summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/acerhdf.c
blob: 8cc86f4e3ac132d86d1da6dc3ee5b3833287af40 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * acerhdf - A driver which monitors the temperature
 *           of the aspire one netbook, turns on/off the fan
 *           as soon as the upper/lower threshold is reached.
 *
 * (C) 2009 - Peter Kaestle     peter (a) piie.net
 *                              http://piie.net
 *     2009 Borislav Petkov	bp (a) alien8.de
 *
 * Inspired by and many thanks to:
 *  o acerfand   - Rachel Greenham
 *  o acer_ec.pl - Michael Kurz     michi.kurz (at) googlemail.com
 *               - Petr Tomasek     tomasek (#) etf,cuni,cz
 *               - Carlos Corbacho  cathectic (at) gmail.com
 *  o lkml       - Matthew Garrett
 *               - Borislav Petkov
 *               - Andreas Mohr
 */

#define pr_fmt(fmt) "acerhdf: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/acpi.h>
#include <linux/thermal.h>
#include <linux/platform_device.h>

/*
 * The driver is started with "kernel mode off" by default. That means, the BIOS
 * is still in control of the fan. In this mode the driver allows to read the
 * temperature of the cpu and a userspace tool may take over control of the fan.
 * If the driver is switched to "kernel mode" (e.g. via module parameter) the
 * driver is in full control of the fan. If you want the module to be started in
 * kernel mode by default, define the following:
 */
#undef START_IN_KERNEL_MODE

#define DRV_VER "0.7.0"

/*
 * According to the Atom N270 datasheet,
 * (http://download.intel.com/design/processor/datashts/320032.pdf) the
 * CPU's optimal operating limits denoted in junction temperature as
 * measured by the on-die thermal monitor are within 0 <= Tj <= 90. So,
 * assume 89°C is critical temperature.
 */
#define ACERHDF_TEMP_CRIT 89000
#define ACERHDF_FAN_OFF 0
#define ACERHDF_FAN_AUTO 1

/*
 * No matter what value the user puts into the fanon variable, turn on the fan
 * at 80 degree Celsius to prevent hardware damage
 */
#define ACERHDF_MAX_FANON 80000

/*
 * Maximum interval between two temperature checks is 15 seconds, as the die
 * can get hot really fast under heavy load (plus we shouldn't forget about
 * possible impact of _external_ aggressive sources such as heaters, sun etc.)
 */
#define ACERHDF_MAX_INTERVAL 15

#ifdef START_IN_KERNEL_MODE
static int kernelmode = 1;
#else
static int kernelmode;
#endif

static unsigned int interval = 10;
static unsigned int fanon = 60000;
static unsigned int fanoff = 53000;
static unsigned int verbose;
static unsigned int list_supported;
static unsigned int fanstate = ACERHDF_FAN_AUTO;
static char force_bios[16];
static char force_product[16];
static unsigned int prev_interval;
static struct thermal_zone_device *thz_dev;
static struct thermal_cooling_device *cl_dev;
static struct platform_device *acerhdf_dev;

module_param(kernelmode, uint, 0);
MODULE_PARM_DESC(kernelmode, "Kernel mode fan control on / off");
module_param(interval, uint, 0600);
MODULE_PARM_DESC(interval, "Polling interval of temperature check");
module_param(fanon, uint, 0600);
MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
module_param(fanoff, uint, 0600);
MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
module_param(verbose, uint, 0600);
MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
module_param(list_supported, uint, 0600);
MODULE_PARM_DESC(list_supported, "List supported models and BIOS versions");
module_param_string(force_bios, force_bios, 16, 0);
MODULE_PARM_DESC(force_bios, "Pretend system has this known supported BIOS version");
module_param_string(force_product, force_product, 16, 0);
MODULE_PARM_DESC(force_product, "Pretend system is this known supported model");

/*
 * cmd_off: to switch the fan completely off and check if the fan is off
 *	cmd_auto: to set the BIOS in control of the fan. The BIOS regulates then
 *		the fan speed depending on the temperature
 */
struct fancmd {
	u8 cmd_off;
	u8 cmd_auto;
};

struct manualcmd {
	u8 mreg;
	u8 moff;
};

/* default register and command to disable fan in manual mode */
static const struct manualcmd mcmd = {
	.mreg = 0x94,
	.moff = 0xff,
};

/* BIOS settings - only used during probe */
struct bios_settings {
	const char *vendor;
	const char *product;
	const char *version;
	u8 fanreg;
	u8 tempreg;
	struct fancmd cmd;
	int mcmd_enable;
};

/* This could be a daughter struct in the above, but not worth the redirect */
struct ctrl_settings {
	u8 fanreg;
	u8 tempreg;
	struct fancmd cmd;
	int mcmd_enable;
};

static struct ctrl_settings ctrl_cfg __read_mostly;

/* Register addresses and values for different BIOS versions */
static const struct bios_settings bios_tbl[] __initconst = {
	/* AOA110 */
	{"Acer", "AOA110", "v0.3109", 0x55, 0x58, {0x1f, 0x00}, 0},
	{"Acer", "AOA110", "v0.3114", 0x55, 0x58, {0x1f, 0x00}, 0},
	{"Acer", "AOA110", "v0.3301", 0x55, 0x58, {0xaf, 0x00}, 0},
	{"Acer", "AOA110", "v0.3304", 0x55, 0x58, {0xaf, 0x00}, 0},
	{"Acer", "AOA110", "v0.3305", 0x55, 0x58, {0xaf, 0x00}, 0},
	{"Acer", "AOA110", "v0.3307", 0x55, 0x58, {0xaf, 0x00}, 0},
	{"Acer", "AOA110", "v0.3308", 0x55, 0x58, {0x21, 0x00}, 0},
	{"Acer", "AOA110", "v0.3309", 0x55, 0x58, {0x21, 0x00}, 0},
	{"Acer", "AOA110", "v0.3310", 0x55, 0x58, {0x21, 0x00}, 0},
	/* AOA150 */
	{"Acer", "AOA150", "v0.3114", 0x55, 0x58, {0x1f, 0x00}, 0},
	{"Acer", "AOA150", "v0.3301", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3304", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3305", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3307", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3308", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3309", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AOA150", "v0.3310", 0x55, 0x58, {0x20, 0x00}, 0},
	/* LT1005u */
	{"Acer", "LT-10Q", "v0.3310", 0x55, 0x58, {0x20, 0x00}, 0},
	/* Acer 1410 */
	{"Acer", "Aspire 1410", "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1410", "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
	/* Acer 1810xx */
	{"Acer", "Aspire 1810TZ", "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810TZ", "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1810T",  "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
	/* Acer 5755G */
	{"Acer", "Aspire 5755G",  "V1.20",   0xab, 0xb4, {0x00, 0x08}, 0},
	{"Acer", "Aspire 5755G",  "V1.21",   0xab, 0xb3, {0x00, 0x08}, 0},
	/* Acer 521 */
	{"Acer", "AO521", "V1.11", 0x55, 0x58, {0x1f, 0x00}, 0},
	/* Acer 531 */
	{"Acer", "AO531h", "v0.3104", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00}, 0},
	{"Acer", "AO531h", "v0.3304", 0x55, 0x58, {0x20, 0x00}, 0},
	/* Acer 751 */
	{"Acer", "AO751h", "V0.3206", 0x55, 0x58, {0x21, 0x00}, 0},
	{"Acer", "AO751h", "V0.3212", 0x55, 0x58, {0x21, 0x00}, 0},
	/* Acer 753 */
	{"Acer", "Aspire One 753", "V1.24", 0x93, 0xac, {0x14, 0x04}, 1},
	/* Acer 1825 */
	{"Acer", "Aspire 1825PTZ", "V1.3118", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Acer", "Aspire 1825PTZ", "V1.3127", 0x55, 0x58, {0x9e, 0x00}, 0},
	/* Acer Extensa 5420 */
	{"Acer", "Extensa 5420", "V1.17", 0x93, 0xac, {0x14, 0x04}, 1},
	/* Acer Aspire 5315 */
	{"Acer", "Aspire 5315", "V1.19", 0x93, 0xac, {0x14, 0x04}, 1},
	/* Acer Aspire 5739 */
	{"Acer", "Aspire 5739G", "V1.3311", 0x55, 0x58, {0x20, 0x00}, 0},
	/* Acer TravelMate 7730 */
	{"Acer", "TravelMate 7730G", "v0.3509", 0x55, 0x58, {0xaf, 0x00}, 0},
	/* Acer Aspire 7551 */
	{"Acer", "Aspire 7551", "V1.18", 0x93, 0xa8, {0x14, 0x04}, 1},
	/* Acer TravelMate TM8573T */
	{"Acer", "TM8573T", "V1.13", 0x93, 0xa8, {0x14, 0x04}, 1},
	/* Gateway */
	{"Gateway", "AOA110", "v0.3103",  0x55, 0x58, {0x21, 0x00}, 0},
	{"Gateway", "AOA150", "v0.3103",  0x55, 0x58, {0x20, 0x00}, 0},
	{"Gateway", "LT31",   "v1.3103",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Gateway", "LT31",   "v1.3201",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Gateway", "LT31",   "v1.3302",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Gateway", "LT31",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Gateway", "LT31",   "v1.3307",  0x55, 0x58, {0x9e, 0x00}, 0},
	/* Packard Bell */
	{"Packard Bell", "DOA150",  "v0.3104",  0x55, 0x58, {0x21, 0x00}, 0},
	{"Packard Bell", "DOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00}, 0},
	{"Packard Bell", "AOA110",  "v0.3105",  0x55, 0x58, {0x21, 0x00}, 0},
	{"Packard Bell", "AOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00}, 0},
	{"Packard Bell", "ENBFT",   "V1.3118",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "ENBFT",   "V1.3127",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v1.3303",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3120",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3108",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3113",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3115",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3117",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v0.3119",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMU",   "v1.3204",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMA",   "v1.3201",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMA",   "v1.3302",  0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTMA",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00}, 0},
	{"Packard Bell", "DOTVR46", "v1.3308",  0x55, 0x58, {0x9e, 0x00}, 0},
	/* pewpew-terminator */
	{"", "", "", 0, 0, {0, 0}, 0}
};

/*
 * this struct is used to instruct thermal layer to use bang_bang instead of
 * default governor for acerhdf
 */
static struct thermal_zone_params acerhdf_zone_params = {
	.governor_name = "bang_bang",
};

static int acerhdf_get_temp(int *temp)
{
	u8 read_temp;

	if (ec_read(ctrl_cfg.tempreg, &read_temp))
		return -EINVAL;

	*temp = read_temp * 1000;

	return 0;
}

static int acerhdf_get_fanstate(int *state)
{
	u8 fan;

	if (ec_read(ctrl_cfg.fanreg, &fan))
		return -EINVAL;

	if (fan != ctrl_cfg.cmd.cmd_off)
		*state = ACERHDF_FAN_AUTO;
	else
		*state = ACERHDF_FAN_OFF;

	return 0;
}

static void acerhdf_change_fanstate(int state)
{
	unsigned char cmd;

	if (verbose)
		pr_notice("fan %s\n", state == ACERHDF_FAN_OFF ? "OFF" : "ON");

	if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
		pr_err("invalid fan state %d requested, setting to auto!\n",
		       state);
		state = ACERHDF_FAN_AUTO;
	}

	cmd = (state == ACERHDF_FAN_OFF) ? ctrl_cfg.cmd.cmd_off
					 : ctrl_cfg.cmd.cmd_auto;
	fanstate = state;

	ec_write(ctrl_cfg.fanreg, cmd);

	if (ctrl_cfg.mcmd_enable && state == ACERHDF_FAN_OFF) {
		if (verbose)
			pr_notice("turning off fan manually\n");
		ec_write(mcmd.mreg, mcmd.moff);
	}
}

static void acerhdf_check_param(struct thermal_zone_device *thermal)
{
	if (fanon > ACERHDF_MAX_FANON) {
		pr_err("fanon temperature too high, set to %d\n",
		       ACERHDF_MAX_FANON);
		fanon = ACERHDF_MAX_FANON;
	}

	if (kernelmode && prev_interval != interval) {
		if (interval > ACERHDF_MAX_INTERVAL) {
			pr_err("interval too high, set to %d\n",
			       ACERHDF_MAX_INTERVAL);
			interval = ACERHDF_MAX_INTERVAL;
		}
		if (verbose)
			pr_notice("interval changed to: %d\n", interval);
		thermal->polling_delay = interval*1000;
		prev_interval = interval;
	}
}

/*
 * This is the thermal zone callback which does the delayed polling of the fan
 * state. We do check /sysfs-originating settings here in acerhdf_check_param()
 * as late as the polling interval is since we can't do that in the respective
 * accessors of the module parameters.
 */
static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal, int *t)
{
	int temp, err = 0;

	acerhdf_check_param(thermal);

	err = acerhdf_get_temp(&temp);
	if (err)
		return err;

	if (verbose)
		pr_notice("temp %d\n", temp);

	*t = temp;
	return 0;
}

static int acerhdf_bind(struct thermal_zone_device *thermal,
			struct thermal_cooling_device *cdev)
{
	/* if the cooling device is the one from acerhdf bind it */
	if (cdev != cl_dev)
		return 0;

	if (thermal_zone_bind_cooling_device(thermal, 0, cdev,
			THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
			THERMAL_WEIGHT_DEFAULT)) {
		pr_err("error binding cooling dev\n");
		return -EINVAL;
	}
	return 0;
}

static int acerhdf_unbind(struct thermal_zone_device *thermal,
			  struct thermal_cooling_device *cdev)
{
	if (cdev != cl_dev)
		return 0;

	if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
		pr_err("error unbinding cooling dev\n");
		return -EINVAL;
	}
	return 0;
}

static inline void acerhdf_revert_to_bios_mode(void)
{
	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
	kernelmode = 0;
	if (thz_dev)
		thz_dev->polling_delay = 0;
	pr_notice("kernel mode fan control OFF\n");
}
static inline void acerhdf_enable_kernelmode(void)
{
	kernelmode = 1;

	thz_dev->polling_delay = interval*1000;
	thermal_zone_device_update(thz_dev, THERMAL_EVENT_UNSPECIFIED);
	pr_notice("kernel mode fan control ON\n");
}

static int acerhdf_get_mode(struct thermal_zone_device *thermal,
			    enum thermal_device_mode *mode)
{
	if (verbose)
		pr_notice("kernel mode fan control %d\n", kernelmode);

	*mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
			     : THERMAL_DEVICE_DISABLED;

	return 0;
}

/*
 * set operation mode;
 * enabled: the thermal layer of the kernel takes care about
 *          the temperature and the fan.
 * disabled: the BIOS takes control of the fan.
 */
static int acerhdf_set_mode(struct thermal_zone_device *thermal,
			    enum thermal_device_mode mode)
{
	if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
		acerhdf_revert_to_bios_mode();
	else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
		acerhdf_enable_kernelmode();

	return 0;
}

static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
				 enum thermal_trip_type *type)
{
	if (trip == 0)
		*type = THERMAL_TRIP_ACTIVE;
	else if (trip == 1)
		*type = THERMAL_TRIP_CRITICAL;
	else
		return -EINVAL;

	return 0;
}

static int acerhdf_get_trip_hyst(struct thermal_zone_device *thermal, int trip,
				 int *temp)
{
	if (trip != 0)
		return -EINVAL;

	*temp = fanon - fanoff;

	return 0;
}

static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
				 int *temp)
{
	if (trip == 0)
		*temp = fanon;
	else if (trip == 1)
		*temp = ACERHDF_TEMP_CRIT;
	else
		return -EINVAL;

	return 0;
}

static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
				 int *temperature)
{
	*temperature = ACERHDF_TEMP_CRIT;
	return 0;
}

/* bind callback functions to thermalzone */
static struct thermal_zone_device_ops acerhdf_dev_ops = {
	.bind = acerhdf_bind,
	.unbind = acerhdf_unbind,
	.get_temp = acerhdf_get_ec_temp,
	.get_mode = acerhdf_get_mode,
	.set_mode = acerhdf_set_mode,
	.get_trip_type = acerhdf_get_trip_type,
	.get_trip_hyst = acerhdf_get_trip_hyst,
	.get_trip_temp = acerhdf_get_trip_temp,
	.get_crit_temp = acerhdf_get_crit_temp,
};


/*
 * cooling device callback functions
 * get maximal fan cooling state
 */
static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	*state = 1;

	return 0;
}

static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
				 unsigned long *state)
{
	int err = 0, tmp;

	err = acerhdf_get_fanstate(&tmp);
	if (err)
		return err;

	*state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
	return 0;
}

/* change current fan state - is overwritten when running in kernel mode */
static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
				 unsigned long state)
{
	int cur_temp, cur_state, err = 0;

	if (!kernelmode)
		return 0;

	err = acerhdf_get_temp(&cur_temp);
	if (err) {
		pr_err("error reading temperature, hand off control to BIOS\n");
		goto err_out;
	}

	err = acerhdf_get_fanstate(&cur_state);
	if (err) {
		pr_err("error reading fan state, hand off control to BIOS\n");
		goto err_out;
	}

	if (state == 0) {
		if (cur_state == ACERHDF_FAN_AUTO)
			acerhdf_change_fanstate(ACERHDF_FAN_OFF);
	} else {
		if (cur_state == ACERHDF_FAN_OFF)
			acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
	}
	return 0;

err_out:
	acerhdf_revert_to_bios_mode();
	return -EINVAL;
}

/* bind fan callbacks to fan device */
static const struct thermal_cooling_device_ops acerhdf_cooling_ops = {
	.get_max_state = acerhdf_get_max_state,
	.get_cur_state = acerhdf_get_cur_state,
	.set_cur_state = acerhdf_set_cur_state,
};

/* suspend / resume functionality */
static int acerhdf_suspend(struct device *dev)
{
	if (kernelmode)
		acerhdf_change_fanstate(ACERHDF_FAN_AUTO);

	if (verbose)
		pr_notice("going suspend\n");

	return 0;
}

static int acerhdf_probe(struct platform_device *device)
{
	return 0;
}

static int acerhdf_remove(struct platform_device *device)
{
	return 0;
}

static const struct dev_pm_ops acerhdf_pm_ops = {
	.suspend = acerhdf_suspend,
	.freeze  = acerhdf_suspend,
};

static struct platform_driver acerhdf_driver = {
	.driver = {
		.name  = "acerhdf",
		.pm    = &acerhdf_pm_ops,
	},
	.probe = acerhdf_probe,
	.remove = acerhdf_remove,
};

/* checks if str begins with start */
static int str_starts_with(const char *str, const char *start)
{
	unsigned long str_len = 0, start_len = 0;

	str_len = strlen(str);
	start_len = strlen(start);

	if (str_len >= start_len &&
			!strncmp(str, start, start_len))
		return 1;

	return 0;
}

/* check hardware */
static int __init acerhdf_check_hardware(void)
{
	char const *vendor, *version, *product;
	const struct bios_settings *bt = NULL;
	int found = 0;

	/* get BIOS data */
	vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
	version = dmi_get_system_info(DMI_BIOS_VERSION);
	product = dmi_get_system_info(DMI_PRODUCT_NAME);

	if (!vendor || !version || !product) {
		pr_err("error getting hardware information\n");
		return -EINVAL;
	}

	pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);

	if (list_supported) {
		pr_info("List of supported Manufacturer/Model/BIOS:\n");
		pr_info("---------------------------------------------------\n");
		for (bt = bios_tbl; bt->vendor[0]; bt++) {
			pr_info("%-13s | %-17s | %-10s\n", bt->vendor,
				bt->product, bt->version);
		}
		pr_info("---------------------------------------------------\n");
		return -ECANCELED;
	}

	if (force_bios[0]) {
		version = force_bios;
		pr_info("forcing BIOS version: %s\n", version);
		kernelmode = 0;
	}

	if (force_product[0]) {
		product = force_product;
		pr_info("forcing BIOS product: %s\n", product);
		kernelmode = 0;
	}

	if (verbose)
		pr_info("BIOS info: %s %s, product: %s\n",
			vendor, version, product);

	/* search BIOS version and vendor in BIOS settings table */
	for (bt = bios_tbl; bt->vendor[0]; bt++) {
		/*
		 * check if actual hardware BIOS vendor, product and version
		 * IDs start with the strings of BIOS table entry
		 */
		if (str_starts_with(vendor, bt->vendor) &&
				str_starts_with(product, bt->product) &&
				str_starts_with(version, bt->version)) {
			found = 1;
			break;
		}
	}

	if (!found) {
		pr_err("unknown (unsupported) BIOS version %s/%s/%s, please report, aborting!\n",
		       vendor, product, version);
		return -EINVAL;
	}

	/* Copy control settings from BIOS table before we free it. */
	ctrl_cfg.fanreg = bt->fanreg;
	ctrl_cfg.tempreg = bt->tempreg;
	memcpy(&ctrl_cfg.cmd, &bt->cmd, sizeof(struct fancmd));
	ctrl_cfg.mcmd_enable = bt->mcmd_enable;

	/*
	 * if started with kernel mode off, prevent the kernel from switching
	 * off the fan
	 */
	if (!kernelmode) {
		pr_notice("Fan control off, to enable do:\n");
		pr_notice("echo -n \"enabled\" > /sys/class/thermal/thermal_zoneN/mode # N=0,1,2...\n");
	}

	return 0;
}

static int __init acerhdf_register_platform(void)
{
	int err = 0;

	err = platform_driver_register(&acerhdf_driver);
	if (err)
		return err;

	acerhdf_dev = platform_device_alloc("acerhdf", -1);
	if (!acerhdf_dev) {
		err = -ENOMEM;
		goto err_device_alloc;
	}
	err = platform_device_add(acerhdf_dev);
	if (err)
		goto err_device_add;

	return 0;

err_device_add:
	platform_device_put(acerhdf_dev);
err_device_alloc:
	platform_driver_unregister(&acerhdf_driver);
	return err;
}

static void acerhdf_unregister_platform(void)
{
	platform_device_unregister(acerhdf_dev);
	platform_driver_unregister(&acerhdf_driver);
}

static int __init acerhdf_register_thermal(void)
{
	cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
						 &acerhdf_cooling_ops);

	if (IS_ERR(cl_dev))
		return -EINVAL;

	thz_dev = thermal_zone_device_register("acerhdf", 2, 0, NULL,
					      &acerhdf_dev_ops,
					      &acerhdf_zone_params, 0,
					      (kernelmode) ? interval*1000 : 0);
	if (IS_ERR(thz_dev))
		return -EINVAL;

	if (strcmp(thz_dev->governor->name,
				acerhdf_zone_params.governor_name)) {
		pr_err("Didn't get thermal governor %s, perhaps not compiled into thermal subsystem.\n",
				acerhdf_zone_params.governor_name);
		return -EINVAL;
	}

	return 0;
}

static void acerhdf_unregister_thermal(void)
{
	if (cl_dev) {
		thermal_cooling_device_unregister(cl_dev);
		cl_dev = NULL;
	}

	if (thz_dev) {
		thermal_zone_device_unregister(thz_dev);
		thz_dev = NULL;
	}
}

static int __init acerhdf_init(void)
{
	int err = 0;

	err = acerhdf_check_hardware();
	if (err)
		goto out_err;

	err = acerhdf_register_platform();
	if (err)
		goto out_err;

	err = acerhdf_register_thermal();
	if (err)
		goto err_unreg;

	return 0;

err_unreg:
	acerhdf_unregister_thermal();
	acerhdf_unregister_platform();

out_err:
	return err;
}

static void __exit acerhdf_exit(void)
{
	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
	acerhdf_unregister_thermal();
	acerhdf_unregister_platform();
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Peter Kaestle");
MODULE_DESCRIPTION("Aspire One temperature and fan driver");
MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAO751h*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1410*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1810*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5755G:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1825PTZ:");
MODULE_ALIAS("dmi:*:*Acer*:pnAO521*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5739G:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*One*753:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5315:");
MODULE_ALIAS("dmi:*:*Acer*:TravelMate*7730G:");
MODULE_ALIAS("dmi:*:*Acer*:pnAspire*7551:");
MODULE_ALIAS("dmi:*:*Acer*:TM8573T:");
MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnAOA*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOA*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMU*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnENBFT*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMA*:");
MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTVR46*:");
MODULE_ALIAS("dmi:*:*Acer*:pnExtensa 5420*:");

module_init(acerhdf_init);
module_exit(acerhdf_exit);