Version:  2.0.40 2.2.26 2.4.37 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16

Linux/drivers/acpi/ec.c

  1 /*
  2  *  ec.c - ACPI Embedded Controller Driver (v2.2)
  3  *
  4  *  Copyright (C) 2001-2014 Intel Corporation
  5  *    Author: 2014       Lv Zheng <lv.zheng@intel.com>
  6  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
  7  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
  8  *            2004       Luming Yu <luming.yu@intel.com>
  9  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
 10  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 11  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
 12  *
 13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 14  *
 15  *  This program is free software; you can redistribute it and/or modify
 16  *  it under the terms of the GNU General Public License as published by
 17  *  the Free Software Foundation; either version 2 of the License, or (at
 18  *  your option) any later version.
 19  *
 20  *  This program is distributed in the hope that it will be useful, but
 21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
 22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 23  *  General Public License for more details.
 24  *
 25  *  You should have received a copy of the GNU General Public License along
 26  *  with this program; if not, write to the Free Software Foundation, Inc.,
 27  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 28  *
 29  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 30  */
 31 
 32 /* Uncomment next line to get verbose printout */
 33 /* #define DEBUG */
 34 #define pr_fmt(fmt) "ACPI : EC: " fmt
 35 
 36 #include <linux/kernel.h>
 37 #include <linux/module.h>
 38 #include <linux/init.h>
 39 #include <linux/types.h>
 40 #include <linux/delay.h>
 41 #include <linux/interrupt.h>
 42 #include <linux/list.h>
 43 #include <linux/spinlock.h>
 44 #include <linux/slab.h>
 45 #include <linux/acpi.h>
 46 #include <linux/dmi.h>
 47 #include <asm/io.h>
 48 
 49 #include "internal.h"
 50 
 51 #define ACPI_EC_CLASS                   "embedded_controller"
 52 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
 53 #define ACPI_EC_FILE_INFO               "info"
 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_CMD        0x08    /* Input buffer contains a command */
 59 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
 60 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
 61 
 62 /* EC commands */
 63 enum ec_command {
 64         ACPI_EC_COMMAND_READ = 0x80,
 65         ACPI_EC_COMMAND_WRITE = 0x81,
 66         ACPI_EC_BURST_ENABLE = 0x82,
 67         ACPI_EC_BURST_DISABLE = 0x83,
 68         ACPI_EC_COMMAND_QUERY = 0x84,
 69 };
 70 
 71 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 72 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
 74 #define ACPI_EC_CLEAR_MAX       100     /* Maximum number of events to query
 75                                          * when trying to clear the EC */
 76 
 77 enum {
 78         EC_FLAGS_QUERY_PENDING,         /* Query is pending */
 79         EC_FLAGS_GPE_STORM,             /* GPE storm detected */
 80         EC_FLAGS_HANDLERS_INSTALLED,    /* Handlers for GPE and
 81                                          * OpReg are installed */
 82         EC_FLAGS_BLOCKED,               /* Transactions are blocked */
 83 };
 84 
 85 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 86 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 87 
 88 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
 89 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
 90 module_param(ec_delay, uint, 0644);
 91 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
 92 
 93 /*
 94  * If the number of false interrupts per one transaction exceeds
 95  * this threshold, will think there is a GPE storm happened and
 96  * will disable the GPE for normal transaction.
 97  */
 98 static unsigned int ec_storm_threshold  __read_mostly = 8;
 99 module_param(ec_storm_threshold, uint, 0644);
100 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
101 
102 struct acpi_ec_query_handler {
103         struct list_head node;
104         acpi_ec_query_func func;
105         acpi_handle handle;
106         void *data;
107         u8 query_bit;
108 };
109 
110 struct transaction {
111         const u8 *wdata;
112         u8 *rdata;
113         unsigned short irq_count;
114         u8 command;
115         u8 wi;
116         u8 ri;
117         u8 wlen;
118         u8 rlen;
119         u8 flags;
120 };
121 
122 struct acpi_ec *boot_ec, *first_ec;
123 EXPORT_SYMBOL(first_ec);
124 
125 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
126 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
127 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
128 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
129 
130 /* --------------------------------------------------------------------------
131                              Transaction Management
132    -------------------------------------------------------------------------- */
133 
134 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
135 {
136         u8 x = inb(ec->command_addr);
137         pr_debug("EC_SC(R) = 0x%2.2x "
138                  "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
139                  x,
140                  !!(x & ACPI_EC_FLAG_SCI),
141                  !!(x & ACPI_EC_FLAG_BURST),
142                  !!(x & ACPI_EC_FLAG_CMD),
143                  !!(x & ACPI_EC_FLAG_IBF),
144                  !!(x & ACPI_EC_FLAG_OBF));
145         return x;
146 }
147 
148 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
149 {
150         u8 x = inb(ec->data_addr);
151         pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
152         return x;
153 }
154 
155 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
156 {
157         pr_debug("EC_SC(W) = 0x%2.2x\n", command);
158         outb(command, ec->command_addr);
159 }
160 
161 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
162 {
163         pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
164         outb(data, ec->data_addr);
165 }
166 
167 static int ec_transaction_completed(struct acpi_ec *ec)
168 {
169         unsigned long flags;
170         int ret = 0;
171         spin_lock_irqsave(&ec->lock, flags);
172         if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
173                 ret = 1;
174         spin_unlock_irqrestore(&ec->lock, flags);
175         return ret;
176 }
177 
178 static bool advance_transaction(struct acpi_ec *ec)
179 {
180         struct transaction *t;
181         u8 status;
182         bool wakeup = false;
183 
184         pr_debug("===== %s =====\n", in_interrupt() ? "IRQ" : "TASK");
185         status = acpi_ec_read_status(ec);
186         t = ec->curr;
187         if (!t)
188                 goto err;
189         if (t->flags & ACPI_EC_COMMAND_POLL) {
190                 if (t->wlen > t->wi) {
191                         if ((status & ACPI_EC_FLAG_IBF) == 0)
192                                 acpi_ec_write_data(ec, t->wdata[t->wi++]);
193                         else
194                                 goto err;
195                 } else if (t->rlen > t->ri) {
196                         if ((status & ACPI_EC_FLAG_OBF) == 1) {
197                                 t->rdata[t->ri++] = acpi_ec_read_data(ec);
198                                 if (t->rlen == t->ri) {
199                                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
200                                         wakeup = true;
201                                 }
202                         } else
203                                 goto err;
204                 } else if (t->wlen == t->wi &&
205                            (status & ACPI_EC_FLAG_IBF) == 0) {
206                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
207                         wakeup = true;
208                 }
209                 return wakeup;
210         } else {
211                 if ((status & ACPI_EC_FLAG_IBF) == 0) {
212                         acpi_ec_write_cmd(ec, t->command);
213                         t->flags |= ACPI_EC_COMMAND_POLL;
214                 } else
215                         goto err;
216                 return wakeup;
217         }
218 err:
219         /*
220          * If SCI bit is set, then don't think it's a false IRQ
221          * otherwise will take a not handled IRQ as a false one.
222          */
223         if (!(status & ACPI_EC_FLAG_SCI)) {
224                 if (in_interrupt() && t)
225                         ++t->irq_count;
226         }
227         return wakeup;
228 }
229 
230 static void start_transaction(struct acpi_ec *ec)
231 {
232         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
233         ec->curr->flags = 0;
234         (void)advance_transaction(ec);
235 }
236 
237 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
238 
239 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
240 {
241         if (state & ACPI_EC_FLAG_SCI) {
242                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
243                         return acpi_ec_sync_query(ec, NULL);
244         }
245         return 0;
246 }
247 
248 static int ec_poll(struct acpi_ec *ec)
249 {
250         unsigned long flags;
251         int repeat = 5; /* number of command restarts */
252         while (repeat--) {
253                 unsigned long delay = jiffies +
254                         msecs_to_jiffies(ec_delay);
255                 do {
256                         /* don't sleep with disabled interrupts */
257                         if (EC_FLAGS_MSI || irqs_disabled()) {
258                                 udelay(ACPI_EC_MSI_UDELAY);
259                                 if (ec_transaction_completed(ec))
260                                         return 0;
261                         } else {
262                                 if (wait_event_timeout(ec->wait,
263                                                 ec_transaction_completed(ec),
264                                                 msecs_to_jiffies(1)))
265                                         return 0;
266                         }
267                         spin_lock_irqsave(&ec->lock, flags);
268                         (void)advance_transaction(ec);
269                         spin_unlock_irqrestore(&ec->lock, flags);
270                 } while (time_before(jiffies, delay));
271                 pr_debug("controller reset, restart transaction\n");
272                 spin_lock_irqsave(&ec->lock, flags);
273                 start_transaction(ec);
274                 spin_unlock_irqrestore(&ec->lock, flags);
275         }
276         return -ETIME;
277 }
278 
279 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
280                                         struct transaction *t)
281 {
282         unsigned long tmp;
283         int ret = 0;
284         if (EC_FLAGS_MSI)
285                 udelay(ACPI_EC_MSI_UDELAY);
286         /* start transaction */
287         spin_lock_irqsave(&ec->lock, tmp);
288         /* following two actions should be kept atomic */
289         ec->curr = t;
290         start_transaction(ec);
291         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
292                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
293         spin_unlock_irqrestore(&ec->lock, tmp);
294         ret = ec_poll(ec);
295         spin_lock_irqsave(&ec->lock, tmp);
296         ec->curr = NULL;
297         spin_unlock_irqrestore(&ec->lock, tmp);
298         return ret;
299 }
300 
301 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
302 {
303         int status;
304         u32 glk;
305         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
306                 return -EINVAL;
307         if (t->rdata)
308                 memset(t->rdata, 0, t->rlen);
309         mutex_lock(&ec->mutex);
310         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
311                 status = -EINVAL;
312                 goto unlock;
313         }
314         if (ec->global_lock) {
315                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
316                 if (ACPI_FAILURE(status)) {
317                         status = -ENODEV;
318                         goto unlock;
319                 }
320         }
321         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
322                         t->command, t->wdata ? t->wdata[0] : 0);
323         /* disable GPE during transaction if storm is detected */
324         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
325                 /* It has to be disabled, so that it doesn't trigger. */
326                 acpi_disable_gpe(NULL, ec->gpe);
327         }
328 
329         status = acpi_ec_transaction_unlocked(ec, t);
330 
331         /* check if we received SCI during transaction */
332         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
333         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
334                 msleep(1);
335                 /* It is safe to enable the GPE outside of the transaction. */
336                 acpi_enable_gpe(NULL, ec->gpe);
337         } else if (t->irq_count > ec_storm_threshold) {
338                 pr_info("GPE storm detected(%d GPEs), "
339                         "transactions will use polling mode\n",
340                         t->irq_count);
341                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
342         }
343         pr_debug("transaction end\n");
344         if (ec->global_lock)
345                 acpi_release_global_lock(glk);
346 unlock:
347         mutex_unlock(&ec->mutex);
348         return status;
349 }
350 
351 static int acpi_ec_burst_enable(struct acpi_ec *ec)
352 {
353         u8 d;
354         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
355                                 .wdata = NULL, .rdata = &d,
356                                 .wlen = 0, .rlen = 1};
357 
358         return acpi_ec_transaction(ec, &t);
359 }
360 
361 static int acpi_ec_burst_disable(struct acpi_ec *ec)
362 {
363         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
364                                 .wdata = NULL, .rdata = NULL,
365                                 .wlen = 0, .rlen = 0};
366 
367         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
368                                 acpi_ec_transaction(ec, &t) : 0;
369 }
370 
371 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
372 {
373         int result;
374         u8 d;
375         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
376                                 .wdata = &address, .rdata = &d,
377                                 .wlen = 1, .rlen = 1};
378 
379         result = acpi_ec_transaction(ec, &t);
380         *data = d;
381         return result;
382 }
383 
384 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
385 {
386         u8 wdata[2] = { address, data };
387         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
388                                 .wdata = wdata, .rdata = NULL,
389                                 .wlen = 2, .rlen = 0};
390 
391         return acpi_ec_transaction(ec, &t);
392 }
393 
394 int ec_read(u8 addr, u8 *val)
395 {
396         int err;
397         u8 temp_data;
398 
399         if (!first_ec)
400                 return -ENODEV;
401 
402         err = acpi_ec_read(first_ec, addr, &temp_data);
403 
404         if (!err) {
405                 *val = temp_data;
406                 return 0;
407         } else
408                 return err;
409 }
410 
411 EXPORT_SYMBOL(ec_read);
412 
413 int ec_write(u8 addr, u8 val)
414 {
415         int err;
416 
417         if (!first_ec)
418                 return -ENODEV;
419 
420         err = acpi_ec_write(first_ec, addr, val);
421 
422         return err;
423 }
424 
425 EXPORT_SYMBOL(ec_write);
426 
427 int ec_transaction(u8 command,
428                    const u8 * wdata, unsigned wdata_len,
429                    u8 * rdata, unsigned rdata_len)
430 {
431         struct transaction t = {.command = command,
432                                 .wdata = wdata, .rdata = rdata,
433                                 .wlen = wdata_len, .rlen = rdata_len};
434         if (!first_ec)
435                 return -ENODEV;
436 
437         return acpi_ec_transaction(first_ec, &t);
438 }
439 
440 EXPORT_SYMBOL(ec_transaction);
441 
442 /* Get the handle to the EC device */
443 acpi_handle ec_get_handle(void)
444 {
445         if (!first_ec)
446                 return NULL;
447         return first_ec->handle;
448 }
449 
450 EXPORT_SYMBOL(ec_get_handle);
451 
452 /*
453  * Process _Q events that might have accumulated in the EC.
454  * Run with locked ec mutex.
455  */
456 static void acpi_ec_clear(struct acpi_ec *ec)
457 {
458         int i, status;
459         u8 value = 0;
460 
461         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
462                 status = acpi_ec_sync_query(ec, &value);
463                 if (status || !value)
464                         break;
465         }
466 
467         if (unlikely(i == ACPI_EC_CLEAR_MAX))
468                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
469         else
470                 pr_info("%d stale EC events cleared\n", i);
471 }
472 
473 void acpi_ec_block_transactions(void)
474 {
475         struct acpi_ec *ec = first_ec;
476 
477         if (!ec)
478                 return;
479 
480         mutex_lock(&ec->mutex);
481         /* Prevent transactions from being carried out */
482         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
483         mutex_unlock(&ec->mutex);
484 }
485 
486 void acpi_ec_unblock_transactions(void)
487 {
488         struct acpi_ec *ec = first_ec;
489 
490         if (!ec)
491                 return;
492 
493         mutex_lock(&ec->mutex);
494         /* Allow transactions to be carried out again */
495         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
496 
497         if (EC_FLAGS_CLEAR_ON_RESUME)
498                 acpi_ec_clear(ec);
499 
500         mutex_unlock(&ec->mutex);
501 }
502 
503 void acpi_ec_unblock_transactions_early(void)
504 {
505         /*
506          * Allow transactions to happen again (this function is called from
507          * atomic context during wakeup, so we don't need to acquire the mutex).
508          */
509         if (first_ec)
510                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
511 }
512 
513 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
514 {
515         int result;
516         u8 d;
517         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
518                                 .wdata = NULL, .rdata = &d,
519                                 .wlen = 0, .rlen = 1};
520         if (!ec || !data)
521                 return -EINVAL;
522         /*
523          * Query the EC to find out which _Qxx method we need to evaluate.
524          * Note that successful completion of the query causes the ACPI_EC_SCI
525          * bit to be cleared (and thus clearing the interrupt source).
526          */
527         result = acpi_ec_transaction_unlocked(ec, &t);
528         if (result)
529                 return result;
530         if (!d)
531                 return -ENODATA;
532         *data = d;
533         return 0;
534 }
535 
536 /* --------------------------------------------------------------------------
537                                 Event Management
538    -------------------------------------------------------------------------- */
539 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
540                               acpi_handle handle, acpi_ec_query_func func,
541                               void *data)
542 {
543         struct acpi_ec_query_handler *handler =
544             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
545         if (!handler)
546                 return -ENOMEM;
547 
548         handler->query_bit = query_bit;
549         handler->handle = handle;
550         handler->func = func;
551         handler->data = data;
552         mutex_lock(&ec->mutex);
553         list_add(&handler->node, &ec->list);
554         mutex_unlock(&ec->mutex);
555         return 0;
556 }
557 
558 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
559 
560 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
561 {
562         struct acpi_ec_query_handler *handler, *tmp;
563         mutex_lock(&ec->mutex);
564         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
565                 if (query_bit == handler->query_bit) {
566                         list_del(&handler->node);
567                         kfree(handler);
568                 }
569         }
570         mutex_unlock(&ec->mutex);
571 }
572 
573 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
574 
575 static void acpi_ec_run(void *cxt)
576 {
577         struct acpi_ec_query_handler *handler = cxt;
578         if (!handler)
579                 return;
580         pr_debug("start query execution\n");
581         if (handler->func)
582                 handler->func(handler->data);
583         else if (handler->handle)
584                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
585         pr_debug("stop query execution\n");
586         kfree(handler);
587 }
588 
589 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
590 {
591         u8 value = 0;
592         int status;
593         struct acpi_ec_query_handler *handler, *copy;
594 
595         status = acpi_ec_query_unlocked(ec, &value);
596         if (data)
597                 *data = value;
598         if (status)
599                 return status;
600 
601         list_for_each_entry(handler, &ec->list, node) {
602                 if (value == handler->query_bit) {
603                         /* have custom handler for this bit */
604                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
605                         if (!copy)
606                                 return -ENOMEM;
607                         memcpy(copy, handler, sizeof(*copy));
608                         pr_debug("push query execution (0x%2x) on queue\n",
609                                 value);
610                         return acpi_os_execute((copy->func) ?
611                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
612                                 acpi_ec_run, copy);
613                 }
614         }
615         return 0;
616 }
617 
618 static void acpi_ec_gpe_query(void *ec_cxt)
619 {
620         struct acpi_ec *ec = ec_cxt;
621         if (!ec)
622                 return;
623         mutex_lock(&ec->mutex);
624         acpi_ec_sync_query(ec, NULL);
625         mutex_unlock(&ec->mutex);
626 }
627 
628 static int ec_check_sci(struct acpi_ec *ec, u8 state)
629 {
630         if (state & ACPI_EC_FLAG_SCI) {
631                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
632                         pr_debug("push gpe query to the queue\n");
633                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
634                                 acpi_ec_gpe_query, ec);
635                 }
636         }
637         return 0;
638 }
639 
640 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
641         u32 gpe_number, void *data)
642 {
643         unsigned long flags;
644         struct acpi_ec *ec = data;
645 
646         spin_lock_irqsave(&ec->lock, flags);
647         if (advance_transaction(ec))
648                 wake_up(&ec->wait);
649         spin_unlock_irqrestore(&ec->lock, flags);
650         ec_check_sci(ec, acpi_ec_read_status(ec));
651         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
652 }
653 
654 /* --------------------------------------------------------------------------
655                              Address Space Management
656    -------------------------------------------------------------------------- */
657 
658 static acpi_status
659 acpi_ec_space_handler(u32 function, acpi_physical_address address,
660                       u32 bits, u64 *value64,
661                       void *handler_context, void *region_context)
662 {
663         struct acpi_ec *ec = handler_context;
664         int result = 0, i, bytes = bits / 8;
665         u8 *value = (u8 *)value64;
666 
667         if ((address > 0xFF) || !value || !handler_context)
668                 return AE_BAD_PARAMETER;
669 
670         if (function != ACPI_READ && function != ACPI_WRITE)
671                 return AE_BAD_PARAMETER;
672 
673         if (EC_FLAGS_MSI || bits > 8)
674                 acpi_ec_burst_enable(ec);
675 
676         for (i = 0; i < bytes; ++i, ++address, ++value)
677                 result = (function == ACPI_READ) ?
678                         acpi_ec_read(ec, address, value) :
679                         acpi_ec_write(ec, address, *value);
680 
681         if (EC_FLAGS_MSI || bits > 8)
682                 acpi_ec_burst_disable(ec);
683 
684         switch (result) {
685         case -EINVAL:
686                 return AE_BAD_PARAMETER;
687                 break;
688         case -ENODEV:
689                 return AE_NOT_FOUND;
690                 break;
691         case -ETIME:
692                 return AE_TIME;
693                 break;
694         default:
695                 return AE_OK;
696         }
697 }
698 
699 /* --------------------------------------------------------------------------
700                                Driver Interface
701    -------------------------------------------------------------------------- */
702 static acpi_status
703 ec_parse_io_ports(struct acpi_resource *resource, void *context);
704 
705 static struct acpi_ec *make_acpi_ec(void)
706 {
707         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
708         if (!ec)
709                 return NULL;
710         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
711         mutex_init(&ec->mutex);
712         init_waitqueue_head(&ec->wait);
713         INIT_LIST_HEAD(&ec->list);
714         spin_lock_init(&ec->lock);
715         return ec;
716 }
717 
718 static acpi_status
719 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
720                                void *context, void **return_value)
721 {
722         char node_name[5];
723         struct acpi_buffer buffer = { sizeof(node_name), node_name };
724         struct acpi_ec *ec = context;
725         int value = 0;
726         acpi_status status;
727 
728         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
729 
730         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
731                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
732         }
733         return AE_OK;
734 }
735 
736 static acpi_status
737 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
738 {
739         acpi_status status;
740         unsigned long long tmp = 0;
741 
742         struct acpi_ec *ec = context;
743 
744         /* clear addr values, ec_parse_io_ports depend on it */
745         ec->command_addr = ec->data_addr = 0;
746 
747         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
748                                      ec_parse_io_ports, ec);
749         if (ACPI_FAILURE(status))
750                 return status;
751 
752         /* Get GPE bit assignment (EC events). */
753         /* TODO: Add support for _GPE returning a package */
754         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
755         if (ACPI_FAILURE(status))
756                 return status;
757         ec->gpe = tmp;
758         /* Use the global lock for all EC transactions? */
759         tmp = 0;
760         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
761         ec->global_lock = tmp;
762         ec->handle = handle;
763         return AE_CTRL_TERMINATE;
764 }
765 
766 static int ec_install_handlers(struct acpi_ec *ec)
767 {
768         acpi_status status;
769         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
770                 return 0;
771         status = acpi_install_gpe_handler(NULL, ec->gpe,
772                                   ACPI_GPE_EDGE_TRIGGERED,
773                                   &acpi_ec_gpe_handler, ec);
774         if (ACPI_FAILURE(status))
775                 return -ENODEV;
776 
777         acpi_enable_gpe(NULL, ec->gpe);
778         status = acpi_install_address_space_handler(ec->handle,
779                                                     ACPI_ADR_SPACE_EC,
780                                                     &acpi_ec_space_handler,
781                                                     NULL, ec);
782         if (ACPI_FAILURE(status)) {
783                 if (status == AE_NOT_FOUND) {
784                         /*
785                          * Maybe OS fails in evaluating the _REG object.
786                          * The AE_NOT_FOUND error will be ignored and OS
787                          * continue to initialize EC.
788                          */
789                         pr_err("Fail in evaluating the _REG object"
790                                 " of EC device. Broken bios is suspected.\n");
791                 } else {
792                         acpi_disable_gpe(NULL, ec->gpe);
793                         acpi_remove_gpe_handler(NULL, ec->gpe,
794                                 &acpi_ec_gpe_handler);
795                         return -ENODEV;
796                 }
797         }
798 
799         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
800         return 0;
801 }
802 
803 static void ec_remove_handlers(struct acpi_ec *ec)
804 {
805         acpi_disable_gpe(NULL, ec->gpe);
806         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
807                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
808                 pr_err("failed to remove space handler\n");
809         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
810                                 &acpi_ec_gpe_handler)))
811                 pr_err("failed to remove gpe handler\n");
812         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
813 }
814 
815 static int acpi_ec_add(struct acpi_device *device)
816 {
817         struct acpi_ec *ec = NULL;
818         int ret;
819 
820         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
821         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
822 
823         /* Check for boot EC */
824         if (boot_ec &&
825             (boot_ec->handle == device->handle ||
826              boot_ec->handle == ACPI_ROOT_OBJECT)) {
827                 ec = boot_ec;
828                 boot_ec = NULL;
829         } else {
830                 ec = make_acpi_ec();
831                 if (!ec)
832                         return -ENOMEM;
833         }
834         if (ec_parse_device(device->handle, 0, ec, NULL) !=
835                 AE_CTRL_TERMINATE) {
836                         kfree(ec);
837                         return -EINVAL;
838         }
839 
840         /* Find and register all query methods */
841         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
842                             acpi_ec_register_query_methods, NULL, ec, NULL);
843 
844         if (!first_ec)
845                 first_ec = ec;
846         device->driver_data = ec;
847 
848         ret = !!request_region(ec->data_addr, 1, "EC data");
849         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
850         ret = !!request_region(ec->command_addr, 1, "EC cmd");
851         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
852 
853         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
854                           ec->gpe, ec->command_addr, ec->data_addr);
855 
856         ret = ec_install_handlers(ec);
857 
858         /* EC is fully operational, allow queries */
859         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
860 
861         /* Clear stale _Q events if hardware might require that */
862         if (EC_FLAGS_CLEAR_ON_RESUME) {
863                 mutex_lock(&ec->mutex);
864                 acpi_ec_clear(ec);
865                 mutex_unlock(&ec->mutex);
866         }
867         return ret;
868 }
869 
870 static int acpi_ec_remove(struct acpi_device *device)
871 {
872         struct acpi_ec *ec;
873         struct acpi_ec_query_handler *handler, *tmp;
874 
875         if (!device)
876                 return -EINVAL;
877 
878         ec = acpi_driver_data(device);
879         ec_remove_handlers(ec);
880         mutex_lock(&ec->mutex);
881         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
882                 list_del(&handler->node);
883                 kfree(handler);
884         }
885         mutex_unlock(&ec->mutex);
886         release_region(ec->data_addr, 1);
887         release_region(ec->command_addr, 1);
888         device->driver_data = NULL;
889         if (ec == first_ec)
890                 first_ec = NULL;
891         kfree(ec);
892         return 0;
893 }
894 
895 static acpi_status
896 ec_parse_io_ports(struct acpi_resource *resource, void *context)
897 {
898         struct acpi_ec *ec = context;
899 
900         if (resource->type != ACPI_RESOURCE_TYPE_IO)
901                 return AE_OK;
902 
903         /*
904          * The first address region returned is the data port, and
905          * the second address region returned is the status/command
906          * port.
907          */
908         if (ec->data_addr == 0)
909                 ec->data_addr = resource->data.io.minimum;
910         else if (ec->command_addr == 0)
911                 ec->command_addr = resource->data.io.minimum;
912         else
913                 return AE_CTRL_TERMINATE;
914 
915         return AE_OK;
916 }
917 
918 int __init acpi_boot_ec_enable(void)
919 {
920         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
921                 return 0;
922         if (!ec_install_handlers(boot_ec)) {
923                 first_ec = boot_ec;
924                 return 0;
925         }
926         return -EFAULT;
927 }
928 
929 static const struct acpi_device_id ec_device_ids[] = {
930         {"PNP0C09", 0},
931         {"", 0},
932 };
933 
934 /* Some BIOS do not survive early DSDT scan, skip it */
935 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
936 {
937         EC_FLAGS_SKIP_DSDT_SCAN = 1;
938         return 0;
939 }
940 
941 /* ASUStek often supplies us with broken ECDT, validate it */
942 static int ec_validate_ecdt(const struct dmi_system_id *id)
943 {
944         EC_FLAGS_VALIDATE_ECDT = 1;
945         return 0;
946 }
947 
948 /* MSI EC needs special treatment, enable it */
949 static int ec_flag_msi(const struct dmi_system_id *id)
950 {
951         pr_debug("Detected MSI hardware, enabling workarounds.\n");
952         EC_FLAGS_MSI = 1;
953         EC_FLAGS_VALIDATE_ECDT = 1;
954         return 0;
955 }
956 
957 /*
958  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
959  * the GPE storm threshold back to 20
960  */
961 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
962 {
963         pr_debug("Setting the EC GPE storm threshold to 20\n");
964         ec_storm_threshold  = 20;
965         return 0;
966 }
967 
968 /*
969  * On some hardware it is necessary to clear events accumulated by the EC during
970  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
971  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
972  *
973  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
974  *
975  * Ideally, the EC should also be instructed NOT to accumulate events during
976  * sleep (which Windows seems to do somehow), but the interface to control this
977  * behaviour is not known at this time.
978  *
979  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
980  * however it is very likely that other Samsung models are affected.
981  *
982  * On systems which don't accumulate _Q events during sleep, this extra check
983  * should be harmless.
984  */
985 static int ec_clear_on_resume(const struct dmi_system_id *id)
986 {
987         pr_debug("Detected system needing EC poll on resume.\n");
988         EC_FLAGS_CLEAR_ON_RESUME = 1;
989         return 0;
990 }
991 
992 static struct dmi_system_id ec_dmi_table[] __initdata = {
993         {
994         ec_skip_dsdt_scan, "Compal JFL92", {
995         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
996         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
997         {
998         ec_flag_msi, "MSI hardware", {
999         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1000         {
1001         ec_flag_msi, "MSI hardware", {
1002         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1003         {
1004         ec_flag_msi, "MSI hardware", {
1005         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1006         {
1007         ec_flag_msi, "MSI hardware", {
1008         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1009         {
1010         ec_flag_msi, "Quanta hardware", {
1011         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1012         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1013         {
1014         ec_flag_msi, "Quanta hardware", {
1015         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1016         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1017         {
1018         ec_validate_ecdt, "ASUS hardware", {
1019         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1020         {
1021         ec_validate_ecdt, "ASUS hardware", {
1022         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1023         {
1024         ec_enlarge_storm_threshold, "CLEVO hardware", {
1025         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1026         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1027         {
1028         ec_skip_dsdt_scan, "HP Folio 13", {
1029         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1030         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1031         {
1032         ec_validate_ecdt, "ASUS hardware", {
1033         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1034         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1035         {
1036         ec_clear_on_resume, "Samsung hardware", {
1037         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1038         {},
1039 };
1040 
1041 int __init acpi_ec_ecdt_probe(void)
1042 {
1043         acpi_status status;
1044         struct acpi_ec *saved_ec = NULL;
1045         struct acpi_table_ecdt *ecdt_ptr;
1046 
1047         boot_ec = make_acpi_ec();
1048         if (!boot_ec)
1049                 return -ENOMEM;
1050         /*
1051          * Generate a boot ec context
1052          */
1053         dmi_check_system(ec_dmi_table);
1054         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1055                                 (struct acpi_table_header **)&ecdt_ptr);
1056         if (ACPI_SUCCESS(status)) {
1057                 pr_info("EC description table is found, configuring boot EC\n");
1058                 boot_ec->command_addr = ecdt_ptr->control.address;
1059                 boot_ec->data_addr = ecdt_ptr->data.address;
1060                 boot_ec->gpe = ecdt_ptr->gpe;
1061                 boot_ec->handle = ACPI_ROOT_OBJECT;
1062                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1063                 /* Don't trust ECDT, which comes from ASUSTek */
1064                 if (!EC_FLAGS_VALIDATE_ECDT)
1065                         goto install;
1066                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1067                 if (!saved_ec)
1068                         return -ENOMEM;
1069         /* fall through */
1070         }
1071 
1072         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1073                 kfree(saved_ec);
1074                 return -ENODEV;
1075         }
1076 
1077         /* This workaround is needed only on some broken machines,
1078          * which require early EC, but fail to provide ECDT */
1079         pr_debug("Look up EC in DSDT\n");
1080         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1081                                         boot_ec, NULL);
1082         /* Check that acpi_get_devices actually find something */
1083         if (ACPI_FAILURE(status) || !boot_ec->handle)
1084                 goto error;
1085         if (saved_ec) {
1086                 /* try to find good ECDT from ASUSTek */
1087                 if (saved_ec->command_addr != boot_ec->command_addr ||
1088                     saved_ec->data_addr != boot_ec->data_addr ||
1089                     saved_ec->gpe != boot_ec->gpe ||
1090                     saved_ec->handle != boot_ec->handle)
1091                         pr_info("ASUSTek keeps feeding us with broken "
1092                         "ECDT tables, which are very hard to workaround. "
1093                         "Trying to use DSDT EC info instead. Please send "
1094                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1095                 kfree(saved_ec);
1096                 saved_ec = NULL;
1097         } else {
1098                 /* We really need to limit this workaround, the only ASUS,
1099                 * which needs it, has fake EC._INI method, so use it as flag.
1100                 * Keep boot_ec struct as it will be needed soon.
1101                 */
1102                 if (!dmi_name_in_vendors("ASUS") ||
1103                     !acpi_has_method(boot_ec->handle, "_INI"))
1104                         return -ENODEV;
1105         }
1106 install:
1107         if (!ec_install_handlers(boot_ec)) {
1108                 first_ec = boot_ec;
1109                 return 0;
1110         }
1111 error:
1112         kfree(boot_ec);
1113         kfree(saved_ec);
1114         boot_ec = NULL;
1115         return -ENODEV;
1116 }
1117 
1118 static struct acpi_driver acpi_ec_driver = {
1119         .name = "ec",
1120         .class = ACPI_EC_CLASS,
1121         .ids = ec_device_ids,
1122         .ops = {
1123                 .add = acpi_ec_add,
1124                 .remove = acpi_ec_remove,
1125                 },
1126 };
1127 
1128 int __init acpi_ec_init(void)
1129 {
1130         int result = 0;
1131 
1132         /* Now register the driver for the EC */
1133         result = acpi_bus_register_driver(&acpi_ec_driver);
1134         if (result < 0)
1135                 return -ENODEV;
1136 
1137         return result;
1138 }
1139 
1140 /* EC driver currently not unloadable */
1141 #if 0
1142 static void __exit acpi_ec_exit(void)
1143 {
1144 
1145         acpi_bus_unregister_driver(&acpi_ec_driver);
1146         return;
1147 }
1148 #endif  /* 0 */
1149 

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