ON Semiconductor / mbed-os

5.2.1 - Updated I2C files

Dependents:   mbed-TFT-example-NCS36510 mbed-Accelerometer-example-NCS36510 mbed-Accelerometer-example-NCS36510

drivers/I2C.cpp@0:098463de4c5d, 2017-01-25 (annotated)

Committer:
group-onsemi
Date:
Wed Jan 25 20:34:15 2017 +0000
Revision:
0:098463de4c5d
Initial commit

Who changed what in which revision?

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group-onsemi 0:098463de4c5d 1 /* mbed Microcontroller Library
group-onsemi 0:098463de4c5d 2 * Copyright (c) 2006-2015 ARM Limited
group-onsemi 0:098463de4c5d 3 *
group-onsemi 0:098463de4c5d 4 * Licensed under the Apache License, Version 2.0 (the "License");
group-onsemi 0:098463de4c5d 5 * you may not use this file except in compliance with the License.
group-onsemi 0:098463de4c5d 6 * You may obtain a copy of the License at
group-onsemi 0:098463de4c5d 7 *
group-onsemi 0:098463de4c5d 8 * http://www.apache.org/licenses/LICENSE-2.0
group-onsemi 0:098463de4c5d 9 *
group-onsemi 0:098463de4c5d 10 * Unless required by applicable law or agreed to in writing, software
group-onsemi 0:098463de4c5d 11 * distributed under the License is distributed on an "AS IS" BASIS,
group-onsemi 0:098463de4c5d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
group-onsemi 0:098463de4c5d 13 * See the License for the specific language governing permissions and
group-onsemi 0:098463de4c5d 14 * limitations under the License.
group-onsemi 0:098463de4c5d 15 */
group-onsemi 0:098463de4c5d 16 #include "drivers/I2C.h"
group-onsemi 0:098463de4c5d 17
group-onsemi 0:098463de4c5d 18 #if DEVICE_I2C
group-onsemi 0:098463de4c5d 19
group-onsemi 0:098463de4c5d 20 namespace mbed {
group-onsemi 0:098463de4c5d 21
group-onsemi 0:098463de4c5d 22 I2C *I2C::_owner = NULL;
group-onsemi 0:098463de4c5d 23 SingletonPtr<PlatformMutex> I2C::_mutex;
group-onsemi 0:098463de4c5d 24
group-onsemi 0:098463de4c5d 25 I2C::I2C(PinName sda, PinName scl) :
group-onsemi 0:098463de4c5d 26 #if DEVICE_I2C_ASYNCH
group-onsemi 0:098463de4c5d 27 _irq(this), _usage(DMA_USAGE_NEVER),
group-onsemi 0:098463de4c5d 28 #endif
group-onsemi 0:098463de4c5d 29 _i2c(), _hz(100000) {
group-onsemi 0:098463de4c5d 30 // No lock needed in the constructor
group-onsemi 0:098463de4c5d 31
group-onsemi 0:098463de4c5d 32 // The init function also set the frequency to 100000
group-onsemi 0:098463de4c5d 33 i2c_init(&_i2c, sda, scl);
group-onsemi 0:098463de4c5d 34
group-onsemi 0:098463de4c5d 35 // Used to avoid unnecessary frequency updates
group-onsemi 0:098463de4c5d 36 _owner = this;
group-onsemi 0:098463de4c5d 37 }
group-onsemi 0:098463de4c5d 38
group-onsemi 0:098463de4c5d 39 void I2C::frequency(int hz) {
group-onsemi 0:098463de4c5d 40 lock();
group-onsemi 0:098463de4c5d 41 _hz = hz;
group-onsemi 0:098463de4c5d 42
group-onsemi 0:098463de4c5d 43 // We want to update the frequency even if we are already the bus owners
group-onsemi 0:098463de4c5d 44 i2c_frequency(&_i2c, _hz);
group-onsemi 0:098463de4c5d 45
group-onsemi 0:098463de4c5d 46 // Updating the frequency of the bus we become the owners of it
group-onsemi 0:098463de4c5d 47 _owner = this;
group-onsemi 0:098463de4c5d 48 unlock();
group-onsemi 0:098463de4c5d 49 }
group-onsemi 0:098463de4c5d 50
group-onsemi 0:098463de4c5d 51 void I2C::aquire() {
group-onsemi 0:098463de4c5d 52 lock();
group-onsemi 0:098463de4c5d 53 if (_owner != this) {
group-onsemi 0:098463de4c5d 54 i2c_frequency(&_i2c, _hz);
group-onsemi 0:098463de4c5d 55 _owner = this;
group-onsemi 0:098463de4c5d 56 }
group-onsemi 0:098463de4c5d 57 unlock();
group-onsemi 0:098463de4c5d 58 }
group-onsemi 0:098463de4c5d 59
group-onsemi 0:098463de4c5d 60 // write - Master Transmitter Mode
group-onsemi 0:098463de4c5d 61 int I2C::write(int address, const char* data, int length, bool repeated) {
group-onsemi 0:098463de4c5d 62 lock();
group-onsemi 0:098463de4c5d 63 aquire();
group-onsemi 0:098463de4c5d 64
group-onsemi 0:098463de4c5d 65 int stop = (repeated) ? 0 : 1;
group-onsemi 0:098463de4c5d 66 int written = i2c_write(&_i2c, address, data, length, stop);
group-onsemi 0:098463de4c5d 67
group-onsemi 0:098463de4c5d 68 unlock();
group-onsemi 0:098463de4c5d 69 return length != written;
group-onsemi 0:098463de4c5d 70 }
group-onsemi 0:098463de4c5d 71
group-onsemi 0:098463de4c5d 72 int I2C::write(int data) {
group-onsemi 0:098463de4c5d 73 lock();
group-onsemi 0:098463de4c5d 74 int ret = i2c_byte_write(&_i2c, data);
group-onsemi 0:098463de4c5d 75 unlock();
group-onsemi 0:098463de4c5d 76 return ret;
group-onsemi 0:098463de4c5d 77 }
group-onsemi 0:098463de4c5d 78
group-onsemi 0:098463de4c5d 79 // read - Master Reciever Mode
group-onsemi 0:098463de4c5d 80 int I2C::read(int address, char* data, int length, bool repeated) {
group-onsemi 0:098463de4c5d 81 lock();
group-onsemi 0:098463de4c5d 82 aquire();
group-onsemi 0:098463de4c5d 83
group-onsemi 0:098463de4c5d 84 int stop = (repeated) ? 0 : 1;
group-onsemi 0:098463de4c5d 85 int read = i2c_read(&_i2c, address, data, length, stop);
group-onsemi 0:098463de4c5d 86
group-onsemi 0:098463de4c5d 87 unlock();
group-onsemi 0:098463de4c5d 88 return length != read;
group-onsemi 0:098463de4c5d 89 }
group-onsemi 0:098463de4c5d 90
group-onsemi 0:098463de4c5d 91 int I2C::read(int ack) {
group-onsemi 0:098463de4c5d 92 lock();
group-onsemi 0:098463de4c5d 93 int ret;
group-onsemi 0:098463de4c5d 94 if (ack) {
group-onsemi 0:098463de4c5d 95 ret = i2c_byte_read(&_i2c, 0);
group-onsemi 0:098463de4c5d 96 } else {
group-onsemi 0:098463de4c5d 97 ret = i2c_byte_read(&_i2c, 1);
group-onsemi 0:098463de4c5d 98 }
group-onsemi 0:098463de4c5d 99 unlock();
group-onsemi 0:098463de4c5d 100 return ret;
group-onsemi 0:098463de4c5d 101 }
group-onsemi 0:098463de4c5d 102
group-onsemi 0:098463de4c5d 103 void I2C::start(void) {
group-onsemi 0:098463de4c5d 104 lock();
group-onsemi 0:098463de4c5d 105 i2c_start(&_i2c);
group-onsemi 0:098463de4c5d 106 unlock();
group-onsemi 0:098463de4c5d 107 }
group-onsemi 0:098463de4c5d 108
group-onsemi 0:098463de4c5d 109 void I2C::stop(void) {
group-onsemi 0:098463de4c5d 110 lock();
group-onsemi 0:098463de4c5d 111 i2c_stop(&_i2c);
group-onsemi 0:098463de4c5d 112 unlock();
group-onsemi 0:098463de4c5d 113 }
group-onsemi 0:098463de4c5d 114
group-onsemi 0:098463de4c5d 115 void I2C::lock() {
group-onsemi 0:098463de4c5d 116 _mutex->lock();
group-onsemi 0:098463de4c5d 117 }
group-onsemi 0:098463de4c5d 118
group-onsemi 0:098463de4c5d 119 void I2C::unlock() {
group-onsemi 0:098463de4c5d 120 _mutex->unlock();
group-onsemi 0:098463de4c5d 121 }
group-onsemi 0:098463de4c5d 122
group-onsemi 0:098463de4c5d 123 #if DEVICE_I2C_ASYNCH
group-onsemi 0:098463de4c5d 124
group-onsemi 0:098463de4c5d 125 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)
group-onsemi 0:098463de4c5d 126 {
group-onsemi 0:098463de4c5d 127 lock();
group-onsemi 0:098463de4c5d 128 if (i2c_active(&_i2c)) {
group-onsemi 0:098463de4c5d 129 unlock();
group-onsemi 0:098463de4c5d 130 return -1; // transaction ongoing
group-onsemi 0:098463de4c5d 131 }
group-onsemi 0:098463de4c5d 132 aquire();
group-onsemi 0:098463de4c5d 133
group-onsemi 0:098463de4c5d 134 _callback = callback;
group-onsemi 0:098463de4c5d 135 int stop = (repeated) ? 0 : 1;
group-onsemi 0:098463de4c5d 136 _irq.callback(&I2C::irq_handler_asynch);
group-onsemi 0:098463de4c5d 137 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
group-onsemi 0:098463de4c5d 138 unlock();
group-onsemi 0:098463de4c5d 139 return 0;
group-onsemi 0:098463de4c5d 140 }
group-onsemi 0:098463de4c5d 141
group-onsemi 0:098463de4c5d 142 void I2C::abort_transfer(void)
group-onsemi 0:098463de4c5d 143 {
group-onsemi 0:098463de4c5d 144 lock();
group-onsemi 0:098463de4c5d 145 i2c_abort_asynch(&_i2c);
group-onsemi 0:098463de4c5d 146 unlock();
group-onsemi 0:098463de4c5d 147 }
group-onsemi 0:098463de4c5d 148
group-onsemi 0:098463de4c5d 149 void I2C::irq_handler_asynch(void)
group-onsemi 0:098463de4c5d 150 {
group-onsemi 0:098463de4c5d 151 int event = i2c_irq_handler_asynch(&_i2c);
group-onsemi 0:098463de4c5d 152 if (_callback && event) {
group-onsemi 0:098463de4c5d 153 _callback.call(event);
group-onsemi 0:098463de4c5d 154 }
group-onsemi 0:098463de4c5d 155
group-onsemi 0:098463de4c5d 156 }
group-onsemi 0:098463de4c5d 157
group-onsemi 0:098463de4c5d 158
group-onsemi 0:098463de4c5d 159 #endif
group-onsemi 0:098463de4c5d 160
group-onsemi 0:098463de4c5d 161 } // namespace mbed
group-onsemi 0:098463de4c5d 162
group-onsemi 0:098463de4c5d 163 #endif