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/platform/cc770.h>
  38
  39 #include "cc770.h"
  40
  41 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
  42 MODULE_LICENSE("GPL v2");
  43 MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver");
  44
  45 /*
  46  * The CC770 is a CAN controller from Bosch, which is 100% compatible
  47  * with the AN82527 from Intel, but with "bugs" being fixed and some
  48  * additional functionality, mainly:
  49  *
  50  * 1. RX and TX error counters are readable.
  51  * 2. Support of silent (listen-only) mode.
  52  * 3. Message object 15 can receive all types of frames, also RTR and EFF.
  53  *
  54  * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf",
  55  * which explains in detail the compatibility between the CC770 and the
  56  * 82527. This driver use the additional functionality 3. on real CC770
  57  * devices. Unfortunately, the CC770 does still not store the message
  58  * identifier of received remote transmission request frames and
  59  * therefore it's set to 0.
  60  *
  61  * The message objects 1..14 can be used for TX and RX while the message
  62  * objects 15 is optimized for RX. It has a shadow register for reliable
  63  * data reception under heavy bus load. Therefore it makes sense to use
  64  * this message object for the needed use case. The frame type (EFF/SFF)
  65  * for the message object 15 can be defined via kernel module parameter
  66  * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames,
  67  * otherwise 11 bit SFF messages.
  68  */
  69 static int msgobj15_eff;
  70 module_param(msgobj15_eff, int, S_IRUGO);
  71 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 "
  72                  "(default: 11-bit standard frames)");
  73
  74 static int i82527_compat;
  75 module_param(i82527_compat, int, S_IRUGO);
  76 MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 comptibility mode "
  77                  "without using additional functions");
  78
  79 /*
  80  * This driver uses the last 5 message objects 11..15. The definitions
  81  * and structure below allows to configure and assign them to the real
  82  * message object.
  83  */
  84 static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = {
  85         [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX,
  86         [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF,
  87         [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR,
  88         [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR |
  89                               CC770_OBJ_FLAG_EFF,
  90         [CC770_OBJ_TX] = 0,
  91 };
  92
  93 static const struct can_bittiming_const cc770_bittiming_const = {
  94         .name = KBUILD_MODNAME,
  95         .tseg1_min = 1,
  96         .tseg1_max = 16,
  97         .tseg2_min = 1,
  98         .tseg2_max = 8,
  99         .sjw_max = 4,
 100         .brp_min = 1,
 101         .brp_max = 64,
 102         .brp_inc = 1,
 103 };
 104
 105 static inline int intid2obj(unsigned int intid)
 106 {
 107         if (intid == 2)
 108                 return 0;
 109         else
 110                 return MSGOBJ_LAST + 2 - intid;
 111 }
 112
 113 static void enable_all_objs(const struct net_device *dev)
 114 {
 115         struct cc770_priv *priv = netdev_priv(dev);
 116         u8 msgcfg;
 117         unsigned char obj_flags;
 118         unsigned int o, mo;
 119
 120         for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) {
 121                 obj_flags = priv->obj_flags[o];
 122                 mo = obj2msgobj(o);
 123
 124                 if (obj_flags & CC770_OBJ_FLAG_RX) {
 125                         /*
 126                          * We don't need extra objects for RTR and EFF if
 127                          * the additional CC770 functions are enabled.
 128                          */
 129                         if (priv->control_normal_mode & CTRL_EAF) {
 130                                 if (o > 0)
 131                                         continue;
 132                                 netdev_dbg(dev, "Message object %d for "
 133                                            "RX data, RTR, SFF and EFF\n", mo);
 134                         } else {
 135                                 netdev_dbg(dev,
 136                                            "Message object %d for RX %s %s\n",
 137                                            mo, obj_flags & CC770_OBJ_FLAG_RTR ?
 138                                            "RTR" : "data",
 139                                            obj_flags & CC770_OBJ_FLAG_EFF ?
 140                                            "EFF" : "SFF");
 141                         }
 142
 143                         if (obj_flags & CC770_OBJ_FLAG_EFF)
 144                                 msgcfg = MSGCFG_XTD;
 145                         else
 146                                 msgcfg = 0;
 147                         if (obj_flags & CC770_OBJ_FLAG_RTR)
 148                                 msgcfg |= MSGCFG_DIR;
 149
 150                         cc770_write_reg(priv, msgobj[mo].config, msgcfg);
 151                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 152                                         MSGVAL_SET | TXIE_RES |
 153                                         RXIE_SET | INTPND_RES);
 154
 155                         if (obj_flags & CC770_OBJ_FLAG_RTR)
 156                                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 157                                                 NEWDAT_RES | CPUUPD_SET |
 158                                                 TXRQST_RES | RMTPND_RES);
 159                         else
 160                                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 161                                                 NEWDAT_RES | MSGLST_RES |
 162                                                 TXRQST_RES | RMTPND_RES);
 163                 } else {
 164                         netdev_dbg(dev, "Message object %d for "
 165                                    "TX data, RTR, SFF and EFF\n", mo);
 166
 167                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 168                                         RMTPND_RES | TXRQST_RES |
 169                                         CPUUPD_RES | NEWDAT_RES);
 170                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 171                                         MSGVAL_RES | TXIE_RES |
 172                                         RXIE_RES | INTPND_RES);
 173                 }
 174         }
 175 }
 176
 177 static void disable_all_objs(const struct cc770_priv *priv)
 178 {
 179         int o, mo;
 180
 181         for (o = 0; o <  ARRAY_SIZE(priv->obj_flags); o++) {
 182                 mo = obj2msgobj(o);
 183
 184                 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) {
 185                         if (o > 0 && priv->control_normal_mode & CTRL_EAF)
 186                                 continue;
 187
 188                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 189                                         NEWDAT_RES | MSGLST_RES |
 190                                         TXRQST_RES | RMTPND_RES);
 191                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 192                                         MSGVAL_RES | TXIE_RES |
 193                                         RXIE_RES | INTPND_RES);
 194                 } else {
 195                         /* Clear message object for send */
 196                         cc770_write_reg(priv, msgobj[mo].ctrl1,
 197                                         RMTPND_RES | TXRQST_RES |
 198                                         CPUUPD_RES | NEWDAT_RES);
 199                         cc770_write_reg(priv, msgobj[mo].ctrl0,
 200                                         MSGVAL_RES | TXIE_RES |
 201                                         RXIE_RES | INTPND_RES);
 202                 }
 203         }
 204 }
 205
 206 static void set_reset_mode(struct net_device *dev)
 207 {
 208         struct cc770_priv *priv = netdev_priv(dev);
 209
 210         /* Enable configuration and puts chip in bus-off, disable interrupts */
 211         cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI);
 212
 213         priv->can.state = CAN_STATE_STOPPED;
 214
 215         /* Clear interrupts */
 216         cc770_read_reg(priv, interrupt);
 217
 218         /* Clear status register */
 219         cc770_write_reg(priv, status, 0);
 220
 221         /* Disable all used message objects */
 222         disable_all_objs(priv);
 223 }
 224
 225 static void set_normal_mode(struct net_device *dev)
 226 {
 227         struct cc770_priv *priv = netdev_priv(dev);
 228
 229         /* Clear interrupts */
 230         cc770_read_reg(priv, interrupt);
 231
 232         /* Clear status register and pre-set last error code */
 233         cc770_write_reg(priv, status, STAT_LEC_MASK);
 234
 235         /* Enable all used message objects*/
 236         enable_all_objs(dev);
 237
 238         /*
 239          * Clear bus-off, interrupts only for errors,
 240          * not for status change
 241          */
 242         cc770_write_reg(priv, control, priv->control_normal_mode);
 243
 244         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 245 }
 246
 247 static void chipset_init(struct cc770_priv *priv)
 248 {
 249         int mo, id, data;
 250
 251         /* Enable configuration and put chip in bus-off, disable interrupts */
 252         cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI));
 253
 254         /* Set CLKOUT divider and slew rates */
 255         cc770_write_reg(priv, clkout, priv->clkout);
 256
 257         /* Configure CPU interface / CLKOUT enable */
 258         cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
 259
 260         /* Set bus configuration  */
 261         cc770_write_reg(priv, bus_config, priv->bus_config);
 262
 263         /* Clear interrupts */
 264         cc770_read_reg(priv, interrupt);
 265
 266         /* Clear status register */
 267         cc770_write_reg(priv, status, 0);
 268
 269         /* Clear and invalidate message objects */
 270         for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) {
 271                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 272                                 INTPND_UNC | RXIE_RES |
 273                                 TXIE_RES | MSGVAL_RES);
 274                 cc770_write_reg(priv, msgobj[mo].ctrl0,
 275                                 INTPND_RES | RXIE_RES |
 276                                 TXIE_RES | MSGVAL_RES);
 277                 cc770_write_reg(priv, msgobj[mo].ctrl1,
 278                                 NEWDAT_RES | MSGLST_RES |
 279                                 TXRQST_RES | RMTPND_RES);
 280                 for (data = 0; data < 8; data++)
 281                         cc770_write_reg(priv, msgobj[mo].data[data], 0);
 282                 for (id = 0; id < 4; id++)
 283                         cc770_write_reg(priv, msgobj[mo].id[id], 0);
 284                 cc770_write_reg(priv, msgobj[mo].config, 0);
 285         }
 286
 287         /* Set all global ID masks to "don't care" */
 288         cc770_write_reg(priv, global_mask_std[0], 0);
 289         cc770_write_reg(priv, global_mask_std[1], 0);
 290         cc770_write_reg(priv, global_mask_ext[0], 0);
 291         cc770_write_reg(priv, global_mask_ext[1], 0);
 292         cc770_write_reg(priv, global_mask_ext[2], 0);
 293         cc770_write_reg(priv, global_mask_ext[3], 0);
 294
 295 }
 296
 297 static int cc770_probe_chip(struct net_device *dev)
 298 {
 299         struct cc770_priv *priv = netdev_priv(dev);
 300
 301         /* Enable configuration, put chip in bus-off, disable ints */
 302         cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI);
 303         /* Configure cpu interface / CLKOUT disable */
 304         cc770_write_reg(priv, cpu_interface, priv->cpu_interface);
 305
 306         /*
 307          * Check if hardware reset is still inactive or maybe there
 308          * is no chip in this address space
 309          */
 310         if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) {
 311                 netdev_info(dev, "probing @0x%p failed (reset)\n",
 312                             priv->reg_base);
 313                 return -ENODEV;
 314         }
 315
 316         /* Write and read back test pattern (some arbitrary values) */
 317         cc770_write_reg(priv, msgobj[1].data[1], 0x25);
 318         cc770_write_reg(priv, msgobj[2].data[3], 0x52);
 319         cc770_write_reg(priv, msgobj[10].data[6], 0xc3);
 320         if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) ||
 321             (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) ||
 322             (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) {
 323                 netdev_info(dev, "probing @0x%p failed (pattern)\n",
 324                             priv->reg_base);
 325                 return -ENODEV;
 326         }
 327
 328         /* Check if this chip is a CC770 supporting additional functions */
 329         if (cc770_read_reg(priv, control) & CTRL_EAF)
 330                 priv->control_normal_mode |= CTRL_EAF;
 331
 332         return 0;
 333 }
 334
 335 static void cc770_start(struct net_device *dev)
 336 {
 337         struct cc770_priv *priv = netdev_priv(dev);
 338
 339         /* leave reset mode */
 340         if (priv->can.state != CAN_STATE_STOPPED)
 341                 set_reset_mode(dev);
 342
 343         /* leave reset mode */
 344         set_normal_mode(dev);
 345 }
 346
 347 static int cc770_set_mode(struct net_device *dev, enum can_mode mode)
 348 {
 349         switch (mode) {
 350         case CAN_MODE_START:
 351                 cc770_start(dev);
 352                 netif_wake_queue(dev);
 353                 break;
 354
 355         default:
 356                 return -EOPNOTSUPP;
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int cc770_set_bittiming(struct net_device *dev)
 363 {
 364         struct cc770_priv *priv = netdev_priv(dev);
 365         struct can_bittiming *bt = &priv->can.bittiming;
 366         u8 btr0, btr1;
 367
 368         btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
 369         btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
 370                 (((bt->phase_seg2 - 1) & 0x7) << 4);
 371         if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 372                 btr1 |= 0x80;
 373
 374         netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
 375
 376         cc770_write_reg(priv, bit_timing_0, btr0);
 377         cc770_write_reg(priv, bit_timing_1, btr1);
 378
 379         return 0;
 380 }
 381
 382 static int cc770_get_berr_counter(const struct net_device *dev,
 383                                   struct can_berr_counter *bec)
 384 {
 385         struct cc770_priv *priv = netdev_priv(dev);
 386
 387         bec->txerr = cc770_read_reg(priv, tx_error_counter);
 388         bec->rxerr = cc770_read_reg(priv, rx_error_counter);
 389
 390         return 0;
 391 }
 392
 393 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
 394 {
 395         struct cc770_priv *priv = netdev_priv(dev);
 396         struct net_device_stats *stats = &dev->stats;
 397         struct can_frame *cf = (struct can_frame *)skb->data;
 398         unsigned int mo = obj2msgobj(CC770_OBJ_TX);
 399         u8 dlc, rtr;
 400         u32 id;
 401         int i;
 402
 403         if (can_dropped_invalid_skb(dev, skb))
 404                 return NETDEV_TX_OK;
 405
 406         if ((cc770_read_reg(priv,
 407                             msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) {
 408                 netdev_err(dev, "TX register is still occupied!\n");
 409                 return NETDEV_TX_BUSY;
 410         }
 411
 412         netif_stop_queue(dev);
 413
 414         dlc = cf->can_dlc;
 415         id = cf->can_id;
 416         if (cf->can_id & CAN_RTR_FLAG)
 417                 rtr = 0;
 418         else
 419                 rtr = MSGCFG_DIR;
 420         cc770_write_reg(priv, msgobj[mo].ctrl1,
 421                         RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES);
 422         cc770_write_reg(priv, msgobj[mo].ctrl0,
 423                         MSGVAL_SET | TXIE_SET | RXIE_RES | INTPND_RES);
 424         if (id & CAN_EFF_FLAG) {
 425                 id &= CAN_EFF_MASK;
 426                 cc770_write_reg(priv, msgobj[mo].config,
 427                                 (dlc << 4) | rtr | MSGCFG_XTD);
 428                 cc770_write_reg(priv, msgobj[mo].id[3], id << 3);
 429                 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5);
 430                 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13);
 431                 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21);
 432         } else {
 433                 id &= CAN_SFF_MASK;
 434                 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr);
 435                 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3);
 436                 cc770_write_reg(priv, msgobj[mo].id[1], id << 5);
 437         }
 438
 439         for (i = 0; i < dlc; i++)
 440                 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]);
 441
 442         /* Store echo skb before starting the transfer */
 443         can_put_echo_skb(skb, dev, 0);
 444
 445         cc770_write_reg(priv, msgobj[mo].ctrl1,
 446                         RMTPND_RES | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC);
 447
 448         stats->tx_bytes += dlc;
 449
 450
 451         /*
 452          * HM: We had some cases of repeated IRQs so make sure the
 453          * INT is acknowledged I know it's already further up, but
 454          * doing again fixed the issue
 455          */
 456         cc770_write_reg(priv, msgobj[mo].ctrl0,
 457                         MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
 458
 459         return NETDEV_TX_OK;
 460 }
 461
 462 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1)
 463 {
 464         struct cc770_priv *priv = netdev_priv(dev);
 465         struct net_device_stats *stats = &dev->stats;
 466         struct can_frame *cf;
 467         struct sk_buff *skb;
 468         u8 config;
 469         u32 id;
 470         int i;
 471
 472         skb = alloc_can_skb(dev, &cf);
 473         if (!skb)
 474                 return;
 475
 476         config = cc770_read_reg(priv, msgobj[mo].config);
 477
 478         if (ctrl1 & RMTPND_SET) {
 479                 /*
 480                  * Unfortunately, the chip does not store the real message
 481                  * identifier of the received remote transmission request
 482                  * frame. Therefore we set it to 0.
 483                  */
 484                 cf->can_id = CAN_RTR_FLAG;
 485                 if (config & MSGCFG_XTD)
 486                         cf->can_id |= CAN_EFF_FLAG;
 487                 cf->can_dlc = 0;
 488         } else {
 489                 if (config & MSGCFG_XTD) {
 490                         id = cc770_read_reg(priv, msgobj[mo].id[3]);
 491                         id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8;
 492                         id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16;
 493                         id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24;
 494                         id >>= 3;
 495                         id |= CAN_EFF_FLAG;
 496                 } else {
 497                         id = cc770_read_reg(priv, msgobj[mo].id[1]);
 498                         id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8;
 499                         id >>= 5;
 500                 }
 501
 502                 cf->can_id = id;
 503                 cf->can_dlc = get_can_dlc((config & 0xf0) >> 4);
 504                 for (i = 0; i < cf->can_dlc; i++)
 505                         cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]);
 506         }
 507
 508         stats->rx_packets++;
 509         stats->rx_bytes += cf->can_dlc;
 510         netif_rx(skb);
 511 }
 512
 513 static int cc770_err(struct net_device *dev, u8 status)
 514 {
 515         struct cc770_priv *priv = netdev_priv(dev);
 516         struct net_device_stats *stats = &dev->stats;
 517         struct can_frame *cf;
 518         struct sk_buff *skb;
 519         u8 lec;
 520
 521         netdev_dbg(dev, "status interrupt (%#x)\n", status);
 522
 523         skb = alloc_can_err_skb(dev, &cf);
 524         if (!skb)
 525                 return -ENOMEM;
 526
 527         /* Use extended functions of the CC770 */
 528         if (priv->control_normal_mode & CTRL_EAF) {
 529                 cf->data[6] = cc770_read_reg(priv, tx_error_counter);
 530                 cf->data[7] = cc770_read_reg(priv, rx_error_counter);
 531         }
 532
 533         if (status & STAT_BOFF) {
 534                 /* Disable interrupts */
 535                 cc770_write_reg(priv, control, CTRL_INI);
 536                 cf->can_id |= CAN_ERR_BUSOFF;
 537                 priv->can.state = CAN_STATE_BUS_OFF;
 538                 priv->can.can_stats.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
 588         stats->rx_packets++;
 589         stats->rx_bytes += cf->can_dlc;
 590         netif_rx(skb);
 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 static 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         .ndo_change_mtu = can_change_mtu,
 828 };
 829
 830 int register_cc770dev(struct net_device *dev)
 831 {
 832         struct cc770_priv *priv = netdev_priv(dev);
 833         int err;
 834
 835         err = cc770_probe_chip(dev);
 836         if (err)
 837                 return err;
 838
 839         dev->netdev_ops = &cc770_netdev_ops;
 840
 841         dev->flags |= IFF_ECHO; /* we support local echo */
 842
 843         /* Should we use additional functions? */
 844         if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) {
 845                 priv->can.do_get_berr_counter = cc770_get_berr_counter;
 846                 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE;
 847                 netdev_dbg(dev, "i82527 mode with additional functions\n");
 848         } else {
 849                 priv->control_normal_mode = CTRL_IE | CTRL_EIE;
 850                 netdev_dbg(dev, "strict i82527 compatibility mode\n");
 851         }
 852
 853         chipset_init(priv);
 854         set_reset_mode(dev);
 855
 856         return register_candev(dev);
 857 }
 858 EXPORT_SYMBOL_GPL(register_cc770dev);
 859
 860 void unregister_cc770dev(struct net_device *dev)
 861 {
 862         set_reset_mode(dev);
 863         unregister_candev(dev);
 864 }
 865 EXPORT_SYMBOL_GPL(unregister_cc770dev);
 866
 867 static __init int cc770_init(void)
 868 {
 869         if (msgobj15_eff) {
 870                 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF;
 871                 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF;
 872         }
 873
 874         pr_info("CAN netdevice driver\n");
 875
 876         return 0;
 877 }
 878 module_init(cc770_init);
 879
 880 static __exit void cc770_exit(void)
 881 {
 882         pr_info("driver removed\n");
 883 }
 884 module_exit(cc770_exit);