drivers/net/can/mscan/mscan.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
mscan_set_mode
mscan_start
mscan_restart
mscan_start_xmit
get_new_state
mscan_get_rx_frame
mscan_get_err_frame
mscan_rx_poll
mscan_isr
mscan_do_set_mode
mscan_do_set_bittiming
mscan_get_berr_counter
mscan_open
mscan_close
register_mscandev
unregister_mscandev
alloc_mscandev
   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         case 2:
 213                 if (buf_id < priv->prev_buf_id) {
 214                         priv->cur_pri++;
 215                         if (priv->cur_pri == 0xff) {
 216                                 set_bit(F_TX_WAIT_ALL, &priv->flags);
 217                                 netif_stop_queue(dev);
 218                         }
 219                 }
 220                 set_bit(F_TX_PROGRESS, &priv->flags);
 221                 break;
 222         }
 223         priv->prev_buf_id = buf_id;
 224         out_8(&regs->cantbsel, i);
 225 
 226         rtr = frame->can_id & CAN_RTR_FLAG;
 227 
 228         /* RTR is always the lowest bit of interest, then IDs follow */
 229         if (frame->can_id & CAN_EFF_FLAG) {
 230                 can_id = (frame->can_id & CAN_EFF_MASK)
 231                          << (MSCAN_EFF_RTR_SHIFT + 1);
 232                 if (rtr)
 233                         can_id |= 1 << MSCAN_EFF_RTR_SHIFT;
 234                 out_be16(&regs->tx.idr3_2, can_id);
 235 
 236                 can_id >>= 16;
 237                 /* EFF_FLAGS are between the IDs :( */
 238                 can_id = (can_id & 0x7) | ((can_id << 2) & 0xffe0)
 239                          | MSCAN_EFF_FLAGS;
 240         } else {
 241                 can_id = (frame->can_id & CAN_SFF_MASK)
 242                          << (MSCAN_SFF_RTR_SHIFT + 1);
 243                 if (rtr)
 244                         can_id |= 1 << MSCAN_SFF_RTR_SHIFT;
 245         }
 246         out_be16(&regs->tx.idr1_0, can_id);
 247 
 248         if (!rtr) {
 249                 void __iomem *data = &regs->tx.dsr1_0;
 250                 u16 *payload = (u16 *)frame->data;
 251 
 252                 for (i = 0; i < frame->can_dlc / 2; i++) {
 253                         out_be16(data, *payload++);
 254                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 255                 }
 256                 /* write remaining byte if necessary */
 257                 if (frame->can_dlc & 1)
 258                         out_8(data, frame->data[frame->can_dlc - 1]);
 259         }
 260 
 261         out_8(&regs->tx.dlr, frame->can_dlc);
 262         out_8(&regs->tx.tbpr, priv->cur_pri);
 263 
 264         /* Start transmission. */
 265         out_8(&regs->cantflg, 1 << buf_id);
 266 
 267         if (!test_bit(F_TX_PROGRESS, &priv->flags))
 268                 netif_trans_update(dev);
 269 
 270         list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
 271 
 272         can_put_echo_skb(skb, dev, buf_id);
 273 
 274         /* Enable interrupt. */
 275         priv->tx_active |= 1 << buf_id;
 276         out_8(&regs->cantier, priv->tx_active);
 277 
 278         return NETDEV_TX_OK;
 279 }
 280 
 281 static enum can_state get_new_state(struct net_device *dev, u8 canrflg)
 282 {
 283         struct mscan_priv *priv = netdev_priv(dev);
 284 
 285         if (unlikely(canrflg & MSCAN_CSCIF))
 286                 return state_map[max(MSCAN_STATE_RX(canrflg),
 287                                  MSCAN_STATE_TX(canrflg))];
 288 
 289         return priv->can.state;
 290 }
 291 
 292 static void mscan_get_rx_frame(struct net_device *dev, struct can_frame *frame)
 293 {
 294         struct mscan_priv *priv = netdev_priv(dev);
 295         struct mscan_regs __iomem *regs = priv->reg_base;
 296         u32 can_id;
 297         int i;
 298 
 299         can_id = in_be16(&regs->rx.idr1_0);
 300         if (can_id & (1 << 3)) {
 301                 frame->can_id = CAN_EFF_FLAG;
 302                 can_id = ((can_id << 16) | in_be16(&regs->rx.idr3_2));
 303                 can_id = ((can_id & 0xffe00000) |
 304                           ((can_id & 0x7ffff) << 2)) >> 2;
 305         } else {
 306                 can_id >>= 4;
 307                 frame->can_id = 0;
 308         }
 309 
 310         frame->can_id |= can_id >> 1;
 311         if (can_id & 1)
 312                 frame->can_id |= CAN_RTR_FLAG;
 313 
 314         frame->can_dlc = get_can_dlc(in_8(&regs->rx.dlr) & 0xf);
 315 
 316         if (!(frame->can_id & CAN_RTR_FLAG)) {
 317                 void __iomem *data = &regs->rx.dsr1_0;
 318                 u16 *payload = (u16 *)frame->data;
 319 
 320                 for (i = 0; i < frame->can_dlc / 2; i++) {
 321                         *payload++ = in_be16(data);
 322                         data += 2 + _MSCAN_RESERVED_DSR_SIZE;
 323                 }
 324                 /* read remaining byte if necessary */
 325                 if (frame->can_dlc & 1)
 326                         frame->data[frame->can_dlc - 1] = in_8(data);
 327         }
 328 
 329         out_8(&regs->canrflg, MSCAN_RXF);
 330 }
 331 
 332 static void mscan_get_err_frame(struct net_device *dev, struct can_frame *frame,
 333                                 u8 canrflg)
 334 {
 335         struct mscan_priv *priv = netdev_priv(dev);
 336         struct mscan_regs __iomem *regs = priv->reg_base;
 337         struct net_device_stats *stats = &dev->stats;
 338         enum can_state new_state;
 339 
 340         netdev_dbg(dev, "error interrupt (canrflg=%#x)\n", canrflg);
 341         frame->can_id = CAN_ERR_FLAG;
 342 
 343         if (canrflg & MSCAN_OVRIF) {
 344                 frame->can_id |= CAN_ERR_CRTL;
 345                 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 346                 stats->rx_over_errors++;
 347                 stats->rx_errors++;
 348         } else {
 349                 frame->data[1] = 0;
 350         }
 351 
 352         new_state = get_new_state(dev, canrflg);
 353         if (new_state != priv->can.state) {
 354                 can_change_state(dev, frame,
 355                                  state_map[MSCAN_STATE_TX(canrflg)],
 356                                  state_map[MSCAN_STATE_RX(canrflg)]);
 357 
 358                 if (priv->can.state == CAN_STATE_BUS_OFF) {
 359                         /*
 360                          * The MSCAN on the MPC5200 does recover from bus-off
 361                          * automatically. To avoid that we stop the chip doing
 362                          * a light-weight stop (we are in irq-context).
 363                          */
 364                         if (priv->type != MSCAN_TYPE_MPC5121) {
 365                                 out_8(&regs->cantier, 0);
 366                                 out_8(&regs->canrier, 0);
 367                                 setbits8(&regs->canctl0,
 368                                          MSCAN_SLPRQ | MSCAN_INITRQ);
 369                         }
 370                         can_bus_off(dev);
 371                 }
 372         }
 373         priv->shadow_statflg = canrflg & MSCAN_STAT_MSK;
 374         frame->can_dlc = CAN_ERR_DLC;
 375         out_8(&regs->canrflg, MSCAN_ERR_IF);
 376 }
 377 
 378 static int mscan_rx_poll(struct napi_struct *napi, int quota)
 379 {
 380         struct mscan_priv *priv = container_of(napi, struct mscan_priv, napi);
 381         struct net_device *dev = napi->dev;
 382         struct mscan_regs __iomem *regs = priv->reg_base;
 383         struct net_device_stats *stats = &dev->stats;
 384         int work_done = 0;
 385         struct sk_buff *skb;
 386         struct can_frame *frame;
 387         u8 canrflg;
 388 
 389         while (work_done < quota) {
 390                 canrflg = in_8(&regs->canrflg);
 391                 if (!(canrflg & (MSCAN_RXF | MSCAN_ERR_IF)))
 392                         break;
 393 
 394                 skb = alloc_can_skb(dev, &frame);
 395                 if (!skb) {
 396                         if (printk_ratelimit())
 397                                 netdev_notice(dev, "packet dropped\n");
 398                         stats->rx_dropped++;
 399                         out_8(&regs->canrflg, canrflg);
 400                         continue;
 401                 }
 402 
 403                 if (canrflg & MSCAN_RXF)
 404                         mscan_get_rx_frame(dev, frame);
 405                 else if (canrflg & MSCAN_ERR_IF)
 406                         mscan_get_err_frame(dev, frame, canrflg);
 407 
 408                 stats->rx_packets++;
 409                 stats->rx_bytes += frame->can_dlc;
 410                 work_done++;
 411                 netif_receive_skb(skb);
 412         }
 413 
 414         if (work_done < quota) {
 415                 if (likely(napi_complete_done(&priv->napi, work_done))) {
 416                         clear_bit(F_RX_PROGRESS, &priv->flags);
 417                         if (priv->can.state < CAN_STATE_BUS_OFF)
 418                                 out_8(&regs->canrier, priv->shadow_canrier);
 419                 }
 420         }
 421         return work_done;
 422 }
 423 
 424 static irqreturn_t mscan_isr(int irq, void *dev_id)
 425 {
 426         struct net_device *dev = (struct net_device *)dev_id;
 427         struct mscan_priv *priv = netdev_priv(dev);
 428         struct mscan_regs __iomem *regs = priv->reg_base;
 429         struct net_device_stats *stats = &dev->stats;
 430         u8 cantier, cantflg, canrflg;
 431         irqreturn_t ret = IRQ_NONE;
 432 
 433         cantier = in_8(&regs->cantier) & MSCAN_TXE;
 434         cantflg = in_8(&regs->cantflg) & cantier;
 435 
 436         if (cantier && cantflg) {
 437                 struct list_head *tmp, *pos;
 438 
 439                 list_for_each_safe(pos, tmp, &priv->tx_head) {
 440                         struct tx_queue_entry *entry =
 441                             list_entry(pos, struct tx_queue_entry, list);
 442                         u8 mask = entry->mask;
 443 
 444                         if (!(cantflg & mask))
 445                                 continue;
 446 
 447                         out_8(&regs->cantbsel, mask);
 448                         stats->tx_bytes += in_8(&regs->tx.dlr);
 449                         stats->tx_packets++;
 450                         can_get_echo_skb(dev, entry->id);
 451                         priv->tx_active &= ~mask;
 452                         list_del(pos);
 453                 }
 454 
 455                 if (list_empty(&priv->tx_head)) {
 456                         clear_bit(F_TX_WAIT_ALL, &priv->flags);
 457                         clear_bit(F_TX_PROGRESS, &priv->flags);
 458                         priv->cur_pri = 0;
 459                 } else {
 460                         netif_trans_update(dev);
 461                 }
 462 
 463                 if (!test_bit(F_TX_WAIT_ALL, &priv->flags))
 464                         netif_wake_queue(dev);
 465 
 466                 out_8(&regs->cantier, priv->tx_active);
 467                 ret = IRQ_HANDLED;
 468         }
 469 
 470         canrflg = in_8(&regs->canrflg);
 471         if ((canrflg & ~MSCAN_STAT_MSK) &&
 472             !test_and_set_bit(F_RX_PROGRESS, &priv->flags)) {
 473                 if (canrflg & ~MSCAN_STAT_MSK) {
 474                         priv->shadow_canrier = in_8(&regs->canrier);
 475                         out_8(&regs->canrier, 0);
 476                         napi_schedule(&priv->napi);
 477                         ret = IRQ_HANDLED;
 478                 } else {
 479                         clear_bit(F_RX_PROGRESS, &priv->flags);
 480                 }
 481         }
 482         return ret;
 483 }
 484 
 485 static int mscan_do_set_mode(struct net_device *dev, enum can_mode mode)
 486 {
 487         int ret = 0;
 488 
 489         switch (mode) {
 490         case CAN_MODE_START:
 491                 ret = mscan_restart(dev);
 492                 if (ret)
 493                         break;
 494                 if (netif_queue_stopped(dev))
 495                         netif_wake_queue(dev);
 496                 break;
 497 
 498         default:
 499                 ret = -EOPNOTSUPP;
 500                 break;
 501         }
 502         return ret;
 503 }
 504 
 505 static int mscan_do_set_bittiming(struct net_device *dev)
 506 {
 507         struct mscan_priv *priv = netdev_priv(dev);
 508         struct mscan_regs __iomem *regs = priv->reg_base;
 509         struct can_bittiming *bt = &priv->can.bittiming;
 510         u8 btr0, btr1;
 511 
 512         btr0 = BTR0_SET_BRP(bt->brp) | BTR0_SET_SJW(bt->sjw);
 513         btr1 = (BTR1_SET_TSEG1(bt->prop_seg + bt->phase_seg1) |
 514                 BTR1_SET_TSEG2(bt->phase_seg2) |
 515                 BTR1_SET_SAM(priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES));
 516 
 517         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 518 
 519         out_8(&regs->canbtr0, btr0);
 520         out_8(&regs->canbtr1, btr1);
 521 
 522         return 0;
 523 }
 524 
 525 static int mscan_get_berr_counter(const struct net_device *dev,
 526                                   struct can_berr_counter *bec)
 527 {
 528         struct mscan_priv *priv = netdev_priv(dev);
 529         struct mscan_regs __iomem *regs = priv->reg_base;
 530 
 531         bec->txerr = in_8(&regs->cantxerr);
 532         bec->rxerr = in_8(&regs->canrxerr);
 533 
 534         return 0;
 535 }
 536 
 537 static int mscan_open(struct net_device *dev)
 538 {
 539         int ret;
 540         struct mscan_priv *priv = netdev_priv(dev);
 541         struct mscan_regs __iomem *regs = priv->reg_base;
 542 
 543         if (priv->clk_ipg) {
 544                 ret = clk_prepare_enable(priv->clk_ipg);
 545                 if (ret)
 546                         goto exit_retcode;
 547         }
 548         if (priv->clk_can) {
 549                 ret = clk_prepare_enable(priv->clk_can);
 550                 if (ret)
 551                         goto exit_dis_ipg_clock;
 552         }
 553 
 554         /* common open */
 555         ret = open_candev(dev);
 556         if (ret)
 557                 goto exit_dis_can_clock;
 558 
 559         napi_enable(&priv->napi);
 560 
 561         ret = request_irq(dev->irq, mscan_isr, 0, dev->name, dev);
 562         if (ret < 0) {
 563                 netdev_err(dev, "failed to attach interrupt\n");
 564                 goto exit_napi_disable;
 565         }
 566 
 567         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 568                 setbits8(&regs->canctl1, MSCAN_LISTEN);
 569         else
 570                 clrbits8(&regs->canctl1, MSCAN_LISTEN);
 571 
 572         ret = mscan_start(dev);
 573         if (ret)
 574                 goto exit_free_irq;
 575 
 576         netif_start_queue(dev);
 577 
 578         return 0;
 579 
 580 exit_free_irq:
 581         free_irq(dev->irq, dev);
 582 exit_napi_disable:
 583         napi_disable(&priv->napi);
 584         close_candev(dev);
 585 exit_dis_can_clock:
 586         if (priv->clk_can)
 587                 clk_disable_unprepare(priv->clk_can);
 588 exit_dis_ipg_clock:
 589         if (priv->clk_ipg)
 590                 clk_disable_unprepare(priv->clk_ipg);
 591 exit_retcode:
 592         return ret;
 593 }
 594 
 595 static int mscan_close(struct net_device *dev)
 596 {
 597         struct mscan_priv *priv = netdev_priv(dev);
 598         struct mscan_regs __iomem *regs = priv->reg_base;
 599 
 600         netif_stop_queue(dev);
 601         napi_disable(&priv->napi);
 602 
 603         out_8(&regs->cantier, 0);
 604         out_8(&regs->canrier, 0);
 605         mscan_set_mode(dev, MSCAN_INIT_MODE);
 606         close_candev(dev);
 607         free_irq(dev->irq, dev);
 608 
 609         if (priv->clk_can)
 610                 clk_disable_unprepare(priv->clk_can);
 611         if (priv->clk_ipg)
 612                 clk_disable_unprepare(priv->clk_ipg);
 613 
 614         return 0;
 615 }
 616 
 617 static const struct net_device_ops mscan_netdev_ops = {
 618         .ndo_open       = mscan_open,
 619         .ndo_stop       = mscan_close,
 620         .ndo_start_xmit = mscan_start_xmit,
 621         .ndo_change_mtu = can_change_mtu,
 622 };
 623 
 624 int register_mscandev(struct net_device *dev, int mscan_clksrc)
 625 {
 626         struct mscan_priv *priv = netdev_priv(dev);
 627         struct mscan_regs __iomem *regs = priv->reg_base;
 628         u8 ctl1;
 629 
 630         ctl1 = in_8(&regs->canctl1);
 631         if (mscan_clksrc)
 632                 ctl1 |= MSCAN_CLKSRC;
 633         else
 634                 ctl1 &= ~MSCAN_CLKSRC;
 635 
 636         if (priv->type == MSCAN_TYPE_MPC5121) {
 637                 priv->can.do_get_berr_counter = mscan_get_berr_counter;
 638                 ctl1 |= MSCAN_BORM; /* bus-off recovery upon request */
 639         }
 640 
 641         ctl1 |= MSCAN_CANE;
 642         out_8(&regs->canctl1, ctl1);
 643         udelay(100);
 644 
 645         /* acceptance mask/acceptance code (accept everything) */
 646         out_be16(&regs->canidar1_0, 0);
 647         out_be16(&regs->canidar3_2, 0);
 648         out_be16(&regs->canidar5_4, 0);
 649         out_be16(&regs->canidar7_6, 0);
 650 
 651         out_be16(&regs->canidmr1_0, 0xffff);
 652         out_be16(&regs->canidmr3_2, 0xffff);
 653         out_be16(&regs->canidmr5_4, 0xffff);
 654         out_be16(&regs->canidmr7_6, 0xffff);
 655         /* Two 32 bit Acceptance Filters */
 656         out_8(&regs->canidac, MSCAN_AF_32BIT);
 657 
 658         mscan_set_mode(dev, MSCAN_INIT_MODE);
 659 
 660         return register_candev(dev);
 661 }
 662 
 663 void unregister_mscandev(struct net_device *dev)
 664 {
 665         struct mscan_priv *priv = netdev_priv(dev);
 666         struct mscan_regs __iomem *regs = priv->reg_base;
 667         mscan_set_mode(dev, MSCAN_INIT_MODE);
 668         clrbits8(&regs->canctl1, MSCAN_CANE);
 669         unregister_candev(dev);
 670 }
 671 
 672 struct net_device *alloc_mscandev(void)
 673 {
 674         struct net_device *dev;
 675         struct mscan_priv *priv;
 676         int i;
 677 
 678         dev = alloc_candev(sizeof(struct mscan_priv), MSCAN_ECHO_SKB_MAX);
 679         if (!dev)
 680                 return NULL;
 681         priv = netdev_priv(dev);
 682 
 683         dev->netdev_ops = &mscan_netdev_ops;
 684 
 685         dev->flags |= IFF_ECHO; /* we support local echo */
 686 
 687         netif_napi_add(dev, &priv->napi, mscan_rx_poll, 8);
 688 
 689         priv->can.bittiming_const = &mscan_bittiming_const;
 690         priv->can.do_set_bittiming = mscan_do_set_bittiming;
 691         priv->can.do_set_mode = mscan_do_set_mode;
 692         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 693                 CAN_CTRLMODE_LISTENONLY;
 694 
 695         for (i = 0; i < TX_QUEUE_SIZE; i++) {
 696                 priv->tx_queue[i].id = i;
 697                 priv->tx_queue[i].mask = 1 << i;
 698         }
 699 
 700         return dev;
 701 }
 702 
 703 MODULE_AUTHOR("Andrey Volkov <avolkov@varma-el.com>");
 704 MODULE_LICENSE("GPL v2");
 705 MODULE_DESCRIPTION("CAN port driver for a MSCAN based chips");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/net/can/mscan/mscan.c

DEFINITIONS
