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Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD b/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD new file mode 100644 index 0000000000..bc44bc903b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-platform-ACPI-TAD @@ -0,0 +1,117 @@ + ACPI Time and Alarm (TAD) device attributes. + +What: /sys/bus/platform/devices/ACPI000E:00/caps +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RO) Hexadecimal bitmask of the TAD attributes are reported by + the platform firmware (see ACPI 6.2, section 9.18.2): + + ======= ====================================================== + BIT(0): AC wakeup implemented if set + BIT(1): DC wakeup implemented if set + BIT(2): Get/set real time features implemented if set + BIT(3): Real time accuracy in milliseconds if set + BIT(4): Correct status reported for wakeups from S4/S5 if set + BIT(5): The AC timer wakes up from S4 if set + BIT(6): The AC timer wakes up from S5 if set + BIT(7): The DC timer wakes up from S4 if set + BIT(8): The DC timer wakes up from S5 if set + ======= ====================================================== + + The other bits are reserved. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_alarm +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm timer value. + + Reads return the current AC alarm timer value in seconds or + "disabled", if the AC alarm is not set to wake up the system. + + Write a new AC alarm timer value in seconds or "disabled" to it + to set the AC alarm timer or to disable it, respectively. + + If the AC alarm timer is set through this attribute and it + expires, it will immediately wake up the system from the S3 + sleep state (and from S4/S5 too if supported) until its status + is explicitly cleared via the ac_status attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_policy +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm expired timer wake policy (see ACPI 6.2, + Section 9.18 for details). + + Reads return the current expired timer wake delay for the AC + alarm timer or "never", if the policy is to discard AC timer + wakeups if the system is on DC power. + + Write a new expired timer wake delay for the AC alarm timer in + seconds or "never" to it to set the expired timer wake delay for + the AC alarm timer or to set its expired wake policy to discard + wakeups if the system is on DC power, respectively. + +What: /sys/bus/platform/devices/ACPI000E:00/ac_status +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW) The AC alarm status. + + Reads return a hexadecimal bitmask representing the AC alarm + timer status with the following meaning of bits (see ACPI 6.2, + Section 9.18.5): + + ======= ====================================================== + Bit(0): The timer has expired if set. + Bit(1): The timer has woken up the system from a sleep state + (S3 or S4/S5 if supported) if set. + ======= ====================================================== + + The other bits are reserved. + + Reads also cause the AC alarm timer status to be reset. + + Another way to reset the status of the AC alarm timer is to + write (the number) 0 to this file. + + If the status return value indicates that the timer has expired, + it will immediately wake up the system from the S3 sleep state + (and from S4/S5 too if supported) until its status is explicitly + cleared through this attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_alarm +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW,optional) The DC alarm timer value. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_alarm attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_policy +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> +Description: + (RW,optional) The DC alarm expired timer wake policy. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_policy attribute. + +What: /sys/bus/platform/devices/ACPI000E:00/dc_status +Date: March 2018 +Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com> + +Description: + (RW,optional) The DC alarm status. + + This attribute is only present if the TAD supports a separate + DC timer. + + It is analogous to the ac_status attribute. |