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 2000000
  84
  85 /* SMIC Flags Register Bits */
  86 #define SMIC_RX_DATA_READY      0x80
  87 #define SMIC_TX_DATA_READY      0x40
  88 /*
  89  * SMIC_SMI and SMIC_EVM_DATA_AVAIL are only used by
  90  * a few systems, and then only by Systems Management
  91  * Interrupts, not by the OS.  Always ignore these bits.
  92  *
  93  */
  94 #define SMIC_SMI                0x10
  95 #define SMIC_EVM_DATA_AVAIL     0x08
  96 #define SMIC_SMS_DATA_AVAIL     0x04
  97 #define SMIC_FLAG_BSY           0x01
  98
  99 /* SMIC Error Codes */
 100 #define EC_NO_ERROR             0x00
 101 #define EC_ABORTED              0x01
 102 #define EC_ILLEGAL_CONTROL      0x02
 103 #define EC_NO_RESPONSE          0x03
 104 #define EC_ILLEGAL_COMMAND      0x04
 105 #define EC_BUFFER_FULL          0x05
 106
 107 struct si_sm_data
 108 {
 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_INFO "start_smic_transaction -");
 154                 for (i = 0; i < size; i ++) {
 155                         printk (" %02x", (unsigned char) (data [i]));
 156                 }
 157                 printk ("\n");
 158         }
 159         smic->error_retries = 0;
 160         memcpy(smic->write_data, data, size);
 161         smic->write_count = size;
 162         smic->orig_write_count = size;
 163         smic->write_pos = 0;
 164         smic->read_pos = 0;
 165         smic->state = SMIC_START_OP;
 166         smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 167         return 0;
 168 }
 169
 170 static int smic_get_result(struct si_sm_data *smic,
 171                            unsigned char *data, unsigned int length)
 172 {
 173         int i;
 174
 175         if (smic_debug & SMIC_DEBUG_MSG) {
 176                 printk (KERN_INFO "smic_get result -");
 177                 for (i = 0; i < smic->read_pos; i ++) {
 178                         printk (" %02x", (smic->read_data [i]));
 179                 }
 180                 printk ("\n");
 181         }
 182         if (length < smic->read_pos) {
 183                 smic->read_pos = length;
 184                 smic->truncated = 1;
 185         }
 186         memcpy(data, smic->read_data, smic->read_pos);
 187
 188         if ((length >= 3) && (smic->read_pos < 3)) {
 189                 data[2] = IPMI_ERR_UNSPECIFIED;
 190                 smic->read_pos = 3;
 191         }
 192         if (smic->truncated) {
 193                 data[2] = IPMI_ERR_MSG_TRUNCATED;
 194                 smic->truncated = 0;
 195         }
 196         return smic->read_pos;
 197 }
 198
 199 static inline unsigned char read_smic_flags(struct si_sm_data *smic)
 200 {
 201         return smic->io->inputb(smic->io, 2);
 202 }
 203
 204 static inline unsigned char read_smic_status(struct si_sm_data *smic)
 205 {
 206         return smic->io->inputb(smic->io, 1);
 207 }
 208
 209 static inline unsigned char read_smic_data(struct si_sm_data *smic)
 210 {
 211         return smic->io->inputb(smic->io, 0);
 212 }
 213
 214 static inline void write_smic_flags(struct si_sm_data *smic,
 215                                     unsigned char   flags)
 216 {
 217         smic->io->outputb(smic->io, 2, flags);
 218 }
 219
 220 static inline void write_smic_control(struct si_sm_data *smic,
 221                                       unsigned char   control)
 222 {
 223         smic->io->outputb(smic->io, 1, control);
 224 }
 225
 226 static inline void write_si_sm_data (struct si_sm_data *smic,
 227                                    unsigned char   data)
 228 {
 229         smic->io->outputb(smic->io, 0, data);
 230 }
 231
 232 static inline void start_error_recovery(struct si_sm_data *smic, char *reason)
 233 {
 234         (smic->error_retries)++;
 235         if (smic->error_retries > SMIC_MAX_ERROR_RETRIES) {
 236                 if (smic_debug & SMIC_DEBUG_ENABLE) {
 237                         printk(KERN_WARNING
 238                                "ipmi_smic_drv: smic hosed: %s\n", reason);
 239                 }
 240                 smic->state = SMIC_HOSED;
 241         } else {
 242                 smic->write_count = smic->orig_write_count;
 243                 smic->write_pos = 0;
 244                 smic->read_pos = 0;
 245                 smic->state = SMIC_START_OP;
 246                 smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 247         }
 248 }
 249
 250 static inline void write_next_byte(struct si_sm_data *smic)
 251 {
 252         write_si_sm_data(smic, smic->write_data[smic->write_pos]);
 253         (smic->write_pos)++;
 254         (smic->write_count)--;
 255 }
 256
 257 static inline void read_next_byte (struct si_sm_data *smic)
 258 {
 259         if (smic->read_pos >= MAX_SMIC_READ_SIZE) {
 260                 read_smic_data (smic);
 261                 smic->truncated = 1;
 262         } else {
 263                 smic->read_data[smic->read_pos] = read_smic_data(smic);
 264                 (smic->read_pos)++;
 265         }
 266 }
 267
 268 /*  SMIC Control/Status Code Components */
 269 #define SMIC_GET_STATUS         0x00    /* Control form's name */
 270 #define SMIC_READY              0x00    /* Status  form's name */
 271 #define SMIC_WR_START           0x01    /* Unified Control/Status names... */
 272 #define SMIC_WR_NEXT            0x02
 273 #define SMIC_WR_END             0x03
 274 #define SMIC_RD_START           0x04
 275 #define SMIC_RD_NEXT            0x05
 276 #define SMIC_RD_END             0x06
 277 #define SMIC_CODE_MASK          0x0f
 278
 279 #define SMIC_CONTROL            0x00
 280 #define SMIC_STATUS             0x80
 281 #define SMIC_CS_MASK            0x80
 282
 283 #define SMIC_SMS                0x40
 284 #define SMIC_SMM                0x60
 285 #define SMIC_STREAM_MASK        0x60
 286
 287 /*  SMIC Control Codes */
 288 #define SMIC_CC_SMS_GET_STATUS  (SMIC_CONTROL|SMIC_SMS|SMIC_GET_STATUS)
 289 #define SMIC_CC_SMS_WR_START    (SMIC_CONTROL|SMIC_SMS|SMIC_WR_START)
 290 #define SMIC_CC_SMS_WR_NEXT     (SMIC_CONTROL|SMIC_SMS|SMIC_WR_NEXT)
 291 #define SMIC_CC_SMS_WR_END      (SMIC_CONTROL|SMIC_SMS|SMIC_WR_END)
 292 #define SMIC_CC_SMS_RD_START    (SMIC_CONTROL|SMIC_SMS|SMIC_RD_START)
 293 #define SMIC_CC_SMS_RD_NEXT     (SMIC_CONTROL|SMIC_SMS|SMIC_RD_NEXT)
 294 #define SMIC_CC_SMS_RD_END      (SMIC_CONTROL|SMIC_SMS|SMIC_RD_END)
 295
 296 #define SMIC_CC_SMM_GET_STATUS  (SMIC_CONTROL|SMIC_SMM|SMIC_GET_STATUS)
 297 #define SMIC_CC_SMM_WR_START    (SMIC_CONTROL|SMIC_SMM|SMIC_WR_START)
 298 #define SMIC_CC_SMM_WR_NEXT     (SMIC_CONTROL|SMIC_SMM|SMIC_WR_NEXT)
 299 #define SMIC_CC_SMM_WR_END      (SMIC_CONTROL|SMIC_SMM|SMIC_WR_END)
 300 #define SMIC_CC_SMM_RD_START    (SMIC_CONTROL|SMIC_SMM|SMIC_RD_START)
 301 #define SMIC_CC_SMM_RD_NEXT     (SMIC_CONTROL|SMIC_SMM|SMIC_RD_NEXT)
 302 #define SMIC_CC_SMM_RD_END      (SMIC_CONTROL|SMIC_SMM|SMIC_RD_END)
 303
 304 /*  SMIC Status Codes */
 305 #define SMIC_SC_SMS_READY       (SMIC_STATUS|SMIC_SMS|SMIC_READY)
 306 #define SMIC_SC_SMS_WR_START    (SMIC_STATUS|SMIC_SMS|SMIC_WR_START)
 307 #define SMIC_SC_SMS_WR_NEXT     (SMIC_STATUS|SMIC_SMS|SMIC_WR_NEXT)
 308 #define SMIC_SC_SMS_WR_END      (SMIC_STATUS|SMIC_SMS|SMIC_WR_END)
 309 #define SMIC_SC_SMS_RD_START    (SMIC_STATUS|SMIC_SMS|SMIC_RD_START)
 310 #define SMIC_SC_SMS_RD_NEXT     (SMIC_STATUS|SMIC_SMS|SMIC_RD_NEXT)
 311 #define SMIC_SC_SMS_RD_END      (SMIC_STATUS|SMIC_SMS|SMIC_RD_END)
 312
 313 #define SMIC_SC_SMM_READY       (SMIC_STATUS|SMIC_SMM|SMIC_READY)
 314 #define SMIC_SC_SMM_WR_START    (SMIC_STATUS|SMIC_SMM|SMIC_WR_START)
 315 #define SMIC_SC_SMM_WR_NEXT     (SMIC_STATUS|SMIC_SMM|SMIC_WR_NEXT)
 316 #define SMIC_SC_SMM_WR_END      (SMIC_STATUS|SMIC_SMM|SMIC_WR_END)
 317 #define SMIC_SC_SMM_RD_START    (SMIC_STATUS|SMIC_SMM|SMIC_RD_START)
 318 #define SMIC_SC_SMM_RD_NEXT     (SMIC_STATUS|SMIC_SMM|SMIC_RD_NEXT)
 319 #define SMIC_SC_SMM_RD_END      (SMIC_STATUS|SMIC_SMM|SMIC_RD_END)
 320
 321 /* these are the control/status codes we actually use
 322         SMIC_CC_SMS_GET_STATUS  0x40
 323         SMIC_CC_SMS_WR_START    0x41
 324         SMIC_CC_SMS_WR_NEXT     0x42
 325         SMIC_CC_SMS_WR_END      0x43
 326         SMIC_CC_SMS_RD_START    0x44
 327         SMIC_CC_SMS_RD_NEXT     0x45
 328         SMIC_CC_SMS_RD_END      0x46
 329
 330         SMIC_SC_SMS_READY       0xC0
 331         SMIC_SC_SMS_WR_START    0xC1
 332         SMIC_SC_SMS_WR_NEXT     0xC2
 333         SMIC_SC_SMS_WR_END      0xC3
 334         SMIC_SC_SMS_RD_START    0xC4
 335         SMIC_SC_SMS_RD_NEXT     0xC5
 336         SMIC_SC_SMS_RD_END      0xC6
 337 */
 338
 339 static enum si_sm_result smic_event (struct si_sm_data *smic, long time)
 340 {
 341         unsigned char status;
 342         unsigned char flags;
 343         unsigned char data;
 344
 345         if (smic->state == SMIC_HOSED) {
 346                 init_smic_data(smic, smic->io);
 347                 return SI_SM_HOSED;
 348         }
 349         if (smic->state != SMIC_IDLE) {
 350                 if (smic_debug & SMIC_DEBUG_STATES) {
 351                         printk(KERN_INFO
 352                                "smic_event - smic->smic_timeout = %ld,"
 353                                " time = %ld\n",
 354                                smic->smic_timeout, time);
 355                 }
 356 /* FIXME: smic_event is sometimes called with time > SMIC_RETRY_TIMEOUT */
 357                 if (time < SMIC_RETRY_TIMEOUT) {
 358                         smic->smic_timeout -= time;
 359                         if (smic->smic_timeout < 0) {
 360                                 start_error_recovery(smic, "smic timed out.");
 361                                 return SI_SM_CALL_WITH_DELAY;
 362                         }
 363                 }
 364         }
 365         flags = read_smic_flags(smic);
 366         if (flags & SMIC_FLAG_BSY)
 367                 return SI_SM_CALL_WITH_DELAY;
 368
 369         status = read_smic_status (smic);
 370         if (smic_debug & SMIC_DEBUG_STATES)
 371                 printk(KERN_INFO
 372                        "smic_event - state = %d, flags = 0x%02x,"
 373                        " status = 0x%02x\n",
 374                        smic->state, flags, status);
 375
 376         switch (smic->state) {
 377         case SMIC_IDLE:
 378                 /* in IDLE we check for available messages */
 379                 if (flags & SMIC_SMS_DATA_AVAIL)
 380                 {
 381                         return SI_SM_ATTN;
 382                 }
 383                 return SI_SM_IDLE;
 384
 385         case SMIC_START_OP:
 386                 /* sanity check whether smic is really idle */
 387                 write_smic_control(smic, SMIC_CC_SMS_GET_STATUS);
 388                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 389                 smic->state = SMIC_OP_OK;
 390                 break;
 391
 392         case SMIC_OP_OK:
 393                 if (status != SMIC_SC_SMS_READY) {
 394                                 /* this should not happen */
 395                         start_error_recovery(smic,
 396                                              "state = SMIC_OP_OK,"
 397                                              " status != SMIC_SC_SMS_READY");
 398                         return SI_SM_CALL_WITH_DELAY;
 399                 }
 400                 /* OK so far; smic is idle let us start ... */
 401                 write_smic_control(smic, SMIC_CC_SMS_WR_START);
 402                 write_next_byte(smic);
 403                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 404                 smic->state = SMIC_WRITE_START;
 405                 break;
 406
 407         case SMIC_WRITE_START:
 408                 if (status != SMIC_SC_SMS_WR_START) {
 409                         start_error_recovery(smic,
 410                                              "state = SMIC_WRITE_START, "
 411                                              "status != SMIC_SC_SMS_WR_START");
 412                         return SI_SM_CALL_WITH_DELAY;
 413                 }
 414                 /* we must not issue WR_(NEXT|END) unless
 415                    TX_DATA_READY is set */
 416                 if (flags & SMIC_TX_DATA_READY) {
 417                         if (smic->write_count == 1) {
 418                                 /* last byte */
 419                                 write_smic_control(smic, SMIC_CC_SMS_WR_END);
 420                                 smic->state = SMIC_WRITE_END;
 421                         } else {
 422                                 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
 423                                 smic->state = SMIC_WRITE_NEXT;
 424                         }
 425                         write_next_byte(smic);
 426                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 427                 }
 428                 else {
 429                         return SI_SM_CALL_WITH_DELAY;
 430                 }
 431                 break;
 432
 433         case SMIC_WRITE_NEXT:
 434                 if (status != SMIC_SC_SMS_WR_NEXT) {
 435                         start_error_recovery(smic,
 436                                              "state = SMIC_WRITE_NEXT, "
 437                                              "status != SMIC_SC_SMS_WR_NEXT");
 438                         return SI_SM_CALL_WITH_DELAY;
 439                 }
 440                 /* this is the same code as in SMIC_WRITE_START */
 441                 if (flags & SMIC_TX_DATA_READY) {
 442                         if (smic->write_count == 1) {
 443                                 write_smic_control(smic, SMIC_CC_SMS_WR_END);
 444                                 smic->state = SMIC_WRITE_END;
 445                         }
 446                         else {
 447                                 write_smic_control(smic, SMIC_CC_SMS_WR_NEXT);
 448                                 smic->state = SMIC_WRITE_NEXT;
 449                         }
 450                         write_next_byte(smic);
 451                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 452                 }
 453                 else {
 454                         return SI_SM_CALL_WITH_DELAY;
 455                 }
 456                 break;
 457
 458         case SMIC_WRITE_END:
 459                 if (status != SMIC_SC_SMS_WR_END) {
 460                         start_error_recovery (smic,
 461                                               "state = SMIC_WRITE_END, "
 462                                               "status != SMIC_SC_SMS_WR_END");
 463                         return SI_SM_CALL_WITH_DELAY;
 464                 }
 465                 /* data register holds an error code */
 466                 data = read_smic_data(smic);
 467                 if (data != 0) {
 468                         if (smic_debug & SMIC_DEBUG_ENABLE) {
 469                                 printk(KERN_INFO
 470                                        "SMIC_WRITE_END: data = %02x\n", data);
 471                         }
 472                         start_error_recovery(smic,
 473                                              "state = SMIC_WRITE_END, "
 474                                              "data != SUCCESS");
 475                         return SI_SM_CALL_WITH_DELAY;
 476                 } else {
 477                         smic->state = SMIC_WRITE2READ;
 478                 }
 479                 break;
 480
 481         case SMIC_WRITE2READ:
 482                 /* we must wait for RX_DATA_READY to be set before we
 483                    can continue */
 484                 if (flags & SMIC_RX_DATA_READY) {
 485                         write_smic_control(smic, SMIC_CC_SMS_RD_START);
 486                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 487                         smic->state = SMIC_READ_START;
 488                 } else {
 489                         return SI_SM_CALL_WITH_DELAY;
 490                 }
 491                 break;
 492
 493         case SMIC_READ_START:
 494                 if (status != SMIC_SC_SMS_RD_START) {
 495                         start_error_recovery(smic,
 496                                              "state = SMIC_READ_START, "
 497                                              "status != SMIC_SC_SMS_RD_START");
 498                         return SI_SM_CALL_WITH_DELAY;
 499                 }
 500                 if (flags & SMIC_RX_DATA_READY) {
 501                         read_next_byte(smic);
 502                         write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
 503                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 504                         smic->state = SMIC_READ_NEXT;
 505                 } else {
 506                         return SI_SM_CALL_WITH_DELAY;
 507                 }
 508                 break;
 509
 510         case SMIC_READ_NEXT:
 511                 switch (status) {
 512                 /* smic tells us that this is the last byte to be read
 513                    --> clean up */
 514                 case SMIC_SC_SMS_RD_END:
 515                         read_next_byte(smic);
 516                         write_smic_control(smic, SMIC_CC_SMS_RD_END);
 517                         write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 518                         smic->state = SMIC_READ_END;
 519                         break;
 520                 case SMIC_SC_SMS_RD_NEXT:
 521                         if (flags & SMIC_RX_DATA_READY) {
 522                                 read_next_byte(smic);
 523                                 write_smic_control(smic, SMIC_CC_SMS_RD_NEXT);
 524                                 write_smic_flags(smic, flags | SMIC_FLAG_BSY);
 525                                 smic->state = SMIC_READ_NEXT;
 526                         } else {
 527                                 return SI_SM_CALL_WITH_DELAY;
 528                         }
 529                         break;
 530                 default:
 531                         start_error_recovery(
 532                                 smic,
 533                                 "state = SMIC_READ_NEXT, "
 534                                 "status != SMIC_SC_SMS_RD_(NEXT|END)");
 535                         return SI_SM_CALL_WITH_DELAY;
 536                 }
 537                 break;
 538
 539         case SMIC_READ_END:
 540                 if (status != SMIC_SC_SMS_READY) {
 541                         start_error_recovery(smic,
 542                                              "state = SMIC_READ_END, "
 543                                              "status != SMIC_SC_SMS_READY");
 544                         return SI_SM_CALL_WITH_DELAY;
 545                 }
 546                 data = read_smic_data(smic);
 547                 /* data register holds an error code */
 548                 if (data != 0) {
 549                         if (smic_debug & SMIC_DEBUG_ENABLE) {
 550                                 printk(KERN_INFO
 551                                        "SMIC_READ_END: data = %02x\n", data);
 552                         }
 553                         start_error_recovery(smic,
 554                                              "state = SMIC_READ_END, "
 555                                              "data != SUCCESS");
 556                         return SI_SM_CALL_WITH_DELAY;
 557                 } else {
 558                         smic->state = SMIC_IDLE;
 559                         return SI_SM_TRANSACTION_COMPLETE;
 560                 }
 561
 562         case SMIC_HOSED:
 563                 init_smic_data(smic, smic->io);
 564                 return SI_SM_HOSED;
 565
 566         default:
 567                 if (smic_debug & SMIC_DEBUG_ENABLE) {
 568                         printk(KERN_WARNING "smic->state = %d\n", smic->state);
 569                         start_error_recovery(smic, "state = UNKNOWN");
 570                         return SI_SM_CALL_WITH_DELAY;
 571                 }
 572         }
 573         smic->smic_timeout = SMIC_RETRY_TIMEOUT;
 574         return SI_SM_CALL_WITHOUT_DELAY;
 575 }
 576
 577 static int smic_detect(struct si_sm_data *smic)
 578 {
 579         /* It's impossible for the SMIC fnags register to be all 1's,
 580            (assuming a properly functioning, self-initialized BMC)
 581            but that's what you get from reading a bogus address, so we
 582            test that first. */
 583         if (read_smic_flags(smic) == 0xff)
 584                 return 1;
 585
 586         return 0;
 587 }
 588
 589 static void smic_cleanup(struct si_sm_data *kcs)
 590 {
 591 }
 592
 593 static int smic_size(void)
 594 {
 595         return sizeof(struct si_sm_data);
 596 }
 597
 598 struct si_sm_handlers smic_smi_handlers =
 599 {
 600         .init_data         = init_smic_data,
 601         .start_transaction = start_smic_transaction,
 602         .get_result        = smic_get_result,
 603         .event             = smic_event,
 604         .detect            = smic_detect,
 605         .cleanup           = smic_cleanup,
 606         .size              = smic_size,
 607 };