LXR linux/drivers/net/can/bfin

   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 */
  34struct 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 */
  47static 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
  64static 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
  90static 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
 152static 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
 196static 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
 208static 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
 224static 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
 238static 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
 282static 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
 330static 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
 415static 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
 448static 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
 481exit_err_irq:
 482        free_irq(priv->tx_irq, dev);
 483exit_tx_irq:
 484        free_irq(priv->rx_irq, dev);
 485exit_rx_irq:
 486        close_candev(dev);
 487exit_open:
 488        return err;
 489}
 490
 491static 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
 507static 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
 528static 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
 534static 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        dev_set_drvdata(&pdev->dev, 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
 604exit_candev_free:
 605        free_candev(dev);
 606exit_peri_pin_free:
 607        peripheral_free_list(pdata);
 608exit_mem_release:
 609        release_mem_region(res_mem->start, resource_size(res_mem));
 610exit:
 611        return err;
 612}
 613
 614static int bfin_can_remove(struct platform_device *pdev)
 615{
 616        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 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        dev_set_drvdata(&pdev->dev, NULL);
 625
 626        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 627        release_mem_region(res->start, resource_size(res));
 628
 629        peripheral_free_list(priv->pin_list);
 630
 631        free_candev(dev);
 632        return 0;
 633}
 634
 635#ifdef CONFIG_PM
 636static int bfin_can_suspend(struct platform_device *pdev, pm_message_t mesg)
 637{
 638        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 639        struct bfin_can_priv *priv = netdev_priv(dev);
 640        struct bfin_can_regs __iomem *reg = priv->membase;
 641        int timeout = BFIN_CAN_TIMEOUT;
 642
 643        if (netif_running(dev)) {
 644                /* enter sleep mode */
 645                bfin_write(&reg->control, bfin_read(&reg->control) | SMR);
 646                SSYNC();
 647                while (!(bfin_read(&reg->intr) & SMACK)) {
 648                        udelay(10);
 649                        if (--timeout == 0) {
 650                                netdev_err(dev, "fail to enter sleep mode\n");
 651                                BUG();
 652                        }
 653                }
 654        }
 655
 656        return 0;
 657}
 658
 659static int bfin_can_resume(struct platform_device *pdev)
 660{
 661        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 662        struct bfin_can_priv *priv = netdev_priv(dev);
 663        struct bfin_can_regs __iomem *reg = priv->membase;
 664
 665        if (netif_running(dev)) {
 666                /* leave sleep mode */
 667                bfin_write(&reg->intr, 0);
 668                SSYNC();
 669        }
 670
 671        return 0;
 672}
 673#else
 674#define bfin_can_suspend NULL
 675#define bfin_can_resume NULL
 676#endif  /* CONFIG_PM */
 677
 678static struct platform_driver bfin_can_driver = {
 679        .probe = bfin_can_probe,
 680        .remove = bfin_can_remove,
 681        .suspend = bfin_can_suspend,
 682        .resume = bfin_can_resume,
 683        .driver = {
 684                .name = DRV_NAME,
 685                .owner = THIS_MODULE,
 686        },
 687};
 688
 689module_platform_driver(bfin_can_driver);
 690
 691MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 692MODULE_LICENSE("GPL");
 693MODULE_DESCRIPTION("Blackfin on-chip CAN netdevice driver");
 694MODULE_ALIAS("platform:" DRV_NAME);
 695