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
|
/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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 3 of the License, or
(at your option) any later version.
ChibiOS/RT 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file io_serial.h
* @brief I/O serial devices access.
* @details This header defines abstract interfaces useful to access generic
* I/O serial devices in a standardized way.
*
* @addtogroup IO_SERIAL
* @details This module defines an abstract interface for I/O channels by
* extending the @p BaseSequentialStream interface. Note that no code
* is present, I/O channels are just abstract interface like
* structures, you should look at the systems as to a set of abstract
* C++ classes (even if written in C). Specific device drivers can
* use/extend the interface and implement them.<br>
* This system has the advantage to make the access to channels
* independent from the implementation logic.
* @{
*/
#ifndef _IO_SERIAL_H_
#define _IO_SERIAL_H_
/**
* @brief @p BaseChannel specific methods.
*/
#define _base_channel_methods \
_base_sequential_stream_methods \
/* Channel output check.*/ \
bool_t (*putwouldblock)(void *instance); \
/* Channel input check.*/ \
bool_t (*getwouldblock)(void *instance); \
/* Channel put method with timeout specification.*/ \
msg_t (*put)(void *instance, uint8_t b, systime_t time); \
/* Channel get method with timeout specification.*/ \
msg_t (*get)(void *instance, systime_t time); \
/* Channel write method with timeout specification.*/ \
size_t (*writet)(void *instance, const uint8_t *bp, \
size_t n, systime_t time); \
/* Channel read method with timeout specification.*/ \
size_t (*readt)(void *instance, uint8_t *bp, size_t n, systime_t time);
/**
* @brief @p BaseChannel specific data.
* @note It is empty because @p BaseChannel is only an interface without
* implementation.
*/
#define _base_channel_data \
_base_sequential_stream_data
/**
* @extends BaseSequentialStreamVMT
*
* @brief @p BaseChannel virtual methods table.
*/
struct BaseChannelVMT {
_base_channel_methods
};
/**
* @extends BaseSequentialStream
*
* @brief Base channel class.
* @details This class represents a generic, byte-wide, I/O channel. This class
* introduces generic I/O primitives with timeout specification.
*/
typedef struct {
/** @brief Virtual Methods Table.*/
const struct BaseChannelVMT *vmt;
_base_channel_data
} BaseChannel;
/**
* @name Macro Functions (BaseChannel)
* @{
*/
/**
* @brief Channel output check.
* @details This function verifies if a subsequent put/write operation would
* block.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @return The output queue status.
* @retval FALSE if the output queue has space and would not block a
* write operation.
* @retval TRUE if the output queue is full and would block a write
* operation.
*
* @api
*/
#define srlPutWouldBlock(ip) ((ip)->vmt->putwouldblock(ip))
/**
* @brief Channel input check.
* @details This function verifies if a subsequent get/read operation would
* block.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @return The input queue status.
* @retval FALSE if the input queue contains data and would not block a
* read operation.
* @retval TRUE if the input queue is empty and would block a read
* operation.
*
* @api
*/
#define srlGetWouldBlock(ip) ((ip)->vmt->getwouldblock(ip))
/**
* @brief Channel blocking byte write.
* @details This function writes a byte value to a channel. If the channel
* is not ready to accept data then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[in] b the byte value to be written to the channel
* @return The operation status.
* @retval Q_OK if the operation succeeded.
* @retval Q_RESET if the channel associated queue (if any) was reset.
*
* @api
*/
#define srlPut(ip, b) ((ip)->vmt->put(ip, b, TIME_INFINITE))
/**
* @brief Channel blocking byte write with timeout.
* @details This function writes a byte value to a channel. If the channel
* is not ready to accept data then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[in] b the byte value to be written to the channel
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval Q_OK if the operation succeeded.
* @retval Q_TIMEOUT if the specified time expired.
* @retval Q_RESET if the channel associated queue (if any) was reset.
*
* @api
*/
#define srlPutTimeout(ip, b, time) ((ip)->vmt->put(ip, b, time))
/**
* @brief Channel blocking byte read.
* @details This function reads a byte value from a channel. If the data
* is not available then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @return A byte value from the queue.
* @retval Q_RESET if the channel associated queue (if any) has been
* reset.
*
* @api
*/
#define srlGet(ip) ((ip)->vmt->get(ip, TIME_INFINITE))
/**
* @brief Channel blocking byte read with timeout.
* @details This function reads a byte value from a channel. If the data
* is not available then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return A byte value from the queue.
* @retval Q_TIMEOUT if the specified time expired.
* @retval Q_RESET if the channel associated queue (if any) has been
* reset.
*
* @api
*/
#define srlGetTimeout(ip, time) ((ip)->vmt->get(ip, time))
/**
* @brief Channel blocking write with timeout.
* @details The function writes data from a buffer to a channel. If the channel
* is not ready to accept data then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[out] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The number of bytes transferred.
*
* @api
*/
#define srlWriteTimeout(ip, bp, n, time) ((ip)->vmt->writet(ip, bp, n, time))
/**
* @brief Channel blocking read with timeout.
* @details The function reads data from a channel into a buffer. If the data
* is not available then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[in] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The number of bytes transferred.
*
* @api
*/
#define srlReadTimeout(ip, bp, n, time) ((ip)->vmt->readt(ip, bp, n, time))
/** @} */
#if CH_USE_EVENTS || defined(__DOXYGEN__)
/**
* @name I/O status flags
* @{
*/
/** @brief No pending conditions.*/
#define IO_NO_ERROR 0
/** @brief Connection happened.*/
#define IO_CONNECTED 1
/** @brief Disconnection happened.*/
#define IO_DISCONNECTED 2
/** @brief Data available in the input queue.*/
#define IO_INPUT_AVAILABLE 4
/** @brief Output queue empty.*/
#define IO_OUTPUT_EMPTY 8
/** @brief Transmission end.*/
#define IO_TRANSMISSION_END 16
/** @} */
/**
* @brief Type of an I/O condition flags mask.
*/
typedef uint_fast16_t ioflags_t;
/**
* @brief @p BaseAsynchronousChannel specific methods.
*/
#define _base_asynchronous_channel_methods \
_base_channel_methods \
/* Channel read method with timeout specification.*/ \
ioflags_t (*getflags)(void *instance);
/**
* @brief @p BaseAsynchronousChannel specific data.
*/
#define _base_asynchronous_channel_data \
_base_channel_data \
/* I/O condition event source.*/ \
EventSource event; \
/* I/O condition flags.*/ \
ioflags_t flags;
/**
* @extends BaseChannelVMT
*
* @brief @p BaseAsynchronousChannel virtual methods table.
*/
struct BaseAsynchronousChannelVMT {
_base_asynchronous_channel_methods
};
/**
* @extends BaseChannel
*
* @brief Base asynchronous channel class.
* @details This class extends @p BaseChannel by adding event sources fields
* for asynchronous I/O for use in an event-driven environment.
*/
typedef struct {
/** @brief Virtual Methods Table.*/
const struct BaseAsynchronousChannelVMT *vmt;
_base_asynchronous_channel_data
} BaseAsynchronousChannel;
/**
* @name Macro Functions (BaseAsynchronousChannel)
* @{
*/
/**
* @brief Returns the I/O condition event source.
* @details The event source is broadcasted when an I/O condition happens.
*
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
* class
* @return A pointer to an @p EventSource object.
*
* @api
*/
#define srlGetEventSource(ip) (&((ip)->event))
/**
* @brief Adds status flags to the channel's mask.
* @details This function is usually called from the I/O ISRs in order to
* notify I/O conditions such as data events, errors, signal
* changes etc.
*
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
* class
* @param[in] mask condition flags to be added to the mask
*
* @iclass
*/
#define srlAddFlagsI(ip, mask) { \
(ip)->flags |= (mask); \
chEvtBroadcastI(&(ip)->event); \
}
/**
* @brief Returns and clears the status flags associated to the channel.
*
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
* class
* @return The condition flags modified since last time this
* function was invoked.
*
* @api
*/
#define srlGetAndClearFlags(ip) ((ip)->vmt->getflags(ip))
/** @} */
/**
* @brief Default implementation of the @p getflags virtual method.
*
* @param[in] ip pointer to a @p BaseAsynchronousChannel or derived
* class
* @return The condition flags modified since last time this
* function was invoked.
*
* @notapi
*/
#define _ser_get_and_clear_flags_impl(ip) \
ioflags_t mask; \
chSysLock(); \
mask = ((BaseAsynchronousChannel *)(ip))->flags; \
((BaseAsynchronousChannel *)(ip))->flags = IO_NO_ERROR; \
chSysUnlock(); \
return mask
#endif /* CH_USE_EVENTS */
#endif /* _IO_SERIAL_H_ */
/** @} */
|
