joey shelton / LED_Demo2

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Dependencies:   MAX44000 PWM_Tone_Library nexpaq_mdk

Fork of LED_Demo by joey shelton

mbd_os/hal/common/I2C.cpp@1:55a6170b404f, 2016-09-17 (annotated)

Committer:
nexpaq
Date:
Sat Sep 17 16:32:05 2016 +0000
Revision:
1:55a6170b404f
checking in for sharing

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nexpaq 1:55a6170b404f 1 /* mbed Microcontroller Library
nexpaq 1:55a6170b404f 2 * Copyright (c) 2006-2015 ARM Limited
nexpaq 1:55a6170b404f 3 *
nexpaq 1:55a6170b404f 4 * Licensed under the Apache License, Version 2.0 (the "License");
nexpaq 1:55a6170b404f 5 * you may not use this file except in compliance with the License.
nexpaq 1:55a6170b404f 6 * You may obtain a copy of the License at
nexpaq 1:55a6170b404f 7 *
nexpaq 1:55a6170b404f 8 * http://www.apache.org/licenses/LICENSE-2.0
nexpaq 1:55a6170b404f 9 *
nexpaq 1:55a6170b404f 10 * Unless required by applicable law or agreed to in writing, software
nexpaq 1:55a6170b404f 11 * distributed under the License is distributed on an "AS IS" BASIS,
nexpaq 1:55a6170b404f 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nexpaq 1:55a6170b404f 13 * See the License for the specific language governing permissions and
nexpaq 1:55a6170b404f 14 * limitations under the License.
nexpaq 1:55a6170b404f 15 */
nexpaq 1:55a6170b404f 16 #include "I2C.h"
nexpaq 1:55a6170b404f 17
nexpaq 1:55a6170b404f 18 #if DEVICE_I2C
nexpaq 1:55a6170b404f 19
nexpaq 1:55a6170b404f 20 namespace mbed {
nexpaq 1:55a6170b404f 21
nexpaq 1:55a6170b404f 22 I2C *I2C::_owner = NULL;
nexpaq 1:55a6170b404f 23 SingletonPtr<PlatformMutex> I2C::_mutex;
nexpaq 1:55a6170b404f 24
nexpaq 1:55a6170b404f 25 I2C::I2C(PinName sda, PinName scl) :
nexpaq 1:55a6170b404f 26 #if DEVICE_I2C_ASYNCH
nexpaq 1:55a6170b404f 27 _irq(this), _usage(DMA_USAGE_NEVER),
nexpaq 1:55a6170b404f 28 #endif
nexpaq 1:55a6170b404f 29 _i2c(), _hz(100000) {
nexpaq 1:55a6170b404f 30 // No lock needed in the constructor
nexpaq 1:55a6170b404f 31
nexpaq 1:55a6170b404f 32 // The init function also set the frequency to 100000
nexpaq 1:55a6170b404f 33 i2c_init(&_i2c, sda, scl);
nexpaq 1:55a6170b404f 34
nexpaq 1:55a6170b404f 35 // Used to avoid unnecessary frequency updates
nexpaq 1:55a6170b404f 36 _owner = this;
nexpaq 1:55a6170b404f 37 }
nexpaq 1:55a6170b404f 38
nexpaq 1:55a6170b404f 39 void I2C::frequency(int hz) {
nexpaq 1:55a6170b404f 40 lock();
nexpaq 1:55a6170b404f 41 _hz = hz;
nexpaq 1:55a6170b404f 42
nexpaq 1:55a6170b404f 43 // We want to update the frequency even if we are already the bus owners
nexpaq 1:55a6170b404f 44 i2c_frequency(&_i2c, _hz);
nexpaq 1:55a6170b404f 45
nexpaq 1:55a6170b404f 46 // Updating the frequency of the bus we become the owners of it
nexpaq 1:55a6170b404f 47 _owner = this;
nexpaq 1:55a6170b404f 48 unlock();
nexpaq 1:55a6170b404f 49 }
nexpaq 1:55a6170b404f 50
nexpaq 1:55a6170b404f 51 void I2C::aquire() {
nexpaq 1:55a6170b404f 52 lock();
nexpaq 1:55a6170b404f 53 if (_owner != this) {
nexpaq 1:55a6170b404f 54 i2c_frequency(&_i2c, _hz);
nexpaq 1:55a6170b404f 55 _owner = this;
nexpaq 1:55a6170b404f 56 }
nexpaq 1:55a6170b404f 57 unlock();
nexpaq 1:55a6170b404f 58 }
nexpaq 1:55a6170b404f 59
nexpaq 1:55a6170b404f 60 // write - Master Transmitter Mode
nexpaq 1:55a6170b404f 61 int I2C::write(int address, const char* data, int length, bool repeated) {
nexpaq 1:55a6170b404f 62 lock();
nexpaq 1:55a6170b404f 63 aquire();
nexpaq 1:55a6170b404f 64
nexpaq 1:55a6170b404f 65 int stop = (repeated) ? 0 : 1;
nexpaq 1:55a6170b404f 66 int written = i2c_write(&_i2c, address, data, length, stop);
nexpaq 1:55a6170b404f 67
nexpaq 1:55a6170b404f 68 unlock();
nexpaq 1:55a6170b404f 69 return length != written;
nexpaq 1:55a6170b404f 70 }
nexpaq 1:55a6170b404f 71
nexpaq 1:55a6170b404f 72 int I2C::write(int data) {
nexpaq 1:55a6170b404f 73 lock();
nexpaq 1:55a6170b404f 74 int ret = i2c_byte_write(&_i2c, data);
nexpaq 1:55a6170b404f 75 unlock();
nexpaq 1:55a6170b404f 76 return ret;
nexpaq 1:55a6170b404f 77 }
nexpaq 1:55a6170b404f 78
nexpaq 1:55a6170b404f 79 // read - Master Reciever Mode
nexpaq 1:55a6170b404f 80 int I2C::read(int address, char* data, int length, bool repeated) {
nexpaq 1:55a6170b404f 81 lock();
nexpaq 1:55a6170b404f 82 aquire();
nexpaq 1:55a6170b404f 83
nexpaq 1:55a6170b404f 84 int stop = (repeated) ? 0 : 1;
nexpaq 1:55a6170b404f 85 int read = i2c_read(&_i2c, address, data, length, stop);
nexpaq 1:55a6170b404f 86
nexpaq 1:55a6170b404f 87 unlock();
nexpaq 1:55a6170b404f 88 return length != read;
nexpaq 1:55a6170b404f 89 }
nexpaq 1:55a6170b404f 90
nexpaq 1:55a6170b404f 91 int I2C::read(int ack) {
nexpaq 1:55a6170b404f 92 lock();
nexpaq 1:55a6170b404f 93 int ret;
nexpaq 1:55a6170b404f 94 if (ack) {
nexpaq 1:55a6170b404f 95 ret = i2c_byte_read(&_i2c, 0);
nexpaq 1:55a6170b404f 96 } else {
nexpaq 1:55a6170b404f 97 ret = i2c_byte_read(&_i2c, 1);
nexpaq 1:55a6170b404f 98 }
nexpaq 1:55a6170b404f 99 unlock();
nexpaq 1:55a6170b404f 100 return ret;
nexpaq 1:55a6170b404f 101 }
nexpaq 1:55a6170b404f 102
nexpaq 1:55a6170b404f 103 void I2C::start(void) {
nexpaq 1:55a6170b404f 104 lock();
nexpaq 1:55a6170b404f 105 i2c_start(&_i2c);
nexpaq 1:55a6170b404f 106 unlock();
nexpaq 1:55a6170b404f 107 }
nexpaq 1:55a6170b404f 108
nexpaq 1:55a6170b404f 109 void I2C::stop(void) {
nexpaq 1:55a6170b404f 110 lock();
nexpaq 1:55a6170b404f 111 i2c_stop(&_i2c);
nexpaq 1:55a6170b404f 112 unlock();
nexpaq 1:55a6170b404f 113 }
nexpaq 1:55a6170b404f 114
nexpaq 1:55a6170b404f 115 void I2C::lock() {
nexpaq 1:55a6170b404f 116 _mutex->lock();
nexpaq 1:55a6170b404f 117 }
nexpaq 1:55a6170b404f 118
nexpaq 1:55a6170b404f 119 void I2C::unlock() {
nexpaq 1:55a6170b404f 120 _mutex->unlock();
nexpaq 1:55a6170b404f 121 }
nexpaq 1:55a6170b404f 122
nexpaq 1:55a6170b404f 123 #if DEVICE_I2C_ASYNCH
nexpaq 1:55a6170b404f 124
nexpaq 1:55a6170b404f 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)
nexpaq 1:55a6170b404f 126 {
nexpaq 1:55a6170b404f 127 lock();
nexpaq 1:55a6170b404f 128 if (i2c_active(&_i2c)) {
nexpaq 1:55a6170b404f 129 unlock();
nexpaq 1:55a6170b404f 130 return -1; // transaction ongoing
nexpaq 1:55a6170b404f 131 }
nexpaq 1:55a6170b404f 132 aquire();
nexpaq 1:55a6170b404f 133
nexpaq 1:55a6170b404f 134 _callback = callback;
nexpaq 1:55a6170b404f 135 int stop = (repeated) ? 0 : 1;
nexpaq 1:55a6170b404f 136 _irq.callback(&I2C::irq_handler_asynch);
nexpaq 1:55a6170b404f 137 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
nexpaq 1:55a6170b404f 138 unlock();
nexpaq 1:55a6170b404f 139 return 0;
nexpaq 1:55a6170b404f 140 }
nexpaq 1:55a6170b404f 141
nexpaq 1:55a6170b404f 142 void I2C::abort_transfer(void)
nexpaq 1:55a6170b404f 143 {
nexpaq 1:55a6170b404f 144 lock();
nexpaq 1:55a6170b404f 145 i2c_abort_asynch(&_i2c);
nexpaq 1:55a6170b404f 146 unlock();
nexpaq 1:55a6170b404f 147 }
nexpaq 1:55a6170b404f 148
nexpaq 1:55a6170b404f 149 void I2C::irq_handler_asynch(void)
nexpaq 1:55a6170b404f 150 {
nexpaq 1:55a6170b404f 151 int event = i2c_irq_handler_asynch(&_i2c);
nexpaq 1:55a6170b404f 152 if (_callback && event) {
nexpaq 1:55a6170b404f 153 _callback.call(event);
nexpaq 1:55a6170b404f 154 }
nexpaq 1:55a6170b404f 155
nexpaq 1:55a6170b404f 156 }
nexpaq 1:55a6170b404f 157
nexpaq 1:55a6170b404f 158
nexpaq 1:55a6170b404f 159 #endif
nexpaq 1:55a6170b404f 160
nexpaq 1:55a6170b404f 161 } // namespace mbed
nexpaq 1:55a6170b404f 162
nexpaq 1:55a6170b404f 163 #endif