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1 | /* | |
2 | * ec.c - ACPI Embedded Controller Driver (v2.1) | |
3 | * | |
4 | * Copyright (C) 2006-2008 Alexey Starikovskiy <astarikovskiy@suse.de> | |
5 | * Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com> | |
6 | * Copyright (C) 2004 Luming Yu <luming.yu@intel.com> | |
7 | * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> | |
8 | * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> | |
9 | * | |
10 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or (at | |
15 | * your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, but | |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
20 | * General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with this program; if not, write to the Free Software Foundation, Inc., | |
24 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
25 | * | |
26 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
27 | */ | |
28 | ||
29 | /* Uncomment next line to get verbose printout */ | |
30 | /* #define DEBUG */ | |
31 | ||
32 | #include <linux/kernel.h> | |
33 | #include <linux/module.h> | |
34 | #include <linux/init.h> | |
35 | #include <linux/types.h> | |
36 | #include <linux/delay.h> | |
37 | #include <linux/interrupt.h> | |
38 | #include <linux/list.h> | |
39 | #include <linux/spinlock.h> | |
40 | #include <linux/slab.h> | |
41 | #include <asm/io.h> | |
42 | #include <acpi/acpi_bus.h> | |
43 | #include <acpi/acpi_drivers.h> | |
44 | #include <linux/dmi.h> | |
45 | ||
46 | #include "internal.h" | |
47 | ||
48 | #define ACPI_EC_CLASS "embedded_controller" | |
49 | #define ACPI_EC_DEVICE_NAME "Embedded Controller" | |
50 | #define ACPI_EC_FILE_INFO "info" | |
51 | ||
52 | #undef PREFIX | |
53 | #define PREFIX "ACPI: EC: " | |
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_BURST 0x10 /* burst mode */ | |
59 | #define ACPI_EC_FLAG_SCI 0x20 /* EC-SCI occurred */ | |
60 | ||
61 | /* EC commands */ | |
62 | enum ec_command { | |
63 | ACPI_EC_COMMAND_READ = 0x80, | |
64 | ACPI_EC_COMMAND_WRITE = 0x81, | |
65 | ACPI_EC_BURST_ENABLE = 0x82, | |
66 | ACPI_EC_BURST_DISABLE = 0x83, | |
67 | ACPI_EC_COMMAND_QUERY = 0x84, | |
68 | }; | |
69 | ||
70 | #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */ | |
71 | #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */ | |
72 | #define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */ | |
73 | ||
74 | enum { | |
75 | EC_FLAGS_QUERY_PENDING, /* Query is pending */ | |
76 | EC_FLAGS_GPE_STORM, /* GPE storm detected */ | |
77 | EC_FLAGS_HANDLERS_INSTALLED, /* Handlers for GPE and | |
78 | * OpReg are installed */ | |
79 | EC_FLAGS_BLOCKED, /* Transactions are blocked */ | |
80 | }; | |
81 | ||
82 | /* ec.c is compiled in acpi namespace so this shows up as acpi.ec_delay param */ | |
83 | static unsigned int ec_delay __read_mostly = ACPI_EC_DELAY; | |
84 | module_param(ec_delay, uint, 0644); | |
85 | MODULE_PARM_DESC(ec_delay, "Timeout(ms) waited until an EC command completes"); | |
86 | ||
87 | /* | |
88 | * If the number of false interrupts per one transaction exceeds | |
89 | * this threshold, will think there is a GPE storm happened and | |
90 | * will disable the GPE for normal transaction. | |
91 | */ | |
92 | static unsigned int ec_storm_threshold __read_mostly = 8; | |
93 | module_param(ec_storm_threshold, uint, 0644); | |
94 | MODULE_PARM_DESC(ec_storm_threshold, "Maxim false GPE numbers not considered as GPE storm"); | |
95 | ||
96 | /* If we find an EC via the ECDT, we need to keep a ptr to its context */ | |
97 | /* External interfaces use first EC only, so remember */ | |
98 | typedef int (*acpi_ec_query_func) (void *data); | |
99 | ||
100 | struct acpi_ec_query_handler { | |
101 | struct list_head node; | |
102 | acpi_ec_query_func func; | |
103 | acpi_handle handle; | |
104 | void *data; | |
105 | u8 query_bit; | |
106 | }; | |
107 | ||
108 | struct transaction { | |
109 | const u8 *wdata; | |
110 | u8 *rdata; | |
111 | unsigned short irq_count; | |
112 | u8 command; | |
113 | u8 wi; | |
114 | u8 ri; | |
115 | u8 wlen; | |
116 | u8 rlen; | |
117 | bool done; | |
118 | }; | |
119 | ||
120 | struct acpi_ec *boot_ec, *first_ec; | |
121 | EXPORT_SYMBOL(first_ec); | |
122 | ||
123 | static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */ | |
124 | static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */ | |
125 | static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */ | |
126 | ||
127 | /* -------------------------------------------------------------------------- | |
128 | Transaction Management | |
129 | -------------------------------------------------------------------------- */ | |
130 | ||
131 | static inline u8 acpi_ec_read_status(struct acpi_ec *ec) | |
132 | { | |
133 | u8 x = inb(ec->command_addr); | |
134 | pr_debug(PREFIX "---> status = 0x%2.2x\n", x); | |
135 | return x; | |
136 | } | |
137 | ||
138 | static inline u8 acpi_ec_read_data(struct acpi_ec *ec) | |
139 | { | |
140 | u8 x = inb(ec->data_addr); | |
141 | pr_debug(PREFIX "---> data = 0x%2.2x\n", x); | |
142 | return x; | |
143 | } | |
144 | ||
145 | static inline void acpi_ec_write_cmd(struct acpi_ec *ec, u8 command) | |
146 | { | |
147 | pr_debug(PREFIX "<--- command = 0x%2.2x\n", command); | |
148 | outb(command, ec->command_addr); | |
149 | } | |
150 | ||
151 | static inline void acpi_ec_write_data(struct acpi_ec *ec, u8 data) | |
152 | { | |
153 | pr_debug(PREFIX "<--- data = 0x%2.2x\n", data); | |
154 | outb(data, ec->data_addr); | |
155 | } | |
156 | ||
157 | static int ec_transaction_done(struct acpi_ec *ec) | |
158 | { | |
159 | unsigned long flags; | |
160 | int ret = 0; | |
161 | spin_lock_irqsave(&ec->lock, flags); | |
162 | if (!ec->curr || ec->curr->done) | |
163 | ret = 1; | |
164 | spin_unlock_irqrestore(&ec->lock, flags); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | static void start_transaction(struct acpi_ec *ec) | |
169 | { | |
170 | ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0; | |
171 | ec->curr->done = false; | |
172 | acpi_ec_write_cmd(ec, ec->curr->command); | |
173 | } | |
174 | ||
175 | static void advance_transaction(struct acpi_ec *ec, u8 status) | |
176 | { | |
177 | unsigned long flags; | |
178 | struct transaction *t = ec->curr; | |
179 | ||
180 | spin_lock_irqsave(&ec->lock, flags); | |
181 | if (!t) | |
182 | goto unlock; | |
183 | if (t->wlen > t->wi) { | |
184 | if ((status & ACPI_EC_FLAG_IBF) == 0) | |
185 | acpi_ec_write_data(ec, | |
186 | t->wdata[t->wi++]); | |
187 | else | |
188 | goto err; | |
189 | } else if (t->rlen > t->ri) { | |
190 | if ((status & ACPI_EC_FLAG_OBF) == 1) { | |
191 | t->rdata[t->ri++] = acpi_ec_read_data(ec); | |
192 | if (t->rlen == t->ri) | |
193 | t->done = true; | |
194 | } else | |
195 | goto err; | |
196 | } else if (t->wlen == t->wi && | |
197 | (status & ACPI_EC_FLAG_IBF) == 0) | |
198 | t->done = true; | |
199 | goto unlock; | |
200 | err: | |
201 | /* | |
202 | * If SCI bit is set, then don't think it's a false IRQ | |
203 | * otherwise will take a not handled IRQ as a false one. | |
204 | */ | |
205 | if (in_interrupt() && !(status & ACPI_EC_FLAG_SCI)) | |
206 | ++t->irq_count; | |
207 | ||
208 | unlock: | |
209 | spin_unlock_irqrestore(&ec->lock, flags); | |
210 | } | |
211 | ||
212 | static int acpi_ec_sync_query(struct acpi_ec *ec); | |
213 | ||
214 | static int ec_check_sci_sync(struct acpi_ec *ec, u8 state) | |
215 | { | |
216 | if (state & ACPI_EC_FLAG_SCI) { | |
217 | if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) | |
218 | return acpi_ec_sync_query(ec); | |
219 | } | |
220 | return 0; | |
221 | } | |
222 | ||
223 | static int ec_poll(struct acpi_ec *ec) | |
224 | { | |
225 | unsigned long flags; | |
226 | int repeat = 5; /* number of command restarts */ | |
227 | while (repeat--) { | |
228 | unsigned long delay = jiffies + | |
229 | msecs_to_jiffies(ec_delay); | |
230 | do { | |
231 | /* don't sleep with disabled interrupts */ | |
232 | if (EC_FLAGS_MSI || irqs_disabled()) { | |
233 | udelay(ACPI_EC_MSI_UDELAY); | |
234 | if (ec_transaction_done(ec)) | |
235 | return 0; | |
236 | } else { | |
237 | if (wait_event_timeout(ec->wait, | |
238 | ec_transaction_done(ec), | |
239 | msecs_to_jiffies(1))) | |
240 | return 0; | |
241 | } | |
242 | advance_transaction(ec, acpi_ec_read_status(ec)); | |
243 | } while (time_before(jiffies, delay)); | |
244 | pr_debug(PREFIX "controller reset, restart transaction\n"); | |
245 | spin_lock_irqsave(&ec->lock, flags); | |
246 | start_transaction(ec); | |
247 | spin_unlock_irqrestore(&ec->lock, flags); | |
248 | } | |
249 | return -ETIME; | |
250 | } | |
251 | ||
252 | static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, | |
253 | struct transaction *t) | |
254 | { | |
255 | unsigned long tmp; | |
256 | int ret = 0; | |
257 | if (EC_FLAGS_MSI) | |
258 | udelay(ACPI_EC_MSI_UDELAY); | |
259 | /* start transaction */ | |
260 | spin_lock_irqsave(&ec->lock, tmp); | |
261 | /* following two actions should be kept atomic */ | |
262 | ec->curr = t; | |
263 | start_transaction(ec); | |
264 | if (ec->curr->command == ACPI_EC_COMMAND_QUERY) | |
265 | clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); | |
266 | spin_unlock_irqrestore(&ec->lock, tmp); | |
267 | ret = ec_poll(ec); | |
268 | spin_lock_irqsave(&ec->lock, tmp); | |
269 | ec->curr = NULL; | |
270 | spin_unlock_irqrestore(&ec->lock, tmp); | |
271 | return ret; | |
272 | } | |
273 | ||
274 | static int ec_check_ibf0(struct acpi_ec *ec) | |
275 | { | |
276 | u8 status = acpi_ec_read_status(ec); | |
277 | return (status & ACPI_EC_FLAG_IBF) == 0; | |
278 | } | |
279 | ||
280 | static int ec_wait_ibf0(struct acpi_ec *ec) | |
281 | { | |
282 | unsigned long delay = jiffies + msecs_to_jiffies(ec_delay); | |
283 | /* interrupt wait manually if GPE mode is not active */ | |
284 | while (time_before(jiffies, delay)) | |
285 | if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), | |
286 | msecs_to_jiffies(1))) | |
287 | return 0; | |
288 | return -ETIME; | |
289 | } | |
290 | ||
291 | static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) | |
292 | { | |
293 | int status; | |
294 | u32 glk; | |
295 | if (!ec || (!t) || (t->wlen && !t->wdata) || (t->rlen && !t->rdata)) | |
296 | return -EINVAL; | |
297 | if (t->rdata) | |
298 | memset(t->rdata, 0, t->rlen); | |
299 | mutex_lock(&ec->mutex); | |
300 | if (test_bit(EC_FLAGS_BLOCKED, &ec->flags)) { | |
301 | status = -EINVAL; | |
302 | goto unlock; | |
303 | } | |
304 | if (ec->global_lock) { | |
305 | status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk); | |
306 | if (ACPI_FAILURE(status)) { | |
307 | status = -ENODEV; | |
308 | goto unlock; | |
309 | } | |
310 | } | |
311 | if (ec_wait_ibf0(ec)) { | |
312 | pr_err(PREFIX "input buffer is not empty, " | |
313 | "aborting transaction\n"); | |
314 | status = -ETIME; | |
315 | goto end; | |
316 | } | |
317 | pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n", | |
318 | t->command, t->wdata ? t->wdata[0] : 0); | |
319 | /* disable GPE during transaction if storm is detected */ | |
320 | if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { | |
321 | /* It has to be disabled, so that it doesn't trigger. */ | |
322 | acpi_disable_gpe(NULL, ec->gpe); | |
323 | } | |
324 | ||
325 | status = acpi_ec_transaction_unlocked(ec, t); | |
326 | ||
327 | /* check if we received SCI during transaction */ | |
328 | ec_check_sci_sync(ec, acpi_ec_read_status(ec)); | |
329 | if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { | |
330 | msleep(1); | |
331 | /* It is safe to enable the GPE outside of the transaction. */ | |
332 | acpi_enable_gpe(NULL, ec->gpe); | |
333 | } else if (t->irq_count > ec_storm_threshold) { | |
334 | pr_info(PREFIX "GPE storm detected(%d GPEs), " | |
335 | "transactions will use polling mode\n", | |
336 | t->irq_count); | |
337 | set_bit(EC_FLAGS_GPE_STORM, &ec->flags); | |
338 | } | |
339 | pr_debug(PREFIX "transaction end\n"); | |
340 | end: | |
341 | if (ec->global_lock) | |
342 | acpi_release_global_lock(glk); | |
343 | unlock: | |
344 | mutex_unlock(&ec->mutex); | |
345 | return status; | |
346 | } | |
347 | ||
348 | static int acpi_ec_burst_enable(struct acpi_ec *ec) | |
349 | { | |
350 | u8 d; | |
351 | struct transaction t = {.command = ACPI_EC_BURST_ENABLE, | |
352 | .wdata = NULL, .rdata = &d, | |
353 | .wlen = 0, .rlen = 1}; | |
354 | ||
355 | return acpi_ec_transaction(ec, &t); | |
356 | } | |
357 | ||
358 | static int acpi_ec_burst_disable(struct acpi_ec *ec) | |
359 | { | |
360 | struct transaction t = {.command = ACPI_EC_BURST_DISABLE, | |
361 | .wdata = NULL, .rdata = NULL, | |
362 | .wlen = 0, .rlen = 0}; | |
363 | ||
364 | return (acpi_ec_read_status(ec) & ACPI_EC_FLAG_BURST) ? | |
365 | acpi_ec_transaction(ec, &t) : 0; | |
366 | } | |
367 | ||
368 | static int acpi_ec_read(struct acpi_ec *ec, u8 address, u8 * data) | |
369 | { | |
370 | int result; | |
371 | u8 d; | |
372 | struct transaction t = {.command = ACPI_EC_COMMAND_READ, | |
373 | .wdata = &address, .rdata = &d, | |
374 | .wlen = 1, .rlen = 1}; | |
375 | ||
376 | result = acpi_ec_transaction(ec, &t); | |
377 | *data = d; | |
378 | return result; | |
379 | } | |
380 | ||
381 | static int acpi_ec_write(struct acpi_ec *ec, u8 address, u8 data) | |
382 | { | |
383 | u8 wdata[2] = { address, data }; | |
384 | struct transaction t = {.command = ACPI_EC_COMMAND_WRITE, | |
385 | .wdata = wdata, .rdata = NULL, | |
386 | .wlen = 2, .rlen = 0}; | |
387 | ||
388 | return acpi_ec_transaction(ec, &t); | |
389 | } | |
390 | ||
391 | /* | |
392 | * Externally callable EC access functions. For now, assume 1 EC only | |
393 | */ | |
394 | int ec_burst_enable(void) | |
395 | { | |
396 | if (!first_ec) | |
397 | return -ENODEV; | |
398 | return acpi_ec_burst_enable(first_ec); | |
399 | } | |
400 | ||
401 | EXPORT_SYMBOL(ec_burst_enable); | |
402 | ||
403 | int ec_burst_disable(void) | |
404 | { | |
405 | if (!first_ec) | |
406 | return -ENODEV; | |
407 | return acpi_ec_burst_disable(first_ec); | |
408 | } | |
409 | ||
410 | EXPORT_SYMBOL(ec_burst_disable); | |
411 | ||
412 | int ec_read(u8 addr, u8 *val) | |
413 | { | |
414 | int err; | |
415 | u8 temp_data; | |
416 | ||
417 | if (!first_ec) | |
418 | return -ENODEV; | |
419 | ||
420 | err = acpi_ec_read(first_ec, addr, &temp_data); | |
421 | ||
422 | if (!err) { | |
423 | *val = temp_data; | |
424 | return 0; | |
425 | } else | |
426 | return err; | |
427 | } | |
428 | ||
429 | EXPORT_SYMBOL(ec_read); | |
430 | ||
431 | int ec_write(u8 addr, u8 val) | |
432 | { | |
433 | int err; | |
434 | ||
435 | if (!first_ec) | |
436 | return -ENODEV; | |
437 | ||
438 | err = acpi_ec_write(first_ec, addr, val); | |
439 | ||
440 | return err; | |
441 | } | |
442 | ||
443 | EXPORT_SYMBOL(ec_write); | |
444 | ||
445 | int ec_transaction(u8 command, | |
446 | const u8 * wdata, unsigned wdata_len, | |
447 | u8 * rdata, unsigned rdata_len) | |
448 | { | |
449 | struct transaction t = {.command = command, | |
450 | .wdata = wdata, .rdata = rdata, | |
451 | .wlen = wdata_len, .rlen = rdata_len}; | |
452 | if (!first_ec) | |
453 | return -ENODEV; | |
454 | ||
455 | return acpi_ec_transaction(first_ec, &t); | |
456 | } | |
457 | ||
458 | EXPORT_SYMBOL(ec_transaction); | |
459 | ||
460 | /* Get the handle to the EC device */ | |
461 | acpi_handle ec_get_handle(void) | |
462 | { | |
463 | if (!first_ec) | |
464 | return NULL; | |
465 | return first_ec->handle; | |
466 | } | |
467 | ||
468 | EXPORT_SYMBOL(ec_get_handle); | |
469 | ||
470 | void acpi_ec_block_transactions(void) | |
471 | { | |
472 | struct acpi_ec *ec = first_ec; | |
473 | ||
474 | if (!ec) | |
475 | return; | |
476 | ||
477 | mutex_lock(&ec->mutex); | |
478 | /* Prevent transactions from being carried out */ | |
479 | set_bit(EC_FLAGS_BLOCKED, &ec->flags); | |
480 | mutex_unlock(&ec->mutex); | |
481 | } | |
482 | ||
483 | void acpi_ec_unblock_transactions(void) | |
484 | { | |
485 | struct acpi_ec *ec = first_ec; | |
486 | ||
487 | if (!ec) | |
488 | return; | |
489 | ||
490 | mutex_lock(&ec->mutex); | |
491 | /* Allow transactions to be carried out again */ | |
492 | clear_bit(EC_FLAGS_BLOCKED, &ec->flags); | |
493 | mutex_unlock(&ec->mutex); | |
494 | } | |
495 | ||
496 | void acpi_ec_unblock_transactions_early(void) | |
497 | { | |
498 | /* | |
499 | * Allow transactions to happen again (this function is called from | |
500 | * atomic context during wakeup, so we don't need to acquire the mutex). | |
501 | */ | |
502 | if (first_ec) | |
503 | clear_bit(EC_FLAGS_BLOCKED, &first_ec->flags); | |
504 | } | |
505 | ||
506 | static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data) | |
507 | { | |
508 | int result; | |
509 | u8 d; | |
510 | struct transaction t = {.command = ACPI_EC_COMMAND_QUERY, | |
511 | .wdata = NULL, .rdata = &d, | |
512 | .wlen = 0, .rlen = 1}; | |
513 | if (!ec || !data) | |
514 | return -EINVAL; | |
515 | /* | |
516 | * Query the EC to find out which _Qxx method we need to evaluate. | |
517 | * Note that successful completion of the query causes the ACPI_EC_SCI | |
518 | * bit to be cleared (and thus clearing the interrupt source). | |
519 | */ | |
520 | result = acpi_ec_transaction_unlocked(ec, &t); | |
521 | if (result) | |
522 | return result; | |
523 | if (!d) | |
524 | return -ENODATA; | |
525 | *data = d; | |
526 | return 0; | |
527 | } | |
528 | ||
529 | /* -------------------------------------------------------------------------- | |
530 | Event Management | |
531 | -------------------------------------------------------------------------- */ | |
532 | int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, | |
533 | acpi_handle handle, acpi_ec_query_func func, | |
534 | void *data) | |
535 | { | |
536 | struct acpi_ec_query_handler *handler = | |
537 | kzalloc(sizeof(struct acpi_ec_query_handler), GFP_KERNEL); | |
538 | if (!handler) | |
539 | return -ENOMEM; | |
540 | ||
541 | handler->query_bit = query_bit; | |
542 | handler->handle = handle; | |
543 | handler->func = func; | |
544 | handler->data = data; | |
545 | mutex_lock(&ec->mutex); | |
546 | list_add(&handler->node, &ec->list); | |
547 | mutex_unlock(&ec->mutex); | |
548 | return 0; | |
549 | } | |
550 | ||
551 | EXPORT_SYMBOL_GPL(acpi_ec_add_query_handler); | |
552 | ||
553 | void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) | |
554 | { | |
555 | struct acpi_ec_query_handler *handler, *tmp; | |
556 | mutex_lock(&ec->mutex); | |
557 | list_for_each_entry_safe(handler, tmp, &ec->list, node) { | |
558 | if (query_bit == handler->query_bit) { | |
559 | list_del(&handler->node); | |
560 | kfree(handler); | |
561 | } | |
562 | } | |
563 | mutex_unlock(&ec->mutex); | |
564 | } | |
565 | ||
566 | EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); | |
567 | ||
568 | static void acpi_ec_run(void *cxt) | |
569 | { | |
570 | struct acpi_ec_query_handler *handler = cxt; | |
571 | if (!handler) | |
572 | return; | |
573 | pr_debug(PREFIX "start query execution\n"); | |
574 | if (handler->func) | |
575 | handler->func(handler->data); | |
576 | else if (handler->handle) | |
577 | acpi_evaluate_object(handler->handle, NULL, NULL, NULL); | |
578 | pr_debug(PREFIX "stop query execution\n"); | |
579 | kfree(handler); | |
580 | } | |
581 | ||
582 | static int acpi_ec_sync_query(struct acpi_ec *ec) | |
583 | { | |
584 | u8 value = 0; | |
585 | int status; | |
586 | struct acpi_ec_query_handler *handler, *copy; | |
587 | if ((status = acpi_ec_query_unlocked(ec, &value))) | |
588 | return status; | |
589 | list_for_each_entry(handler, &ec->list, node) { | |
590 | if (value == handler->query_bit) { | |
591 | /* have custom handler for this bit */ | |
592 | copy = kmalloc(sizeof(*handler), GFP_KERNEL); | |
593 | if (!copy) | |
594 | return -ENOMEM; | |
595 | memcpy(copy, handler, sizeof(*copy)); | |
596 | pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value); | |
597 | return acpi_os_execute((copy->func) ? | |
598 | OSL_NOTIFY_HANDLER : OSL_GPE_HANDLER, | |
599 | acpi_ec_run, copy); | |
600 | } | |
601 | } | |
602 | return 0; | |
603 | } | |
604 | ||
605 | static void acpi_ec_gpe_query(void *ec_cxt) | |
606 | { | |
607 | struct acpi_ec *ec = ec_cxt; | |
608 | if (!ec) | |
609 | return; | |
610 | mutex_lock(&ec->mutex); | |
611 | acpi_ec_sync_query(ec); | |
612 | mutex_unlock(&ec->mutex); | |
613 | } | |
614 | ||
615 | static int ec_check_sci(struct acpi_ec *ec, u8 state) | |
616 | { | |
617 | if (state & ACPI_EC_FLAG_SCI) { | |
618 | if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { | |
619 | pr_debug(PREFIX "push gpe query to the queue\n"); | |
620 | return acpi_os_execute(OSL_NOTIFY_HANDLER, | |
621 | acpi_ec_gpe_query, ec); | |
622 | } | |
623 | } | |
624 | return 0; | |
625 | } | |
626 | ||
627 | static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, | |
628 | u32 gpe_number, void *data) | |
629 | { | |
630 | struct acpi_ec *ec = data; | |
631 | u8 status = acpi_ec_read_status(ec); | |
632 | ||
633 | pr_debug(PREFIX "~~~> interrupt, status:0x%02x\n", status); | |
634 | ||
635 | advance_transaction(ec, status); | |
636 | if (ec_transaction_done(ec) && | |
637 | (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) { | |
638 | wake_up(&ec->wait); | |
639 | ec_check_sci(ec, acpi_ec_read_status(ec)); | |
640 | } | |
641 | return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE; | |
642 | } | |
643 | ||
644 | /* -------------------------------------------------------------------------- | |
645 | Address Space Management | |
646 | -------------------------------------------------------------------------- */ | |
647 | ||
648 | static acpi_status | |
649 | acpi_ec_space_handler(u32 function, acpi_physical_address address, | |
650 | u32 bits, u64 *value64, | |
651 | void *handler_context, void *region_context) | |
652 | { | |
653 | struct acpi_ec *ec = handler_context; | |
654 | int result = 0, i, bytes = bits / 8; | |
655 | u8 *value = (u8 *)value64; | |
656 | ||
657 | if ((address > 0xFF) || !value || !handler_context) | |
658 | return AE_BAD_PARAMETER; | |
659 | ||
660 | if (function != ACPI_READ && function != ACPI_WRITE) | |
661 | return AE_BAD_PARAMETER; | |
662 | ||
663 | if (EC_FLAGS_MSI || bits > 8) | |
664 | acpi_ec_burst_enable(ec); | |
665 | ||
666 | for (i = 0; i < bytes; ++i, ++address, ++value) | |
667 | result = (function == ACPI_READ) ? | |
668 | acpi_ec_read(ec, address, value) : | |
669 | acpi_ec_write(ec, address, *value); | |
670 | ||
671 | if (EC_FLAGS_MSI || bits > 8) | |
672 | acpi_ec_burst_disable(ec); | |
673 | ||
674 | switch (result) { | |
675 | case -EINVAL: | |
676 | return AE_BAD_PARAMETER; | |
677 | break; | |
678 | case -ENODEV: | |
679 | return AE_NOT_FOUND; | |
680 | break; | |
681 | case -ETIME: | |
682 | return AE_TIME; | |
683 | break; | |
684 | default: | |
685 | return AE_OK; | |
686 | } | |
687 | } | |
688 | ||
689 | /* -------------------------------------------------------------------------- | |
690 | Driver Interface | |
691 | -------------------------------------------------------------------------- */ | |
692 | static acpi_status | |
693 | ec_parse_io_ports(struct acpi_resource *resource, void *context); | |
694 | ||
695 | static struct acpi_ec *make_acpi_ec(void) | |
696 | { | |
697 | struct acpi_ec *ec = kzalloc(sizeof(struct acpi_ec), GFP_KERNEL); | |
698 | if (!ec) | |
699 | return NULL; | |
700 | ec->flags = 1 << EC_FLAGS_QUERY_PENDING; | |
701 | mutex_init(&ec->mutex); | |
702 | init_waitqueue_head(&ec->wait); | |
703 | INIT_LIST_HEAD(&ec->list); | |
704 | spin_lock_init(&ec->lock); | |
705 | return ec; | |
706 | } | |
707 | ||
708 | static acpi_status | |
709 | acpi_ec_register_query_methods(acpi_handle handle, u32 level, | |
710 | void *context, void **return_value) | |
711 | { | |
712 | char node_name[5]; | |
713 | struct acpi_buffer buffer = { sizeof(node_name), node_name }; | |
714 | struct acpi_ec *ec = context; | |
715 | int value = 0; | |
716 | acpi_status status; | |
717 | ||
718 | status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer); | |
719 | ||
720 | if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) { | |
721 | acpi_ec_add_query_handler(ec, value, handle, NULL, NULL); | |
722 | } | |
723 | return AE_OK; | |
724 | } | |
725 | ||
726 | static acpi_status | |
727 | ec_parse_device(acpi_handle handle, u32 Level, void *context, void **retval) | |
728 | { | |
729 | acpi_status status; | |
730 | unsigned long long tmp = 0; | |
731 | ||
732 | struct acpi_ec *ec = context; | |
733 | ||
734 | /* clear addr values, ec_parse_io_ports depend on it */ | |
735 | ec->command_addr = ec->data_addr = 0; | |
736 | ||
737 | status = acpi_walk_resources(handle, METHOD_NAME__CRS, | |
738 | ec_parse_io_ports, ec); | |
739 | if (ACPI_FAILURE(status)) | |
740 | return status; | |
741 | ||
742 | /* Get GPE bit assignment (EC events). */ | |
743 | /* TODO: Add support for _GPE returning a package */ | |
744 | status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp); | |
745 | if (ACPI_FAILURE(status)) | |
746 | return status; | |
747 | ec->gpe = tmp; | |
748 | /* Use the global lock for all EC transactions? */ | |
749 | tmp = 0; | |
750 | acpi_evaluate_integer(handle, "_GLK", NULL, &tmp); | |
751 | ec->global_lock = tmp; | |
752 | ec->handle = handle; | |
753 | return AE_CTRL_TERMINATE; | |
754 | } | |
755 | ||
756 | static int ec_install_handlers(struct acpi_ec *ec) | |
757 | { | |
758 | acpi_status status; | |
759 | if (test_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags)) | |
760 | return 0; | |
761 | status = acpi_install_gpe_handler(NULL, ec->gpe, | |
762 | ACPI_GPE_EDGE_TRIGGERED, | |
763 | &acpi_ec_gpe_handler, ec); | |
764 | if (ACPI_FAILURE(status)) | |
765 | return -ENODEV; | |
766 | ||
767 | acpi_enable_gpe(NULL, ec->gpe); | |
768 | status = acpi_install_address_space_handler(ec->handle, | |
769 | ACPI_ADR_SPACE_EC, | |
770 | &acpi_ec_space_handler, | |
771 | NULL, ec); | |
772 | if (ACPI_FAILURE(status)) { | |
773 | if (status == AE_NOT_FOUND) { | |
774 | /* | |
775 | * Maybe OS fails in evaluating the _REG object. | |
776 | * The AE_NOT_FOUND error will be ignored and OS | |
777 | * continue to initialize EC. | |
778 | */ | |
779 | printk(KERN_ERR "Fail in evaluating the _REG object" | |
780 | " of EC device. Broken bios is suspected.\n"); | |
781 | } else { | |
782 | acpi_remove_gpe_handler(NULL, ec->gpe, | |
783 | &acpi_ec_gpe_handler); | |
784 | acpi_disable_gpe(NULL, ec->gpe); | |
785 | return -ENODEV; | |
786 | } | |
787 | } | |
788 | ||
789 | set_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags); | |
790 | return 0; | |
791 | } | |
792 | ||
793 | static void ec_remove_handlers(struct acpi_ec *ec) | |
794 | { | |
795 | acpi_disable_gpe(NULL, ec->gpe); | |
796 | if (ACPI_FAILURE(acpi_remove_address_space_handler(ec->handle, | |
797 | ACPI_ADR_SPACE_EC, &acpi_ec_space_handler))) | |
798 | pr_err(PREFIX "failed to remove space handler\n"); | |
799 | if (ACPI_FAILURE(acpi_remove_gpe_handler(NULL, ec->gpe, | |
800 | &acpi_ec_gpe_handler))) | |
801 | pr_err(PREFIX "failed to remove gpe handler\n"); | |
802 | clear_bit(EC_FLAGS_HANDLERS_INSTALLED, &ec->flags); | |
803 | } | |
804 | ||
805 | static int acpi_ec_add(struct acpi_device *device) | |
806 | { | |
807 | struct acpi_ec *ec = NULL; | |
808 | int ret; | |
809 | ||
810 | strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME); | |
811 | strcpy(acpi_device_class(device), ACPI_EC_CLASS); | |
812 | ||
813 | /* Check for boot EC */ | |
814 | if (boot_ec && | |
815 | (boot_ec->handle == device->handle || | |
816 | boot_ec->handle == ACPI_ROOT_OBJECT)) { | |
817 | ec = boot_ec; | |
818 | boot_ec = NULL; | |
819 | } else { | |
820 | ec = make_acpi_ec(); | |
821 | if (!ec) | |
822 | return -ENOMEM; | |
823 | } | |
824 | if (ec_parse_device(device->handle, 0, ec, NULL) != | |
825 | AE_CTRL_TERMINATE) { | |
826 | kfree(ec); | |
827 | return -EINVAL; | |
828 | } | |
829 | ||
830 | /* Find and register all query methods */ | |
831 | acpi_walk_namespace(ACPI_TYPE_METHOD, ec->handle, 1, | |
832 | acpi_ec_register_query_methods, NULL, ec, NULL); | |
833 | ||
834 | if (!first_ec) | |
835 | first_ec = ec; | |
836 | device->driver_data = ec; | |
837 | ||
838 | ret = !!request_region(ec->data_addr, 1, "EC data"); | |
839 | WARN(!ret, "Could not request EC data io port 0x%lx", ec->data_addr); | |
840 | ret = !!request_region(ec->command_addr, 1, "EC cmd"); | |
841 | WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr); | |
842 | ||
843 | pr_info(PREFIX "GPE = 0x%lx, I/O: command/status = 0x%lx, data = 0x%lx\n", | |
844 | ec->gpe, ec->command_addr, ec->data_addr); | |
845 | ||
846 | ret = ec_install_handlers(ec); | |
847 | ||
848 | /* EC is fully operational, allow queries */ | |
849 | clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); | |
850 | return ret; | |
851 | } | |
852 | ||
853 | static int acpi_ec_remove(struct acpi_device *device) | |
854 | { | |
855 | struct acpi_ec *ec; | |
856 | struct acpi_ec_query_handler *handler, *tmp; | |
857 | ||
858 | if (!device) | |
859 | return -EINVAL; | |
860 | ||
861 | ec = acpi_driver_data(device); | |
862 | ec_remove_handlers(ec); | |
863 | mutex_lock(&ec->mutex); | |
864 | list_for_each_entry_safe(handler, tmp, &ec->list, node) { | |
865 | list_del(&handler->node); | |
866 | kfree(handler); | |
867 | } | |
868 | mutex_unlock(&ec->mutex); | |
869 | release_region(ec->data_addr, 1); | |
870 | release_region(ec->command_addr, 1); | |
871 | device->driver_data = NULL; | |
872 | if (ec == first_ec) | |
873 | first_ec = NULL; | |
874 | kfree(ec); | |
875 | return 0; | |
876 | } | |
877 | ||
878 | static acpi_status | |
879 | ec_parse_io_ports(struct acpi_resource *resource, void *context) | |
880 | { | |
881 | struct acpi_ec *ec = context; | |
882 | ||
883 | if (resource->type != ACPI_RESOURCE_TYPE_IO) | |
884 | return AE_OK; | |
885 | ||
886 | /* | |
887 | * The first address region returned is the data port, and | |
888 | * the second address region returned is the status/command | |
889 | * port. | |
890 | */ | |
891 | if (ec->data_addr == 0) | |
892 | ec->data_addr = resource->data.io.minimum; | |
893 | else if (ec->command_addr == 0) | |
894 | ec->command_addr = resource->data.io.minimum; | |
895 | else | |
896 | return AE_CTRL_TERMINATE; | |
897 | ||
898 | return AE_OK; | |
899 | } | |
900 | ||
901 | int __init acpi_boot_ec_enable(void) | |
902 | { | |
903 | if (!boot_ec || test_bit(EC_FLAGS_HANDLERS_INSTALLED, &boot_ec->flags)) | |
904 | return 0; | |
905 | if (!ec_install_handlers(boot_ec)) { | |
906 | first_ec = boot_ec; | |
907 | return 0; | |
908 | } | |
909 | return -EFAULT; | |
910 | } | |
911 | ||
912 | static const struct acpi_device_id ec_device_ids[] = { | |
913 | {"PNP0C09", 0}, | |
914 | {"", 0}, | |
915 | }; | |
916 | ||
917 | /* Some BIOS do not survive early DSDT scan, skip it */ | |
918 | static int ec_skip_dsdt_scan(const struct dmi_system_id *id) | |
919 | { | |
920 | EC_FLAGS_SKIP_DSDT_SCAN = 1; | |
921 | return 0; | |
922 | } | |
923 | ||
924 | /* ASUStek often supplies us with broken ECDT, validate it */ | |
925 | static int ec_validate_ecdt(const struct dmi_system_id *id) | |
926 | { | |
927 | EC_FLAGS_VALIDATE_ECDT = 1; | |
928 | return 0; | |
929 | } | |
930 | ||
931 | /* MSI EC needs special treatment, enable it */ | |
932 | static int ec_flag_msi(const struct dmi_system_id *id) | |
933 | { | |
934 | printk(KERN_DEBUG PREFIX "Detected MSI hardware, enabling workarounds.\n"); | |
935 | EC_FLAGS_MSI = 1; | |
936 | EC_FLAGS_VALIDATE_ECDT = 1; | |
937 | return 0; | |
938 | } | |
939 | ||
940 | /* | |
941 | * Clevo M720 notebook actually works ok with IRQ mode, if we lifted | |
942 | * the GPE storm threshold back to 20 | |
943 | */ | |
944 | static int ec_enlarge_storm_threshold(const struct dmi_system_id *id) | |
945 | { | |
946 | pr_debug("Setting the EC GPE storm threshold to 20\n"); | |
947 | ec_storm_threshold = 20; | |
948 | return 0; | |
949 | } | |
950 | ||
951 | static struct dmi_system_id __initdata ec_dmi_table[] = { | |
952 | { | |
953 | ec_skip_dsdt_scan, "Compal JFL92", { | |
954 | DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"), | |
955 | DMI_MATCH(DMI_BOARD_NAME, "JFL92") }, NULL}, | |
956 | { | |
957 | ec_flag_msi, "MSI hardware", { | |
958 | DMI_MATCH(DMI_BIOS_VENDOR, "Micro-Star")}, NULL}, | |
959 | { | |
960 | ec_flag_msi, "MSI hardware", { | |
961 | DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star")}, NULL}, | |
962 | { | |
963 | ec_flag_msi, "MSI hardware", { | |
964 | DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-Star")}, NULL}, | |
965 | { | |
966 | ec_flag_msi, "MSI hardware", { | |
967 | DMI_MATCH(DMI_CHASSIS_VENDOR, "MICRO-STAR")}, NULL}, | |
968 | { | |
969 | ec_flag_msi, "Quanta hardware", { | |
970 | DMI_MATCH(DMI_SYS_VENDOR, "Quanta"), | |
971 | DMI_MATCH(DMI_PRODUCT_NAME, "TW8/SW8/DW8"),}, NULL}, | |
972 | { | |
973 | ec_flag_msi, "Quanta hardware", { | |
974 | DMI_MATCH(DMI_SYS_VENDOR, "Quanta"), | |
975 | DMI_MATCH(DMI_PRODUCT_NAME, "TW9/SW9"),}, NULL}, | |
976 | { | |
977 | ec_validate_ecdt, "ASUS hardware", { | |
978 | DMI_MATCH(DMI_BIOS_VENDOR, "ASUS") }, NULL}, | |
979 | { | |
980 | ec_validate_ecdt, "ASUS hardware", { | |
981 | DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc.") }, NULL}, | |
982 | { | |
983 | ec_enlarge_storm_threshold, "CLEVO hardware", { | |
984 | DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."), | |
985 | DMI_MATCH(DMI_PRODUCT_NAME, "M720T/M730T"),}, NULL}, | |
986 | { | |
987 | ec_skip_dsdt_scan, "HP Folio 13", { | |
988 | DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), | |
989 | DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13"),}, NULL}, | |
990 | {}, | |
991 | }; | |
992 | ||
993 | int __init acpi_ec_ecdt_probe(void) | |
994 | { | |
995 | acpi_status status; | |
996 | struct acpi_ec *saved_ec = NULL; | |
997 | struct acpi_table_ecdt *ecdt_ptr; | |
998 | ||
999 | boot_ec = make_acpi_ec(); | |
1000 | if (!boot_ec) | |
1001 | return -ENOMEM; | |
1002 | /* | |
1003 | * Generate a boot ec context | |
1004 | */ | |
1005 | dmi_check_system(ec_dmi_table); | |
1006 | status = acpi_get_table(ACPI_SIG_ECDT, 1, | |
1007 | (struct acpi_table_header **)&ecdt_ptr); | |
1008 | if (ACPI_SUCCESS(status)) { | |
1009 | pr_info(PREFIX "EC description table is found, configuring boot EC\n"); | |
1010 | boot_ec->command_addr = ecdt_ptr->control.address; | |
1011 | boot_ec->data_addr = ecdt_ptr->data.address; | |
1012 | boot_ec->gpe = ecdt_ptr->gpe; | |
1013 | boot_ec->handle = ACPI_ROOT_OBJECT; | |
1014 | acpi_get_handle(ACPI_ROOT_OBJECT, ecdt_ptr->id, &boot_ec->handle); | |
1015 | /* Don't trust ECDT, which comes from ASUSTek */ | |
1016 | if (!EC_FLAGS_VALIDATE_ECDT) | |
1017 | goto install; | |
1018 | saved_ec = kmemdup(boot_ec, sizeof(struct acpi_ec), GFP_KERNEL); | |
1019 | if (!saved_ec) | |
1020 | return -ENOMEM; | |
1021 | /* fall through */ | |
1022 | } | |
1023 | ||
1024 | if (EC_FLAGS_SKIP_DSDT_SCAN) | |
1025 | return -ENODEV; | |
1026 | ||
1027 | /* This workaround is needed only on some broken machines, | |
1028 | * which require early EC, but fail to provide ECDT */ | |
1029 | printk(KERN_DEBUG PREFIX "Look up EC in DSDT\n"); | |
1030 | status = acpi_get_devices(ec_device_ids[0].id, ec_parse_device, | |
1031 | boot_ec, NULL); | |
1032 | /* Check that acpi_get_devices actually find something */ | |
1033 | if (ACPI_FAILURE(status) || !boot_ec->handle) | |
1034 | goto error; | |
1035 | if (saved_ec) { | |
1036 | /* try to find good ECDT from ASUSTek */ | |
1037 | if (saved_ec->command_addr != boot_ec->command_addr || | |
1038 | saved_ec->data_addr != boot_ec->data_addr || | |
1039 | saved_ec->gpe != boot_ec->gpe || | |
1040 | saved_ec->handle != boot_ec->handle) | |
1041 | pr_info(PREFIX "ASUSTek keeps feeding us with broken " | |
1042 | "ECDT tables, which are very hard to workaround. " | |
1043 | "Trying to use DSDT EC info instead. Please send " | |
1044 | "output of acpidump to linux-acpi@vger.kernel.org\n"); | |
1045 | kfree(saved_ec); | |
1046 | saved_ec = NULL; | |
1047 | } else { | |
1048 | /* We really need to limit this workaround, the only ASUS, | |
1049 | * which needs it, has fake EC._INI method, so use it as flag. | |
1050 | * Keep boot_ec struct as it will be needed soon. | |
1051 | */ | |
1052 | acpi_handle dummy; | |
1053 | if (!dmi_name_in_vendors("ASUS") || | |
1054 | ACPI_FAILURE(acpi_get_handle(boot_ec->handle, "_INI", | |
1055 | &dummy))) | |
1056 | return -ENODEV; | |
1057 | } | |
1058 | install: | |
1059 | if (!ec_install_handlers(boot_ec)) { | |
1060 | first_ec = boot_ec; | |
1061 | return 0; | |
1062 | } | |
1063 | error: | |
1064 | kfree(boot_ec); | |
1065 | boot_ec = NULL; | |
1066 | return -ENODEV; | |
1067 | } | |
1068 | ||
1069 | static struct acpi_driver acpi_ec_driver = { | |
1070 | .name = "ec", | |
1071 | .class = ACPI_EC_CLASS, | |
1072 | .ids = ec_device_ids, | |
1073 | .ops = { | |
1074 | .add = acpi_ec_add, | |
1075 | .remove = acpi_ec_remove, | |
1076 | }, | |
1077 | }; | |
1078 | ||
1079 | int __init acpi_ec_init(void) | |
1080 | { | |
1081 | int result = 0; | |
1082 | ||
1083 | /* Now register the driver for the EC */ | |
1084 | result = acpi_bus_register_driver(&acpi_ec_driver); | |
1085 | if (result < 0) | |
1086 | return -ENODEV; | |
1087 | ||
1088 | return result; | |
1089 | } | |
1090 | ||
1091 | /* EC driver currently not unloadable */ | |
1092 | #if 0 | |
1093 | static void __exit acpi_ec_exit(void) | |
1094 | { | |
1095 | ||
1096 | acpi_bus_unregister_driver(&acpi_ec_driver); | |
1097 | return; | |
1098 | } | |
1099 | #endif /* 0 */ |