c8d141ce1b
USB is a HOST/DEVICE protocol, as per the specification and all documentation. Fix up terms that are not applicable to make things match up with the terms used through the rest of the USB stack. Acked-by: Felipe Balbi <balbi@kernel.org> Link: https://lore.kernel.org/r/20200701171555.3198836-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
101 lines
3.9 KiB
C
101 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* This file holds USB constants and structures that are needed for
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* USB device APIs. These are used by the USB device model, which is
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* defined in chapter 9 of the USB 2.0 specification and in the
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* Wireless USB 1.0 (spread around). Linux has several APIs in C that
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* need these:
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*
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* - the host side Linux-USB kernel driver API;
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* - the "usbfs" user space API; and
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* - the Linux "gadget" device/peripheral side driver API.
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*
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* USB 2.0 adds an additional "On The Go" (OTG) mode, which lets systems
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* act either as a USB host or as a USB device. That means the host and
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* device side APIs benefit from working well together.
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*
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* There's also "Wireless USB", using low power short range radios for
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* peripheral interconnection but otherwise building on the USB framework.
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*
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* Note all descriptors are declared '__attribute__((packed))' so that:
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*
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* [a] they never get padded, either internally (USB spec writers
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* probably handled that) or externally;
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*
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* [b] so that accessing bigger-than-a-bytes fields will never
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* generate bus errors on any platform, even when the location of
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* its descriptor inside a bundle isn't "naturally aligned", and
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*
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* [c] for consistency, removing all doubt even when it appears to
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* someone that the two other points are non-issues for that
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* particular descriptor type.
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*/
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#ifndef __LINUX_USB_CH9_H
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#define __LINUX_USB_CH9_H
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#include <linux/device.h>
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#include <uapi/linux/usb/ch9.h>
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/**
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* usb_ep_type_string() - Returns human readable-name of the endpoint type.
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* @ep_type: The endpoint type to return human-readable name for. If it's not
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* any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
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* usually got by usb_endpoint_type(), the string 'unknown' will be returned.
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*/
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extern const char *usb_ep_type_string(int ep_type);
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/**
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* usb_speed_string() - Returns human readable-name of the speed.
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* @speed: The speed to return human-readable name for. If it's not
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* any of the speeds defined in usb_device_speed enum, string for
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* USB_SPEED_UNKNOWN will be returned.
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*/
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extern const char *usb_speed_string(enum usb_device_speed speed);
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/**
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* usb_get_maximum_speed - Get maximum requested speed for a given USB
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* controller.
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* @dev: Pointer to the given USB controller device
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*
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* The function gets the maximum speed string from property "maximum-speed",
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* and returns the corresponding enum usb_device_speed.
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*/
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extern enum usb_device_speed usb_get_maximum_speed(struct device *dev);
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/**
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* usb_state_string - Returns human readable name for the state.
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* @state: The state to return a human-readable name for. If it's not
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* any of the states devices in usb_device_state_string enum,
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* the string UNKNOWN will be returned.
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*/
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extern const char *usb_state_string(enum usb_device_state state);
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#ifdef CONFIG_TRACING
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/**
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* usb_decode_ctrl - Returns human readable representation of control request.
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* @str: buffer to return a human-readable representation of control request.
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* This buffer should have about 200 bytes.
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* @size: size of str buffer.
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* @bRequestType: matches the USB bmRequestType field
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* @bRequest: matches the USB bRequest field
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* @wValue: matches the USB wValue field (CPU byte order)
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* @wIndex: matches the USB wIndex field (CPU byte order)
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* @wLength: matches the USB wLength field (CPU byte order)
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*
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* Function returns decoded, formatted and human-readable description of
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* control request packet.
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*
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* The usage scenario for this is for tracepoints, so function as a return
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* use the same value as in parameters. This approach allows to use this
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* function in TP_printk
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*
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* Important: wValue, wIndex, wLength parameters before invoking this function
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* should be processed by le16_to_cpu macro.
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*/
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extern const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
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__u8 bRequest, __u16 wValue, __u16 wIndex,
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__u16 wLength);
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#endif
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#endif /* __LINUX_USB_CH9_H */
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