i2c.c
9.85 KB
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
/*
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/>.
---
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes ChibiOS/RT, without being obliged to provide
the source code for any proprietary components. See the file exception.txt
for full details of how and when the exception can be applied.
*/
/*
Concepts and parts of this file have been contributed by Uladzimir Pylinsky
aka barthess.
*/
/**
* @file i2c.c
* @brief I2C Driver code.
*
* @addtogroup I2C
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief I2C Driver initialization.
* @note This function is implicitly invoked by @p halInit(), there is
* no need to explicitly initialize the driver.
*
* @init
*/
void i2cInit(void) {
i2c_lld_init();
}
/**
* @brief Initializes the standard part of a @p I2CDriver structure.
*
* @param[out] i2cp pointer to the @p I2CDriver object
*
* @init
*/
void i2cObjectInit(I2CDriver *i2cp) {
i2cp->state = I2C_STOP;
i2cp->config = NULL;
#if I2C_USE_MUTUAL_EXCLUSION
#if CH_USE_MUTEXES
chMtxInit(&i2cp->mutex);
#else
chSemInit(&i2cp->semaphore, 1);
#endif /* CH_USE_MUTEXES */
#endif /* I2C_USE_MUTUAL_EXCLUSION */
#if defined(I2C_DRIVER_EXT_INIT_HOOK)
I2C_DRIVER_EXT_INIT_HOOK(i2cp);
#endif
}
/**
* @brief Configures and activates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] config pointer to the @p I2CConfig object
*
* @api
*/
void i2cStart(I2CDriver *i2cp, const I2CConfig *config) {
chDbgCheck((i2cp != NULL) && (config != NULL), "i2cStart");
chDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) ||
(i2cp->state == I2C_LOCKED),
"i2cStart(), #1",
"invalid state");
chSysLock();
i2cp->config = config;
i2c_lld_start(i2cp);
i2cp->state = I2C_READY;
chSysUnlock();
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @api
*/
void i2cStop(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cStop");
chDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) ||
(i2cp->state == I2C_LOCKED),
"i2cStop(), #1",
"invalid state");
chSysLock();
i2c_lld_stop(i2cp);
i2cp->state = I2C_STOP;
chSysUnlock();
}
/**
* @brief Returns the errors mask associated to the previous operation.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @return The errors mask.
*
* @api
*/
i2cflags_t i2cGetErrors(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cGetErrors");
return i2c_lld_get_errors(i2cp);
}
/**
* @brief Sends data via the I2C bus.
* @details Function designed to realize "read-through-write" transfer
* paradigm. If you want transmit data without any further read,
* than set @b rxbytes field to 0.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address (7 bits) without R/W bit
* @param[in] txbuf pointer to transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to receive buffer
* @param[in] rxbytes number of bytes to be received, set it to 0 if
* you want transmit only
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
*
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end.
*
* @api
*/
msg_t i2cMasterTransmitTimeout(I2CDriver *i2cp,
i2caddr_t addr,
const uint8_t *txbuf,
size_t txbytes,
uint8_t *rxbuf,
size_t rxbytes,
systime_t timeout) {
msg_t rdymsg;
chDbgCheck((i2cp != NULL) && (addr != 0) &&
(txbytes > 0) && (txbuf != NULL) &&
((rxbytes == 0) || ((rxbytes > 0) && (rxbuf != NULL))) &&
(timeout != TIME_IMMEDIATE),
"i2cMasterTransmitTimeout");
chDbgAssert(i2cp->state == I2C_READY,
"i2cMasterTransmitTimeout(), #1", "not ready");
chSysLock();
i2cp->errors = I2CD_NO_ERROR;
i2cp->state = I2C_ACTIVE_TX;
rdymsg = i2c_lld_master_transmit_timeout(i2cp, addr, txbuf, txbytes,
rxbuf, rxbytes, timeout);
if (rdymsg == RDY_TIMEOUT)
i2cp->state = I2C_LOCKED;
else
i2cp->state = I2C_READY;
chSysUnlock();
return rdymsg;
}
/**
* @brief Receives data from the I2C bus.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address (7 bits) without R/W bit
* @param[out] rxbuf pointer to receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
*
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end.
*
* @api
*/
msg_t i2cMasterReceiveTimeout(I2CDriver *i2cp,
i2caddr_t addr,
uint8_t *rxbuf,
size_t rxbytes,
systime_t timeout){
msg_t rdymsg;
chDbgCheck((i2cp != NULL) && (addr != 0) &&
(rxbytes > 0) && (rxbuf != NULL) &&
(timeout != TIME_IMMEDIATE),
"i2cMasterReceiveTimeout");
chDbgAssert(i2cp->state == I2C_READY,
"i2cMasterReceive(), #1", "not ready");
chSysLock();
i2cp->errors = I2CD_NO_ERROR;
i2cp->state = I2C_ACTIVE_RX;
rdymsg = i2c_lld_master_receive_timeout(i2cp, addr, rxbuf, rxbytes, timeout);
if (rdymsg == RDY_TIMEOUT)
i2cp->state = I2C_LOCKED;
else
i2cp->state = I2C_READY;
chSysUnlock();
return rdymsg;
}
#if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
/**
* @brief Gains exclusive access to the I2C 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 I2C_USE_MUTUAL_EXCLUSION
* must be enabled.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @api
*/
void i2cAcquireBus(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cAcquireBus");
#if CH_USE_MUTEXES
chMtxLock(&i2cp->mutex);
#elif CH_USE_SEMAPHORES
chSemWait(&i2cp->semaphore);
#endif
}
/**
* @brief Releases exclusive access to the I2C bus.
* @pre In order to use this function the option @p I2C_USE_MUTUAL_EXCLUSION
* must be enabled.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @api
*/
void i2cReleaseBus(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cReleaseBus");
#if CH_USE_MUTEXES
chMtxUnlock();
#elif CH_USE_SEMAPHORES
chSemSignal(&i2cp->semaphore);
#endif
}
#endif /* I2C_USE_MUTUAL_EXCLUSION */
#endif /* HAL_USE_I2C */
/** @} */