powerhook_establish(9) [netbsd man page]

POWERHOOK_ESTABLISH(9)					   BSD Kernel Developer's Manual				    POWERHOOK_ESTABLISH(9)

NAME

     powerhook_establish, powerhook_disestablish -- add or remove a power change hook

SYNOPSIS

     void *
     powerhook_establish(const char *name, void (*fn)(int why, void *a), void *arg);

     void
     powerhook_disestablish(void *cookie);

DESCRIPTION

     The powerhook_establish API is deprecated.

     The powerhook_establish() function adds fn of the list of hooks invoked by dopowerhooks(9) at power change.  When invoked, the hook function
     fn will be passed the new power state as the first argument and arg as its second argument.

     The powerhook_disestablish() function removes the hook described by the opaque pointer cookie from the list of hooks to be invoked at power
     change.  If cookie is invalid, the result of powerhook_disestablish() is undefined.

     Power hooks should be used to perform activities that must happen when the power situation to the computer changes.  Because of the environ-
     ment in which they are run, power hooks cannot rely on many system services (including file systems, and timeouts and other interrupt-driven
     services).  The power hooks are typically executed from an interrupt context.

     The different reasons for calling the power hooks are: suspend, standby, and resume.  The reason is reflected in the why argument and the
     values PWR_SOFTSUSPEND, PWR_SUSPEND, PWR_SOFTSTANDBY, PWR_STANDBY, PWR_SOFTRESUME, and PWR_RESUME.  It calls with PWR_SOFTxxx in the normal
     priority level while the other callings are protected with splhigh(9).  At suspend the system is going to lose (almost) all power, standby
     retains some power (e.g., minimal power to USB devices), and at resume power is back to normal.

RETURN VALUES

     If successful, powerhook_establish() returns an opaque pointer describing the newly-established power hook.  Otherwise, it returns NULL.

SEE ALSO

     dopowerhooks(9)

BSD
								   May 14, 2009 							       BSD

power(9E)							Driver Entry Points							 power(9E)

NAME

       power - power a device attached to the system

SYNOPSIS

       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       int prefixpower(dev_info_t *dip, int component, int level);

INTERFACE LEVEL

       Solaris	DDI  specific  (Solaris  DDI). This entry point is required. If the driver writer does not supply this entry point, the value NULL
       must be used in the cb_ops(9S) structure instead.

PARAMETERS

       dip	    Pointer to the device's dev_info structure.

       component    Component of the driver to be managed.

       level	    Desired component power level.

DESCRIPTION

       The power(9E) function is the device-specific Power Management entry point. This function is called when the system wants the driver to set
       the power level of component to level.

       The level argument is the driver-defined power level to which the component needs to be set. Except for power level 0, which is interpreted
       by the framework to mean "powered off," the interpretation of level is entirely up to the driver.

       The component argument is the component of the device to be power-managed. The interpretation of component is entirely up to the driver.

       When a requested power transition would cause the device to lose state, the driver must save the state of the  device  in  memory.  When  a
       requested power transition requires state to be restored, the driver must restore that state.

       If  a  requested power transition for one component requires another component to change power state before it can be completed, the driver
       must call pm_raise_power(9F) to get the other component changed, and the power(9E) entry point must support being re-entered.

       If the system requests an inappropriate power transition for the device (for example, a request to power  down  a  device  which  has  just
       become busy), then the power level should not be changed and power should return DDI_FAILURE.

RETURN VALUES

       The power() function returns:

       DDI_SUCCESS    Successfully set the power to the requested level.

       DDI_FAILURE    Failed to set the power to the requested level.

CONTEXT

       The power() function is called from user or kernel context only.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |Committed 		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       attach(9E), detach(9E), pm_busy_component(9F), pm_idle_component(9F), pm_raise_power(9F), cb_ops(9S)

       Writing Device Drivers

       Using Power Management

SunOS 5.11							    12 Dec 2003 							 power(9E)