drivers/net/can/mscan/mscan.c

   1 /*
   2  * CAN bus driver for the alone generic (as possible as) MSCAN controller.
   3  *
   4  * Copyright (C) 2005-2006 Andrey Volkov <avolkov@varma-el.com>,
   5  *                         Varma Electronics Oy
   6  * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
   7  * Copyright (C) 2008-2009 Pengutronix <kernel@pengutronix.de>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the version 2 of the GNU General Public License
  11  * as published by the Free Software Foundation
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/delay.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/list.h>
  31 #include <linux/can/dev.h>
  32 #include <linux/can/error.h>
  33 #include <linux/io.h>
  34
  35 #include "mscan.h"
  36
  37 static struct can_bittiming_const mscan_bittiming_const = {
  38         .name = "mscan",
  39         .tseg1_min = 4,
  40         .tseg1_max = 16,
  41         .tseg2_min = 2,
  42         .tseg2_max = 8,
  43         .sjw_max = 4,
  44         .brp_min = 1,
  45         .brp_max = 64,
  46         .brp_inc = 1,
  47 };
  48
  49 struct mscan_state {
  50         u8 mode;
  51         u8 canrier;
  52         u8 cantier;
  53 };
  54
  55 static enum can_state state_map[] = {
  56         CAN_STATE_ERROR_ACTIVE,
  57         CAN_STATE_ERROR_WARNING,
  58         CAN_STATE_ERROR_PASSIVE,
  59         CAN_STATE_BUS_OFF
  60 };
  61
  62 static int mscan_set_mode(struct net_device *dev, u8 mode)
  63 {
  64         struct mscan_priv *priv = netdev_priv(dev);
  65         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
  66         int ret = 0;
  67         int i;
  68         u8 canctl1;
  69
  70         if (mode != MSCAN_NORMAL_MODE) {
  71                 if (priv->tx_active) {
  72                         /* Abort transfers before going to sleep */#
  73                         out_8(&regs->cantarq, priv->tx_active);
  74                         /* Suppress TX done interrupts */
  75                         out_8(&regs->cantier, 0);
  76                 }
  77
  78                 canctl1 = in_8(&regs->canctl1);
  79                 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
  80                         setbits8(&regs->canctl0, MSCAN_SLPRQ);
  81                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
  82                                 if (in_8(&regs->canctl1) & MSCAN_SLPAK)
  83                                         break;
  84                                 udelay(100);
  85                         }
  86                         /*
  87                          * The mscan controller will fail to enter sleep mode,
  88                          * while there are irregular activities on bus, like
  89                          * somebody keeps retransmitting. This behavior is
  90                          * undocumented and seems to differ between mscan built
  91                          * in mpc5200b and mpc5200. We proceed in that case,
  92                          * since otherwise the slprq will be kept set and the
  93                          * controller will get stuck. NOTE: INITRQ or CSWAI
  94                          * will abort all active transmit actions, if still
  95                          * any, at once.
  96                          */
  97                         if (i >= MSCAN_SET_MODE_RETRIES)
  98                                 dev_dbg(dev->dev.parent,
  99                                         "device failed to enter sleep mode. "
 100                                         "We proceed anyhow.\n");
 101                         else
 102                                 priv->can.state = CAN_STATE_SLEEPING;
 103                 }
 104
 105                 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
 106                         setbits8(&regs->canctl0, MSCAN_INITRQ);
 107                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
 108                                 if (in_8(&regs->canctl1) & MSCAN_INITAK)
 109                                         break;
 110                         }
 111                         if (i >= MSCAN_SET_MODE_RETRIES)
 112                                 ret = -ENODEV;
 113                 }
 114                 if (!ret)
 115                         priv->can.state = CAN_STATE_STOPPED;
 116
 117                 if (mode & MSCAN_CSWAI)
 118                         setbits8(&regs->canctl0, MSCAN_CSWAI);
 119
 120         } else {
 121                 canctl1 = in_8(&regs->canctl1);
 122                 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
 123                         clrbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
 124                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
 125                                 canctl1 = in_8(&regs->canctl1);
 126                                 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
 127                                         break;
 128                         }
 129                         if (i >= MSCAN_SET_MODE_RETRIES)
 130                                 ret = -ENODEV;
 131                         else
 132                                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 133                 }
 134         }
 135         return ret;
 136 }
 137
 138 static int mscan_start(struct net_device *dev)
 139 {
 140         struct mscan_priv *priv = netdev_priv(dev);
 141         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 142         u8 canrflg;
 143         int err;
 144
 145         out_8(&regs->canrier, 0);
 146
 147         INIT_LIST_HEAD(&priv->tx_head);
 148         priv->prev_buf_id = 0;
 149         priv->cur_pri = 0;
 150         priv->tx_active = 0;
 151         priv->shadow_canrier = 0;
 152         priv->flags = 0;
 153
 154         if (priv->type == MSCAN_TYPE_MPC5121) {
 155                 /* Clear pending bus-off condition */
 156                 if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
 157                         out_8(&regs->canmisc, MSCAN_BOHOLD);
 158         }
 159
 160         err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
 161         if (err)
 162                 return err;
 163
 164         canrflg = in_8(&regs->canrflg);
 165         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 166         priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
 167                                     MSCAN_STATE_TX(canrflg))];
 168         out_8(&regs->cantier, 0);
 169
 170         /* Enable receive interrupts. */
 171         out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 172
 173         return 0;
 174 }
 175
 176 static int mscan_restart(struct net_device *dev)
 177 {
 178         struct mscan_priv *priv = netdev_priv(dev);
 179
 180         if (priv->type == MSCAN_TYPE_MPC5121) {
 181                 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 182
 183                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 184                 WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
 185                      "bus-off state expected\n");
 186                 out_8(&regs->canmisc, MSCAN_BOHOLD);
 187                 /* Re-enable receive interrupts. */
 188                 out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 189         } else {
 190                 if (priv->can.state <= CAN_STATE_BUS_OFF)
 191                         mscan_set_mode(dev, MSCAN_INIT_MODE);
 192                 return mscan_start(dev);
 193         }
 194
 195         return 0;
 196 }
 197
 198 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 199 {
 200         struct can_frame *frame = (struct can_frame *)skb->data;
 201         struct mscan_priv *priv = netdev_priv(dev);
 202         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 203         int i, rtr, buf_id;
 204         u32 can_id;
 205
 206         if (can_dropped_invalid_skb(dev, skb))
 207                 return NETDEV_TX_OK;
 208
 209         out_8(&regs->cantier, 0);
 210
 211         i = ~priv->tx_active & MSCAN_TXE;
 212         buf_id = ffs(i) - 1;
 213         switch (hweight8(i)) {
 214         case 0:
 215                 netif_stop_queue(dev);
 216                 dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
 217                 return NETDEV_TX_BUSY;
 218         case 1:
 219                 /*
 220                  * if buf_id < 3, then current frame will be send out of order,
 221                  * since buffer with lower id have higher priority (hell..)
 222                  */
 223                 netif_stop_queue(dev);
 224         case 2:
 225                 if (buf_id < priv->prev_buf_id) {
 226                         priv->cur_pri++;
 227                         if (priv->cur_pri == 0xff) {
 228                                 set_bit(F_TX_WAIT_ALL, &priv->flags);
 229                                 netif_stop_queue(dev);
 230                         }
 231                 }
 232                 set_bit(F_TX_PROGRESS, &priv->flags);
 233                 break;
 234         }
 235         priv->prev_buf_id = buf_id;
 236         out_8(&regs->cantbsel, i);
 237
 238         rtr = frame->can_id & CAN_RTR_FLAG;
 239
 240         /* RTR is always the lowest bit of interest, then IDs follow */
 241         if (frame->can_id & CAN_EFF_FLAG) {
 242                 can_id = (frame->can_id & CAN_EFF_MASK)
 243                          << (MSCAN_EFF_RTR_SHIFT + 1);
 244                 if (rtr)
 245                         can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
 246                 out_be16(&regs->tx.idr3_2, can_id);
 247
 248                 can_id >>= 16;
 249                 /* EFF_FLAGS are between the IDs :( */
 250                 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
 251                          | MSCAN_EFF_FLAGS;
 252         } else {
 253                 can_id = (frame->can_id & CAN_SFF_MASK)
 254                          << (MSCAN_SFF_RTR_SHIFT + 1);
 255                 if (rtr)
 256                         can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
 257         }
 258         out_be16(&regs->tx.idr1_0, can_id);
 259
 260         if (!rtr) {
 261                 void __iomem *data = &regs->tx.dsr1_0;
 262                 u16 *payload = (u16 *)frame->data;
 263
 264                 /* It is safe to write into dsr[dlc+1] */
 265                 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
 266                         out_be16(data, *payload++);
 267                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 268                 }
 269         }
 270
 271         out_8(&regs->tx.dlr, frame->can_dlc);
 272         out_8(&regs->tx.tbpr, priv->cur_pri);
 273
 274         /* Start transmission. */
 275         out_8(&regs->cantflg, 1 << buf_id);
 276
 277         if (!test_bit(F_TX_PROGRESS, &priv->flags))
 278                 dev->trans_start = jiffies;
 279
 280         list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
 281
 282         can_put_echo_skb(skb, dev, buf_id);
 283
 284         /* Enable interrupt. */
 285         priv->tx_active |= 1 << buf_id;
 286         out_8(&regs->cantier, priv->tx_active);
 287
 288         return NETDEV_TX_OK;
 289 }
 290
 291 /* This function returns the old state to see where we came from */
 292 static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
 293 {
 294         struct mscan_priv *priv = netdev_priv(dev);
 295         enum can_state state, old_state = priv->can.state;
 296
 297         if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
 298                 state = state_map[max(MSCAN_STATE_RX(canrflg),
 299                                       MSCAN_STATE_TX(canrflg))];
 300                 priv->can.state = state;
 301         }
 302         return old_state;
 303 }
 304
 305 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
 306 {
 307         struct mscan_priv *priv = netdev_priv(dev);
 308         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 309         u32 can_id;
 310         int i;
 311
 312         can_id = in_be16(&regs->rx.idr1_0);
 313         if (can_id & (1 << 3)) {
 314                 frame->can_id = CAN_EFF_FLAG;
 315                 can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
 316                 can_id = ((can_id & 0xffe00000) |
 317                           ((can_id & 0x7ffff) << 2)) >> 2;
 318         } else {
 319                 can_id >>= 4;
 320                 frame->can_id = 0;
 321         }
 322
 323         frame->can_id |= can_id >> 1;
 324         if (can_id & 1)
 325                 frame->can_id |= CAN_RTR_FLAG;
 326
 327         frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
 328
 329         if (!(frame->can_id & CAN_RTR_FLAG)) {
 330                 void __iomem *data = &regs->rx.dsr1_0;
 331                 u16 *payload = (u16 *)frame->data;
 332
 333                 for (i = 0; i < (frame->can_dlc + 1) / 2; i++) {
 334                         *payload++ = in_be16(data);
 335                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 336                 }
 337         }
 338
 339         out_8(&regs->canrflg, MSCAN_RXF);
 340 }
 341
 342 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
 343                                 u8 canrflg)
 344 {
 345         struct mscan_priv *priv = netdev_priv(dev);
 346         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 347         struct net_device_stats *stats = &dev->stats;
 348         enum can_state old_state;
 349
 350         dev_dbg(dev->dev.parent, "error interrupt (canrflg=%#x)\n", canrflg);
 351         frame->can_id = CAN_ERR_FLAG;
 352
 353         if (canrflg & MSCAN_OVRIF) {
 354                 frame->can_id |= CAN_ERR_CRTL;
 355                 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 356                 stats->rx_over_errors++;
 357                 stats->rx_errors++;
 358         } else {
 359                 frame->data[1] = 0;
 360         }
 361
 362         old_state = check_set_state(dev, canrflg);
 363         /* State changed */
 364         if (old_state != priv->can.state) {
 365                 switch (priv->can.state) {
 366                 case CAN_STATE_ERROR_WARNING:
 367                         frame->can_id |= CAN_ERR_CRTL;
 368                         priv->can.can_stats.error_warning++;
 369                         if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
 370                             (canrflg & MSCAN_RSTAT_MSK))
 371                                 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
 372                         if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
 373                             (canrflg & MSCAN_TSTAT_MSK))
 374                                 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
 375                         break;
 376                 case CAN_STATE_ERROR_PASSIVE:
 377                         frame->can_id |= CAN_ERR_CRTL;
 378                         priv->can.can_stats.error_passive++;
 379                         frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 380                         break;
 381                 case CAN_STATE_BUS_OFF:
 382                         frame->can_id |= CAN_ERR_BUSOFF;
 383                         /*
 384                          * The MSCAN on the MPC5200 does recover from bus-off
 385                          * automatically. To avoid that we stop the chip doing
 386                          * a light-weight stop (we are in irq-context).
 387                          */
 388                         if (priv->type != MSCAN_TYPE_MPC5121) {
 389                                 out_8(&regs->cantier, 0);
 390                                 out_8(&regs->canrier, 0);
 391                                 setbits8(&regs->canctl0,
 392                                          MSCAN_SLPRQ | MSCAN_INITRQ);
 393                         }
 394                         can_bus_off(dev);
 395                         break;
 396                 default:
 397                         break;
 398                 }
 399         }
 400         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 401         frame->can_dlc = CAN_ERR_DLC;
 402         out_8(&regs->canrflg, MSCAN_ERR_IF);
 403 }
 404
 405 static int mscan_rx_poll(struct napi_struct *napi, int quota)
 406 {
 407         struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
 408         struct net_device *dev = napi->dev;
 409         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 410         struct net_device_stats *stats = &dev->stats;
 411         int npackets = 0;
 412         int ret = 1;
 413         struct sk_buff *skb;
 414         struct can_frame *frame;
 415         u8 canrflg;
 416
 417         while (npackets < quota) {
 418                 canrflg = in_8(&regs->canrflg);
 419                 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
 420                         break;
 421
 422                 skb = alloc_can_skb(dev, &frame);
 423                 if (!skb) {
 424                         if (printk_ratelimit())
 425                                 dev_notice(dev->dev.parent, "packet dropped\n");
 426                         stats->rx_dropped++;
 427                         out_8(&regs->canrflg, canrflg);
 428                         continue;
 429                 }
 430
 431                 if (canrflg & MSCAN_RXF)
 432                         mscan_get_rx_frame(dev, frame);
 433                 else if (canrflg & MSCAN_ERR_IF)
 434                         mscan_get_err_frame(dev, frame, canrflg);
 435
 436                 stats->rx_packets++;
 437                 stats->rx_bytes += frame->can_dlc;
 438                 npackets++;
 439                 netif_receive_skb(skb);
 440         }
 441
 442         if (!(in_8(&regs->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
 443                 napi_complete(&priv->napi);
 444                 clear_bit(F_RX_PROGRESS, &priv->flags);
 445                 if (priv->can.state < CAN_STATE_BUS_OFF)
 446                         out_8(&regs->canrier, priv->shadow_canrier);
 447                 ret = 0;
 448         }
 449         return ret;
 450 }
 451
 452 static irqreturn_t mscan_isr(int irq, void *dev_id)
 453 {
 454         struct net_device *dev = (struct net_device *)dev_id;
 455         struct mscan_priv *priv = netdev_priv(dev);
 456         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 457         struct net_device_stats *stats = &dev->stats;
 458         u8 cantier, cantflg, canrflg;
 459         irqreturn_t ret = IRQ_NONE;
 460
 461         cantier = in_8(&regs->cantier) & MSCAN_TXE;
 462         cantflg = in_8(&regs->cantflg) & cantier;
 463
 464         if (cantier && cantflg) {
 465                 struct list_head *tmp, *pos;
 466
 467                 list_for_each_safe(pos, tmp, &priv->tx_head) {
 468                         struct tx_queue_entry *entry =
 469                             list_entry(pos, struct tx_queue_entry, list);
 470                         u8 mask = entry->mask;
 471
 472                         if (!(cantflg & mask))
 473                                 continue;
 474
 475                         out_8(&regs->cantbsel, mask);
 476                         stats->tx_bytes += in_8(&regs->tx.dlr);
 477                         stats->tx_packets++;
 478                         can_get_echo_skb(dev, entry->id);
 479                         priv->tx_active &= ~mask;
 480                         list_del(pos);
 481                 }
 482
 483                 if (list_empty(&priv->tx_head)) {
 484                         clear_bit(F_TX_WAIT_ALL, &priv->flags);
 485                         clear_bit(F_TX_PROGRESS, &priv->flags);
 486                         priv->cur_pri = 0;
 487                 } else {
 488                         dev->trans_start = jiffies;
 489                 }
 490
 491                 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
 492                         netif_wake_queue(dev);
 493
 494                 out_8(&regs->cantier, priv->tx_active);
 495                 ret = IRQ_HANDLED;
 496         }
 497
 498         canrflg = in_8(&regs->canrflg);
 499         if ((canrflg & ~MSCAN_STAT_MSK) &&
 500             !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
 501                 if (canrflg & ~MSCAN_STAT_MSK) {
 502                         priv->shadow_canrier = in_8(&regs->canrier);
 503                         out_8(&regs->canrier, 0);
 504                         napi_schedule(&priv->napi);
 505                         ret = IRQ_HANDLED;
 506                 } else {
 507                         clear_bit(F_RX_PROGRESS, &priv->flags);
 508                 }
 509         }
 510         return ret;
 511 }
 512
 513 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
 514 {
 515         struct mscan_priv *priv = netdev_priv(dev);
 516         int ret = 0;
 517
 518         if (!priv->open_time)
 519                 return -EINVAL;
 520
 521         switch (mode) {
 522         case CAN_MODE_START:
 523                 ret = mscan_restart(dev);
 524                 if (ret)
 525                         break;
 526                 if (netif_queue_stopped(dev))
 527                         netif_wake_queue(dev);
 528                 break;
 529
 530         default:
 531                 ret = -EOPNOTSUPP;
 532                 break;
 533         }
 534         return ret;
 535 }
 536
 537 static int mscan_do_set_bittiming(struct net_device *dev)
 538 {
 539         struct mscan_priv *priv = netdev_priv(dev);
 540         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 541         struct can_bittiming *bt = &priv->can.bittiming;
 542         u8 btr0, btr1;
 543
 544         btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
 545         btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
 546                 BTR1_SET_TSEG2(bt->phase_seg2) |
 547                 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
 548
 549         dev_info(dev->dev.parent, "setting BTR0=0x%02x BTR1=0x%02x\n",
 550                 btr0, btr1);
 551
 552         out_8(&regs->canbtr0, btr0);
 553         out_8(&regs->canbtr1, btr1);
 554
 555         return 0;
 556 }
 557
 558 static int mscan_open(struct net_device *dev)
 559 {
 560         int ret;
 561         struct mscan_priv *priv = netdev_priv(dev);
 562         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 563
 564         /* common open */
 565         ret = open_candev(dev);
 566         if (ret)
 567                 return ret;
 568
 569         napi_enable(&priv->napi);
 570
 571         ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
 572         if (ret < 0) {
 573                 dev_err(dev->dev.parent, "failed to attach interrupt\n");
 574                 goto exit_napi_disable;
 575         }
 576
 577         priv->open_time = jiffies;
 578
 579         clrbits8(&regs->canctl1, MSCAN_LISTEN);
 580
 581         ret = mscan_start(dev);
 582         if (ret)
 583                 goto exit_free_irq;
 584
 585         netif_start_queue(dev);
 586
 587         return 0;
 588
 589 exit_free_irq:
 590         priv->open_time = 0;
 591         free_irq(dev->irq, dev);
 592 exit_napi_disable:
 593         napi_disable(&priv->napi);
 594         close_candev(dev);
 595         return ret;
 596 }
 597
 598 static int mscan_close(struct net_device *dev)
 599 {
 600         struct mscan_priv *priv = netdev_priv(dev);
 601         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 602
 603         netif_stop_queue(dev);
 604         napi_disable(&priv->napi);
 605
 606         out_8(&regs->cantier, 0);
 607         out_8(&regs->canrier, 0);
 608         mscan_set_mode(dev, MSCAN_INIT_MODE);
 609         close_candev(dev);
 610         free_irq(dev->irq, dev);
 611         priv->open_time = 0;
 612
 613         return 0;
 614 }
 615
 616 static const struct net_device_ops mscan_netdev_ops = {
 617        .ndo_open               = mscan_open,
 618        .ndo_stop               = mscan_close,
 619        .ndo_start_xmit         = mscan_start_xmit,
 620 };
 621
 622 int register_mscandev(struct net_device *dev, int mscan_clksrc)
 623 {
 624         struct mscan_priv *priv = netdev_priv(dev);
 625         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 626         u8 ctl1;
 627
 628         ctl1 = in_8(&regs->canctl1);
 629         if (mscan_clksrc)
 630                 ctl1 |= MSCAN_CLKSRC;
 631         else
 632                 ctl1 &= ~MSCAN_CLKSRC;
 633
 634         if (priv->type == MSCAN_TYPE_MPC5121)
 635                 ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
 636
 637         ctl1 |= MSCAN_CANE;
 638         out_8(&regs->canctl1, ctl1);
 639         udelay(100);
 640
 641         /* acceptance mask/acceptance code (accept everything) */
 642         out_be16(&regs->canidar1_0, 0);
 643         out_be16(&regs->canidar3_2, 0);
 644         out_be16(&regs->canidar5_4, 0);
 645         out_be16(&regs->canidar7_6, 0);
 646
 647         out_be16(&regs->canidmr1_0, 0xffff);
 648         out_be16(&regs->canidmr3_2, 0xffff);
 649         out_be16(&regs->canidmr5_4, 0xffff);
 650         out_be16(&regs->canidmr7_6, 0xffff);
 651         /* Two 32 bit Acceptance Filters */
 652         out_8(&regs->canidac, MSCAN_AF_32BIT);
 653
 654         mscan_set_mode(dev, MSCAN_INIT_MODE);
 655
 656         return register_candev(dev);
 657 }
 658
 659 void unregister_mscandev(struct net_device *dev)
 660 {
 661         struct mscan_priv *priv = netdev_priv(dev);
 662         struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
 663         mscan_set_mode(dev, MSCAN_INIT_MODE);
 664         clrbits8(&regs->canctl1, MSCAN_CANE);
 665         unregister_candev(dev);
 666 }
 667
 668 struct net_device *alloc_mscandev(void)
 669 {
 670         struct net_device *dev;
 671         struct mscan_priv *priv;
 672         int i;
 673
 674         dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
 675         if (!dev)
 676                 return NULL;
 677         priv = netdev_priv(dev);
 678
 679         dev->netdev_ops = &mscan_netdev_ops;
 680
 681         dev->flags |= IFF_ECHO; /* we support local echo */
 682
 683         netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
 684
 685         priv->can.bittiming_const = &mscan_bittiming_const;
 686         priv->can.do_set_bittiming = mscan_do_set_bittiming;
 687         priv->can.do_set_mode = mscan_do_set_mode;
 688         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 689
 690         for (i = 0; i < TX_QUEUE_SIZE; i++) {
 691                 priv->tx_queue[i].id = i;
 692                 priv->tx_queue[i].mask = 1 << i;
 693         }
 694
 695         return dev;
 696 }
 697
 698 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
 699 MODULE_LICENSE("GPL v2");
 700 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");