1 /*
2 * devfreq_cooling: Thermal cooling device implementation for devices using
3 * devfreq
4 *
5 * Copyright (C) 2014-2015 ARM Limited
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
12 * kind, whether express or implied; without even the implied warranty
13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17 #ifndef __DEVFREQ_COOLING_H__
18 #define __DEVFREQ_COOLING_H__
19
20 #include <linux/devfreq.h>
21 #include <linux/thermal.h>
22
23
24 /**
25 * struct devfreq_cooling_power - Devfreq cooling power ops
26 * @get_static_power: Take voltage, in mV, and return the static power
27 * in mW. If NULL, the static power is assumed
28 * to be 0.
29 * @get_dynamic_power: Take voltage, in mV, and frequency, in HZ, and
30 * return the dynamic power draw in mW. If NULL,
31 * a simple power model is used.
32 * @dyn_power_coeff: Coefficient for the simple dynamic power model in
33 * mW/(MHz mV mV).
34 * If get_dynamic_power() is NULL, then the
35 * dynamic power is calculated as
36 * @dyn_power_coeff * frequency * voltage^2
37 * @get_real_power: When this is set, the framework uses it to ask the
38 * device driver for the actual power.
39 * Some devices have more sophisticated methods
40 * (like power counters) to approximate the actual power
41 * that they use.
42 * This function provides more accurate data to the
43 * thermal governor. When the driver does not provide
44 * such function, framework just uses pre-calculated
45 * table and scale the power by 'utilization'
46 * (based on 'busy_time' and 'total_time' taken from
47 * devfreq 'last_status').
48 * The value returned by this function must be lower
49 * or equal than the maximum power value
50 * for the current state
51 * (which can be found in power_table[state]).
52 * When this interface is used, the power_table holds
53 * max total (static + dynamic) power value for each OPP.
54 */
55 struct devfreq_cooling_power {
56 unsigned long (*get_static_power)(struct devfreq *devfreq,
57 unsigned long voltage);
58 unsigned long (*get_dynamic_power)(struct devfreq *devfreq,
59 unsigned long freq,
60 unsigned long voltage);
61 int (*get_real_power)(struct devfreq *df, u32 *power,
62 unsigned long freq, unsigned long voltage);
63 unsigned long dyn_power_coeff;
64 };
65
66 #ifdef CONFIG_DEVFREQ_THERMAL
67
68 struct thermal_cooling_device *
69 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
70 struct devfreq_cooling_power *dfc_power);
71 struct thermal_cooling_device *
72 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df);
73 struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df);
74 void devfreq_cooling_unregister(struct thermal_cooling_device *dfc);
75
76 #else /* !CONFIG_DEVFREQ_THERMAL */
77
78 static inline struct thermal_cooling_device *
79 of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
80 struct devfreq_cooling_power *dfc_power)
81 {
82 return ERR_PTR(-EINVAL);
83 }
84
85 static inline struct thermal_cooling_device *
86 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
87 {
88 return ERR_PTR(-EINVAL);
89 }
90
91 static inline struct thermal_cooling_device *
92 devfreq_cooling_register(struct devfreq *df)
93 {
94 return ERR_PTR(-EINVAL);
95 }
96
97 static inline void
98 devfreq_cooling_unregister(struct thermal_cooling_device *dfc)
99 {
100 }
101
102 #endif /* CONFIG_DEVFREQ_THERMAL */
103 #endif /* __DEVFREQ_COOLING_H__ */