xref: /openbmc/linux/drivers/platform/x86/acerhdf.c (revision 275876e2)
1 /*
2  * acerhdf - A driver which monitors the temperature
3  *           of the aspire one netbook, turns on/off the fan
4  *           as soon as the upper/lower threshold is reached.
5  *
6  * (C) 2009 - Peter Feuerer     peter (a) piie.net
7  *                              http://piie.net
8  *     2009 Borislav Petkov	bp (a) alien8.de
9  *
10  * Inspired by and many thanks to:
11  *  o acerfand   - Rachel Greenham
12  *  o acer_ec.pl - Michael Kurz     michi.kurz (at) googlemail.com
13  *               - Petr Tomasek     tomasek (#) etf,cuni,cz
14  *               - Carlos Corbacho  cathectic (at) gmail.com
15  *  o lkml       - Matthew Garrett
16  *               - Borislav Petkov
17  *               - Andreas Mohr
18  *
19  *  This program is free software; you can redistribute it and/or modify
20  *  it under the terms of the GNU General Public License as published by
21  *  the Free Software Foundation; either version 2 of the License, or
22  *  (at your option) any later version.
23  *
24  *  This program is distributed in the hope that it will be useful,
25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  *  GNU General Public License for more details.
28  *
29  *  You should have received a copy of the GNU General Public License
30  *  along with this program; if not, write to the Free Software
31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
32  */
33 
34 #define pr_fmt(fmt) "acerhdf: " fmt
35 
36 #include <linux/kernel.h>
37 #include <linux/module.h>
38 #include <linux/dmi.h>
39 #include <linux/acpi.h>
40 #include <linux/thermal.h>
41 #include <linux/platform_device.h>
42 
43 /*
44  * The driver is started with "kernel mode off" by default. That means, the BIOS
45  * is still in control of the fan. In this mode the driver allows to read the
46  * temperature of the cpu and a userspace tool may take over control of the fan.
47  * If the driver is switched to "kernel mode" (e.g. via module parameter) the
48  * driver is in full control of the fan. If you want the module to be started in
49  * kernel mode by default, define the following:
50  */
51 #undef START_IN_KERNEL_MODE
52 
53 #define DRV_VER "0.5.26"
54 
55 /*
56  * According to the Atom N270 datasheet,
57  * (http://download.intel.com/design/processor/datashts/320032.pdf) the
58  * CPU's optimal operating limits denoted in junction temperature as
59  * measured by the on-die thermal monitor are within 0 <= Tj <= 90. So,
60  * assume 89°C is critical temperature.
61  */
62 #define ACERHDF_TEMP_CRIT 89000
63 #define ACERHDF_FAN_OFF 0
64 #define ACERHDF_FAN_AUTO 1
65 
66 /*
67  * No matter what value the user puts into the fanon variable, turn on the fan
68  * at 80 degree Celsius to prevent hardware damage
69  */
70 #define ACERHDF_MAX_FANON 80000
71 
72 /*
73  * Maximum interval between two temperature checks is 15 seconds, as the die
74  * can get hot really fast under heavy load (plus we shouldn't forget about
75  * possible impact of _external_ aggressive sources such as heaters, sun etc.)
76  */
77 #define ACERHDF_MAX_INTERVAL 15
78 
79 #ifdef START_IN_KERNEL_MODE
80 static int kernelmode = 1;
81 #else
82 static int kernelmode;
83 #endif
84 
85 static unsigned int interval = 10;
86 static unsigned int fanon = 60000;
87 static unsigned int fanoff = 53000;
88 static unsigned int verbose;
89 static unsigned int fanstate = ACERHDF_FAN_AUTO;
90 static char force_bios[16];
91 static char force_product[16];
92 static unsigned int prev_interval;
93 static struct thermal_zone_device *thz_dev;
94 static struct thermal_cooling_device *cl_dev;
95 static struct platform_device *acerhdf_dev;
96 
97 module_param(kernelmode, uint, 0);
98 MODULE_PARM_DESC(kernelmode, "Kernel mode fan control on / off");
99 module_param(interval, uint, 0600);
100 MODULE_PARM_DESC(interval, "Polling interval of temperature check");
101 module_param(fanon, uint, 0600);
102 MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
103 module_param(fanoff, uint, 0600);
104 MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
105 module_param(verbose, uint, 0600);
106 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
107 module_param_string(force_bios, force_bios, 16, 0);
108 MODULE_PARM_DESC(force_bios, "Force BIOS version and omit BIOS check");
109 module_param_string(force_product, force_product, 16, 0);
110 MODULE_PARM_DESC(force_product, "Force BIOS product and omit BIOS check");
111 
112 /*
113  * cmd_off: to switch the fan completely off and check if the fan is off
114  *	cmd_auto: to set the BIOS in control of the fan. The BIOS regulates then
115  *		the fan speed depending on the temperature
116  */
117 struct fancmd {
118 	u8 cmd_off;
119 	u8 cmd_auto;
120 };
121 
122 /* BIOS settings */
123 struct bios_settings_t {
124 	const char *vendor;
125 	const char *product;
126 	const char *version;
127 	unsigned char fanreg;
128 	unsigned char tempreg;
129 	struct fancmd cmd;
130 };
131 
132 /* Register addresses and values for different BIOS versions */
133 static const struct bios_settings_t bios_tbl[] = {
134 	/* AOA110 */
135 	{"Acer", "AOA110", "v0.3109", 0x55, 0x58, {0x1f, 0x00} },
136 	{"Acer", "AOA110", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
137 	{"Acer", "AOA110", "v0.3301", 0x55, 0x58, {0xaf, 0x00} },
138 	{"Acer", "AOA110", "v0.3304", 0x55, 0x58, {0xaf, 0x00} },
139 	{"Acer", "AOA110", "v0.3305", 0x55, 0x58, {0xaf, 0x00} },
140 	{"Acer", "AOA110", "v0.3307", 0x55, 0x58, {0xaf, 0x00} },
141 	{"Acer", "AOA110", "v0.3308", 0x55, 0x58, {0x21, 0x00} },
142 	{"Acer", "AOA110", "v0.3309", 0x55, 0x58, {0x21, 0x00} },
143 	{"Acer", "AOA110", "v0.3310", 0x55, 0x58, {0x21, 0x00} },
144 	/* AOA150 */
145 	{"Acer", "AOA150", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
146 	{"Acer", "AOA150", "v0.3301", 0x55, 0x58, {0x20, 0x00} },
147 	{"Acer", "AOA150", "v0.3304", 0x55, 0x58, {0x20, 0x00} },
148 	{"Acer", "AOA150", "v0.3305", 0x55, 0x58, {0x20, 0x00} },
149 	{"Acer", "AOA150", "v0.3307", 0x55, 0x58, {0x20, 0x00} },
150 	{"Acer", "AOA150", "v0.3308", 0x55, 0x58, {0x20, 0x00} },
151 	{"Acer", "AOA150", "v0.3309", 0x55, 0x58, {0x20, 0x00} },
152 	{"Acer", "AOA150", "v0.3310", 0x55, 0x58, {0x20, 0x00} },
153 	/* LT1005u */
154 	{"Acer", "LT-10Q", "v0.3310", 0x55, 0x58, {0x20, 0x00} },
155 	/* Acer 1410 */
156 	{"Acer", "Aspire 1410", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
157 	{"Acer", "Aspire 1410", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
158 	{"Acer", "Aspire 1410", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
159 	{"Acer", "Aspire 1410", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
160 	{"Acer", "Aspire 1410", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
161 	{"Acer", "Aspire 1410", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
162 	{"Acer", "Aspire 1410", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
163 	{"Acer", "Aspire 1410", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
164 	{"Acer", "Aspire 1410", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
165 	{"Acer", "Aspire 1410", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
166 	{"Acer", "Aspire 1410", "v1.3314", 0x55, 0x58, {0x9e, 0x00} },
167 	/* Acer 1810xx */
168 	{"Acer", "Aspire 1810TZ", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
169 	{"Acer", "Aspire 1810T",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
170 	{"Acer", "Aspire 1810TZ", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
171 	{"Acer", "Aspire 1810T",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
172 	{"Acer", "Aspire 1810TZ", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
173 	{"Acer", "Aspire 1810T",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
174 	{"Acer", "Aspire 1810TZ", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
175 	{"Acer", "Aspire 1810T",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
176 	{"Acer", "Aspire 1810TZ", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
177 	{"Acer", "Aspire 1810T",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
178 	{"Acer", "Aspire 1810TZ", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
179 	{"Acer", "Aspire 1810T",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
180 	{"Acer", "Aspire 1810TZ", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
181 	{"Acer", "Aspire 1810T",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
182 	{"Acer", "Aspire 1810TZ", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
183 	{"Acer", "Aspire 1810T",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
184 	{"Acer", "Aspire 1810TZ", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
185 	{"Acer", "Aspire 1810T",  "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
186 	{"Acer", "Aspire 1810TZ", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
187 	{"Acer", "Aspire 1810T",  "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
188 	{"Acer", "Aspire 1810TZ", "v1.3314", 0x55, 0x58, {0x9e, 0x00} },
189 	{"Acer", "Aspire 1810T",  "v1.3314", 0x55, 0x58, {0x9e, 0x00} },
190 	/* Acer 531 */
191 	{"Acer", "AO531h", "v0.3104", 0x55, 0x58, {0x20, 0x00} },
192 	{"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00} },
193 	{"Acer", "AO531h", "v0.3304", 0x55, 0x58, {0x20, 0x00} },
194 	/* Acer 751 */
195 	{"Acer", "AO751h", "V0.3212", 0x55, 0x58, {0x21, 0x00} },
196 	/* Acer 1825 */
197 	{"Acer", "Aspire 1825PTZ", "V1.3118", 0x55, 0x58, {0x9e, 0x00} },
198 	{"Acer", "Aspire 1825PTZ", "V1.3127", 0x55, 0x58, {0x9e, 0x00} },
199 	/* Acer TravelMate 7730 */
200 	{"Acer", "TravelMate 7730G", "v0.3509", 0x55, 0x58, {0xaf, 0x00} },
201 	/* Gateway */
202 	{"Gateway", "AOA110", "v0.3103",  0x55, 0x58, {0x21, 0x00} },
203 	{"Gateway", "AOA150", "v0.3103",  0x55, 0x58, {0x20, 0x00} },
204 	{"Gateway", "LT31",   "v1.3103",  0x55, 0x58, {0x9e, 0x00} },
205 	{"Gateway", "LT31",   "v1.3201",  0x55, 0x58, {0x9e, 0x00} },
206 	{"Gateway", "LT31",   "v1.3302",  0x55, 0x58, {0x9e, 0x00} },
207 	{"Gateway", "LT31",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00} },
208 	/* Packard Bell */
209 	{"Packard Bell", "DOA150",  "v0.3104",  0x55, 0x58, {0x21, 0x00} },
210 	{"Packard Bell", "DOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00} },
211 	{"Packard Bell", "AOA110",  "v0.3105",  0x55, 0x58, {0x21, 0x00} },
212 	{"Packard Bell", "AOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00} },
213 	{"Packard Bell", "ENBFT",   "V1.3118",  0x55, 0x58, {0x9e, 0x00} },
214 	{"Packard Bell", "ENBFT",   "V1.3127",  0x55, 0x58, {0x9e, 0x00} },
215 	{"Packard Bell", "DOTMU",   "v1.3303",  0x55, 0x58, {0x9e, 0x00} },
216 	{"Packard Bell", "DOTMU",   "v0.3120",  0x55, 0x58, {0x9e, 0x00} },
217 	{"Packard Bell", "DOTMU",   "v0.3108",  0x55, 0x58, {0x9e, 0x00} },
218 	{"Packard Bell", "DOTMU",   "v0.3113",  0x55, 0x58, {0x9e, 0x00} },
219 	{"Packard Bell", "DOTMU",   "v0.3115",  0x55, 0x58, {0x9e, 0x00} },
220 	{"Packard Bell", "DOTMU",   "v0.3117",  0x55, 0x58, {0x9e, 0x00} },
221 	{"Packard Bell", "DOTMU",   "v0.3119",  0x55, 0x58, {0x9e, 0x00} },
222 	{"Packard Bell", "DOTMU",   "v1.3204",  0x55, 0x58, {0x9e, 0x00} },
223 	{"Packard Bell", "DOTMA",   "v1.3201",  0x55, 0x58, {0x9e, 0x00} },
224 	{"Packard Bell", "DOTMA",   "v1.3302",  0x55, 0x58, {0x9e, 0x00} },
225 	{"Packard Bell", "DOTMA",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00} },
226 	{"Packard Bell", "DOTVR46", "v1.3308",  0x55, 0x58, {0x9e, 0x00} },
227 	/* pewpew-terminator */
228 	{"", "", "", 0, 0, {0, 0} }
229 };
230 
231 static const struct bios_settings_t *bios_cfg __read_mostly;
232 
233 static int acerhdf_get_temp(int *temp)
234 {
235 	u8 read_temp;
236 
237 	if (ec_read(bios_cfg->tempreg, &read_temp))
238 		return -EINVAL;
239 
240 	*temp = read_temp * 1000;
241 
242 	return 0;
243 }
244 
245 static int acerhdf_get_fanstate(int *state)
246 {
247 	u8 fan;
248 
249 	if (ec_read(bios_cfg->fanreg, &fan))
250 		return -EINVAL;
251 
252 	if (fan != bios_cfg->cmd.cmd_off)
253 		*state = ACERHDF_FAN_AUTO;
254 	else
255 		*state = ACERHDF_FAN_OFF;
256 
257 	return 0;
258 }
259 
260 static void acerhdf_change_fanstate(int state)
261 {
262 	unsigned char cmd;
263 
264 	if (verbose)
265 		pr_notice("fan %s\n", state == ACERHDF_FAN_OFF ? "OFF" : "ON");
266 
267 	if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
268 		pr_err("invalid fan state %d requested, setting to auto!\n",
269 		       state);
270 		state = ACERHDF_FAN_AUTO;
271 	}
272 
273 	cmd = (state == ACERHDF_FAN_OFF) ? bios_cfg->cmd.cmd_off
274 					 : bios_cfg->cmd.cmd_auto;
275 	fanstate = state;
276 
277 	ec_write(bios_cfg->fanreg, cmd);
278 }
279 
280 static void acerhdf_check_param(struct thermal_zone_device *thermal)
281 {
282 	if (fanon > ACERHDF_MAX_FANON) {
283 		pr_err("fanon temperature too high, set to %d\n",
284 		       ACERHDF_MAX_FANON);
285 		fanon = ACERHDF_MAX_FANON;
286 	}
287 
288 	if (kernelmode && prev_interval != interval) {
289 		if (interval > ACERHDF_MAX_INTERVAL) {
290 			pr_err("interval too high, set to %d\n",
291 			       ACERHDF_MAX_INTERVAL);
292 			interval = ACERHDF_MAX_INTERVAL;
293 		}
294 		if (verbose)
295 			pr_notice("interval changed to: %d\n", interval);
296 		thermal->polling_delay = interval*1000;
297 		prev_interval = interval;
298 	}
299 }
300 
301 /*
302  * This is the thermal zone callback which does the delayed polling of the fan
303  * state. We do check /sysfs-originating settings here in acerhdf_check_param()
304  * as late as the polling interval is since we can't do that in the respective
305  * accessors of the module parameters.
306  */
307 static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal,
308 			       unsigned long *t)
309 {
310 	int temp, err = 0;
311 
312 	acerhdf_check_param(thermal);
313 
314 	err = acerhdf_get_temp(&temp);
315 	if (err)
316 		return err;
317 
318 	if (verbose)
319 		pr_notice("temp %d\n", temp);
320 
321 	*t = temp;
322 	return 0;
323 }
324 
325 static int acerhdf_bind(struct thermal_zone_device *thermal,
326 			struct thermal_cooling_device *cdev)
327 {
328 	/* if the cooling device is the one from acerhdf bind it */
329 	if (cdev != cl_dev)
330 		return 0;
331 
332 	if (thermal_zone_bind_cooling_device(thermal, 0, cdev,
333 			THERMAL_NO_LIMIT, THERMAL_NO_LIMIT)) {
334 		pr_err("error binding cooling dev\n");
335 		return -EINVAL;
336 	}
337 	return 0;
338 }
339 
340 static int acerhdf_unbind(struct thermal_zone_device *thermal,
341 			  struct thermal_cooling_device *cdev)
342 {
343 	if (cdev != cl_dev)
344 		return 0;
345 
346 	if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
347 		pr_err("error unbinding cooling dev\n");
348 		return -EINVAL;
349 	}
350 	return 0;
351 }
352 
353 static inline void acerhdf_revert_to_bios_mode(void)
354 {
355 	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
356 	kernelmode = 0;
357 	if (thz_dev)
358 		thz_dev->polling_delay = 0;
359 	pr_notice("kernel mode fan control OFF\n");
360 }
361 static inline void acerhdf_enable_kernelmode(void)
362 {
363 	kernelmode = 1;
364 
365 	thz_dev->polling_delay = interval*1000;
366 	thermal_zone_device_update(thz_dev);
367 	pr_notice("kernel mode fan control ON\n");
368 }
369 
370 static int acerhdf_get_mode(struct thermal_zone_device *thermal,
371 			    enum thermal_device_mode *mode)
372 {
373 	if (verbose)
374 		pr_notice("kernel mode fan control %d\n", kernelmode);
375 
376 	*mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
377 			     : THERMAL_DEVICE_DISABLED;
378 
379 	return 0;
380 }
381 
382 /*
383  * set operation mode;
384  * enabled: the thermal layer of the kernel takes care about
385  *          the temperature and the fan.
386  * disabled: the BIOS takes control of the fan.
387  */
388 static int acerhdf_set_mode(struct thermal_zone_device *thermal,
389 			    enum thermal_device_mode mode)
390 {
391 	if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
392 		acerhdf_revert_to_bios_mode();
393 	else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
394 		acerhdf_enable_kernelmode();
395 
396 	return 0;
397 }
398 
399 static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
400 				 enum thermal_trip_type *type)
401 {
402 	if (trip == 0)
403 		*type = THERMAL_TRIP_ACTIVE;
404 
405 	return 0;
406 }
407 
408 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
409 				 unsigned long *temp)
410 {
411 	if (trip == 0)
412 		*temp = fanon;
413 
414 	return 0;
415 }
416 
417 static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
418 				 unsigned long *temperature)
419 {
420 	*temperature = ACERHDF_TEMP_CRIT;
421 	return 0;
422 }
423 
424 /* bind callback functions to thermalzone */
425 static struct thermal_zone_device_ops acerhdf_dev_ops = {
426 	.bind = acerhdf_bind,
427 	.unbind = acerhdf_unbind,
428 	.get_temp = acerhdf_get_ec_temp,
429 	.get_mode = acerhdf_get_mode,
430 	.set_mode = acerhdf_set_mode,
431 	.get_trip_type = acerhdf_get_trip_type,
432 	.get_trip_temp = acerhdf_get_trip_temp,
433 	.get_crit_temp = acerhdf_get_crit_temp,
434 };
435 
436 
437 /*
438  * cooling device callback functions
439  * get maximal fan cooling state
440  */
441 static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
442 				 unsigned long *state)
443 {
444 	*state = 1;
445 
446 	return 0;
447 }
448 
449 static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
450 				 unsigned long *state)
451 {
452 	int err = 0, tmp;
453 
454 	err = acerhdf_get_fanstate(&tmp);
455 	if (err)
456 		return err;
457 
458 	*state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
459 	return 0;
460 }
461 
462 /* change current fan state - is overwritten when running in kernel mode */
463 static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
464 				 unsigned long state)
465 {
466 	int cur_temp, cur_state, err = 0;
467 
468 	if (!kernelmode)
469 		return 0;
470 
471 	err = acerhdf_get_temp(&cur_temp);
472 	if (err) {
473 		pr_err("error reading temperature, hand off control to BIOS\n");
474 		goto err_out;
475 	}
476 
477 	err = acerhdf_get_fanstate(&cur_state);
478 	if (err) {
479 		pr_err("error reading fan state, hand off control to BIOS\n");
480 		goto err_out;
481 	}
482 
483 	if (state == 0) {
484 		/* turn fan off only if below fanoff temperature */
485 		if ((cur_state == ACERHDF_FAN_AUTO) &&
486 		    (cur_temp < fanoff))
487 			acerhdf_change_fanstate(ACERHDF_FAN_OFF);
488 	} else {
489 		if (cur_state == ACERHDF_FAN_OFF)
490 			acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
491 	}
492 	return 0;
493 
494 err_out:
495 	acerhdf_revert_to_bios_mode();
496 	return -EINVAL;
497 }
498 
499 /* bind fan callbacks to fan device */
500 static struct thermal_cooling_device_ops acerhdf_cooling_ops = {
501 	.get_max_state = acerhdf_get_max_state,
502 	.get_cur_state = acerhdf_get_cur_state,
503 	.set_cur_state = acerhdf_set_cur_state,
504 };
505 
506 /* suspend / resume functionality */
507 static int acerhdf_suspend(struct device *dev)
508 {
509 	if (kernelmode)
510 		acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
511 
512 	if (verbose)
513 		pr_notice("going suspend\n");
514 
515 	return 0;
516 }
517 
518 static int acerhdf_probe(struct platform_device *device)
519 {
520 	return 0;
521 }
522 
523 static int acerhdf_remove(struct platform_device *device)
524 {
525 	return 0;
526 }
527 
528 static const struct dev_pm_ops acerhdf_pm_ops = {
529 	.suspend = acerhdf_suspend,
530 	.freeze  = acerhdf_suspend,
531 };
532 
533 static struct platform_driver acerhdf_driver = {
534 	.driver = {
535 		.name  = "acerhdf",
536 		.owner = THIS_MODULE,
537 		.pm    = &acerhdf_pm_ops,
538 	},
539 	.probe = acerhdf_probe,
540 	.remove = acerhdf_remove,
541 };
542 
543 /* checks if str begins with start */
544 static int str_starts_with(const char *str, const char *start)
545 {
546 	unsigned long str_len = 0, start_len = 0;
547 
548 	str_len = strlen(str);
549 	start_len = strlen(start);
550 
551 	if (str_len >= start_len &&
552 			!strncmp(str, start, start_len))
553 		return 1;
554 
555 	return 0;
556 }
557 
558 /* check hardware */
559 static int acerhdf_check_hardware(void)
560 {
561 	char const *vendor, *version, *product;
562 	const struct bios_settings_t *bt = NULL;
563 
564 	/* get BIOS data */
565 	vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
566 	version = dmi_get_system_info(DMI_BIOS_VERSION);
567 	product = dmi_get_system_info(DMI_PRODUCT_NAME);
568 
569 	if (!vendor || !version || !product) {
570 		pr_err("error getting hardware information\n");
571 		return -EINVAL;
572 	}
573 
574 	pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);
575 
576 	if (force_bios[0]) {
577 		version = force_bios;
578 		pr_info("forcing BIOS version: %s\n", version);
579 		kernelmode = 0;
580 	}
581 
582 	if (force_product[0]) {
583 		product = force_product;
584 		pr_info("forcing BIOS product: %s\n", product);
585 		kernelmode = 0;
586 	}
587 
588 	if (verbose)
589 		pr_info("BIOS info: %s %s, product: %s\n",
590 			vendor, version, product);
591 
592 	/* search BIOS version and vendor in BIOS settings table */
593 	for (bt = bios_tbl; bt->vendor[0]; bt++) {
594 		/*
595 		 * check if actual hardware BIOS vendor, product and version
596 		 * IDs start with the strings of BIOS table entry
597 		 */
598 		if (str_starts_with(vendor, bt->vendor) &&
599 				str_starts_with(product, bt->product) &&
600 				str_starts_with(version, bt->version)) {
601 			bios_cfg = bt;
602 			break;
603 		}
604 	}
605 
606 	if (!bios_cfg) {
607 		pr_err("unknown (unsupported) BIOS version %s/%s/%s, please report, aborting!\n",
608 		       vendor, product, version);
609 		return -EINVAL;
610 	}
611 
612 	/*
613 	 * if started with kernel mode off, prevent the kernel from switching
614 	 * off the fan
615 	 */
616 	if (!kernelmode) {
617 		pr_notice("Fan control off, to enable do:\n");
618 		pr_notice("echo -n \"enabled\" > /sys/class/thermal/thermal_zone0/mode\n");
619 	}
620 
621 	return 0;
622 }
623 
624 static int acerhdf_register_platform(void)
625 {
626 	int err = 0;
627 
628 	err = platform_driver_register(&acerhdf_driver);
629 	if (err)
630 		return err;
631 
632 	acerhdf_dev = platform_device_alloc("acerhdf", -1);
633 	if (!acerhdf_dev) {
634 		err = -ENOMEM;
635 		goto err_device_alloc;
636 	}
637 	err = platform_device_add(acerhdf_dev);
638 	if (err)
639 		goto err_device_add;
640 
641 	return 0;
642 
643 err_device_add:
644 	platform_device_put(acerhdf_dev);
645 err_device_alloc:
646 	platform_driver_unregister(&acerhdf_driver);
647 	return err;
648 }
649 
650 static void acerhdf_unregister_platform(void)
651 {
652 	platform_device_unregister(acerhdf_dev);
653 	platform_driver_unregister(&acerhdf_driver);
654 }
655 
656 static int acerhdf_register_thermal(void)
657 {
658 	cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
659 						 &acerhdf_cooling_ops);
660 
661 	if (IS_ERR(cl_dev))
662 		return -EINVAL;
663 
664 	thz_dev = thermal_zone_device_register("acerhdf", 1, 0, NULL,
665 					      &acerhdf_dev_ops, NULL, 0,
666 					      (kernelmode) ? interval*1000 : 0);
667 	if (IS_ERR(thz_dev))
668 		return -EINVAL;
669 
670 	return 0;
671 }
672 
673 static void acerhdf_unregister_thermal(void)
674 {
675 	if (cl_dev) {
676 		thermal_cooling_device_unregister(cl_dev);
677 		cl_dev = NULL;
678 	}
679 
680 	if (thz_dev) {
681 		thermal_zone_device_unregister(thz_dev);
682 		thz_dev = NULL;
683 	}
684 }
685 
686 static int __init acerhdf_init(void)
687 {
688 	int err = 0;
689 
690 	err = acerhdf_check_hardware();
691 	if (err)
692 		goto out_err;
693 
694 	err = acerhdf_register_platform();
695 	if (err)
696 		goto out_err;
697 
698 	err = acerhdf_register_thermal();
699 	if (err)
700 		goto err_unreg;
701 
702 	return 0;
703 
704 err_unreg:
705 	acerhdf_unregister_thermal();
706 	acerhdf_unregister_platform();
707 
708 out_err:
709 	return err;
710 }
711 
712 static void __exit acerhdf_exit(void)
713 {
714 	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
715 	acerhdf_unregister_thermal();
716 	acerhdf_unregister_platform();
717 }
718 
719 MODULE_LICENSE("GPL");
720 MODULE_AUTHOR("Peter Feuerer");
721 MODULE_DESCRIPTION("Aspire One temperature and fan driver");
722 MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
723 MODULE_ALIAS("dmi:*:*Acer*:pnAO751h*:");
724 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1410*:");
725 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1810*:");
726 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1825PTZ:");
727 MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
728 MODULE_ALIAS("dmi:*:*Acer*:TravelMate*7730G:");
729 MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
730 MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
731 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnAOA*:");
732 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOA*:");
733 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMU*:");
734 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnENBFT*:");
735 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMA*:");
736 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTVR46*:");
737 
738 module_init(acerhdf_init);
739 module_exit(acerhdf_exit);
740