Ermanno Brusadin / mbed

mbed library sources

Dependents:   FRDM-KL46Z_LCD_Test FRDM-KL46Z_LCD_Test FRDM-KL46Z_Plantilla FRDM-KL46Z_Plantilla ... more

common/I2C.cpp@0:6bc4ac881c8e, 2016-07-28 (annotated)

Committer:
ebrus
Date:
Thu Jul 28 15:56:34 2016 +0000
Revision:
0:6bc4ac881c8e
1;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ebrus 0:6bc4ac881c8e 1 /* mbed Microcontroller Library
ebrus 0:6bc4ac881c8e 2 * Copyright (c) 2006-2013 ARM Limited
ebrus 0:6bc4ac881c8e 3 *
ebrus 0:6bc4ac881c8e 4 * Licensed under the Apache License, Version 2.0 (the "License");
ebrus 0:6bc4ac881c8e 5 * you may not use this file except in compliance with the License.
ebrus 0:6bc4ac881c8e 6 * You may obtain a copy of the License at
ebrus 0:6bc4ac881c8e 7 *
ebrus 0:6bc4ac881c8e 8 * http://www.apache.org/licenses/LICENSE-2.0
ebrus 0:6bc4ac881c8e 9 *
ebrus 0:6bc4ac881c8e 10 * Unless required by applicable law or agreed to in writing, software
ebrus 0:6bc4ac881c8e 11 * distributed under the License is distributed on an "AS IS" BASIS,
ebrus 0:6bc4ac881c8e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ebrus 0:6bc4ac881c8e 13 * See the License for the specific language governing permissions and
ebrus 0:6bc4ac881c8e 14 * limitations under the License.
ebrus 0:6bc4ac881c8e 15 */
ebrus 0:6bc4ac881c8e 16 #include "I2C.h"
ebrus 0:6bc4ac881c8e 17
ebrus 0:6bc4ac881c8e 18 #if DEVICE_I2C
ebrus 0:6bc4ac881c8e 19
ebrus 0:6bc4ac881c8e 20 namespace mbed {
ebrus 0:6bc4ac881c8e 21
ebrus 0:6bc4ac881c8e 22 I2C *I2C::_owner = NULL;
ebrus 0:6bc4ac881c8e 23
ebrus 0:6bc4ac881c8e 24 I2C::I2C(PinName sda, PinName scl) : _i2c(), _hz(100000) {
ebrus 0:6bc4ac881c8e 25 // The init function also set the frequency to 100000
ebrus 0:6bc4ac881c8e 26 i2c_init(&_i2c, sda, scl);
ebrus 0:6bc4ac881c8e 27
ebrus 0:6bc4ac881c8e 28 // Used to avoid unnecessary frequency updates
ebrus 0:6bc4ac881c8e 29 _owner = this;
ebrus 0:6bc4ac881c8e 30 }
ebrus 0:6bc4ac881c8e 31
ebrus 0:6bc4ac881c8e 32 void I2C::frequency(int hz) {
ebrus 0:6bc4ac881c8e 33 _hz = hz;
ebrus 0:6bc4ac881c8e 34
ebrus 0:6bc4ac881c8e 35 // We want to update the frequency even if we are already the bus owners
ebrus 0:6bc4ac881c8e 36 i2c_frequency(&_i2c, _hz);
ebrus 0:6bc4ac881c8e 37
ebrus 0:6bc4ac881c8e 38 // Updating the frequency of the bus we become the owners of it
ebrus 0:6bc4ac881c8e 39 _owner = this;
ebrus 0:6bc4ac881c8e 40 }
ebrus 0:6bc4ac881c8e 41
ebrus 0:6bc4ac881c8e 42 void I2C::aquire() {
ebrus 0:6bc4ac881c8e 43 if (_owner != this) {
ebrus 0:6bc4ac881c8e 44 i2c_frequency(&_i2c, _hz);
ebrus 0:6bc4ac881c8e 45 _owner = this;
ebrus 0:6bc4ac881c8e 46 }
ebrus 0:6bc4ac881c8e 47 }
ebrus 0:6bc4ac881c8e 48
ebrus 0:6bc4ac881c8e 49 // write - Master Transmitter Mode
ebrus 0:6bc4ac881c8e 50 int I2C::write(int address, const char* data, int length, bool repeated) {
ebrus 0:6bc4ac881c8e 51 aquire();
ebrus 0:6bc4ac881c8e 52
ebrus 0:6bc4ac881c8e 53 int stop = (repeated) ? 0 : 1;
ebrus 0:6bc4ac881c8e 54 int written = i2c_write(&_i2c, address, data, length, stop);
ebrus 0:6bc4ac881c8e 55
ebrus 0:6bc4ac881c8e 56 return length != written;
ebrus 0:6bc4ac881c8e 57 }
ebrus 0:6bc4ac881c8e 58
ebrus 0:6bc4ac881c8e 59 int I2C::write(int data) {
ebrus 0:6bc4ac881c8e 60 return i2c_byte_write(&_i2c, data);
ebrus 0:6bc4ac881c8e 61 }
ebrus 0:6bc4ac881c8e 62
ebrus 0:6bc4ac881c8e 63 // read - Master Reciever Mode
ebrus 0:6bc4ac881c8e 64 int I2C::read(int address, char* data, int length, bool repeated) {
ebrus 0:6bc4ac881c8e 65 aquire();
ebrus 0:6bc4ac881c8e 66
ebrus 0:6bc4ac881c8e 67 int stop = (repeated) ? 0 : 1;
ebrus 0:6bc4ac881c8e 68 int read = i2c_read(&_i2c, address, data, length, stop);
ebrus 0:6bc4ac881c8e 69
ebrus 0:6bc4ac881c8e 70 return length != read;
ebrus 0:6bc4ac881c8e 71 }
ebrus 0:6bc4ac881c8e 72
ebrus 0:6bc4ac881c8e 73 int I2C::read(int ack) {
ebrus 0:6bc4ac881c8e 74 if (ack) {
ebrus 0:6bc4ac881c8e 75 return i2c_byte_read(&_i2c, 0);
ebrus 0:6bc4ac881c8e 76 } else {
ebrus 0:6bc4ac881c8e 77 return i2c_byte_read(&_i2c, 1);
ebrus 0:6bc4ac881c8e 78 }
ebrus 0:6bc4ac881c8e 79 }
ebrus 0:6bc4ac881c8e 80
ebrus 0:6bc4ac881c8e 81 void I2C::start(void) {
ebrus 0:6bc4ac881c8e 82 i2c_start(&_i2c);
ebrus 0:6bc4ac881c8e 83 }
ebrus 0:6bc4ac881c8e 84
ebrus 0:6bc4ac881c8e 85 void I2C::stop(void) {
ebrus 0:6bc4ac881c8e 86 i2c_stop(&_i2c);
ebrus 0:6bc4ac881c8e 87 }
ebrus 0:6bc4ac881c8e 88
ebrus 0:6bc4ac881c8e 89 } // namespace mbed
ebrus 0:6bc4ac881c8e 90
ebrus 0:6bc4ac881c8e 91 #endif