drivers/net/can/cc770/cc770.c

   1 /*
   2  * Core driver for the CC770 and AN82527 CAN controllers
   3  *
   4  * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the version 2 of the GNU General Public License
   8  * as published by the Free Software Foundation
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/types.h>
  23 #include <linux/fcntl.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/string.h>
  27 #include <linux/errno.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/if_arp.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/skbuff.h>
  32 #include <linux/delay.h>
  33
  34 #include <linux/can.h>
  35 #include <linux/can/dev.h>
  36 #include <linux/can/error.h>
  37 #include <linux/can/dev.h>
  38 #include <linux/can/platform/cc770.h>
  39
  40 #include "cc770.h"
  41
  42 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  43 MODULE_LICENSE("GPL v2");
  44 MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
  45
  46 /*
  47  * The CC770 is a CAN controller from Bosch, which is 100% compatible
  48  * with the AN82527 from Intel, but with "bugs" being fixed and some
  49  * additional functionality, mainly:
  50  *
  51  * 1. RX and TX error counters are readable.
  52  * 2. Support of silent (listen-only) mode.
  53  * 3. Message object 15 can receive all types of frames, also RTR and EFF.
  54  *
  55  * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
  56  * which explains in detail the compatibility between the CC770 and the
  57  * 82527. This driver use the additional functionality 3. on real CC770
  58  * devices. Unfortunately, the CC770 does still not store the message
  59  * identifier of received remote transmission request frames and
  60  * therefore it's set to 0.
  61  *
  62  * The message objects 1..14 can be used for TX and RX while the message
  63  * objects 15 is optimized for RX. It has a shadow register for reliable
  64  * data receiption under heavy bus load. Therefore it makes sense to use
  65  * this message object for the needed use case. The frame type (EFF/SFF)
  66  * for the message object 15 can be defined via kernel module parameter
  67  * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
  68  * otherwise 11 bit SFF messages.
  69  */
  70 static int msgobj15_eff;
  71 module_param(msgobj15_eff, int, S_IRUGO);
  72 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
  73                  "(default: 11-bit standard frames)");
  74
  75 static int i82527_compat;
  76 module_param(i82527_compat, int, S_IRUGO);
  77 MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
  78                  "without using additional functions");
  79
  80 /*
  81  * This driver uses the last 5 message objects 11..15. The definitions
  82  * and structure below allows to configure and assign them to the real
  83  * message object.
  84  */
  85 static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
  86         [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
  87         [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
  88         [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
  89         [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
  90                               CC770_OBJ_FLAG_EFF,
  91         [CC770_OBJ_TX] = 0,
  92 };
  93
  94 static struct can_bittiming_const cc770_bittiming_const = {
  95         .name = KBUILD_MODNAME,
  96         .tseg1_min = 1,
  97         .tseg1_max = 16,
  98         .tseg2_min = 1,
  99         .tseg2_max = 8,
 100         .sjw_max = 4,
 101         .brp_min = 1,
 102         .brp_max = 64,
 103         .brp_inc = 1,
 104 };
 105
 106 static inline int intid2obj(unsigned int intid)
 107 {
 108         if (intid == 2)
 109                 return 0;
 110         else
 111                 return MSGOBJ_LAST + 2 - intid;
 112 }
 113
 114 static void enable_all_objs(const struct net_device *dev)
 115 {
 116         struct cc770_priv *priv = netdev_priv(dev);
 117         u8 msgcfg;
 118         unsigned char obj_flags;
 119         unsigned int o, mo;
 120
 121         for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
 122                 obj_flags = priv->obj_flags[o];
 123                 mo = obj2msgobj(o);
 124
 125                 if (obj_flags & CC770_OBJ_FLAG_RX) {
 126                         /*
 127                          * We don't need extra objects for RTR and EFF if
 128                          * the additional CC770 functions are enabled.
 129                          */
 130                         if (priv->control_normal_mode & CTRL_EAF) {
 131                                 if (o > 0)
 132                                         continue;
 133                                 netdev_dbg(dev, "Message object %d for "
 134                                            "RX data, RTR, SFF and EFF\n", mo);
 135                         } else {
 136                                 netdev_dbg(dev,
 137                                            "Message object %d for RX %s %s\n",
 138                                            mo, obj_flags & CC770_OBJ_FLAG_RTR ?
 139                                            "RTR" : "data",
 140                                            obj_flags & CC770_OBJ_FLAG_EFF ?
 141                                            "EFF" : "SFF");
 142                         }
 143
 144                         if (obj_flags & CC770_OBJ_FLAG_EFF)
 145                                 msgcfg = MSGCFG_XTD;
 146                         else
 147                                 msgcfg = 0;
 148                         if (obj_flags & CC770_OBJ_FLAG_RTR)
 149                                 msgcfg |= MSGCFG_DIR;
 150
 151                         cc770_write_reg(priv, msgobj[mo].config, msgcfg);
 152                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 153                                         MSGVAL_SET | TXIE_RES |
 154                                         RXIE_SET | INTPND_RES);
 155
 156                         if (obj_flags & CC770_OBJ_FLAG_RTR)
 157                                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 158                                                 NEWDAT_RES | CPUUPD_SET |
 159                                                 TXRQST_RES | RMTPND_RES);
 160                         else
 161                                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 162                                                 NEWDAT_RES | MSGLST_RES |
 163                                                 TXRQST_RES | RMTPND_RES);
 164                 } else {
 165                         netdev_dbg(dev, "Message object %d for "
 166                                    "TX data, RTR, SFF and EFF\n", mo);
 167
 168                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 169                                         RMTPND_RES | TXRQST_RES |
 170                                         CPUUPD_RES | NEWDAT_RES);
 171                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 172                                         MSGVAL_RES | TXIE_RES |
 173                                         RXIE_RES | INTPND_RES);
 174                 }
 175         }
 176 }
 177
 178 static void disable_all_objs(const struct cc770_priv *priv)
 179 {
 180         int o, mo;
 181
 182         for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
 183                 mo = obj2msgobj(o);
 184
 185                 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
 186                         if (o > 0 && priv->control_normal_mode & CTRL_EAF)
 187                                 continue;
 188
 189                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 190                                         NEWDAT_RES | MSGLST_RES |
 191                                         TXRQST_RES | RMTPND_RES);
 192                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 193                                         MSGVAL_RES | TXIE_RES |
 194                                         RXIE_RES | INTPND_RES);
 195                 } else {
 196                         /* Clear message object for send */
 197                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 198                                         RMTPND_RES | TXRQST_RES |
 199                                         CPUUPD_RES | NEWDAT_RES);
 200                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 201                                         MSGVAL_RES | TXIE_RES |
 202                                         RXIE_RES | INTPND_RES);
 203                 }
 204         }
 205 }
 206
 207 static void set_reset_mode(struct net_device *dev)
 208 {
 209         struct cc770_priv *priv = netdev_priv(dev);
 210
 211         /* Enable configuration and puts chip in bus-off, disable interrupts */
 212         cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
 213
 214         priv->can.state = CAN_STATE_STOPPED;
 215
 216         /* Clear interrupts */
 217         cc770_read_reg(priv, interrupt);
 218
 219         /* Clear status register */
 220         cc770_write_reg(priv, status, 0);
 221
 222         /* Disable all used message objects */
 223         disable_all_objs(priv);
 224 }
 225
 226 static void set_normal_mode(struct net_device *dev)
 227 {
 228         struct cc770_priv *priv = netdev_priv(dev);
 229
 230         /* Clear interrupts */
 231         cc770_read_reg(priv, interrupt);
 232
 233         /* Clear status register and pre-set last error code */
 234         cc770_write_reg(priv, status, STAT_LEC_MASK);
 235
 236         /* Enable all used message objects*/
 237         enable_all_objs(dev);
 238
 239         /*
 240          * Clear bus-off, interrupts only for errors,
 241          * not for status change
 242          */
 243         cc770_write_reg(priv, control, priv->control_normal_mode);
 244
 245         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 246 }
 247
 248 static void chipset_init(struct cc770_priv *priv)
 249 {
 250         int mo, id, data;
 251
 252         /* Enable configuration and put chip in bus-off, disable interrupts */
 253         cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
 254
 255         /* Set CLKOUT divider and slew rates */
 256         cc770_write_reg(priv, clkout, priv->clkout);
 257
 258         /* Configure CPU interface / CLKOUT enable */
 259         cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
 260
 261         /* Set bus configuration  */
 262         cc770_write_reg(priv, bus_config, priv->bus_config);
 263
 264         /* Clear interrupts */
 265         cc770_read_reg(priv, interrupt);
 266
 267         /* Clear status register */
 268         cc770_write_reg(priv, status, 0);
 269
 270         /* Clear and invalidate message objects */
 271         for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
 272                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 273                                 INTPND_UNC | RXIE_RES |
 274                                 TXIE_RES | MSGVAL_RES);
 275                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 276                                 INTPND_RES | RXIE_RES |
 277                                 TXIE_RES | MSGVAL_RES);
 278                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 279                                 NEWDAT_RES | MSGLST_RES |
 280                                 TXRQST_RES | RMTPND_RES);
 281                 for (data = 0; data < 8; data++)
 282                         cc770_write_reg(priv, msgobj[mo].data[data], 0);
 283                 for (id = 0; id < 4; id++)
 284                         cc770_write_reg(priv, msgobj[mo].id[id], 0);
 285                 cc770_write_reg(priv, msgobj[mo].config, 0);
 286         }
 287
 288         /* Set all global ID masks to "don't care" */
 289         cc770_write_reg(priv, global_mask_std[0], 0);
 290         cc770_write_reg(priv, global_mask_std[1], 0);
 291         cc770_write_reg(priv, global_mask_ext[0], 0);
 292         cc770_write_reg(priv, global_mask_ext[1], 0);
 293         cc770_write_reg(priv, global_mask_ext[2], 0);
 294         cc770_write_reg(priv, global_mask_ext[3], 0);
 295
 296 }
 297
 298 static int cc770_probe_chip(struct net_device *dev)
 299 {
 300         struct cc770_priv *priv = netdev_priv(dev);
 301
 302         /* Enable configuration, put chip in bus-off, disable ints */
 303         cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
 304         /* Configure cpu interface / CLKOUT disable */
 305         cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
 306
 307         /*
 308          * Check if hardware reset is still inactive or maybe there
 309          * is no chip in this address space
 310          */
 311         if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
 312                 netdev_info(dev, "probing @0x%p failed (reset)\n",
 313                             priv->reg_base);
 314                 return -ENODEV;
 315         }
 316
 317         /* Write and read back test pattern (some arbitrary values) */
 318         cc770_write_reg(priv, msgobj[1].data[1], 0x25);
 319         cc770_write_reg(priv, msgobj[2].data[3], 0x52);
 320         cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
 321         if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
 322             (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
 323             (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
 324                 netdev_info(dev, "probing @0x%p failed (pattern)\n",
 325                             priv->reg_base);
 326                 return -ENODEV;
 327         }
 328
 329         /* Check if this chip is a CC770 supporting additional functions */
 330         if (cc770_read_reg(priv, control) & CTRL_EAF)
 331                 priv->control_normal_mode |= CTRL_EAF;
 332
 333         return 0;
 334 }
 335
 336 static void cc770_start(struct net_device *dev)
 337 {
 338         struct cc770_priv *priv = netdev_priv(dev);
 339
 340         /* leave reset mode */
 341         if (priv->can.state != CAN_STATE_STOPPED)
 342                 set_reset_mode(dev);
 343
 344         /* leave reset mode */
 345         set_normal_mode(dev);
 346 }
 347
 348 static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
 349 {
 350         switch (mode) {
 351         case CAN_MODE_START:
 352                 cc770_start(dev);
 353                 netif_wake_queue(dev);
 354                 break;
 355
 356         default:
 357                 return -EOPNOTSUPP;
 358         }
 359
 360         return 0;
 361 }
 362
 363 static int cc770_set_bittiming(struct net_device *dev)
 364 {
 365         struct cc770_priv *priv = netdev_priv(dev);
 366         struct can_bittiming *bt = &priv->can.bittiming;
 367         u8 btr0, btr1;
 368
 369         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 370         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 371                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 372         if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 373                 btr1 |= 0x80;
 374
 375         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 376
 377         cc770_write_reg(priv, bit_timing_0, btr0);
 378         cc770_write_reg(priv, bit_timing_1, btr1);
 379
 380         return 0;
 381 }
 382
 383 static int cc770_get_berr_counter(const struct net_device *dev,
 384                                   struct can_berr_counter *bec)
 385 {
 386         struct cc770_priv *priv = netdev_priv(dev);
 387
 388         bec->txerr = cc770_read_reg(priv, tx_error_counter);
 389         bec->rxerr = cc770_read_reg(priv, rx_error_counter);
 390
 391         return 0;
 392 }
 393
 394 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
 395 {
 396         struct cc770_priv *priv = netdev_priv(dev);
 397         struct net_device_stats *stats = &dev->stats;
 398         struct can_frame *cf = (struct can_frame *)skb->data;
 399         unsigned int mo = obj2msgobj(CC770_OBJ_TX);
 400         u8 dlc, rtr;
 401         u32 id;
 402         int i;
 403
 404         if (can_dropped_invalid_skb(dev, skb))
 405                 return NETDEV_TX_OK;
 406
 407         if ((cc770_read_reg(priv,
 408                             msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
 409                 netdev_err(dev, "TX register is still occupied!\n");
 410                 return NETDEV_TX_BUSY;
 411         }
 412
 413         netif_stop_queue(dev);
 414
 415         dlc = cf->can_dlc;
 416         id = cf->can_id;
 417         if (cf->can_id & CAN_RTR_FLAG)
 418                 rtr = 0;
 419         else
 420                 rtr = MSGCFG_DIR;
 421         cc770_write_reg(priv, msgobj[mo].ctrl1,
 422                         RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
 423         cc770_write_reg(priv, msgobj[mo].ctrl0,
 424                         MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
 425         if (id & CAN_EFF_FLAG) {
 426                 id &= CAN_EFF_MASK;
 427                 cc770_write_reg(priv, msgobj[mo].config,
 428                                 (dlc << 4) | rtr | MSGCFG_XTD);
 429                 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
 430                 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
 431                 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
 432                 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
 433         } else {
 434                 id &= CAN_SFF_MASK;
 435                 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
 436                 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
 437                 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
 438         }
 439
 440         for (i = 0; i < dlc; i++)
 441                 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
 442
 443         /* Store echo skb before starting the transfer */
 444         can_put_echo_skb(skb, dev, 0);
 445
 446         cc770_write_reg(priv, msgobj[mo].ctrl1,
 447                         RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
 448
 449         stats->tx_bytes += dlc;
 450
 451
 452         /*
 453          * HM: We had some cases of repeated IRQs so make sure the
 454          * INT is acknowledged I know it's already further up, but
 455          * doing again fixed the issue
 456          */
 457         cc770_write_reg(priv, msgobj[mo].ctrl0,
 458                         MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
 459
 460         return NETDEV_TX_OK;
 461 }
 462
 463 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
 464 {
 465         struct cc770_priv *priv = netdev_priv(dev);
 466         struct net_device_stats *stats = &dev->stats;
 467         struct can_frame *cf;
 468         struct sk_buff *skb;
 469         u8 config;
 470         u32 id;
 471         int i;
 472
 473         skb = alloc_can_skb(dev, &cf);
 474         if (!skb)
 475                 return;
 476
 477         config = cc770_read_reg(priv, msgobj[mo].config);
 478
 479         if (ctrl1 & RMTPND_SET) {
 480                 /*
 481                  * Unfortunately, the chip does not store the real message
 482                  * identifier of the received remote transmission request
 483                  * frame. Therefore we set it to 0.
 484                  */
 485                 cf->can_id = CAN_RTR_FLAG;
 486                 if (config & MSGCFG_XTD)
 487                         cf->can_id |= CAN_EFF_FLAG;
 488                 cf->can_dlc = 0;
 489         } else {
 490                 if (config & MSGCFG_XTD) {
 491                         id = cc770_read_reg(priv, msgobj[mo].id[3]);
 492                         id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
 493                         id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
 494                         id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
 495                         id >>= 3;
 496                         id |= CAN_EFF_FLAG;
 497                 } else {
 498                         id = cc770_read_reg(priv, msgobj[mo].id[1]);
 499                         id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
 500                         id >>= 5;
 501                 }
 502
 503                 cf->can_id = id;
 504                 cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
 505                 for (i = 0; i < cf->can_dlc; i++)
 506                         cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
 507         }
 508         netif_rx(skb);
 509
 510         stats->rx_packets++;
 511         stats->rx_bytes += cf->can_dlc;
 512 }
 513
 514 static int cc770_err(struct net_device *dev, u8 status)
 515 {
 516         struct cc770_priv *priv = netdev_priv(dev);
 517         struct net_device_stats *stats = &dev->stats;
 518         struct can_frame *cf;
 519         struct sk_buff *skb;
 520         u8 lec;
 521
 522         netdev_dbg(dev, "status interrupt (%#x)\n", status);
 523
 524         skb = alloc_can_err_skb(dev, &cf);
 525         if (!skb)
 526                 return -ENOMEM;
 527
 528         /* Use extended functions of the CC770 */
 529         if (priv->control_normal_mode & CTRL_EAF) {
 530                 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
 531                 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
 532         }
 533
 534         if (status & STAT_BOFF) {
 535                 /* Disable interrupts */
 536                 cc770_write_reg(priv, control, CTRL_INI);
 537                 cf->can_id |= CAN_ERR_BUSOFF;
 538                 priv->can.state = CAN_STATE_BUS_OFF;
 539                 can_bus_off(dev);
 540         } else if (status & STAT_WARN) {
 541                 cf->can_id |= CAN_ERR_CRTL;
 542                 /* Only the CC770 does show error passive */
 543                 if (cf->data[7] > 127) {
 544                         cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE |
 545                                 CAN_ERR_CRTL_TX_PASSIVE;
 546                         priv->can.state = CAN_STATE_ERROR_PASSIVE;
 547                         priv->can.can_stats.error_passive++;
 548                 } else {
 549                         cf->data[1] = CAN_ERR_CRTL_RX_WARNING |
 550                                 CAN_ERR_CRTL_TX_WARNING;
 551                         priv->can.state = CAN_STATE_ERROR_WARNING;
 552                         priv->can.can_stats.error_warning++;
 553                 }
 554         } else {
 555                 /* Back to error avtive */
 556                 cf->can_id |= CAN_ERR_PROT;
 557                 cf->data[2] = CAN_ERR_PROT_ACTIVE;
 558                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 559         }
 560
 561         lec = status & STAT_LEC_MASK;
 562         if (lec < 7 && lec > 0) {
 563                 if (lec == STAT_LEC_ACK) {
 564                         cf->can_id |= CAN_ERR_ACK;
 565                 } else {
 566                         cf->can_id |= CAN_ERR_PROT;
 567                         switch (lec) {
 568                         case STAT_LEC_STUFF:
 569                                 cf->data[2] |= CAN_ERR_PROT_STUFF;
 570                                 break;
 571                         case STAT_LEC_FORM:
 572                                 cf->data[2] |= CAN_ERR_PROT_FORM;
 573                                 break;
 574                         case STAT_LEC_BIT1:
 575                                 cf->data[2] |= CAN_ERR_PROT_BIT1;
 576                                 break;
 577                         case STAT_LEC_BIT0:
 578                                 cf->data[2] |= CAN_ERR_PROT_BIT0;
 579                                 break;
 580                         case STAT_LEC_CRC:
 581                                 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
 582                                 break;
 583                         }
 584                 }
 585         }
 586
 587         netif_rx(skb);
 588
 589         stats->rx_packets++;
 590         stats->rx_bytes += cf->can_dlc;
 591
 592         return 0;
 593 }
 594
 595 static int cc770_status_interrupt(struct net_device *dev)
 596 {
 597         struct cc770_priv *priv = netdev_priv(dev);
 598         u8 status;
 599
 600         status = cc770_read_reg(priv, status);
 601         /* Reset the status register including RXOK and TXOK */
 602         cc770_write_reg(priv, status, STAT_LEC_MASK);
 603
 604         if (status & (STAT_WARN | STAT_BOFF) ||
 605             (status & STAT_LEC_MASK) != STAT_LEC_MASK) {
 606                 cc770_err(dev, status);
 607                 return status & STAT_BOFF;
 608         }
 609
 610         return 0;
 611 }
 612
 613 static void cc770_rx_interrupt(struct net_device *dev, unsigned int o)
 614 {
 615         struct cc770_priv *priv = netdev_priv(dev);
 616         struct net_device_stats *stats = &dev->stats;
 617         unsigned int mo = obj2msgobj(o);
 618         u8 ctrl1;
 619         int n = CC770_MAX_MSG;
 620
 621         while (n--) {
 622                 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
 623
 624                 if (!(ctrl1 & NEWDAT_SET))  {
 625                         /* Check for RTR if additional functions are enabled */
 626                         if (priv->control_normal_mode & CTRL_EAF) {
 627                                 if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) &
 628                                       INTPND_SET))
 629                                         break;
 630                         } else {
 631                                 break;
 632                         }
 633                 }
 634
 635                 if (ctrl1 & MSGLST_SET) {
 636                         stats->rx_over_errors++;
 637                         stats->rx_errors++;
 638                 }
 639                 if (mo < MSGOBJ_LAST)
 640                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 641                                         NEWDAT_RES | MSGLST_RES |
 642                                         TXRQST_UNC | RMTPND_UNC);
 643                 cc770_rx(dev, mo, ctrl1);
 644
 645                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 646                                 MSGVAL_SET | TXIE_RES |
 647                                 RXIE_SET | INTPND_RES);
 648                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 649                                 NEWDAT_RES | MSGLST_RES |
 650                                 TXRQST_RES | RMTPND_RES);
 651         }
 652 }
 653
 654 static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o)
 655 {
 656         struct cc770_priv *priv = netdev_priv(dev);
 657         unsigned int mo = obj2msgobj(o);
 658         u8 ctrl0, ctrl1;
 659         int n = CC770_MAX_MSG;
 660
 661         while (n--) {
 662                 ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0);
 663                 if (!(ctrl0 & INTPND_SET))
 664                         break;
 665
 666                 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1);
 667                 cc770_rx(dev, mo, ctrl1);
 668
 669                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 670                                 MSGVAL_SET | TXIE_RES |
 671                                 RXIE_SET | INTPND_RES);
 672                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 673                                 NEWDAT_RES | CPUUPD_SET |
 674                                 TXRQST_RES | RMTPND_RES);
 675         }
 676 }
 677
 678 static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
 679 {
 680         struct cc770_priv *priv = netdev_priv(dev);
 681         struct net_device_stats *stats = &dev->stats;
 682         unsigned int mo = obj2msgobj(o);
 683
 684         /* Nothing more to send, switch off interrupts */
 685         cc770_write_reg(priv, msgobj[mo].ctrl0,
 686                         MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
 687         /*
 688          * We had some cases of repeated IRQ so make sure the
 689          * INT is acknowledged
 690          */
 691         cc770_write_reg(priv, msgobj[mo].ctrl0,
 692                         MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
 693
 694         stats->tx_packets++;
 695         can_get_echo_skb(dev, 0);
 696         netif_wake_queue(dev);
 697 }
 698
 699 irqreturn_t cc770_interrupt(int irq, void *dev_id)
 700 {
 701         struct net_device *dev = (struct net_device *)dev_id;
 702         struct cc770_priv *priv = netdev_priv(dev);
 703         u8 intid;
 704         int o, n = 0;
 705
 706         /* Shared interrupts and IRQ off? */
 707         if (priv->can.state == CAN_STATE_STOPPED)
 708                 return IRQ_NONE;
 709
 710         if (priv->pre_irq)
 711                 priv->pre_irq(priv);
 712
 713         while (n < CC770_MAX_IRQ) {
 714                 /* Read the highest pending interrupt request */
 715                 intid = cc770_read_reg(priv, interrupt);
 716                 if (!intid)
 717                         break;
 718                 n++;
 719
 720                 if (intid == 1) {
 721                         /* Exit in case of bus-off */
 722                         if (cc770_status_interrupt(dev))
 723                                 break;
 724                 } else {
 725                         o = intid2obj(intid);
 726
 727                         if (o >= CC770_OBJ_MAX) {
 728                                 netdev_err(dev, "Unexpected interrupt id %d\n",
 729                                            intid);
 730                                 continue;
 731                         }
 732
 733                         if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR)
 734                                 cc770_rtr_interrupt(dev, o);
 735                         else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX)
 736                                 cc770_rx_interrupt(dev, o);
 737                         else
 738                                 cc770_tx_interrupt(dev, o);
 739                 }
 740         }
 741
 742         if (priv->post_irq)
 743                 priv->post_irq(priv);
 744
 745         if (n >= CC770_MAX_IRQ)
 746                 netdev_dbg(dev, "%d messages handled in ISR", n);
 747
 748         return (n) ? IRQ_HANDLED : IRQ_NONE;
 749 }
 750
 751 static int cc770_open(struct net_device *dev)
 752 {
 753         struct cc770_priv *priv = netdev_priv(dev);
 754         int err;
 755
 756         /* set chip into reset mode */
 757         set_reset_mode(dev);
 758
 759         /* common open */
 760         err = open_candev(dev);
 761         if (err)
 762                 return err;
 763
 764         err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags,
 765                           dev->name, dev);
 766         if (err) {
 767                 close_candev(dev);
 768                 return -EAGAIN;
 769         }
 770
 771         /* init and start chip */
 772         cc770_start(dev);
 773
 774         netif_start_queue(dev);
 775
 776         return 0;
 777 }
 778
 779 static int cc770_close(struct net_device *dev)
 780 {
 781         netif_stop_queue(dev);
 782         set_reset_mode(dev);
 783
 784         free_irq(dev->irq, dev);
 785         close_candev(dev);
 786
 787         return 0;
 788 }
 789
 790 struct net_device *alloc_cc770dev(int sizeof_priv)
 791 {
 792         struct net_device *dev;
 793         struct cc770_priv *priv;
 794
 795         dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv,
 796                            CC770_ECHO_SKB_MAX);
 797         if (!dev)
 798                 return NULL;
 799
 800         priv = netdev_priv(dev);
 801
 802         priv->dev = dev;
 803         priv->can.bittiming_const = &cc770_bittiming_const;
 804         priv->can.do_set_bittiming = cc770_set_bittiming;
 805         priv->can.do_set_mode = cc770_set_mode;
 806         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
 807
 808         memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags));
 809
 810         if (sizeof_priv)
 811                 priv->priv = (void *)priv + sizeof(struct cc770_priv);
 812
 813         return dev;
 814 }
 815 EXPORT_SYMBOL_GPL(alloc_cc770dev);
 816
 817 void free_cc770dev(struct net_device *dev)
 818 {
 819         free_candev(dev);
 820 }
 821 EXPORT_SYMBOL_GPL(free_cc770dev);
 822
 823 static const struct net_device_ops cc770_netdev_ops = {
 824         .ndo_open = cc770_open,
 825         .ndo_stop = cc770_close,
 826         .ndo_start_xmit = cc770_start_xmit,
 827 };
 828
 829 int register_cc770dev(struct net_device *dev)
 830 {
 831         struct cc770_priv *priv = netdev_priv(dev);
 832         int err;
 833
 834         err = cc770_probe_chip(dev);
 835         if (err)
 836                 return err;
 837
 838         dev->netdev_ops = &cc770_netdev_ops;
 839
 840         dev->flags |= IFF_ECHO; /* we support local echo */
 841
 842         /* Should we use additional functions? */
 843         if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
 844                 priv->can.do_get_berr_counter = cc770_get_berr_counter;
 845                 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
 846                 netdev_dbg(dev, "i82527 mode with additional functions\n");
 847         } else {
 848                 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
 849                 netdev_dbg(dev, "strict i82527 compatibility mode\n");
 850         }
 851
 852         chipset_init(priv);
 853         set_reset_mode(dev);
 854
 855         return register_candev(dev);
 856 }
 857 EXPORT_SYMBOL_GPL(register_cc770dev);
 858
 859 void unregister_cc770dev(struct net_device *dev)
 860 {
 861         set_reset_mode(dev);
 862         unregister_candev(dev);
 863 }
 864 EXPORT_SYMBOL_GPL(unregister_cc770dev);
 865
 866 static __init int cc770_init(void)
 867 {
 868         if (msgobj15_eff) {
 869                 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
 870                 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
 871         }
 872
 873         pr_info("CAN netdevice driver\n");
 874
 875         return 0;
 876 }
 877 module_init(cc770_init);
 878
 879 static __exit void cc770_exit(void)
 880 {
 881         pr_info("driver removed\n");
 882 }
 883 module_exit(cc770_exit);