aboutsummaryrefslogtreecommitdiffstats
path: root/os/hal/src/spi.c
blob: 966db3de576d3a47988532f0a169d6322d382423 (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
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 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    spi.c
 * @brief   SPI Driver code.
 *
 * @addtogroup SPI
 * @{
 */

#include "ch.h"
#include "hal.h"

#if HAL_USE_SPI || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   SPI Driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void spiInit(void) {

  spi_lld_init();
}

/**
 * @brief   Initializes the standard part of a @p SPIDriver structure.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @init
 */
void spiObjectInit(SPIDriver *spip) {

  spip->spd_state = SPI_STOP;
  spip->spd_config = NULL;
#if SPI_USE_WAIT
  spip->spd_thread = NULL;
#endif /* SPI_USE_WAIT */
#if SPI_USE_MUTUAL_EXCLUSION
#if CH_USE_MUTEXES
  chMtxInit(&spip->spd_mutex);
#else
  chSemInit(&spip->spd_semaphore, 1);
#endif
#endif /* SPI_USE_MUTUAL_EXCLUSION */
#if defined(SPI_DRIVER_EXT_INIT_HOOK)
  SPI_DRIVER_EXT_INIT_HOOK(spip);
#endif
}

/**
 * @brief   Configures and activates the SPI peripheral.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] config    pointer to the @p SPIConfig object
 *
 * @api
 */
void spiStart(SPIDriver *spip, const SPIConfig *config) {

  chDbgCheck((spip != NULL) && (config != NULL), "spiStart");

  chSysLock();
  chDbgAssert((spip->spd_state == SPI_STOP) || (spip->spd_state == SPI_READY),
              "spiStart(), #1", "invalid state");
  spip->spd_config = config;
  spi_lld_start(spip);
  spip->spd_state = SPI_READY;
  chSysUnlock();
}

/**
 * @brief Deactivates the SPI peripheral.
 * @note  Deactivating the peripheral also enforces a release of the slave
 *        select line.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @api
 */
void spiStop(SPIDriver *spip) {

  chDbgCheck(spip != NULL, "spiStop");

  chSysLock();
  chDbgAssert((spip->spd_state == SPI_STOP) || (spip->spd_state == SPI_READY),
              "spiStop(), #1", "invalid state");
  spi_lld_unselect(spip);
  spi_lld_stop(spip);
  spip->spd_state = SPI_STOP;
  chSysUnlock();
}

/**
 * @brief   Asserts the slave select signal and prepares for transfers.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @api
 */
void spiSelect(SPIDriver *spip) {

  chDbgCheck(spip != NULL, "spiSelect");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiSelect(), #1", "not ready");
  spiSelectI(spip);
  chSysUnlock();
}

/**
 * @brief   Deasserts the slave select signal.
 * @details The previously selected peripheral is unselected.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @api
 */
void spiUnselect(SPIDriver *spip) {

  chDbgCheck(spip != NULL, "spiUnselect");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiUnselect(), #1", "not ready");
  spiUnselectI(spip);
  chSysUnlock();
}

/**
 * @brief   Ignores data on the SPI bus.
 * @details This asynchronous function starts the transmission of a series of
 *          idle words on the SPI bus and ignores the received data.
 * @pre     A slave must have been selected using @p spiSelect() or
 *          @p spiSelectI().
 * @post    At the end of the operation the configured callback is invoked.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to be ignored
 *
 * @api
 */
void spiStartIgnore(SPIDriver *spip, size_t n) {

  chDbgCheck((spip != NULL) && (n > 0), "spiStartIgnore");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiStartIgnore(), #1", "not ready");
  spiStartIgnoreI(spip, n);
  chSysUnlock();
}

/**
 * @brief   Exchanges data on the SPI bus.
 * @details This asynchronous function starts a simultaneous transmit/receive
 *          operation.
 * @pre     A slave must have been selected using @p spiSelect() or
 *          @p spiSelectI().
 * @post    At the end of the operation the configured callback is invoked.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to be exchanged
 * @param[in] txbuf     the pointer to the transmit buffer
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 * @api
 */
void spiStartExchange(SPIDriver *spip, size_t n,
                      const void *txbuf, void *rxbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL) && (txbuf != NULL),
             "spiStartExchange");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiStartExchange(), #1", "not ready");
  spiStartExchangeI(spip, n, txbuf, rxbuf);
  chSysUnlock();
}

/**
 * @brief   Sends data over the SPI bus.
 * @details This asynchronous function starts a transmit operation.
 * @pre     A slave must have been selected using @p spiSelect() or
 *          @p spiSelectI().
 * @post    At the end of the operation the configured callback is invoked.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to send
 * @param[in] txbuf     the pointer to the transmit buffer
 *
 * @api
 */
void spiStartSend(SPIDriver *spip, size_t n, const void *txbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (txbuf != NULL),
             "spiStartSend");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiStartSend(), #1", "not ready");
  spiStartSendI(spip, n, txbuf);
  chSysUnlock();
}

/**
 * @brief   Receives data from the SPI bus.
 * @details This asynchronous function starts a receive operation.
 * @pre     A slave must have been selected using @p spiSelect() or
 *          @p spiSelectI().
 * @post    At the end of the operation the configured callback is invoked.
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to receive
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 * @api
 */
void spiStartReceive(SPIDriver *spip, size_t n, void *rxbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL),
             "spiStartReceive");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiStartReceive(), #1", "not ready");
  spiStartReceiveI(spip, n, rxbuf);
  chSysUnlock();
}

#if SPI_USE_WAIT || defined(__DOXYGEN__)
/**
 * @brief   Ignores data on the SPI bus.
 * @details This synchronous function performs the transmission of a series of
 *          idle words on the SPI bus and ignores the received data.
 * @pre     In order to use this function the option @p SPI_USE_WAIT must be
 *          enabled.
 * @pre     In order to use this function the driver must have been configured
 *          without callbacks (@p spc_endcb = @p NULL).
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to be ignored
 *
 * @api
 */
void spiIgnore(SPIDriver *spip, size_t n) {

  chDbgCheck((spip != NULL) && (n > 0), "spiIgnoreWait");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiIgnore(), #1", "not ready");
  chDbgAssert(spip->spd_config->spc_endcb == NULL,
              "spiIgnore(), #2", "has callback");
  spiStartIgnoreI(spip, n);
  _spi_wait_s(spip);
  chSysUnlock();
}

/**
 * @brief   Exchanges data on the SPI bus.
 * @details This synchronous function performs a simultaneous transmit/receive
 *          operation.
 * @pre     In order to use this function the option @p SPI_USE_WAIT must be
 *          enabled.
 * @pre     In order to use this function the driver must have been configured
 *          without callbacks (@p spc_endcb = @p NULL).
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to be exchanged
 * @param[in] txbuf     the pointer to the transmit buffer
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 * @api
 */
void spiExchange(SPIDriver *spip, size_t n,
                     const void *txbuf, void *rxbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL) && (txbuf != NULL),
             "spiExchange");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiExchange(), #1", "not ready");
  chDbgAssert(spip->spd_config->spc_endcb == NULL,
              "spiExchange(), #2", "has callback");
  spiStartExchangeI(spip, n, txbuf, rxbuf);
  _spi_wait_s(spip);
  chSysUnlock();
}

/**
 * @brief   Sends data over the SPI bus.
 * @details This synchronous function performs a transmit operation.
 * @pre     In order to use this function the option @p SPI_USE_WAIT must be
 *          enabled.
 * @pre     In order to use this function the driver must have been configured
 *          without callbacks (@p spc_endcb = @p NULL).
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to send
 * @param[in] txbuf     the pointer to the transmit buffer
 *
 * @api
 */
void spiSend(SPIDriver *spip, size_t n, const void *txbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (txbuf != NULL),
             "spiSend");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiSend(), #1", "not ready");
  chDbgAssert(spip->spd_config->spc_endcb == NULL,
              "spiSend(), #2", "has callback");
  spiStartSendI(spip, n, txbuf);
  _spi_wait_s(spip);
  chSysUnlock();
}

/**
 * @brief   Receives data from the SPI bus.
 * @details This synchronous function performs a receive operation.
 * @pre     In order to use this function the option @p SPI_USE_WAIT must be
 *          enabled.
 * @pre     In order to use this function the driver must have been configured
 *          without callbacks (@p spc_endcb = @p NULL).
 * @note    The buffers are organized as uint8_t arrays for data sizes below
 *          or equal to 8 bits else it is organized as uint16_t arrays.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 * @param[in] n         number of words to receive
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 * @api
 */
void spiReceive(SPIDriver *spip, size_t n, void *rxbuf) {

  chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL),
             "spiReceive");

  chSysLock();
  chDbgAssert(spip->spd_state == SPI_READY,
              "spiReceive(), #1", "not ready");
  chDbgAssert(spip->spd_config->spc_endcb == NULL,
              "spiReceive(), #2", "has callback");
  spiStartReceiveI(spip, n, rxbuf);
  _spi_wait_s(spip);
  chSysUnlock();
}
#endif /* SPI_USE_WAIT */

#if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
/**
 * @brief   Gains exclusive access to the SPI bus.
 * @details This function tries to gain ownership to the SPI bus, if the bus
 *          is already being used then the invoking thread is queued.
 * @pre     In order to use this function the option @p SPI_USE_MUTUAL_EXCLUSION
 *          must be enabled.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @api
 */
void spiAcquireBus(SPIDriver *spip) {

  chDbgCheck(spip != NULL, "spiAcquireBus");

#if CH_USE_MUTEXES
  chMtxLock(&spip->spd_mutex);
#elif CH_USE_SEMAPHORES
  chSemWait(&spip->spd_semaphore);
#endif
}

/**
 * @brief   Releases exclusive access to the SPI bus.
 * @pre     In order to use this function the option @p SPI_USE_MUTUAL_EXCLUSION
 *          must be enabled.
 *
 * @param[in] spip      pointer to the @p SPIDriver object
 *
 * @api
 */
void spiReleaseBus(SPIDriver *spip) {

  chDbgCheck(spip != NULL, "spiReleaseBus");

#if CH_USE_MUTEXES
  (void)spip;
  chMtxUnlock();
#elif CH_USE_SEMAPHORES
  chSemSignal(&spip->spd_semaphore);
#endif
}
#endif /* SPI_USE_MUTUAL_EXCLUSION */

#endif /* HAL_USE_SPI */

/** @} */