xref: /openbmc/linux/drivers/acpi/ec.c (revision af958a38)
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