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/* 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_ep_type_string() - Returns human readable-name of the endpoint type.
* @ep_type: The endpoint type to return human-readable name for. If it's not
* usually got by usb_endpoint_type(), the string 'unknown' will be returned.
extern const char *usb_ep_type_string(int ep_type);
* 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_get_maximum_speed - Get maximum requested speed for a given USB
* controller.
* @dev: Pointer to the given USB controller device
* The function gets the maximum speed string from property "maximum-speed",
* and returns the corresponding enum usb_device_speed.
extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
* usb_get_maximum_ssp_rate - Get the signaling rate generation and lane count
* of a SuperSpeed Plus capable device.
* @dev: Pointer to the given USB controller device
* If the string from "maximum-speed" property is super-speed-plus-genXxY where
* 'X' is the generation number and 'Y' is the number of lanes, then this
* function returns the corresponding enum usb_ssp_rate.
extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev);
* 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);
* usb_decode_ctrl - Returns human readable representation of control request.
* @str: buffer to return a human-readable representation of control request.
* This buffer should have about 200 bytes.
* @size: size of str buffer.
* @bRequestType: matches the USB bmRequestType field
* @bRequest: matches the USB bRequest field
* @wValue: matches the USB wValue field (CPU byte order)
* @wIndex: matches the USB wIndex field (CPU byte order)
* @wLength: matches the USB wLength field (CPU byte order)
* Function returns decoded, formatted and human-readable description of
* control request packet.
* The usage scenario for this is for tracepoints, so function as a return
* use the same value as in parameters. This approach allows to use this
* function in TP_printk
* Important: wValue, wIndex, wLength parameters before invoking this function
* should be processed by le16_to_cpu macro.
extern const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
__u8 bRequest, __u16 wValue, __u16 wIndex,
__u16 wLength);
#endif /* __LINUX_USB_CH9_H */