xref: /linux-6.15/include/linux/thermal.h (revision caecb05c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  thermal.h  ($Revision: 0 $)
4  *
5  *  Copyright (C) 2008  Intel Corp
6  *  Copyright (C) 2008  Zhang Rui <[email protected]>
7  *  Copyright (C) 2008  Sujith Thomas <[email protected]>
8  */
9 
10 #ifndef __THERMAL_H__
11 #define __THERMAL_H__
12 
13 #include <linux/of.h>
14 #include <linux/idr.h>
15 #include <linux/device.h>
16 #include <linux/sysfs.h>
17 #include <linux/workqueue.h>
18 #include <uapi/linux/thermal.h>
19 
20 #define THERMAL_TRIPS_NONE	-1
21 #define THERMAL_MAX_TRIPS	12
22 
23 /* invalid cooling state */
24 #define THERMAL_CSTATE_INVALID -1UL
25 
26 /* No upper/lower limit requirement */
27 #define THERMAL_NO_LIMIT	((u32)~0)
28 
29 /* Default weight of a bound cooling device */
30 #define THERMAL_WEIGHT_DEFAULT 0
31 
32 /* use value, which < 0K, to indicate an invalid/uninitialized temperature */
33 #define THERMAL_TEMP_INVALID	-274000
34 
35 struct thermal_zone_device;
36 struct thermal_cooling_device;
37 struct thermal_instance;
38 struct thermal_attr;
39 
40 enum thermal_device_mode {
41 	THERMAL_DEVICE_DISABLED = 0,
42 	THERMAL_DEVICE_ENABLED,
43 };
44 
45 enum thermal_trip_type {
46 	THERMAL_TRIP_ACTIVE = 0,
47 	THERMAL_TRIP_PASSIVE,
48 	THERMAL_TRIP_HOT,
49 	THERMAL_TRIP_CRITICAL,
50 };
51 
52 enum thermal_trend {
53 	THERMAL_TREND_STABLE, /* temperature is stable */
54 	THERMAL_TREND_RAISING, /* temperature is raising */
55 	THERMAL_TREND_DROPPING, /* temperature is dropping */
56 	THERMAL_TREND_RAISE_FULL, /* apply highest cooling action */
57 	THERMAL_TREND_DROP_FULL, /* apply lowest cooling action */
58 };
59 
60 /* Thermal notification reason */
61 enum thermal_notify_event {
62 	THERMAL_EVENT_UNSPECIFIED, /* Unspecified event */
63 	THERMAL_EVENT_TEMP_SAMPLE, /* New Temperature sample */
64 	THERMAL_TRIP_VIOLATED, /* TRIP Point violation */
65 	THERMAL_TRIP_CHANGED, /* TRIP Point temperature changed */
66 	THERMAL_DEVICE_DOWN, /* Thermal device is down */
67 	THERMAL_DEVICE_UP, /* Thermal device is up after a down event */
68 	THERMAL_DEVICE_POWER_CAPABILITY_CHANGED, /* power capability changed */
69 	THERMAL_TABLE_CHANGED, /* Thermal table(s) changed */
70 };
71 
72 struct thermal_zone_device_ops {
73 	int (*bind) (struct thermal_zone_device *,
74 		     struct thermal_cooling_device *);
75 	int (*unbind) (struct thermal_zone_device *,
76 		       struct thermal_cooling_device *);
77 	int (*get_temp) (struct thermal_zone_device *, int *);
78 	int (*set_trips) (struct thermal_zone_device *, int, int);
79 	int (*get_mode) (struct thermal_zone_device *,
80 			 enum thermal_device_mode *);
81 	int (*set_mode) (struct thermal_zone_device *,
82 		enum thermal_device_mode);
83 	int (*get_trip_type) (struct thermal_zone_device *, int,
84 		enum thermal_trip_type *);
85 	int (*get_trip_temp) (struct thermal_zone_device *, int, int *);
86 	int (*set_trip_temp) (struct thermal_zone_device *, int, int);
87 	int (*get_trip_hyst) (struct thermal_zone_device *, int, int *);
88 	int (*set_trip_hyst) (struct thermal_zone_device *, int, int);
89 	int (*get_crit_temp) (struct thermal_zone_device *, int *);
90 	int (*set_emul_temp) (struct thermal_zone_device *, int);
91 	int (*get_trend) (struct thermal_zone_device *, int,
92 			  enum thermal_trend *);
93 	int (*notify) (struct thermal_zone_device *, int,
94 		       enum thermal_trip_type);
95 };
96 
97 struct thermal_cooling_device_ops {
98 	int (*get_max_state) (struct thermal_cooling_device *, unsigned long *);
99 	int (*get_cur_state) (struct thermal_cooling_device *, unsigned long *);
100 	int (*set_cur_state) (struct thermal_cooling_device *, unsigned long);
101 	int (*get_requested_power)(struct thermal_cooling_device *,
102 				   struct thermal_zone_device *, u32 *);
103 	int (*state2power)(struct thermal_cooling_device *,
104 			   struct thermal_zone_device *, unsigned long, u32 *);
105 	int (*power2state)(struct thermal_cooling_device *,
106 			   struct thermal_zone_device *, u32, unsigned long *);
107 };
108 
109 struct thermal_cooling_device {
110 	int id;
111 	char type[THERMAL_NAME_LENGTH];
112 	struct device device;
113 	struct device_node *np;
114 	void *devdata;
115 	void *stats;
116 	const struct thermal_cooling_device_ops *ops;
117 	bool updated; /* true if the cooling device does not need update */
118 	struct mutex lock; /* protect thermal_instances list */
119 	struct list_head thermal_instances;
120 	struct list_head node;
121 };
122 
123 /**
124  * struct thermal_zone_device - structure for a thermal zone
125  * @id:		unique id number for each thermal zone
126  * @type:	the thermal zone device type
127  * @device:	&struct device for this thermal zone
128  * @trip_temp_attrs:	attributes for trip points for sysfs: trip temperature
129  * @trip_type_attrs:	attributes for trip points for sysfs: trip type
130  * @trip_hyst_attrs:	attributes for trip points for sysfs: trip hysteresis
131  * @devdata:	private pointer for device private data
132  * @trips:	number of trip points the thermal zone supports
133  * @trips_disabled;	bitmap for disabled trips
134  * @passive_delay:	number of milliseconds to wait between polls when
135  *			performing passive cooling.
136  * @polling_delay:	number of milliseconds to wait between polls when
137  *			checking whether trip points have been crossed (0 for
138  *			interrupt driven systems)
139  * @temperature:	current temperature.  This is only for core code,
140  *			drivers should use thermal_zone_get_temp() to get the
141  *			current temperature
142  * @last_temperature:	previous temperature read
143  * @emul_temperature:	emulated temperature when using CONFIG_THERMAL_EMULATION
144  * @passive:		1 if you've crossed a passive trip point, 0 otherwise.
145  * @prev_low_trip:	the low current temperature if you've crossed a passive
146 			trip point.
147  * @prev_high_trip:	the above current temperature if you've crossed a
148 			passive trip point.
149  * @forced_passive:	If > 0, temperature at which to switch on all ACPI
150  *			processor cooling devices.  Currently only used by the
151  *			step-wise governor.
152  * @need_update:	if equals 1, thermal_zone_device_update needs to be invoked.
153  * @ops:	operations this &thermal_zone_device supports
154  * @tzp:	thermal zone parameters
155  * @governor:	pointer to the governor for this thermal zone
156  * @governor_data:	private pointer for governor data
157  * @thermal_instances:	list of &struct thermal_instance of this thermal zone
158  * @ida:	&struct ida to generate unique id for this zone's cooling
159  *		devices
160  * @lock:	lock to protect thermal_instances list
161  * @node:	node in thermal_tz_list (in thermal_core.c)
162  * @poll_queue:	delayed work for polling
163  * @notify_event: Last notification event
164  */
165 struct thermal_zone_device {
166 	int id;
167 	char type[THERMAL_NAME_LENGTH];
168 	struct device device;
169 	struct attribute_group trips_attribute_group;
170 	struct thermal_attr *trip_temp_attrs;
171 	struct thermal_attr *trip_type_attrs;
172 	struct thermal_attr *trip_hyst_attrs;
173 	void *devdata;
174 	int trips;
175 	unsigned long trips_disabled;	/* bitmap for disabled trips */
176 	int passive_delay;
177 	int polling_delay;
178 	int temperature;
179 	int last_temperature;
180 	int emul_temperature;
181 	int passive;
182 	int prev_low_trip;
183 	int prev_high_trip;
184 	unsigned int forced_passive;
185 	atomic_t need_update;
186 	struct thermal_zone_device_ops *ops;
187 	struct thermal_zone_params *tzp;
188 	struct thermal_governor *governor;
189 	void *governor_data;
190 	struct list_head thermal_instances;
191 	struct ida ida;
192 	struct mutex lock;
193 	struct list_head node;
194 	struct delayed_work poll_queue;
195 	enum thermal_notify_event notify_event;
196 };
197 
198 /**
199  * struct thermal_governor - structure that holds thermal governor information
200  * @name:	name of the governor
201  * @bind_to_tz: callback called when binding to a thermal zone.  If it
202  *		returns 0, the governor is bound to the thermal zone,
203  *		otherwise it fails.
204  * @unbind_from_tz:	callback called when a governor is unbound from a
205  *			thermal zone.
206  * @throttle:	callback called for every trip point even if temperature is
207  *		below the trip point temperature
208  * @governor_list:	node in thermal_governor_list (in thermal_core.c)
209  */
210 struct thermal_governor {
211 	char name[THERMAL_NAME_LENGTH];
212 	int (*bind_to_tz)(struct thermal_zone_device *tz);
213 	void (*unbind_from_tz)(struct thermal_zone_device *tz);
214 	int (*throttle)(struct thermal_zone_device *tz, int trip);
215 	struct list_head	governor_list;
216 };
217 
218 /* Structure that holds binding parameters for a zone */
219 struct thermal_bind_params {
220 	struct thermal_cooling_device *cdev;
221 
222 	/*
223 	 * This is a measure of 'how effectively these devices can
224 	 * cool 'this' thermal zone. It shall be determined by
225 	 * platform characterization. This value is relative to the
226 	 * rest of the weights so a cooling device whose weight is
227 	 * double that of another cooling device is twice as
228 	 * effective. See Documentation/driver-api/thermal/sysfs-api.rst for more
229 	 * information.
230 	 */
231 	int weight;
232 
233 	/*
234 	 * This is a bit mask that gives the binding relation between this
235 	 * thermal zone and cdev, for a particular trip point.
236 	 * See Documentation/driver-api/thermal/sysfs-api.rst for more information.
237 	 */
238 	int trip_mask;
239 
240 	/*
241 	 * This is an array of cooling state limits. Must have exactly
242 	 * 2 * thermal_zone.number_of_trip_points. It is an array consisting
243 	 * of tuples <lower-state upper-state> of state limits. Each trip
244 	 * will be associated with one state limit tuple when binding.
245 	 * A NULL pointer means <THERMAL_NO_LIMITS THERMAL_NO_LIMITS>
246 	 * on all trips.
247 	 */
248 	unsigned long *binding_limits;
249 	int (*match) (struct thermal_zone_device *tz,
250 			struct thermal_cooling_device *cdev);
251 };
252 
253 /* Structure to define Thermal Zone parameters */
254 struct thermal_zone_params {
255 	char governor_name[THERMAL_NAME_LENGTH];
256 
257 	/*
258 	 * a boolean to indicate if the thermal to hwmon sysfs interface
259 	 * is required. when no_hwmon == false, a hwmon sysfs interface
260 	 * will be created. when no_hwmon == true, nothing will be done
261 	 */
262 	bool no_hwmon;
263 
264 	int num_tbps;	/* Number of tbp entries */
265 	struct thermal_bind_params *tbp;
266 
267 	/*
268 	 * Sustainable power (heat) that this thermal zone can dissipate in
269 	 * mW
270 	 */
271 	u32 sustainable_power;
272 
273 	/*
274 	 * Proportional parameter of the PID controller when
275 	 * overshooting (i.e., when temperature is below the target)
276 	 */
277 	s32 k_po;
278 
279 	/*
280 	 * Proportional parameter of the PID controller when
281 	 * undershooting
282 	 */
283 	s32 k_pu;
284 
285 	/* Integral parameter of the PID controller */
286 	s32 k_i;
287 
288 	/* Derivative parameter of the PID controller */
289 	s32 k_d;
290 
291 	/* threshold below which the error is no longer accumulated */
292 	s32 integral_cutoff;
293 
294 	/*
295 	 * @slope:	slope of a linear temperature adjustment curve.
296 	 * 		Used by thermal zone drivers.
297 	 */
298 	int slope;
299 	/*
300 	 * @offset:	offset of a linear temperature adjustment curve.
301 	 * 		Used by thermal zone drivers (default 0).
302 	 */
303 	int offset;
304 };
305 
306 struct thermal_genl_event {
307 	u32 orig;
308 	enum events event;
309 };
310 
311 /**
312  * struct thermal_zone_of_device_ops - scallbacks for handling DT based zones
313  *
314  * Mandatory:
315  * @get_temp: a pointer to a function that reads the sensor temperature.
316  *
317  * Optional:
318  * @get_trend: a pointer to a function that reads the sensor temperature trend.
319  * @set_trips: a pointer to a function that sets a temperature window. When
320  *	       this window is left the driver must inform the thermal core via
321  *	       thermal_zone_device_update.
322  * @set_emul_temp: a pointer to a function that sets sensor emulated
323  *		   temperature.
324  * @set_trip_temp: a pointer to a function that sets the trip temperature on
325  *		   hardware.
326  */
327 struct thermal_zone_of_device_ops {
328 	int (*get_temp)(void *, int *);
329 	int (*get_trend)(void *, int, enum thermal_trend *);
330 	int (*set_trips)(void *, int, int);
331 	int (*set_emul_temp)(void *, int);
332 	int (*set_trip_temp)(void *, int, int);
333 };
334 
335 /* Function declarations */
336 #ifdef CONFIG_THERMAL_OF
337 int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
338 				  struct device_node *sensor_np,
339 				  u32 *id);
340 struct thermal_zone_device *
341 thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
342 				const struct thermal_zone_of_device_ops *ops);
343 void thermal_zone_of_sensor_unregister(struct device *dev,
344 				       struct thermal_zone_device *tz);
345 struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
346 		struct device *dev, int id, void *data,
347 		const struct thermal_zone_of_device_ops *ops);
348 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
349 					    struct thermal_zone_device *tz);
350 #else
351 
352 static inline int thermal_zone_of_get_sensor_id(struct device_node *tz_np,
353 					 struct device_node *sensor_np,
354 					 u32 *id)
355 {
356 	return -ENOENT;
357 }
358 static inline struct thermal_zone_device *
359 thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
360 				const struct thermal_zone_of_device_ops *ops)
361 {
362 	return ERR_PTR(-ENODEV);
363 }
364 
365 static inline
366 void thermal_zone_of_sensor_unregister(struct device *dev,
367 				       struct thermal_zone_device *tz)
368 {
369 }
370 
371 static inline struct thermal_zone_device *devm_thermal_zone_of_sensor_register(
372 		struct device *dev, int id, void *data,
373 		const struct thermal_zone_of_device_ops *ops)
374 {
375 	return ERR_PTR(-ENODEV);
376 }
377 
378 static inline
379 void devm_thermal_zone_of_sensor_unregister(struct device *dev,
380 					    struct thermal_zone_device *tz)
381 {
382 }
383 
384 #endif
385 
386 #ifdef CONFIG_THERMAL
387 struct thermal_zone_device *thermal_zone_device_register(const char *, int, int,
388 		void *, struct thermal_zone_device_ops *,
389 		struct thermal_zone_params *, int, int);
390 void thermal_zone_device_unregister(struct thermal_zone_device *);
391 
392 int thermal_zone_bind_cooling_device(struct thermal_zone_device *, int,
393 				     struct thermal_cooling_device *,
394 				     unsigned long, unsigned long,
395 				     unsigned int);
396 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, int,
397 				       struct thermal_cooling_device *);
398 void thermal_zone_device_update(struct thermal_zone_device *,
399 				enum thermal_notify_event);
400 
401 struct thermal_cooling_device *thermal_cooling_device_register(const char *,
402 		void *, const struct thermal_cooling_device_ops *);
403 struct thermal_cooling_device *
404 thermal_of_cooling_device_register(struct device_node *np, const char *, void *,
405 				   const struct thermal_cooling_device_ops *);
406 struct thermal_cooling_device *
407 devm_thermal_of_cooling_device_register(struct device *dev,
408 				struct device_node *np,
409 				char *type, void *devdata,
410 				const struct thermal_cooling_device_ops *ops);
411 void thermal_cooling_device_unregister(struct thermal_cooling_device *);
412 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name);
413 int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp);
414 int thermal_zone_get_slope(struct thermal_zone_device *tz);
415 int thermal_zone_get_offset(struct thermal_zone_device *tz);
416 
417 void thermal_cdev_update(struct thermal_cooling_device *);
418 void thermal_notify_framework(struct thermal_zone_device *, int);
419 #else
420 static inline struct thermal_zone_device *thermal_zone_device_register(
421 	const char *type, int trips, int mask, void *devdata,
422 	struct thermal_zone_device_ops *ops,
423 	struct thermal_zone_params *tzp,
424 	int passive_delay, int polling_delay)
425 { return ERR_PTR(-ENODEV); }
426 static inline void thermal_zone_device_unregister(
427 	struct thermal_zone_device *tz)
428 { }
429 static inline struct thermal_cooling_device *
430 thermal_cooling_device_register(char *type, void *devdata,
431 	const struct thermal_cooling_device_ops *ops)
432 { return ERR_PTR(-ENODEV); }
433 static inline struct thermal_cooling_device *
434 thermal_of_cooling_device_register(struct device_node *np,
435 	char *type, void *devdata, const struct thermal_cooling_device_ops *ops)
436 { return ERR_PTR(-ENODEV); }
437 static inline struct thermal_cooling_device *
438 devm_thermal_of_cooling_device_register(struct device *dev,
439 				struct device_node *np,
440 				char *type, void *devdata,
441 				const struct thermal_cooling_device_ops *ops)
442 {
443 	return ERR_PTR(-ENODEV);
444 }
445 static inline void thermal_cooling_device_unregister(
446 	struct thermal_cooling_device *cdev)
447 { }
448 static inline struct thermal_zone_device *thermal_zone_get_zone_by_name(
449 		const char *name)
450 { return ERR_PTR(-ENODEV); }
451 static inline int thermal_zone_get_temp(
452 		struct thermal_zone_device *tz, int *temp)
453 { return -ENODEV; }
454 static inline int thermal_zone_get_slope(
455 		struct thermal_zone_device *tz)
456 { return -ENODEV; }
457 static inline int thermal_zone_get_offset(
458 		struct thermal_zone_device *tz)
459 { return -ENODEV; }
460 
461 static inline void thermal_cdev_update(struct thermal_cooling_device *cdev)
462 { }
463 static inline void thermal_notify_framework(struct thermal_zone_device *tz,
464 	int trip)
465 { }
466 #endif /* CONFIG_THERMAL */
467 
468 #endif /* __THERMAL_H__ */
469