| # |
| # USB Core configuration |
| # |
| config USB_DEBUG |
| bool "USB verbose debug messages" |
| depends on USB |
| help |
| Say Y here if you want the USB core & hub drivers to produce a bunch |
| of debug messages to the system log. Select this if you are having a |
| problem with USB support and want to see more of what is going on. |
| |
| config USB_ANNOUNCE_NEW_DEVICES |
| bool "USB announce new devices" |
| depends on USB |
| default N |
| help |
| Say Y here if you want the USB core to always announce the |
| idVendor, idProduct, Manufacturer, Product, and SerialNumber |
| strings for every new USB device to the syslog. This option is |
| usually used by distro vendors to help with debugging and to |
| let users know what specific device was added to the machine |
| in what location. |
| |
| If you do not want this kind of information sent to the system |
| log, or have any doubts about this, say N here. |
| |
| comment "Miscellaneous USB options" |
| depends on USB |
| |
| config USB_DEVICEFS |
| bool "USB device filesystem (DEPRECATED)" |
| depends on USB |
| ---help--- |
| If you say Y here (and to "/proc file system support" in the "File |
| systems" section, above), you will get a file /proc/bus/usb/devices |
| which lists the devices currently connected to your USB bus or |
| busses, and for every connected device a file named |
| "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the |
| device number; the latter files can be used by user space programs |
| to talk directly to the device. These files are "virtual", meaning |
| they are generated on the fly and not stored on the hard drive. |
| |
| You may need to mount the usbfs file system to see the files, use |
| mount -t usbfs none /proc/bus/usb |
| |
| For the format of the various /proc/bus/usb/ files, please read |
| <file:Documentation/usb/proc_usb_info.txt>. |
| |
| Modern Linux systems do not use this. |
| |
| Usbfs entries are files and not character devices; usbfs can't |
| handle Access Control Lists (ACL) which are the default way to |
| grant access to USB devices for untrusted users of a desktop |
| system. |
| |
| The usbfs functionality is replaced by real device-nodes managed by |
| udev. These nodes lived in /dev/bus/usb and are used by libusb. |
| |
| config USB_DEVICE_CLASS |
| bool "USB device class-devices (DEPRECATED)" |
| depends on USB |
| default y |
| ---help--- |
| Userspace access to USB devices is granted by device-nodes exported |
| directly from the usbdev in sysfs. Old versions of the driver |
| core and udev needed additional class devices to export device nodes. |
| |
| These additional devices are difficult to handle in userspace, if |
| information about USB interfaces must be available. One device |
| contains the device node, the other device contains the interface |
| data. Both devices are at the same level in sysfs (siblings) and one |
| can't access the other. The device node created directly by the |
| usb device is the parent device of the interface and therefore |
| easily accessible from the interface event. |
| |
| This option provides backward compatibility for libusb device |
| nodes (lsusb) when usbfs is not used, and the following udev rule |
| doesn't exist: |
| SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ |
| NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" |
| |
| config USB_DYNAMIC_MINORS |
| bool "Dynamic USB minor allocation" |
| depends on USB |
| help |
| If you say Y here, the USB subsystem will use dynamic minor |
| allocation for any device that uses the USB major number. |
| This means that you can have more than 16 of a single type |
| of device (like USB printers). |
| |
| If you are unsure about this, say N here. |
| |
| config USB_SUSPEND |
| bool "USB runtime power management (autosuspend) and wakeup" |
| depends on USB && PM_RUNTIME |
| help |
| If you say Y here, you can use driver calls or the sysfs |
| "power/control" file to enable or disable autosuspend for |
| individual USB peripherals (see |
| Documentation/usb/power-management.txt for more details). |
| |
| Also, USB "remote wakeup" signaling is supported, whereby some |
| USB devices (like keyboards and network adapters) can wake up |
| their parent hub. That wakeup cascades up the USB tree, and |
| could wake the system from states like suspend-to-RAM. |
| |
| If you are unsure about this, say N here. |
| |
| config USB_OTG |
| bool "OTG support" |
| depends on USB && EXPERIMENTAL |
| depends on USB_SUSPEND |
| default n |
| help |
| The most notable feature of USB OTG is support for a |
| "Dual-Role" device, which can act as either a device |
| or a host. The initial role is decided by the type of |
| plug inserted and can be changed later when two dual |
| role devices talk to each other. |
| |
| Select this only if your board has Mini-AB/Micro-AB |
| connector. |
| |
| config USB_OTG_WHITELIST |
| bool "Rely on OTG Targeted Peripherals List" |
| depends on USB_OTG || EXPERT |
| default y if USB_OTG |
| default n if EXPERT |
| help |
| If you say Y here, the "otg_whitelist.h" file will be used as a |
| product whitelist, so USB peripherals not listed there will be |
| rejected during enumeration. This behavior is required by the |
| USB OTG specification for all devices not on your product's |
| "Targeted Peripherals List". "Embedded Hosts" are likewise |
| allowed to support only a limited number of peripherals. |
| |
| Otherwise, peripherals not listed there will only generate a |
| warning and enumeration will continue. That's more like what |
| normal Linux-USB hosts do (other than the warning), and is |
| convenient for many stages of product development. |
| |
| config USB_OTG_BLACKLIST_HUB |
| bool "Disable external hubs" |
| depends on USB_OTG || EXPERT |
| help |
| If you say Y here, then Linux will refuse to enumerate |
| external hubs. OTG hosts are allowed to reduce hardware |
| and software costs by not supporting external hubs. So |
| are "Embedded Hosts" that don't offer OTG support. |
| |