Version:  2.0.40 2.2.26 2.4.37 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 3.17

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                                         if (t->command == ACPI_EC_COMMAND_QUERY)
201                                                 pr_debug("hardware QR_EC completion\n");
202                                         wakeup = true;
203                                 }
204                         } else
205                                 goto err;
206                 } else if (t->wlen == t->wi &&
207                            (status & ACPI_EC_FLAG_IBF) == 0) {
208                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
209                         wakeup = true;
210                 }
211                 return wakeup;
212         } else {
213                 /*
214                  * There is firmware refusing to respond QR_EC when SCI_EVT
215                  * is not set, for which case, we complete the QR_EC
216                  * without issuing it to the firmware.
217                  * https://bugzilla.kernel.org/show_bug.cgi?id=86211
218                  */
219                 if (!(status & ACPI_EC_FLAG_SCI) &&
220                     (t->command == ACPI_EC_COMMAND_QUERY)) {
221                         t->flags |= ACPI_EC_COMMAND_POLL;
222                         t->rdata[t->ri++] = 0x00;
223                         t->flags |= ACPI_EC_COMMAND_COMPLETE;
224                         pr_debug("software QR_EC completion\n");
225                         wakeup = true;
226                 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
227                         acpi_ec_write_cmd(ec, t->command);
228                         t->flags |= ACPI_EC_COMMAND_POLL;
229                 } else
230                         goto err;
231                 return wakeup;
232         }
233 err:
234         /*
235          * If SCI bit is set, then don't think it's a false IRQ
236          * otherwise will take a not handled IRQ as a false one.
237          */
238         if (!(status & ACPI_EC_FLAG_SCI)) {
239                 if (in_interrupt() && t)
240                         ++t->irq_count;
241         }
242         return wakeup;
243 }
244 
245 static void start_transaction(struct acpi_ec *ec)
246 {
247         ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
248         ec->curr->flags = 0;
249         (void)advance_transaction(ec);
250 }
251 
252 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
253 
254 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
255 {
256         if (state & ACPI_EC_FLAG_SCI) {
257                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
258                         return acpi_ec_sync_query(ec, NULL);
259         }
260         return 0;
261 }
262 
263 static int ec_poll(struct acpi_ec *ec)
264 {
265         unsigned long flags;
266         int repeat = 5; /* number of command restarts */
267         while (repeat--) {
268                 unsigned long delay = jiffies +
269                         msecs_to_jiffies(ec_delay);
270                 do {
271                         /* don't sleep with disabled interrupts */
272                         if (EC_FLAGS_MSI || irqs_disabled()) {
273                                 udelay(ACPI_EC_MSI_UDELAY);
274                                 if (ec_transaction_completed(ec))
275                                         return 0;
276                         } else {
277                                 if (wait_event_timeout(ec->wait,
278                                                 ec_transaction_completed(ec),
279                                                 msecs_to_jiffies(1)))
280                                         return 0;
281                         }
282                         spin_lock_irqsave(&ec->lock, flags);
283                         (void)advance_transaction(ec);
284                         spin_unlock_irqrestore(&ec->lock, flags);
285                 } while (time_before(jiffies, delay));
286                 pr_debug("controller reset, restart transaction\n");
287                 spin_lock_irqsave(&ec->lock, flags);
288                 start_transaction(ec);
289                 spin_unlock_irqrestore(&ec->lock, flags);
290         }
291         return -ETIME;
292 }
293 
294 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
295                                         struct transaction *t)
296 {
297         unsigned long tmp;
298         int ret = 0;
299         if (EC_FLAGS_MSI)
300                 udelay(ACPI_EC_MSI_UDELAY);
301         /* start transaction */
302         spin_lock_irqsave(&ec->lock, tmp);
303         /* following two actions should be kept atomic */
304         ec->curr = t;
305         start_transaction(ec);
306         spin_unlock_irqrestore(&ec->lock, tmp);
307         ret = ec_poll(ec);
308         spin_lock_irqsave(&ec->lock, tmp);
309         if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
310                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
311         ec->curr = NULL;
312         spin_unlock_irqrestore(&ec->lock, tmp);
313         return ret;
314 }
315 
316 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
317 {
318         int status;
319         u32 glk;
320         if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
321                 return -EINVAL;
322         if (t->rdata)
323                 memset(t->rdata, 0, t->rlen);
324         mutex_lock(&ec->mutex);
325         if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
326                 status = -EINVAL;
327                 goto unlock;
328         }
329         if (ec->global_lock) {
330                 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
331                 if (ACPI_FAILURE(status)) {
332                         status = -ENODEV;
333                         goto unlock;
334                 }
335         }
336         pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
337                         t->command, t->wdata ? t->wdata[0] : 0);
338         /* disable GPE during transaction if storm is detected */
339         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
340                 /* It has to be disabled, so that it doesn't trigger. */
341                 acpi_disable_gpe(NULL, ec->gpe);
342         }
343 
344         status = acpi_ec_transaction_unlocked(ec, t);
345 
346         /* check if we received SCI during transaction */
347         ec_check_sci_sync(ec, acpi_ec_read_status(ec));
348         if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
349                 msleep(1);
350                 /* It is safe to enable the GPE outside of the transaction. */
351                 acpi_enable_gpe(NULL, ec->gpe);
352         } else if (t->irq_count > ec_storm_threshold) {
353                 pr_info("GPE storm detected(%d GPEs), "
354                         "transactions will use polling mode\n",
355                         t->irq_count);
356                 set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
357         }
358         pr_debug("transaction end\n");
359         if (ec->global_lock)
360                 acpi_release_global_lock(glk);
361 unlock:
362         mutex_unlock(&ec->mutex);
363         return status;
364 }
365 
366 static int acpi_ec_burst_enable(struct acpi_ec *ec)
367 {
368         u8 d;
369         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
370                                 .wdata = NULL, .rdata = &d,
371                                 .wlen = 0, .rlen = 1};
372 
373         return acpi_ec_transaction(ec, &t);
374 }
375 
376 static int acpi_ec_burst_disable(struct acpi_ec *ec)
377 {
378         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
379                                 .wdata = NULL, .rdata = NULL,
380                                 .wlen = 0, .rlen = 0};
381 
382         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
383                                 acpi_ec_transaction(ec, &t) : 0;
384 }
385 
386 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
387 {
388         int result;
389         u8 d;
390         struct transaction t = {.command = ACPI_EC_COMMAND_READ,
391                                 .wdata = &address, .rdata = &d,
392                                 .wlen = 1, .rlen = 1};
393 
394         result = acpi_ec_transaction(ec, &t);
395         *data = d;
396         return result;
397 }
398 
399 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
400 {
401         u8 wdata[2] = { address, data };
402         struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
403                                 .wdata = wdata, .rdata = NULL,
404                                 .wlen = 2, .rlen = 0};
405 
406         return acpi_ec_transaction(ec, &t);
407 }
408 
409 int ec_read(u8 addr, u8 *val)
410 {
411         int err;
412         u8 temp_data;
413 
414         if (!first_ec)
415                 return -ENODEV;
416 
417         err = acpi_ec_read(first_ec, addr, &temp_data);
418 
419         if (!err) {
420                 *val = temp_data;
421                 return 0;
422         } else
423                 return err;
424 }
425 
426 EXPORT_SYMBOL(ec_read);
427 
428 int ec_write(u8 addr, u8 val)
429 {
430         int err;
431 
432         if (!first_ec)
433                 return -ENODEV;
434 
435         err = acpi_ec_write(first_ec, addr, val);
436 
437         return err;
438 }
439 
440 EXPORT_SYMBOL(ec_write);
441 
442 int ec_transaction(u8 command,
443                    const u8 * wdata, unsigned wdata_len,
444                    u8 * rdata, unsigned rdata_len)
445 {
446         struct transaction t = {.command = command,
447                                 .wdata = wdata, .rdata = rdata,
448                                 .wlen = wdata_len, .rlen = rdata_len};
449         if (!first_ec)
450                 return -ENODEV;
451 
452         return acpi_ec_transaction(first_ec, &t);
453 }
454 
455 EXPORT_SYMBOL(ec_transaction);
456 
457 /* Get the handle to the EC device */
458 acpi_handle ec_get_handle(void)
459 {
460         if (!first_ec)
461                 return NULL;
462         return first_ec->handle;
463 }
464 
465 EXPORT_SYMBOL(ec_get_handle);
466 
467 /*
468  * Process _Q events that might have accumulated in the EC.
469  * Run with locked ec mutex.
470  */
471 static void acpi_ec_clear(struct acpi_ec *ec)
472 {
473         int i, status;
474         u8 value = 0;
475 
476         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
477                 status = acpi_ec_sync_query(ec, &value);
478                 if (status || !value)
479                         break;
480         }
481 
482         if (unlikely(i == ACPI_EC_CLEAR_MAX))
483                 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
484         else
485                 pr_info("%d stale EC events cleared\n", i);
486 }
487 
488 void acpi_ec_block_transactions(void)
489 {
490         struct acpi_ec *ec = first_ec;
491 
492         if (!ec)
493                 return;
494 
495         mutex_lock(&ec->mutex);
496         /* Prevent transactions from being carried out */
497         set_bit(EC_FLAGS_BLOCKED, &ec->flags);
498         mutex_unlock(&ec->mutex);
499 }
500 
501 void acpi_ec_unblock_transactions(void)
502 {
503         struct acpi_ec *ec = first_ec;
504 
505         if (!ec)
506                 return;
507 
508         mutex_lock(&ec->mutex);
509         /* Allow transactions to be carried out again */
510         clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
511 
512         if (EC_FLAGS_CLEAR_ON_RESUME)
513                 acpi_ec_clear(ec);
514 
515         mutex_unlock(&ec->mutex);
516 }
517 
518 void acpi_ec_unblock_transactions_early(void)
519 {
520         /*
521          * Allow transactions to happen again (this function is called from
522          * atomic context during wakeup, so we don't need to acquire the mutex).
523          */
524         if (first_ec)
525                 clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
526 }
527 
528 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
529 {
530         int result;
531         u8 d;
532         struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
533                                 .wdata = NULL, .rdata = &d,
534                                 .wlen = 0, .rlen = 1};
535         if (!ec || !data)
536                 return -EINVAL;
537         /*
538          * Query the EC to find out which _Qxx method we need to evaluate.
539          * Note that successful completion of the query causes the ACPI_EC_SCI
540          * bit to be cleared (and thus clearing the interrupt source).
541          */
542         result = acpi_ec_transaction_unlocked(ec, &t);
543         if (result)
544                 return result;
545         if (!d)
546                 return -ENODATA;
547         *data = d;
548         return 0;
549 }
550 
551 /* --------------------------------------------------------------------------
552                                 Event Management
553    -------------------------------------------------------------------------- */
554 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
555                               acpi_handle handle, acpi_ec_query_func func,
556                               void *data)
557 {
558         struct acpi_ec_query_handler *handler =
559             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
560         if (!handler)
561                 return -ENOMEM;
562 
563         handler->query_bit = query_bit;
564         handler->handle = handle;
565         handler->func = func;
566         handler->data = data;
567         mutex_lock(&ec->mutex);
568         list_add(&handler->node, &ec->list);
569         mutex_unlock(&ec->mutex);
570         return 0;
571 }
572 
573 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
574 
575 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
576 {
577         struct acpi_ec_query_handler *handler, *tmp;
578         mutex_lock(&ec->mutex);
579         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
580                 if (query_bit == handler->query_bit) {
581                         list_del(&handler->node);
582                         kfree(handler);
583                 }
584         }
585         mutex_unlock(&ec->mutex);
586 }
587 
588 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
589 
590 static void acpi_ec_run(void *cxt)
591 {
592         struct acpi_ec_query_handler *handler = cxt;
593         if (!handler)
594                 return;
595         pr_debug("start query execution\n");
596         if (handler->func)
597                 handler->func(handler->data);
598         else if (handler->handle)
599                 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
600         pr_debug("stop query execution\n");
601         kfree(handler);
602 }
603 
604 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
605 {
606         u8 value = 0;
607         int status;
608         struct acpi_ec_query_handler *handler, *copy;
609 
610         status = acpi_ec_query_unlocked(ec, &value);
611         if (data)
612                 *data = value;
613         if (status)
614                 return status;
615 
616         list_for_each_entry(handler, &ec->list, node) {
617                 if (value == handler->query_bit) {
618                         /* have custom handler for this bit */
619                         copy = kmalloc(sizeof(*handler), GFP_KERNEL);
620                         if (!copy)
621                                 return -ENOMEM;
622                         memcpy(copy, handler, sizeof(*copy));
623                         pr_debug("push query execution (0x%2x) on queue\n",
624                                 value);
625                         return acpi_os_execute((copy->func) ?
626                                 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
627                                 acpi_ec_run, copy);
628                 }
629         }
630         return 0;
631 }
632 
633 static void acpi_ec_gpe_query(void *ec_cxt)
634 {
635         struct acpi_ec *ec = ec_cxt;
636         if (!ec)
637                 return;
638         mutex_lock(&ec->mutex);
639         acpi_ec_sync_query(ec, NULL);
640         mutex_unlock(&ec->mutex);
641 }
642 
643 static int ec_check_sci(struct acpi_ec *ec, u8 state)
644 {
645         if (state & ACPI_EC_FLAG_SCI) {
646                 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
647                         pr_debug("push gpe query to the queue\n");
648                         return acpi_os_execute(OSL_NOTIFY_HANDLER,
649                                 acpi_ec_gpe_query, ec);
650                 }
651         }
652         return 0;
653 }
654 
655 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
656         u32 gpe_number, void *data)
657 {
658         unsigned long flags;
659         struct acpi_ec *ec = data;
660 
661         spin_lock_irqsave(&ec->lock, flags);
662         if (advance_transaction(ec))
663                 wake_up(&ec->wait);
664         spin_unlock_irqrestore(&ec->lock, flags);
665         ec_check_sci(ec, acpi_ec_read_status(ec));
666         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
667 }
668 
669 /* --------------------------------------------------------------------------
670                              Address Space Management
671    -------------------------------------------------------------------------- */
672 
673 static acpi_status
674 acpi_ec_space_handler(u32 function, acpi_physical_address address,
675                       u32 bits, u64 *value64,
676                       void *handler_context, void *region_context)
677 {
678         struct acpi_ec *ec = handler_context;
679         int result = 0, i, bytes = bits / 8;
680         u8 *value = (u8 *)value64;
681 
682         if ((address > 0xFF) || !value || !handler_context)
683                 return AE_BAD_PARAMETER;
684 
685         if (function != ACPI_READ && function != ACPI_WRITE)
686                 return AE_BAD_PARAMETER;
687 
688         if (EC_FLAGS_MSI || bits > 8)
689                 acpi_ec_burst_enable(ec);
690 
691         for (i = 0; i < bytes; ++i, ++address, ++value)
692                 result = (function == ACPI_READ) ?
693                         acpi_ec_read(ec, address, value) :
694                         acpi_ec_write(ec, address, *value);
695 
696         if (EC_FLAGS_MSI || bits > 8)
697                 acpi_ec_burst_disable(ec);
698 
699         switch (result) {
700         case -EINVAL:
701                 return AE_BAD_PARAMETER;
702                 break;
703         case -ENODEV:
704                 return AE_NOT_FOUND;
705                 break;
706         case -ETIME:
707                 return AE_TIME;
708                 break;
709         default:
710                 return AE_OK;
711         }
712 }
713 
714 /* --------------------------------------------------------------------------
715                                Driver Interface
716    -------------------------------------------------------------------------- */
717 static acpi_status
718 ec_parse_io_ports(struct acpi_resource *resource, void *context);
719 
720 static struct acpi_ec *make_acpi_ec(void)
721 {
722         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
723         if (!ec)
724                 return NULL;
725         ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
726         mutex_init(&ec->mutex);
727         init_waitqueue_head(&ec->wait);
728         INIT_LIST_HEAD(&ec->list);
729         spin_lock_init(&ec->lock);
730         return ec;
731 }
732 
733 static acpi_status
734 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
735                                void *context, void **return_value)
736 {
737         char node_name[5];
738         struct acpi_buffer buffer = { sizeof(node_name), node_name };
739         struct acpi_ec *ec = context;
740         int value = 0;
741         acpi_status status;
742 
743         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
744 
745         if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
746                 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
747         }
748         return AE_OK;
749 }
750 
751 static acpi_status
752 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
753 {
754         acpi_status status;
755         unsigned long long tmp = 0;
756 
757         struct acpi_ec *ec = context;
758 
759         /* clear addr values, ec_parse_io_ports depend on it */
760         ec->command_addr = ec->data_addr = 0;
761 
762         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
763                                      ec_parse_io_ports, ec);
764         if (ACPI_FAILURE(status))
765                 return status;
766 
767         /* Get GPE bit assignment (EC events). */
768         /* TODO: Add support for _GPE returning a package */
769         status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
770         if (ACPI_FAILURE(status))
771                 return status;
772         ec->gpe = tmp;
773         /* Use the global lock for all EC transactions? */
774         tmp = 0;
775         acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
776         ec->global_lock = tmp;
777         ec->handle = handle;
778         return AE_CTRL_TERMINATE;
779 }
780 
781 static int ec_install_handlers(struct acpi_ec *ec)
782 {
783         acpi_status status;
784         if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
785                 return 0;
786         status = acpi_install_gpe_handler(NULL, ec->gpe,
787                                   ACPI_GPE_EDGE_TRIGGERED,
788                                   &acpi_ec_gpe_handler, ec);
789         if (ACPI_FAILURE(status))
790                 return -ENODEV;
791 
792         acpi_enable_gpe(NULL, ec->gpe);
793         status = acpi_install_address_space_handler(ec->handle,
794                                                     ACPI_ADR_SPACE_EC,
795                                                     &acpi_ec_space_handler,
796                                                     NULL, ec);
797         if (ACPI_FAILURE(status)) {
798                 if (status == AE_NOT_FOUND) {
799                         /*
800                          * Maybe OS fails in evaluating the _REG object.
801                          * The AE_NOT_FOUND error will be ignored and OS
802                          * continue to initialize EC.
803                          */
804                         pr_err("Fail in evaluating the _REG object"
805                                 " of EC device. Broken bios is suspected.\n");
806                 } else {
807                         acpi_disable_gpe(NULL, ec->gpe);
808                         acpi_remove_gpe_handler(NULL, ec->gpe,
809                                 &acpi_ec_gpe_handler);
810                         return -ENODEV;
811                 }
812         }
813 
814         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
815         return 0;
816 }
817 
818 static void ec_remove_handlers(struct acpi_ec *ec)
819 {
820         acpi_disable_gpe(NULL, ec->gpe);
821         if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
822                                 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
823                 pr_err("failed to remove space handler\n");
824         if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
825                                 &acpi_ec_gpe_handler)))
826                 pr_err("failed to remove gpe handler\n");
827         clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
828 }
829 
830 static int acpi_ec_add(struct acpi_device *device)
831 {
832         struct acpi_ec *ec = NULL;
833         int ret;
834 
835         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
836         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
837 
838         /* Check for boot EC */
839         if (boot_ec &&
840             (boot_ec->handle == device->handle ||
841              boot_ec->handle == ACPI_ROOT_OBJECT)) {
842                 ec = boot_ec;
843                 boot_ec = NULL;
844         } else {
845                 ec = make_acpi_ec();
846                 if (!ec)
847                         return -ENOMEM;
848         }
849         if (ec_parse_device(device->handle, 0, ec, NULL) !=
850                 AE_CTRL_TERMINATE) {
851                         kfree(ec);
852                         return -EINVAL;
853         }
854 
855         /* Find and register all query methods */
856         acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
857                             acpi_ec_register_query_methods, NULL, ec, NULL);
858 
859         if (!first_ec)
860                 first_ec = ec;
861         device->driver_data = ec;
862 
863         ret = !!request_region(ec->data_addr, 1, "EC data");
864         WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
865         ret = !!request_region(ec->command_addr, 1, "EC cmd");
866         WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
867 
868         pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
869                           ec->gpe, ec->command_addr, ec->data_addr);
870 
871         ret = ec_install_handlers(ec);
872 
873         /* EC is fully operational, allow queries */
874         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
875 
876         /* Clear stale _Q events if hardware might require that */
877         if (EC_FLAGS_CLEAR_ON_RESUME) {
878                 mutex_lock(&ec->mutex);
879                 acpi_ec_clear(ec);
880                 mutex_unlock(&ec->mutex);
881         }
882         return ret;
883 }
884 
885 static int acpi_ec_remove(struct acpi_device *device)
886 {
887         struct acpi_ec *ec;
888         struct acpi_ec_query_handler *handler, *tmp;
889 
890         if (!device)
891                 return -EINVAL;
892 
893         ec = acpi_driver_data(device);
894         ec_remove_handlers(ec);
895         mutex_lock(&ec->mutex);
896         list_for_each_entry_safe(handler, tmp, &ec->list, node) {
897                 list_del(&handler->node);
898                 kfree(handler);
899         }
900         mutex_unlock(&ec->mutex);
901         release_region(ec->data_addr, 1);
902         release_region(ec->command_addr, 1);
903         device->driver_data = NULL;
904         if (ec == first_ec)
905                 first_ec = NULL;
906         kfree(ec);
907         return 0;
908 }
909 
910 static acpi_status
911 ec_parse_io_ports(struct acpi_resource *resource, void *context)
912 {
913         struct acpi_ec *ec = context;
914 
915         if (resource->type != ACPI_RESOURCE_TYPE_IO)
916                 return AE_OK;
917 
918         /*
919          * The first address region returned is the data port, and
920          * the second address region returned is the status/command
921          * port.
922          */
923         if (ec->data_addr == 0)
924                 ec->data_addr = resource->data.io.minimum;
925         else if (ec->command_addr == 0)
926                 ec->command_addr = resource->data.io.minimum;
927         else
928                 return AE_CTRL_TERMINATE;
929 
930         return AE_OK;
931 }
932 
933 int __init acpi_boot_ec_enable(void)
934 {
935         if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
936                 return 0;
937         if (!ec_install_handlers(boot_ec)) {
938                 first_ec = boot_ec;
939                 return 0;
940         }
941         return -EFAULT;
942 }
943 
944 static const struct acpi_device_id ec_device_ids[] = {
945         {"PNP0C09", 0},
946         {"", 0},
947 };
948 
949 /* Some BIOS do not survive early DSDT scan, skip it */
950 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
951 {
952         EC_FLAGS_SKIP_DSDT_SCAN = 1;
953         return 0;
954 }
955 
956 /* ASUStek often supplies us with broken ECDT, validate it */
957 static int ec_validate_ecdt(const struct dmi_system_id *id)
958 {
959         EC_FLAGS_VALIDATE_ECDT = 1;
960         return 0;
961 }
962 
963 /* MSI EC needs special treatment, enable it */
964 static int ec_flag_msi(const struct dmi_system_id *id)
965 {
966         pr_debug("Detected MSI hardware, enabling workarounds.\n");
967         EC_FLAGS_MSI = 1;
968         EC_FLAGS_VALIDATE_ECDT = 1;
969         return 0;
970 }
971 
972 /*
973  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
974  * the GPE storm threshold back to 20
975  */
976 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
977 {
978         pr_debug("Setting the EC GPE storm threshold to 20\n");
979         ec_storm_threshold  = 20;
980         return 0;
981 }
982 
983 /*
984  * On some hardware it is necessary to clear events accumulated by the EC during
985  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
986  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
987  *
988  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
989  *
990  * Ideally, the EC should also be instructed NOT to accumulate events during
991  * sleep (which Windows seems to do somehow), but the interface to control this
992  * behaviour is not known at this time.
993  *
994  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
995  * however it is very likely that other Samsung models are affected.
996  *
997  * On systems which don't accumulate _Q events during sleep, this extra check
998  * should be harmless.
999  */
1000 static int ec_clear_on_resume(const struct dmi_system_id *id)
1001 {
1002         pr_debug("Detected system needing EC poll on resume.\n");
1003         EC_FLAGS_CLEAR_ON_RESUME = 1;
1004         return 0;
1005 }
1006 
1007 static struct dmi_system_id ec_dmi_table[] __initdata = {
1008         {
1009         ec_skip_dsdt_scan, "Compal JFL92", {
1010         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1011         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1012         {
1013         ec_flag_msi, "MSI hardware", {
1014         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1015         {
1016         ec_flag_msi, "MSI hardware", {
1017         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1018         {
1019         ec_flag_msi, "MSI hardware", {
1020         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1021         {
1022         ec_flag_msi, "MSI hardware", {
1023         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1024         {
1025         ec_flag_msi, "Quanta hardware", {
1026         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1027         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1028         {
1029         ec_flag_msi, "Quanta hardware", {
1030         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1031         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1032         {
1033         ec_flag_msi, "Clevo W350etq", {
1034         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1035         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1036         {
1037         ec_validate_ecdt, "ASUS hardware", {
1038         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1039         {
1040         ec_validate_ecdt, "ASUS hardware", {
1041         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1042         {
1043         ec_enlarge_storm_threshold, "CLEVO hardware", {
1044         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1045         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1046         {
1047         ec_skip_dsdt_scan, "HP Folio 13", {
1048         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1049         DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1050         {
1051         ec_validate_ecdt, "ASUS hardware", {
1052         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1053         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1054         {
1055         ec_clear_on_resume, "Samsung hardware", {
1056         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1057         {},
1058 };
1059 
1060 int __init acpi_ec_ecdt_probe(void)
1061 {
1062         acpi_status status;
1063         struct acpi_ec *saved_ec = NULL;
1064         struct acpi_table_ecdt *ecdt_ptr;
1065 
1066         boot_ec = make_acpi_ec();
1067         if (!boot_ec)
1068                 return -ENOMEM;
1069         /*
1070          * Generate a boot ec context
1071          */
1072         dmi_check_system(ec_dmi_table);
1073         status = acpi_get_table(ACPI_SIG_ECDT, 1,
1074                                 (struct acpi_table_header **)&ecdt_ptr);
1075         if (ACPI_SUCCESS(status)) {
1076                 pr_info("EC description table is found, configuring boot EC\n");
1077                 boot_ec->command_addr = ecdt_ptr->control.address;
1078                 boot_ec->data_addr = ecdt_ptr->data.address;
1079                 boot_ec->gpe = ecdt_ptr->gpe;
1080                 boot_ec->handle = ACPI_ROOT_OBJECT;
1081                 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1082                 /* Don't trust ECDT, which comes from ASUSTek */
1083                 if (!EC_FLAGS_VALIDATE_ECDT)
1084                         goto install;
1085                 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1086                 if (!saved_ec)
1087                         return -ENOMEM;
1088         /* fall through */
1089         }
1090 
1091         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1092                 kfree(saved_ec);
1093                 return -ENODEV;
1094         }
1095 
1096         /* This workaround is needed only on some broken machines,
1097          * which require early EC, but fail to provide ECDT */
1098         pr_debug("Look up EC in DSDT\n");
1099         status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1100                                         boot_ec, NULL);
1101         /* Check that acpi_get_devices actually find something */
1102         if (ACPI_FAILURE(status) || !boot_ec->handle)
1103                 goto error;
1104         if (saved_ec) {
1105                 /* try to find good ECDT from ASUSTek */
1106                 if (saved_ec->command_addr != boot_ec->command_addr ||
1107                     saved_ec->data_addr != boot_ec->data_addr ||
1108                     saved_ec->gpe != boot_ec->gpe ||
1109                     saved_ec->handle != boot_ec->handle)
1110                         pr_info("ASUSTek keeps feeding us with broken "
1111                         "ECDT tables, which are very hard to workaround. "
1112                         "Trying to use DSDT EC info instead. Please send "
1113                         "output of acpidump to linux-acpi@vger.kernel.org\n");
1114                 kfree(saved_ec);
1115                 saved_ec = NULL;
1116         } else {
1117                 /* We really need to limit this workaround, the only ASUS,
1118                 * which needs it, has fake EC._INI method, so use it as flag.
1119                 * Keep boot_ec struct as it will be needed soon.
1120                 */
1121                 if (!dmi_name_in_vendors("ASUS") ||
1122                     !acpi_has_method(boot_ec->handle, "_INI"))
1123                         return -ENODEV;
1124         }
1125 install:
1126         if (!ec_install_handlers(boot_ec)) {
1127                 first_ec = boot_ec;
1128                 return 0;
1129         }
1130 error:
1131         kfree(boot_ec);
1132         kfree(saved_ec);
1133         boot_ec = NULL;
1134         return -ENODEV;
1135 }
1136 
1137 static struct acpi_driver acpi_ec_driver = {
1138         .name = "ec",
1139         .class = ACPI_EC_CLASS,
1140         .ids = ec_device_ids,
1141         .ops = {
1142                 .add = acpi_ec_add,
1143                 .remove = acpi_ec_remove,
1144                 },
1145 };
1146 
1147 int __init acpi_ec_init(void)
1148 {
1149         int result = 0;
1150 
1151         /* Now register the driver for the EC */
1152         result = acpi_bus_register_driver(&acpi_ec_driver);
1153         if (result < 0)
1154                 return -ENODEV;
1155 
1156         return result;
1157 }
1158 
1159 /* EC driver currently not unloadable */
1160 #if 0
1161 static void __exit acpi_ec_exit(void)
1162 {
1163 
1164         acpi_bus_unregister_driver(&acpi_ec_driver);
1165         return;
1166 }
1167 #endif  /* 0 */
1168 

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