Per USB PD standard, we have to drop duplicate PD messages.
We can not expect lower protocol layers to drop such messages,
since lower layers don't know if a message was dropped somewhere
else in the stack.
Originally-from: Puma Hsu <puma_hsu@htc.com>
Cc: Yueyao Zhu <yueyao.zhu@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver implements the USB Type-C Power Delivery state machine
for both source and sink ports. Alternate mode support is not
fully implemented.
The driver attaches to the USB Type-C class code implemented in
the following patches.
usb: typec: add driver for Intel Whiskey Cove PMIC USB Type-C PHY
usb: USB Type-C connector class
This driver only implements the state machine. Lower level drivers are
responsible for
- Reporting VBUS status and activating VBUS
- Setting CC lines and providing CC line status
- Setting line polarity
- Activating and deactivating VCONN
- Setting the current limit
- Activating and deactivating PD message transfers
- Sending and receiving PD messages
The driver provides both a functional API as well as callbacks for
lower level drivers.
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
