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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 <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,
- };
- struct device;
- 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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