hidraw
—
Raw Access to HID devices
To compile this driver into the kernel, place the following line in your kernel
configuration file:
device hidraw
device hid
device hidbus
Alternatively, to load the driver as a module at boot time, place
the following line in
loader.conf(5):
The hidraw
driver provides a raw interface to Human
Interface Devices (HIDs). The reports are sent to and received from the device
unmodified.
The device handles 2 sets of
ioctl(2)
calls:
FreeBSD
uhid(4)
-compatible calls:
HID_GET_REPORT_ID
(int)
- Get the report identifier used by this HID report.
HID_GET_REPORT_DESC
(struct hidraw_gen_descriptor)
- Get the HID report descriptor. Copies a maximum of
hgd_maxlen bytes of the report descriptor data into
the memory specified by hgd_data. Upon return
hgd_actlen is set to the number of bytes copied.
Using this descriptor the exact layout and meaning of data to/from the
device can be found. The report descriptor is delivered without any
processing.
struct hidraw_gen_descriptor {
void *hgd_data;
uint16_t hgd_maxlen;
uint16_t hgd_actlen;
uint8_t hgd_report_type;
...
};
HID_SET_IMMED
(int)
- Sets the device in a mode where each
read(2)
will return the current value of the input report. Normally a
read(2)
will only return the data that the device reports on its interrupt pipe.
This call may fail if the device does not support this feature.
HID_GET_REPORT
(struct hidraw_gen_descriptor)
- Get a report from the device without waiting for data on the interrupt
pipe. Copies a maximum of hgd_maxlen bytes of the
report data into the memory specified by hgd_data.
Upon return hgd_actlen is set to the number of bytes
copied. The hgd_report_type field indicates which
report is requested. It should be
HID_INPUT_REPORT
,
HID_OUTPUT_REPORT
, or
HID_FEATURE_REPORT
. On a device which uses
numbered reports, the first byte of the returned data is the report
number. The report data begins from the second byte. For devices which do
not use numbered reports, the report data begins at the first byte. This
call may fail if the device does not support this feature.
HID_SET_REPORT
(struct hidraw_gen_descriptor)
- Set a report in the device. The hgd_report_type
field indicates which report is to be set. It should be
HID_INPUT_REPORT
,
HID_OUTPUT_REPORT
, or
HID_FEATURE_REPORT
. The value of the report is
specified by the hgd_data and the
hgd_maxlen fields. On a device which uses numbered
reports, the first byte of data to be sent is the report number. The
report data begins from the second byte. For devices which do not use
numbered reports, the report data begins at the first byte. This call may
fail if the device does not support this feature.
Linux hidraw
-compatible calls:
HIDIOCGRDESCSIZE
(int)
- Get the HID report descriptor size. Returns the size of the device report
descriptor to use with
HIDIOCGRDESC
ioctl(2).
HIDIOCGRDESC
(struct hidraw_report_descriptor)
- Get the HID report descriptor. Copies a maximum of
size bytes of the report descriptor data into the
memory specified by value.
struct hidraw_report_descriptor {
uint32_t size;
uint8_t value[HID_MAX_DESCRIPTOR_SIZE];
};
HIDIOCGRAWINFO
(struct hidraw_devinfo)
- Get structure containing the bus type, the vendor ID (VID), and product ID
(PID) of the device. The bus type can be one of:
BUS_USB
or BUS_I2C
which
are defined in dev/evdev/input.h.
struct hidraw_devinfo {
uint32_t bustype;
int16_t vendor;
int16_t product;
};
HIDIOCGRAWNAME(len)
(char[] buf)
- Get device description. Copies a maximum of len
bytes of the device description previously set with
device_set_desc(9)
procedure into the memory specified by buf.
HIDIOCGRAWPHYS(len)
(char[] buf)
- Get the newbus path to the device. Copies a maximum of
len bytes of the newbus device path into the memory
specified by buf.
HIDIOCGFEATURE(len)
(void[] buf)
- Get a feature report from the device. Copies a maximum of
len bytes of the feature report data into the memory
specified by buf. The first byte of the supplied
buffer should be set to the report number of the requested report. For
devices which do not use numbered reports, set the first byte to 0. The
report will be returned starting at the first byte of the buffer (ie: the
report number is not returned). This call may fail if the device does not
support this feature.
HIDIOCSFEATURE(len)
(void[] buf)
- Set a feature Report in the device. The value of the report is specified
by the buf and the len
parameters. Set the first byte of the supplied buffer to the report
number. For devices which do not use numbered reports, set the first byte
to 0. The report data begins in the second byte. Make sure to set len
accordingly, to one more than the length of the report (to account for the
report number). This call may fail if the device does not support this
feature.
Use
read(2)
to get data from the device. Data should be read in chunks of the size
prescribed by the report descriptor. On a device which uses numbered
reports, the first byte of the returned data is the report number. The
report data begins from the second byte. For devices which do not use
numbered reports, the report data begins at the first byte.
Use
write(2)
to send data to the device. Data should be written in chunks of the size
prescribed by the report descriptor. The first byte of the buffer passed to
write(2)
should be set to the report number. If the device does not use numbered
reports, there are 2 operation modes: hidraw
mode
and
uhid(4)
mode. In the hidraw
mode, the first byte should be
set to 0 and the report data itself should begin at the second byte. In the
uhid(4)
mode, the report data should begin at the first byte. The modes can be
switched with issuing one of HIDIOCGRDESC
or
HID_GET_REPORT_DESC
ioctl(2)
accordingly. Default mode is hidraw
.
The following variables are available as both
sysctl(8)
variables and
loader(8)
tunables:
- hw.hid.hidraw.debug
- Debug output level, where 0 is debugging disabled and larger values
increase debug message verbosity. Default is 0.
The uhid(4)
driver appeared in NetBSD 1.4.
hidraw
protocol support was added in
FreeBSD 13 by Vladimir
Kondratyev
<wulf@FreeBSD.org>.
This manual page was adopted from NetBSD by
Tom Rhodes
<trhodes@FreeBSD.org>
in April 2002.