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@xxxxxxx> --- Changes for v4 - Add explanation for charger type and related doc at usb.org Changes for v3: - Change kernel version for 5.6, and delete the kernel printk time Documentation/ABI/testing/usb-charger-uevent | 46 ++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 Documentation/ABI/testing/usb-charger-uevent diff --git a/Documentation/ABI/testing/usb-charger-uevent b/Documentation/ABI/testing/usb-charger-uevent new file mode 100644 index 000000000000..419a92dd0d86 --- /dev/null +++ b/Documentation/ABI/testing/usb-charger-uevent @@ -0,0 +1,46 @@ +What: Raise a uevent when a USB charger is inserted or removed +Date: 2020-01-14 +KernelVersion: 5.6 +Contact: linux-usb@xxxxxxxxxxxxxxx +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 -- 2.17.1
