.\" $NetBSD: ugen.4,v 1.15 2002/02/13 08:17:50 ross Exp $ .\" .\" Copyright (c) 1999 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Lennart Augustsson. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the NetBSD .\" Foundation, Inc. and its contributors. .\" 4. Neither the name of The NetBSD Foundation nor the names of its .\" contributors may be used to endorse or promote products derived .\" from this software without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .Dd July 12, 1998 .Dt UGEN 4 .Os .Sh NAME .Nm ugen .Nd USB generic device support .Sh SYNOPSIS .Cd "ugen* at uhub?" .Sh DESCRIPTION The .Nm 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. .Pp 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 determines which endpoint the device accesses and the rest of the bits determines which USB device. .Pp If an endpoint address is used both for input and output the device can be opened for both read or write. .Pp To find out what endpoints that exist there are a series of .Xr ioctl 2 operation on the control endpoint that returns the USB descriptors of the device, configurations, interfaces, and endpoints. .Pp The control transfer mode can only happen on the control endpoint which is always endpoint 0. The control endpoint accepts request and may respond with an answer to such request. Control request are issued by .Xr ioctl 2 calls. .\" .Pp .\" The isochronous transfer mode can be in or out depending on the .\" endpoint. To perform IO on an isochronous endpoint .\" .Xr read 2 .\" and .\" .Xr write 2 .\" should be used. .\" Before any IO operations can take place the transfer rate in .\" bytes/second has to be set. This is done with .\" .Xr ioctl 2 .\" .Dv USB_SET_ISO_RATE . .\" Performing this call sets up a buffer corresponding to .\" about 1 second of data. .Pp The bulk transfer mode can be in or out depending on the endpoint. To perform IO on a bulk endpoint .Xr read 2 and .Xr write 2 should be used. All IO operations on a bulk endpoint are unbuffered. .Pp The interrupt transfer mode can only be in. To perform input from an interrupt endpoint .Xr read 2 should be used. A moderate amount of buffering is done by the driver. .Pp All endpoints handle the following .Xr ioctl 2 calls: .Pp .Bl -tag -width indent -compact .It Dv USB_SET_SHORT_XFER (int) Allow short read transfer. Normally a transfer from the device which is shorter than the request specified is reported as an error. .It Dv 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. .El .Pp The control endpoint (endpoint 0) handles the following .Xr ioctl 2 calls: .Pp .Bl -tag -width indent -compact .It Dv USB_GET_CONFIG (int) Get the device configuration number. .It Dv USB_SET_CONFIG (int) Set the device into the given configuration number. .br This operation can only be performed when the control endpoint is the sole open endpoint. .It Dv USB_GET_ALTINTERFACE (struct usb_alt_interface) Get the alternative setting number for the interface with the given index. The .Dv config_index is ignored in this call. .Bd -literal struct usb_alt_interface { int config_index; int interface_index; int alt_no; }; .Ed .It Dv USB_SET_ALTINTERFACE (struct usb_alt_interface) Set the alternative setting to the given number in the interface with the given index. The .Dv config_index is ignored in this call. .br This operation can only be performed when no endpoints for the interface are open. .It Dv USB_GET_NO_ALT (struct usb_alt_interface) Return the number of different alternate settings in the .Dv alt_no field. .It Dv USB_GET_DEVICE_DESC (usb_device_descriptor_t) Return the device descriptor. .It Dv 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 .Dv USB_CURRENT_CONFIG_INDEX . .Bd -literal struct usb_config_desc { int config_index; usb_config_descriptor_t desc; }; .Ed .It Dv 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 by .Dv USB_CURRENT_ALT_INDEX . .Bd -literal struct usb_interface_desc { int config_index; int interface_index; int alt_index; usb_interface_descriptor_t desc; }; .Ed .It Dv 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 index. .Bd -literal struct usb_endpoint_desc { int config_index; int interface_index; int alt_index; int endpoint_index; usb_endpoint_descriptor_t desc; }; .Ed .It Dv USB_GET_FULL_DESC (struct usb_full_desc) Return all the descriptors for the given configuration. .Bd -literal struct usb_full_desc { int config_index; u_int size; u_char *data; }; .Ed The .Dv data field should point to a memory area of of the size given in the .Dv size field. The proper size can be determined by first issuing a .Dv USB_GET_CONFIG_DESC and inspecting the .Dv wTotalLength field. .It Dv USB_GET_STRING_DESC (struct usb_string_desc) Get a string descriptor for the given language id and string index. .Bd -literal struct usb_string_desc { int string_index; int language_id; usb_string_descriptor_t desc; }; .Ed .It Dv USB_DO_REQUEST Send a USB request to the device on the control endpoint. Any data sent to/from the device is located at .Dv data . The size of the transferred data is determined from the .Dv request . The .Dv addr field is ignored in this call. The .Dv flags field can be used to flag that the request is allowed to be shorter than the requested size, and the .Dv actlen will contain the actual size on completion. .Bd -literal struct usb_ctl_request { int addr; usb_device_request_t request; void *data; int flags; #define USBD_SHORT_XFER_OK 0x04 /* allow short reads */ int actlen; /* actual length transferred */ }; .Ed This is a dangerous operation in that it can perform arbitrary operations on the device. Some of the most dangerous (e.g., changing the device address) are not allowed. .It Dv USB_GET_DEVICEINFO (struct usb_device_info) Get an information summary for the device. This call will not issue any USB transactions. .El .Pp 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. .Pp Example: All endpoints (except the control endpoint) for the current configuration can be found by iterating the .Dv interface_index from 0 to .Dv config_desc-\*[Gt]bNumInterface-1 and for each of these iterating the .Dv endpoint_index from 0 to .Dv interface_desc-\*[Gt]bNumEndpoints . The .Dv config_index should set to .Dv USB_CURRENT_CONFIG_INDEX and .Dv alt_index should be set to .Dv USB_CURRENT_ALT_INDEX . .Sh FILES .Bl -tag -width Pa .It Pa /dev/ugenN.EE Endpoint .Pa EE of device .Pa N . .El .Sh SEE ALSO .Xr usb 4 .Sh HISTORY The .Nm driver appeared in .Nx 1.4 . .\" .Sh BUGS .\" The driver is not yet finished; there is no access to isochronous endpoints.