hid.h File Reference

USB HID (Human Interface Device) device class, HID 1.11. More...

#include "usb_class.h"

Data Structures
struct	hid_iface
	One generic HID interface: a single instance of the class on a device. More...
struct	usb_hid_descriptor
	The 9-byte HID descriptor that points at the Report descriptor (Sec.6.2.1). More...
struct	hid_opts
	Per-instance configuration for a generic HID interface. More...

Macros
#define	HID_REPORT_INPUT
	Report types (high byte of wValue in Get/Set_Report), HID 1.11 Sec.7.2.1.
#define	HID_REPORT_OUTPUT
	Output report (host -> device)
#define	HID_REPORT_FEATURE
	Feature report (either direction, control only)
#define	HID_SUBCLASS_NONE
	hid_opts::subclass - bInterfaceSubClass, HID 1.11 Sec.4.2.
#define	HID_SUBCLASS_BOOT
	Boot interface: the fixed report layout a BIOS parses.
#define	HID_PROTOCOL_NONE
	hid_opts::protocol - bInterfaceProtocol, HID 1.11 Sec.4.3.
#define	HID_PROTOCOL_KEYBOARD
	Boot keyboard: 8-byte Input report.
#define	HID_PROTOCOL_MOUSE
	Boot mouse: 3-byte Input report.
#define	HID_BOOT_PROTOCOL
	hid_iface::protocol - Get/Set_Protocol values, HID 1.11 Sec.7.2.5.
#define	HID_REPORT_PROTOCOL
	Host wants the Report descriptor's layout (default)
Report-descriptor item helpers (HID 1.11 Sec.6.2.2 short items)
Each macro expands to one short item (prefix byte + data byte(s)), so a Report descriptor reads like the spec when written as a static const uint8_t[]: static const uint8_t mouse[] = { HID_USAGE_PAGE(0x01), HID_USAGE(0x02), HID_COLLECTION(0x01), ... HID_END_COLLECTION }; The three item classes behave differently, and mixing them up is the usual reason a descriptor parses but describes the wrong device: Global (Usage Page, Logical Min/Max, Report Size/Count/ID) stays in force for every item that follows, until changed again. Local (Usage, Usage Min/Max) applies only to the next Main item, then is discarded. Main (Input, Output, Feature, Collection) is what actually declares fields in a report, out of the Global and Local state standing at that point.
#define	HID_USAGE_PAGE(x)
	Global: Usage Page in force for the Usages that follow - 1-byte page id, e.g.
#define	HID_USAGE_PAGE16(x)
	Global: HID_USAGE_PAGE with a 2-byte page id, for pages above 0xFF - notably the vendor-defined 0xFF00..0xFFFF range used by raw devices.
#define	HID_USAGE(x)
	Local: Usage for the next Main item, within the current Usage Page - e.g.
#define	HID_USAGE_MIN(x)
	Local: first Usage of a consecutive run applied to the next Main item.
#define	HID_USAGE_MAX(x)
	Local: last Usage of that run - HID_USAGE_MIN(0xE0), HID_USAGE_MAX(0xE7) hands the eight keyboard modifier Usages to the eight fields of the next Main item, in order.
#define	HID_LOGICAL_MIN(x)
	Global: smallest value a field may report, as one signed byte (-128..127).
#define	HID_LOGICAL_MAX(x)
	Global: largest value a field may report, as one signed byte - so it tops out at.
#define	HID_LOGICAL_MAX16(x)
	Global: HID_LOGICAL_MAX with 2 little-endian data bytes, for ranges a signed byte cannot hold - HID_LOGICAL_MAX16(255) for a byte-wide raw field, or a digitiser's absolute coordinate range.
#define	HID_REPORT_SIZE(x)
	Global: width of one field, in bits (not bytes).
#define	HID_REPORT_COUNT(x)
	Global: how many fields of that width the next Main item declares.
#define	HID_REPORT_ID(x)
	Global: start a numbered report.
#define	HID_COLLECTION(x)
	Main: open a collection - 0x00 Physical, 0x01 Application, 0x02 Logical (Sec.6.2.2.6).
#define	HID_END_COLLECTION
	Main: close the innermost open collection.
#define	HID_INPUT(x)
	Main: declare device -> host fields, sent on the interrupt IN pipe.
#define	HID_OUTPUT(x)
	Main: declare host -> device fields, taken from the interrupt OUT pipe or a SET_REPORT(Output) - keyboard LEDs are the classic case.
#define	HID_FEATURE(x)
	Main: declare fields the host reads and writes over EP0 only, with GET_REPORT/SET_REPORT(Feature) - configuration and state rather than live data.

Functions
hid_iface *	hid_add (usbip_device *dev, const hid_opts *opts)
	Add a generic HID interface to a device.
int	hid_send_report (hid_iface *iface, const void *data, int len)
	Send one Input report to the host on the interrupt-IN pipe (device -> host).

Variables
const usbip_device_class	usbip_device_hid
	The HID class, for usbip_device_add_class()

Detailed Description

USB HID (Human Interface Device) device class, HID 1.11.

A generic HID interface: hand it any Report descriptor and it presents a proper HID device - keyboard, mouse, consumer control, or a vendor-defined raw device. It answers the full HID 1.11 request set on EP0 (GET/SET_REPORT, GET/SET_IDLE, GET/SET_PROTOCOL) plus the required interrupt IN and an optional interrupt OUT for Output reports (HID 1.11 Sec.4.4, Sec.7.2, Appendix G).

Built only on the public API (usbip_device.h). Mirrors python classes/device/hid.py.