tree d590194513645bdccec8ce12dfacff312d9620b2
parent 08790720bd5cf0940dddda805eb5b2661e682f96
author Manu Gautam <mgautam@codeaurora.org> 1341203021 +0530
committer Manu Gautam <mgautam@codeaurora.org> 1342669317 +0530

usb: dwc3-msm: Add support for LPM on cable disconnect

Add runtime power management support in the driver which allows
putting the hardware in low power state, turning off LDOs
and releasing wakelock.
This LPM (aka low power state) support is currently added as part
of USB disconnect and wall-charger connect. LPM support would
later be extended to USB bus suspend as well. Also, support for PHY
retention mode and VDD minimization would be added later.

This commit also adds debugfs nodes that can used to simulate
cable connect and disconnects as A or B device. Following are
the nodes:
-->msm_dwc3/id          : Boolean value
-->msm_dwc3/bsv         : Boolean value
-->msm_dwc3/connect     : can be set to enable/disable

User should first update id/bsv values before enabling 'connect'.

dwc3-msm device is parent of dwc3-core and its runtime PM is managed
by dwc3_otg driver which is responsible for the state transitions
based on notifications from DWC3 h/w or ext_xceiver (using PMIC) for
cable connect and disconnect. This change also allows dwc3 gadget and
host to acquire PM count for the case when dwc3-otg is not present -
e.g. host and device only configurations.

Change-Id: Idd9a59c1ffd46bd98228c9fd4441f668b763534d
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>