zain aftab / mbed-src

mbed library sources

Fork of mbed-src by mbed official

common/I2C.cpp@9:0ce32e54c9a7, 2013-06-10 (annotated)

Committer:
emilmont
Date:
Mon Jun 10 16:03:00 2013 +0100
Revision:
9:0ce32e54c9a7
Parent:
cpp/I2C.cpp@2:143cac498751
Child:
10:3bc89ef62ce7
Refactoring of the mbed SDK:

- Provide a well defined HAL and API

- Keep separated the HAL implementations for the different targets

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:fd0d7bdfcdc2 1 /* mbed Microcontroller Library
emilmont 2:143cac498751 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 0:fd0d7bdfcdc2 3 *
emilmont 2:143cac498751 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 2:143cac498751 5 * you may not use this file except in compliance with the License.
emilmont 2:143cac498751 6 * You may obtain a copy of the License at
mbed_official 0:fd0d7bdfcdc2 7 *
emilmont 2:143cac498751 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 0:fd0d7bdfcdc2 9 *
emilmont 2:143cac498751 10 * Unless required by applicable law or agreed to in writing, software
emilmont 2:143cac498751 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 2:143cac498751 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 2:143cac498751 13 * See the License for the specific language governing permissions and
emilmont 2:143cac498751 14 * limitations under the License.
mbed_official 0:fd0d7bdfcdc2 15 */
mbed_official 0:fd0d7bdfcdc2 16 #include "I2C.h"
mbed_official 0:fd0d7bdfcdc2 17
mbed_official 0:fd0d7bdfcdc2 18 #if DEVICE_I2C
mbed_official 0:fd0d7bdfcdc2 19
mbed_official 0:fd0d7bdfcdc2 20 namespace mbed {
mbed_official 0:fd0d7bdfcdc2 21
mbed_official 0:fd0d7bdfcdc2 22 I2C *I2C::_owner = NULL;
mbed_official 0:fd0d7bdfcdc2 23
mbed_official 0:fd0d7bdfcdc2 24 I2C::I2C(PinName sda, PinName scl) {
mbed_official 0:fd0d7bdfcdc2 25 // The init function also set the frequency to 100000
mbed_official 0:fd0d7bdfcdc2 26 i2c_init(&_i2c, sda, scl);
mbed_official 0:fd0d7bdfcdc2 27 _hz = 100000;
emilmont 2:143cac498751 28
mbed_official 0:fd0d7bdfcdc2 29 // Used to avoid unnecessary frequency updates
mbed_official 0:fd0d7bdfcdc2 30 _owner = this;
mbed_official 0:fd0d7bdfcdc2 31 }
mbed_official 0:fd0d7bdfcdc2 32
mbed_official 0:fd0d7bdfcdc2 33 void I2C::frequency(int hz) {
mbed_official 0:fd0d7bdfcdc2 34 _hz = hz;
emilmont 2:143cac498751 35
mbed_official 0:fd0d7bdfcdc2 36 // We want to update the frequency even if we are already the bus owners
mbed_official 0:fd0d7bdfcdc2 37 i2c_frequency(&_i2c, _hz);
emilmont 2:143cac498751 38
mbed_official 0:fd0d7bdfcdc2 39 // Updating the frequency of the bus we become the owners of it
mbed_official 0:fd0d7bdfcdc2 40 _owner = this;
mbed_official 0:fd0d7bdfcdc2 41 }
mbed_official 0:fd0d7bdfcdc2 42
mbed_official 0:fd0d7bdfcdc2 43 void I2C::aquire() {
mbed_official 0:fd0d7bdfcdc2 44 if (_owner != this) {
mbed_official 0:fd0d7bdfcdc2 45 i2c_frequency(&_i2c, _hz);
mbed_official 0:fd0d7bdfcdc2 46 _owner = this;
mbed_official 0:fd0d7bdfcdc2 47 }
mbed_official 0:fd0d7bdfcdc2 48 }
mbed_official 0:fd0d7bdfcdc2 49
mbed_official 0:fd0d7bdfcdc2 50 // write - Master Transmitter Mode
mbed_official 0:fd0d7bdfcdc2 51 int I2C::write(int address, const char* data, int length, bool repeated) {
emilmont 2:143cac498751 52 aquire();
emilmont 2:143cac498751 53
mbed_official 0:fd0d7bdfcdc2 54 int stop = (repeated) ? 0 : 1;
mbed_official 0:fd0d7bdfcdc2 55 int retval = i2c_write(&_i2c, address, data, length, stop);
emilmont 2:143cac498751 56
mbed_official 0:fd0d7bdfcdc2 57 return retval;
mbed_official 0:fd0d7bdfcdc2 58 }
mbed_official 0:fd0d7bdfcdc2 59
mbed_official 0:fd0d7bdfcdc2 60 int I2C::write(int data) {
mbed_official 0:fd0d7bdfcdc2 61 return i2c_byte_write(&_i2c, data);
mbed_official 0:fd0d7bdfcdc2 62 }
mbed_official 0:fd0d7bdfcdc2 63
mbed_official 0:fd0d7bdfcdc2 64 // read - Master Reciever Mode
mbed_official 0:fd0d7bdfcdc2 65 int I2C::read(int address, char* data, int length, bool repeated) {
mbed_official 0:fd0d7bdfcdc2 66 aquire();
emilmont 2:143cac498751 67
mbed_official 0:fd0d7bdfcdc2 68 int stop = (repeated) ? 0 : 1;
mbed_official 0:fd0d7bdfcdc2 69 int retval = i2c_read(&_i2c, address, data, length, stop);
emilmont 2:143cac498751 70
mbed_official 0:fd0d7bdfcdc2 71 return retval;
mbed_official 0:fd0d7bdfcdc2 72 }
mbed_official 0:fd0d7bdfcdc2 73
mbed_official 0:fd0d7bdfcdc2 74 int I2C::read(int ack) {
mbed_official 0:fd0d7bdfcdc2 75 if (ack) {
mbed_official 0:fd0d7bdfcdc2 76 return i2c_byte_read(&_i2c, 0);
mbed_official 0:fd0d7bdfcdc2 77 } else {
mbed_official 0:fd0d7bdfcdc2 78 return i2c_byte_read(&_i2c, 1);
mbed_official 0:fd0d7bdfcdc2 79 }
mbed_official 0:fd0d7bdfcdc2 80 }
mbed_official 0:fd0d7bdfcdc2 81
mbed_official 0:fd0d7bdfcdc2 82 void I2C::start(void) {
mbed_official 0:fd0d7bdfcdc2 83 i2c_start(&_i2c);
mbed_official 0:fd0d7bdfcdc2 84 }
mbed_official 0:fd0d7bdfcdc2 85
mbed_official 0:fd0d7bdfcdc2 86 void I2C::stop(void) {
mbed_official 0:fd0d7bdfcdc2 87 i2c_stop(&_i2c);
mbed_official 0:fd0d7bdfcdc2 88 }
mbed_official 0:fd0d7bdfcdc2 89
mbed_official 0:fd0d7bdfcdc2 90 } // namespace mbed
mbed_official 0:fd0d7bdfcdc2 91
mbed_official 0:fd0d7bdfcdc2 92 #endif