summaryrefslogtreecommitdiff
path: root/ecos/packages/io/usb/slave/current/include/usbs.h
blob: 2c2b6f5b0ad8c68b7a991464319bdb1a55dc21d5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
#ifndef CYGONCE_USBS_H
# define CYGONCE_USBS_H
//==========================================================================
//
//      include/usbs.h
//
//      The generic USB slave-side support
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 or (at your option) any later version.
//
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with eCos; if not, write to the Free Software Foundation, Inc.,
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
//
// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. However the source code for this file must still be made available
// in accordance with section (3) of the GNU General Public License.
//
// This exception does not invalidate any other reasons why a work based on
// this file might be covered by the GNU General Public License.
//
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
// at http://sources.redhat.com/ecos/ecos-license/
// -------------------------------------------
//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    bartv
// Contributors: bartv
// Date:         2000-10-04
// Purpose:
// Description:  USB slave-side support
//
//
//####DESCRIPTIONEND####
//==========================================================================

# include <pkgconf/system.h>
# include <cyg/infra/cyg_type.h>
# include <cyg/io/usb/usb.h>

#ifdef __cplusplus
extern "C" {
#endif
    
// The USB slave-side eCos support involves a number of different
// components:
//
// 1) a hardware-specific package to drive a specific chip implementation.
//    This provides access to the endpoints. All the hardware-specific
//    packages implement a common interface.
//
// 2) a common package (this one). This defines the interface implemented
//    by the hardware-specific packages. It also provides support for
//    the various generic control messages, using information provided
//    by higher-level code and invoking callbacks as appropriate.
//
// 3) some number of support packages for particular types of
//    application, for example ethernet or mass-storage.
//
// Typically there will only be one USB slave device, although the design
// does allow for multiple devices. Each device should provide a
// usbs_control_endpoint structure and zero or more usbs_data_endpoint
// structures. Each usbs_data_endpoint structure supports uni-directional
// transfers on a single endpoint. If an endpoint can support multiple
// types of transfer then there will be some control operation to switch
// between bulk, interrupt and isochronous.
//
// Access to the USB endpoints can go either via usbs_ calls which
// take a usbs_endpoint structure, or via open/read/write calls. The
// latter is more likely to be used in application code since it
// involves a familiar interface. The former is more appropriate for
// eCos packages layered on top of the USB code. The difference is
// synchronous vs. asynchronous: the open/read/write model involves
// blocking operations, implying a need for extra threads; the usbs_
// calls involve start operations and a completion callback. In
// practice the read and write calls are implemented using the
// lower-level code.

// Enumeration data. This requires information about the hardware,
// specifically what endpoints are available and what they get used
// for. It also requires information about the application class
// packages that are in the configuration, and quite possibly about
// things in application space. Some of the enumeration info such as
// the vendor id is inherently application-specific. Hence there is no
// way of generating part or all of the the enumeration information
// automatically, instead it is up to application code to supply this.
//
// The intention is that application provides all the data via const
// static objects, allowing the data to live in ROM. Alternatively the
// data structures can go into the .data section as normal, allowing
// them to be edited at run-time.
//
// There can be only one device descriptor, so that is part of the
// main enumeration data structure. There can be an unknown number of
// configurations so application code has to initialize an array of
// these. Ditto for interfaces and endpoints. The first x interfaces
// in the array correspond to the first configuration, the next y
// interfaces to the second configuration, etc. The endpoints array
// works in the same way.
//
// In the initial implementation multiple languages are not supported
// so a simple array of strings suffices. The first entry of these
// is still special in that it should define a single supported
// LANGID. All strings should be encoded as per the USB standard:
// a length field, a type code of USB_STRING_DESCRIPTOR_TYPE,
// and data in unicode format. In future multiple language support
// may be supported via configury with the default case remaining
// a single language, thus avoiding incompatibility problems.
    
typedef struct usbs_enumeration_data {
    usb_device_descriptor               device;
    int                                 total_number_interfaces;
    int                                 total_number_endpoints;
    int                                 total_number_strings;
    const usb_configuration_descriptor* configurations;
    const usb_interface_descriptor*     interfaces;
    const usb_endpoint_descriptor*      endpoints;
    const unsigned char**               strings;
} usbs_enumeration_data;
    
// The current state of a USB device. This involves a bit to mark
// whether or not the device has been suspended, plus a state machine.
// On some hardware it may not be possible to distinguish between the
// detached, attached and powered states. If so then the initial state
// will be POWERED.

#define USBS_STATE_DETACHED             0x01
#define USBS_STATE_ATTACHED             0x02
#define USBS_STATE_POWERED              0x03
#define USBS_STATE_DEFAULT              0x04
#define USBS_STATE_ADDRESSED            0x05
#define USBS_STATE_CONFIGURED           0x06
#define USBS_STATE_MASK                 0x7F
#define USBS_STATE_SUSPENDED            (1 << 7)

// State changes. Application code or higher-level packages should
// install an appropriate state change function which will get
// invoked with details of the state change.
typedef enum {
    USBS_STATE_CHANGE_DETACHED          = 1,
    USBS_STATE_CHANGE_ATTACHED          = 2,
    USBS_STATE_CHANGE_POWERED           = 3,
    USBS_STATE_CHANGE_RESET             = 4,    
    USBS_STATE_CHANGE_ADDRESSED         = 5,
    USBS_STATE_CHANGE_CONFIGURED        = 6,
    USBS_STATE_CHANGE_DECONFIGURED      = 7,    
    USBS_STATE_CHANGE_SUSPENDED         = 8,
    USBS_STATE_CHANGE_RESUMED           = 9
} usbs_state_change;

typedef enum {
    USBS_CONTROL_RETURN_HANDLED = 0,
    USBS_CONTROL_RETURN_UNKNOWN = 1,
    USBS_CONTROL_RETURN_STALL   = 2
} usbs_control_return;

typedef struct usbs_control_endpoint {
    // The state is maintained by the USB code and should not be
    // modified by anything higher up.
    int                 state;

    // The enumeration data should be supplied by higher level code,
    // usually the application. Often this data will be constant.
    const usbs_enumeration_data* enumeration_data;
    
    // This function pointer is supplied by the USB device driver.
    // Application code should invoke it directly or via the
    // usbs_start() function when the system is ready. Typically it
    // will cause the USB lines to switch from tristate to active,
    // and the USB host/hub should detect this.
    void                (*start_fn)(struct usbs_control_endpoint*);

    // This function is used for polled operation when interrupts
    // are disabled. This can happen in some debugging contexts.
    // Higher-level code may also need to know about the interrupt
    // number(s) used.
    void                (*poll_fn)(struct usbs_control_endpoint*);
    int                 interrupt_vector;
    
    // When a new control message arrives it will be in this buffer
    // where the appropriate callback functions can examine it. The
    // USB code will not modify the buffer unless a new control
    // message arrives. The control_buffer can also be re-used
    // by handlers to maintain some state information, e.g.
    // for coping with complicated IN requests, but this is only
    // allowed if they actually handle the request.
    unsigned char       control_buffer[8];

    // This callback will be invoked by the USB code following a
    // change in USB state, e.g. to SUSPENDED mode. Higher-level code
    // should install a suitable function. There is some callback data
    // as well. This gets passed explicitly to the callback function,
    // in addition to the control endpoint structure. The reason is
    // that the actual state change callback may be some sort of
    // multiplexer inside a multifunction peripheral, and this
    // multiplexer wants to invoke device-specific state change
    // functions. However in simple devices those device-specific
    // state change functions could be invoked directly.
    void                (*state_change_fn)(struct usbs_control_endpoint*, void*, usbs_state_change, int /* old state */);
    void*               state_change_data;
    // When a standard control message arrives, the device driver will
    // detect some requests such as SET_ADDRESS and handle it
    // internally. Otherwise if higher-level code has installed a
    // callback then that will be invoked. If the callback returns
    // UNKNOWN then the default handler usbs_handle_standard_control()
    // is used to process the request. 
    usbs_control_return (*standard_control_fn)(struct usbs_control_endpoint*, void*);
    void*               standard_control_data;
    
    // These three callbacks are used for other types of control
    // messages. The generic USB code has no way of knowing what
    // such control messages are about.
    usbs_control_return (*class_control_fn)(struct usbs_control_endpoint*, void*);
    void*               class_control_data;
    usbs_control_return (*vendor_control_fn)(struct usbs_control_endpoint*, void*);
    void*               vendor_control_data;
    usbs_control_return (*reserved_control_fn)(struct usbs_control_endpoint*, void*);
    void*               reserved_control_data;

    // If a control operation involves transferring more data than
    // just the initial eight-byte packet, the following fields are
    // used to keep track of the current operation. The original
    // control request indicates the direction of the transfer (IN or
    // OUT) and a length field. For OUT this length is exact, for IN
    // it is an upper bound. The transfer operates mostly as per the
    // bulk protocol, but if the length requested is an exact multiple
    // of the control fifo size (typically eight bytes) then there
    // is no need for an empty packet at the end.
    //
    // For an OUT operation the control message handler should supply
    // a suitable buffer via the "buffer" field below. The only other
    // field of interest is the complete_fn which must be provided and
    // will be invoked once all the data has arrived. Alternatively
    // the OUT operation may get aborted if a new control message
    // arrives. The second argument is an error code -EPIPE or -EIO,
    // or zero to indicate success. The return code is used by the
    // device driver during the status phase.
    //
    // IN is more complicated and the defined interface makes it
    // possible to gather data from multiple locations, eliminating
    // the need for copying into large buffers in some circumstances.
    // Basically when an IN request arrives the device driver will
    // look at the buffer and buffer_size fields, extracting data from
    // there if possible. If the current buffer has been exhausted
    // then the the refill function will be invoked, and this can
    // reset the buffer and size fields to point somewhere else. 
    // This continues until such time that there is no longer
    // a refill function and the current buffer is empty. The
    // refill function can use the refill_data and refill_index
    // to keep track of the current state. The control_buffer
    // fields are available as well. At the end of the transfer,
    // if a completion function has been supplied then it will
    // be invoked. The return code will be ignored.
    unsigned char*      buffer;
    int                 buffer_size;
    void                (*fill_buffer_fn)(struct usbs_control_endpoint*);
    void*               fill_data;
    int                 fill_index;
    usbs_control_return (*complete_fn)(struct usbs_control_endpoint*, int);
} usbs_control_endpoint;

// Data endpoints are a little bit simpler, but not much. From the
// perspective of a device driver things a single buffer is most
// convenient, but that is quite likely to require a max-size buffer
// at a higher level and an additional copy operation. Supplying
// a vector of buffers is a bit more general, but in a layered
// system it may be desirable to prepend to this vector...
// A combination of a current buffer and a refill/empty function
// offers flexibility, at the cost of additional function calls
// from inside the device driver.
//
// FIXME: implement support for fill/empty functions.
//
// Some USB devices may prefer buffers of particular alignment,
// e.g. for DMA purposes. This is hard to reconcile with the
// current interface. However pushing such alignment restrictions
// etc. up into the higher levels is difficult, e.g. it does
// not map at all onto a conventional read/write interface.
// The device driver will just have to do the best it can.
//
// The completion function will be invoked at the end of the transfer.
// The second argument indicates per-transfer completion data. The
// third argument indicates the total amount received, or an error
// code: typically -EPIPE to indicate a broken conenction; -EAGAIN to
// indicate a stall condition; -EMSGSIZE if the host is sending more
// data than the target is expecting; or -EIO to indicate some other
// error. Individual device drivers should avoid generating other
// errors.
typedef struct usbs_rx_endpoint {
    void                (*start_rx_fn)(struct usbs_rx_endpoint*);
    void                (*set_halted_fn)(struct usbs_rx_endpoint*, cyg_bool);
    void                (*complete_fn)(void*, int);
    void*               complete_data;
    unsigned char*      buffer;
    int                 buffer_size;
    cyg_bool            halted;
} usbs_rx_endpoint;

typedef struct usbs_tx_endpoint {
    void                (*start_tx_fn)(struct usbs_tx_endpoint*);
    void                (*set_halted_fn)(struct usbs_tx_endpoint*, cyg_bool);
    void                (*complete_fn)(void*, int);
    void*               complete_data;
    const unsigned char*buffer;
    int                 buffer_size;
    cyg_bool            halted;
} usbs_tx_endpoint;

// Functions called by device drivers.
extern usbs_control_return usbs_handle_standard_control(struct usbs_control_endpoint*);
    
// Utility functions. These just invoke the corresponding function
// pointers in the endpoint structures. It is assumed that the
// necessary fields in the endpoint structures will have been
// filled in already.
extern void     usbs_start(usbs_control_endpoint*);
extern void     usbs_start_rx(usbs_rx_endpoint*);
extern void     usbs_start_tx(usbs_tx_endpoint*);
extern void     usbs_start_rx_buffer(usbs_rx_endpoint*, unsigned char*, int, void (*)(void*, int), void*);
extern void     usbs_start_tx_buffer(usbs_tx_endpoint*, const unsigned char*, int, void (*)(void*, int), void*);
extern cyg_bool usbs_rx_endpoint_halted(usbs_rx_endpoint*);
extern cyg_bool usbs_tx_endpoint_halted(usbs_tx_endpoint*);
extern void     usbs_set_rx_endpoint_halted(usbs_rx_endpoint*, cyg_bool);
extern void     usbs_set_tx_endpoint_halted(usbs_tx_endpoint*, cyg_bool);
extern void     usbs_start_rx_endpoint_wait(usbs_rx_endpoint*, void (*)(void*, int), void*);
extern void     usbs_start_tx_endpoint_wait(usbs_tx_endpoint*, void (*)(void*, int), void*);
    
// Functions that can go into devtab entries. These should not be
// called directly, they are intended only for use by USB device
// drivers.
#if defined(CYGPKG_IO) && defined(CYGPKG_ERROR)
#include <cyg/io/io.h>
extern Cyg_ErrNo usbs_devtab_cwrite(cyg_io_handle_t, const void*, cyg_uint32*);
extern Cyg_ErrNo usbs_devtab_cread(cyg_io_handle_t, void*, cyg_uint32*);
extern Cyg_ErrNo usbs_devtab_get_config(cyg_io_handle_t, cyg_uint32, void*, cyg_uint32*);
extern Cyg_ErrNo usbs_devtab_set_config(cyg_io_handle_t, cyg_uint32, const void*, cyg_uint32*);
#endif

// Additional support for testing.
// Test cases need to have some way of finding out about what support is
// actually provided by the USB device driver, for example what endpoints
// are available. There is no perfect way of achieving this. One approach
// would be to scan through the devtab table looking for devices of the
// form /dev/usbs1r. That is not reliable: the devtab entries may have been
// configured out if higher-level code uses the usb-specific API; or the
// devtab entries may have been renamed. Also having a devtab entry does not
// really give the kind of information a general-purpose testcase needs,
// for example upper bounds on transfer size.    
// 
// An alternative approach is to have a data structure that somehow
// defines the USB hardware, and the USB device driver then creates an
// instance of this. This is the approach actually taken. The problem
// now is how the test code can access this instance. Accessing by
// unique name is simple, as long as there is only one USB device in
// the system (which of course will usually be the case on the USB
// slave side). Alternative approaches such as creating a table at
// link time or a list during static construction time are vulnerable
// either to selective linking or to having these structures present
// in applications other than the test cases. In future it might be
// possible to address the latter issue by extending the build system
// support, e.g. a new library libtesting.a and a new object file
// testing.o.
//
// Note that a given endpoint could be used for bulk transfers some
// of the time, then for isochronous transfers, etc. It is the
// responsibility of the host to only perform one type of IN operation
// for a given endpoint number, and ditto for OUT.    

typedef struct usbs_testing_endpoint {
    int         endpoint_type;          // One of ATTR_CONTROL, ATTR_BULK, ...
    int         endpoint_number;        // Between 0 and 15
    int         endpoint_direction;     // ENDPOINT_IN or ENDPOINT_OUT
    void*       endpoint;               // pointer to the usbs_control_endpoint, usbs_rx_endpoint, ...
    const char* devtab_entry;           // e.g. "/dev/usbs1r", or 0 if inaccessible via devtab
    int         min_size;               // Minimum transfer size
    int         max_size;               // -1 indicates no specific upper bound
    int         max_in_padding;         // extra bytes that the target may send, usually 0.
                                        // Primarily for SA11x0 hardware. It is assumed
                                        // for now that no other hardware will exhibit
                                        // comparable problems.
    int         alignment;              // Buffer should be aligned to a suitable boundary
} usbs_testing_endpoint;

// A specific instance provided by the device driver. The end of
// the table is indicated by a NULL endpoint field.    
extern usbs_testing_endpoint usbs_testing_endpoints[];    

#define USBS_TESTING_ENDPOINTS_TERMINATOR                           \
    {                                                               \
        endpoint_type       : USB_ENDPOINT_DESCRIPTOR_ATTR_CONTROL, \
        endpoint_number     : 0,                                    \
        endpoint_direction  : USB_ENDPOINT_DESCRIPTOR_ENDPOINT_IN,  \
        endpoint            : (void*) 0,                            \
        devtab_entry        : (const char*) 0,                      \
        min_size            : 0,                                    \
        max_size            : 0,                                    \
        max_in_padding      : 0,                                    \
        alignment           : 0                                     \
    }

#define USBS_TESTING_ENDPOINTS_IS_TERMINATOR(_endpoint_) ((void*)0 == (_endpoint_).endpoint)
    
#ifdef __cplusplus
} // extern "C" {
#endif

#endif // CYGONCE_USBS_H