1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Windfarm PowerMac thermal control.
4  *
5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *                    <benh@kernel.crashing.org>
7  */
8 
9 #ifndef __WINDFARM_H__
10 #define __WINDFARM_H__
11 
12 #include <linux/kref.h>
13 #include <linux/list.h>
14 #include <linux/module.h>
15 #include <linux/notifier.h>
16 #include <linux/device.h>
17 
18 /* Display a 16.16 fixed point value */
19 #define FIX32TOPRINT(f)	(((s32)(f)) >> 16),(((((s32)(f)) & 0xffff) * 1000) >> 16)
20 
21 /*
22  * Control objects
23  */
24 
25 struct wf_control;
26 
27 struct wf_control_ops {
28 	int			(*set_value)(struct wf_control *ct, s32 val);
29 	int			(*get_value)(struct wf_control *ct, s32 *val);
30 	s32			(*get_min)(struct wf_control *ct);
31 	s32			(*get_max)(struct wf_control *ct);
32 	void			(*release)(struct wf_control *ct);
33 	struct module		*owner;
34 };
35 
36 struct wf_control {
37 	struct list_head		link;
38 	const struct wf_control_ops	*ops;
39 	const char			*name;
40 	int				type;
41 	struct kref			ref;
42 	struct device_attribute		attr;
43 	void				*priv;
44 };
45 
46 #define WF_CONTROL_TYPE_GENERIC		0
47 #define WF_CONTROL_RPM_FAN		1
48 #define WF_CONTROL_PWM_FAN		2
49 
50 
51 /* Note about lifetime rules: wf_register_control() will initialize
52  * the kref and wf_unregister_control will decrement it, thus the
53  * object creating/disposing a given control shouldn't assume it
54  * still exists after wf_unregister_control has been called.
55  */
56 extern int wf_register_control(struct wf_control *ct);
57 extern void wf_unregister_control(struct wf_control *ct);
58 extern int wf_get_control(struct wf_control *ct);
59 extern void wf_put_control(struct wf_control *ct);
60 
wf_control_set_max(struct wf_control * ct)61 static inline int wf_control_set_max(struct wf_control *ct)
62 {
63 	s32 vmax = ct->ops->get_max(ct);
64 	return ct->ops->set_value(ct, vmax);
65 }
66 
wf_control_set_min(struct wf_control * ct)67 static inline int wf_control_set_min(struct wf_control *ct)
68 {
69 	s32 vmin = ct->ops->get_min(ct);
70 	return ct->ops->set_value(ct, vmin);
71 }
72 
wf_control_set(struct wf_control * ct,s32 val)73 static inline int wf_control_set(struct wf_control *ct, s32 val)
74 {
75 	return ct->ops->set_value(ct, val);
76 }
77 
wf_control_get(struct wf_control * ct,s32 * val)78 static inline int wf_control_get(struct wf_control *ct, s32 *val)
79 {
80 	return ct->ops->get_value(ct, val);
81 }
82 
wf_control_get_min(struct wf_control * ct)83 static inline s32 wf_control_get_min(struct wf_control *ct)
84 {
85 	return ct->ops->get_min(ct);
86 }
87 
wf_control_get_max(struct wf_control * ct)88 static inline s32 wf_control_get_max(struct wf_control *ct)
89 {
90 	return ct->ops->get_max(ct);
91 }
92 
93 /*
94  * Sensor objects
95  */
96 
97 struct wf_sensor;
98 
99 struct wf_sensor_ops {
100 	int			(*get_value)(struct wf_sensor *sr, s32 *val);
101 	void			(*release)(struct wf_sensor *sr);
102 	struct module		*owner;
103 };
104 
105 struct wf_sensor {
106 	struct list_head		link;
107 	const struct wf_sensor_ops	*ops;
108 	const char			*name;
109 	struct kref			ref;
110 	struct device_attribute		attr;
111 	void				*priv;
112 };
113 
114 /* Same lifetime rules as controls */
115 extern int wf_register_sensor(struct wf_sensor *sr);
116 extern void wf_unregister_sensor(struct wf_sensor *sr);
117 extern int wf_get_sensor(struct wf_sensor *sr);
118 extern void wf_put_sensor(struct wf_sensor *sr);
119 
wf_sensor_get(struct wf_sensor * sr,s32 * val)120 static inline int wf_sensor_get(struct wf_sensor *sr, s32 *val)
121 {
122 	return sr->ops->get_value(sr, val);
123 }
124 
125 /* For use by clients. Note that we are a bit racy here since
126  * notifier_block doesn't have a module owner field. I may fix
127  * it one day ...
128  *
129  * LOCKING NOTE !
130  *
131  * All "events" except WF_EVENT_TICK are called with an internal mutex
132  * held which will deadlock if you call basically any core routine.
133  * So don't ! Just take note of the event and do your actual operations
134  * from the ticker.
135  *
136  */
137 extern int wf_register_client(struct notifier_block *nb);
138 extern int wf_unregister_client(struct notifier_block *nb);
139 
140 /* Overtemp conditions. Those are refcounted */
141 extern void wf_set_overtemp(void);
142 extern void wf_clear_overtemp(void);
143 
144 #define WF_EVENT_NEW_CONTROL	0 /* param is wf_control * */
145 #define WF_EVENT_NEW_SENSOR	1 /* param is wf_sensor * */
146 #define WF_EVENT_OVERTEMP	2 /* no param */
147 #define WF_EVENT_NORMALTEMP	3 /* overtemp condition cleared */
148 #define WF_EVENT_TICK		4 /* 1 second tick */
149 
150 /* Note: If that driver gets more broad use, we could replace the
151  * simplistic overtemp bits with "environmental conditions". That
152  * could then be used to also notify of things like fan failure,
153  * case open, battery conditions, ...
154  */
155 
156 #endif /* __WINDFARM_H__ */
157