linux/drivers/acpi/ec.c
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   1/*
   2 *  ec.c - ACPI Embedded Controller Driver (v2.1)
   3 *
   4 *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
   5 *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
   6 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   7 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   8 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   9 *
  10 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11 *
  12 *  This program is free software; you can redistribute it and/or modify
  13 *  it under the terms of the GNU General Public License as published by
  14 *  the Free Software Foundation; either version 2 of the License, or (at
  15 *  your option) any later version.
  16 *
  17 *  This program is distributed in the hope that it will be useful, but
  18 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 *  General Public License for more details.
  21 *
  22 *  You should have received a copy of the GNU General Public License along
  23 *  with this program; if not, write to the Free Software Foundation, Inc.,
  24 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25 *
  26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27 */
  28
  29/* Uncomment next line to get verbose printout */
  30/* #define DEBUG */
  31
  32#include <linux/kernel.h>
  33#include <linux/module.h>
  34#include <linux/init.h>
  35#include <linux/types.h>
  36#include <linux/delay.h>
  37#include <linux/interrupt.h>
  38#include <linux/list.h>
  39#include <linux/spinlock.h>
  40#include <linux/slab.h>
  41#include <asm/io.h>
  42#include <acpi/acpi_bus.h>
  43#include <acpi/acpi_drivers.h>
  44#include <linux/dmi.h>
  45
  46#include "internal.h"
  47
  48#define ACPI_EC_CLASS                   "embedded_controller"
  49#define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  50#define ACPI_EC_FILE_INFO               "info"
  51
  52#undef PREFIX
  53#define PREFIX                          "ACPI: EC: "
  54
  55/* EC status register */
  56#define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  57#define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  58#define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  59#define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  60
  61/* EC commands */
  62enum ec_command {
  63        ACPI_EC_COMMAND_READ = 0x80,
  64        ACPI_EC_COMMAND_WRITE = 0x81,
  65        ACPI_EC_BURST_ENABLE = 0x82,
  66        ACPI_EC_BURST_DISABLE = 0x83,
  67        ACPI_EC_COMMAND_QUERY = 0x84,
  68};
  69
  70#define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  71#define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  72#define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
  73
  74enum {
  75        EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  76        EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  77        EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
  78                                         * OpReg are installed */
  79        EC_FLAGS_BLOCKED,               /* Transactions are blocked */
  80};
  81
  82/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
  83static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
  84module_param(ec_delay, uint, 0644);
  85MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
  86
  87/*
  88 * If the number of false interrupts per one transaction exceeds
  89 * this threshold, will think there is a GPE storm happened and
  90 * will disable the GPE for normal transaction.
  91 */
  92static unsigned int ec_storm_threshold  __read_mostly = 8;
  93module_param(ec_storm_threshold, uint, 0644);
  94MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
  95
  96/* If we find an EC via the ECDT, we need to keep a ptr to its context */
  97/* External interfaces use first EC only, so remember */
  98typedef int (*acpi_ec_query_func) (void *data);
  99
 100struct acpi_ec_query_handler {
 101        struct list_head node;
 102        acpi_ec_query_func func;
 103        acpi_handle handle;
 104        void *data;
 105        u8 query_bit;
 106};
 107
 108struct transaction {
 109        const u8 *wdata;
 110        u8 *rdata;
 111        unsigned short irq_count;
 112        u8 command;
 113        u8 wi;
 114        u8 ri;
 115        u8 wlen;
 116        u8 rlen;
 117        bool done;
 118};
 119
 120struct acpi_ec *boot_ec, *first_ec;
 121EXPORT_SYMBOL(first_ec);
 122
 123static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 124static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
 125static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
 126
 127/* --------------------------------------------------------------------------
 128                             Transaction Management
 129   -------------------------------------------------------------------------- */
 130
 131static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 132{
 133        u8 x = inb(ec->command_addr);
 134        pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 135        return x;
 136}
 137
 138static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 139{
 140        u8 x = inb(ec->data_addr);
 141        pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 142        return x;
 143}
 144
 145static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 146{
 147        pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 148        outb(command, ec->command_addr);
 149}
 150
 151static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 152{
 153        pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 154        outb(data, ec->data_addr);
 155}
 156
 157static int ec_transaction_done(struct acpi_ec *ec)
 158{
 159        unsigned long flags;
 160        int ret = 0;
 161        spin_lock_irqsave(&ec->lock, flags);
 162        if (!ec->curr || ec->curr->done)
 163                ret = 1;
 164        spin_unlock_irqrestore(&ec->lock, flags);
 165        return ret;
 166}
 167
 168static void start_transaction(struct acpi_ec *ec)
 169{
 170        ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 171        ec->curr->done = false;
 172        acpi_ec_write_cmd(ec, ec->curr->command);
 173}
 174
 175static void advance_transaction(struct acpi_ec *ec, u8 status)
 176{
 177        unsigned long flags;
 178        struct transaction *t = ec->curr;
 179
 180        spin_lock_irqsave(&ec->lock, flags);
 181        if (!t)
 182                goto unlock;
 183        if (t->wlen > t->wi) {
 184                if ((status & ACPI_EC_FLAG_IBF) == 0)
 185                        acpi_ec_write_data(ec,
 186                                t->wdata[t->wi++]);
 187                else
 188                        goto err;
 189        } else if (t->rlen > t->ri) {
 190                if ((status & ACPI_EC_FLAG_OBF) == 1) {
 191                        t->rdata[t->ri++] = acpi_ec_read_data(ec);
 192                        if (t->rlen == t->ri)
 193                                t->done = true;
 194                } else
 195                        goto err;
 196        } else if (t->wlen == t->wi &&
 197                   (status & ACPI_EC_FLAG_IBF) == 0)
 198                t->done = true;
 199        goto unlock;
 200err:
 201        /*
 202         * If SCI bit is set, then don't think it's a false IRQ
 203         * otherwise will take a not handled IRQ as a false one.
 204         */
 205        if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
 206                ++t->irq_count;
 207
 208unlock:
 209        spin_unlock_irqrestore(&ec->lock, flags);
 210}
 211
 212static int acpi_ec_sync_query(struct acpi_ec *ec);
 213
 214static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
 215{
 216        if (state & ACPI_EC_FLAG_SCI) {
 217                if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 218                        return acpi_ec_sync_query(ec);
 219        }
 220        return 0;
 221}
 222
 223static int ec_poll(struct acpi_ec *ec)
 224{
 225        unsigned long flags;
 226        int repeat = 2; /* number of command restarts */
 227        while (repeat--) {
 228                unsigned long delay = jiffies +
 229                        msecs_to_jiffies(ec_delay);
 230                do {
 231                        /* don't sleep with disabled interrupts */
 232                        if (EC_FLAGS_MSI || irqs_disabled()) {
 233                                udelay(ACPI_EC_MSI_UDELAY);
 234                                if (ec_transaction_done(ec))
 235                                        return 0;
 236                        } else {
 237                                if (wait_event_timeout(ec->wait,
 238                                                ec_transaction_done(ec),
 239                                                msecs_to_jiffies(1)))
 240                                        return 0;
 241                        }
 242                        advance_transaction(ec, acpi_ec_read_status(ec));
 243                } while (time_before(jiffies, delay));
 244                if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
 245                        break;
 246                pr_debug(PREFIX "controller reset, restart transaction\n");
 247                spin_lock_irqsave(&ec->lock, flags);
 248                start_transaction(ec);
 249                spin_unlock_irqrestore(&ec->lock, flags);
 250        }
 251        return -ETIME;
 252}
 253
 254static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 255                                        struct transaction *t)
 256{
 257        unsigned long tmp;
 258        int ret = 0;
 259        if (EC_FLAGS_MSI)
 260                udelay(ACPI_EC_MSI_UDELAY);
 261        /* start transaction */
 262        spin_lock_irqsave(&ec->lock, tmp);
 263        /* following two actions should be kept atomic */
 264        ec->curr = t;
 265        start_transaction(ec);
 266        if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 267                clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 268        spin_unlock_irqrestore(&ec->lock, tmp);
 269        ret = ec_poll(ec);
 270        spin_lock_irqsave(&ec->lock, tmp);
 271        ec->curr = NULL;
 272        spin_unlock_irqrestore(&ec->lock, tmp);
 273        return ret;
 274}
 275
 276static int ec_check_ibf0(struct acpi_ec *ec)
 277{
 278        u8 status = acpi_ec_read_status(ec);
 279        return (status & ACPI_EC_FLAG_IBF) == 0;
 280}
 281
 282static int ec_wait_ibf0(struct acpi_ec *ec)
 283{
 284        unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
 285        /* interrupt wait manually if GPE mode is not active */
 286        while (time_before(jiffies, delay))
 287                if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
 288                                        msecs_to_jiffies(1)))
 289                        return 0;
 290        return -ETIME;
 291}
 292
 293static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
 294{
 295        int status;
 296        u32 glk;
 297        if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 298                return -EINVAL;
 299        if (t->rdata)
 300                memset(t->rdata, 0, t->rlen);
 301        mutex_lock(&ec->mutex);
 302        if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
 303                status = -EINVAL;
 304                goto unlock;
 305        }
 306        if (ec->global_lock) {
 307                status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 308                if (ACPI_FAILURE(status)) {
 309                        status = -ENODEV;
 310                        goto unlock;
 311                }
 312        }
 313        if (ec_wait_ibf0(ec)) {
 314                pr_err(PREFIX "input buffer is not empty, "
 315                                "aborting transaction\n");
 316                status = -ETIME;
 317                goto end;
 318        }
 319        pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n",
 320                        t->command, t->wdata ? t->wdata[0] : 0);
 321        /* disable GPE during transaction if storm is detected */
 322        if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 323                /* It has to be disabled, so that it doesn't trigger. */
 324                acpi_disable_gpe(NULL, ec->gpe);
 325        }
 326
 327        status = acpi_ec_transaction_unlocked(ec, t);
 328
 329        /* check if we received SCI during transaction */
 330        ec_check_sci_sync(ec, acpi_ec_read_status(ec));
 331        if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 332                msleep(1);
 333                /* It is safe to enable the GPE outside of the transaction. */
 334                acpi_enable_gpe(NULL, ec->gpe);
 335        } else if (t->irq_count > ec_storm_threshold) {
 336                pr_info(PREFIX "GPE storm detected(%d GPEs), "
 337                        "transactions will use polling mode\n",
 338                        t->irq_count);
 339                set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 340        }
 341        pr_debug(PREFIX "transaction end\n");
 342end:
 343        if (ec->global_lock)
 344                acpi_release_global_lock(glk);
 345unlock:
 346        mutex_unlock(&ec->mutex);
 347        return status;
 348}
 349
 350static int acpi_ec_burst_enable(struct acpi_ec *ec)
 351{
 352        u8 d;
 353        struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 354                                .wdata = NULL, .rdata = &d,
 355                                .wlen = 0, .rlen = 1};
 356
 357        return acpi_ec_transaction(ec, &t);
 358}
 359
 360static int acpi_ec_burst_disable(struct acpi_ec *ec)
 361{
 362        struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 363                                .wdata = NULL, .rdata = NULL,
 364                                .wlen = 0, .rlen = 0};
 365
 366        return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 367                                acpi_ec_transaction(ec, &t) : 0;
 368}
 369
 370static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 371{
 372        int result;
 373        u8 d;
 374        struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 375                                .wdata = &address, .rdata = &d,
 376                                .wlen = 1, .rlen = 1};
 377
 378        result = acpi_ec_transaction(ec, &t);
 379        *data = d;
 380        return result;
 381}
 382
 383static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 384{
 385        u8 wdata[2] = { address, data };
 386        struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 387                                .wdata = wdata, .rdata = NULL,
 388                                .wlen = 2, .rlen = 0};
 389
 390        return acpi_ec_transaction(ec, &t);
 391}
 392
 393/*
 394 * Externally callable EC access functions. For now, assume 1 EC only
 395 */
 396int ec_burst_enable(void)
 397{
 398        if (!first_ec)
 399                return -ENODEV;
 400        return acpi_ec_burst_enable(first_ec);
 401}
 402
 403EXPORT_SYMBOL(ec_burst_enable);
 404
 405int ec_burst_disable(void)
 406{
 407        if (!first_ec)
 408                return -ENODEV;
 409        return acpi_ec_burst_disable(first_ec);
 410}
 411
 412EXPORT_SYMBOL(ec_burst_disable);
 413
 414int ec_read(u8 addr, u8 *val)
 415{
 416        int err;
 417        u8 temp_data;
 418
 419        if (!first_ec)
 420                return -ENODEV;
 421
 422        err = acpi_ec_read(first_ec, addr, &temp_data);
 423
 424        if (!err) {
 425                *val = temp_data;
 426                return 0;
 427        } else
 428                return err;
 429}
 430
 431EXPORT_SYMBOL(ec_read);
 432
 433int ec_write(u8 addr, u8 val)
 434{
 435        int err;
 436
 437        if (!first_ec)
 438                return -ENODEV;
 439
 440        err = acpi_ec_write(first_ec, addr, val);
 441
 442        return err;
 443}
 444
 445EXPORT_SYMBOL(ec_write);
 446
 447int ec_transaction(u8 command,
 448                   const u8 * wdata, unsigned wdata_len,
 449                   u8 * rdata, unsigned rdata_len)
 450{
 451        struct transaction t = {.command = command,
 452                                .wdata = wdata, .rdata = rdata,
 453                                .wlen = wdata_len, .rlen = rdata_len};
 454        if (!first_ec)
 455                return -ENODEV;
 456
 457        return acpi_ec_transaction(first_ec, &t);
 458}
 459
 460EXPORT_SYMBOL(ec_transaction);
 461
 462/* Get the handle to the EC device */
 463acpi_handle ec_get_handle(void)
 464{
 465        if (!first_ec)
 466                return NULL;
 467        return first_ec->handle;
 468}
 469
 470EXPORT_SYMBOL(ec_get_handle);
 471
 472void acpi_ec_block_transactions(void)
 473{
 474        struct acpi_ec *ec = first_ec;
 475
 476        if (!ec)
 477                return;
 478
 479        mutex_lock(&ec->mutex);
 480        /* Prevent transactions from being carried out */
 481        set_bit(EC_FLAGS_BLOCKED, &ec->flags);
 482        mutex_unlock(&ec->mutex);
 483}
 484
 485void acpi_ec_unblock_transactions(void)
 486{
 487        struct acpi_ec *ec = first_ec;
 488
 489        if (!ec)
 490                return;
 491
 492        mutex_lock(&ec->mutex);
 493        /* Allow transactions to be carried out again */
 494        clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
 495        mutex_unlock(&ec->mutex);
 496}
 497
 498void acpi_ec_unblock_transactions_early(void)
 499{
 500        /*
 501         * Allow transactions to happen again (this function is called from
 502         * atomic context during wakeup, so we don't need to acquire the mutex).
 503         */
 504        if (first_ec)
 505                clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
 506}
 507
 508static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
 509{
 510        int result;
 511        u8 d;
 512        struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 513                                .wdata = NULL, .rdata = &d,
 514                                .wlen = 0, .rlen = 1};
 515        if (!ec || !data)
 516                return -EINVAL;
 517        /*
 518         * Query the EC to find out which _Qxx method we need to evaluate.
 519         * Note that successful completion of the query causes the ACPI_EC_SCI
 520         * bit to be cleared (and thus clearing the interrupt source).
 521         */
 522        result = acpi_ec_transaction_unlocked(ec, &t);
 523        if (result)
 524                return result;
 525        if (!d)
 526                return -ENODATA;
 527        *data = d;
 528        return 0;
 529}
 530
 531/* --------------------------------------------------------------------------
 532                                Event Management
 533   -------------------------------------------------------------------------- */
 534int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 535                              acpi_handle handle, acpi_ec_query_func func,
 536                              void *data)
 537{
 538        struct acpi_ec_query_handler *handler =
 539            kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 540        if (!handler)
 541                return -ENOMEM;
 542
 543        handler->query_bit = query_bit;
 544        handler->handle = handle;
 545        handler->func = func;
 546        handler->data = data;
 547        mutex_lock(&ec->mutex);
 548        list_add(&handler->node, &ec->list);
 549        mutex_unlock(&ec->mutex);
 550        return 0;
 551}
 552
 553EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 554
 555void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 556{
 557        struct acpi_ec_query_handler *handler, *tmp;
 558        mutex_lock(&ec->mutex);
 559        list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 560                if (query_bit == handler->query_bit) {
 561                        list_del(&handler->node);
 562                        kfree(handler);
 563                }
 564        }
 565        mutex_unlock(&ec->mutex);
 566}
 567
 568EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 569
 570static void acpi_ec_run(void *cxt)
 571{
 572        struct acpi_ec_query_handler *handler = cxt;
 573        if (!handler)
 574                return;
 575        pr_debug(PREFIX "start query execution\n");
 576        if (handler->func)
 577                handler->func(handler->data);
 578        else if (handler->handle)
 579                acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
 580        pr_debug(PREFIX "stop query execution\n");
 581        kfree(handler);
 582}
 583
 584static int acpi_ec_sync_query(struct acpi_ec *ec)
 585{
 586        u8 value = 0;
 587        int status;
 588        struct acpi_ec_query_handler *handler, *copy;
 589        if ((status = acpi_ec_query_unlocked(ec, &value)))
 590                return status;
 591        list_for_each_entry(handler, &ec->list, node) {
 592                if (value == handler->query_bit) {
 593                        /* have custom handler for this bit */
 594                        copy = kmalloc(sizeof(*handler), GFP_KERNEL);
 595                        if (!copy)
 596                                return -ENOMEM;
 597                        memcpy(copy, handler, sizeof(*copy));
 598                        pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value);
 599                        return acpi_os_execute((copy->func) ?
 600                                OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
 601                                acpi_ec_run, copy);
 602                }
 603        }
 604        return 0;
 605}
 606
 607static void acpi_ec_gpe_query(void *ec_cxt)
 608{
 609        struct acpi_ec *ec = ec_cxt;
 610        if (!ec)
 611                return;
 612        mutex_lock(&ec->mutex);
 613        acpi_ec_sync_query(ec);
 614        mutex_unlock(&ec->mutex);
 615}
 616
 617static int ec_check_sci(struct acpi_ec *ec, u8 state)
 618{
 619        if (state & ACPI_EC_FLAG_SCI) {
 620                if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
 621                        pr_debug(PREFIX "push gpe query to the queue\n");
 622                        return acpi_os_execute(OSL_NOTIFY_HANDLER,
 623                                acpi_ec_gpe_query, ec);
 624                }
 625        }
 626        return 0;
 627}
 628
 629static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
 630        u32 gpe_number, void *data)
 631{
 632        struct acpi_ec *ec = data;
 633        u8 status = acpi_ec_read_status(ec);
 634
 635        pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status);
 636
 637        advance_transaction(ec, status);
 638        if (ec_transaction_done(ec) &&
 639            (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 640                wake_up(&ec->wait);
 641                ec_check_sci(ec, acpi_ec_read_status(ec));
 642        }
 643        return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 644}
 645
 646/* --------------------------------------------------------------------------
 647                             Address Space Management
 648   -------------------------------------------------------------------------- */
 649
 650static acpi_status
 651acpi_ec_space_handler(u32 function, acpi_physical_address address,
 652                      u32 bits, u64 *value64,
 653                      void *handler_context, void *region_context)
 654{
 655        struct acpi_ec *ec = handler_context;
 656        int result = 0, i, bytes = bits / 8;
 657        u8 *value = (u8 *)value64;
 658
 659        if ((address > 0xFF) || !value || !handler_context)
 660                return AE_BAD_PARAMETER;
 661
 662        if (function != ACPI_READ && function != ACPI_WRITE)
 663                return AE_BAD_PARAMETER;
 664
 665        if (EC_FLAGS_MSI || bits > 8)
 666                acpi_ec_burst_enable(ec);
 667
 668        for (i = 0; i < bytes; ++i, ++address, ++value)
 669                result = (function == ACPI_READ) ?
 670                        acpi_ec_read(ec, address, value) :
 671                        acpi_ec_write(ec, address, *value);
 672
 673        if (EC_FLAGS_MSI || bits > 8)
 674                acpi_ec_burst_disable(ec);
 675
 676        switch (result) {
 677        case -EINVAL:
 678                return AE_BAD_PARAMETER;
 679                break;
 680        case -ENODEV:
 681                return AE_NOT_FOUND;
 682                break;
 683        case -ETIME:
 684                return AE_TIME;
 685                break;
 686        default:
 687                return AE_OK;
 688        }
 689}
 690
 691/* --------------------------------------------------------------------------
 692                               Driver Interface
 693   -------------------------------------------------------------------------- */
 694static acpi_status
 695ec_parse_io_ports(struct acpi_resource *resource, void *context);
 696
 697static struct acpi_ec *make_acpi_ec(void)
 698{
 699        struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 700        if (!ec)
 701                return NULL;
 702        ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 703        mutex_init(&ec->mutex);
 704        init_waitqueue_head(&ec->wait);
 705        INIT_LIST_HEAD(&ec->list);
 706        spin_lock_init(&ec->lock);
 707        return ec;
 708}
 709
 710static acpi_status
 711acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 712                               void *context, void **return_value)
 713{
 714        char node_name[5];
 715        struct acpi_buffer buffer = { sizeof(node_name), node_name };
 716        struct acpi_ec *ec = context;
 717        int value = 0;
 718        acpi_status status;
 719
 720        status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 721
 722        if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 723                acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 724        }
 725        return AE_OK;
 726}
 727
 728static acpi_status
 729ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 730{
 731        acpi_status status;
 732        unsigned long long tmp = 0;
 733
 734        struct acpi_ec *ec = context;
 735
 736        /* clear addr values, ec_parse_io_ports depend on it */
 737        ec->command_addr = ec->data_addr = 0;
 738
 739        status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 740                                     ec_parse_io_ports, ec);
 741        if (ACPI_FAILURE(status))
 742                return status;
 743
 744        /* Get GPE bit assignment (EC events). */
 745        /* TODO: Add support for _GPE returning a package */
 746        status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 747        if (ACPI_FAILURE(status))
 748                return status;
 749        ec->gpe = tmp;
 750        /* Use the global lock for all EC transactions? */
 751        tmp = 0;
 752        acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 753        ec->global_lock = tmp;
 754        ec->handle = handle;
 755        return AE_CTRL_TERMINATE;
 756}
 757
 758static int ec_install_handlers(struct acpi_ec *ec)
 759{
 760        acpi_status status;
 761        if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 762                return 0;
 763        status = acpi_install_gpe_handler(NULL, ec->gpe,
 764                                  ACPI_GPE_EDGE_TRIGGERED,
 765                                  &acpi_ec_gpe_handler, ec);
 766        if (ACPI_FAILURE(status))
 767                return -ENODEV;
 768
 769        acpi_enable_gpe(NULL, ec->gpe);
 770        status = acpi_install_address_space_handler(ec->handle,
 771                                                    ACPI_ADR_SPACE_EC,
 772                                                    &acpi_ec_space_handler,
 773                                                    NULL, ec);
 774        if (ACPI_FAILURE(status)) {
 775                if (status == AE_NOT_FOUND) {
 776                        /*
 777                         * Maybe OS fails in evaluating the _REG object.
 778                         * The AE_NOT_FOUND error will be ignored and OS
 779                         * continue to initialize EC.
 780                         */
 781                        printk(KERN_ERR "Fail in evaluating the _REG object"
 782                                " of EC device. Broken bios is suspected.\n");
 783                } else {
 784                        acpi_remove_gpe_handler(NULL, ec->gpe,
 785                                &acpi_ec_gpe_handler);
 786                        acpi_disable_gpe(NULL, ec->gpe);
 787                        return -ENODEV;
 788                }
 789        }
 790
 791        set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 792        return 0;
 793}
 794
 795static void ec_remove_handlers(struct acpi_ec *ec)
 796{
 797        acpi_disable_gpe(NULL, ec->gpe);
 798        if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 799                                ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 800                pr_err(PREFIX "failed to remove space handler\n");
 801        if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 802                                &acpi_ec_gpe_handler)))
 803                pr_err(PREFIX "failed to remove gpe handler\n");
 804        clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 805}
 806
 807static int acpi_ec_add(struct acpi_device *device)
 808{
 809        struct acpi_ec *ec = NULL;
 810        int ret;
 811
 812        strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 813        strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 814
 815        /* Check for boot EC */
 816        if (boot_ec &&
 817            (boot_ec->handle == device->handle ||
 818             boot_ec->handle == ACPI_ROOT_OBJECT)) {
 819                ec = boot_ec;
 820                boot_ec = NULL;
 821        } else {
 822                ec = make_acpi_ec();
 823                if (!ec)
 824                        return -ENOMEM;
 825        }
 826        if (ec_parse_device(device->handle, 0, ec, NULL) !=
 827                AE_CTRL_TERMINATE) {
 828                        kfree(ec);
 829                        return -EINVAL;
 830        }
 831
 832        /* Find and register all query methods */
 833        acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 834                            acpi_ec_register_query_methods, NULL, ec, NULL);
 835
 836        if (!first_ec)
 837                first_ec = ec;
 838        device->driver_data = ec;
 839
 840        ret = !!request_region(ec->data_addr, 1, "EC data");
 841        WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
 842        ret = !!request_region(ec->command_addr, 1, "EC cmd");
 843        WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
 844
 845        pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 846                          ec->gpe, ec->command_addr, ec->data_addr);
 847
 848        ret = ec_install_handlers(ec);
 849
 850        /* EC is fully operational, allow queries */
 851        clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 852        return ret;
 853}
 854
 855static int acpi_ec_remove(struct acpi_device *device, int type)
 856{
 857        struct acpi_ec *ec;
 858        struct acpi_ec_query_handler *handler, *tmp;
 859
 860        if (!device)
 861                return -EINVAL;
 862
 863        ec = acpi_driver_data(device);
 864        ec_remove_handlers(ec);
 865        mutex_lock(&ec->mutex);
 866        list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 867                list_del(&handler->node);
 868                kfree(handler);
 869        }
 870        mutex_unlock(&ec->mutex);
 871        release_region(ec->data_addr, 1);
 872        release_region(ec->command_addr, 1);
 873        device->driver_data = NULL;
 874        if (ec == first_ec)
 875                first_ec = NULL;
 876        kfree(ec);
 877        return 0;
 878}
 879
 880static acpi_status
 881ec_parse_io_ports(struct acpi_resource *resource, void *context)
 882{
 883        struct acpi_ec *ec = context;
 884
 885        if (resource->type != ACPI_RESOURCE_TYPE_IO)
 886                return AE_OK;
 887
 888        /*
 889         * The first address region returned is the data port, and
 890         * the second address region returned is the status/command
 891         * port.
 892         */
 893        if (ec->data_addr == 0)
 894                ec->data_addr = resource->data.io.minimum;
 895        else if (ec->command_addr == 0)
 896                ec->command_addr = resource->data.io.minimum;
 897        else
 898                return AE_CTRL_TERMINATE;
 899
 900        return AE_OK;
 901}
 902
 903int __init acpi_boot_ec_enable(void)
 904{
 905        if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 906                return 0;
 907        if (!ec_install_handlers(boot_ec)) {
 908                first_ec = boot_ec;
 909                return 0;
 910        }
 911        return -EFAULT;
 912}
 913
 914static const struct acpi_device_id ec_device_ids[] = {
 915        {"PNP0C09", 0},
 916        {"", 0},
 917};
 918
 919/* Some BIOS do not survive early DSDT scan, skip it */
 920static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
 921{
 922        EC_FLAGS_SKIP_DSDT_SCAN = 1;
 923        return 0;
 924}
 925
 926/* ASUStek often supplies us with broken ECDT, validate it */
 927static int ec_validate_ecdt(const struct dmi_system_id *id)
 928{
 929        EC_FLAGS_VALIDATE_ECDT = 1;
 930        return 0;
 931}
 932
 933/* MSI EC needs special treatment, enable it */
 934static int ec_flag_msi(const struct dmi_system_id *id)
 935{
 936        printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n");
 937        EC_FLAGS_MSI = 1;
 938        EC_FLAGS_VALIDATE_ECDT = 1;
 939        return 0;
 940}
 941
 942/*
 943 * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
 944 * the GPE storm threshold back to 20
 945 */
 946static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
 947{
 948        pr_debug("Setting the EC GPE storm threshold to 20\n");
 949        ec_storm_threshold  = 20;
 950        return 0;
 951}
 952
 953static struct dmi_system_id __initdata ec_dmi_table[] = {
 954        {
 955        ec_skip_dsdt_scan, "Compal JFL92", {
 956        DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
 957        DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
 958        {
 959        ec_flag_msi, "MSI hardware", {
 960        DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
 961        {
 962        ec_flag_msi, "MSI hardware", {
 963        DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
 964        {
 965        ec_flag_msi, "MSI hardware", {
 966        DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
 967        {
 968        ec_flag_msi, "MSI hardware", {
 969        DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
 970        {
 971        ec_flag_msi, "Quanta hardware", {
 972        DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 973        DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
 974        {
 975        ec_flag_msi, "Quanta hardware", {
 976        DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
 977        DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
 978        {
 979        ec_validate_ecdt, "ASUS hardware", {
 980        DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
 981        {
 982        ec_validate_ecdt, "ASUS hardware", {
 983        DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
 984        {
 985        ec_enlarge_storm_threshold, "CLEVO hardware", {
 986        DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
 987        DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
 988        {},
 989};
 990
 991int __init acpi_ec_ecdt_probe(void)
 992{
 993        acpi_status status;
 994        struct acpi_ec *saved_ec = NULL;
 995        struct acpi_table_ecdt *ecdt_ptr;
 996
 997        boot_ec = make_acpi_ec();
 998        if (!boot_ec)
 999                return -ENOMEM;
1000        /*
1001         * Generate a boot ec context
1002         */
1003        dmi_check_system(ec_dmi_table);
1004        status = acpi_get_table(ACPI_SIG_ECDT, 1,
1005                                (struct acpi_table_header **)&ecdt_ptr);
1006        if (ACPI_SUCCESS(status)) {
1007                pr_info(PREFIX "EC description table is found, configuring boot EC\n");
1008                boot_ec->command_addr = ecdt_ptr->control.address;
1009                boot_ec->data_addr = ecdt_ptr->data.address;
1010                boot_ec->gpe = ecdt_ptr->gpe;
1011                boot_ec->handle = ACPI_ROOT_OBJECT;
1012                acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1013                /* Don't trust ECDT, which comes from ASUSTek */
1014                if (!EC_FLAGS_VALIDATE_ECDT)
1015                        goto install;
1016                saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1017                if (!saved_ec)
1018                        return -ENOMEM;
1019        /* fall through */
1020        }
1021
1022        if (EC_FLAGS_SKIP_DSDT_SCAN)
1023                return -ENODEV;
1024
1025        /* This workaround is needed only on some broken machines,
1026         * which require early EC, but fail to provide ECDT */
1027        printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1028        status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1029                                        boot_ec, NULL);
1030        /* Check that acpi_get_devices actually find something */
1031        if (ACPI_FAILURE(status) || !boot_ec->handle)
1032                goto error;
1033        if (saved_ec) {
1034                /* try to find good ECDT from ASUSTek */
1035                if (saved_ec->command_addr != boot_ec->command_addr ||
1036                    saved_ec->data_addr != boot_ec->data_addr ||
1037                    saved_ec->gpe != boot_ec->gpe ||
1038                    saved_ec->handle != boot_ec->handle)
1039                        pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1040                        "ECDT tables, which are very hard to workaround. "
1041                        "Trying to use DSDT EC info instead. Please send "
1042                        "output of acpidump to linux-acpi@vger.kernel.org\n");
1043                kfree(saved_ec);
1044                saved_ec = NULL;
1045        } else {
1046                /* We really need to limit this workaround, the only ASUS,
1047                * which needs it, has fake EC._INI method, so use it as flag.
1048                * Keep boot_ec struct as it will be needed soon.
1049                */
1050                acpi_handle dummy;
1051                if (!dmi_name_in_vendors("ASUS") ||
1052                    ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1053                                                        &dummy)))
1054                        return -ENODEV;
1055        }
1056install:
1057        if (!ec_install_handlers(boot_ec)) {
1058                first_ec = boot_ec;
1059                return 0;
1060        }
1061error:
1062        kfree(boot_ec);
1063        boot_ec = NULL;
1064        return -ENODEV;
1065}
1066
1067static struct acpi_driver acpi_ec_driver = {
1068        .name = "ec",
1069        .class = ACPI_EC_CLASS,
1070        .ids = ec_device_ids,
1071        .ops = {
1072                .add = acpi_ec_add,
1073                .remove = acpi_ec_remove,
1074                },
1075};
1076
1077int __init acpi_ec_init(void)
1078{
1079        int result = 0;
1080
1081        /* Now register the driver for the EC */
1082        result = acpi_bus_register_driver(&acpi_ec_driver);
1083        if (result < 0)
1084                return -ENODEV;
1085
1086        return result;
1087}
1088
1089/* EC driver currently not unloadable */
1090#if 0
1091static void __exit acpi_ec_exit(void)
1092{
1093
1094        acpi_bus_unregister_driver(&acpi_ec_driver);
1095        return;
1096}
1097#endif  /* 0 */
1098
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