Doc: ABI: add usb charger uevent

When the USB charger is inserted or removed, the users could get
USB charger state and type through the uevent.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/1579145333-1657-2-git-send-email-peter.chen@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Peter Chen 2020-01-16 11:28:53 +08:00 коммит произвёл Greg Kroah-Hartman
Родитель 3bdcfe6c1d
Коммит 880082666c
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What: Raise a uevent when a USB charger is inserted or removed
Date: 2020-01-14
KernelVersion: 5.6
Contact: linux-usb@vger.kernel.org
Description: There are two USB charger states:
USB_CHARGER_ABSENT
USB_CHARGER_PRESENT
There are five USB charger types:
USB_CHARGER_UNKNOWN_TYPE: Charger type is unknown
USB_CHARGER_SDP_TYPE: Standard Downstream Port
USB_CHARGER_CDP_TYPE: Charging Downstream Port
USB_CHARGER_DCP_TYPE: Dedicated Charging Port
USB_CHARGER_ACA_TYPE: Accessory Charging Adapter
https://www.usb.org/document-library/battery-charging-v12-spec-and-adopters-agreement
Here are two examples taken using udevadm monitor -p when
USB charger is online:
UDEV change /devices/soc0/usbphynop1 (platform)
ACTION=change
DEVPATH=/devices/soc0/usbphynop1
DRIVER=usb_phy_generic
MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
OF_COMPATIBLE_0=usb-nop-xceiv
OF_COMPATIBLE_N=1
OF_FULLNAME=/usbphynop1
OF_NAME=usbphynop1
SEQNUM=2493
SUBSYSTEM=platform
USB_CHARGER_STATE=USB_CHARGER_PRESENT
USB_CHARGER_TYPE=USB_CHARGER_SDP_TYPE
USEC_INITIALIZED=227422826
USB charger is offline:
KERNEL change /devices/soc0/usbphynop1 (platform)
ACTION=change
DEVPATH=/devices/soc0/usbphynop1
DRIVER=usb_phy_generic
MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
OF_COMPATIBLE_0=usb-nop-xceiv
OF_COMPATIBLE_N=1
OF_FULLNAME=/usbphynop1
OF_NAME=usbphynop1
SEQNUM=2494
SUBSYSTEM=platform
USB_CHARGER_STATE=USB_CHARGER_ABSENT
USB_CHARGER_TYPE=USB_CHARGER_UNKNOWN_TYPE