xref: /linux/drivers/acpi/ec.c (revision 1fb8510cdb5b7befe8a59f533c7fc12ef0dac73e)
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 
138 	pr_debug("EC_SC(R) = 0x%2.2x "
139 		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
140 		 x,
141 		 !!(x & ACPI_EC_FLAG_SCI),
142 		 !!(x & ACPI_EC_FLAG_BURST),
143 		 !!(x & ACPI_EC_FLAG_CMD),
144 		 !!(x & ACPI_EC_FLAG_IBF),
145 		 !!(x & ACPI_EC_FLAG_OBF));
146 	return x;
147 }
148 
149 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
150 {
151 	u8 x = inb(ec->data_addr);
152 
153 	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
154 	return x;
155 }
156 
157 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
158 {
159 	pr_debug("EC_SC(W) = 0x%2.2x\n", command);
160 	outb(command, ec->command_addr);
161 }
162 
163 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
164 {
165 	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
166 	outb(data, ec->data_addr);
167 }
168 
169 #ifdef DEBUG
170 static const char *acpi_ec_cmd_string(u8 cmd)
171 {
172 	switch (cmd) {
173 	case 0x80:
174 		return "RD_EC";
175 	case 0x81:
176 		return "WR_EC";
177 	case 0x82:
178 		return "BE_EC";
179 	case 0x83:
180 		return "BD_EC";
181 	case 0x84:
182 		return "QR_EC";
183 	}
184 	return "UNKNOWN";
185 }
186 #else
187 #define acpi_ec_cmd_string(cmd)		"UNDEF"
188 #endif
189 
190 static int ec_transaction_completed(struct acpi_ec *ec)
191 {
192 	unsigned long flags;
193 	int ret = 0;
194 
195 	spin_lock_irqsave(&ec->lock, flags);
196 	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
197 		ret = 1;
198 	spin_unlock_irqrestore(&ec->lock, flags);
199 	return ret;
200 }
201 
202 static bool advance_transaction(struct acpi_ec *ec)
203 {
204 	struct transaction *t;
205 	u8 status;
206 	bool wakeup = false;
207 
208 	pr_debug("===== %s (%d) =====\n",
209 		 in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
210 	status = acpi_ec_read_status(ec);
211 	t = ec->curr;
212 	if (!t)
213 		goto err;
214 	if (t->flags & ACPI_EC_COMMAND_POLL) {
215 		if (t->wlen > t->wi) {
216 			if ((status & ACPI_EC_FLAG_IBF) == 0)
217 				acpi_ec_write_data(ec, t->wdata[t->wi++]);
218 			else
219 				goto err;
220 		} else if (t->rlen > t->ri) {
221 			if ((status & ACPI_EC_FLAG_OBF) == 1) {
222 				t->rdata[t->ri++] = acpi_ec_read_data(ec);
223 				if (t->rlen == t->ri) {
224 					t->flags |= ACPI_EC_COMMAND_COMPLETE;
225 					if (t->command == ACPI_EC_COMMAND_QUERY)
226 						pr_debug("***** Command(%s) hardware completion *****\n",
227 							 acpi_ec_cmd_string(t->command));
228 					wakeup = true;
229 				}
230 			} else
231 				goto err;
232 		} else if (t->wlen == t->wi &&
233 			   (status & ACPI_EC_FLAG_IBF) == 0) {
234 			t->flags |= ACPI_EC_COMMAND_COMPLETE;
235 			wakeup = true;
236 		}
237 		return wakeup;
238 	} else {
239 		/*
240 		 * There is firmware refusing to respond QR_EC when SCI_EVT
241 		 * is not set, for which case, we complete the QR_EC
242 		 * without issuing it to the firmware.
243 		 * https://bugzilla.kernel.org/show_bug.cgi?id=86211
244 		 */
245 		if (!(status & ACPI_EC_FLAG_SCI) &&
246 		    (t->command == ACPI_EC_COMMAND_QUERY)) {
247 			t->flags |= ACPI_EC_COMMAND_POLL;
248 			t->rdata[t->ri++] = 0x00;
249 			t->flags |= ACPI_EC_COMMAND_COMPLETE;
250 			pr_debug("***** Command(%s) software completion *****\n",
251 				 acpi_ec_cmd_string(t->command));
252 			wakeup = true;
253 		} else if ((status & ACPI_EC_FLAG_IBF) == 0) {
254 			acpi_ec_write_cmd(ec, t->command);
255 			t->flags |= ACPI_EC_COMMAND_POLL;
256 		} else
257 			goto err;
258 		return wakeup;
259 	}
260 err:
261 	/*
262 	 * If SCI bit is set, then don't think it's a false IRQ
263 	 * otherwise will take a not handled IRQ as a false one.
264 	 */
265 	if (!(status & ACPI_EC_FLAG_SCI)) {
266 		if (in_interrupt() && t)
267 			++t->irq_count;
268 	}
269 	return wakeup;
270 }
271 
272 static void start_transaction(struct acpi_ec *ec)
273 {
274 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
275 	ec->curr->flags = 0;
276 	(void)advance_transaction(ec);
277 }
278 
279 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
280 
281 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
282 {
283 	if (state & ACPI_EC_FLAG_SCI) {
284 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
285 			return acpi_ec_sync_query(ec, NULL);
286 	}
287 	return 0;
288 }
289 
290 static int ec_poll(struct acpi_ec *ec)
291 {
292 	unsigned long flags;
293 	int repeat = 5; /* number of command restarts */
294 
295 	while (repeat--) {
296 		unsigned long delay = jiffies +
297 			msecs_to_jiffies(ec_delay);
298 		do {
299 			/* don't sleep with disabled interrupts */
300 			if (EC_FLAGS_MSI || irqs_disabled()) {
301 				udelay(ACPI_EC_MSI_UDELAY);
302 				if (ec_transaction_completed(ec))
303 					return 0;
304 			} else {
305 				if (wait_event_timeout(ec->wait,
306 						ec_transaction_completed(ec),
307 						msecs_to_jiffies(1)))
308 					return 0;
309 			}
310 			spin_lock_irqsave(&ec->lock, flags);
311 			(void)advance_transaction(ec);
312 			spin_unlock_irqrestore(&ec->lock, flags);
313 		} while (time_before(jiffies, delay));
314 		pr_debug("controller reset, restart transaction\n");
315 		spin_lock_irqsave(&ec->lock, flags);
316 		start_transaction(ec);
317 		spin_unlock_irqrestore(&ec->lock, flags);
318 	}
319 	return -ETIME;
320 }
321 
322 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
323 					struct transaction *t)
324 {
325 	unsigned long tmp;
326 	int ret = 0;
327 
328 	if (EC_FLAGS_MSI)
329 		udelay(ACPI_EC_MSI_UDELAY);
330 	/* start transaction */
331 	spin_lock_irqsave(&ec->lock, tmp);
332 	/* following two actions should be kept atomic */
333 	ec->curr = t;
334 	pr_debug("***** Command(%s) started *****\n",
335 		 acpi_ec_cmd_string(t->command));
336 	start_transaction(ec);
337 	spin_unlock_irqrestore(&ec->lock, tmp);
338 	ret = ec_poll(ec);
339 	spin_lock_irqsave(&ec->lock, tmp);
340 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
341 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
342 		pr_debug("***** Event stopped *****\n");
343 	}
344 	pr_debug("***** Command(%s) stopped *****\n",
345 		 acpi_ec_cmd_string(t->command));
346 	ec->curr = NULL;
347 	spin_unlock_irqrestore(&ec->lock, tmp);
348 	return ret;
349 }
350 
351 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
352 {
353 	int status;
354 	u32 glk;
355 
356 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
357 		return -EINVAL;
358 	if (t->rdata)
359 		memset(t->rdata, 0, t->rlen);
360 	mutex_lock(&ec->mutex);
361 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
362 		status = -EINVAL;
363 		goto unlock;
364 	}
365 	if (ec->global_lock) {
366 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
367 		if (ACPI_FAILURE(status)) {
368 			status = -ENODEV;
369 			goto unlock;
370 		}
371 	}
372 	/* disable GPE during transaction if storm is detected */
373 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
374 		/* It has to be disabled, so that it doesn't trigger. */
375 		acpi_disable_gpe(NULL, ec->gpe);
376 	}
377 
378 	status = acpi_ec_transaction_unlocked(ec, t);
379 
380 	/* check if we received SCI during transaction */
381 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
382 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
383 		msleep(1);
384 		/* It is safe to enable the GPE outside of the transaction. */
385 		acpi_enable_gpe(NULL, ec->gpe);
386 	} else if (t->irq_count > ec_storm_threshold) {
387 		pr_info("GPE storm detected(%d GPEs), "
388 			"transactions will use polling mode\n",
389 			t->irq_count);
390 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
391 	}
392 	if (ec->global_lock)
393 		acpi_release_global_lock(glk);
394 unlock:
395 	mutex_unlock(&ec->mutex);
396 	return status;
397 }
398 
399 static int acpi_ec_burst_enable(struct acpi_ec *ec)
400 {
401 	u8 d;
402 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
403 				.wdata = NULL, .rdata = &d,
404 				.wlen = 0, .rlen = 1};
405 
406 	return acpi_ec_transaction(ec, &t);
407 }
408 
409 static int acpi_ec_burst_disable(struct acpi_ec *ec)
410 {
411 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
412 				.wdata = NULL, .rdata = NULL,
413 				.wlen = 0, .rlen = 0};
414 
415 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
416 				acpi_ec_transaction(ec, &t) : 0;
417 }
418 
419 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
420 {
421 	int result;
422 	u8 d;
423 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
424 				.wdata = &address, .rdata = &d,
425 				.wlen = 1, .rlen = 1};
426 
427 	result = acpi_ec_transaction(ec, &t);
428 	*data = d;
429 	return result;
430 }
431 
432 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
433 {
434 	u8 wdata[2] = { address, data };
435 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
436 				.wdata = wdata, .rdata = NULL,
437 				.wlen = 2, .rlen = 0};
438 
439 	return acpi_ec_transaction(ec, &t);
440 }
441 
442 int ec_read(u8 addr, u8 *val)
443 {
444 	int err;
445 	u8 temp_data;
446 
447 	if (!first_ec)
448 		return -ENODEV;
449 
450 	err = acpi_ec_read(first_ec, addr, &temp_data);
451 
452 	if (!err) {
453 		*val = temp_data;
454 		return 0;
455 	}
456 	return err;
457 }
458 EXPORT_SYMBOL(ec_read);
459 
460 int ec_write(u8 addr, u8 val)
461 {
462 	int err;
463 
464 	if (!first_ec)
465 		return -ENODEV;
466 
467 	err = acpi_ec_write(first_ec, addr, val);
468 
469 	return err;
470 }
471 EXPORT_SYMBOL(ec_write);
472 
473 int ec_transaction(u8 command,
474 		   const u8 *wdata, unsigned wdata_len,
475 		   u8 *rdata, unsigned rdata_len)
476 {
477 	struct transaction t = {.command = command,
478 				.wdata = wdata, .rdata = rdata,
479 				.wlen = wdata_len, .rlen = rdata_len};
480 
481 	if (!first_ec)
482 		return -ENODEV;
483 
484 	return acpi_ec_transaction(first_ec, &t);
485 }
486 EXPORT_SYMBOL(ec_transaction);
487 
488 /* Get the handle to the EC device */
489 acpi_handle ec_get_handle(void)
490 {
491 	if (!first_ec)
492 		return NULL;
493 	return first_ec->handle;
494 }
495 EXPORT_SYMBOL(ec_get_handle);
496 
497 /*
498  * Process _Q events that might have accumulated in the EC.
499  * Run with locked ec mutex.
500  */
501 static void acpi_ec_clear(struct acpi_ec *ec)
502 {
503 	int i, status;
504 	u8 value = 0;
505 
506 	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
507 		status = acpi_ec_sync_query(ec, &value);
508 		if (status || !value)
509 			break;
510 	}
511 
512 	if (unlikely(i == ACPI_EC_CLEAR_MAX))
513 		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
514 	else
515 		pr_info("%d stale EC events cleared\n", i);
516 }
517 
518 void acpi_ec_block_transactions(void)
519 {
520 	struct acpi_ec *ec = first_ec;
521 
522 	if (!ec)
523 		return;
524 
525 	mutex_lock(&ec->mutex);
526 	/* Prevent transactions from being carried out */
527 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
528 	mutex_unlock(&ec->mutex);
529 }
530 
531 void acpi_ec_unblock_transactions(void)
532 {
533 	struct acpi_ec *ec = first_ec;
534 
535 	if (!ec)
536 		return;
537 
538 	mutex_lock(&ec->mutex);
539 	/* Allow transactions to be carried out again */
540 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
541 
542 	if (EC_FLAGS_CLEAR_ON_RESUME)
543 		acpi_ec_clear(ec);
544 
545 	mutex_unlock(&ec->mutex);
546 }
547 
548 void acpi_ec_unblock_transactions_early(void)
549 {
550 	/*
551 	 * Allow transactions to happen again (this function is called from
552 	 * atomic context during wakeup, so we don't need to acquire the mutex).
553 	 */
554 	if (first_ec)
555 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
556 }
557 
558 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
559 {
560 	int result;
561 	u8 d;
562 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
563 				.wdata = NULL, .rdata = &d,
564 				.wlen = 0, .rlen = 1};
565 
566 	if (!ec || !data)
567 		return -EINVAL;
568 	/*
569 	 * Query the EC to find out which _Qxx method we need to evaluate.
570 	 * Note that successful completion of the query causes the ACPI_EC_SCI
571 	 * bit to be cleared (and thus clearing the interrupt source).
572 	 */
573 	result = acpi_ec_transaction_unlocked(ec, &t);
574 	if (result)
575 		return result;
576 	if (!d)
577 		return -ENODATA;
578 	*data = d;
579 	return 0;
580 }
581 
582 /* --------------------------------------------------------------------------
583                                 Event Management
584    -------------------------------------------------------------------------- */
585 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
586 			      acpi_handle handle, acpi_ec_query_func func,
587 			      void *data)
588 {
589 	struct acpi_ec_query_handler *handler =
590 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
591 
592 	if (!handler)
593 		return -ENOMEM;
594 
595 	handler->query_bit = query_bit;
596 	handler->handle = handle;
597 	handler->func = func;
598 	handler->data = data;
599 	mutex_lock(&ec->mutex);
600 	list_add(&handler->node, &ec->list);
601 	mutex_unlock(&ec->mutex);
602 	return 0;
603 }
604 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
605 
606 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
607 {
608 	struct acpi_ec_query_handler *handler, *tmp;
609 
610 	mutex_lock(&ec->mutex);
611 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
612 		if (query_bit == handler->query_bit) {
613 			list_del(&handler->node);
614 			kfree(handler);
615 		}
616 	}
617 	mutex_unlock(&ec->mutex);
618 }
619 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
620 
621 static void acpi_ec_run(void *cxt)
622 {
623 	struct acpi_ec_query_handler *handler = cxt;
624 
625 	if (!handler)
626 		return;
627 	pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
628 	if (handler->func)
629 		handler->func(handler->data);
630 	else if (handler->handle)
631 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
632 	pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
633 	kfree(handler);
634 }
635 
636 static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
637 {
638 	u8 value = 0;
639 	int status;
640 	struct acpi_ec_query_handler *handler, *copy;
641 
642 	status = acpi_ec_query_unlocked(ec, &value);
643 	if (data)
644 		*data = value;
645 	if (status)
646 		return status;
647 
648 	list_for_each_entry(handler, &ec->list, node) {
649 		if (value == handler->query_bit) {
650 			/* have custom handler for this bit */
651 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
652 			if (!copy)
653 				return -ENOMEM;
654 			memcpy(copy, handler, sizeof(*copy));
655 			pr_debug("##### Query(0x%02x) scheduled #####\n",
656 				 handler->query_bit);
657 			return acpi_os_execute((copy->func) ?
658 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
659 				acpi_ec_run, copy);
660 		}
661 	}
662 	return 0;
663 }
664 
665 static void acpi_ec_gpe_query(void *ec_cxt)
666 {
667 	struct acpi_ec *ec = ec_cxt;
668 
669 	if (!ec)
670 		return;
671 	mutex_lock(&ec->mutex);
672 	acpi_ec_sync_query(ec, NULL);
673 	mutex_unlock(&ec->mutex);
674 }
675 
676 static int ec_check_sci(struct acpi_ec *ec, u8 state)
677 {
678 	if (state & ACPI_EC_FLAG_SCI) {
679 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
680 			pr_debug("***** Event started *****\n");
681 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
682 				acpi_ec_gpe_query, ec);
683 		}
684 	}
685 	return 0;
686 }
687 
688 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
689 	u32 gpe_number, void *data)
690 {
691 	unsigned long flags;
692 	struct acpi_ec *ec = data;
693 
694 	spin_lock_irqsave(&ec->lock, flags);
695 	if (advance_transaction(ec))
696 		wake_up(&ec->wait);
697 	spin_unlock_irqrestore(&ec->lock, flags);
698 	ec_check_sci(ec, acpi_ec_read_status(ec));
699 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
700 }
701 
702 /* --------------------------------------------------------------------------
703  *                           Address Space Management
704  * -------------------------------------------------------------------------- */
705 
706 static acpi_status
707 acpi_ec_space_handler(u32 function, acpi_physical_address address,
708 		      u32 bits, u64 *value64,
709 		      void *handler_context, void *region_context)
710 {
711 	struct acpi_ec *ec = handler_context;
712 	int result = 0, i, bytes = bits / 8;
713 	u8 *value = (u8 *)value64;
714 
715 	if ((address > 0xFF) || !value || !handler_context)
716 		return AE_BAD_PARAMETER;
717 
718 	if (function != ACPI_READ && function != ACPI_WRITE)
719 		return AE_BAD_PARAMETER;
720 
721 	if (EC_FLAGS_MSI || bits > 8)
722 		acpi_ec_burst_enable(ec);
723 
724 	for (i = 0; i < bytes; ++i, ++address, ++value)
725 		result = (function == ACPI_READ) ?
726 			acpi_ec_read(ec, address, value) :
727 			acpi_ec_write(ec, address, *value);
728 
729 	if (EC_FLAGS_MSI || bits > 8)
730 		acpi_ec_burst_disable(ec);
731 
732 	switch (result) {
733 	case -EINVAL:
734 		return AE_BAD_PARAMETER;
735 	case -ENODEV:
736 		return AE_NOT_FOUND;
737 	case -ETIME:
738 		return AE_TIME;
739 	default:
740 		return AE_OK;
741 	}
742 }
743 
744 /* --------------------------------------------------------------------------
745  *                             Driver Interface
746  * -------------------------------------------------------------------------- */
747 
748 static acpi_status
749 ec_parse_io_ports(struct acpi_resource *resource, void *context);
750 
751 static struct acpi_ec *make_acpi_ec(void)
752 {
753 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
754 
755 	if (!ec)
756 		return NULL;
757 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
758 	mutex_init(&ec->mutex);
759 	init_waitqueue_head(&ec->wait);
760 	INIT_LIST_HEAD(&ec->list);
761 	spin_lock_init(&ec->lock);
762 	return ec;
763 }
764 
765 static acpi_status
766 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
767 			       void *context, void **return_value)
768 {
769 	char node_name[5];
770 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
771 	struct acpi_ec *ec = context;
772 	int value = 0;
773 	acpi_status status;
774 
775 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
776 
777 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
778 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
779 	return AE_OK;
780 }
781 
782 static acpi_status
783 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
784 {
785 	acpi_status status;
786 	unsigned long long tmp = 0;
787 	struct acpi_ec *ec = context;
788 
789 	/* clear addr values, ec_parse_io_ports depend on it */
790 	ec->command_addr = ec->data_addr = 0;
791 
792 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
793 				     ec_parse_io_ports, ec);
794 	if (ACPI_FAILURE(status))
795 		return status;
796 
797 	/* Get GPE bit assignment (EC events). */
798 	/* TODO: Add support for _GPE returning a package */
799 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
800 	if (ACPI_FAILURE(status))
801 		return status;
802 	ec->gpe = tmp;
803 	/* Use the global lock for all EC transactions? */
804 	tmp = 0;
805 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
806 	ec->global_lock = tmp;
807 	ec->handle = handle;
808 	return AE_CTRL_TERMINATE;
809 }
810 
811 static int ec_install_handlers(struct acpi_ec *ec)
812 {
813 	acpi_status status;
814 
815 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
816 		return 0;
817 	status = acpi_install_gpe_handler(NULL, ec->gpe,
818 				  ACPI_GPE_EDGE_TRIGGERED,
819 				  &acpi_ec_gpe_handler, ec);
820 	if (ACPI_FAILURE(status))
821 		return -ENODEV;
822 
823 	acpi_enable_gpe(NULL, ec->gpe);
824 	status = acpi_install_address_space_handler(ec->handle,
825 						    ACPI_ADR_SPACE_EC,
826 						    &acpi_ec_space_handler,
827 						    NULL, ec);
828 	if (ACPI_FAILURE(status)) {
829 		if (status == AE_NOT_FOUND) {
830 			/*
831 			 * Maybe OS fails in evaluating the _REG object.
832 			 * The AE_NOT_FOUND error will be ignored and OS
833 			 * continue to initialize EC.
834 			 */
835 			pr_err("Fail in evaluating the _REG object"
836 				" of EC device. Broken bios is suspected.\n");
837 		} else {
838 			acpi_disable_gpe(NULL, ec->gpe);
839 			acpi_remove_gpe_handler(NULL, ec->gpe,
840 				&acpi_ec_gpe_handler);
841 			return -ENODEV;
842 		}
843 	}
844 
845 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
846 	return 0;
847 }
848 
849 static void ec_remove_handlers(struct acpi_ec *ec)
850 {
851 	acpi_disable_gpe(NULL, ec->gpe);
852 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
853 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
854 		pr_err("failed to remove space handler\n");
855 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
856 				&acpi_ec_gpe_handler)))
857 		pr_err("failed to remove gpe handler\n");
858 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
859 }
860 
861 static int acpi_ec_add(struct acpi_device *device)
862 {
863 	struct acpi_ec *ec = NULL;
864 	int ret;
865 
866 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
867 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
868 
869 	/* Check for boot EC */
870 	if (boot_ec &&
871 	    (boot_ec->handle == device->handle ||
872 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
873 		ec = boot_ec;
874 		boot_ec = NULL;
875 	} else {
876 		ec = make_acpi_ec();
877 		if (!ec)
878 			return -ENOMEM;
879 	}
880 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
881 		AE_CTRL_TERMINATE) {
882 			kfree(ec);
883 			return -EINVAL;
884 	}
885 
886 	/* Find and register all query methods */
887 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
888 			    acpi_ec_register_query_methods, NULL, ec, NULL);
889 
890 	if (!first_ec)
891 		first_ec = ec;
892 	device->driver_data = ec;
893 
894 	ret = !!request_region(ec->data_addr, 1, "EC data");
895 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
896 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
897 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
898 
899 	pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
900 			  ec->gpe, ec->command_addr, ec->data_addr);
901 
902 	ret = ec_install_handlers(ec);
903 
904 	/* EC is fully operational, allow queries */
905 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
906 
907 	/* Clear stale _Q events if hardware might require that */
908 	if (EC_FLAGS_CLEAR_ON_RESUME) {
909 		mutex_lock(&ec->mutex);
910 		acpi_ec_clear(ec);
911 		mutex_unlock(&ec->mutex);
912 	}
913 	return ret;
914 }
915 
916 static int acpi_ec_remove(struct acpi_device *device)
917 {
918 	struct acpi_ec *ec;
919 	struct acpi_ec_query_handler *handler, *tmp;
920 
921 	if (!device)
922 		return -EINVAL;
923 
924 	ec = acpi_driver_data(device);
925 	ec_remove_handlers(ec);
926 	mutex_lock(&ec->mutex);
927 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
928 		list_del(&handler->node);
929 		kfree(handler);
930 	}
931 	mutex_unlock(&ec->mutex);
932 	release_region(ec->data_addr, 1);
933 	release_region(ec->command_addr, 1);
934 	device->driver_data = NULL;
935 	if (ec == first_ec)
936 		first_ec = NULL;
937 	kfree(ec);
938 	return 0;
939 }
940 
941 static acpi_status
942 ec_parse_io_ports(struct acpi_resource *resource, void *context)
943 {
944 	struct acpi_ec *ec = context;
945 
946 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
947 		return AE_OK;
948 
949 	/*
950 	 * The first address region returned is the data port, and
951 	 * the second address region returned is the status/command
952 	 * port.
953 	 */
954 	if (ec->data_addr == 0)
955 		ec->data_addr = resource->data.io.minimum;
956 	else if (ec->command_addr == 0)
957 		ec->command_addr = resource->data.io.minimum;
958 	else
959 		return AE_CTRL_TERMINATE;
960 
961 	return AE_OK;
962 }
963 
964 int __init acpi_boot_ec_enable(void)
965 {
966 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
967 		return 0;
968 	if (!ec_install_handlers(boot_ec)) {
969 		first_ec = boot_ec;
970 		return 0;
971 	}
972 	return -EFAULT;
973 }
974 
975 static const struct acpi_device_id ec_device_ids[] = {
976 	{"PNP0C09", 0},
977 	{"", 0},
978 };
979 
980 /* Some BIOS do not survive early DSDT scan, skip it */
981 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
982 {
983 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
984 	return 0;
985 }
986 
987 /* ASUStek often supplies us with broken ECDT, validate it */
988 static int ec_validate_ecdt(const struct dmi_system_id *id)
989 {
990 	EC_FLAGS_VALIDATE_ECDT = 1;
991 	return 0;
992 }
993 
994 /* MSI EC needs special treatment, enable it */
995 static int ec_flag_msi(const struct dmi_system_id *id)
996 {
997 	pr_debug("Detected MSI hardware, enabling workarounds.\n");
998 	EC_FLAGS_MSI = 1;
999 	EC_FLAGS_VALIDATE_ECDT = 1;
1000 	return 0;
1001 }
1002 
1003 /*
1004  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1005  * the GPE storm threshold back to 20
1006  */
1007 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1008 {
1009 	pr_debug("Setting the EC GPE storm threshold to 20\n");
1010 	ec_storm_threshold  = 20;
1011 	return 0;
1012 }
1013 
1014 /*
1015  * On some hardware it is necessary to clear events accumulated by the EC during
1016  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1017  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1018  *
1019  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1020  *
1021  * Ideally, the EC should also be instructed NOT to accumulate events during
1022  * sleep (which Windows seems to do somehow), but the interface to control this
1023  * behaviour is not known at this time.
1024  *
1025  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1026  * however it is very likely that other Samsung models are affected.
1027  *
1028  * On systems which don't accumulate _Q events during sleep, this extra check
1029  * should be harmless.
1030  */
1031 static int ec_clear_on_resume(const struct dmi_system_id *id)
1032 {
1033 	pr_debug("Detected system needing EC poll on resume.\n");
1034 	EC_FLAGS_CLEAR_ON_RESUME = 1;
1035 	return 0;
1036 }
1037 
1038 static struct dmi_system_id ec_dmi_table[] __initdata = {
1039 	{
1040 	ec_skip_dsdt_scan, "Compal JFL92", {
1041 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1042 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1043 	{
1044 	ec_flag_msi, "MSI hardware", {
1045 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1046 	{
1047 	ec_flag_msi, "MSI hardware", {
1048 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1049 	{
1050 	ec_flag_msi, "MSI hardware", {
1051 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1052 	{
1053 	ec_flag_msi, "MSI hardware", {
1054 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1055 	{
1056 	ec_flag_msi, "Quanta hardware", {
1057 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1058 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1059 	{
1060 	ec_flag_msi, "Quanta hardware", {
1061 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1062 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1063 	{
1064 	ec_flag_msi, "Clevo W350etq", {
1065 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1066 	DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1067 	{
1068 	ec_validate_ecdt, "ASUS hardware", {
1069 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1070 	{
1071 	ec_validate_ecdt, "ASUS hardware", {
1072 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1073 	{
1074 	ec_enlarge_storm_threshold, "CLEVO hardware", {
1075 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1076 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1077 	{
1078 	ec_skip_dsdt_scan, "HP Folio 13", {
1079 	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1080 	DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1081 	{
1082 	ec_validate_ecdt, "ASUS hardware", {
1083 	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1084 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1085 	{
1086 	ec_clear_on_resume, "Samsung hardware", {
1087 	DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1088 	{},
1089 };
1090 
1091 int __init acpi_ec_ecdt_probe(void)
1092 {
1093 	acpi_status status;
1094 	struct acpi_ec *saved_ec = NULL;
1095 	struct acpi_table_ecdt *ecdt_ptr;
1096 
1097 	boot_ec = make_acpi_ec();
1098 	if (!boot_ec)
1099 		return -ENOMEM;
1100 	/*
1101 	 * Generate a boot ec context
1102 	 */
1103 	dmi_check_system(ec_dmi_table);
1104 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1105 				(struct acpi_table_header **)&ecdt_ptr);
1106 	if (ACPI_SUCCESS(status)) {
1107 		pr_info("EC description table is found, configuring boot EC\n");
1108 		boot_ec->command_addr = ecdt_ptr->control.address;
1109 		boot_ec->data_addr = ecdt_ptr->data.address;
1110 		boot_ec->gpe = ecdt_ptr->gpe;
1111 		boot_ec->handle = ACPI_ROOT_OBJECT;
1112 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1113 				&boot_ec->handle);
1114 		/* Don't trust ECDT, which comes from ASUSTek */
1115 		if (!EC_FLAGS_VALIDATE_ECDT)
1116 			goto install;
1117 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1118 		if (!saved_ec)
1119 			return -ENOMEM;
1120 	/* fall through */
1121 	}
1122 
1123 	if (EC_FLAGS_SKIP_DSDT_SCAN) {
1124 		kfree(saved_ec);
1125 		return -ENODEV;
1126 	}
1127 
1128 	/* This workaround is needed only on some broken machines,
1129 	 * which require early EC, but fail to provide ECDT */
1130 	pr_debug("Look up EC in DSDT\n");
1131 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1132 					boot_ec, NULL);
1133 	/* Check that acpi_get_devices actually find something */
1134 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1135 		goto error;
1136 	if (saved_ec) {
1137 		/* try to find good ECDT from ASUSTek */
1138 		if (saved_ec->command_addr != boot_ec->command_addr ||
1139 		    saved_ec->data_addr != boot_ec->data_addr ||
1140 		    saved_ec->gpe != boot_ec->gpe ||
1141 		    saved_ec->handle != boot_ec->handle)
1142 			pr_info("ASUSTek keeps feeding us with broken "
1143 			"ECDT tables, which are very hard to workaround. "
1144 			"Trying to use DSDT EC info instead. Please send "
1145 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1146 		kfree(saved_ec);
1147 		saved_ec = NULL;
1148 	} else {
1149 		/* We really need to limit this workaround, the only ASUS,
1150 		* which needs it, has fake EC._INI method, so use it as flag.
1151 		* Keep boot_ec struct as it will be needed soon.
1152 		*/
1153 		if (!dmi_name_in_vendors("ASUS") ||
1154 		    !acpi_has_method(boot_ec->handle, "_INI"))
1155 			return -ENODEV;
1156 	}
1157 install:
1158 	if (!ec_install_handlers(boot_ec)) {
1159 		first_ec = boot_ec;
1160 		return 0;
1161 	}
1162 error:
1163 	kfree(boot_ec);
1164 	kfree(saved_ec);
1165 	boot_ec = NULL;
1166 	return -ENODEV;
1167 }
1168 
1169 static struct acpi_driver acpi_ec_driver = {
1170 	.name = "ec",
1171 	.class = ACPI_EC_CLASS,
1172 	.ids = ec_device_ids,
1173 	.ops = {
1174 		.add = acpi_ec_add,
1175 		.remove = acpi_ec_remove,
1176 		},
1177 };
1178 
1179 int __init acpi_ec_init(void)
1180 {
1181 	int result = 0;
1182 
1183 	/* Now register the driver for the EC */
1184 	result = acpi_bus_register_driver(&acpi_ec_driver);
1185 	if (result < 0)
1186 		return -ENODEV;
1187 
1188 	return result;
1189 }
1190 
1191 /* EC driver currently not unloadable */
1192 #if 0
1193 static void __exit acpi_ec_exit(void)
1194 {
1195 
1196 	acpi_bus_unregister_driver(&acpi_ec_driver);
1197 }
1198 #endif	/* 0 */
1199