xref: /linux/drivers/acpi/ec.c (revision f7511d5f66f01fc451747b24e79f3ada7a3af9af)
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 
77 enum {
78 	EC_FLAGS_WAIT_GPE = 0,		/* Don't check status until GPE arrives */
79 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
80 	EC_FLAGS_GPE_MODE,		/* Expect GPE to be sent for status change */
81 	EC_FLAGS_NO_ADDRESS_GPE,	/* Expect GPE only for non-address event */
82 	EC_FLAGS_ADDRESS,		/* Address is being written */
83 	EC_FLAGS_NO_WDATA_GPE,		/* Don't expect WDATA GPE event */
84 	EC_FLAGS_WDATA,			/* Data is being written */
85 	EC_FLAGS_NO_OBF1_GPE,		/* Don't expect GPE before read */
86 };
87 
88 static int acpi_ec_remove(struct acpi_device *device, int type);
89 static int acpi_ec_start(struct acpi_device *device);
90 static int acpi_ec_stop(struct acpi_device *device, int type);
91 static int acpi_ec_add(struct acpi_device *device);
92 
93 static const struct acpi_device_id ec_device_ids[] = {
94 	{"PNP0C09", 0},
95 	{"", 0},
96 };
97 
98 static struct acpi_driver acpi_ec_driver = {
99 	.name = "ec",
100 	.class = ACPI_EC_CLASS,
101 	.ids = ec_device_ids,
102 	.ops = {
103 		.add = acpi_ec_add,
104 		.remove = acpi_ec_remove,
105 		.start = acpi_ec_start,
106 		.stop = acpi_ec_stop,
107 		},
108 };
109 
110 /* If we find an EC via the ECDT, we need to keep a ptr to its context */
111 /* External interfaces use first EC only, so remember */
112 typedef int (*acpi_ec_query_func) (void *data);
113 
114 struct acpi_ec_query_handler {
115 	struct list_head node;
116 	acpi_ec_query_func func;
117 	acpi_handle handle;
118 	void *data;
119 	u8 query_bit;
120 };
121 
122 static struct acpi_ec {
123 	acpi_handle handle;
124 	unsigned long gpe;
125 	unsigned long command_addr;
126 	unsigned long data_addr;
127 	unsigned long global_lock;
128 	unsigned long flags;
129 	struct mutex lock;
130 	wait_queue_head_t wait;
131 	struct list_head list;
132 	u8 handlers_installed;
133 } *boot_ec, *first_ec;
134 
135 /* --------------------------------------------------------------------------
136                              Transaction Management
137    -------------------------------------------------------------------------- */
138 
139 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
140 {
141 	u8 x = inb(ec->command_addr);
142 	pr_debug(PREFIX "---> status = 0x%2.2x\n", x);
143 	return x;
144 }
145 
146 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
147 {
148 	u8 x = inb(ec->data_addr);
149 	pr_debug(PREFIX "---> data = 0x%2.2x\n", x);
150 	return inb(ec->data_addr);
151 }
152 
153 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
154 {
155 	pr_debug(PREFIX "<--- command = 0x%2.2x\n", command);
156 	outb(command, ec->command_addr);
157 }
158 
159 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
160 {
161 	pr_debug(PREFIX "<--- data = 0x%2.2x\n", data);
162 	outb(data, ec->data_addr);
163 }
164 
165 static inline int acpi_ec_check_status(struct acpi_ec *ec, enum ec_event event)
166 {
167 	if (test_bit(EC_FLAGS_WAIT_GPE, &ec->flags))
168 		return 0;
169 	if (event == ACPI_EC_EVENT_OBF_1) {
170 		if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_OBF)
171 			return 1;
172 	} else if (event == ACPI_EC_EVENT_IBF_0) {
173 		if (!(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF))
174 			return 1;
175 	}
176 
177 	return 0;
178 }
179 
180 static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
181 {
182 	int ret = 0;
183 
184 	if (unlikely(event == ACPI_EC_EVENT_OBF_1 &&
185 		     test_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags)))
186 		force_poll = 1;
187 	if (unlikely(test_bit(EC_FLAGS_ADDRESS, &ec->flags) &&
188 		     test_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags)))
189 		force_poll = 1;
190 	if (unlikely(test_bit(EC_FLAGS_WDATA, &ec->flags) &&
191 		     test_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags)))
192 		force_poll = 1;
193 	if (likely(test_bit(EC_FLAGS_GPE_MODE, &ec->flags)) &&
194 	    likely(!force_poll)) {
195 		if (wait_event_timeout(ec->wait, acpi_ec_check_status(ec, event),
196 				       msecs_to_jiffies(ACPI_EC_DELAY)))
197 			goto end;
198 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
199 		if (acpi_ec_check_status(ec, event)) {
200 			if (event == ACPI_EC_EVENT_OBF_1) {
201 				/* miss OBF_1 GPE, don't expect it */
202 				pr_info(PREFIX "missing OBF confirmation, "
203 					"don't expect it any longer.\n");
204 				set_bit(EC_FLAGS_NO_OBF1_GPE, &ec->flags);
205 			} else if (test_bit(EC_FLAGS_ADDRESS, &ec->flags)) {
206 				/* miss address GPE, don't expect it anymore */
207 				pr_info(PREFIX "missing address confirmation, "
208 					"don't expect it any longer.\n");
209 				set_bit(EC_FLAGS_NO_ADDRESS_GPE, &ec->flags);
210 			} else if (test_bit(EC_FLAGS_WDATA, &ec->flags)) {
211 				/* miss write data GPE, don't expect it */
212 				pr_info(PREFIX "missing write data confirmation, "
213 					"don't expect it any longer.\n");
214 				set_bit(EC_FLAGS_NO_WDATA_GPE, &ec->flags);
215 			} else {
216 				/* missing GPEs, switch back to poll mode */
217 				if (printk_ratelimit())
218 					pr_info(PREFIX "missing confirmations, "
219 						"switch off interrupt mode.\n");
220 				clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
221 			}
222 			goto end;
223 		}
224 	} else {
225 		unsigned long delay = jiffies + msecs_to_jiffies(ACPI_EC_DELAY);
226 		clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
227 		while (time_before(jiffies, delay)) {
228 			if (acpi_ec_check_status(ec, event))
229 				goto end;
230 		}
231 	}
232 	pr_err(PREFIX "acpi_ec_wait timeout,"
233 			       " status = %d, expect_event = %d\n",
234 			       acpi_ec_read_status(ec), event);
235 	ret = -ETIME;
236       end:
237 	clear_bit(EC_FLAGS_ADDRESS, &ec->flags);
238 	return ret;
239 }
240 
241 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, u8 command,
242 					const u8 * wdata, unsigned wdata_len,
243 					u8 * rdata, unsigned rdata_len,
244 					int force_poll)
245 {
246 	int result = 0;
247 	set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
248 	acpi_ec_write_cmd(ec, command);
249 	pr_debug(PREFIX "transaction start\n");
250 	for (; wdata_len > 0; --wdata_len) {
251 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
252 		if (result) {
253 			pr_err(PREFIX
254 			       "write_cmd timeout, command = %d\n", command);
255 			goto end;
256 		}
257 		/* mark the address byte written to EC */
258 		if (rdata_len + wdata_len > 1)
259 			set_bit(EC_FLAGS_ADDRESS, &ec->flags);
260 		set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
261 		acpi_ec_write_data(ec, *(wdata++));
262 	}
263 
264 	if (!rdata_len) {
265 		set_bit(EC_FLAGS_WDATA, &ec->flags);
266 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, force_poll);
267 		if (result) {
268 			pr_err(PREFIX
269 			       "finish-write timeout, command = %d\n", command);
270 			goto end;
271 		}
272 	} else if (command == ACPI_EC_COMMAND_QUERY)
273 		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
274 
275 	for (; rdata_len > 0; --rdata_len) {
276 		result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF_1, force_poll);
277 		if (result) {
278 			pr_err(PREFIX "read timeout, command = %d\n", command);
279 			goto end;
280 		}
281 		/* Don't expect GPE after last read */
282 		if (rdata_len > 1)
283 			set_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
284 		*(rdata++) = acpi_ec_read_data(ec);
285 	}
286       end:
287 	pr_debug(PREFIX "transaction end\n");
288 	return result;
289 }
290 
291 static int acpi_ec_transaction(struct acpi_ec *ec, u8 command,
292 			       const u8 * wdata, unsigned wdata_len,
293 			       u8 * rdata, unsigned rdata_len,
294 			       int force_poll)
295 {
296 	int status;
297 	u32 glk;
298 
299 	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
300 		return -EINVAL;
301 
302 	if (rdata)
303 		memset(rdata, 0, rdata_len);
304 
305 	mutex_lock(&ec->lock);
306 	if (ec->global_lock) {
307 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
308 		if (ACPI_FAILURE(status)) {
309 			mutex_unlock(&ec->lock);
310 			return -ENODEV;
311 		}
312 	}
313 
314 	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBF_0, 0);
315 	if (status) {
316 		pr_err(PREFIX "input buffer is not empty, "
317 				"aborting transaction\n");
318 		goto end;
319 	}
320 
321 	status = acpi_ec_transaction_unlocked(ec, command,
322 					      wdata, wdata_len,
323 					      rdata, rdata_len,
324 					      force_poll);
325 
326       end:
327 
328 	if (ec->global_lock)
329 		acpi_release_global_lock(glk);
330 	mutex_unlock(&ec->lock);
331 
332 	return status;
333 }
334 
335 /*
336  * Note: samsung nv5000 doesn't work with ec burst mode.
337  * http://bugzilla.kernel.org/show_bug.cgi?id=4980
338  */
339 int acpi_ec_burst_enable(struct acpi_ec *ec)
340 {
341 	u8 d;
342 	return acpi_ec_transaction(ec, ACPI_EC_BURST_ENABLE, NULL, 0, &d, 1, 0);
343 }
344 
345 int acpi_ec_burst_disable(struct acpi_ec *ec)
346 {
347 	return acpi_ec_transaction(ec, ACPI_EC_BURST_DISABLE, NULL, 0, NULL, 0, 0);
348 }
349 
350 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data)
351 {
352 	int result;
353 	u8 d;
354 
355 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ,
356 				     &address, 1, &d, 1, 0);
357 	*data = d;
358 	return result;
359 }
360 
361 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
362 {
363 	u8 wdata[2] = { address, data };
364 	return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE,
365 				   wdata, 2, NULL, 0, 0);
366 }
367 
368 /*
369  * Externally callable EC access functions. For now, assume 1 EC only
370  */
371 int ec_burst_enable(void)
372 {
373 	if (!first_ec)
374 		return -ENODEV;
375 	return acpi_ec_burst_enable(first_ec);
376 }
377 
378 EXPORT_SYMBOL(ec_burst_enable);
379 
380 int ec_burst_disable(void)
381 {
382 	if (!first_ec)
383 		return -ENODEV;
384 	return acpi_ec_burst_disable(first_ec);
385 }
386 
387 EXPORT_SYMBOL(ec_burst_disable);
388 
389 int ec_read(u8 addr, u8 * val)
390 {
391 	int err;
392 	u8 temp_data;
393 
394 	if (!first_ec)
395 		return -ENODEV;
396 
397 	err = acpi_ec_read(first_ec, addr, &temp_data);
398 
399 	if (!err) {
400 		*val = temp_data;
401 		return 0;
402 	} else
403 		return err;
404 }
405 
406 EXPORT_SYMBOL(ec_read);
407 
408 int ec_write(u8 addr, u8 val)
409 {
410 	int err;
411 
412 	if (!first_ec)
413 		return -ENODEV;
414 
415 	err = acpi_ec_write(first_ec, addr, val);
416 
417 	return err;
418 }
419 
420 EXPORT_SYMBOL(ec_write);
421 
422 int ec_transaction(u8 command,
423 		   const u8 * wdata, unsigned wdata_len,
424 		   u8 * rdata, unsigned rdata_len,
425 		   int force_poll)
426 {
427 	if (!first_ec)
428 		return -ENODEV;
429 
430 	return acpi_ec_transaction(first_ec, command, wdata,
431 				   wdata_len, rdata, rdata_len,
432 				   force_poll);
433 }
434 
435 EXPORT_SYMBOL(ec_transaction);
436 
437 static int acpi_ec_query(struct acpi_ec *ec, u8 * data)
438 {
439 	int result;
440 	u8 d;
441 
442 	if (!ec || !data)
443 		return -EINVAL;
444 
445 	/*
446 	 * Query the EC to find out which _Qxx method we need to evaluate.
447 	 * Note that successful completion of the query causes the ACPI_EC_SCI
448 	 * bit to be cleared (and thus clearing the interrupt source).
449 	 */
450 
451 	result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1, 0);
452 	if (result)
453 		return result;
454 
455 	if (!d)
456 		return -ENODATA;
457 
458 	*data = d;
459 	return 0;
460 }
461 
462 /* --------------------------------------------------------------------------
463                                 Event Management
464    -------------------------------------------------------------------------- */
465 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
466 			      acpi_handle handle, acpi_ec_query_func func,
467 			      void *data)
468 {
469 	struct acpi_ec_query_handler *handler =
470 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
471 	if (!handler)
472 		return -ENOMEM;
473 
474 	handler->query_bit = query_bit;
475 	handler->handle = handle;
476 	handler->func = func;
477 	handler->data = data;
478 	mutex_lock(&ec->lock);
479 	list_add(&handler->node, &ec->list);
480 	mutex_unlock(&ec->lock);
481 	return 0;
482 }
483 
484 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
485 
486 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
487 {
488 	struct acpi_ec_query_handler *handler, *tmp;
489 	mutex_lock(&ec->lock);
490 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
491 		if (query_bit == handler->query_bit) {
492 			list_del(&handler->node);
493 			kfree(handler);
494 		}
495 	}
496 	mutex_unlock(&ec->lock);
497 }
498 
499 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
500 
501 static void acpi_ec_gpe_query(void *ec_cxt)
502 {
503 	struct acpi_ec *ec = ec_cxt;
504 	u8 value = 0;
505 	struct acpi_ec_query_handler *handler, copy;
506 
507 	if (!ec || acpi_ec_query(ec, &value))
508 		return;
509 	mutex_lock(&ec->lock);
510 	list_for_each_entry(handler, &ec->list, node) {
511 		if (value == handler->query_bit) {
512 			/* have custom handler for this bit */
513 			memcpy(&copy, handler, sizeof(copy));
514 			mutex_unlock(&ec->lock);
515 			if (copy.func) {
516 				copy.func(copy.data);
517 			} else if (copy.handle) {
518 				acpi_evaluate_object(copy.handle, NULL, NULL, NULL);
519 			}
520 			return;
521 		}
522 	}
523 	mutex_unlock(&ec->lock);
524 }
525 
526 static u32 acpi_ec_gpe_handler(void *data)
527 {
528 	acpi_status status = AE_OK;
529 	struct acpi_ec *ec = data;
530 
531 	pr_debug(PREFIX "~~~> interrupt\n");
532 	clear_bit(EC_FLAGS_WAIT_GPE, &ec->flags);
533 	if (test_bit(EC_FLAGS_GPE_MODE, &ec->flags))
534 		wake_up(&ec->wait);
535 
536 	if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_SCI) {
537 		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
538 			status = acpi_os_execute(OSL_EC_BURST_HANDLER,
539 				acpi_ec_gpe_query, ec);
540 	} else if (unlikely(!test_bit(EC_FLAGS_GPE_MODE, &ec->flags))) {
541 		/* this is non-query, must be confirmation */
542 		if (printk_ratelimit())
543 			pr_info(PREFIX "non-query interrupt received,"
544 				" switching to interrupt mode\n");
545 		set_bit(EC_FLAGS_GPE_MODE, &ec->flags);
546 	}
547 
548 	return ACPI_SUCCESS(status) ?
549 	    ACPI_INTERRUPT_HANDLED : ACPI_INTERRUPT_NOT_HANDLED;
550 }
551 
552 /* --------------------------------------------------------------------------
553                              Address Space Management
554    -------------------------------------------------------------------------- */
555 
556 static acpi_status
557 acpi_ec_space_setup(acpi_handle region_handle,
558 		    u32 function, void *handler_context, void **return_context)
559 {
560 	/*
561 	 * The EC object is in the handler context and is needed
562 	 * when calling the acpi_ec_space_handler.
563 	 */
564 	*return_context = (function != ACPI_REGION_DEACTIVATE) ?
565 	    handler_context : NULL;
566 
567 	return AE_OK;
568 }
569 
570 static acpi_status
571 acpi_ec_space_handler(u32 function, acpi_physical_address address,
572 		      u32 bits, acpi_integer *value,
573 		      void *handler_context, void *region_context)
574 {
575 	struct acpi_ec *ec = handler_context;
576 	int result = 0, i;
577 	u8 temp = 0;
578 
579 	if ((address > 0xFF) || !value || !handler_context)
580 		return AE_BAD_PARAMETER;
581 
582 	if (function != ACPI_READ && function != ACPI_WRITE)
583 		return AE_BAD_PARAMETER;
584 
585 	if (bits != 8 && acpi_strict)
586 		return AE_BAD_PARAMETER;
587 
588 	acpi_ec_burst_enable(ec);
589 
590 	if (function == ACPI_READ) {
591 		result = acpi_ec_read(ec, address, &temp);
592 		*value = temp;
593 	} else {
594 		temp = 0xff & (*value);
595 		result = acpi_ec_write(ec, address, temp);
596 	}
597 
598 	for (i = 8; unlikely(bits - i > 0); i += 8) {
599 		++address;
600 		if (function == ACPI_READ) {
601 			result = acpi_ec_read(ec, address, &temp);
602 			(*value) |= ((acpi_integer)temp) << i;
603 		} else {
604 			temp = 0xff & ((*value) >> i);
605 			result = acpi_ec_write(ec, address, temp);
606 		}
607 	}
608 
609 	acpi_ec_burst_disable(ec);
610 
611 	switch (result) {
612 	case -EINVAL:
613 		return AE_BAD_PARAMETER;
614 		break;
615 	case -ENODEV:
616 		return AE_NOT_FOUND;
617 		break;
618 	case -ETIME:
619 		return AE_TIME;
620 		break;
621 	default:
622 		return AE_OK;
623 	}
624 }
625 
626 /* --------------------------------------------------------------------------
627                               FS Interface (/proc)
628    -------------------------------------------------------------------------- */
629 
630 static struct proc_dir_entry *acpi_ec_dir;
631 
632 static int acpi_ec_read_info(struct seq_file *seq, void *offset)
633 {
634 	struct acpi_ec *ec = seq->private;
635 
636 	if (!ec)
637 		goto end;
638 
639 	seq_printf(seq, "gpe:\t\t\t0x%02x\n", (u32) ec->gpe);
640 	seq_printf(seq, "ports:\t\t\t0x%02x, 0x%02x\n",
641 		   (unsigned)ec->command_addr, (unsigned)ec->data_addr);
642 	seq_printf(seq, "use global lock:\t%s\n",
643 		   ec->global_lock ? "yes" : "no");
644       end:
645 	return 0;
646 }
647 
648 static int acpi_ec_info_open_fs(struct inode *inode, struct file *file)
649 {
650 	return single_open(file, acpi_ec_read_info, PDE(inode)->data);
651 }
652 
653 static struct file_operations acpi_ec_info_ops = {
654 	.open = acpi_ec_info_open_fs,
655 	.read = seq_read,
656 	.llseek = seq_lseek,
657 	.release = single_release,
658 	.owner = THIS_MODULE,
659 };
660 
661 static int acpi_ec_add_fs(struct acpi_device *device)
662 {
663 	struct proc_dir_entry *entry = NULL;
664 
665 	if (!acpi_device_dir(device)) {
666 		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
667 						     acpi_ec_dir);
668 		if (!acpi_device_dir(device))
669 			return -ENODEV;
670 	}
671 
672 	entry = proc_create_data(ACPI_EC_FILE_INFO, S_IRUGO,
673 				 acpi_device_dir(device),
674 				 &acpi_ec_info_ops, acpi_driver_data(device));
675 	if (!entry)
676 		return -ENODEV;
677 	return 0;
678 }
679 
680 static int acpi_ec_remove_fs(struct acpi_device *device)
681 {
682 
683 	if (acpi_device_dir(device)) {
684 		remove_proc_entry(ACPI_EC_FILE_INFO, acpi_device_dir(device));
685 		remove_proc_entry(acpi_device_bid(device), acpi_ec_dir);
686 		acpi_device_dir(device) = NULL;
687 	}
688 
689 	return 0;
690 }
691 
692 /* --------------------------------------------------------------------------
693                                Driver Interface
694    -------------------------------------------------------------------------- */
695 static acpi_status
696 ec_parse_io_ports(struct acpi_resource *resource, void *context);
697 
698 static struct acpi_ec *make_acpi_ec(void)
699 {
700 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
701 	if (!ec)
702 		return NULL;
703 	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
704 	mutex_init(&ec->lock);
705 	init_waitqueue_head(&ec->wait);
706 	INIT_LIST_HEAD(&ec->list);
707 	return ec;
708 }
709 
710 static acpi_status
711 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
712 			       void *context, void **return_value)
713 {
714 	struct acpi_namespace_node *node = handle;
715 	struct acpi_ec *ec = context;
716 	int value = 0;
717 	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
718 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
719 	}
720 	return AE_OK;
721 }
722 
723 static acpi_status
724 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
725 {
726 	acpi_status status;
727 
728 	struct acpi_ec *ec = context;
729 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
730 				     ec_parse_io_ports, ec);
731 	if (ACPI_FAILURE(status))
732 		return status;
733 
734 	/* Get GPE bit assignment (EC events). */
735 	/* TODO: Add support for _GPE returning a package */
736 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &ec->gpe);
737 	if (ACPI_FAILURE(status))
738 		return status;
739 	/* Find and register all query methods */
740 	acpi_walk_namespace(ACPI_TYPE_METHOD, handle, 1,
741 			    acpi_ec_register_query_methods, ec, NULL);
742 	/* Use the global lock for all EC transactions? */
743 	acpi_evaluate_integer(handle, "_GLK", NULL, &ec->global_lock);
744 	ec->handle = handle;
745 	return AE_CTRL_TERMINATE;
746 }
747 
748 static void ec_remove_handlers(struct acpi_ec *ec)
749 {
750 	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
751 				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
752 		pr_err(PREFIX "failed to remove space handler\n");
753 	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
754 				&acpi_ec_gpe_handler)))
755 		pr_err(PREFIX "failed to remove gpe handler\n");
756 	ec->handlers_installed = 0;
757 }
758 
759 static int acpi_ec_add(struct acpi_device *device)
760 {
761 	struct acpi_ec *ec = NULL;
762 
763 	if (!device)
764 		return -EINVAL;
765 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
766 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
767 
768 	/* Check for boot EC */
769 	if (boot_ec) {
770 		if (boot_ec->handle == device->handle) {
771 			/* Pre-loaded EC from DSDT, just move pointer */
772 			ec = boot_ec;
773 			boot_ec = NULL;
774 			goto end;
775 		} else if (boot_ec->handle == ACPI_ROOT_OBJECT) {
776 			/* ECDT-based EC, time to shut it down */
777 			ec_remove_handlers(boot_ec);
778 			kfree(boot_ec);
779 			first_ec = boot_ec = NULL;
780 		}
781 	}
782 
783 	ec = make_acpi_ec();
784 	if (!ec)
785 		return -ENOMEM;
786 
787 	if (ec_parse_device(device->handle, 0, ec, NULL) !=
788 	    AE_CTRL_TERMINATE) {
789 		kfree(ec);
790 		return -EINVAL;
791 	}
792 	ec->handle = device->handle;
793       end:
794 	if (!first_ec)
795 		first_ec = ec;
796 	acpi_driver_data(device) = ec;
797 	acpi_ec_add_fs(device);
798 	pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
799 			  ec->gpe, ec->command_addr, ec->data_addr);
800 	pr_info(PREFIX "driver started in %s mode\n",
801 		(test_bit(EC_FLAGS_GPE_MODE, &ec->flags))?"interrupt":"poll");
802 	return 0;
803 }
804 
805 static int acpi_ec_remove(struct acpi_device *device, int type)
806 {
807 	struct acpi_ec *ec;
808 	struct acpi_ec_query_handler *handler, *tmp;
809 
810 	if (!device)
811 		return -EINVAL;
812 
813 	ec = acpi_driver_data(device);
814 	mutex_lock(&ec->lock);
815 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
816 		list_del(&handler->node);
817 		kfree(handler);
818 	}
819 	mutex_unlock(&ec->lock);
820 	acpi_ec_remove_fs(device);
821 	acpi_driver_data(device) = NULL;
822 	if (ec == first_ec)
823 		first_ec = NULL;
824 	kfree(ec);
825 	return 0;
826 }
827 
828 static acpi_status
829 ec_parse_io_ports(struct acpi_resource *resource, void *context)
830 {
831 	struct acpi_ec *ec = context;
832 
833 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
834 		return AE_OK;
835 
836 	/*
837 	 * The first address region returned is the data port, and
838 	 * the second address region returned is the status/command
839 	 * port.
840 	 */
841 	if (ec->data_addr == 0)
842 		ec->data_addr = resource->data.io.minimum;
843 	else if (ec->command_addr == 0)
844 		ec->command_addr = resource->data.io.minimum;
845 	else
846 		return AE_CTRL_TERMINATE;
847 
848 	return AE_OK;
849 }
850 
851 static int ec_install_handlers(struct acpi_ec *ec)
852 {
853 	acpi_status status;
854 	if (ec->handlers_installed)
855 		return 0;
856 	status = acpi_install_gpe_handler(NULL, ec->gpe,
857 					  ACPI_GPE_EDGE_TRIGGERED,
858 					  &acpi_ec_gpe_handler, ec);
859 	if (ACPI_FAILURE(status))
860 		return -ENODEV;
861 
862 	acpi_set_gpe_type(NULL, ec->gpe, ACPI_GPE_TYPE_RUNTIME);
863 	acpi_enable_gpe(NULL, ec->gpe, ACPI_NOT_ISR);
864 
865 	status = acpi_install_address_space_handler(ec->handle,
866 						    ACPI_ADR_SPACE_EC,
867 						    &acpi_ec_space_handler,
868 						    &acpi_ec_space_setup, ec);
869 	if (ACPI_FAILURE(status)) {
870 		acpi_remove_gpe_handler(NULL, ec->gpe, &acpi_ec_gpe_handler);
871 		return -ENODEV;
872 	}
873 
874 	ec->handlers_installed = 1;
875 	return 0;
876 }
877 
878 static int acpi_ec_start(struct acpi_device *device)
879 {
880 	struct acpi_ec *ec;
881 	int ret = 0;
882 
883 	if (!device)
884 		return -EINVAL;
885 
886 	ec = acpi_driver_data(device);
887 
888 	if (!ec)
889 		return -EINVAL;
890 
891 	ret = ec_install_handlers(ec);
892 
893 	/* EC is fully operational, allow queries */
894 	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
895 	return ret;
896 }
897 
898 static int acpi_ec_stop(struct acpi_device *device, int type)
899 {
900 	struct acpi_ec *ec;
901 	if (!device)
902 		return -EINVAL;
903 	ec = acpi_driver_data(device);
904 	if (!ec)
905 		return -EINVAL;
906 	ec_remove_handlers(ec);
907 
908 	return 0;
909 }
910 
911 int __init acpi_boot_ec_enable(void)
912 {
913 	if (!boot_ec || boot_ec->handlers_installed)
914 		return 0;
915 	if (!ec_install_handlers(boot_ec)) {
916 		first_ec = boot_ec;
917 		return 0;
918 	}
919 	return -EFAULT;
920 }
921 
922 int __init acpi_ec_ecdt_probe(void)
923 {
924 	int ret;
925 	acpi_status status;
926 	struct acpi_table_ecdt *ecdt_ptr;
927 
928 	boot_ec = make_acpi_ec();
929 	if (!boot_ec)
930 		return -ENOMEM;
931 	/*
932 	 * Generate a boot ec context
933 	 */
934 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
935 				(struct acpi_table_header **)&ecdt_ptr);
936 	if (ACPI_SUCCESS(status)) {
937 		pr_info(PREFIX "EC description table is found, configuring boot EC\n");
938 		boot_ec->command_addr = ecdt_ptr->control.address;
939 		boot_ec->data_addr = ecdt_ptr->data.address;
940 		boot_ec->gpe = ecdt_ptr->gpe;
941 		boot_ec->handle = ACPI_ROOT_OBJECT;
942 	} else {
943 		/* This workaround is needed only on some broken machines,
944 		 * which require early EC, but fail to provide ECDT */
945 		acpi_handle x;
946 		printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n");
947 		status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
948 						boot_ec, NULL);
949 		/* Check that acpi_get_devices actually find something */
950 		if (ACPI_FAILURE(status) || !boot_ec->handle)
951 			goto error;
952 		/* We really need to limit this workaround, the only ASUS,
953 		 * which needs it, has fake EC._INI method, so use it as flag.
954 		 * Keep boot_ec struct as it will be needed soon.
955 		 */
956 		if (ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", &x)))
957 			return -ENODEV;
958 	}
959 
960 	ret = ec_install_handlers(boot_ec);
961 	if (!ret) {
962 		first_ec = boot_ec;
963 		return 0;
964 	}
965       error:
966 	kfree(boot_ec);
967 	boot_ec = NULL;
968 	return -ENODEV;
969 }
970 
971 static int __init acpi_ec_init(void)
972 {
973 	int result = 0;
974 
975 	if (acpi_disabled)
976 		return 0;
977 
978 	acpi_ec_dir = proc_mkdir(ACPI_EC_CLASS, acpi_root_dir);
979 	if (!acpi_ec_dir)
980 		return -ENODEV;
981 
982 	/* Now register the driver for the EC */
983 	result = acpi_bus_register_driver(&acpi_ec_driver);
984 	if (result < 0) {
985 		remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
986 		return -ENODEV;
987 	}
988 
989 	return result;
990 }
991 
992 subsys_initcall(acpi_ec_init);
993 
994 /* EC driver currently not unloadable */
995 #if 0
996 static void __exit acpi_ec_exit(void)
997 {
998 
999 	acpi_bus_unregister_driver(&acpi_ec_driver);
1000 
1001 	remove_proc_entry(ACPI_EC_CLASS, acpi_root_dir);
1002 
1003 	return;
1004 }
1005 #endif	/* 0 */
1006