Linux 4.1.16
[linux/fpc-iii.git] / drivers / acpi / ec.c
blob5e8fed448850fc1c8f50448f6b344066d2e730ef
1 /*
2 * ec.c - ACPI Embedded Controller Driver (v3)
4 * Copyright (C) 2001-2015 Intel Corporation
5 * Author: 2014, 2015 Lv Zheng <lv.zheng@intel.com>
6 * 2006, 2007 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
7 * 2006 Denis Sadykov <denis.m.sadykov@intel.com>
8 * 2004 Luming Yu <luming.yu@intel.com>
9 * 2001, 2002 Andy Grover <andrew.grover@intel.com>
10 * 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
11 * Copyright (C) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
13 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 2 of the License, or (at
18 * your option) any later version.
20 * This program is distributed in the hope that it will be useful, but
21 * WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23 * General Public License for more details.
25 * You should have received a copy of the GNU General Public License along
26 * with this program; if not, write to the Free Software Foundation, Inc.,
27 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32 /* Uncomment next line to get verbose printout */
33 /* #define DEBUG */
34 #define pr_fmt(fmt) "ACPI : EC: " fmt
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/types.h>
40 #include <linux/delay.h>
41 #include <linux/interrupt.h>
42 #include <linux/list.h>
43 #include <linux/spinlock.h>
44 #include <linux/slab.h>
45 #include <linux/acpi.h>
46 #include <linux/dmi.h>
47 #include <asm/io.h>
49 #include "internal.h"
51 #define ACPI_EC_CLASS "embedded_controller"
52 #define ACPI_EC_DEVICE_NAME "Embedded Controller"
53 #define ACPI_EC_FILE_INFO "info"
55 /* EC status register */
56 #define ACPI_EC_FLAG_OBF 0x01 /* Output buffer full */
57 #define ACPI_EC_FLAG_IBF 0x02 /* Input buffer full */
58 #define ACPI_EC_FLAG_CMD 0x08 /* Input buffer contains a command */
59 #define ACPI_EC_FLAG_BURST 0x10 /* burst mode */
60 #define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */
62 /* EC commands */
63 enum ec_command {
64 ACPI_EC_COMMAND_READ = 0x80,
65 ACPI_EC_COMMAND_WRITE = 0x81,
66 ACPI_EC_BURST_ENABLE = 0x82,
67 ACPI_EC_BURST_DISABLE = 0x83,
68 ACPI_EC_COMMAND_QUERY = 0x84,
71 #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
72 #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
73 #define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */
74 #define ACPI_EC_UDELAY_POLL 1000 /* Wait 1ms for EC transaction polling */
75 #define ACPI_EC_CLEAR_MAX 100 /* Maximum number of events to query
76 * when trying to clear the EC */
78 enum {
79 EC_FLAGS_QUERY_PENDING, /* Query is pending */
80 EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and
81 * OpReg are installed */
82 EC_FLAGS_STARTED, /* Driver is started */
83 EC_FLAGS_STOPPED, /* Driver is stopped */
84 EC_FLAGS_COMMAND_STORM, /* GPE storms occurred to the
85 * current command processing */
88 #define ACPI_EC_COMMAND_POLL 0x01 /* Available for command byte */
89 #define ACPI_EC_COMMAND_COMPLETE 0x02 /* Completed last byte */
91 /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */
92 static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY;
93 module_param(ec_delay, uint, 0644);
94 MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes");
97 * If the number of false interrupts per one transaction exceeds
98 * this threshold, will think there is a GPE storm happened and
99 * will disable the GPE for normal transaction.
101 static unsigned int ec_storm_threshold __read_mostly = 8;
102 module_param(ec_storm_threshold, uint, 0644);
103 MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm");
105 struct acpi_ec_query_handler {
106 struct list_head node;
107 acpi_ec_query_func func;
108 acpi_handle handle;
109 void *data;
110 u8 query_bit;
111 struct kref kref;
114 struct transaction {
115 const u8 *wdata;
116 u8 *rdata;
117 unsigned short irq_count;
118 u8 command;
119 u8 wi;
120 u8 ri;
121 u8 wlen;
122 u8 rlen;
123 u8 flags;
124 unsigned long timestamp;
127 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
128 static void advance_transaction(struct acpi_ec *ec);
130 struct acpi_ec *boot_ec, *first_ec;
131 EXPORT_SYMBOL(first_ec);
133 static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
134 static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
135 static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
136 static int EC_FLAGS_CLEAR_ON_RESUME; /* Needs acpi_ec_clear() on boot/resume */
137 static int EC_FLAGS_QUERY_HANDSHAKE; /* Needs QR_EC issued when SCI_EVT set */
139 /* --------------------------------------------------------------------------
140 * Logging/Debugging
141 * -------------------------------------------------------------------------- */
144 * Splitters used by the developers to track the boundary of the EC
145 * handling processes.
147 #ifdef DEBUG
148 #define EC_DBG_SEP " "
149 #define EC_DBG_DRV "+++++"
150 #define EC_DBG_STM "====="
151 #define EC_DBG_REQ "*****"
152 #define EC_DBG_EVT "#####"
153 #else
154 #define EC_DBG_SEP ""
155 #define EC_DBG_DRV
156 #define EC_DBG_STM
157 #define EC_DBG_REQ
158 #define EC_DBG_EVT
159 #endif
161 #define ec_log_raw(fmt, ...) \
162 pr_info(fmt "\n", ##__VA_ARGS__)
163 #define ec_dbg_raw(fmt, ...) \
164 pr_debug(fmt "\n", ##__VA_ARGS__)
165 #define ec_log(filter, fmt, ...) \
166 ec_log_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
167 #define ec_dbg(filter, fmt, ...) \
168 ec_dbg_raw(filter EC_DBG_SEP fmt EC_DBG_SEP filter, ##__VA_ARGS__)
170 #define ec_log_drv(fmt, ...) \
171 ec_log(EC_DBG_DRV, fmt, ##__VA_ARGS__)
172 #define ec_dbg_drv(fmt, ...) \
173 ec_dbg(EC_DBG_DRV, fmt, ##__VA_ARGS__)
174 #define ec_dbg_stm(fmt, ...) \
175 ec_dbg(EC_DBG_STM, fmt, ##__VA_ARGS__)
176 #define ec_dbg_req(fmt, ...) \
177 ec_dbg(EC_DBG_REQ, fmt, ##__VA_ARGS__)
178 #define ec_dbg_evt(fmt, ...) \
179 ec_dbg(EC_DBG_EVT, fmt, ##__VA_ARGS__)
180 #define ec_dbg_ref(ec, fmt, ...) \
181 ec_dbg_raw("%lu: " fmt, ec->reference_count, ## __VA_ARGS__)
183 /* --------------------------------------------------------------------------
184 * Device Flags
185 * -------------------------------------------------------------------------- */
187 static bool acpi_ec_started(struct acpi_ec *ec)
189 return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
190 !test_bit(EC_FLAGS_STOPPED, &ec->flags);
193 static bool acpi_ec_flushed(struct acpi_ec *ec)
195 return ec->reference_count == 1;
198 /* --------------------------------------------------------------------------
199 * EC Registers
200 * -------------------------------------------------------------------------- */
202 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
204 u8 x = inb(ec->command_addr);
206 ec_dbg_raw("EC_SC(R) = 0x%2.2x "
207 "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
209 !!(x & ACPI_EC_FLAG_SCI),
210 !!(x & ACPI_EC_FLAG_BURST),
211 !!(x & ACPI_EC_FLAG_CMD),
212 !!(x & ACPI_EC_FLAG_IBF),
213 !!(x & ACPI_EC_FLAG_OBF));
214 return x;
217 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
219 u8 x = inb(ec->data_addr);
221 ec->curr->timestamp = jiffies;
222 ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
223 return x;
226 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
228 ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
229 outb(command, ec->command_addr);
230 ec->curr->timestamp = jiffies;
233 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
235 ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
236 outb(data, ec->data_addr);
237 ec->curr->timestamp = jiffies;
240 #ifdef DEBUG
241 static const char *acpi_ec_cmd_string(u8 cmd)
243 switch (cmd) {
244 case 0x80:
245 return "RD_EC";
246 case 0x81:
247 return "WR_EC";
248 case 0x82:
249 return "BE_EC";
250 case 0x83:
251 return "BD_EC";
252 case 0x84:
253 return "QR_EC";
255 return "UNKNOWN";
257 #else
258 #define acpi_ec_cmd_string(cmd) "UNDEF"
259 #endif
261 /* --------------------------------------------------------------------------
262 * GPE Registers
263 * -------------------------------------------------------------------------- */
265 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
267 acpi_event_status gpe_status = 0;
269 (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
270 return (gpe_status & ACPI_EVENT_FLAG_SET) ? true : false;
273 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
275 if (open)
276 acpi_enable_gpe(NULL, ec->gpe);
277 else {
278 BUG_ON(ec->reference_count < 1);
279 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);
281 if (acpi_ec_is_gpe_raised(ec)) {
283 * On some platforms, EN=1 writes cannot trigger GPE. So
284 * software need to manually trigger a pseudo GPE event on
285 * EN=1 writes.
287 ec_dbg_raw("Polling quirk");
288 advance_transaction(ec);
292 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
294 if (close)
295 acpi_disable_gpe(NULL, ec->gpe);
296 else {
297 BUG_ON(ec->reference_count < 1);
298 acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
302 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
305 * GPE STS is a W1C register, which means:
306 * 1. Software can clear it without worrying about clearing other
307 * GPEs' STS bits when the hardware sets them in parallel.
308 * 2. As long as software can ensure only clearing it when it is
309 * set, hardware won't set it in parallel.
310 * So software can clear GPE in any contexts.
311 * Warning: do not move the check into advance_transaction() as the
312 * EC commands will be sent without GPE raised.
314 if (!acpi_ec_is_gpe_raised(ec))
315 return;
316 acpi_clear_gpe(NULL, ec->gpe);
319 /* --------------------------------------------------------------------------
320 * Transaction Management
321 * -------------------------------------------------------------------------- */
323 static void acpi_ec_submit_request(struct acpi_ec *ec)
325 ec->reference_count++;
326 if (ec->reference_count == 1)
327 acpi_ec_enable_gpe(ec, true);
330 static void acpi_ec_complete_request(struct acpi_ec *ec)
332 bool flushed = false;
334 ec->reference_count--;
335 if (ec->reference_count == 0)
336 acpi_ec_disable_gpe(ec, true);
337 flushed = acpi_ec_flushed(ec);
338 if (flushed)
339 wake_up(&ec->wait);
342 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
344 if (!test_bit(flag, &ec->flags)) {
345 acpi_ec_disable_gpe(ec, false);
346 ec_dbg_drv("Polling enabled");
347 set_bit(flag, &ec->flags);
351 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
353 if (test_bit(flag, &ec->flags)) {
354 clear_bit(flag, &ec->flags);
355 acpi_ec_enable_gpe(ec, false);
356 ec_dbg_drv("Polling disabled");
361 * acpi_ec_submit_flushable_request() - Increase the reference count unless
362 * the flush operation is not in
363 * progress
364 * @ec: the EC device
366 * This function must be used before taking a new action that should hold
367 * the reference count. If this function returns false, then the action
368 * must be discarded or it will prevent the flush operation from being
369 * completed.
371 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
373 if (!acpi_ec_started(ec))
374 return false;
375 acpi_ec_submit_request(ec);
376 return true;
379 static void acpi_ec_submit_query(struct acpi_ec *ec)
381 if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
382 ec_dbg_req("Event started");
383 schedule_work(&ec->work);
387 static void acpi_ec_complete_query(struct acpi_ec *ec)
389 if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
390 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
391 ec_dbg_req("Event stopped");
395 static int ec_transaction_completed(struct acpi_ec *ec)
397 unsigned long flags;
398 int ret = 0;
400 spin_lock_irqsave(&ec->lock, flags);
401 if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))
402 ret = 1;
403 spin_unlock_irqrestore(&ec->lock, flags);
404 return ret;
407 static void advance_transaction(struct acpi_ec *ec)
409 struct transaction *t;
410 u8 status;
411 bool wakeup = false;
413 ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
414 smp_processor_id());
416 * By always clearing STS before handling all indications, we can
417 * ensure a hardware STS 0->1 change after this clearing can always
418 * trigger a GPE interrupt.
420 acpi_ec_clear_gpe(ec);
421 status = acpi_ec_read_status(ec);
422 t = ec->curr;
423 if (!t)
424 goto err;
425 if (t->flags & ACPI_EC_COMMAND_POLL) {
426 if (t->wlen > t->wi) {
427 if ((status & ACPI_EC_FLAG_IBF) == 0)
428 acpi_ec_write_data(ec, t->wdata[t->wi++]);
429 else
430 goto err;
431 } else if (t->rlen > t->ri) {
432 if ((status & ACPI_EC_FLAG_OBF) == 1) {
433 t->rdata[t->ri++] = acpi_ec_read_data(ec);
434 if (t->rlen == t->ri) {
435 t->flags |= ACPI_EC_COMMAND_COMPLETE;
436 if (t->command == ACPI_EC_COMMAND_QUERY)
437 ec_dbg_req("Command(%s) hardware completion",
438 acpi_ec_cmd_string(t->command));
439 wakeup = true;
441 } else
442 goto err;
443 } else if (t->wlen == t->wi &&
444 (status & ACPI_EC_FLAG_IBF) == 0) {
445 t->flags |= ACPI_EC_COMMAND_COMPLETE;
446 wakeup = true;
448 goto out;
449 } else {
450 if (EC_FLAGS_QUERY_HANDSHAKE &&
451 !(status & ACPI_EC_FLAG_SCI) &&
452 (t->command == ACPI_EC_COMMAND_QUERY)) {
453 t->flags |= ACPI_EC_COMMAND_POLL;
454 acpi_ec_complete_query(ec);
455 t->rdata[t->ri++] = 0x00;
456 t->flags |= ACPI_EC_COMMAND_COMPLETE;
457 ec_dbg_req("Command(%s) software completion",
458 acpi_ec_cmd_string(t->command));
459 wakeup = true;
460 } else if ((status & ACPI_EC_FLAG_IBF) == 0) {
461 acpi_ec_write_cmd(ec, t->command);
462 t->flags |= ACPI_EC_COMMAND_POLL;
463 acpi_ec_complete_query(ec);
464 } else
465 goto err;
466 goto out;
468 err:
470 * If SCI bit is set, then don't think it's a false IRQ
471 * otherwise will take a not handled IRQ as a false one.
473 if (!(status & ACPI_EC_FLAG_SCI)) {
474 if (in_interrupt() && t) {
475 if (t->irq_count < ec_storm_threshold)
476 ++t->irq_count;
477 /* Allow triggering on 0 threshold */
478 if (t->irq_count == ec_storm_threshold)
479 acpi_ec_set_storm(ec, EC_FLAGS_COMMAND_STORM);
482 out:
483 if (status & ACPI_EC_FLAG_SCI)
484 acpi_ec_submit_query(ec);
485 if (wakeup && in_interrupt())
486 wake_up(&ec->wait);
489 static void start_transaction(struct acpi_ec *ec)
491 ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
492 ec->curr->flags = 0;
493 ec->curr->timestamp = jiffies;
494 advance_transaction(ec);
497 static int ec_poll(struct acpi_ec *ec)
499 unsigned long flags;
500 int repeat = 5; /* number of command restarts */
502 while (repeat--) {
503 unsigned long delay = jiffies +
504 msecs_to_jiffies(ec_delay);
505 unsigned long usecs = ACPI_EC_UDELAY_POLL;
506 do {
507 /* don't sleep with disabled interrupts */
508 if (EC_FLAGS_MSI || irqs_disabled()) {
509 usecs = ACPI_EC_MSI_UDELAY;
510 udelay(usecs);
511 if (ec_transaction_completed(ec))
512 return 0;
513 } else {
514 if (wait_event_timeout(ec->wait,
515 ec_transaction_completed(ec),
516 usecs_to_jiffies(usecs)))
517 return 0;
519 spin_lock_irqsave(&ec->lock, flags);
520 if (time_after(jiffies,
521 ec->curr->timestamp +
522 usecs_to_jiffies(usecs)))
523 advance_transaction(ec);
524 spin_unlock_irqrestore(&ec->lock, flags);
525 } while (time_before(jiffies, delay));
526 pr_debug("controller reset, restart transaction\n");
527 spin_lock_irqsave(&ec->lock, flags);
528 start_transaction(ec);
529 spin_unlock_irqrestore(&ec->lock, flags);
531 return -ETIME;
534 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
535 struct transaction *t)
537 unsigned long tmp;
538 int ret = 0;
540 if (EC_FLAGS_MSI)
541 udelay(ACPI_EC_MSI_UDELAY);
542 /* start transaction */
543 spin_lock_irqsave(&ec->lock, tmp);
544 /* Enable GPE for command processing (IBF=0/OBF=1) */
545 if (!acpi_ec_submit_flushable_request(ec)) {
546 ret = -EINVAL;
547 goto unlock;
549 ec_dbg_ref(ec, "Increase command");
550 /* following two actions should be kept atomic */
551 ec->curr = t;
552 ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));
553 start_transaction(ec);
554 spin_unlock_irqrestore(&ec->lock, tmp);
555 ret = ec_poll(ec);
556 spin_lock_irqsave(&ec->lock, tmp);
557 if (t->irq_count == ec_storm_threshold)
558 acpi_ec_clear_storm(ec, EC_FLAGS_COMMAND_STORM);
559 ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
560 ec->curr = NULL;
561 /* Disable GPE for command processing (IBF=0/OBF=1) */
562 acpi_ec_complete_request(ec);
563 ec_dbg_ref(ec, "Decrease command");
564 unlock:
565 spin_unlock_irqrestore(&ec->lock, tmp);
566 return ret;
569 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
571 int status;
572 u32 glk;
574 if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata))
575 return -EINVAL;
576 if (t->rdata)
577 memset(t->rdata, 0, t->rlen);
578 mutex_lock(&ec->mutex);
579 if (ec->global_lock) {
580 status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
581 if (ACPI_FAILURE(status)) {
582 status = -ENODEV;
583 goto unlock;
587 status = acpi_ec_transaction_unlocked(ec, t);
589 if (test_bit(EC_FLAGS_COMMAND_STORM, &ec->flags))
590 msleep(1);
591 if (ec->global_lock)
592 acpi_release_global_lock(glk);
593 unlock:
594 mutex_unlock(&ec->mutex);
595 return status;
598 static int acpi_ec_burst_enable(struct acpi_ec *ec)
600 u8 d;
601 struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
602 .wdata = NULL, .rdata = &d,
603 .wlen = 0, .rlen = 1};
605 return acpi_ec_transaction(ec, &t);
608 static int acpi_ec_burst_disable(struct acpi_ec *ec)
610 struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
611 .wdata = NULL, .rdata = NULL,
612 .wlen = 0, .rlen = 0};
614 return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
615 acpi_ec_transaction(ec, &t) : 0;
618 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
620 int result;
621 u8 d;
622 struct transaction t = {.command = ACPI_EC_COMMAND_READ,
623 .wdata = &address, .rdata = &d,
624 .wlen = 1, .rlen = 1};
626 result = acpi_ec_transaction(ec, &t);
627 *data = d;
628 return result;
631 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
633 u8 wdata[2] = { address, data };
634 struct transaction t = {.command = ACPI_EC_COMMAND_WRITE,
635 .wdata = wdata, .rdata = NULL,
636 .wlen = 2, .rlen = 0};
638 return acpi_ec_transaction(ec, &t);
641 int ec_read(u8 addr, u8 *val)
643 int err;
644 u8 temp_data;
646 if (!first_ec)
647 return -ENODEV;
649 err = acpi_ec_read(first_ec, addr, &temp_data);
651 if (!err) {
652 *val = temp_data;
653 return 0;
655 return err;
657 EXPORT_SYMBOL(ec_read);
659 int ec_write(u8 addr, u8 val)
661 int err;
663 if (!first_ec)
664 return -ENODEV;
666 err = acpi_ec_write(first_ec, addr, val);
668 return err;
670 EXPORT_SYMBOL(ec_write);
672 int ec_transaction(u8 command,
673 const u8 *wdata, unsigned wdata_len,
674 u8 *rdata, unsigned rdata_len)
676 struct transaction t = {.command = command,
677 .wdata = wdata, .rdata = rdata,
678 .wlen = wdata_len, .rlen = rdata_len};
680 if (!first_ec)
681 return -ENODEV;
683 return acpi_ec_transaction(first_ec, &t);
685 EXPORT_SYMBOL(ec_transaction);
687 /* Get the handle to the EC device */
688 acpi_handle ec_get_handle(void)
690 if (!first_ec)
691 return NULL;
692 return first_ec->handle;
694 EXPORT_SYMBOL(ec_get_handle);
697 * Process _Q events that might have accumulated in the EC.
698 * Run with locked ec mutex.
700 static void acpi_ec_clear(struct acpi_ec *ec)
702 int i, status;
703 u8 value = 0;
705 for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
706 status = acpi_ec_query(ec, &value);
707 if (status || !value)
708 break;
711 if (unlikely(i == ACPI_EC_CLEAR_MAX))
712 pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
713 else
714 pr_info("%d stale EC events cleared\n", i);
717 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
719 unsigned long flags;
721 spin_lock_irqsave(&ec->lock, flags);
722 if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {
723 ec_dbg_drv("Starting EC");
724 /* Enable GPE for event processing (SCI_EVT=1) */
725 if (!resuming) {
726 acpi_ec_submit_request(ec);
727 ec_dbg_ref(ec, "Increase driver");
729 ec_log_drv("EC started");
731 spin_unlock_irqrestore(&ec->lock, flags);
734 static bool acpi_ec_stopped(struct acpi_ec *ec)
736 unsigned long flags;
737 bool flushed;
739 spin_lock_irqsave(&ec->lock, flags);
740 flushed = acpi_ec_flushed(ec);
741 spin_unlock_irqrestore(&ec->lock, flags);
742 return flushed;
745 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
747 unsigned long flags;
749 spin_lock_irqsave(&ec->lock, flags);
750 if (acpi_ec_started(ec)) {
751 ec_dbg_drv("Stopping EC");
752 set_bit(EC_FLAGS_STOPPED, &ec->flags);
753 spin_unlock_irqrestore(&ec->lock, flags);
754 wait_event(ec->wait, acpi_ec_stopped(ec));
755 spin_lock_irqsave(&ec->lock, flags);
756 /* Disable GPE for event processing (SCI_EVT=1) */
757 if (!suspending) {
758 acpi_ec_complete_request(ec);
759 ec_dbg_ref(ec, "Decrease driver");
761 clear_bit(EC_FLAGS_STARTED, &ec->flags);
762 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
763 ec_log_drv("EC stopped");
765 spin_unlock_irqrestore(&ec->lock, flags);
768 void acpi_ec_block_transactions(void)
770 struct acpi_ec *ec = first_ec;
772 if (!ec)
773 return;
775 mutex_lock(&ec->mutex);
776 /* Prevent transactions from being carried out */
777 acpi_ec_stop(ec, true);
778 mutex_unlock(&ec->mutex);
781 void acpi_ec_unblock_transactions(void)
783 struct acpi_ec *ec = first_ec;
785 if (!ec)
786 return;
788 /* Allow transactions to be carried out again */
789 acpi_ec_start(ec, true);
791 if (EC_FLAGS_CLEAR_ON_RESUME)
792 acpi_ec_clear(ec);
795 void acpi_ec_unblock_transactions_early(void)
798 * Allow transactions to happen again (this function is called from
799 * atomic context during wakeup, so we don't need to acquire the mutex).
801 if (first_ec)
802 acpi_ec_start(first_ec, true);
805 /* --------------------------------------------------------------------------
806 Event Management
807 -------------------------------------------------------------------------- */
808 static struct acpi_ec_query_handler *
809 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
811 if (handler)
812 kref_get(&handler->kref);
813 return handler;
816 static void acpi_ec_query_handler_release(struct kref *kref)
818 struct acpi_ec_query_handler *handler =
819 container_of(kref, struct acpi_ec_query_handler, kref);
821 kfree(handler);
824 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
826 kref_put(&handler->kref, acpi_ec_query_handler_release);
829 int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
830 acpi_handle handle, acpi_ec_query_func func,
831 void *data)
833 struct acpi_ec_query_handler *handler =
834 kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
836 if (!handler)
837 return -ENOMEM;
839 handler->query_bit = query_bit;
840 handler->handle = handle;
841 handler->func = func;
842 handler->data = data;
843 mutex_lock(&ec->mutex);
844 kref_init(&handler->kref);
845 list_add(&handler->node, &ec->list);
846 mutex_unlock(&ec->mutex);
847 return 0;
849 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
851 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
853 struct acpi_ec_query_handler *handler, *tmp;
854 LIST_HEAD(free_list);
856 mutex_lock(&ec->mutex);
857 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
858 if (query_bit == handler->query_bit) {
859 list_del_init(&handler->node);
860 list_add(&handler->node, &free_list);
863 mutex_unlock(&ec->mutex);
864 list_for_each_entry_safe(handler, tmp, &free_list, node)
865 acpi_ec_put_query_handler(handler);
867 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
869 static void acpi_ec_run(void *cxt)
871 struct acpi_ec_query_handler *handler = cxt;
873 if (!handler)
874 return;
875 ec_dbg_evt("Query(0x%02x) started", handler->query_bit);
876 if (handler->func)
877 handler->func(handler->data);
878 else if (handler->handle)
879 acpi_evaluate_object(handler->handle, NULL, NULL, NULL);
880 ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);
881 acpi_ec_put_query_handler(handler);
884 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
886 u8 value = 0;
887 int result;
888 acpi_status status;
889 struct acpi_ec_query_handler *handler;
890 struct transaction t = {.command = ACPI_EC_COMMAND_QUERY,
891 .wdata = NULL, .rdata = &value,
892 .wlen = 0, .rlen = 1};
895 * Query the EC to find out which _Qxx method we need to evaluate.
896 * Note that successful completion of the query causes the ACPI_EC_SCI
897 * bit to be cleared (and thus clearing the interrupt source).
899 result = acpi_ec_transaction(ec, &t);
900 if (result)
901 return result;
902 if (data)
903 *data = value;
904 if (!value)
905 return -ENODATA;
907 mutex_lock(&ec->mutex);
908 list_for_each_entry(handler, &ec->list, node) {
909 if (value == handler->query_bit) {
910 /* have custom handler for this bit */
911 handler = acpi_ec_get_query_handler(handler);
912 ec_dbg_evt("Query(0x%02x) scheduled",
913 handler->query_bit);
914 status = acpi_os_execute((handler->func) ?
915 OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER,
916 acpi_ec_run, handler);
917 if (ACPI_FAILURE(status))
918 result = -EBUSY;
919 break;
922 mutex_unlock(&ec->mutex);
923 return result;
926 static void acpi_ec_gpe_poller(struct work_struct *work)
928 struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
930 acpi_ec_query(ec, NULL);
933 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
934 u32 gpe_number, void *data)
936 unsigned long flags;
937 struct acpi_ec *ec = data;
939 spin_lock_irqsave(&ec->lock, flags);
940 advance_transaction(ec);
941 spin_unlock_irqrestore(&ec->lock, flags);
942 return ACPI_INTERRUPT_HANDLED;
945 /* --------------------------------------------------------------------------
946 * Address Space Management
947 * -------------------------------------------------------------------------- */
949 static acpi_status
950 acpi_ec_space_handler(u32 function, acpi_physical_address address,
951 u32 bits, u64 *value64,
952 void *handler_context, void *region_context)
954 struct acpi_ec *ec = handler_context;
955 int result = 0, i, bytes = bits / 8;
956 u8 *value = (u8 *)value64;
958 if ((address > 0xFF) || !value || !handler_context)
959 return AE_BAD_PARAMETER;
961 if (function != ACPI_READ && function != ACPI_WRITE)
962 return AE_BAD_PARAMETER;
964 if (EC_FLAGS_MSI || bits > 8)
965 acpi_ec_burst_enable(ec);
967 for (i = 0; i < bytes; ++i, ++address, ++value)
968 result = (function == ACPI_READ) ?
969 acpi_ec_read(ec, address, value) :
970 acpi_ec_write(ec, address, *value);
972 if (EC_FLAGS_MSI || bits > 8)
973 acpi_ec_burst_disable(ec);
975 switch (result) {
976 case -EINVAL:
977 return AE_BAD_PARAMETER;
978 case -ENODEV:
979 return AE_NOT_FOUND;
980 case -ETIME:
981 return AE_TIME;
982 default:
983 return AE_OK;
987 /* --------------------------------------------------------------------------
988 * Driver Interface
989 * -------------------------------------------------------------------------- */
991 static acpi_status
992 ec_parse_io_ports(struct acpi_resource *resource, void *context);
994 static struct acpi_ec *make_acpi_ec(void)
996 struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
998 if (!ec)
999 return NULL;
1000 ec->flags = 1 << EC_FLAGS_QUERY_PENDING;
1001 mutex_init(&ec->mutex);
1002 init_waitqueue_head(&ec->wait);
1003 INIT_LIST_HEAD(&ec->list);
1004 spin_lock_init(&ec->lock);
1005 INIT_WORK(&ec->work, acpi_ec_gpe_poller);
1006 return ec;
1009 static acpi_status
1010 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1011 void *context, void **return_value)
1013 char node_name[5];
1014 struct acpi_buffer buffer = { sizeof(node_name), node_name };
1015 struct acpi_ec *ec = context;
1016 int value = 0;
1017 acpi_status status;
1019 status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1021 if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1)
1022 acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
1023 return AE_OK;
1026 static acpi_status
1027 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1029 acpi_status status;
1030 unsigned long long tmp = 0;
1031 struct acpi_ec *ec = context;
1033 /* clear addr values, ec_parse_io_ports depend on it */
1034 ec->command_addr = ec->data_addr = 0;
1036 status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1037 ec_parse_io_ports, ec);
1038 if (ACPI_FAILURE(status))
1039 return status;
1041 /* Get GPE bit assignment (EC events). */
1042 /* TODO: Add support for _GPE returning a package */
1043 status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
1044 if (ACPI_FAILURE(status))
1045 return status;
1046 ec->gpe = tmp;
1047 /* Use the global lock for all EC transactions? */
1048 tmp = 0;
1049 acpi_evaluate_integer(handle, "_GLK", NULL, &tmp);
1050 ec->global_lock = tmp;
1051 ec->handle = handle;
1052 return AE_CTRL_TERMINATE;
1055 static int ec_install_handlers(struct acpi_ec *ec)
1057 acpi_status status;
1059 if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1060 return 0;
1061 status = acpi_install_gpe_raw_handler(NULL, ec->gpe,
1062 ACPI_GPE_EDGE_TRIGGERED,
1063 &acpi_ec_gpe_handler, ec);
1064 if (ACPI_FAILURE(status))
1065 return -ENODEV;
1067 acpi_ec_start(ec, false);
1068 status = acpi_install_address_space_handler(ec->handle,
1069 ACPI_ADR_SPACE_EC,
1070 &acpi_ec_space_handler,
1071 NULL, ec);
1072 if (ACPI_FAILURE(status)) {
1073 if (status == AE_NOT_FOUND) {
1075 * Maybe OS fails in evaluating the _REG object.
1076 * The AE_NOT_FOUND error will be ignored and OS
1077 * continue to initialize EC.
1079 pr_err("Fail in evaluating the _REG object"
1080 " of EC device. Broken bios is suspected.\n");
1081 } else {
1082 acpi_ec_stop(ec, false);
1083 acpi_remove_gpe_handler(NULL, ec->gpe,
1084 &acpi_ec_gpe_handler);
1085 return -ENODEV;
1089 set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1090 return 0;
1093 static void ec_remove_handlers(struct acpi_ec *ec)
1095 if (!test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags))
1096 return;
1097 acpi_ec_stop(ec, false);
1098 if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle,
1099 ACPI_ADR_SPACE_EC, &acpi_ec_space_handler)))
1100 pr_err("failed to remove space handler\n");
1101 if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe,
1102 &acpi_ec_gpe_handler)))
1103 pr_err("failed to remove gpe handler\n");
1104 clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1107 static int acpi_ec_add(struct acpi_device *device)
1109 struct acpi_ec *ec = NULL;
1110 int ret;
1112 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1113 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1115 /* Check for boot EC */
1116 if (boot_ec &&
1117 (boot_ec->handle == device->handle ||
1118 boot_ec->handle == ACPI_ROOT_OBJECT)) {
1119 ec = boot_ec;
1120 boot_ec = NULL;
1121 } else {
1122 ec = make_acpi_ec();
1123 if (!ec)
1124 return -ENOMEM;
1126 if (ec_parse_device(device->handle, 0, ec, NULL) !=
1127 AE_CTRL_TERMINATE) {
1128 kfree(ec);
1129 return -EINVAL;
1132 /* Find and register all query methods */
1133 acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1,
1134 acpi_ec_register_query_methods, NULL, ec, NULL);
1136 if (!first_ec)
1137 first_ec = ec;
1138 device->driver_data = ec;
1140 ret = !!request_region(ec->data_addr, 1, "EC data");
1141 WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr);
1142 ret = !!request_region(ec->command_addr, 1, "EC cmd");
1143 WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
1145 pr_info("GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n",
1146 ec->gpe, ec->command_addr, ec->data_addr);
1148 ret = ec_install_handlers(ec);
1150 /* Reprobe devices depending on the EC */
1151 acpi_walk_dep_device_list(ec->handle);
1153 /* EC is fully operational, allow queries */
1154 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1156 /* Clear stale _Q events if hardware might require that */
1157 if (EC_FLAGS_CLEAR_ON_RESUME)
1158 acpi_ec_clear(ec);
1159 return ret;
1162 static int acpi_ec_remove(struct acpi_device *device)
1164 struct acpi_ec *ec;
1165 struct acpi_ec_query_handler *handler, *tmp;
1167 if (!device)
1168 return -EINVAL;
1170 ec = acpi_driver_data(device);
1171 ec_remove_handlers(ec);
1172 mutex_lock(&ec->mutex);
1173 list_for_each_entry_safe(handler, tmp, &ec->list, node) {
1174 list_del(&handler->node);
1175 kfree(handler);
1177 mutex_unlock(&ec->mutex);
1178 release_region(ec->data_addr, 1);
1179 release_region(ec->command_addr, 1);
1180 device->driver_data = NULL;
1181 if (ec == first_ec)
1182 first_ec = NULL;
1183 kfree(ec);
1184 return 0;
1187 static acpi_status
1188 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1190 struct acpi_ec *ec = context;
1192 if (resource->type != ACPI_RESOURCE_TYPE_IO)
1193 return AE_OK;
1196 * The first address region returned is the data port, and
1197 * the second address region returned is the status/command
1198 * port.
1200 if (ec->data_addr == 0)
1201 ec->data_addr = resource->data.io.minimum;
1202 else if (ec->command_addr == 0)
1203 ec->command_addr = resource->data.io.minimum;
1204 else
1205 return AE_CTRL_TERMINATE;
1207 return AE_OK;
1210 int __init acpi_boot_ec_enable(void)
1212 if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags))
1213 return 0;
1214 if (!ec_install_handlers(boot_ec)) {
1215 first_ec = boot_ec;
1216 return 0;
1218 return -EFAULT;
1221 static const struct acpi_device_id ec_device_ids[] = {
1222 {"PNP0C09", 0},
1223 {"", 0},
1226 /* Some BIOS do not survive early DSDT scan, skip it */
1227 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1229 EC_FLAGS_SKIP_DSDT_SCAN = 1;
1230 return 0;
1233 /* ASUStek often supplies us with broken ECDT, validate it */
1234 static int ec_validate_ecdt(const struct dmi_system_id *id)
1236 EC_FLAGS_VALIDATE_ECDT = 1;
1237 return 0;
1240 /* MSI EC needs special treatment, enable it */
1241 static int ec_flag_msi(const struct dmi_system_id *id)
1243 pr_debug("Detected MSI hardware, enabling workarounds.\n");
1244 EC_FLAGS_MSI = 1;
1245 EC_FLAGS_VALIDATE_ECDT = 1;
1246 return 0;
1250 * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1251 * the GPE storm threshold back to 20
1253 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1255 pr_debug("Setting the EC GPE storm threshold to 20\n");
1256 ec_storm_threshold = 20;
1257 return 0;
1261 * Acer EC firmware refuses to respond QR_EC when SCI_EVT is not set, for
1262 * which case, we complete the QR_EC without issuing it to the firmware.
1263 * https://bugzilla.kernel.org/show_bug.cgi?id=86211
1265 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1267 pr_debug("Detected the EC firmware requiring QR_EC issued when SCI_EVT set\n");
1268 EC_FLAGS_QUERY_HANDSHAKE = 1;
1269 return 0;
1273 * On some hardware it is necessary to clear events accumulated by the EC during
1274 * sleep. These ECs stop reporting GPEs until they are manually polled, if too
1275 * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
1277 * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1279 * Ideally, the EC should also be instructed NOT to accumulate events during
1280 * sleep (which Windows seems to do somehow), but the interface to control this
1281 * behaviour is not known at this time.
1283 * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
1284 * however it is very likely that other Samsung models are affected.
1286 * On systems which don't accumulate _Q events during sleep, this extra check
1287 * should be harmless.
1289 static int ec_clear_on_resume(const struct dmi_system_id *id)
1291 pr_debug("Detected system needing EC poll on resume.\n");
1292 EC_FLAGS_CLEAR_ON_RESUME = 1;
1293 return 0;
1296 static struct dmi_system_id ec_dmi_table[] __initdata = {
1298 ec_skip_dsdt_scan, "Compal JFL92", {
1299 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1300 DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1302 ec_flag_msi, "MSI hardware", {
1303 DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1305 ec_flag_msi, "MSI hardware", {
1306 DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1308 ec_flag_msi, "MSI hardware", {
1309 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1311 ec_flag_msi, "MSI hardware", {
1312 DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1314 ec_flag_msi, "Quanta hardware", {
1315 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1316 DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1318 ec_flag_msi, "Quanta hardware", {
1319 DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1320 DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1322 ec_flag_msi, "Clevo W350etq", {
1323 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1324 DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1326 ec_validate_ecdt, "ASUS hardware", {
1327 DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1329 ec_validate_ecdt, "ASUS hardware", {
1330 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1332 ec_enlarge_storm_threshold, "CLEVO hardware", {
1333 DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1334 DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1336 ec_skip_dsdt_scan, "HP Folio 13", {
1337 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1338 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL},
1340 ec_validate_ecdt, "ASUS hardware", {
1341 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1342 DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1344 ec_clear_on_resume, "Samsung hardware", {
1345 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1347 ec_flag_query_handshake, "Acer hardware", {
1348 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1352 int __init acpi_ec_ecdt_probe(void)
1354 acpi_status status;
1355 struct acpi_ec *saved_ec = NULL;
1356 struct acpi_table_ecdt *ecdt_ptr;
1358 boot_ec = make_acpi_ec();
1359 if (!boot_ec)
1360 return -ENOMEM;
1362 * Generate a boot ec context
1364 dmi_check_system(ec_dmi_table);
1365 status = acpi_get_table(ACPI_SIG_ECDT, 1,
1366 (struct acpi_table_header **)&ecdt_ptr);
1367 if (ACPI_SUCCESS(status)) {
1368 pr_info("EC description table is found, configuring boot EC\n");
1369 boot_ec->command_addr = ecdt_ptr->control.address;
1370 boot_ec->data_addr = ecdt_ptr->data.address;
1371 boot_ec->gpe = ecdt_ptr->gpe;
1372 boot_ec->handle = ACPI_ROOT_OBJECT;
1373 acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id,
1374 &boot_ec->handle);
1375 /* Don't trust ECDT, which comes from ASUSTek */
1376 if (!EC_FLAGS_VALIDATE_ECDT)
1377 goto install;
1378 saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL);
1379 if (!saved_ec)
1380 return -ENOMEM;
1381 /* fall through */
1384 if (EC_FLAGS_SKIP_DSDT_SCAN) {
1385 kfree(saved_ec);
1386 return -ENODEV;
1389 /* This workaround is needed only on some broken machines,
1390 * which require early EC, but fail to provide ECDT */
1391 pr_debug("Look up EC in DSDT\n");
1392 status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
1393 boot_ec, NULL);
1394 /* Check that acpi_get_devices actually find something */
1395 if (ACPI_FAILURE(status) || !boot_ec->handle)
1396 goto error;
1397 if (saved_ec) {
1398 /* try to find good ECDT from ASUSTek */
1399 if (saved_ec->command_addr != boot_ec->command_addr ||
1400 saved_ec->data_addr != boot_ec->data_addr ||
1401 saved_ec->gpe != boot_ec->gpe ||
1402 saved_ec->handle != boot_ec->handle)
1403 pr_info("ASUSTek keeps feeding us with broken "
1404 "ECDT tables, which are very hard to workaround. "
1405 "Trying to use DSDT EC info instead. Please send "
1406 "output of acpidump to linux-acpi@vger.kernel.org\n");
1407 kfree(saved_ec);
1408 saved_ec = NULL;
1409 } else {
1410 /* We really need to limit this workaround, the only ASUS,
1411 * which needs it, has fake EC._INI method, so use it as flag.
1412 * Keep boot_ec struct as it will be needed soon.
1414 if (!dmi_name_in_vendors("ASUS") ||
1415 !acpi_has_method(boot_ec->handle, "_INI"))
1416 return -ENODEV;
1418 install:
1419 if (!ec_install_handlers(boot_ec)) {
1420 first_ec = boot_ec;
1421 return 0;
1423 error:
1424 kfree(boot_ec);
1425 kfree(saved_ec);
1426 boot_ec = NULL;
1427 return -ENODEV;
1430 static struct acpi_driver acpi_ec_driver = {
1431 .name = "ec",
1432 .class = ACPI_EC_CLASS,
1433 .ids = ec_device_ids,
1434 .ops = {
1435 .add = acpi_ec_add,
1436 .remove = acpi_ec_remove,
1440 int __init acpi_ec_init(void)
1442 int result = 0;
1444 /* Now register the driver for the EC */
1445 result = acpi_bus_register_driver(&acpi_ec_driver);
1446 if (result < 0)
1447 return -ENODEV;
1449 return result;
1452 /* EC driver currently not unloadable */
1453 #if 0
1454 static void __exit acpi_ec_exit(void)
1457 acpi_bus_unregister_driver(&acpi_ec_driver);
1459 #endif /* 0 */