18c2ecf20Sopenharmony_ciWhat: /sys/devices/.../power_state 28c2ecf20Sopenharmony_ciDate: January 2013 38c2ecf20Sopenharmony_ciContact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 48c2ecf20Sopenharmony_ciDescription: 58c2ecf20Sopenharmony_ci The /sys/devices/.../power_state attribute is only present for 68c2ecf20Sopenharmony_ci device objects representing ACPI device nodes that provide power 78c2ecf20Sopenharmony_ci management methods. 88c2ecf20Sopenharmony_ci 98c2ecf20Sopenharmony_ci If present, it contains a string representing the current ACPI 108c2ecf20Sopenharmony_ci power state of the given device node. Its possible values, 118c2ecf20Sopenharmony_ci "D0", "D1", "D2", "D3hot", and "D3cold", reflect the power state 128c2ecf20Sopenharmony_ci names defined by the ACPI specification (ACPI 4 and above). 138c2ecf20Sopenharmony_ci 148c2ecf20Sopenharmony_ci If the device node uses shared ACPI power resources, this state 158c2ecf20Sopenharmony_ci determines a list of power resources required not to be turned 168c2ecf20Sopenharmony_ci off. However, some power resources needed by the device node in 178c2ecf20Sopenharmony_ci higher-power (lower-number) states may also be ON because of 188c2ecf20Sopenharmony_ci some other devices using them at the moment. 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci This attribute is read-only. 21