include/linux/pm_qos.h

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