xref: /openbmc/linux/drivers/macintosh/windfarm.h (revision 9cfc5c90)
1 /*
2  * Windfarm PowerMac thermal control.
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5  *                    <benh@kernel.crashing.org>
6  *
7  * Released under the term of the GNU GPL v2.
8  */
9 
10 #ifndef __WINDFARM_H__
11 #define __WINDFARM_H__
12 
13 #include <linux/kref.h>
14 #include <linux/list.h>
15 #include <linux/module.h>
16 #include <linux/notifier.h>
17 #include <linux/device.h>
18 
19 /* Display a 16.16 fixed point value */
20 #define FIX32TOPRINT(f)	(((s32)(f)) >> 16),(((((s32)(f)) & 0xffff) * 1000) >> 16)
21 
22 /*
23  * Control objects
24  */
25 
26 struct wf_control;
27 
28 struct wf_control_ops {
29 	int			(*set_value)(struct wf_control *ct, s32 val);
30 	int			(*get_value)(struct wf_control *ct, s32 *val);
31 	s32			(*get_min)(struct wf_control *ct);
32 	s32			(*get_max)(struct wf_control *ct);
33 	void			(*release)(struct wf_control *ct);
34 	struct module		*owner;
35 };
36 
37 struct wf_control {
38 	struct list_head		link;
39 	const struct wf_control_ops	*ops;
40 	const char			*name;
41 	int				type;
42 	struct kref			ref;
43 	struct device_attribute		attr;
44 	void				*priv;
45 };
46 
47 #define WF_CONTROL_TYPE_GENERIC		0
48 #define WF_CONTROL_RPM_FAN		1
49 #define WF_CONTROL_PWM_FAN		2
50 
51 
52 /* Note about lifetime rules: wf_register_control() will initialize
53  * the kref and wf_unregister_control will decrement it, thus the
54  * object creating/disposing a given control shouldn't assume it
55  * still exists after wf_unregister_control has been called.
56  */
57 extern int wf_register_control(struct wf_control *ct);
58 extern void wf_unregister_control(struct wf_control *ct);
59 extern int wf_get_control(struct wf_control *ct);
60 extern void wf_put_control(struct wf_control *ct);
61 
62 static inline int wf_control_set_max(struct wf_control *ct)
63 {
64 	s32 vmax = ct->ops->get_max(ct);
65 	return ct->ops->set_value(ct, vmax);
66 }
67 
68 static inline int wf_control_set_min(struct wf_control *ct)
69 {
70 	s32 vmin = ct->ops->get_min(ct);
71 	return ct->ops->set_value(ct, vmin);
72 }
73 
74 static inline int wf_control_set(struct wf_control *ct, s32 val)
75 {
76 	return ct->ops->set_value(ct, val);
77 }
78 
79 static inline int wf_control_get(struct wf_control *ct, s32 *val)
80 {
81 	return ct->ops->get_value(ct, val);
82 }
83 
84 static inline s32 wf_control_get_min(struct wf_control *ct)
85 {
86 	return ct->ops->get_min(ct);
87 }
88 
89 static inline s32 wf_control_get_max(struct wf_control *ct)
90 {
91 	return ct->ops->get_max(ct);
92 }
93 
94 /*
95  * Sensor objects
96  */
97 
98 struct wf_sensor;
99 
100 struct wf_sensor_ops {
101 	int			(*get_value)(struct wf_sensor *sr, s32 *val);
102 	void			(*release)(struct wf_sensor *sr);
103 	struct module		*owner;
104 };
105 
106 struct wf_sensor {
107 	struct list_head		link;
108 	const struct wf_sensor_ops	*ops;
109 	const char			*name;
110 	struct kref			ref;
111 	struct device_attribute		attr;
112 	void				*priv;
113 };
114 
115 /* Same lifetime rules as controls */
116 extern int wf_register_sensor(struct wf_sensor *sr);
117 extern void wf_unregister_sensor(struct wf_sensor *sr);
118 extern int wf_get_sensor(struct wf_sensor *sr);
119 extern void wf_put_sensor(struct wf_sensor *sr);
120 
121 static inline int wf_sensor_get(struct wf_sensor *sr, s32 *val)
122 {
123 	return sr->ops->get_value(sr, val);
124 }
125 
126 /* For use by clients. Note that we are a bit racy here since
127  * notifier_block doesn't have a module owner field. I may fix
128  * it one day ...
129  *
130  * LOCKING NOTE !
131  *
132  * All "events" except WF_EVENT_TICK are called with an internal mutex
133  * held which will deadlock if you call basically any core routine.
134  * So don't ! Just take note of the event and do your actual operations
135  * from the ticker.
136  *
137  */
138 extern int wf_register_client(struct notifier_block *nb);
139 extern int wf_unregister_client(struct notifier_block *nb);
140 
141 /* Overtemp conditions. Those are refcounted */
142 extern void wf_set_overtemp(void);
143 extern void wf_clear_overtemp(void);
144 
145 #define WF_EVENT_NEW_CONTROL	0 /* param is wf_control * */
146 #define WF_EVENT_NEW_SENSOR	1 /* param is wf_sensor * */
147 #define WF_EVENT_OVERTEMP	2 /* no param */
148 #define WF_EVENT_NORMALTEMP	3 /* overtemp condition cleared */
149 #define WF_EVENT_TICK		4 /* 1 second tick */
150 
151 /* Note: If that driver gets more broad use, we could replace the
152  * simplistic overtemp bits with "environmental conditions". That
153  * could then be used to also notify of things like fan failure,
154  * case open, battery conditions, ...
155  */
156 
157 #endif /* __WINDFARM_H__ */
158