xref: /openbmc/linux/drivers/hwmon/applesmc.c (revision 95e9fd10)
1 /*
2  * drivers/hwmon/applesmc.c - driver for Apple's SMC (accelerometer, temperature
3  * sensors, fan control, keyboard backlight control) used in Intel-based Apple
4  * computers.
5  *
6  * Copyright (C) 2007 Nicolas Boichat <nicolas@boichat.ch>
7  * Copyright (C) 2010 Henrik Rydberg <rydberg@euromail.se>
8  *
9  * Based on hdaps.c driver:
10  * Copyright (C) 2005 Robert Love <rml@novell.com>
11  * Copyright (C) 2005 Jesper Juhl <jj@chaosbits.net>
12  *
13  * Fan control based on smcFanControl:
14  * Copyright (C) 2006 Hendrik Holtmann <holtmann@mac.com>
15  *
16  * This program is free software; you can redistribute it and/or modify it
17  * under the terms of the GNU General Public License v2 as published by the
18  * Free Software Foundation.
19  *
20  * This program is distributed in the hope that it will be useful, but WITHOUT
21  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
22  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
23  * more details.
24  *
25  * You should have received a copy of the GNU General Public License along with
26  * this program; if not, write to the Free Software Foundation, Inc.,
27  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
28  */
29 
30 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 
32 #include <linux/delay.h>
33 #include <linux/platform_device.h>
34 #include <linux/input-polldev.h>
35 #include <linux/kernel.h>
36 #include <linux/slab.h>
37 #include <linux/module.h>
38 #include <linux/timer.h>
39 #include <linux/dmi.h>
40 #include <linux/mutex.h>
41 #include <linux/hwmon-sysfs.h>
42 #include <linux/io.h>
43 #include <linux/leds.h>
44 #include <linux/hwmon.h>
45 #include <linux/workqueue.h>
46 
47 /* data port used by Apple SMC */
48 #define APPLESMC_DATA_PORT	0x300
49 /* command/status port used by Apple SMC */
50 #define APPLESMC_CMD_PORT	0x304
51 
52 #define APPLESMC_NR_PORTS	32 /* 0x300-0x31f */
53 
54 #define APPLESMC_MAX_DATA_LENGTH 32
55 
56 /* wait up to 32 ms for a status change. */
57 #define APPLESMC_MIN_WAIT	0x0010
58 #define APPLESMC_RETRY_WAIT	0x0100
59 #define APPLESMC_MAX_WAIT	0x8000
60 
61 #define APPLESMC_READ_CMD	0x10
62 #define APPLESMC_WRITE_CMD	0x11
63 #define APPLESMC_GET_KEY_BY_INDEX_CMD	0x12
64 #define APPLESMC_GET_KEY_TYPE_CMD	0x13
65 
66 #define KEY_COUNT_KEY		"#KEY" /* r-o ui32 */
67 
68 #define LIGHT_SENSOR_LEFT_KEY	"ALV0" /* r-o {alv (6-10 bytes) */
69 #define LIGHT_SENSOR_RIGHT_KEY	"ALV1" /* r-o {alv (6-10 bytes) */
70 #define BACKLIGHT_KEY		"LKSB" /* w-o {lkb (2 bytes) */
71 
72 #define CLAMSHELL_KEY		"MSLD" /* r-o ui8 (unused) */
73 
74 #define MOTION_SENSOR_X_KEY	"MO_X" /* r-o sp78 (2 bytes) */
75 #define MOTION_SENSOR_Y_KEY	"MO_Y" /* r-o sp78 (2 bytes) */
76 #define MOTION_SENSOR_Z_KEY	"MO_Z" /* r-o sp78 (2 bytes) */
77 #define MOTION_SENSOR_KEY	"MOCN" /* r/w ui16 */
78 
79 #define FANS_COUNT		"FNum" /* r-o ui8 */
80 #define FANS_MANUAL		"FS! " /* r-w ui16 */
81 #define FAN_ID_FMT		"F%dID" /* r-o char[16] */
82 
83 #define TEMP_SENSOR_TYPE	"sp78"
84 
85 /* List of keys used to read/write fan speeds */
86 static const char *const fan_speed_fmt[] = {
87 	"F%dAc",		/* actual speed */
88 	"F%dMn",		/* minimum speed (rw) */
89 	"F%dMx",		/* maximum speed */
90 	"F%dSf",		/* safe speed - not all models */
91 	"F%dTg",		/* target speed (manual: rw) */
92 };
93 
94 #define INIT_TIMEOUT_MSECS	5000	/* wait up to 5s for device init ... */
95 #define INIT_WAIT_MSECS		50	/* ... in 50ms increments */
96 
97 #define APPLESMC_POLL_INTERVAL	50	/* msecs */
98 #define APPLESMC_INPUT_FUZZ	4	/* input event threshold */
99 #define APPLESMC_INPUT_FLAT	4
100 
101 #define to_index(attr) (to_sensor_dev_attr(attr)->index & 0xffff)
102 #define to_option(attr) (to_sensor_dev_attr(attr)->index >> 16)
103 
104 /* Dynamic device node attributes */
105 struct applesmc_dev_attr {
106 	struct sensor_device_attribute sda;	/* hwmon attributes */
107 	char name[32];				/* room for node file name */
108 };
109 
110 /* Dynamic device node group */
111 struct applesmc_node_group {
112 	char *format;				/* format string */
113 	void *show;				/* show function */
114 	void *store;				/* store function */
115 	int option;				/* function argument */
116 	struct applesmc_dev_attr *nodes;	/* dynamic node array */
117 };
118 
119 /* AppleSMC entry - cached register information */
120 struct applesmc_entry {
121 	char key[5];		/* four-letter key code */
122 	u8 valid;		/* set when entry is successfully read once */
123 	u8 len;			/* bounded by APPLESMC_MAX_DATA_LENGTH */
124 	char type[5];		/* four-letter type code */
125 	u8 flags;		/* 0x10: func; 0x40: write; 0x80: read */
126 };
127 
128 /* Register lookup and registers common to all SMCs */
129 static struct applesmc_registers {
130 	struct mutex mutex;		/* register read/write mutex */
131 	unsigned int key_count;		/* number of SMC registers */
132 	unsigned int fan_count;		/* number of fans */
133 	unsigned int temp_count;	/* number of temperature registers */
134 	unsigned int temp_begin;	/* temperature lower index bound */
135 	unsigned int temp_end;		/* temperature upper index bound */
136 	unsigned int index_count;	/* size of temperature index array */
137 	int num_light_sensors;		/* number of light sensors */
138 	bool has_accelerometer;		/* has motion sensor */
139 	bool has_key_backlight;		/* has keyboard backlight */
140 	bool init_complete;		/* true when fully initialized */
141 	struct applesmc_entry *cache;	/* cached key entries */
142 	const char **index;		/* temperature key index */
143 } smcreg = {
144 	.mutex = __MUTEX_INITIALIZER(smcreg.mutex),
145 };
146 
147 static const int debug;
148 static struct platform_device *pdev;
149 static s16 rest_x;
150 static s16 rest_y;
151 static u8 backlight_state[2];
152 
153 static struct device *hwmon_dev;
154 static struct input_polled_dev *applesmc_idev;
155 
156 /*
157  * Last index written to key_at_index sysfs file, and value to use for all other
158  * key_at_index_* sysfs files.
159  */
160 static unsigned int key_at_index;
161 
162 static struct workqueue_struct *applesmc_led_wq;
163 
164 /*
165  * wait_read - Wait for a byte to appear on SMC port. Callers must
166  * hold applesmc_lock.
167  */
168 static int wait_read(void)
169 {
170 	u8 status;
171 	int us;
172 	for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) {
173 		udelay(us);
174 		status = inb(APPLESMC_CMD_PORT);
175 		/* read: wait for smc to settle */
176 		if (status & 0x01)
177 			return 0;
178 	}
179 
180 	pr_warn("wait_read() fail: 0x%02x\n", status);
181 	return -EIO;
182 }
183 
184 /*
185  * send_byte - Write to SMC port, retrying when necessary. Callers
186  * must hold applesmc_lock.
187  */
188 static int send_byte(u8 cmd, u16 port)
189 {
190 	u8 status;
191 	int us;
192 
193 	outb(cmd, port);
194 	for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) {
195 		udelay(us);
196 		status = inb(APPLESMC_CMD_PORT);
197 		/* write: wait for smc to settle */
198 		if (status & 0x02)
199 			continue;
200 		/* ready: cmd accepted, return */
201 		if (status & 0x04)
202 			return 0;
203 		/* timeout: give up */
204 		if (us << 1 == APPLESMC_MAX_WAIT)
205 			break;
206 		/* busy: long wait and resend */
207 		udelay(APPLESMC_RETRY_WAIT);
208 		outb(cmd, port);
209 	}
210 
211 	pr_warn("send_byte(0x%02x, 0x%04x) fail: 0x%02x\n", cmd, port, status);
212 	return -EIO;
213 }
214 
215 static int send_command(u8 cmd)
216 {
217 	return send_byte(cmd, APPLESMC_CMD_PORT);
218 }
219 
220 static int send_argument(const char *key)
221 {
222 	int i;
223 
224 	for (i = 0; i < 4; i++)
225 		if (send_byte(key[i], APPLESMC_DATA_PORT))
226 			return -EIO;
227 	return 0;
228 }
229 
230 static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len)
231 {
232 	int i;
233 
234 	if (send_command(cmd) || send_argument(key)) {
235 		pr_warn("%.4s: read arg fail\n", key);
236 		return -EIO;
237 	}
238 
239 	if (send_byte(len, APPLESMC_DATA_PORT)) {
240 		pr_warn("%.4s: read len fail\n", key);
241 		return -EIO;
242 	}
243 
244 	for (i = 0; i < len; i++) {
245 		if (wait_read()) {
246 			pr_warn("%.4s: read data[%d] fail\n", key, i);
247 			return -EIO;
248 		}
249 		buffer[i] = inb(APPLESMC_DATA_PORT);
250 	}
251 
252 	return 0;
253 }
254 
255 static int write_smc(u8 cmd, const char *key, const u8 *buffer, u8 len)
256 {
257 	int i;
258 
259 	if (send_command(cmd) || send_argument(key)) {
260 		pr_warn("%s: write arg fail\n", key);
261 		return -EIO;
262 	}
263 
264 	if (send_byte(len, APPLESMC_DATA_PORT)) {
265 		pr_warn("%.4s: write len fail\n", key);
266 		return -EIO;
267 	}
268 
269 	for (i = 0; i < len; i++) {
270 		if (send_byte(buffer[i], APPLESMC_DATA_PORT)) {
271 			pr_warn("%s: write data fail\n", key);
272 			return -EIO;
273 		}
274 	}
275 
276 	return 0;
277 }
278 
279 static int read_register_count(unsigned int *count)
280 {
281 	__be32 be;
282 	int ret;
283 
284 	ret = read_smc(APPLESMC_READ_CMD, KEY_COUNT_KEY, (u8 *)&be, 4);
285 	if (ret)
286 		return ret;
287 
288 	*count = be32_to_cpu(be);
289 	return 0;
290 }
291 
292 /*
293  * Serialized I/O
294  *
295  * Returns zero on success or a negative error on failure.
296  * All functions below are concurrency safe - callers should NOT hold lock.
297  */
298 
299 static int applesmc_read_entry(const struct applesmc_entry *entry,
300 			       u8 *buf, u8 len)
301 {
302 	int ret;
303 
304 	if (entry->len != len)
305 		return -EINVAL;
306 	mutex_lock(&smcreg.mutex);
307 	ret = read_smc(APPLESMC_READ_CMD, entry->key, buf, len);
308 	mutex_unlock(&smcreg.mutex);
309 
310 	return ret;
311 }
312 
313 static int applesmc_write_entry(const struct applesmc_entry *entry,
314 				const u8 *buf, u8 len)
315 {
316 	int ret;
317 
318 	if (entry->len != len)
319 		return -EINVAL;
320 	mutex_lock(&smcreg.mutex);
321 	ret = write_smc(APPLESMC_WRITE_CMD, entry->key, buf, len);
322 	mutex_unlock(&smcreg.mutex);
323 	return ret;
324 }
325 
326 static const struct applesmc_entry *applesmc_get_entry_by_index(int index)
327 {
328 	struct applesmc_entry *cache = &smcreg.cache[index];
329 	u8 key[4], info[6];
330 	__be32 be;
331 	int ret = 0;
332 
333 	if (cache->valid)
334 		return cache;
335 
336 	mutex_lock(&smcreg.mutex);
337 
338 	if (cache->valid)
339 		goto out;
340 	be = cpu_to_be32(index);
341 	ret = read_smc(APPLESMC_GET_KEY_BY_INDEX_CMD, (u8 *)&be, key, 4);
342 	if (ret)
343 		goto out;
344 	ret = read_smc(APPLESMC_GET_KEY_TYPE_CMD, key, info, 6);
345 	if (ret)
346 		goto out;
347 
348 	memcpy(cache->key, key, 4);
349 	cache->len = info[0];
350 	memcpy(cache->type, &info[1], 4);
351 	cache->flags = info[5];
352 	cache->valid = 1;
353 
354 out:
355 	mutex_unlock(&smcreg.mutex);
356 	if (ret)
357 		return ERR_PTR(ret);
358 	return cache;
359 }
360 
361 static int applesmc_get_lower_bound(unsigned int *lo, const char *key)
362 {
363 	int begin = 0, end = smcreg.key_count;
364 	const struct applesmc_entry *entry;
365 
366 	while (begin != end) {
367 		int middle = begin + (end - begin) / 2;
368 		entry = applesmc_get_entry_by_index(middle);
369 		if (IS_ERR(entry)) {
370 			*lo = 0;
371 			return PTR_ERR(entry);
372 		}
373 		if (strcmp(entry->key, key) < 0)
374 			begin = middle + 1;
375 		else
376 			end = middle;
377 	}
378 
379 	*lo = begin;
380 	return 0;
381 }
382 
383 static int applesmc_get_upper_bound(unsigned int *hi, const char *key)
384 {
385 	int begin = 0, end = smcreg.key_count;
386 	const struct applesmc_entry *entry;
387 
388 	while (begin != end) {
389 		int middle = begin + (end - begin) / 2;
390 		entry = applesmc_get_entry_by_index(middle);
391 		if (IS_ERR(entry)) {
392 			*hi = smcreg.key_count;
393 			return PTR_ERR(entry);
394 		}
395 		if (strcmp(key, entry->key) < 0)
396 			end = middle;
397 		else
398 			begin = middle + 1;
399 	}
400 
401 	*hi = begin;
402 	return 0;
403 }
404 
405 static const struct applesmc_entry *applesmc_get_entry_by_key(const char *key)
406 {
407 	int begin, end;
408 	int ret;
409 
410 	ret = applesmc_get_lower_bound(&begin, key);
411 	if (ret)
412 		return ERR_PTR(ret);
413 	ret = applesmc_get_upper_bound(&end, key);
414 	if (ret)
415 		return ERR_PTR(ret);
416 	if (end - begin != 1)
417 		return ERR_PTR(-EINVAL);
418 
419 	return applesmc_get_entry_by_index(begin);
420 }
421 
422 static int applesmc_read_key(const char *key, u8 *buffer, u8 len)
423 {
424 	const struct applesmc_entry *entry;
425 
426 	entry = applesmc_get_entry_by_key(key);
427 	if (IS_ERR(entry))
428 		return PTR_ERR(entry);
429 
430 	return applesmc_read_entry(entry, buffer, len);
431 }
432 
433 static int applesmc_write_key(const char *key, const u8 *buffer, u8 len)
434 {
435 	const struct applesmc_entry *entry;
436 
437 	entry = applesmc_get_entry_by_key(key);
438 	if (IS_ERR(entry))
439 		return PTR_ERR(entry);
440 
441 	return applesmc_write_entry(entry, buffer, len);
442 }
443 
444 static int applesmc_has_key(const char *key, bool *value)
445 {
446 	const struct applesmc_entry *entry;
447 
448 	entry = applesmc_get_entry_by_key(key);
449 	if (IS_ERR(entry) && PTR_ERR(entry) != -EINVAL)
450 		return PTR_ERR(entry);
451 
452 	*value = !IS_ERR(entry);
453 	return 0;
454 }
455 
456 /*
457  * applesmc_read_s16 - Read 16-bit signed big endian register
458  */
459 static int applesmc_read_s16(const char *key, s16 *value)
460 {
461 	u8 buffer[2];
462 	int ret;
463 
464 	ret = applesmc_read_key(key, buffer, 2);
465 	if (ret)
466 		return ret;
467 
468 	*value = ((s16)buffer[0] << 8) | buffer[1];
469 	return 0;
470 }
471 
472 /*
473  * applesmc_device_init - initialize the accelerometer.  Can sleep.
474  */
475 static void applesmc_device_init(void)
476 {
477 	int total;
478 	u8 buffer[2];
479 
480 	if (!smcreg.has_accelerometer)
481 		return;
482 
483 	for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
484 		if (!applesmc_read_key(MOTION_SENSOR_KEY, buffer, 2) &&
485 				(buffer[0] != 0x00 || buffer[1] != 0x00))
486 			return;
487 		buffer[0] = 0xe0;
488 		buffer[1] = 0x00;
489 		applesmc_write_key(MOTION_SENSOR_KEY, buffer, 2);
490 		msleep(INIT_WAIT_MSECS);
491 	}
492 
493 	pr_warn("failed to init the device\n");
494 }
495 
496 static int applesmc_init_index(struct applesmc_registers *s)
497 {
498 	const struct applesmc_entry *entry;
499 	unsigned int i;
500 
501 	if (s->index)
502 		return 0;
503 
504 	s->index = kcalloc(s->temp_count, sizeof(s->index[0]), GFP_KERNEL);
505 	if (!s->index)
506 		return -ENOMEM;
507 
508 	for (i = s->temp_begin; i < s->temp_end; i++) {
509 		entry = applesmc_get_entry_by_index(i);
510 		if (IS_ERR(entry))
511 			continue;
512 		if (strcmp(entry->type, TEMP_SENSOR_TYPE))
513 			continue;
514 		s->index[s->index_count++] = entry->key;
515 	}
516 
517 	return 0;
518 }
519 
520 /*
521  * applesmc_init_smcreg_try - Try to initialize register cache. Idempotent.
522  */
523 static int applesmc_init_smcreg_try(void)
524 {
525 	struct applesmc_registers *s = &smcreg;
526 	bool left_light_sensor, right_light_sensor;
527 	u8 tmp[1];
528 	int ret;
529 
530 	if (s->init_complete)
531 		return 0;
532 
533 	ret = read_register_count(&s->key_count);
534 	if (ret)
535 		return ret;
536 
537 	if (!s->cache)
538 		s->cache = kcalloc(s->key_count, sizeof(*s->cache), GFP_KERNEL);
539 	if (!s->cache)
540 		return -ENOMEM;
541 
542 	ret = applesmc_read_key(FANS_COUNT, tmp, 1);
543 	if (ret)
544 		return ret;
545 	s->fan_count = tmp[0];
546 
547 	ret = applesmc_get_lower_bound(&s->temp_begin, "T");
548 	if (ret)
549 		return ret;
550 	ret = applesmc_get_lower_bound(&s->temp_end, "U");
551 	if (ret)
552 		return ret;
553 	s->temp_count = s->temp_end - s->temp_begin;
554 
555 	ret = applesmc_init_index(s);
556 	if (ret)
557 		return ret;
558 
559 	ret = applesmc_has_key(LIGHT_SENSOR_LEFT_KEY, &left_light_sensor);
560 	if (ret)
561 		return ret;
562 	ret = applesmc_has_key(LIGHT_SENSOR_RIGHT_KEY, &right_light_sensor);
563 	if (ret)
564 		return ret;
565 	ret = applesmc_has_key(MOTION_SENSOR_KEY, &s->has_accelerometer);
566 	if (ret)
567 		return ret;
568 	ret = applesmc_has_key(BACKLIGHT_KEY, &s->has_key_backlight);
569 	if (ret)
570 		return ret;
571 
572 	s->num_light_sensors = left_light_sensor + right_light_sensor;
573 	s->init_complete = true;
574 
575 	pr_info("key=%d fan=%d temp=%d index=%d acc=%d lux=%d kbd=%d\n",
576 	       s->key_count, s->fan_count, s->temp_count, s->index_count,
577 	       s->has_accelerometer,
578 	       s->num_light_sensors,
579 	       s->has_key_backlight);
580 
581 	return 0;
582 }
583 
584 static void applesmc_destroy_smcreg(void)
585 {
586 	kfree(smcreg.index);
587 	smcreg.index = NULL;
588 	kfree(smcreg.cache);
589 	smcreg.cache = NULL;
590 	smcreg.init_complete = false;
591 }
592 
593 /*
594  * applesmc_init_smcreg - Initialize register cache.
595  *
596  * Retries until initialization is successful, or the operation times out.
597  *
598  */
599 static int applesmc_init_smcreg(void)
600 {
601 	int ms, ret;
602 
603 	for (ms = 0; ms < INIT_TIMEOUT_MSECS; ms += INIT_WAIT_MSECS) {
604 		ret = applesmc_init_smcreg_try();
605 		if (!ret) {
606 			if (ms)
607 				pr_info("init_smcreg() took %d ms\n", ms);
608 			return 0;
609 		}
610 		msleep(INIT_WAIT_MSECS);
611 	}
612 
613 	applesmc_destroy_smcreg();
614 
615 	return ret;
616 }
617 
618 /* Device model stuff */
619 static int applesmc_probe(struct platform_device *dev)
620 {
621 	int ret;
622 
623 	ret = applesmc_init_smcreg();
624 	if (ret)
625 		return ret;
626 
627 	applesmc_device_init();
628 
629 	return 0;
630 }
631 
632 /* Synchronize device with memorized backlight state */
633 static int applesmc_pm_resume(struct device *dev)
634 {
635 	if (smcreg.has_key_backlight)
636 		applesmc_write_key(BACKLIGHT_KEY, backlight_state, 2);
637 	return 0;
638 }
639 
640 /* Reinitialize device on resume from hibernation */
641 static int applesmc_pm_restore(struct device *dev)
642 {
643 	applesmc_device_init();
644 	return applesmc_pm_resume(dev);
645 }
646 
647 static const struct dev_pm_ops applesmc_pm_ops = {
648 	.resume = applesmc_pm_resume,
649 	.restore = applesmc_pm_restore,
650 };
651 
652 static struct platform_driver applesmc_driver = {
653 	.probe = applesmc_probe,
654 	.driver	= {
655 		.name = "applesmc",
656 		.owner = THIS_MODULE,
657 		.pm = &applesmc_pm_ops,
658 	},
659 };
660 
661 /*
662  * applesmc_calibrate - Set our "resting" values.  Callers must
663  * hold applesmc_lock.
664  */
665 static void applesmc_calibrate(void)
666 {
667 	applesmc_read_s16(MOTION_SENSOR_X_KEY, &rest_x);
668 	applesmc_read_s16(MOTION_SENSOR_Y_KEY, &rest_y);
669 	rest_x = -rest_x;
670 }
671 
672 static void applesmc_idev_poll(struct input_polled_dev *dev)
673 {
674 	struct input_dev *idev = dev->input;
675 	s16 x, y;
676 
677 	if (applesmc_read_s16(MOTION_SENSOR_X_KEY, &x))
678 		return;
679 	if (applesmc_read_s16(MOTION_SENSOR_Y_KEY, &y))
680 		return;
681 
682 	x = -x;
683 	input_report_abs(idev, ABS_X, x - rest_x);
684 	input_report_abs(idev, ABS_Y, y - rest_y);
685 	input_sync(idev);
686 }
687 
688 /* Sysfs Files */
689 
690 static ssize_t applesmc_name_show(struct device *dev,
691 				   struct device_attribute *attr, char *buf)
692 {
693 	return snprintf(buf, PAGE_SIZE, "applesmc\n");
694 }
695 
696 static ssize_t applesmc_position_show(struct device *dev,
697 				   struct device_attribute *attr, char *buf)
698 {
699 	int ret;
700 	s16 x, y, z;
701 
702 	ret = applesmc_read_s16(MOTION_SENSOR_X_KEY, &x);
703 	if (ret)
704 		goto out;
705 	ret = applesmc_read_s16(MOTION_SENSOR_Y_KEY, &y);
706 	if (ret)
707 		goto out;
708 	ret = applesmc_read_s16(MOTION_SENSOR_Z_KEY, &z);
709 	if (ret)
710 		goto out;
711 
712 out:
713 	if (ret)
714 		return ret;
715 	else
716 		return snprintf(buf, PAGE_SIZE, "(%d,%d,%d)\n", x, y, z);
717 }
718 
719 static ssize_t applesmc_light_show(struct device *dev,
720 				struct device_attribute *attr, char *sysfsbuf)
721 {
722 	const struct applesmc_entry *entry;
723 	static int data_length;
724 	int ret;
725 	u8 left = 0, right = 0;
726 	u8 buffer[10];
727 
728 	if (!data_length) {
729 		entry = applesmc_get_entry_by_key(LIGHT_SENSOR_LEFT_KEY);
730 		if (IS_ERR(entry))
731 			return PTR_ERR(entry);
732 		if (entry->len > 10)
733 			return -ENXIO;
734 		data_length = entry->len;
735 		pr_info("light sensor data length set to %d\n", data_length);
736 	}
737 
738 	ret = applesmc_read_key(LIGHT_SENSOR_LEFT_KEY, buffer, data_length);
739 	/* newer macbooks report a single 10-bit bigendian value */
740 	if (data_length == 10) {
741 		left = be16_to_cpu(*(__be16 *)(buffer + 6)) >> 2;
742 		goto out;
743 	}
744 	left = buffer[2];
745 	if (ret)
746 		goto out;
747 	ret = applesmc_read_key(LIGHT_SENSOR_RIGHT_KEY, buffer, data_length);
748 	right = buffer[2];
749 
750 out:
751 	if (ret)
752 		return ret;
753 	else
754 		return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", left, right);
755 }
756 
757 /* Displays sensor key as label */
758 static ssize_t applesmc_show_sensor_label(struct device *dev,
759 			struct device_attribute *devattr, char *sysfsbuf)
760 {
761 	const char *key = smcreg.index[to_index(devattr)];
762 
763 	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", key);
764 }
765 
766 /* Displays degree Celsius * 1000 */
767 static ssize_t applesmc_show_temperature(struct device *dev,
768 			struct device_attribute *devattr, char *sysfsbuf)
769 {
770 	const char *key = smcreg.index[to_index(devattr)];
771 	int ret;
772 	s16 value;
773 	int temp;
774 
775 	ret = applesmc_read_s16(key, &value);
776 	if (ret)
777 		return ret;
778 
779 	temp = 250 * (value >> 6);
780 
781 	return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", temp);
782 }
783 
784 static ssize_t applesmc_show_fan_speed(struct device *dev,
785 				struct device_attribute *attr, char *sysfsbuf)
786 {
787 	int ret;
788 	unsigned int speed = 0;
789 	char newkey[5];
790 	u8 buffer[2];
791 
792 	sprintf(newkey, fan_speed_fmt[to_option(attr)], to_index(attr));
793 
794 	ret = applesmc_read_key(newkey, buffer, 2);
795 	speed = ((buffer[0] << 8 | buffer[1]) >> 2);
796 
797 	if (ret)
798 		return ret;
799 	else
800 		return snprintf(sysfsbuf, PAGE_SIZE, "%u\n", speed);
801 }
802 
803 static ssize_t applesmc_store_fan_speed(struct device *dev,
804 					struct device_attribute *attr,
805 					const char *sysfsbuf, size_t count)
806 {
807 	int ret;
808 	unsigned long speed;
809 	char newkey[5];
810 	u8 buffer[2];
811 
812 	if (kstrtoul(sysfsbuf, 10, &speed) < 0 || speed >= 0x4000)
813 		return -EINVAL;		/* Bigger than a 14-bit value */
814 
815 	sprintf(newkey, fan_speed_fmt[to_option(attr)], to_index(attr));
816 
817 	buffer[0] = (speed >> 6) & 0xff;
818 	buffer[1] = (speed << 2) & 0xff;
819 	ret = applesmc_write_key(newkey, buffer, 2);
820 
821 	if (ret)
822 		return ret;
823 	else
824 		return count;
825 }
826 
827 static ssize_t applesmc_show_fan_manual(struct device *dev,
828 			struct device_attribute *attr, char *sysfsbuf)
829 {
830 	int ret;
831 	u16 manual = 0;
832 	u8 buffer[2];
833 
834 	ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
835 	manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01;
836 
837 	if (ret)
838 		return ret;
839 	else
840 		return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", manual);
841 }
842 
843 static ssize_t applesmc_store_fan_manual(struct device *dev,
844 					 struct device_attribute *attr,
845 					 const char *sysfsbuf, size_t count)
846 {
847 	int ret;
848 	u8 buffer[2];
849 	unsigned long input;
850 	u16 val;
851 
852 	if (kstrtoul(sysfsbuf, 10, &input) < 0)
853 		return -EINVAL;
854 
855 	ret = applesmc_read_key(FANS_MANUAL, buffer, 2);
856 	val = (buffer[0] << 8 | buffer[1]);
857 	if (ret)
858 		goto out;
859 
860 	if (input)
861 		val = val | (0x01 << to_index(attr));
862 	else
863 		val = val & ~(0x01 << to_index(attr));
864 
865 	buffer[0] = (val >> 8) & 0xFF;
866 	buffer[1] = val & 0xFF;
867 
868 	ret = applesmc_write_key(FANS_MANUAL, buffer, 2);
869 
870 out:
871 	if (ret)
872 		return ret;
873 	else
874 		return count;
875 }
876 
877 static ssize_t applesmc_show_fan_position(struct device *dev,
878 				struct device_attribute *attr, char *sysfsbuf)
879 {
880 	int ret;
881 	char newkey[5];
882 	u8 buffer[17];
883 
884 	sprintf(newkey, FAN_ID_FMT, to_index(attr));
885 
886 	ret = applesmc_read_key(newkey, buffer, 16);
887 	buffer[16] = 0;
888 
889 	if (ret)
890 		return ret;
891 	else
892 		return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", buffer+4);
893 }
894 
895 static ssize_t applesmc_calibrate_show(struct device *dev,
896 				struct device_attribute *attr, char *sysfsbuf)
897 {
898 	return snprintf(sysfsbuf, PAGE_SIZE, "(%d,%d)\n", rest_x, rest_y);
899 }
900 
901 static ssize_t applesmc_calibrate_store(struct device *dev,
902 	struct device_attribute *attr, const char *sysfsbuf, size_t count)
903 {
904 	applesmc_calibrate();
905 
906 	return count;
907 }
908 
909 static void applesmc_backlight_set(struct work_struct *work)
910 {
911 	applesmc_write_key(BACKLIGHT_KEY, backlight_state, 2);
912 }
913 static DECLARE_WORK(backlight_work, &applesmc_backlight_set);
914 
915 static void applesmc_brightness_set(struct led_classdev *led_cdev,
916 						enum led_brightness value)
917 {
918 	int ret;
919 
920 	backlight_state[0] = value;
921 	ret = queue_work(applesmc_led_wq, &backlight_work);
922 
923 	if (debug && (!ret))
924 		printk(KERN_DEBUG "applesmc: work was already on the queue.\n");
925 }
926 
927 static ssize_t applesmc_key_count_show(struct device *dev,
928 				struct device_attribute *attr, char *sysfsbuf)
929 {
930 	int ret;
931 	u8 buffer[4];
932 	u32 count;
933 
934 	ret = applesmc_read_key(KEY_COUNT_KEY, buffer, 4);
935 	count = ((u32)buffer[0]<<24) + ((u32)buffer[1]<<16) +
936 						((u32)buffer[2]<<8) + buffer[3];
937 
938 	if (ret)
939 		return ret;
940 	else
941 		return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", count);
942 }
943 
944 static ssize_t applesmc_key_at_index_read_show(struct device *dev,
945 				struct device_attribute *attr, char *sysfsbuf)
946 {
947 	const struct applesmc_entry *entry;
948 	int ret;
949 
950 	entry = applesmc_get_entry_by_index(key_at_index);
951 	if (IS_ERR(entry))
952 		return PTR_ERR(entry);
953 	ret = applesmc_read_entry(entry, sysfsbuf, entry->len);
954 	if (ret)
955 		return ret;
956 
957 	return entry->len;
958 }
959 
960 static ssize_t applesmc_key_at_index_data_length_show(struct device *dev,
961 				struct device_attribute *attr, char *sysfsbuf)
962 {
963 	const struct applesmc_entry *entry;
964 
965 	entry = applesmc_get_entry_by_index(key_at_index);
966 	if (IS_ERR(entry))
967 		return PTR_ERR(entry);
968 
969 	return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", entry->len);
970 }
971 
972 static ssize_t applesmc_key_at_index_type_show(struct device *dev,
973 				struct device_attribute *attr, char *sysfsbuf)
974 {
975 	const struct applesmc_entry *entry;
976 
977 	entry = applesmc_get_entry_by_index(key_at_index);
978 	if (IS_ERR(entry))
979 		return PTR_ERR(entry);
980 
981 	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", entry->type);
982 }
983 
984 static ssize_t applesmc_key_at_index_name_show(struct device *dev,
985 				struct device_attribute *attr, char *sysfsbuf)
986 {
987 	const struct applesmc_entry *entry;
988 
989 	entry = applesmc_get_entry_by_index(key_at_index);
990 	if (IS_ERR(entry))
991 		return PTR_ERR(entry);
992 
993 	return snprintf(sysfsbuf, PAGE_SIZE, "%s\n", entry->key);
994 }
995 
996 static ssize_t applesmc_key_at_index_show(struct device *dev,
997 				struct device_attribute *attr, char *sysfsbuf)
998 {
999 	return snprintf(sysfsbuf, PAGE_SIZE, "%d\n", key_at_index);
1000 }
1001 
1002 static ssize_t applesmc_key_at_index_store(struct device *dev,
1003 	struct device_attribute *attr, const char *sysfsbuf, size_t count)
1004 {
1005 	unsigned long newkey;
1006 
1007 	if (kstrtoul(sysfsbuf, 10, &newkey) < 0
1008 	    || newkey >= smcreg.key_count)
1009 		return -EINVAL;
1010 
1011 	key_at_index = newkey;
1012 	return count;
1013 }
1014 
1015 static struct led_classdev applesmc_backlight = {
1016 	.name			= "smc::kbd_backlight",
1017 	.default_trigger	= "nand-disk",
1018 	.brightness_set		= applesmc_brightness_set,
1019 };
1020 
1021 static struct applesmc_node_group info_group[] = {
1022 	{ "name", applesmc_name_show },
1023 	{ "key_count", applesmc_key_count_show },
1024 	{ "key_at_index", applesmc_key_at_index_show, applesmc_key_at_index_store },
1025 	{ "key_at_index_name", applesmc_key_at_index_name_show },
1026 	{ "key_at_index_type", applesmc_key_at_index_type_show },
1027 	{ "key_at_index_data_length", applesmc_key_at_index_data_length_show },
1028 	{ "key_at_index_data", applesmc_key_at_index_read_show },
1029 	{ }
1030 };
1031 
1032 static struct applesmc_node_group accelerometer_group[] = {
1033 	{ "position", applesmc_position_show },
1034 	{ "calibrate", applesmc_calibrate_show, applesmc_calibrate_store },
1035 	{ }
1036 };
1037 
1038 static struct applesmc_node_group light_sensor_group[] = {
1039 	{ "light", applesmc_light_show },
1040 	{ }
1041 };
1042 
1043 static struct applesmc_node_group fan_group[] = {
1044 	{ "fan%d_label", applesmc_show_fan_position },
1045 	{ "fan%d_input", applesmc_show_fan_speed, NULL, 0 },
1046 	{ "fan%d_min", applesmc_show_fan_speed, applesmc_store_fan_speed, 1 },
1047 	{ "fan%d_max", applesmc_show_fan_speed, NULL, 2 },
1048 	{ "fan%d_safe", applesmc_show_fan_speed, NULL, 3 },
1049 	{ "fan%d_output", applesmc_show_fan_speed, applesmc_store_fan_speed, 4 },
1050 	{ "fan%d_manual", applesmc_show_fan_manual, applesmc_store_fan_manual },
1051 	{ }
1052 };
1053 
1054 static struct applesmc_node_group temp_group[] = {
1055 	{ "temp%d_label", applesmc_show_sensor_label },
1056 	{ "temp%d_input", applesmc_show_temperature },
1057 	{ }
1058 };
1059 
1060 /* Module stuff */
1061 
1062 /*
1063  * applesmc_destroy_nodes - remove files and free associated memory
1064  */
1065 static void applesmc_destroy_nodes(struct applesmc_node_group *groups)
1066 {
1067 	struct applesmc_node_group *grp;
1068 	struct applesmc_dev_attr *node;
1069 
1070 	for (grp = groups; grp->nodes; grp++) {
1071 		for (node = grp->nodes; node->sda.dev_attr.attr.name; node++)
1072 			sysfs_remove_file(&pdev->dev.kobj,
1073 					  &node->sda.dev_attr.attr);
1074 		kfree(grp->nodes);
1075 		grp->nodes = NULL;
1076 	}
1077 }
1078 
1079 /*
1080  * applesmc_create_nodes - create a two-dimensional group of sysfs files
1081  */
1082 static int applesmc_create_nodes(struct applesmc_node_group *groups, int num)
1083 {
1084 	struct applesmc_node_group *grp;
1085 	struct applesmc_dev_attr *node;
1086 	struct attribute *attr;
1087 	int ret, i;
1088 
1089 	for (grp = groups; grp->format; grp++) {
1090 		grp->nodes = kcalloc(num + 1, sizeof(*node), GFP_KERNEL);
1091 		if (!grp->nodes) {
1092 			ret = -ENOMEM;
1093 			goto out;
1094 		}
1095 		for (i = 0; i < num; i++) {
1096 			node = &grp->nodes[i];
1097 			sprintf(node->name, grp->format, i + 1);
1098 			node->sda.index = (grp->option << 16) | (i & 0xffff);
1099 			node->sda.dev_attr.show = grp->show;
1100 			node->sda.dev_attr.store = grp->store;
1101 			attr = &node->sda.dev_attr.attr;
1102 			sysfs_attr_init(attr);
1103 			attr->name = node->name;
1104 			attr->mode = S_IRUGO | (grp->store ? S_IWUSR : 0);
1105 			ret = sysfs_create_file(&pdev->dev.kobj, attr);
1106 			if (ret) {
1107 				attr->name = NULL;
1108 				goto out;
1109 			}
1110 		}
1111 	}
1112 
1113 	return 0;
1114 out:
1115 	applesmc_destroy_nodes(groups);
1116 	return ret;
1117 }
1118 
1119 /* Create accelerometer ressources */
1120 static int applesmc_create_accelerometer(void)
1121 {
1122 	struct input_dev *idev;
1123 	int ret;
1124 
1125 	if (!smcreg.has_accelerometer)
1126 		return 0;
1127 
1128 	ret = applesmc_create_nodes(accelerometer_group, 1);
1129 	if (ret)
1130 		goto out;
1131 
1132 	applesmc_idev = input_allocate_polled_device();
1133 	if (!applesmc_idev) {
1134 		ret = -ENOMEM;
1135 		goto out_sysfs;
1136 	}
1137 
1138 	applesmc_idev->poll = applesmc_idev_poll;
1139 	applesmc_idev->poll_interval = APPLESMC_POLL_INTERVAL;
1140 
1141 	/* initial calibrate for the input device */
1142 	applesmc_calibrate();
1143 
1144 	/* initialize the input device */
1145 	idev = applesmc_idev->input;
1146 	idev->name = "applesmc";
1147 	idev->id.bustype = BUS_HOST;
1148 	idev->dev.parent = &pdev->dev;
1149 	idev->evbit[0] = BIT_MASK(EV_ABS);
1150 	input_set_abs_params(idev, ABS_X,
1151 			-256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
1152 	input_set_abs_params(idev, ABS_Y,
1153 			-256, 256, APPLESMC_INPUT_FUZZ, APPLESMC_INPUT_FLAT);
1154 
1155 	ret = input_register_polled_device(applesmc_idev);
1156 	if (ret)
1157 		goto out_idev;
1158 
1159 	return 0;
1160 
1161 out_idev:
1162 	input_free_polled_device(applesmc_idev);
1163 
1164 out_sysfs:
1165 	applesmc_destroy_nodes(accelerometer_group);
1166 
1167 out:
1168 	pr_warn("driver init failed (ret=%d)!\n", ret);
1169 	return ret;
1170 }
1171 
1172 /* Release all ressources used by the accelerometer */
1173 static void applesmc_release_accelerometer(void)
1174 {
1175 	if (!smcreg.has_accelerometer)
1176 		return;
1177 	input_unregister_polled_device(applesmc_idev);
1178 	input_free_polled_device(applesmc_idev);
1179 	applesmc_destroy_nodes(accelerometer_group);
1180 }
1181 
1182 static int applesmc_create_light_sensor(void)
1183 {
1184 	if (!smcreg.num_light_sensors)
1185 		return 0;
1186 	return applesmc_create_nodes(light_sensor_group, 1);
1187 }
1188 
1189 static void applesmc_release_light_sensor(void)
1190 {
1191 	if (!smcreg.num_light_sensors)
1192 		return;
1193 	applesmc_destroy_nodes(light_sensor_group);
1194 }
1195 
1196 static int applesmc_create_key_backlight(void)
1197 {
1198 	if (!smcreg.has_key_backlight)
1199 		return 0;
1200 	applesmc_led_wq = create_singlethread_workqueue("applesmc-led");
1201 	if (!applesmc_led_wq)
1202 		return -ENOMEM;
1203 	return led_classdev_register(&pdev->dev, &applesmc_backlight);
1204 }
1205 
1206 static void applesmc_release_key_backlight(void)
1207 {
1208 	if (!smcreg.has_key_backlight)
1209 		return;
1210 	led_classdev_unregister(&applesmc_backlight);
1211 	destroy_workqueue(applesmc_led_wq);
1212 }
1213 
1214 static int applesmc_dmi_match(const struct dmi_system_id *id)
1215 {
1216 	return 1;
1217 }
1218 
1219 /*
1220  * Note that DMI_MATCH(...,"MacBook") will match "MacBookPro1,1".
1221  * So we need to put "Apple MacBook Pro" before "Apple MacBook".
1222  */
1223 static __initdata struct dmi_system_id applesmc_whitelist[] = {
1224 	{ applesmc_dmi_match, "Apple MacBook Air", {
1225 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1226 	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir") },
1227 	},
1228 	{ applesmc_dmi_match, "Apple MacBook Pro", {
1229 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1230 	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro") },
1231 	},
1232 	{ applesmc_dmi_match, "Apple MacBook", {
1233 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1234 	  DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
1235 	},
1236 	{ applesmc_dmi_match, "Apple Macmini", {
1237 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1238 	  DMI_MATCH(DMI_PRODUCT_NAME, "Macmini") },
1239 	},
1240 	{ applesmc_dmi_match, "Apple MacPro", {
1241 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1242 	  DMI_MATCH(DMI_PRODUCT_NAME, "MacPro") },
1243 	},
1244 	{ applesmc_dmi_match, "Apple iMac", {
1245 	  DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
1246 	  DMI_MATCH(DMI_PRODUCT_NAME, "iMac") },
1247 	},
1248 	{ .ident = NULL }
1249 };
1250 
1251 static int __init applesmc_init(void)
1252 {
1253 	int ret;
1254 
1255 	if (!dmi_check_system(applesmc_whitelist)) {
1256 		pr_warn("supported laptop not found!\n");
1257 		ret = -ENODEV;
1258 		goto out;
1259 	}
1260 
1261 	if (!request_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS,
1262 								"applesmc")) {
1263 		ret = -ENXIO;
1264 		goto out;
1265 	}
1266 
1267 	ret = platform_driver_register(&applesmc_driver);
1268 	if (ret)
1269 		goto out_region;
1270 
1271 	pdev = platform_device_register_simple("applesmc", APPLESMC_DATA_PORT,
1272 					       NULL, 0);
1273 	if (IS_ERR(pdev)) {
1274 		ret = PTR_ERR(pdev);
1275 		goto out_driver;
1276 	}
1277 
1278 	/* create register cache */
1279 	ret = applesmc_init_smcreg();
1280 	if (ret)
1281 		goto out_device;
1282 
1283 	ret = applesmc_create_nodes(info_group, 1);
1284 	if (ret)
1285 		goto out_smcreg;
1286 
1287 	ret = applesmc_create_nodes(fan_group, smcreg.fan_count);
1288 	if (ret)
1289 		goto out_info;
1290 
1291 	ret = applesmc_create_nodes(temp_group, smcreg.index_count);
1292 	if (ret)
1293 		goto out_fans;
1294 
1295 	ret = applesmc_create_accelerometer();
1296 	if (ret)
1297 		goto out_temperature;
1298 
1299 	ret = applesmc_create_light_sensor();
1300 	if (ret)
1301 		goto out_accelerometer;
1302 
1303 	ret = applesmc_create_key_backlight();
1304 	if (ret)
1305 		goto out_light_sysfs;
1306 
1307 	hwmon_dev = hwmon_device_register(&pdev->dev);
1308 	if (IS_ERR(hwmon_dev)) {
1309 		ret = PTR_ERR(hwmon_dev);
1310 		goto out_light_ledclass;
1311 	}
1312 
1313 	return 0;
1314 
1315 out_light_ledclass:
1316 	applesmc_release_key_backlight();
1317 out_light_sysfs:
1318 	applesmc_release_light_sensor();
1319 out_accelerometer:
1320 	applesmc_release_accelerometer();
1321 out_temperature:
1322 	applesmc_destroy_nodes(temp_group);
1323 out_fans:
1324 	applesmc_destroy_nodes(fan_group);
1325 out_info:
1326 	applesmc_destroy_nodes(info_group);
1327 out_smcreg:
1328 	applesmc_destroy_smcreg();
1329 out_device:
1330 	platform_device_unregister(pdev);
1331 out_driver:
1332 	platform_driver_unregister(&applesmc_driver);
1333 out_region:
1334 	release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
1335 out:
1336 	pr_warn("driver init failed (ret=%d)!\n", ret);
1337 	return ret;
1338 }
1339 
1340 static void __exit applesmc_exit(void)
1341 {
1342 	hwmon_device_unregister(hwmon_dev);
1343 	applesmc_release_key_backlight();
1344 	applesmc_release_light_sensor();
1345 	applesmc_release_accelerometer();
1346 	applesmc_destroy_nodes(temp_group);
1347 	applesmc_destroy_nodes(fan_group);
1348 	applesmc_destroy_nodes(info_group);
1349 	applesmc_destroy_smcreg();
1350 	platform_device_unregister(pdev);
1351 	platform_driver_unregister(&applesmc_driver);
1352 	release_region(APPLESMC_DATA_PORT, APPLESMC_NR_PORTS);
1353 }
1354 
1355 module_init(applesmc_init);
1356 module_exit(applesmc_exit);
1357 
1358 MODULE_AUTHOR("Nicolas Boichat");
1359 MODULE_DESCRIPTION("Apple SMC");
1360 MODULE_LICENSE("GPL v2");
1361 MODULE_DEVICE_TABLE(dmi, applesmc_whitelist);
1362