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 #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 struct dev_pm_qos {
  61         struct pm_qos_constraints latency;
  62 };
  63
  64 /* Action requested to pm_qos_update_target */
  65 enum pm_qos_req_action {
  66         PM_QOS_ADD_REQ,         /* Add a new request */
  67         PM_QOS_UPDATE_REQ,      /* Update an existing request */
  68         PM_QOS_REMOVE_REQ       /* Remove an existing request */
  69 };
  70
  71 static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
  72 {
  73         return req->dev != NULL;
  74 }
  75
  76 int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
  77                          enum pm_qos_req_action action, int value);
  78 void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
  79                         s32 value);
  80 void pm_qos_update_request(struct pm_qos_request *req,
  81                            s32 new_value);
  82 void pm_qos_update_request_timeout(struct pm_qos_request *req,
  83                                    s32 new_value, unsigned long timeout_us);
  84 void pm_qos_remove_request(struct pm_qos_request *req);
  85
  86 int pm_qos_request(int pm_qos_class);
  87 int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
  88 int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
  89 int pm_qos_request_active(struct pm_qos_request *req);
  90 s32 pm_qos_read_value(struct pm_qos_constraints *c);
  91
  92 #ifdef CONFIG_PM
  93 s32 __dev_pm_qos_read_value(struct device *dev);
  94 s32 dev_pm_qos_read_value(struct device *dev);
  95 int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
  96                            s32 value);
  97 int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
  98 int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
  99 int dev_pm_qos_add_notifier(struct device *dev,
 100                             struct notifier_block *notifier);
 101 int dev_pm_qos_remove_notifier(struct device *dev,
 102                                struct notifier_block *notifier);
 103 int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
 104 int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
 105 void dev_pm_qos_constraints_init(struct device *dev);
 106 void dev_pm_qos_constraints_destroy(struct device *dev);
 107 int dev_pm_qos_add_ancestor_request(struct device *dev,
 108                                     struct dev_pm_qos_request *req, s32 value);
 109 #else
 110 static inline s32 __dev_pm_qos_read_value(struct device *dev)
 111                         { return 0; }
 112 static inline s32 dev_pm_qos_read_value(struct device *dev)
 113                         { return 0; }
 114 static inline int dev_pm_qos_add_request(struct device *dev,
 115                                          struct dev_pm_qos_request *req,
 116                                          s32 value)
 117                         { return 0; }
 118 static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
 119                                             s32 new_value)
 120                         { return 0; }
 121 static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
 122                         { return 0; }
 123 static inline int dev_pm_qos_add_notifier(struct device *dev,
 124                                           struct notifier_block *notifier)
 125                         { return 0; }
 126 static inline int dev_pm_qos_remove_notifier(struct device *dev,
 127                                              struct notifier_block *notifier)
 128                         { return 0; }
 129 static inline int dev_pm_qos_add_global_notifier(
 130                                         struct notifier_block *notifier)
 131                         { return 0; }
 132 static inline int dev_pm_qos_remove_global_notifier(
 133                                         struct notifier_block *notifier)
 134                         { return 0; }
 135 static inline void dev_pm_qos_constraints_init(struct device *dev)
 136 {
 137         dev->power.power_state = PMSG_ON;
 138 }
 139 static inline void dev_pm_qos_constraints_destroy(struct device *dev)
 140 {
 141         dev->power.power_state = PMSG_INVALID;
 142 }
 143 static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
 144                                     struct dev_pm_qos_request *req, s32 value)
 145                         { return 0; }
 146 #endif
 147
 148 #ifdef CONFIG_PM_RUNTIME
 149 int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value);
 150 void dev_pm_qos_hide_latency_limit(struct device *dev);
 151 #else
 152 static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
 153                         { return 0; }
 154 static inline void dev_pm_qos_hide_latency_limit(struct device *dev) {}
 155 #endif
 156
 157 #endif