1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * devfreq_cooling: Thermal cooling device implementation for devices using
4  *                  devfreq
5  *
6  * Copyright (C) 2014-2015 ARM Limited
7  *
8  */
9 
10 #ifndef __DEVFREQ_COOLING_H__
11 #define __DEVFREQ_COOLING_H__
12 
13 #include <linux/devfreq.h>
14 #include <linux/thermal.h>
15 
16 
17 /**
18  * struct devfreq_cooling_power - Devfreq cooling power ops
19  * @get_static_power:	Take voltage, in mV, and return the static power
20  *			in mW.  If NULL, the static power is assumed
21  *			to be 0.
22  * @get_dynamic_power:	Take voltage, in mV, and frequency, in HZ, and
23  *			return the dynamic power draw in mW.  If NULL,
24  *			a simple power model is used.
25  * @dyn_power_coeff:	Coefficient for the simple dynamic power model in
26  *			mW/(MHz mV mV).
27  *			If get_dynamic_power() is NULL, then the
28  *			dynamic power is calculated as
29  *			@dyn_power_coeff * frequency * voltage^2
30  * @get_real_power:	When this is set, the framework uses it to ask the
31  *			device driver for the actual power.
32  *			Some devices have more sophisticated methods
33  *			(like power counters) to approximate the actual power
34  *			that they use.
35  *			This function provides more accurate data to the
36  *			thermal governor. When the driver does not provide
37  *			such function, framework just uses pre-calculated
38  *			table and scale the power by 'utilization'
39  *			(based on 'busy_time' and 'total_time' taken from
40  *			devfreq 'last_status').
41  *			The value returned by this function must be lower
42  *			or equal than the maximum power value
43  *			for the current	state
44  *			(which can be found in power_table[state]).
45  *			When this interface is used, the power_table holds
46  *			max total (static + dynamic) power value for each OPP.
47  */
48 struct devfreq_cooling_power {
49 	unsigned long (*get_static_power)(struct devfreq *devfreq,
50 					  unsigned long voltage);
51 	unsigned long (*get_dynamic_power)(struct devfreq *devfreq,
52 					   unsigned long freq,
53 					   unsigned long voltage);
54 	int (*get_real_power)(struct devfreq *df, u32 *power,
55 			      unsigned long freq, unsigned long voltage);
56 	unsigned long dyn_power_coeff;
57 };
58 
59 #ifdef CONFIG_DEVFREQ_THERMAL
60 
61 struct thermal_cooling_device *
62 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
63 				  struct devfreq_cooling_power *dfc_power);
64 struct thermal_cooling_device *
65 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df);
66 struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df);
67 void devfreq_cooling_unregister(struct thermal_cooling_device *dfc);
68 struct thermal_cooling_device *
69 devfreq_cooling_em_register(struct devfreq *df,
70 			    struct devfreq_cooling_power *dfc_power);
71 
72 #else /* !CONFIG_DEVFREQ_THERMAL */
73 
74 static inline struct thermal_cooling_device *
75 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
76 				  struct devfreq_cooling_power *dfc_power)
77 {
78 	return ERR_PTR(-EINVAL);
79 }
80 
81 static inline struct thermal_cooling_device *
82 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
83 {
84 	return ERR_PTR(-EINVAL);
85 }
86 
87 static inline struct thermal_cooling_device *
88 devfreq_cooling_register(struct devfreq *df)
89 {
90 	return ERR_PTR(-EINVAL);
91 }
92 
93 static inline struct thermal_cooling_device *
94 devfreq_cooling_em_register(struct devfreq *df,
95 			    struct devfreq_cooling_power *dfc_power)
96 {
97 	return ERR_PTR(-EINVAL);
98 }
99 
100 static inline void
101 devfreq_cooling_unregister(struct thermal_cooling_device *dfc)
102 {
103 }
104 
105 #endif /* CONFIG_DEVFREQ_THERMAL */
106 #endif /* __DEVFREQ_COOLING_H__ */
107