1/*
2 *  ec.c - ACPI Embedded Controller Driver (v2.2)
3 *
4 *  Copyright (C) 2001-2014 Intel Corporation
5 *    Author: 2014       Lv Zheng <lv.zheng@intel.com>
6 *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
7 *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
8 *            2004       Luming Yu <luming.yu@intel.com>
9 *            2001, 2002 Andy Grover <andrew.grover@intel.com>
10 *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
11 *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
12 *
13 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 *
15 *  This program is free software; you can redistribute it and/or modify
16 *  it under the terms of the GNU General Public License as published by
17 *  the Free Software Foundation; either version 2 of the License, or (at
18 *  your option) any later version.
19 *
20 *  This program is distributed in the hope that it will be useful, but
21 *  WITHOUT ANY WARRANTY; without even the implied warranty of
22 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
23 *  General Public License for more details.
24 *
25 *  You should have received a copy of the GNU General Public License along
26 *  with this program; if not, write to the Free Software Foundation, Inc.,
27 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
28 *
29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
30 */
31
32/* Uncomment next line to get verbose printout */
33/* #define DEBUG */
34#define pr_fmt(fmt) "ACPI : EC: " fmt
35
36#include <linux/kernel.h>
37#include <linux/module.h>
38#include <linux/init.h>
39#include <linux/types.h>
40#include <linux/delay.h>
41#include <linux/interrupt.h>
42#include <linux/list.h>
43#include <linux/spinlock.h>
44#include <linux/slab.h>
45#include <linux/acpi.h>
46#include <linux/dmi.h>
47#include <asm/io.h>
48
49#include "internal.h"
50
51#define ACPI_EC_CLASS			"embedded_controller"
52#define ACPI_EC_DEVICE_NAME		"Embedded Controller"
53#define ACPI_EC_FILE_INFO		"info"
54
55/* EC status register */
56#define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
57#define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
58#define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */
59#define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
60#define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
61
62/* EC commands */
63enum ec_command {
64	ACPI_EC_COMMAND_READ = 0x80,
65	ACPI_EC_COMMAND_WRITE = 0x81,
66	ACPI_EC_BURST_ENABLE = 0x82,
67	ACPI_EC_BURST_DISABLE = 0x83,
68	ACPI_EC_COMMAND_QUERY = 0x84,
69};
70
71#define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
72#define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
73#define ACPI_EC_MSI_UDELAY	550	/* Wait 550us for MSI EC */
74#define ACPI_EC_CLEAR_MAX	100	/* Maximum number of events to query
75					 * when trying to clear the EC */
76
77enum {
78	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
79	EC_FLAGS_GPE_STORM,		/* GPE storm detected */
80	EC_FLAGS_HANDLERS_INSTALLED,	/* Handlers for GPE and
81					 * OpReg are installed */
82	EC_FLAGS_BLOCKED,		/* Transactions are blocked */
83};
84
85#define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */
86#define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */
87
88/* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
89static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
90module_param(ec_delay, uint, 0644);
91MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
92
93/*
94 * If the number of false interrupts per one transaction exceeds
95 * this threshold, will think there is a GPE storm happened and
96 * will disable the GPE for normal transaction.
97 */
98static unsigned int ec_storm_threshold  __read_mostly = 8;
99module_param(ec_storm_threshold, uint, 0644);
100MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
101
102struct acpi_ec_query_handler {
103	struct list_head node;
104	acpi_ec_query_func func;
105	acpi_handle handle;
106	void *data;
107	u8 query_bit;
108};
109
110struct transaction {
111	const u8 *wdata;
112	u8 *rdata;
113	unsigned short irq_count;
114	u8 command;
115	u8 wi;
116	u8 ri;
117	u8 wlen;
118	u8 rlen;
119	u8 flags;
120};
121
122struct acpi_ec *boot_ec, *first_ec;
123EXPORT_SYMBOL(first_ec);
124
125static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
126static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
127static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
128static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
129static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
130
131/* --------------------------------------------------------------------------
132 *                           Transaction Management
133 * -------------------------------------------------------------------------- */
134
135static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
136{
137	u8 x = inb(ec->command_addr);
138
139	pr_debug("EC_SC(R) = 0x%2.2x "
140		 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d\n",
141		 x,
142		 !!(x & ACPI_EC_FLAG_SCI),
143		 !!(x & ACPI_EC_FLAG_BURST),
144		 !!(x & ACPI_EC_FLAG_CMD),
145		 !!(x & ACPI_EC_FLAG_IBF),
146		 !!(x & ACPI_EC_FLAG_OBF));
147	return x;
148}
149
150static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
151{
152	u8 x = inb(ec->data_addr);
153
154	pr_debug("EC_DATA(R) = 0x%2.2x\n", x);
155	return x;
156}
157
158static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
159{
160	pr_debug("EC_SC(W) = 0x%2.2x\n", command);
161	outb(command, ec->command_addr);
162}
163
164static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
165{
166	pr_debug("EC_DATA(W) = 0x%2.2x\n", data);
167	outb(data, ec->data_addr);
168}
169
170#ifdef DEBUG
171static const char *acpi_ec_cmd_string(u8 cmd)
172{
173	switch (cmd) {
174	case 0x80:
175		return "RD_EC";
176	case 0x81:
177		return "WR_EC";
178	case 0x82:
179		return "BE_EC";
180	case 0x83:
181		return "BD_EC";
182	case 0x84:
183		return "QR_EC";
184	}
185	return "UNKNOWN";
186}
187#else
188#define acpi_ec_cmd_string(cmd)		"UNDEF"
189#endif
190
191static int ec_transaction_completed(struct acpi_ec *ec)
192{
193	unsigned long flags;
194	int ret = 0;
195
196	spin_lock_irqsave(&ec->lock, flags);
197	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
198		ret = 1;
199	spin_unlock_irqrestore(&ec->lock, flags);
200	return ret;
201}
202
203static bool advance_transaction(struct acpi_ec *ec)
204{
205	struct transaction *t;
206	u8 status;
207	bool wakeup = false;
208
209	pr_debug("===== %s (%d) =====\n",
210		 in_interrupt() ? "IRQ" : "TASK", smp_processor_id());
211	status = acpi_ec_read_status(ec);
212	t = ec->curr;
213	if (!t)
214		goto err;
215	if (t->flags & ACPI_EC_COMMAND_POLL) {
216		if (t->wlen > t->wi) {
217			if ((status & ACPI_EC_FLAG_IBF) == 0)
218				acpi_ec_write_data(ec, t->wdata[t->wi++]);
219			else
220				goto err;
221		} else if (t->rlen > t->ri) {
222			if ((status & ACPI_EC_FLAG_OBF) == 1) {
223				t->rdata[t->ri++] = acpi_ec_read_data(ec);
224				if (t->rlen == t->ri) {
225					t->flags |= ACPI_EC_COMMAND_COMPLETE;
226					if (t->command == ACPI_EC_COMMAND_QUERY)
227						pr_debug("***** Command(%s) hardware completion *****\n",
228							 acpi_ec_cmd_string(t->command));
229					wakeup = true;
230				}
231			} else
232				goto err;
233		} else if (t->wlen == t->wi &&
234			   (status & ACPI_EC_FLAG_IBF) == 0) {
235			t->flags |= ACPI_EC_COMMAND_COMPLETE;
236			wakeup = true;
237		}
238		return wakeup;
239	} else {
240		if (EC_FLAGS_QUERY_HANDSHAKE &&
241		    !(status & ACPI_EC_FLAG_SCI) &&
242		    (t->command == ACPI_EC_COMMAND_QUERY)) {
243			t->flags |= ACPI_EC_COMMAND_POLL;
244			t->rdata[t->ri++] = 0x00;
245			t->flags |= ACPI_EC_COMMAND_COMPLETE;
246			pr_debug("***** Command(%s) software completion *****\n",
247				 acpi_ec_cmd_string(t->command));
248			wakeup = true;
249		} else if ((status & ACPI_EC_FLAG_IBF) == 0) {
250			acpi_ec_write_cmd(ec, t->command);
251			t->flags |= ACPI_EC_COMMAND_POLL;
252		} else
253			goto err;
254		return wakeup;
255	}
256err:
257	/*
258	 * If SCI bit is set, then don't think it's a false IRQ
259	 * otherwise will take a not handled IRQ as a false one.
260	 */
261	if (!(status & ACPI_EC_FLAG_SCI)) {
262		if (in_interrupt() && t)
263			++t->irq_count;
264	}
265	return wakeup;
266}
267
268static void start_transaction(struct acpi_ec *ec)
269{
270	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
271	ec->curr->flags = 0;
272	(void)advance_transaction(ec);
273}
274
275static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data);
276
277static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
278{
279	if (state & ACPI_EC_FLAG_SCI) {
280		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
281			return acpi_ec_sync_query(ec, NULL);
282	}
283	return 0;
284}
285
286static int ec_poll(struct acpi_ec *ec)
287{
288	unsigned long flags;
289	int repeat = 5; /* number of command restarts */
290
291	while (repeat--) {
292		unsigned long delay = jiffies +
293			msecs_to_jiffies(ec_delay);
294		do {
295			/* don't sleep with disabled interrupts */
296			if (EC_FLAGS_MSI || irqs_disabled()) {
297				udelay(ACPI_EC_MSI_UDELAY);
298				if (ec_transaction_completed(ec))
299					return 0;
300			} else {
301				if (wait_event_timeout(ec->wait,
302						ec_transaction_completed(ec),
303						msecs_to_jiffies(1)))
304					return 0;
305			}
306			spin_lock_irqsave(&ec->lock, flags);
307			(void)advance_transaction(ec);
308			spin_unlock_irqrestore(&ec->lock, flags);
309		} while (time_before(jiffies, delay));
310		pr_debug("controller reset, restart transaction\n");
311		spin_lock_irqsave(&ec->lock, flags);
312		start_transaction(ec);
313		spin_unlock_irqrestore(&ec->lock, flags);
314	}
315	return -ETIME;
316}
317
318static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
319					struct transaction *t)
320{
321	unsigned long tmp;
322	int ret = 0;
323
324	if (EC_FLAGS_MSI)
325		udelay(ACPI_EC_MSI_UDELAY);
326	/* start transaction */
327	spin_lock_irqsave(&ec->lock, tmp);
328	/* following two actions should be kept atomic */
329	ec->curr = t;
330	pr_debug("***** Command(%s) started *****\n",
331		 acpi_ec_cmd_string(t->command));
332	start_transaction(ec);
333	if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
334		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
335		pr_debug("***** Event stopped *****\n");
336	}
337	spin_unlock_irqrestore(&ec->lock, tmp);
338	ret = ec_poll(ec);
339	spin_lock_irqsave(&ec->lock, tmp);
340	pr_debug("***** Command(%s) stopped *****\n",
341		 acpi_ec_cmd_string(t->command));
342	ec->curr = NULL;
343	spin_unlock_irqrestore(&ec->lock, tmp);
344	return ret;
345}
346
347static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
348{
349	int status;
350	u32 glk;
351
352	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
353		return -EINVAL;
354	if (t->rdata)
355		memset(t->rdata, 0, t->rlen);
356	mutex_lock(&ec->mutex);
357	if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) {
358		status = -EINVAL;
359		goto unlock;
360	}
361	if (ec->global_lock) {
362		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
363		if (ACPI_FAILURE(status)) {
364			status = -ENODEV;
365			goto unlock;
366		}
367	}
368	/* disable GPE during transaction if storm is detected */
369	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
370		/* It has to be disabled, so that it doesn't trigger. */
371		acpi_disable_gpe(NULL, ec->gpe);
372	}
373
374	status = acpi_ec_transaction_unlocked(ec, t);
375
376	/* check if we received SCI during transaction */
377	ec_check_sci_sync(ec, acpi_ec_read_status(ec));
378	if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) {
379		msleep(1);
380		/* It is safe to enable the GPE outside of the transaction. */
381		acpi_enable_gpe(NULL, ec->gpe);
382	} else if (t->irq_count > ec_storm_threshold) {
383		pr_info("GPE storm detected(%d GPEs), "
384			"transactions will use polling mode\n",
385			t->irq_count);
386		set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
387	}
388	if (ec->global_lock)
389		acpi_release_global_lock(glk);
390unlock:
391	mutex_unlock(&ec->mutex);
392	return status;
393}
394
395static int acpi_ec_burst_enable(struct acpi_ec *ec)
396{
397	u8 d;
398	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
399				.wdata = NULL, .rdata = &d,
400				.wlen = 0, .rlen = 1};
401
402	return acpi_ec_transaction(ec, &t);
403}
404
405static int acpi_ec_burst_disable(struct acpi_ec *ec)
406{
407	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
408				.wdata = NULL, .rdata = NULL,
409				.wlen = 0, .rlen = 0};
410
411	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
412				acpi_ec_transaction(ec, &t) : 0;
413}
414
415static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
416{
417	int result;
418	u8 d;
419	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
420				.wdata = &address, .rdata = &d,
421				.wlen = 1, .rlen = 1};
422
423	result = acpi_ec_transaction(ec, &t);
424	*data = d;
425	return result;
426}
427
428static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
429{
430	u8 wdata[2] = { address, data };
431	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
432				.wdata = wdata, .rdata = NULL,
433				.wlen = 2, .rlen = 0};
434
435	return acpi_ec_transaction(ec, &t);
436}
437
438int ec_read(u8 addr, u8 *val)
439{
440	int err;
441	u8 temp_data;
442
443	if (!first_ec)
444		return -ENODEV;
445
446	err = acpi_ec_read(first_ec, addr, &temp_data);
447
448	if (!err) {
449		*val = temp_data;
450		return 0;
451	}
452	return err;
453}
454EXPORT_SYMBOL(ec_read);
455
456int ec_write(u8 addr, u8 val)
457{
458	int err;
459
460	if (!first_ec)
461		return -ENODEV;
462
463	err = acpi_ec_write(first_ec, addr, val);
464
465	return err;
466}
467EXPORT_SYMBOL(ec_write);
468
469int ec_transaction(u8 command,
470		   const u8 *wdata, unsigned wdata_len,
471		   u8 *rdata, unsigned rdata_len)
472{
473	struct transaction t = {.command = command,
474				.wdata = wdata, .rdata = rdata,
475				.wlen = wdata_len, .rlen = rdata_len};
476
477	if (!first_ec)
478		return -ENODEV;
479
480	return acpi_ec_transaction(first_ec, &t);
481}
482EXPORT_SYMBOL(ec_transaction);
483
484/* Get the handle to the EC device */
485acpi_handle ec_get_handle(void)
486{
487	if (!first_ec)
488		return NULL;
489	return first_ec->handle;
490}
491EXPORT_SYMBOL(ec_get_handle);
492
493/*
494 * Process _Q events that might have accumulated in the EC.
495 * Run with locked ec mutex.
496 */
497static void acpi_ec_clear(struct acpi_ec *ec)
498{
499	int i, status;
500	u8 value = 0;
501
502	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
503		status = acpi_ec_sync_query(ec, &value);
504		if (status || !value)
505			break;
506	}
507
508	if (unlikely(i == ACPI_EC_CLEAR_MAX))
509		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
510	else
511		pr_info("%d stale EC events cleared\n", i);
512}
513
514void acpi_ec_block_transactions(void)
515{
516	struct acpi_ec *ec = first_ec;
517
518	if (!ec)
519		return;
520
521	mutex_lock(&ec->mutex);
522	/* Prevent transactions from being carried out */
523	set_bit(EC_FLAGS_BLOCKED, &ec->flags);
524	mutex_unlock(&ec->mutex);
525}
526
527void acpi_ec_unblock_transactions(void)
528{
529	struct acpi_ec *ec = first_ec;
530
531	if (!ec)
532		return;
533
534	mutex_lock(&ec->mutex);
535	/* Allow transactions to be carried out again */
536	clear_bit(EC_FLAGS_BLOCKED, &ec->flags);
537
538	if (EC_FLAGS_CLEAR_ON_RESUME)
539		acpi_ec_clear(ec);
540
541	mutex_unlock(&ec->mutex);
542}
543
544void acpi_ec_unblock_transactions_early(void)
545{
546	/*
547	 * Allow transactions to happen again (this function is called from
548	 * atomic context during wakeup, so we don't need to acquire the mutex).
549	 */
550	if (first_ec)
551		clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags);
552}
553
554static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data)
555{
556	int result;
557	u8 d;
558	struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
559				.wdata = NULL, .rdata = &d,
560				.wlen = 0, .rlen = 1};
561
562	if (!ec || !data)
563		return -EINVAL;
564	/*
565	 * Query the EC to find out which _Qxx method we need to evaluate.
566	 * Note that successful completion of the query causes the ACPI_EC_SCI
567	 * bit to be cleared (and thus clearing the interrupt source).
568	 */
569	result = acpi_ec_transaction_unlocked(ec, &t);
570	if (result)
571		return result;
572	if (!d)
573		return -ENODATA;
574	*data = d;
575	return 0;
576}
577
578/* --------------------------------------------------------------------------
579                                Event Management
580   -------------------------------------------------------------------------- */
581int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
582			      acpi_handle handle, acpi_ec_query_func func,
583			      void *data)
584{
585	struct acpi_ec_query_handler *handler =
586	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
587
588	if (!handler)
589		return -ENOMEM;
590
591	handler->query_bit = query_bit;
592	handler->handle = handle;
593	handler->func = func;
594	handler->data = data;
595	mutex_lock(&ec->mutex);
596	list_add(&handler->node, &ec->list);
597	mutex_unlock(&ec->mutex);
598	return 0;
599}
600EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
601
602void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
603{
604	struct acpi_ec_query_handler *handler, *tmp;
605
606	mutex_lock(&ec->mutex);
607	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
608		if (query_bit == handler->query_bit) {
609			list_del(&handler->node);
610			kfree(handler);
611		}
612	}
613	mutex_unlock(&ec->mutex);
614}
615EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
616
617static void acpi_ec_run(void *cxt)
618{
619	struct acpi_ec_query_handler *handler = cxt;
620
621	if (!handler)
622		return;
623	pr_debug("##### Query(0x%02x) started #####\n", handler->query_bit);
624	if (handler->func)
625		handler->func(handler->data);
626	else if (handler->handle)
627		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
628	pr_debug("##### Query(0x%02x) stopped #####\n", handler->query_bit);
629	kfree(handler);
630}
631
632static int acpi_ec_sync_query(struct acpi_ec *ec, u8 *data)
633{
634	u8 value = 0;
635	int status;
636	struct acpi_ec_query_handler *handler, *copy;
637
638	status = acpi_ec_query_unlocked(ec, &value);
639	if (data)
640		*data = value;
641	if (status)
642		return status;
643
644	list_for_each_entry(handler, &ec->list, node) {
645		if (value == handler->query_bit) {
646			/* have custom handler for this bit */
647			copy = kmalloc(sizeof(*handler), GFP_KERNEL);
648			if (!copy)
649				return -ENOMEM;
650			memcpy(copy, handler, sizeof(*copy));
651			pr_debug("##### Query(0x%02x) scheduled #####\n",
652				 handler->query_bit);
653			return acpi_os_execute((copy->func) ?
654				OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
655				acpi_ec_run, copy);
656		}
657	}
658	return 0;
659}
660
661static void acpi_ec_gpe_query(void *ec_cxt)
662{
663	struct acpi_ec *ec = ec_cxt;
664
665	if (!ec)
666		return;
667	mutex_lock(&ec->mutex);
668	acpi_ec_sync_query(ec, NULL);
669	mutex_unlock(&ec->mutex);
670}
671
672static int ec_check_sci(struct acpi_ec *ec, u8 state)
673{
674	if (state & ACPI_EC_FLAG_SCI) {
675		if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
676			pr_debug("***** Event started *****\n");
677			return acpi_os_execute(OSL_NOTIFY_HANDLER,
678				acpi_ec_gpe_query, ec);
679		}
680	}
681	return 0;
682}
683
684static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
685	u32 gpe_number, void *data)
686{
687	unsigned long flags;
688	struct acpi_ec *ec = data;
689
690	spin_lock_irqsave(&ec->lock, flags);
691	if (advance_transaction(ec))
692		wake_up(&ec->wait);
693	spin_unlock_irqrestore(&ec->lock, flags);
694	ec_check_sci(ec, acpi_ec_read_status(ec));
695	return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
696}
697
698/* --------------------------------------------------------------------------
699 *                           Address Space Management
700 * -------------------------------------------------------------------------- */
701
702static acpi_status
703acpi_ec_space_handler(u32 function, acpi_physical_address address,
704		      u32 bits, u64 *value64,
705		      void *handler_context, void *region_context)
706{
707	struct acpi_ec *ec = handler_context;
708	int result = 0, i, bytes = bits / 8;
709	u8 *value = (u8 *)value64;
710
711	if ((address > 0xFF) || !value || !handler_context)
712		return AE_BAD_PARAMETER;
713
714	if (function != ACPI_READ && function != ACPI_WRITE)
715		return AE_BAD_PARAMETER;
716
717	if (EC_FLAGS_MSI || bits > 8)
718		acpi_ec_burst_enable(ec);
719
720	for (i = 0; i < bytes; ++i, ++address, ++value)
721		result = (function == ACPI_READ) ?
722			acpi_ec_read(ec, address, value) :
723			acpi_ec_write(ec, address, *value);
724
725	if (EC_FLAGS_MSI || bits > 8)
726		acpi_ec_burst_disable(ec);
727
728	switch (result) {
729	case -EINVAL:
730		return AE_BAD_PARAMETER;
731	case -ENODEV:
732		return AE_NOT_FOUND;
733	case -ETIME:
734		return AE_TIME;
735	default:
736		return AE_OK;
737	}
738}
739
740/* --------------------------------------------------------------------------
741 *                             Driver Interface
742 * -------------------------------------------------------------------------- */
743
744static acpi_status
745ec_parse_io_ports(struct acpi_resource *resource, void *context);
746
747static struct acpi_ec *make_acpi_ec(void)
748{
749	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
750
751	if (!ec)
752		return NULL;
753	ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
754	mutex_init(&ec->mutex);
755	init_waitqueue_head(&ec->wait);
756	INIT_LIST_HEAD(&ec->list);
757	spin_lock_init(&ec->lock);
758	return ec;
759}
760
761static acpi_status
762acpi_ec_register_query_methods(acpi_handle handle, u32 level,
763			       void *context, void **return_value)
764{
765	char node_name[5];
766	struct acpi_buffer buffer = { sizeof(node_name), node_name };
767	struct acpi_ec *ec = context;
768	int value = 0;
769	acpi_status status;
770
771	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
772
773	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
774		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
775	return AE_OK;
776}
777
778static acpi_status
779ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
780{
781	acpi_status status;
782	unsigned long long tmp = 0;
783	struct acpi_ec *ec = context;
784
785	/* clear addr values, ec_parse_io_ports depend on it */
786	ec->command_addr = ec->data_addr = 0;
787
788	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
789				     ec_parse_io_ports, ec);
790	if (ACPI_FAILURE(status))
791		return status;
792
793	/* Get GPE bit assignment (EC events). */
794	/* TODO: Add support for _GPE returning a package */
795	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
796	if (ACPI_FAILURE(status))
797		return status;
798	ec->gpe = tmp;
799	/* Use the global lock for all EC transactions? */
800	tmp = 0;
801	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
802	ec->global_lock = tmp;
803	ec->handle = handle;
804	return AE_CTRL_TERMINATE;
805}
806
807static int ec_install_handlers(struct acpi_ec *ec)
808{
809	acpi_status status;
810
811	if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
812		return 0;
813	status = acpi_install_gpe_handler(NULL, ec->gpe,
814				  ACPI_GPE_EDGE_TRIGGERED,
815				  &acpi_ec_gpe_handler, ec);
816	if (ACPI_FAILURE(status))
817		return -ENODEV;
818
819	acpi_enable_gpe(NULL, ec->gpe);
820	status = acpi_install_address_space_handler(ec->handle,
821						    ACPI_ADR_SPACE_EC,
822						    &acpi_ec_space_handler,
823						    NULL, ec);
824	if (ACPI_FAILURE(status)) {
825		if (status == AE_NOT_FOUND) {
826			/*
827			 * Maybe OS fails in evaluating the _REG object.
828			 * The AE_NOT_FOUND error will be ignored and OS
829			 * continue to initialize EC.
830			 */
831			pr_err("Fail in evaluating the _REG object"
832				" of EC device. Broken bios is suspected.\n");
833		} else {
834			acpi_disable_gpe(NULL, ec->gpe);
835			acpi_remove_gpe_handler(NULL, ec->gpe,
836				&acpi_ec_gpe_handler);
837			return -ENODEV;
838		}
839	}
840
841	set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
842	return 0;
843}
844
845static void ec_remove_handlers(struct acpi_ec *ec)
846{
847	acpi_disable_gpe(NULL, ec->gpe);
848	if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
849				ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
850		pr_err("failed to remove space handler\n");
851	if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
852				&acpi_ec_gpe_handler)))
853		pr_err("failed to remove gpe handler\n");
854	clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
855}
856
857static int acpi_ec_add(struct acpi_device *device)
858{
859	struct acpi_ec *ec = NULL;
860	int ret;
861
862	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
863	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
864
865	/* Check for boot EC */
866	if (boot_ec &&
867	    (boot_ec->handle == device->handle ||
868	     boot_ec->handle == ACPI_ROOT_OBJECT)) {
869		ec = boot_ec;
870		boot_ec = NULL;
871	} else {
872		ec = make_acpi_ec();
873		if (!ec)
874			return -ENOMEM;
875	}
876	if (ec_parse_device(device->handle, 0, ec, NULL) !=
877		AE_CTRL_TERMINATE) {
878			kfree(ec);
879			return -EINVAL;
880	}
881
882	/* Find and register all query methods */
883	acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
884			    acpi_ec_register_query_methods, NULL, ec, NULL);
885
886	if (!first_ec)
887		first_ec = ec;
888	device->driver_data = ec;
889
890	ret = !!request_region(ec->data_addr, 1, "EC data");
891	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
892	ret = !!request_region(ec->command_addr, 1, "EC cmd");
893	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
894
895	pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
896			  ec->gpe, ec->command_addr, ec->data_addr);
897
898	ret = ec_install_handlers(ec);
899
900	/* EC is fully operational, allow queries */
901	clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
902
903	/* Clear stale _Q events if hardware might require that */
904	if (EC_FLAGS_CLEAR_ON_RESUME) {
905		mutex_lock(&ec->mutex);
906		acpi_ec_clear(ec);
907		mutex_unlock(&ec->mutex);
908	}
909	return ret;
910}
911
912static int acpi_ec_remove(struct acpi_device *device)
913{
914	struct acpi_ec *ec;
915	struct acpi_ec_query_handler *handler, *tmp;
916
917	if (!device)
918		return -EINVAL;
919
920	ec = acpi_driver_data(device);
921	ec_remove_handlers(ec);
922	mutex_lock(&ec->mutex);
923	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
924		list_del(&handler->node);
925		kfree(handler);
926	}
927	mutex_unlock(&ec->mutex);
928	release_region(ec->data_addr, 1);
929	release_region(ec->command_addr, 1);
930	device->driver_data = NULL;
931	if (ec == first_ec)
932		first_ec = NULL;
933	kfree(ec);
934	return 0;
935}
936
937static acpi_status
938ec_parse_io_ports(struct acpi_resource *resource, void *context)
939{
940	struct acpi_ec *ec = context;
941
942	if (resource->type != ACPI_RESOURCE_TYPE_IO)
943		return AE_OK;
944
945	/*
946	 * The first address region returned is the data port, and
947	 * the second address region returned is the status/command
948	 * port.
949	 */
950	if (ec->data_addr == 0)
951		ec->data_addr = resource->data.io.minimum;
952	else if (ec->command_addr == 0)
953		ec->command_addr = resource->data.io.minimum;
954	else
955		return AE_CTRL_TERMINATE;
956
957	return AE_OK;
958}
959
960int __init acpi_boot_ec_enable(void)
961{
962	if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
963		return 0;
964	if (!ec_install_handlers(boot_ec)) {
965		first_ec = boot_ec;
966		return 0;
967	}
968	return -EFAULT;
969}
970
971static const struct acpi_device_id ec_device_ids[] = {
972	{"PNP0C09", 0},
973	{"", 0},
974};
975
976/* Some BIOS do not survive early DSDT scan, skip it */
977static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
978{
979	EC_FLAGS_SKIP_DSDT_SCAN = 1;
980	return 0;
981}
982
983/* ASUStek often supplies us with broken ECDT, validate it */
984static int ec_validate_ecdt(const struct dmi_system_id *id)
985{
986	EC_FLAGS_VALIDATE_ECDT = 1;
987	return 0;
988}
989
990/* MSI EC needs special treatment, enable it */
991static int ec_flag_msi(const struct dmi_system_id *id)
992{
993	pr_debug("Detected MSI hardware, enabling workarounds.\n");
994	EC_FLAGS_MSI = 1;
995	EC_FLAGS_VALIDATE_ECDT = 1;
996	return 0;
997}
998
999/*
1000 * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1001 * the GPE storm threshold back to 20
1002 */
1003static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1004{
1005	pr_debug("Setting the EC GPE storm threshold to 20\n");
1006	ec_storm_threshold  = 20;
1007	return 0;
1008}
1009
1010/*
1011 * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1012 * which case, we complete the QR_EC without issuing it to the firmware.
1013 * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1014 */
1015static int ec_flag_query_handshake(const struct dmi_system_id *id)
1016{
1017	pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1018	EC_FLAGS_QUERY_HANDSHAKE = 1;
1019	return 0;
1020}
1021
1022/*
1023 * On some hardware it is necessary to clear events accumulated by the EC during
1024 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1025 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1026 *
1027 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1028 *
1029 * Ideally, the EC should also be instructed NOT to accumulate events during
1030 * sleep (which Windows seems to do somehow), but the interface to control this
1031 * behaviour is not known at this time.
1032 *
1033 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1034 * however it is very likely that other Samsung models are affected.
1035 *
1036 * On systems which don't accumulate _Q events during sleep, this extra check
1037 * should be harmless.
1038 */
1039static int ec_clear_on_resume(const struct dmi_system_id *id)
1040{
1041	pr_debug("Detected system needing EC poll on resume.\n");
1042	EC_FLAGS_CLEAR_ON_RESUME = 1;
1043	return 0;
1044}
1045
1046static struct dmi_system_id ec_dmi_table[] __initdata = {
1047	{
1048	ec_skip_dsdt_scan, "Compal JFL92", {
1049	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1050	DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1051	{
1052	ec_flag_msi, "MSI hardware", {
1053	DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1054	{
1055	ec_flag_msi, "MSI hardware", {
1056	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1057	{
1058	ec_flag_msi, "MSI hardware", {
1059	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1060	{
1061	ec_flag_msi, "MSI hardware", {
1062	DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1063	{
1064	ec_flag_msi, "Quanta hardware", {
1065	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1066	DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1067	{
1068	ec_flag_msi, "Quanta hardware", {
1069	DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1070	DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1071	{
1072	ec_flag_msi, "Clevo W350etq", {
1073	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1074	DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1075	{
1076	ec_validate_ecdt, "ASUS hardware", {
1077	DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1078	{
1079	ec_validate_ecdt, "ASUS hardware", {
1080	DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1081	{
1082	ec_enlarge_storm_threshold, "CLEVO hardware", {
1083	DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1084	DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1085	{
1086	ec_skip_dsdt_scan, "HP Folio 13", {
1087	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1088	DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1089	{
1090	ec_validate_ecdt, "ASUS hardware", {
1091	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1092	DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1093	{
1094	ec_clear_on_resume, "Samsung hardware", {
1095	DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1096	{
1097	ec_flag_query_handshake, "Acer hardware", {
1098	DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1099	{},
1100};
1101
1102int __init acpi_ec_ecdt_probe(void)
1103{
1104	acpi_status status;
1105	struct acpi_ec *saved_ec = NULL;
1106	struct acpi_table_ecdt *ecdt_ptr;
1107
1108	boot_ec = make_acpi_ec();
1109	if (!boot_ec)
1110		return -ENOMEM;
1111	/*
1112	 * Generate a boot ec context
1113	 */
1114	dmi_check_system(ec_dmi_table);
1115	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1116				(struct acpi_table_header **)&ecdt_ptr);
1117	if (ACPI_SUCCESS(status)) {
1118		pr_info("EC description table is found, configuring boot EC\n");
1119		boot_ec->command_addr = ecdt_ptr->control.address;
1120		boot_ec->data_addr = ecdt_ptr->data.address;
1121		boot_ec->gpe = ecdt_ptr->gpe;
1122		boot_ec->handle = ACPI_ROOT_OBJECT;
1123		acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1124				&boot_ec->handle);
1125		/* Don't trust ECDT, which comes from ASUSTek */
1126		if (!EC_FLAGS_VALIDATE_ECDT)
1127			goto install;
1128		saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1129		if (!saved_ec)
1130			return -ENOMEM;
1131	/* fall through */
1132	}
1133
1134	if (EC_FLAGS_SKIP_DSDT_SCAN) {
1135		kfree(saved_ec);
1136		return -ENODEV;
1137	}
1138
1139	/* This workaround is needed only on some broken machines,
1140	 * which require early EC, but fail to provide ECDT */
1141	pr_debug("Look up EC in DSDT\n");
1142	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1143					boot_ec, NULL);
1144	/* Check that acpi_get_devices actually find something */
1145	if (ACPI_FAILURE(status) || !boot_ec->handle)
1146		goto error;
1147	if (saved_ec) {
1148		/* try to find good ECDT from ASUSTek */
1149		if (saved_ec->command_addr != boot_ec->command_addr ||
1150		    saved_ec->data_addr != boot_ec->data_addr ||
1151		    saved_ec->gpe != boot_ec->gpe ||
1152		    saved_ec->handle != boot_ec->handle)
1153			pr_info("ASUSTek keeps feeding us with broken "
1154			"ECDT tables, which are very hard to workaround. "
1155			"Trying to use DSDT EC info instead. Please send "
1156			"output of acpidump to linux-acpi@vger.kernel.org\n");
1157		kfree(saved_ec);
1158		saved_ec = NULL;
1159	} else {
1160		/* We really need to limit this workaround, the only ASUS,
1161		* which needs it, has fake EC._INI method, so use it as flag.
1162		* Keep boot_ec struct as it will be needed soon.
1163		*/
1164		if (!dmi_name_in_vendors("ASUS") ||
1165		    !acpi_has_method(boot_ec->handle, "_INI"))
1166			return -ENODEV;
1167	}
1168install:
1169	if (!ec_install_handlers(boot_ec)) {
1170		first_ec = boot_ec;
1171		return 0;
1172	}
1173error:
1174	kfree(boot_ec);
1175	kfree(saved_ec);
1176	boot_ec = NULL;
1177	return -ENODEV;
1178}
1179
1180static struct acpi_driver acpi_ec_driver = {
1181	.name = "ec",
1182	.class = ACPI_EC_CLASS,
1183	.ids = ec_device_ids,
1184	.ops = {
1185		.add = acpi_ec_add,
1186		.remove = acpi_ec_remove,
1187		},
1188};
1189
1190int __init acpi_ec_init(void)
1191{
1192	int result = 0;
1193
1194	/* Now register the driver for the EC */
1195	result = acpi_bus_register_driver(&acpi_ec_driver);
1196	if (result < 0)
1197		return -ENODEV;
1198
1199	return result;
1200}
1201
1202/* EC driver currently not unloadable */
1203#if 0
1204static void __exit acpi_ec_exit(void)
1205{
1206
1207	acpi_bus_unregister_driver(&acpi_ec_driver);
1208}
1209#endif	/* 0 */
1210