xref: /freebsd/share/man/man4/hidraw.4 (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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30.Dd August 6, 2023
31.Dt HIDRAW 4
32.Os
33.Sh NAME
34.Nm hidraw
35.Nd Raw Access to HID devices
36.Sh SYNOPSIS
37To compile this driver into the kernel,
38place the following line in your
39kernel configuration file:
40.Bd -ragged -offset indent
41.Cd "device hidraw"
42.Cd "device hid"
43.Cd "device hidbus"
44.Ed
45.Pp
46Alternatively, to load the driver as a
47module at boot time, place the following line in
48.Xr loader.conf 5 :
49.Bd -literal -offset indent
50hidraw_load="YES"
51.Ed
52.Sh DESCRIPTION
53The
54.Nm
55driver provides a raw interface to Human Interface Devices (HIDs).
56The reports are sent to and received from the device unmodified.
57.Pp
58The device handles 2 sets of
59.Xr ioctl 2
60calls:
61.Pp
62.Fx
63.Xr uhid 4
64\-compatible calls:
65.Bl -tag -width indent
66.It Dv HIDRAW_GET_REPORT_ID Pq Vt int
67Get the report identifier used by this HID report.
68.It Dv HIDRAW_GET_REPORT_DESC Pq Vt "struct hidraw_gen_descriptor"
69Get the HID report descriptor.
70Copies a maximum of
71.Va hgd_maxlen
72bytes of the report descriptor data into the memory
73specified by
74.Va hgd_data .
75Upon return
76.Va hgd_actlen
77is set to the number of bytes copied.
78Using
79this descriptor the exact layout and meaning of data to/from
80the device can be found.
81The report descriptor is delivered
82without any processing.
83.Bd -literal
84struct hidraw_gen_descriptor {
85	void   *hgd_data;
86	uint16_t hgd_maxlen;
87	uint16_t hgd_actlen;
88	uint8_t	hgd_report_type;
89	...
90};
91.Ed
92.It Dv HIDRAW_SET_IMMED Pq Vt int
93Sets the device in a mode where each
94.Xr read 2
95will return the current value of the input report.
96Normally
97a
98.Xr read 2
99will only return the data that the device reports on its
100interrupt pipe.
101This call may fail if the device does not support
102this feature.
103.It Dv HIDRAW_GET_REPORT Pq Vt "struct hidraw_gen_descriptor"
104Get a report from the device without waiting for data on
105the interrupt pipe.
106Copies a maximum of
107.Va hgd_maxlen
108bytes of the report data into the memory specified by
109.Va hgd_data .
110Upon return
111.Va hgd_actlen
112is set to the number of bytes copied.
113The
114.Va hgd_report_type
115field indicates which report is requested.
116It should be
117.Dv HID_INPUT_REPORT ,
118.Dv HID_OUTPUT_REPORT ,
119or
120.Dv HID_FEATURE_REPORT .
121On a device which uses numbered reports, the first byte of the returned data
122is the report number.
123The report data begins from the second byte.
124For devices which do not use numbered reports, the report data begins at the
125first byte.
126This call may fail if the device does not support this feature.
127.It Dv HIDRAW_SET_REPORT Pq Vt "struct hidraw_gen_descriptor"
128Set a report in the device.
129The
130.Va hgd_report_type
131field indicates which report is to be set.
132It should be
133.Dv HID_INPUT_REPORT ,
134.Dv HID_OUTPUT_REPORT ,
135or
136.Dv HID_FEATURE_REPORT .
137The value of the report is specified by the
138.Va hgd_data
139and the
140.Va hgd_maxlen
141fields.
142On a device which uses numbered reports, the first byte of data to be sent is
143the report number.
144The report data begins from the second byte.
145For devices which do not use numbered reports, the report data begins at the
146first byte.
147This call may fail if the device does not support this feature.
148.It Dv HIDRAW_GET_DEVICEINFO Pq Vt "struct hidraw_device_info"
149Returns information about the device, like vendor ID and product ID.
150This call will not issue any hardware transfers.
151.El
152.Pp
153Linux
154.Nm
155\-compatible calls:
156.Bl -tag -width indent
157.It Dv HIDIOCGRDESCSIZE Pq Vt int
158Get the HID report descriptor size.
159Returns the size of the device report descriptor to use with
160.Dv HIDIOCGRDESC
161.Xr ioctl 2 .
162.It Dv HIDIOCGRDESC Pq Vt "struct hidraw_report_descriptor"
163Get the HID report descriptor.
164Copies a maximum of
165.Va size
166bytes of the report descriptor data into the memory
167specified by
168.Va value .
169.Bd -literal
170struct hidraw_report_descriptor {
171	uint32_t	size;
172	uint8_t		value[HID_MAX_DESCRIPTOR_SIZE];
173};
174.Ed
175.It Dv HIDIOCGRAWINFO Pq Vt "struct hidraw_devinfo"
176Get structure containing the bus type, the vendor ID (VID), and product ID
177(PID) of the device.
178The bus type can be one of:
179.Dv BUS_USB
180or
181.Dv BUS_I2C
182which are defined in dev/evdev/input.h.
183.Bd -literal
184struct hidraw_devinfo {
185	uint32_t	bustype;
186	int16_t		vendor;
187	int16_t		product;
188};
189.Ed
190.It Dv HIDIOCGRAWNAME(len) Pq Vt "char[] buf"
191Get device description.
192Copies a maximum of
193.Va len
194bytes of the device description previously set with
195.Xr device_set_desc 9
196procedure into the memory
197specified by
198.Va buf .
199.It Dv HIDIOCGRAWPHYS(len) Pq Vt "char[] buf"
200Get the newbus path to the device.
201.\For Bluetooth devices, it returns the hardware (MAC) address of the device.
202Copies a maximum of
203.Va len
204bytes of the newbus device path
205into the memory
206specified by
207.Va buf .
208.It Dv HIDIOCGFEATURE(len) Pq Vt "void[] buf"
209Get a feature report from the device.
210Copies a maximum of
211.Va len
212bytes of the feature report data into the memory specified by
213.Va buf .
214The first byte of the supplied buffer should be set to the report
215number of the requested report.
216For devices which do not use numbered reports, set the first byte to 0.
217The report will be returned starting at the first byte of the buffer
218(ie: the report number is not returned).
219This call may fail if the device does not support this feature.
220.It Dv HIDIOCSFEATURE(len) Pq Vt "void[] buf"
221Set a feature Report in the device.
222The value of the report is specified by the
223.Va buf
224and the
225.Va len
226parameters.
227Set the first byte of the supplied buffer to the report number.
228For devices which do not use numbered reports, set the first byte to 0.
229The report data begins in the second byte.
230Make sure to set len accordingly, to one more than the length of the report
231(to account for the report number).
232This call may fail if the device does not support this feature.
233.El
234.Pp
235Use
236.Xr read 2
237to get data from the device.
238Data should be read in chunks of the
239size prescribed by the report descriptor.
240On a device which uses numbered reports, the first byte of the returned data
241is the report number.
242The report data begins from the second byte.
243For devices which do not use numbered reports, the report data begins at the
244first byte.
245.Pp
246Use
247.Xr write 2
248to send data to the device.
249Data should be written in chunks of the
250size prescribed by the report descriptor.
251The first byte of the buffer passed to
252.Xr write 2
253should be set to the report number.
254If the device does not use numbered reports, there are 2 operation modes:
255.Nm
256mode and
257.Xr uhid 4
258mode.
259In the
260.Nm
261mode, the first byte should be set to 0 and the report data itself should
262begin at the second byte.
263In the
264.Xr uhid 4
265mode, the report data should begin at the first byte.
266The modes can be switched with issuing one of
267.Dv HIDIOCGRDESC
268or
269.Dv HID_GET_REPORT_DESC
270.Xr ioctl 2
271accordingly.
272Default mode is
273.Nm .
274.Sh SYSCTL VARIABLES
275The following variables are available as both
276.Xr sysctl 8
277variables and
278.Xr loader 8
279tunables:
280.Bl -tag -width indent
281.It Va hw.hid.hidraw.debug
282Debug output level, where 0 is debugging disabled and larger values increase
283debug message verbosity.
284Default is 0.
285.El
286.Sh FILES
287.Bl -tag -width ".Pa /dev/hidraw?"
288.It Pa /dev/hidraw?
289.El
290.Sh SEE ALSO
291.Xr usbhidctl 1 ,
292.Xr hid 4 ,
293.Xr hidbus 4 ,
294.Xr uhid 4
295.Sh HISTORY
296The
297.Xr uhid 4
298driver
299appeared in
300.Nx 1.4 .
301.Nm
302protocol support was added in
303.Fx 13
304by
305.An Vladimir Kondratyev Aq Mt wulf@FreeBSD.org .
306This manual page was adopted from
307.Nx
308by
309.An Tom Rhodes Aq Mt trhodes@FreeBSD.org
310in April 2002.
311