drivers/char/ipmi/ipmi_smic_sm.c

   1 /*
   2  * ipmi_smic_sm.c
   3  *
   4  * The state-machine driver for an IPMI SMIC driver
   5  *
   6  * It started as a copy of Corey Minyard's driver for the KSC interface
   7  * and the kernel patch "mmcdev-patch-245" by HP
   8  *
   9  * modified by: Hannes Schulz <schulz@schwaar.com>
  10  *              ipmi@schwaar.com
  11  *
  12  *
  13  * Corey Minyard's driver for the KSC interface has the following
  14  * copyright notice:
  15  *   Copyright 2002 MontaVista Software Inc.
  16  *
  17  * the kernel patch "mmcdev-patch-245" by HP has the following
  18  * copyright notice:
  19  * (c) Copyright 2001 Grant Grundler (c) Copyright
  20  * 2001 Hewlett-Packard Company
  21  *
  22  *
  23  *  This program is free software; you can redistribute it and/or modify it
  24  *  under the terms of the GNU General Public License as published by the
  25  *  Free Software Foundation; either version 2 of the License, or (at your
  26  *  option) any later version.
  27  *
  28  *
  29  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  30  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  31  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  32  *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  33  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  34  *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  35  *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  36  *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  37  *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  38  *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  *  You should have received a copy of the GNU General Public License along
  41  *  with this program; if not, write to the Free Software Foundation, Inc.,
  42  *  675 Mass Ave, Cambridge, MA 02139, USA.  */
  43
  44 #include <linux/kernel.h> /* For printk. */
  45 #include <linux/string.h>
  46 #include <linux/module.h>
  47 #include <linux/moduleparam.h>
  48 #include <linux/ipmi_msgdefs.h>         /* for completion codes */
  49 #include "ipmi_si_sm.h"
  50
  51 /* smic_debug is a bit-field
  52  *      SMIC_DEBUG_ENABLE -     turned on for now
  53  *      SMIC_DEBUG_MSG -        commands and their responses
  54  *      SMIC_DEBUG_STATES -     state machine
  55 */
  56 #define SMIC_DEBUG_STATES       4
  57 #define SMIC_DEBUG_MSG          2
  58 #define SMIC_DEBUG_ENABLE       1
  59
  60 static int smic_debug = 1;
  61 module_param(smic_debug, int, 0644);
  62 MODULE_PARM_DESC(smic_debug, "debug bitmask, 1=enable, 2=messages, 4=states");
  63
  64 enum smic_states {
  65         SMIC_IDLE,
  66         SMIC_START_OP,
  67         SMIC_OP_OK,
  68         SMIC_WRITE_START,
  69         SMIC_WRITE_NEXT,
  70         SMIC_WRITE_END,
  71         SMIC_WRITE2READ,
  72         SMIC_READ_START,
  73         SMIC_READ_NEXT,
  74         SMIC_READ_END,
  75         SMIC_HOSED
  76 };
  77
  78 #define MAX_SMIC_READ_SIZE 80
  79 #define MAX_SMIC_WRITE_SIZE 80
  80 #define SMIC_MAX_ERROR_RETRIES 3
  81
  82 /* Timeouts in microseconds. */
  83 #define SMIC_RETRY_TIMEOUT (2*USEC_PER_SEC)
  84
  85 /* SMIC Flags Register Bits */
  86 #define SMIC_RX_DATA_READY      0x80
  87 #define SMIC_TX_DATA_READY      0x40
  88
  89 /*
  90  * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by
  91  * a few systems, and then only by Systems Management
  92  * Interrupts, not by the OS.  Always ignore these bits.
  93  *
  94  */
  95 #define SMIC_SMI                0x10
  96 #define SMIC_EVM_DATA_AVAIL     0x08
  97 #define SMIC_SMS_DATA_AVAIL     0x04
  98 #define SMIC_FLAG_BSY           0x01
  99
 100 /* SMIC Error Codes */
 101 #define EC_NO_ERROR             0x00
 102 #define EC_ABORTED              0x01
 103 #define EC_ILLEGAL_CONTROL      0x02
 104 #define EC_NO_RESPONSE          0x03
 105 #define EC_ILLEGAL_COMMAND      0x04
 106 #define EC_BUFFER_FULL          0x05
 107
 108 struct si_sm_data {
 109         enum smic_states state;
 110         struct si_sm_io *io;
 111         unsigned char    write_data[MAX_SMIC_WRITE_SIZE];
 112         int              write_pos;
 113         int              write_count;
 114         int              orig_write_count;
 115         unsigned char    read_data[MAX_SMIC_READ_SIZE];
 116         int              read_pos;
 117         int              truncated;
 118         unsigned int     error_retries;
 119         long             smic_timeout;
 120 };
 121
 122 static unsigned int init_smic_data(struct si_sm_data *smic,
 123                                    struct si_sm_io *io)
 124 {
 125         smic->state = SMIC_IDLE;
 126         smic->io = io;
 127         smic->write_pos = 0;
 128         smic->write_count = 0;
 129         smic->orig_write_count = 0;
 130         smic->read_pos = 0;
 131         smic->error_retries = 0;
 132         smic->truncated = 0;
 133         smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 134
 135         /* We use 3 bytes of I/O. */
 136         return 3;
 137 }
 138
 139 static int start_smic_transaction(struct si_sm_data *smic,
 140                                   unsigned char *data, unsigned int size)
 141 {
 142         unsigned int i;
 143
 144         if (size < 2)
 145                 return IPMI_REQ_LEN_INVALID_ERR;
 146         if (size > MAX_SMIC_WRITE_SIZE)
 147                 return IPMI_REQ_LEN_EXCEEDED_ERR;
 148
 149         if ((smic->state != SMIC_IDLE) && (smic->state != SMIC_HOSED))
 150                 return IPMI_NOT_IN_MY_STATE_ERR;
 151
 152         if (smic_debug & SMIC_DEBUG_MSG) {
 153                 printk(KERN_DEBUG "start_smic_transaction -");
 154                 for (i = 0; i < size; i++)
 155                         printk(" %02x", (unsigned char) data[i]);
 156                 printk("\n");
 157         }
 158         smic->error_retries = 0;
 159         memcpy(smic->write_data, data, size);
 160         smic->write_count = size;
 161         smic->orig_write_count = size;
 162         smic->write_pos = 0;
 163         smic->read_pos = 0;
 164         smic->state = SMIC_START_OP;
 165         smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 166         return 0;
 167 }
 168
 169 static int smic_get_result(struct si_sm_data *smic,
 170                            unsigned char *data, unsigned int length)
 171 {
 172         int i;
 173
 174         if (smic_debug & SMIC_DEBUG_MSG) {
 175                 printk(KERN_DEBUG "smic_get result -");
 176                 for (i = 0; i < smic->read_pos; i++)
 177                         printk(" %02x", smic->read_data[i]);
 178                 printk("\n");
 179         }
 180         if (length < smic->read_pos) {
 181                 smic->read_pos = length;
 182                 smic->truncated = 1;
 183         }
 184         memcpy(data, smic->read_data, smic->read_pos);
 185
 186         if ((length >= 3) && (smic->read_pos < 3)) {
 187                 data[2] = IPMI_ERR_UNSPECIFIED;
 188                 smic->read_pos = 3;
 189         }
 190         if (smic->truncated) {
 191                 data[2] = IPMI_ERR_MSG_TRUNCATED;
 192                 smic->truncated = 0;
 193         }
 194         return smic->read_pos;
 195 }
 196
 197 static inline unsigned char read_smic_flags(struct si_sm_data *smic)
 198 {
 199         return smic->io->inputb(smic->io, 2);
 200 }
 201
 202 static inline unsigned char read_smic_status(struct si_sm_data *smic)
 203 {
 204         return smic->io->inputb(smic->io, 1);
 205 }
 206
 207 static inline unsigned char read_smic_data(struct si_sm_data *smic)
 208 {
 209         return smic->io->inputb(smic->io, 0);
 210 }
 211
 212 static inline void write_smic_flags(struct si_sm_data *smic,
 213                                     unsigned char   flags)
 214 {
 215         smic->io->outputb(smic->io, 2, flags);
 216 }
 217
 218 static inline void write_smic_control(struct si_sm_data *smic,
 219                                       unsigned char   control)
 220 {
 221         smic->io->outputb(smic->io, 1, control);
 222 }
 223
 224 static inline void write_si_sm_data(struct si_sm_data *smic,
 225                                     unsigned char   data)
 226 {
 227         smic->io->outputb(smic->io, 0, data);
 228 }
 229
 230 static inline void start_error_recovery(struct si_sm_data *smic, char *reason)
 231 {
 232         (smic->error_retries)++;
 233         if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) {
 234                 if (smic_debug & SMIC_DEBUG_ENABLE)
 235                         printk(KERN_WARNING
 236                                "ipmi_smic_drv: smic hosed: %s\n", reason);
 237                 smic->state = SMIC_HOSED;
 238         } else {
 239                 smic->write_count = smic->orig_write_count;
 240                 smic->write_pos = 0;
 241                 smic->read_pos = 0;
 242                 smic->state = SMIC_START_OP;
 243                 smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 244         }
 245 }
 246
 247 static inline void write_next_byte(struct si_sm_data *smic)
 248 {
 249         write_si_sm_data(smic, smic->write_data[smic->write_pos]);
 250         (smic->write_pos)++;
 251         (smic->write_count)--;
 252 }
 253
 254 static inline void read_next_byte(struct si_sm_data *smic)
 255 {
 256         if (smic->read_pos >= MAX_SMIC_READ_SIZE) {
 257                 read_smic_data(smic);
 258                 smic->truncated = 1;
 259         } else {
 260                 smic->read_data[smic->read_pos] = read_smic_data(smic);
 261                 smic->read_pos++;
 262         }
 263 }
 264
 265 /*  SMIC Control/Status Code Components */
 266 #define SMIC_GET_STATUS         0x00    /* Control form's name */
 267 #define SMIC_READY              0x00    /* Status  form's name */
 268 #define SMIC_WR_START           0x01    /* Unified Control/Status names... */
 269 #define SMIC_WR_NEXT            0x02
 270 #define SMIC_WR_END             0x03
 271 #define SMIC_RD_START           0x04
 272 #define SMIC_RD_NEXT            0x05
 273 #define SMIC_RD_END             0x06
 274 #define SMIC_CODE_MASK          0x0f
 275
 276 #define SMIC_CONTROL            0x00
 277 #define SMIC_STATUS             0x80
 278 #define SMIC_CS_MASK            0x80
 279
 280 #define SMIC_SMS                0x40
 281 #define SMIC_SMM                0x60
 282 #define SMIC_STREAM_MASK        0x60
 283
 284 /*  SMIC Control Codes */
 285 #define SMIC_CC_SMS_GET_STATUS  (SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS)
 286 #define SMIC_CC_SMS_WR_START    (SMIC_CONTROL|SMIC_SMS|SMIC_WR_START)
 287 #define SMIC_CC_SMS_WR_NEXT     (SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT)
 288 #define SMIC_CC_SMS_WR_END      (SMIC_CONTROL|SMIC_SMS|SMIC_WR_END)
 289 #define SMIC_CC_SMS_RD_START    (SMIC_CONTROL|SMIC_SMS|SMIC_RD_START)
 290 #define SMIC_CC_SMS_RD_NEXT     (SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT)
 291 #define SMIC_CC_SMS_RD_END      (SMIC_CONTROL|SMIC_SMS|SMIC_RD_END)
 292
 293 #define SMIC_CC_SMM_GET_STATUS  (SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS)
 294 #define SMIC_CC_SMM_WR_START    (SMIC_CONTROL|SMIC_SMM|SMIC_WR_START)
 295 #define SMIC_CC_SMM_WR_NEXT     (SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT)
 296 #define SMIC_CC_SMM_WR_END      (SMIC_CONTROL|SMIC_SMM|SMIC_WR_END)
 297 #define SMIC_CC_SMM_RD_START    (SMIC_CONTROL|SMIC_SMM|SMIC_RD_START)
 298 #define SMIC_CC_SMM_RD_NEXT     (SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT)
 299 #define SMIC_CC_SMM_RD_END      (SMIC_CONTROL|SMIC_SMM|SMIC_RD_END)
 300
 301 /*  SMIC Status Codes */
 302 #define SMIC_SC_SMS_READY       (SMIC_STATUS|SMIC_SMS|SMIC_READY)
 303 #define SMIC_SC_SMS_WR_START    (SMIC_STATUS|SMIC_SMS|SMIC_WR_START)
 304 #define SMIC_SC_SMS_WR_NEXT     (SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT)
 305 #define SMIC_SC_SMS_WR_END      (SMIC_STATUS|SMIC_SMS|SMIC_WR_END)
 306 #define SMIC_SC_SMS_RD_START    (SMIC_STATUS|SMIC_SMS|SMIC_RD_START)
 307 #define SMIC_SC_SMS_RD_NEXT     (SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT)
 308 #define SMIC_SC_SMS_RD_END      (SMIC_STATUS|SMIC_SMS|SMIC_RD_END)
 309
 310 #define SMIC_SC_SMM_READY       (SMIC_STATUS|SMIC_SMM|SMIC_READY)
 311 #define SMIC_SC_SMM_WR_START    (SMIC_STATUS|SMIC_SMM|SMIC_WR_START)
 312 #define SMIC_SC_SMM_WR_NEXT     (SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT)
 313 #define SMIC_SC_SMM_WR_END      (SMIC_STATUS|SMIC_SMM|SMIC_WR_END)
 314 #define SMIC_SC_SMM_RD_START    (SMIC_STATUS|SMIC_SMM|SMIC_RD_START)
 315 #define SMIC_SC_SMM_RD_NEXT     (SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT)
 316 #define SMIC_SC_SMM_RD_END      (SMIC_STATUS|SMIC_SMM|SMIC_RD_END)
 317
 318 /* these are the control/status codes we actually use
 319         SMIC_CC_SMS_GET_STATUS  0x40
 320         SMIC_CC_SMS_WR_START    0x41
 321         SMIC_CC_SMS_WR_NEXT     0x42
 322         SMIC_CC_SMS_WR_END      0x43
 323         SMIC_CC_SMS_RD_START    0x44
 324         SMIC_CC_SMS_RD_NEXT     0x45
 325         SMIC_CC_SMS_RD_END      0x46
 326
 327         SMIC_SC_SMS_READY       0xC0
 328         SMIC_SC_SMS_WR_START    0xC1
 329         SMIC_SC_SMS_WR_NEXT     0xC2
 330         SMIC_SC_SMS_WR_END      0xC3
 331         SMIC_SC_SMS_RD_START    0xC4
 332         SMIC_SC_SMS_RD_NEXT     0xC5
 333         SMIC_SC_SMS_RD_END      0xC6
 334 */
 335
 336 static enum si_sm_result smic_event(struct si_sm_data *smic, long time)
 337 {
 338         unsigned char status;
 339         unsigned char flags;
 340         unsigned char data;
 341
 342         if (smic->state == SMIC_HOSED) {
 343                 init_smic_data(smic, smic->io);
 344                 return SI_SM_HOSED;
 345         }
 346         if (smic->state != SMIC_IDLE) {
 347                 if (smic_debug & SMIC_DEBUG_STATES)
 348                         printk(KERN_DEBUG
 349                                "smic_event - smic->smic_timeout = %ld,"
 350                                " time = %ld\n",
 351                                smic->smic_timeout, time);
 352                 /*
 353                  * FIXME: smic_event is sometimes called with time >
 354                  * SMIC_RETRY_TIMEOUT
 355                  */
 356                 if (time < SMIC_RETRY_TIMEOUT) {
 357                         smic->smic_timeout -= time;
 358                         if (smic->smic_timeout < 0) {
 359                                 start_error_recovery(smic, "smic timed out.");
 360                                 return SI_SM_CALL_WITH_DELAY;
 361                         }
 362                 }
 363         }
 364         flags = read_smic_flags(smic);
 365         if (flags & SMIC_FLAG_BSY)
 366                 return SI_SM_CALL_WITH_DELAY;
 367
 368         status = read_smic_status(smic);
 369         if (smic_debug & SMIC_DEBUG_STATES)
 370                 printk(KERN_DEBUG
 371                        "smic_event - state = %d, flags = 0x%02x,"
 372                        " status = 0x%02x\n",
 373                        smic->state, flags, status);
 374
 375         switch (smic->state) {
 376         case SMIC_IDLE:
 377                 /* in IDLE we check for available messages */
 378                 if (flags & SMIC_SMS_DATA_AVAIL)
 379                         return SI_SM_ATTN;
 380                 return SI_SM_IDLE;
 381
 382         case SMIC_START_OP:
 383                 /* sanity check whether smic is really idle */
 384                 write_smic_control(smic, SMIC_CC_SMS_GET_STATUS);
 385                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 386                 smic->state = SMIC_OP_OK;
 387                 break;
 388
 389         case SMIC_OP_OK:
 390                 if (status != SMIC_SC_SMS_READY) {
 391                         /* this should not happen */
 392                         start_error_recovery(smic,
 393                                              "state = SMIC_OP_OK,"
 394                                              " status != SMIC_SC_SMS_READY");
 395                         return SI_SM_CALL_WITH_DELAY;
 396                 }
 397                 /* OK so far; smic is idle let us start ... */
 398                 write_smic_control(smic, SMIC_CC_SMS_WR_START);
 399                 write_next_byte(smic);
 400                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 401                 smic->state = SMIC_WRITE_START;
 402                 break;
 403
 404         case SMIC_WRITE_START:
 405                 if (status != SMIC_SC_SMS_WR_START) {
 406                         start_error_recovery(smic,
 407                                              "state = SMIC_WRITE_START, "
 408                                              "status != SMIC_SC_SMS_WR_START");
 409                         return SI_SM_CALL_WITH_DELAY;
 410                 }
 411                 /*
 412                  * we must not issue WR_(NEXT|END) unless
 413                  * TX_DATA_READY is set
 414                  * */
 415                 if (flags & SMIC_TX_DATA_READY) {
 416                         if (smic->write_count == 1) {
 417                                 /* last byte */
 418                                 write_smic_control(smic, SMIC_CC_SMS_WR_END);
 419                                 smic->state = SMIC_WRITE_END;
 420                         } else {
 421                                 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
 422                                 smic->state = SMIC_WRITE_NEXT;
 423                         }
 424                         write_next_byte(smic);
 425                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 426                 } else
 427                         return SI_SM_CALL_WITH_DELAY;
 428                 break;
 429
 430         case SMIC_WRITE_NEXT:
 431                 if (status != SMIC_SC_SMS_WR_NEXT) {
 432                         start_error_recovery(smic,
 433                                              "state = SMIC_WRITE_NEXT, "
 434                                              "status != SMIC_SC_SMS_WR_NEXT");
 435                         return SI_SM_CALL_WITH_DELAY;
 436                 }
 437                 /* this is the same code as in SMIC_WRITE_START */
 438                 if (flags & SMIC_TX_DATA_READY) {
 439                         if (smic->write_count == 1) {
 440                                 write_smic_control(smic, SMIC_CC_SMS_WR_END);
 441                                 smic->state = SMIC_WRITE_END;
 442                         } else {
 443                                 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
 444                                 smic->state = SMIC_WRITE_NEXT;
 445                         }
 446                         write_next_byte(smic);
 447                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 448                 } else
 449                         return SI_SM_CALL_WITH_DELAY;
 450                 break;
 451
 452         case SMIC_WRITE_END:
 453                 if (status != SMIC_SC_SMS_WR_END) {
 454                         start_error_recovery(smic,
 455                                              "state = SMIC_WRITE_END, "
 456                                              "status != SMIC_SC_SMS_WR_END");
 457                         return SI_SM_CALL_WITH_DELAY;
 458                 }
 459                 /* data register holds an error code */
 460                 data = read_smic_data(smic);
 461                 if (data != 0) {
 462                         if (smic_debug & SMIC_DEBUG_ENABLE)
 463                                 printk(KERN_DEBUG
 464                                        "SMIC_WRITE_END: data = %02x\n", data);
 465                         start_error_recovery(smic,
 466                                              "state = SMIC_WRITE_END, "
 467                                              "data != SUCCESS");
 468                         return SI_SM_CALL_WITH_DELAY;
 469                 } else
 470                         smic->state = SMIC_WRITE2READ;
 471                 break;
 472
 473         case SMIC_WRITE2READ:
 474                 /*
 475                  * we must wait for RX_DATA_READY to be set before we
 476                  * can continue
 477                  */
 478                 if (flags & SMIC_RX_DATA_READY) {
 479                         write_smic_control(smic, SMIC_CC_SMS_RD_START);
 480                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 481                         smic->state = SMIC_READ_START;
 482                 } else
 483                         return SI_SM_CALL_WITH_DELAY;
 484                 break;
 485
 486         case SMIC_READ_START:
 487                 if (status != SMIC_SC_SMS_RD_START) {
 488                         start_error_recovery(smic,
 489                                              "state = SMIC_READ_START, "
 490                                              "status != SMIC_SC_SMS_RD_START");
 491                         return SI_SM_CALL_WITH_DELAY;
 492                 }
 493                 if (flags & SMIC_RX_DATA_READY) {
 494                         read_next_byte(smic);
 495                         write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
 496                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 497                         smic->state = SMIC_READ_NEXT;
 498                 } else
 499                         return SI_SM_CALL_WITH_DELAY;
 500                 break;
 501
 502         case SMIC_READ_NEXT:
 503                 switch (status) {
 504                 /*
 505                  * smic tells us that this is the last byte to be read
 506                  * --> clean up
 507                  */
 508                 case SMIC_SC_SMS_RD_END:
 509                         read_next_byte(smic);
 510                         write_smic_control(smic, SMIC_CC_SMS_RD_END);
 511                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 512                         smic->state = SMIC_READ_END;
 513                         break;
 514                 case SMIC_SC_SMS_RD_NEXT:
 515                         if (flags & SMIC_RX_DATA_READY) {
 516                                 read_next_byte(smic);
 517                                 write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
 518                                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 519                                 smic->state = SMIC_READ_NEXT;
 520                         } else
 521                                 return SI_SM_CALL_WITH_DELAY;
 522                         break;
 523                 default:
 524                         start_error_recovery(
 525                                 smic,
 526                                 "state = SMIC_READ_NEXT, "
 527                                 "status != SMIC_SC_SMS_RD_(NEXT|END)");
 528                         return SI_SM_CALL_WITH_DELAY;
 529                 }
 530                 break;
 531
 532         case SMIC_READ_END:
 533                 if (status != SMIC_SC_SMS_READY) {
 534                         start_error_recovery(smic,
 535                                              "state = SMIC_READ_END, "
 536                                              "status != SMIC_SC_SMS_READY");
 537                         return SI_SM_CALL_WITH_DELAY;
 538                 }
 539                 data = read_smic_data(smic);
 540                 /* data register holds an error code */
 541                 if (data != 0) {
 542                         if (smic_debug & SMIC_DEBUG_ENABLE)
 543                                 printk(KERN_DEBUG
 544                                        "SMIC_READ_END: data = %02x\n", data);
 545                         start_error_recovery(smic,
 546                                              "state = SMIC_READ_END, "
 547                                              "data != SUCCESS");
 548                         return SI_SM_CALL_WITH_DELAY;
 549                 } else {
 550                         smic->state = SMIC_IDLE;
 551                         return SI_SM_TRANSACTION_COMPLETE;
 552                 }
 553
 554         case SMIC_HOSED:
 555                 init_smic_data(smic, smic->io);
 556                 return SI_SM_HOSED;
 557
 558         default:
 559                 if (smic_debug & SMIC_DEBUG_ENABLE) {
 560                         printk(KERN_DEBUG "smic->state = %d\n", smic->state);
 561                         start_error_recovery(smic, "state = UNKNOWN");
 562                         return SI_SM_CALL_WITH_DELAY;
 563                 }
 564         }
 565         smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 566         return SI_SM_CALL_WITHOUT_DELAY;
 567 }
 568
 569 static int smic_detect(struct si_sm_data *smic)
 570 {
 571         /*
 572          * It's impossible for the SMIC fnags register to be all 1's,
 573          * (assuming a properly functioning, self-initialized BMC)
 574          * but that's what you get from reading a bogus address, so we
 575          * test that first.
 576          */
 577         if (read_smic_flags(smic) == 0xff)
 578                 return 1;
 579
 580         return 0;
 581 }
 582
 583 static void smic_cleanup(struct si_sm_data *kcs)
 584 {
 585 }
 586
 587 static int smic_size(void)
 588 {
 589         return sizeof(struct si_sm_data);
 590 }
 591
 592 const struct si_sm_handlers smic_smi_handlers = {
 593         .init_data         = init_smic_data,
 594         .start_transaction = start_smic_transaction,
 595         .get_result        = smic_get_result,
 596         .event             = smic_event,
 597         .detect            = smic_detect,
 598         .cleanup           = smic_cleanup,
 599         .size              = smic_size,
 600 };