• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  ec.c - ACPI Embedded Controller Driver (v3)
4  *
5  *  Copyright (C) 2001-2015 Intel Corporation
6  *    Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
7  *            2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
8  *            2006       Denis Sadykov <denis.m.sadykov@intel.com>
9  *            2004       Luming Yu <luming.yu@intel.com>
10  *            2001, 2002 Andy Grover <andrew.grover@intel.com>
11  *            2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
12  *  Copyright (C) 2008      Alexey Starikovskiy <astarikovskiy@suse.de>
13  */
14 
15 /* Uncomment next line to get verbose printout */
16 /* #define DEBUG */
17 #define pr_fmt(fmt) "ACPI: EC: " fmt
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/types.h>
23 #include <linux/delay.h>
24 #include <linux/interrupt.h>
25 #include <linux/list.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/suspend.h>
29 #include <linux/acpi.h>
30 #include <linux/dmi.h>
31 #include <asm/io.h>
32 
33 #include "internal.h"
34 
35 #define ACPI_EC_CLASS			"embedded_controller"
36 #define ACPI_EC_DEVICE_NAME		"Embedded Controller"
37 
38 /* EC status register */
39 #define ACPI_EC_FLAG_OBF	0x01	/* Output buffer full */
40 #define ACPI_EC_FLAG_IBF	0x02	/* Input buffer full */
41 #define ACPI_EC_FLAG_CMD	0x08	/* Input buffer contains a command */
42 #define ACPI_EC_FLAG_BURST	0x10	/* burst mode */
43 #define ACPI_EC_FLAG_SCI	0x20	/* EC-SCI occurred */
44 
45 /*
46  * The SCI_EVT clearing timing is not defined by the ACPI specification.
47  * This leads to lots of practical timing issues for the host EC driver.
48  * The following variations are defined (from the target EC firmware's
49  * perspective):
50  * STATUS: After indicating SCI_EVT edge triggered IRQ to the host, the
51  *         target can clear SCI_EVT at any time so long as the host can see
52  *         the indication by reading the status register (EC_SC). So the
53  *         host should re-check SCI_EVT after the first time the SCI_EVT
54  *         indication is seen, which is the same time the query request
55  *         (QR_EC) is written to the command register (EC_CMD). SCI_EVT set
56  *         at any later time could indicate another event. Normally such
57  *         kind of EC firmware has implemented an event queue and will
58  *         return 0x00 to indicate "no outstanding event".
59  * QUERY: After seeing the query request (QR_EC) written to the command
60  *        register (EC_CMD) by the host and having prepared the responding
61  *        event value in the data register (EC_DATA), the target can safely
62  *        clear SCI_EVT because the target can confirm that the current
63  *        event is being handled by the host. The host then should check
64  *        SCI_EVT right after reading the event response from the data
65  *        register (EC_DATA).
66  * EVENT: After seeing the event response read from the data register
67  *        (EC_DATA) by the host, the target can clear SCI_EVT. As the
68  *        target requires time to notice the change in the data register
69  *        (EC_DATA), the host may be required to wait additional guarding
70  *        time before checking the SCI_EVT again. Such guarding may not be
71  *        necessary if the host is notified via another IRQ.
72  */
73 #define ACPI_EC_EVT_TIMING_STATUS	0x00
74 #define ACPI_EC_EVT_TIMING_QUERY	0x01
75 #define ACPI_EC_EVT_TIMING_EVENT	0x02
76 
77 /* EC commands */
78 enum ec_command {
79 	ACPI_EC_COMMAND_READ = 0x80,
80 	ACPI_EC_COMMAND_WRITE = 0x81,
81 	ACPI_EC_BURST_ENABLE = 0x82,
82 	ACPI_EC_BURST_DISABLE = 0x83,
83 	ACPI_EC_COMMAND_QUERY = 0x84,
84 };
85 
86 #define ACPI_EC_DELAY		500	/* Wait 500ms max. during EC ops */
87 #define ACPI_EC_UDELAY_GLK	1000	/* Wait 1ms max. to get global lock */
88 #define ACPI_EC_UDELAY_POLL	550	/* Wait 1ms for EC transaction polling */
89 #define ACPI_EC_CLEAR_MAX	100	/* Maximum number of events to query
90 					 * when trying to clear the EC */
91 #define ACPI_EC_MAX_QUERIES	16	/* Maximum number of parallel queries */
92 
93 enum {
94 	EC_FLAGS_QUERY_ENABLED,		/* Query is enabled */
95 	EC_FLAGS_QUERY_PENDING,		/* Query is pending */
96 	EC_FLAGS_QUERY_GUARDING,	/* Guard for SCI_EVT check */
97 	EC_FLAGS_EVENT_HANDLER_INSTALLED,	/* Event handler installed */
98 	EC_FLAGS_EC_HANDLER_INSTALLED,	/* OpReg handler installed */
99 	EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
100 	EC_FLAGS_STARTED,		/* Driver is started */
101 	EC_FLAGS_STOPPED,		/* Driver is stopped */
102 	EC_FLAGS_EVENTS_MASKED,		/* Events masked */
103 };
104 
105 #define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */
106 #define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */
107 
108 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
109 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
110 module_param(ec_delay, uint, 0644);
111 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
112 
113 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
114 module_param(ec_max_queries, uint, 0644);
115 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
116 
117 static bool ec_busy_polling __read_mostly;
118 module_param(ec_busy_polling, bool, 0644);
119 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
120 
121 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
122 module_param(ec_polling_guard, uint, 0644);
123 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
124 
125 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
126 
127 /*
128  * If the number of false interrupts per one transaction exceeds
129  * this threshold, will think there is a GPE storm happened and
130  * will disable the GPE for normal transaction.
131  */
132 static unsigned int ec_storm_threshold  __read_mostly = 8;
133 module_param(ec_storm_threshold, uint, 0644);
134 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
135 
136 static bool ec_freeze_events __read_mostly = false;
137 module_param(ec_freeze_events, bool, 0644);
138 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
139 
140 static bool ec_no_wakeup __read_mostly;
141 module_param(ec_no_wakeup, bool, 0644);
142 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
143 
144 struct acpi_ec_query_handler {
145 	struct list_head node;
146 	acpi_ec_query_func func;
147 	acpi_handle handle;
148 	void *data;
149 	u8 query_bit;
150 	struct kref kref;
151 };
152 
153 struct transaction {
154 	const u8 *wdata;
155 	u8 *rdata;
156 	unsigned short irq_count;
157 	u8 command;
158 	u8 wi;
159 	u8 ri;
160 	u8 wlen;
161 	u8 rlen;
162 	u8 flags;
163 };
164 
165 struct acpi_ec_query {
166 	struct transaction transaction;
167 	struct work_struct work;
168 	struct acpi_ec_query_handler *handler;
169 	struct acpi_ec *ec;
170 };
171 
172 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
173 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
174 static void acpi_ec_event_handler(struct work_struct *work);
175 static void acpi_ec_event_processor(struct work_struct *work);
176 
177 struct acpi_ec *first_ec;
178 EXPORT_SYMBOL(first_ec);
179 
180 static struct acpi_ec *boot_ec;
181 static bool boot_ec_is_ecdt = false;
182 static struct workqueue_struct *ec_wq;
183 static struct workqueue_struct *ec_query_wq;
184 
185 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
186 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
187 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
188 
189 /* --------------------------------------------------------------------------
190  *                           Logging/Debugging
191  * -------------------------------------------------------------------------- */
192 
193 /*
194  * Splitters used by the developers to track the boundary of the EC
195  * handling processes.
196  */
197 #ifdef DEBUG
198 #define EC_DBG_SEP	" "
199 #define EC_DBG_DRV	"+++++"
200 #define EC_DBG_STM	"====="
201 #define EC_DBG_REQ	"*****"
202 #define EC_DBG_EVT	"#####"
203 #else
204 #define EC_DBG_SEP	""
205 #define EC_DBG_DRV
206 #define EC_DBG_STM
207 #define EC_DBG_REQ
208 #define EC_DBG_EVT
209 #endif
210 
211 #define ec_log_raw(fmt, ...) \
212 	pr_info(fmt "\n", ##__VA_ARGS__)
213 #define ec_dbg_raw(fmt, ...) \
214 	pr_debug(fmt "\n", ##__VA_ARGS__)
215 #define ec_log(filter, fmt, ...) \
216 	ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217 #define ec_dbg(filter, fmt, ...) \
218 	ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
219 
220 #define ec_log_drv(fmt, ...) \
221 	ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222 #define ec_dbg_drv(fmt, ...) \
223 	ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
224 #define ec_dbg_stm(fmt, ...) \
225 	ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
226 #define ec_dbg_req(fmt, ...) \
227 	ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
228 #define ec_dbg_evt(fmt, ...) \
229 	ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
230 #define ec_dbg_ref(ec, fmt, ...) \
231 	ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
232 
233 /* --------------------------------------------------------------------------
234  *                           Device Flags
235  * -------------------------------------------------------------------------- */
236 
acpi_ec_started(struct acpi_ec * ec)237 static bool acpi_ec_started(struct acpi_ec *ec)
238 {
239 	return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
240 	       !test_bit(EC_FLAGS_STOPPED, &ec->flags);
241 }
242 
acpi_ec_event_enabled(struct acpi_ec * ec)243 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
244 {
245 	/*
246 	 * There is an OSPM early stage logic. During the early stages
247 	 * (boot/resume), OSPMs shouldn't enable the event handling, only
248 	 * the EC transactions are allowed to be performed.
249 	 */
250 	if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
251 		return false;
252 	/*
253 	 * However, disabling the event handling is experimental for late
254 	 * stage (suspend), and is controlled by the boot parameter of
255 	 * "ec_freeze_events":
256 	 * 1. true:  The EC event handling is disabled before entering
257 	 *           the noirq stage.
258 	 * 2. false: The EC event handling is automatically disabled as
259 	 *           soon as the EC driver is stopped.
260 	 */
261 	if (ec_freeze_events)
262 		return acpi_ec_started(ec);
263 	else
264 		return test_bit(EC_FLAGS_STARTED, &ec->flags);
265 }
266 
acpi_ec_flushed(struct acpi_ec * ec)267 static bool acpi_ec_flushed(struct acpi_ec *ec)
268 {
269 	return ec->reference_count == 1;
270 }
271 
272 /* --------------------------------------------------------------------------
273  *                           EC Registers
274  * -------------------------------------------------------------------------- */
275 
acpi_ec_read_status(struct acpi_ec * ec)276 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
277 {
278 	u8 x = inb(ec->command_addr);
279 
280 	ec_dbg_raw("EC_SC(R) = 0x%2.2x "
281 		   "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
282 		   x,
283 		   !!(x & ACPI_EC_FLAG_SCI),
284 		   !!(x & ACPI_EC_FLAG_BURST),
285 		   !!(x & ACPI_EC_FLAG_CMD),
286 		   !!(x & ACPI_EC_FLAG_IBF),
287 		   !!(x & ACPI_EC_FLAG_OBF));
288 	return x;
289 }
290 
acpi_ec_read_data(struct acpi_ec * ec)291 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
292 {
293 	u8 x = inb(ec->data_addr);
294 
295 	ec->timestamp = jiffies;
296 	ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
297 	return x;
298 }
299 
acpi_ec_write_cmd(struct acpi_ec * ec,u8 command)300 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
301 {
302 	ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
303 	outb(command, ec->command_addr);
304 	ec->timestamp = jiffies;
305 }
306 
acpi_ec_write_data(struct acpi_ec * ec,u8 data)307 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
308 {
309 	ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
310 	outb(data, ec->data_addr);
311 	ec->timestamp = jiffies;
312 }
313 
314 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
acpi_ec_cmd_string(u8 cmd)315 static const char *acpi_ec_cmd_string(u8 cmd)
316 {
317 	switch (cmd) {
318 	case 0x80:
319 		return "RD_EC";
320 	case 0x81:
321 		return "WR_EC";
322 	case 0x82:
323 		return "BE_EC";
324 	case 0x83:
325 		return "BD_EC";
326 	case 0x84:
327 		return "QR_EC";
328 	}
329 	return "UNKNOWN";
330 }
331 #else
332 #define acpi_ec_cmd_string(cmd)		"UNDEF"
333 #endif
334 
335 /* --------------------------------------------------------------------------
336  *                           GPE Registers
337  * -------------------------------------------------------------------------- */
338 
acpi_ec_gpe_status_set(struct acpi_ec * ec)339 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
340 {
341 	acpi_event_status gpe_status = 0;
342 
343 	(void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
344 	return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
345 }
346 
acpi_ec_enable_gpe(struct acpi_ec * ec,bool open)347 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
348 {
349 	if (open)
350 		acpi_enable_gpe(NULL, ec->gpe);
351 	else {
352 		BUG_ON(ec->reference_count < 1);
353 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
354 	}
355 	if (acpi_ec_gpe_status_set(ec)) {
356 		/*
357 		 * On some platforms, EN=1 writes cannot trigger GPE. So
358 		 * software need to manually trigger a pseudo GPE event on
359 		 * EN=1 writes.
360 		 */
361 		ec_dbg_raw("Polling quirk");
362 		advance_transaction(ec, false);
363 	}
364 }
365 
acpi_ec_disable_gpe(struct acpi_ec * ec,bool close)366 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
367 {
368 	if (close)
369 		acpi_disable_gpe(NULL, ec->gpe);
370 	else {
371 		BUG_ON(ec->reference_count < 1);
372 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
373 	}
374 }
375 
376 /* --------------------------------------------------------------------------
377  *                           Transaction Management
378  * -------------------------------------------------------------------------- */
379 
acpi_ec_submit_request(struct acpi_ec * ec)380 static void acpi_ec_submit_request(struct acpi_ec *ec)
381 {
382 	ec->reference_count++;
383 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
384 	    ec->gpe >= 0 && ec->reference_count == 1)
385 		acpi_ec_enable_gpe(ec, true);
386 }
387 
acpi_ec_complete_request(struct acpi_ec * ec)388 static void acpi_ec_complete_request(struct acpi_ec *ec)
389 {
390 	bool flushed = false;
391 
392 	ec->reference_count--;
393 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
394 	    ec->gpe >= 0 && ec->reference_count == 0)
395 		acpi_ec_disable_gpe(ec, true);
396 	flushed = acpi_ec_flushed(ec);
397 	if (flushed)
398 		wake_up(&ec->wait);
399 }
400 
acpi_ec_mask_events(struct acpi_ec * ec)401 static void acpi_ec_mask_events(struct acpi_ec *ec)
402 {
403 	if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
404 		if (ec->gpe >= 0)
405 			acpi_ec_disable_gpe(ec, false);
406 		else
407 			disable_irq_nosync(ec->irq);
408 
409 		ec_dbg_drv("Polling enabled");
410 		set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
411 	}
412 }
413 
acpi_ec_unmask_events(struct acpi_ec * ec)414 static void acpi_ec_unmask_events(struct acpi_ec *ec)
415 {
416 	if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
417 		clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
418 		if (ec->gpe >= 0)
419 			acpi_ec_enable_gpe(ec, false);
420 		else
421 			enable_irq(ec->irq);
422 
423 		ec_dbg_drv("Polling disabled");
424 	}
425 }
426 
427 /*
428  * acpi_ec_submit_flushable_request() - Increase the reference count unless
429  *                                      the flush operation is not in
430  *                                      progress
431  * @ec: the EC device
432  *
433  * This function must be used before taking a new action that should hold
434  * the reference count.  If this function returns false, then the action
435  * must be discarded or it will prevent the flush operation from being
436  * completed.
437  */
acpi_ec_submit_flushable_request(struct acpi_ec * ec)438 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
439 {
440 	if (!acpi_ec_started(ec))
441 		return false;
442 	acpi_ec_submit_request(ec);
443 	return true;
444 }
445 
acpi_ec_submit_query(struct acpi_ec * ec)446 static void acpi_ec_submit_query(struct acpi_ec *ec)
447 {
448 	acpi_ec_mask_events(ec);
449 	if (!acpi_ec_event_enabled(ec))
450 		return;
451 	if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
452 		ec_dbg_evt("Command(%s) submitted/blocked",
453 			   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
454 		ec->nr_pending_queries++;
455 		ec->events_in_progress++;
456 		queue_work(ec_wq, &ec->work);
457 	}
458 }
459 
acpi_ec_complete_query(struct acpi_ec * ec)460 static void acpi_ec_complete_query(struct acpi_ec *ec)
461 {
462 	if (test_and_clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags))
463 		ec_dbg_evt("Command(%s) unblocked",
464 			   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
465 	acpi_ec_unmask_events(ec);
466 }
467 
__acpi_ec_enable_event(struct acpi_ec * ec)468 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
469 {
470 	if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
471 		ec_log_drv("event unblocked");
472 	/*
473 	 * Unconditionally invoke this once after enabling the event
474 	 * handling mechanism to detect the pending events.
475 	 */
476 	advance_transaction(ec, false);
477 }
478 
__acpi_ec_disable_event(struct acpi_ec * ec)479 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
480 {
481 	if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
482 		ec_log_drv("event blocked");
483 }
484 
485 /*
486  * Process _Q events that might have accumulated in the EC.
487  * Run with locked ec mutex.
488  */
acpi_ec_clear(struct acpi_ec * ec)489 static void acpi_ec_clear(struct acpi_ec *ec)
490 {
491 	int i, status;
492 	u8 value = 0;
493 
494 	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
495 		status = acpi_ec_query(ec, &value);
496 		if (status || !value)
497 			break;
498 	}
499 	if (unlikely(i == ACPI_EC_CLEAR_MAX))
500 		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
501 	else
502 		pr_info("%d stale EC events cleared\n", i);
503 }
504 
acpi_ec_enable_event(struct acpi_ec * ec)505 static void acpi_ec_enable_event(struct acpi_ec *ec)
506 {
507 	unsigned long flags;
508 
509 	spin_lock_irqsave(&ec->lock, flags);
510 	if (acpi_ec_started(ec))
511 		__acpi_ec_enable_event(ec);
512 	spin_unlock_irqrestore(&ec->lock, flags);
513 
514 	/* Drain additional events if hardware requires that */
515 	if (EC_FLAGS_CLEAR_ON_RESUME)
516 		acpi_ec_clear(ec);
517 }
518 
519 #ifdef CONFIG_PM_SLEEP
__acpi_ec_flush_work(void)520 static void __acpi_ec_flush_work(void)
521 {
522 	flush_workqueue(ec_wq); /* flush ec->work */
523 	flush_workqueue(ec_query_wq); /* flush queries */
524 }
525 
acpi_ec_disable_event(struct acpi_ec * ec)526 static void acpi_ec_disable_event(struct acpi_ec *ec)
527 {
528 	unsigned long flags;
529 
530 	spin_lock_irqsave(&ec->lock, flags);
531 	__acpi_ec_disable_event(ec);
532 	spin_unlock_irqrestore(&ec->lock, flags);
533 
534 	/*
535 	 * When ec_freeze_events is true, we need to flush events in
536 	 * the proper position before entering the noirq stage.
537 	 */
538 	__acpi_ec_flush_work();
539 }
540 
acpi_ec_flush_work(void)541 void acpi_ec_flush_work(void)
542 {
543 	/* Without ec_wq there is nothing to flush. */
544 	if (!ec_wq)
545 		return;
546 
547 	__acpi_ec_flush_work();
548 }
549 #endif /* CONFIG_PM_SLEEP */
550 
acpi_ec_guard_event(struct acpi_ec * ec)551 static bool acpi_ec_guard_event(struct acpi_ec *ec)
552 {
553 	bool guarded = true;
554 	unsigned long flags;
555 
556 	spin_lock_irqsave(&ec->lock, flags);
557 	/*
558 	 * If firmware SCI_EVT clearing timing is "event", we actually
559 	 * don't know when the SCI_EVT will be cleared by firmware after
560 	 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
561 	 * acceptable period.
562 	 *
563 	 * The guarding period begins when EC_FLAGS_QUERY_PENDING is
564 	 * flagged, which means SCI_EVT check has just been performed.
565 	 * But if the current transaction is ACPI_EC_COMMAND_QUERY, the
566 	 * guarding should have already been performed (via
567 	 * EC_FLAGS_QUERY_GUARDING) and should not be applied so that the
568 	 * ACPI_EC_COMMAND_QUERY transaction can be transitioned into
569 	 * ACPI_EC_COMMAND_POLL state immediately.
570 	 */
571 	if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
572 	    ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY ||
573 	    !test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags) ||
574 	    (ec->curr && ec->curr->command == ACPI_EC_COMMAND_QUERY))
575 		guarded = false;
576 	spin_unlock_irqrestore(&ec->lock, flags);
577 	return guarded;
578 }
579 
ec_transaction_polled(struct acpi_ec * ec)580 static int ec_transaction_polled(struct acpi_ec *ec)
581 {
582 	unsigned long flags;
583 	int ret = 0;
584 
585 	spin_lock_irqsave(&ec->lock, flags);
586 	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
587 		ret = 1;
588 	spin_unlock_irqrestore(&ec->lock, flags);
589 	return ret;
590 }
591 
ec_transaction_completed(struct acpi_ec * ec)592 static int ec_transaction_completed(struct acpi_ec *ec)
593 {
594 	unsigned long flags;
595 	int ret = 0;
596 
597 	spin_lock_irqsave(&ec->lock, flags);
598 	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
599 		ret = 1;
600 	spin_unlock_irqrestore(&ec->lock, flags);
601 	return ret;
602 }
603 
ec_transaction_transition(struct acpi_ec * ec,unsigned long flag)604 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
605 {
606 	ec->curr->flags |= flag;
607 	if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
608 		if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS &&
609 		    flag == ACPI_EC_COMMAND_POLL)
610 			acpi_ec_complete_query(ec);
611 		if (ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY &&
612 		    flag == ACPI_EC_COMMAND_COMPLETE)
613 			acpi_ec_complete_query(ec);
614 		if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
615 		    flag == ACPI_EC_COMMAND_COMPLETE)
616 			set_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
617 	}
618 }
619 
acpi_ec_spurious_interrupt(struct acpi_ec * ec,struct transaction * t)620 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
621 {
622 	if (t->irq_count < ec_storm_threshold)
623 		++t->irq_count;
624 
625 	/* Trigger if the threshold is 0 too. */
626 	if (t->irq_count == ec_storm_threshold)
627 		acpi_ec_mask_events(ec);
628 }
629 
advance_transaction(struct acpi_ec * ec,bool interrupt)630 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
631 {
632 	struct transaction *t = ec->curr;
633 	bool wakeup = false;
634 	u8 status;
635 
636 	ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
637 
638 	/*
639 	 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
640 	 * changes to always trigger a GPE interrupt.
641 	 *
642 	 * GPE STS is a W1C register, which means:
643 	 *
644 	 * 1. Software can clear it without worrying about clearing the other
645 	 *    GPEs' STS bits when the hardware sets them in parallel.
646 	 *
647 	 * 2. As long as software can ensure only clearing it when it is set,
648 	 *    hardware won't set it in parallel.
649 	 */
650 	if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
651 		acpi_clear_gpe(NULL, ec->gpe);
652 
653 	status = acpi_ec_read_status(ec);
654 
655 	/*
656 	 * Another IRQ or a guarded polling mode advancement is detected,
657 	 * the next QR_EC submission is then allowed.
658 	 */
659 	if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
660 		if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
661 		    (!ec->nr_pending_queries ||
662 		     test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) {
663 			clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags);
664 			acpi_ec_complete_query(ec);
665 		}
666 		if (!t)
667 			goto out;
668 	}
669 
670 	if (t->flags & ACPI_EC_COMMAND_POLL) {
671 		if (t->wlen > t->wi) {
672 			if (!(status & ACPI_EC_FLAG_IBF))
673 				acpi_ec_write_data(ec, t->wdata[t->wi++]);
674 			else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
675 				acpi_ec_spurious_interrupt(ec, t);
676 		} else if (t->rlen > t->ri) {
677 			if (status & ACPI_EC_FLAG_OBF) {
678 				t->rdata[t->ri++] = acpi_ec_read_data(ec);
679 				if (t->rlen == t->ri) {
680 					ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
681 					wakeup = true;
682 					if (t->command == ACPI_EC_COMMAND_QUERY)
683 						ec_dbg_evt("Command(%s) completed by hardware",
684 							   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
685 				}
686 			} else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
687 				acpi_ec_spurious_interrupt(ec, t);
688 			}
689 		} else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
690 			ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 			wakeup = true;
692 		}
693 	} else if (!(status & ACPI_EC_FLAG_IBF)) {
694 		acpi_ec_write_cmd(ec, t->command);
695 		ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
696 	}
697 
698 out:
699 	if (status & ACPI_EC_FLAG_SCI)
700 		acpi_ec_submit_query(ec);
701 
702 	if (wakeup && interrupt)
703 		wake_up(&ec->wait);
704 }
705 
start_transaction(struct acpi_ec * ec)706 static void start_transaction(struct acpi_ec *ec)
707 {
708 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
709 	ec->curr->flags = 0;
710 }
711 
ec_guard(struct acpi_ec * ec)712 static int ec_guard(struct acpi_ec *ec)
713 {
714 	unsigned long guard = usecs_to_jiffies(ec->polling_guard);
715 	unsigned long timeout = ec->timestamp + guard;
716 
717 	/* Ensure guarding period before polling EC status */
718 	do {
719 		if (ec->busy_polling) {
720 			/* Perform busy polling */
721 			if (ec_transaction_completed(ec))
722 				return 0;
723 			udelay(jiffies_to_usecs(guard));
724 		} else {
725 			/*
726 			 * Perform wait polling
727 			 * 1. Wait the transaction to be completed by the
728 			 *    GPE handler after the transaction enters
729 			 *    ACPI_EC_COMMAND_POLL state.
730 			 * 2. A special guarding logic is also required
731 			 *    for event clearing mode "event" before the
732 			 *    transaction enters ACPI_EC_COMMAND_POLL
733 			 *    state.
734 			 */
735 			if (!ec_transaction_polled(ec) &&
736 			    !acpi_ec_guard_event(ec))
737 				break;
738 			if (wait_event_timeout(ec->wait,
739 					       ec_transaction_completed(ec),
740 					       guard))
741 				return 0;
742 		}
743 	} while (time_before(jiffies, timeout));
744 	return -ETIME;
745 }
746 
ec_poll(struct acpi_ec * ec)747 static int ec_poll(struct acpi_ec *ec)
748 {
749 	unsigned long flags;
750 	int repeat = 5; /* number of command restarts */
751 
752 	while (repeat--) {
753 		unsigned long delay = jiffies +
754 			msecs_to_jiffies(ec_delay);
755 		do {
756 			if (!ec_guard(ec))
757 				return 0;
758 			spin_lock_irqsave(&ec->lock, flags);
759 			advance_transaction(ec, false);
760 			spin_unlock_irqrestore(&ec->lock, flags);
761 		} while (time_before(jiffies, delay));
762 		pr_debug("controller reset, restart transaction\n");
763 		spin_lock_irqsave(&ec->lock, flags);
764 		start_transaction(ec);
765 		spin_unlock_irqrestore(&ec->lock, flags);
766 	}
767 	return -ETIME;
768 }
769 
acpi_ec_transaction_unlocked(struct acpi_ec * ec,struct transaction * t)770 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
771 					struct transaction *t)
772 {
773 	unsigned long tmp;
774 	int ret = 0;
775 
776 	/* start transaction */
777 	spin_lock_irqsave(&ec->lock, tmp);
778 	/* Enable GPE for command processing (IBF=0/OBF=1) */
779 	if (!acpi_ec_submit_flushable_request(ec)) {
780 		ret = -EINVAL;
781 		goto unlock;
782 	}
783 	ec_dbg_ref(ec, "Increase command");
784 	/* following two actions should be kept atomic */
785 	ec->curr = t;
786 	ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
787 	start_transaction(ec);
788 	spin_unlock_irqrestore(&ec->lock, tmp);
789 
790 	ret = ec_poll(ec);
791 
792 	spin_lock_irqsave(&ec->lock, tmp);
793 	if (t->irq_count == ec_storm_threshold)
794 		acpi_ec_unmask_events(ec);
795 	ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
796 	ec->curr = NULL;
797 	/* Disable GPE for command processing (IBF=0/OBF=1) */
798 	acpi_ec_complete_request(ec);
799 	ec_dbg_ref(ec, "Decrease command");
800 unlock:
801 	spin_unlock_irqrestore(&ec->lock, tmp);
802 	return ret;
803 }
804 
acpi_ec_transaction(struct acpi_ec * ec,struct transaction * t)805 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
806 {
807 	int status;
808 	u32 glk;
809 
810 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
811 		return -EINVAL;
812 	if (t->rdata)
813 		memset(t->rdata, 0, t->rlen);
814 
815 	mutex_lock(&ec->mutex);
816 	if (ec->global_lock) {
817 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
818 		if (ACPI_FAILURE(status)) {
819 			status = -ENODEV;
820 			goto unlock;
821 		}
822 	}
823 
824 	status = acpi_ec_transaction_unlocked(ec, t);
825 
826 	if (ec->global_lock)
827 		acpi_release_global_lock(glk);
828 unlock:
829 	mutex_unlock(&ec->mutex);
830 	return status;
831 }
832 
acpi_ec_burst_enable(struct acpi_ec * ec)833 static int acpi_ec_burst_enable(struct acpi_ec *ec)
834 {
835 	u8 d;
836 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
837 				.wdata = NULL, .rdata = &d,
838 				.wlen = 0, .rlen = 1};
839 
840 	return acpi_ec_transaction(ec, &t);
841 }
842 
acpi_ec_burst_disable(struct acpi_ec * ec)843 static int acpi_ec_burst_disable(struct acpi_ec *ec)
844 {
845 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
846 				.wdata = NULL, .rdata = NULL,
847 				.wlen = 0, .rlen = 0};
848 
849 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
850 				acpi_ec_transaction(ec, &t) : 0;
851 }
852 
acpi_ec_read(struct acpi_ec * ec,u8 address,u8 * data)853 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
854 {
855 	int result;
856 	u8 d;
857 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
858 				.wdata = &address, .rdata = &d,
859 				.wlen = 1, .rlen = 1};
860 
861 	result = acpi_ec_transaction(ec, &t);
862 	*data = d;
863 	return result;
864 }
865 
acpi_ec_write(struct acpi_ec * ec,u8 address,u8 data)866 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
867 {
868 	u8 wdata[2] = { address, data };
869 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
870 				.wdata = wdata, .rdata = NULL,
871 				.wlen = 2, .rlen = 0};
872 
873 	return acpi_ec_transaction(ec, &t);
874 }
875 
ec_read(u8 addr,u8 * val)876 int ec_read(u8 addr, u8 *val)
877 {
878 	int err;
879 	u8 temp_data;
880 
881 	if (!first_ec)
882 		return -ENODEV;
883 
884 	err = acpi_ec_read(first_ec, addr, &temp_data);
885 
886 	if (!err) {
887 		*val = temp_data;
888 		return 0;
889 	}
890 	return err;
891 }
892 EXPORT_SYMBOL(ec_read);
893 
ec_write(u8 addr,u8 val)894 int ec_write(u8 addr, u8 val)
895 {
896 	int err;
897 
898 	if (!first_ec)
899 		return -ENODEV;
900 
901 	err = acpi_ec_write(first_ec, addr, val);
902 
903 	return err;
904 }
905 EXPORT_SYMBOL(ec_write);
906 
ec_transaction(u8 command,const u8 * wdata,unsigned wdata_len,u8 * rdata,unsigned rdata_len)907 int ec_transaction(u8 command,
908 		   const u8 *wdata, unsigned wdata_len,
909 		   u8 *rdata, unsigned rdata_len)
910 {
911 	struct transaction t = {.command = command,
912 				.wdata = wdata, .rdata = rdata,
913 				.wlen = wdata_len, .rlen = rdata_len};
914 
915 	if (!first_ec)
916 		return -ENODEV;
917 
918 	return acpi_ec_transaction(first_ec, &t);
919 }
920 EXPORT_SYMBOL(ec_transaction);
921 
922 /* Get the handle to the EC device */
ec_get_handle(void)923 acpi_handle ec_get_handle(void)
924 {
925 	if (!first_ec)
926 		return NULL;
927 	return first_ec->handle;
928 }
929 EXPORT_SYMBOL(ec_get_handle);
930 
acpi_ec_start(struct acpi_ec * ec,bool resuming)931 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
932 {
933 	unsigned long flags;
934 
935 	spin_lock_irqsave(&ec->lock, flags);
936 	if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
937 		ec_dbg_drv("Starting EC");
938 		/* Enable GPE for event processing (SCI_EVT=1) */
939 		if (!resuming) {
940 			acpi_ec_submit_request(ec);
941 			ec_dbg_ref(ec, "Increase driver");
942 		}
943 		ec_log_drv("EC started");
944 	}
945 	spin_unlock_irqrestore(&ec->lock, flags);
946 }
947 
acpi_ec_stopped(struct acpi_ec * ec)948 static bool acpi_ec_stopped(struct acpi_ec *ec)
949 {
950 	unsigned long flags;
951 	bool flushed;
952 
953 	spin_lock_irqsave(&ec->lock, flags);
954 	flushed = acpi_ec_flushed(ec);
955 	spin_unlock_irqrestore(&ec->lock, flags);
956 	return flushed;
957 }
958 
acpi_ec_stop(struct acpi_ec * ec,bool suspending)959 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
960 {
961 	unsigned long flags;
962 
963 	spin_lock_irqsave(&ec->lock, flags);
964 	if (acpi_ec_started(ec)) {
965 		ec_dbg_drv("Stopping EC");
966 		set_bit(EC_FLAGS_STOPPED, &ec->flags);
967 		spin_unlock_irqrestore(&ec->lock, flags);
968 		wait_event(ec->wait, acpi_ec_stopped(ec));
969 		spin_lock_irqsave(&ec->lock, flags);
970 		/* Disable GPE for event processing (SCI_EVT=1) */
971 		if (!suspending) {
972 			acpi_ec_complete_request(ec);
973 			ec_dbg_ref(ec, "Decrease driver");
974 		} else if (!ec_freeze_events)
975 			__acpi_ec_disable_event(ec);
976 		clear_bit(EC_FLAGS_STARTED, &ec->flags);
977 		clear_bit(EC_FLAGS_STOPPED, &ec->flags);
978 		ec_log_drv("EC stopped");
979 	}
980 	spin_unlock_irqrestore(&ec->lock, flags);
981 }
982 
acpi_ec_enter_noirq(struct acpi_ec * ec)983 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
984 {
985 	unsigned long flags;
986 
987 	spin_lock_irqsave(&ec->lock, flags);
988 	ec->busy_polling = true;
989 	ec->polling_guard = 0;
990 	ec_log_drv("interrupt blocked");
991 	spin_unlock_irqrestore(&ec->lock, flags);
992 }
993 
acpi_ec_leave_noirq(struct acpi_ec * ec)994 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
995 {
996 	unsigned long flags;
997 
998 	spin_lock_irqsave(&ec->lock, flags);
999 	ec->busy_polling = ec_busy_polling;
1000 	ec->polling_guard = ec_polling_guard;
1001 	ec_log_drv("interrupt unblocked");
1002 	spin_unlock_irqrestore(&ec->lock, flags);
1003 }
1004 
acpi_ec_block_transactions(void)1005 void acpi_ec_block_transactions(void)
1006 {
1007 	struct acpi_ec *ec = first_ec;
1008 
1009 	if (!ec)
1010 		return;
1011 
1012 	mutex_lock(&ec->mutex);
1013 	/* Prevent transactions from being carried out */
1014 	acpi_ec_stop(ec, true);
1015 	mutex_unlock(&ec->mutex);
1016 }
1017 
acpi_ec_unblock_transactions(void)1018 void acpi_ec_unblock_transactions(void)
1019 {
1020 	/*
1021 	 * Allow transactions to happen again (this function is called from
1022 	 * atomic context during wakeup, so we don't need to acquire the mutex).
1023 	 */
1024 	if (first_ec)
1025 		acpi_ec_start(first_ec, true);
1026 }
1027 
1028 /* --------------------------------------------------------------------------
1029                                 Event Management
1030    -------------------------------------------------------------------------- */
1031 static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec * ec,u8 value)1032 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1033 {
1034 	struct acpi_ec_query_handler *handler;
1035 
1036 	mutex_lock(&ec->mutex);
1037 	list_for_each_entry(handler, &ec->list, node) {
1038 		if (value == handler->query_bit) {
1039 			kref_get(&handler->kref);
1040 			mutex_unlock(&ec->mutex);
1041 			return handler;
1042 		}
1043 	}
1044 	mutex_unlock(&ec->mutex);
1045 	return NULL;
1046 }
1047 
acpi_ec_query_handler_release(struct kref * kref)1048 static void acpi_ec_query_handler_release(struct kref *kref)
1049 {
1050 	struct acpi_ec_query_handler *handler =
1051 		container_of(kref, struct acpi_ec_query_handler, kref);
1052 
1053 	kfree(handler);
1054 }
1055 
acpi_ec_put_query_handler(struct acpi_ec_query_handler * handler)1056 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1057 {
1058 	kref_put(&handler->kref, acpi_ec_query_handler_release);
1059 }
1060 
acpi_ec_add_query_handler(struct acpi_ec * ec,u8 query_bit,acpi_handle handle,acpi_ec_query_func func,void * data)1061 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1062 			      acpi_handle handle, acpi_ec_query_func func,
1063 			      void *data)
1064 {
1065 	struct acpi_ec_query_handler *handler =
1066 	    kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
1067 
1068 	if (!handler)
1069 		return -ENOMEM;
1070 
1071 	handler->query_bit = query_bit;
1072 	handler->handle = handle;
1073 	handler->func = func;
1074 	handler->data = data;
1075 	mutex_lock(&ec->mutex);
1076 	kref_init(&handler->kref);
1077 	list_add(&handler->node, &ec->list);
1078 	mutex_unlock(&ec->mutex);
1079 	return 0;
1080 }
1081 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1082 
acpi_ec_remove_query_handlers(struct acpi_ec * ec,bool remove_all,u8 query_bit)1083 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1084 					  bool remove_all, u8 query_bit)
1085 {
1086 	struct acpi_ec_query_handler *handler, *tmp;
1087 	LIST_HEAD(free_list);
1088 
1089 	mutex_lock(&ec->mutex);
1090 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1091 		if (remove_all || query_bit == handler->query_bit) {
1092 			list_del_init(&handler->node);
1093 			list_add(&handler->node, &free_list);
1094 		}
1095 	}
1096 	mutex_unlock(&ec->mutex);
1097 	list_for_each_entry_safe(handler, tmp, &free_list, node)
1098 		acpi_ec_put_query_handler(handler);
1099 }
1100 
acpi_ec_remove_query_handler(struct acpi_ec * ec,u8 query_bit)1101 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1102 {
1103 	acpi_ec_remove_query_handlers(ec, false, query_bit);
1104 	flush_workqueue(ec_query_wq);
1105 }
1106 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1107 
acpi_ec_create_query(struct acpi_ec * ec,u8 * pval)1108 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1109 {
1110 	struct acpi_ec_query *q;
1111 	struct transaction *t;
1112 
1113 	q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1114 	if (!q)
1115 		return NULL;
1116 
1117 	INIT_WORK(&q->work, acpi_ec_event_processor);
1118 	t = &q->transaction;
1119 	t->command = ACPI_EC_COMMAND_QUERY;
1120 	t->rdata = pval;
1121 	t->rlen = 1;
1122 	q->ec = ec;
1123 	return q;
1124 }
1125 
acpi_ec_delete_query(struct acpi_ec_query * q)1126 static void acpi_ec_delete_query(struct acpi_ec_query *q)
1127 {
1128 	if (q) {
1129 		if (q->handler)
1130 			acpi_ec_put_query_handler(q->handler);
1131 		kfree(q);
1132 	}
1133 }
1134 
acpi_ec_event_processor(struct work_struct * work)1135 static void acpi_ec_event_processor(struct work_struct *work)
1136 {
1137 	struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1138 	struct acpi_ec_query_handler *handler = q->handler;
1139 	struct acpi_ec *ec = q->ec;
1140 
1141 	ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1142 
1143 	if (handler->func)
1144 		handler->func(handler->data);
1145 	else if (handler->handle)
1146 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1147 
1148 	ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1149 
1150 	spin_lock_irq(&ec->lock);
1151 	ec->queries_in_progress--;
1152 	spin_unlock_irq(&ec->lock);
1153 
1154 	acpi_ec_delete_query(q);
1155 }
1156 
acpi_ec_query(struct acpi_ec * ec,u8 * data)1157 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
1158 {
1159 	u8 value = 0;
1160 	int result;
1161 	struct acpi_ec_query *q;
1162 
1163 	q = acpi_ec_create_query(ec, &value);
1164 	if (!q)
1165 		return -ENOMEM;
1166 
1167 	/*
1168 	 * Query the EC to find out which _Qxx method we need to evaluate.
1169 	 * Note that successful completion of the query causes the ACPI_EC_SCI
1170 	 * bit to be cleared (and thus clearing the interrupt source).
1171 	 */
1172 	result = acpi_ec_transaction(ec, &q->transaction);
1173 	if (!value)
1174 		result = -ENODATA;
1175 	if (result)
1176 		goto err_exit;
1177 
1178 	q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1179 	if (!q->handler) {
1180 		result = -ENODATA;
1181 		goto err_exit;
1182 	}
1183 
1184 	/*
1185 	 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1186 	 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1187 	 *
1188 	 * Put this log entry before queue_work() to make it appear in the log
1189 	 * before any other messages emitted during workqueue handling.
1190 	 */
1191 	ec_dbg_evt("Query(0x%02x) scheduled", value);
1192 
1193 	spin_lock_irq(&ec->lock);
1194 
1195 	ec->queries_in_progress++;
1196 	queue_work(ec_query_wq, &q->work);
1197 
1198 	spin_unlock_irq(&ec->lock);
1199 
1200 err_exit:
1201 	if (result)
1202 		acpi_ec_delete_query(q);
1203 	if (data)
1204 		*data = value;
1205 	return result;
1206 }
1207 
acpi_ec_check_event(struct acpi_ec * ec)1208 static void acpi_ec_check_event(struct acpi_ec *ec)
1209 {
1210 	unsigned long flags;
1211 
1212 	if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1213 		if (ec_guard(ec)) {
1214 			spin_lock_irqsave(&ec->lock, flags);
1215 			/*
1216 			 * Take care of the SCI_EVT unless no one else is
1217 			 * taking care of it.
1218 			 */
1219 			if (!ec->curr)
1220 				advance_transaction(ec, false);
1221 			spin_unlock_irqrestore(&ec->lock, flags);
1222 		}
1223 	}
1224 }
1225 
acpi_ec_event_handler(struct work_struct * work)1226 static void acpi_ec_event_handler(struct work_struct *work)
1227 {
1228 	unsigned long flags;
1229 	struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1230 
1231 	ec_dbg_evt("Event started");
1232 
1233 	spin_lock_irqsave(&ec->lock, flags);
1234 	while (ec->nr_pending_queries) {
1235 		spin_unlock_irqrestore(&ec->lock, flags);
1236 		(void)acpi_ec_query(ec, NULL);
1237 		spin_lock_irqsave(&ec->lock, flags);
1238 		ec->nr_pending_queries--;
1239 		/*
1240 		 * Before exit, make sure that this work item can be
1241 		 * scheduled again. There might be QR_EC failures, leaving
1242 		 * EC_FLAGS_QUERY_PENDING uncleared and preventing this work
1243 		 * item from being scheduled again.
1244 		 */
1245 		if (!ec->nr_pending_queries) {
1246 			if (ec_event_clearing == ACPI_EC_EVT_TIMING_STATUS ||
1247 			    ec_event_clearing == ACPI_EC_EVT_TIMING_QUERY)
1248 				acpi_ec_complete_query(ec);
1249 		}
1250 	}
1251 	spin_unlock_irqrestore(&ec->lock, flags);
1252 
1253 	ec_dbg_evt("Event stopped");
1254 
1255 	acpi_ec_check_event(ec);
1256 
1257 	spin_lock_irqsave(&ec->lock, flags);
1258 	ec->events_in_progress--;
1259 	spin_unlock_irqrestore(&ec->lock, flags);
1260 }
1261 
acpi_ec_handle_interrupt(struct acpi_ec * ec)1262 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1263 {
1264 	unsigned long flags;
1265 
1266 	spin_lock_irqsave(&ec->lock, flags);
1267 	advance_transaction(ec, true);
1268 	spin_unlock_irqrestore(&ec->lock, flags);
1269 }
1270 
acpi_ec_gpe_handler(acpi_handle gpe_device,u32 gpe_number,void * data)1271 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1272 			       u32 gpe_number, void *data)
1273 {
1274 	acpi_ec_handle_interrupt(data);
1275 	return ACPI_INTERRUPT_HANDLED;
1276 }
1277 
acpi_ec_irq_handler(int irq,void * data)1278 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1279 {
1280 	acpi_ec_handle_interrupt(data);
1281 	return IRQ_HANDLED;
1282 }
1283 
1284 /* --------------------------------------------------------------------------
1285  *                           Address Space Management
1286  * -------------------------------------------------------------------------- */
1287 
1288 static acpi_status
acpi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value64,void * handler_context,void * region_context)1289 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1290 		      u32 bits, u64 *value64,
1291 		      void *handler_context, void *region_context)
1292 {
1293 	struct acpi_ec *ec = handler_context;
1294 	int result = 0, i, bytes = bits / 8;
1295 	u8 *value = (u8 *)value64;
1296 
1297 	if ((address > 0xFF) || !value || !handler_context)
1298 		return AE_BAD_PARAMETER;
1299 
1300 	if (function != ACPI_READ && function != ACPI_WRITE)
1301 		return AE_BAD_PARAMETER;
1302 
1303 	if (ec->busy_polling || bits > 8)
1304 		acpi_ec_burst_enable(ec);
1305 
1306 	for (i = 0; i < bytes; ++i, ++address, ++value)
1307 		result = (function == ACPI_READ) ?
1308 			acpi_ec_read(ec, address, value) :
1309 			acpi_ec_write(ec, address, *value);
1310 
1311 	if (ec->busy_polling || bits > 8)
1312 		acpi_ec_burst_disable(ec);
1313 
1314 	switch (result) {
1315 	case -EINVAL:
1316 		return AE_BAD_PARAMETER;
1317 	case -ENODEV:
1318 		return AE_NOT_FOUND;
1319 	case -ETIME:
1320 		return AE_TIME;
1321 	default:
1322 		return AE_OK;
1323 	}
1324 }
1325 
1326 /* --------------------------------------------------------------------------
1327  *                             Driver Interface
1328  * -------------------------------------------------------------------------- */
1329 
1330 static acpi_status
1331 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1332 
acpi_ec_free(struct acpi_ec * ec)1333 static void acpi_ec_free(struct acpi_ec *ec)
1334 {
1335 	if (first_ec == ec)
1336 		first_ec = NULL;
1337 	if (boot_ec == ec)
1338 		boot_ec = NULL;
1339 	kfree(ec);
1340 }
1341 
acpi_ec_alloc(void)1342 static struct acpi_ec *acpi_ec_alloc(void)
1343 {
1344 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1345 
1346 	if (!ec)
1347 		return NULL;
1348 	mutex_init(&ec->mutex);
1349 	init_waitqueue_head(&ec->wait);
1350 	INIT_LIST_HEAD(&ec->list);
1351 	spin_lock_init(&ec->lock);
1352 	INIT_WORK(&ec->work, acpi_ec_event_handler);
1353 	ec->timestamp = jiffies;
1354 	ec->busy_polling = true;
1355 	ec->polling_guard = 0;
1356 	ec->gpe = -1;
1357 	ec->irq = -1;
1358 	return ec;
1359 }
1360 
1361 static acpi_status
acpi_ec_register_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)1362 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1363 			       void *context, void **return_value)
1364 {
1365 	char node_name[5];
1366 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
1367 	struct acpi_ec *ec = context;
1368 	int value = 0;
1369 	acpi_status status;
1370 
1371 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1372 
1373 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1374 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1375 	return AE_OK;
1376 }
1377 
1378 static acpi_status
ec_parse_device(acpi_handle handle,u32 Level,void * context,void ** retval)1379 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1380 {
1381 	acpi_status status;
1382 	unsigned long long tmp = 0;
1383 	struct acpi_ec *ec = context;
1384 
1385 	/* clear addr values, ec_parse_io_ports depend on it */
1386 	ec->command_addr = ec->data_addr = 0;
1387 
1388 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1389 				     ec_parse_io_ports, ec);
1390 	if (ACPI_FAILURE(status))
1391 		return status;
1392 	if (ec->data_addr == 0 || ec->command_addr == 0)
1393 		return AE_OK;
1394 
1395 	/* Get GPE bit assignment (EC events). */
1396 	/* TODO: Add support for _GPE returning a package */
1397 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1398 	if (ACPI_SUCCESS(status))
1399 		ec->gpe = tmp;
1400 	/*
1401 	 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1402 	 * platforms which use GpioInt instead of GPE.
1403 	 */
1404 
1405 	/* Use the global lock for all EC transactions? */
1406 	tmp = 0;
1407 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1408 	ec->global_lock = tmp;
1409 	ec->handle = handle;
1410 	return AE_CTRL_TERMINATE;
1411 }
1412 
install_gpe_event_handler(struct acpi_ec * ec)1413 static bool install_gpe_event_handler(struct acpi_ec *ec)
1414 {
1415 	acpi_status status;
1416 
1417 	status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1418 					      ACPI_GPE_EDGE_TRIGGERED,
1419 					      &acpi_ec_gpe_handler, ec);
1420 	if (ACPI_FAILURE(status))
1421 		return false;
1422 
1423 	if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1424 		acpi_ec_enable_gpe(ec, true);
1425 
1426 	return true;
1427 }
1428 
install_gpio_irq_event_handler(struct acpi_ec * ec)1429 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1430 {
1431 	return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1432 			   "ACPI EC", ec) >= 0;
1433 }
1434 
1435 /**
1436  * ec_install_handlers - Install service callbacks and register query methods.
1437  * @ec: Target EC.
1438  * @device: ACPI device object corresponding to @ec.
1439  *
1440  * Install a handler for the EC address space type unless it has been installed
1441  * already.  If @device is not NULL, also look for EC query methods in the
1442  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1443  * handler for the EC, if possible.
1444  *
1445  * Return:
1446  * -ENODEV if the address space handler cannot be installed, which means
1447  *  "unable to handle transactions",
1448  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1449  * or 0 (success) otherwise.
1450  */
ec_install_handlers(struct acpi_ec * ec,struct acpi_device * device)1451 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device)
1452 {
1453 	acpi_status status;
1454 
1455 	acpi_ec_start(ec, false);
1456 
1457 	if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1458 		acpi_ec_enter_noirq(ec);
1459 		status = acpi_install_address_space_handler(ec->handle,
1460 							    ACPI_ADR_SPACE_EC,
1461 							    &acpi_ec_space_handler,
1462 							    NULL, ec);
1463 		if (ACPI_FAILURE(status)) {
1464 			acpi_ec_stop(ec, false);
1465 			return -ENODEV;
1466 		}
1467 		set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1468 	}
1469 
1470 	if (!device)
1471 		return 0;
1472 
1473 	if (ec->gpe < 0) {
1474 		/* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1475 		int irq = acpi_dev_gpio_irq_get(device, 0);
1476 		/*
1477 		 * Bail out right away for deferred probing or complete the
1478 		 * initialization regardless of any other errors.
1479 		 */
1480 		if (irq == -EPROBE_DEFER)
1481 			return -EPROBE_DEFER;
1482 		else if (irq >= 0)
1483 			ec->irq = irq;
1484 	}
1485 
1486 	if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1487 		/* Find and register all query methods */
1488 		acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1489 				    acpi_ec_register_query_methods,
1490 				    NULL, ec, NULL);
1491 		set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1492 	}
1493 	if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1494 		bool ready = false;
1495 
1496 		if (ec->gpe >= 0)
1497 			ready = install_gpe_event_handler(ec);
1498 		else if (ec->irq >= 0)
1499 			ready = install_gpio_irq_event_handler(ec);
1500 
1501 		if (ready) {
1502 			set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1503 			acpi_ec_leave_noirq(ec);
1504 		}
1505 		/*
1506 		 * Failures to install an event handler are not fatal, because
1507 		 * the EC can be polled for events.
1508 		 */
1509 	}
1510 	/* EC is fully operational, allow queries */
1511 	acpi_ec_enable_event(ec);
1512 
1513 	return 0;
1514 }
1515 
ec_remove_handlers(struct acpi_ec * ec)1516 static void ec_remove_handlers(struct acpi_ec *ec)
1517 {
1518 	if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1519 		if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1520 					ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1521 			pr_err("failed to remove space handler\n");
1522 		clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1523 	}
1524 
1525 	/*
1526 	 * Stops handling the EC transactions after removing the operation
1527 	 * region handler. This is required because _REG(DISCONNECT)
1528 	 * invoked during the removal can result in new EC transactions.
1529 	 *
1530 	 * Flushes the EC requests and thus disables the GPE before
1531 	 * removing the GPE handler. This is required by the current ACPICA
1532 	 * GPE core. ACPICA GPE core will automatically disable a GPE when
1533 	 * it is indicated but there is no way to handle it. So the drivers
1534 	 * must disable the GPEs prior to removing the GPE handlers.
1535 	 */
1536 	acpi_ec_stop(ec, false);
1537 
1538 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1539 		if (ec->gpe >= 0 &&
1540 		    ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1541 				 &acpi_ec_gpe_handler)))
1542 			pr_err("failed to remove gpe handler\n");
1543 
1544 		if (ec->irq >= 0)
1545 			free_irq(ec->irq, ec);
1546 
1547 		clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1548 	}
1549 	if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1550 		acpi_ec_remove_query_handlers(ec, true, 0);
1551 		clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1552 	}
1553 }
1554 
acpi_ec_setup(struct acpi_ec * ec,struct acpi_device * device)1555 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device)
1556 {
1557 	int ret;
1558 
1559 	ret = ec_install_handlers(ec, device);
1560 	if (ret)
1561 		return ret;
1562 
1563 	/* First EC capable of handling transactions */
1564 	if (!first_ec)
1565 		first_ec = ec;
1566 
1567 	pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1568 		ec->data_addr);
1569 
1570 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1571 		if (ec->gpe >= 0)
1572 			pr_info("GPE=0x%x\n", ec->gpe);
1573 		else
1574 			pr_info("IRQ=%d\n", ec->irq);
1575 	}
1576 
1577 	return ret;
1578 }
1579 
acpi_ec_add(struct acpi_device * device)1580 static int acpi_ec_add(struct acpi_device *device)
1581 {
1582 	struct acpi_ec *ec;
1583 	int ret;
1584 
1585 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1586 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1587 
1588 	if (boot_ec && (boot_ec->handle == device->handle ||
1589 	    !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1590 		/* Fast path: this device corresponds to the boot EC. */
1591 		ec = boot_ec;
1592 	} else {
1593 		acpi_status status;
1594 
1595 		ec = acpi_ec_alloc();
1596 		if (!ec)
1597 			return -ENOMEM;
1598 
1599 		status = ec_parse_device(device->handle, 0, ec, NULL);
1600 		if (status != AE_CTRL_TERMINATE) {
1601 			ret = -EINVAL;
1602 			goto err;
1603 		}
1604 
1605 		if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1606 		    ec->data_addr == boot_ec->data_addr &&
1607 		    !EC_FLAGS_TRUST_DSDT_GPE) {
1608 			/*
1609 			 * Trust PNP0C09 namespace location rather than
1610 			 * ECDT ID. But trust ECDT GPE rather than _GPE
1611 			 * because of ASUS quirks, so do not change
1612 			 * boot_ec->gpe to ec->gpe.
1613 			 */
1614 			boot_ec->handle = ec->handle;
1615 			acpi_handle_debug(ec->handle, "duplicated.\n");
1616 			acpi_ec_free(ec);
1617 			ec = boot_ec;
1618 		}
1619 	}
1620 
1621 	ret = acpi_ec_setup(ec, device);
1622 	if (ret)
1623 		goto err;
1624 
1625 	if (ec == boot_ec)
1626 		acpi_handle_info(boot_ec->handle,
1627 				 "Boot %s EC initialization complete\n",
1628 				 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1629 
1630 	acpi_handle_info(ec->handle,
1631 			 "EC: Used to handle transactions and events\n");
1632 
1633 	device->driver_data = ec;
1634 
1635 	ret = !!request_region(ec->data_addr, 1, "EC data");
1636 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1637 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
1638 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1639 
1640 	/* Reprobe devices depending on the EC */
1641 	acpi_dev_clear_dependencies(device);
1642 
1643 	acpi_handle_debug(ec->handle, "enumerated.\n");
1644 	return 0;
1645 
1646 err:
1647 	if (ec != boot_ec)
1648 		acpi_ec_free(ec);
1649 
1650 	return ret;
1651 }
1652 
acpi_ec_remove(struct acpi_device * device)1653 static int acpi_ec_remove(struct acpi_device *device)
1654 {
1655 	struct acpi_ec *ec;
1656 
1657 	if (!device)
1658 		return -EINVAL;
1659 
1660 	ec = acpi_driver_data(device);
1661 	release_region(ec->data_addr, 1);
1662 	release_region(ec->command_addr, 1);
1663 	device->driver_data = NULL;
1664 	if (ec != boot_ec) {
1665 		ec_remove_handlers(ec);
1666 		acpi_ec_free(ec);
1667 	}
1668 	return 0;
1669 }
1670 
1671 static acpi_status
ec_parse_io_ports(struct acpi_resource * resource,void * context)1672 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1673 {
1674 	struct acpi_ec *ec = context;
1675 
1676 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
1677 		return AE_OK;
1678 
1679 	/*
1680 	 * The first address region returned is the data port, and
1681 	 * the second address region returned is the status/command
1682 	 * port.
1683 	 */
1684 	if (ec->data_addr == 0)
1685 		ec->data_addr = resource->data.io.minimum;
1686 	else if (ec->command_addr == 0)
1687 		ec->command_addr = resource->data.io.minimum;
1688 	else
1689 		return AE_CTRL_TERMINATE;
1690 
1691 	return AE_OK;
1692 }
1693 
1694 static const struct acpi_device_id ec_device_ids[] = {
1695 	{"PNP0C09", 0},
1696 	{ACPI_ECDT_HID, 0},
1697 	{"", 0},
1698 };
1699 
1700 /*
1701  * This function is not Windows-compatible as Windows never enumerates the
1702  * namespace EC before the main ACPI device enumeration process. It is
1703  * retained for historical reason and will be deprecated in the future.
1704  */
acpi_ec_dsdt_probe(void)1705 void __init acpi_ec_dsdt_probe(void)
1706 {
1707 	struct acpi_ec *ec;
1708 	acpi_status status;
1709 	int ret;
1710 
1711 	/*
1712 	 * If a platform has ECDT, there is no need to proceed as the
1713 	 * following probe is not a part of the ACPI device enumeration,
1714 	 * executing _STA is not safe, and thus this probe may risk of
1715 	 * picking up an invalid EC device.
1716 	 */
1717 	if (boot_ec)
1718 		return;
1719 
1720 	ec = acpi_ec_alloc();
1721 	if (!ec)
1722 		return;
1723 
1724 	/*
1725 	 * At this point, the namespace is initialized, so start to find
1726 	 * the namespace objects.
1727 	 */
1728 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1729 	if (ACPI_FAILURE(status) || !ec->handle) {
1730 		acpi_ec_free(ec);
1731 		return;
1732 	}
1733 
1734 	/*
1735 	 * When the DSDT EC is available, always re-configure boot EC to
1736 	 * have _REG evaluated. _REG can only be evaluated after the
1737 	 * namespace initialization.
1738 	 * At this point, the GPE is not fully initialized, so do not to
1739 	 * handle the events.
1740 	 */
1741 	ret = acpi_ec_setup(ec, NULL);
1742 	if (ret) {
1743 		acpi_ec_free(ec);
1744 		return;
1745 	}
1746 
1747 	boot_ec = ec;
1748 
1749 	acpi_handle_info(ec->handle,
1750 			 "Boot DSDT EC used to handle transactions\n");
1751 }
1752 
1753 /*
1754  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1755  *
1756  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1757  * found a matching object in the namespace.
1758  *
1759  * Next, in case the DSDT EC is not functioning, it is still necessary to
1760  * provide a functional ECDT EC to handle events, so add an extra device object
1761  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1762  *
1763  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1764  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1765  */
acpi_ec_ecdt_start(void)1766 static void __init acpi_ec_ecdt_start(void)
1767 {
1768 	struct acpi_table_ecdt *ecdt_ptr;
1769 	acpi_handle handle;
1770 	acpi_status status;
1771 
1772 	/* Bail out if a matching EC has been found in the namespace. */
1773 	if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1774 		return;
1775 
1776 	/* Look up the object pointed to from the ECDT in the namespace. */
1777 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1778 				(struct acpi_table_header **)&ecdt_ptr);
1779 	if (ACPI_FAILURE(status))
1780 		return;
1781 
1782 	status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1783 	if (ACPI_SUCCESS(status)) {
1784 		boot_ec->handle = handle;
1785 
1786 		/* Add a special ACPI device object to represent the boot EC. */
1787 		acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1788 	}
1789 
1790 	acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1791 }
1792 
1793 /*
1794  * On some hardware it is necessary to clear events accumulated by the EC during
1795  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1796  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1797  *
1798  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1799  *
1800  * Ideally, the EC should also be instructed NOT to accumulate events during
1801  * sleep (which Windows seems to do somehow), but the interface to control this
1802  * behaviour is not known at this time.
1803  *
1804  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1805  * however it is very likely that other Samsung models are affected.
1806  *
1807  * On systems which don't accumulate _Q events during sleep, this extra check
1808  * should be harmless.
1809  */
ec_clear_on_resume(const struct dmi_system_id * id)1810 static int ec_clear_on_resume(const struct dmi_system_id *id)
1811 {
1812 	pr_debug("Detected system needing EC poll on resume.\n");
1813 	EC_FLAGS_CLEAR_ON_RESUME = 1;
1814 	ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1815 	return 0;
1816 }
1817 
1818 /*
1819  * Some ECDTs contain wrong register addresses.
1820  * MSI MS-171F
1821  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1822  */
ec_correct_ecdt(const struct dmi_system_id * id)1823 static int ec_correct_ecdt(const struct dmi_system_id *id)
1824 {
1825 	pr_debug("Detected system needing ECDT address correction.\n");
1826 	EC_FLAGS_CORRECT_ECDT = 1;
1827 	return 0;
1828 }
1829 
1830 /*
1831  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1832  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1833  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1834  */
ec_honor_dsdt_gpe(const struct dmi_system_id * id)1835 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1836 {
1837 	pr_debug("Detected system needing DSDT GPE setting.\n");
1838 	EC_FLAGS_TRUST_DSDT_GPE = 1;
1839 	return 0;
1840 }
1841 
1842 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1843 	{
1844 	ec_correct_ecdt, "MSI MS-171F", {
1845 	DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1846 	DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),}, NULL},
1847 	{
1848 	/* https://bugzilla.kernel.org/show_bug.cgi?id=209989 */
1849 	ec_honor_dsdt_gpe, "HP Pavilion Gaming Laptop 15-cx0xxx", {
1850 	DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1851 	DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),}, NULL},
1852 	{
1853 	ec_clear_on_resume, "Samsung hardware", {
1854 	DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1855 	{},
1856 };
1857 
acpi_ec_ecdt_probe(void)1858 void __init acpi_ec_ecdt_probe(void)
1859 {
1860 	struct acpi_table_ecdt *ecdt_ptr;
1861 	struct acpi_ec *ec;
1862 	acpi_status status;
1863 	int ret;
1864 
1865 	/* Generate a boot ec context. */
1866 	dmi_check_system(ec_dmi_table);
1867 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1868 				(struct acpi_table_header **)&ecdt_ptr);
1869 	if (ACPI_FAILURE(status))
1870 		return;
1871 
1872 	if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1873 		/*
1874 		 * Asus X50GL:
1875 		 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1876 		 */
1877 		goto out;
1878 	}
1879 
1880 	ec = acpi_ec_alloc();
1881 	if (!ec)
1882 		goto out;
1883 
1884 	if (EC_FLAGS_CORRECT_ECDT) {
1885 		ec->command_addr = ecdt_ptr->data.address;
1886 		ec->data_addr = ecdt_ptr->control.address;
1887 	} else {
1888 		ec->command_addr = ecdt_ptr->control.address;
1889 		ec->data_addr = ecdt_ptr->data.address;
1890 	}
1891 
1892 	/*
1893 	 * Ignore the GPE value on Reduced Hardware platforms.
1894 	 * Some products have this set to an erroneous value.
1895 	 */
1896 	if (!acpi_gbl_reduced_hardware)
1897 		ec->gpe = ecdt_ptr->gpe;
1898 
1899 	ec->handle = ACPI_ROOT_OBJECT;
1900 
1901 	/*
1902 	 * At this point, the namespace is not initialized, so do not find
1903 	 * the namespace objects, or handle the events.
1904 	 */
1905 	ret = acpi_ec_setup(ec, NULL);
1906 	if (ret) {
1907 		acpi_ec_free(ec);
1908 		goto out;
1909 	}
1910 
1911 	boot_ec = ec;
1912 	boot_ec_is_ecdt = true;
1913 
1914 	pr_info("Boot ECDT EC used to handle transactions\n");
1915 
1916 out:
1917 	acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1918 }
1919 
1920 #ifdef CONFIG_PM_SLEEP
acpi_ec_suspend(struct device * dev)1921 static int acpi_ec_suspend(struct device *dev)
1922 {
1923 	struct acpi_ec *ec =
1924 		acpi_driver_data(to_acpi_device(dev));
1925 
1926 	if (!pm_suspend_no_platform() && ec_freeze_events)
1927 		acpi_ec_disable_event(ec);
1928 	return 0;
1929 }
1930 
acpi_ec_suspend_noirq(struct device * dev)1931 static int acpi_ec_suspend_noirq(struct device *dev)
1932 {
1933 	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1934 
1935 	/*
1936 	 * The SCI handler doesn't run at this point, so the GPE can be
1937 	 * masked at the low level without side effects.
1938 	 */
1939 	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1940 	    ec->gpe >= 0 && ec->reference_count >= 1)
1941 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
1942 
1943 	acpi_ec_enter_noirq(ec);
1944 
1945 	return 0;
1946 }
1947 
acpi_ec_resume_noirq(struct device * dev)1948 static int acpi_ec_resume_noirq(struct device *dev)
1949 {
1950 	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
1951 
1952 	acpi_ec_leave_noirq(ec);
1953 
1954 	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
1955 	    ec->gpe >= 0 && ec->reference_count >= 1)
1956 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
1957 
1958 	return 0;
1959 }
1960 
acpi_ec_resume(struct device * dev)1961 static int acpi_ec_resume(struct device *dev)
1962 {
1963 	struct acpi_ec *ec =
1964 		acpi_driver_data(to_acpi_device(dev));
1965 
1966 	acpi_ec_enable_event(ec);
1967 	return 0;
1968 }
1969 
acpi_ec_mark_gpe_for_wake(void)1970 void acpi_ec_mark_gpe_for_wake(void)
1971 {
1972 	if (first_ec && !ec_no_wakeup)
1973 		acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
1974 }
1975 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
1976 
acpi_ec_set_gpe_wake_mask(u8 action)1977 void acpi_ec_set_gpe_wake_mask(u8 action)
1978 {
1979 	if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
1980 		acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
1981 }
1982 
acpi_ec_dispatch_gpe(void)1983 bool acpi_ec_dispatch_gpe(void)
1984 {
1985 	bool work_in_progress;
1986 	u32 ret;
1987 
1988 	if (!first_ec)
1989 		return acpi_any_gpe_status_set(U32_MAX);
1990 
1991 	/*
1992 	 * Report wakeup if the status bit is set for any enabled GPE other
1993 	 * than the EC one.
1994 	 */
1995 	if (acpi_any_gpe_status_set(first_ec->gpe))
1996 		return true;
1997 
1998 	/*
1999 	 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2000 	 * to allow the caller to process events properly after that.
2001 	 */
2002 	ret = acpi_dispatch_gpe(NULL, first_ec->gpe);
2003 	if (ret == ACPI_INTERRUPT_HANDLED)
2004 		pm_pr_dbg("ACPI EC GPE dispatched\n");
2005 
2006 	/* Drain EC work. */
2007 	do {
2008 		acpi_ec_flush_work();
2009 
2010 		pm_pr_dbg("ACPI EC work flushed\n");
2011 
2012 		spin_lock_irq(&first_ec->lock);
2013 
2014 		work_in_progress = first_ec->events_in_progress +
2015 			first_ec->queries_in_progress > 0;
2016 
2017 		spin_unlock_irq(&first_ec->lock);
2018 	} while (work_in_progress && !pm_wakeup_pending());
2019 
2020 	return false;
2021 }
2022 #endif /* CONFIG_PM_SLEEP */
2023 
2024 static const struct dev_pm_ops acpi_ec_pm = {
2025 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2026 	SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2027 };
2028 
param_set_event_clearing(const char * val,const struct kernel_param * kp)2029 static int param_set_event_clearing(const char *val,
2030 				    const struct kernel_param *kp)
2031 {
2032 	int result = 0;
2033 
2034 	if (!strncmp(val, "status", sizeof("status") - 1)) {
2035 		ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2036 		pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2037 	} else if (!strncmp(val, "query", sizeof("query") - 1)) {
2038 		ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2039 		pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2040 	} else if (!strncmp(val, "event", sizeof("event") - 1)) {
2041 		ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2042 		pr_info("Assuming SCI_EVT clearing on event reads\n");
2043 	} else
2044 		result = -EINVAL;
2045 	return result;
2046 }
2047 
param_get_event_clearing(char * buffer,const struct kernel_param * kp)2048 static int param_get_event_clearing(char *buffer,
2049 				    const struct kernel_param *kp)
2050 {
2051 	switch (ec_event_clearing) {
2052 	case ACPI_EC_EVT_TIMING_STATUS:
2053 		return sprintf(buffer, "status\n");
2054 	case ACPI_EC_EVT_TIMING_QUERY:
2055 		return sprintf(buffer, "query\n");
2056 	case ACPI_EC_EVT_TIMING_EVENT:
2057 		return sprintf(buffer, "event\n");
2058 	default:
2059 		return sprintf(buffer, "invalid\n");
2060 	}
2061 	return 0;
2062 }
2063 
2064 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2065 		  NULL, 0644);
2066 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2067 
2068 static struct acpi_driver acpi_ec_driver = {
2069 	.name = "ec",
2070 	.class = ACPI_EC_CLASS,
2071 	.ids = ec_device_ids,
2072 	.ops = {
2073 		.add = acpi_ec_add,
2074 		.remove = acpi_ec_remove,
2075 		},
2076 	.drv.pm = &acpi_ec_pm,
2077 };
2078 
acpi_ec_destroy_workqueues(void)2079 static void acpi_ec_destroy_workqueues(void)
2080 {
2081 	if (ec_wq) {
2082 		destroy_workqueue(ec_wq);
2083 		ec_wq = NULL;
2084 	}
2085 	if (ec_query_wq) {
2086 		destroy_workqueue(ec_query_wq);
2087 		ec_query_wq = NULL;
2088 	}
2089 }
2090 
acpi_ec_init_workqueues(void)2091 static int acpi_ec_init_workqueues(void)
2092 {
2093 	if (!ec_wq)
2094 		ec_wq = alloc_ordered_workqueue("kec", 0);
2095 
2096 	if (!ec_query_wq)
2097 		ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2098 
2099 	if (!ec_wq || !ec_query_wq) {
2100 		acpi_ec_destroy_workqueues();
2101 		return -ENODEV;
2102 	}
2103 	return 0;
2104 }
2105 
2106 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2107 	{
2108 		.ident = "Thinkpad X1 Carbon 6th",
2109 		.matches = {
2110 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2111 			DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2112 		},
2113 	},
2114 	{
2115 		.ident = "ThinkPad X1 Yoga 3rd",
2116 		.matches = {
2117 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2118 			DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2119 		},
2120 	},
2121 	{ },
2122 };
2123 
acpi_ec_init(void)2124 void __init acpi_ec_init(void)
2125 {
2126 	int result;
2127 
2128 	result = acpi_ec_init_workqueues();
2129 	if (result)
2130 		return;
2131 
2132 	/*
2133 	 * Disable EC wakeup on following systems to prevent periodic
2134 	 * wakeup from EC GPE.
2135 	 */
2136 	if (dmi_check_system(acpi_ec_no_wakeup)) {
2137 		ec_no_wakeup = true;
2138 		pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2139 	}
2140 
2141 	/* Driver must be registered after acpi_ec_init_workqueues(). */
2142 	acpi_bus_register_driver(&acpi_ec_driver);
2143 
2144 	acpi_ec_ecdt_start();
2145 }
2146 
2147 /* EC driver currently not unloadable */
2148 #if 0
2149 static void __exit acpi_ec_exit(void)
2150 {
2151 
2152 	acpi_bus_unregister_driver(&acpi_ec_driver);
2153 	acpi_ec_destroy_workqueues();
2154 }
2155 #endif	/* 0 */
2156