Certain Low power SOC states (e.g. deep sleep) will result in device
IP blocks losing state. In such a scenario it can be useful to have
a mechanism for devices (driver code) to signal the power manager /
policy that they are in the middle of a transaction.
We expect the device driver code to make a call to
device_busy_set(device *) before initiating a transaction and
device_busy_clear(device *) on completion. It is expected that device
driver developers will add this as necessary in their drivers.
Further an API is provided for power manager application / policy to
check this. Based on this the power manager / policy can decide
whether or not to go into a particular power state.
Change-Id: I0fedd90b98e182cd41b53c7f9e08655532822faa
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>