*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->OpenBSD man pages -> ugen (4)              



NAME    [Toc]    [Back]

     ugen - USB generic device support

SYNOPSIS    [Toc]    [Back]

     ugen* at uhub? port ? configuration ?

DESCRIPTION    [Toc]    [Back]

     The ugen driver provides support for all USB devices that do
not have a
     special  driver.  It supports access to all parts of the device, but not
     in a way that is as convenient as a special purpose  driver.

     There  can  be up to 127 USB devices connected to a USB bus.
Each USB device
 can have up to 16 endpoints.  Each of  these  endpoints
will communicate
  in  one of four different modes: control, isochronous,
bulk, or interrupt.
  Each of the endpoints will have a different device
node.  The
     four  least  significant bits in the minor device number determine which
     endpoint the device accesses and the rest of the bits determine which USB

     If an endpoint address is used both for input and output the
device can
     be opened for both read or write.

     To find out what endpoints  exist  there  are  a  series  of
ioctl(2) operations
 available for the control endpoint that return the USB
     of the device, configurations, interfaces, and endpoints.

     The control transfer mode can only  happen  on  the  control
endpoint, which
     is  always  endpoint  0.   Control  requests  are  issued by
ioctl(2) calls.

     The bulk transfer mode can be in or  out  depending  on  the
endpoint.  To
     perform  I/O  on a bulk endpoint read(2) and write(2) should
be used.  All
     I/O operations on a bulk endpoint are unbuffered.

     The interrupt transfer mode can only be in.  To perform  input from an interrupt
  endpoint read(2) should be used.  A moderate amount
of buffering
     is done by the driver.

     All endpoints handle the following ioctl(2) calls:

             Allow short read transfer.  Normally a transfer from
the device
             which  is  shorter than the request specified is reported as an error.

     USB_SET_TIMEOUT (int)
             Set the timeout on the device operations,  the  time
is specified
             in  milliseconds.   The  value 0 is used to indicate
that there is
             no timeout.

     The control endpoint  (endpoint  0)  handles  the  following
ioctl(2) calls:

     USB_GET_CONFIG (int)
             Get the device configuration number.

     USB_SET_CONFIG (int)
             Set  the device into the given configuration number.
This operation
 can only be performed when the control endpoint
is the sole
             open endpoint.

     USB_GET_ALTINTERFACE (struct usb_alt_interface)
             Get the alternative setting number for the interface
with the
             given index.  The  uai_config_index  is  ignored  in
this call.

             struct usb_alt_interface {
                     int     uai_config_index;
                     int     uai_interface_index;
                     int     uai_alt_no;
     USB_SET_ALTINTERFACE (struct usb_alt_interface)
             Set  the  alternative setting to the given number in
the interface
             with the given index.  The uai_config_index  is  ignored in this

             This  operation  can  only be performed when no endpoints for the
             interface are open.

     USB_GET_NO_ALT (struct usb_alt_interface)
             Return the number of different alternate settings in
             uai_alt_no field.

     USB_GET_DEVICE_DESC (usb_device_descriptor_t)
             Return the device descriptor.

     USB_GET_CONFIG_DESC (struct usb_config_desc)
             Return the descriptor for the configuration with the
given index.
             For convenience the  current  configuration  can  be
specified by

             struct usb_config_desc {
                     int     ucd_config_index;
                     usb_config_descriptor_t ucd_desc;

     USB_GET_INTERFACE_DESC (struct usb_interface_desc)
             Return  the  interface  descriptor  for an interface
specified by its
             configuration index, interface index,  and  alternative index.  For
             convenience the current alternative can be specified

             struct usb_interface_desc {
                     int     uid_config_index;
                     int     uid_interface_index;
                     int     uid_alt_index;
                     usb_interface_descriptor_t uid_desc;

     USB_GET_ENDPOINT_DESC (struct usb_endpoint_desc)
             Return the  endpoint  descriptor  for  the  endpoint
specified by its
             configuration  index,  interface  index, alternative
index, and endpoint

             struct usb_endpoint_desc {
                     int     ued_config_index;
                     int     ued_interface_index;
                     int     ued_alt_index;
                     int     ued_endpoint_index;
                     usb_endpoint_descriptor_t ued_desc;

     USB_GET_FULL_DESC (struct usb_full_desc)
             Return all the descriptors for the given  configuration.

             struct usb_full_desc {
                     int     ufd_config_index;
                     u_int   ufd_size;
                     u_char  *ufd_data;

             The  ufd_data field should point to a memory area of
the size given
 in the ufd_size field.  The proper  size  can  be
determined by
             first  issuing  a USB_GET_CONFIG_DESC and inspecting
             wTotalLength field.

     USB_GET_STRING_DESC (struct usb_string_desc)
             Get a string descriptor for the  given  language  id
and string index.

             struct usb_string_desc {
                     int     usd_string_index;
                     int     usd_language_id;
                     usb_string_descriptor_t usd_desc;

             Send a USB request to the device on the control endpoint.  Any
             data sent to/from the device is located at ucr_data.
The size of
             the   transferred   data   is  determined  from  the
ucr_request.  The
             ucr_addr field is ignored in this call.

             struct usb_ctl_request {
                     int     ucr_addr;
                     usb_device_request_t ucr_request;
                     void    *ucr_data;
                     int     ucr_flags;
             #define  USBD_SHORT_XFER_OK       0x04     /*  allow
short reads */
                     int      ucr_actlen;              /*  actual
length transferred */
             This is a dangerous operation in that it can perform
             operations  on the device.  Some of the most dangerous (e.g.,
             changing the device address) are not allowed.

     USB_GET_DEVICEINFO (struct usb_device_info)
             Get an information summary  for  the  device.   This
call will not
             issue any USB transactions.

     Note that there are two different ways of addressing configurations, interfaces,
 alternatives, and endpoints: by index or  by  number.  The index
     is the ordinal number (starting from 0) of the descriptor as
presented by
     the device.  The number is the respective number of the  entity as found
     in  its  descriptor.  Enumeration of descriptors use the index, getting and
     setting typically uses numbers.

     Example: All endpoints (except the control endpoint) for the
current configuration
  can  be  found  by iterating the interface_index
from 0 to
     config_desc->bNumInterface-1 and for each of these iterating
     endpoint_index  from  0 to interface_desc-*(GtbNumEndpoints.
     config_index  should  set  to  USB_CURRENT_CONFIG_INDEX  and
alt_index should
     be set to USB_CURRENT_ALT_INDEX.

FILES    [Toc]    [Back]

     /dev/ugenN.EE                     Endpoint EE of device N.

SEE ALSO    [Toc]    [Back]

     intro(4), uhub(4), usb(4)

HISTORY    [Toc]    [Back]

     The ugen driver appeared in OpenBSD 2.6.

BUGS    [Toc]    [Back]

     The  driver  is  not  yet  finished;  there  is no access to
isochronous endpoints.

OpenBSD     3.6                        December     15,      2003
[ Back ]
 Similar pages
Name OS Title
wsdisplay OpenBSD generic display device support in wscons
uhid FreeBSD USB generic HID support
uhid OpenBSD USB generic HID support
wskbd OpenBSD generic keyboard support in wscons
wlan FreeBSD generic 802.11 link-layer support
wsmouse OpenBSD generic mouse support in wscons
smb FreeBSD SMB generic I/O device driver
iic FreeBSD I2C generic i/o device driver
lpt FreeBSD generic printer device driver
ioctl HP-UX generic device control commands
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service