Mateusz Kowalik / Application

USB Serial application

Fork of USBSerial_HelloWorld by Samuel Mokrani

mbed-dev/drivers/I2C.cpp@11:b3f2a8bdac4d, 2017-12-16 (annotated)

Committer:
Zaitsev
Date:
Sat Dec 16 10:26:48 2017 +0000
Revision:
11:b3f2a8bdac4d
Parent:
10:41552d038a69 
A copy for D.S;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Zaitsev 10:41552d038a69 1 /* mbed Microcontroller Library
Zaitsev 10:41552d038a69 2 * Copyright (c) 2006-2015 ARM Limited
Zaitsev 10:41552d038a69 3 *
Zaitsev 10:41552d038a69 4 * Licensed under the Apache License, Version 2.0 (the "License");
Zaitsev 10:41552d038a69 5 * you may not use this file except in compliance with the License.
Zaitsev 10:41552d038a69 6 * You may obtain a copy of the License at
Zaitsev 10:41552d038a69 7 *
Zaitsev 10:41552d038a69 8 * http://www.apache.org/licenses/LICENSE-2.0
Zaitsev 10:41552d038a69 9 *
Zaitsev 10:41552d038a69 10 * Unless required by applicable law or agreed to in writing, software
Zaitsev 10:41552d038a69 11 * distributed under the License is distributed on an "AS IS" BASIS,
Zaitsev 10:41552d038a69 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Zaitsev 10:41552d038a69 13 * See the License for the specific language governing permissions and
Zaitsev 10:41552d038a69 14 * limitations under the License.
Zaitsev 10:41552d038a69 15 */
Zaitsev 10:41552d038a69 16 #include "drivers/I2C.h"
Zaitsev 10:41552d038a69 17
Zaitsev 10:41552d038a69 18 #if DEVICE_I2C
Zaitsev 10:41552d038a69 19
Zaitsev 10:41552d038a69 20 namespace mbed {
Zaitsev 10:41552d038a69 21
Zaitsev 10:41552d038a69 22 I2C *I2C::_owner = NULL;
Zaitsev 10:41552d038a69 23 SingletonPtr<PlatformMutex> I2C::_mutex;
Zaitsev 10:41552d038a69 24
Zaitsev 10:41552d038a69 25 I2C::I2C(PinName sda, PinName scl) :
Zaitsev 10:41552d038a69 26 #if DEVICE_I2C_ASYNCH
Zaitsev 10:41552d038a69 27 _irq(this), _usage(DMA_USAGE_NEVER),
Zaitsev 10:41552d038a69 28 #endif
Zaitsev 10:41552d038a69 29 _i2c(), _hz(100000) {
Zaitsev 10:41552d038a69 30 // No lock needed in the constructor
Zaitsev 10:41552d038a69 31
Zaitsev 10:41552d038a69 32 // The init function also set the frequency to 100000
Zaitsev 10:41552d038a69 33 i2c_init(&_i2c, sda, scl);
Zaitsev 10:41552d038a69 34
Zaitsev 10:41552d038a69 35 // Used to avoid unnecessary frequency updates
Zaitsev 10:41552d038a69 36 _owner = this;
Zaitsev 10:41552d038a69 37 }
Zaitsev 10:41552d038a69 38
Zaitsev 10:41552d038a69 39 void I2C::frequency(int hz) {
Zaitsev 10:41552d038a69 40 lock();
Zaitsev 10:41552d038a69 41 _hz = hz;
Zaitsev 10:41552d038a69 42
Zaitsev 10:41552d038a69 43 // We want to update the frequency even if we are already the bus owners
Zaitsev 10:41552d038a69 44 i2c_frequency(&_i2c, _hz);
Zaitsev 10:41552d038a69 45
Zaitsev 10:41552d038a69 46 // Updating the frequency of the bus we become the owners of it
Zaitsev 10:41552d038a69 47 _owner = this;
Zaitsev 10:41552d038a69 48 unlock();
Zaitsev 10:41552d038a69 49 }
Zaitsev 10:41552d038a69 50
Zaitsev 10:41552d038a69 51 void I2C::aquire() {
Zaitsev 10:41552d038a69 52 lock();
Zaitsev 10:41552d038a69 53 if (_owner != this) {
Zaitsev 10:41552d038a69 54 i2c_frequency(&_i2c, _hz);
Zaitsev 10:41552d038a69 55 _owner = this;
Zaitsev 10:41552d038a69 56 }
Zaitsev 10:41552d038a69 57 unlock();
Zaitsev 10:41552d038a69 58 }
Zaitsev 10:41552d038a69 59
Zaitsev 10:41552d038a69 60 // write - Master Transmitter Mode
Zaitsev 10:41552d038a69 61 int I2C::write(int address, const char* data, int length, bool repeated) {
Zaitsev 10:41552d038a69 62 lock();
Zaitsev 10:41552d038a69 63 aquire();
Zaitsev 10:41552d038a69 64
Zaitsev 10:41552d038a69 65 int stop = (repeated) ? 0 : 1;
Zaitsev 10:41552d038a69 66 int written = i2c_write(&_i2c, address, data, length, stop);
Zaitsev 10:41552d038a69 67
Zaitsev 10:41552d038a69 68 unlock();
Zaitsev 10:41552d038a69 69 return length != written;
Zaitsev 10:41552d038a69 70 }
Zaitsev 10:41552d038a69 71
Zaitsev 10:41552d038a69 72 int I2C::write(int data) {
Zaitsev 10:41552d038a69 73 lock();
Zaitsev 10:41552d038a69 74 int ret = i2c_byte_write(&_i2c, data);
Zaitsev 10:41552d038a69 75 unlock();
Zaitsev 10:41552d038a69 76 return ret;
Zaitsev 10:41552d038a69 77 }
Zaitsev 10:41552d038a69 78
Zaitsev 10:41552d038a69 79 // read - Master Reciever Mode
Zaitsev 10:41552d038a69 80 int I2C::read(int address, char* data, int length, bool repeated) {
Zaitsev 10:41552d038a69 81 lock();
Zaitsev 10:41552d038a69 82 aquire();
Zaitsev 10:41552d038a69 83
Zaitsev 10:41552d038a69 84 int stop = (repeated) ? 0 : 1;
Zaitsev 10:41552d038a69 85 int read = i2c_read(&_i2c, address, data, length, stop);
Zaitsev 10:41552d038a69 86
Zaitsev 10:41552d038a69 87 unlock();
Zaitsev 10:41552d038a69 88 return length != read;
Zaitsev 10:41552d038a69 89 }
Zaitsev 10:41552d038a69 90
Zaitsev 10:41552d038a69 91 int I2C::read(int ack) {
Zaitsev 10:41552d038a69 92 lock();
Zaitsev 10:41552d038a69 93 int ret;
Zaitsev 10:41552d038a69 94 if (ack) {
Zaitsev 10:41552d038a69 95 ret = i2c_byte_read(&_i2c, 0);
Zaitsev 10:41552d038a69 96 } else {
Zaitsev 10:41552d038a69 97 ret = i2c_byte_read(&_i2c, 1);
Zaitsev 10:41552d038a69 98 }
Zaitsev 10:41552d038a69 99 unlock();
Zaitsev 10:41552d038a69 100 return ret;
Zaitsev 10:41552d038a69 101 }
Zaitsev 10:41552d038a69 102
Zaitsev 10:41552d038a69 103 void I2C::start(void) {
Zaitsev 10:41552d038a69 104 lock();
Zaitsev 10:41552d038a69 105 i2c_start(&_i2c);
Zaitsev 10:41552d038a69 106 unlock();
Zaitsev 10:41552d038a69 107 }
Zaitsev 10:41552d038a69 108
Zaitsev 10:41552d038a69 109 void I2C::stop(void) {
Zaitsev 10:41552d038a69 110 lock();
Zaitsev 10:41552d038a69 111 i2c_stop(&_i2c);
Zaitsev 10:41552d038a69 112 unlock();
Zaitsev 10:41552d038a69 113 }
Zaitsev 10:41552d038a69 114
Zaitsev 10:41552d038a69 115 void I2C::lock() {
Zaitsev 10:41552d038a69 116 _mutex->lock();
Zaitsev 10:41552d038a69 117 }
Zaitsev 10:41552d038a69 118
Zaitsev 10:41552d038a69 119 void I2C::unlock() {
Zaitsev 10:41552d038a69 120 _mutex->unlock();
Zaitsev 10:41552d038a69 121 }
Zaitsev 10:41552d038a69 122
Zaitsev 10:41552d038a69 123 #if DEVICE_I2C_ASYNCH
Zaitsev 10:41552d038a69 124
Zaitsev 10:41552d038a69 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)
Zaitsev 10:41552d038a69 126 {
Zaitsev 10:41552d038a69 127 lock();
Zaitsev 10:41552d038a69 128 if (i2c_active(&_i2c)) {
Zaitsev 10:41552d038a69 129 unlock();
Zaitsev 10:41552d038a69 130 return -1; // transaction ongoing
Zaitsev 10:41552d038a69 131 }
Zaitsev 10:41552d038a69 132 aquire();
Zaitsev 10:41552d038a69 133
Zaitsev 10:41552d038a69 134 _callback = callback;
Zaitsev 10:41552d038a69 135 int stop = (repeated) ? 0 : 1;
Zaitsev 10:41552d038a69 136 _irq.callback(&I2C::irq_handler_asynch);
Zaitsev 10:41552d038a69 137 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
Zaitsev 10:41552d038a69 138 unlock();
Zaitsev 10:41552d038a69 139 return 0;
Zaitsev 10:41552d038a69 140 }
Zaitsev 10:41552d038a69 141
Zaitsev 10:41552d038a69 142 void I2C::abort_transfer(void)
Zaitsev 10:41552d038a69 143 {
Zaitsev 10:41552d038a69 144 lock();
Zaitsev 10:41552d038a69 145 i2c_abort_asynch(&_i2c);
Zaitsev 10:41552d038a69 146 unlock();
Zaitsev 10:41552d038a69 147 }
Zaitsev 10:41552d038a69 148
Zaitsev 10:41552d038a69 149 void I2C::irq_handler_asynch(void)
Zaitsev 10:41552d038a69 150 {
Zaitsev 10:41552d038a69 151 int event = i2c_irq_handler_asynch(&_i2c);
Zaitsev 10:41552d038a69 152 if (_callback && event) {
Zaitsev 10:41552d038a69 153 _callback.call(event);
Zaitsev 10:41552d038a69 154 }
Zaitsev 10:41552d038a69 155
Zaitsev 10:41552d038a69 156 }
Zaitsev 10:41552d038a69 157
Zaitsev 10:41552d038a69 158
Zaitsev 10:41552d038a69 159 #endif
Zaitsev 10:41552d038a69 160
Zaitsev 10:41552d038a69 161 } // namespace mbed
Zaitsev 10:41552d038a69 162
Zaitsev 10:41552d038a69 163 #endif