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
