xref: /linux/drivers/acpi/ec.c (revision 93d546399c2b7d66a54d5fbd5eee17de19246bf6)
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 
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/init.h>
35 #include <linux/types.h>
36 #include <linux/delay.h>
37 #include <linux/proc_fs.h>
38 #include <linux/seq_file.h>
39 #include <linux/interrupt.h>
40 #include <linux/list.h>
41 #include <linux/spinlock.h>
42 #include <asm/io.h>
43 #include <acpi/acpi_bus.h>
44 #include <acpi/acpi_drivers.h>
45 #include <acpi/actypes.h>
46 
47 #define ACPI_EC_CLASS			"embedded_controller"
48 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
49 #define ACPI_EC_FILE_INFO		"info"
50 
51 #undef PREFIX
52 #define PREFIX				"ACPI: EC: "
53 
54 /* EC status register */
55 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
56 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
57 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
58 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
59 
60 /* EC commands */
61 enum ec_command {
62 	ACPI_EC_COMMAND_READ = 0x80,
63 	ACPI_EC_COMMAND_WRITE = 0x81,
64 	ACPI_EC_BURST_ENABLE = 0x82,
65 	ACPI_EC_BURST_DISABLE = 0x83,
66 	ACPI_EC_COMMAND_QUERY = 0x84,
67 };
68 
69 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
70 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
71 #define ACPI_EC_UDELAY		100	/* Wait 100us before polling EC again */
72 
73 #define ACPI_EC_STORM_THRESHOLD 8	/* number of false interrupts
74 					   per one transaction */
75 
76 enum {
77 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
78 	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent
79 					 * for status change */
80 	EC_FLAGS_NO_GPE,		/* Don't use GPE mode */
81 	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
82 	EC_FLAGS_HANDLERS_INSTALLED	/* Handlers for GPE and
83 					 * OpReg are installed */
84 };
85 
86 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
87 /* External interfaces use first EC only, so remember */
88 typedef int (*acpi_ec_query_func) (void *data);
89 
90 struct acpi_ec_query_handler {
91 	struct list_head node;
92 	acpi_ec_query_func func;
93 	acpi_handle handle;
94 	void *data;
95 	u8 query_bit;
96 };
97 
98 struct transaction {
99 	const u8 *wdata;
100 	u8 *rdata;
101 	unsigned short irq_count;
102 	u8 command;
103 	u8 wi;
104 	u8 ri;
105 	u8 wlen;
106 	u8 rlen;
107 	bool done;
108 };
109 
110 static struct acpi_ec {
111 	acpi_handle handle;
112 	unsigned long gpe;
113 	unsigned long command_addr;
114 	unsigned long data_addr;
115 	unsigned long global_lock;
116 	unsigned long flags;
117 	struct mutex lock;
118 	wait_queue_head_t wait;
119 	struct list_head list;
120 	struct transaction *curr;
121 	spinlock_t curr_lock;
122 } *boot_ec, *first_ec;
123 
124 /*
125  * Some Asus system have exchanged ECDT data/command IO addresses.
126  */
127 static int print_ecdt_error(const struct dmi_system_id *id)
128 {
129 	printk(KERN_NOTICE PREFIX "%s detected - "
130 		"ECDT has exchanged control/data I/O address\n",
131 		id->ident);
132 	return 0;
133 }
134 
135 static struct dmi_system_id __cpuinitdata ec_dmi_table[] = {
136 	{
137 	print_ecdt_error, "Asus L4R", {
138 	DMI_MATCH(DMI_BIOS_VERSION, "1008.006"),
139 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),
140 	DMI_MATCH(DMI_BOARD_NAME, "L4R") }, NULL},
141 	{
142 	print_ecdt_error, "Asus M6R", {
143 	DMI_MATCH(DMI_BIOS_VERSION, "0207"),
144 	DMI_MATCH(DMI_PRODUCT_NAME, "M6R"),
145 	DMI_MATCH(DMI_BOARD_NAME, "M6R") }, NULL},
146 	{},
147 };
148 
149 /* --------------------------------------------------------------------------
150                              Transaction Management
151    -------------------------------------------------------------------------- */
152 
153 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
154 {
155 	u8 x = inb(ec->command_addr);
156 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
157 	return x;
158 }
159 
160 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
161 {
162 	u8 x = inb(ec->data_addr);
163 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
164 	return x;
165 }
166 
167 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
168 {
169 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
170 	outb(command, ec->command_addr);
171 }
172 
173 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
174 {
175 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
176 	outb(data, ec->data_addr);
177 }
178 
179 static int ec_transaction_done(struct acpi_ec *ec)
180 {
181 	unsigned long flags;
182 	int ret = 0;
183 	spin_lock_irqsave(&ec->curr_lock, flags);
184 	if (!ec->curr || ec->curr->done)
185 		ret = 1;
186 	spin_unlock_irqrestore(&ec->curr_lock, flags);
187 	return ret;
188 }
189 
190 static void start_transaction(struct acpi_ec *ec)
191 {
192 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
193 	ec->curr->done = false;
194 	acpi_ec_write_cmd(ec, ec->curr->command);
195 }
196 
197 static void gpe_transaction(struct acpi_ec *ec, u8 status)
198 {
199 	unsigned long flags;
200 	spin_lock_irqsave(&ec->curr_lock, flags);
201 	if (!ec->curr)
202 		goto unlock;
203 	if (ec->curr->wlen > ec->curr->wi) {
204 		if ((status & ACPI_EC_FLAG_IBF) == 0)
205 			acpi_ec_write_data(ec,
206 				ec->curr->wdata[ec->curr->wi++]);
207 		else
208 			goto err;
209 	} else if (ec->curr->rlen > ec->curr->ri) {
210 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
211 			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
212 			if (ec->curr->rlen == ec->curr->ri)
213 				ec->curr->done = true;
214 		} else
215 			goto err;
216 	} else if (ec->curr->wlen == ec->curr->wi &&
217 		   (status & ACPI_EC_FLAG_IBF) == 0)
218 		ec->curr->done = true;
219 	goto unlock;
220 err:
221 	/* false interrupt, state didn't change */
222 	if (in_interrupt())
223 		++ec->curr->irq_count;
224 unlock:
225 	spin_unlock_irqrestore(&ec->curr_lock, flags);
226 }
227 
228 static int acpi_ec_wait(struct acpi_ec *ec)
229 {
230 	if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
231 			       msecs_to_jiffies(ACPI_EC_DELAY)))
232 		return 0;
233 	/* try restart command if we get any false interrupts */
234 	if (ec->curr->irq_count &&
235 	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
236 		pr_debug(PREFIX "controller reset, restart transaction\n");
237 		start_transaction(ec);
238 		if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
239 					msecs_to_jiffies(ACPI_EC_DELAY)))
240 			return 0;
241 	}
242 	/* missing GPEs, switch back to poll mode */
243 	if (printk_ratelimit())
244 		pr_info(PREFIX "missing confirmations, "
245 				"switch off interrupt mode.\n");
246 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
247 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
248 	return 1;
249 }
250 
251 static void acpi_ec_gpe_query(void *ec_cxt);
252 
253 static int ec_check_sci(struct acpi_ec *ec, u8 state)
254 {
255 	if (state & ACPI_EC_FLAG_SCI) {
256 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
257 			return acpi_os_execute(OSL_EC_BURST_HANDLER,
258 				acpi_ec_gpe_query, ec);
259 	}
260 	return 0;
261 }
262 
263 static int ec_poll(struct acpi_ec *ec)
264 {
265 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
266 	udelay(ACPI_EC_UDELAY);
267 	while (time_before(jiffies, delay)) {
268 		gpe_transaction(ec, acpi_ec_read_status(ec));
269 		udelay(ACPI_EC_UDELAY);
270 		if (ec_transaction_done(ec))
271 			return 0;
272 	}
273 	return -ETIME;
274 }
275 
276 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
277 					struct transaction *t,
278 					int force_poll)
279 {
280 	unsigned long tmp;
281 	int ret = 0;
282 	pr_debug(PREFIX "transaction start\n");
283 	/* disable GPE during transaction if storm is detected */
284 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
285 		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
286 		acpi_disable_gpe(NULL, ec->gpe);
287 	}
288 	/* start transaction */
289 	spin_lock_irqsave(&ec->curr_lock, tmp);
290 	/* following two actions should be kept atomic */
291 	ec->curr = t;
292 	start_transaction(ec);
293 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
294 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
295 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
296 	/* if we selected poll mode or failed in GPE-mode do a poll loop */
297 	if (force_poll ||
298 	    !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
299 	    acpi_ec_wait(ec))
300 		ret = ec_poll(ec);
301 	pr_debug(PREFIX "transaction end\n");
302 	spin_lock_irqsave(&ec->curr_lock, tmp);
303 	ec->curr = NULL;
304 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
305 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
306 		/* check if we received SCI during transaction */
307 		ec_check_sci(ec, acpi_ec_read_status(ec));
308 		/* it is safe to enable GPE outside of transaction */
309 		acpi_enable_gpe(NULL, ec->gpe);
310 	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
311 		   t->irq_count > ACPI_EC_STORM_THRESHOLD) {
312 		pr_info(PREFIX "GPE storm detected, "
313 			"transactions will use polling mode\n");
314 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
315 	}
316 	return ret;
317 }
318 
319 static int ec_check_ibf0(struct acpi_ec *ec)
320 {
321 	u8 status = acpi_ec_read_status(ec);
322 	return (status & ACPI_EC_FLAG_IBF) == 0;
323 }
324 
325 static int ec_wait_ibf0(struct acpi_ec *ec)
326 {
327 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
328 	/* interrupt wait manually if GPE mode is not active */
329 	unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
330 		msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
331 	while (time_before(jiffies, delay))
332 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
333 			return 0;
334 	return -ETIME;
335 }
336 
337 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
338 			       int force_poll)
339 {
340 	int status;
341 	u32 glk;
342 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
343 		return -EINVAL;
344 	if (t->rdata)
345 		memset(t->rdata, 0, t->rlen);
346 	mutex_lock(&ec->lock);
347 	if (ec->global_lock) {
348 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
349 		if (ACPI_FAILURE(status)) {
350 			status = -ENODEV;
351 			goto unlock;
352 		}
353 	}
354 	if (ec_wait_ibf0(ec)) {
355 		pr_err(PREFIX "input buffer is not empty, "
356 				"aborting transaction\n");
357 		status = -ETIME;
358 		goto end;
359 	}
360 	status = acpi_ec_transaction_unlocked(ec, t, force_poll);
361 end:
362 	if (ec->global_lock)
363 		acpi_release_global_lock(glk);
364 unlock:
365 	mutex_unlock(&ec->lock);
366 	return status;
367 }
368 
369 /*
370  * Note: samsung nv5000 doesn't work with ec burst mode.
371  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
372  */
373 int acpi_ec_burst_enable(struct acpi_ec *ec)
374 {
375 	u8 d;
376 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
377 				.wdata = NULL, .rdata = &d,
378 				.wlen = 0, .rlen = 1};
379 
380 	return acpi_ec_transaction(ec, &t, 0);
381 }
382 
383 int acpi_ec_burst_disable(struct acpi_ec *ec)
384 {
385 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
386 				.wdata = NULL, .rdata = NULL,
387 				.wlen = 0, .rlen = 0};
388 
389 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
390 				acpi_ec_transaction(ec, &t, 0) : 0;
391 }
392 
393 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
394 {
395 	int result;
396 	u8 d;
397 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
398 				.wdata = &address, .rdata = &d,
399 				.wlen = 1, .rlen = 1};
400 
401 	result = acpi_ec_transaction(ec, &t, 0);
402 	*data = d;
403 	return result;
404 }
405 
406 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
407 {
408 	u8 wdata[2] = { address, data };
409 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
410 				.wdata = wdata, .rdata = NULL,
411 				.wlen = 2, .rlen = 0};
412 
413 	return acpi_ec_transaction(ec, &t, 0);
414 }
415 
416 /*
417  * Externally callable EC access functions. For now, assume 1 EC only
418  */
419 int ec_burst_enable(void)
420 {
421 	if (!first_ec)
422 		return -ENODEV;
423 	return acpi_ec_burst_enable(first_ec);
424 }
425 
426 EXPORT_SYMBOL(ec_burst_enable);
427 
428 int ec_burst_disable(void)
429 {
430 	if (!first_ec)
431 		return -ENODEV;
432 	return acpi_ec_burst_disable(first_ec);
433 }
434 
435 EXPORT_SYMBOL(ec_burst_disable);
436 
437 int ec_read(u8 addr, u8 * val)
438 {
439 	int err;
440 	u8 temp_data;
441 
442 	if (!first_ec)
443 		return -ENODEV;
444 
445 	err = acpi_ec_read(first_ec, addr, &temp_data);
446 
447 	if (!err) {
448 		*val = temp_data;
449 		return 0;
450 	} else
451 		return err;
452 }
453 
454 EXPORT_SYMBOL(ec_read);
455 
456 int ec_write(u8 addr, u8 val)
457 {
458 	int err;
459 
460 	if (!first_ec)
461 		return -ENODEV;
462 
463 	err = acpi_ec_write(first_ec, addr, val);
464 
465 	return err;
466 }
467 
468 EXPORT_SYMBOL(ec_write);
469 
470 int ec_transaction(u8 command,
471 		   const u8 * wdata, unsigned wdata_len,
472 		   u8 * rdata, unsigned rdata_len,
473 		   int force_poll)
474 {
475 	struct transaction t = {.command = command,
476 				.wdata = wdata, .rdata = rdata,
477 				.wlen = wdata_len, .rlen = rdata_len};
478 	if (!first_ec)
479 		return -ENODEV;
480 
481 	return acpi_ec_transaction(first_ec, &t, force_poll);
482 }
483 
484 EXPORT_SYMBOL(ec_transaction);
485 
486 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
487 {
488 	int result;
489 	u8 d;
490 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
491 				.wdata = NULL, .rdata = &d,
492 				.wlen = 0, .rlen = 1};
493 	if (!ec || !data)
494 		return -EINVAL;
495 
496 	/*
497 	 * Query the EC to find out which _Qxx method we need to evaluate.
498 	 * Note that successful completion of the query causes the ACPI_EC_SCI
499 	 * bit to be cleared (and thus clearing the interrupt source).
500 	 */
501 
502 	result = acpi_ec_transaction(ec, &t, 0);
503 	if (result)
504 		return result;
505 
506 	if (!d)
507 		return -ENODATA;
508 
509 	*data = d;
510 	return 0;
511 }
512 
513 /* --------------------------------------------------------------------------
514                                 Event Management
515    -------------------------------------------------------------------------- */
516 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
517 			      acpi_handle handle, acpi_ec_query_func func,
518 			      void *data)
519 {
520 	struct acpi_ec_query_handler *handler =
521 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
522 	if (!handler)
523 		return -ENOMEM;
524 
525 	handler->query_bit = query_bit;
526 	handler->handle = handle;
527 	handler->func = func;
528 	handler->data = data;
529 	mutex_lock(&ec->lock);
530 	list_add(&handler->node, &ec->list);
531 	mutex_unlock(&ec->lock);
532 	return 0;
533 }
534 
535 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
536 
537 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
538 {
539 	struct acpi_ec_query_handler *handler, *tmp;
540 	mutex_lock(&ec->lock);
541 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
542 		if (query_bit == handler->query_bit) {
543 			list_del(&handler->node);
544 			kfree(handler);
545 		}
546 	}
547 	mutex_unlock(&ec->lock);
548 }
549 
550 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
551 
552 static void acpi_ec_gpe_query(void *ec_cxt)
553 {
554 	struct acpi_ec *ec = ec_cxt;
555 	u8 value = 0;
556 	struct acpi_ec_query_handler *handler, copy;
557 
558 	if (!ec || acpi_ec_query(ec, &value))
559 		return;
560 	mutex_lock(&ec->lock);
561 	list_for_each_entry(handler, &ec->list, node) {
562 		if (value == handler->query_bit) {
563 			/* have custom handler for this bit */
564 			memcpy(&copy, handler, sizeof(copy));
565 			mutex_unlock(&ec->lock);
566 			if (copy.func) {
567 				copy.func(copy.data);
568 			} else if (copy.handle) {
569 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
570 			}
571 			return;
572 		}
573 	}
574 	mutex_unlock(&ec->lock);
575 }
576 
577 static u32 acpi_ec_gpe_handler(void *data)
578 {
579 	struct acpi_ec *ec = data;
580 	u8 status;
581 
582 	pr_debug(PREFIX "~~~> interrupt\n");
583 	status = acpi_ec_read_status(ec);
584 
585 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) {
586 		gpe_transaction(ec, status);
587 		if (ec_transaction_done(ec) &&
588 		    (status & ACPI_EC_FLAG_IBF) == 0)
589 			wake_up(&ec->wait);
590 	}
591 
592 	ec_check_sci(ec, status);
593 	if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
594 	    !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
595 		/* this is non-query, must be confirmation */
596 		if (!test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
597 			if (printk_ratelimit())
598 				pr_info(PREFIX "non-query interrupt received,"
599 					" switching to interrupt mode\n");
600 		} else {
601 			/* hush, STORM switches the mode every transaction */
602 			pr_debug(PREFIX "non-query interrupt received,"
603 				" switching to interrupt mode\n");
604 		}
605 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
606 	}
607 	return ACPI_INTERRUPT_HANDLED;
608 }
609 
610 /* --------------------------------------------------------------------------
611                              Address Space Management
612    -------------------------------------------------------------------------- */
613 
614 static acpi_status
615 acpi_ec_space_handler(u32 function, acpi_physical_address address,
616 		      u32 bits, acpi_integer *value,
617 		      void *handler_context, void *region_context)
618 {
619 	struct acpi_ec *ec = handler_context;
620 	int result = 0, i;
621 	u8 temp = 0;
622 
623 	if ((address > 0xFF) || !value || !handler_context)
624 		return AE_BAD_PARAMETER;
625 
626 	if (function != ACPI_READ && function != ACPI_WRITE)
627 		return AE_BAD_PARAMETER;
628 
629 	if (bits != 8 && acpi_strict)
630 		return AE_BAD_PARAMETER;
631 
632 	acpi_ec_burst_enable(ec);
633 
634 	if (function == ACPI_READ) {
635 		result = acpi_ec_read(ec, address, &temp);
636 		*value = temp;
637 	} else {
638 		temp = 0xff & (*value);
639 		result = acpi_ec_write(ec, address, temp);
640 	}
641 
642 	for (i = 8; unlikely(bits - i > 0); i += 8) {
643 		++address;
644 		if (function == ACPI_READ) {
645 			result = acpi_ec_read(ec, address, &temp);
646 			(*value) |= ((acpi_integer)temp) << i;
647 		} else {
648 			temp = 0xff & ((*value) >> i);
649 			result = acpi_ec_write(ec, address, temp);
650 		}
651 	}
652 
653 	acpi_ec_burst_disable(ec);
654 
655 	switch (result) {
656 	case -EINVAL:
657 		return AE_BAD_PARAMETER;
658 		break;
659 	case -ENODEV:
660 		return AE_NOT_FOUND;
661 		break;
662 	case -ETIME:
663 		return AE_TIME;
664 		break;
665 	default:
666 		return AE_OK;
667 	}
668 }
669 
670 /* --------------------------------------------------------------------------
671                               FS Interface (/proc)
672    -------------------------------------------------------------------------- */
673 
674 static struct proc_dir_entry *acpi_ec_dir;
675 
676 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
677 {
678 	struct acpi_ec *ec = seq->private;
679 
680 	if (!ec)
681 		goto end;
682 
683 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
684 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
685 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
686 	seq_printf(seq, "use global lock:\t%s\n",
687 		   ec->global_lock ? "yes" : "no");
688       end:
689 	return 0;
690 }
691 
692 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
693 {
694 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
695 }
696 
697 static struct file_operations acpi_ec_info_ops = {
698 	.open = acpi_ec_info_open_fs,
699 	.read = seq_read,
700 	.llseek = seq_lseek,
701 	.release = single_release,
702 	.owner = THIS_MODULE,
703 };
704 
705 static int acpi_ec_add_fs(struct acpi_device *device)
706 {
707 	struct proc_dir_entry *entry = NULL;
708 
709 	if (!acpi_device_dir(device)) {
710 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
711 						     acpi_ec_dir);
712 		if (!acpi_device_dir(device))
713 			return -ENODEV;
714 	}
715 
716 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
717 				 acpi_device_dir(device),
718 				 &acpi_ec_info_ops, acpi_driver_data(device));
719 	if (!entry)
720 		return -ENODEV;
721 	return 0;
722 }
723 
724 static int acpi_ec_remove_fs(struct acpi_device *device)
725 {
726 
727 	if (acpi_device_dir(device)) {
728 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
729 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
730 		acpi_device_dir(device) = NULL;
731 	}
732 
733 	return 0;
734 }
735 
736 /* --------------------------------------------------------------------------
737                                Driver Interface
738    -------------------------------------------------------------------------- */
739 static acpi_status
740 ec_parse_io_ports(struct acpi_resource *resource, void *context);
741 
742 static struct acpi_ec *make_acpi_ec(void)
743 {
744 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
745 	if (!ec)
746 		return NULL;
747 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
748 	mutex_init(&ec->lock);
749 	init_waitqueue_head(&ec->wait);
750 	INIT_LIST_HEAD(&ec->list);
751 	spin_lock_init(&ec->curr_lock);
752 	return ec;
753 }
754 
755 static acpi_status
756 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
757 			       void *context, void **return_value)
758 {
759 	struct acpi_namespace_node *node = handle;
760 	struct acpi_ec *ec = context;
761 	int value = 0;
762 	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
763 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
764 	}
765 	return AE_OK;
766 }
767 
768 static acpi_status
769 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
770 {
771 	acpi_status status;
772 	unsigned long long tmp = 0;
773 
774 	struct acpi_ec *ec = context;
775 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
776 				     ec_parse_io_ports, ec);
777 	if (ACPI_FAILURE(status))
778 		return status;
779 
780 	/* Get GPE bit assignment (EC events). */
781 	/* TODO: Add support for _GPE returning a package */
782 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
783 	if (ACPI_FAILURE(status))
784 		return status;
785 	ec->gpe = tmp;
786 	/* Use the global lock for all EC transactions? */
787 	tmp = 0;
788 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
789 	ec->global_lock = tmp;
790 	ec->handle = handle;
791 	return AE_CTRL_TERMINATE;
792 }
793 
794 static void ec_remove_handlers(struct acpi_ec *ec)
795 {
796 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
797 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
798 		pr_err(PREFIX "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(PREFIX "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 
809 	if (!device)
810 		return -EINVAL;
811 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
812 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
813 
814 	/* Check for boot EC */
815 	if (boot_ec &&
816 	    (boot_ec->handle == device->handle ||
817 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
818 		ec = boot_ec;
819 		boot_ec = NULL;
820 	} else {
821 		ec = make_acpi_ec();
822 		if (!ec)
823 			return -ENOMEM;
824 		if (ec_parse_device(device->handle, 0, ec, NULL) !=
825 		    AE_CTRL_TERMINATE) {
826 			kfree(ec);
827 			return -EINVAL;
828 		}
829 	}
830 
831 	ec->handle = device->handle;
832 
833 	/* Find and register all query methods */
834 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
835 			    acpi_ec_register_query_methods, ec, NULL);
836 
837 	if (!first_ec)
838 		first_ec = ec;
839 	device->driver_data = ec;
840 	acpi_ec_add_fs(device);
841 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
842 			  ec->gpe, ec->command_addr, ec->data_addr);
843 	pr_info(PREFIX "driver started in %s mode\n",
844 		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
845 	return 0;
846 }
847 
848 static int acpi_ec_remove(struct acpi_device *device, int type)
849 {
850 	struct acpi_ec *ec;
851 	struct acpi_ec_query_handler *handler, *tmp;
852 
853 	if (!device)
854 		return -EINVAL;
855 
856 	ec = acpi_driver_data(device);
857 	mutex_lock(&ec->lock);
858 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
859 		list_del(&handler->node);
860 		kfree(handler);
861 	}
862 	mutex_unlock(&ec->lock);
863 	acpi_ec_remove_fs(device);
864 	device->driver_data = NULL;
865 	if (ec == first_ec)
866 		first_ec = NULL;
867 	kfree(ec);
868 	return 0;
869 }
870 
871 static acpi_status
872 ec_parse_io_ports(struct acpi_resource *resource, void *context)
873 {
874 	struct acpi_ec *ec = context;
875 
876 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
877 		return AE_OK;
878 
879 	/*
880 	 * The first address region returned is the data port, and
881 	 * the second address region returned is the status/command
882 	 * port.
883 	 */
884 	if (ec->data_addr == 0)
885 		ec->data_addr = resource->data.io.minimum;
886 	else if (ec->command_addr == 0)
887 		ec->command_addr = resource->data.io.minimum;
888 	else
889 		return AE_CTRL_TERMINATE;
890 
891 	return AE_OK;
892 }
893 
894 static int ec_install_handlers(struct acpi_ec *ec)
895 {
896 	acpi_status status;
897 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
898 		return 0;
899 	status = acpi_install_gpe_handler(NULL, ec->gpe,
900 				  ACPI_GPE_EDGE_TRIGGERED,
901 				  &acpi_ec_gpe_handler, ec);
902 	if (ACPI_FAILURE(status))
903 		return -ENODEV;
904 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
905 	acpi_enable_gpe(NULL, ec->gpe);
906 	status = acpi_install_address_space_handler(ec->handle,
907 						    ACPI_ADR_SPACE_EC,
908 						    &acpi_ec_space_handler,
909 						    NULL, ec);
910 	if (ACPI_FAILURE(status)) {
911 		if (status == AE_NOT_FOUND) {
912 			/*
913 			 * Maybe OS fails in evaluating the _REG object.
914 			 * The AE_NOT_FOUND error will be ignored and OS
915 			 * continue to initialize EC.
916 			 */
917 			printk(KERN_ERR "Fail in evaluating the _REG object"
918 				" of EC device. Broken bios is suspected.\n");
919 		} else {
920 			acpi_remove_gpe_handler(NULL, ec->gpe,
921 				&acpi_ec_gpe_handler);
922 			return -ENODEV;
923 		}
924 	}
925 
926 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
927 	return 0;
928 }
929 
930 static int acpi_ec_start(struct acpi_device *device)
931 {
932 	struct acpi_ec *ec;
933 	int ret = 0;
934 
935 	if (!device)
936 		return -EINVAL;
937 
938 	ec = acpi_driver_data(device);
939 
940 	if (!ec)
941 		return -EINVAL;
942 
943 	ret = ec_install_handlers(ec);
944 
945 	/* EC is fully operational, allow queries */
946 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
947 	return ret;
948 }
949 
950 static int acpi_ec_stop(struct acpi_device *device, int type)
951 {
952 	struct acpi_ec *ec;
953 	if (!device)
954 		return -EINVAL;
955 	ec = acpi_driver_data(device);
956 	if (!ec)
957 		return -EINVAL;
958 	ec_remove_handlers(ec);
959 
960 	return 0;
961 }
962 
963 int __init acpi_boot_ec_enable(void)
964 {
965 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
966 		return 0;
967 	if (!ec_install_handlers(boot_ec)) {
968 		first_ec = boot_ec;
969 		return 0;
970 	}
971 	return -EFAULT;
972 }
973 
974 static const struct acpi_device_id ec_device_ids[] = {
975 	{"PNP0C09", 0},
976 	{"", 0},
977 };
978 
979 int __init acpi_ec_ecdt_probe(void)
980 {
981 	int ret;
982 	acpi_status status;
983 	struct acpi_table_ecdt *ecdt_ptr;
984 
985 	boot_ec = make_acpi_ec();
986 	if (!boot_ec)
987 		return -ENOMEM;
988 	/*
989 	 * Generate a boot ec context
990 	 */
991 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
992 				(struct acpi_table_header **)&ecdt_ptr);
993 	if (ACPI_SUCCESS(status)) {
994 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
995 		boot_ec->command_addr = ecdt_ptr->control.address;
996 		boot_ec->data_addr = ecdt_ptr->data.address;
997 		if (dmi_check_system(ec_dmi_table)) {
998 			/*
999 			 * If the board falls into ec_dmi_table, it means
1000 			 * that ECDT table gives the incorrect command/status
1001 			 * & data I/O address. Just fix it.
1002 			 */
1003 			boot_ec->data_addr = ecdt_ptr->control.address;
1004 			boot_ec->command_addr = ecdt_ptr->data.address;
1005 		}
1006 		boot_ec->gpe = ecdt_ptr->gpe;
1007 		boot_ec->handle = ACPI_ROOT_OBJECT;
1008 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
1009 	} else {
1010 		/* This workaround is needed only on some broken machines,
1011 		 * which require early EC, but fail to provide ECDT */
1012 		acpi_handle x;
1013 		printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
1014 		status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1015 						boot_ec, NULL);
1016 		/* Check that acpi_get_devices actually find something */
1017 		if (ACPI_FAILURE(status) || !boot_ec->handle)
1018 			goto error;
1019 		/* We really need to limit this workaround, the only ASUS,
1020 		 * which needs it, has fake EC._INI method, so use it as flag.
1021 		 * Keep boot_ec struct as it will be needed soon.
1022 		 */
1023 		if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
1024 			return -ENODEV;
1025 	}
1026 
1027 	ret = ec_install_handlers(boot_ec);
1028 	if (!ret) {
1029 		first_ec = boot_ec;
1030 		return 0;
1031 	}
1032       error:
1033 	kfree(boot_ec);
1034 	boot_ec = NULL;
1035 	return -ENODEV;
1036 }
1037 
1038 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1039 {
1040 	struct acpi_ec *ec = acpi_driver_data(device);
1041 	/* Stop using GPE */
1042 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1043 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1044 	acpi_disable_gpe(NULL, ec->gpe);
1045 	return 0;
1046 }
1047 
1048 static int acpi_ec_resume(struct acpi_device *device)
1049 {
1050 	struct acpi_ec *ec = acpi_driver_data(device);
1051 	/* Enable use of GPE back */
1052 	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1053 	acpi_enable_gpe(NULL, ec->gpe);
1054 	return 0;
1055 }
1056 
1057 static struct acpi_driver acpi_ec_driver = {
1058 	.name = "ec",
1059 	.class = ACPI_EC_CLASS,
1060 	.ids = ec_device_ids,
1061 	.ops = {
1062 		.add = acpi_ec_add,
1063 		.remove = acpi_ec_remove,
1064 		.start = acpi_ec_start,
1065 		.stop = acpi_ec_stop,
1066 		.suspend = acpi_ec_suspend,
1067 		.resume = acpi_ec_resume,
1068 		},
1069 };
1070 
1071 static int __init acpi_ec_init(void)
1072 {
1073 	int result = 0;
1074 
1075 	if (acpi_disabled)
1076 		return 0;
1077 
1078 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1079 	if (!acpi_ec_dir)
1080 		return -ENODEV;
1081 
1082 	/* Now register the driver for the EC */
1083 	result = acpi_bus_register_driver(&acpi_ec_driver);
1084 	if (result < 0) {
1085 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1086 		return -ENODEV;
1087 	}
1088 
1089 	return result;
1090 }
1091 
1092 subsys_initcall(acpi_ec_init);
1093 
1094 /* EC driver currently not unloadable */
1095 #if 0
1096 static void __exit acpi_ec_exit(void)
1097 {
1098 
1099 	acpi_bus_unregister_driver(&acpi_ec_driver);
1100 
1101 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1102 
1103 	return;
1104 }
1105 #endif	/* 0 */
1106