The power.runtime_auto device flag and the helper functions
pm_runtime_allow() and pm_runtime_forbid() used to modify it are a
part of the run-time power management framework and therefore they
should be described in Documentation/power/runtime_pm.txt.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

This patch (as1318) updates the runtime PM documentation, adding a
section discussing the interaction between runtime PM and system sleep.

[rjw: Rebased and made it agree with the other updates better.]
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The power management of some devices is handled through device types
and device classes rather than through bus types.  Since these
devices may also benefit from using the run-time power management
core, extend it so that the device type and device class run-time PM
callbacks can be taken into consideration by it if the bus type
callback is not defined.

Update the run-time PM core documentation to reflect this change.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Apparently, there are devices that can wake up the system from sleep
states and yet are incapable of generating wake-up events at run
time.  Thus, introduce a flag indicating if given device is capable
of generating run-time wake-up events.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Currently the ->runtime_idle() callback is documented as having no
return value, but in fact it returns int.  Although its return value
is ignored at the PM core level, it may be used by bus type routines
executing the drivers' ->runtime_idle() callbacks.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reported-by: NAlan Stern <stern@rowland.harvard.edu>

Introduce a core framework for run-time power management of I/O
devices.  Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'.  Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level.  Document all these things.

Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NMagnus Damm <damm@igel.co.jp>