Documentation: ACPI: move lpit.txt to firmware-guide/acpi and convert to reST

This converts the plain text documentation to reStructuredText format
and adds it to Sphinx TOC tree.

No essential content change.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Changbin Du 2019-04-25 01:53:04 +08:00 committed by Rafael J. Wysocki
parent 3e57460f00
commit 4887954cac
2 changed files with 14 additions and 5 deletions

View File

@ -22,3 +22,4 @@ ACPI Support
gpio-properties
i2c-muxes
acpi-lid
lpit

View File

@ -1,3 +1,9 @@
.. SPDX-License-Identifier: GPL-2.0
===========================
Low Power Idle Table (LPIT)
===========================
To enumerate platform Low Power Idle states, Intel platforms are using
“Low Power Idle Table” (LPIT). More details about this table can be
downloaded from:
@ -8,13 +14,15 @@ Residencies for each low power state can be read via FFH
On platforms supporting S0ix sleep states, there can be two types of
residencies:
- CPU PKG C10 (Read via FFH interface)
- Platform Controller Hub (PCH) SLP_S0 (Read via memory mapped interface)
- CPU PKG C10 (Read via FFH interface)
- Platform Controller Hub (PCH) SLP_S0 (Read via memory mapped interface)
The following attributes are added dynamically to the cpuidle
sysfs attribute group:
/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us
sysfs attribute group::
/sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us
The "low_power_idle_cpu_residency_us" attribute shows time spent
by the CPU package in PKG C10