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, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/delay.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/list.h>
  30 #include <linux/can/dev.h>
  31 #include <linux/can/error.h>
  32 #include <linux/io.h>
  33
  34 #include "mscan.h"
  35
  36 static const struct can_bittiming_const mscan_bittiming_const = {
  37         .name = "mscan",
  38         .tseg1_min = 4,
  39         .tseg1_max = 16,
  40         .tseg2_min = 2,
  41         .tseg2_max = 8,
  42         .sjw_max = 4,
  43         .brp_min = 1,
  44         .brp_max = 64,
  45         .brp_inc = 1,
  46 };
  47
  48 struct mscan_state {
  49         u8 mode;
  50         u8 canrier;
  51         u8 cantier;
  52 };
  53
  54 static enum can_state state_map[] = {
  55         CAN_STATE_ERROR_ACTIVE,
  56         CAN_STATE_ERROR_WARNING,
  57         CAN_STATE_ERROR_PASSIVE,
  58         CAN_STATE_BUS_OFF
  59 };
  60
  61 static int mscan_set_mode(struct net_device *dev, u8 mode)
  62 {
  63         struct mscan_priv *priv = netdev_priv(dev);
  64         struct mscan_regs __iomem *regs = priv->reg_base;
  65         int ret = 0;
  66         int i;
  67         u8 canctl1;
  68
  69         if (mode != MSCAN_NORMAL_MODE) {
  70                 if (priv->tx_active) {
  71                         /* Abort transfers before going to sleep */#
  72                         out_8(&regs->cantarq, priv->tx_active);
  73                         /* Suppress TX done interrupts */
  74                         out_8(&regs->cantier, 0);
  75                 }
  76
  77                 canctl1 = in_8(&regs->canctl1);
  78                 if ((mode & MSCAN_SLPRQ) && !(canctl1 & MSCAN_SLPAK)) {
  79                         setbits8(&regs->canctl0, MSCAN_SLPRQ);
  80                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
  81                                 if (in_8(&regs->canctl1) & MSCAN_SLPAK)
  82                                         break;
  83                                 udelay(100);
  84                         }
  85                         /*
  86                          * The mscan controller will fail to enter sleep mode,
  87                          * while there are irregular activities on bus, like
  88                          * somebody keeps retransmitting. This behavior is
  89                          * undocumented and seems to differ between mscan built
  90                          * in mpc5200b and mpc5200. We proceed in that case,
  91                          * since otherwise the slprq will be kept set and the
  92                          * controller will get stuck. NOTE: INITRQ or CSWAI
  93                          * will abort all active transmit actions, if still
  94                          * any, at once.
  95                          */
  96                         if (i >= MSCAN_SET_MODE_RETRIES)
  97                                 netdev_dbg(dev,
  98                                            "device failed to enter sleep mode. "
  99                                            "We proceed anyhow.\n");
 100                         else
 101                                 priv->can.state = CAN_STATE_SLEEPING;
 102                 }
 103
 104                 if ((mode & MSCAN_INITRQ) && !(canctl1 & MSCAN_INITAK)) {
 105                         setbits8(&regs->canctl0, MSCAN_INITRQ);
 106                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
 107                                 if (in_8(&regs->canctl1) & MSCAN_INITAK)
 108                                         break;
 109                         }
 110                         if (i >= MSCAN_SET_MODE_RETRIES)
 111                                 ret = -ENODEV;
 112                 }
 113                 if (!ret)
 114                         priv->can.state = CAN_STATE_STOPPED;
 115
 116                 if (mode & MSCAN_CSWAI)
 117                         setbits8(&regs->canctl0, MSCAN_CSWAI);
 118
 119         } else {
 120                 canctl1 = in_8(&regs->canctl1);
 121                 if (canctl1 & (MSCAN_SLPAK | MSCAN_INITAK)) {
 122                         clrbits8(&regs->canctl0, MSCAN_SLPRQ | MSCAN_INITRQ);
 123                         for (i = 0; i < MSCAN_SET_MODE_RETRIES; i++) {
 124                                 canctl1 = in_8(&regs->canctl1);
 125                                 if (!(canctl1 & (MSCAN_INITAK | MSCAN_SLPAK)))
 126                                         break;
 127                         }
 128                         if (i >= MSCAN_SET_MODE_RETRIES)
 129                                 ret = -ENODEV;
 130                         else
 131                                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 132                 }
 133         }
 134         return ret;
 135 }
 136
 137 static int mscan_start(struct net_device *dev)
 138 {
 139         struct mscan_priv *priv = netdev_priv(dev);
 140         struct mscan_regs __iomem *regs = priv->reg_base;
 141         u8 canrflg;
 142         int err;
 143
 144         out_8(&regs->canrier, 0);
 145
 146         INIT_LIST_HEAD(&priv->tx_head);
 147         priv->prev_buf_id = 0;
 148         priv->cur_pri = 0;
 149         priv->tx_active = 0;
 150         priv->shadow_canrier = 0;
 151         priv->flags = 0;
 152
 153         if (priv->type == MSCAN_TYPE_MPC5121) {
 154                 /* Clear pending bus-off condition */
 155                 if (in_8(&regs->canmisc) & MSCAN_BOHOLD)
 156                         out_8(&regs->canmisc, MSCAN_BOHOLD);
 157         }
 158
 159         err = mscan_set_mode(dev, MSCAN_NORMAL_MODE);
 160         if (err)
 161                 return err;
 162
 163         canrflg = in_8(&regs->canrflg);
 164         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 165         priv->can.state = state_map[max(MSCAN_STATE_RX(canrflg),
 166                                     MSCAN_STATE_TX(canrflg))];
 167         out_8(&regs->cantier, 0);
 168
 169         /* Enable receive interrupts. */
 170         out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 171
 172         return 0;
 173 }
 174
 175 static int mscan_restart(struct net_device *dev)
 176 {
 177         struct mscan_priv *priv = netdev_priv(dev);
 178
 179         if (priv->type == MSCAN_TYPE_MPC5121) {
 180                 struct mscan_regs __iomem *regs = priv->reg_base;
 181
 182                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 183                 WARN(!(in_8(&regs->canmisc) & MSCAN_BOHOLD),
 184                      "bus-off state expected\n");
 185                 out_8(&regs->canmisc, MSCAN_BOHOLD);
 186                 /* Re-enable receive interrupts. */
 187                 out_8(&regs->canrier, MSCAN_RX_INTS_ENABLE);
 188         } else {
 189                 if (priv->can.state <= CAN_STATE_BUS_OFF)
 190                         mscan_set_mode(dev, MSCAN_INIT_MODE);
 191                 return mscan_start(dev);
 192         }
 193
 194         return 0;
 195 }
 196
 197 static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 198 {
 199         struct can_frame *frame = (struct can_frame *)skb->data;
 200         struct mscan_priv *priv = netdev_priv(dev);
 201         struct mscan_regs __iomem *regs = priv->reg_base;
 202         int i, rtr, buf_id;
 203         u32 can_id;
 204
 205         if (can_dropped_invalid_skb(dev, skb))
 206                 return NETDEV_TX_OK;
 207
 208         out_8(&regs->cantier, 0);
 209
 210         i = ~priv->tx_active & MSCAN_TXE;
 211         buf_id = ffs(i) - 1;
 212         switch (hweight8(i)) {
 213         case 0:
 214                 netif_stop_queue(dev);
 215                 netdev_err(dev, "Tx Ring full when queue awake!\n");
 216                 return NETDEV_TX_BUSY;
 217         case 1:
 218                 /*
 219                  * if buf_id < 3, then current frame will be send out of order,
 220                  * since buffer with lower id have higher priority (hell..)
 221                  */
 222                 netif_stop_queue(dev);
 223         case 2:
 224                 if (buf_id < priv->prev_buf_id) {
 225                         priv->cur_pri++;
 226                         if (priv->cur_pri == 0xff) {
 227                                 set_bit(F_TX_WAIT_ALL, &priv->flags);
 228                                 netif_stop_queue(dev);
 229                         }
 230                 }
 231                 set_bit(F_TX_PROGRESS, &priv->flags);
 232                 break;
 233         }
 234         priv->prev_buf_id = buf_id;
 235         out_8(&regs->cantbsel, i);
 236
 237         rtr = frame->can_id & CAN_RTR_FLAG;
 238
 239         /* RTR is always the lowest bit of interest, then IDs follow */
 240         if (frame->can_id & CAN_EFF_FLAG) {
 241                 can_id = (frame->can_id & CAN_EFF_MASK)
 242                          << (MSCAN_EFF_RTR_SHIFT + 1);
 243                 if (rtr)
 244                         can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
 245                 out_be16(&regs->tx.idr3_2, can_id);
 246
 247                 can_id >>= 16;
 248                 /* EFF_FLAGS are between the IDs :( */
 249                 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
 250                          | MSCAN_EFF_FLAGS;
 251         } else {
 252                 can_id = (frame->can_id & CAN_SFF_MASK)
 253                          << (MSCAN_SFF_RTR_SHIFT + 1);
 254                 if (rtr)
 255                         can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
 256         }
 257         out_be16(&regs->tx.idr1_0, can_id);
 258
 259         if (!rtr) {
 260                 void __iomem *data = &regs->tx.dsr1_0;
 261                 u16 *payload = (u16 *)frame->data;
 262
 263                 for (i = 0; i < frame->can_dlc / 2; i++) {
 264                         out_be16(data, *payload++);
 265                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 266                 }
 267                 /* write remaining byte if necessary */
 268                 if (frame->can_dlc & 1)
 269                         out_8(data, frame->data[frame->can_dlc - 1]);
 270         }
 271
 272         out_8(&regs->tx.dlr, frame->can_dlc);
 273         out_8(&regs->tx.tbpr, priv->cur_pri);
 274
 275         /* Start transmission. */
 276         out_8(&regs->cantflg, 1 << buf_id);
 277
 278         if (!test_bit(F_TX_PROGRESS, &priv->flags))
 279                 dev->trans_start = jiffies;
 280
 281         list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
 282
 283         can_put_echo_skb(skb, dev, buf_id);
 284
 285         /* Enable interrupt. */
 286         priv->tx_active |= 1 << buf_id;
 287         out_8(&regs->cantier, priv->tx_active);
 288
 289         return NETDEV_TX_OK;
 290 }
 291
 292 /* This function returns the old state to see where we came from */
 293 static enum can_state check_set_state(struct net_device *dev, u8 canrflg)
 294 {
 295         struct mscan_priv *priv = netdev_priv(dev);
 296         enum can_state state, old_state = priv->can.state;
 297
 298         if (canrflg & MSCAN_CSCIF && old_state <= CAN_STATE_BUS_OFF) {
 299                 state = state_map[max(MSCAN_STATE_RX(canrflg),
 300                                       MSCAN_STATE_TX(canrflg))];
 301                 priv->can.state = state;
 302         }
 303         return old_state;
 304 }
 305
 306 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
 307 {
 308         struct mscan_priv *priv = netdev_priv(dev);
 309         struct mscan_regs __iomem *regs = priv->reg_base;
 310         u32 can_id;
 311         int i;
 312
 313         can_id = in_be16(&regs->rx.idr1_0);
 314         if (can_id & (1 << 3)) {
 315                 frame->can_id = CAN_EFF_FLAG;
 316                 can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
 317                 can_id = ((can_id & 0xffe00000) |
 318                           ((can_id & 0x7ffff) << 2)) >> 2;
 319         } else {
 320                 can_id >>= 4;
 321                 frame->can_id = 0;
 322         }
 323
 324         frame->can_id |= can_id >> 1;
 325         if (can_id & 1)
 326                 frame->can_id |= CAN_RTR_FLAG;
 327
 328         frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
 329
 330         if (!(frame->can_id & CAN_RTR_FLAG)) {
 331                 void __iomem *data = &regs->rx.dsr1_0;
 332                 u16 *payload = (u16 *)frame->data;
 333
 334                 for (i = 0; i < frame->can_dlc / 2; i++) {
 335                         *payload++ = in_be16(data);
 336                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 337                 }
 338                 /* read remaining byte if necessary */
 339                 if (frame->can_dlc & 1)
 340                         frame->data[frame->can_dlc - 1] = in_8(data);
 341         }
 342
 343         out_8(&regs->canrflg, MSCAN_RXF);
 344 }
 345
 346 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
 347                                 u8 canrflg)
 348 {
 349         struct mscan_priv *priv = netdev_priv(dev);
 350         struct mscan_regs __iomem *regs = priv->reg_base;
 351         struct net_device_stats *stats = &dev->stats;
 352         enum can_state old_state;
 353
 354         netdev_dbg(dev, "error interrupt (canrflg=%#x)\n", canrflg);
 355         frame->can_id = CAN_ERR_FLAG;
 356
 357         if (canrflg & MSCAN_OVRIF) {
 358                 frame->can_id |= CAN_ERR_CRTL;
 359                 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 360                 stats->rx_over_errors++;
 361                 stats->rx_errors++;
 362         } else {
 363                 frame->data[1] = 0;
 364         }
 365
 366         old_state = check_set_state(dev, canrflg);
 367         /* State changed */
 368         if (old_state != priv->can.state) {
 369                 switch (priv->can.state) {
 370                 case CAN_STATE_ERROR_WARNING:
 371                         frame->can_id |= CAN_ERR_CRTL;
 372                         priv->can.can_stats.error_warning++;
 373                         if ((priv->shadow_statflg & MSCAN_RSTAT_MSK) <
 374                             (canrflg & MSCAN_RSTAT_MSK))
 375                                 frame->data[1] |= CAN_ERR_CRTL_RX_WARNING;
 376                         if ((priv->shadow_statflg & MSCAN_TSTAT_MSK) <
 377                             (canrflg & MSCAN_TSTAT_MSK))
 378                                 frame->data[1] |= CAN_ERR_CRTL_TX_WARNING;
 379                         break;
 380                 case CAN_STATE_ERROR_PASSIVE:
 381                         frame->can_id |= CAN_ERR_CRTL;
 382                         priv->can.can_stats.error_passive++;
 383                         frame->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 384                         break;
 385                 case CAN_STATE_BUS_OFF:
 386                         frame->can_id |= CAN_ERR_BUSOFF;
 387                         /*
 388                          * The MSCAN on the MPC5200 does recover from bus-off
 389                          * automatically. To avoid that we stop the chip doing
 390                          * a light-weight stop (we are in irq-context).
 391                          */
 392                         if (priv->type != MSCAN_TYPE_MPC5121) {
 393                                 out_8(&regs->cantier, 0);
 394                                 out_8(&regs->canrier, 0);
 395                                 setbits8(&regs->canctl0,
 396                                          MSCAN_SLPRQ | MSCAN_INITRQ);
 397                         }
 398                         can_bus_off(dev);
 399                         break;
 400                 default:
 401                         break;
 402                 }
 403         }
 404         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 405         frame->can_dlc = CAN_ERR_DLC;
 406         out_8(&regs->canrflg, MSCAN_ERR_IF);
 407 }
 408
 409 static int mscan_rx_poll(struct napi_struct *napi, int quota)
 410 {
 411         struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
 412         struct net_device *dev = napi->dev;
 413         struct mscan_regs __iomem *regs = priv->reg_base;
 414         struct net_device_stats *stats = &dev->stats;
 415         int npackets = 0;
 416         int ret = 1;
 417         struct sk_buff *skb;
 418         struct can_frame *frame;
 419         u8 canrflg;
 420
 421         while (npackets < quota) {
 422                 canrflg = in_8(&regs->canrflg);
 423                 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
 424                         break;
 425
 426                 skb = alloc_can_skb(dev, &frame);
 427                 if (!skb) {
 428                         if (printk_ratelimit())
 429                                 netdev_notice(dev, "packet dropped\n");
 430                         stats->rx_dropped++;
 431                         out_8(&regs->canrflg, canrflg);
 432                         continue;
 433                 }
 434
 435                 if (canrflg & MSCAN_RXF)
 436                         mscan_get_rx_frame(dev, frame);
 437                 else if (canrflg & MSCAN_ERR_IF)
 438                         mscan_get_err_frame(dev, frame, canrflg);
 439
 440                 stats->rx_packets++;
 441                 stats->rx_bytes += frame->can_dlc;
 442                 npackets++;
 443                 netif_receive_skb(skb);
 444         }
 445
 446         if (!(in_8(&regs->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
 447                 napi_complete(&priv->napi);
 448                 clear_bit(F_RX_PROGRESS, &priv->flags);
 449                 if (priv->can.state < CAN_STATE_BUS_OFF)
 450                         out_8(&regs->canrier, priv->shadow_canrier);
 451                 ret = 0;
 452         }
 453         return ret;
 454 }
 455
 456 static irqreturn_t mscan_isr(int irq, void *dev_id)
 457 {
 458         struct net_device *dev = (struct net_device *)dev_id;
 459         struct mscan_priv *priv = netdev_priv(dev);
 460         struct mscan_regs __iomem *regs = priv->reg_base;
 461         struct net_device_stats *stats = &dev->stats;
 462         u8 cantier, cantflg, canrflg;
 463         irqreturn_t ret = IRQ_NONE;
 464
 465         cantier = in_8(&regs->cantier) & MSCAN_TXE;
 466         cantflg = in_8(&regs->cantflg) & cantier;
 467
 468         if (cantier && cantflg) {
 469                 struct list_head *tmp, *pos;
 470
 471                 list_for_each_safe(pos, tmp, &priv->tx_head) {
 472                         struct tx_queue_entry *entry =
 473                             list_entry(pos, struct tx_queue_entry, list);
 474                         u8 mask = entry->mask;
 475
 476                         if (!(cantflg & mask))
 477                                 continue;
 478
 479                         out_8(&regs->cantbsel, mask);
 480                         stats->tx_bytes += in_8(&regs->tx.dlr);
 481                         stats->tx_packets++;
 482                         can_get_echo_skb(dev, entry->id);
 483                         priv->tx_active &= ~mask;
 484                         list_del(pos);
 485                 }
 486
 487                 if (list_empty(&priv->tx_head)) {
 488                         clear_bit(F_TX_WAIT_ALL, &priv->flags);
 489                         clear_bit(F_TX_PROGRESS, &priv->flags);
 490                         priv->cur_pri = 0;
 491                 } else {
 492                         dev->trans_start = jiffies;
 493                 }
 494
 495                 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
 496                         netif_wake_queue(dev);
 497
 498                 out_8(&regs->cantier, priv->tx_active);
 499                 ret = IRQ_HANDLED;
 500         }
 501
 502         canrflg = in_8(&regs->canrflg);
 503         if ((canrflg & ~MSCAN_STAT_MSK) &&
 504             !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
 505                 if (canrflg & ~MSCAN_STAT_MSK) {
 506                         priv->shadow_canrier = in_8(&regs->canrier);
 507                         out_8(&regs->canrier, 0);
 508                         napi_schedule(&priv->napi);
 509                         ret = IRQ_HANDLED;
 510                 } else {
 511                         clear_bit(F_RX_PROGRESS, &priv->flags);
 512                 }
 513         }
 514         return ret;
 515 }
 516
 517 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
 518 {
 519         int ret = 0;
 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 __iomem *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         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 550
 551         out_8(&regs->canbtr0, btr0);
 552         out_8(&regs->canbtr1, btr1);
 553
 554         return 0;
 555 }
 556
 557 static int mscan_get_berr_counter(const struct net_device *dev,
 558                                   struct can_berr_counter *bec)
 559 {
 560         struct mscan_priv *priv = netdev_priv(dev);
 561         struct mscan_regs __iomem *regs = priv->reg_base;
 562
 563         bec->txerr = in_8(&regs->cantxerr);
 564         bec->rxerr = in_8(&regs->canrxerr);
 565
 566         return 0;
 567 }
 568
 569 static int mscan_open(struct net_device *dev)
 570 {
 571         int ret;
 572         struct mscan_priv *priv = netdev_priv(dev);
 573         struct mscan_regs __iomem *regs = priv->reg_base;
 574
 575         if (priv->clk_ipg) {
 576                 ret = clk_prepare_enable(priv->clk_ipg);
 577                 if (ret)
 578                         goto exit_retcode;
 579         }
 580         if (priv->clk_can) {
 581                 ret = clk_prepare_enable(priv->clk_can);
 582                 if (ret)
 583                         goto exit_dis_ipg_clock;
 584         }
 585
 586         /* common open */
 587         ret = open_candev(dev);
 588         if (ret)
 589                 goto exit_dis_can_clock;
 590
 591         napi_enable(&priv->napi);
 592
 593         ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
 594         if (ret < 0) {
 595                 netdev_err(dev, "failed to attach interrupt\n");
 596                 goto exit_napi_disable;
 597         }
 598
 599         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 600                 setbits8(&regs->canctl1, MSCAN_LISTEN);
 601         else
 602                 clrbits8(&regs->canctl1, MSCAN_LISTEN);
 603
 604         ret = mscan_start(dev);
 605         if (ret)
 606                 goto exit_free_irq;
 607
 608         netif_start_queue(dev);
 609
 610         return 0;
 611
 612 exit_free_irq:
 613         free_irq(dev->irq, dev);
 614 exit_napi_disable:
 615         napi_disable(&priv->napi);
 616         close_candev(dev);
 617 exit_dis_can_clock:
 618         if (priv->clk_can)
 619                 clk_disable_unprepare(priv->clk_can);
 620 exit_dis_ipg_clock:
 621         if (priv->clk_ipg)
 622                 clk_disable_unprepare(priv->clk_ipg);
 623 exit_retcode:
 624         return ret;
 625 }
 626
 627 static int mscan_close(struct net_device *dev)
 628 {
 629         struct mscan_priv *priv = netdev_priv(dev);
 630         struct mscan_regs __iomem *regs = priv->reg_base;
 631
 632         netif_stop_queue(dev);
 633         napi_disable(&priv->napi);
 634
 635         out_8(&regs->cantier, 0);
 636         out_8(&regs->canrier, 0);
 637         mscan_set_mode(dev, MSCAN_INIT_MODE);
 638         close_candev(dev);
 639         free_irq(dev->irq, dev);
 640
 641         if (priv->clk_can)
 642                 clk_disable_unprepare(priv->clk_can);
 643         if (priv->clk_ipg)
 644                 clk_disable_unprepare(priv->clk_ipg);
 645
 646         return 0;
 647 }
 648
 649 static const struct net_device_ops mscan_netdev_ops = {
 650        .ndo_open               = mscan_open,
 651        .ndo_stop               = mscan_close,
 652        .ndo_start_xmit         = mscan_start_xmit,
 653 };
 654
 655 int register_mscandev(struct net_device *dev, int mscan_clksrc)
 656 {
 657         struct mscan_priv *priv = netdev_priv(dev);
 658         struct mscan_regs __iomem *regs = priv->reg_base;
 659         u8 ctl1;
 660
 661         ctl1 = in_8(&regs->canctl1);
 662         if (mscan_clksrc)
 663                 ctl1 |= MSCAN_CLKSRC;
 664         else
 665                 ctl1 &= ~MSCAN_CLKSRC;
 666
 667         if (priv->type == MSCAN_TYPE_MPC5121) {
 668                 priv->can.do_get_berr_counter = mscan_get_berr_counter;
 669                 ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
 670         }
 671
 672         ctl1 |= MSCAN_CANE;
 673         out_8(&regs->canctl1, ctl1);
 674         udelay(100);
 675
 676         /* acceptance mask/acceptance code (accept everything) */
 677         out_be16(&regs->canidar1_0, 0);
 678         out_be16(&regs->canidar3_2, 0);
 679         out_be16(&regs->canidar5_4, 0);
 680         out_be16(&regs->canidar7_6, 0);
 681
 682         out_be16(&regs->canidmr1_0, 0xffff);
 683         out_be16(&regs->canidmr3_2, 0xffff);
 684         out_be16(&regs->canidmr5_4, 0xffff);
 685         out_be16(&regs->canidmr7_6, 0xffff);
 686         /* Two 32 bit Acceptance Filters */
 687         out_8(&regs->canidac, MSCAN_AF_32BIT);
 688
 689         mscan_set_mode(dev, MSCAN_INIT_MODE);
 690
 691         return register_candev(dev);
 692 }
 693
 694 void unregister_mscandev(struct net_device *dev)
 695 {
 696         struct mscan_priv *priv = netdev_priv(dev);
 697         struct mscan_regs __iomem *regs = priv->reg_base;
 698         mscan_set_mode(dev, MSCAN_INIT_MODE);
 699         clrbits8(&regs->canctl1, MSCAN_CANE);
 700         unregister_candev(dev);
 701 }
 702
 703 struct net_device *alloc_mscandev(void)
 704 {
 705         struct net_device *dev;
 706         struct mscan_priv *priv;
 707         int i;
 708
 709         dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
 710         if (!dev)
 711                 return NULL;
 712         priv = netdev_priv(dev);
 713
 714         dev->netdev_ops = &mscan_netdev_ops;
 715
 716         dev->flags |= IFF_ECHO; /* we support local echo */
 717
 718         netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
 719
 720         priv->can.bittiming_const = &mscan_bittiming_const;
 721         priv->can.do_set_bittiming = mscan_do_set_bittiming;
 722         priv->can.do_set_mode = mscan_do_set_mode;
 723         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 724                 CAN_CTRLMODE_LISTENONLY;
 725
 726         for (i = 0; i < TX_QUEUE_SIZE; i++) {
 727                 priv->tx_queue[i].id = i;
 728                 priv->tx_queue[i].mask = 1 << i;
 729         }
 730
 731         return dev;
 732 }
 733
 734 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
 735 MODULE_LICENSE("GPL v2");
 736 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");