xref: /linux/drivers/acpi/ec.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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 20	/* 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 wlen;
104 	u8 rlen;
105 };
106 
107 static struct acpi_ec {
108 	acpi_handle handle;
109 	unsigned long gpe;
110 	unsigned long command_addr;
111 	unsigned long data_addr;
112 	unsigned long global_lock;
113 	unsigned long flags;
114 	struct mutex lock;
115 	wait_queue_head_t wait;
116 	struct list_head list;
117 	struct transaction *curr;
118 	spinlock_t curr_lock;
119 } *boot_ec, *first_ec;
120 
121 /*
122  * Some Asus system have exchanged ECDT data/command IO addresses.
123  */
124 static int print_ecdt_error(const struct dmi_system_id *id)
125 {
126 	printk(KERN_NOTICE PREFIX "%s detected - "
127 		"ECDT has exchanged control/data I/O address\n",
128 		id->ident);
129 	return 0;
130 }
131 
132 static struct dmi_system_id __cpuinitdata ec_dmi_table[] = {
133 	{
134 	print_ecdt_error, "Asus L4R", {
135 	DMI_MATCH(DMI_BIOS_VERSION, "1008.006"),
136 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),
137 	DMI_MATCH(DMI_BOARD_NAME, "L4R") }, NULL},
138 	{
139 	print_ecdt_error, "Asus M6R", {
140 	DMI_MATCH(DMI_BIOS_VERSION, "0207"),
141 	DMI_MATCH(DMI_PRODUCT_NAME, "M6R"),
142 	DMI_MATCH(DMI_BOARD_NAME, "M6R") }, NULL},
143 	{},
144 };
145 
146 /* --------------------------------------------------------------------------
147                              Transaction Management
148    -------------------------------------------------------------------------- */
149 
150 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
151 {
152 	u8 x = inb(ec->command_addr);
153 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
154 	return x;
155 }
156 
157 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
158 {
159 	u8 x = inb(ec->data_addr);
160 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
161 	return x;
162 }
163 
164 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
165 {
166 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
167 	outb(command, ec->command_addr);
168 }
169 
170 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
171 {
172 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
173 	outb(data, ec->data_addr);
174 }
175 
176 static int ec_transaction_done(struct acpi_ec *ec)
177 {
178 	unsigned long flags;
179 	int ret = 0;
180 	spin_lock_irqsave(&ec->curr_lock, flags);
181 	if (!ec->curr || (!ec->curr->wlen && !ec->curr->rlen))
182 		ret = 1;
183 	spin_unlock_irqrestore(&ec->curr_lock, flags);
184 	return ret;
185 }
186 
187 static void gpe_transaction(struct acpi_ec *ec, u8 status)
188 {
189 	unsigned long flags;
190 	spin_lock_irqsave(&ec->curr_lock, flags);
191 	if (!ec->curr)
192 		goto unlock;
193 	if (ec->curr->wlen > 0) {
194 		if ((status & ACPI_EC_FLAG_IBF) == 0) {
195 			acpi_ec_write_data(ec, *(ec->curr->wdata++));
196 			--ec->curr->wlen;
197 		} else
198 			/* false interrupt, state didn't change */
199 			++ec->curr->irq_count;
200 
201 	} else if (ec->curr->rlen > 0) {
202 		if ((status & ACPI_EC_FLAG_OBF) == 1) {
203 			*(ec->curr->rdata++) = acpi_ec_read_data(ec);
204 			--ec->curr->rlen;
205 		} else
206 			/* false interrupt, state didn't change */
207 			++ec->curr->irq_count;
208 	}
209 unlock:
210 	spin_unlock_irqrestore(&ec->curr_lock, flags);
211 }
212 
213 static int acpi_ec_wait(struct acpi_ec *ec)
214 {
215 	if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
216 			       msecs_to_jiffies(ACPI_EC_DELAY)))
217 		return 0;
218 	/* missing GPEs, switch back to poll mode */
219 	if (printk_ratelimit())
220 		pr_info(PREFIX "missing confirmations, "
221 				"switch off interrupt mode.\n");
222 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
223 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
224 	return 1;
225 }
226 
227 static void acpi_ec_gpe_query(void *ec_cxt);
228 
229 static int ec_check_sci(struct acpi_ec *ec, u8 state)
230 {
231 	if (state & ACPI_EC_FLAG_SCI) {
232 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
233 			return acpi_os_execute(OSL_EC_BURST_HANDLER,
234 				acpi_ec_gpe_query, ec);
235 	}
236 	return 0;
237 }
238 
239 static int ec_poll(struct acpi_ec *ec)
240 {
241 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
242 	msleep(1);
243 	while (time_before(jiffies, delay)) {
244 		gpe_transaction(ec, acpi_ec_read_status(ec));
245 		msleep(1);
246 		if (ec_transaction_done(ec))
247 			return 0;
248 	}
249 	return -ETIME;
250 }
251 
252 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
253 					struct transaction *t,
254 					int force_poll)
255 {
256 	unsigned long tmp;
257 	int ret = 0;
258 	pr_debug(PREFIX "transaction start\n");
259 	/* disable GPE during transaction if storm is detected */
260 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
261 		clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
262 		acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
263 	}
264 	/* start transaction */
265 	spin_lock_irqsave(&ec->curr_lock, tmp);
266 	/* following two actions should be kept atomic */
267 	t->irq_count = 0;
268 	ec->curr = t;
269 	acpi_ec_write_cmd(ec, ec->curr->command);
270 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
271 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
272 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
273 	/* if we selected poll mode or failed in GPE-mode do a poll loop */
274 	if (force_poll ||
275 	    !test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ||
276 	    acpi_ec_wait(ec))
277 		ret = ec_poll(ec);
278 	pr_debug(PREFIX "transaction end\n");
279 	spin_lock_irqsave(&ec->curr_lock, tmp);
280 	ec->curr = NULL;
281 	spin_unlock_irqrestore(&ec->curr_lock, tmp);
282 	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
283 		/* check if we received SCI during transaction */
284 		ec_check_sci(ec, acpi_ec_read_status(ec));
285 		/* it is safe to enable GPE outside of transaction */
286 		acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
287 	} else if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
288 		   t->irq_count > ACPI_EC_STORM_THRESHOLD) {
289 		pr_debug(PREFIX "GPE storm detected\n");
290 		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
291 	}
292 	return ret;
293 }
294 
295 static int ec_check_ibf0(struct acpi_ec *ec)
296 {
297 	u8 status = acpi_ec_read_status(ec);
298 	return (status & ACPI_EC_FLAG_IBF) == 0;
299 }
300 
301 static int ec_wait_ibf0(struct acpi_ec *ec)
302 {
303 	unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
304 	/* interrupt wait manually if GPE mode is not active */
305 	unsigned long timeout = test_bit(EC_FLAGS_GPE_MODE, &ec->flags) ?
306 		msecs_to_jiffies(ACPI_EC_DELAY) : msecs_to_jiffies(1);
307 	while (time_before(jiffies, delay))
308 		if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), timeout))
309 			return 0;
310 	return -ETIME;
311 }
312 
313 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t,
314 			       int force_poll)
315 {
316 	int status;
317 	u32 glk;
318 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
319 		return -EINVAL;
320 	if (t->rdata)
321 		memset(t->rdata, 0, t->rlen);
322 	mutex_lock(&ec->lock);
323 	if (ec->global_lock) {
324 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
325 		if (ACPI_FAILURE(status)) {
326 			status = -ENODEV;
327 			goto unlock;
328 		}
329 	}
330 	if (ec_wait_ibf0(ec)) {
331 		pr_err(PREFIX "input buffer is not empty, "
332 				"aborting transaction\n");
333 		status = -ETIME;
334 		goto end;
335 	}
336 	status = acpi_ec_transaction_unlocked(ec, t, force_poll);
337 end:
338 	if (ec->global_lock)
339 		acpi_release_global_lock(glk);
340 unlock:
341 	mutex_unlock(&ec->lock);
342 	return status;
343 }
344 
345 /*
346  * Note: samsung nv5000 doesn't work with ec burst mode.
347  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
348  */
349 int acpi_ec_burst_enable(struct acpi_ec *ec)
350 {
351 	u8 d;
352 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
353 				.wdata = NULL, .rdata = &d,
354 				.wlen = 0, .rlen = 1};
355 
356 	return acpi_ec_transaction(ec, &t, 0);
357 }
358 
359 int acpi_ec_burst_disable(struct acpi_ec *ec)
360 {
361 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
362 				.wdata = NULL, .rdata = NULL,
363 				.wlen = 0, .rlen = 0};
364 
365 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
366 				acpi_ec_transaction(ec, &t, 0) : 0;
367 }
368 
369 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
370 {
371 	int result;
372 	u8 d;
373 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
374 				.wdata = &address, .rdata = &d,
375 				.wlen = 1, .rlen = 1};
376 
377 	result = acpi_ec_transaction(ec, &t, 0);
378 	*data = d;
379 	return result;
380 }
381 
382 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
383 {
384 	u8 wdata[2] = { address, data };
385 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
386 				.wdata = wdata, .rdata = NULL,
387 				.wlen = 2, .rlen = 0};
388 
389 	return acpi_ec_transaction(ec, &t, 0);
390 }
391 
392 /*
393  * Externally callable EC access functions. For now, assume 1 EC only
394  */
395 int ec_burst_enable(void)
396 {
397 	if (!first_ec)
398 		return -ENODEV;
399 	return acpi_ec_burst_enable(first_ec);
400 }
401 
402 EXPORT_SYMBOL(ec_burst_enable);
403 
404 int ec_burst_disable(void)
405 {
406 	if (!first_ec)
407 		return -ENODEV;
408 	return acpi_ec_burst_disable(first_ec);
409 }
410 
411 EXPORT_SYMBOL(ec_burst_disable);
412 
413 int ec_read(u8 addr, u8 * val)
414 {
415 	int err;
416 	u8 temp_data;
417 
418 	if (!first_ec)
419 		return -ENODEV;
420 
421 	err = acpi_ec_read(first_ec, addr, &temp_data);
422 
423 	if (!err) {
424 		*val = temp_data;
425 		return 0;
426 	} else
427 		return err;
428 }
429 
430 EXPORT_SYMBOL(ec_read);
431 
432 int ec_write(u8 addr, u8 val)
433 {
434 	int err;
435 
436 	if (!first_ec)
437 		return -ENODEV;
438 
439 	err = acpi_ec_write(first_ec, addr, val);
440 
441 	return err;
442 }
443 
444 EXPORT_SYMBOL(ec_write);
445 
446 int ec_transaction(u8 command,
447 		   const u8 * wdata, unsigned wdata_len,
448 		   u8 * rdata, unsigned rdata_len,
449 		   int force_poll)
450 {
451 	struct transaction t = {.command = command,
452 				.wdata = wdata, .rdata = rdata,
453 				.wlen = wdata_len, .rlen = rdata_len};
454 	if (!first_ec)
455 		return -ENODEV;
456 
457 	return acpi_ec_transaction(first_ec, &t, force_poll);
458 }
459 
460 EXPORT_SYMBOL(ec_transaction);
461 
462 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
463 {
464 	int result;
465 	u8 d;
466 	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
467 				.wdata = NULL, .rdata = &d,
468 				.wlen = 0, .rlen = 1};
469 	if (!ec || !data)
470 		return -EINVAL;
471 
472 	/*
473 	 * Query the EC to find out which _Qxx method we need to evaluate.
474 	 * Note that successful completion of the query causes the ACPI_EC_SCI
475 	 * bit to be cleared (and thus clearing the interrupt source).
476 	 */
477 
478 	result = acpi_ec_transaction(ec, &t, 0);
479 	if (result)
480 		return result;
481 
482 	if (!d)
483 		return -ENODATA;
484 
485 	*data = d;
486 	return 0;
487 }
488 
489 /* --------------------------------------------------------------------------
490                                 Event Management
491    -------------------------------------------------------------------------- */
492 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
493 			      acpi_handle handle, acpi_ec_query_func func,
494 			      void *data)
495 {
496 	struct acpi_ec_query_handler *handler =
497 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
498 	if (!handler)
499 		return -ENOMEM;
500 
501 	handler->query_bit = query_bit;
502 	handler->handle = handle;
503 	handler->func = func;
504 	handler->data = data;
505 	mutex_lock(&ec->lock);
506 	list_add(&handler->node, &ec->list);
507 	mutex_unlock(&ec->lock);
508 	return 0;
509 }
510 
511 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
512 
513 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
514 {
515 	struct acpi_ec_query_handler *handler, *tmp;
516 	mutex_lock(&ec->lock);
517 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
518 		if (query_bit == handler->query_bit) {
519 			list_del(&handler->node);
520 			kfree(handler);
521 		}
522 	}
523 	mutex_unlock(&ec->lock);
524 }
525 
526 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
527 
528 static void acpi_ec_gpe_query(void *ec_cxt)
529 {
530 	struct acpi_ec *ec = ec_cxt;
531 	u8 value = 0;
532 	struct acpi_ec_query_handler *handler, copy;
533 
534 	if (!ec || acpi_ec_query(ec, &value))
535 		return;
536 	mutex_lock(&ec->lock);
537 	list_for_each_entry(handler, &ec->list, node) {
538 		if (value == handler->query_bit) {
539 			/* have custom handler for this bit */
540 			memcpy(&copy, handler, sizeof(copy));
541 			mutex_unlock(&ec->lock);
542 			if (copy.func) {
543 				copy.func(copy.data);
544 			} else if (copy.handle) {
545 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
546 			}
547 			return;
548 		}
549 	}
550 	mutex_unlock(&ec->lock);
551 }
552 
553 static u32 acpi_ec_gpe_handler(void *data)
554 {
555 	struct acpi_ec *ec = data;
556 	u8 status;
557 
558 	pr_debug(PREFIX "~~~> interrupt\n");
559 	status = acpi_ec_read_status(ec);
560 
561 	gpe_transaction(ec, status);
562 	if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0)
563 		wake_up(&ec->wait);
564 
565 	ec_check_sci(ec, status);
566 	if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
567 	    !test_bit(EC_FLAGS_NO_GPE, &ec->flags)) {
568 		/* this is non-query, must be confirmation */
569 		if (printk_ratelimit())
570 			pr_info(PREFIX "non-query interrupt received,"
571 				" switching to interrupt mode\n");
572 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
573 	}
574 	return ACPI_INTERRUPT_HANDLED;
575 }
576 
577 /* --------------------------------------------------------------------------
578                              Address Space Management
579    -------------------------------------------------------------------------- */
580 
581 static acpi_status
582 acpi_ec_space_handler(u32 function, acpi_physical_address address,
583 		      u32 bits, acpi_integer *value,
584 		      void *handler_context, void *region_context)
585 {
586 	struct acpi_ec *ec = handler_context;
587 	int result = 0, i;
588 	u8 temp = 0;
589 
590 	if ((address > 0xFF) || !value || !handler_context)
591 		return AE_BAD_PARAMETER;
592 
593 	if (function != ACPI_READ && function != ACPI_WRITE)
594 		return AE_BAD_PARAMETER;
595 
596 	if (bits != 8 && acpi_strict)
597 		return AE_BAD_PARAMETER;
598 
599 	acpi_ec_burst_enable(ec);
600 
601 	if (function == ACPI_READ) {
602 		result = acpi_ec_read(ec, address, &temp);
603 		*value = temp;
604 	} else {
605 		temp = 0xff & (*value);
606 		result = acpi_ec_write(ec, address, temp);
607 	}
608 
609 	for (i = 8; unlikely(bits - i > 0); i += 8) {
610 		++address;
611 		if (function == ACPI_READ) {
612 			result = acpi_ec_read(ec, address, &temp);
613 			(*value) |= ((acpi_integer)temp) << i;
614 		} else {
615 			temp = 0xff & ((*value) >> i);
616 			result = acpi_ec_write(ec, address, temp);
617 		}
618 	}
619 
620 	acpi_ec_burst_disable(ec);
621 
622 	switch (result) {
623 	case -EINVAL:
624 		return AE_BAD_PARAMETER;
625 		break;
626 	case -ENODEV:
627 		return AE_NOT_FOUND;
628 		break;
629 	case -ETIME:
630 		return AE_TIME;
631 		break;
632 	default:
633 		return AE_OK;
634 	}
635 }
636 
637 /* --------------------------------------------------------------------------
638                               FS Interface (/proc)
639    -------------------------------------------------------------------------- */
640 
641 static struct proc_dir_entry *acpi_ec_dir;
642 
643 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
644 {
645 	struct acpi_ec *ec = seq->private;
646 
647 	if (!ec)
648 		goto end;
649 
650 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
651 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
652 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
653 	seq_printf(seq, "use global lock:\t%s\n",
654 		   ec->global_lock ? "yes" : "no");
655       end:
656 	return 0;
657 }
658 
659 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
660 {
661 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
662 }
663 
664 static struct file_operations acpi_ec_info_ops = {
665 	.open = acpi_ec_info_open_fs,
666 	.read = seq_read,
667 	.llseek = seq_lseek,
668 	.release = single_release,
669 	.owner = THIS_MODULE,
670 };
671 
672 static int acpi_ec_add_fs(struct acpi_device *device)
673 {
674 	struct proc_dir_entry *entry = NULL;
675 
676 	if (!acpi_device_dir(device)) {
677 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
678 						     acpi_ec_dir);
679 		if (!acpi_device_dir(device))
680 			return -ENODEV;
681 	}
682 
683 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
684 				 acpi_device_dir(device),
685 				 &acpi_ec_info_ops, acpi_driver_data(device));
686 	if (!entry)
687 		return -ENODEV;
688 	return 0;
689 }
690 
691 static int acpi_ec_remove_fs(struct acpi_device *device)
692 {
693 
694 	if (acpi_device_dir(device)) {
695 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
696 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
697 		acpi_device_dir(device) = NULL;
698 	}
699 
700 	return 0;
701 }
702 
703 /* --------------------------------------------------------------------------
704                                Driver Interface
705    -------------------------------------------------------------------------- */
706 static acpi_status
707 ec_parse_io_ports(struct acpi_resource *resource, void *context);
708 
709 static struct acpi_ec *make_acpi_ec(void)
710 {
711 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
712 	if (!ec)
713 		return NULL;
714 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
715 	mutex_init(&ec->lock);
716 	init_waitqueue_head(&ec->wait);
717 	INIT_LIST_HEAD(&ec->list);
718 	spin_lock_init(&ec->curr_lock);
719 	return ec;
720 }
721 
722 static acpi_status
723 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
724 			       void *context, void **return_value)
725 {
726 	struct acpi_namespace_node *node = handle;
727 	struct acpi_ec *ec = context;
728 	int value = 0;
729 	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
730 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
731 	}
732 	return AE_OK;
733 }
734 
735 static acpi_status
736 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
737 {
738 	acpi_status status;
739 	unsigned long long tmp;
740 
741 	struct acpi_ec *ec = context;
742 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
743 				     ec_parse_io_ports, ec);
744 	if (ACPI_FAILURE(status))
745 		return status;
746 
747 	/* Get GPE bit assignment (EC events). */
748 	/* TODO: Add support for _GPE returning a package */
749 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
750 	if (ACPI_FAILURE(status))
751 		return status;
752 	ec->gpe = tmp;
753 	/* Use the global lock for all EC transactions? */
754 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
755 	ec->global_lock = tmp;
756 	ec->handle = handle;
757 	return AE_CTRL_TERMINATE;
758 }
759 
760 static void ec_remove_handlers(struct acpi_ec *ec)
761 {
762 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
763 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
764 		pr_err(PREFIX "failed to remove space handler\n");
765 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
766 				&acpi_ec_gpe_handler)))
767 		pr_err(PREFIX "failed to remove gpe handler\n");
768 	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
769 }
770 
771 static int acpi_ec_add(struct acpi_device *device)
772 {
773 	struct acpi_ec *ec = NULL;
774 
775 	if (!device)
776 		return -EINVAL;
777 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
778 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
779 
780 	/* Check for boot EC */
781 	if (boot_ec &&
782 	    (boot_ec->handle == device->handle ||
783 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
784 		ec = boot_ec;
785 		boot_ec = NULL;
786 	} else {
787 		ec = make_acpi_ec();
788 		if (!ec)
789 			return -ENOMEM;
790 		if (ec_parse_device(device->handle, 0, ec, NULL) !=
791 		    AE_CTRL_TERMINATE) {
792 			kfree(ec);
793 			return -EINVAL;
794 		}
795 	}
796 
797 	ec->handle = device->handle;
798 
799 	/* Find and register all query methods */
800 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
801 			    acpi_ec_register_query_methods, ec, NULL);
802 
803 	if (!first_ec)
804 		first_ec = ec;
805 	device->driver_data = ec;
806 	acpi_ec_add_fs(device);
807 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
808 			  ec->gpe, ec->command_addr, ec->data_addr);
809 	pr_info(PREFIX "driver started in %s mode\n",
810 		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
811 	return 0;
812 }
813 
814 static int acpi_ec_remove(struct acpi_device *device, int type)
815 {
816 	struct acpi_ec *ec;
817 	struct acpi_ec_query_handler *handler, *tmp;
818 
819 	if (!device)
820 		return -EINVAL;
821 
822 	ec = acpi_driver_data(device);
823 	mutex_lock(&ec->lock);
824 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
825 		list_del(&handler->node);
826 		kfree(handler);
827 	}
828 	mutex_unlock(&ec->lock);
829 	acpi_ec_remove_fs(device);
830 	device->driver_data = NULL;
831 	if (ec == first_ec)
832 		first_ec = NULL;
833 	kfree(ec);
834 	return 0;
835 }
836 
837 static acpi_status
838 ec_parse_io_ports(struct acpi_resource *resource, void *context)
839 {
840 	struct acpi_ec *ec = context;
841 
842 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
843 		return AE_OK;
844 
845 	/*
846 	 * The first address region returned is the data port, and
847 	 * the second address region returned is the status/command
848 	 * port.
849 	 */
850 	if (ec->data_addr == 0)
851 		ec->data_addr = resource->data.io.minimum;
852 	else if (ec->command_addr == 0)
853 		ec->command_addr = resource->data.io.minimum;
854 	else
855 		return AE_CTRL_TERMINATE;
856 
857 	return AE_OK;
858 }
859 
860 static int ec_install_handlers(struct acpi_ec *ec)
861 {
862 	acpi_status status;
863 	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
864 		return 0;
865 	status = acpi_install_gpe_handler(NULL, ec->gpe,
866 				  ACPI_GPE_EDGE_TRIGGERED,
867 				  &acpi_ec_gpe_handler, ec);
868 	if (ACPI_FAILURE(status))
869 		return -ENODEV;
870 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
871 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
872 	status = acpi_install_address_space_handler(ec->handle,
873 						    ACPI_ADR_SPACE_EC,
874 						    &acpi_ec_space_handler,
875 						    NULL, ec);
876 	if (ACPI_FAILURE(status)) {
877 		if (status == AE_NOT_FOUND) {
878 			/*
879 			 * Maybe OS fails in evaluating the _REG object.
880 			 * The AE_NOT_FOUND error will be ignored and OS
881 			 * continue to initialize EC.
882 			 */
883 			printk(KERN_ERR "Fail in evaluating the _REG object"
884 				" of EC device. Broken bios is suspected.\n");
885 		} else {
886 			acpi_remove_gpe_handler(NULL, ec->gpe,
887 				&acpi_ec_gpe_handler);
888 			return -ENODEV;
889 		}
890 	}
891 
892 	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
893 	return 0;
894 }
895 
896 static int acpi_ec_start(struct acpi_device *device)
897 {
898 	struct acpi_ec *ec;
899 	int ret = 0;
900 
901 	if (!device)
902 		return -EINVAL;
903 
904 	ec = acpi_driver_data(device);
905 
906 	if (!ec)
907 		return -EINVAL;
908 
909 	ret = ec_install_handlers(ec);
910 
911 	/* EC is fully operational, allow queries */
912 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
913 	return ret;
914 }
915 
916 static int acpi_ec_stop(struct acpi_device *device, int type)
917 {
918 	struct acpi_ec *ec;
919 	if (!device)
920 		return -EINVAL;
921 	ec = acpi_driver_data(device);
922 	if (!ec)
923 		return -EINVAL;
924 	ec_remove_handlers(ec);
925 
926 	return 0;
927 }
928 
929 int __init acpi_boot_ec_enable(void)
930 {
931 	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
932 		return 0;
933 	if (!ec_install_handlers(boot_ec)) {
934 		first_ec = boot_ec;
935 		return 0;
936 	}
937 	return -EFAULT;
938 }
939 
940 static const struct acpi_device_id ec_device_ids[] = {
941 	{"PNP0C09", 0},
942 	{"", 0},
943 };
944 
945 int __init acpi_ec_ecdt_probe(void)
946 {
947 	int ret;
948 	acpi_status status;
949 	struct acpi_table_ecdt *ecdt_ptr;
950 
951 	boot_ec = make_acpi_ec();
952 	if (!boot_ec)
953 		return -ENOMEM;
954 	/*
955 	 * Generate a boot ec context
956 	 */
957 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
958 				(struct acpi_table_header **)&ecdt_ptr);
959 	if (ACPI_SUCCESS(status)) {
960 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
961 		boot_ec->command_addr = ecdt_ptr->control.address;
962 		boot_ec->data_addr = ecdt_ptr->data.address;
963 		if (dmi_check_system(ec_dmi_table)) {
964 			/*
965 			 * If the board falls into ec_dmi_table, it means
966 			 * that ECDT table gives the incorrect command/status
967 			 * & data I/O address. Just fix it.
968 			 */
969 			boot_ec->data_addr = ecdt_ptr->control.address;
970 			boot_ec->command_addr = ecdt_ptr->data.address;
971 		}
972 		boot_ec->gpe = ecdt_ptr->gpe;
973 		boot_ec->handle = ACPI_ROOT_OBJECT;
974 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
975 	} else {
976 		/* This workaround is needed only on some broken machines,
977 		 * which require early EC, but fail to provide ECDT */
978 		acpi_handle x;
979 		printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
980 		status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
981 						boot_ec, NULL);
982 		/* Check that acpi_get_devices actually find something */
983 		if (ACPI_FAILURE(status) || !boot_ec->handle)
984 			goto error;
985 		/* We really need to limit this workaround, the only ASUS,
986 		 * which needs it, has fake EC._INI method, so use it as flag.
987 		 * Keep boot_ec struct as it will be needed soon.
988 		 */
989 		if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
990 			return -ENODEV;
991 	}
992 
993 	ret = ec_install_handlers(boot_ec);
994 	if (!ret) {
995 		first_ec = boot_ec;
996 		return 0;
997 	}
998       error:
999 	kfree(boot_ec);
1000 	boot_ec = NULL;
1001 	return -ENODEV;
1002 }
1003 
1004 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
1005 {
1006 	struct acpi_ec *ec = acpi_driver_data(device);
1007 	/* Stop using GPE */
1008 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
1009 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
1010 	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
1011 	return 0;
1012 }
1013 
1014 static int acpi_ec_resume(struct acpi_device *device)
1015 {
1016 	struct acpi_ec *ec = acpi_driver_data(device);
1017 	/* Enable use of GPE back */
1018 	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
1019 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
1020 	return 0;
1021 }
1022 
1023 static struct acpi_driver acpi_ec_driver = {
1024 	.name = "ec",
1025 	.class = ACPI_EC_CLASS,
1026 	.ids = ec_device_ids,
1027 	.ops = {
1028 		.add = acpi_ec_add,
1029 		.remove = acpi_ec_remove,
1030 		.start = acpi_ec_start,
1031 		.stop = acpi_ec_stop,
1032 		.suspend = acpi_ec_suspend,
1033 		.resume = acpi_ec_resume,
1034 		},
1035 };
1036 
1037 static int __init acpi_ec_init(void)
1038 {
1039 	int result = 0;
1040 
1041 	if (acpi_disabled)
1042 		return 0;
1043 
1044 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1045 	if (!acpi_ec_dir)
1046 		return -ENODEV;
1047 
1048 	/* Now register the driver for the EC */
1049 	result = acpi_bus_register_driver(&acpi_ec_driver);
1050 	if (result < 0) {
1051 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1052 		return -ENODEV;
1053 	}
1054 
1055 	return result;
1056 }
1057 
1058 subsys_initcall(acpi_ec_init);
1059 
1060 /* EC driver currently not unloadable */
1061 #if 0
1062 static void __exit acpi_ec_exit(void)
1063 {
1064 
1065 	acpi_bus_unregister_driver(&acpi_ec_driver);
1066 
1067 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1068 
1069 	return;
1070 }
1071 #endif	/* 0 */
1072