usb: dwc3-msm: Add support for proprietary charger detection

Proprietary chargers pull D+/- to specific voltages between 2.0-3.3V
(VLGC) for identification.  The DM voltage may not exceed VLGC due
to pull-down resistor.  Hence a proprietary charger is detected as
a Standard downstream port (SDP).  Read line state to distinguish
between SDP and proprietary charger.  The DP voltage would exceed
VLGC for proprietary chargers.

CRs-fixed: 383075
Change-Id: Ic9afbdd0996a4c1c7a2af76cd99182d8ae5f3b68
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
3 files changed