Documentation: driver-api: PM: Add cpuidle document

Replace the remaining documents under Documentation/cpuidle/
with one more complete governor and driver API document for cpuidle
under Documentation/driver-api/pm/.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/cpuidle/driver.txt

-
-
-		Supporting multiple CPU idle levels in kernel
-
-				cpuidle drivers
-
-
-
-
-cpuidle driver hooks into the cpuidle infrastructure and handles the
-architecture/platform dependent part of CPU idle states. Driver
-provides the platform idle state detection capability and also
-has mechanisms in place to support actual entry-exit into CPU idle states.
-
-cpuidle driver initializes the cpuidle_device structure for each CPU device
-and registers with cpuidle using cpuidle_register_device.
-
-If all the idle states are the same, the wrapper function cpuidle_register
-could be used instead.
-
-It can also support the dynamic changes (like battery <-> AC), by using
-cpuidle_pause_and_lock, cpuidle_disable_device and cpuidle_enable_device,
-cpuidle_resume_and_unlock.
-
-Interfaces:
-extern int cpuidle_register(struct cpuidle_driver *drv,
-                            const struct cpumask *const coupled_cpus);
-extern int cpuidle_unregister(struct cpuidle_driver *drv);
-extern int cpuidle_register_driver(struct cpuidle_driver *drv);
-extern void cpuidle_unregister_driver(struct cpuidle_driver *drv);
-extern int cpuidle_register_device(struct cpuidle_device *dev);
-extern void cpuidle_unregister_device(struct cpuidle_device *dev);
-
-extern void cpuidle_pause_and_lock(void);
-extern void cpuidle_resume_and_unlock(void);
-extern int cpuidle_enable_device(struct cpuidle_device *dev);
-extern void cpuidle_disable_device(struct cpuidle_device *dev);

Documentation/cpuidle/governor.txt

-
-
-
-		Supporting multiple CPU idle levels in kernel
-
-				cpuidle governors
-
-
-
-
-cpuidle governor is policy routine that decides what idle state to enter at
-any given time. cpuidle core uses different callbacks to the governor.
-
-* enable() to enable governor for a particular device
-* disable() to disable governor for a particular device
-* select() to select an idle state to enter
-* reflect() called after returning from the idle state, which can be used
-  by the governor for some record keeping.
-
-More than one governor can be registered at the same time and
-users can switch between drivers using /sysfs interface (when enabled).
-More than one governor part is supported for developers to easily experiment
-with different governors. By default, most optimal governor based on your
-kernel configuration and platform will be selected by cpuidle.
-
-Interfaces:
-extern int cpuidle_register_governor(struct cpuidle_governor *gov);
-struct cpuidle_governor

Documentation/driver-api/pm/index.rst

-=======================
-Device Power Management
-=======================
+===============================
+CPU and Device Power Management
+===============================
 
 .. toctree::
 
+   cpuidle
    devices
    notifiers
    types

MAINTAINERS

@@ -4016,6 +4016,7 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
 B:	https://bugzilla.kernel.org
 F:	Documentation/admin-guide/pm/cpuidle.rst
+F:	Documentation/driver-api/pm/cpuidle.rst
 F:	drivers/cpuidle/*
 F:	include/linux/cpuidle.h