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 #include <linux/device.h>
  11
  12 #define PM_QOS_RESERVED 0
  13 #define PM_QOS_CPU_DMA_LATENCY 1
  14 #define PM_QOS_NETWORK_LATENCY 2
  15 #define PM_QOS_NETWORK_THROUGHPUT 3
  16
  17 #define PM_QOS_NUM_CLASSES 4
  18 #define PM_QOS_DEFAULT_VALUE -1
  19
  20 #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE        (2000 * USEC_PER_SEC)
  21 #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE        (2000 * USEC_PER_SEC)
  22 #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0
  23 #define PM_QOS_DEV_LAT_DEFAULT_VALUE            0
  24
  25 struct pm_qos_request {
  26         struct plist_node node;
  27         int pm_qos_class;
  28 };
  29
  30 struct dev_pm_qos_request {
  31         struct plist_node node;
  32         struct device *dev;
  33 };
  34
  35 enum pm_qos_type {
  36         PM_QOS_UNITIALIZED,
  37         PM_QOS_MAX,             /* return the largest value */
  38         PM_QOS_MIN              /* return the smallest value */
  39 };
  40
  41 /*
  42  * Note: The lockless read path depends on the CPU accessing
  43  * target_value atomically.  Atomic access is only guaranteed on all CPU
  44  * types linux supports for 32 bit quantites
  45  */
  46 struct pm_qos_constraints {
  47         struct plist_head list;
  48         s32 target_value;       /* Do not change to 64 bit */
  49         s32 default_value;
  50         enum pm_qos_type type;
  51         struct blocking_notifier_head *notifiers;
  52 };
  53
  54 /* Action requested to pm_qos_update_target */
  55 enum pm_qos_req_action {
  56         PM_QOS_ADD_REQ,         /* Add a new request */
  57         PM_QOS_UPDATE_REQ,      /* Update an existing request */
  58         PM_QOS_REMOVE_REQ       /* Remove an existing request */
  59 };
  60
  61 static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
  62 {
  63         return req->dev != 0;
  64 }
  65
  66 #ifdef CONFIG_PM
  67 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
  68                          enum pm_qos_req_action action, int value);
  69 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
  70                         s32 value);
  71 void pm_qos_update_request(struct pm_qos_request *req,
  72                            s32 new_value);
  73 void pm_qos_remove_request(struct pm_qos_request *req);
  74
  75 int pm_qos_request(int pm_qos_class);
  76 int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
  77 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
  78 int pm_qos_request_active(struct pm_qos_request *req);
  79 s32 pm_qos_read_value(struct pm_qos_constraints *c);
  80
  81 s32 __dev_pm_qos_read_value(struct device *dev);
  82 s32 dev_pm_qos_read_value(struct device *dev);
  83 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
  84                            s32 value);
  85 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
  86 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
  87 int dev_pm_qos_add_notifier(struct device *dev,
  88                             struct notifier_block *notifier);
  89 int dev_pm_qos_remove_notifier(struct device *dev,
  90                                struct notifier_block *notifier);
  91 int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
  92 int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
  93 void dev_pm_qos_constraints_init(struct device *dev);
  94 void dev_pm_qos_constraints_destroy(struct device *dev);
  95 int dev_pm_qos_add_ancestor_request(struct device *dev,
  96                                     struct dev_pm_qos_request *req, s32 value);
  97 #else
  98 static inline int pm_qos_update_target(struct pm_qos_constraints *c,
  99                                        struct plist_node *node,
 100                                        enum pm_qos_req_action action,
 101                                        int value)
 102                         { return 0; }
 103 static inline void pm_qos_add_request(struct pm_qos_request *req,
 104                                       int pm_qos_class, s32 value)
 105                         { return; }
 106 static inline void pm_qos_update_request(struct pm_qos_request *req,
 107                                          s32 new_value)
 108                         { return; }
 109 static inline void pm_qos_remove_request(struct pm_qos_request *req)
 110                         { return; }
 111
 112 static inline int pm_qos_request(int pm_qos_class)
 113 {
 114         switch (pm_qos_class) {
 115         case PM_QOS_CPU_DMA_LATENCY:
 116                 return PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
 117         case PM_QOS_NETWORK_LATENCY:
 118                 return PM_QOS_NETWORK_LAT_DEFAULT_VALUE;
 119         case PM_QOS_NETWORK_THROUGHPUT:
 120                 return PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE;
 121         default:
 122                 return PM_QOS_DEFAULT_VALUE;
 123         }
 124 }
 125
 126 static inline int pm_qos_add_notifier(int pm_qos_class,
 127                                       struct notifier_block *notifier)
 128                         { return 0; }
 129 static inline int pm_qos_remove_notifier(int pm_qos_class,
 130                                          struct notifier_block *notifier)
 131                         { return 0; }
 132 static inline int pm_qos_request_active(struct pm_qos_request *req)
 133                         { return 0; }
 134 static inline s32 pm_qos_read_value(struct pm_qos_constraints *c)
 135                         { return 0; }
 136
 137 static inline s32 __dev_pm_qos_read_value(struct device *dev)
 138                         { return 0; }
 139 static inline s32 dev_pm_qos_read_value(struct device *dev)
 140                         { return 0; }
 141 static inline int dev_pm_qos_add_request(struct device *dev,
 142                                          struct dev_pm_qos_request *req,
 143                                          s32 value)
 144                         { return 0; }
 145 static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 146                                             s32 new_value)
 147                         { return 0; }
 148 static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 149                         { return 0; }
 150 static inline int dev_pm_qos_add_notifier(struct device *dev,
 151                                           struct notifier_block *notifier)
 152                         { return 0; }
 153 static inline int dev_pm_qos_remove_notifier(struct device *dev,
 154                                              struct notifier_block *notifier)
 155                         { return 0; }
 156 static inline int dev_pm_qos_add_global_notifier(
 157                                         struct notifier_block *notifier)
 158                         { return 0; }
 159 static inline int dev_pm_qos_remove_global_notifier(
 160                                         struct notifier_block *notifier)
 161                         { return 0; }
 162 static inline void dev_pm_qos_constraints_init(struct device *dev)
 163 {
 164         dev->power.power_state = PMSG_ON;
 165 }
 166 static inline void dev_pm_qos_constraints_destroy(struct device *dev)
 167 {
 168         dev->power.power_state = PMSG_INVALID;
 169 }
 170 static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
 171                                     struct dev_pm_qos_request *req, s32 value)
 172                         { return 0; }
 173 #endif
 174
 175 #endif