man Pages(9E) : DDI and DKI Driver Entry Points

power(9E)

NAME

power- power a device attached to the system

SYNOPSIS

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

prefix

*dip

component

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: A pointer to the device's dev_info structure.
component: The component of the driver to be managed.
level: The desired power level for the component.

DESCRIPTION

The power() 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 component is set. Except for power level 0 which is defined 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. Except for component 0, which must represent the entire device, the interpretation of component is entirely up to the driver.

The power() function can assume that the driver will be suspended (using detach(9E) with command DDI_PM_SUSPEND), before a request is made to set component 0 to power level 0 and resumed (using attach(9E) with command DDI_PM_RESUME) after setting component 0 from power level 0 to a non-zero power level.

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.