Current File : //usr/src/linux-headers-5.15.0-125-generic/include/linux/usb/ch9.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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 host side Linux-USB kernel driver API;
* - the "usbfs" user space API; and
* - the Linux "gadget" device/peripheral side driver API.
*
* USB 2.0 adds an additional "On The Go" (OTG) mode, which lets systems
* act either as a USB host or as a USB device. That means the host and
* device 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 <linux/device.h>
#include <uapi/linux/usb/ch9.h>
/* USB 3.2 SuperSpeed Plus phy signaling rate generation and lane count */
enum usb_ssp_rate {
USB_SSP_GEN_UNKNOWN = 0,
USB_SSP_GEN_2x1,
USB_SSP_GEN_1x2,
USB_SSP_GEN_2x2,
};
extern const char *usb_ep_type_string(int ep_type);
extern const char *usb_speed_string(enum usb_device_speed speed);
extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev);
extern const char *usb_state_string(enum usb_device_state state);
unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd,
enum usb_device_speed speed);
#ifdef CONFIG_TRACING
extern const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
__u8 bRequest, __u16 wValue, __u16 wIndex,
__u16 wLength);
#endif
#endif /* __LINUX_USB_CH9_H */
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