Earlysuspend sleep mode for Android-implementation code

(1) Add a header file:

# Include <Linux/earlysuspend. h>

(2) Add the early_suspend structure to the specific driver struct:

# Ifdef config_has_earlysuspend
Struct early_suspend;
# Endif

(3) register the early_suspend struct in the driver probe function:

# Ifdef config_has_earlysuspend
Ftk_ts-> early_suspend.level = early_suspend_level_blk_screen + 1;
Ftk_ts-> early_suspend.suspend = pai_ts_early_suspend;
Ftk_ts-> early_suspend.resume = pai_ts_late_resume;
Register_early_suspend (& ftk_ts-> early_suspend );
# Endif

All early_suspend structures registered to the system are added to the global linked list early_suspend_handlers in order of level values.

The device that wants to execute early suspend, his device driverProgramYou need to register with the power management system. This struct is used to register earlysuspend/lateresume with the power management system. When the power management system starts the suspend process, the callback function suspend will be called. On the contrary, in the final stage of resume, the callback function resume will be called. The level field is used to adjust the position of the struct in the registered linked list. During suspend,The smaller the level value, the earlier the callback function is called.And resume. Android pre-defines three levels:

 

 
Enum {region = 50, region = 100, region = 150,}; struct early_suspend {# ifdef config_has_earlysuspendstruct list_head link; int level; void (* suspend) (struct early_suspend * H ); void (* resume) (struct early_suspend * H); # endif };
 

 

(4) cancel the registration of the early_suspend struct in the drive Remove function:

# Ifdef config_has_earlysuspend
Unregister_early_suspend (& TS-> early_suspend );
# Endif

(5) define related suspend and resume functions:

# Ifdef config_has_earlysuspend
Static void pai_ts_early_suspend (struct early_suspend * H)
{
Struct ftk_ts * ts;
TS = container_of (H, struct ftk_ts, early_suspend );
Pai_ts_suspend (ts-> client, pmsg_suspend );
}

Static void pai_ts_late_resume (struct early_suspend * H)
{
Struct ftk_ts * ts;
TS = container_of (H, struct ftk_ts, early_suspend );
Cmd_ts_resume (ts-> client );
}
# Endif

(6) set the function interface that does not use earlysuspend in the system driver struct:

# Ifndef config_has_earlysuspend
. Suspend = pai_ts_suspend,
. Resume = pai_ts_resume,
# Endif