xref: /openbmc/linux/drivers/platform/x86/acerhdf.c (revision 0e17c50f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * acerhdf - A driver which monitors the temperature
4  *           of the aspire one netbook, turns on/off the fan
5  *           as soon as the upper/lower threshold is reached.
6  *
7  * (C) 2009 - Peter Kaestle     peter (a) piie.net
8  *                              http://piie.net
9  *     2009 Borislav Petkov	bp (a) alien8.de
10  *
11  * Inspired by and many thanks to:
12  *  o acerfand   - Rachel Greenham
13  *  o acer_ec.pl - Michael Kurz     michi.kurz (at) googlemail.com
14  *               - Petr Tomasek     tomasek (#) etf,cuni,cz
15  *               - Carlos Corbacho  cathectic (at) gmail.com
16  *  o lkml       - Matthew Garrett
17  *               - Borislav Petkov
18  *               - Andreas Mohr
19  */
20 
21 #define pr_fmt(fmt) "acerhdf: " fmt
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/dmi.h>
26 #include <linux/acpi.h>
27 #include <linux/thermal.h>
28 #include <linux/platform_device.h>
29 
30 /*
31  * The driver is started with "kernel mode off" by default. That means, the BIOS
32  * is still in control of the fan. In this mode the driver allows to read the
33  * temperature of the cpu and a userspace tool may take over control of the fan.
34  * If the driver is switched to "kernel mode" (e.g. via module parameter) the
35  * driver is in full control of the fan. If you want the module to be started in
36  * kernel mode by default, define the following:
37  */
38 #undef START_IN_KERNEL_MODE
39 
40 #define DRV_VER "0.7.0"
41 
42 /*
43  * According to the Atom N270 datasheet,
44  * (http://download.intel.com/design/processor/datashts/320032.pdf) the
45  * CPU's optimal operating limits denoted in junction temperature as
46  * measured by the on-die thermal monitor are within 0 <= Tj <= 90. So,
47  * assume 89°C is critical temperature.
48  */
49 #define ACERHDF_TEMP_CRIT 89000
50 #define ACERHDF_FAN_OFF 0
51 #define ACERHDF_FAN_AUTO 1
52 
53 /*
54  * No matter what value the user puts into the fanon variable, turn on the fan
55  * at 80 degree Celsius to prevent hardware damage
56  */
57 #define ACERHDF_MAX_FANON 80000
58 
59 /*
60  * Maximum interval between two temperature checks is 15 seconds, as the die
61  * can get hot really fast under heavy load (plus we shouldn't forget about
62  * possible impact of _external_ aggressive sources such as heaters, sun etc.)
63  */
64 #define ACERHDF_MAX_INTERVAL 15
65 
66 #ifdef START_IN_KERNEL_MODE
67 static int kernelmode = 1;
68 #else
69 static int kernelmode;
70 #endif
71 
72 static unsigned int interval = 10;
73 static unsigned int fanon = 60000;
74 static unsigned int fanoff = 53000;
75 static unsigned int verbose;
76 static unsigned int list_supported;
77 static unsigned int fanstate = ACERHDF_FAN_AUTO;
78 static char force_bios[16];
79 static char force_product[16];
80 static unsigned int prev_interval;
81 static struct thermal_zone_device *thz_dev;
82 static struct thermal_cooling_device *cl_dev;
83 static struct platform_device *acerhdf_dev;
84 
85 module_param(kernelmode, uint, 0);
86 MODULE_PARM_DESC(kernelmode, "Kernel mode fan control on / off");
87 module_param(interval, uint, 0600);
88 MODULE_PARM_DESC(interval, "Polling interval of temperature check");
89 module_param(fanon, uint, 0600);
90 MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
91 module_param(fanoff, uint, 0600);
92 MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
93 module_param(verbose, uint, 0600);
94 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
95 module_param(list_supported, uint, 0600);
96 MODULE_PARM_DESC(list_supported, "List supported models and BIOS versions");
97 module_param_string(force_bios, force_bios, 16, 0);
98 MODULE_PARM_DESC(force_bios, "Pretend system has this known supported BIOS version");
99 module_param_string(force_product, force_product, 16, 0);
100 MODULE_PARM_DESC(force_product, "Pretend system is this known supported model");
101 
102 /*
103  * cmd_off: to switch the fan completely off and check if the fan is off
104  *	cmd_auto: to set the BIOS in control of the fan. The BIOS regulates then
105  *		the fan speed depending on the temperature
106  */
107 struct fancmd {
108 	u8 cmd_off;
109 	u8 cmd_auto;
110 };
111 
112 struct manualcmd {
113 	u8 mreg;
114 	u8 moff;
115 };
116 
117 /* default register and command to disable fan in manual mode */
118 static const struct manualcmd mcmd = {
119 	.mreg = 0x94,
120 	.moff = 0xff,
121 };
122 
123 /* BIOS settings - only used during probe */
124 struct bios_settings {
125 	const char *vendor;
126 	const char *product;
127 	const char *version;
128 	u8 fanreg;
129 	u8 tempreg;
130 	struct fancmd cmd;
131 	int mcmd_enable;
132 };
133 
134 /* This could be a daughter struct in the above, but not worth the redirect */
135 struct ctrl_settings {
136 	u8 fanreg;
137 	u8 tempreg;
138 	struct fancmd cmd;
139 	int mcmd_enable;
140 };
141 
142 static struct ctrl_settings ctrl_cfg __read_mostly;
143 
144 /* Register addresses and values for different BIOS versions */
145 static const struct bios_settings bios_tbl[] __initconst = {
146 	/* AOA110 */
147 	{"Acer", "AOA110", "v0.3109", 0x55, 0x58, {0x1f, 0x00}, 0},
148 	{"Acer", "AOA110", "v0.3114", 0x55, 0x58, {0x1f, 0x00}, 0},
149 	{"Acer", "AOA110", "v0.3301", 0x55, 0x58, {0xaf, 0x00}, 0},
150 	{"Acer", "AOA110", "v0.3304", 0x55, 0x58, {0xaf, 0x00}, 0},
151 	{"Acer", "AOA110", "v0.3305", 0x55, 0x58, {0xaf, 0x00}, 0},
152 	{"Acer", "AOA110", "v0.3307", 0x55, 0x58, {0xaf, 0x00}, 0},
153 	{"Acer", "AOA110", "v0.3308", 0x55, 0x58, {0x21, 0x00}, 0},
154 	{"Acer", "AOA110", "v0.3309", 0x55, 0x58, {0x21, 0x00}, 0},
155 	{"Acer", "AOA110", "v0.3310", 0x55, 0x58, {0x21, 0x00}, 0},
156 	/* AOA150 */
157 	{"Acer", "AOA150", "v0.3114", 0x55, 0x58, {0x1f, 0x00}, 0},
158 	{"Acer", "AOA150", "v0.3301", 0x55, 0x58, {0x20, 0x00}, 0},
159 	{"Acer", "AOA150", "v0.3304", 0x55, 0x58, {0x20, 0x00}, 0},
160 	{"Acer", "AOA150", "v0.3305", 0x55, 0x58, {0x20, 0x00}, 0},
161 	{"Acer", "AOA150", "v0.3307", 0x55, 0x58, {0x20, 0x00}, 0},
162 	{"Acer", "AOA150", "v0.3308", 0x55, 0x58, {0x20, 0x00}, 0},
163 	{"Acer", "AOA150", "v0.3309", 0x55, 0x58, {0x20, 0x00}, 0},
164 	{"Acer", "AOA150", "v0.3310", 0x55, 0x58, {0x20, 0x00}, 0},
165 	/* LT1005u */
166 	{"Acer", "LT-10Q", "v0.3310", 0x55, 0x58, {0x20, 0x00}, 0},
167 	/* Acer 1410 */
168 	{"Acer", "Aspire 1410", "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
169 	{"Acer", "Aspire 1410", "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
170 	{"Acer", "Aspire 1410", "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
171 	{"Acer", "Aspire 1410", "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
172 	{"Acer", "Aspire 1410", "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
173 	{"Acer", "Aspire 1410", "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
174 	{"Acer", "Aspire 1410", "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
175 	{"Acer", "Aspire 1410", "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
176 	{"Acer", "Aspire 1410", "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
177 	{"Acer", "Aspire 1410", "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
178 	{"Acer", "Aspire 1410", "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
179 	/* Acer 1810xx */
180 	{"Acer", "Aspire 1810TZ", "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
181 	{"Acer", "Aspire 1810T",  "v0.3108", 0x55, 0x58, {0x9e, 0x00}, 0},
182 	{"Acer", "Aspire 1810TZ", "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
183 	{"Acer", "Aspire 1810T",  "v0.3113", 0x55, 0x58, {0x9e, 0x00}, 0},
184 	{"Acer", "Aspire 1810TZ", "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
185 	{"Acer", "Aspire 1810T",  "v0.3115", 0x55, 0x58, {0x9e, 0x00}, 0},
186 	{"Acer", "Aspire 1810TZ", "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
187 	{"Acer", "Aspire 1810T",  "v0.3117", 0x55, 0x58, {0x9e, 0x00}, 0},
188 	{"Acer", "Aspire 1810TZ", "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
189 	{"Acer", "Aspire 1810T",  "v0.3119", 0x55, 0x58, {0x9e, 0x00}, 0},
190 	{"Acer", "Aspire 1810TZ", "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
191 	{"Acer", "Aspire 1810T",  "v0.3120", 0x55, 0x58, {0x9e, 0x00}, 0},
192 	{"Acer", "Aspire 1810TZ", "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
193 	{"Acer", "Aspire 1810T",  "v1.3204", 0x55, 0x58, {0x9e, 0x00}, 0},
194 	{"Acer", "Aspire 1810TZ", "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
195 	{"Acer", "Aspire 1810T",  "v1.3303", 0x55, 0x58, {0x9e, 0x00}, 0},
196 	{"Acer", "Aspire 1810TZ", "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
197 	{"Acer", "Aspire 1810T",  "v1.3308", 0x55, 0x58, {0x9e, 0x00}, 0},
198 	{"Acer", "Aspire 1810TZ", "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
199 	{"Acer", "Aspire 1810T",  "v1.3310", 0x55, 0x58, {0x9e, 0x00}, 0},
200 	{"Acer", "Aspire 1810TZ", "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
201 	{"Acer", "Aspire 1810T",  "v1.3314", 0x55, 0x58, {0x9e, 0x00}, 0},
202 	/* Acer 5755G */
203 	{"Acer", "Aspire 5755G",  "V1.20",   0xab, 0xb4, {0x00, 0x08}, 0},
204 	{"Acer", "Aspire 5755G",  "V1.21",   0xab, 0xb3, {0x00, 0x08}, 0},
205 	/* Acer 521 */
206 	{"Acer", "AO521", "V1.11", 0x55, 0x58, {0x1f, 0x00}, 0},
207 	/* Acer 531 */
208 	{"Acer", "AO531h", "v0.3104", 0x55, 0x58, {0x20, 0x00}, 0},
209 	{"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00}, 0},
210 	{"Acer", "AO531h", "v0.3304", 0x55, 0x58, {0x20, 0x00}, 0},
211 	/* Acer 751 */
212 	{"Acer", "AO751h", "V0.3206", 0x55, 0x58, {0x21, 0x00}, 0},
213 	{"Acer", "AO751h", "V0.3212", 0x55, 0x58, {0x21, 0x00}, 0},
214 	/* Acer 753 */
215 	{"Acer", "Aspire One 753", "V1.24", 0x93, 0xac, {0x14, 0x04}, 1},
216 	/* Acer 1825 */
217 	{"Acer", "Aspire 1825PTZ", "V1.3118", 0x55, 0x58, {0x9e, 0x00}, 0},
218 	{"Acer", "Aspire 1825PTZ", "V1.3127", 0x55, 0x58, {0x9e, 0x00}, 0},
219 	/* Acer Extensa 5420 */
220 	{"Acer", "Extensa 5420", "V1.17", 0x93, 0xac, {0x14, 0x04}, 1},
221 	/* Acer Aspire 5315 */
222 	{"Acer", "Aspire 5315", "V1.19", 0x93, 0xac, {0x14, 0x04}, 1},
223 	/* Acer Aspire 5739 */
224 	{"Acer", "Aspire 5739G", "V1.3311", 0x55, 0x58, {0x20, 0x00}, 0},
225 	/* Acer TravelMate 7730 */
226 	{"Acer", "TravelMate 7730G", "v0.3509", 0x55, 0x58, {0xaf, 0x00}, 0},
227 	/* Acer Aspire 7551 */
228 	{"Acer", "Aspire 7551", "V1.18", 0x93, 0xa8, {0x14, 0x04}, 1},
229 	/* Acer TravelMate TM8573T */
230 	{"Acer", "TM8573T", "V1.13", 0x93, 0xa8, {0x14, 0x04}, 1},
231 	/* Gateway */
232 	{"Gateway", "AOA110", "v0.3103",  0x55, 0x58, {0x21, 0x00}, 0},
233 	{"Gateway", "AOA150", "v0.3103",  0x55, 0x58, {0x20, 0x00}, 0},
234 	{"Gateway", "LT31",   "v1.3103",  0x55, 0x58, {0x9e, 0x00}, 0},
235 	{"Gateway", "LT31",   "v1.3201",  0x55, 0x58, {0x9e, 0x00}, 0},
236 	{"Gateway", "LT31",   "v1.3302",  0x55, 0x58, {0x9e, 0x00}, 0},
237 	{"Gateway", "LT31",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00}, 0},
238 	{"Gateway", "LT31",   "v1.3307",  0x55, 0x58, {0x9e, 0x00}, 0},
239 	/* Packard Bell */
240 	{"Packard Bell", "DOA150",  "v0.3104",  0x55, 0x58, {0x21, 0x00}, 0},
241 	{"Packard Bell", "DOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00}, 0},
242 	{"Packard Bell", "AOA110",  "v0.3105",  0x55, 0x58, {0x21, 0x00}, 0},
243 	{"Packard Bell", "AOA150",  "v0.3105",  0x55, 0x58, {0x20, 0x00}, 0},
244 	{"Packard Bell", "ENBFT",   "V1.3118",  0x55, 0x58, {0x9e, 0x00}, 0},
245 	{"Packard Bell", "ENBFT",   "V1.3127",  0x55, 0x58, {0x9e, 0x00}, 0},
246 	{"Packard Bell", "DOTMU",   "v1.3303",  0x55, 0x58, {0x9e, 0x00}, 0},
247 	{"Packard Bell", "DOTMU",   "v0.3120",  0x55, 0x58, {0x9e, 0x00}, 0},
248 	{"Packard Bell", "DOTMU",   "v0.3108",  0x55, 0x58, {0x9e, 0x00}, 0},
249 	{"Packard Bell", "DOTMU",   "v0.3113",  0x55, 0x58, {0x9e, 0x00}, 0},
250 	{"Packard Bell", "DOTMU",   "v0.3115",  0x55, 0x58, {0x9e, 0x00}, 0},
251 	{"Packard Bell", "DOTMU",   "v0.3117",  0x55, 0x58, {0x9e, 0x00}, 0},
252 	{"Packard Bell", "DOTMU",   "v0.3119",  0x55, 0x58, {0x9e, 0x00}, 0},
253 	{"Packard Bell", "DOTMU",   "v1.3204",  0x55, 0x58, {0x9e, 0x00}, 0},
254 	{"Packard Bell", "DOTMA",   "v1.3201",  0x55, 0x58, {0x9e, 0x00}, 0},
255 	{"Packard Bell", "DOTMA",   "v1.3302",  0x55, 0x58, {0x9e, 0x00}, 0},
256 	{"Packard Bell", "DOTMA",   "v1.3303t", 0x55, 0x58, {0x9e, 0x00}, 0},
257 	{"Packard Bell", "DOTVR46", "v1.3308",  0x55, 0x58, {0x9e, 0x00}, 0},
258 	/* pewpew-terminator */
259 	{"", "", "", 0, 0, {0, 0}, 0}
260 };
261 
262 /*
263  * this struct is used to instruct thermal layer to use bang_bang instead of
264  * default governor for acerhdf
265  */
266 static struct thermal_zone_params acerhdf_zone_params = {
267 	.governor_name = "bang_bang",
268 };
269 
270 static int acerhdf_get_temp(int *temp)
271 {
272 	u8 read_temp;
273 
274 	if (ec_read(ctrl_cfg.tempreg, &read_temp))
275 		return -EINVAL;
276 
277 	*temp = read_temp * 1000;
278 
279 	return 0;
280 }
281 
282 static int acerhdf_get_fanstate(int *state)
283 {
284 	u8 fan;
285 
286 	if (ec_read(ctrl_cfg.fanreg, &fan))
287 		return -EINVAL;
288 
289 	if (fan != ctrl_cfg.cmd.cmd_off)
290 		*state = ACERHDF_FAN_AUTO;
291 	else
292 		*state = ACERHDF_FAN_OFF;
293 
294 	return 0;
295 }
296 
297 static void acerhdf_change_fanstate(int state)
298 {
299 	unsigned char cmd;
300 
301 	if (verbose)
302 		pr_notice("fan %s\n", state == ACERHDF_FAN_OFF ? "OFF" : "ON");
303 
304 	if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
305 		pr_err("invalid fan state %d requested, setting to auto!\n",
306 		       state);
307 		state = ACERHDF_FAN_AUTO;
308 	}
309 
310 	cmd = (state == ACERHDF_FAN_OFF) ? ctrl_cfg.cmd.cmd_off
311 					 : ctrl_cfg.cmd.cmd_auto;
312 	fanstate = state;
313 
314 	ec_write(ctrl_cfg.fanreg, cmd);
315 
316 	if (ctrl_cfg.mcmd_enable && state == ACERHDF_FAN_OFF) {
317 		if (verbose)
318 			pr_notice("turning off fan manually\n");
319 		ec_write(mcmd.mreg, mcmd.moff);
320 	}
321 }
322 
323 static void acerhdf_check_param(struct thermal_zone_device *thermal)
324 {
325 	if (fanon > ACERHDF_MAX_FANON) {
326 		pr_err("fanon temperature too high, set to %d\n",
327 		       ACERHDF_MAX_FANON);
328 		fanon = ACERHDF_MAX_FANON;
329 	}
330 
331 	if (kernelmode && prev_interval != interval) {
332 		if (interval > ACERHDF_MAX_INTERVAL) {
333 			pr_err("interval too high, set to %d\n",
334 			       ACERHDF_MAX_INTERVAL);
335 			interval = ACERHDF_MAX_INTERVAL;
336 		}
337 		if (verbose)
338 			pr_notice("interval changed to: %d\n", interval);
339 		thermal->polling_delay = interval*1000;
340 		prev_interval = interval;
341 	}
342 }
343 
344 /*
345  * This is the thermal zone callback which does the delayed polling of the fan
346  * state. We do check /sysfs-originating settings here in acerhdf_check_param()
347  * as late as the polling interval is since we can't do that in the respective
348  * accessors of the module parameters.
349  */
350 static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal, int *t)
351 {
352 	int temp, err = 0;
353 
354 	acerhdf_check_param(thermal);
355 
356 	err = acerhdf_get_temp(&temp);
357 	if (err)
358 		return err;
359 
360 	if (verbose)
361 		pr_notice("temp %d\n", temp);
362 
363 	*t = temp;
364 	return 0;
365 }
366 
367 static int acerhdf_bind(struct thermal_zone_device *thermal,
368 			struct thermal_cooling_device *cdev)
369 {
370 	/* if the cooling device is the one from acerhdf bind it */
371 	if (cdev != cl_dev)
372 		return 0;
373 
374 	if (thermal_zone_bind_cooling_device(thermal, 0, cdev,
375 			THERMAL_NO_LIMIT, THERMAL_NO_LIMIT,
376 			THERMAL_WEIGHT_DEFAULT)) {
377 		pr_err("error binding cooling dev\n");
378 		return -EINVAL;
379 	}
380 	return 0;
381 }
382 
383 static int acerhdf_unbind(struct thermal_zone_device *thermal,
384 			  struct thermal_cooling_device *cdev)
385 {
386 	if (cdev != cl_dev)
387 		return 0;
388 
389 	if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
390 		pr_err("error unbinding cooling dev\n");
391 		return -EINVAL;
392 	}
393 	return 0;
394 }
395 
396 static inline void acerhdf_revert_to_bios_mode(void)
397 {
398 	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
399 	kernelmode = 0;
400 	if (thz_dev)
401 		thz_dev->polling_delay = 0;
402 	pr_notice("kernel mode fan control OFF\n");
403 }
404 static inline void acerhdf_enable_kernelmode(void)
405 {
406 	kernelmode = 1;
407 
408 	thz_dev->polling_delay = interval*1000;
409 	thermal_zone_device_update(thz_dev, THERMAL_EVENT_UNSPECIFIED);
410 	pr_notice("kernel mode fan control ON\n");
411 }
412 
413 static int acerhdf_get_mode(struct thermal_zone_device *thermal,
414 			    enum thermal_device_mode *mode)
415 {
416 	if (verbose)
417 		pr_notice("kernel mode fan control %d\n", kernelmode);
418 
419 	*mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
420 			     : THERMAL_DEVICE_DISABLED;
421 
422 	return 0;
423 }
424 
425 /*
426  * set operation mode;
427  * enabled: the thermal layer of the kernel takes care about
428  *          the temperature and the fan.
429  * disabled: the BIOS takes control of the fan.
430  */
431 static int acerhdf_set_mode(struct thermal_zone_device *thermal,
432 			    enum thermal_device_mode mode)
433 {
434 	if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
435 		acerhdf_revert_to_bios_mode();
436 	else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
437 		acerhdf_enable_kernelmode();
438 
439 	return 0;
440 }
441 
442 static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
443 				 enum thermal_trip_type *type)
444 {
445 	if (trip == 0)
446 		*type = THERMAL_TRIP_ACTIVE;
447 	else if (trip == 1)
448 		*type = THERMAL_TRIP_CRITICAL;
449 	else
450 		return -EINVAL;
451 
452 	return 0;
453 }
454 
455 static int acerhdf_get_trip_hyst(struct thermal_zone_device *thermal, int trip,
456 				 int *temp)
457 {
458 	if (trip != 0)
459 		return -EINVAL;
460 
461 	*temp = fanon - fanoff;
462 
463 	return 0;
464 }
465 
466 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
467 				 int *temp)
468 {
469 	if (trip == 0)
470 		*temp = fanon;
471 	else if (trip == 1)
472 		*temp = ACERHDF_TEMP_CRIT;
473 	else
474 		return -EINVAL;
475 
476 	return 0;
477 }
478 
479 static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
480 				 int *temperature)
481 {
482 	*temperature = ACERHDF_TEMP_CRIT;
483 	return 0;
484 }
485 
486 /* bind callback functions to thermalzone */
487 static struct thermal_zone_device_ops acerhdf_dev_ops = {
488 	.bind = acerhdf_bind,
489 	.unbind = acerhdf_unbind,
490 	.get_temp = acerhdf_get_ec_temp,
491 	.get_mode = acerhdf_get_mode,
492 	.set_mode = acerhdf_set_mode,
493 	.get_trip_type = acerhdf_get_trip_type,
494 	.get_trip_hyst = acerhdf_get_trip_hyst,
495 	.get_trip_temp = acerhdf_get_trip_temp,
496 	.get_crit_temp = acerhdf_get_crit_temp,
497 };
498 
499 
500 /*
501  * cooling device callback functions
502  * get maximal fan cooling state
503  */
504 static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
505 				 unsigned long *state)
506 {
507 	*state = 1;
508 
509 	return 0;
510 }
511 
512 static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
513 				 unsigned long *state)
514 {
515 	int err = 0, tmp;
516 
517 	err = acerhdf_get_fanstate(&tmp);
518 	if (err)
519 		return err;
520 
521 	*state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
522 	return 0;
523 }
524 
525 /* change current fan state - is overwritten when running in kernel mode */
526 static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
527 				 unsigned long state)
528 {
529 	int cur_temp, cur_state, err = 0;
530 
531 	if (!kernelmode)
532 		return 0;
533 
534 	err = acerhdf_get_temp(&cur_temp);
535 	if (err) {
536 		pr_err("error reading temperature, hand off control to BIOS\n");
537 		goto err_out;
538 	}
539 
540 	err = acerhdf_get_fanstate(&cur_state);
541 	if (err) {
542 		pr_err("error reading fan state, hand off control to BIOS\n");
543 		goto err_out;
544 	}
545 
546 	if (state == 0) {
547 		if (cur_state == ACERHDF_FAN_AUTO)
548 			acerhdf_change_fanstate(ACERHDF_FAN_OFF);
549 	} else {
550 		if (cur_state == ACERHDF_FAN_OFF)
551 			acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
552 	}
553 	return 0;
554 
555 err_out:
556 	acerhdf_revert_to_bios_mode();
557 	return -EINVAL;
558 }
559 
560 /* bind fan callbacks to fan device */
561 static const struct thermal_cooling_device_ops acerhdf_cooling_ops = {
562 	.get_max_state = acerhdf_get_max_state,
563 	.get_cur_state = acerhdf_get_cur_state,
564 	.set_cur_state = acerhdf_set_cur_state,
565 };
566 
567 /* suspend / resume functionality */
568 static int acerhdf_suspend(struct device *dev)
569 {
570 	if (kernelmode)
571 		acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
572 
573 	if (verbose)
574 		pr_notice("going suspend\n");
575 
576 	return 0;
577 }
578 
579 static int acerhdf_probe(struct platform_device *device)
580 {
581 	return 0;
582 }
583 
584 static int acerhdf_remove(struct platform_device *device)
585 {
586 	return 0;
587 }
588 
589 static const struct dev_pm_ops acerhdf_pm_ops = {
590 	.suspend = acerhdf_suspend,
591 	.freeze  = acerhdf_suspend,
592 };
593 
594 static struct platform_driver acerhdf_driver = {
595 	.driver = {
596 		.name  = "acerhdf",
597 		.pm    = &acerhdf_pm_ops,
598 	},
599 	.probe = acerhdf_probe,
600 	.remove = acerhdf_remove,
601 };
602 
603 /* checks if str begins with start */
604 static int str_starts_with(const char *str, const char *start)
605 {
606 	unsigned long str_len = 0, start_len = 0;
607 
608 	str_len = strlen(str);
609 	start_len = strlen(start);
610 
611 	if (str_len >= start_len &&
612 			!strncmp(str, start, start_len))
613 		return 1;
614 
615 	return 0;
616 }
617 
618 /* check hardware */
619 static int __init acerhdf_check_hardware(void)
620 {
621 	char const *vendor, *version, *product;
622 	const struct bios_settings *bt = NULL;
623 	int found = 0;
624 
625 	/* get BIOS data */
626 	vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
627 	version = dmi_get_system_info(DMI_BIOS_VERSION);
628 	product = dmi_get_system_info(DMI_PRODUCT_NAME);
629 
630 	if (!vendor || !version || !product) {
631 		pr_err("error getting hardware information\n");
632 		return -EINVAL;
633 	}
634 
635 	pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);
636 
637 	if (list_supported) {
638 		pr_info("List of supported Manufacturer/Model/BIOS:\n");
639 		pr_info("---------------------------------------------------\n");
640 		for (bt = bios_tbl; bt->vendor[0]; bt++) {
641 			pr_info("%-13s | %-17s | %-10s\n", bt->vendor,
642 				bt->product, bt->version);
643 		}
644 		pr_info("---------------------------------------------------\n");
645 		return -ECANCELED;
646 	}
647 
648 	if (force_bios[0]) {
649 		version = force_bios;
650 		pr_info("forcing BIOS version: %s\n", version);
651 		kernelmode = 0;
652 	}
653 
654 	if (force_product[0]) {
655 		product = force_product;
656 		pr_info("forcing BIOS product: %s\n", product);
657 		kernelmode = 0;
658 	}
659 
660 	if (verbose)
661 		pr_info("BIOS info: %s %s, product: %s\n",
662 			vendor, version, product);
663 
664 	/* search BIOS version and vendor in BIOS settings table */
665 	for (bt = bios_tbl; bt->vendor[0]; bt++) {
666 		/*
667 		 * check if actual hardware BIOS vendor, product and version
668 		 * IDs start with the strings of BIOS table entry
669 		 */
670 		if (str_starts_with(vendor, bt->vendor) &&
671 				str_starts_with(product, bt->product) &&
672 				str_starts_with(version, bt->version)) {
673 			found = 1;
674 			break;
675 		}
676 	}
677 
678 	if (!found) {
679 		pr_err("unknown (unsupported) BIOS version %s/%s/%s, please report, aborting!\n",
680 		       vendor, product, version);
681 		return -EINVAL;
682 	}
683 
684 	/* Copy control settings from BIOS table before we free it. */
685 	ctrl_cfg.fanreg = bt->fanreg;
686 	ctrl_cfg.tempreg = bt->tempreg;
687 	memcpy(&ctrl_cfg.cmd, &bt->cmd, sizeof(struct fancmd));
688 	ctrl_cfg.mcmd_enable = bt->mcmd_enable;
689 
690 	/*
691 	 * if started with kernel mode off, prevent the kernel from switching
692 	 * off the fan
693 	 */
694 	if (!kernelmode) {
695 		pr_notice("Fan control off, to enable do:\n");
696 		pr_notice("echo -n \"enabled\" > /sys/class/thermal/thermal_zoneN/mode # N=0,1,2...\n");
697 	}
698 
699 	return 0;
700 }
701 
702 static int __init acerhdf_register_platform(void)
703 {
704 	int err = 0;
705 
706 	err = platform_driver_register(&acerhdf_driver);
707 	if (err)
708 		return err;
709 
710 	acerhdf_dev = platform_device_alloc("acerhdf", -1);
711 	if (!acerhdf_dev) {
712 		err = -ENOMEM;
713 		goto err_device_alloc;
714 	}
715 	err = platform_device_add(acerhdf_dev);
716 	if (err)
717 		goto err_device_add;
718 
719 	return 0;
720 
721 err_device_add:
722 	platform_device_put(acerhdf_dev);
723 err_device_alloc:
724 	platform_driver_unregister(&acerhdf_driver);
725 	return err;
726 }
727 
728 static void acerhdf_unregister_platform(void)
729 {
730 	platform_device_unregister(acerhdf_dev);
731 	platform_driver_unregister(&acerhdf_driver);
732 }
733 
734 static int __init acerhdf_register_thermal(void)
735 {
736 	cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
737 						 &acerhdf_cooling_ops);
738 
739 	if (IS_ERR(cl_dev))
740 		return -EINVAL;
741 
742 	thz_dev = thermal_zone_device_register("acerhdf", 2, 0, NULL,
743 					      &acerhdf_dev_ops,
744 					      &acerhdf_zone_params, 0,
745 					      (kernelmode) ? interval*1000 : 0);
746 	if (IS_ERR(thz_dev))
747 		return -EINVAL;
748 
749 	if (strcmp(thz_dev->governor->name,
750 				acerhdf_zone_params.governor_name)) {
751 		pr_err("Didn't get thermal governor %s, perhaps not compiled into thermal subsystem.\n",
752 				acerhdf_zone_params.governor_name);
753 		return -EINVAL;
754 	}
755 
756 	return 0;
757 }
758 
759 static void acerhdf_unregister_thermal(void)
760 {
761 	if (cl_dev) {
762 		thermal_cooling_device_unregister(cl_dev);
763 		cl_dev = NULL;
764 	}
765 
766 	if (thz_dev) {
767 		thermal_zone_device_unregister(thz_dev);
768 		thz_dev = NULL;
769 	}
770 }
771 
772 static int __init acerhdf_init(void)
773 {
774 	int err = 0;
775 
776 	err = acerhdf_check_hardware();
777 	if (err)
778 		goto out_err;
779 
780 	err = acerhdf_register_platform();
781 	if (err)
782 		goto out_err;
783 
784 	err = acerhdf_register_thermal();
785 	if (err)
786 		goto err_unreg;
787 
788 	return 0;
789 
790 err_unreg:
791 	acerhdf_unregister_thermal();
792 	acerhdf_unregister_platform();
793 
794 out_err:
795 	return err;
796 }
797 
798 static void __exit acerhdf_exit(void)
799 {
800 	acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
801 	acerhdf_unregister_thermal();
802 	acerhdf_unregister_platform();
803 }
804 
805 MODULE_LICENSE("GPL");
806 MODULE_AUTHOR("Peter Kaestle");
807 MODULE_DESCRIPTION("Aspire One temperature and fan driver");
808 MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
809 MODULE_ALIAS("dmi:*:*Acer*:pnAO751h*:");
810 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1410*:");
811 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1810*:");
812 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5755G:");
813 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1825PTZ:");
814 MODULE_ALIAS("dmi:*:*Acer*:pnAO521*:");
815 MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
816 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5739G:");
817 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*One*753:");
818 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*5315:");
819 MODULE_ALIAS("dmi:*:*Acer*:TravelMate*7730G:");
820 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*7551:");
821 MODULE_ALIAS("dmi:*:*Acer*:TM8573T:");
822 MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
823 MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
824 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnAOA*:");
825 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOA*:");
826 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMU*:");
827 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnENBFT*:");
828 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMA*:");
829 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTVR46*:");
830 MODULE_ALIAS("dmi:*:*Acer*:pnExtensa 5420*:");
831 
832 module_init(acerhdf_init);
833 module_exit(acerhdf_exit);
834