xref: /freebsd/share/man/man4/ugen.4 (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
1.\" $NetBSD: ugen.4,v 1.13 2001/09/11 22:52:54 wiz Exp $
2.\"
3.\" Copyright (c) 1999 The NetBSD Foundation, Inc.
4.\" All rights reserved.
5.\"
6.\" This code is derived from software contributed to The NetBSD Foundation
7.\" by Lennart Augustsson.
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30.\" $FreeBSD$
31.\"
32.Dd November 22, 2006
33.Dt UGEN 4
34.Os
35.Sh NAME
36.Nm ugen
37.Nd USB generic device support
38.Sh SYNOPSIS
39To compile this driver into the kernel,
40place the following line in your
41kernel configuration file:
42.Bd -ragged -offset indent
43.Cd "device ugen"
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
50ugen_load="YES"
51.Ed
52.Sh DESCRIPTION
53The
54.Nm
55driver provides support for all USB devices that do not have
56a special driver.
57It supports access to all parts of the device,
58but not in a way that is as convenient as a special purpose driver.
59.Pp
60There can be up to 127 USB devices connected to a USB bus.
61Each USB device can have up to 16 endpoints.
62Each of these endpoints
63will communicate in one of four different modes: control, isochronous,
64bulk, or interrupt.
65Each of the endpoints will have a different
66device node.
67The four least significant bits in the minor device
68number determines which endpoint the device accesses and the rest
69of the bits determines which USB device.
70.Pp
71If an endpoint address is used both for input and output the device
72can be opened for both read or write.
73.Pp
74To find out what endpoints that exist there are a series of
75.Xr ioctl 2
76operation on the control endpoint that returns the USB descriptors
77of the device, configurations, interfaces, and endpoints.
78.Pp
79The control transfer mode can only happen on the control endpoint
80which is always endpoint 0.
81The control endpoint accepts request
82and may respond with an answer to such request.
83Control request
84are issued by
85.Xr ioctl 2
86calls.
87.\" .Pp
88.\" The isochronous transfer mode can be in or out depending on the
89.\" endpoint.
90.\" To perform I/O on an isochronous endpoint
91.\" .Xr read 2
92.\" and
93.\" .Xr write 2
94.\" should be used.
95.\" Before any I/O operations can take place the transfer rate in
96.\" bytes/second has to be set.
97.\" This is done with
98.\" .Xr ioctl 2
99.\" .Dv USB_SET_ISO_RATE .
100.\" Performing this call sets up a buffer corresponding to
101.\" about 1 second of data.
102.Pp
103The bulk transfer mode can be in or out depending on the
104endpoint.
105To perform I/O on a bulk endpoint
106.Xr read 2
107and
108.Xr write 2
109should be used.
110All I/O operations on a bulk endpoint are unbuffered.
111.Pp
112The interrupt transfer mode can be in or out depending on the
113endpoint.
114To perform I/O on an interrupt endpoint
115.Xr read 2
116and
117.Xr write 2
118should be used.
119A moderate amount of buffering is done
120by the driver.
121.Pp
122All endpoints handle the following
123.Xr ioctl 2
124calls:
125.Bl -tag -width indent
126.It Dv USB_SET_SHORT_XFER Pq Vt int
127Allow short read transfer.
128Normally a transfer from the device
129which is shorter than the request specified is reported as an
130error.
131.It Dv USB_SET_TIMEOUT Pq Vt int
132Set the timeout on the device operations, the time is specified
133in milliseconds.
134The value 0 is used to indicate that there is
135no timeout.
136.El
137.Pp
138The control endpoint (endpoint 0) handles the following
139.Xr ioctl 2
140calls:
141.Bl -tag -width indent
142.It Dv USB_GET_CONFIG Pq Vt int
143Get the device configuration number.
144.It Dv USB_SET_CONFIG Pq Vt int
145Set the device into the given configuration number.
146.Pp
147This operation can only be performed when the control endpoint
148is the sole open endpoint.
149.It Dv USB_GET_ALTINTERFACE Pq Vt "struct usb_alt_interface"
150Get the alternative setting number for the interface with the given
151index.
152The
153.Va uai_config_index
154is ignored in this call.
155.Bd -literal
156struct usb_alt_interface {
157	int	uai_config_index;
158	int	uai_interface_index;
159	int	uai_alt_no;
160};
161.Ed
162.It Dv USB_SET_ALTINTERFACE Pq Vt "struct usb_alt_interface"
163Set the alternative setting to the given number in the interface with the
164given index.
165The
166.Va uai_config_index
167is ignored in this call.
168.Pp
169This operation can only be performed when no endpoints for the interface
170are open.
171.It Dv USB_GET_NO_ALT Pq Vt "struct usb_alt_interface"
172Return the number of different alternate settings in the
173.Va uai_alt_no
174field.
175.It Dv USB_GET_DEVICE_DESC Pq Vt usb_device_descriptor_t
176Return the device descriptor.
177.It Dv USB_GET_CONFIG_DESC Pq Vt "struct usb_config_desc"
178Return the descriptor for the configuration with the given index.
179For convenience the current configuration can be specified by
180.Dv USB_CURRENT_CONFIG_INDEX .
181.Bd -literal
182struct usb_config_desc {
183	int	ucd_config_index;
184	usb_config_descriptor_t ucd_desc;
185};
186.Ed
187.It Dv USB_GET_INTERFACE_DESC Pq Vt "struct usb_interface_desc"
188Return the interface descriptor for an interface specified by its
189configuration index, interface index, and alternative index.
190For convenience the current alternative can be specified by
191.Dv USB_CURRENT_ALT_INDEX .
192.Bd -literal
193struct usb_interface_desc {
194	int	uid_config_index;
195	int	uid_interface_index;
196	int	uid_alt_index;
197	usb_interface_descriptor_t uid_desc;
198};
199.Ed
200.It Dv USB_GET_ENDPOINT_DESC Pq Vt "struct usb_endpoint_desc"
201Return the endpoint descriptor for the endpoint specified by its
202configuration index, interface index, alternative index, and
203endpoint index.
204.Bd -literal
205struct usb_endpoint_desc {
206	int	ued_config_index;
207	int	ued_interface_index;
208	int	ued_alt_index;
209	int	ued_endpoint_index;
210	usb_endpoint_descriptor_t ued_desc;
211};
212.Ed
213.It Dv USB_GET_FULL_DESC Pq Vt "struct usb_full_desc"
214Return all the descriptors for the given configuration.
215.Bd -literal
216struct usb_full_desc {
217	int	ufd_config_index;
218	u_int	ufd_size;
219	u_char	*ufd_data;
220};
221.Ed
222The
223.Va ufd_data
224field should point to a memory area of the size given in the
225.Va ufd_size
226field.
227The proper size can be determined by first issuing a
228.Dv USB_GET_CONFIG_DESC
229and inspecting the
230.Va wTotalLength
231field.
232.It Dv USB_GET_STRING_DESC Pq Vt "struct usb_string_desc"
233Get a string descriptor for the given language ID and
234string index.
235.Bd -literal
236struct usb_string_desc {
237	int	usd_string_index;
238	int	usd_language_id;
239	usb_string_descriptor_t usd_desc;
240};
241.Ed
242.It Dv USB_DO_REQUEST Pq Vt "struct usb_ctl_request"
243Send a USB request to the device on the control endpoint.
244Any data sent to/from the device is located at
245.Va ucr_data .
246The size of the transferred data is determined from the
247.Va ucr_request .
248The
249.Va ucr_addr
250field is ignored in this call.
251The
252.Va ucr_flags
253field can be used to flag that the request is allowed to
254be shorter than the requested size, and the
255.Va ucr_actlen
256will contain the actual size on completion.
257.Bd -literal
258struct usb_ctl_request {
259	int	ucr_addr;
260	usb_device_request_t ucr_request;
261	void	*ucr_data;
262	int	ucr_flags;
263#define USBD_SHORT_XFER_OK	0x04	/* allow short reads */
264	int	ucr_actlen;		/* actual length transferred */
265};
266.Ed
267This is a dangerous operation in that it can perform arbitrary operations
268on the device.
269Some of the most dangerous (e.g., changing the device
270address) are not allowed.
271.It Dv USB_GET_DEVICEINFO Pq Vt "struct usb_device_info"
272Get an information summary for the device.
273This call will not
274issue any USB transactions.
275.El
276.Pp
277Note that there are two different ways of addressing configurations, interfaces,
278alternatives, and endpoints: by index or by number.
279The index is the ordinal number (starting from 0) of the descriptor
280as presented by the device.
281The number is the respective number of
282the entity as found in its descriptor.
283Enumeration of descriptors
284use the index, getting and setting typically uses numbers.
285.Pp
286Example:
287all endpoints (except the control endpoint) for the current configuration
288can be found by iterating the
289.Va interface_index
290from 0 to
291.Va config_desc->bNumInterface Ns \-1
292and for each of these iterating the
293.Va endpoint_index
294from 0 to
295.Va interface_desc->bNumEndpoints .
296The
297.Va config_index
298should set to
299.Dv USB_CURRENT_CONFIG_INDEX
300and
301.Va alt_index
302should be set to
303.Dv USB_CURRENT_ALT_INDEX .
304.Sh FILES
305.Bl -tag -width ".Pa /dev/ugen Ns Ar N Ns Pa \&. Ns Ar EE" -compact
306.It Pa /dev/ugen Ns Ar N Ns Pa \&. Ns Ar EE
307Endpoint
308.Ar EE
309of device
310.Ar N .
311.El
312.Sh SEE ALSO
313.Xr usb 4
314.Sh HISTORY
315The
316.Nm
317driver
318appeared in
319.Nx 1.4 .
320.\" .Sh BUGS
321.\" The driver is not yet finished; there is no access to isochronous endpoints.
322