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_EVENT_HANDLER_INSTALLED,	/* Event handler installed */
96 	EC_FLAGS_EC_HANDLER_INSTALLED,	/* OpReg handler installed */
97 	EC_FLAGS_EC_REG_CALLED,		/* OpReg ACPI _REG method called */
98 	EC_FLAGS_QUERY_METHODS_INSTALLED, /* _Qxx handlers installed */
99 	EC_FLAGS_STARTED,		/* Driver is started */
100 	EC_FLAGS_STOPPED,		/* Driver is stopped */
101 	EC_FLAGS_EVENTS_MASKED,		/* Events masked */
102 };
103 
104 #define ACPI_EC_COMMAND_POLL		0x01 /* Available for command byte */
105 #define ACPI_EC_COMMAND_COMPLETE	0x02 /* Completed last byte */
106 
107 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
108 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
109 module_param(ec_delay, uint, 0644);
110 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
111 
112 static unsigned int ec_max_queries __read_mostly = ACPI_EC_MAX_QUERIES;
113 module_param(ec_max_queries, uint, 0644);
114 MODULE_PARM_DESC(ec_max_queries, "Maximum parallel _Qxx evaluations");
115 
116 static bool ec_busy_polling __read_mostly;
117 module_param(ec_busy_polling, bool, 0644);
118 MODULE_PARM_DESC(ec_busy_polling, "Use busy polling to advance EC transaction");
119 
120 static unsigned int ec_polling_guard __read_mostly = ACPI_EC_UDELAY_POLL;
121 module_param(ec_polling_guard, uint, 0644);
122 MODULE_PARM_DESC(ec_polling_guard, "Guard time(us) between EC accesses in polling modes");
123 
124 static unsigned int ec_event_clearing __read_mostly = ACPI_EC_EVT_TIMING_QUERY;
125 
126 /*
127  * If the number of false interrupts per one transaction exceeds
128  * this threshold, will think there is a GPE storm happened and
129  * will disable the GPE for normal transaction.
130  */
131 static unsigned int ec_storm_threshold  __read_mostly = 8;
132 module_param(ec_storm_threshold, uint, 0644);
133 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
134 
135 static bool ec_freeze_events __read_mostly;
136 module_param(ec_freeze_events, bool, 0644);
137 MODULE_PARM_DESC(ec_freeze_events, "Disabling event handling during suspend/resume");
138 
139 static bool ec_no_wakeup __read_mostly;
140 module_param(ec_no_wakeup, bool, 0644);
141 MODULE_PARM_DESC(ec_no_wakeup, "Do not wake up from suspend-to-idle");
142 
143 struct acpi_ec_query_handler {
144 	struct list_head node;
145 	acpi_ec_query_func func;
146 	acpi_handle handle;
147 	void *data;
148 	u8 query_bit;
149 	struct kref kref;
150 };
151 
152 struct transaction {
153 	const u8 *wdata;
154 	u8 *rdata;
155 	unsigned short irq_count;
156 	u8 command;
157 	u8 wi;
158 	u8 ri;
159 	u8 wlen;
160 	u8 rlen;
161 	u8 flags;
162 };
163 
164 struct acpi_ec_query {
165 	struct transaction transaction;
166 	struct work_struct work;
167 	struct acpi_ec_query_handler *handler;
168 	struct acpi_ec *ec;
169 };
170 
171 static int acpi_ec_submit_query(struct acpi_ec *ec);
172 static void advance_transaction(struct acpi_ec *ec, bool interrupt);
173 static void acpi_ec_event_handler(struct work_struct *work);
174 
175 struct acpi_ec *first_ec;
176 EXPORT_SYMBOL(first_ec);
177 
178 static struct acpi_ec *boot_ec;
179 static bool boot_ec_is_ecdt;
180 static struct workqueue_struct *ec_wq;
181 static struct workqueue_struct *ec_query_wq;
182 
183 static int EC_FLAGS_CORRECT_ECDT; /* Needs ECDT port address correction */
184 static int EC_FLAGS_TRUST_DSDT_GPE; /* Needs DSDT GPE as correction setting */
185 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
186 
187 /* --------------------------------------------------------------------------
188  *                           Logging/Debugging
189  * -------------------------------------------------------------------------- */
190 
191 /*
192  * Splitters used by the developers to track the boundary of the EC
193  * handling processes.
194  */
195 #ifdef DEBUG
196 #define EC_DBG_SEP	" "
197 #define EC_DBG_DRV	"+++++"
198 #define EC_DBG_STM	"====="
199 #define EC_DBG_REQ	"*****"
200 #define EC_DBG_EVT	"#####"
201 #else
202 #define EC_DBG_SEP	""
203 #define EC_DBG_DRV
204 #define EC_DBG_STM
205 #define EC_DBG_REQ
206 #define EC_DBG_EVT
207 #endif
208 
209 #define ec_log_raw(fmt, ...) \
210 	pr_info(fmt "\n", ##__VA_ARGS__)
211 #define ec_dbg_raw(fmt, ...) \
212 	pr_debug(fmt "\n", ##__VA_ARGS__)
213 #define ec_log(filter, fmt, ...) \
214 	ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
215 #define ec_dbg(filter, fmt, ...) \
216 	ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
217 
218 #define ec_log_drv(fmt, ...) \
219 	ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
220 #define ec_dbg_drv(fmt, ...) \
221 	ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
222 #define ec_dbg_stm(fmt, ...) \
223 	ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
224 #define ec_dbg_req(fmt, ...) \
225 	ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
226 #define ec_dbg_evt(fmt, ...) \
227 	ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
228 #define ec_dbg_ref(ec, fmt, ...) \
229 	ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
230 
231 /* --------------------------------------------------------------------------
232  *                           Device Flags
233  * -------------------------------------------------------------------------- */
234 
acpi_ec_started(struct acpi_ec * ec)235 static bool acpi_ec_started(struct acpi_ec *ec)
236 {
237 	return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
238 	       !test_bit(EC_FLAGS_STOPPED, &ec->flags);
239 }
240 
acpi_ec_event_enabled(struct acpi_ec * ec)241 static bool acpi_ec_event_enabled(struct acpi_ec *ec)
242 {
243 	/*
244 	 * There is an OSPM early stage logic. During the early stages
245 	 * (boot/resume), OSPMs shouldn't enable the event handling, only
246 	 * the EC transactions are allowed to be performed.
247 	 */
248 	if (!test_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
249 		return false;
250 	/*
251 	 * However, disabling the event handling is experimental for late
252 	 * stage (suspend), and is controlled by the boot parameter of
253 	 * "ec_freeze_events":
254 	 * 1. true:  The EC event handling is disabled before entering
255 	 *           the noirq stage.
256 	 * 2. false: The EC event handling is automatically disabled as
257 	 *           soon as the EC driver is stopped.
258 	 */
259 	if (ec_freeze_events)
260 		return acpi_ec_started(ec);
261 	else
262 		return test_bit(EC_FLAGS_STARTED, &ec->flags);
263 }
264 
acpi_ec_flushed(struct acpi_ec * ec)265 static bool acpi_ec_flushed(struct acpi_ec *ec)
266 {
267 	return ec->reference_count == 1;
268 }
269 
270 /* --------------------------------------------------------------------------
271  *                           EC Registers
272  * -------------------------------------------------------------------------- */
273 
acpi_ec_read_status(struct acpi_ec * ec)274 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
275 {
276 	u8 x = inb(ec->command_addr);
277 
278 	ec_dbg_raw("EC_SC(R) = 0x%2.2x "
279 		   "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
280 		   x,
281 		   !!(x & ACPI_EC_FLAG_SCI),
282 		   !!(x & ACPI_EC_FLAG_BURST),
283 		   !!(x & ACPI_EC_FLAG_CMD),
284 		   !!(x & ACPI_EC_FLAG_IBF),
285 		   !!(x & ACPI_EC_FLAG_OBF));
286 	return x;
287 }
288 
acpi_ec_read_data(struct acpi_ec * ec)289 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
290 {
291 	u8 x = inb(ec->data_addr);
292 
293 	ec->timestamp = jiffies;
294 	ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
295 	return x;
296 }
297 
acpi_ec_write_cmd(struct acpi_ec * ec,u8 command)298 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
299 {
300 	ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
301 	outb(command, ec->command_addr);
302 	ec->timestamp = jiffies;
303 }
304 
acpi_ec_write_data(struct acpi_ec * ec,u8 data)305 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
306 {
307 	ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
308 	outb(data, ec->data_addr);
309 	ec->timestamp = jiffies;
310 }
311 
312 #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
acpi_ec_cmd_string(u8 cmd)313 static const char *acpi_ec_cmd_string(u8 cmd)
314 {
315 	switch (cmd) {
316 	case 0x80:
317 		return "RD_EC";
318 	case 0x81:
319 		return "WR_EC";
320 	case 0x82:
321 		return "BE_EC";
322 	case 0x83:
323 		return "BD_EC";
324 	case 0x84:
325 		return "QR_EC";
326 	}
327 	return "UNKNOWN";
328 }
329 #else
330 #define acpi_ec_cmd_string(cmd)		"UNDEF"
331 #endif
332 
333 /* --------------------------------------------------------------------------
334  *                           GPE Registers
335  * -------------------------------------------------------------------------- */
336 
acpi_ec_gpe_status_set(struct acpi_ec * ec)337 static inline bool acpi_ec_gpe_status_set(struct acpi_ec *ec)
338 {
339 	acpi_event_status gpe_status = 0;
340 
341 	(void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
342 	return !!(gpe_status & ACPI_EVENT_FLAG_STATUS_SET);
343 }
344 
acpi_ec_enable_gpe(struct acpi_ec * ec,bool open)345 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
346 {
347 	if (open)
348 		acpi_enable_gpe(NULL, ec->gpe);
349 	else {
350 		BUG_ON(ec->reference_count < 1);
351 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
352 	}
353 	if (acpi_ec_gpe_status_set(ec)) {
354 		/*
355 		 * On some platforms, EN=1 writes cannot trigger GPE. So
356 		 * software need to manually trigger a pseudo GPE event on
357 		 * EN=1 writes.
358 		 */
359 		ec_dbg_raw("Polling quirk");
360 		advance_transaction(ec, false);
361 	}
362 }
363 
acpi_ec_disable_gpe(struct acpi_ec * ec,bool close)364 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
365 {
366 	if (close)
367 		acpi_disable_gpe(NULL, ec->gpe);
368 	else {
369 		BUG_ON(ec->reference_count < 1);
370 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
371 	}
372 }
373 
374 /* --------------------------------------------------------------------------
375  *                           Transaction Management
376  * -------------------------------------------------------------------------- */
377 
acpi_ec_submit_request(struct acpi_ec * ec)378 static void acpi_ec_submit_request(struct acpi_ec *ec)
379 {
380 	ec->reference_count++;
381 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
382 	    ec->gpe >= 0 && ec->reference_count == 1)
383 		acpi_ec_enable_gpe(ec, true);
384 }
385 
acpi_ec_complete_request(struct acpi_ec * ec)386 static void acpi_ec_complete_request(struct acpi_ec *ec)
387 {
388 	bool flushed = false;
389 
390 	ec->reference_count--;
391 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags) &&
392 	    ec->gpe >= 0 && ec->reference_count == 0)
393 		acpi_ec_disable_gpe(ec, true);
394 	flushed = acpi_ec_flushed(ec);
395 	if (flushed)
396 		wake_up(&ec->wait);
397 }
398 
acpi_ec_mask_events(struct acpi_ec * ec)399 static void acpi_ec_mask_events(struct acpi_ec *ec)
400 {
401 	if (!test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
402 		if (ec->gpe >= 0)
403 			acpi_ec_disable_gpe(ec, false);
404 		else
405 			disable_irq_nosync(ec->irq);
406 
407 		ec_dbg_drv("Polling enabled");
408 		set_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
409 	}
410 }
411 
acpi_ec_unmask_events(struct acpi_ec * ec)412 static void acpi_ec_unmask_events(struct acpi_ec *ec)
413 {
414 	if (test_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags)) {
415 		clear_bit(EC_FLAGS_EVENTS_MASKED, &ec->flags);
416 		if (ec->gpe >= 0)
417 			acpi_ec_enable_gpe(ec, false);
418 		else
419 			enable_irq(ec->irq);
420 
421 		ec_dbg_drv("Polling disabled");
422 	}
423 }
424 
425 /*
426  * acpi_ec_submit_flushable_request() - Increase the reference count unless
427  *                                      the flush operation is not in
428  *                                      progress
429  * @ec: the EC device
430  *
431  * This function must be used before taking a new action that should hold
432  * the reference count.  If this function returns false, then the action
433  * must be discarded or it will prevent the flush operation from being
434  * completed.
435  */
acpi_ec_submit_flushable_request(struct acpi_ec * ec)436 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
437 {
438 	if (!acpi_ec_started(ec))
439 		return false;
440 	acpi_ec_submit_request(ec);
441 	return true;
442 }
443 
acpi_ec_submit_event(struct acpi_ec * ec)444 static void acpi_ec_submit_event(struct acpi_ec *ec)
445 {
446 	/*
447 	 * It is safe to mask the events here, because acpi_ec_close_event()
448 	 * will run at least once after this.
449 	 */
450 	acpi_ec_mask_events(ec);
451 	if (!acpi_ec_event_enabled(ec))
452 		return;
453 
454 	if (ec->event_state != EC_EVENT_READY)
455 		return;
456 
457 	ec_dbg_evt("Command(%s) submitted/blocked",
458 		   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
459 
460 	ec->event_state = EC_EVENT_IN_PROGRESS;
461 	/*
462 	 * If events_to_process is greater than 0 at this point, the while ()
463 	 * loop in acpi_ec_event_handler() is still running and incrementing
464 	 * events_to_process will cause it to invoke acpi_ec_submit_query() once
465 	 * more, so it is not necessary to queue up the event work to start the
466 	 * same loop again.
467 	 */
468 	if (ec->events_to_process++ > 0)
469 		return;
470 
471 	ec->events_in_progress++;
472 	queue_work(ec_wq, &ec->work);
473 }
474 
acpi_ec_complete_event(struct acpi_ec * ec)475 static void acpi_ec_complete_event(struct acpi_ec *ec)
476 {
477 	if (ec->event_state == EC_EVENT_IN_PROGRESS)
478 		ec->event_state = EC_EVENT_COMPLETE;
479 }
480 
acpi_ec_close_event(struct acpi_ec * ec)481 static void acpi_ec_close_event(struct acpi_ec *ec)
482 {
483 	if (ec->event_state != EC_EVENT_READY)
484 		ec_dbg_evt("Command(%s) unblocked",
485 			   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
486 
487 	ec->event_state = EC_EVENT_READY;
488 	acpi_ec_unmask_events(ec);
489 }
490 
__acpi_ec_enable_event(struct acpi_ec * ec)491 static inline void __acpi_ec_enable_event(struct acpi_ec *ec)
492 {
493 	if (!test_and_set_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
494 		ec_log_drv("event unblocked");
495 	/*
496 	 * Unconditionally invoke this once after enabling the event
497 	 * handling mechanism to detect the pending events.
498 	 */
499 	advance_transaction(ec, false);
500 }
501 
__acpi_ec_disable_event(struct acpi_ec * ec)502 static inline void __acpi_ec_disable_event(struct acpi_ec *ec)
503 {
504 	if (test_and_clear_bit(EC_FLAGS_QUERY_ENABLED, &ec->flags))
505 		ec_log_drv("event blocked");
506 }
507 
508 /*
509  * Process _Q events that might have accumulated in the EC.
510  * Run with locked ec mutex.
511  */
acpi_ec_clear(struct acpi_ec * ec)512 static void acpi_ec_clear(struct acpi_ec *ec)
513 {
514 	int i;
515 
516 	for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
517 		if (acpi_ec_submit_query(ec))
518 			break;
519 	}
520 	if (unlikely(i == ACPI_EC_CLEAR_MAX))
521 		pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
522 	else
523 		pr_info("%d stale EC events cleared\n", i);
524 }
525 
acpi_ec_enable_event(struct acpi_ec * ec)526 static void acpi_ec_enable_event(struct acpi_ec *ec)
527 {
528 	unsigned long flags;
529 
530 	spin_lock_irqsave(&ec->lock, flags);
531 	if (acpi_ec_started(ec))
532 		__acpi_ec_enable_event(ec);
533 	spin_unlock_irqrestore(&ec->lock, flags);
534 
535 	/* Drain additional events if hardware requires that */
536 	if (EC_FLAGS_CLEAR_ON_RESUME)
537 		acpi_ec_clear(ec);
538 }
539 
540 #ifdef CONFIG_PM_SLEEP
__acpi_ec_flush_work(void)541 static void __acpi_ec_flush_work(void)
542 {
543 	flush_workqueue(ec_wq); /* flush ec->work */
544 	flush_workqueue(ec_query_wq); /* flush queries */
545 }
546 
acpi_ec_disable_event(struct acpi_ec * ec)547 static void acpi_ec_disable_event(struct acpi_ec *ec)
548 {
549 	unsigned long flags;
550 
551 	spin_lock_irqsave(&ec->lock, flags);
552 	__acpi_ec_disable_event(ec);
553 	spin_unlock_irqrestore(&ec->lock, flags);
554 
555 	/*
556 	 * When ec_freeze_events is true, we need to flush events in
557 	 * the proper position before entering the noirq stage.
558 	 */
559 	__acpi_ec_flush_work();
560 }
561 
acpi_ec_flush_work(void)562 void acpi_ec_flush_work(void)
563 {
564 	/* Without ec_wq there is nothing to flush. */
565 	if (!ec_wq)
566 		return;
567 
568 	__acpi_ec_flush_work();
569 }
570 #endif /* CONFIG_PM_SLEEP */
571 
acpi_ec_guard_event(struct acpi_ec * ec)572 static bool acpi_ec_guard_event(struct acpi_ec *ec)
573 {
574 	unsigned long flags;
575 	bool guarded;
576 
577 	spin_lock_irqsave(&ec->lock, flags);
578 	/*
579 	 * If firmware SCI_EVT clearing timing is "event", we actually
580 	 * don't know when the SCI_EVT will be cleared by firmware after
581 	 * evaluating _Qxx, so we need to re-check SCI_EVT after waiting an
582 	 * acceptable period.
583 	 *
584 	 * The guarding period is applicable if the event state is not
585 	 * EC_EVENT_READY, but otherwise if the current transaction is of the
586 	 * ACPI_EC_COMMAND_QUERY type, the guarding should have elapsed already
587 	 * and it should not be applied to let the transaction transition into
588 	 * the ACPI_EC_COMMAND_POLL state immediately.
589 	 */
590 	guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
591 		ec->event_state != EC_EVENT_READY &&
592 		(!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);
593 	spin_unlock_irqrestore(&ec->lock, flags);
594 	return guarded;
595 }
596 
ec_transaction_polled(struct acpi_ec * ec)597 static int ec_transaction_polled(struct acpi_ec *ec)
598 {
599 	unsigned long flags;
600 	int ret = 0;
601 
602 	spin_lock_irqsave(&ec->lock, flags);
603 	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))
604 		ret = 1;
605 	spin_unlock_irqrestore(&ec->lock, flags);
606 	return ret;
607 }
608 
ec_transaction_completed(struct acpi_ec * ec)609 static int ec_transaction_completed(struct acpi_ec *ec)
610 {
611 	unsigned long flags;
612 	int ret = 0;
613 
614 	spin_lock_irqsave(&ec->lock, flags);
615 	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
616 		ret = 1;
617 	spin_unlock_irqrestore(&ec->lock, flags);
618 	return ret;
619 }
620 
ec_transaction_transition(struct acpi_ec * ec,unsigned long flag)621 static inline void ec_transaction_transition(struct acpi_ec *ec, unsigned long flag)
622 {
623 	ec->curr->flags |= flag;
624 
625 	if (ec->curr->command != ACPI_EC_COMMAND_QUERY)
626 		return;
627 
628 	switch (ec_event_clearing) {
629 	case ACPI_EC_EVT_TIMING_STATUS:
630 		if (flag == ACPI_EC_COMMAND_POLL)
631 			acpi_ec_close_event(ec);
632 
633 		return;
634 
635 	case ACPI_EC_EVT_TIMING_QUERY:
636 		if (flag == ACPI_EC_COMMAND_COMPLETE)
637 			acpi_ec_close_event(ec);
638 
639 		return;
640 
641 	case ACPI_EC_EVT_TIMING_EVENT:
642 		if (flag == ACPI_EC_COMMAND_COMPLETE)
643 			acpi_ec_complete_event(ec);
644 	}
645 }
646 
acpi_ec_spurious_interrupt(struct acpi_ec * ec,struct transaction * t)647 static void acpi_ec_spurious_interrupt(struct acpi_ec *ec, struct transaction *t)
648 {
649 	if (t->irq_count < ec_storm_threshold)
650 		++t->irq_count;
651 
652 	/* Trigger if the threshold is 0 too. */
653 	if (t->irq_count == ec_storm_threshold)
654 		acpi_ec_mask_events(ec);
655 }
656 
advance_transaction(struct acpi_ec * ec,bool interrupt)657 static void advance_transaction(struct acpi_ec *ec, bool interrupt)
658 {
659 	struct transaction *t = ec->curr;
660 	bool wakeup = false;
661 	u8 status;
662 
663 	ec_dbg_stm("%s (%d)", interrupt ? "IRQ" : "TASK", smp_processor_id());
664 
665 	status = acpi_ec_read_status(ec);
666 
667 	/*
668 	 * Another IRQ or a guarded polling mode advancement is detected,
669 	 * the next QR_EC submission is then allowed.
670 	 */
671 	if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) {
672 		if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&
673 		    ec->event_state == EC_EVENT_COMPLETE)
674 			acpi_ec_close_event(ec);
675 
676 		if (!t)
677 			goto out;
678 	}
679 
680 	if (t->flags & ACPI_EC_COMMAND_POLL) {
681 		if (t->wlen > t->wi) {
682 			if (!(status & ACPI_EC_FLAG_IBF))
683 				acpi_ec_write_data(ec, t->wdata[t->wi++]);
684 			else if (interrupt && !(status & ACPI_EC_FLAG_SCI))
685 				acpi_ec_spurious_interrupt(ec, t);
686 		} else if (t->rlen > t->ri) {
687 			if (status & ACPI_EC_FLAG_OBF) {
688 				t->rdata[t->ri++] = acpi_ec_read_data(ec);
689 				if (t->rlen == t->ri) {
690 					ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
691 					wakeup = true;
692 					if (t->command == ACPI_EC_COMMAND_QUERY)
693 						ec_dbg_evt("Command(%s) completed by hardware",
694 							   acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY));
695 				}
696 			} else if (interrupt && !(status & ACPI_EC_FLAG_SCI)) {
697 				acpi_ec_spurious_interrupt(ec, t);
698 			}
699 		} else if (t->wlen == t->wi && !(status & ACPI_EC_FLAG_IBF)) {
700 			ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE);
701 			wakeup = true;
702 		}
703 	} else if (!(status & ACPI_EC_FLAG_IBF)) {
704 		acpi_ec_write_cmd(ec, t->command);
705 		ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL);
706 	}
707 
708 out:
709 	if (status & ACPI_EC_FLAG_SCI)
710 		acpi_ec_submit_event(ec);
711 
712 	if (wakeup && interrupt)
713 		wake_up(&ec->wait);
714 }
715 
start_transaction(struct acpi_ec * ec)716 static void start_transaction(struct acpi_ec *ec)
717 {
718 	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
719 	ec->curr->flags = 0;
720 }
721 
ec_guard(struct acpi_ec * ec)722 static int ec_guard(struct acpi_ec *ec)
723 {
724 	unsigned long guard = usecs_to_jiffies(ec->polling_guard);
725 	unsigned long timeout = ec->timestamp + guard;
726 
727 	/* Ensure guarding period before polling EC status */
728 	do {
729 		if (ec->busy_polling) {
730 			/* Perform busy polling */
731 			if (ec_transaction_completed(ec))
732 				return 0;
733 			udelay(jiffies_to_usecs(guard));
734 		} else {
735 			/*
736 			 * Perform wait polling
737 			 * 1. Wait the transaction to be completed by the
738 			 *    GPE handler after the transaction enters
739 			 *    ACPI_EC_COMMAND_POLL state.
740 			 * 2. A special guarding logic is also required
741 			 *    for event clearing mode "event" before the
742 			 *    transaction enters ACPI_EC_COMMAND_POLL
743 			 *    state.
744 			 */
745 			if (!ec_transaction_polled(ec) &&
746 			    !acpi_ec_guard_event(ec))
747 				break;
748 			if (wait_event_timeout(ec->wait,
749 					       ec_transaction_completed(ec),
750 					       guard))
751 				return 0;
752 		}
753 	} while (time_before(jiffies, timeout));
754 	return -ETIME;
755 }
756 
ec_poll(struct acpi_ec * ec)757 static int ec_poll(struct acpi_ec *ec)
758 {
759 	unsigned long flags;
760 	int repeat = 5; /* number of command restarts */
761 
762 	while (repeat--) {
763 		unsigned long delay = jiffies +
764 			msecs_to_jiffies(ec_delay);
765 		do {
766 			if (!ec_guard(ec))
767 				return 0;
768 			spin_lock_irqsave(&ec->lock, flags);
769 			advance_transaction(ec, false);
770 			spin_unlock_irqrestore(&ec->lock, flags);
771 		} while (time_before(jiffies, delay));
772 		pr_debug("controller reset, restart transaction\n");
773 		spin_lock_irqsave(&ec->lock, flags);
774 		start_transaction(ec);
775 		spin_unlock_irqrestore(&ec->lock, flags);
776 	}
777 	return -ETIME;
778 }
779 
acpi_ec_transaction_unlocked(struct acpi_ec * ec,struct transaction * t)780 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
781 					struct transaction *t)
782 {
783 	unsigned long tmp;
784 	int ret = 0;
785 
786 	/* start transaction */
787 	spin_lock_irqsave(&ec->lock, tmp);
788 	/* Enable GPE for command processing (IBF=0/OBF=1) */
789 	if (!acpi_ec_submit_flushable_request(ec)) {
790 		ret = -EINVAL;
791 		goto unlock;
792 	}
793 	ec_dbg_ref(ec, "Increase command");
794 	/* following two actions should be kept atomic */
795 	ec->curr = t;
796 	ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
797 	start_transaction(ec);
798 	spin_unlock_irqrestore(&ec->lock, tmp);
799 
800 	ret = ec_poll(ec);
801 
802 	spin_lock_irqsave(&ec->lock, tmp);
803 	if (t->irq_count == ec_storm_threshold)
804 		acpi_ec_unmask_events(ec);
805 	ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
806 	ec->curr = NULL;
807 	/* Disable GPE for command processing (IBF=0/OBF=1) */
808 	acpi_ec_complete_request(ec);
809 	ec_dbg_ref(ec, "Decrease command");
810 unlock:
811 	spin_unlock_irqrestore(&ec->lock, tmp);
812 	return ret;
813 }
814 
acpi_ec_transaction(struct acpi_ec * ec,struct transaction * t)815 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
816 {
817 	int status;
818 	u32 glk;
819 
820 	if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
821 		return -EINVAL;
822 	if (t->rdata)
823 		memset(t->rdata, 0, t->rlen);
824 
825 	mutex_lock(&ec->mutex);
826 	if (ec->global_lock) {
827 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
828 		if (ACPI_FAILURE(status)) {
829 			status = -ENODEV;
830 			goto unlock;
831 		}
832 	}
833 
834 	status = acpi_ec_transaction_unlocked(ec, t);
835 
836 	if (ec->global_lock)
837 		acpi_release_global_lock(glk);
838 unlock:
839 	mutex_unlock(&ec->mutex);
840 	return status;
841 }
842 
acpi_ec_burst_enable(struct acpi_ec * ec)843 static int acpi_ec_burst_enable(struct acpi_ec *ec)
844 {
845 	u8 d;
846 	struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
847 				.wdata = NULL, .rdata = &d,
848 				.wlen = 0, .rlen = 1};
849 
850 	return acpi_ec_transaction(ec, &t);
851 }
852 
acpi_ec_burst_disable(struct acpi_ec * ec)853 static int acpi_ec_burst_disable(struct acpi_ec *ec)
854 {
855 	struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
856 				.wdata = NULL, .rdata = NULL,
857 				.wlen = 0, .rlen = 0};
858 
859 	return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
860 				acpi_ec_transaction(ec, &t) : 0;
861 }
862 
acpi_ec_read(struct acpi_ec * ec,u8 address,u8 * data)863 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
864 {
865 	int result;
866 	u8 d;
867 	struct transaction t = {.command = ACPI_EC_COMMAND_READ,
868 				.wdata = &address, .rdata = &d,
869 				.wlen = 1, .rlen = 1};
870 
871 	result = acpi_ec_transaction(ec, &t);
872 	*data = d;
873 	return result;
874 }
875 
acpi_ec_write(struct acpi_ec * ec,u8 address,u8 data)876 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
877 {
878 	u8 wdata[2] = { address, data };
879 	struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
880 				.wdata = wdata, .rdata = NULL,
881 				.wlen = 2, .rlen = 0};
882 
883 	return acpi_ec_transaction(ec, &t);
884 }
885 
ec_read(u8 addr,u8 * val)886 int ec_read(u8 addr, u8 *val)
887 {
888 	int err;
889 	u8 temp_data;
890 
891 	if (!first_ec)
892 		return -ENODEV;
893 
894 	err = acpi_ec_read(first_ec, addr, &temp_data);
895 
896 	if (!err) {
897 		*val = temp_data;
898 		return 0;
899 	}
900 	return err;
901 }
902 EXPORT_SYMBOL(ec_read);
903 
ec_write(u8 addr,u8 val)904 int ec_write(u8 addr, u8 val)
905 {
906 	if (!first_ec)
907 		return -ENODEV;
908 
909 	return acpi_ec_write(first_ec, addr, val);
910 }
911 EXPORT_SYMBOL(ec_write);
912 
ec_transaction(u8 command,const u8 * wdata,unsigned wdata_len,u8 * rdata,unsigned rdata_len)913 int ec_transaction(u8 command,
914 		   const u8 *wdata, unsigned wdata_len,
915 		   u8 *rdata, unsigned rdata_len)
916 {
917 	struct transaction t = {.command = command,
918 				.wdata = wdata, .rdata = rdata,
919 				.wlen = wdata_len, .rlen = rdata_len};
920 
921 	if (!first_ec)
922 		return -ENODEV;
923 
924 	return acpi_ec_transaction(first_ec, &t);
925 }
926 EXPORT_SYMBOL(ec_transaction);
927 
928 /* Get the handle to the EC device */
ec_get_handle(void)929 acpi_handle ec_get_handle(void)
930 {
931 	if (!first_ec)
932 		return NULL;
933 	return first_ec->handle;
934 }
935 EXPORT_SYMBOL(ec_get_handle);
936 
acpi_ec_start(struct acpi_ec * ec,bool resuming)937 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
938 {
939 	unsigned long flags;
940 
941 	spin_lock_irqsave(&ec->lock, flags);
942 	if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
943 		ec_dbg_drv("Starting EC");
944 		/* Enable GPE for event processing (SCI_EVT=1) */
945 		if (!resuming) {
946 			acpi_ec_submit_request(ec);
947 			ec_dbg_ref(ec, "Increase driver");
948 		}
949 		ec_log_drv("EC started");
950 	}
951 	spin_unlock_irqrestore(&ec->lock, flags);
952 }
953 
acpi_ec_stopped(struct acpi_ec * ec)954 static bool acpi_ec_stopped(struct acpi_ec *ec)
955 {
956 	unsigned long flags;
957 	bool flushed;
958 
959 	spin_lock_irqsave(&ec->lock, flags);
960 	flushed = acpi_ec_flushed(ec);
961 	spin_unlock_irqrestore(&ec->lock, flags);
962 	return flushed;
963 }
964 
acpi_ec_stop(struct acpi_ec * ec,bool suspending)965 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
966 {
967 	unsigned long flags;
968 
969 	spin_lock_irqsave(&ec->lock, flags);
970 	if (acpi_ec_started(ec)) {
971 		ec_dbg_drv("Stopping EC");
972 		set_bit(EC_FLAGS_STOPPED, &ec->flags);
973 		spin_unlock_irqrestore(&ec->lock, flags);
974 		wait_event(ec->wait, acpi_ec_stopped(ec));
975 		spin_lock_irqsave(&ec->lock, flags);
976 		/* Disable GPE for event processing (SCI_EVT=1) */
977 		if (!suspending) {
978 			acpi_ec_complete_request(ec);
979 			ec_dbg_ref(ec, "Decrease driver");
980 		} else if (!ec_freeze_events)
981 			__acpi_ec_disable_event(ec);
982 		clear_bit(EC_FLAGS_STARTED, &ec->flags);
983 		clear_bit(EC_FLAGS_STOPPED, &ec->flags);
984 		ec_log_drv("EC stopped");
985 	}
986 	spin_unlock_irqrestore(&ec->lock, flags);
987 }
988 
acpi_ec_enter_noirq(struct acpi_ec * ec)989 static void acpi_ec_enter_noirq(struct acpi_ec *ec)
990 {
991 	unsigned long flags;
992 
993 	spin_lock_irqsave(&ec->lock, flags);
994 	ec->busy_polling = true;
995 	ec->polling_guard = 0;
996 	ec_log_drv("interrupt blocked");
997 	spin_unlock_irqrestore(&ec->lock, flags);
998 }
999 
acpi_ec_leave_noirq(struct acpi_ec * ec)1000 static void acpi_ec_leave_noirq(struct acpi_ec *ec)
1001 {
1002 	unsigned long flags;
1003 
1004 	spin_lock_irqsave(&ec->lock, flags);
1005 	ec->busy_polling = ec_busy_polling;
1006 	ec->polling_guard = ec_polling_guard;
1007 	ec_log_drv("interrupt unblocked");
1008 	spin_unlock_irqrestore(&ec->lock, flags);
1009 }
1010 
acpi_ec_block_transactions(void)1011 void acpi_ec_block_transactions(void)
1012 {
1013 	struct acpi_ec *ec = first_ec;
1014 
1015 	if (!ec)
1016 		return;
1017 
1018 	mutex_lock(&ec->mutex);
1019 	/* Prevent transactions from being carried out */
1020 	acpi_ec_stop(ec, true);
1021 	mutex_unlock(&ec->mutex);
1022 }
1023 
acpi_ec_unblock_transactions(void)1024 void acpi_ec_unblock_transactions(void)
1025 {
1026 	/*
1027 	 * Allow transactions to happen again (this function is called from
1028 	 * atomic context during wakeup, so we don't need to acquire the mutex).
1029 	 */
1030 	if (first_ec)
1031 		acpi_ec_start(first_ec, true);
1032 }
1033 
1034 /* --------------------------------------------------------------------------
1035                                 Event Management
1036    -------------------------------------------------------------------------- */
1037 static struct acpi_ec_query_handler *
acpi_ec_get_query_handler_by_value(struct acpi_ec * ec,u8 value)1038 acpi_ec_get_query_handler_by_value(struct acpi_ec *ec, u8 value)
1039 {
1040 	struct acpi_ec_query_handler *handler;
1041 
1042 	mutex_lock(&ec->mutex);
1043 	list_for_each_entry(handler, &ec->list, node) {
1044 		if (value == handler->query_bit) {
1045 			kref_get(&handler->kref);
1046 			mutex_unlock(&ec->mutex);
1047 			return handler;
1048 		}
1049 	}
1050 	mutex_unlock(&ec->mutex);
1051 	return NULL;
1052 }
1053 
acpi_ec_query_handler_release(struct kref * kref)1054 static void acpi_ec_query_handler_release(struct kref *kref)
1055 {
1056 	struct acpi_ec_query_handler *handler =
1057 		container_of(kref, struct acpi_ec_query_handler, kref);
1058 
1059 	kfree(handler);
1060 }
1061 
acpi_ec_put_query_handler(struct acpi_ec_query_handler * handler)1062 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
1063 {
1064 	kref_put(&handler->kref, acpi_ec_query_handler_release);
1065 }
1066 
acpi_ec_add_query_handler(struct acpi_ec * ec,u8 query_bit,acpi_handle handle,acpi_ec_query_func func,void * data)1067 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
1068 			      acpi_handle handle, acpi_ec_query_func func,
1069 			      void *data)
1070 {
1071 	struct acpi_ec_query_handler *handler;
1072 
1073 	if (!handle && !func)
1074 		return -EINVAL;
1075 
1076 	handler = kzalloc(sizeof(*handler), GFP_KERNEL);
1077 	if (!handler)
1078 		return -ENOMEM;
1079 
1080 	handler->query_bit = query_bit;
1081 	handler->handle = handle;
1082 	handler->func = func;
1083 	handler->data = data;
1084 	mutex_lock(&ec->mutex);
1085 	kref_init(&handler->kref);
1086 	list_add(&handler->node, &ec->list);
1087 	mutex_unlock(&ec->mutex);
1088 
1089 	return 0;
1090 }
1091 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
1092 
acpi_ec_remove_query_handlers(struct acpi_ec * ec,bool remove_all,u8 query_bit)1093 static void acpi_ec_remove_query_handlers(struct acpi_ec *ec,
1094 					  bool remove_all, u8 query_bit)
1095 {
1096 	struct acpi_ec_query_handler *handler, *tmp;
1097 	LIST_HEAD(free_list);
1098 
1099 	mutex_lock(&ec->mutex);
1100 	list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1101 		/*
1102 		 * When remove_all is false, only remove custom query handlers
1103 		 * which have handler->func set. This is done to preserve query
1104 		 * handlers discovered thru ACPI, as they should continue handling
1105 		 * EC queries.
1106 		 */
1107 		if (remove_all || (handler->func && handler->query_bit == query_bit)) {
1108 			list_del_init(&handler->node);
1109 			list_add(&handler->node, &free_list);
1110 
1111 		}
1112 	}
1113 	mutex_unlock(&ec->mutex);
1114 	list_for_each_entry_safe(handler, tmp, &free_list, node)
1115 		acpi_ec_put_query_handler(handler);
1116 }
1117 
acpi_ec_remove_query_handler(struct acpi_ec * ec,u8 query_bit)1118 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
1119 {
1120 	acpi_ec_remove_query_handlers(ec, false, query_bit);
1121 	flush_workqueue(ec_query_wq);
1122 }
1123 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
1124 
acpi_ec_event_processor(struct work_struct * work)1125 static void acpi_ec_event_processor(struct work_struct *work)
1126 {
1127 	struct acpi_ec_query *q = container_of(work, struct acpi_ec_query, work);
1128 	struct acpi_ec_query_handler *handler = q->handler;
1129 	struct acpi_ec *ec = q->ec;
1130 
1131 	ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
1132 
1133 	if (handler->func)
1134 		handler->func(handler->data);
1135 	else if (handler->handle)
1136 		acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
1137 
1138 	ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
1139 
1140 	spin_lock_irq(&ec->lock);
1141 	ec->queries_in_progress--;
1142 	spin_unlock_irq(&ec->lock);
1143 
1144 	acpi_ec_put_query_handler(handler);
1145 	kfree(q);
1146 }
1147 
acpi_ec_create_query(struct acpi_ec * ec,u8 * pval)1148 static struct acpi_ec_query *acpi_ec_create_query(struct acpi_ec *ec, u8 *pval)
1149 {
1150 	struct acpi_ec_query *q;
1151 	struct transaction *t;
1152 
1153 	q = kzalloc(sizeof (struct acpi_ec_query), GFP_KERNEL);
1154 	if (!q)
1155 		return NULL;
1156 
1157 	INIT_WORK(&q->work, acpi_ec_event_processor);
1158 	t = &q->transaction;
1159 	t->command = ACPI_EC_COMMAND_QUERY;
1160 	t->rdata = pval;
1161 	t->rlen = 1;
1162 	q->ec = ec;
1163 	return q;
1164 }
1165 
acpi_ec_submit_query(struct acpi_ec * ec)1166 static int acpi_ec_submit_query(struct acpi_ec *ec)
1167 {
1168 	struct acpi_ec_query *q;
1169 	u8 value = 0;
1170 	int result;
1171 
1172 	q = acpi_ec_create_query(ec, &value);
1173 	if (!q)
1174 		return -ENOMEM;
1175 
1176 	/*
1177 	 * Query the EC to find out which _Qxx method we need to evaluate.
1178 	 * Note that successful completion of the query causes the ACPI_EC_SCI
1179 	 * bit to be cleared (and thus clearing the interrupt source).
1180 	 */
1181 	result = acpi_ec_transaction(ec, &q->transaction);
1182 	if (result)
1183 		goto err_exit;
1184 
1185 	if (!value) {
1186 		result = -ENODATA;
1187 		goto err_exit;
1188 	}
1189 
1190 	q->handler = acpi_ec_get_query_handler_by_value(ec, value);
1191 	if (!q->handler) {
1192 		result = -ENODATA;
1193 		goto err_exit;
1194 	}
1195 
1196 	/*
1197 	 * It is reported that _Qxx are evaluated in a parallel way on Windows:
1198 	 * https://bugzilla.kernel.org/show_bug.cgi?id=94411
1199 	 *
1200 	 * Put this log entry before queue_work() to make it appear in the log
1201 	 * before any other messages emitted during workqueue handling.
1202 	 */
1203 	ec_dbg_evt("Query(0x%02x) scheduled", value);
1204 
1205 	spin_lock_irq(&ec->lock);
1206 
1207 	ec->queries_in_progress++;
1208 	queue_work(ec_query_wq, &q->work);
1209 
1210 	spin_unlock_irq(&ec->lock);
1211 
1212 	return 0;
1213 
1214 err_exit:
1215 	kfree(q);
1216 
1217 	return result;
1218 }
1219 
acpi_ec_event_handler(struct work_struct * work)1220 static void acpi_ec_event_handler(struct work_struct *work)
1221 {
1222 	struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
1223 
1224 	ec_dbg_evt("Event started");
1225 
1226 	spin_lock_irq(&ec->lock);
1227 
1228 	while (ec->events_to_process) {
1229 		spin_unlock_irq(&ec->lock);
1230 
1231 		acpi_ec_submit_query(ec);
1232 
1233 		spin_lock_irq(&ec->lock);
1234 
1235 		ec->events_to_process--;
1236 	}
1237 
1238 	/*
1239 	 * Before exit, make sure that the it will be possible to queue up the
1240 	 * event handling work again regardless of whether or not the query
1241 	 * queued up above is processed successfully.
1242 	 */
1243 	if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT) {
1244 		bool guard_timeout;
1245 
1246 		acpi_ec_complete_event(ec);
1247 
1248 		ec_dbg_evt("Event stopped");
1249 
1250 		spin_unlock_irq(&ec->lock);
1251 
1252 		guard_timeout = !!ec_guard(ec);
1253 
1254 		spin_lock_irq(&ec->lock);
1255 
1256 		/* Take care of SCI_EVT unless someone else is doing that. */
1257 		if (guard_timeout && !ec->curr)
1258 			advance_transaction(ec, false);
1259 	} else {
1260 		acpi_ec_close_event(ec);
1261 
1262 		ec_dbg_evt("Event stopped");
1263 	}
1264 
1265 	ec->events_in_progress--;
1266 
1267 	spin_unlock_irq(&ec->lock);
1268 }
1269 
clear_gpe_and_advance_transaction(struct acpi_ec * ec,bool interrupt)1270 static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
1271 {
1272 	/*
1273 	 * Clear GPE_STS upfront to allow subsequent hardware GPE_STS 0->1
1274 	 * changes to always trigger a GPE interrupt.
1275 	 *
1276 	 * GPE STS is a W1C register, which means:
1277 	 *
1278 	 * 1. Software can clear it without worrying about clearing the other
1279 	 *    GPEs' STS bits when the hardware sets them in parallel.
1280 	 *
1281 	 * 2. As long as software can ensure only clearing it when it is set,
1282 	 *    hardware won't set it in parallel.
1283 	 */
1284 	if (ec->gpe >= 0 && acpi_ec_gpe_status_set(ec))
1285 		acpi_clear_gpe(NULL, ec->gpe);
1286 
1287 	advance_transaction(ec, true);
1288 }
1289 
acpi_ec_handle_interrupt(struct acpi_ec * ec)1290 static void acpi_ec_handle_interrupt(struct acpi_ec *ec)
1291 {
1292 	unsigned long flags;
1293 
1294 	spin_lock_irqsave(&ec->lock, flags);
1295 
1296 	clear_gpe_and_advance_transaction(ec, true);
1297 
1298 	spin_unlock_irqrestore(&ec->lock, flags);
1299 }
1300 
acpi_ec_gpe_handler(acpi_handle gpe_device,u32 gpe_number,void * data)1301 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
1302 			       u32 gpe_number, void *data)
1303 {
1304 	acpi_ec_handle_interrupt(data);
1305 	return ACPI_INTERRUPT_HANDLED;
1306 }
1307 
acpi_ec_irq_handler(int irq,void * data)1308 static irqreturn_t acpi_ec_irq_handler(int irq, void *data)
1309 {
1310 	acpi_ec_handle_interrupt(data);
1311 	return IRQ_HANDLED;
1312 }
1313 
1314 /* --------------------------------------------------------------------------
1315  *                           Address Space Management
1316  * -------------------------------------------------------------------------- */
1317 
1318 static acpi_status
acpi_ec_space_handler(u32 function,acpi_physical_address address,u32 bits,u64 * value64,void * handler_context,void * region_context)1319 acpi_ec_space_handler(u32 function, acpi_physical_address address,
1320 		      u32 bits, u64 *value64,
1321 		      void *handler_context, void *region_context)
1322 {
1323 	struct acpi_ec *ec = handler_context;
1324 	int result = 0, i, bytes = bits / 8;
1325 	u8 *value = (u8 *)value64;
1326 
1327 	if ((address > 0xFF) || !value || !handler_context)
1328 		return AE_BAD_PARAMETER;
1329 
1330 	if (function != ACPI_READ && function != ACPI_WRITE)
1331 		return AE_BAD_PARAMETER;
1332 
1333 	if (ec->busy_polling || bits > 8)
1334 		acpi_ec_burst_enable(ec);
1335 
1336 	for (i = 0; i < bytes; ++i, ++address, ++value)
1337 		result = (function == ACPI_READ) ?
1338 			acpi_ec_read(ec, address, value) :
1339 			acpi_ec_write(ec, address, *value);
1340 
1341 	if (ec->busy_polling || bits > 8)
1342 		acpi_ec_burst_disable(ec);
1343 
1344 	switch (result) {
1345 	case -EINVAL:
1346 		return AE_BAD_PARAMETER;
1347 	case -ENODEV:
1348 		return AE_NOT_FOUND;
1349 	case -ETIME:
1350 		return AE_TIME;
1351 	default:
1352 		return AE_OK;
1353 	}
1354 }
1355 
1356 /* --------------------------------------------------------------------------
1357  *                             Driver Interface
1358  * -------------------------------------------------------------------------- */
1359 
1360 static acpi_status
1361 ec_parse_io_ports(struct acpi_resource *resource, void *context);
1362 
acpi_ec_free(struct acpi_ec * ec)1363 static void acpi_ec_free(struct acpi_ec *ec)
1364 {
1365 	if (first_ec == ec)
1366 		first_ec = NULL;
1367 	if (boot_ec == ec)
1368 		boot_ec = NULL;
1369 	kfree(ec);
1370 }
1371 
acpi_ec_alloc(void)1372 static struct acpi_ec *acpi_ec_alloc(void)
1373 {
1374 	struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
1375 
1376 	if (!ec)
1377 		return NULL;
1378 	mutex_init(&ec->mutex);
1379 	init_waitqueue_head(&ec->wait);
1380 	INIT_LIST_HEAD(&ec->list);
1381 	spin_lock_init(&ec->lock);
1382 	INIT_WORK(&ec->work, acpi_ec_event_handler);
1383 	ec->timestamp = jiffies;
1384 	ec->busy_polling = true;
1385 	ec->polling_guard = 0;
1386 	ec->gpe = -1;
1387 	ec->irq = -1;
1388 	return ec;
1389 }
1390 
1391 static acpi_status
acpi_ec_register_query_methods(acpi_handle handle,u32 level,void * context,void ** return_value)1392 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1393 			       void *context, void **return_value)
1394 {
1395 	char node_name[5];
1396 	struct acpi_buffer buffer = { sizeof(node_name), node_name };
1397 	struct acpi_ec *ec = context;
1398 	int value = 0;
1399 	acpi_status status;
1400 
1401 	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1402 
1403 	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1404 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1405 	return AE_OK;
1406 }
1407 
1408 static acpi_status
ec_parse_device(acpi_handle handle,u32 Level,void * context,void ** retval)1409 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1410 {
1411 	acpi_status status;
1412 	unsigned long long tmp = 0;
1413 	struct acpi_ec *ec = context;
1414 
1415 	/* clear addr values, ec_parse_io_ports depend on it */
1416 	ec->command_addr = ec->data_addr = 0;
1417 
1418 	status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1419 				     ec_parse_io_ports, ec);
1420 	if (ACPI_FAILURE(status))
1421 		return status;
1422 	if (ec->data_addr == 0 || ec->command_addr == 0)
1423 		return AE_OK;
1424 
1425 	/* Get GPE bit assignment (EC events). */
1426 	/* TODO: Add support for _GPE returning a package */
1427 	status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1428 	if (ACPI_SUCCESS(status))
1429 		ec->gpe = tmp;
1430 	/*
1431 	 * Errors are non-fatal, allowing for ACPI Reduced Hardware
1432 	 * platforms which use GpioInt instead of GPE.
1433 	 */
1434 
1435 	/* Use the global lock for all EC transactions? */
1436 	tmp = 0;
1437 	acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1438 	ec->global_lock = tmp;
1439 	ec->handle = handle;
1440 	return AE_CTRL_TERMINATE;
1441 }
1442 
install_gpe_event_handler(struct acpi_ec * ec)1443 static bool install_gpe_event_handler(struct acpi_ec *ec)
1444 {
1445 	acpi_status status;
1446 
1447 	status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1448 					      ACPI_GPE_EDGE_TRIGGERED,
1449 					      &acpi_ec_gpe_handler, ec);
1450 	if (ACPI_FAILURE(status))
1451 		return false;
1452 
1453 	if (test_bit(EC_FLAGS_STARTED, &ec->flags) && ec->reference_count >= 1)
1454 		acpi_ec_enable_gpe(ec, true);
1455 
1456 	return true;
1457 }
1458 
install_gpio_irq_event_handler(struct acpi_ec * ec)1459 static bool install_gpio_irq_event_handler(struct acpi_ec *ec)
1460 {
1461 	return request_irq(ec->irq, acpi_ec_irq_handler, IRQF_SHARED,
1462 			   "ACPI EC", ec) >= 0;
1463 }
1464 
1465 /**
1466  * ec_install_handlers - Install service callbacks and register query methods.
1467  * @ec: Target EC.
1468  * @device: ACPI device object corresponding to @ec.
1469  * @call_reg: If _REG should be called to notify OpRegion availability
1470  *
1471  * Install a handler for the EC address space type unless it has been installed
1472  * already.  If @device is not NULL, also look for EC query methods in the
1473  * namespace and register them, and install an event (either GPE or GPIO IRQ)
1474  * handler for the EC, if possible.
1475  *
1476  * Return:
1477  * -ENODEV if the address space handler cannot be installed, which means
1478  *  "unable to handle transactions",
1479  * -EPROBE_DEFER if GPIO IRQ acquisition needs to be deferred,
1480  * or 0 (success) otherwise.
1481  */
ec_install_handlers(struct acpi_ec * ec,struct acpi_device * device,bool call_reg)1482 static int ec_install_handlers(struct acpi_ec *ec, struct acpi_device *device,
1483 			       bool call_reg)
1484 {
1485 	acpi_status status;
1486 
1487 	acpi_ec_start(ec, false);
1488 
1489 	if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1490 		acpi_ec_enter_noirq(ec);
1491 		status = acpi_install_address_space_handler_no_reg(ec->handle,
1492 								   ACPI_ADR_SPACE_EC,
1493 								   &acpi_ec_space_handler,
1494 								   NULL, ec);
1495 		if (ACPI_FAILURE(status)) {
1496 			acpi_ec_stop(ec, false);
1497 			return -ENODEV;
1498 		}
1499 		set_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1500 		ec->address_space_handler_holder = ec->handle;
1501 	}
1502 
1503 	if (call_reg && !test_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags)) {
1504 		acpi_execute_reg_methods(ec->handle, ACPI_ADR_SPACE_EC);
1505 		set_bit(EC_FLAGS_EC_REG_CALLED, &ec->flags);
1506 	}
1507 
1508 	if (!device)
1509 		return 0;
1510 
1511 	if (ec->gpe < 0) {
1512 		/* ACPI reduced hardware platforms use a GpioInt from _CRS. */
1513 		int irq = acpi_dev_gpio_irq_get(device, 0);
1514 		/*
1515 		 * Bail out right away for deferred probing or complete the
1516 		 * initialization regardless of any other errors.
1517 		 */
1518 		if (irq == -EPROBE_DEFER)
1519 			return -EPROBE_DEFER;
1520 		else if (irq >= 0)
1521 			ec->irq = irq;
1522 	}
1523 
1524 	if (!test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1525 		/* Find and register all query methods */
1526 		acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1527 				    acpi_ec_register_query_methods,
1528 				    NULL, ec, NULL);
1529 		set_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1530 	}
1531 	if (!test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1532 		bool ready = false;
1533 
1534 		if (ec->gpe >= 0)
1535 			ready = install_gpe_event_handler(ec);
1536 		else if (ec->irq >= 0)
1537 			ready = install_gpio_irq_event_handler(ec);
1538 
1539 		if (ready) {
1540 			set_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1541 			acpi_ec_leave_noirq(ec);
1542 		}
1543 		/*
1544 		 * Failures to install an event handler are not fatal, because
1545 		 * the EC can be polled for events.
1546 		 */
1547 	}
1548 	/* EC is fully operational, allow queries */
1549 	acpi_ec_enable_event(ec);
1550 
1551 	return 0;
1552 }
1553 
ec_remove_handlers(struct acpi_ec * ec)1554 static void ec_remove_handlers(struct acpi_ec *ec)
1555 {
1556 	if (test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
1557 		if (ACPI_FAILURE(acpi_remove_address_space_handler(
1558 					ec->address_space_handler_holder,
1559 					ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1560 			pr_err("failed to remove space handler\n");
1561 		clear_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags);
1562 	}
1563 
1564 	/*
1565 	 * Stops handling the EC transactions after removing the operation
1566 	 * region handler. This is required because _REG(DISCONNECT)
1567 	 * invoked during the removal can result in new EC transactions.
1568 	 *
1569 	 * Flushes the EC requests and thus disables the GPE before
1570 	 * removing the GPE handler. This is required by the current ACPICA
1571 	 * GPE core. ACPICA GPE core will automatically disable a GPE when
1572 	 * it is indicated but there is no way to handle it. So the drivers
1573 	 * must disable the GPEs prior to removing the GPE handlers.
1574 	 */
1575 	acpi_ec_stop(ec, false);
1576 
1577 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1578 		if (ec->gpe >= 0 &&
1579 		    ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1580 				 &acpi_ec_gpe_handler)))
1581 			pr_err("failed to remove gpe handler\n");
1582 
1583 		if (ec->irq >= 0)
1584 			free_irq(ec->irq, ec);
1585 
1586 		clear_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags);
1587 	}
1588 	if (test_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags)) {
1589 		acpi_ec_remove_query_handlers(ec, true, 0);
1590 		clear_bit(EC_FLAGS_QUERY_METHODS_INSTALLED, &ec->flags);
1591 	}
1592 }
1593 
acpi_ec_setup(struct acpi_ec * ec,struct acpi_device * device,bool call_reg)1594 static int acpi_ec_setup(struct acpi_ec *ec, struct acpi_device *device, bool call_reg)
1595 {
1596 	int ret;
1597 
1598 	ret = ec_install_handlers(ec, device, call_reg);
1599 	if (ret)
1600 		return ret;
1601 
1602 	/* First EC capable of handling transactions */
1603 	if (!first_ec)
1604 		first_ec = ec;
1605 
1606 	pr_info("EC_CMD/EC_SC=0x%lx, EC_DATA=0x%lx\n", ec->command_addr,
1607 		ec->data_addr);
1608 
1609 	if (test_bit(EC_FLAGS_EVENT_HANDLER_INSTALLED, &ec->flags)) {
1610 		if (ec->gpe >= 0)
1611 			pr_info("GPE=0x%x\n", ec->gpe);
1612 		else
1613 			pr_info("IRQ=%d\n", ec->irq);
1614 	}
1615 
1616 	return ret;
1617 }
1618 
acpi_ec_add(struct acpi_device * device)1619 static int acpi_ec_add(struct acpi_device *device)
1620 {
1621 	struct acpi_ec *ec;
1622 	int ret;
1623 
1624 	strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1625 	strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1626 
1627 	if (boot_ec && (boot_ec->handle == device->handle ||
1628 	    !strcmp(acpi_device_hid(device), ACPI_ECDT_HID))) {
1629 		/* Fast path: this device corresponds to the boot EC. */
1630 		ec = boot_ec;
1631 	} else {
1632 		acpi_status status;
1633 
1634 		ec = acpi_ec_alloc();
1635 		if (!ec)
1636 			return -ENOMEM;
1637 
1638 		status = ec_parse_device(device->handle, 0, ec, NULL);
1639 		if (status != AE_CTRL_TERMINATE) {
1640 			ret = -EINVAL;
1641 			goto err;
1642 		}
1643 
1644 		if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1645 		    ec->data_addr == boot_ec->data_addr) {
1646 			/*
1647 			 * Trust PNP0C09 namespace location rather than ECDT ID.
1648 			 * But trust ECDT GPE rather than _GPE because of ASUS
1649 			 * quirks. So do not change boot_ec->gpe to ec->gpe,
1650 			 * except when the TRUST_DSDT_GPE quirk is set.
1651 			 */
1652 			boot_ec->handle = ec->handle;
1653 
1654 			if (EC_FLAGS_TRUST_DSDT_GPE)
1655 				boot_ec->gpe = ec->gpe;
1656 
1657 			acpi_handle_debug(ec->handle, "duplicated.\n");
1658 			acpi_ec_free(ec);
1659 			ec = boot_ec;
1660 		}
1661 	}
1662 
1663 	ret = acpi_ec_setup(ec, device, true);
1664 	if (ret)
1665 		goto err;
1666 
1667 	if (ec == boot_ec)
1668 		acpi_handle_info(boot_ec->handle,
1669 				 "Boot %s EC initialization complete\n",
1670 				 boot_ec_is_ecdt ? "ECDT" : "DSDT");
1671 
1672 	acpi_handle_info(ec->handle,
1673 			 "EC: Used to handle transactions and events\n");
1674 
1675 	device->driver_data = ec;
1676 
1677 	ret = !!request_region(ec->data_addr, 1, "EC data");
1678 	WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1679 	ret = !!request_region(ec->command_addr, 1, "EC cmd");
1680 	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1681 
1682 	/* Reprobe devices depending on the EC */
1683 	acpi_dev_clear_dependencies(device);
1684 
1685 	acpi_handle_debug(ec->handle, "enumerated.\n");
1686 	return 0;
1687 
1688 err:
1689 	if (ec != boot_ec)
1690 		acpi_ec_free(ec);
1691 
1692 	return ret;
1693 }
1694 
acpi_ec_remove(struct acpi_device * device)1695 static void acpi_ec_remove(struct acpi_device *device)
1696 {
1697 	struct acpi_ec *ec;
1698 
1699 	if (!device)
1700 		return;
1701 
1702 	ec = acpi_driver_data(device);
1703 	release_region(ec->data_addr, 1);
1704 	release_region(ec->command_addr, 1);
1705 	device->driver_data = NULL;
1706 	if (ec != boot_ec) {
1707 		ec_remove_handlers(ec);
1708 		acpi_ec_free(ec);
1709 	}
1710 }
1711 
1712 static acpi_status
ec_parse_io_ports(struct acpi_resource * resource,void * context)1713 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1714 {
1715 	struct acpi_ec *ec = context;
1716 
1717 	if (resource->type != ACPI_RESOURCE_TYPE_IO)
1718 		return AE_OK;
1719 
1720 	/*
1721 	 * The first address region returned is the data port, and
1722 	 * the second address region returned is the status/command
1723 	 * port.
1724 	 */
1725 	if (ec->data_addr == 0)
1726 		ec->data_addr = resource->data.io.minimum;
1727 	else if (ec->command_addr == 0)
1728 		ec->command_addr = resource->data.io.minimum;
1729 	else
1730 		return AE_CTRL_TERMINATE;
1731 
1732 	return AE_OK;
1733 }
1734 
1735 static const struct acpi_device_id ec_device_ids[] = {
1736 	{"PNP0C09", 0},
1737 	{ACPI_ECDT_HID, 0},
1738 	{"", 0},
1739 };
1740 
1741 /*
1742  * This function is not Windows-compatible as Windows never enumerates the
1743  * namespace EC before the main ACPI device enumeration process. It is
1744  * retained for historical reason and will be deprecated in the future.
1745  */
acpi_ec_dsdt_probe(void)1746 void __init acpi_ec_dsdt_probe(void)
1747 {
1748 	struct acpi_ec *ec;
1749 	acpi_status status;
1750 	int ret;
1751 
1752 	/*
1753 	 * If a platform has ECDT, there is no need to proceed as the
1754 	 * following probe is not a part of the ACPI device enumeration,
1755 	 * executing _STA is not safe, and thus this probe may risk of
1756 	 * picking up an invalid EC device.
1757 	 */
1758 	if (boot_ec)
1759 		return;
1760 
1761 	ec = acpi_ec_alloc();
1762 	if (!ec)
1763 		return;
1764 
1765 	/*
1766 	 * At this point, the namespace is initialized, so start to find
1767 	 * the namespace objects.
1768 	 */
1769 	status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, ec, NULL);
1770 	if (ACPI_FAILURE(status) || !ec->handle) {
1771 		acpi_ec_free(ec);
1772 		return;
1773 	}
1774 
1775 	/*
1776 	 * When the DSDT EC is available, always re-configure boot EC to
1777 	 * have _REG evaluated. _REG can only be evaluated after the
1778 	 * namespace initialization.
1779 	 * At this point, the GPE is not fully initialized, so do not to
1780 	 * handle the events.
1781 	 */
1782 	ret = acpi_ec_setup(ec, NULL, true);
1783 	if (ret) {
1784 		acpi_ec_free(ec);
1785 		return;
1786 	}
1787 
1788 	boot_ec = ec;
1789 
1790 	acpi_handle_info(ec->handle,
1791 			 "Boot DSDT EC used to handle transactions\n");
1792 }
1793 
1794 /*
1795  * acpi_ec_ecdt_start - Finalize the boot ECDT EC initialization.
1796  *
1797  * First, look for an ACPI handle for the boot ECDT EC if acpi_ec_add() has not
1798  * found a matching object in the namespace.
1799  *
1800  * Next, in case the DSDT EC is not functioning, it is still necessary to
1801  * provide a functional ECDT EC to handle events, so add an extra device object
1802  * to represent it (see https://bugzilla.kernel.org/show_bug.cgi?id=115021).
1803  *
1804  * This is useful on platforms with valid ECDT and invalid DSDT EC settings,
1805  * like ASUS X550ZE (see https://bugzilla.kernel.org/show_bug.cgi?id=196847).
1806  */
acpi_ec_ecdt_start(void)1807 static void __init acpi_ec_ecdt_start(void)
1808 {
1809 	struct acpi_table_ecdt *ecdt_ptr;
1810 	acpi_handle handle;
1811 	acpi_status status;
1812 
1813 	/* Bail out if a matching EC has been found in the namespace. */
1814 	if (!boot_ec || boot_ec->handle != ACPI_ROOT_OBJECT)
1815 		return;
1816 
1817 	/* Look up the object pointed to from the ECDT in the namespace. */
1818 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1819 				(struct acpi_table_header **)&ecdt_ptr);
1820 	if (ACPI_FAILURE(status))
1821 		return;
1822 
1823 	status = acpi_get_handle(NULL, ecdt_ptr->id, &handle);
1824 	if (ACPI_SUCCESS(status)) {
1825 		boot_ec->handle = handle;
1826 
1827 		/* Add a special ACPI device object to represent the boot EC. */
1828 		acpi_bus_register_early_device(ACPI_BUS_TYPE_ECDT_EC);
1829 	}
1830 
1831 	acpi_put_table((struct acpi_table_header *)ecdt_ptr);
1832 }
1833 
1834 /*
1835  * On some hardware it is necessary to clear events accumulated by the EC during
1836  * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1837  * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1838  *
1839  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1840  *
1841  * Ideally, the EC should also be instructed NOT to accumulate events during
1842  * sleep (which Windows seems to do somehow), but the interface to control this
1843  * behaviour is not known at this time.
1844  *
1845  * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1846  * however it is very likely that other Samsung models are affected.
1847  *
1848  * On systems which don't accumulate _Q events during sleep, this extra check
1849  * should be harmless.
1850  */
ec_clear_on_resume(const struct dmi_system_id * id)1851 static int ec_clear_on_resume(const struct dmi_system_id *id)
1852 {
1853 	pr_debug("Detected system needing EC poll on resume.\n");
1854 	EC_FLAGS_CLEAR_ON_RESUME = 1;
1855 	ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
1856 	return 0;
1857 }
1858 
1859 /*
1860  * Some ECDTs contain wrong register addresses.
1861  * MSI MS-171F
1862  * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1863  */
ec_correct_ecdt(const struct dmi_system_id * id)1864 static int ec_correct_ecdt(const struct dmi_system_id *id)
1865 {
1866 	pr_debug("Detected system needing ECDT address correction.\n");
1867 	EC_FLAGS_CORRECT_ECDT = 1;
1868 	return 0;
1869 }
1870 
1871 /*
1872  * Some ECDTs contain wrong GPE setting, but they share the same port addresses
1873  * with DSDT EC, don't duplicate the DSDT EC with ECDT EC in this case.
1874  * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1875  */
ec_honor_dsdt_gpe(const struct dmi_system_id * id)1876 static int ec_honor_dsdt_gpe(const struct dmi_system_id *id)
1877 {
1878 	pr_debug("Detected system needing DSDT GPE setting.\n");
1879 	EC_FLAGS_TRUST_DSDT_GPE = 1;
1880 	return 0;
1881 }
1882 
1883 static const struct dmi_system_id ec_dmi_table[] __initconst = {
1884 	{
1885 		/*
1886 		 * MSI MS-171F
1887 		 * https://bugzilla.kernel.org/show_bug.cgi?id=12461
1888 		 */
1889 		.callback = ec_correct_ecdt,
1890 		.matches = {
1891 			DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star"),
1892 			DMI_MATCH(DMI_PRODUCT_NAME, "MS-171F"),
1893 		},
1894 	},
1895 	{
1896 		/*
1897 		 * HP Pavilion Gaming Laptop 15-cx0xxx
1898 		 * https://bugzilla.kernel.org/show_bug.cgi?id=209989
1899 		 */
1900 		.callback = ec_honor_dsdt_gpe,
1901 		.matches = {
1902 			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1903 			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-cx0xxx"),
1904 		},
1905 	},
1906 	{
1907 		/*
1908 		 * HP Pavilion Gaming Laptop 15-cx0041ur
1909 		 */
1910 		.callback = ec_honor_dsdt_gpe,
1911 		.matches = {
1912 			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1913 			DMI_MATCH(DMI_PRODUCT_NAME, "HP 15-cx0041ur"),
1914 		},
1915 	},
1916 	{
1917 		/*
1918 		 * HP Pavilion Gaming Laptop 15-dk1xxx
1919 		 * https://github.com/systemd/systemd/issues/28942
1920 		 */
1921 		.callback = ec_honor_dsdt_gpe,
1922 		.matches = {
1923 			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1924 			DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion Gaming Laptop 15-dk1xxx"),
1925 		},
1926 	},
1927 	{
1928 		/*
1929 		 * HP 250 G7 Notebook PC
1930 		 */
1931 		.callback = ec_honor_dsdt_gpe,
1932 		.matches = {
1933 			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
1934 			DMI_MATCH(DMI_PRODUCT_NAME, "HP 250 G7 Notebook PC"),
1935 		},
1936 	},
1937 	{
1938 		/*
1939 		 * Samsung hardware
1940 		 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1941 		 */
1942 		.callback = ec_clear_on_resume,
1943 		.matches = {
1944 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
1945 		},
1946 	},
1947 	{}
1948 };
1949 
acpi_ec_ecdt_probe(void)1950 void __init acpi_ec_ecdt_probe(void)
1951 {
1952 	struct acpi_table_ecdt *ecdt_ptr;
1953 	struct acpi_ec *ec;
1954 	acpi_status status;
1955 	int ret;
1956 
1957 	/* Generate a boot ec context. */
1958 	dmi_check_system(ec_dmi_table);
1959 	status = acpi_get_table(ACPI_SIG_ECDT, 1,
1960 				(struct acpi_table_header **)&ecdt_ptr);
1961 	if (ACPI_FAILURE(status))
1962 		return;
1963 
1964 	if (!ecdt_ptr->control.address || !ecdt_ptr->data.address) {
1965 		/*
1966 		 * Asus X50GL:
1967 		 * https://bugzilla.kernel.org/show_bug.cgi?id=11880
1968 		 */
1969 		goto out;
1970 	}
1971 
1972 	ec = acpi_ec_alloc();
1973 	if (!ec)
1974 		goto out;
1975 
1976 	if (EC_FLAGS_CORRECT_ECDT) {
1977 		ec->command_addr = ecdt_ptr->data.address;
1978 		ec->data_addr = ecdt_ptr->control.address;
1979 	} else {
1980 		ec->command_addr = ecdt_ptr->control.address;
1981 		ec->data_addr = ecdt_ptr->data.address;
1982 	}
1983 
1984 	/*
1985 	 * Ignore the GPE value on Reduced Hardware platforms.
1986 	 * Some products have this set to an erroneous value.
1987 	 */
1988 	if (!acpi_gbl_reduced_hardware)
1989 		ec->gpe = ecdt_ptr->gpe;
1990 
1991 	ec->handle = ACPI_ROOT_OBJECT;
1992 
1993 	/*
1994 	 * At this point, the namespace is not initialized, so do not find
1995 	 * the namespace objects, or handle the events.
1996 	 */
1997 	ret = acpi_ec_setup(ec, NULL, false);
1998 	if (ret) {
1999 		acpi_ec_free(ec);
2000 		goto out;
2001 	}
2002 
2003 	boot_ec = ec;
2004 	boot_ec_is_ecdt = true;
2005 
2006 	pr_info("Boot ECDT EC used to handle transactions\n");
2007 
2008 out:
2009 	acpi_put_table((struct acpi_table_header *)ecdt_ptr);
2010 }
2011 
2012 #ifdef CONFIG_PM_SLEEP
acpi_ec_suspend(struct device * dev)2013 static int acpi_ec_suspend(struct device *dev)
2014 {
2015 	struct acpi_ec *ec =
2016 		acpi_driver_data(to_acpi_device(dev));
2017 
2018 	if (!pm_suspend_no_platform() && ec_freeze_events)
2019 		acpi_ec_disable_event(ec);
2020 	return 0;
2021 }
2022 
acpi_ec_suspend_noirq(struct device * dev)2023 static int acpi_ec_suspend_noirq(struct device *dev)
2024 {
2025 	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2026 
2027 	/*
2028 	 * The SCI handler doesn't run at this point, so the GPE can be
2029 	 * masked at the low level without side effects.
2030 	 */
2031 	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2032 	    ec->gpe >= 0 && ec->reference_count >= 1)
2033 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
2034 
2035 	acpi_ec_enter_noirq(ec);
2036 
2037 	return 0;
2038 }
2039 
acpi_ec_resume_noirq(struct device * dev)2040 static int acpi_ec_resume_noirq(struct device *dev)
2041 {
2042 	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
2043 
2044 	acpi_ec_leave_noirq(ec);
2045 
2046 	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
2047 	    ec->gpe >= 0 && ec->reference_count >= 1)
2048 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
2049 
2050 	return 0;
2051 }
2052 
acpi_ec_resume(struct device * dev)2053 static int acpi_ec_resume(struct device *dev)
2054 {
2055 	struct acpi_ec *ec =
2056 		acpi_driver_data(to_acpi_device(dev));
2057 
2058 	acpi_ec_enable_event(ec);
2059 	return 0;
2060 }
2061 
acpi_ec_mark_gpe_for_wake(void)2062 void acpi_ec_mark_gpe_for_wake(void)
2063 {
2064 	if (first_ec && !ec_no_wakeup)
2065 		acpi_mark_gpe_for_wake(NULL, first_ec->gpe);
2066 }
2067 EXPORT_SYMBOL_GPL(acpi_ec_mark_gpe_for_wake);
2068 
acpi_ec_set_gpe_wake_mask(u8 action)2069 void acpi_ec_set_gpe_wake_mask(u8 action)
2070 {
2071 	if (pm_suspend_no_platform() && first_ec && !ec_no_wakeup)
2072 		acpi_set_gpe_wake_mask(NULL, first_ec->gpe, action);
2073 }
2074 
acpi_ec_work_in_progress(struct acpi_ec * ec)2075 static bool acpi_ec_work_in_progress(struct acpi_ec *ec)
2076 {
2077 	return ec->events_in_progress + ec->queries_in_progress > 0;
2078 }
2079 
acpi_ec_dispatch_gpe(void)2080 bool acpi_ec_dispatch_gpe(void)
2081 {
2082 	bool work_in_progress = false;
2083 
2084 	if (!first_ec)
2085 		return acpi_any_gpe_status_set(U32_MAX);
2086 
2087 	/*
2088 	 * Report wakeup if the status bit is set for any enabled GPE other
2089 	 * than the EC one.
2090 	 */
2091 	if (acpi_any_gpe_status_set(first_ec->gpe))
2092 		return true;
2093 
2094 	/*
2095 	 * Cancel the SCI wakeup and process all pending events in case there
2096 	 * are any wakeup ones in there.
2097 	 *
2098 	 * Note that if any non-EC GPEs are active at this point, the SCI will
2099 	 * retrigger after the rearming in acpi_s2idle_wake(), so no events
2100 	 * should be missed by canceling the wakeup here.
2101 	 */
2102 	pm_system_cancel_wakeup();
2103 
2104 	/*
2105 	 * Dispatch the EC GPE in-band, but do not report wakeup in any case
2106 	 * to allow the caller to process events properly after that.
2107 	 */
2108 	spin_lock_irq(&first_ec->lock);
2109 
2110 	if (acpi_ec_gpe_status_set(first_ec)) {
2111 		pm_pr_dbg("ACPI EC GPE status set\n");
2112 
2113 		clear_gpe_and_advance_transaction(first_ec, false);
2114 		work_in_progress = acpi_ec_work_in_progress(first_ec);
2115 	}
2116 
2117 	spin_unlock_irq(&first_ec->lock);
2118 
2119 	if (!work_in_progress)
2120 		return false;
2121 
2122 	pm_pr_dbg("ACPI EC GPE dispatched\n");
2123 
2124 	/* Drain EC work. */
2125 	do {
2126 		acpi_ec_flush_work();
2127 
2128 		pm_pr_dbg("ACPI EC work flushed\n");
2129 
2130 		spin_lock_irq(&first_ec->lock);
2131 
2132 		work_in_progress = acpi_ec_work_in_progress(first_ec);
2133 
2134 		spin_unlock_irq(&first_ec->lock);
2135 	} while (work_in_progress && !pm_wakeup_pending());
2136 
2137 	return false;
2138 }
2139 #endif /* CONFIG_PM_SLEEP */
2140 
2141 static const struct dev_pm_ops acpi_ec_pm = {
2142 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
2143 	SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
2144 };
2145 
param_set_event_clearing(const char * val,const struct kernel_param * kp)2146 static int param_set_event_clearing(const char *val,
2147 				    const struct kernel_param *kp)
2148 {
2149 	int result = 0;
2150 
2151 	if (!strncmp(val, "status", sizeof("status") - 1)) {
2152 		ec_event_clearing = ACPI_EC_EVT_TIMING_STATUS;
2153 		pr_info("Assuming SCI_EVT clearing on EC_SC accesses\n");
2154 	} else if (!strncmp(val, "query", sizeof("query") - 1)) {
2155 		ec_event_clearing = ACPI_EC_EVT_TIMING_QUERY;
2156 		pr_info("Assuming SCI_EVT clearing on QR_EC writes\n");
2157 	} else if (!strncmp(val, "event", sizeof("event") - 1)) {
2158 		ec_event_clearing = ACPI_EC_EVT_TIMING_EVENT;
2159 		pr_info("Assuming SCI_EVT clearing on event reads\n");
2160 	} else
2161 		result = -EINVAL;
2162 	return result;
2163 }
2164 
param_get_event_clearing(char * buffer,const struct kernel_param * kp)2165 static int param_get_event_clearing(char *buffer,
2166 				    const struct kernel_param *kp)
2167 {
2168 	switch (ec_event_clearing) {
2169 	case ACPI_EC_EVT_TIMING_STATUS:
2170 		return sprintf(buffer, "status\n");
2171 	case ACPI_EC_EVT_TIMING_QUERY:
2172 		return sprintf(buffer, "query\n");
2173 	case ACPI_EC_EVT_TIMING_EVENT:
2174 		return sprintf(buffer, "event\n");
2175 	default:
2176 		return sprintf(buffer, "invalid\n");
2177 	}
2178 	return 0;
2179 }
2180 
2181 module_param_call(ec_event_clearing, param_set_event_clearing, param_get_event_clearing,
2182 		  NULL, 0644);
2183 MODULE_PARM_DESC(ec_event_clearing, "Assumed SCI_EVT clearing timing");
2184 
2185 static struct acpi_driver acpi_ec_driver = {
2186 	.name = "ec",
2187 	.class = ACPI_EC_CLASS,
2188 	.ids = ec_device_ids,
2189 	.ops = {
2190 		.add = acpi_ec_add,
2191 		.remove = acpi_ec_remove,
2192 		},
2193 	.drv.pm = &acpi_ec_pm,
2194 };
2195 
acpi_ec_destroy_workqueues(void)2196 static void acpi_ec_destroy_workqueues(void)
2197 {
2198 	if (ec_wq) {
2199 		destroy_workqueue(ec_wq);
2200 		ec_wq = NULL;
2201 	}
2202 	if (ec_query_wq) {
2203 		destroy_workqueue(ec_query_wq);
2204 		ec_query_wq = NULL;
2205 	}
2206 }
2207 
acpi_ec_init_workqueues(void)2208 static int acpi_ec_init_workqueues(void)
2209 {
2210 	if (!ec_wq)
2211 		ec_wq = alloc_ordered_workqueue("kec", 0);
2212 
2213 	if (!ec_query_wq)
2214 		ec_query_wq = alloc_workqueue("kec_query", 0, ec_max_queries);
2215 
2216 	if (!ec_wq || !ec_query_wq) {
2217 		acpi_ec_destroy_workqueues();
2218 		return -ENODEV;
2219 	}
2220 	return 0;
2221 }
2222 
2223 static const struct dmi_system_id acpi_ec_no_wakeup[] = {
2224 	{
2225 		.matches = {
2226 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2227 			DMI_MATCH(DMI_PRODUCT_FAMILY, "Thinkpad X1 Carbon 6th"),
2228 		},
2229 	},
2230 	{
2231 		.matches = {
2232 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
2233 			DMI_MATCH(DMI_PRODUCT_FAMILY, "ThinkPad X1 Yoga 3rd"),
2234 		},
2235 	},
2236 	{
2237 		.matches = {
2238 			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
2239 			DMI_MATCH(DMI_PRODUCT_FAMILY, "103C_5336AN HP ZHAN 66 Pro"),
2240 		},
2241 	},
2242 	{ },
2243 };
2244 
acpi_ec_init(void)2245 void __init acpi_ec_init(void)
2246 {
2247 	int result;
2248 
2249 	result = acpi_ec_init_workqueues();
2250 	if (result)
2251 		return;
2252 
2253 	/*
2254 	 * Disable EC wakeup on following systems to prevent periodic
2255 	 * wakeup from EC GPE.
2256 	 */
2257 	if (dmi_check_system(acpi_ec_no_wakeup)) {
2258 		ec_no_wakeup = true;
2259 		pr_debug("Disabling EC wakeup on suspend-to-idle\n");
2260 	}
2261 
2262 	/* Driver must be registered after acpi_ec_init_workqueues(). */
2263 	acpi_bus_register_driver(&acpi_ec_driver);
2264 
2265 	acpi_ec_ecdt_start();
2266 }
2267 
2268 /* EC driver currently not unloadable */
2269 #if 0
2270 static void __exit acpi_ec_exit(void)
2271 {
2272 
2273 	acpi_bus_unregister_driver(&acpi_ec_driver);
2274 	acpi_ec_destroy_workqueues();
2275 }
2276 #endif	/* 0 */
2277