xref: /openbmc/linux/drivers/acpi/ec.c (revision 79f08d9e)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.1)
3  *
4  *  Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de>
5  *  Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com>
6  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
7  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
8  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
9  *
10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2 of the License, or (at
15  *  your option) any later version.
16  *
17  *  This program is distributed in the hope that it will be useful, but
18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20  *  General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License along
23  *  with this program; if not, write to the Free Software Foundation, Inc.,
24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
25  *
26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
27  */
28 
29 /* Uncomment next line to get verbose printout */
30 /* #define DEBUG */
31 #define pr_fmt(fmt) "ACPI : EC: " fmt
32 
33 #include <linux/kernel.h>
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/types.h>
37 #include <linux/delay.h>
38 #include <linux/interrupt.h>
39 #include <linux/list.h>
40 #include <linux/spinlock.h>
41 #include <linux/slab.h>
42 #include <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45 #include <linux/dmi.h>
46 
47 #include "internal.h"
48 
49 #define ACPI_EC_CLASS			"embedded_controller"
50 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
51 #define ACPI_EC_FILE_INFO		"info"
52 
53 /* EC status register */
54 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
55 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
56 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
57 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
58 
59 /* EC commands */
60 enum ec_command {
61 	ACPI_EC_COMMAND_READ = 0x80,
62 	ACPI_EC_COMMAND_WRITE = 0x81,
63 	ACPI_EC_BURST_ENABLE = 0x82,
64 	ACPI_EC_BURST_DISABLE = 0x83,
65 	ACPI_EC_COMMAND_QUERY = 0x84,
66 };
67 
68 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
69 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
70 #define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
71 
72 enum {
73 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
74 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
75 	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
76 					 * OpReg are installed */
77 	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
78 };
79 
80 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
81 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
82 module_param(ec_delay, uint, 0644);
83 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
84 
85 /*
86  * If the number of false interrupts per one transaction exceeds
87  * this threshold, will think there is a GPE storm happened and
88  * will disable the GPE for normal transaction.
89  */
90 static unsigned int ec_storm_threshold  __read_mostly = 8;
91 module_param(ec_storm_threshold, uint, 0644);
92 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
93 
94 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
95 /* External interfaces use first EC only, so remember */
96 typedef int (*acpi_ec_query_func) (void *data);
97 
98 struct acpi_ec_query_handler {
99 	struct list_head node;
100 	acpi_ec_query_func func;
101 	acpi_handle handle;
102 	void *data;
103 	u8 query_bit;
104 };
105 
106 struct transaction {
107 	const u8 *wdata;
108 	u8 *rdata;
109 	unsigned short irq_count;
110 	u8 command;
111 	u8 wi;
112 	u8 ri;
113 	u8 wlen;
114 	u8 rlen;
115 	bool done;
116 };
117 
118 struct acpi_ec *boot_ec, *first_ec;
119 EXPORT_SYMBOL(first_ec);
120 
121 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
122 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
123 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
124 
125 /* --------------------------------------------------------------------------
126                              Transaction Management
127    -------------------------------------------------------------------------- */
128 
129 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
130 {
131 	u8 x = inb(ec->command_addr);
132 	pr_debug("---> status = 0x%2.2x\n", x);
133 	return x;
134 }
135 
136 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
137 {
138 	u8 x = inb(ec->data_addr);
139 	pr_debug("---> data = 0x%2.2x\n", x);
140 	return x;
141 }
142 
143 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
144 {
145 	pr_debug("<--- command = 0x%2.2x\n", command);
146 	outb(command, ec->command_addr);
147 }
148 
149 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
150 {
151 	pr_debug("<--- data = 0x%2.2x\n", data);
152 	outb(data, ec->data_addr);
153 }
154 
155 static int ec_transaction_done(struct acpi_ec *ec)
156 {
157 	unsigned long flags;
158 	int ret = 0;
159 	spin_lock_irqsave(&ec->lock, flags);
160 	if (!ec->curr || ec->curr->done)
161 		ret = 1;
162 	spin_unlock_irqrestore(&ec->lock, flags);
163 	return ret;
164 }
165 
166 static void start_transaction(struct acpi_ec *ec)
167 {
168 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
169 	ec->curr->done = false;
170 	acpi_ec_write_cmd(ec, ec->curr->command);
171 }
172 
173 static void advance_transaction(struct acpi_ec *ec, u8 status)
174 {
175 	unsigned long flags;
176 	struct transaction *t;
177 
178 	spin_lock_irqsave(&ec->lock, flags);
179 	t = ec->curr;
180 	if (!t)
181 		goto unlock;
182 	if (t->wlen > t->wi) {
183 		if ((status & ACPI_EC_FLAG_IBF) == 0)
184 			acpi_ec_write_data(ec,
185 				t->wdata[t->wi++]);
186 		else
187 			goto err;
188 	} else if (t->rlen > t->ri) {
189 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
190 			t->rdata[t->ri++] = acpi_ec_read_data(ec);
191 			if (t->rlen == t->ri)
192 				t->done = true;
193 		} else
194 			goto err;
195 	} else if (t->wlen == t->wi &&
196 		   (status & ACPI_EC_FLAG_IBF) == 0)
197 		t->done = true;
198 	goto unlock;
199 err:
200 	/*
201 	 * If SCI bit is set, then don't think it's a false IRQ
202 	 * otherwise will take a not handled IRQ as a false one.
203 	 */
204 	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
205 		++t->irq_count;
206 
207 unlock:
208 	spin_unlock_irqrestore(&ec->lock, flags);
209 }
210 
211 static int acpi_ec_sync_query(struct acpi_ec *ec);
212 
213 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
214 {
215 	if (state & ACPI_EC_FLAG_SCI) {
216 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
217 			return acpi_ec_sync_query(ec);
218 	}
219 	return 0;
220 }
221 
222 static int ec_poll(struct acpi_ec *ec)
223 {
224 	unsigned long flags;
225 	int repeat = 5; /* number of command restarts */
226 	while (repeat--) {
227 		unsigned long delay = jiffies +
228 			msecs_to_jiffies(ec_delay);
229 		do {
230 			/* don't sleep with disabled interrupts */
231 			if (EC_FLAGS_MSI || irqs_disabled()) {
232 				udelay(ACPI_EC_MSI_UDELAY);
233 				if (ec_transaction_done(ec))
234 					return 0;
235 			} else {
236 				if (wait_event_timeout(ec->wait,
237 						ec_transaction_done(ec),
238 						msecs_to_jiffies(1)))
239 					return 0;
240 			}
241 			advance_transaction(ec, acpi_ec_read_status(ec));
242 		} while (time_before(jiffies, delay));
243 		pr_debug("controller reset, restart transaction\n");
244 		spin_lock_irqsave(&ec->lock, flags);
245 		start_transaction(ec);
246 		spin_unlock_irqrestore(&ec->lock, flags);
247 	}
248 	return -ETIME;
249 }
250 
251 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
252 					struct transaction *t)
253 {
254 	unsigned long tmp;
255 	int ret = 0;
256 	if (EC_FLAGS_MSI)
257 		udelay(ACPI_EC_MSI_UDELAY);
258 	/* start transaction */
259 	spin_lock_irqsave(&ec->lock, tmp);
260 	/* following two actions should be kept atomic */
261 	ec->curr = t;
262 	start_transaction(ec);
263 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
264 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
265 	spin_unlock_irqrestore(&ec->lock, tmp);
266 	ret = ec_poll(ec);
267 	spin_lock_irqsave(&ec->lock, tmp);
268 	ec->curr = NULL;
269 	spin_unlock_irqrestore(&ec->lock, tmp);
270 	return ret;
271 }
272 
273 static int ec_check_ibf0(struct acpi_ec *ec)
274 {
275 	u8 status = acpi_ec_read_status(ec);
276 	return (status & ACPI_EC_FLAG_IBF) == 0;
277 }
278 
279 static int ec_wait_ibf0(struct acpi_ec *ec)
280 {
281 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
282 	/* interrupt wait manually if GPE mode is not active */
283 	while (time_before(jiffies, delay))
284 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
285 					msecs_to_jiffies(1)))
286 			return 0;
287 	return -ETIME;
288 }
289 
290 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
291 {
292 	int status;
293 	u32 glk;
294 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
295 		return -EINVAL;
296 	if (t->rdata)
297 		memset(t->rdata, 0, t->rlen);
298 	mutex_lock(&ec->mutex);
299 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
300 		status = -EINVAL;
301 		goto unlock;
302 	}
303 	if (ec->global_lock) {
304 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
305 		if (ACPI_FAILURE(status)) {
306 			status = -ENODEV;
307 			goto unlock;
308 		}
309 	}
310 	if (ec_wait_ibf0(ec)) {
311 		pr_err("input buffer is not empty, "
312 				"aborting transaction\n");
313 		status = -ETIME;
314 		goto end;
315 	}
316 	pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
317 			t->command, t->wdata ? t->wdata[0] : 0);
318 	/* disable GPE during transaction if storm is detected */
319 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
320 		/* It has to be disabled, so that it doesn't trigger. */
321 		acpi_disable_gpe(NULL, ec->gpe);
322 	}
323 
324 	status = acpi_ec_transaction_unlocked(ec, t);
325 
326 	/* check if we received SCI during transaction */
327 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
328 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
329 		msleep(1);
330 		/* It is safe to enable the GPE outside of the transaction. */
331 		acpi_enable_gpe(NULL, ec->gpe);
332 	} else if (t->irq_count > ec_storm_threshold) {
333 		pr_info("GPE storm detected(%d GPEs), "
334 			"transactions will use polling mode\n",
335 			t->irq_count);
336 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
337 	}
338 	pr_debug("transaction end\n");
339 end:
340 	if (ec->global_lock)
341 		acpi_release_global_lock(glk);
342 unlock:
343 	mutex_unlock(&ec->mutex);
344 	return status;
345 }
346 
347 static int acpi_ec_burst_enable(struct acpi_ec *ec)
348 {
349 	u8 d;
350 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
351 				.wdata = NULL, .rdata = &d,
352 				.wlen = 0, .rlen = 1};
353 
354 	return acpi_ec_transaction(ec, &t);
355 }
356 
357 static int acpi_ec_burst_disable(struct acpi_ec *ec)
358 {
359 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
360 				.wdata = NULL, .rdata = NULL,
361 				.wlen = 0, .rlen = 0};
362 
363 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
364 				acpi_ec_transaction(ec, &t) : 0;
365 }
366 
367 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
368 {
369 	int result;
370 	u8 d;
371 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
372 				.wdata = &address, .rdata = &d,
373 				.wlen = 1, .rlen = 1};
374 
375 	result = acpi_ec_transaction(ec, &t);
376 	*data = d;
377 	return result;
378 }
379 
380 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
381 {
382 	u8 wdata[2] = { address, data };
383 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
384 				.wdata = wdata, .rdata = NULL,
385 				.wlen = 2, .rlen = 0};
386 
387 	return acpi_ec_transaction(ec, &t);
388 }
389 
390 /*
391  * Externally callable EC access functions. For now, assume 1 EC only
392  */
393 int ec_burst_enable(void)
394 {
395 	if (!first_ec)
396 		return -ENODEV;
397 	return acpi_ec_burst_enable(first_ec);
398 }
399 
400 EXPORT_SYMBOL(ec_burst_enable);
401 
402 int ec_burst_disable(void)
403 {
404 	if (!first_ec)
405 		return -ENODEV;
406 	return acpi_ec_burst_disable(first_ec);
407 }
408 
409 EXPORT_SYMBOL(ec_burst_disable);
410 
411 int ec_read(u8 addr, u8 *val)
412 {
413 	int err;
414 	u8 temp_data;
415 
416 	if (!first_ec)
417 		return -ENODEV;
418 
419 	err = acpi_ec_read(first_ec, addr, &temp_data);
420 
421 	if (!err) {
422 		*val = temp_data;
423 		return 0;
424 	} else
425 		return err;
426 }
427 
428 EXPORT_SYMBOL(ec_read);
429 
430 int ec_write(u8 addr, u8 val)
431 {
432 	int err;
433 
434 	if (!first_ec)
435 		return -ENODEV;
436 
437 	err = acpi_ec_write(first_ec, addr, val);
438 
439 	return err;
440 }
441 
442 EXPORT_SYMBOL(ec_write);
443 
444 int ec_transaction(u8 command,
445 		   const u8 * wdata, unsigned wdata_len,
446 		   u8 * rdata, unsigned rdata_len)
447 {
448 	struct transaction t = {.command = command,
449 				.wdata = wdata, .rdata = rdata,
450 				.wlen = wdata_len, .rlen = rdata_len};
451 	if (!first_ec)
452 		return -ENODEV;
453 
454 	return acpi_ec_transaction(first_ec, &t);
455 }
456 
457 EXPORT_SYMBOL(ec_transaction);
458 
459 /* Get the handle to the EC device */
460 acpi_handle ec_get_handle(void)
461 {
462 	if (!first_ec)
463 		return NULL;
464 	return first_ec->handle;
465 }
466 
467 EXPORT_SYMBOL(ec_get_handle);
468 
469 void acpi_ec_block_transactions(void)
470 {
471 	struct acpi_ec *ec = first_ec;
472 
473 	if (!ec)
474 		return;
475 
476 	mutex_lock(&ec->mutex);
477 	/* Prevent transactions from being carried out */
478 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
479 	mutex_unlock(&ec->mutex);
480 }
481 
482 void acpi_ec_unblock_transactions(void)
483 {
484 	struct acpi_ec *ec = first_ec;
485 
486 	if (!ec)
487 		return;
488 
489 	mutex_lock(&ec->mutex);
490 	/* Allow transactions to be carried out again */
491 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
492 	mutex_unlock(&ec->mutex);
493 }
494 
495 void acpi_ec_unblock_transactions_early(void)
496 {
497 	/*
498 	 * Allow transactions to happen again (this function is called from
499 	 * atomic context during wakeup, so we don't need to acquire the mutex).
500 	 */
501 	if (first_ec)
502 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
503 }
504 
505 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
506 {
507 	int result;
508 	u8 d;
509 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
510 				.wdata = NULL, .rdata = &d,
511 				.wlen = 0, .rlen = 1};
512 	if (!ec || !data)
513 		return -EINVAL;
514 	/*
515 	 * Query the EC to find out which _Qxx method we need to evaluate.
516 	 * Note that successful completion of the query causes the ACPI_EC_SCI
517 	 * bit to be cleared (and thus clearing the interrupt source).
518 	 */
519 	result = acpi_ec_transaction_unlocked(ec, &t);
520 	if (result)
521 		return result;
522 	if (!d)
523 		return -ENODATA;
524 	*data = d;
525 	return 0;
526 }
527 
528 /* --------------------------------------------------------------------------
529                                 Event Management
530    -------------------------------------------------------------------------- */
531 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
532 			      acpi_handle handle, acpi_ec_query_func func,
533 			      void *data)
534 {
535 	struct acpi_ec_query_handler *handler =
536 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
537 	if (!handler)
538 		return -ENOMEM;
539 
540 	handler->query_bit = query_bit;
541 	handler->handle = handle;
542 	handler->func = func;
543 	handler->data = data;
544 	mutex_lock(&ec->mutex);
545 	list_add(&handler->node, &ec->list);
546 	mutex_unlock(&ec->mutex);
547 	return 0;
548 }
549 
550 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
551 
552 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
553 {
554 	struct acpi_ec_query_handler *handler, *tmp;
555 	mutex_lock(&ec->mutex);
556 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
557 		if (query_bit == handler->query_bit) {
558 			list_del(&handler->node);
559 			kfree(handler);
560 		}
561 	}
562 	mutex_unlock(&ec->mutex);
563 }
564 
565 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
566 
567 static void acpi_ec_run(void *cxt)
568 {
569 	struct acpi_ec_query_handler *handler = cxt;
570 	if (!handler)
571 		return;
572 	pr_debug("start query execution\n");
573 	if (handler->func)
574 		handler->func(handler->data);
575 	else if (handler->handle)
576 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
577 	pr_debug("stop query execution\n");
578 	kfree(handler);
579 }
580 
581 static int acpi_ec_sync_query(struct acpi_ec *ec)
582 {
583 	u8 value = 0;
584 	int status;
585 	struct acpi_ec_query_handler *handler, *copy;
586 	if ((status = acpi_ec_query_unlocked(ec, &value)))
587 		return status;
588 	list_for_each_entry(handler, &ec->list, node) {
589 		if (value == handler->query_bit) {
590 			/* have custom handler for this bit */
591 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
592 			if (!copy)
593 				return -ENOMEM;
594 			memcpy(copy, handler, sizeof(*copy));
595 			pr_debug("push query execution (0x%2x) on queue\n",
596 				value);
597 			return acpi_os_execute((copy->func) ?
598 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
599 				acpi_ec_run, copy);
600 		}
601 	}
602 	return 0;
603 }
604 
605 static void acpi_ec_gpe_query(void *ec_cxt)
606 {
607 	struct acpi_ec *ec = ec_cxt;
608 	if (!ec)
609 		return;
610 	mutex_lock(&ec->mutex);
611 	acpi_ec_sync_query(ec);
612 	mutex_unlock(&ec->mutex);
613 }
614 
615 static int ec_check_sci(struct acpi_ec *ec, u8 state)
616 {
617 	if (state & ACPI_EC_FLAG_SCI) {
618 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
619 			pr_debug("push gpe query to the queue\n");
620 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
621 				acpi_ec_gpe_query, ec);
622 		}
623 	}
624 	return 0;
625 }
626 
627 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
628 	u32 gpe_number, void *data)
629 {
630 	struct acpi_ec *ec = data;
631 	u8 status = acpi_ec_read_status(ec);
632 
633 	pr_debug("~~~> interrupt, status:0x%02x\n", status);
634 
635 	advance_transaction(ec, status);
636 	if (ec_transaction_done(ec) &&
637 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
638 		wake_up(&ec->wait);
639 		ec_check_sci(ec, acpi_ec_read_status(ec));
640 	}
641 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
642 }
643 
644 /* --------------------------------------------------------------------------
645                              Address Space Management
646    -------------------------------------------------------------------------- */
647 
648 static acpi_status
649 acpi_ec_space_handler(u32 function, acpi_physical_address address,
650 		      u32 bits, u64 *value64,
651 		      void *handler_context, void *region_context)
652 {
653 	struct acpi_ec *ec = handler_context;
654 	int result = 0, i, bytes = bits / 8;
655 	u8 *value = (u8 *)value64;
656 
657 	if ((address > 0xFF) || !value || !handler_context)
658 		return AE_BAD_PARAMETER;
659 
660 	if (function != ACPI_READ && function != ACPI_WRITE)
661 		return AE_BAD_PARAMETER;
662 
663 	if (EC_FLAGS_MSI || bits > 8)
664 		acpi_ec_burst_enable(ec);
665 
666 	for (i = 0; i < bytes; ++i, ++address, ++value)
667 		result = (function == ACPI_READ) ?
668 			acpi_ec_read(ec, address, value) :
669 			acpi_ec_write(ec, address, *value);
670 
671 	if (EC_FLAGS_MSI || bits > 8)
672 		acpi_ec_burst_disable(ec);
673 
674 	switch (result) {
675 	case -EINVAL:
676 		return AE_BAD_PARAMETER;
677 		break;
678 	case -ENODEV:
679 		return AE_NOT_FOUND;
680 		break;
681 	case -ETIME:
682 		return AE_TIME;
683 		break;
684 	default:
685 		return AE_OK;
686 	}
687 }
688 
689 /* --------------------------------------------------------------------------
690                                Driver Interface
691    -------------------------------------------------------------------------- */
692 static acpi_status
693 ec_parse_io_ports(struct acpi_resource *resource, void *context);
694 
695 static struct acpi_ec *make_acpi_ec(void)
696 {
697 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
698 	if (!ec)
699 		return NULL;
700 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
701 	mutex_init(&ec->mutex);
702 	init_waitqueue_head(&ec->wait);
703 	INIT_LIST_HEAD(&ec->list);
704 	spin_lock_init(&ec->lock);
705 	return ec;
706 }
707 
708 static acpi_status
709 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
710 			       void *context, void **return_value)
711 {
712 	char node_name[5];
713 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
714 	struct acpi_ec *ec = context;
715 	int value = 0;
716 	acpi_status status;
717 
718 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
719 
720 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
721 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
722 	}
723 	return AE_OK;
724 }
725 
726 static acpi_status
727 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
728 {
729 	acpi_status status;
730 	unsigned long long tmp = 0;
731 
732 	struct acpi_ec *ec = context;
733 
734 	/* clear addr values, ec_parse_io_ports depend on it */
735 	ec->command_addr = ec->data_addr = 0;
736 
737 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
738 				     ec_parse_io_ports, ec);
739 	if (ACPI_FAILURE(status))
740 		return status;
741 
742 	/* Get GPE bit assignment (EC events). */
743 	/* TODO: Add support for _GPE returning a package */
744 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
745 	if (ACPI_FAILURE(status))
746 		return status;
747 	ec->gpe = tmp;
748 	/* Use the global lock for all EC transactions? */
749 	tmp = 0;
750 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
751 	ec->global_lock = tmp;
752 	ec->handle = handle;
753 	return AE_CTRL_TERMINATE;
754 }
755 
756 static int ec_install_handlers(struct acpi_ec *ec)
757 {
758 	acpi_status status;
759 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
760 		return 0;
761 	status = acpi_install_gpe_handler(NULL, ec->gpe,
762 				  ACPI_GPE_EDGE_TRIGGERED,
763 				  &acpi_ec_gpe_handler, ec);
764 	if (ACPI_FAILURE(status))
765 		return -ENODEV;
766 
767 	acpi_enable_gpe(NULL, ec->gpe);
768 	status = acpi_install_address_space_handler(ec->handle,
769 						    ACPI_ADR_SPACE_EC,
770 						    &acpi_ec_space_handler,
771 						    NULL, ec);
772 	if (ACPI_FAILURE(status)) {
773 		if (status == AE_NOT_FOUND) {
774 			/*
775 			 * Maybe OS fails in evaluating the _REG object.
776 			 * The AE_NOT_FOUND error will be ignored and OS
777 			 * continue to initialize EC.
778 			 */
779 			pr_err("Fail in evaluating the _REG object"
780 				" of EC device. Broken bios is suspected.\n");
781 		} else {
782 			acpi_remove_gpe_handler(NULL, ec->gpe,
783 				&acpi_ec_gpe_handler);
784 			acpi_disable_gpe(NULL, ec->gpe);
785 			return -ENODEV;
786 		}
787 	}
788 
789 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
790 	return 0;
791 }
792 
793 static void ec_remove_handlers(struct acpi_ec *ec)
794 {
795 	acpi_disable_gpe(NULL, ec->gpe);
796 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
797 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
798 		pr_err("failed to remove space handler\n");
799 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
800 				&acpi_ec_gpe_handler)))
801 		pr_err("failed to remove gpe handler\n");
802 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
803 }
804 
805 static int acpi_ec_add(struct acpi_device *device)
806 {
807 	struct acpi_ec *ec = NULL;
808 	int ret;
809 
810 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
811 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
812 
813 	/* Check for boot EC */
814 	if (boot_ec &&
815 	    (boot_ec->handle == device->handle ||
816 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
817 		ec = boot_ec;
818 		boot_ec = NULL;
819 	} else {
820 		ec = make_acpi_ec();
821 		if (!ec)
822 			return -ENOMEM;
823 	}
824 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
825 		AE_CTRL_TERMINATE) {
826 			kfree(ec);
827 			return -EINVAL;
828 	}
829 
830 	/* Find and register all query methods */
831 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
832 			    acpi_ec_register_query_methods, NULL, ec, NULL);
833 
834 	if (!first_ec)
835 		first_ec = ec;
836 	device->driver_data = ec;
837 
838 	ret = !!request_region(ec->data_addr, 1, "EC data");
839 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
840 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
841 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
842 
843 	pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
844 			  ec->gpe, ec->command_addr, ec->data_addr);
845 
846 	ret = ec_install_handlers(ec);
847 
848 	/* EC is fully operational, allow queries */
849 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
850 	return ret;
851 }
852 
853 static int acpi_ec_remove(struct acpi_device *device)
854 {
855 	struct acpi_ec *ec;
856 	struct acpi_ec_query_handler *handler, *tmp;
857 
858 	if (!device)
859 		return -EINVAL;
860 
861 	ec = acpi_driver_data(device);
862 	ec_remove_handlers(ec);
863 	mutex_lock(&ec->mutex);
864 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
865 		list_del(&handler->node);
866 		kfree(handler);
867 	}
868 	mutex_unlock(&ec->mutex);
869 	release_region(ec->data_addr, 1);
870 	release_region(ec->command_addr, 1);
871 	device->driver_data = NULL;
872 	if (ec == first_ec)
873 		first_ec = NULL;
874 	kfree(ec);
875 	return 0;
876 }
877 
878 static acpi_status
879 ec_parse_io_ports(struct acpi_resource *resource, void *context)
880 {
881 	struct acpi_ec *ec = context;
882 
883 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
884 		return AE_OK;
885 
886 	/*
887 	 * The first address region returned is the data port, and
888 	 * the second address region returned is the status/command
889 	 * port.
890 	 */
891 	if (ec->data_addr == 0)
892 		ec->data_addr = resource->data.io.minimum;
893 	else if (ec->command_addr == 0)
894 		ec->command_addr = resource->data.io.minimum;
895 	else
896 		return AE_CTRL_TERMINATE;
897 
898 	return AE_OK;
899 }
900 
901 int __init acpi_boot_ec_enable(void)
902 {
903 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
904 		return 0;
905 	if (!ec_install_handlers(boot_ec)) {
906 		first_ec = boot_ec;
907 		return 0;
908 	}
909 	return -EFAULT;
910 }
911 
912 static const struct acpi_device_id ec_device_ids[] = {
913 	{"PNP0C09", 0},
914 	{"", 0},
915 };
916 
917 /* Some BIOS do not survive early DSDT scan, skip it */
918 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
919 {
920 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
921 	return 0;
922 }
923 
924 /* ASUStek often supplies us with broken ECDT, validate it */
925 static int ec_validate_ecdt(const struct dmi_system_id *id)
926 {
927 	EC_FLAGS_VALIDATE_ECDT = 1;
928 	return 0;
929 }
930 
931 /* MSI EC needs special treatment, enable it */
932 static int ec_flag_msi(const struct dmi_system_id *id)
933 {
934 	pr_debug("Detected MSI hardware, enabling workarounds.\n");
935 	EC_FLAGS_MSI = 1;
936 	EC_FLAGS_VALIDATE_ECDT = 1;
937 	return 0;
938 }
939 
940 /*
941  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
942  * the GPE storm threshold back to 20
943  */
944 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
945 {
946 	pr_debug("Setting the EC GPE storm threshold to 20\n");
947 	ec_storm_threshold  = 20;
948 	return 0;
949 }
950 
951 static struct dmi_system_id ec_dmi_table[] __initdata = {
952 	{
953 	ec_skip_dsdt_scan, "Compal JFL92", {
954 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
955 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
956 	{
957 	ec_flag_msi, "MSI hardware", {
958 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
959 	{
960 	ec_flag_msi, "MSI hardware", {
961 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
962 	{
963 	ec_flag_msi, "MSI hardware", {
964 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
965 	{
966 	ec_flag_msi, "MSI hardware", {
967 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
968 	{
969 	ec_flag_msi, "Quanta hardware", {
970 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
971 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
972 	{
973 	ec_flag_msi, "Quanta hardware", {
974 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
975 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
976 	{
977 	ec_validate_ecdt, "ASUS hardware", {
978 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
979 	{
980 	ec_validate_ecdt, "ASUS hardware", {
981 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
982 	{
983 	ec_enlarge_storm_threshold, "CLEVO hardware", {
984 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
985 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
986 	{
987 	ec_skip_dsdt_scan, "HP Folio 13", {
988 	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
989 	DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
990 	{
991 	ec_validate_ecdt, "ASUS hardware", {
992 	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
993 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
994 	{},
995 };
996 
997 int __init acpi_ec_ecdt_probe(void)
998 {
999 	acpi_status status;
1000 	struct acpi_ec *saved_ec = NULL;
1001 	struct acpi_table_ecdt *ecdt_ptr;
1002 
1003 	boot_ec = make_acpi_ec();
1004 	if (!boot_ec)
1005 		return -ENOMEM;
1006 	/*
1007 	 * Generate a boot ec context
1008 	 */
1009 	dmi_check_system(ec_dmi_table);
1010 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1011 				(struct acpi_table_header **)&ecdt_ptr);
1012 	if (ACPI_SUCCESS(status)) {
1013 		pr_info("EC description table is found, configuring boot EC\n");
1014 		boot_ec->command_addr = ecdt_ptr->control.address;
1015 		boot_ec->data_addr = ecdt_ptr->data.address;
1016 		boot_ec->gpe = ecdt_ptr->gpe;
1017 		boot_ec->handle = ACPI_ROOT_OBJECT;
1018 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1019 		/* Don't trust ECDT, which comes from ASUSTek */
1020 		if (!EC_FLAGS_VALIDATE_ECDT)
1021 			goto install;
1022 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1023 		if (!saved_ec)
1024 			return -ENOMEM;
1025 	/* fall through */
1026 	}
1027 
1028 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1029 		return -ENODEV;
1030 
1031 	/* This workaround is needed only on some broken machines,
1032 	 * which require early EC, but fail to provide ECDT */
1033 	pr_debug("Look up EC in DSDT\n");
1034 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1035 					boot_ec, NULL);
1036 	/* Check that acpi_get_devices actually find something */
1037 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1038 		goto error;
1039 	if (saved_ec) {
1040 		/* try to find good ECDT from ASUSTek */
1041 		if (saved_ec->command_addr != boot_ec->command_addr ||
1042 		    saved_ec->data_addr != boot_ec->data_addr ||
1043 		    saved_ec->gpe != boot_ec->gpe ||
1044 		    saved_ec->handle != boot_ec->handle)
1045 			pr_info("ASUSTek keeps feeding us with broken "
1046 			"ECDT tables, which are very hard to workaround. "
1047 			"Trying to use DSDT EC info instead. Please send "
1048 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1049 		kfree(saved_ec);
1050 		saved_ec = NULL;
1051 	} else {
1052 		/* We really need to limit this workaround, the only ASUS,
1053 		* which needs it, has fake EC._INI method, so use it as flag.
1054 		* Keep boot_ec struct as it will be needed soon.
1055 		*/
1056 		if (!dmi_name_in_vendors("ASUS") ||
1057 		    !acpi_has_method(boot_ec->handle, "_INI"))
1058 			return -ENODEV;
1059 	}
1060 install:
1061 	if (!ec_install_handlers(boot_ec)) {
1062 		first_ec = boot_ec;
1063 		return 0;
1064 	}
1065 error:
1066 	kfree(boot_ec);
1067 	boot_ec = NULL;
1068 	return -ENODEV;
1069 }
1070 
1071 static struct acpi_driver acpi_ec_driver = {
1072 	.name = "ec",
1073 	.class = ACPI_EC_CLASS,
1074 	.ids = ec_device_ids,
1075 	.ops = {
1076 		.add = acpi_ec_add,
1077 		.remove = acpi_ec_remove,
1078 		},
1079 };
1080 
1081 int __init acpi_ec_init(void)
1082 {
1083 	int result = 0;
1084 
1085 	/* Now register the driver for the EC */
1086 	result = acpi_bus_register_driver(&acpi_ec_driver);
1087 	if (result < 0)
1088 		return -ENODEV;
1089 
1090 	return result;
1091 }
1092 
1093 /* EC driver currently not unloadable */
1094 #if 0
1095 static void __exit acpi_ec_exit(void)
1096 {
1097 
1098 	acpi_bus_unregister_driver(&acpi_ec_driver);
1099 	return;
1100 }
1101 #endif	/* 0 */
1102