Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

mbed-os/drivers/I2C.cpp@0:9fca2b23d0ba, 2019-02-23 (annotated)

Committer:
marcozecchini
Date:
Sat Feb 23 12:13:36 2019 +0000
Revision:
0:9fca2b23d0ba
final commit

Who changed what in which revision?

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marcozecchini 0:9fca2b23d0ba 1 /* mbed Microcontroller Library
marcozecchini 0:9fca2b23d0ba 2 * Copyright (c) 2006-2015 ARM Limited
marcozecchini 0:9fca2b23d0ba 3 *
marcozecchini 0:9fca2b23d0ba 4 * Licensed under the Apache License, Version 2.0 (the "License");
marcozecchini 0:9fca2b23d0ba 5 * you may not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 6 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 7 *
marcozecchini 0:9fca2b23d0ba 8 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 9 *
marcozecchini 0:9fca2b23d0ba 10 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 11 * distributed under the License is distributed on an "AS IS" BASIS,
marcozecchini 0:9fca2b23d0ba 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 13 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 14 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 15 */
marcozecchini 0:9fca2b23d0ba 16 #include "drivers/I2C.h"
marcozecchini 0:9fca2b23d0ba 17
marcozecchini 0:9fca2b23d0ba 18 #if DEVICE_I2C
marcozecchini 0:9fca2b23d0ba 19
marcozecchini 0:9fca2b23d0ba 20 #if DEVICE_I2C_ASYNCH
marcozecchini 0:9fca2b23d0ba 21 #include "platform/mbed_sleep.h"
marcozecchini 0:9fca2b23d0ba 22 #endif
marcozecchini 0:9fca2b23d0ba 23
marcozecchini 0:9fca2b23d0ba 24 namespace mbed {
marcozecchini 0:9fca2b23d0ba 25
marcozecchini 0:9fca2b23d0ba 26 I2C *I2C::_owner = NULL;
marcozecchini 0:9fca2b23d0ba 27 SingletonPtr<PlatformMutex> I2C::_mutex;
marcozecchini 0:9fca2b23d0ba 28
marcozecchini 0:9fca2b23d0ba 29 I2C::I2C(PinName sda, PinName scl) :
marcozecchini 0:9fca2b23d0ba 30 #if DEVICE_I2C_ASYNCH
marcozecchini 0:9fca2b23d0ba 31 _irq(this), _usage(DMA_USAGE_NEVER),
marcozecchini 0:9fca2b23d0ba 32 #endif
marcozecchini 0:9fca2b23d0ba 33 _i2c(), _hz(100000) {
marcozecchini 0:9fca2b23d0ba 34 // No lock needed in the constructor
marcozecchini 0:9fca2b23d0ba 35
marcozecchini 0:9fca2b23d0ba 36 // The init function also set the frequency to 100000
marcozecchini 0:9fca2b23d0ba 37 i2c_init(&_i2c, sda, scl);
marcozecchini 0:9fca2b23d0ba 38
marcozecchini 0:9fca2b23d0ba 39 // Used to avoid unnecessary frequency updates
marcozecchini 0:9fca2b23d0ba 40 _owner = this;
marcozecchini 0:9fca2b23d0ba 41 }
marcozecchini 0:9fca2b23d0ba 42
marcozecchini 0:9fca2b23d0ba 43 void I2C::frequency(int hz) {
marcozecchini 0:9fca2b23d0ba 44 lock();
marcozecchini 0:9fca2b23d0ba 45 _hz = hz;
marcozecchini 0:9fca2b23d0ba 46
marcozecchini 0:9fca2b23d0ba 47 // We want to update the frequency even if we are already the bus owners
marcozecchini 0:9fca2b23d0ba 48 i2c_frequency(&_i2c, _hz);
marcozecchini 0:9fca2b23d0ba 49
marcozecchini 0:9fca2b23d0ba 50 // Updating the frequency of the bus we become the owners of it
marcozecchini 0:9fca2b23d0ba 51 _owner = this;
marcozecchini 0:9fca2b23d0ba 52 unlock();
marcozecchini 0:9fca2b23d0ba 53 }
marcozecchini 0:9fca2b23d0ba 54
marcozecchini 0:9fca2b23d0ba 55 void I2C::aquire() {
marcozecchini 0:9fca2b23d0ba 56 lock();
marcozecchini 0:9fca2b23d0ba 57 if (_owner != this) {
marcozecchini 0:9fca2b23d0ba 58 i2c_frequency(&_i2c, _hz);
marcozecchini 0:9fca2b23d0ba 59 _owner = this;
marcozecchini 0:9fca2b23d0ba 60 }
marcozecchini 0:9fca2b23d0ba 61 unlock();
marcozecchini 0:9fca2b23d0ba 62 }
marcozecchini 0:9fca2b23d0ba 63
marcozecchini 0:9fca2b23d0ba 64 // write - Master Transmitter Mode
marcozecchini 0:9fca2b23d0ba 65 int I2C::write(int address, const char* data, int length, bool repeated) {
marcozecchini 0:9fca2b23d0ba 66 lock();
marcozecchini 0:9fca2b23d0ba 67 aquire();
marcozecchini 0:9fca2b23d0ba 68
marcozecchini 0:9fca2b23d0ba 69 int stop = (repeated) ? 0 : 1;
marcozecchini 0:9fca2b23d0ba 70 int written = i2c_write(&_i2c, address, data, length, stop);
marcozecchini 0:9fca2b23d0ba 71
marcozecchini 0:9fca2b23d0ba 72 unlock();
marcozecchini 0:9fca2b23d0ba 73 return length != written;
marcozecchini 0:9fca2b23d0ba 74 }
marcozecchini 0:9fca2b23d0ba 75
marcozecchini 0:9fca2b23d0ba 76 int I2C::write(int data) {
marcozecchini 0:9fca2b23d0ba 77 lock();
marcozecchini 0:9fca2b23d0ba 78 int ret = i2c_byte_write(&_i2c, data);
marcozecchini 0:9fca2b23d0ba 79 unlock();
marcozecchini 0:9fca2b23d0ba 80 return ret;
marcozecchini 0:9fca2b23d0ba 81 }
marcozecchini 0:9fca2b23d0ba 82
marcozecchini 0:9fca2b23d0ba 83 // read - Master Reciever Mode
marcozecchini 0:9fca2b23d0ba 84 int I2C::read(int address, char* data, int length, bool repeated) {
marcozecchini 0:9fca2b23d0ba 85 lock();
marcozecchini 0:9fca2b23d0ba 86 aquire();
marcozecchini 0:9fca2b23d0ba 87
marcozecchini 0:9fca2b23d0ba 88 int stop = (repeated) ? 0 : 1;
marcozecchini 0:9fca2b23d0ba 89 int read = i2c_read(&_i2c, address, data, length, stop);
marcozecchini 0:9fca2b23d0ba 90
marcozecchini 0:9fca2b23d0ba 91 unlock();
marcozecchini 0:9fca2b23d0ba 92 return length != read;
marcozecchini 0:9fca2b23d0ba 93 }
marcozecchini 0:9fca2b23d0ba 94
marcozecchini 0:9fca2b23d0ba 95 int I2C::read(int ack) {
marcozecchini 0:9fca2b23d0ba 96 lock();
marcozecchini 0:9fca2b23d0ba 97 int ret;
marcozecchini 0:9fca2b23d0ba 98 if (ack) {
marcozecchini 0:9fca2b23d0ba 99 ret = i2c_byte_read(&_i2c, 0);
marcozecchini 0:9fca2b23d0ba 100 } else {
marcozecchini 0:9fca2b23d0ba 101 ret = i2c_byte_read(&_i2c, 1);
marcozecchini 0:9fca2b23d0ba 102 }
marcozecchini 0:9fca2b23d0ba 103 unlock();
marcozecchini 0:9fca2b23d0ba 104 return ret;
marcozecchini 0:9fca2b23d0ba 105 }
marcozecchini 0:9fca2b23d0ba 106
marcozecchini 0:9fca2b23d0ba 107 void I2C::start(void) {
marcozecchini 0:9fca2b23d0ba 108 lock();
marcozecchini 0:9fca2b23d0ba 109 i2c_start(&_i2c);
marcozecchini 0:9fca2b23d0ba 110 unlock();
marcozecchini 0:9fca2b23d0ba 111 }
marcozecchini 0:9fca2b23d0ba 112
marcozecchini 0:9fca2b23d0ba 113 void I2C::stop(void) {
marcozecchini 0:9fca2b23d0ba 114 lock();
marcozecchini 0:9fca2b23d0ba 115 i2c_stop(&_i2c);
marcozecchini 0:9fca2b23d0ba 116 unlock();
marcozecchini 0:9fca2b23d0ba 117 }
marcozecchini 0:9fca2b23d0ba 118
marcozecchini 0:9fca2b23d0ba 119 void I2C::lock() {
marcozecchini 0:9fca2b23d0ba 120 _mutex->lock();
marcozecchini 0:9fca2b23d0ba 121 }
marcozecchini 0:9fca2b23d0ba 122
marcozecchini 0:9fca2b23d0ba 123 void I2C::unlock() {
marcozecchini 0:9fca2b23d0ba 124 _mutex->unlock();
marcozecchini 0:9fca2b23d0ba 125 }
marcozecchini 0:9fca2b23d0ba 126
marcozecchini 0:9fca2b23d0ba 127 #if DEVICE_I2C_ASYNCH
marcozecchini 0:9fca2b23d0ba 128
marcozecchini 0:9fca2b23d0ba 129 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)
marcozecchini 0:9fca2b23d0ba 130 {
marcozecchini 0:9fca2b23d0ba 131 lock();
marcozecchini 0:9fca2b23d0ba 132 if (i2c_active(&_i2c)) {
marcozecchini 0:9fca2b23d0ba 133 unlock();
marcozecchini 0:9fca2b23d0ba 134 return -1; // transaction ongoing
marcozecchini 0:9fca2b23d0ba 135 }
marcozecchini 0:9fca2b23d0ba 136 sleep_manager_lock_deep_sleep();
marcozecchini 0:9fca2b23d0ba 137 aquire();
marcozecchini 0:9fca2b23d0ba 138
marcozecchini 0:9fca2b23d0ba 139 _callback = callback;
marcozecchini 0:9fca2b23d0ba 140 int stop = (repeated) ? 0 : 1;
marcozecchini 0:9fca2b23d0ba 141 _irq.callback(&I2C::irq_handler_asynch);
marcozecchini 0:9fca2b23d0ba 142 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
marcozecchini 0:9fca2b23d0ba 143 unlock();
marcozecchini 0:9fca2b23d0ba 144 return 0;
marcozecchini 0:9fca2b23d0ba 145 }
marcozecchini 0:9fca2b23d0ba 146
marcozecchini 0:9fca2b23d0ba 147 void I2C::abort_transfer(void)
marcozecchini 0:9fca2b23d0ba 148 {
marcozecchini 0:9fca2b23d0ba 149 lock();
marcozecchini 0:9fca2b23d0ba 150 i2c_abort_asynch(&_i2c);
marcozecchini 0:9fca2b23d0ba 151 sleep_manager_unlock_deep_sleep();
marcozecchini 0:9fca2b23d0ba 152 unlock();
marcozecchini 0:9fca2b23d0ba 153 }
marcozecchini 0:9fca2b23d0ba 154
marcozecchini 0:9fca2b23d0ba 155 void I2C::irq_handler_asynch(void)
marcozecchini 0:9fca2b23d0ba 156 {
marcozecchini 0:9fca2b23d0ba 157 int event = i2c_irq_handler_asynch(&_i2c);
marcozecchini 0:9fca2b23d0ba 158 if (_callback && event) {
marcozecchini 0:9fca2b23d0ba 159 _callback.call(event);
marcozecchini 0:9fca2b23d0ba 160 }
marcozecchini 0:9fca2b23d0ba 161 if (event) {
marcozecchini 0:9fca2b23d0ba 162 sleep_manager_unlock_deep_sleep();
marcozecchini 0:9fca2b23d0ba 163 }
marcozecchini 0:9fca2b23d0ba 164
marcozecchini 0:9fca2b23d0ba 165 }
marcozecchini 0:9fca2b23d0ba 166
marcozecchini 0:9fca2b23d0ba 167
marcozecchini 0:9fca2b23d0ba 168 #endif
marcozecchini 0:9fca2b23d0ba 169
marcozecchini 0:9fca2b23d0ba 170 } // namespace mbed
marcozecchini 0:9fca2b23d0ba 171
marcozecchini 0:9fca2b23d0ba 172 #endif