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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /include/linux/usb/ch9.h |
Initial import
Diffstat (limited to 'include/linux/usb/ch9.h')
-rw-r--r-- | include/linux/usb/ch9.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h new file mode 100644 index 000000000..27603bcbb --- /dev/null +++ b/include/linux/usb/ch9.h @@ -0,0 +1,55 @@ +/* + * This file holds USB constants and structures that are needed for + * USB device APIs. These are used by the USB device model, which is + * defined in chapter 9 of the USB 2.0 specification and in the + * Wireless USB 1.0 (spread around). Linux has several APIs in C that + * need these: + * + * - the master/host side Linux-USB kernel driver API; + * - the "usbfs" user space API; and + * - the Linux "gadget" slave/device/peripheral side driver API. + * + * USB 2.0 adds an additional "On The Go" (OTG) mode, which lets systems + * act either as a USB master/host or as a USB slave/device. That means + * the master and slave side APIs benefit from working well together. + * + * There's also "Wireless USB", using low power short range radios for + * peripheral interconnection but otherwise building on the USB framework. + * + * Note all descriptors are declared '__attribute__((packed))' so that: + * + * [a] they never get padded, either internally (USB spec writers + * probably handled that) or externally; + * + * [b] so that accessing bigger-than-a-bytes fields will never + * generate bus errors on any platform, even when the location of + * its descriptor inside a bundle isn't "naturally aligned", and + * + * [c] for consistency, removing all doubt even when it appears to + * someone that the two other points are non-issues for that + * particular descriptor type. + */ +#ifndef __LINUX_USB_CH9_H +#define __LINUX_USB_CH9_H + +#include <uapi/linux/usb/ch9.h> + + +/** + * usb_speed_string() - Returns human readable-name of the speed. + * @speed: The speed to return human-readable name for. If it's not + * any of the speeds defined in usb_device_speed enum, string for + * USB_SPEED_UNKNOWN will be returned. + */ +extern const char *usb_speed_string(enum usb_device_speed speed); + + +/** + * usb_state_string - Returns human readable name for the state. + * @state: The state to return a human-readable name for. If it's not + * any of the states devices in usb_device_state_string enum, + * the string UNKNOWN will be returned. + */ +extern const char *usb_state_string(enum usb_device_state state); + +#endif /* __LINUX_USB_CH9_H */ |