aboutsummaryrefslogtreecommitdiffstats
path: root/os/hal/src/i2c.c
blob: 5a0471e0f6aea05bca37acf3f9495e7f180f65dd (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
/*
    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    i2c.c
 * @brief   I2C Driver code.
 *
 * @addtogroup I2C
 * @{
 */

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

#if HAL_USE_I2C || defined(__DOXYGEN__)

/*===========================================================================*/
/* 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->id_state  = I2C_STOP;
  i2cp->id_config = NULL;
  i2cp->id_slave_config = NULL;
#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, I2CConfig *config) {

  chDbgCheck((i2cp != NULL) && (config != NULL), "i2cStart");

  chSysLock();
  chDbgAssert((i2cp->id_state == I2C_STOP) || (i2cp->id_state == I2C_READY),
              "i2cStart(), #1",
              "invalid state");
  i2cp->id_config = config;
  i2c_lld_start(i2cp);
  i2cp->id_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");

  chSysLock();
  chDbgAssert((i2cp->id_state == I2C_STOP) || (i2cp->id_state == I2C_READY),
              "i2cStop(), #1",
              "invalid state");
  i2c_lld_stop(i2cp);
  i2cp->id_state = I2C_STOP;
  chSysUnlock();
}

/**
 * @brief Sends data ever the I2C bus.
 *
 * @param[in] i2cp           pointer to the @p I2CDriver object
 * @param[in] slave_addr1    7-bit address of the slave
 * @param[in] slave_addr1    used in 10-bit address mode
 * @param[in] n              number of words to send
 * @param[in] txbuf          the pointer to the transmit buffer
 *
 */
void i2cMasterTransmit(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg) {

  chDbgCheck((i2cp != NULL) && (i2cscfg != NULL),
             "i2cMasterTransmit");
  chDbgAssert(i2cp->id_state == I2C_READY,
              "i2cMasterTransmit(), #1",
              "not active");

  i2c_lld_master_transmitI(i2cp, i2cscfg);
}


/**
 * @brief Receives data from the I2C bus.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 * @param[in] slave_addr1    7-bit address of the slave
 * @param[in] slave_addr1    used in 10-bit address mode
 * @param[in] n         number of words to receive
 * @param[out] rxbuf    the pointer to the receive buffer
 *
 */
void i2cMasterReceive(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg) {

  chDbgCheck((i2cp != NULL) && (i2cscfg != NULL),
             "i2cMasterReceive");
  chDbgAssert(i2cp->id_state == I2C_READY,
              "i2cMasterReceive(), #1",
              "not active");

  i2c_lld_master_receiveI(i2cp, i2cscfg);
}






#if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
/**
 * @brief   Gains exclusive access to the I2C bus.
 * @details This function tries to gain ownership to the I2C 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->id_mutex);
#elif CH_USE_SEMAPHORES
  chSemWait(&i2cp->id_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
  (void)i2cp;
  chMtxUnlock();
#elif CH_USE_SEMAPHORES
  chSemSignal(&i2cp->id_semaphore);
#endif
}
#endif /* I2C_USE_MUTUAL_EXCLUSION */

#endif /* HAL_USE_I2C */

/** @} */