include/linux/pm_qos.h

#ifndef _LINUX_PM_QOS_H
#define _LINUX_PM_QOS_H
/* interface for the pm_qos_power infrastructure of the linux kernel.
 *
 * Mark Gross <mgross@linux.intel.com>
 */
#include <linux/plist.h>
#include <linux/notifier.h>
#include <linux/miscdevice.h>
#include <linux/device.h>

#define PM_QOS_RESERVED 0
#define PM_QOS_CPU_DMA_LATENCY 1
#define PM_QOS_NETWORK_LATENCY 2
#define PM_QOS_NETWORK_THROUGHPUT 3

#define PM_QOS_NUM_CLASSES 4
#define PM_QOS_DEFAULT_VALUE -1

#define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE	(2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_LAT_DEFAULT_VALUE	(2000 * USEC_PER_SEC)
#define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE	0
#define PM_QOS_DEV_LAT_DEFAULT_VALUE		0

struct pm_qos_request {
	struct plist_node node;
	int pm_qos_class;
};

struct dev_pm_qos_request {
	struct plist_node node;
	struct device *dev;
};

enum pm_qos_type {
	PM_QOS_UNITIALIZED,
	PM_QOS_MAX,		/* return the largest value */
	PM_QOS_MIN		/* return the smallest value */
};

/*
 * Note: The lockless read path depends on the CPU accessing
 * target_value atomically.  Atomic access is only guaranteed on all CPU
 * types linux supports for 32 bit quantites
 */
struct pm_qos_constraints {
	struct plist_head list;
	s32 target_value;	/* Do not change to 64 bit */
	s32 default_value;
	enum pm_qos_type type;
	struct blocking_notifier_head *notifiers;
};

/* Action requested to pm_qos_update_target */
enum pm_qos_req_action {
	PM_QOS_ADD_REQ,		/* Add a new request */
	PM_QOS_UPDATE_REQ,	/* Update an existing request */
	PM_QOS_REMOVE_REQ	/* Remove an existing request */
};

static inline int dev_pm_qos_request_active(struct dev_pm_qos_request *req)
{
	return req->dev != 0;
}

#ifdef CONFIG_PM
int pm_qos_update_target(struct pm_qos_constraints *c, struct plist_node *node,
			 enum pm_qos_req_action action, int value);
void pm_qos_add_request(struct pm_qos_request *req, int pm_qos_class,
			s32 value);
void pm_qos_update_request(struct pm_qos_request *req,
			   s32 new_value);
void pm_qos_remove_request(struct pm_qos_request *req);

int pm_qos_request(int pm_qos_class);
int pm_qos_add_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier);
int pm_qos_request_active(struct pm_qos_request *req);
s32 pm_qos_read_value(struct pm_qos_constraints *c);

s32 __dev_pm_qos_read_value(struct device *dev);
s32 dev_pm_qos_read_value(struct device *dev);
int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req,
			   s32 value);
int dev_pm_qos_update_request(struct dev_pm_qos_request *req, s32 new_value);
int dev_pm_qos_remove_request(struct dev_pm_qos_request *req);
int dev_pm_qos_add_notifier(struct device *dev,
			    struct notifier_block *notifier);
int dev_pm_qos_remove_notifier(struct device *dev,
			       struct notifier_block *notifier);
int dev_pm_qos_add_global_notifier(struct notifier_block *notifier);
int dev_pm_qos_remove_global_notifier(struct notifier_block *notifier);
void dev_pm_qos_constraints_init(struct device *dev);
void dev_pm_qos_constraints_destroy(struct device *dev);
int dev_pm_qos_add_ancestor_request(struct device *dev,
				    struct dev_pm_qos_request *req, s32 value);
#else
static inline int pm_qos_update_target(struct pm_qos_constraints *c,
				       struct plist_node *node,
				       enum pm_qos_req_action action,
				       int value)
			{ return 0; }
static inline void pm_qos_add_request(struct pm_qos_request *req,
				      int pm_qos_class, s32 value)
			{ return; }
static inline void pm_qos_update_request(struct pm_qos_request *req,
					 s32 new_value)
			{ return; }
static inline void pm_qos_remove_request(struct pm_qos_request *req)
			{ return; }

static inline int pm_qos_request(int pm_qos_class)
{
	switch (pm_qos_class) {
	case PM_QOS_CPU_DMA_LATENCY:
		return PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
	case PM_QOS_NETWORK_LATENCY:
		return PM_QOS_NETWORK_LAT_DEFAULT_VALUE;
	case PM_QOS_NETWORK_THROUGHPUT:
		return PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE;
	default:
		return PM_QOS_DEFAULT_VALUE;
	}
}

static inline int pm_qos_add_notifier(int pm_qos_class,
				      struct notifier_block *notifier)
			{ return 0; }
static inline int pm_qos_remove_notifier(int pm_qos_class,
					 struct notifier_block *notifier)
			{ return 0; }
static inline int pm_qos_request_active(struct pm_qos_request *req)
			{ return 0; }
static inline s32 pm_qos_read_value(struct pm_qos_constraints *c)
			{ return 0; }

static inline s32 __dev_pm_qos_read_value(struct device *dev)
			{ return 0; }
static inline s32 dev_pm_qos_read_value(struct device *dev)
			{ return 0; }
static inline int dev_pm_qos_add_request(struct device *dev,
					 struct dev_pm_qos_request *req,
					 s32 value)
			{ return 0; }
static inline int dev_pm_qos_update_request(struct dev_pm_qos_request *req,
					    s32 new_value)
			{ return 0; }
static inline int dev_pm_qos_remove_request(struct dev_pm_qos_request *req)
			{ return 0; }
static inline int dev_pm_qos_add_notifier(struct device *dev,
					  struct notifier_block *notifier)
			{ return 0; }
static inline int dev_pm_qos_remove_notifier(struct device *dev,
					     struct notifier_block *notifier)
			{ return 0; }
static inline int dev_pm_qos_add_global_notifier(
					struct notifier_block *notifier)
			{ return 0; }
static inline int dev_pm_qos_remove_global_notifier(
					struct notifier_block *notifier)
			{ return 0; }
static inline void dev_pm_qos_constraints_init(struct device *dev)
{
	dev->power.power_state = PMSG_ON;
}
static inline void dev_pm_qos_constraints_destroy(struct device *dev)
{
	dev->power.power_state = PMSG_INVALID;
}
static inline int dev_pm_qos_add_ancestor_request(struct device *dev,
				    struct dev_pm_qos_request *req, s32 value)
			{ return 0; }
#endif

#endif