/share/man/man4/ugen.4

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  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.
  8. .\"
  9. .\" Redistribution and use in source and binary forms, with or without
  10. .\" modification, are permitted provided that the following conditions
  11. .\" are met:
  12. .\" 1. Redistributions of source code must retain the above copyright
  13. .\" notice, this list of conditions and the following disclaimer.
  14. .\" 2. Redistributions in binary form must reproduce the above copyright
  15. .\" notice, this list of conditions and the following disclaimer in the
  16. .\" documentation and/or other materials provided with the distribution.
  17. .\"
  18. .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  19. .\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  20. .\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  21. .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  22. .\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23. .\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24. .\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25. .\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26. .\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27. .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28. .\" POSSIBILITY OF SUCH DAMAGE.
  29. .\"
  30. .\" $FreeBSD$
  31. .\"
  32. .Dd July 22, 2012
  33. .Dt UGEN 4
  34. .Os
  35. .Sh NAME
  36. .Nm ugen
  37. .Nd USB generic device support
  38. .Sh SYNOPSIS
  39. .Nm
  40. is integrated into the
  41. .Xr usb 4
  42. kernel module.
  43. .Sh DESCRIPTION
  44. The
  45. .Nm
  46. driver provides support for all USB devices that do not have
  47. a special driver.
  48. It supports access to all parts of the device,
  49. but not in a way that is as convenient as a special purpose driver.
  50. .Pp
  51. There can be up to 127 USB devices connected to a USB bus.
  52. Each USB device can have up to 16 endpoints.
  53. Each of these endpoints
  54. will communicate in one of four different modes: control, isochronous,
  55. bulk, or interrupt.
  56. Each of the endpoints will have a different
  57. device node.
  58. The four least significant bits in the minor device
  59. number determine which endpoint the device accesses, and the rest
  60. of the bits determine which USB device.
  61. .Pp
  62. If an endpoint address is used both for input and output, the device
  63. can be opened for both read or write.
  64. .Pp
  65. To find out which endpoints exist, there are a series of
  66. .Xr ioctl 2
  67. operations on the control endpoint that return the USB descriptors
  68. of the device, configurations, interfaces, and endpoints.
  69. .Pp
  70. The control transfer mode can only happen on the control endpoint
  71. which is always endpoint 0.
  72. The control endpoint accepts a request
  73. and may respond with an answer to such a request.
  74. Control requests
  75. are issued by
  76. .Xr ioctl 2
  77. calls.
  78. .\" .Pp
  79. .\" The isochronous transfer mode can be in or out depending on the
  80. .\" endpoint.
  81. .\" To perform I/O on an isochronous endpoint
  82. .\" .Xr read 2
  83. .\" and
  84. .\" .Xr write 2
  85. .\" should be used.
  86. .\" Before any I/O operations can take place the transfer rate in
  87. .\" bytes/second has to be set.
  88. .\" This is done with
  89. .\" .Xr ioctl 2
  90. .\" .Dv USB_SET_ISO_RATE .
  91. .\" Performing this call sets up a buffer corresponding to
  92. .\" about 1 second of data.
  93. .Pp
  94. The bulk transfer mode can be in or out depending on the
  95. endpoint.
  96. To perform I/O on a bulk endpoint
  97. .Xr read 2
  98. and
  99. .Xr write 2
  100. should be used.
  101. All I/O operations on a bulk endpoint are unbuffered.
  102. .Pp
  103. The interrupt transfer mode can be in or out depending on the
  104. endpoint.
  105. To perform I/O on an interrupt endpoint
  106. .Xr read 2
  107. and
  108. .Xr write 2
  109. should be used.
  110. A moderate amount of buffering is done
  111. by the driver.
  112. .Pp
  113. All endpoints handle the following
  114. .Xr ioctl 2
  115. calls:
  116. .Bl -tag -width indent
  117. .It Dv USB_SET_SHORT_XFER Pq Vt int
  118. Allow short read transfer.
  119. Normally a transfer from the device
  120. which is shorter than the request specified is reported as an
  121. error.
  122. .It Dv USB_SET_TIMEOUT Pq Vt int
  123. Set the timeout on the device operations
  124. The time is specified in milliseconds.
  125. The value 0 is used to indicate that there is
  126. no timeout.
  127. .El
  128. .Pp
  129. The control endpoint (endpoint 0) handles the following
  130. .Xr ioctl 2
  131. calls:
  132. .Bl -tag -width indent
  133. .It Dv USB_GET_CONFIG Pq Vt int
  134. Get the device configuration number.
  135. .It Dv USB_SET_CONFIG Pq Vt int
  136. Set the device into the given configuration number.
  137. .Pp
  138. This operation can only be performed when the control endpoint
  139. is the sole open endpoint.
  140. .It Dv USB_GET_ALTINTERFACE Pq Vt "struct usb_alt_interface"
  141. Get the alternative setting number for the interface with the given
  142. index.
  143. The
  144. .Va uai_config_index
  145. is ignored in this call.
  146. .Bd -literal
  147. struct usb_alt_interface {
  148. int uai_config_index;
  149. int uai_interface_index;
  150. int uai_alt_no;
  151. };
  152. .Ed
  153. .It Dv USB_SET_ALTINTERFACE Pq Vt "struct usb_alt_interface"
  154. Set the alternative setting to the given number in the interface with the
  155. given index.
  156. The
  157. .Va uai_config_index
  158. is ignored in this call.
  159. .Pp
  160. This operation can only be performed when no endpoints for the interface
  161. are open.
  162. .It Dv USB_GET_NO_ALT Pq Vt "struct usb_alt_interface"
  163. Return the number of different alternate settings in the
  164. .Va uai_alt_no
  165. field.
  166. .It Dv USB_GET_DEVICE_DESC Pq Vt usb_device_descriptor_t
  167. Return the device descriptor.
  168. .It Dv USB_GET_CONFIG_DESC Pq Vt "struct usb_config_desc"
  169. Return the descriptor for the configuration with the given index.
  170. For convenience, the current configuration can be specified by
  171. .Dv USB_CURRENT_CONFIG_INDEX .
  172. .Bd -literal
  173. struct usb_config_desc {
  174. int ucd_config_index;
  175. usb_config_descriptor_t ucd_desc;
  176. };
  177. .Ed
  178. .It Dv USB_GET_INTERFACE_DESC Pq Vt "struct usb_interface_desc"
  179. Return the interface descriptor for an interface specified by its
  180. configuration index, interface index, and alternative index.
  181. For convenience, the current alternative can be specified by
  182. .Dv USB_CURRENT_ALT_INDEX .
  183. .Bd -literal
  184. struct usb_interface_desc {
  185. int uid_config_index;
  186. int uid_interface_index;
  187. int uid_alt_index;
  188. usb_interface_descriptor_t uid_desc;
  189. };
  190. .Ed
  191. .It Dv USB_GET_ENDPOINT_DESC Pq Vt "struct usb_endpoint_desc"
  192. Return the endpoint descriptor for the endpoint specified by its
  193. configuration index, interface index, alternative index, and
  194. endpoint index.
  195. .Bd -literal
  196. struct usb_endpoint_desc {
  197. int ued_config_index;
  198. int ued_interface_index;
  199. int ued_alt_index;
  200. int ued_endpoint_index;
  201. usb_endpoint_descriptor_t ued_desc;
  202. };
  203. .Ed
  204. .It Dv USB_GET_FULL_DESC Pq Vt "struct usb_full_desc"
  205. Return all the descriptors for the given configuration.
  206. .Bd -literal
  207. struct usb_full_desc {
  208. int ufd_config_index;
  209. u_int ufd_size;
  210. u_char *ufd_data;
  211. };
  212. .Ed
  213. The
  214. .Va ufd_data
  215. field should point to a memory area of the size given in the
  216. .Va ufd_size
  217. field.
  218. The proper size can be determined by first issuing a
  219. .Dv USB_GET_CONFIG_DESC
  220. and inspecting the
  221. .Va wTotalLength
  222. field.
  223. .It Dv USB_GET_STRING_DESC Pq Vt "struct usb_string_desc"
  224. Get a string descriptor for the given language ID and
  225. string index.
  226. .Bd -literal
  227. struct usb_string_desc {
  228. int usd_string_index;
  229. int usd_language_id;
  230. usb_string_descriptor_t usd_desc;
  231. };
  232. .Ed
  233. .It Dv USB_DO_REQUEST Pq Vt "struct usb_ctl_request"
  234. Send a USB request to the device on the control endpoint.
  235. Any data sent to/from the device is located at
  236. .Va ucr_data .
  237. The size of the transferred data is determined from the
  238. .Va ucr_request .
  239. The
  240. .Va ucr_addr
  241. field is ignored in this call.
  242. The
  243. .Va ucr_flags
  244. field can be used to flag that the request is allowed to
  245. be shorter than the requested size, and
  246. .Va ucr_actlen
  247. will contain the actual size on completion.
  248. .Bd -literal
  249. struct usb_ctl_request {
  250. int ucr_addr;
  251. usb_device_request_t ucr_request;
  252. void *ucr_data;
  253. int ucr_flags;
  254. #define USBD_SHORT_XFER_OK 0x04 /* allow short reads */
  255. int ucr_actlen; /* actual length transferred */
  256. };
  257. .Ed
  258. This is a dangerous operation in that it can perform arbitrary operations
  259. on the device.
  260. Some of the most dangerous (e.g., changing the device
  261. address) are not allowed.
  262. .It Dv USB_GET_DEVICEINFO Pq Vt "struct usb_device_info"
  263. Get an information summary for the device.
  264. This call will not issue any USB transactions.
  265. .El
  266. .Pp
  267. Note that there are two different ways of addressing configurations,
  268. interfaces, alternatives, and endpoints: by index or by number.
  269. The index is the ordinal number (starting from 0) of the descriptor
  270. as presented by the device.
  271. The number is the respective number of
  272. the entity as found in its descriptor.
  273. Enumeration of descriptors
  274. uses the index, getting and setting typically uses numbers.
  275. .Pp
  276. Example:
  277. all endpoints (except the control endpoint) for the current configuration
  278. can be found by iterating the
  279. .Va interface_index
  280. from 0 to
  281. .Va config_desc->bNumInterface Ns \-1
  282. and for each of these, iterating the
  283. .Va endpoint_index
  284. from 0 to
  285. .Va interface_desc->bNumEndpoints .
  286. The
  287. .Va config_index
  288. should be set to
  289. .Dv USB_CURRENT_CONFIG_INDEX
  290. and
  291. .Va alt_index
  292. should be set to
  293. .Dv USB_CURRENT_ALT_INDEX .
  294. .Sh FILES
  295. .Bl -tag -width ".Pa /dev/ugen Ns Ar N Ns Pa \&. Ns Ar EE" -compact
  296. .It Pa /dev/ugen Ns Ar N Ns Pa \&. Ns Ar EE
  297. Endpoint
  298. .Ar EE
  299. of device
  300. .Ar N .
  301. .El
  302. .Sh SEE ALSO
  303. .Xr usb 4
  304. .Sh HISTORY
  305. The
  306. .Nm
  307. driver
  308. appeared in
  309. .Nx 1.4 .
  310. .\" .Sh BUGS
  311. .\" The driver is not yet finished; there is no access to isochronous endpoints.