE;
 387                 }
 388         }
 389
 390         if (status) {
 391                 priv->can.can_stats.bus_error++;
 392
 393                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 394
 395                 if (status & BEF)
 396                         cf->data[2] |= CAN_ERR_PROT_BIT;
 397                 else if (status & FER)
 398                         cf->data[2] |= CAN_ERR_PROT_FORM;
 399                 else if (status & SER)
 400                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 401                 else
 402                         cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 403         }
 404
 405         priv->can.state = state;
 406
 407         netif_rx(skb);
 408
 409         stats->rx_packets++;
 410         stats->rx_bytes += cf->can_dlc;
 411
 412         return 0;
 413 }
 414
 415 static irqreturn_t bfin_can_interrupt(int irq, void *dev_id)
 416 {
 417         struct net_device *dev = dev_id;
 418         struct bfin_can_priv *priv = netdev_priv(dev);
 419         struct bfin_can_regs __iomem *reg = priv->membase;
 420         struct net_device_stats *stats = &dev->stats;
 421         u16 status, isrc;
 422
 423         if ((irq == priv->tx_irq) && bfin_read(&reg->mbtif2)) {
 424                 /* transmission complete interrupt */
 425                 bfin_write(&reg->mbtif2, 0xFFFF);
 426                 stats->tx_packets++;
 427                 stats->tx_bytes += bfin_read(&reg->chl[TRANSMIT_CHL].dlc);
 428                 can_get_echo_skb(dev, 0);
 429                 netif_wake_queue(dev);
 430         } else if ((irq == priv->rx_irq) && bfin_read(&reg->mbrif1)) {
 431                 /* receive interrupt */
 432                 isrc = bfin_read(&reg->mbrif1);
 433                 bfin_write(&reg->mbrif1, 0xFFFF);
 434                 bfin_can_rx(dev, isrc);
 435         } else if ((irq == priv->err_irq) && bfin_read(&reg->gis)) {
 436                 /* error interrupt */
 437                 isrc = bfin_read(&reg->gis);
 438                 status = bfin_read(&reg->esr);
 439                 bfin_write(&reg->gis, 0x7FF);
 440                 bfin_can_err(dev, isrc, status);
 441         } else {
 442                 return IRQ_NONE;
 443         }
 444
 445         return IRQ_HANDLED;
 446 }
 447
 448 static int bfin_can_open(struct net_device *dev)
 449 {
 450         struct bfin_can_priv *priv = netdev_priv(dev);
 451         int err;
 452
 453         /* set chip into reset mode */
 454         bfin_can_set_reset_mode(dev);
 455
 456         /* common open */
 457         err = open_candev(dev);
 458         if (err)
 459                 goto exit_open;
 460
 461         /* register interrupt handler */
 462         err = request_irq(priv->rx_irq, &bfin_can_interrupt, 0,
 463                         "bfin-can-rx", dev);
 464         if (err)
 465                 goto exit_rx_irq;
 466         err = request_irq(priv->tx_irq, &bfin_can_interrupt, 0,
 467                         "bfin-can-tx", dev);
 468         if (err)
 469                 goto exit_tx_irq;
 470         err = request_irq(priv->err_irq, &bfin_can_interrupt, 0,
 471                         "bfin-can-err", dev);
 472         if (err)
 473                 goto exit_err_irq;
 474
 475         bfin_can_start(dev);
 476
 477         netif_start_queue(dev);
 478
 479         return 0;
 480
 481 exit_err_irq:
 482         free_irq(priv->tx_irq, dev);
 483 exit_tx_irq:
 484         free_irq(priv->rx_irq, dev);
 485 exit_rx_irq:
 486         close_candev(dev);
 487 exit_open:
 488         return err;
 489 }
 490
 491 static int bfin_can_close(struct net_device *dev)
 492 {
 493         struct bfin_can_priv *priv = netdev_priv(dev);
 494
 495         netif_stop_queue(dev);
 496         bfin_can_set_reset_mode(dev);
 497
 498         close_candev(dev);
 499
 500         free_irq(priv->rx_irq, dev);
 501         free_irq(priv->tx_irq, dev);
 502         free_irq(priv->err_irq, dev);
 503
 504         return 0;
 505 }
 506
 507 static struct net_device *alloc_bfin_candev(void)
 508 {
 509         struct net_device *dev;
 510         struct bfin_can_priv *priv;
 511
 512         dev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
 513         if (!dev)
 514                 return NULL;
 515
 516         priv = netdev_priv(dev);
 517
 518         priv->dev = dev;
 519         priv->can.bittiming_const = &bfin_can_bittiming_const;
 520         priv->can.do_set_bittiming = bfin_can_set_bittiming;
 521         priv->can.do_set_mode = bfin_can_set_mode;
 522         priv->can.do_get_berr_counter = bfin_can_get_berr_counter;
 523         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 524
 525         return dev;
 526 }
 527
 528 static const struct net_device_ops bfin_can_netdev_ops = {
 529         .ndo_open               = bfin_can_open,
 530         .ndo_stop               = bfin_can_close,
 531         .ndo_start_xmit         = bfin_can_start_xmit,
 532 };
 533
 534 static int bfin_can_probe(struct platform_device *pdev)
 535 {
 536         int err;
 537         struct net_device *dev;
 538         struct bfin_can_priv *priv;
 539         struct resource *res_mem, *rx_irq, *tx_irq, *err_irq;
 540         unsigned short *pdata;
 541
 542         pdata = pdev->dev.platform_data;
 543         if (!pdata) {
 544                 dev_err(&pdev->dev, "No platform data provided!\n");
 545                 err = -EINVAL;
 546                 goto exit;
 547         }
 548
 549         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 550         rx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 551         tx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
 552         err_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 2);
 553         if (!res_mem || !rx_irq || !tx_irq || !err_irq) {
 554                 err = -EINVAL;
 555                 goto exit;
 556         }
 557
 558         if (!request_mem_region(res_mem->start, resource_size(res_mem),
 559                                 dev_name(&pdev->dev))) {
 560                 err = -EBUSY;
 561                 goto exit;
 562         }
 563
 564         /* request peripheral pins */
 565         err = peripheral_request_list(pdata, dev_name(&pdev->dev));
 566         if (err)
 567                 goto exit_mem_release;
 568
 569         dev = alloc_bfin_candev();
 570         if (!dev) {
 571                 err = -ENOMEM;
 572                 goto exit_peri_pin_free;
 573         }
 574
 575         priv = netdev_priv(dev);
 576         priv->membase = (void __iomem *)res_mem->start;
 577         priv->rx_irq = rx_irq->start;
 578         priv->tx_irq = tx_irq->start;
 579         priv->err_irq = err_irq->start;
 580         priv->pin_list = pdata;
 581         priv->can.clock.freq = get_sclk();
 582
 583         platform_set_drvdata(pdev, dev);
 584         SET_NETDEV_DEV(dev, &pdev->dev);
 585
 586         dev->flags |= IFF_ECHO; /* we support local echo */
 587         dev->netdev_ops = &bfin_can_netdev_ops;
 588
 589         bfin_can_set_reset_mode(dev);
 590
 591         err = register_candev(dev);
 592         if (err) {
 593                 dev_err(&pdev->dev, "registering failed (err=%d)\n", err);
 594                 goto exit_candev_free;
 595         }
 596
 597         dev_info(&pdev->dev,
 598                 "%s device registered"
 599                 "(&reg_base=%p, rx_irq=%d, tx_irq=%d, err_irq=%d, sclk=%d)\n",
 600                 DRV_NAME, priv->membase, priv->rx_irq,
 601                 priv->tx_irq, priv->err_irq, priv->can.clock.freq);
 602         return 0;
 603
 604 exit_candev_free:
 605         free_candev(dev);
 606 exit_peri_pin_free:
 607         peripheral_free_list(pdata);
 608 exit_mem_release:
 609         release_mem_region(res_mem->start, resource_size(res_mem));
 610 exit:
 611         return err;
 612 }
 613
 614 static int bfin_can_remove(struct platform_device *pdev)
 615 {
 616         struct net_device *dev = platform_get_drvdata(pdev);
 617         struct bfin_can_priv *priv = netdev_priv(dev);
 618         struct resource *res;
 619
 620         bfin_can_set_reset_mode(dev);
 621
 622         unregister_candev(dev);
 623
 624         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 625         release_mem_region(res->start, resource_size(res));
 626
 627         peripheral_free_list(priv->pin_list);
 628
 629         free_candev(dev);
 630         return 0;
 631 }
 632
 633 #ifdef CONFIG_PM
 634 static int bfin_can_suspend(struct platform_device *pdev, pm_message_t mesg)
 635 {
 636         struct net_device *dev = platform_get_drvdata(pdev);
 637         struct bfin_can_priv *priv = netdev_priv(dev);
 638         struct bfin_can_regs __iomem *reg = priv->membase;
 639         int timeout = BFIN_CAN_TIMEOUT;
 640
 641         if (netif_running(dev)) {
 642                 /* enter sleep mode */
 643                 bfin_write(&reg->control, bfin_read(&reg->control) | SMR);
 644                 SSYNC();
 645                 while (!(bfin_read(&reg->intr) & SMACK)) {
 646                         udelay(10);
 647                         if (--timeout == 0) {
 648                                 netdev_err(dev, "fail to enter sleep mode\n");
 649                                 BUG();
 650                         }
 651                 }
 652         }
 653
 654         return 0;
 655 }
 656
 657 static int bfin_can_resume(struct platform_device *pdev)
 658 {
 659         struct net_device *dev = platform_get_drvdata(pdev);
 660         struct bfin_can_priv *priv = netdev_priv(dev);
 661         struct bfin_can_regs __iomem *reg = priv->membase;
 662
 663         if (netif_running(dev)) {
 664                 /* leave sleep mode */
 665                 bfin_write(&reg->intr, 0);
 666                 SSYNC();
 667         }
 668
 669         return 0;
 670 }
 671 #else
 672 #define bfin_can_suspend NULL
 673 #define bfin_can_resume NULL
 674 #endif  /* CONFIG_PM */
 675
 676 static struct platform_driver bfin_can_driver = {
 677         .probe = bfin_can_probe,
 678         .remove = bfin_can_remove,
 679         .suspend = bfin_can_suspend,
 680         .resume = bfin_can_resume,
 681         .driver = {
 682                 .name = DRV_NAME,
 683                 .owner = THIS_MODULE,
 684         },
 685 };
 686
 687 module_platform_driver(bfin_can_driver);
 688
 689 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 690 MODULE_LICENSE("GPL");
 691 MODULE_DESCRIPTION("Blackfin on-chip CAN netdevice driver");
 692 MODULE_ALIAS("platform:" DRV_NAME);