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pm_qos.h
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1 #ifndef _LINUX_PM_QOS_H
2 #define _LINUX_PM_QOS_H
3 /* interface for the pm_qos_power infrastructure of the linux kernel.
4  *
5  * Mark Gross <[email protected]>
6  */
7 #include <linux/plist.h>
8 #include <linux/notifier.h>
9 #include <linux/miscdevice.h>
10 #include <linux/device.h>
11 #include <linux/workqueue.h>
12 
13 enum {
14  PM_QOS_RESERVED = 0,
15  PM_QOS_CPU_DMA_LATENCY,
16  PM_QOS_NETWORK_LATENCY,
17  PM_QOS_NETWORK_THROUGHPUT,
18 
19  /* insert new class ID */
20  PM_QOS_NUM_CLASSES,
21 };
22 
23 #define PM_QOS_DEFAULT_VALUE -1
24 
25 #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
26 #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC)
27 #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
28 #define PM_QOS_DEV_LAT_DEFAULT_VALUE 0
29 
30 struct pm_qos_request {
31  struct plist_node node;
32  int pm_qos_class;
33  struct delayed_work work; /* for pm_qos_update_request_timeout */
34 };
35 
36 struct dev_pm_qos_request {
37  struct plist_node node;
38  struct device *dev;
39 };
40 
41 enum pm_qos_type {
42  PM_QOS_UNITIALIZED,
43  PM_QOS_MAX, /* return the largest value */
44  PM_QOS_MIN /* return the smallest value */
45 };
46 
47 /*
48  * Note: The lockless read path depends on the CPU accessing
49  * target_value atomically. Atomic access is only guaranteed on all CPU
50  * types linux supports for 32 bit quantites
51  */
52 struct pm_qos_constraints {
53  struct plist_head list;
54  s32 target_value; /* Do not change to 64 bit */
55  s32 default_value;
56  enum pm_qos_type type;
57  struct blocking_notifier_head *notifiers;
58 };
59 
60 /* Action requested to pm_qos_update_target */
61 enum pm_qos_req_action {
62  PM_QOS_ADD_REQ, /* Add a new request */
63  PM_QOS_UPDATE_REQ, /* Update an existing request */
64  PM_QOS_REMOVE_REQ /* Remove an existing request */
65 };
66 
67 static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
68 {
69  return req->dev != NULL;
70 }
71 
72 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
73  enum pm_qos_req_action action, int value);
74 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
75  s32 value);
76 void pm_qos_update_request(struct pm_qos_request *req,
77  s32 new_value);
78 void pm_qos_update_request_timeout(struct pm_qos_request *req,
79  s32 new_value, unsigned long timeout_us);
80 void pm_qos_remove_request(struct pm_qos_request *req);
81 
82 int pm_qos_request(int pm_qos_class);
83 int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
84 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
85 int pm_qos_request_active(struct pm_qos_request *req);
86 s32 pm_qos_read_value(struct pm_qos_constraints *c);
87 
88 #ifdef CONFIG_PM
89 s32 __dev_pm_qos_read_value(struct device *dev);
90 s32 dev_pm_qos_read_value(struct device *dev);
91 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
92  s32 value);
93 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
94 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
95 int dev_pm_qos_add_notifier(struct device *dev,
96  struct notifier_block *notifier);
97 int dev_pm_qos_remove_notifier(struct device *dev,
98  struct notifier_block *notifier);
99 int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
100 int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
101 void dev_pm_qos_constraints_init(struct device *dev);
102 void dev_pm_qos_constraints_destroy(struct device *dev);
103 int dev_pm_qos_add_ancestor_request(struct device *dev,
104  struct dev_pm_qos_request *req, s32 value);
105 #else
106 static inline s32 __dev_pm_qos_read_value(struct device *dev)
107  { return 0; }
108 static inline s32 dev_pm_qos_read_value(struct device *dev)
109  { return 0; }
110 static inline int dev_pm_qos_add_request(struct device *dev,
111  struct dev_pm_qos_request *req,
112  s32 value)
113  { return 0; }
114 static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
115  s32 new_value)
116  { return 0; }
117 static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
118  { return 0; }
119 static inline int dev_pm_qos_add_notifier(struct device *dev,
120  struct notifier_block *notifier)
121  { return 0; }
122 static inline int dev_pm_qos_remove_notifier(struct device *dev,
123  struct notifier_block *notifier)
124  { return 0; }
125 static inline int dev_pm_qos_add_global_notifier(
126  struct notifier_block *notifier)
127  { return 0; }
128 static inline int dev_pm_qos_remove_global_notifier(
129  struct notifier_block *notifier)
130  { return 0; }
131 static inline void dev_pm_qos_constraints_init(struct device *dev)
132 {
133  dev->power.power_state = PMSG_ON;
134 }
135 static inline void dev_pm_qos_constraints_destroy(struct device *dev)
136 {
137  dev->power.power_state = PMSG_INVALID;
138 }
139 static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
140  struct dev_pm_qos_request *req, s32 value)
141  { return 0; }
142 #endif
143 
144 #ifdef CONFIG_PM_RUNTIME
145 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
146 void dev_pm_qos_hide_latency_limit(struct device *dev);
147 #else
148 static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
149  { return 0; }
150 static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
151 #endif
152 
153 #endif
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