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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-usb')
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diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb new file mode 100644 index 000000000..a44bfe020 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -0,0 +1,588 @@ +What: /sys/bus/usb/devices/<INTERFACE>/authorized +Date: August 2015 +Description: + This allows to authorize (1) or deauthorize (0) + individual interfaces instead a whole device + in contrast to the device authorization. + If a deauthorized interface will be authorized + so the driver probing must be triggered manually + by writing INTERFACE to /sys/bus/usb/drivers_probe + This allows to avoid side-effects with drivers + that need multiple interfaces. + + A deauthorized interface cannot be probed or claimed. + +What: /sys/bus/usb/devices/usbX/interface_authorized_default +Date: August 2015 +Description: + This is used as value that determines if interfaces + would be authorized by default. + The value can be 1 or 0. It's by default 1. + +What: /sys/bus/usb/device/.../authorized +Date: July 2008 +KernelVersion: 2.6.26 +Contact: David Vrabel <david.vrabel@csr.com> +Description: + Authorized devices are available for use by device + drivers, non-authorized one are not. By default, wired + USB devices are authorized. + +What: /sys/bus/usb/drivers/.../new_id +Date: October 2011 +Contact: linux-usb@vger.kernel.org +Description: + Writing a device ID to this file will attempt to + dynamically add a new device ID to a USB device driver. + This may allow the driver to support more hardware than + was included in the driver's static device ID support + table at compile time. The format for the device ID is: + idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct + The vendor ID and device ID fields are required, the + rest is optional. The `Ref*` tuple can be used to tell the + driver to use the same driver_data for the new device as + it is used for the reference device. + Upon successfully adding an ID, the driver will probe + for the device and attempt to bind to it. For example:: + + # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id + + Here add a new device (0458:7045) using driver_data from + an already supported device (0458:704c):: + + # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id + + Reading from this file will list all dynamically added + device IDs in the same format, with one entry per + line. For example:: + + # cat /sys/bus/usb/drivers/foo/new_id + 8086 10f5 + dead beef 06 + f00d cafe + + The list will be truncated at PAGE_SIZE bytes due to + sysfs restrictions. + +What: /sys/bus/usb-serial/drivers/.../new_id +Date: October 2011 +Contact: linux-usb@vger.kernel.org +Description: + For serial USB drivers, this attribute appears under the + extra bus folder "usb-serial" in sysfs; apart from that + difference, all descriptions from the entry + "/sys/bus/usb/drivers/.../new_id" apply. + +What: /sys/bus/usb/drivers/.../remove_id +Date: November 2009 +Contact: CHENG Renquan <rqcheng@smu.edu.sg> +Description: + Writing a device ID to this file will remove an ID + that was dynamically added via the new_id sysfs entry. + The format for the device ID is: + idVendor idProduct. After successfully + removing an ID, the driver will no longer support the + device. This is useful to ensure auto probing won't + match the driver to the device. For example: + # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id + + Reading from this file will list the dynamically added + device IDs, exactly like reading from the entry + "/sys/bus/usb/drivers/.../new_id" + +What: /sys/bus/usb/devices/.../power/usb2_hardware_lpm +Date: September 2011 +Contact: Andiry Xu <andiry.xu@amd.com> +Description: + If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged + in to a xHCI host which support link PM, it will perform a LPM + test; if the test is passed and host supports USB2 hardware LPM + (xHCI 1.0 feature), USB2 hardware LPM will be enabled for the + device and the USB device directory will contain a file named + power/usb2_hardware_lpm. The file holds a string value (enable + or disable) indicating whether or not USB2 hardware LPM is + enabled for the device. Developer can write y/Y/1 or n/N/0 to + the file to enable/disable the feature. + +What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1 + /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2 +Date: November 2015 +Contact: Kevin Strasser <kevin.strasser@linux.intel.com> + Lu Baolu <baolu.lu@linux.intel.com> +Description: + If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged + in to a xHCI host which supports link PM, it will check if U1 + and U2 exit latencies have been set in the BOS descriptor; if + the check is passed and the host supports USB3 hardware LPM, + USB3 hardware LPM will be enabled for the device and the USB + device directory will contain two files named + power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These + files hold a string value (enable or disable) indicating whether + or not USB3 hardware LPM U1 or U2 is enabled for the device. + +What: /sys/bus/usb/devices/.../ltm_capable +Date: July 2012 +Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> +Description: + USB 3.0 devices may optionally support Latency Tolerance + Messaging (LTM). They indicate their support by setting a bit + in the bmAttributes field of their SuperSpeed BOS descriptors. + If that bit is set for the device, ltm_capable will read "yes". + If the device doesn't support LTM, the file will read "no". + The file will be present for all speeds of USB devices, and will + always read "no" for USB 1.1 and USB 2.0 devices. + +What: /sys/bus/usb/devices/<INTERFACE>/wireless_status +Date: February 2023 +Contact: Bastien Nocera <hadess@hadess.net> +Description: + Some USB devices use a USB receiver dongle to communicate + wirelessly with their device using proprietary protocols. This + attribute allows user-space to know whether the device is + connected to its receiver dongle, and, for example, consider + the device to be absent when choosing whether to show the + device's battery, show a headset in a list of outputs, or show + an on-screen keyboard if the only wireless keyboard is + turned off. + This attribute is not to be used to replace protocol specific + statuses available in WWAN, WLAN/Wi-Fi, Bluetooth, etc. + If the device does not use a receiver dongle with a wireless + device, then this attribute will not exist. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X> +Date: August 2012 +Contact: Lan Tianyu <tianyu.lan@intel.com> +Description: + The /sys/bus/usb/devices/.../<hub_interface>/port<X> + is usb port device's sysfs directory. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type +Date: January 2013 +Contact: Lan Tianyu <tianyu.lan@intel.com> +Description: + Some platforms provide usb port connect types through ACPI. + This attribute is to expose these information to user space. + The file will read "hotplug", "hardwired" and "not used" if the + information is available, and "unknown" otherwise. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/location +Date: October 2018 +Contact: Bjørn Mork <bjorn@mork.no> +Description: + Some platforms provide usb port physical location through + firmware. This is used by the kernel to pair up logical ports + mapping to the same physical connector. The attribute exposes the + raw location value as a hex integer. + + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks +Date: May 2018 +Contact: Nicolas Boichat <drinkcat@chromium.org> +Description: + In some cases, we care about time-to-active for devices + connected on a specific port (e.g. non-standard USB port like + pogo pins), where the device to be connected is known in + advance, and behaves well according to the specification. + This attribute is a bit-field that controls the behavior of + a specific port: + + - Bit 0 of this field selects the "old" enumeration scheme, + as it is considerably faster (it only causes one USB reset + instead of 2). + + The old enumeration scheme can also be selected globally + using /sys/module/usbcore/parameters/old_scheme_first, but + it is often not desirable as the new scheme was introduced to + increase compatibility with more devices. + - Bit 1 reduces TRSTRCY to the 10 ms that are required by the + USB 2.0 specification, instead of the 50 ms that are normally + used to help make enumeration work better on some high speed + devices. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count +Date: February 2018 +Contact: Richard Leitner <richard.leitner@skidata.com> +Description: + Most hubs are able to detect over-current situations on their + ports and report them to the kernel. This attribute is to expose + the number of over-current situation occurred on a specific port + to user space. This file will contain an unsigned 32 bit value + which wraps to 0 after its maximum is reached. This file supports + poll() for monitoring changes to this value in user space. + + Any time this value changes the corresponding hub device will send a + udev event with the following attributes:: + + OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X> + OVER_CURRENT_COUNT=[current value of this sysfs attribute] + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit +Date: November 2015 +Contact: Lu Baolu <baolu.lu@linux.intel.com> +Description: + Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit + attribute allows enabling/disabling usb3 lpm of a port. It takes + effect both before and after a usb device is enumerated. Supported + values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1 + is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and + u2 are permitted. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connector +Date: December 2021 +Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com> +Description: + Link to the USB Type-C connector when available. This link is + only created when USB Type-C Connector Class is enabled, and + only if the system firmware is capable of describing the + connection between a port and its connector. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/disable +Date: June 2022 +Contact: Michael Grzeschik <m.grzeschik@pengutronix.de> +Description: + This file controls the state of a USB port, including + Vbus power output (but only on hubs that support + power switching -- most hubs don't support it). If + a port is disabled, the port is unusable: Devices + attached to the port will not be detected, initialized, + or enumerated. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/early_stop +Date: Sep 2022 +Contact: Ray Chi <raychi@google.com> +Description: + Some USB hosts have some watchdog mechanisms so that the device + may enter ramdump if it takes a long time during port initialization. + This attribute allows each port just has two attempts so that the + port initialization will be failed quickly. In addition, if a port + which is marked with early_stop has failed to initialize, it will ignore + all future connections until this attribute is clear. + +What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/state +Date: June 2023 +Contact: Roy Luo <royluo@google.com> +Description: + Indicates current state of the USB device attached to the port. + Valid states are: 'not-attached', 'attached', 'powered', + 'reconnecting', 'unauthenticated', 'default', 'addressed', + 'configured', and 'suspended'. This file supports poll() to + monitor the state change from user space. + +What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout +Date: May 2013 +Contact: Mathias Nyman <mathias.nyman@linux.intel.com> +Description: + USB 2.0 devices may support hardware link power management (LPM) + L1 sleep state. The usb2_lpm_l1_timeout attribute allows + tuning the timeout for L1 inactivity timer (LPM timer), e.g. + needed inactivity time before host requests the device to go to L1 sleep. + Useful for power management tuning. + Supported values are 0 - 65535 microseconds. + +What: /sys/bus/usb/devices/.../power/usb2_lpm_besl +Date: May 2013 +Contact: Mathias Nyman <mathias.nyman@linux.intel.com> +Description: + USB 2.0 devices that support hardware link power management (LPM) + L1 sleep state now use a best effort service latency value (BESL) to + indicate the best effort to resumption of service to the device after the + initiation of the resume event. + If the device does not have a preferred besl value then the host can select + one instead. This usb2_lpm_besl attribute allows to tune the host selected besl + value in order to tune power saving and service latency. + + Supported values are 0 - 15. + More information on how besl values map to microseconds can be found in + USB 2.0 ECN Errata for Link Power Management, section 4.10) + +What: /sys/bus/usb/devices/.../rx_lanes +Date: March 2018 +Contact: Mathias Nyman <mathias.nyman@linux.intel.com> +Description: + Number of rx lanes the device is using. + USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C. + Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per + direction. Devices before USB 3.2 are single lane (rx_lanes = 1) + +What: /sys/bus/usb/devices/.../tx_lanes +Date: March 2018 +Contact: Mathias Nyman <mathias.nyman@linux.intel.com> +Description: + Number of tx lanes the device is using. + USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C. + Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per + direction. Devices before USB 3.2 are single lane (tx_lanes = 1) + +What: /sys/bus/usb/devices/usbX/bAlternateSetting +Description: + The current interface alternate setting number, in decimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bcdDevice +Description: + The device's release number, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bConfigurationValue +Description: + While a USB device typically have just one configuration + setting, some devices support multiple configurations. + + This value shows the current configuration, in decimal. + + Changing its value will change the device's configuration + to another setting. + + The number of configurations supported by a device is at: + + /sys/bus/usb/devices/usbX/bNumConfigurations + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bDeviceClass +Description: + Class code of the device, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bDeviceProtocol +Description: + Protocol code of the device, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bDeviceSubClass +Description: + Subclass code of the device, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bInterfaceClass +Description: + Class code of the interface, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bInterfaceNumber +Description: + Interface number, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bInterfaceProtocol +Description: + Protocol code of the interface, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bInterfaceSubClass +Description: + Subclass code of the interface, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bmAttributes +Description: + Attributes of the current configuration, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bMaxPacketSize0 +Description: + Maximum endpoint 0 packet size, in decimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bMaxPower +Description: + Maximum power consumption of the active configuration of + the device, in miliamperes. + +What: /sys/bus/usb/devices/usbX/bNumConfigurations +Description: + Number of the possible configurations of the device, in + decimal. The current configuration is controlled via: + + /sys/bus/usb/devices/usbX/bConfigurationValue + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bNumEndpoints +Description: + Number of endpoints used on this interface, in hexadecimal. + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/bNumInterfaces +Description: + Number of interfaces on this device, in decimal. + +What: /sys/bus/usb/devices/usbX/busnum +Description: + Number of the bus. + +What: /sys/bus/usb/devices/usbX/configuration +Description: + Contents of the string descriptor associated with the + current configuration. It may include the firmware version + of a device and/or its serial number. + +What: /sys/bus/usb/devices/usbX/descriptors +Description: + Contains the interface descriptors, in binary. + +What: /sys/bus/usb/devices/usbX/idProduct +Description: + Product ID, in hexadecimal. + +What: /sys/bus/usb/devices/usbX/idVendor +Description: + Vendor ID, in hexadecimal. + +What: /sys/bus/usb/devices/usbX/devspec +Description: + Displays the Device Tree Open Firmware node of the interface. + +What: /sys/bus/usb/devices/usbX/avoid_reset_quirk +Description: + Most devices have this set to zero. + + If the value is 1, enable a USB quirk that prevents this + device to use reset. + + (read/write) + +What: /sys/bus/usb/devices/usbX/devnum +Description: + USB interface device number, in decimal. + +What: /sys/bus/usb/devices/usbX/devpath +Description: + String containing the USB interface device path. + +What: /sys/bus/usb/devices/usbX/manufacturer +Description: + Vendor specific string containing the name of the + manufacturer of the device. + +What: /sys/bus/usb/devices/usbX/maxchild +Description: + Number of ports of an USB hub + +What: /sys/bus/usb/devices/usbX/persist +Description: + Keeps the device even if it gets disconnected. + +What: /sys/bus/usb/devices/usbX/product +Description: + Vendor specific string containing the name of the + device's product. + +What: /sys/bus/usb/devices/usbX/speed +Description: + Shows the device's max speed, according to the USB version, + in Mbps. + Can be: + + ======= ==================== + Unknown speed unknown + 1.5 Low speed + 15 Full speed + 480 High Speed + 5000 Super Speed + 10000 Super Speed+ + 20000 Super Speed+ Gen 2x2 + ======= ==================== + +What: /sys/bus/usb/devices/usbX/supports_autosuspend +Description: + Returns 1 if the device doesn't support autosuspend. + Otherwise, returns 0. + +What: /sys/bus/usb/devices/usbX/urbnum +Description: + Number of URBs submitted for the whole device. + +What: /sys/bus/usb/devices/usbX/version +Description: + String containing the USB device version, as encoded + at the BCD descriptor. + +What: /sys/bus/usb/devices/usbX/power/autosuspend +Description: + Time in milliseconds for the device to autosuspend. If the + value is negative, then autosuspend is prevented. + + (read/write) + +What: /sys/bus/usb/devices/usbX/power/active_duration +Description: + The total time the device has not been suspended. + +What: /sys/bus/usb/devices/usbX/power/connected_duration +Description: + The total time (in msec) that the device has been connected. + +What: /sys/bus/usb/devices/usbX/power/level +Description: + +What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress +Description: + The address of the endpoint described by this descriptor, + in hexadecimal. The endpoint direction on this bitmapped field + is also shown at: + + /sys/bus/usb/devices/usbX/ep_<N>/direction + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval +Description: + The interval of the endpoint as described on its descriptor, + in hexadecimal. The actual interval depends on the version + of the USB. Also shown in time units at + /sys/bus/usb/devices/usbX/ep_<N>/interval. + +What: /sys/bus/usb/devices/usbX/ep_<N>/bLength +Description: + Number of bytes of the endpoint descriptor, in hexadecimal. + +What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes +Description: + Attributes which apply to the endpoint as described on its + descriptor, in hexadecimal. The endpoint type on this + bitmapped field is also shown at: + + /sys/bus/usb/devices/usbX/ep_<N>/type + + See USB specs for its meaning. + +What: /sys/bus/usb/devices/usbX/ep_<N>/direction +Description: + Direction of the endpoint. Can be: + + - both (on control endpoints) + - in + - out + +What: /sys/bus/usb/devices/usbX/ep_<N>/interval +Description: + Interval for polling endpoint for data transfers, in + milisseconds or microseconds. + +What: /sys/bus/usb/devices/usbX/ep_<N>/type +Description: + Descriptor type. Can be: + + - Control + - Isoc + - Bulk + - Interrupt + - unknown + +What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize +Description: + Maximum packet size this endpoint is capable of + sending or receiving, in hexadecimal. |