drivers/net/can/mscan/mscan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * CAN bus driver for the alone generic (as possible as) MSCAN controller.
   4  *
   5  * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
   6  *                         Varma Electronics Oy
   7  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   8  * Copyright (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/delay.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/if_arp.h>
  17 #include <linux/if_ether.h>
  18 #include <linux/list.h>
  19 #include <linux/can/dev.h>
  20 #include <linux/can/error.h>
  21 #include <linux/io.h>
  22
  23 #include "mscan.h"
  24
  25 static const struct can_bittiming_const mscan_bittiming_const = {
  26         .name = "mscan",
  27         .tseg1_min = 4,
  28         .tseg1_max = 16,
  29         .tseg2_min = 2,
  30         .tseg2_max = 8,
  31         .sjw_max = 4,
  32         .brp_min = 1,
  33         .brp_max = 64,
  34         .brp_inc = 1,
  35 };
  36
  37 struct mscan_state {
  38         u8 mode;
  39         u8 canrier;
  40         u8 cantier;
  41 };
  42
  43 static enum can_state state_map[] = {
  44         CAN_STATE_ERROR_ACTIVE,
  45         CAN_STATE_ERROR_WARNING,
  46         CAN_STATE_ERROR_PASSIVE,
  47         CAN_STATE_BUS_OFF
  48 };
  49
  50 static int mscan_set_mode(struct net_device *dev, u8 mode)
  51 {
  52         struct mscan_priv *priv = netdev_priv(dev);
  53         struct mscan_regs __iomem *regs = priv->reg_base;
  54         int ret = 0;
  55         int i;
  56         u8 canctl1;
  57
  58         if (mode != MSCAN_NORMAL_MODE) {
  59                 if (priv->tx_active) {
  60                         /* Abort transfers before going to sleep */#
  61                         out_8(&regs->cantarq, priv->tx_active);
  62                         /* Suppress TX done interrupts */
  63                         out_8(&regs->cantier, 0);
  64                 }
  65
  66                 canctl1 = in_8(&regs->canctl1);
  67                 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
  68                         setbits8(&regs->canctl0, MSCAN_SLPRQ);
  69                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
  70                                 if (in_8(&regs->canctl1) & MSCAN_SLPAK)
  71                                         break;
  72                                 udelay(100);
  73                         }
  74                         /*
  75                          * The mscan controller will fail to enter sleep mode,
  76                          * while there are irregular activities on bus, like
  77                          * somebody keeps retransmitting. This behavior is
  78                          * undocumented and seems to differ between mscan built
  79                          * in mpc5200b and mpc5200. We proceed in that case,
  80                          * since otherwise the slprq will be kept set and the
  81                          * controller will get stuck. NOTE: INITRQ or CSWAI
  82                          * will abort all active transmit actions, if still
  83                          * any, at once.
  84                          */
  85                         if (i >= MSCAN_SET_MODE_RETRIES)
  86                                 netdev_dbg(dev,
  87                                            "device failed to enter sleep mode. "
  88                                            "We proceed anyhow.\n");
  89                         else
  90                                 priv->can.state = CAN_STATE_SLEEPING;
  91                 }
  92
  93                 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
  94                         setbits8(&regs->canctl0, MSCAN_INITRQ);
  95                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
  96                                 if (in_8(&regs->canctl1) & MSCAN_INITAK)
  97                                         break;
  98                         }
  99                         if (i >= MSCAN_SET_MODE_RETRIES)
 100                                 ret = -ENODEV;
 101                 }
 102                 if (!ret)
 103                         priv->can.state = CAN_STATE_STOPPED;
 104
 105                 if (mode & MSCAN_CSWAI)
 106                         setbits8(&regs->canctl0, MSCAN_CSWAI);
 107
 108         } else {
 109                 canctl1 = in_8(&regs->canctl1);
 110                 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
 111                         clrbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
 112                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
 113                                 canctl1 = in_8(&regs->canctl1);
 114                                 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
 115                                         break;
 116                         }
 117                         if (i >= MSCAN_SET_MODE_RETRIES)
 118                                 ret = -ENODEV;
 119                         else
 120                                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 121                 }
 122         }
 123         return ret;
 124 }
 125
 126 static int mscan_start(struct net_device *dev)
 127 {
 128         struct mscan_priv *priv = netdev_priv(dev);
 129         struct mscan_regs __iomem *regs = priv->reg_base;
 130         u8 canrflg;
 131         int err;
 132
 133         out_8(&regs->canrier, 0);
 134
 135         INIT_LIST_HEAD(&priv->tx_head);
 136         priv->prev_buf_id = 0;
 137         priv->cur_pri = 0;
 138         priv->tx_active = 0;
 139         priv->shadow_canrier = 0;
 140         priv->flags = 0;
 141
 142         if (priv->type == MSCAN_TYPE_MPC5121) {
 143                 /* Clear pending bus-off condition */
 144                 if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
 145                         out_8(&regs->canmisc, MSCAN_BOHOLD);
 146         }
 147
 148         err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
 149         if (err)
 150                 return err;
 151
 152         canrflg = in_8(&regs->canrflg);
 153         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 154         priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
 155                                     MSCAN_STATE_TX(canrflg))];
 156         out_8(&regs->cantier, 0);
 157
 158         /* Enable receive interrupts. */
 159         out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 160
 161         return 0;
 162 }
 163
 164 static int mscan_restart(struct net_device *dev)
 165 {
 166         struct mscan_priv *priv = netdev_priv(dev);
 167
 168         if (priv->type == MSCAN_TYPE_MPC5121) {
 169                 struct mscan_regs __iomem *regs = priv->reg_base;
 170
 171                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 172                 WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
 173                      "bus-off state expected\n");
 174                 out_8(&regs->canmisc, MSCAN_BOHOLD);
 175                 /* Re-enable receive interrupts. */
 176                 out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 177         } else {
 178                 if (priv->can.state <= CAN_STATE_BUS_OFF)
 179                         mscan_set_mode(dev, MSCAN_INIT_MODE);
 180                 return mscan_start(dev);
 181         }
 182
 183         return 0;
 184 }
 185
 186 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 187 {
 188         struct can_frame *frame = (struct can_frame *)skb->data;
 189         struct mscan_priv *priv = netdev_priv(dev);
 190         struct mscan_regs __iomem *regs = priv->reg_base;
 191         int i, rtr, buf_id;
 192         u32 can_id;
 193
 194         if (can_dropped_invalid_skb(dev, skb))
 195                 return NETDEV_TX_OK;
 196
 197         out_8(&regs->cantier, 0);
 198
 199         i = ~priv->tx_active & MSCAN_TXE;
 200         buf_id = ffs(i) - 1;
 201         switch (hweight8(i)) {
 202         case 0:
 203                 netif_stop_queue(dev);
 204                 netdev_err(dev, "Tx Ring full when queue awake!\n");
 205                 return NETDEV_TX_BUSY;
 206         case 1:
 207                 /*
 208                  * if buf_id < 3, then current frame will be send out of order,
 209                  * since buffer with lower id have higher priority (hell..)
 210                  */
 211                 netif_stop_queue(dev);
 212                 fallthrough;
 213         case 2:
 214                 if (buf_id < priv->prev_buf_id) {
 215                         priv->cur_pri++;
 216                         if (priv->cur_pri == 0xff) {
 217                                 set_bit(F_TX_WAIT_ALL, &priv->flags);
 218                                 netif_stop_queue(dev);
 219                         }
 220                 }
 221                 set_bit(F_TX_PROGRESS, &priv->flags);
 222                 break;
 223         }
 224         priv->prev_buf_id = buf_id;
 225         out_8(&regs->cantbsel, i);
 226
 227         rtr = frame->can_id & CAN_RTR_FLAG;
 228
 229         /* RTR is always the lowest bit of interest, then IDs follow */
 230         if (frame->can_id & CAN_EFF_FLAG) {
 231                 can_id = (frame->can_id & CAN_EFF_MASK)
 232                          << (MSCAN_EFF_RTR_SHIFT + 1);
 233                 if (rtr)
 234                         can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
 235                 out_be16(&regs->tx.idr3_2, can_id);
 236
 237                 can_id >>= 16;
 238                 /* EFF_FLAGS are between the IDs :( */
 239                 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
 240                          | MSCAN_EFF_FLAGS;
 241         } else {
 242                 can_id = (frame->can_id & CAN_SFF_MASK)
 243                          << (MSCAN_SFF_RTR_SHIFT + 1);
 244                 if (rtr)
 245                         can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
 246         }
 247         out_be16(&regs->tx.idr1_0, can_id);
 248
 249         if (!rtr) {
 250                 void __iomem *data = &regs->tx.dsr1_0;
 251                 u16 *payload = (u16 *)frame->data;
 252
 253                 for (i = 0; i < frame->len / 2; i++) {
 254                         out_be16(data, *payload++);
 255                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 256                 }
 257                 /* write remaining byte if necessary */
 258                 if (frame->len & 1)
 259                         out_8(data, frame->data[frame->len - 1]);
 260         }
 261
 262         out_8(&regs->tx.dlr, frame->len);
 263         out_8(&regs->tx.tbpr, priv->cur_pri);
 264
 265         /* Start transmission. */
 266         out_8(&regs->cantflg, 1 << buf_id);
 267
 268         if (!test_bit(F_TX_PROGRESS, &priv->flags))
 269                 netif_trans_update(dev);
 270
 271         list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
 272
 273         can_put_echo_skb(skb, dev, buf_id);
 274
 275         /* Enable interrupt. */
 276         priv->tx_active |= 1 << buf_id;
 277         out_8(&regs->cantier, priv->tx_active);
 278
 279         return NETDEV_TX_OK;
 280 }
 281
 282 static enum can_state get_new_state(struct net_device *dev, u8 canrflg)
 283 {
 284         struct mscan_priv *priv = netdev_priv(dev);
 285
 286         if (unlikely(canrflg & MSCAN_CSCIF))
 287                 return state_map[max(MSCAN_STATE_RX(canrflg),
 288                                  MSCAN_STATE_TX(canrflg))];
 289
 290         return priv->can.state;
 291 }
 292
 293 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
 294 {
 295         struct mscan_priv *priv = netdev_priv(dev);
 296         struct mscan_regs __iomem *regs = priv->reg_base;
 297         u32 can_id;
 298         int i;
 299
 300         can_id = in_be16(&regs->rx.idr1_0);
 301         if (can_id & (1 << 3)) {
 302                 frame->can_id = CAN_EFF_FLAG;
 303                 can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
 304                 can_id = ((can_id & 0xffe00000) |
 305                           ((can_id & 0x7ffff) << 2)) >> 2;
 306         } else {
 307                 can_id >>= 4;
 308                 frame->can_id = 0;
 309         }
 310
 311         frame->can_id |= can_id >> 1;
 312         if (can_id & 1)
 313                 frame->can_id |= CAN_RTR_FLAG;
 314
 315         frame->len = can_cc_dlc2len(in_8(&regs->rx.dlr) & 0xf);
 316
 317         if (!(frame->can_id & CAN_RTR_FLAG)) {
 318                 void __iomem *data = &regs->rx.dsr1_0;
 319                 u16 *payload = (u16 *)frame->data;
 320
 321                 for (i = 0; i < frame->len / 2; i++) {
 322                         *payload++ = in_be16(data);
 323                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 324                 }
 325                 /* read remaining byte if necessary */
 326                 if (frame->len & 1)
 327                         frame->data[frame->len - 1] = in_8(data);
 328         }
 329
 330         out_8(&regs->canrflg, MSCAN_RXF);
 331 }
 332
 333 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
 334                                 u8 canrflg)
 335 {
 336         struct mscan_priv *priv = netdev_priv(dev);
 337         struct mscan_regs __iomem *regs = priv->reg_base;
 338         struct net_device_stats *stats = &dev->stats;
 339         enum can_state new_state;
 340
 341         netdev_dbg(dev, "error interrupt (canrflg=%#x)\n", canrflg);
 342         frame->can_id = CAN_ERR_FLAG;
 343
 344         if (canrflg & MSCAN_OVRIF) {
 345                 frame->can_id |= CAN_ERR_CRTL;
 346                 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 347                 stats->rx_over_errors++;
 348                 stats->rx_errors++;
 349         } else {
 350                 frame->data[1] = 0;
 351         }
 352
 353         new_state = get_new_state(dev, canrflg);
 354         if (new_state != priv->can.state) {
 355                 can_change_state(dev, frame,
 356                                  state_map[MSCAN_STATE_TX(canrflg)],
 357                                  state_map[MSCAN_STATE_RX(canrflg)]);
 358
 359                 if (priv->can.state == CAN_STATE_BUS_OFF) {
 360                         /*
 361                          * The MSCAN on the MPC5200 does recover from bus-off
 362                          * automatically. To avoid that we stop the chip doing
 363                          * a light-weight stop (we are in irq-context).
 364                          */
 365                         if (priv->type != MSCAN_TYPE_MPC5121) {
 366                                 out_8(&regs->cantier, 0);
 367                                 out_8(&regs->canrier, 0);
 368                                 setbits8(&regs->canctl0,
 369                                          MSCAN_SLPRQ | MSCAN_INITRQ);
 370                         }
 371                         can_bus_off(dev);
 372                 }
 373         }
 374         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 375         frame->len = CAN_ERR_DLC;
 376         out_8(&regs->canrflg, MSCAN_ERR_IF);
 377 }
 378
 379 static int mscan_rx_poll(struct napi_struct *napi, int quota)
 380 {
 381         struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
 382         struct net_device *dev = napi->dev;
 383         struct mscan_regs __iomem *regs = priv->reg_base;
 384         struct net_device_stats *stats = &dev->stats;
 385         int work_done = 0;
 386         struct sk_buff *skb;
 387         struct can_frame *frame;
 388         u8 canrflg;
 389
 390         while (work_done < quota) {
 391                 canrflg = in_8(&regs->canrflg);
 392                 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
 393                         break;
 394
 395                 skb = alloc_can_skb(dev, &frame);
 396                 if (!skb) {
 397                         if (printk_ratelimit())
 398                                 netdev_notice(dev, "packet dropped\n");
 399                         stats->rx_dropped++;
 400                         out_8(&regs->canrflg, canrflg);
 401                         continue;
 402                 }
 403
 404                 if (canrflg & MSCAN_RXF)
 405                         mscan_get_rx_frame(dev, frame);
 406                 else if (canrflg & MSCAN_ERR_IF)
 407                         mscan_get_err_frame(dev, frame, canrflg);
 408
 409                 stats->rx_packets++;
 410                 stats->rx_bytes += frame->len;
 411                 work_done++;
 412                 netif_receive_skb(skb);
 413         }
 414
 415         if (work_done < quota) {
 416                 if (likely(napi_complete_done(&priv->napi, work_done))) {
 417                         clear_bit(F_RX_PROGRESS, &priv->flags);
 418                         if (priv->can.state < CAN_STATE_BUS_OFF)
 419                                 out_8(&regs->canrier, priv->shadow_canrier);
 420                 }
 421         }
 422         return work_done;
 423 }
 424
 425 static irqreturn_t mscan_isr(int irq, void *dev_id)
 426 {
 427         struct net_device *dev = (struct net_device *)dev_id;
 428         struct mscan_priv *priv = netdev_priv(dev);
 429         struct mscan_regs __iomem *regs = priv->reg_base;
 430         struct net_device_stats *stats = &dev->stats;
 431         u8 cantier, cantflg, canrflg;
 432         irqreturn_t ret = IRQ_NONE;
 433
 434         cantier = in_8(&regs->cantier) & MSCAN_TXE;
 435         cantflg = in_8(&regs->cantflg) & cantier;
 436
 437         if (cantier && cantflg) {
 438                 struct list_head *tmp, *pos;
 439
 440                 list_for_each_safe(pos, tmp, &priv->tx_head) {
 441                         struct tx_queue_entry *entry =
 442                             list_entry(pos, struct tx_queue_entry, list);
 443                         u8 mask = entry->mask;
 444
 445                         if (!(cantflg & mask))
 446                                 continue;
 447
 448                         out_8(&regs->cantbsel, mask);
 449                         stats->tx_bytes += in_8(&regs->tx.dlr);
 450                         stats->tx_packets++;
 451                         can_get_echo_skb(dev, entry->id);
 452                         priv->tx_active &= ~mask;
 453                         list_del(pos);
 454                 }
 455
 456                 if (list_empty(&priv->tx_head)) {
 457                         clear_bit(F_TX_WAIT_ALL, &priv->flags);
 458                         clear_bit(F_TX_PROGRESS, &priv->flags);
 459                         priv->cur_pri = 0;
 460                 } else {
 461                         netif_trans_update(dev);
 462                 }
 463
 464                 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
 465                         netif_wake_queue(dev);
 466
 467                 out_8(&regs->cantier, priv->tx_active);
 468                 ret = IRQ_HANDLED;
 469         }
 470
 471         canrflg = in_8(&regs->canrflg);
 472         if ((canrflg & ~MSCAN_STAT_MSK) &&
 473             !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
 474                 if (canrflg & ~MSCAN_STAT_MSK) {
 475                         priv->shadow_canrier = in_8(&regs->canrier);
 476                         out_8(&regs->canrier, 0);
 477                         napi_schedule(&priv->napi);
 478                         ret = IRQ_HANDLED;
 479                 } else {
 480                         clear_bit(F_RX_PROGRESS, &priv->flags);
 481                 }
 482         }
 483         return ret;
 484 }
 485
 486 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
 487 {
 488         int ret = 0;
 489
 490         switch (mode) {
 491         case CAN_MODE_START:
 492                 ret = mscan_restart(dev);
 493                 if (ret)
 494                         break;
 495                 if (netif_queue_stopped(dev))
 496                         netif_wake_queue(dev);
 497                 break;
 498
 499         default:
 500                 ret = -EOPNOTSUPP;
 501                 break;
 502         }
 503         return ret;
 504 }
 505
 506 static int mscan_do_set_bittiming(struct net_device *dev)
 507 {
 508         struct mscan_priv *priv = netdev_priv(dev);
 509         struct mscan_regs __iomem *regs = priv->reg_base;
 510         struct can_bittiming *bt = &priv->can.bittiming;
 511         u8 btr0, btr1;
 512
 513         btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
 514         btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
 515                 BTR1_SET_TSEG2(bt->phase_seg2) |
 516                 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
 517
 518         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 519
 520         out_8(&regs->canbtr0, btr0);
 521         out_8(&regs->canbtr1, btr1);
 522
 523         return 0;
 524 }
 525
 526 static int mscan_get_berr_counter(const struct net_device *dev,
 527                                   struct can_berr_counter *bec)
 528 {
 529         struct mscan_priv *priv = netdev_priv(dev);
 530         struct mscan_regs __iomem *regs = priv->reg_base;
 531
 532         bec->txerr = in_8(&regs->cantxerr);
 533         bec->rxerr = in_8(&regs->canrxerr);
 534
 535         return 0;
 536 }
 537
 538 static int mscan_open(struct net_device *dev)
 539 {
 540         int ret;
 541         struct mscan_priv *priv = netdev_priv(dev);
 542         struct mscan_regs __iomem *regs = priv->reg_base;
 543
 544         ret = clk_prepare_enable(priv->clk_ipg);
 545         if (ret)
 546                 goto exit_retcode;
 547         ret = clk_prepare_enable(priv->clk_can);
 548         if (ret)
 549                 goto exit_dis_ipg_clock;
 550
 551         /* common open */
 552         ret = open_candev(dev);
 553         if (ret)
 554                 goto exit_dis_can_clock;
 555
 556         napi_enable(&priv->napi);
 557
 558         ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
 559         if (ret < 0) {
 560                 netdev_err(dev, "failed to attach interrupt\n");
 561                 goto exit_napi_disable;
 562         }
 563
 564         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 565                 setbits8(&regs->canctl1, MSCAN_LISTEN);
 566         else
 567                 clrbits8(&regs->canctl1, MSCAN_LISTEN);
 568
 569         ret = mscan_start(dev);
 570         if (ret)
 571                 goto exit_free_irq;
 572
 573         netif_start_queue(dev);
 574
 575         return 0;
 576
 577 exit_free_irq:
 578         free_irq(dev->irq, dev);
 579 exit_napi_disable:
 580         napi_disable(&priv->napi);
 581         close_candev(dev);
 582 exit_dis_can_clock:
 583         clk_disable_unprepare(priv->clk_can);
 584 exit_dis_ipg_clock:
 585         clk_disable_unprepare(priv->clk_ipg);
 586 exit_retcode:
 587         return ret;
 588 }
 589
 590 static int mscan_close(struct net_device *dev)
 591 {
 592         struct mscan_priv *priv = netdev_priv(dev);
 593         struct mscan_regs __iomem *regs = priv->reg_base;
 594
 595         netif_stop_queue(dev);
 596         napi_disable(&priv->napi);
 597
 598         out_8(&regs->cantier, 0);
 599         out_8(&regs->canrier, 0);
 600         mscan_set_mode(dev, MSCAN_INIT_MODE);
 601         close_candev(dev);
 602         free_irq(dev->irq, dev);
 603
 604         clk_disable_unprepare(priv->clk_can);
 605         clk_disable_unprepare(priv->clk_ipg);
 606
 607         return 0;
 608 }
 609
 610 static const struct net_device_ops mscan_netdev_ops = {
 611         .ndo_open       = mscan_open,
 612         .ndo_stop       = mscan_close,
 613         .ndo_start_xmit = mscan_start_xmit,
 614         .ndo_change_mtu = can_change_mtu,
 615 };
 616
 617 int register_mscandev(struct net_device *dev, int mscan_clksrc)
 618 {
 619         struct mscan_priv *priv = netdev_priv(dev);
 620         struct mscan_regs __iomem *regs = priv->reg_base;
 621         u8 ctl1;
 622
 623         ctl1 = in_8(&regs->canctl1);
 624         if (mscan_clksrc)
 625                 ctl1 |= MSCAN_CLKSRC;
 626         else
 627                 ctl1 &= ~MSCAN_CLKSRC;
 628
 629         if (priv->type == MSCAN_TYPE_MPC5121) {
 630                 priv->can.do_get_berr_counter = mscan_get_berr_counter;
 631                 ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
 632         }
 633
 634         ctl1 |= MSCAN_CANE;
 635         out_8(&regs->canctl1, ctl1);
 636         udelay(100);
 637
 638         /* acceptance mask/acceptance code (accept everything) */
 639         out_be16(&regs->canidar1_0, 0);
 640         out_be16(&regs->canidar3_2, 0);
 641         out_be16(&regs->canidar5_4, 0);
 642         out_be16(&regs->canidar7_6, 0);
 643
 644         out_be16(&regs->canidmr1_0, 0xffff);
 645         out_be16(&regs->canidmr3_2, 0xffff);
 646         out_be16(&regs->canidmr5_4, 0xffff);
 647         out_be16(&regs->canidmr7_6, 0xffff);
 648         /* Two 32 bit Acceptance Filters */
 649         out_8(&regs->canidac, MSCAN_AF_32BIT);
 650
 651         mscan_set_mode(dev, MSCAN_INIT_MODE);
 652
 653         return register_candev(dev);
 654 }
 655
 656 void unregister_mscandev(struct net_device *dev)
 657 {
 658         struct mscan_priv *priv = netdev_priv(dev);
 659         struct mscan_regs __iomem *regs = priv->reg_base;
 660         mscan_set_mode(dev, MSCAN_INIT_MODE);
 661         clrbits8(&regs->canctl1, MSCAN_CANE);
 662         unregister_candev(dev);
 663 }
 664
 665 struct net_device *alloc_mscandev(void)
 666 {
 667         struct net_device *dev;
 668         struct mscan_priv *priv;
 669         int i;
 670
 671         dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
 672         if (!dev)
 673                 return NULL;
 674         priv = netdev_priv(dev);
 675
 676         dev->netdev_ops = &mscan_netdev_ops;
 677
 678         dev->flags |= IFF_ECHO; /* we support local echo */
 679
 680         netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
 681
 682         priv->can.bittiming_const = &mscan_bittiming_const;
 683         priv->can.do_set_bittiming = mscan_do_set_bittiming;
 684         priv->can.do_set_mode = mscan_do_set_mode;
 685         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 686                 CAN_CTRLMODE_LISTENONLY;
 687
 688         for (i = 0; i < TX_QUEUE_SIZE; i++) {
 689                 priv->tx_queue[i].id = i;
 690                 priv->tx_queue[i].mask = 1 << i;
 691         }
 692
 693         return dev;
 694 }
 695
 696 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
 697 MODULE_LICENSE("GPL v2");
 698 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");