MouseHid.c File Reference

#include "UsbMouse.h"

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Functions
UINT8 *	GetNextHidItem (IN UINT8 *StartPos, IN UINT8 *EndPos, OUT HID_ITEM *HidItem)
UINT32	GetItemData (IN HID_ITEM *HidItem)
VOID	ParseHidItem (IN USB_MOUSE_DEV *UsbMouse, IN HID_ITEM *HidItem)
EFI_STATUS	ParseMouseReportDescriptor (OUT USB_MOUSE_DEV *UsbMouse, IN UINT8 *ReportDescriptor, IN UINTN ReportSize)

Detailed Description

Helper functions to parse HID report descriptor and items.

Copyright (c) 2004 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file MouseHid.c.

Function Documentation

GetItemData()

UINT32 GetItemData

(

IN HID_ITEM *

HidItem

)

Get data from HID item.

This function retrieves data from HID item. It only supports short items, which has 4 types of data: 0, 1, 2, or 4 bytes.

Parameters

HidItem

Pointer to the HID item.

Returns

The data of HID item.

Definition at line 131 of file MouseHid.c.

GetNextHidItem()

UINT8 * GetNextHidItem	(	IN UINT8 *	StartPos,
		IN UINT8 *	EndPos,
		OUT HID_ITEM *	HidItem
	)

Get next HID item from report descriptor.

This function retrieves next HID item from report descriptor, according to the start position. According to USB HID Specification, An item is piece of information about the device. All items have a one-byte prefix that contains the item tag, item type, and item size. There are two basic types of items: short items and long items. If the item is a short item, its optional data size may be 0, 1, 2, or 4 bytes. Only short item is supported here.

Parameters

StartPos	Start position of the HID item to get.
EndPos	End position of the range to get the next HID item.
HidItem	Buffer for the HID Item to return.

Returns

Pointer to end of the HID item returned. NULL if no HID item retrieved.

Definition at line 32 of file MouseHid.c.

ParseHidItem()

VOID ParseHidItem	(	IN USB_MOUSE_DEV *	UsbMouse,
		IN HID_ITEM *	HidItem
	)

Parse HID item from report descriptor.

There are three item types: Main, Global, and Local. This function parses these types of HID items according to tag info.

Parameters

UsbMouse	The instance of USB_MOUSE_DEV
HidItem	The HID item to parse

Definition at line 162 of file MouseHid.c.

ParseMouseReportDescriptor()

EFI_STATUS ParseMouseReportDescriptor	(	OUT USB_MOUSE_DEV *	UsbMouse,
		IN UINT8 *	ReportDescriptor,
		IN UINTN	ReportSize
	)

Parse Mouse Report Descriptor.

According to USB HID Specification, report descriptors are composed of pieces of information. Each piece of information is called an Item. This function retrieves each item from the report descriptor and updates USB_MOUSE_DEV.

Parameters

UsbMouse	The instance of USB_MOUSE_DEV
ReportDescriptor	Report descriptor to parse
ReportSize	Report descriptor size

Return values

EFI_SUCCESS	Report descriptor successfully parsed.
EFI_UNSUPPORTED	Report descriptor contains long item.

Definition at line 242 of file MouseHid.c.