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
25struct wf_control;
26
27struct 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
36struct 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 */
56extern int wf_register_control(struct wf_control *ct);
57extern void wf_unregister_control(struct wf_control *ct);
58extern int wf_get_control(struct wf_control *ct);
59extern void wf_put_control(struct wf_control *ct);
60
61static 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
67static 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
73static inline int wf_control_set(struct wf_control *ct, s32 val)
74{
75	return ct->ops->set_value(ct, val);
76}
77
78static inline int wf_control_get(struct wf_control *ct, s32 *val)
79{
80	return ct->ops->get_value(ct, val);
81}
82
83static inline s32 wf_control_get_min(struct wf_control *ct)
84{
85	return ct->ops->get_min(ct);
86}
87
88static 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
97struct wf_sensor;
98
99struct 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
105struct 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 */
115extern int wf_register_sensor(struct wf_sensor *sr);
116extern void wf_unregister_sensor(struct wf_sensor *sr);
117extern int wf_get_sensor(struct wf_sensor *sr);
118extern void wf_put_sensor(struct wf_sensor *sr);
119
120static 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 */
137extern int wf_register_client(struct notifier_block *nb);
138extern int wf_unregister_client(struct notifier_block *nb);
139
140/* Overtemp conditions. Those are refcounted */
141extern void wf_set_overtemp(void);
142extern 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