13 unstall - USB device driver library
16 .ta 8n +8n +8n +8n +8n +8n +8n
19 #include "../lib/usb.h"
23 char* dir; /* path for the endpoint dir */
24 int id; /* usb id for device or ep. number */
25 int dfd; /* descriptor for the data file */
26 int cfd; /* descriptor for the control file */
27 int maxpkt; /* cached from usb description */
28 Usbdev* usb; /* USB description */
29 void* aux; /* for the device driver */
30 void (*free)(void*); /* idem. to release aux */
31 char* hname; /* hash name, unique for device */
35 ulong csp; /* USB class/subclass/proto */
36 int vid; /* vendor id */
37 int did; /* product (device) id */
38 int dno; /* device release number */
42 int ls; /* low speed */
43 int class; /* from descriptor */
44 int nconf; /* from descriptor */
45 Conf* conf[Nconf]; /* configurations */
46 Ep* ep[Nep]; /* all endpoints in device */
47 Desc* ddesc[Nddesc]; /* (raw) device specific descriptors */
51 uchar addr; /* endpt address */
52 uchar dir; /* direction, Ein/Eout */
53 uchar type; /* Econtrol, Eiso, Ebulk, Eintr */
54 uchar isotype; /* Eunknown, Easync, Eadapt, Esync */
56 int maxpkt; /* max. packet size */
57 Conf* conf; /* the endpoint belongs to */
58 Iface* iface; /* the endpoint belongs to */
64 void* aux; /* for the driver program */
68 int id; /* interface number */
69 ulong csp; /* USB class/subclass/proto */
72 void* aux; /* for the driver program */
76 int cval; /* value for set configuration */
78 int milliamps; /* maximum power in this config. */
79 Iface* iface[Niface]; /* up to 16 interfaces */
83 Conf* conf; /* where this descriptor was read */
84 Iface* iface; /* last iface before desc in conf. */
85 Ep* ep; /* last endpt before desc in conf. */
86 Altc* altc; /* last alt.c. before desc in conf. */
87 DDesc data; /* unparsed standard USB descriptor */
92 uchar bDescriptorType;
94 /* extra bytes allocated here to keep the rest of it */
97 #define Class(csp) ((csp)&0xff)
98 #define Subclass(csp) (((csp)>>8)&0xff)
99 #define Proto(csp) (((csp)>>16)&0xff)
100 #define CSP(c, s, p) ((c) | ((s)<<8) | ((p)<<16))
102 #define PUT2(p,v) ...
104 #define PUT4(p,v) ...
105 #define dprint if(usbdebug)fprint
106 #define ddprint if(usbdebug > 1)fprint
109 char* classname(int c);
110 void closedev(Dev *d);
111 int configdev(Dev *d);
112 int devctl(Dev *dev, char *fmt, ...);
113 void* emallocz(ulong size, int zero);
114 char* estrdup(char *s);
115 char* hexstr(void *a, int n);
116 char* loaddevstr(Dev *d, int sid);
117 Dev* opendev(char *fn);
118 int opendevdata(Dev *d, int mode);
119 Dev* openep(Dev *d, int id);
120 int unstall(Dev *dev, Dev *ep, int dir);
121 int usbcmd(Dev *d, int type, int req,
122 int value, int index, uchar *data, int count);
123 Dev* getdev(char *devid);
125 extern int usbdebug; /* more messages for bigger values */
128 This library provides convenience structures and functions to write
130 It is not intended for user programs using USB devices.
133 for a description of the interfaces provided for that purpose.
137 to perform I/O through USB as well as on
139 to perform the initial configuration for the device's setup endpoint.
140 The rest of the work is up to the driver and is where this library may help.
142 An endpoint as provided by
147 The setup endpoint for a
148 device represents the USB device, because it is the means to
149 configure and operate the device.
150 This structure is reference counted.
153 adjust the number of references to one, initially.
154 The driver is free to call
158 to add references and
160 to drop references (and release resources when the last one vanishes).
161 As an aid to the driver, the field
163 may keep driver-specific data and the function
165 will be called (if not null) to release the
167 structure when the reference count goes down to zero.
170 holds the path for the endpoint's directory.
174 keeps the device number for setup endpoints and the endpoint number
175 for all other endpoints.
176 For example, it would be
184 It is easy to remember this because the former is created to operate
185 on the device, while the later has been created as a particular endpoint
193 control file descriptors, respectively.
196 is created the control file is open, initially.
198 file requires calling
200 with the appropriate mode.
202 When the device configuration information has been loaded (see below),
204 holds the maximum packet size (in bytes) for the endpoint and
206 keeps the rest of the USB information.
208 Most of the information in
211 various device and configuration descriptors provided by the device,
212 by calling one of the functions described later.
213 Only descriptors unknown
214 to the library are kept unparsed at
216 as an aid for the driver
217 (which should know how to parse them and what to do with the information).
223 for the endpoint with directory
225 Usually, the endpoint is a setup endpoint representing a device. The endpoint
226 control file is open, but the data file is not. The USB description is void.
227 In most cases drivers call
231 and do not call this function directly.
234 opens the data file for the device supplied and
235 loads and parses its configuration information.
236 After calling it, the device is ready for I/O and the USB description in
240 Control requests for an endpoint may be written by calling
244 It is better not to call
246 directly because the control request should be issued as a single
251 for a list of available control requests (not to be confused with
252 USB control transfers performed on a control endpoint).
255 opens the data file for the device according to the given
257 The mode must match that of the endpoint, doing otherwise is considered
259 Actual I/O is performed by reading/writing the descriptor kept in the
264 For control endpoints,
265 it is not necessary to call
272 issues a USB control request to the device
274 (not to be confused with a
276 control request sent to its control file).
278 retries the control request several times upon failure because some devices
280 The format of requests is fixed per the USB standard:
282 is the type of request and
284 identifies the request. Arguments
288 are parameters to the request and the last two arguments,
301 if no transfer (other than the control request) has to take place.
302 The library header file includes numerous symbols defined to help writing
303 the type and arguments for a request.
305 The return value from
307 is the number of bytes transferred, zero to indicate a stall and -1
308 to indicate an error.
310 A common request is to unstall an endpoint that has been stalled
311 due to some reason by the device (eg., when read or write indicate
312 a count of zero bytes read or written on the endpoint). The function
315 It is given the device that stalled the endpoint,
320 and the direction of the stall (one of
324 The function takes care of notifying the device of the unstall as well
325 as notifying the kernel.
328 returns the class part of the number given, representing a CSP.
330 does the same for the device subclass and
335 which builds a CSP from the device class, subclass, and protocol.
338 knows the name (for those with constants in the library header file).
344 get and put a (little-endian) two-byte value and are useful to
345 parse descriptors and replies for control requests.
355 but abort program operation upon failure.
359 is a format routine suitable for
366 returns a string representing a dump (in hexadecimal) of
370 The string is allocated using
372 and memory must be released by the caller.
375 returns the string obtained by reading the device string descriptor number
378 .B /sys/src/cmd/nusb/lib
383 Not heavily exercised yet.