xref: /openbmc/linux/drivers/acpi/ec.c (revision 384740dc)
1 /*
2  *  ec.c - ACPI Embedded Controller Driver (v2.0)
3  *
4  *  Copyright (C) 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
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 print outs*/
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 <asm/io.h>
42 #include <acpi/acpi_bus.h>
43 #include <acpi/acpi_drivers.h>
44 #include <acpi/actypes.h>
45 
46 #define ACPI_EC_CLASS			"embedded_controller"
47 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
48 #define ACPI_EC_FILE_INFO		"info"
49 
50 #undef PREFIX
51 #define PREFIX				"ACPI: EC: "
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 /* EC events */
69 enum ec_event {
70 	ACPI_EC_EVENT_OBF_1 = 1,	/* Output buffer full */
71 	ACPI_EC_EVENT_IBF_0,		/* Input buffer empty */
72 };
73 
74 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
75 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
76 #define ACPI_EC_UDELAY		100	/* Wait 100us before polling EC again */
77 
78 enum {
79 	EC_FLAGS_WAIT_GPE = 0,		/* Don't check status until GPE arrives */
80 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
81 	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent for status change */
82 	EC_FLAGS_NO_GPE,		/* Don't use GPE mode */
83 	EC_FLAGS_RESCHEDULE_POLL	/* Re-schedule poll */
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 static struct acpi_ec {
99 	acpi_handle handle;
100 	unsigned long gpe;
101 	unsigned long command_addr;
102 	unsigned long data_addr;
103 	unsigned long global_lock;
104 	unsigned long flags;
105 	struct mutex lock;
106 	wait_queue_head_t wait;
107 	struct list_head list;
108 	struct delayed_work work;
109 	atomic_t irq_count;
110 	u8 handlers_installed;
111 } *boot_ec, *first_ec;
112 
113 /*
114  * Some Asus system have exchanged ECDT data/command IO addresses.
115  */
116 static int print_ecdt_error(const struct dmi_system_id *id)
117 {
118 	printk(KERN_NOTICE PREFIX "%s detected - "
119 		"ECDT has exchanged control/data I/O address\n",
120 		id->ident);
121 	return 0;
122 }
123 
124 static struct dmi_system_id __cpuinitdata ec_dmi_table[] = {
125 	{
126 	print_ecdt_error, "Asus L4R", {
127 	DMI_MATCH(DMI_BIOS_VERSION, "1008.006"),
128 	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),
129 	DMI_MATCH(DMI_BOARD_NAME, "L4R") }, NULL},
130 	{
131 	print_ecdt_error, "Asus M6R", {
132 	DMI_MATCH(DMI_BIOS_VERSION, "0207"),
133 	DMI_MATCH(DMI_PRODUCT_NAME, "M6R"),
134 	DMI_MATCH(DMI_BOARD_NAME, "M6R") }, NULL},
135 	{},
136 };
137 
138 /* --------------------------------------------------------------------------
139                              Transaction Management
140    -------------------------------------------------------------------------- */
141 
142 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
143 {
144 	u8 x = inb(ec->command_addr);
145 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
146 	return x;
147 }
148 
149 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
150 {
151 	u8 x = inb(ec->data_addr);
152 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
153 	return inb(ec->data_addr);
154 }
155 
156 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
157 {
158 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
159 	outb(command, ec->command_addr);
160 }
161 
162 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
163 {
164 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
165 	outb(data, ec->data_addr);
166 }
167 
168 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
169 {
170 	if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
171 		return 0;
172 	if (event == ACPI_EC_EVENT_OBF_1) {
173 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
174 			return 1;
175 	} else if (event == ACPI_EC_EVENT_IBF_0) {
176 		if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
177 			return 1;
178 	}
179 
180 	return 0;
181 }
182 
183 static void ec_schedule_ec_poll(struct acpi_ec *ec)
184 {
185 	if (test_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags))
186 		schedule_delayed_work(&ec->work,
187 				      msecs_to_jiffies(ACPI_EC_DELAY));
188 }
189 
190 static void ec_switch_to_poll_mode(struct acpi_ec *ec)
191 {
192 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
193 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
194 	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
195 	set_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
196 }
197 
198 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
199 {
200 	atomic_set(&ec->irq_count, 0);
201 	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
202 	    likely(!force_poll)) {
203 		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
204 				       msecs_to_jiffies(ACPI_EC_DELAY)))
205 			return 0;
206 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
207 		if (acpi_ec_check_status(ec, event)) {
208 			/* missing GPEs, switch back to poll mode */
209 			if (printk_ratelimit())
210 				pr_info(PREFIX "missing confirmations, "
211 						"switch off interrupt mode.\n");
212 			ec_switch_to_poll_mode(ec);
213 			ec_schedule_ec_poll(ec);
214 			return 0;
215 		}
216 	} else {
217 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
218 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
219 		while (time_before(jiffies, delay)) {
220 			if (acpi_ec_check_status(ec, event))
221 				return 0;
222 			msleep(1);
223 		}
224 		if (acpi_ec_check_status(ec,event))
225 			return 0;
226 	}
227 	pr_err(PREFIX "acpi_ec_wait timeout, status = 0x%2.2x, event = %s\n",
228 		acpi_ec_read_status(ec),
229 		(event == ACPI_EC_EVENT_OBF_1) ? "\"b0=1\"" : "\"b1=0\"");
230 	return -ETIME;
231 }
232 
233 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
234 					const u8 * wdata, unsigned wdata_len,
235 					u8 * rdata, unsigned rdata_len,
236 					int force_poll)
237 {
238 	int result = 0;
239 	set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
240 	pr_debug(PREFIX "transaction start\n");
241 	acpi_ec_write_cmd(ec, command);
242 	for (; wdata_len > 0; --wdata_len) {
243 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
244 		if (result) {
245 			pr_err(PREFIX
246 			       "write_cmd timeout, command = %d\n", command);
247 			goto end;
248 		}
249 		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
250 		acpi_ec_write_data(ec, *(wdata++));
251 	}
252 
253 	if (!rdata_len) {
254 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
255 		if (result) {
256 			pr_err(PREFIX
257 			       "finish-write timeout, command = %d\n", command);
258 			goto end;
259 		}
260 	} else if (command == ACPI_EC_COMMAND_QUERY)
261 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
262 
263 	for (; rdata_len > 0; --rdata_len) {
264 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
265 		if (result) {
266 			pr_err(PREFIX "read timeout, command = %d\n", command);
267 			goto end;
268 		}
269 		/* Don't expect GPE after last read */
270 		if (rdata_len > 1)
271 			set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
272 		*(rdata++) = acpi_ec_read_data(ec);
273 	}
274       end:
275 	pr_debug(PREFIX "transaction end\n");
276 	return result;
277 }
278 
279 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
280 			       const u8 * wdata, unsigned wdata_len,
281 			       u8 * rdata, unsigned rdata_len,
282 			       int force_poll)
283 {
284 	int status;
285 	u32 glk;
286 
287 	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
288 		return -EINVAL;
289 
290 	if (rdata)
291 		memset(rdata, 0, rdata_len);
292 
293 	mutex_lock(&ec->lock);
294 	if (ec->global_lock) {
295 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
296 		if (ACPI_FAILURE(status)) {
297 			mutex_unlock(&ec->lock);
298 			return -ENODEV;
299 		}
300 	}
301 
302 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
303 	if (status) {
304 		pr_err(PREFIX "input buffer is not empty, "
305 				"aborting transaction\n");
306 		goto end;
307 	}
308 
309 	status = acpi_ec_transaction_unlocked(ec, command,
310 					      wdata, wdata_len,
311 					      rdata, rdata_len,
312 					      force_poll);
313 
314       end:
315 
316 	if (ec->global_lock)
317 		acpi_release_global_lock(glk);
318 	mutex_unlock(&ec->lock);
319 
320 	return status;
321 }
322 
323 /*
324  * Note: samsung nv5000 doesn't work with ec burst mode.
325  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
326  */
327 int acpi_ec_burst_enable(struct acpi_ec *ec)
328 {
329 	u8 d;
330 	return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
331 }
332 
333 int acpi_ec_burst_disable(struct acpi_ec *ec)
334 {
335 	return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
336 }
337 
338 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
339 {
340 	int result;
341 	u8 d;
342 
343 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
344 				     &address, 1, &d, 1, 0);
345 	*data = d;
346 	return result;
347 }
348 
349 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
350 {
351 	u8 wdata[2] = { address, data };
352 	return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
353 				   wdata, 2, NULL, 0, 0);
354 }
355 
356 /*
357  * Externally callable EC access functions. For now, assume 1 EC only
358  */
359 int ec_burst_enable(void)
360 {
361 	if (!first_ec)
362 		return -ENODEV;
363 	return acpi_ec_burst_enable(first_ec);
364 }
365 
366 EXPORT_SYMBOL(ec_burst_enable);
367 
368 int ec_burst_disable(void)
369 {
370 	if (!first_ec)
371 		return -ENODEV;
372 	return acpi_ec_burst_disable(first_ec);
373 }
374 
375 EXPORT_SYMBOL(ec_burst_disable);
376 
377 int ec_read(u8 addr, u8 * val)
378 {
379 	int err;
380 	u8 temp_data;
381 
382 	if (!first_ec)
383 		return -ENODEV;
384 
385 	err = acpi_ec_read(first_ec, addr, &temp_data);
386 
387 	if (!err) {
388 		*val = temp_data;
389 		return 0;
390 	} else
391 		return err;
392 }
393 
394 EXPORT_SYMBOL(ec_read);
395 
396 int ec_write(u8 addr, u8 val)
397 {
398 	int err;
399 
400 	if (!first_ec)
401 		return -ENODEV;
402 
403 	err = acpi_ec_write(first_ec, addr, val);
404 
405 	return err;
406 }
407 
408 EXPORT_SYMBOL(ec_write);
409 
410 int ec_transaction(u8 command,
411 		   const u8 * wdata, unsigned wdata_len,
412 		   u8 * rdata, unsigned rdata_len,
413 		   int force_poll)
414 {
415 	if (!first_ec)
416 		return -ENODEV;
417 
418 	return acpi_ec_transaction(first_ec, command, wdata,
419 				   wdata_len, rdata, rdata_len,
420 				   force_poll);
421 }
422 
423 EXPORT_SYMBOL(ec_transaction);
424 
425 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
426 {
427 	int result;
428 	u8 d;
429 
430 	if (!ec || !data)
431 		return -EINVAL;
432 
433 	/*
434 	 * Query the EC to find out which _Qxx method we need to evaluate.
435 	 * Note that successful completion of the query causes the ACPI_EC_SCI
436 	 * bit to be cleared (and thus clearing the interrupt source).
437 	 */
438 
439 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
440 	if (result)
441 		return result;
442 
443 	if (!d)
444 		return -ENODATA;
445 
446 	*data = d;
447 	return 0;
448 }
449 
450 /* --------------------------------------------------------------------------
451                                 Event Management
452    -------------------------------------------------------------------------- */
453 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
454 			      acpi_handle handle, acpi_ec_query_func func,
455 			      void *data)
456 {
457 	struct acpi_ec_query_handler *handler =
458 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
459 	if (!handler)
460 		return -ENOMEM;
461 
462 	handler->query_bit = query_bit;
463 	handler->handle = handle;
464 	handler->func = func;
465 	handler->data = data;
466 	mutex_lock(&ec->lock);
467 	list_add(&handler->node, &ec->list);
468 	mutex_unlock(&ec->lock);
469 	return 0;
470 }
471 
472 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
473 
474 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
475 {
476 	struct acpi_ec_query_handler *handler, *tmp;
477 	mutex_lock(&ec->lock);
478 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
479 		if (query_bit == handler->query_bit) {
480 			list_del(&handler->node);
481 			kfree(handler);
482 		}
483 	}
484 	mutex_unlock(&ec->lock);
485 }
486 
487 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
488 
489 static void acpi_ec_gpe_query(void *ec_cxt)
490 {
491 	struct acpi_ec *ec = ec_cxt;
492 	u8 value = 0;
493 	struct acpi_ec_query_handler *handler, copy;
494 
495 	if (!ec || acpi_ec_query(ec, &value))
496 		return;
497 	mutex_lock(&ec->lock);
498 	list_for_each_entry(handler, &ec->list, node) {
499 		if (value == handler->query_bit) {
500 			/* have custom handler for this bit */
501 			memcpy(&copy, handler, sizeof(copy));
502 			mutex_unlock(&ec->lock);
503 			if (copy.func) {
504 				copy.func(copy.data);
505 			} else if (copy.handle) {
506 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
507 			}
508 			return;
509 		}
510 	}
511 	mutex_unlock(&ec->lock);
512 }
513 
514 static u32 acpi_ec_gpe_handler(void *data)
515 {
516 	acpi_status status = AE_OK;
517 	struct acpi_ec *ec = data;
518 	u8 state = acpi_ec_read_status(ec);
519 
520 	pr_debug(PREFIX "~~~> interrupt\n");
521 	atomic_inc(&ec->irq_count);
522 	if (atomic_read(&ec->irq_count) > 5) {
523 		pr_err(PREFIX "GPE storm detected, disabling EC GPE\n");
524 		ec_switch_to_poll_mode(ec);
525 		goto end;
526 	}
527 	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
528 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
529 		wake_up(&ec->wait);
530 
531 	if (state & ACPI_EC_FLAG_SCI) {
532 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
533 			status = acpi_os_execute(OSL_EC_BURST_HANDLER,
534 				acpi_ec_gpe_query, ec);
535 	} else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
536 		   !test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
537 		   in_interrupt()) {
538 		/* this is non-query, must be confirmation */
539 		if (printk_ratelimit())
540 			pr_info(PREFIX "non-query interrupt received,"
541 				" switching to interrupt mode\n");
542 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
543 		clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
544 	}
545 end:
546 	ec_schedule_ec_poll(ec);
547 	return ACPI_SUCCESS(status) ?
548 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
549 }
550 
551 static void do_ec_poll(struct work_struct *work)
552 {
553 	struct acpi_ec *ec = container_of(work, struct acpi_ec, work.work);
554 	atomic_set(&ec->irq_count, 0);
555 	(void)acpi_ec_gpe_handler(ec);
556 }
557 
558 /* --------------------------------------------------------------------------
559                              Address Space Management
560    -------------------------------------------------------------------------- */
561 
562 static acpi_status
563 acpi_ec_space_handler(u32 function, acpi_physical_address address,
564 		      u32 bits, acpi_integer *value,
565 		      void *handler_context, void *region_context)
566 {
567 	struct acpi_ec *ec = handler_context;
568 	int result = 0, i;
569 	u8 temp = 0;
570 
571 	if ((address > 0xFF) || !value || !handler_context)
572 		return AE_BAD_PARAMETER;
573 
574 	if (function != ACPI_READ && function != ACPI_WRITE)
575 		return AE_BAD_PARAMETER;
576 
577 	if (bits != 8 && acpi_strict)
578 		return AE_BAD_PARAMETER;
579 
580 	acpi_ec_burst_enable(ec);
581 
582 	if (function == ACPI_READ) {
583 		result = acpi_ec_read(ec, address, &temp);
584 		*value = temp;
585 	} else {
586 		temp = 0xff & (*value);
587 		result = acpi_ec_write(ec, address, temp);
588 	}
589 
590 	for (i = 8; unlikely(bits - i > 0); i += 8) {
591 		++address;
592 		if (function == ACPI_READ) {
593 			result = acpi_ec_read(ec, address, &temp);
594 			(*value) |= ((acpi_integer)temp) << i;
595 		} else {
596 			temp = 0xff & ((*value) >> i);
597 			result = acpi_ec_write(ec, address, temp);
598 		}
599 	}
600 
601 	acpi_ec_burst_disable(ec);
602 
603 	switch (result) {
604 	case -EINVAL:
605 		return AE_BAD_PARAMETER;
606 		break;
607 	case -ENODEV:
608 		return AE_NOT_FOUND;
609 		break;
610 	case -ETIME:
611 		return AE_TIME;
612 		break;
613 	default:
614 		return AE_OK;
615 	}
616 }
617 
618 /* --------------------------------------------------------------------------
619                               FS Interface (/proc)
620    -------------------------------------------------------------------------- */
621 
622 static struct proc_dir_entry *acpi_ec_dir;
623 
624 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
625 {
626 	struct acpi_ec *ec = seq->private;
627 
628 	if (!ec)
629 		goto end;
630 
631 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
632 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
633 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
634 	seq_printf(seq, "use global lock:\t%s\n",
635 		   ec->global_lock ? "yes" : "no");
636       end:
637 	return 0;
638 }
639 
640 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
641 {
642 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
643 }
644 
645 static struct file_operations acpi_ec_info_ops = {
646 	.open = acpi_ec_info_open_fs,
647 	.read = seq_read,
648 	.llseek = seq_lseek,
649 	.release = single_release,
650 	.owner = THIS_MODULE,
651 };
652 
653 static int acpi_ec_add_fs(struct acpi_device *device)
654 {
655 	struct proc_dir_entry *entry = NULL;
656 
657 	if (!acpi_device_dir(device)) {
658 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
659 						     acpi_ec_dir);
660 		if (!acpi_device_dir(device))
661 			return -ENODEV;
662 	}
663 
664 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
665 				 acpi_device_dir(device),
666 				 &acpi_ec_info_ops, acpi_driver_data(device));
667 	if (!entry)
668 		return -ENODEV;
669 	return 0;
670 }
671 
672 static int acpi_ec_remove_fs(struct acpi_device *device)
673 {
674 
675 	if (acpi_device_dir(device)) {
676 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
677 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
678 		acpi_device_dir(device) = NULL;
679 	}
680 
681 	return 0;
682 }
683 
684 /* --------------------------------------------------------------------------
685                                Driver Interface
686    -------------------------------------------------------------------------- */
687 static acpi_status
688 ec_parse_io_ports(struct acpi_resource *resource, void *context);
689 
690 static struct acpi_ec *make_acpi_ec(void)
691 {
692 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
693 	if (!ec)
694 		return NULL;
695 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
696 	mutex_init(&ec->lock);
697 	init_waitqueue_head(&ec->wait);
698 	INIT_LIST_HEAD(&ec->list);
699 	INIT_DELAYED_WORK_DEFERRABLE(&ec->work, do_ec_poll);
700 	atomic_set(&ec->irq_count, 0);
701 	return ec;
702 }
703 
704 static acpi_status
705 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
706 			       void *context, void **return_value)
707 {
708 	struct acpi_namespace_node *node = handle;
709 	struct acpi_ec *ec = context;
710 	int value = 0;
711 	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
712 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
713 	}
714 	return AE_OK;
715 }
716 
717 static acpi_status
718 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
719 {
720 	acpi_status status;
721 
722 	struct acpi_ec *ec = context;
723 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
724 				     ec_parse_io_ports, ec);
725 	if (ACPI_FAILURE(status))
726 		return status;
727 
728 	/* Get GPE bit assignment (EC events). */
729 	/* TODO: Add support for _GPE returning a package */
730 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
731 	if (ACPI_FAILURE(status))
732 		return status;
733 	/* Use the global lock for all EC transactions? */
734 	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
735 	ec->handle = handle;
736 	return AE_CTRL_TERMINATE;
737 }
738 
739 static void ec_poll_stop(struct acpi_ec *ec)
740 {
741 	clear_bit(EC_FLAGS_RESCHEDULE_POLL, &ec->flags);
742 	cancel_delayed_work(&ec->work);
743 }
744 
745 static void ec_remove_handlers(struct acpi_ec *ec)
746 {
747 	ec_poll_stop(ec);
748 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
749 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
750 		pr_err(PREFIX "failed to remove space handler\n");
751 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
752 				&acpi_ec_gpe_handler)))
753 		pr_err(PREFIX "failed to remove gpe handler\n");
754 	ec->handlers_installed = 0;
755 }
756 
757 static int acpi_ec_add(struct acpi_device *device)
758 {
759 	struct acpi_ec *ec = NULL;
760 
761 	if (!device)
762 		return -EINVAL;
763 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
764 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
765 
766 	/* Check for boot EC */
767 	if (boot_ec &&
768 	    (boot_ec->handle == device->handle ||
769 	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
770 		ec = boot_ec;
771 		boot_ec = NULL;
772 	} else {
773 		ec = make_acpi_ec();
774 		if (!ec)
775 			return -ENOMEM;
776 		if (ec_parse_device(device->handle, 0, ec, NULL) !=
777 		    AE_CTRL_TERMINATE) {
778 			kfree(ec);
779 			return -EINVAL;
780 		}
781 	}
782 
783 	ec->handle = device->handle;
784 
785 	/* Find and register all query methods */
786 	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
787 			    acpi_ec_register_query_methods, ec, NULL);
788 
789 	if (!first_ec)
790 		first_ec = ec;
791 	acpi_driver_data(device) = ec;
792 	acpi_ec_add_fs(device);
793 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
794 			  ec->gpe, ec->command_addr, ec->data_addr);
795 	pr_info(PREFIX "driver started in %s mode\n",
796 		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
797 	return 0;
798 }
799 
800 static int acpi_ec_remove(struct acpi_device *device, int type)
801 {
802 	struct acpi_ec *ec;
803 	struct acpi_ec_query_handler *handler, *tmp;
804 
805 	if (!device)
806 		return -EINVAL;
807 
808 	ec = acpi_driver_data(device);
809 	mutex_lock(&ec->lock);
810 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
811 		list_del(&handler->node);
812 		kfree(handler);
813 	}
814 	mutex_unlock(&ec->lock);
815 	acpi_ec_remove_fs(device);
816 	acpi_driver_data(device) = NULL;
817 	if (ec == first_ec)
818 		first_ec = NULL;
819 	kfree(ec);
820 	return 0;
821 }
822 
823 static acpi_status
824 ec_parse_io_ports(struct acpi_resource *resource, void *context)
825 {
826 	struct acpi_ec *ec = context;
827 
828 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
829 		return AE_OK;
830 
831 	/*
832 	 * The first address region returned is the data port, and
833 	 * the second address region returned is the status/command
834 	 * port.
835 	 */
836 	if (ec->data_addr == 0)
837 		ec->data_addr = resource->data.io.minimum;
838 	else if (ec->command_addr == 0)
839 		ec->command_addr = resource->data.io.minimum;
840 	else
841 		return AE_CTRL_TERMINATE;
842 
843 	return AE_OK;
844 }
845 
846 static int ec_install_handlers(struct acpi_ec *ec)
847 {
848 	acpi_status status;
849 	if (ec->handlers_installed)
850 		return 0;
851 	status = acpi_install_gpe_handler(NULL, ec->gpe,
852 					  ACPI_GPE_EDGE_TRIGGERED,
853 					  &acpi_ec_gpe_handler, ec);
854 	if (ACPI_FAILURE(status))
855 		return -ENODEV;
856 
857 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
858 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
859 
860 	status = acpi_install_address_space_handler(ec->handle,
861 						    ACPI_ADR_SPACE_EC,
862 						    &acpi_ec_space_handler,
863 						    NULL, ec);
864 	if (ACPI_FAILURE(status)) {
865 		acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
866 		return -ENODEV;
867 	}
868 
869 	ec->handlers_installed = 1;
870 	return 0;
871 }
872 
873 static int acpi_ec_start(struct acpi_device *device)
874 {
875 	struct acpi_ec *ec;
876 	int ret = 0;
877 
878 	if (!device)
879 		return -EINVAL;
880 
881 	ec = acpi_driver_data(device);
882 
883 	if (!ec)
884 		return -EINVAL;
885 
886 	ret = ec_install_handlers(ec);
887 
888 	/* EC is fully operational, allow queries */
889 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
890 	ec_schedule_ec_poll(ec);
891 	return ret;
892 }
893 
894 static int acpi_ec_stop(struct acpi_device *device, int type)
895 {
896 	struct acpi_ec *ec;
897 	if (!device)
898 		return -EINVAL;
899 	ec = acpi_driver_data(device);
900 	if (!ec)
901 		return -EINVAL;
902 	ec_remove_handlers(ec);
903 
904 	return 0;
905 }
906 
907 int __init acpi_boot_ec_enable(void)
908 {
909 	if (!boot_ec || boot_ec->handlers_installed)
910 		return 0;
911 	if (!ec_install_handlers(boot_ec)) {
912 		first_ec = boot_ec;
913 		return 0;
914 	}
915 	return -EFAULT;
916 }
917 
918 static const struct acpi_device_id ec_device_ids[] = {
919 	{"PNP0C09", 0},
920 	{"", 0},
921 };
922 
923 int __init acpi_ec_ecdt_probe(void)
924 {
925 	int ret;
926 	acpi_status status;
927 	struct acpi_table_ecdt *ecdt_ptr;
928 
929 	boot_ec = make_acpi_ec();
930 	if (!boot_ec)
931 		return -ENOMEM;
932 	/*
933 	 * Generate a boot ec context
934 	 */
935 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
936 				(struct acpi_table_header **)&ecdt_ptr);
937 	if (ACPI_SUCCESS(status)) {
938 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
939 		boot_ec->command_addr = ecdt_ptr->control.address;
940 		boot_ec->data_addr = ecdt_ptr->data.address;
941 		if (dmi_check_system(ec_dmi_table)) {
942 			/*
943 			 * If the board falls into ec_dmi_table, it means
944 			 * that ECDT table gives the incorrect command/status
945 			 * & data I/O address. Just fix it.
946 			 */
947 			boot_ec->data_addr = ecdt_ptr->control.address;
948 			boot_ec->command_addr = ecdt_ptr->data.address;
949 		}
950 		boot_ec->gpe = ecdt_ptr->gpe;
951 		boot_ec->handle = ACPI_ROOT_OBJECT;
952 		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle);
953 	} else {
954 		/* This workaround is needed only on some broken machines,
955 		 * which require early EC, but fail to provide ECDT */
956 		acpi_handle x;
957 		printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
958 		status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
959 						boot_ec, NULL);
960 		/* Check that acpi_get_devices actually find something */
961 		if (ACPI_FAILURE(status) || !boot_ec->handle)
962 			goto error;
963 		/* We really need to limit this workaround, the only ASUS,
964 		 * which needs it, has fake EC._INI method, so use it as flag.
965 		 * Keep boot_ec struct as it will be needed soon.
966 		 */
967 		if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
968 			return -ENODEV;
969 	}
970 
971 	ret = ec_install_handlers(boot_ec);
972 	if (!ret) {
973 		first_ec = boot_ec;
974 		return 0;
975 	}
976       error:
977 	kfree(boot_ec);
978 	boot_ec = NULL;
979 	return -ENODEV;
980 }
981 
982 static int acpi_ec_suspend(struct acpi_device *device, pm_message_t state)
983 {
984 	struct acpi_ec *ec = acpi_driver_data(device);
985 	/* Stop using GPE */
986 	set_bit(EC_FLAGS_NO_GPE, &ec->flags);
987 	clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
988 	acpi_disable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
989 	return 0;
990 }
991 
992 static int acpi_ec_resume(struct acpi_device *device)
993 {
994 	struct acpi_ec *ec = acpi_driver_data(device);
995 	/* Enable use of GPE back */
996 	clear_bit(EC_FLAGS_NO_GPE, &ec->flags);
997 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
998 	return 0;
999 }
1000 
1001 static struct acpi_driver acpi_ec_driver = {
1002 	.name = "ec",
1003 	.class = ACPI_EC_CLASS,
1004 	.ids = ec_device_ids,
1005 	.ops = {
1006 		.add = acpi_ec_add,
1007 		.remove = acpi_ec_remove,
1008 		.start = acpi_ec_start,
1009 		.stop = acpi_ec_stop,
1010 		.suspend = acpi_ec_suspend,
1011 		.resume = acpi_ec_resume,
1012 		},
1013 };
1014 
1015 static int __init acpi_ec_init(void)
1016 {
1017 	int result = 0;
1018 
1019 	if (acpi_disabled)
1020 		return 0;
1021 
1022 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
1023 	if (!acpi_ec_dir)
1024 		return -ENODEV;
1025 
1026 	/* Now register the driver for the EC */
1027 	result = acpi_bus_register_driver(&acpi_ec_driver);
1028 	if (result < 0) {
1029 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1030 		return -ENODEV;
1031 	}
1032 
1033 	return result;
1034 }
1035 
1036 subsys_initcall(acpi_ec_init);
1037 
1038 /* EC driver currently not unloadable */
1039 #if 0
1040 static void __exit acpi_ec_exit(void)
1041 {
1042 
1043 	acpi_bus_unregister_driver(&acpi_ec_driver);
1044 
1045 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1046 
1047 	return;
1048 }
1049 #endif	/* 0 */
1050