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 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_write16(&reg->clock, clk);
  83        bfin_write16(&reg->timing, timing);
  84
  85        dev_info(dev->dev.parent, "setting CLOCK=0x%04x TIMING=0x%04x\n",
  86                        clk, timing);
  87
  88        return 0;
  89}
  90
  91static void bfin_can_set_reset_mode(struct net_device *dev)
  92{
  93        struct bfin_can_priv *priv = netdev_priv(dev);
  94        struct bfin_can_regs __iomem *reg = priv->membase;
  95        int timeout = BFIN_CAN_TIMEOUT;
  96        int i;
  97
  98        /* disable interrupts */
  99        bfin_write16(&reg->mbim1, 0);
 100        bfin_write16(&reg->mbim2, 0);
 101        bfin_write16(&reg->gim, 0);
 102
 103        /* reset can and enter configuration mode */
 104        bfin_write16(&reg->control, SRS | CCR);
 105        SSYNC();
 106        bfin_write16(&reg->control, CCR);
 107        SSYNC();
 108        while (!(bfin_read16(&reg->control) & CCA)) {
 109                udelay(10);
 110                if (--timeout == 0) {
 111                        dev_err(dev->dev.parent,
 112                                        "fail to enter configuration mode\n");
 113                        BUG();
 114                }
 115        }
 116
 117        /*
 118         * All mailbox configurations are marked as inactive
 119         * by writing to CAN Mailbox Configuration Registers 1 and 2
 120         * For all bits: 0 - Mailbox disabled, 1 - Mailbox enabled
 121         */
 122        bfin_write16(&reg->mc1, 0);
 123        bfin_write16(&reg->mc2, 0);
 124
 125        /* Set Mailbox Direction */
 126        bfin_write16(&reg->md1, 0xFFFF);   /* mailbox 1-16 are RX */
 127        bfin_write16(&reg->md2, 0);   /* mailbox 17-32 are TX */
 128
 129        /* RECEIVE_STD_CHL */
 130        for (i = 0; i < 2; i++) {
 131                bfin_write16(&reg->chl[RECEIVE_STD_CHL + i].id0, 0);
 132                bfin_write16(&reg->chl[RECEIVE_STD_CHL + i].id1, AME);
 133                bfin_write16(&reg->chl[RECEIVE_STD_CHL + i].dlc, 0);
 134                bfin_write16(&reg->msk[RECEIVE_STD_CHL + i].amh, 0x1FFF);
 135                bfin_write16(&reg->msk[RECEIVE_STD_CHL + i].aml, 0xFFFF);
 136        }
 137
 138        /* RECEIVE_EXT_CHL */
 139        for (i = 0; i < 2; i++) {
 140                bfin_write16(&reg->chl[RECEIVE_EXT_CHL + i].id0, 0);
 141                bfin_write16(&reg->chl[RECEIVE_EXT_CHL + i].id1, AME | IDE);
 142                bfin_write16(&reg->chl[RECEIVE_EXT_CHL + i].dlc, 0);
 143                bfin_write16(&reg->msk[RECEIVE_EXT_CHL + i].amh, 0x1FFF);
 144                bfin_write16(&reg->msk[RECEIVE_EXT_CHL + i].aml, 0xFFFF);
 145        }
 146
 147        bfin_write16(&reg->mc2, BIT(TRANSMIT_CHL - 16));
 148        bfin_write16(&reg->mc1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
 149        SSYNC();
 150
 151        priv->can.state = CAN_STATE_STOPPED;
 152}
 153
 154static void bfin_can_set_normal_mode(struct net_device *dev)
 155{
 156        struct bfin_can_priv *priv = netdev_priv(dev);
 157        struct bfin_can_regs __iomem *reg = priv->membase;
 158        int timeout = BFIN_CAN_TIMEOUT;
 159
 160        /*
 161         * leave configuration mode
 162         */
 163        bfin_write16(&reg->control, bfin_read16(&reg->control) & ~CCR);
 164
 165        while (bfin_read16(&reg->status) & CCA) {
 166                udelay(10);
 167                if (--timeout == 0) {
 168                        dev_err(dev->dev.parent,
 169                                        "fail to leave configuration mode\n");
 170                        BUG();
 171                }
 172        }
 173
 174        /*
 175         * clear _All_  tx and rx interrupts
 176         */
 177        bfin_write16(&reg->mbtif1, 0xFFFF);
 178        bfin_write16(&reg->mbtif2, 0xFFFF);
 179        bfin_write16(&reg->mbrif1, 0xFFFF);
 180        bfin_write16(&reg->mbrif2, 0xFFFF);
 181
 182        /*
 183         * clear global interrupt status register
 184         */
 185        bfin_write16(&reg->gis, 0x7FF); /* overwrites with '1' */
 186
 187        /*
 188         * Initialize Interrupts
 189         * - set bits in the mailbox interrupt mask register
 190         * - global interrupt mask
 191         */
 192        bfin_write16(&reg->mbim1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
 193        bfin_write16(&reg->mbim2, BIT(TRANSMIT_CHL - 16));
 194
 195        bfin_write16(&reg->gim, EPIM | BOIM | RMLIM);
 196        SSYNC();
 197}
 198
 199static void bfin_can_start(struct net_device *dev)
 200{
 201        struct bfin_can_priv *priv = netdev_priv(dev);
 202
 203        /* enter reset mode */
 204        if (priv->can.state != CAN_STATE_STOPPED)
 205                bfin_can_set_reset_mode(dev);
 206
 207        /* leave reset mode */
 208        bfin_can_set_normal_mode(dev);
 209}
 210
 211static int bfin_can_set_mode(struct net_device *dev, enum can_mode mode)
 212{
 213        switch (mode) {
 214        case CAN_MODE_START:
 215                bfin_can_start(dev);
 216                if (netif_queue_stopped(dev))
 217                        netif_wake_queue(dev);
 218                break;
 219
 220        default:
 221                return -EOPNOTSUPP;
 222        }
 223
 224        return 0;
 225}
 226
 227static int bfin_can_start_xmit(struct sk_buff *skb, struct net_device *dev)
 228{
 229        struct bfin_can_priv *priv = netdev_priv(dev);
 230        struct bfin_can_regs __iomem *reg = priv->membase;
 231        struct can_frame *cf = (struct can_frame *)skb->data;
 232        u8 dlc = cf->can_dlc;
 233        canid_t id = cf->can_id;
 234        u8 *data = cf->data;
 235        u16 val;
 236        int i;
 237
 238        if (can_dropped_invalid_skb(dev, skb))
 239                return NETDEV_TX_OK;
 240
 241        netif_stop_queue(dev);
 242
 243        /* fill id */
 244        if (id & CAN_EFF_FLAG) {
 245                bfin_write16(&reg->chl[TRANSMIT_CHL].id0, id);
 246                if (id & CAN_RTR_FLAG)
 247                        writew(((id & 0x1FFF0000) >> 16) | IDE | AME | RTR,
 248                                        &reg->chl[TRANSMIT_CHL].id1);
 249                else
 250                        writew(((id & 0x1FFF0000) >> 16) | IDE | AME,
 251                                        &reg->chl[TRANSMIT_CHL].id1);
 252
 253        } else {
 254                if (id & CAN_RTR_FLAG)
 255                        writew((id << 2) | AME | RTR,
 256                                &reg->chl[TRANSMIT_CHL].id1);
 257                else
 258                        bfin_write16(&reg->chl[TRANSMIT_CHL].id1,
 259                                        (id << 2) | AME);
 260        }
 261
 262        /* fill payload */
 263        for (i = 0; i < 8; i += 2) {
 264                val = ((7 - i) < dlc ? (data[7 - i]) : 0) +
 265                        ((6 - i) < dlc ? (data[6 - i] << 8) : 0);
 266                bfin_write16(&reg->chl[TRANSMIT_CHL].data[i], val);
 267        }
 268
 269        /* fill data length code */
 270        bfin_write16(&reg->chl[TRANSMIT_CHL].dlc, dlc);
 271
 272        can_put_echo_skb(skb, dev, 0);
 273
 274        /* set transmit request */
 275        bfin_write16(&reg->trs2, BIT(TRANSMIT_CHL - 16));
 276
 277        return 0;
 278}
 279
 280static void bfin_can_rx(struct net_device *dev, u16 isrc)
 281{
 282        struct bfin_can_priv *priv = netdev_priv(dev);
 283        struct net_device_stats *stats = &dev->stats;
 284        struct bfin_can_regs __iomem *reg = priv->membase;
 285        struct can_frame *cf;
 286        struct sk_buff *skb;
 287        int obj;
 288        int i;
 289        u16 val;
 290
 291        skb = alloc_can_skb(dev, &cf);
 292        if (skb == NULL)
 293                return;
 294
 295        /* get id */
 296        if (isrc & BIT(RECEIVE_EXT_CHL)) {
 297                /* extended frame format (EFF) */
 298                cf->can_id = ((bfin_read16(&reg->chl[RECEIVE_EXT_CHL].id1)
 299                             & 0x1FFF) << 16)
 300                             + bfin_read16(&reg->chl[RECEIVE_EXT_CHL].id0);
 301                cf->can_id |= CAN_EFF_FLAG;
 302                obj = RECEIVE_EXT_CHL;
 303        } else {
 304                /* standard frame format (SFF) */
 305                cf->can_id = (bfin_read16(&reg->chl[RECEIVE_STD_CHL].id1)
 306                             & 0x1ffc) >> 2;
 307                obj = RECEIVE_STD_CHL;
 308        }
 309        if (bfin_read16(&reg->chl[obj].id1) & RTR)
 310                cf->can_id |= CAN_RTR_FLAG;
 311
 312        /* get data length code */
 313        cf->can_dlc = get_can_dlc(bfin_read16(&reg->chl[obj].dlc) & 0xF);
 314
 315        /* get payload */
 316        for (i = 0; i < 8; i += 2) {
 317                val = bfin_read16(&reg->chl[obj].data[i]);
 318                cf->data[7 - i] = (7 - i) < cf->can_dlc ? val : 0;
 319                cf->data[6 - i] = (6 - i) < cf->can_dlc ? (val >> 8) : 0;
 320        }
 321
 322        netif_rx(skb);
 323
 324        stats->rx_packets++;
 325        stats->rx_bytes += cf->can_dlc;
 326}
 327
 328static int bfin_can_err(struct net_device *dev, u16 isrc, u16 status)
 329{
 330        struct bfin_can_priv *priv = netdev_priv(dev);
 331        struct bfin_can_regs __iomem *reg = priv->membase;
 332        struct net_device_stats *stats = &dev->stats;
 333        struct can_frame *cf;
 334        struct sk_buff *skb;
 335        enum can_state state = priv->can.state;
 336
 337        skb = alloc_can_err_skb(dev, &cf);
 338        if (skb == NULL)
 339                return -ENOMEM;
 340
 341        if (isrc & RMLIS) {
 342                /* data overrun interrupt */
 343                dev_dbg(dev->dev.parent, "data overrun interrupt\n");
 344                cf->can_id |= CAN_ERR_CRTL;
 345                cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 346                stats->rx_over_errors++;
 347                stats->rx_errors++;
 348        }
 349
 350        if (isrc & BOIS) {
 351                dev_dbg(dev->dev.parent, "bus-off mode interrupt\n");
 352                state = CAN_STATE_BUS_OFF;
 353                cf->can_id |= CAN_ERR_BUSOFF;
 354                can_bus_off(dev);
 355        }
 356
 357        if (isrc & EPIS) {
 358                /* error passive interrupt */
 359                dev_dbg(dev->dev.parent, "error passive interrupt\n");
 360                state = CAN_STATE_ERROR_PASSIVE;
 361        }
 362
 363        if ((isrc & EWTIS) || (isrc & EWRIS)) {
 364                dev_dbg(dev->dev.parent,
 365                                "Error Warning Transmit/Receive Interrupt\n");
 366                state = CAN_STATE_ERROR_WARNING;
 367        }
 368
 369        if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
 370                                state == CAN_STATE_ERROR_PASSIVE)) {
 371                u16 cec = bfin_read16(&reg->cec);
 372                u8 rxerr = cec;
 373                u8 txerr = cec >> 8;
 374
 375                cf->can_id |= CAN_ERR_CRTL;
 376                if (state == CAN_STATE_ERROR_WARNING) {
 377                        priv->can.can_stats.error_warning++;
 378                        cf->data[1] = (txerr > rxerr) ?
 379                                CAN_ERR_CRTL_TX_WARNING :
 380                                CAN_ERR_CRTL_RX_WARNING;
 381                } else {
 382                        priv->can.can_stats.error_passive++;
 383                        cf->data[1] = (txerr > rxerr) ?
 384                                CAN_ERR_CRTL_TX_PASSIVE :
 385                                CAN_ERR_CRTL_RX_PASSIVE;
 386                }
 387        }
 388
 389        if (status) {
 390                priv->can.can_stats.bus_error++;
 391
 392                cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 393
 394                if (status & BEF)
 395                        cf->data[2] |= CAN_ERR_PROT_BIT;
 396                else if (status & FER)
 397                        cf->data[2] |= CAN_ERR_PROT_FORM;
 398                else if (status & SER)
 399                        cf->data[2] |= CAN_ERR_PROT_STUFF;
 400                else
 401                        cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 402        }
 403
 404        priv->can.state = state;
 405
 406        netif_rx(skb);
 407
 408        stats->rx_packets++;
 409        stats->rx_bytes += cf->can_dlc;
 410
 411        return 0;
 412}
 413
 414irqreturn_t bfin_can_interrupt(int irq, void *dev_id)
 415{
 416        struct net_device *dev = dev_id;
 417        struct bfin_can_priv *priv = netdev_priv(dev);
 418        struct bfin_can_regs __iomem *reg = priv->membase;
 419        struct net_device_stats *stats = &dev->stats;
 420        u16 status, isrc;
 421
 422        if ((irq == priv->tx_irq) && bfin_read16(&reg->mbtif2)) {
 423                /* transmission complete interrupt */
 424                bfin_write16(&reg->mbtif2, 0xFFFF);
 425                stats->tx_packets++;
 426                stats->tx_bytes += bfin_read16(&reg->chl[TRANSMIT_CHL].dlc);
 427                can_get_echo_skb(dev, 0);
 428                netif_wake_queue(dev);
 429        } else if ((irq == priv->rx_irq) && bfin_read16(&reg->mbrif1)) {
 430                /* receive interrupt */
 431                isrc = bfin_read16(&reg->mbrif1);
 432                bfin_write16(&reg->mbrif1, 0xFFFF);
 433                bfin_can_rx(dev, isrc);
 434        } else if ((irq == priv->err_irq) && bfin_read16(&reg->gis)) {
 435                /* error interrupt */
 436                isrc = bfin_read16(&reg->gis);
 437                status = bfin_read16(&reg->esr);
 438                bfin_write16(&reg->gis, 0x7FF);
 439                bfin_can_err(dev, isrc, status);
 440        } else {
 441                return IRQ_NONE;
 442        }
 443
 444        return IRQ_HANDLED;
 445}
 446
 447static int bfin_can_open(struct net_device *dev)
 448{
 449        struct bfin_can_priv *priv = netdev_priv(dev);
 450        int err;
 451
 452        /* set chip into reset mode */
 453        bfin_can_set_reset_mode(dev);
 454
 455        /* common open */
 456        err = open_candev(dev);
 457        if (err)
 458                goto exit_open;
 459
 460        /* register interrupt handler */
 461        err = request_irq(priv->rx_irq, &bfin_can_interrupt, 0,
 462                        "bfin-can-rx", dev);
 463        if (err)
 464                goto exit_rx_irq;
 465        err = request_irq(priv->tx_irq, &bfin_can_interrupt, 0,
 466                        "bfin-can-tx", dev);
 467        if (err)
 468                goto exit_tx_irq;
 469        err = request_irq(priv->err_irq, &bfin_can_interrupt, 0,
 470                        "bfin-can-err", dev);
 471        if (err)
 472                goto exit_err_irq;
 473
 474        bfin_can_start(dev);
 475
 476        netif_start_queue(dev);
 477
 478        return 0;
 479
 480exit_err_irq:
 481        free_irq(priv->tx_irq, dev);
 482exit_tx_irq:
 483        free_irq(priv->rx_irq, dev);
 484exit_rx_irq:
 485        close_candev(dev);
 486exit_open:
 487        return err;
 488}
 489
 490static int bfin_can_close(struct net_device *dev)
 491{
 492        struct bfin_can_priv *priv = netdev_priv(dev);
 493
 494        netif_stop_queue(dev);
 495        bfin_can_set_reset_mode(dev);
 496
 497        close_candev(dev);
 498
 499        free_irq(priv->rx_irq, dev);
 500        free_irq(priv->tx_irq, dev);
 501        free_irq(priv->err_irq, dev);
 502
 503        return 0;
 504}
 505
 506struct net_device *alloc_bfin_candev(void)
 507{
 508        struct net_device *dev;
 509        struct bfin_can_priv *priv;
 510
 511        dev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
 512        if (!dev)
 513                return NULL;
 514
 515        priv = netdev_priv(dev);
 516
 517        priv->dev = dev;
 518        priv->can.bittiming_const = &bfin_can_bittiming_const;
 519        priv->can.do_set_bittiming = bfin_can_set_bittiming;
 520        priv->can.do_set_mode = bfin_can_set_mode;
 521        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 522
 523        return dev;
 524}
 525
 526static const struct net_device_ops bfin_can_netdev_ops = {
 527        .ndo_open               = bfin_can_open,
 528        .ndo_stop               = bfin_can_close,
 529        .ndo_start_xmit         = bfin_can_start_xmit,
 530};
 531
 532static int __devinit bfin_can_probe(struct platform_device *pdev)
 533{
 534        int err;
 535        struct net_device *dev;
 536        struct bfin_can_priv *priv;
 537        struct resource *res_mem, *rx_irq, *tx_irq, *err_irq;
 538        unsigned short *pdata;
 539
 540        pdata = pdev->dev.platform_data;
 541        if (!pdata) {
 542                dev_err(&pdev->dev, "No platform data provided!\n");
 543                err = -EINVAL;
 544                goto exit;
 545        }
 546
 547        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 548        rx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 549        tx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
 550        err_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 2);
 551        if (!res_mem || !rx_irq || !tx_irq || !err_irq) {
 552                err = -EINVAL;
 553                goto exit;
 554        }
 555
 556        if (!request_mem_region(res_mem->start, resource_size(res_mem),
 557                                dev_name(&pdev->dev))) {
 558                err = -EBUSY;
 559                goto exit;
 560        }
 561
 562        /* request peripheral pins */
 563        err = peripheral_request_list(pdata, dev_name(&pdev->dev));
 564        if (err)
 565                goto exit_mem_release;
 566
 567        dev = alloc_bfin_candev();
 568        if (!dev) {
 569                err = -ENOMEM;
 570                goto exit_peri_pin_free;
 571        }
 572
 573        priv = netdev_priv(dev);
 574        priv->membase = (void __iomem *)res_mem->start;
 575        priv->rx_irq = rx_irq->start;
 576        priv->tx_irq = tx_irq->start;
 577        priv->err_irq = err_irq->start;
 578        priv->pin_list = pdata;
 579        priv->can.clock.freq = get_sclk();
 580
 581        dev_set_drvdata(&pdev->dev, dev);
 582        SET_NETDEV_DEV(dev, &pdev->dev);
 583
 584        dev->flags |= IFF_ECHO; /* we support local echo */
 585        dev->netdev_ops = &bfin_can_netdev_ops;
 586
 587        bfin_can_set_reset_mode(dev);
 588
 589        err = register_candev(dev);
 590        if (err) {
 591                dev_err(&pdev->dev, "registering failed (err=%d)\n", err);
 592                goto exit_candev_free;
 593        }
 594
 595        dev_info(&pdev->dev,
 596                "%s device registered"
 597                "(&reg_base=%p, rx_irq=%d, tx_irq=%d, err_irq=%d, sclk=%d)\n",
 598                DRV_NAME, (void *)priv->membase, priv->rx_irq,
 599                priv->tx_irq, priv->err_irq, priv->can.clock.freq);
 600        return 0;
 601
 602exit_candev_free:
 603        free_candev(dev);
 604exit_peri_pin_free:
 605        peripheral_free_list(pdata);
 606exit_mem_release:
 607        release_mem_region(res_mem->start, resource_size(res_mem));
 608exit:
 609        return err;
 610}
 611
 612static int __devexit bfin_can_remove(struct platform_device *pdev)
 613{
 614        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 615        struct bfin_can_priv *priv = netdev_priv(dev);
 616        struct resource *res;
 617
 618        bfin_can_set_reset_mode(dev);
 619
 620        unregister_candev(dev);
 621
 622        dev_set_drvdata(&pdev->dev, NULL);
 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
 634static int bfin_can_suspend(struct platform_device *pdev, pm_message_t mesg)
 635{
 636        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 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_write16(&reg->control, bfin_read16(&reg->control) | SMR);
 644                SSYNC();
 645                while (!(bfin_read16(&reg->intr) & SMACK)) {
 646                        udelay(10);
 647                        if (--timeout == 0) {
 648                                dev_err(dev->dev.parent,
 649                                                "fail to enter sleep mode\n");
 650                                BUG();
 651                        }
 652                }
 653        }
 654
 655        return 0;
 656}
 657
 658static int bfin_can_resume(struct platform_device *pdev)
 659{
 660        struct net_device *dev = dev_get_drvdata(&pdev->dev);
 661        struct bfin_can_priv *priv = netdev_priv(dev);
 662        struct bfin_can_regs __iomem *reg = priv->membase;
 663
 664        if (netif_running(dev)) {
 665                /* leave sleep mode */
 666                bfin_write16(&reg->intr, 0);
 667                SSYNC();
 668        }
 669
 670        return 0;
 671}
 672#else
 673#define bfin_can_suspend NULL
 674#define bfin_can_resume NULL
 675#endif  /* CONFIG_PM */
 676
 677static struct platform_driver bfin_can_driver = {
 678        .probe = bfin_can_probe,
 679        .remove = __devexit_p(bfin_can_remove),
 680        .suspend = bfin_can_suspend,
 681        .resume = bfin_can_resume,
 682        .driver = {
 683                .name = DRV_NAME,
 684                .owner = THIS_MODULE,
 685        },
 686};
 687
 688static int __init bfin_can_init(void)
 689{
 690        return platform_driver_register(&bfin_can_driver);
 691}
 692module_init(bfin_can_init);
 693
 694static void __exit bfin_can_exit(void)
 695{
 696        platform_driver_unregister(&bfin_can_driver);
 697}
 698module_exit(bfin_can_exit);
 699
 700MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 701MODULE_LICENSE("GPL");
 702MODULE_DESCRIPTION("Blackfin on-chip CAN netdevice driver");
 703