drivers/char/ipmi/ipmi_ssif.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * ipmi_ssif.c
   4  *
   5  * The interface to the IPMI driver for SMBus access to a SMBus
   6  * compliant device.  Called SSIF by the IPMI spec.
   7  *
   8  * Author: Intel Corporation
   9  *         Todd Davis <todd.c.davis@intel.com>
  10  *
  11  * Rewritten by Corey Minyard <minyard@acm.org> to support the
  12  * non-blocking I2C interface, add support for multi-part
  13  * transactions, add PEC support, and general clenaup.
  14  *
  15  * Copyright 2003 Intel Corporation
  16  * Copyright 2005 MontaVista Software
  17  */
  18
  19 /*
  20  * This file holds the "policy" for the interface to the SSIF state
  21  * machine.  It does the configuration, handles timers and interrupts,
  22  * and drives the real SSIF state machine.
  23  */
  24
  25 /*
  26  * TODO: Figure out how to use SMB alerts.  This will require a new
  27  * interface into the I2C driver, I believe.
  28  */
  29
  30 #define pr_fmt(fmt) "ipmi_ssif: " fmt
  31
  32 #if defined(MODVERSIONS)
  33 #include <linux/modversions.h>
  34 #endif
  35
  36 #include <linux/module.h>
  37 #include <linux/moduleparam.h>
  38 #include <linux/sched.h>
  39 #include <linux/seq_file.h>
  40 #include <linux/timer.h>
  41 #include <linux/delay.h>
  42 #include <linux/errno.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/slab.h>
  45 #include <linux/list.h>
  46 #include <linux/i2c.h>
  47 #include <linux/ipmi_smi.h>
  48 #include <linux/init.h>
  49 #include <linux/dmi.h>
  50 #include <linux/kthread.h>
  51 #include <linux/acpi.h>
  52 #include <linux/ctype.h>
  53 #include <linux/time64.h>
  54 #include "ipmi_si_sm.h"
  55 #include "ipmi_dmi.h"
  56
  57 #define DEVICE_NAME "ipmi_ssif"
  58
  59 #define IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD      0x57
  60
  61 #define SSIF_IPMI_REQUEST                       2
  62 #define SSIF_IPMI_MULTI_PART_REQUEST_START      6
  63 #define SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE     7
  64 #define SSIF_IPMI_MULTI_PART_REQUEST_END        8
  65 #define SSIF_IPMI_RESPONSE                      3
  66 #define SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE    9
  67
  68 /* ssif_debug is a bit-field
  69  *      SSIF_DEBUG_MSG -        commands and their responses
  70  *      SSIF_DEBUG_STATES -     message states
  71  *      SSIF_DEBUG_TIMING -      Measure times between events in the driver
  72  */
  73 #define SSIF_DEBUG_TIMING       4
  74 #define SSIF_DEBUG_STATE        2
  75 #define SSIF_DEBUG_MSG          1
  76 #define SSIF_NODEBUG            0
  77 #define SSIF_DEFAULT_DEBUG      (SSIF_NODEBUG)
  78
  79 /*
  80  * Timer values
  81  */
  82 #define SSIF_MSG_USEC           20000   /* 20ms between message tries. */
  83 #define SSIF_MSG_PART_USEC      5000    /* 5ms for a message part */
  84
  85 /* How many times to we retry sending/receiving the message. */
  86 #define SSIF_SEND_RETRIES       5
  87 #define SSIF_RECV_RETRIES       250
  88
  89 #define SSIF_MSG_MSEC           (SSIF_MSG_USEC / 1000)
  90 #define SSIF_MSG_JIFFIES        ((SSIF_MSG_USEC * 1000) / TICK_NSEC)
  91 #define SSIF_MSG_PART_JIFFIES   ((SSIF_MSG_PART_USEC * 1000) / TICK_NSEC)
  92
  93 enum ssif_intf_state {
  94         SSIF_NORMAL,
  95         SSIF_GETTING_FLAGS,
  96         SSIF_GETTING_EVENTS,
  97         SSIF_CLEARING_FLAGS,
  98         SSIF_GETTING_MESSAGES,
  99         /* FIXME - add watchdog stuff. */
 100 };
 101
 102 #define SSIF_IDLE(ssif)  ((ssif)->ssif_state == SSIF_NORMAL \
 103                           && (ssif)->curr_msg == NULL)
 104
 105 /*
 106  * Indexes into stats[] in ssif_info below.
 107  */
 108 enum ssif_stat_indexes {
 109         /* Number of total messages sent. */
 110         SSIF_STAT_sent_messages = 0,
 111
 112         /*
 113          * Number of message parts sent.  Messages may be broken into
 114          * parts if they are long.
 115          */
 116         SSIF_STAT_sent_messages_parts,
 117
 118         /*
 119          * Number of time a message was retried.
 120          */
 121         SSIF_STAT_send_retries,
 122
 123         /*
 124          * Number of times the send of a message failed.
 125          */
 126         SSIF_STAT_send_errors,
 127
 128         /*
 129          * Number of message responses received.
 130          */
 131         SSIF_STAT_received_messages,
 132
 133         /*
 134          * Number of message fragments received.
 135          */
 136         SSIF_STAT_received_message_parts,
 137
 138         /*
 139          * Number of times the receive of a message was retried.
 140          */
 141         SSIF_STAT_receive_retries,
 142
 143         /*
 144          * Number of errors receiving messages.
 145          */
 146         SSIF_STAT_receive_errors,
 147
 148         /*
 149          * Number of times a flag fetch was requested.
 150          */
 151         SSIF_STAT_flag_fetches,
 152
 153         /*
 154          * Number of times the hardware didn't follow the state machine.
 155          */
 156         SSIF_STAT_hosed,
 157
 158         /*
 159          * Number of received events.
 160          */
 161         SSIF_STAT_events,
 162
 163         /* Number of asyncronous messages received. */
 164         SSIF_STAT_incoming_messages,
 165
 166         /* Number of watchdog pretimeouts. */
 167         SSIF_STAT_watchdog_pretimeouts,
 168
 169         /* Number of alers received. */
 170         SSIF_STAT_alerts,
 171
 172         /* Always add statistics before this value, it must be last. */
 173         SSIF_NUM_STATS
 174 };
 175
 176 struct ssif_addr_info {
 177         struct i2c_board_info binfo;
 178         char *adapter_name;
 179         int debug;
 180         int slave_addr;
 181         enum ipmi_addr_src addr_src;
 182         union ipmi_smi_info_union addr_info;
 183         struct device *dev;
 184         struct i2c_client *client;
 185
 186         struct i2c_client *added_client;
 187
 188         struct mutex clients_mutex;
 189         struct list_head clients;
 190
 191         struct list_head link;
 192 };
 193
 194 struct ssif_info;
 195
 196 typedef void (*ssif_i2c_done)(struct ssif_info *ssif_info, int result,
 197                              unsigned char *data, unsigned int len);
 198
 199 struct ssif_info {
 200         struct ipmi_smi     *intf;
 201         spinlock_t          lock;
 202         struct ipmi_smi_msg *waiting_msg;
 203         struct ipmi_smi_msg *curr_msg;
 204         enum ssif_intf_state ssif_state;
 205         unsigned long       ssif_debug;
 206
 207         struct ipmi_smi_handlers handlers;
 208
 209         enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
 210         union ipmi_smi_info_union addr_info;
 211
 212         /*
 213          * Flags from the last GET_MSG_FLAGS command, used when an ATTN
 214          * is set to hold the flags until we are done handling everything
 215          * from the flags.
 216          */
 217 #define RECEIVE_MSG_AVAIL       0x01
 218 #define EVENT_MSG_BUFFER_FULL   0x02
 219 #define WDT_PRE_TIMEOUT_INT     0x08
 220         unsigned char       msg_flags;
 221
 222         u8                  global_enables;
 223         bool                has_event_buffer;
 224         bool                supports_alert;
 225
 226         /*
 227          * Used to tell what we should do with alerts.  If we are
 228          * waiting on a response, read the data immediately.
 229          */
 230         bool                got_alert;
 231         bool                waiting_alert;
 232
 233         /*
 234          * If set to true, this will request events the next time the
 235          * state machine is idle.
 236          */
 237         bool                req_events;
 238
 239         /*
 240          * If set to true, this will request flags the next time the
 241          * state machine is idle.
 242          */
 243         bool                req_flags;
 244
 245         /*
 246          * Used to perform timer operations when run-to-completion
 247          * mode is on.  This is a countdown timer.
 248          */
 249         int                 rtc_us_timer;
 250
 251         /* Used for sending/receiving data.  +1 for the length. */
 252         unsigned char data[IPMI_MAX_MSG_LENGTH + 1];
 253         unsigned int  data_len;
 254
 255         /* Temp receive buffer, gets copied into data. */
 256         unsigned char recv[I2C_SMBUS_BLOCK_MAX];
 257
 258         struct i2c_client *client;
 259         ssif_i2c_done done_handler;
 260
 261         /* Thread interface handling */
 262         struct task_struct *thread;
 263         struct completion wake_thread;
 264         bool stopping;
 265         int i2c_read_write;
 266         int i2c_command;
 267         unsigned char *i2c_data;
 268         unsigned int i2c_size;
 269
 270         struct timer_list retry_timer;
 271         int retries_left;
 272
 273         /* Info from SSIF cmd */
 274         unsigned char max_xmit_msg_size;
 275         unsigned char max_recv_msg_size;
 276         bool cmd8_works; /* See test_multipart_messages() for details. */
 277         unsigned int  multi_support;
 278         int           supports_pec;
 279
 280 #define SSIF_NO_MULTI           0
 281 #define SSIF_MULTI_2_PART       1
 282 #define SSIF_MULTI_n_PART       2
 283         unsigned char *multi_data;
 284         unsigned int  multi_len;
 285         unsigned int  multi_pos;
 286
 287         atomic_t stats[SSIF_NUM_STATS];
 288 };
 289
 290 #define ssif_inc_stat(ssif, stat) \
 291         atomic_inc(&(ssif)->stats[SSIF_STAT_ ## stat])
 292 #define ssif_get_stat(ssif, stat) \
 293         ((unsigned int) atomic_read(&(ssif)->stats[SSIF_STAT_ ## stat]))
 294
 295 static bool initialized;
 296
 297 static void return_hosed_msg(struct ssif_info *ssif_info,
 298                              struct ipmi_smi_msg *msg);
 299 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags);
 300 static int start_send(struct ssif_info *ssif_info,
 301                       unsigned char   *data,
 302                       unsigned int    len);
 303
 304 static unsigned long *ipmi_ssif_lock_cond(struct ssif_info *ssif_info,
 305                                           unsigned long *flags)
 306 {
 307         spin_lock_irqsave(&ssif_info->lock, *flags);
 308         return flags;
 309 }
 310
 311 static void ipmi_ssif_unlock_cond(struct ssif_info *ssif_info,
 312                                   unsigned long *flags)
 313 {
 314         spin_unlock_irqrestore(&ssif_info->lock, *flags);
 315 }
 316
 317 static void deliver_recv_msg(struct ssif_info *ssif_info,
 318                              struct ipmi_smi_msg *msg)
 319 {
 320         if (msg->rsp_size < 0) {
 321                 return_hosed_msg(ssif_info, msg);
 322                 pr_err("%s: Malformed message: rsp_size = %d\n",
 323                        __func__, msg->rsp_size);
 324         } else {
 325                 ipmi_smi_msg_received(ssif_info->intf, msg);
 326         }
 327 }
 328
 329 static void return_hosed_msg(struct ssif_info *ssif_info,
 330                              struct ipmi_smi_msg *msg)
 331 {
 332         ssif_inc_stat(ssif_info, hosed);
 333
 334         /* Make it a response */
 335         msg->rsp[0] = msg->data[0] | 4;
 336         msg->rsp[1] = msg->data[1];
 337         msg->rsp[2] = 0xFF; /* Unknown error. */
 338         msg->rsp_size = 3;
 339
 340         deliver_recv_msg(ssif_info, msg);
 341 }
 342
 343 /*
 344  * Must be called with the message lock held.  This will release the
 345  * message lock.  Note that the caller will check SSIF_IDLE and start a
 346  * new operation, so there is no need to check for new messages to
 347  * start in here.
 348  */
 349 static void start_clear_flags(struct ssif_info *ssif_info, unsigned long *flags)
 350 {
 351         unsigned char msg[3];
 352
 353         ssif_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
 354         ssif_info->ssif_state = SSIF_CLEARING_FLAGS;
 355         ipmi_ssif_unlock_cond(ssif_info, flags);
 356
 357         /* Make sure the watchdog pre-timeout flag is not set at startup. */
 358         msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
 359         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
 360         msg[2] = WDT_PRE_TIMEOUT_INT;
 361
 362         if (start_send(ssif_info, msg, 3) != 0) {
 363                 /* Error, just go to normal state. */
 364                 ssif_info->ssif_state = SSIF_NORMAL;
 365         }
 366 }
 367
 368 static void start_flag_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 369 {
 370         unsigned char mb[2];
 371
 372         ssif_info->req_flags = false;
 373         ssif_info->ssif_state = SSIF_GETTING_FLAGS;
 374         ipmi_ssif_unlock_cond(ssif_info, flags);
 375
 376         mb[0] = (IPMI_NETFN_APP_REQUEST << 2);
 377         mb[1] = IPMI_GET_MSG_FLAGS_CMD;
 378         if (start_send(ssif_info, mb, 2) != 0)
 379                 ssif_info->ssif_state = SSIF_NORMAL;
 380 }
 381
 382 static void check_start_send(struct ssif_info *ssif_info, unsigned long *flags,
 383                              struct ipmi_smi_msg *msg)
 384 {
 385         if (start_send(ssif_info, msg->data, msg->data_size) != 0) {
 386                 unsigned long oflags;
 387
 388                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 389                 ssif_info->curr_msg = NULL;
 390                 ssif_info->ssif_state = SSIF_NORMAL;
 391                 ipmi_ssif_unlock_cond(ssif_info, flags);
 392                 ipmi_free_smi_msg(msg);
 393         }
 394 }
 395
 396 static void start_event_fetch(struct ssif_info *ssif_info, unsigned long *flags)
 397 {
 398         struct ipmi_smi_msg *msg;
 399
 400         ssif_info->req_events = false;
 401
 402         msg = ipmi_alloc_smi_msg();
 403         if (!msg) {
 404                 ssif_info->ssif_state = SSIF_NORMAL;
 405                 ipmi_ssif_unlock_cond(ssif_info, flags);
 406                 return;
 407         }
 408
 409         ssif_info->curr_msg = msg;
 410         ssif_info->ssif_state = SSIF_GETTING_EVENTS;
 411         ipmi_ssif_unlock_cond(ssif_info, flags);
 412
 413         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 414         msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
 415         msg->data_size = 2;
 416
 417         check_start_send(ssif_info, flags, msg);
 418 }
 419
 420 static void start_recv_msg_fetch(struct ssif_info *ssif_info,
 421                                  unsigned long *flags)
 422 {
 423         struct ipmi_smi_msg *msg;
 424
 425         msg = ipmi_alloc_smi_msg();
 426         if (!msg) {
 427                 ssif_info->ssif_state = SSIF_NORMAL;
 428                 ipmi_ssif_unlock_cond(ssif_info, flags);
 429                 return;
 430         }
 431
 432         ssif_info->curr_msg = msg;
 433         ssif_info->ssif_state = SSIF_GETTING_MESSAGES;
 434         ipmi_ssif_unlock_cond(ssif_info, flags);
 435
 436         msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
 437         msg->data[1] = IPMI_GET_MSG_CMD;
 438         msg->data_size = 2;
 439
 440         check_start_send(ssif_info, flags, msg);
 441 }
 442
 443 /*
 444  * Must be called with the message lock held.  This will release the
 445  * message lock.  Note that the caller will check SSIF_IDLE and start a
 446  * new operation, so there is no need to check for new messages to
 447  * start in here.
 448  */
 449 static void handle_flags(struct ssif_info *ssif_info, unsigned long *flags)
 450 {
 451         if (ssif_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
 452                 /* Watchdog pre-timeout */
 453                 ssif_inc_stat(ssif_info, watchdog_pretimeouts);
 454                 start_clear_flags(ssif_info, flags);
 455                 ipmi_smi_watchdog_pretimeout(ssif_info->intf);
 456         } else if (ssif_info->msg_flags & RECEIVE_MSG_AVAIL)
 457                 /* Messages available. */
 458                 start_recv_msg_fetch(ssif_info, flags);
 459         else if (ssif_info->msg_flags & EVENT_MSG_BUFFER_FULL)
 460                 /* Events available. */
 461                 start_event_fetch(ssif_info, flags);
 462         else {
 463                 ssif_info->ssif_state = SSIF_NORMAL;
 464                 ipmi_ssif_unlock_cond(ssif_info, flags);
 465         }
 466 }
 467
 468 static int ipmi_ssif_thread(void *data)
 469 {
 470         struct ssif_info *ssif_info = data;
 471
 472         while (!kthread_should_stop()) {
 473                 int result;
 474
 475                 /* Wait for something to do */
 476                 result = wait_for_completion_interruptible(
 477                                                 &ssif_info->wake_thread);
 478                 if (ssif_info->stopping)
 479                         break;
 480                 if (result == -ERESTARTSYS)
 481                         continue;
 482                 init_completion(&ssif_info->wake_thread);
 483
 484                 if (ssif_info->i2c_read_write == I2C_SMBUS_WRITE) {
 485                         result = i2c_smbus_write_block_data(
 486                                 ssif_info->client, ssif_info->i2c_command,
 487                                 ssif_info->i2c_data[0],
 488                                 ssif_info->i2c_data + 1);
 489                         ssif_info->done_handler(ssif_info, result, NULL, 0);
 490                 } else {
 491                         result = i2c_smbus_read_block_data(
 492                                 ssif_info->client, ssif_info->i2c_command,
 493                                 ssif_info->i2c_data);
 494                         if (result < 0)
 495                                 ssif_info->done_handler(ssif_info, result,
 496                                                         NULL, 0);
 497                         else
 498                                 ssif_info->done_handler(ssif_info, 0,
 499                                                         ssif_info->i2c_data,
 500                                                         result);
 501                 }
 502         }
 503
 504         return 0;
 505 }
 506
 507 static int ssif_i2c_send(struct ssif_info *ssif_info,
 508                         ssif_i2c_done handler,
 509                         int read_write, int command,
 510                         unsigned char *data, unsigned int size)
 511 {
 512         ssif_info->done_handler = handler;
 513
 514         ssif_info->i2c_read_write = read_write;
 515         ssif_info->i2c_command = command;
 516         ssif_info->i2c_data = data;
 517         ssif_info->i2c_size = size;
 518         complete(&ssif_info->wake_thread);
 519         return 0;
 520 }
 521
 522
 523 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 524                              unsigned char *data, unsigned int len);
 525
 526 static void start_get(struct ssif_info *ssif_info)
 527 {
 528         int rv;
 529
 530         ssif_info->rtc_us_timer = 0;
 531         ssif_info->multi_pos = 0;
 532
 533         rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 534                           SSIF_IPMI_RESPONSE,
 535                           ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 536         if (rv < 0) {
 537                 /* request failed, just return the error. */
 538                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 539                         pr_info("Error from i2c_non_blocking_op(5)\n");
 540
 541                 msg_done_handler(ssif_info, -EIO, NULL, 0);
 542         }
 543 }
 544
 545 static void retry_timeout(struct timer_list *t)
 546 {
 547         struct ssif_info *ssif_info = from_timer(ssif_info, t, retry_timer);
 548         unsigned long oflags, *flags;
 549         bool waiting;
 550
 551         if (ssif_info->stopping)
 552                 return;
 553
 554         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 555         waiting = ssif_info->waiting_alert;
 556         ssif_info->waiting_alert = false;
 557         ipmi_ssif_unlock_cond(ssif_info, flags);
 558
 559         if (waiting)
 560                 start_get(ssif_info);
 561 }
 562
 563
 564 static void ssif_alert(struct i2c_client *client, enum i2c_alert_protocol type,
 565                        unsigned int data)
 566 {
 567         struct ssif_info *ssif_info = i2c_get_clientdata(client);
 568         unsigned long oflags, *flags;
 569         bool do_get = false;
 570
 571         if (type != I2C_PROTOCOL_SMBUS_ALERT)
 572                 return;
 573
 574         ssif_inc_stat(ssif_info, alerts);
 575
 576         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 577         if (ssif_info->waiting_alert) {
 578                 ssif_info->waiting_alert = false;
 579                 del_timer(&ssif_info->retry_timer);
 580                 do_get = true;
 581         } else if (ssif_info->curr_msg) {
 582                 ssif_info->got_alert = true;
 583         }
 584         ipmi_ssif_unlock_cond(ssif_info, flags);
 585         if (do_get)
 586                 start_get(ssif_info);
 587 }
 588
 589 static int start_resend(struct ssif_info *ssif_info);
 590
 591 static void msg_done_handler(struct ssif_info *ssif_info, int result,
 592                              unsigned char *data, unsigned int len)
 593 {
 594         struct ipmi_smi_msg *msg;
 595         unsigned long oflags, *flags;
 596         int rv;
 597
 598         /*
 599          * We are single-threaded here, so no need for a lock until we
 600          * start messing with driver states or the queues.
 601          */
 602
 603         if (result < 0) {
 604                 ssif_info->retries_left--;
 605                 if (ssif_info->retries_left > 0) {
 606                         ssif_inc_stat(ssif_info, receive_retries);
 607
 608                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 609                         ssif_info->waiting_alert = true;
 610                         ssif_info->rtc_us_timer = SSIF_MSG_USEC;
 611                         if (!ssif_info->stopping)
 612                                 mod_timer(&ssif_info->retry_timer,
 613                                           jiffies + SSIF_MSG_JIFFIES);
 614                         ipmi_ssif_unlock_cond(ssif_info, flags);
 615                         return;
 616                 }
 617
 618                 ssif_inc_stat(ssif_info, receive_errors);
 619
 620                 if  (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 621                         pr_info("Error in msg_done_handler: %d\n", result);
 622                 len = 0;
 623                 goto continue_op;
 624         }
 625
 626         if ((len > 1) && (ssif_info->multi_pos == 0)
 627                                 && (data[0] == 0x00) && (data[1] == 0x01)) {
 628                 /* Start of multi-part read.  Start the next transaction. */
 629                 int i;
 630
 631                 ssif_inc_stat(ssif_info, received_message_parts);
 632
 633                 /* Remove the multi-part read marker. */
 634                 len -= 2;
 635                 data += 2;
 636                 for (i = 0; i < len; i++)
 637                         ssif_info->data[i] = data[i];
 638                 ssif_info->multi_len = len;
 639                 ssif_info->multi_pos = 1;
 640
 641                 rv = ssif_i2c_send(ssif_info, msg_done_handler, I2C_SMBUS_READ,
 642                                   SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 643                                   ssif_info->recv, I2C_SMBUS_BLOCK_DATA);
 644                 if (rv < 0) {
 645                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 646                                 pr_info("Error from i2c_non_blocking_op(1)\n");
 647
 648                         result = -EIO;
 649                 } else
 650                         return;
 651         } else if (ssif_info->multi_pos) {
 652                 /* Middle of multi-part read.  Start the next transaction. */
 653                 int i;
 654                 unsigned char blocknum;
 655
 656                 if (len == 0) {
 657                         result = -EIO;
 658                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 659                                 pr_info("Middle message with no data\n");
 660
 661                         goto continue_op;
 662                 }
 663
 664                 blocknum = data[0];
 665                 len--;
 666                 data++;
 667
 668                 if (blocknum != 0xff && len != 31) {
 669                     /* All blocks but the last must have 31 data bytes. */
 670                         result = -EIO;
 671                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 672                                 pr_info("Received middle message <31\n");
 673
 674                         goto continue_op;
 675                 }
 676
 677                 if (ssif_info->multi_len + len > IPMI_MAX_MSG_LENGTH) {
 678                         /* Received message too big, abort the operation. */
 679                         result = -E2BIG;
 680                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 681                                 pr_info("Received message too big\n");
 682
 683                         goto continue_op;
 684                 }
 685
 686                 for (i = 0; i < len; i++)
 687                         ssif_info->data[i + ssif_info->multi_len] = data[i];
 688                 ssif_info->multi_len += len;
 689                 if (blocknum == 0xff) {
 690                         /* End of read */
 691                         len = ssif_info->multi_len;
 692                         data = ssif_info->data;
 693                 } else if (blocknum != ssif_info->multi_pos) {
 694                         /*
 695                          * Out of sequence block, just abort.  Block
 696                          * numbers start at zero for the second block,
 697                          * but multi_pos starts at one, so the +1.
 698                          */
 699                         result = -EIO;
 700                 } else {
 701                         ssif_inc_stat(ssif_info, received_message_parts);
 702
 703                         ssif_info->multi_pos++;
 704
 705                         rv = ssif_i2c_send(ssif_info, msg_done_handler,
 706                                            I2C_SMBUS_READ,
 707                                            SSIF_IPMI_MULTI_PART_RESPONSE_MIDDLE,
 708                                            ssif_info->recv,
 709                                            I2C_SMBUS_BLOCK_DATA);
 710                         if (rv < 0) {
 711                                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 712                                         pr_info("Error from ssif_i2c_send\n");
 713
 714                                 result = -EIO;
 715                         } else
 716                                 return;
 717                 }
 718         }
 719
 720  continue_op:
 721         if (result < 0) {
 722                 ssif_inc_stat(ssif_info, receive_errors);
 723         } else {
 724                 ssif_inc_stat(ssif_info, received_messages);
 725                 ssif_inc_stat(ssif_info, received_message_parts);
 726         }
 727
 728         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 729                 pr_info("DONE 1: state = %d, result=%d\n",
 730                         ssif_info->ssif_state, result);
 731
 732         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 733         msg = ssif_info->curr_msg;
 734         if (msg) {
 735                 msg->rsp_size = len;
 736                 if (msg->rsp_size > IPMI_MAX_MSG_LENGTH)
 737                         msg->rsp_size = IPMI_MAX_MSG_LENGTH;
 738                 memcpy(msg->rsp, data, msg->rsp_size);
 739                 ssif_info->curr_msg = NULL;
 740         }
 741
 742         switch (ssif_info->ssif_state) {
 743         case SSIF_NORMAL:
 744                 ipmi_ssif_unlock_cond(ssif_info, flags);
 745                 if (!msg)
 746                         break;
 747
 748                 if (result < 0)
 749                         return_hosed_msg(ssif_info, msg);
 750                 else
 751                         deliver_recv_msg(ssif_info, msg);
 752                 break;
 753
 754         case SSIF_GETTING_FLAGS:
 755                 /* We got the flags from the SSIF, now handle them. */
 756                 if ((result < 0) || (len < 4) || (data[2] != 0)) {
 757                         /*
 758                          * Error fetching flags, or invalid length,
 759                          * just give up for now.
 760                          */
 761                         ssif_info->ssif_state = SSIF_NORMAL;
 762                         ipmi_ssif_unlock_cond(ssif_info, flags);
 763                         pr_warn("Error getting flags: %d %d, %x\n",
 764                                 result, len, (len >= 3) ? data[2] : 0);
 765                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 766                            || data[1] != IPMI_GET_MSG_FLAGS_CMD) {
 767                         /*
 768                          * Don't abort here, maybe it was a queued
 769                          * response to a previous command.
 770                          */
 771                         ipmi_ssif_unlock_cond(ssif_info, flags);
 772                         pr_warn("Invalid response getting flags: %x %x\n",
 773                                 data[0], data[1]);
 774                 } else {
 775                         ssif_inc_stat(ssif_info, flag_fetches);
 776                         ssif_info->msg_flags = data[3];
 777                         handle_flags(ssif_info, flags);
 778                 }
 779                 break;
 780
 781         case SSIF_CLEARING_FLAGS:
 782                 /* We cleared the flags. */
 783                 if ((result < 0) || (len < 3) || (data[2] != 0)) {
 784                         /* Error clearing flags */
 785                         pr_warn("Error clearing flags: %d %d, %x\n",
 786                                 result, len, (len >= 3) ? data[2] : 0);
 787                 } else if (data[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 788                            || data[1] != IPMI_CLEAR_MSG_FLAGS_CMD) {
 789                         pr_warn("Invalid response clearing flags: %x %x\n",
 790                                 data[0], data[1]);
 791                 }
 792                 ssif_info->ssif_state = SSIF_NORMAL;
 793                 ipmi_ssif_unlock_cond(ssif_info, flags);
 794                 break;
 795
 796         case SSIF_GETTING_EVENTS:
 797                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 798                         /* Error getting event, probably done. */
 799                         msg->done(msg);
 800
 801                         /* Take off the event flag. */
 802                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 803                         handle_flags(ssif_info, flags);
 804                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 805                            || msg->rsp[1] != IPMI_READ_EVENT_MSG_BUFFER_CMD) {
 806                         pr_warn("Invalid response getting events: %x %x\n",
 807                                 msg->rsp[0], msg->rsp[1]);
 808                         msg->done(msg);
 809                         /* Take off the event flag. */
 810                         ssif_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
 811                         handle_flags(ssif_info, flags);
 812                 } else {
 813                         handle_flags(ssif_info, flags);
 814                         ssif_inc_stat(ssif_info, events);
 815                         deliver_recv_msg(ssif_info, msg);
 816                 }
 817                 break;
 818
 819         case SSIF_GETTING_MESSAGES:
 820                 if ((result < 0) || (len < 3) || (msg->rsp[2] != 0)) {
 821                         /* Error getting event, probably done. */
 822                         msg->done(msg);
 823
 824                         /* Take off the msg flag. */
 825                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 826                         handle_flags(ssif_info, flags);
 827                 } else if (msg->rsp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2
 828                            || msg->rsp[1] != IPMI_GET_MSG_CMD) {
 829                         pr_warn("Invalid response clearing flags: %x %x\n",
 830                                 msg->rsp[0], msg->rsp[1]);
 831                         msg->done(msg);
 832
 833                         /* Take off the msg flag. */
 834                         ssif_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
 835                         handle_flags(ssif_info, flags);
 836                 } else {
 837                         ssif_inc_stat(ssif_info, incoming_messages);
 838                         handle_flags(ssif_info, flags);
 839                         deliver_recv_msg(ssif_info, msg);
 840                 }
 841                 break;
 842         }
 843
 844         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 845         if (SSIF_IDLE(ssif_info) && !ssif_info->stopping) {
 846                 if (ssif_info->req_events)
 847                         start_event_fetch(ssif_info, flags);
 848                 else if (ssif_info->req_flags)
 849                         start_flag_fetch(ssif_info, flags);
 850                 else
 851                         start_next_msg(ssif_info, flags);
 852         } else
 853                 ipmi_ssif_unlock_cond(ssif_info, flags);
 854
 855         if (ssif_info->ssif_debug & SSIF_DEBUG_STATE)
 856                 pr_info("DONE 2: state = %d.\n", ssif_info->ssif_state);
 857 }
 858
 859 static void msg_written_handler(struct ssif_info *ssif_info, int result,
 860                                 unsigned char *data, unsigned int len)
 861 {
 862         int rv;
 863
 864         /* We are single-threaded here, so no need for a lock. */
 865         if (result < 0) {
 866                 ssif_info->retries_left--;
 867                 if (ssif_info->retries_left > 0) {
 868                         if (!start_resend(ssif_info)) {
 869                                 ssif_inc_stat(ssif_info, send_retries);
 870                                 return;
 871                         }
 872                         /* request failed, just return the error. */
 873                         ssif_inc_stat(ssif_info, send_errors);
 874
 875                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 876                                 pr_info("%s: Out of retries\n", __func__);
 877                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 878                         return;
 879                 }
 880
 881                 ssif_inc_stat(ssif_info, send_errors);
 882
 883                 /*
 884                  * Got an error on transmit, let the done routine
 885                  * handle it.
 886                  */
 887                 if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 888                         pr_info("Error in msg_written_handler: %d\n", result);
 889
 890                 msg_done_handler(ssif_info, result, NULL, 0);
 891                 return;
 892         }
 893
 894         if (ssif_info->multi_data) {
 895                 /*
 896                  * In the middle of a multi-data write.  See the comment
 897                  * in the SSIF_MULTI_n_PART case in the probe function
 898                  * for details on the intricacies of this.
 899                  */
 900                 int left, to_write;
 901                 unsigned char *data_to_send;
 902                 unsigned char cmd;
 903
 904                 ssif_inc_stat(ssif_info, sent_messages_parts);
 905
 906                 left = ssif_info->multi_len - ssif_info->multi_pos;
 907                 to_write = left;
 908                 if (to_write > 32)
 909                         to_write = 32;
 910                 /* Length byte. */
 911                 ssif_info->multi_data[ssif_info->multi_pos] = to_write;
 912                 data_to_send = ssif_info->multi_data + ssif_info->multi_pos;
 913                 ssif_info->multi_pos += to_write;
 914                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE;
 915                 if (ssif_info->cmd8_works) {
 916                         if (left == to_write) {
 917                                 cmd = SSIF_IPMI_MULTI_PART_REQUEST_END;
 918                                 ssif_info->multi_data = NULL;
 919                         }
 920                 } else if (to_write < 32) {
 921                         ssif_info->multi_data = NULL;
 922                 }
 923
 924                 rv = ssif_i2c_send(ssif_info, msg_written_handler,
 925                                    I2C_SMBUS_WRITE, cmd,
 926                                    data_to_send, I2C_SMBUS_BLOCK_DATA);
 927                 if (rv < 0) {
 928                         /* request failed, just return the error. */
 929                         ssif_inc_stat(ssif_info, send_errors);
 930
 931                         if (ssif_info->ssif_debug & SSIF_DEBUG_MSG)
 932                                 pr_info("Error from i2c_non_blocking_op(3)\n");
 933                         msg_done_handler(ssif_info, -EIO, NULL, 0);
 934                 }
 935         } else {
 936                 /* Ready to request the result. */
 937                 unsigned long oflags, *flags;
 938
 939                 ssif_inc_stat(ssif_info, sent_messages);
 940                 ssif_inc_stat(ssif_info, sent_messages_parts);
 941
 942                 flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
 943                 if (ssif_info->got_alert) {
 944                         /* The result is already ready, just start it. */
 945                         ssif_info->got_alert = false;
 946                         ipmi_ssif_unlock_cond(ssif_info, flags);
 947                         start_get(ssif_info);
 948                 } else {
 949                         /* Wait a jiffie then request the next message */
 950                         ssif_info->waiting_alert = true;
 951                         ssif_info->retries_left = SSIF_RECV_RETRIES;
 952                         ssif_info->rtc_us_timer = SSIF_MSG_PART_USEC;
 953                         if (!ssif_info->stopping)
 954                                 mod_timer(&ssif_info->retry_timer,
 955                                           jiffies + SSIF_MSG_PART_JIFFIES);
 956                         ipmi_ssif_unlock_cond(ssif_info, flags);
 957                 }
 958         }
 959 }
 960
 961 static int start_resend(struct ssif_info *ssif_info)
 962 {
 963         int rv;
 964         int command;
 965
 966         ssif_info->got_alert = false;
 967
 968         if (ssif_info->data_len > 32) {
 969                 command = SSIF_IPMI_MULTI_PART_REQUEST_START;
 970                 ssif_info->multi_data = ssif_info->data;
 971                 ssif_info->multi_len = ssif_info->data_len;
 972                 /*
 973                  * Subtle thing, this is 32, not 33, because we will
 974                  * overwrite the thing at position 32 (which was just
 975                  * transmitted) with the new length.
 976                  */
 977                 ssif_info->multi_pos = 32;
 978                 ssif_info->data[0] = 32;
 979         } else {
 980                 ssif_info->multi_data = NULL;
 981                 command = SSIF_IPMI_REQUEST;
 982                 ssif_info->data[0] = ssif_info->data_len;
 983         }
 984
 985         rv = ssif_i2c_send(ssif_info, msg_written_handler, I2C_SMBUS_WRITE,
 986                           command, ssif_info->data, I2C_SMBUS_BLOCK_DATA);
 987         if (rv && (ssif_info->ssif_debug & SSIF_DEBUG_MSG))
 988                 pr_info("Error from i2c_non_blocking_op(4)\n");
 989         return rv;
 990 }
 991
 992 static int start_send(struct ssif_info *ssif_info,
 993                       unsigned char   *data,
 994                       unsigned int    len)
 995 {
 996         if (len > IPMI_MAX_MSG_LENGTH)
 997                 return -E2BIG;
 998         if (len > ssif_info->max_xmit_msg_size)
 999                 return -E2BIG;
1000
1001         ssif_info->retries_left = SSIF_SEND_RETRIES;
1002         memcpy(ssif_info->data + 1, data, len);
1003         ssif_info->data_len = len;
1004         return start_resend(ssif_info);
1005 }
1006
1007 /* Must be called with the message lock held. */
1008 static void start_next_msg(struct ssif_info *ssif_info, unsigned long *flags)
1009 {
1010         struct ipmi_smi_msg *msg;
1011         unsigned long oflags;
1012
1013  restart:
1014         if (!SSIF_IDLE(ssif_info)) {
1015                 ipmi_ssif_unlock_cond(ssif_info, flags);
1016                 return;
1017         }
1018
1019         if (!ssif_info->waiting_msg) {
1020                 ssif_info->curr_msg = NULL;
1021                 ipmi_ssif_unlock_cond(ssif_info, flags);
1022         } else {
1023                 int rv;
1024
1025                 ssif_info->curr_msg = ssif_info->waiting_msg;
1026                 ssif_info->waiting_msg = NULL;
1027                 ipmi_ssif_unlock_cond(ssif_info, flags);
1028                 rv = start_send(ssif_info,
1029                                 ssif_info->curr_msg->data,
1030                                 ssif_info->curr_msg->data_size);
1031                 if (rv) {
1032                         msg = ssif_info->curr_msg;
1033                         ssif_info->curr_msg = NULL;
1034                         return_hosed_msg(ssif_info, msg);
1035                         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1036                         goto restart;
1037                 }
1038         }
1039 }
1040
1041 static void sender(void                *send_info,
1042                    struct ipmi_smi_msg *msg)
1043 {
1044         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1045         unsigned long oflags, *flags;
1046
1047         BUG_ON(ssif_info->waiting_msg);
1048         ssif_info->waiting_msg = msg;
1049
1050         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1051         start_next_msg(ssif_info, flags);
1052
1053         if (ssif_info->ssif_debug & SSIF_DEBUG_TIMING) {
1054                 struct timespec64 t;
1055
1056                 ktime_get_real_ts64(&t);
1057                 pr_info("**Enqueue %02x %02x: %lld.%6.6ld\n",
1058                         msg->data[0], msg->data[1],
1059                         (long long)t.tv_sec, (long)t.tv_nsec / NSEC_PER_USEC);
1060         }
1061 }
1062
1063 static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
1064 {
1065         struct ssif_info *ssif_info = send_info;
1066
1067         data->addr_src = ssif_info->addr_source;
1068         data->dev = &ssif_info->client->dev;
1069         data->addr_info = ssif_info->addr_info;
1070         get_device(data->dev);
1071
1072         return 0;
1073 }
1074
1075 /*
1076  * Instead of having our own timer to periodically check the message
1077  * flags, we let the message handler drive us.
1078  */
1079 static void request_events(void *send_info)
1080 {
1081         struct ssif_info *ssif_info = (struct ssif_info *) send_info;
1082         unsigned long oflags, *flags;
1083
1084         if (!ssif_info->has_event_buffer)
1085                 return;
1086
1087         flags = ipmi_ssif_lock_cond(ssif_info, &oflags);
1088         /*
1089          * Request flags first, not events, because the lower layer
1090          * doesn't have a way to send an attention.  But make sure
1091          * event checking still happens.
1092          */
1093         ssif_info->req_events = true;
1094         if (SSIF_IDLE(ssif_info))
1095                 start_flag_fetch(ssif_info, flags);
1096         else {
1097                 ssif_info->req_flags = true;
1098                 ipmi_ssif_unlock_cond(ssif_info, flags);
1099         }
1100 }
1101
1102 static int ssif_start_processing(void            *send_info,
1103                                  struct ipmi_smi *intf)
1104 {
1105         struct ssif_info *ssif_info = send_info;
1106
1107         ssif_info->intf = intf;
1108
1109         return 0;
1110 }
1111
1112 #define MAX_SSIF_BMCS 4
1113
1114 static unsigned short addr[MAX_SSIF_BMCS];
1115 static int num_addrs;
1116 module_param_array(addr, ushort, &num_addrs, 0);
1117 MODULE_PARM_DESC(addr, "The addresses to scan for IPMI BMCs on the SSIFs.");
1118
1119 static char *adapter_name[MAX_SSIF_BMCS];
1120 static int num_adapter_names;
1121 module_param_array(adapter_name, charp, &num_adapter_names, 0);
1122 MODULE_PARM_DESC(adapter_name, "The string name of the I2C device that has the BMC.  By default all devices are scanned.");
1123
1124 static int slave_addrs[MAX_SSIF_BMCS];
1125 static int num_slave_addrs;
1126 module_param_array(slave_addrs, int, &num_slave_addrs, 0);
1127 MODULE_PARM_DESC(slave_addrs,
1128                  "The default IPMB slave address for the controller.");
1129
1130 static bool alerts_broken;
1131 module_param(alerts_broken, bool, 0);
1132 MODULE_PARM_DESC(alerts_broken, "Don't enable alerts for the controller.");
1133
1134 /*
1135  * Bit 0 enables message debugging, bit 1 enables state debugging, and
1136  * bit 2 enables timing debugging.  This is an array indexed by
1137  * interface number"
1138  */
1139 static int dbg[MAX_SSIF_BMCS];
1140 static int num_dbg;
1141 module_param_array(dbg, int, &num_dbg, 0);
1142 MODULE_PARM_DESC(dbg, "Turn on debugging.");
1143
1144 static bool ssif_dbg_probe;
1145 module_param_named(dbg_probe, ssif_dbg_probe, bool, 0);
1146 MODULE_PARM_DESC(dbg_probe, "Enable debugging of probing of adapters.");
1147
1148 static bool ssif_tryacpi = true;
1149 module_param_named(tryacpi, ssif_tryacpi, bool, 0);
1150 MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the default scan of the interfaces identified via ACPI");
1151
1152 static bool ssif_trydmi = true;
1153 module_param_named(trydmi, ssif_trydmi, bool, 0);
1154 MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the default scan of the interfaces identified via DMI (SMBIOS)");
1155
1156 static DEFINE_MUTEX(ssif_infos_mutex);
1157 static LIST_HEAD(ssif_infos);
1158
1159 #define IPMI_SSIF_ATTR(name) \
1160 static ssize_t ipmi_##name##_show(struct device *dev,                   \
1161                                   struct device_attribute *attr,        \
1162                                   char *buf)                            \
1163 {                                                                       \
1164         struct ssif_info *ssif_info = dev_get_drvdata(dev);             \
1165                                                                         \
1166         return snprintf(buf, 10, "%u\n", ssif_get_stat(ssif_info, name));\
1167 }                                                                       \
1168 static DEVICE_ATTR(name, S_IRUGO, ipmi_##name##_show, NULL)
1169
1170 static ssize_t ipmi_type_show(struct device *dev,
1171                               struct device_attribute *attr,
1172                               char *buf)
1173 {
1174         return snprintf(buf, 10, "ssif\n");
1175 }
1176 static DEVICE_ATTR(type, S_IRUGO, ipmi_type_show, NULL);
1177
1178 IPMI_SSIF_ATTR(sent_messages);
1179 IPMI_SSIF_ATTR(sent_messages_parts);
1180 IPMI_SSIF_ATTR(send_retries);
1181 IPMI_SSIF_ATTR(send_errors);
1182 IPMI_SSIF_ATTR(received_messages);
1183 IPMI_SSIF_ATTR(received_message_parts);
1184 IPMI_SSIF_ATTR(receive_retries);
1185 IPMI_SSIF_ATTR(receive_errors);
1186 IPMI_SSIF_ATTR(flag_fetches);
1187 IPMI_SSIF_ATTR(hosed);
1188 IPMI_SSIF_ATTR(events);
1189 IPMI_SSIF_ATTR(watchdog_pretimeouts);
1190 IPMI_SSIF_ATTR(alerts);
1191
1192 static struct attribute *ipmi_ssif_dev_attrs[] = {
1193         &dev_attr_type.attr,
1194         &dev_attr_sent_messages.attr,
1195         &dev_attr_sent_messages_parts.attr,
1196         &dev_attr_send_retries.attr,
1197         &dev_attr_send_errors.attr,
1198         &dev_attr_received_messages.attr,
1199         &dev_attr_received_message_parts.attr,
1200         &dev_attr_receive_retries.attr,
1201         &dev_attr_receive_errors.attr,
1202         &dev_attr_flag_fetches.attr,
1203         &dev_attr_hosed.attr,
1204         &dev_attr_events.attr,
1205         &dev_attr_watchdog_pretimeouts.attr,
1206         &dev_attr_alerts.attr,
1207         NULL
1208 };
1209
1210 static const struct attribute_group ipmi_ssif_dev_attr_group = {
1211         .attrs          = ipmi_ssif_dev_attrs,
1212 };
1213
1214 static void shutdown_ssif(void *send_info)
1215 {
1216         struct ssif_info *ssif_info = send_info;
1217
1218         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1219         dev_set_drvdata(&ssif_info->client->dev, NULL);
1220
1221         /* make sure the driver is not looking for flags any more. */
1222         while (ssif_info->ssif_state != SSIF_NORMAL)
1223                 schedule_timeout(1);
1224
1225         ssif_info->stopping = true;
1226         del_timer_sync(&ssif_info->retry_timer);
1227         if (ssif_info->thread) {
1228                 complete(&ssif_info->wake_thread);
1229                 kthread_stop(ssif_info->thread);
1230         }
1231 }
1232
1233 static int ssif_remove(struct i2c_client *client)
1234 {
1235         struct ssif_info *ssif_info = i2c_get_clientdata(client);
1236         struct ssif_addr_info *addr_info;
1237
1238         if (!ssif_info)
1239                 return 0;
1240
1241         /*
1242          * After this point, we won't deliver anything asychronously
1243          * to the message handler.  We can unregister ourself.
1244          */
1245         ipmi_unregister_smi(ssif_info->intf);
1246
1247         list_for_each_entry(addr_info, &ssif_infos, link) {
1248                 if (addr_info->client == client) {
1249                         addr_info->client = NULL;
1250                         break;
1251                 }
1252         }
1253
1254         kfree(ssif_info);
1255
1256         return 0;
1257 }
1258
1259 static int read_response(struct i2c_client *client, unsigned char *resp)
1260 {
1261         int ret = -ENODEV, retry_cnt = SSIF_RECV_RETRIES;
1262
1263         while (retry_cnt > 0) {
1264                 ret = i2c_smbus_read_block_data(client, SSIF_IPMI_RESPONSE,
1265                                                 resp);
1266                 if (ret > 0)
1267                         break;
1268                 msleep(SSIF_MSG_MSEC);
1269                 retry_cnt--;
1270                 if (retry_cnt <= 0)
1271                         break;
1272         }
1273
1274         return ret;
1275 }
1276
1277 static int do_cmd(struct i2c_client *client, int len, unsigned char *msg,
1278                   int *resp_len, unsigned char *resp)
1279 {
1280         int retry_cnt;
1281         int ret;
1282
1283         retry_cnt = SSIF_SEND_RETRIES;
1284  retry1:
1285         ret = i2c_smbus_write_block_data(client, SSIF_IPMI_REQUEST, len, msg);
1286         if (ret) {
1287                 retry_cnt--;
1288                 if (retry_cnt > 0)
1289                         goto retry1;
1290                 return -ENODEV;
1291         }
1292
1293         ret = read_response(client, resp);
1294         if (ret > 0) {
1295                 /* Validate that the response is correct. */
1296                 if (ret < 3 ||
1297                     (resp[0] != (msg[0] | (1 << 2))) ||
1298                     (resp[1] != msg[1]))
1299                         ret = -EINVAL;
1300                 else if (ret > IPMI_MAX_MSG_LENGTH) {
1301                         ret = -E2BIG;
1302                 } else {
1303                         *resp_len = ret;
1304                         ret = 0;
1305                 }
1306         }
1307
1308         return ret;
1309 }
1310
1311 static int ssif_detect(struct i2c_client *client, struct i2c_board_info *info)
1312 {
1313         unsigned char *resp;
1314         unsigned char msg[3];
1315         int           rv;
1316         int           len;
1317
1318         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1319         if (!resp)
1320                 return -ENOMEM;
1321
1322         /* Do a Get Device ID command, since it is required. */
1323         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1324         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1325         rv = do_cmd(client, 2, msg, &len, resp);
1326         if (rv)
1327                 rv = -ENODEV;
1328         else
1329                 strlcpy(info->type, DEVICE_NAME, I2C_NAME_SIZE);
1330         kfree(resp);
1331         return rv;
1332 }
1333
1334 static int strcmp_nospace(char *s1, char *s2)
1335 {
1336         while (*s1 && *s2) {
1337                 while (isspace(*s1))
1338                         s1++;
1339                 while (isspace(*s2))
1340                         s2++;
1341                 if (*s1 > *s2)
1342                         return 1;
1343                 if (*s1 < *s2)
1344                         return -1;
1345                 s1++;
1346                 s2++;
1347         }
1348         return 0;
1349 }
1350
1351 static struct ssif_addr_info *ssif_info_find(unsigned short addr,
1352                                              char *adapter_name,
1353                                              bool match_null_name)
1354 {
1355         struct ssif_addr_info *info, *found = NULL;
1356
1357 restart:
1358         list_for_each_entry(info, &ssif_infos, link) {
1359                 if (info->binfo.addr == addr) {
1360                         if (info->adapter_name || adapter_name) {
1361                                 if (!info->adapter_name != !adapter_name) {
1362                                         /* One is NULL and one is not */
1363                                         continue;
1364                                 }
1365                                 if (adapter_name &&
1366                                     strcmp_nospace(info->adapter_name,
1367                                                    adapter_name))
1368                                         /* Names do not match */
1369                                         continue;
1370                         }
1371                         found = info;
1372                         break;
1373                 }
1374         }
1375
1376         if (!found && match_null_name) {
1377                 /* Try to get an exact match first, then try with a NULL name */
1378                 adapter_name = NULL;
1379                 match_null_name = false;
1380                 goto restart;
1381         }
1382
1383         return found;
1384 }
1385
1386 static bool check_acpi(struct ssif_info *ssif_info, struct device *dev)
1387 {
1388 #ifdef CONFIG_ACPI
1389         acpi_handle acpi_handle;
1390
1391         acpi_handle = ACPI_HANDLE(dev);
1392         if (acpi_handle) {
1393                 ssif_info->addr_source = SI_ACPI;
1394                 ssif_info->addr_info.acpi_info.acpi_handle = acpi_handle;
1395                 return true;
1396         }
1397 #endif
1398         return false;
1399 }
1400
1401 static int find_slave_address(struct i2c_client *client, int slave_addr)
1402 {
1403 #ifdef CONFIG_IPMI_DMI_DECODE
1404         if (!slave_addr)
1405                 slave_addr = ipmi_dmi_get_slave_addr(
1406                         SI_TYPE_INVALID,
1407                         i2c_adapter_id(client->adapter),
1408                         client->addr);
1409 #endif
1410
1411         return slave_addr;
1412 }
1413
1414 static int start_multipart_test(struct i2c_client *client,
1415                                 unsigned char *msg, bool do_middle)
1416 {
1417         int retry_cnt = SSIF_SEND_RETRIES, ret;
1418
1419 retry_write:
1420         ret = i2c_smbus_write_block_data(client,
1421                                          SSIF_IPMI_MULTI_PART_REQUEST_START,
1422                                          32, msg);
1423         if (ret) {
1424                 retry_cnt--;
1425                 if (retry_cnt > 0)
1426                         goto retry_write;
1427                 dev_err(&client->dev, "Could not write multi-part start, though the BMC said it could handle it.  Just limit sends to one part.\n");
1428                 return ret;
1429         }
1430
1431         if (!do_middle)
1432                 return 0;
1433
1434         ret = i2c_smbus_write_block_data(client,
1435                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1436                                          32, msg + 32);
1437         if (ret) {
1438                 dev_err(&client->dev, "Could not write multi-part middle, though the BMC said it could handle it.  Just limit sends to one part.\n");
1439                 return ret;
1440         }
1441
1442         return 0;
1443 }
1444
1445 static void test_multipart_messages(struct i2c_client *client,
1446                                     struct ssif_info *ssif_info,
1447                                     unsigned char *resp)
1448 {
1449         unsigned char msg[65];
1450         int ret;
1451         bool do_middle;
1452
1453         if (ssif_info->max_xmit_msg_size <= 32)
1454                 return;
1455
1456         do_middle = ssif_info->max_xmit_msg_size > 63;
1457
1458         memset(msg, 0, sizeof(msg));
1459         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1460         msg[1] = IPMI_GET_DEVICE_ID_CMD;
1461
1462         /*
1463          * The specification is all messed up dealing with sending
1464          * multi-part messages.  Per what the specification says, it
1465          * is impossible to send a message that is a multiple of 32
1466          * bytes, except for 32 itself.  It talks about a "start"
1467          * transaction (cmd=6) that must be 32 bytes, "middle"
1468          * transaction (cmd=7) that must be 32 bytes, and an "end"
1469          * transaction.  The "end" transaction is shown as cmd=7 in
1470          * the text, but if that's the case there is no way to
1471          * differentiate between a middle and end part except the
1472          * length being less than 32.  But there is a table at the far
1473          * end of the section (that I had never noticed until someone
1474          * pointed it out to me) that mentions it as cmd=8.
1475          *
1476          * After some thought, I think the example is wrong and the
1477          * end transaction should be cmd=8.  But some systems don't
1478          * implement cmd=8, they use a zero-length end transaction,
1479          * even though that violates the SMBus specification.
1480          *
1481          * So, to work around this, this code tests if cmd=8 works.
1482          * If it does, then we use that.  If not, it tests zero-
1483          * byte end transactions.  If that works, good.  If not,
1484          * we only allow 63-byte transactions max.
1485          */
1486
1487         ret = start_multipart_test(client, msg, do_middle);
1488         if (ret)
1489                 goto out_no_multi_part;
1490
1491         ret = i2c_smbus_write_block_data(client,
1492                                          SSIF_IPMI_MULTI_PART_REQUEST_END,
1493                                          1, msg + 64);
1494
1495         if (!ret)
1496                 ret = read_response(client, resp);
1497
1498         if (ret > 0) {
1499                 /* End transactions work, we are good. */
1500                 ssif_info->cmd8_works = true;
1501                 return;
1502         }
1503
1504         ret = start_multipart_test(client, msg, do_middle);
1505         if (ret) {
1506                 dev_err(&client->dev, "Second multipart test failed.\n");
1507                 goto out_no_multi_part;
1508         }
1509
1510         ret = i2c_smbus_write_block_data(client,
1511                                          SSIF_IPMI_MULTI_PART_REQUEST_MIDDLE,
1512                                          0, msg + 64);
1513         if (!ret)
1514                 ret = read_response(client, resp);
1515         if (ret > 0)
1516                 /* Zero-size end parts work, use those. */
1517                 return;
1518
1519         /* Limit to 63 bytes and use a short middle command to mark the end. */
1520         if (ssif_info->max_xmit_msg_size > 63)
1521                 ssif_info->max_xmit_msg_size = 63;
1522         return;
1523
1524 out_no_multi_part:
1525         ssif_info->max_xmit_msg_size = 32;
1526         return;
1527 }
1528
1529 /*
1530  * Global enables we care about.
1531  */
1532 #define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
1533                              IPMI_BMC_EVT_MSG_INTR)
1534
1535 static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id)
1536 {
1537         unsigned char     msg[3];
1538         unsigned char     *resp;
1539         struct ssif_info   *ssif_info;
1540         int               rv = 0;
1541         int               len;
1542         int               i;
1543         u8                slave_addr = 0;
1544         struct ssif_addr_info *addr_info = NULL;
1545
1546         resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
1547         if (!resp)
1548                 return -ENOMEM;
1549
1550         ssif_info = kzalloc(sizeof(*ssif_info), GFP_KERNEL);
1551         if (!ssif_info) {
1552                 kfree(resp);
1553                 return -ENOMEM;
1554         }
1555
1556         if (!check_acpi(ssif_info, &client->dev)) {
1557                 addr_info = ssif_info_find(client->addr, client->adapter->name,
1558                                            true);
1559                 if (!addr_info) {
1560                         /* Must have come in through sysfs. */
1561                         ssif_info->addr_source = SI_HOTMOD;
1562                 } else {
1563                         ssif_info->addr_source = addr_info->addr_src;
1564                         ssif_info->ssif_debug = addr_info->debug;
1565                         ssif_info->addr_info = addr_info->addr_info;
1566                         addr_info->client = client;
1567                         slave_addr = addr_info->slave_addr;
1568                 }
1569         }
1570
1571         slave_addr = find_slave_address(client, slave_addr);
1572
1573         pr_info("Trying %s-specified SSIF interface at i2c address 0x%x, adapter %s, slave address 0x%x\n",
1574                 ipmi_addr_src_to_str(ssif_info->addr_source),
1575                 client->addr, client->adapter->name, slave_addr);
1576
1577         ssif_info->client = client;
1578         i2c_set_clientdata(client, ssif_info);
1579
1580         /* Now check for system interface capabilities */
1581         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1582         msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD;
1583         msg[2] = 0; /* SSIF */
1584         rv = do_cmd(client, 3, msg, &len, resp);
1585         if (!rv && (len >= 3) && (resp[2] == 0)) {
1586                 if (len < 7) {
1587                         if (ssif_dbg_probe)
1588                                 pr_info("SSIF info too short: %d\n", len);
1589                         goto no_support;
1590                 }
1591
1592                 /* Got a good SSIF response, handle it. */
1593                 ssif_info->max_xmit_msg_size = resp[5];
1594                 ssif_info->max_recv_msg_size = resp[6];
1595                 ssif_info->multi_support = (resp[4] >> 6) & 0x3;
1596                 ssif_info->supports_pec = (resp[4] >> 3) & 0x1;
1597
1598                 /* Sanitize the data */
1599                 switch (ssif_info->multi_support) {
1600                 case SSIF_NO_MULTI:
1601                         if (ssif_info->max_xmit_msg_size > 32)
1602                                 ssif_info->max_xmit_msg_size = 32;
1603                         if (ssif_info->max_recv_msg_size > 32)
1604                                 ssif_info->max_recv_msg_size = 32;
1605                         break;
1606
1607                 case SSIF_MULTI_2_PART:
1608                         if (ssif_info->max_xmit_msg_size > 63)
1609                                 ssif_info->max_xmit_msg_size = 63;
1610                         if (ssif_info->max_recv_msg_size > 62)
1611                                 ssif_info->max_recv_msg_size = 62;
1612                         break;
1613
1614                 case SSIF_MULTI_n_PART:
1615                         /* We take whatever size given, but do some testing. */
1616                         break;
1617
1618                 default:
1619                         /* Data is not sane, just give up. */
1620                         goto no_support;
1621                 }
1622         } else {
1623  no_support:
1624                 /* Assume no multi-part or PEC support */
1625                 pr_info("Error fetching SSIF: %d %d %2.2x, your system probably doesn't support this command so using defaults\n",
1626                         rv, len, resp[2]);
1627
1628                 ssif_info->max_xmit_msg_size = 32;
1629                 ssif_info->max_recv_msg_size = 32;
1630                 ssif_info->multi_support = SSIF_NO_MULTI;
1631                 ssif_info->supports_pec = 0;
1632         }
1633
1634         test_multipart_messages(client, ssif_info, resp);
1635
1636         /* Make sure the NMI timeout is cleared. */
1637         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1638         msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
1639         msg[2] = WDT_PRE_TIMEOUT_INT;
1640         rv = do_cmd(client, 3, msg, &len, resp);
1641         if (rv || (len < 3) || (resp[2] != 0))
1642                 pr_warn("Unable to clear message flags: %d %d %2.2x\n",
1643                         rv, len, resp[2]);
1644
1645         /* Attempt to enable the event buffer. */
1646         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1647         msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
1648         rv = do_cmd(client, 2, msg, &len, resp);
1649         if (rv || (len < 4) || (resp[2] != 0)) {
1650                 pr_warn("Error getting global enables: %d %d %2.2x\n",
1651                         rv, len, resp[2]);
1652                 rv = 0; /* Not fatal */
1653                 goto found;
1654         }
1655
1656         ssif_info->global_enables = resp[3];
1657
1658         if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
1659                 ssif_info->has_event_buffer = true;
1660                 /* buffer is already enabled, nothing to do. */
1661                 goto found;
1662         }
1663
1664         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1665         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1666         msg[2] = ssif_info->global_enables | IPMI_BMC_EVT_MSG_BUFF;
1667         rv = do_cmd(client, 3, msg, &len, resp);
1668         if (rv || (len < 2)) {
1669                 pr_warn("Error setting global enables: %d %d %2.2x\n",
1670                         rv, len, resp[2]);
1671                 rv = 0; /* Not fatal */
1672                 goto found;
1673         }
1674
1675         if (resp[2] == 0) {
1676                 /* A successful return means the event buffer is supported. */
1677                 ssif_info->has_event_buffer = true;
1678                 ssif_info->global_enables |= IPMI_BMC_EVT_MSG_BUFF;
1679         }
1680
1681         /* Some systems don't behave well if you enable alerts. */
1682         if (alerts_broken)
1683                 goto found;
1684
1685         msg[0] = IPMI_NETFN_APP_REQUEST << 2;
1686         msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
1687         msg[2] = ssif_info->global_enables | IPMI_BMC_RCV_MSG_INTR;
1688         rv = do_cmd(client, 3, msg, &len, resp);
1689         if (rv || (len < 2)) {
1690                 pr_warn("Error setting global enables: %d %d %2.2x\n",
1691                         rv, len, resp[2]);
1692                 rv = 0; /* Not fatal */
1693                 goto found;
1694         }
1695
1696         if (resp[2] == 0) {
1697                 /* A successful return means the alert is supported. */
1698                 ssif_info->supports_alert = true;
1699                 ssif_info->global_enables |= IPMI_BMC_RCV_MSG_INTR;
1700         }
1701
1702  found:
1703         if (ssif_dbg_probe) {
1704                 pr_info("ssif_probe: i2c_probe found device at i2c address %x\n",
1705                         client->addr);
1706         }
1707
1708         spin_lock_init(&ssif_info->lock);
1709         ssif_info->ssif_state = SSIF_NORMAL;
1710         timer_setup(&ssif_info->retry_timer, retry_timeout, 0);
1711
1712         for (i = 0; i < SSIF_NUM_STATS; i++)
1713                 atomic_set(&ssif_info->stats[i], 0);
1714
1715         if (ssif_info->supports_pec)
1716                 ssif_info->client->flags |= I2C_CLIENT_PEC;
1717
1718         ssif_info->handlers.owner = THIS_MODULE;
1719         ssif_info->handlers.start_processing = ssif_start_processing;
1720         ssif_info->handlers.shutdown = shutdown_ssif;
1721         ssif_info->handlers.get_smi_info = get_smi_info;
1722         ssif_info->handlers.sender = sender;
1723         ssif_info->handlers.request_events = request_events;
1724
1725         {
1726                 unsigned int thread_num;
1727
1728                 thread_num = ((i2c_adapter_id(ssif_info->client->adapter)
1729                                << 8) |
1730                               ssif_info->client->addr);
1731                 init_completion(&ssif_info->wake_thread);
1732                 ssif_info->thread = kthread_run(ipmi_ssif_thread, ssif_info,
1733                                                "kssif%4.4x", thread_num);
1734                 if (IS_ERR(ssif_info->thread)) {
1735                         rv = PTR_ERR(ssif_info->thread);
1736                         dev_notice(&ssif_info->client->dev,
1737                                    "Could not start kernel thread: error %d\n",
1738                                    rv);
1739                         goto out;
1740                 }
1741         }
1742
1743         dev_set_drvdata(&ssif_info->client->dev, ssif_info);
1744         rv = device_add_group(&ssif_info->client->dev,
1745                               &ipmi_ssif_dev_attr_group);
1746         if (rv) {
1747                 dev_err(&ssif_info->client->dev,
1748                         "Unable to add device attributes: error %d\n",
1749                         rv);
1750                 goto out;
1751         }
1752
1753         rv = ipmi_register_smi(&ssif_info->handlers,
1754                                ssif_info,
1755                                &ssif_info->client->dev,
1756                                slave_addr);
1757          if (rv) {
1758                 pr_err("Unable to register device: error %d\n", rv);
1759                 goto out_remove_attr;
1760         }
1761
1762  out:
1763         if (rv) {
1764                 if (addr_info)
1765                         addr_info->client = NULL;
1766
1767                 dev_err(&client->dev, "Unable to start IPMI SSIF: %d\n", rv);
1768                 kfree(ssif_info);
1769         }
1770         kfree(resp);
1771         return rv;
1772
1773 out_remove_attr:
1774         device_remove_group(&ssif_info->client->dev, &ipmi_ssif_dev_attr_group);
1775         dev_set_drvdata(&ssif_info->client->dev, NULL);
1776         goto out;
1777 }
1778
1779 static int ssif_adapter_handler(struct device *adev, void *opaque)
1780 {
1781         struct ssif_addr_info *addr_info = opaque;
1782
1783         if (adev->type != &i2c_adapter_type)
1784                 return 0;
1785
1786         addr_info->added_client = i2c_new_device(to_i2c_adapter(adev),
1787                                                  &addr_info->binfo);
1788
1789         if (!addr_info->adapter_name)
1790                 return 1; /* Only try the first I2C adapter by default. */
1791         return 0;
1792 }
1793
1794 static int new_ssif_client(int addr, char *adapter_name,
1795                            int debug, int slave_addr,
1796                            enum ipmi_addr_src addr_src,
1797                            struct device *dev)
1798 {
1799         struct ssif_addr_info *addr_info;
1800         int rv = 0;
1801
1802         mutex_lock(&ssif_infos_mutex);
1803         if (ssif_info_find(addr, adapter_name, false)) {
1804                 rv = -EEXIST;
1805                 goto out_unlock;
1806         }
1807
1808         addr_info = kzalloc(sizeof(*addr_info), GFP_KERNEL);
1809         if (!addr_info) {
1810                 rv = -ENOMEM;
1811                 goto out_unlock;
1812         }
1813
1814         if (adapter_name) {
1815                 addr_info->adapter_name = kstrdup(adapter_name, GFP_KERNEL);
1816                 if (!addr_info->adapter_name) {
1817                         kfree(addr_info);
1818                         rv = -ENOMEM;
1819                         goto out_unlock;
1820                 }
1821         }
1822
1823         strncpy(addr_info->binfo.type, DEVICE_NAME,
1824                 sizeof(addr_info->binfo.type));
1825         addr_info->binfo.addr = addr;
1826         addr_info->binfo.platform_data = addr_info;
1827         addr_info->debug = debug;
1828         addr_info->slave_addr = slave_addr;
1829         addr_info->addr_src = addr_src;
1830         addr_info->dev = dev;
1831
1832         if (dev)
1833                 dev_set_drvdata(dev, addr_info);
1834
1835         list_add_tail(&addr_info->link, &ssif_infos);
1836
1837         if (initialized)
1838                 i2c_for_each_dev(addr_info, ssif_adapter_handler);
1839         /* Otherwise address list will get it */
1840
1841 out_unlock:
1842         mutex_unlock(&ssif_infos_mutex);
1843         return rv;
1844 }
1845
1846 static void free_ssif_clients(void)
1847 {
1848         struct ssif_addr_info *info, *tmp;
1849
1850         mutex_lock(&ssif_infos_mutex);
1851         list_for_each_entry_safe(info, tmp, &ssif_infos, link) {
1852                 list_del(&info->link);
1853                 kfree(info->adapter_name);
1854                 kfree(info);
1855         }
1856         mutex_unlock(&ssif_infos_mutex);
1857 }
1858
1859 static unsigned short *ssif_address_list(void)
1860 {
1861         struct ssif_addr_info *info;
1862         unsigned int count = 0, i = 0;
1863         unsigned short *address_list;
1864
1865         list_for_each_entry(info, &ssif_infos, link)
1866                 count++;
1867
1868         address_list = kcalloc(count + 1, sizeof(*address_list),
1869                                GFP_KERNEL);
1870         if (!address_list)
1871                 return NULL;
1872
1873         list_for_each_entry(info, &ssif_infos, link) {
1874                 unsigned short addr = info->binfo.addr;
1875                 int j;
1876
1877                 for (j = 0; j < i; j++) {
1878                         if (address_list[j] == addr)
1879                                 /* Found a dup. */
1880                                 break;
1881                 }
1882                 if (j == i) /* Didn't find it in the list. */
1883                         address_list[i++] = addr;
1884         }
1885         address_list[i] = I2C_CLIENT_END;
1886
1887         return address_list;
1888 }
1889
1890 #ifdef CONFIG_ACPI
1891 static const struct acpi_device_id ssif_acpi_match[] = {
1892         { "IPI0001", 0 },
1893         { },
1894 };
1895 MODULE_DEVICE_TABLE(acpi, ssif_acpi_match);
1896 #endif
1897
1898 #ifdef CONFIG_DMI
1899 static int dmi_ipmi_probe(struct platform_device *pdev)
1900 {
1901         u8 slave_addr = 0;
1902         u16 i2c_addr;
1903         int rv;
1904
1905         if (!ssif_trydmi)
1906                 return -ENODEV;
1907
1908         rv = device_property_read_u16(&pdev->dev, "i2c-addr", &i2c_addr);
1909         if (rv) {
1910                 dev_warn(&pdev->dev, "No i2c-addr property\n");
1911                 return -ENODEV;
1912         }
1913
1914         rv = device_property_read_u8(&pdev->dev, "slave-addr", &slave_addr);
1915         if (rv)
1916                 dev_warn(&pdev->dev, "device has no slave-addr property");
1917
1918         return new_ssif_client(i2c_addr, NULL, 0,
1919                                slave_addr, SI_SMBIOS, &pdev->dev);
1920 }
1921 #else
1922 static int dmi_ipmi_probe(struct platform_device *pdev)
1923 {
1924         return -ENODEV;
1925 }
1926 #endif
1927
1928 static const struct i2c_device_id ssif_id[] = {
1929         { DEVICE_NAME, 0 },
1930         { }
1931 };
1932 MODULE_DEVICE_TABLE(i2c, ssif_id);
1933
1934 static struct i2c_driver ssif_i2c_driver = {
1935         .class          = I2C_CLASS_HWMON,
1936         .driver         = {
1937                 .name                   = DEVICE_NAME
1938         },
1939         .probe          = ssif_probe,
1940         .remove         = ssif_remove,
1941         .alert          = ssif_alert,
1942         .id_table       = ssif_id,
1943         .detect         = ssif_detect
1944 };
1945
1946 static int ssif_platform_probe(struct platform_device *dev)
1947 {
1948         return dmi_ipmi_probe(dev);
1949 }
1950
1951 static int ssif_platform_remove(struct platform_device *dev)
1952 {
1953         struct ssif_addr_info *addr_info = dev_get_drvdata(&dev->dev);
1954
1955         if (!addr_info)
1956                 return 0;
1957
1958         mutex_lock(&ssif_infos_mutex);
1959         i2c_unregister_device(addr_info->added_client);
1960
1961         list_del(&addr_info->link);
1962         kfree(addr_info);
1963         mutex_unlock(&ssif_infos_mutex);
1964         return 0;
1965 }
1966
1967 static const struct platform_device_id ssif_plat_ids[] = {
1968     { "dmi-ipmi-ssif", 0 },
1969     { }
1970 };
1971
1972 static struct platform_driver ipmi_driver = {
1973         .driver = {
1974                 .name = DEVICE_NAME,
1975         },
1976         .probe          = ssif_platform_probe,
1977         .remove         = ssif_platform_remove,
1978         .id_table       = ssif_plat_ids
1979 };
1980
1981 static int init_ipmi_ssif(void)
1982 {
1983         int i;
1984         int rv;
1985
1986         if (initialized)
1987                 return 0;
1988
1989         pr_info("IPMI SSIF Interface driver\n");
1990
1991         /* build list for i2c from addr list */
1992         for (i = 0; i < num_addrs; i++) {
1993                 rv = new_ssif_client(addr[i], adapter_name[i],
1994                                      dbg[i], slave_addrs[i],
1995                                      SI_HARDCODED, NULL);
1996                 if (rv)
1997                         pr_err("Couldn't add hardcoded device at addr 0x%x\n",
1998                                addr[i]);
1999         }
2000
2001         if (ssif_tryacpi)
2002                 ssif_i2c_driver.driver.acpi_match_table =
2003                         ACPI_PTR(ssif_acpi_match);
2004
2005         if (ssif_trydmi) {
2006                 rv = platform_driver_register(&ipmi_driver);
2007                 if (rv)
2008                         pr_err("Unable to register driver: %d\n", rv);
2009         }
2010
2011         ssif_i2c_driver.address_list = ssif_address_list();
2012
2013         rv = i2c_add_driver(&ssif_i2c_driver);
2014         if (!rv)
2015                 initialized = true;
2016
2017         return rv;
2018 }
2019 module_init(init_ipmi_ssif);
2020
2021 static void cleanup_ipmi_ssif(void)
2022 {
2023         if (!initialized)
2024                 return;
2025
2026         initialized = false;
2027
2028         i2c_del_driver(&ssif_i2c_driver);
2029
2030         kfree(ssif_i2c_driver.address_list);
2031
2032         platform_driver_unregister(&ipmi_driver);
2033
2034         free_ssif_clients();
2035 }
2036 module_exit(cleanup_ipmi_ssif);
2037
2038 MODULE_ALIAS("platform:dmi-ipmi-ssif");
2039 MODULE_AUTHOR("Todd C Davis <todd.c.davis@intel.com>, Corey Minyard <minyard@acm.org>");
2040 MODULE_DESCRIPTION("IPMI driver for management controllers on a SMBus");
2041 MODULE_LICENSE("GPL");