drivers/acpi/ec.c

   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/proc_fs.h>
  38 #include <linux/seq_file.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/list.h>
  41 #include <linux/spinlock.h>
  42 #include <asm/io.h>
  43 #include <acpi/acpi_bus.h>
  44 #include <acpi/acpi_drivers.h>
  45
  46 #define ACPI_EC_CLASS                   "embedded_controller"
  47 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
  48 #define ACPI_EC_FILE_INFO               "info"
  49
  50 #undef PREFIX
  51 #define PREFIX                          "ACPI: EC: "
  52
  53 /* EC status register */
  54 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
  55 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
  56 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
  57 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
  58
  59 /* EC commands */
  60 enum ec_command {
  61         ACPI_EC_COMMAND_READ = 0x80,
  62         ACPI_EC_COMMAND_WRITE = 0x81,
  63         ACPI_EC_BURST_ENABLE = 0x82,
  64         ACPI_EC_BURST_DISABLE = 0x83,
  65         ACPI_EC_COMMAND_QUERY = 0x84,
  66 };
  67
  68 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
  69 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
  70 #define ACPI_EC_CDELAY          10      /* Wait 10us before polling EC */
  71
  72 #define ACPI_EC_STORM_THRESHOLD 8       /* number of false interrupts
  73                                            per one transaction */
  74
  75 enum {
  76         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
  77         EC_FLAGS_GPE_MODE,              /* Expect GPE to be sent
  78                                          * for status change */
  79         EC_FLAGS_NO_GPE,                /* Don't use GPE mode */
  80         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
  81         EC_FLAGS_HANDLERS_INSTALLED     /* Handlers for GPE and
  82                                          * OpReg are installed */
  83 };
  84
  85 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
  86 /* External interfaces use first EC only, so remember */
  87 typedef int (*acpi_ec_query_func) (void *data);
  88
  89 struct acpi_ec_query_handler {
  90         struct list_head node;
  91         acpi_ec_query_func func;
  92         acpi_handle handle;
  93         void *data;
  94         u8 query_bit;
  95 };
  96
  97 struct transaction {
  98         const u8 *wdata;
  99         u8 *rdata;
 100         unsigned short irq_count;
 101         u8 command;
 102         u8 wi;
 103         u8 ri;
 104         u8 wlen;
 105         u8 rlen;
 106         bool done;
 107 };
 108
 109 static struct acpi_ec {
 110         acpi_handle handle;
 111         unsigned long gpe;
 112         unsigned long command_addr;
 113         unsigned long data_addr;
 114         unsigned long global_lock;
 115         unsigned long flags;
 116         struct mutex lock;
 117         wait_queue_head_t wait;
 118         struct list_head list;
 119         struct transaction *curr;
 120         spinlock_t curr_lock;
 121 } *boot_ec, *first_ec;
 122
 123 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
 124
 125 /* --------------------------------------------------------------------------
 126                              Transaction Management
 127    -------------------------------------------------------------------------- */
 128
 129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
 130 {
 131         u8 x = inb(ec->command_addr);
 132         pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
 133         return x;
 134 }
 135
 136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
 137 {
 138         u8 x = inb(ec->data_addr);
 139         pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
 140         return x;
 141 }
 142
 143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
 144 {
 145         pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
 146         outb(command, ec->command_addr);
 147 }
 148
 149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
 150 {
 151         pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
 152         outb(data, ec->data_addr);
 153 }
 154
 155 static int ec_transaction_done(struct acpi_ec *ec)
 156 {
 157         unsigned long flags;
 158         int ret = 0;
 159         spin_lock_irqsave(&ec->curr_lock, flags);
 160         if (!ec->curr || ec->curr->done)
 161                 ret = 1;
 162         spin_unlock_irqrestore(&ec->curr_lock, flags);
 163         return ret;
 164 }
 165
 166 static void start_transaction(struct acpi_ec *ec)
 167 {
 168         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
 169         ec->curr->done = false;
 170         acpi_ec_write_cmd(ec, ec->curr->command);
 171 }
 172
 173 static void gpe_transaction(struct acpi_ec *ec, u8 status)
 174 {
 175         unsigned long flags;
 176         spin_lock_irqsave(&ec->curr_lock, flags);
 177         if (!ec->curr)
 178                 goto unlock;
 179         if (ec->curr->wlen > ec->curr->wi) {
 180                 if ((status & ACPI_EC_FLAG_IBF) == 0)
 181                         acpi_ec_write_data(ec,
 182                                 ec->curr->wdata[ec->curr->wi++]);
 183                 else
 184                         goto err;
 185         } else if (ec->curr->rlen > ec->curr->ri) {
 186                 if ((status & ACPI_EC_FLAG_OBF) == 1) {
 187                         ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
 188                         if (ec->curr->rlen == ec->curr->ri)
 189                                 ec->curr->done = true;
 190                 } else
 191                         goto err;
 192         } else if (ec->curr->wlen == ec->curr->wi &&
 193                    (status & ACPI_EC_FLAG_IBF) == 0)
 194                 ec->curr->done = true;
 195         goto unlock;
 196 err:
 197         /* false interrupt, state didn't change */
 198         if (in_interrupt())
 199                 ++ec->curr->irq_count;
 200 unlock:
 201         spin_unlock_irqrestore(&ec->curr_lock, flags);
 202 }
 203
 204 static int acpi_ec_wait(struct acpi_ec *ec)
 205 {
 206         if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 207                                msecs_to_jiffies(ACPI_EC_DELAY)))
 208                 return 0;
 209         /* try restart command if we get any false interrupts */
 210         if (ec->curr->irq_count &&
 211             (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
 212                 pr_debug(PREFIX "controller reset, restart transaction\n");
 213                 start_transaction(ec);
 214                 if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
 215                                         msecs_to_jiffies(ACPI_EC_DELAY)))
 216                         return 0;
 217         }
 218         /* missing GPEs, switch back to poll mode */
 219         if (printk_ratelimit())
 220                 pr_info(PREFIX "missing confirmations, "
 221                                 "switch off interrupt mode.\n");
 222         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
 223         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 224         return 1;
 225 }
 226
 227 static void acpi_ec_gpe_query(void *ec_cxt);
 228
 229 static int ec_check_sci(struct acpi_ec *ec, u8 state)
 230 {
 231         if (state & ACPI_EC_FLAG_SCI) {
 232                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
 233                         return acpi_os_execute(OSL_EC_BURST_HANDLER,
 234                                 acpi_ec_gpe_query, ec);
 235         }
 236         return 0;
 237 }
 238
 239 static void ec_delay(void)
 240 {
 241         /* EC in MSI notebooks don't tolerate delays other than 550 usec */
 242         if (EC_FLAGS_MSI)
 243                 udelay(ACPI_EC_DELAY);
 244         else
 245                 /* Use shortest sleep available */
 246                 msleep(1);
 247 }
 248
 249 static int ec_poll(struct acpi_ec *ec)
 250 {
 251         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 252         udelay(ACPI_EC_CDELAY);
 253         while (time_before(jiffies, delay)) {
 254                 gpe_transaction(ec, acpi_ec_read_status(ec));
 255                 ec_delay();
 256                 if (ec_transaction_done(ec))
 257                         return 0;
 258         }
 259         return -ETIME;
 260 }
 261
 262 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
 263                                         struct transaction *t,
 264                                         int force_poll)
 265 {
 266         unsigned long tmp;
 267         int ret = 0;
 268         pr_debug(PREFIX "transaction start\n");
 269         /* disable GPE during transaction if storm is detected */
 270         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 271                 clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 272                 acpi_disable_gpe(NULL, ec->gpe);
 273         }
 274         if (EC_FLAGS_MSI)
 275                 udelay(ACPI_EC_DELAY);
 276         /* start transaction */
 277         spin_lock_irqsave(&ec->curr_lock, tmp);
 278         /* following two actions should be kept atomic */
 279         ec->curr = t;
 280         start_transaction(ec);
 281         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
 282                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 283         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 284         /* if we selected poll mode or failed in GPE-mode do a poll loop */
 285         if (force_poll ||
 286             !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
 287             acpi_ec_wait(ec))
 288                 ret = ec_poll(ec);
 289         pr_debug(PREFIX "transaction end\n");
 290         spin_lock_irqsave(&ec->curr_lock, tmp);
 291         ec->curr = NULL;
 292         spin_unlock_irqrestore(&ec->curr_lock, tmp);
 293         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 294                 /* check if we received SCI during transaction */
 295                 ec_check_sci(ec, acpi_ec_read_status(ec));
 296                 /* it is safe to enable GPE outside of transaction */
 297                 acpi_enable_gpe(NULL, ec->gpe);
 298         } else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 299                    t->irq_count > ACPI_EC_STORM_THRESHOLD) {
 300                 pr_info(PREFIX "GPE storm detected, "
 301                         "transactions will use polling mode\n");
 302                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
 303         }
 304         return ret;
 305 }
 306
 307 static int ec_check_ibf0(struct acpi_ec *ec)
 308 {
 309         u8 status = acpi_ec_read_status(ec);
 310         return (status & ACPI_EC_FLAG_IBF) == 0;
 311 }
 312
 313 static int ec_wait_ibf0(struct acpi_ec *ec)
 314 {
 315         unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
 316         /* interrupt wait manually if GPE mode is not active */
 317         unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
 318                 msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
 319         while (time_before(jiffies, delay))
 320                 if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
 321                         return 0;
 322         return -ETIME;
 323 }
 324
 325 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
 326                                int force_poll)
 327 {
 328         int status;
 329         u32 glk;
 330         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
 331                 return -EINVAL;
 332         if (t->rdata)
 333                 memset(t->rdata, 0, t->rlen);
 334         mutex_lock(&ec->lock);
 335         if (ec->global_lock) {
 336                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 337                 if (ACPI_FAILURE(status)) {
 338                         status = -ENODEV;
 339                         goto unlock;
 340                 }
 341         }
 342         if (ec_wait_ibf0(ec)) {
 343                 pr_err(PREFIX "input buffer is not empty, "
 344                                 "aborting transaction\n");
 345                 status = -ETIME;
 346                 goto end;
 347         }
 348         status = acpi_ec_transaction_unlocked(ec, t, force_poll);
 349 end:
 350         if (ec->global_lock)
 351                 acpi_release_global_lock(glk);
 352 unlock:
 353         mutex_unlock(&ec->lock);
 354         return status;
 355 }
 356
 357 /*
 358  * Note: samsung nv5000 doesn't work with ec burst mode.
 359  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
 360  */
 361 static int acpi_ec_burst_enable(struct acpi_ec *ec)
 362 {
 363         u8 d;
 364         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
 365                                 .wdata = NULL, .rdata = &d,
 366                                 .wlen = 0, .rlen = 1};
 367
 368         return acpi_ec_transaction(ec, &t, 0);
 369 }
 370
 371 static int acpi_ec_burst_disable(struct acpi_ec *ec)
 372 {
 373         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
 374                                 .wdata = NULL, .rdata = NULL,
 375                                 .wlen = 0, .rlen = 0};
 376
 377         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
 378                                 acpi_ec_transaction(ec, &t, 0) : 0;
 379 }
 380
 381 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
 382 {
 383         int result;
 384         u8 d;
 385         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
 386                                 .wdata = &address, .rdata = &d,
 387                                 .wlen = 1, .rlen = 1};
 388
 389         result = acpi_ec_transaction(ec, &t, 0);
 390         *data = d;
 391         return result;
 392 }
 393
 394 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
 395 {
 396         u8 wdata[2] = { address, data };
 397         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
 398                                 .wdata = wdata, .rdata = NULL,
 399                                 .wlen = 2, .rlen = 0};
 400
 401         return acpi_ec_transaction(ec, &t, 0);
 402 }
 403
 404 /*
 405  * Externally callable EC access functions. For now, assume 1 EC only
 406  */
 407 int ec_burst_enable(void)
 408 {
 409         if (!first_ec)
 410                 return -ENODEV;
 411         return acpi_ec_burst_enable(first_ec);
 412 }
 413
 414 EXPORT_SYMBOL(ec_burst_enable);
 415
 416 int ec_burst_disable(void)
 417 {
 418         if (!first_ec)
 419                 return -ENODEV;
 420         return acpi_ec_burst_disable(first_ec);
 421 }
 422
 423 EXPORT_SYMBOL(ec_burst_disable);
 424
 425 int ec_read(u8 addr, u8 * val)
 426 {
 427         int err;
 428         u8 temp_data;
 429
 430         if (!first_ec)
 431                 return -ENODEV;
 432
 433         err = acpi_ec_read(first_ec, addr, &temp_data);
 434
 435         if (!err) {
 436                 *val = temp_data;
 437                 return 0;
 438         } else
 439                 return err;
 440 }
 441
 442 EXPORT_SYMBOL(ec_read);
 443
 444 int ec_write(u8 addr, u8 val)
 445 {
 446         int err;
 447
 448         if (!first_ec)
 449                 return -ENODEV;
 450
 451         err = acpi_ec_write(first_ec, addr, val);
 452
 453         return err;
 454 }
 455
 456 EXPORT_SYMBOL(ec_write);
 457
 458 int ec_transaction(u8 command,
 459                    const u8 * wdata, unsigned wdata_len,
 460                    u8 * rdata, unsigned rdata_len,
 461                    int force_poll)
 462 {
 463         struct transaction t = {.command = command,
 464                                 .wdata = wdata, .rdata = rdata,
 465                                 .wlen = wdata_len, .rlen = rdata_len};
 466         if (!first_ec)
 467                 return -ENODEV;
 468
 469         return acpi_ec_transaction(first_ec, &t, force_poll);
 470 }
 471
 472 EXPORT_SYMBOL(ec_transaction);
 473
 474 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
 475 {
 476         int result;
 477         u8 d;
 478         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
 479                                 .wdata = NULL, .rdata = &d,
 480                                 .wlen = 0, .rlen = 1};
 481         if (!ec || !data)
 482                 return -EINVAL;
 483
 484         /*
 485          * Query the EC to find out which _Qxx method we need to evaluate.
 486          * Note that successful completion of the query causes the ACPI_EC_SCI
 487          * bit to be cleared (and thus clearing the interrupt source).
 488          */
 489
 490         result = acpi_ec_transaction(ec, &t, 0);
 491         if (result)
 492                 return result;
 493
 494         if (!d)
 495                 return -ENODATA;
 496
 497         *data = d;
 498         return 0;
 499 }
 500
 501 /* --------------------------------------------------------------------------
 502                                 Event Management
 503    -------------------------------------------------------------------------- */
 504 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 505                               acpi_handle handle, acpi_ec_query_func func,
 506                               void *data)
 507 {
 508         struct acpi_ec_query_handler *handler =
 509             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
 510         if (!handler)
 511                 return -ENOMEM;
 512
 513         handler->query_bit = query_bit;
 514         handler->handle = handle;
 515         handler->func = func;
 516         handler->data = data;
 517         mutex_lock(&ec->lock);
 518         list_add(&handler->node, &ec->list);
 519         mutex_unlock(&ec->lock);
 520         return 0;
 521 }
 522
 523 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
 524
 525 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
 526 {
 527         struct acpi_ec_query_handler *handler, *tmp;
 528         mutex_lock(&ec->lock);
 529         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 530                 if (query_bit == handler->query_bit) {
 531                         list_del(&handler->node);
 532                         kfree(handler);
 533                 }
 534         }
 535         mutex_unlock(&ec->lock);
 536 }
 537
 538 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
 539
 540 static void acpi_ec_gpe_query(void *ec_cxt)
 541 {
 542         struct acpi_ec *ec = ec_cxt;
 543         u8 value = 0;
 544         struct acpi_ec_query_handler *handler, copy;
 545
 546         if (!ec || acpi_ec_query(ec, &value))
 547                 return;
 548         mutex_lock(&ec->lock);
 549         list_for_each_entry(handler, &ec->list, node) {
 550                 if (value == handler->query_bit) {
 551                         /* have custom handler for this bit */
 552                         memcpy(&copy, handler, sizeof(copy));
 553                         mutex_unlock(&ec->lock);
 554                         if (copy.func) {
 555                                 copy.func(copy.data);
 556                         } else if (copy.handle) {
 557                                 acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
 558                         }
 559                         return;
 560                 }
 561         }
 562         mutex_unlock(&ec->lock);
 563 }
 564
 565 static u32 acpi_ec_gpe_handler(void *data)
 566 {
 567         struct acpi_ec *ec = data;
 568         u8 status;
 569
 570         pr_debug(PREFIX "~~~> interrupt\n");
 571         status = acpi_ec_read_status(ec);
 572
 573         if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
 574                 gpe_transaction(ec, status);
 575                 if (ec_transaction_done(ec) &&
 576                     (status & ACPI_EC_FLAG_IBF) == 0)
 577                         wake_up(&ec->wait);
 578         }
 579
 580         ec_check_sci(ec, status);
 581         if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
 582             !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
 583                 /* this is non-query, must be confirmation */
 584                 if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
 585                         if (printk_ratelimit())
 586                                 pr_info(PREFIX "non-query interrupt received,"
 587                                         " switching to interrupt mode\n");
 588                 } else {
 589                         /* hush, STORM switches the mode every transaction */
 590                         pr_debug(PREFIX "non-query interrupt received,"
 591                                 " switching to interrupt mode\n");
 592                 }
 593                 set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
 594         }
 595         return ACPI_INTERRUPT_HANDLED;
 596 }
 597
 598 /* --------------------------------------------------------------------------
 599                              Address Space Management
 600    -------------------------------------------------------------------------- */
 601
 602 static acpi_status
 603 acpi_ec_space_handler(u32 function, acpi_physical_address address,
 604                       u32 bits, acpi_integer *value,
 605                       void *handler_context, void *region_context)
 606 {
 607         struct acpi_ec *ec = handler_context;
 608         int result = 0, i;
 609         u8 temp = 0;
 610
 611         if ((address > 0xFF) || !value || !handler_context)
 612                 return AE_BAD_PARAMETER;
 613
 614         if (function != ACPI_READ && function != ACPI_WRITE)
 615                 return AE_BAD_PARAMETER;
 616
 617         if (bits != 8 && acpi_strict)
 618                 return AE_BAD_PARAMETER;
 619
 620         acpi_ec_burst_enable(ec);
 621
 622         if (function == ACPI_READ) {
 623                 result = acpi_ec_read(ec, address, &temp);
 624                 *value = temp;
 625         } else {
 626                 temp = 0xff & (*value);
 627                 result = acpi_ec_write(ec, address, temp);
 628         }
 629
 630         for (i = 8; unlikely(bits - i > 0); i += 8) {
 631                 ++address;
 632                 if (function == ACPI_READ) {
 633                         result = acpi_ec_read(ec, address, &temp);
 634                         (*value) |= ((acpi_integer)temp) << i;
 635                 } else {
 636                         temp = 0xff & ((*value) >> i);
 637                         result = acpi_ec_write(ec, address, temp);
 638                 }
 639         }
 640
 641         acpi_ec_burst_disable(ec);
 642
 643         switch (result) {
 644         case -EINVAL:
 645                 return AE_BAD_PARAMETER;
 646                 break;
 647         case -ENODEV:
 648                 return AE_NOT_FOUND;
 649                 break;
 650         case -ETIME:
 651                 return AE_TIME;
 652                 break;
 653         default:
 654                 return AE_OK;
 655         }
 656 }
 657
 658 /* --------------------------------------------------------------------------
 659                               FS Interface (/proc)
 660    -------------------------------------------------------------------------- */
 661
 662 static struct proc_dir_entry *acpi_ec_dir;
 663
 664 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
 665 {
 666         struct acpi_ec *ec = seq->private;
 667
 668         if (!ec)
 669                 goto end;
 670
 671         seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
 672         seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
 673                    (unsigned)ec->command_addr, (unsigned)ec->data_addr);
 674         seq_printf(seq, "use global lock:\t%s\n",
 675                    ec->global_lock ? "yes" : "no");
 676       end:
 677         return 0;
 678 }
 679
 680 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
 681 {
 682         return single_open(file, acpi_ec_read_info, PDE(inode)->data);
 683 }
 684
 685 static const struct file_operations acpi_ec_info_ops = {
 686         .open = acpi_ec_info_open_fs,
 687         .read = seq_read,
 688         .llseek = seq_lseek,
 689         .release = single_release,
 690         .owner = THIS_MODULE,
 691 };
 692
 693 static int acpi_ec_add_fs(struct acpi_device *device)
 694 {
 695         struct proc_dir_entry *entry = NULL;
 696
 697         if (!acpi_device_dir(device)) {
 698                 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
 699                                                      acpi_ec_dir);
 700                 if (!acpi_device_dir(device))
 701                         return -ENODEV;
 702         }
 703
 704         entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
 705                                  acpi_device_dir(device),
 706                                  &acpi_ec_info_ops, acpi_driver_data(device));
 707         if (!entry)
 708                 return -ENODEV;
 709         return 0;
 710 }
 711
 712 static int acpi_ec_remove_fs(struct acpi_device *device)
 713 {
 714
 715         if (acpi_device_dir(device)) {
 716                 remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
 717                 remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
 718                 acpi_device_dir(device) = NULL;
 719         }
 720
 721         return 0;
 722 }
 723
 724 /* --------------------------------------------------------------------------
 725                                Driver Interface
 726    -------------------------------------------------------------------------- */
 727 static acpi_status
 728 ec_parse_io_ports(struct acpi_resource *resource, void *context);
 729
 730 static struct acpi_ec *make_acpi_ec(void)
 731 {
 732         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
 733         if (!ec)
 734                 return NULL;
 735         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
 736         mutex_init(&ec->lock);
 737         init_waitqueue_head(&ec->wait);
 738         INIT_LIST_HEAD(&ec->list);
 739         spin_lock_init(&ec->curr_lock);
 740         return ec;
 741 }
 742
 743 static acpi_status
 744 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 745                                void *context, void **return_value)
 746 {
 747         char node_name[5];
 748         struct acpi_buffer buffer = { sizeof(node_name), node_name };
 749         struct acpi_ec *ec = context;
 750         int value = 0;
 751         acpi_status status;
 752
 753         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
 754
 755         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 756                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 757         }
 758         return AE_OK;
 759 }
 760
 761 static acpi_status
 762 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
 763 {
 764         acpi_status status;
 765         unsigned long long tmp = 0;
 766
 767         struct acpi_ec *ec = context;
 768
 769         /* clear addr values, ec_parse_io_ports depend on it */
 770         ec->command_addr = ec->data_addr = 0;
 771
 772         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
 773                                      ec_parse_io_ports, ec);
 774         if (ACPI_FAILURE(status))
 775                 return status;
 776
 777         /* Get GPE bit assignment (EC events). */
 778         /* TODO: Add support for _GPE returning a package */
 779         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
 780         if (ACPI_FAILURE(status))
 781                 return status;
 782         ec->gpe = tmp;
 783         /* Use the global lock for all EC transactions? */
 784         tmp = 0;
 785         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
 786         ec->global_lock = tmp;
 787         ec->handle = handle;
 788         return AE_CTRL_TERMINATE;
 789 }
 790
 791 static void ec_remove_handlers(struct acpi_ec *ec)
 792 {
 793         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
 794                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
 795                 pr_err(PREFIX "failed to remove space handler\n");
 796         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
 797                                 &acpi_ec_gpe_handler)))
 798                 pr_err(PREFIX "failed to remove gpe handler\n");
 799         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 800 }
 801
 802 static int acpi_ec_add(struct acpi_device *device)
 803 {
 804         struct acpi_ec *ec = NULL;
 805
 806         if (!device)
 807                 return -EINVAL;
 808         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
 809         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
 810
 811         /* Check for boot EC */
 812         if (boot_ec &&
 813             (boot_ec->handle == device->handle ||
 814              boot_ec->handle == ACPI_ROOT_OBJECT)) {
 815                 ec = boot_ec;
 816                 boot_ec = NULL;
 817         } else {
 818                 ec = make_acpi_ec();
 819                 if (!ec)
 820                         return -ENOMEM;
 821         }
 822         if (ec_parse_device(device->handle, 0, ec, NULL) !=
 823                 AE_CTRL_TERMINATE) {
 824                         kfree(ec);
 825                         return -EINVAL;
 826         }
 827
 828         ec->handle = device->handle;
 829
 830         /* Find and register all query methods */
 831         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
 832                             acpi_ec_register_query_methods, ec, NULL);
 833
 834         if (!first_ec)
 835                 first_ec = ec;
 836         device->driver_data = ec;
 837         acpi_ec_add_fs(device);
 838         pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
 839                           ec->gpe, ec->command_addr, ec->data_addr);
 840         pr_info(PREFIX "driver started in %s mode\n",
 841                 (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
 842         return 0;
 843 }
 844
 845 static int acpi_ec_remove(struct acpi_device *device, int type)
 846 {
 847         struct acpi_ec *ec;
 848         struct acpi_ec_query_handler *handler, *tmp;
 849
 850         if (!device)
 851                 return -EINVAL;
 852
 853         ec = acpi_driver_data(device);
 854         mutex_lock(&ec->lock);
 855         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
 856                 list_del(&handler->node);
 857                 kfree(handler);
 858         }
 859         mutex_unlock(&ec->lock);
 860         acpi_ec_remove_fs(device);
 861         device->driver_data = NULL;
 862         if (ec == first_ec)
 863                 first_ec = NULL;
 864         kfree(ec);
 865         return 0;
 866 }
 867
 868 static acpi_status
 869 ec_parse_io_ports(struct acpi_resource *resource, void *context)
 870 {
 871         struct acpi_ec *ec = context;
 872
 873         if (resource->type != ACPI_RESOURCE_TYPE_IO)
 874                 return AE_OK;
 875
 876         /*
 877          * The first address region returned is the data port, and
 878          * the second address region returned is the status/command
 879          * port.
 880          */
 881         if (ec->data_addr == 0)
 882                 ec->data_addr = resource->data.io.minimum;
 883         else if (ec->command_addr == 0)
 884                 ec->command_addr = resource->data.io.minimum;
 885         else
 886                 return AE_CTRL_TERMINATE;
 887
 888         return AE_OK;
 889 }
 890
 891 static int ec_install_handlers(struct acpi_ec *ec)
 892 {
 893         acpi_status status;
 894         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
 895                 return 0;
 896         status = acpi_install_gpe_handler(NULL, ec->gpe,
 897                                   ACPI_GPE_EDGE_TRIGGERED,
 898                                   &acpi_ec_gpe_handler, ec);
 899         if (ACPI_FAILURE(status))
 900                 return -ENODEV;
 901         acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
 902         acpi_enable_gpe(NULL, ec->gpe);
 903         status = acpi_install_address_space_handler(ec->handle,
 904                                                     ACPI_ADR_SPACE_EC,
 905                                                     &acpi_ec_space_handler,
 906                                                     NULL, ec);
 907         if (ACPI_FAILURE(status)) {
 908                 if (status == AE_NOT_FOUND) {
 909                         /*
 910                          * Maybe OS fails in evaluating the _REG object.
 911                          * The AE_NOT_FOUND error will be ignored and OS
 912                          * continue to initialize EC.
 913                          */
 914                         printk(KERN_ERR "Fail in evaluating the _REG object"
 915                                 " of EC device. Broken bios is suspected.\n");
 916                 } else {
 917                         acpi_remove_gpe_handler(NULL, ec->gpe,
 918                                 &acpi_ec_gpe_handler);
 919                         return -ENODEV;
 920                 }
 921         }
 922
 923         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
 924         return 0;
 925 }
 926
 927 static int acpi_ec_start(struct acpi_device *device)
 928 {
 929         struct acpi_ec *ec;
 930         int ret = 0;
 931
 932         if (!device)
 933                 return -EINVAL;
 934
 935         ec = acpi_driver_data(device);
 936
 937         if (!ec)
 938                 return -EINVAL;
 939
 940         ret = ec_install_handlers(ec);
 941
 942         /* EC is fully operational, allow queries */
 943         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
 944         return ret;
 945 }
 946
 947 static int acpi_ec_stop(struct acpi_device *device, int type)
 948 {
 949         struct acpi_ec *ec;
 950         if (!device)
 951                 return -EINVAL;
 952         ec = acpi_driver_data(device);
 953         if (!ec)
 954                 return -EINVAL;
 955         ec_remove_handlers(ec);
 956
 957         return 0;
 958 }
 959
 960 int __init acpi_boot_ec_enable(void)
 961 {
 962         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
 963                 return 0;
 964         if (!ec_install_handlers(boot_ec)) {
 965                 first_ec = boot_ec;
 966                 return 0;
 967         }
 968         return -EFAULT;
 969 }
 970
 971 static const struct acpi_device_id ec_device_ids[] = {
 972         {"PNP0C09", 0},
 973         {"", 0},
 974 };
 975
 976 int __init acpi_ec_ecdt_probe(void)
 977 {
 978         acpi_status status;
 979         struct acpi_ec *saved_ec = NULL;
 980         struct acpi_table_ecdt *ecdt_ptr;
 981
 982         boot_ec = make_acpi_ec();
 983         if (!boot_ec)
 984                 return -ENOMEM;
 985         /*
 986          * Generate a boot ec context
 987          */
 988         if (dmi_name_in_vendors("Micro-Star") ||
 989             dmi_name_in_vendors("Notebook")) {
 990                 pr_info(PREFIX "Enabling special treatment for EC from MSI.\n");
 991                 EC_FLAGS_MSI = 1;
 992         }
 993         status = acpi_get_table(ACPI_SIG_ECDT, 1,
 994                                 (struct acpi_table_header **)&ecdt_ptr);
 995         if (ACPI_SUCCESS(status)) {
 996                 pr_info(PREFIX "EC description table is found, configuring boot EC\n");
 997                 boot_ec->command_addr = ecdt_ptr->control.address;
 998                 boot_ec->data_addr = ecdt_ptr->data.address;
 999                 boot_ec->gpe = ecdt_ptr->gpe;
1000                 boot_ec->handle = ACPI_ROOT_OBJECT;
1001                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1002                 /* Don't trust ECDT, which comes from ASUSTek */
1003                 if (!dmi_name_in_vendors("ASUS") && EC_FLAGS_MSI == 0)
1004                         goto install;
1005                 saved_ec = kmalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1006                 if (!saved_ec)
1007                         return -ENOMEM;
1008                 memcpy(saved_ec, boot_ec, sizeof(struct acpi_ec));
1009         /* fall through */
1010         }
1011         /* This workaround is needed only on some broken machines,
1012          * which require early EC, but fail to provide ECDT */
1013         printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1014         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1015                                         boot_ec, NULL);
1016         /* Check that acpi_get_devices actually find something */
1017         if (ACPI_FAILURE(status) || !boot_ec->handle)
1018                 goto error;
1019         if (saved_ec) {
1020                 /* try to find good ECDT from ASUSTek */
1021                 if (saved_ec->command_addr != boot_ec->command_addr ||
1022                     saved_ec->data_addr != boot_ec->data_addr ||
1023                     saved_ec->gpe != boot_ec->gpe ||
1024                     saved_ec->handle != boot_ec->handle)
1025                         pr_info(PREFIX "ASUSTek keeps feeding us with broken "
1026                         "ECDT tables, which are very hard to workaround. "
1027                         "Trying to use DSDT EC info instead. Please send "
1028                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1029                 kfree(saved_ec);
1030                 saved_ec = NULL;
1031         } else {
1032                 /* We really need to limit this workaround, the only ASUS,
1033                 * which needs it, has fake EC._INI method, so use it as flag.
1034                 * Keep boot_ec struct as it will be needed soon.
1035                 */
1036                 acpi_handle dummy;
1037                 if (!dmi_name_in_vendors("ASUS") ||
1038                     ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI",
1039                                                         &dummy)))
1040                         return -ENODEV;
1041         }
1042 install:
1043         if (!ec_install_handlers(boot_ec)) {
1044                 first_ec = boot_ec;
1045                 return 0;
1046         }
1047 error:
1048         kfree(boot_ec);
1049         boot_ec = NULL;
1050         return -ENODEV;
1051 }
1052
1053 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1054 {
1055         struct acpi_ec *ec = acpi_driver_data(device);
1056         /* Stop using GPE */
1057         set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1058         clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1059         acpi_disable_gpe(NULL, ec->gpe);
1060         return 0;
1061 }
1062
1063 static int acpi_ec_resume(struct acpi_device *device)
1064 {
1065         struct acpi_ec *ec = acpi_driver_data(device);
1066         /* Enable use of GPE back */
1067         clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1068         acpi_enable_gpe(NULL, ec->gpe);
1069         return 0;
1070 }
1071
1072 static struct acpi_driver acpi_ec_driver = {
1073         .name = "ec",
1074         .class = ACPI_EC_CLASS,
1075         .ids = ec_device_ids,
1076         .ops = {
1077                 .add = acpi_ec_add,
1078                 .remove = acpi_ec_remove,
1079                 .start = acpi_ec_start,
1080                 .stop = acpi_ec_stop,
1081                 .suspend = acpi_ec_suspend,
1082                 .resume = acpi_ec_resume,
1083                 },
1084 };
1085
1086 int __init acpi_ec_init(void)
1087 {
1088         int result = 0;
1089
1090         acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1091         if (!acpi_ec_dir)
1092                 return -ENODEV;
1093
1094         /* Now register the driver for the EC */
1095         result = acpi_bus_register_driver(&acpi_ec_driver);
1096         if (result < 0) {
1097                 remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1098                 return -ENODEV;
1099         }
1100
1101         return result;
1102 }
1103
1104 /* EC driver currently not unloadable */
1105 #if 0
1106 static void __exit acpi_ec_exit(void)
1107 {
1108
1109         acpi_bus_unregister_driver(&acpi_ec_driver);
1110
1111         remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1112
1113         return;
1114 }
1115 #endif  /* 0 */