Denislam Valeev / Mbed OS Nucleo_rtos_basic

1

mbed-os/drivers/I2C.cpp@0:e056ac8fecf8, 2018-03-13 (annotated)

Committer:
valeyev
Date:
Tue Mar 13 07:17:50 2018 +0000
Revision:
0:e056ac8fecf8
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valeyev 0:e056ac8fecf8 1 /* mbed Microcontroller Library
valeyev 0:e056ac8fecf8 2 * Copyright (c) 2006-2015 ARM Limited
valeyev 0:e056ac8fecf8 3 *
valeyev 0:e056ac8fecf8 4 * Licensed under the Apache License, Version 2.0 (the "License");
valeyev 0:e056ac8fecf8 5 * you may not use this file except in compliance with the License.
valeyev 0:e056ac8fecf8 6 * You may obtain a copy of the License at
valeyev 0:e056ac8fecf8 7 *
valeyev 0:e056ac8fecf8 8 * http://www.apache.org/licenses/LICENSE-2.0
valeyev 0:e056ac8fecf8 9 *
valeyev 0:e056ac8fecf8 10 * Unless required by applicable law or agreed to in writing, software
valeyev 0:e056ac8fecf8 11 * distributed under the License is distributed on an "AS IS" BASIS,
valeyev 0:e056ac8fecf8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
valeyev 0:e056ac8fecf8 13 * See the License for the specific language governing permissions and
valeyev 0:e056ac8fecf8 14 * limitations under the License.
valeyev 0:e056ac8fecf8 15 */
valeyev 0:e056ac8fecf8 16 #include "drivers/I2C.h"
valeyev 0:e056ac8fecf8 17
valeyev 0:e056ac8fecf8 18 #if DEVICE_I2C
valeyev 0:e056ac8fecf8 19
valeyev 0:e056ac8fecf8 20 #if DEVICE_I2C_ASYNCH
valeyev 0:e056ac8fecf8 21 #include "platform/mbed_power_mgmt.h"
valeyev 0:e056ac8fecf8 22 #endif
valeyev 0:e056ac8fecf8 23
valeyev 0:e056ac8fecf8 24 namespace mbed {
valeyev 0:e056ac8fecf8 25
valeyev 0:e056ac8fecf8 26 I2C *I2C::_owner = NULL;
valeyev 0:e056ac8fecf8 27 SingletonPtr<PlatformMutex> I2C::_mutex;
valeyev 0:e056ac8fecf8 28
valeyev 0:e056ac8fecf8 29 I2C::I2C(PinName sda, PinName scl) :
valeyev 0:e056ac8fecf8 30 #if DEVICE_I2C_ASYNCH
valeyev 0:e056ac8fecf8 31 _irq(this), _usage(DMA_USAGE_NEVER), _deep_sleep_locked(false),
valeyev 0:e056ac8fecf8 32 #endif
valeyev 0:e056ac8fecf8 33 _i2c(), _hz(100000)
valeyev 0:e056ac8fecf8 34 {
valeyev 0:e056ac8fecf8 35 // No lock needed in the constructor
valeyev 0:e056ac8fecf8 36
valeyev 0:e056ac8fecf8 37 // The init function also set the frequency to 100000
valeyev 0:e056ac8fecf8 38 i2c_init(&_i2c, sda, scl);
valeyev 0:e056ac8fecf8 39
valeyev 0:e056ac8fecf8 40 // Used to avoid unnecessary frequency updates
valeyev 0:e056ac8fecf8 41 _owner = this;
valeyev 0:e056ac8fecf8 42 }
valeyev 0:e056ac8fecf8 43
valeyev 0:e056ac8fecf8 44 void I2C::frequency(int hz) {
valeyev 0:e056ac8fecf8 45 lock();
valeyev 0:e056ac8fecf8 46 _hz = hz;
valeyev 0:e056ac8fecf8 47
valeyev 0:e056ac8fecf8 48 // We want to update the frequency even if we are already the bus owners
valeyev 0:e056ac8fecf8 49 i2c_frequency(&_i2c, _hz);
valeyev 0:e056ac8fecf8 50
valeyev 0:e056ac8fecf8 51 // Updating the frequency of the bus we become the owners of it
valeyev 0:e056ac8fecf8 52 _owner = this;
valeyev 0:e056ac8fecf8 53 unlock();
valeyev 0:e056ac8fecf8 54 }
valeyev 0:e056ac8fecf8 55
valeyev 0:e056ac8fecf8 56 void I2C::aquire() {
valeyev 0:e056ac8fecf8 57 lock();
valeyev 0:e056ac8fecf8 58 if (_owner != this) {
valeyev 0:e056ac8fecf8 59 i2c_frequency(&_i2c, _hz);
valeyev 0:e056ac8fecf8 60 _owner = this;
valeyev 0:e056ac8fecf8 61 }
valeyev 0:e056ac8fecf8 62 unlock();
valeyev 0:e056ac8fecf8 63 }
valeyev 0:e056ac8fecf8 64
valeyev 0:e056ac8fecf8 65 // write - Master Transmitter Mode
valeyev 0:e056ac8fecf8 66 int I2C::write(int address, const char* data, int length, bool repeated) {
valeyev 0:e056ac8fecf8 67 lock();
valeyev 0:e056ac8fecf8 68 aquire();
valeyev 0:e056ac8fecf8 69
valeyev 0:e056ac8fecf8 70 int stop = (repeated) ? 0 : 1;
valeyev 0:e056ac8fecf8 71 int written = i2c_write(&_i2c, address, data, length, stop);
valeyev 0:e056ac8fecf8 72
valeyev 0:e056ac8fecf8 73 unlock();
valeyev 0:e056ac8fecf8 74 return length != written;
valeyev 0:e056ac8fecf8 75 }
valeyev 0:e056ac8fecf8 76
valeyev 0:e056ac8fecf8 77 int I2C::write(int data) {
valeyev 0:e056ac8fecf8 78 lock();
valeyev 0:e056ac8fecf8 79 int ret = i2c_byte_write(&_i2c, data);
valeyev 0:e056ac8fecf8 80 unlock();
valeyev 0:e056ac8fecf8 81 return ret;
valeyev 0:e056ac8fecf8 82 }
valeyev 0:e056ac8fecf8 83
valeyev 0:e056ac8fecf8 84 // read - Master Reciever Mode
valeyev 0:e056ac8fecf8 85 int I2C::read(int address, char* data, int length, bool repeated) {
valeyev 0:e056ac8fecf8 86 lock();
valeyev 0:e056ac8fecf8 87 aquire();
valeyev 0:e056ac8fecf8 88
valeyev 0:e056ac8fecf8 89 int stop = (repeated) ? 0 : 1;
valeyev 0:e056ac8fecf8 90 int read = i2c_read(&_i2c, address, data, length, stop);
valeyev 0:e056ac8fecf8 91
valeyev 0:e056ac8fecf8 92 unlock();
valeyev 0:e056ac8fecf8 93 return length != read;
valeyev 0:e056ac8fecf8 94 }
valeyev 0:e056ac8fecf8 95
valeyev 0:e056ac8fecf8 96 int I2C::read(int ack) {
valeyev 0:e056ac8fecf8 97 lock();
valeyev 0:e056ac8fecf8 98 int ret;
valeyev 0:e056ac8fecf8 99 if (ack) {
valeyev 0:e056ac8fecf8 100 ret = i2c_byte_read(&_i2c, 0);
valeyev 0:e056ac8fecf8 101 } else {
valeyev 0:e056ac8fecf8 102 ret = i2c_byte_read(&_i2c, 1);
valeyev 0:e056ac8fecf8 103 }
valeyev 0:e056ac8fecf8 104 unlock();
valeyev 0:e056ac8fecf8 105 return ret;
valeyev 0:e056ac8fecf8 106 }
valeyev 0:e056ac8fecf8 107
valeyev 0:e056ac8fecf8 108 void I2C::start(void) {
valeyev 0:e056ac8fecf8 109 lock();
valeyev 0:e056ac8fecf8 110 i2c_start(&_i2c);
valeyev 0:e056ac8fecf8 111 unlock();
valeyev 0:e056ac8fecf8 112 }
valeyev 0:e056ac8fecf8 113
valeyev 0:e056ac8fecf8 114 void I2C::stop(void) {
valeyev 0:e056ac8fecf8 115 lock();
valeyev 0:e056ac8fecf8 116 i2c_stop(&_i2c);
valeyev 0:e056ac8fecf8 117 unlock();
valeyev 0:e056ac8fecf8 118 }
valeyev 0:e056ac8fecf8 119
valeyev 0:e056ac8fecf8 120 void I2C::lock() {
valeyev 0:e056ac8fecf8 121 _mutex->lock();
valeyev 0:e056ac8fecf8 122 }
valeyev 0:e056ac8fecf8 123
valeyev 0:e056ac8fecf8 124 void I2C::unlock() {
valeyev 0:e056ac8fecf8 125 _mutex->unlock();
valeyev 0:e056ac8fecf8 126 }
valeyev 0:e056ac8fecf8 127
valeyev 0:e056ac8fecf8 128 #if DEVICE_I2C_ASYNCH
valeyev 0:e056ac8fecf8 129
valeyev 0:e056ac8fecf8 130 int I2C::transfer(int address, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, const event_callback_t& callback, int event, bool repeated)
valeyev 0:e056ac8fecf8 131 {
valeyev 0:e056ac8fecf8 132 lock();
valeyev 0:e056ac8fecf8 133 if (i2c_active(&_i2c)) {
valeyev 0:e056ac8fecf8 134 unlock();
valeyev 0:e056ac8fecf8 135 return -1; // transaction ongoing
valeyev 0:e056ac8fecf8 136 }
valeyev 0:e056ac8fecf8 137 lock_deep_sleep();
valeyev 0:e056ac8fecf8 138 aquire();
valeyev 0:e056ac8fecf8 139
valeyev 0:e056ac8fecf8 140 _callback = callback;
valeyev 0:e056ac8fecf8 141 int stop = (repeated) ? 0 : 1;
valeyev 0:e056ac8fecf8 142 _irq.callback(&I2C::irq_handler_asynch);
valeyev 0:e056ac8fecf8 143 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
valeyev 0:e056ac8fecf8 144 unlock();
valeyev 0:e056ac8fecf8 145 return 0;
valeyev 0:e056ac8fecf8 146 }
valeyev 0:e056ac8fecf8 147
valeyev 0:e056ac8fecf8 148 void I2C::abort_transfer(void)
valeyev 0:e056ac8fecf8 149 {
valeyev 0:e056ac8fecf8 150 lock();
valeyev 0:e056ac8fecf8 151 i2c_abort_asynch(&_i2c);
valeyev 0:e056ac8fecf8 152 unlock_deep_sleep();
valeyev 0:e056ac8fecf8 153 unlock();
valeyev 0:e056ac8fecf8 154 }
valeyev 0:e056ac8fecf8 155
valeyev 0:e056ac8fecf8 156 void I2C::irq_handler_asynch(void)
valeyev 0:e056ac8fecf8 157 {
valeyev 0:e056ac8fecf8 158 int event = i2c_irq_handler_asynch(&_i2c);
valeyev 0:e056ac8fecf8 159 if (_callback && event) {
valeyev 0:e056ac8fecf8 160 _callback.call(event);
valeyev 0:e056ac8fecf8 161 }
valeyev 0:e056ac8fecf8 162 if (event) {
valeyev 0:e056ac8fecf8 163 unlock_deep_sleep();
valeyev 0:e056ac8fecf8 164 }
valeyev 0:e056ac8fecf8 165
valeyev 0:e056ac8fecf8 166 }
valeyev 0:e056ac8fecf8 167
valeyev 0:e056ac8fecf8 168 void I2C::lock_deep_sleep()
valeyev 0:e056ac8fecf8 169 {
valeyev 0:e056ac8fecf8 170 if (_deep_sleep_locked == false) {
valeyev 0:e056ac8fecf8 171 sleep_manager_lock_deep_sleep();
valeyev 0:e056ac8fecf8 172 _deep_sleep_locked = true;
valeyev 0:e056ac8fecf8 173 }
valeyev 0:e056ac8fecf8 174 }
valeyev 0:e056ac8fecf8 175
valeyev 0:e056ac8fecf8 176 void I2C::unlock_deep_sleep()
valeyev 0:e056ac8fecf8 177 {
valeyev 0:e056ac8fecf8 178 if (_deep_sleep_locked == true) {
valeyev 0:e056ac8fecf8 179 sleep_manager_unlock_deep_sleep();
valeyev 0:e056ac8fecf8 180 _deep_sleep_locked = false;
valeyev 0:e056ac8fecf8 181 }
valeyev 0:e056ac8fecf8 182 }
valeyev 0:e056ac8fecf8 183
valeyev 0:e056ac8fecf8 184 #endif
valeyev 0:e056ac8fecf8 185
valeyev 0:e056ac8fecf8 186 } // namespace mbed
valeyev 0:e056ac8fecf8 187
valeyev 0:e056ac8fecf8 188 #endif