xref: /linux/drivers/acpi/ec.c (revision 498d319bb512992ef0784c278fa03679f2f5649d)
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 = ec->curr;
177 
178 	spin_lock_irqsave(&ec->lock, flags);
179 	if (!t)
180 		goto unlock;
181 	if (t->wlen > t->wi) {
182 		if ((status & ACPI_EC_FLAG_IBF) == 0)
183 			acpi_ec_write_data(ec,
184 				t->wdata[t->wi++]);
185 		else
186 			goto err;
187 	} else if (t->rlen > t->ri) {
188 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
189 			t->rdata[t->ri++] = acpi_ec_read_data(ec);
190 			if (t->rlen == t->ri)
191 				t->done = true;
192 		} else
193 			goto err;
194 	} else if (t->wlen == t->wi &&
195 		   (status & ACPI_EC_FLAG_IBF) == 0)
196 		t->done = true;
197 	goto unlock;
198 err:
199 	/*
200 	 * If SCI bit is set, then don't think it's a false IRQ
201 	 * otherwise will take a not handled IRQ as a false one.
202 	 */
203 	if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI))
204 		++t->irq_count;
205 
206 unlock:
207 	spin_unlock_irqrestore(&ec->lock, flags);
208 }
209 
210 static int acpi_ec_sync_query(struct acpi_ec *ec);
211 
212 static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
213 {
214 	if (state & ACPI_EC_FLAG_SCI) {
215 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
216 			return acpi_ec_sync_query(ec);
217 	}
218 	return 0;
219 }
220 
221 static int ec_poll(struct acpi_ec *ec)
222 {
223 	unsigned long flags;
224 	int repeat = 5; /* number of command restarts */
225 	while (repeat--) {
226 		unsigned long delay = jiffies +
227 			msecs_to_jiffies(ec_delay);
228 		do {
229 			/* don't sleep with disabled interrupts */
230 			if (EC_FLAGS_MSI || irqs_disabled()) {
231 				udelay(ACPI_EC_MSI_UDELAY);
232 				if (ec_transaction_done(ec))
233 					return 0;
234 			} else {
235 				if (wait_event_timeout(ec->wait,
236 						ec_transaction_done(ec),
237 						msecs_to_jiffies(1)))
238 					return 0;
239 			}
240 			advance_transaction(ec, acpi_ec_read_status(ec));
241 		} while (time_before(jiffies, delay));
242 		pr_debug("controller reset, restart transaction\n");
243 		spin_lock_irqsave(&ec->lock, flags);
244 		start_transaction(ec);
245 		spin_unlock_irqrestore(&ec->lock, flags);
246 	}
247 	return -ETIME;
248 }
249 
250 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
251 					struct transaction *t)
252 {
253 	unsigned long tmp;
254 	int ret = 0;
255 	if (EC_FLAGS_MSI)
256 		udelay(ACPI_EC_MSI_UDELAY);
257 	/* start transaction */
258 	spin_lock_irqsave(&ec->lock, tmp);
259 	/* following two actions should be kept atomic */
260 	ec->curr = t;
261 	start_transaction(ec);
262 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
263 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
264 	spin_unlock_irqrestore(&ec->lock, tmp);
265 	ret = ec_poll(ec);
266 	spin_lock_irqsave(&ec->lock, tmp);
267 	ec->curr = NULL;
268 	spin_unlock_irqrestore(&ec->lock, tmp);
269 	return ret;
270 }
271 
272 static int ec_check_ibf0(struct acpi_ec *ec)
273 {
274 	u8 status = acpi_ec_read_status(ec);
275 	return (status & ACPI_EC_FLAG_IBF) == 0;
276 }
277 
278 static int ec_wait_ibf0(struct acpi_ec *ec)
279 {
280 	unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
281 	/* interrupt wait manually if GPE mode is not active */
282 	while (time_before(jiffies, delay))
283 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
284 					msecs_to_jiffies(1)))
285 			return 0;
286 	return -ETIME;
287 }
288 
289 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
290 {
291 	int status;
292 	u32 glk;
293 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
294 		return -EINVAL;
295 	if (t->rdata)
296 		memset(t->rdata, 0, t->rlen);
297 	mutex_lock(&ec->mutex);
298 	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
299 		status = -EINVAL;
300 		goto unlock;
301 	}
302 	if (ec->global_lock) {
303 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
304 		if (ACPI_FAILURE(status)) {
305 			status = -ENODEV;
306 			goto unlock;
307 		}
308 	}
309 	if (ec_wait_ibf0(ec)) {
310 		pr_err("input buffer is not empty, "
311 				"aborting transaction\n");
312 		status = -ETIME;
313 		goto end;
314 	}
315 	pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
316 			t->command, t->wdata ? t->wdata[0] : 0);
317 	/* disable GPE during transaction if storm is detected */
318 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
319 		/* It has to be disabled, so that it doesn't trigger. */
320 		acpi_disable_gpe(NULL, ec->gpe);
321 	}
322 
323 	status = acpi_ec_transaction_unlocked(ec, t);
324 
325 	/* check if we received SCI during transaction */
326 	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
327 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
328 		msleep(1);
329 		/* It is safe to enable the GPE outside of the transaction. */
330 		acpi_enable_gpe(NULL, ec->gpe);
331 	} else if (t->irq_count > ec_storm_threshold) {
332 		pr_info("GPE storm detected(%d GPEs), "
333 			"transactions will use polling mode\n",
334 			t->irq_count);
335 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
336 	}
337 	pr_debug("transaction end\n");
338 end:
339 	if (ec->global_lock)
340 		acpi_release_global_lock(glk);
341 unlock:
342 	mutex_unlock(&ec->mutex);
343 	return status;
344 }
345 
346 static int acpi_ec_burst_enable(struct acpi_ec *ec)
347 {
348 	u8 d;
349 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
350 				.wdata = NULL, .rdata = &d,
351 				.wlen = 0, .rlen = 1};
352 
353 	return acpi_ec_transaction(ec, &t);
354 }
355 
356 static int acpi_ec_burst_disable(struct acpi_ec *ec)
357 {
358 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
359 				.wdata = NULL, .rdata = NULL,
360 				.wlen = 0, .rlen = 0};
361 
362 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
363 				acpi_ec_transaction(ec, &t) : 0;
364 }
365 
366 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
367 {
368 	int result;
369 	u8 d;
370 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
371 				.wdata = &address, .rdata = &d,
372 				.wlen = 1, .rlen = 1};
373 
374 	result = acpi_ec_transaction(ec, &t);
375 	*data = d;
376 	return result;
377 }
378 
379 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
380 {
381 	u8 wdata[2] = { address, data };
382 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
383 				.wdata = wdata, .rdata = NULL,
384 				.wlen = 2, .rlen = 0};
385 
386 	return acpi_ec_transaction(ec, &t);
387 }
388 
389 /*
390  * Externally callable EC access functions. For now, assume 1 EC only
391  */
392 int ec_burst_enable(void)
393 {
394 	if (!first_ec)
395 		return -ENODEV;
396 	return acpi_ec_burst_enable(first_ec);
397 }
398 
399 EXPORT_SYMBOL(ec_burst_enable);
400 
401 int ec_burst_disable(void)
402 {
403 	if (!first_ec)
404 		return -ENODEV;
405 	return acpi_ec_burst_disable(first_ec);
406 }
407 
408 EXPORT_SYMBOL(ec_burst_disable);
409 
410 int ec_read(u8 addr, u8 *val)
411 {
412 	int err;
413 	u8 temp_data;
414 
415 	if (!first_ec)
416 		return -ENODEV;
417 
418 	err = acpi_ec_read(first_ec, addr, &temp_data);
419 
420 	if (!err) {
421 		*val = temp_data;
422 		return 0;
423 	} else
424 		return err;
425 }
426 
427 EXPORT_SYMBOL(ec_read);
428 
429 int ec_write(u8 addr, u8 val)
430 {
431 	int err;
432 
433 	if (!first_ec)
434 		return -ENODEV;
435 
436 	err = acpi_ec_write(first_ec, addr, val);
437 
438 	return err;
439 }
440 
441 EXPORT_SYMBOL(ec_write);
442 
443 int ec_transaction(u8 command,
444 		   const u8 * wdata, unsigned wdata_len,
445 		   u8 * rdata, unsigned rdata_len)
446 {
447 	struct transaction t = {.command = command,
448 				.wdata = wdata, .rdata = rdata,
449 				.wlen = wdata_len, .rlen = rdata_len};
450 	if (!first_ec)
451 		return -ENODEV;
452 
453 	return acpi_ec_transaction(first_ec, &t);
454 }
455 
456 EXPORT_SYMBOL(ec_transaction);
457 
458 /* Get the handle to the EC device */
459 acpi_handle ec_get_handle(void)
460 {
461 	if (!first_ec)
462 		return NULL;
463 	return first_ec->handle;
464 }
465 
466 EXPORT_SYMBOL(ec_get_handle);
467 
468 void acpi_ec_block_transactions(void)
469 {
470 	struct acpi_ec *ec = first_ec;
471 
472 	if (!ec)
473 		return;
474 
475 	mutex_lock(&ec->mutex);
476 	/* Prevent transactions from being carried out */
477 	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
478 	mutex_unlock(&ec->mutex);
479 }
480 
481 void acpi_ec_unblock_transactions(void)
482 {
483 	struct acpi_ec *ec = first_ec;
484 
485 	if (!ec)
486 		return;
487 
488 	mutex_lock(&ec->mutex);
489 	/* Allow transactions to be carried out again */
490 	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
491 	mutex_unlock(&ec->mutex);
492 }
493 
494 void acpi_ec_unblock_transactions_early(void)
495 {
496 	/*
497 	 * Allow transactions to happen again (this function is called from
498 	 * atomic context during wakeup, so we don't need to acquire the mutex).
499 	 */
500 	if (first_ec)
501 		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
502 }
503 
504 static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data)
505 {
506 	int result;
507 	u8 d;
508 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
509 				.wdata = NULL, .rdata = &d,
510 				.wlen = 0, .rlen = 1};
511 	if (!ec || !data)
512 		return -EINVAL;
513 	/*
514 	 * Query the EC to find out which _Qxx method we need to evaluate.
515 	 * Note that successful completion of the query causes the ACPI_EC_SCI
516 	 * bit to be cleared (and thus clearing the interrupt source).
517 	 */
518 	result = acpi_ec_transaction_unlocked(ec, &t);
519 	if (result)
520 		return result;
521 	if (!d)
522 		return -ENODATA;
523 	*data = d;
524 	return 0;
525 }
526 
527 /* --------------------------------------------------------------------------
528                                 Event Management
529    -------------------------------------------------------------------------- */
530 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
531 			      acpi_handle handle, acpi_ec_query_func func,
532 			      void *data)
533 {
534 	struct acpi_ec_query_handler *handler =
535 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
536 	if (!handler)
537 		return -ENOMEM;
538 
539 	handler->query_bit = query_bit;
540 	handler->handle = handle;
541 	handler->func = func;
542 	handler->data = data;
543 	mutex_lock(&ec->mutex);
544 	list_add(&handler->node, &ec->list);
545 	mutex_unlock(&ec->mutex);
546 	return 0;
547 }
548 
549 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
550 
551 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
552 {
553 	struct acpi_ec_query_handler *handler, *tmp;
554 	mutex_lock(&ec->mutex);
555 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
556 		if (query_bit == handler->query_bit) {
557 			list_del(&handler->node);
558 			kfree(handler);
559 		}
560 	}
561 	mutex_unlock(&ec->mutex);
562 }
563 
564 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
565 
566 static void acpi_ec_run(void *cxt)
567 {
568 	struct acpi_ec_query_handler *handler = cxt;
569 	if (!handler)
570 		return;
571 	pr_debug("start query execution\n");
572 	if (handler->func)
573 		handler->func(handler->data);
574 	else if (handler->handle)
575 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
576 	pr_debug("stop query execution\n");
577 	kfree(handler);
578 }
579 
580 static int acpi_ec_sync_query(struct acpi_ec *ec)
581 {
582 	u8 value = 0;
583 	int status;
584 	struct acpi_ec_query_handler *handler, *copy;
585 	if ((status = acpi_ec_query_unlocked(ec, &value)))
586 		return status;
587 	list_for_each_entry(handler, &ec->list, node) {
588 		if (value == handler->query_bit) {
589 			/* have custom handler for this bit */
590 			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
591 			if (!copy)
592 				return -ENOMEM;
593 			memcpy(copy, handler, sizeof(*copy));
594 			pr_debug("push query execution (0x%2x) on queue\n",
595 				value);
596 			return acpi_os_execute((copy->func) ?
597 				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
598 				acpi_ec_run, copy);
599 		}
600 	}
601 	return 0;
602 }
603 
604 static void acpi_ec_gpe_query(void *ec_cxt)
605 {
606 	struct acpi_ec *ec = ec_cxt;
607 	if (!ec)
608 		return;
609 	mutex_lock(&ec->mutex);
610 	acpi_ec_sync_query(ec);
611 	mutex_unlock(&ec->mutex);
612 }
613 
614 static int ec_check_sci(struct acpi_ec *ec, u8 state)
615 {
616 	if (state & ACPI_EC_FLAG_SCI) {
617 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
618 			pr_debug("push gpe query to the queue\n");
619 			return acpi_os_execute(OSL_NOTIFY_HANDLER,
620 				acpi_ec_gpe_query, ec);
621 		}
622 	}
623 	return 0;
624 }
625 
626 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
627 	u32 gpe_number, void *data)
628 {
629 	struct acpi_ec *ec = data;
630 	u8 status = acpi_ec_read_status(ec);
631 
632 	pr_debug("~~~> interrupt, status:0x%02x\n", status);
633 
634 	advance_transaction(ec, status);
635 	if (ec_transaction_done(ec) &&
636 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
637 		wake_up(&ec->wait);
638 		ec_check_sci(ec, acpi_ec_read_status(ec));
639 	}
640 	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
641 }
642 
643 /* --------------------------------------------------------------------------
644                              Address Space Management
645    -------------------------------------------------------------------------- */
646 
647 static acpi_status
648 acpi_ec_space_handler(u32 function, acpi_physical_address address,
649 		      u32 bits, u64 *value64,
650 		      void *handler_context, void *region_context)
651 {
652 	struct acpi_ec *ec = handler_context;
653 	int result = 0, i, bytes = bits / 8;
654 	u8 *value = (u8 *)value64;
655 
656 	if ((address > 0xFF) || !value || !handler_context)
657 		return AE_BAD_PARAMETER;
658 
659 	if (function != ACPI_READ && function != ACPI_WRITE)
660 		return AE_BAD_PARAMETER;
661 
662 	if (EC_FLAGS_MSI || bits > 8)
663 		acpi_ec_burst_enable(ec);
664 
665 	for (i = 0; i < bytes; ++i, ++address, ++value)
666 		result = (function == ACPI_READ) ?
667 			acpi_ec_read(ec, address, value) :
668 			acpi_ec_write(ec, address, *value);
669 
670 	if (EC_FLAGS_MSI || bits > 8)
671 		acpi_ec_burst_disable(ec);
672 
673 	switch (result) {
674 	case -EINVAL:
675 		return AE_BAD_PARAMETER;
676 		break;
677 	case -ENODEV:
678 		return AE_NOT_FOUND;
679 		break;
680 	case -ETIME:
681 		return AE_TIME;
682 		break;
683 	default:
684 		return AE_OK;
685 	}
686 }
687 
688 /* --------------------------------------------------------------------------
689                                Driver Interface
690    -------------------------------------------------------------------------- */
691 static acpi_status
692 ec_parse_io_ports(struct acpi_resource *resource, void *context);
693 
694 static struct acpi_ec *make_acpi_ec(void)
695 {
696 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
697 	if (!ec)
698 		return NULL;
699 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
700 	mutex_init(&ec->mutex);
701 	init_waitqueue_head(&ec->wait);
702 	INIT_LIST_HEAD(&ec->list);
703 	spin_lock_init(&ec->lock);
704 	return ec;
705 }
706 
707 static acpi_status
708 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
709 			       void *context, void **return_value)
710 {
711 	char node_name[5];
712 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
713 	struct acpi_ec *ec = context;
714 	int value = 0;
715 	acpi_status status;
716 
717 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
718 
719 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
720 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
721 	}
722 	return AE_OK;
723 }
724 
725 static acpi_status
726 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
727 {
728 	acpi_status status;
729 	unsigned long long tmp = 0;
730 
731 	struct acpi_ec *ec = context;
732 
733 	/* clear addr values, ec_parse_io_ports depend on it */
734 	ec->command_addr = ec->data_addr = 0;
735 
736 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
737 				     ec_parse_io_ports, ec);
738 	if (ACPI_FAILURE(status))
739 		return status;
740 
741 	/* Get GPE bit assignment (EC events). */
742 	/* TODO: Add support for _GPE returning a package */
743 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
744 	if (ACPI_FAILURE(status))
745 		return status;
746 	ec->gpe = tmp;
747 	/* Use the global lock for all EC transactions? */
748 	tmp = 0;
749 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
750 	ec->global_lock = tmp;
751 	ec->handle = handle;
752 	return AE_CTRL_TERMINATE;
753 }
754 
755 static int ec_install_handlers(struct acpi_ec *ec)
756 {
757 	acpi_status status;
758 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
759 		return 0;
760 	status = acpi_install_gpe_handler(NULL, ec->gpe,
761 				  ACPI_GPE_EDGE_TRIGGERED,
762 				  &acpi_ec_gpe_handler, ec);
763 	if (ACPI_FAILURE(status))
764 		return -ENODEV;
765 
766 	acpi_enable_gpe(NULL, ec->gpe);
767 	status = acpi_install_address_space_handler(ec->handle,
768 						    ACPI_ADR_SPACE_EC,
769 						    &acpi_ec_space_handler,
770 						    NULL, ec);
771 	if (ACPI_FAILURE(status)) {
772 		if (status == AE_NOT_FOUND) {
773 			/*
774 			 * Maybe OS fails in evaluating the _REG object.
775 			 * The AE_NOT_FOUND error will be ignored and OS
776 			 * continue to initialize EC.
777 			 */
778 			pr_err("Fail in evaluating the _REG object"
779 				" of EC device. Broken bios is suspected.\n");
780 		} else {
781 			acpi_remove_gpe_handler(NULL, ec->gpe,
782 				&acpi_ec_gpe_handler);
783 			acpi_disable_gpe(NULL, ec->gpe);
784 			return -ENODEV;
785 		}
786 	}
787 
788 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
789 	return 0;
790 }
791 
792 static void ec_remove_handlers(struct acpi_ec *ec)
793 {
794 	acpi_disable_gpe(NULL, ec->gpe);
795 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
796 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
797 		pr_err("failed to remove space handler\n");
798 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
799 				&acpi_ec_gpe_handler)))
800 		pr_err("failed to remove gpe handler\n");
801 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
802 }
803 
804 static int acpi_ec_add(struct acpi_device *device)
805 {
806 	struct acpi_ec *ec = NULL;
807 	int ret;
808 
809 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
810 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
811 
812 	/* Check for boot EC */
813 	if (boot_ec &&
814 	    (boot_ec->handle == device->handle ||
815 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
816 		ec = boot_ec;
817 		boot_ec = NULL;
818 	} else {
819 		ec = make_acpi_ec();
820 		if (!ec)
821 			return -ENOMEM;
822 	}
823 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
824 		AE_CTRL_TERMINATE) {
825 			kfree(ec);
826 			return -EINVAL;
827 	}
828 
829 	/* Find and register all query methods */
830 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
831 			    acpi_ec_register_query_methods, NULL, ec, NULL);
832 
833 	if (!first_ec)
834 		first_ec = ec;
835 	device->driver_data = ec;
836 
837 	ret = !!request_region(ec->data_addr, 1, "EC data");
838 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
839 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
840 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
841 
842 	pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
843 			  ec->gpe, ec->command_addr, ec->data_addr);
844 
845 	ret = ec_install_handlers(ec);
846 
847 	/* EC is fully operational, allow queries */
848 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
849 	return ret;
850 }
851 
852 static int acpi_ec_remove(struct acpi_device *device)
853 {
854 	struct acpi_ec *ec;
855 	struct acpi_ec_query_handler *handler, *tmp;
856 
857 	if (!device)
858 		return -EINVAL;
859 
860 	ec = acpi_driver_data(device);
861 	ec_remove_handlers(ec);
862 	mutex_lock(&ec->mutex);
863 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
864 		list_del(&handler->node);
865 		kfree(handler);
866 	}
867 	mutex_unlock(&ec->mutex);
868 	release_region(ec->data_addr, 1);
869 	release_region(ec->command_addr, 1);
870 	device->driver_data = NULL;
871 	if (ec == first_ec)
872 		first_ec = NULL;
873 	kfree(ec);
874 	return 0;
875 }
876 
877 static acpi_status
878 ec_parse_io_ports(struct acpi_resource *resource, void *context)
879 {
880 	struct acpi_ec *ec = context;
881 
882 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
883 		return AE_OK;
884 
885 	/*
886 	 * The first address region returned is the data port, and
887 	 * the second address region returned is the status/command
888 	 * port.
889 	 */
890 	if (ec->data_addr == 0)
891 		ec->data_addr = resource->data.io.minimum;
892 	else if (ec->command_addr == 0)
893 		ec->command_addr = resource->data.io.minimum;
894 	else
895 		return AE_CTRL_TERMINATE;
896 
897 	return AE_OK;
898 }
899 
900 int __init acpi_boot_ec_enable(void)
901 {
902 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
903 		return 0;
904 	if (!ec_install_handlers(boot_ec)) {
905 		first_ec = boot_ec;
906 		return 0;
907 	}
908 	return -EFAULT;
909 }
910 
911 static const struct acpi_device_id ec_device_ids[] = {
912 	{"PNP0C09", 0},
913 	{"", 0},
914 };
915 
916 /* Some BIOS do not survive early DSDT scan, skip it */
917 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
918 {
919 	EC_FLAGS_SKIP_DSDT_SCAN = 1;
920 	return 0;
921 }
922 
923 /* ASUStek often supplies us with broken ECDT, validate it */
924 static int ec_validate_ecdt(const struct dmi_system_id *id)
925 {
926 	EC_FLAGS_VALIDATE_ECDT = 1;
927 	return 0;
928 }
929 
930 /* MSI EC needs special treatment, enable it */
931 static int ec_flag_msi(const struct dmi_system_id *id)
932 {
933 	pr_debug("Detected MSI hardware, enabling workarounds.\n");
934 	EC_FLAGS_MSI = 1;
935 	EC_FLAGS_VALIDATE_ECDT = 1;
936 	return 0;
937 }
938 
939 /*
940  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
941  * the GPE storm threshold back to 20
942  */
943 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
944 {
945 	pr_debug("Setting the EC GPE storm threshold to 20\n");
946 	ec_storm_threshold  = 20;
947 	return 0;
948 }
949 
950 static struct dmi_system_id ec_dmi_table[] __initdata = {
951 	{
952 	ec_skip_dsdt_scan, "Compal JFL92", {
953 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
954 	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
955 	{
956 	ec_flag_msi, "MSI hardware", {
957 	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
958 	{
959 	ec_flag_msi, "MSI hardware", {
960 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
961 	{
962 	ec_flag_msi, "MSI hardware", {
963 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
964 	{
965 	ec_flag_msi, "MSI hardware", {
966 	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
967 	{
968 	ec_flag_msi, "Quanta hardware", {
969 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
970 	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
971 	{
972 	ec_flag_msi, "Quanta hardware", {
973 	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
974 	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
975 	{
976 	ec_validate_ecdt, "ASUS hardware", {
977 	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
978 	{
979 	ec_validate_ecdt, "ASUS hardware", {
980 	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
981 	{
982 	ec_enlarge_storm_threshold, "CLEVO hardware", {
983 	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
984 	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
985 	{
986 	ec_skip_dsdt_scan, "HP Folio 13", {
987 	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
988 	DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
989 	{
990 	ec_validate_ecdt, "ASUS hardware", {
991 	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
992 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
993 	{},
994 };
995 
996 int __init acpi_ec_ecdt_probe(void)
997 {
998 	acpi_status status;
999 	struct acpi_ec *saved_ec = NULL;
1000 	struct acpi_table_ecdt *ecdt_ptr;
1001 
1002 	boot_ec = make_acpi_ec();
1003 	if (!boot_ec)
1004 		return -ENOMEM;
1005 	/*
1006 	 * Generate a boot ec context
1007 	 */
1008 	dmi_check_system(ec_dmi_table);
1009 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1010 				(struct acpi_table_header **)&ecdt_ptr);
1011 	if (ACPI_SUCCESS(status)) {
1012 		pr_info("EC description table is found, configuring boot EC\n");
1013 		boot_ec->command_addr = ecdt_ptr->control.address;
1014 		boot_ec->data_addr = ecdt_ptr->data.address;
1015 		boot_ec->gpe = ecdt_ptr->gpe;
1016 		boot_ec->handle = ACPI_ROOT_OBJECT;
1017 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1018 		/* Don't trust ECDT, which comes from ASUSTek */
1019 		if (!EC_FLAGS_VALIDATE_ECDT)
1020 			goto install;
1021 		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1022 		if (!saved_ec)
1023 			return -ENOMEM;
1024 	/* fall through */
1025 	}
1026 
1027 	if (EC_FLAGS_SKIP_DSDT_SCAN)
1028 		return -ENODEV;
1029 
1030 	/* This workaround is needed only on some broken machines,
1031 	 * which require early EC, but fail to provide ECDT */
1032 	pr_debug("Look up EC in DSDT\n");
1033 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1034 					boot_ec, NULL);
1035 	/* Check that acpi_get_devices actually find something */
1036 	if (ACPI_FAILURE(status) || !boot_ec->handle)
1037 		goto error;
1038 	if (saved_ec) {
1039 		/* try to find good ECDT from ASUSTek */
1040 		if (saved_ec->command_addr != boot_ec->command_addr ||
1041 		    saved_ec->data_addr != boot_ec->data_addr ||
1042 		    saved_ec->gpe != boot_ec->gpe ||
1043 		    saved_ec->handle != boot_ec->handle)
1044 			pr_info("ASUSTek keeps feeding us with broken "
1045 			"ECDT tables, which are very hard to workaround. "
1046 			"Trying to use DSDT EC info instead. Please send "
1047 			"output of acpidump to linux-acpi@vger.kernel.org\n");
1048 		kfree(saved_ec);
1049 		saved_ec = NULL;
1050 	} else {
1051 		/* We really need to limit this workaround, the only ASUS,
1052 		* which needs it, has fake EC._INI method, so use it as flag.
1053 		* Keep boot_ec struct as it will be needed soon.
1054 		*/
1055 		if (!dmi_name_in_vendors("ASUS") ||
1056 		    !acpi_has_method(boot_ec->handle, "_INI"))
1057 			return -ENODEV;
1058 	}
1059 install:
1060 	if (!ec_install_handlers(boot_ec)) {
1061 		first_ec = boot_ec;
1062 		return 0;
1063 	}
1064 error:
1065 	kfree(boot_ec);
1066 	boot_ec = NULL;
1067 	return -ENODEV;
1068 }
1069 
1070 static struct acpi_driver acpi_ec_driver = {
1071 	.name = "ec",
1072 	.class = ACPI_EC_CLASS,
1073 	.ids = ec_device_ids,
1074 	.ops = {
1075 		.add = acpi_ec_add,
1076 		.remove = acpi_ec_remove,
1077 		},
1078 };
1079 
1080 int __init acpi_ec_init(void)
1081 {
1082 	int result = 0;
1083 
1084 	/* Now register the driver for the EC */
1085 	result = acpi_bus_register_driver(&acpi_ec_driver);
1086 	if (result < 0)
1087 		return -ENODEV;
1088 
1089 	return result;
1090 }
1091 
1092 /* EC driver currently not unloadable */
1093 #if 0
1094 static void __exit acpi_ec_exit(void)
1095 {
1096 
1097 	acpi_bus_unregister_driver(&acpi_ec_driver);
1098 	return;
1099 }
1100 #endif	/* 0 */
1101