pci_set_power_state — Set the power state of a PCI device
PCI device to be suspended
PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
Transition a device to a new power state, using the Power Management Capabilities in the device's config space.
-EINVAL if trying to enter a lower state than we're already in. 0 if we're already in the requested state. -EIO if device does not support PCI PM. 0 if we can successfully change the power state.