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
  23 struct pm_qos_request {
  24         struct plist_node node;
  25         int pm_qos_class;
  26 };
  27
  28 enum pm_qos_type {
  29         PM_QOS_UNITIALIZED,
  30         PM_QOS_MAX,             /* return the largest value */
  31         PM_QOS_MIN              /* return the smallest value */
  32 };
  33
  34 /*
  35  * Note: The lockless read path depends on the CPU accessing
  36  * target_value atomically.  Atomic access is only guaranteed on all CPU
  37  * types linux supports for 32 bit quantites
  38  */
  39 struct pm_qos_constraints {
  40         struct plist_head list;
  41         s32 target_value;       /* Do not change to 64 bit */
  42         s32 default_value;
  43         enum pm_qos_type type;
  44         struct blocking_notifier_head *notifiers;
  45 };
  46
  47 /* Action requested to pm_qos_update_target */
  48 enum pm_qos_req_action {
  49         PM_QOS_ADD_REQ,         /* Add a new request */
  50         PM_QOS_UPDATE_REQ,      /* Update an existing request */
  51         PM_QOS_REMOVE_REQ       /* Remove an existing request */
  52 };
  53
  54 #ifdef CONFIG_PM
  55 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
  56                          enum pm_qos_req_action action, int value);
  57 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
  58                         s32 value);
  59 void pm_qos_update_request(struct pm_qos_request *req,
  60                            s32 new_value);
  61 void pm_qos_remove_request(struct pm_qos_request *req);
  62
  63 int pm_qos_request(int pm_qos_class);
  64 int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
  65 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
  66 int pm_qos_request_active(struct pm_qos_request *req);
  67 #else
  68 static inline int pm_qos_update_target(struct pm_qos_constraints *c,
  69                                        struct plist_node *node,
  70                                        enum pm_qos_req_action action,
  71                                        int value)
  72                         { return 0; }
  73 static inline void pm_qos_add_request(struct pm_qos_request *req,
  74                                       int pm_qos_class, s32 value)
  75                         { return; }
  76 static inline void pm_qos_update_request(struct pm_qos_request *req,
  77                                          s32 new_value)
  78                         { return; }
  79 static inline void pm_qos_remove_request(struct pm_qos_request *req)
  80                         { return; }
  81
  82 static inline int pm_qos_request(int pm_qos_class)
  83                         { return 0; }
  84 static inline int pm_qos_add_notifier(int pm_qos_class,
  85                                       struct notifier_block *notifier)
  86                         { return 0; }
  87 static inline int pm_qos_remove_notifier(int pm_qos_class,
  88                                          struct notifier_block *notifier)
  89                         { return 0; }
  90 static inline int pm_qos_request_active(struct pm_qos_request *req)
  91                         { return 0; }
  92 #endif
  93
  94 #endif