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 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 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 73 static inline int wf_control_set(struct wf_control *ct, s32 val) 74 { 75 return ct->ops->set_value(ct, val); 76 } 77 78 static inline int wf_control_get(struct wf_control *ct, s32 *val) 79 { 80 return ct->ops->get_value(ct, val); 81 } 82 83 static inline s32 wf_control_get_min(struct wf_control *ct) 84 { 85 return ct->ops->get_min(ct); 86 } 87 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); 119 120 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