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 static enum can_state get_new_state(struct net_device *dev, u8 canrflg)
 293 {
 294         struct mscan_priv *priv = netdev_priv(dev);
 295
 296         if (unlikely(canrflg & MSCAN_CSCIF))
 297                 return state_map[max(MSCAN_STATE_RX(canrflg),
 298                                  MSCAN_STATE_TX(canrflg))];
 299
 300         return priv->can.state;
 301 }
 302
 303 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
 304 {
 305         struct mscan_priv *priv = netdev_priv(dev);
 306         struct mscan_regs __iomem *regs = priv->reg_base;
 307         u32 can_id;
 308         int i;
 309
 310         can_id = in_be16(&regs->rx.idr1_0);
 311         if (can_id & (1 << 3)) {
 312                 frame->can_id = CAN_EFF_FLAG;
 313                 can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
 314                 can_id = ((can_id & 0xffe00000) |
 315                           ((can_id & 0x7ffff) << 2)) >> 2;
 316         } else {
 317                 can_id >>= 4;
 318                 frame->can_id = 0;
 319         }
 320
 321         frame->can_id |= can_id >> 1;
 322         if (can_id & 1)
 323                 frame->can_id |= CAN_RTR_FLAG;
 324
 325         frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
 326
 327         if (!(frame->can_id & CAN_RTR_FLAG)) {
 328                 void __iomem *data = &regs->rx.dsr1_0;
 329                 u16 *payload = (u16 *)frame->data;
 330
 331                 for (i = 0; i < frame->can_dlc / 2; i++) {
 332                         *payload++ = in_be16(data);
 333                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 334                 }
 335                 /* read remaining byte if necessary */
 336                 if (frame->can_dlc & 1)
 337                         frame->data[frame->can_dlc - 1] = in_8(data);
 338         }
 339
 340         out_8(&regs->canrflg, MSCAN_RXF);
 341 }
 342
 343 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
 344                                 u8 canrflg)
 345 {
 346         struct mscan_priv *priv = netdev_priv(dev);
 347         struct mscan_regs __iomem *regs = priv->reg_base;
 348         struct net_device_stats *stats = &dev->stats;
 349         enum can_state new_state;
 350
 351         netdev_dbg(dev, "error interrupt (canrflg=%#x)\n", canrflg);
 352         frame->can_id = CAN_ERR_FLAG;
 353
 354         if (canrflg & MSCAN_OVRIF) {
 355                 frame->can_id |= CAN_ERR_CRTL;
 356                 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 357                 stats->rx_over_errors++;
 358                 stats->rx_errors++;
 359         } else {
 360                 frame->data[1] = 0;
 361         }
 362
 363         new_state = get_new_state(dev, canrflg);
 364         if (new_state != priv->can.state) {
 365                 can_change_state(dev, frame,
 366                                  state_map[MSCAN_STATE_TX(canrflg)],
 367                                  state_map[MSCAN_STATE_RX(canrflg)]);
 368
 369                 if (priv->can.state == CAN_STATE_BUS_OFF) {
 370                         /*
 371                          * The MSCAN on the MPC5200 does recover from bus-off
 372                          * automatically. To avoid that we stop the chip doing
 373                          * a light-weight stop (we are in irq-context).
 374                          */
 375                         if (priv->type != MSCAN_TYPE_MPC5121) {
 376                                 out_8(&regs->cantier, 0);
 377                                 out_8(&regs->canrier, 0);
 378                                 setbits8(&regs->canctl0,
 379                                          MSCAN_SLPRQ | MSCAN_INITRQ);
 380                         }
 381                         can_bus_off(dev);
 382                 }
 383         }
 384         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 385         frame->can_dlc = CAN_ERR_DLC;
 386         out_8(&regs->canrflg, MSCAN_ERR_IF);
 387 }
 388
 389 static int mscan_rx_poll(struct napi_struct *napi, int quota)
 390 {
 391         struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
 392         struct net_device *dev = napi->dev;
 393         struct mscan_regs __iomem *regs = priv->reg_base;
 394         struct net_device_stats *stats = &dev->stats;
 395         int npackets = 0;
 396         int ret = 1;
 397         struct sk_buff *skb;
 398         struct can_frame *frame;
 399         u8 canrflg;
 400
 401         while (npackets < quota) {
 402                 canrflg = in_8(&regs->canrflg);
 403                 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
 404                         break;
 405
 406                 skb = alloc_can_skb(dev, &frame);
 407                 if (!skb) {
 408                         if (printk_ratelimit())
 409                                 netdev_notice(dev, "packet dropped\n");
 410                         stats->rx_dropped++;
 411                         out_8(&regs->canrflg, canrflg);
 412                         continue;
 413                 }
 414
 415                 if (canrflg & MSCAN_RXF)
 416                         mscan_get_rx_frame(dev, frame);
 417                 else if (canrflg & MSCAN_ERR_IF)
 418                         mscan_get_err_frame(dev, frame, canrflg);
 419
 420                 stats->rx_packets++;
 421                 stats->rx_bytes += frame->can_dlc;
 422                 npackets++;
 423                 netif_receive_skb(skb);
 424         }
 425
 426         if (!(in_8(&regs->canrflg) & (MSCAN_RXF | MSCAN_ERR_IF))) {
 427                 napi_complete(&priv->napi);
 428                 clear_bit(F_RX_PROGRESS, &priv->flags);
 429                 if (priv->can.state < CAN_STATE_BUS_OFF)
 430                         out_8(&regs->canrier, priv->shadow_canrier);
 431                 ret = 0;
 432         }
 433         return ret;
 434 }
 435
 436 static irqreturn_t mscan_isr(int irq, void *dev_id)
 437 {
 438         struct net_device *dev = (struct net_device *)dev_id;
 439         struct mscan_priv *priv = netdev_priv(dev);
 440         struct mscan_regs __iomem *regs = priv->reg_base;
 441         struct net_device_stats *stats = &dev->stats;
 442         u8 cantier, cantflg, canrflg;
 443         irqreturn_t ret = IRQ_NONE;
 444
 445         cantier = in_8(&regs->cantier) & MSCAN_TXE;
 446         cantflg = in_8(&regs->cantflg) & cantier;
 447
 448         if (cantier && cantflg) {
 449                 struct list_head *tmp, *pos;
 450
 451                 list_for_each_safe(pos, tmp, &priv->tx_head) {
 452                         struct tx_queue_entry *entry =
 453                             list_entry(pos, struct tx_queue_entry, list);
 454                         u8 mask = entry->mask;
 455
 456                         if (!(cantflg & mask))
 457                                 continue;
 458
 459                         out_8(&regs->cantbsel, mask);
 460                         stats->tx_bytes += in_8(&regs->tx.dlr);
 461                         stats->tx_packets++;
 462                         can_get_echo_skb(dev, entry->id);
 463                         priv->tx_active &= ~mask;
 464                         list_del(pos);
 465                 }
 466
 467                 if (list_empty(&priv->tx_head)) {
 468                         clear_bit(F_TX_WAIT_ALL, &priv->flags);
 469                         clear_bit(F_TX_PROGRESS, &priv->flags);
 470                         priv->cur_pri = 0;
 471                 } else {
 472                         dev->trans_start = jiffies;
 473                 }
 474
 475                 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
 476                         netif_wake_queue(dev);
 477
 478                 out_8(&regs->cantier, priv->tx_active);
 479                 ret = IRQ_HANDLED;
 480         }
 481
 482         canrflg = in_8(&regs->canrflg);
 483         if ((canrflg & ~MSCAN_STAT_MSK) &&
 484             !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
 485                 if (canrflg & ~MSCAN_STAT_MSK) {
 486                         priv->shadow_canrier = in_8(&regs->canrier);
 487                         out_8(&regs->canrier, 0);
 488                         napi_schedule(&priv->napi);
 489                         ret = IRQ_HANDLED;
 490                 } else {
 491                         clear_bit(F_RX_PROGRESS, &priv->flags);
 492                 }
 493         }
 494         return ret;
 495 }
 496
 497 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
 498 {
 499         int ret = 0;
 500
 501         switch (mode) {
 502         case CAN_MODE_START:
 503                 ret = mscan_restart(dev);
 504                 if (ret)
 505                         break;
 506                 if (netif_queue_stopped(dev))
 507                         netif_wake_queue(dev);
 508                 break;
 509
 510         default:
 511                 ret = -EOPNOTSUPP;
 512                 break;
 513         }
 514         return ret;
 515 }
 516
 517 static int mscan_do_set_bittiming(struct net_device *dev)
 518 {
 519         struct mscan_priv *priv = netdev_priv(dev);
 520         struct mscan_regs __iomem *regs = priv->reg_base;
 521         struct can_bittiming *bt = &priv->can.bittiming;
 522         u8 btr0, btr1;
 523
 524         btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
 525         btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
 526                 BTR1_SET_TSEG2(bt->phase_seg2) |
 527                 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
 528
 529         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 530
 531         out_8(&regs->canbtr0, btr0);
 532         out_8(&regs->canbtr1, btr1);
 533
 534         return 0;
 535 }
 536
 537 static int mscan_get_berr_counter(const struct net_device *dev,
 538                                   struct can_berr_counter *bec)
 539 {
 540         struct mscan_priv *priv = netdev_priv(dev);
 541         struct mscan_regs __iomem *regs = priv->reg_base;
 542
 543         bec->txerr = in_8(&regs->cantxerr);
 544         bec->rxerr = in_8(&regs->canrxerr);
 545
 546         return 0;
 547 }
 548
 549 static int mscan_open(struct net_device *dev)
 550 {
 551         int ret;
 552         struct mscan_priv *priv = netdev_priv(dev);
 553         struct mscan_regs __iomem *regs = priv->reg_base;
 554
 555         if (priv->clk_ipg) {
 556                 ret = clk_prepare_enable(priv->clk_ipg);
 557                 if (ret)
 558                         goto exit_retcode;
 559         }
 560         if (priv->clk_can) {
 561                 ret = clk_prepare_enable(priv->clk_can);
 562                 if (ret)
 563                         goto exit_dis_ipg_clock;
 564         }
 565
 566         /* common open */
 567         ret = open_candev(dev);
 568         if (ret)
 569                 goto exit_dis_can_clock;
 570
 571         napi_enable(&priv->napi);
 572
 573         ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
 574         if (ret < 0) {
 575                 netdev_err(dev, "failed to attach interrupt\n");
 576                 goto exit_napi_disable;
 577         }
 578
 579         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 580                 setbits8(&regs->canctl1, MSCAN_LISTEN);
 581         else
 582                 clrbits8(&regs->canctl1, MSCAN_LISTEN);
 583
 584         ret = mscan_start(dev);
 585         if (ret)
 586                 goto exit_free_irq;
 587
 588         netif_start_queue(dev);
 589
 590         return 0;
 591
 592 exit_free_irq:
 593         free_irq(dev->irq, dev);
 594 exit_napi_disable:
 595         napi_disable(&priv->napi);
 596         close_candev(dev);
 597 exit_dis_can_clock:
 598         if (priv->clk_can)
 599                 clk_disable_unprepare(priv->clk_can);
 600 exit_dis_ipg_clock:
 601         if (priv->clk_ipg)
 602                 clk_disable_unprepare(priv->clk_ipg);
 603 exit_retcode:
 604         return ret;
 605 }
 606
 607 static int mscan_close(struct net_device *dev)
 608 {
 609         struct mscan_priv *priv = netdev_priv(dev);
 610         struct mscan_regs __iomem *regs = priv->reg_base;
 611
 612         netif_stop_queue(dev);
 613         napi_disable(&priv->napi);
 614
 615         out_8(&regs->cantier, 0);
 616         out_8(&regs->canrier, 0);
 617         mscan_set_mode(dev, MSCAN_INIT_MODE);
 618         close_candev(dev);
 619         free_irq(dev->irq, dev);
 620
 621         if (priv->clk_can)
 622                 clk_disable_unprepare(priv->clk_can);
 623         if (priv->clk_ipg)
 624                 clk_disable_unprepare(priv->clk_ipg);
 625
 626         return 0;
 627 }
 628
 629 static const struct net_device_ops mscan_netdev_ops = {
 630         .ndo_open       = mscan_open,
 631         .ndo_stop       = mscan_close,
 632         .ndo_start_xmit = mscan_start_xmit,
 633         .ndo_change_mtu = can_change_mtu,
 634 };
 635
 636 int register_mscandev(struct net_device *dev, int mscan_clksrc)
 637 {
 638         struct mscan_priv *priv = netdev_priv(dev);
 639         struct mscan_regs __iomem *regs = priv->reg_base;
 640         u8 ctl1;
 641
 642         ctl1 = in_8(&regs->canctl1);
 643         if (mscan_clksrc)
 644                 ctl1 |= MSCAN_CLKSRC;
 645         else
 646                 ctl1 &= ~MSCAN_CLKSRC;
 647
 648         if (priv->type == MSCAN_TYPE_MPC5121) {
 649                 priv->can.do_get_berr_counter = mscan_get_berr_counter;
 650                 ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
 651         }
 652
 653         ctl1 |= MSCAN_CANE;
 654         out_8(&regs->canctl1, ctl1);
 655         udelay(100);
 656
 657         /* acceptance mask/acceptance code (accept everything) */
 658         out_be16(&regs->canidar1_0, 0);
 659         out_be16(&regs->canidar3_2, 0);
 660         out_be16(&regs->canidar5_4, 0);
 661         out_be16(&regs->canidar7_6, 0);
 662
 663         out_be16(&regs->canidmr1_0, 0xffff);
 664         out_be16(&regs->canidmr3_2, 0xffff);
 665         out_be16(&regs->canidmr5_4, 0xffff);
 666         out_be16(&regs->canidmr7_6, 0xffff);
 667         /* Two 32 bit Acceptance Filters */
 668         out_8(&regs->canidac, MSCAN_AF_32BIT);
 669
 670         mscan_set_mode(dev, MSCAN_INIT_MODE);
 671
 672         return register_candev(dev);
 673 }
 674
 675 void unregister_mscandev(struct net_device *dev)
 676 {
 677         struct mscan_priv *priv = netdev_priv(dev);
 678         struct mscan_regs __iomem *regs = priv->reg_base;
 679         mscan_set_mode(dev, MSCAN_INIT_MODE);
 680         clrbits8(&regs->canctl1, MSCAN_CANE);
 681         unregister_candev(dev);
 682 }
 683
 684 struct net_device *alloc_mscandev(void)
 685 {
 686         struct net_device *dev;
 687         struct mscan_priv *priv;
 688         int i;
 689
 690         dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
 691         if (!dev)
 692                 return NULL;
 693         priv = netdev_priv(dev);
 694
 695         dev->netdev_ops = &mscan_netdev_ops;
 696
 697         dev->flags |= IFF_ECHO; /* we support local echo */
 698
 699         netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
 700
 701         priv->can.bittiming_const = &mscan_bittiming_const;
 702         priv->can.do_set_bittiming = mscan_do_set_bittiming;
 703         priv->can.do_set_mode = mscan_do_set_mode;
 704         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 705                 CAN_CTRLMODE_LISTENONLY;
 706
 707         for (i = 0; i < TX_QUEUE_SIZE; i++) {
 708                 priv->tx_queue[i].id = i;
 709                 priv->tx_queue[i].mask = 1 << i;
 710         }
 711
 712         return dev;
 713 }
 714
 715 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
 716 MODULE_LICENSE("GPL v2");
 717 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");