Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/drivers/acpi/ec.c

  1 /*
  2  *  ec.c - ACPI Embedded Controller Driver (v3)
  3  *
  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>
 12  *
 13  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 14  *
 15  *  This program is free software; you can redistribute it and/or modify
 16  *  it under the terms of the GNU General Public License as published by
 17  *  the Free Software Foundation; either version 2 of the License, or (at
 18  *  your option) any later version.
 19  *
 20  *  This program is distributed in the hope that it will be useful, but
 21  *  WITHOUT ANY WARRANTY; without even the implied warranty of
 22  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 23  *  General Public License for more details.
 24  *
 25  *  You should have received a copy of the GNU General Public License along
 26  *  with this program; if not, write to the Free Software Foundation, Inc.,
 27  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 28  *
 29  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 30  */
 31 
 32 /* Uncomment next line to get verbose printout */
 33 /* #define DEBUG */
 34 #define pr_fmt(fmt) "ACPI : EC: " fmt
 35 
 36 #include <linux/kernel.h>
 37 #include <linux/module.h>
 38 #include <linux/init.h>
 39 #include <linux/types.h>
 40 #include <linux/delay.h>
 41 #include <linux/interrupt.h>
 42 #include <linux/list.h>
 43 #include <linux/spinlock.h>
 44 #include <linux/slab.h>
 45 #include <linux/acpi.h>
 46 #include <linux/dmi.h>
 47 #include <asm/io.h>
 48 
 49 #include "internal.h"
 50 
 51 #define ACPI_EC_CLASS                   "embedded_controller"
 52 #define ACPI_EC_DEVICE_NAME             "Embedded Controller"
 53 #define ACPI_EC_FILE_INFO               "info"
 54 
 55 /* EC status register */
 56 #define ACPI_EC_FLAG_OBF        0x01    /* Output buffer full */
 57 #define ACPI_EC_FLAG_IBF        0x02    /* Input buffer full */
 58 #define ACPI_EC_FLAG_CMD        0x08    /* Input buffer contains a command */
 59 #define ACPI_EC_FLAG_BURST      0x10    /* burst mode */
 60 #define ACPI_EC_FLAG_SCI        0x20    /* EC-SCI occurred */
 61 
 62 /* EC commands */
 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,
 69 };
 70 
 71 #define ACPI_EC_DELAY           500     /* Wait 500ms max. during EC ops */
 72 #define ACPI_EC_UDELAY_GLK      1000    /* Wait 1ms max. to get global lock */
 73 #define ACPI_EC_MSI_UDELAY      550     /* Wait 550us for MSI EC */
 74 #define ACPI_EC_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 */
 77 
 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 */
 86 };
 87 
 88 #define ACPI_EC_COMMAND_POLL            0x01 /* Available for command byte */
 89 #define ACPI_EC_COMMAND_COMPLETE        0x02 /* Completed last byte */
 90 
 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");
 95 
 96 /*
 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.
100  */
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");
104 
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;
112 };
113 
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;
125 };
126 
127 static int acpi_ec_query(struct acpi_ec *ec, u8 *data);
128 static void advance_transaction(struct acpi_ec *ec);
129 
130 struct acpi_ec *boot_ec, *first_ec;
131 EXPORT_SYMBOL(first_ec);
132 
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 */
138 
139 /* --------------------------------------------------------------------------
140  *                           Logging/Debugging
141  * -------------------------------------------------------------------------- */
142 
143 /*
144  * Splitters used by the developers to track the boundary of the EC
145  * handling processes.
146  */
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
160 
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__)
169 
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__)
182 
183 /* --------------------------------------------------------------------------
184  *                           Device Flags
185  * -------------------------------------------------------------------------- */
186 
187 static bool acpi_ec_started(struct acpi_ec *ec)
188 {
189         return test_bit(EC_FLAGS_STARTED, &ec->flags) &&
190                !test_bit(EC_FLAGS_STOPPED, &ec->flags);
191 }
192 
193 static bool acpi_ec_flushed(struct acpi_ec *ec)
194 {
195         return ec->reference_count == 1;
196 }
197 
198 /* --------------------------------------------------------------------------
199  *                           EC Registers
200  * -------------------------------------------------------------------------- */
201 
202 static inline u8 acpi_ec_read_status(struct acpi_ec *ec)
203 {
204         u8 x = inb(ec->command_addr);
205 
206         ec_dbg_raw("EC_SC(R) = 0x%2.2x "
207                    "SCI_EVT=%d BURST=%d CMD=%d IBF=%d OBF=%d",
208                    x,
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;
215 }
216 
217 static inline u8 acpi_ec_read_data(struct acpi_ec *ec)
218 {
219         u8 x = inb(ec->data_addr);
220 
221         ec->curr->timestamp = jiffies;
222         ec_dbg_raw("EC_DATA(R) = 0x%2.2x", x);
223         return x;
224 }
225 
226 static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command)
227 {
228         ec_dbg_raw("EC_SC(W) = 0x%2.2x", command);
229         outb(command, ec->command_addr);
230         ec->curr->timestamp = jiffies;
231 }
232 
233 static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data)
234 {
235         ec_dbg_raw("EC_DATA(W) = 0x%2.2x", data);
236         outb(data, ec->data_addr);
237         ec->curr->timestamp = jiffies;
238 }
239 
240 #ifdef DEBUG
241 static const char *acpi_ec_cmd_string(u8 cmd)
242 {
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";
254         }
255         return "UNKNOWN";
256 }
257 #else
258 #define acpi_ec_cmd_string(cmd)         "UNDEF"
259 #endif
260 
261 /* --------------------------------------------------------------------------
262  *                           GPE Registers
263  * -------------------------------------------------------------------------- */
264 
265 static inline bool acpi_ec_is_gpe_raised(struct acpi_ec *ec)
266 {
267         acpi_event_status gpe_status = 0;
268 
269         (void)acpi_get_gpe_status(NULL, ec->gpe, &gpe_status);
270         return (gpe_status & ACPI_EVENT_FLAG_SET) ? true : false;
271 }
272 
273 static inline void acpi_ec_enable_gpe(struct acpi_ec *ec, bool open)
274 {
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);
280         }
281         if (acpi_ec_is_gpe_raised(ec)) {
282                 /*
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.
286                  */
287                 ec_dbg_raw("Polling quirk");
288                 advance_transaction(ec);
289         }
290 }
291 
292 static inline void acpi_ec_disable_gpe(struct acpi_ec *ec, bool close)
293 {
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);
299         }
300 }
301 
302 static inline void acpi_ec_clear_gpe(struct acpi_ec *ec)
303 {
304         /*
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.
313          */
314         if (!acpi_ec_is_gpe_raised(ec))
315                 return;
316         acpi_clear_gpe(NULL, ec->gpe);
317 }
318 
319 /* --------------------------------------------------------------------------
320  *                           Transaction Management
321  * -------------------------------------------------------------------------- */
322 
323 static void acpi_ec_submit_request(struct acpi_ec *ec)
324 {
325         ec->reference_count++;
326         if (ec->reference_count == 1)
327                 acpi_ec_enable_gpe(ec, true);
328 }
329 
330 static void acpi_ec_complete_request(struct acpi_ec *ec)
331 {
332         bool flushed = false;
333 
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);
340 }
341 
342 static void acpi_ec_set_storm(struct acpi_ec *ec, u8 flag)
343 {
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);
348         }
349 }
350 
351 static void acpi_ec_clear_storm(struct acpi_ec *ec, u8 flag)
352 {
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");
357         }
358 }
359 
360 /*
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
365  *
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.
370  */
371 static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec)
372 {
373         if (!acpi_ec_started(ec))
374                 return false;
375         acpi_ec_submit_request(ec);
376         return true;
377 }
378 
379 static void acpi_ec_submit_query(struct acpi_ec *ec)
380 {
381         if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) {
382                 ec_dbg_req("Event started");
383                 schedule_work(&ec->work);
384         }
385 }
386 
387 static void acpi_ec_complete_query(struct acpi_ec *ec)
388 {
389         if (ec->curr->command == ACPI_EC_COMMAND_QUERY) {
390                 clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
391                 ec_dbg_req("Event stopped");
392         }
393 }
394 
395 static int ec_transaction_completed(struct acpi_ec *ec)
396 {
397         unsigned long flags;
398         int ret = 0;
399 
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;
405 }
406 
407 static void advance_transaction(struct acpi_ec *ec)
408 {
409         struct transaction *t;
410         u8 status;
411         bool wakeup = false;
412 
413         ec_dbg_stm("%s (%d)", in_interrupt() ? "IRQ" : "TASK",
414                    smp_processor_id());
415         /*
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.
419          */
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;
440                                 }
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;
447                 }
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;
467         }
468 err:
469         /*
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.
472          */
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);
480                 }
481         }
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);
487 }
488 
489 static void start_transaction(struct acpi_ec *ec)
490 {
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);
495 }
496 
497 static int ec_poll(struct acpi_ec *ec)
498 {
499         unsigned long flags;
500         int repeat = 5; /* number of command restarts */
501 
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;
518                         }
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);
530         }
531         return -ETIME;
532 }
533 
534 static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
535                                         struct transaction *t)
536 {
537         unsigned long tmp;
538         int ret = 0;
539 
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;
548         }
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;
567 }
568 
569 static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
570 {
571         int status;
572         u32 glk;
573 
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;
584                 }
585         }
586 
587         status = acpi_ec_transaction_unlocked(ec, t);
588 
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;
596 }
597 
598 static int acpi_ec_burst_enable(struct acpi_ec *ec)
599 {
600         u8 d;
601         struct transaction t = {.command = ACPI_EC_BURST_ENABLE,
602                                 .wdata = NULL, .rdata = &d,
603                                 .wlen = 0, .rlen = 1};
604 
605         return acpi_ec_transaction(ec, &t);
606 }
607 
608 static int acpi_ec_burst_disable(struct acpi_ec *ec)
609 {
610         struct transaction t = {.command = ACPI_EC_BURST_DISABLE,
611                                 .wdata = NULL, .rdata = NULL,
612                                 .wlen = 0, .rlen = 0};
613 
614         return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ?
615                                 acpi_ec_transaction(ec, &t) : 0;
616 }
617 
618 static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 *data)
619 {
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};
625 
626         result = acpi_ec_transaction(ec, &t);
627         *data = d;
628         return result;
629 }
630 
631 static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data)
632 {
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};
637 
638         return acpi_ec_transaction(ec, &t);
639 }
640 
641 int ec_read(u8 addr, u8 *val)
642 {
643         int err;
644         u8 temp_data;
645 
646         if (!first_ec)
647                 return -ENODEV;
648 
649         err = acpi_ec_read(first_ec, addr, &temp_data);
650 
651         if (!err) {
652                 *val = temp_data;
653                 return 0;
654         }
655         return err;
656 }
657 EXPORT_SYMBOL(ec_read);
658 
659 int ec_write(u8 addr, u8 val)
660 {
661         int err;
662 
663         if (!first_ec)
664                 return -ENODEV;
665 
666         err = acpi_ec_write(first_ec, addr, val);
667 
668         return err;
669 }
670 EXPORT_SYMBOL(ec_write);
671 
672 int ec_transaction(u8 command,
673                    const u8 *wdata, unsigned wdata_len,
674                    u8 *rdata, unsigned rdata_len)
675 {
676         struct transaction t = {.command = command,
677                                 .wdata = wdata, .rdata = rdata,
678                                 .wlen = wdata_len, .rlen = rdata_len};
679 
680         if (!first_ec)
681                 return -ENODEV;
682 
683         return acpi_ec_transaction(first_ec, &t);
684 }
685 EXPORT_SYMBOL(ec_transaction);
686 
687 /* Get the handle to the EC device */
688 acpi_handle ec_get_handle(void)
689 {
690         if (!first_ec)
691                 return NULL;
692         return first_ec->handle;
693 }
694 EXPORT_SYMBOL(ec_get_handle);
695 
696 /*
697  * Process _Q events that might have accumulated in the EC.
698  * Run with locked ec mutex.
699  */
700 static void acpi_ec_clear(struct acpi_ec *ec)
701 {
702         int i, status;
703         u8 value = 0;
704 
705         for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) {
706                 status = acpi_ec_query(ec, &value);
707                 if (status || !value)
708                         break;
709         }
710 
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);
715 }
716 
717 static void acpi_ec_start(struct acpi_ec *ec, bool resuming)
718 {
719         unsigned long flags;
720 
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");
728                 }
729                 ec_log_drv("EC started");
730         }
731         spin_unlock_irqrestore(&ec->lock, flags);
732 }
733 
734 static bool acpi_ec_stopped(struct acpi_ec *ec)
735 {
736         unsigned long flags;
737         bool flushed;
738 
739         spin_lock_irqsave(&ec->lock, flags);
740         flushed = acpi_ec_flushed(ec);
741         spin_unlock_irqrestore(&ec->lock, flags);
742         return flushed;
743 }
744 
745 static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
746 {
747         unsigned long flags;
748 
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");
760                 }
761                 clear_bit(EC_FLAGS_STARTED, &ec->flags);
762                 clear_bit(EC_FLAGS_STOPPED, &ec->flags);
763                 ec_log_drv("EC stopped");
764         }
765         spin_unlock_irqrestore(&ec->lock, flags);
766 }
767 
768 void acpi_ec_block_transactions(void)
769 {
770         struct acpi_ec *ec = first_ec;
771 
772         if (!ec)
773                 return;
774 
775         mutex_lock(&ec->mutex);
776         /* Prevent transactions from being carried out */
777         acpi_ec_stop(ec, true);
778         mutex_unlock(&ec->mutex);
779 }
780 
781 void acpi_ec_unblock_transactions(void)
782 {
783         struct acpi_ec *ec = first_ec;
784 
785         if (!ec)
786                 return;
787 
788         /* Allow transactions to be carried out again */
789         acpi_ec_start(ec, true);
790 
791         if (EC_FLAGS_CLEAR_ON_RESUME)
792                 acpi_ec_clear(ec);
793 }
794 
795 void acpi_ec_unblock_transactions_early(void)
796 {
797         /*
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).
800          */
801         if (first_ec)
802                 acpi_ec_start(first_ec, true);
803 }
804 
805 /* --------------------------------------------------------------------------
806                                 Event Management
807    -------------------------------------------------------------------------- */
808 static struct acpi_ec_query_handler *
809 acpi_ec_get_query_handler(struct acpi_ec_query_handler *handler)
810 {
811         if (handler)
812                 kref_get(&handler->kref);
813         return handler;
814 }
815 
816 static void acpi_ec_query_handler_release(struct kref *kref)
817 {
818         struct acpi_ec_query_handler *handler =
819                 container_of(kref, struct acpi_ec_query_handler, kref);
820 
821         kfree(handler);
822 }
823 
824 static void acpi_ec_put_query_handler(struct acpi_ec_query_handler *handler)
825 {
826         kref_put(&handler->kref, acpi_ec_query_handler_release);
827 }
828 
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)
832 {
833         struct acpi_ec_query_handler *handler =
834             kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL);
835 
836         if (!handler)
837                 return -ENOMEM;
838 
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;
848 }
849 EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler);
850 
851 void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit)
852 {
853         struct acpi_ec_query_handler *handler, *tmp;
854         LIST_HEAD(free_list);
855 
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);
861                 }
862         }
863         mutex_unlock(&ec->mutex);
864         list_for_each_entry_safe(handler, tmp, &free_list, node)
865                 acpi_ec_put_query_handler(handler);
866 }
867 EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);
868 
869 static void acpi_ec_run(void *cxt)
870 {
871         struct acpi_ec_query_handler *handler = cxt;
872 
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);
882 }
883 
884 static int acpi_ec_query(struct acpi_ec *ec, u8 *data)
885 {
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};
893 
894         /*
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).
898          */
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;
906 
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;
920                 }
921         }
922         mutex_unlock(&ec->mutex);
923         return result;
924 }
925 
926 static void acpi_ec_gpe_poller(struct work_struct *work)
927 {
928         struct acpi_ec *ec = container_of(work, struct acpi_ec, work);
929 
930         acpi_ec_query(ec, NULL);
931 }
932 
933 static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
934         u32 gpe_number, void *data)
935 {
936         unsigned long flags;
937         struct acpi_ec *ec = data;
938 
939         spin_lock_irqsave(&ec->lock, flags);
940         advance_transaction(ec);
941         spin_unlock_irqrestore(&ec->lock, flags);
942         return ACPI_INTERRUPT_HANDLED;
943 }
944 
945 /* --------------------------------------------------------------------------
946  *                           Address Space Management
947  * -------------------------------------------------------------------------- */
948 
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)
953 {
954         struct acpi_ec *ec = handler_context;
955         int result = 0, i, bytes = bits / 8;
956         u8 *value = (u8 *)value64;
957 
958         if ((address > 0xFF) || !value || !handler_context)
959                 return AE_BAD_PARAMETER;
960 
961         if (function != ACPI_READ && function != ACPI_WRITE)
962                 return AE_BAD_PARAMETER;
963 
964         if (EC_FLAGS_MSI || bits > 8)
965                 acpi_ec_burst_enable(ec);
966 
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);
971 
972         if (EC_FLAGS_MSI || bits > 8)
973                 acpi_ec_burst_disable(ec);
974 
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;
984         }
985 }
986 
987 /* --------------------------------------------------------------------------
988  *                             Driver Interface
989  * -------------------------------------------------------------------------- */
990 
991 static acpi_status
992 ec_parse_io_ports(struct acpi_resource *resource, void *context);
993 
994 static struct acpi_ec *make_acpi_ec(void)
995 {
996         struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL);
997 
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;
1007 }
1008 
1009 static acpi_status
1010 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
1011                                void *context, void **return_value)
1012 {
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;
1018 
1019         status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
1020 
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;
1024 }
1025 
1026 static acpi_status
1027 ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval)
1028 {
1029         acpi_status status;
1030         unsigned long long tmp = 0;
1031         struct acpi_ec *ec = context;
1032 
1033         /* clear addr values, ec_parse_io_ports depend on it */
1034         ec->command_addr = ec->data_addr = 0;
1035 
1036         status = acpi_walk_resources(handle, METHOD_NAME__CRS,
1037                                      ec_parse_io_ports, ec);
1038         if (ACPI_FAILURE(status))
1039                 return status;
1040 
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;
1053 }
1054 
1055 static int ec_install_handlers(struct acpi_ec *ec)
1056 {
1057         acpi_status status;
1058 
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;
1066 
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) {
1074                         /*
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.
1078                          */
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;
1086                 }
1087         }
1088 
1089         set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags);
1090         return 0;
1091 }
1092 
1093 static void ec_remove_handlers(struct acpi_ec *ec)
1094 {
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);
1105 }
1106 
1107 static int acpi_ec_add(struct acpi_device *device)
1108 {
1109         struct acpi_ec *ec = NULL;
1110         int ret;
1111 
1112         strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1113         strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1114 
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;
1125         }
1126         if (ec_parse_device(device->handle, 0, ec, NULL) !=
1127                 AE_CTRL_TERMINATE) {
1128                         kfree(ec);
1129                         return -EINVAL;
1130         }
1131 
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);
1135 
1136         if (!first_ec)
1137                 first_ec = ec;
1138         device->driver_data = ec;
1139 
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);
1144 
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);
1147 
1148         ret = ec_install_handlers(ec);
1149 
1150         /* Reprobe devices depending on the EC */
1151         acpi_walk_dep_device_list(ec->handle);
1152 
1153         /* EC is fully operational, allow queries */
1154         clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
1155 
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;
1160 }
1161 
1162 static int acpi_ec_remove(struct acpi_device *device)
1163 {
1164         struct acpi_ec *ec;
1165         struct acpi_ec_query_handler *handler, *tmp;
1166 
1167         if (!device)
1168                 return -EINVAL;
1169 
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);
1176         }
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;
1185 }
1186 
1187 static acpi_status
1188 ec_parse_io_ports(struct acpi_resource *resource, void *context)
1189 {
1190         struct acpi_ec *ec = context;
1191 
1192         if (resource->type != ACPI_RESOURCE_TYPE_IO)
1193                 return AE_OK;
1194 
1195         /*
1196          * The first address region returned is the data port, and
1197          * the second address region returned is the status/command
1198          * port.
1199          */
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;
1206 
1207         return AE_OK;
1208 }
1209 
1210 int __init acpi_boot_ec_enable(void)
1211 {
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;
1217         }
1218         return -EFAULT;
1219 }
1220 
1221 static const struct acpi_device_id ec_device_ids[] = {
1222         {"PNP0C09", 0},
1223         {"", 0},
1224 };
1225 
1226 /* Some BIOS do not survive early DSDT scan, skip it */
1227 static int ec_skip_dsdt_scan(const struct dmi_system_id *id)
1228 {
1229         EC_FLAGS_SKIP_DSDT_SCAN = 1;
1230         return 0;
1231 }
1232 
1233 /* ASUStek often supplies us with broken ECDT, validate it */
1234 static int ec_validate_ecdt(const struct dmi_system_id *id)
1235 {
1236         EC_FLAGS_VALIDATE_ECDT = 1;
1237         return 0;
1238 }
1239 
1240 /* MSI EC needs special treatment, enable it */
1241 static int ec_flag_msi(const struct dmi_system_id *id)
1242 {
1243         pr_debug("Detected MSI hardware, enabling workarounds.\n");
1244         EC_FLAGS_MSI = 1;
1245         EC_FLAGS_VALIDATE_ECDT = 1;
1246         return 0;
1247 }
1248 
1249 /*
1250  * Clevo M720 notebook actually works ok with IRQ mode, if we lifted
1251  * the GPE storm threshold back to 20
1252  */
1253 static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
1254 {
1255         pr_debug("Setting the EC GPE storm threshold to 20\n");
1256         ec_storm_threshold  = 20;
1257         return 0;
1258 }
1259 
1260 /*
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
1264  */
1265 static int ec_flag_query_handshake(const struct dmi_system_id *id)
1266 {
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;
1270 }
1271 
1272 /*
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)
1276  *
1277  * https://bugzilla.kernel.org/show_bug.cgi?id=44161
1278  *
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.
1282  *
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.
1285  *
1286  * On systems which don't accumulate _Q events during sleep, this extra check
1287  * should be harmless.
1288  */
1289 static int ec_clear_on_resume(const struct dmi_system_id *id)
1290 {
1291         pr_debug("Detected system needing EC poll on resume.\n");
1292         EC_FLAGS_CLEAR_ON_RESUME = 1;
1293         return 0;
1294 }
1295 
1296 static struct dmi_system_id ec_dmi_table[] __initdata = {
1297         {
1298         ec_skip_dsdt_scan, "Compal JFL92", {
1299         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
1300         DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL},
1301         {
1302         ec_flag_msi, "MSI hardware", {
1303         DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL},
1304         {
1305         ec_flag_msi, "MSI hardware", {
1306         DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL},
1307         {
1308         ec_flag_msi, "MSI hardware", {
1309         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL},
1310         {
1311         ec_flag_msi, "MSI hardware", {
1312         DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL},
1313         {
1314         ec_flag_msi, "Quanta hardware", {
1315         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1316         DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL},
1317         {
1318         ec_flag_msi, "Quanta hardware", {
1319         DMI_MATCH(DMI_SYS_VENDOR, "Quanta"),
1320         DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL},
1321         {
1322         ec_flag_msi, "Clevo W350etq", {
1323         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO CO."),
1324         DMI_MATCH(DMI_PRODUCT_NAME, "W35_37ET"),}, NULL},
1325         {
1326         ec_validate_ecdt, "ASUS hardware", {
1327         DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL},
1328         {
1329         ec_validate_ecdt, "ASUS hardware", {
1330         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL},
1331         {
1332         ec_enlarge_storm_threshold, "CLEVO hardware", {
1333         DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
1334         DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL},
1335         {
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},
1339         {
1340         ec_validate_ecdt, "ASUS hardware", {
1341         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
1342         DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
1343         {
1344         ec_clear_on_resume, "Samsung hardware", {
1345         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
1346         {
1347         ec_flag_query_handshake, "Acer hardware", {
1348         DMI_MATCH(DMI_SYS_VENDOR, "Acer"), }, NULL},
1349         {},
1350 };
1351 
1352 int __init acpi_ec_ecdt_probe(void)
1353 {
1354         acpi_status status;
1355         struct acpi_ec *saved_ec = NULL;
1356         struct acpi_table_ecdt *ecdt_ptr;
1357 
1358         boot_ec = make_acpi_ec();
1359         if (!boot_ec)
1360                 return -ENOMEM;
1361         /*
1362          * Generate a boot ec context
1363          */
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 */
1382         }
1383 
1384         if (EC_FLAGS_SKIP_DSDT_SCAN) {
1385                 kfree(saved_ec);
1386                 return -ENODEV;
1387         }
1388 
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.
1413                 */
1414                 if (!dmi_name_in_vendors("ASUS") ||
1415                     !acpi_has_method(boot_ec->handle, "_INI"))
1416                         return -ENODEV;
1417         }
1418 install:
1419         if (!ec_install_handlers(boot_ec)) {
1420                 first_ec = boot_ec;
1421                 return 0;
1422         }
1423 error:
1424         kfree(boot_ec);
1425         kfree(saved_ec);
1426         boot_ec = NULL;
1427         return -ENODEV;
1428 }
1429 
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,
1437                 },
1438 };
1439 
1440 int __init acpi_ec_init(void)
1441 {
1442         int result = 0;
1443 
1444         /* Now register the driver for the EC */
1445         result = acpi_bus_register_driver(&acpi_ec_driver);
1446         if (result < 0)
1447                 return -ENODEV;
1448 
1449         return result;
1450 }
1451 
1452 /* EC driver currently not unloadable */
1453 #if 0
1454 static void __exit acpi_ec_exit(void)
1455 {
1456 
1457         acpi_bus_unregister_driver(&acpi_ec_driver);
1458 }
1459 #endif  /* 0 */
1460 

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