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mbed library sources

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Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

common/I2C.cpp@635:a11c0372f0ba, 2015-09-30 (annotated)

Committer:
mbed_official
Date:
Wed Sep 30 17:00:09 2015 +0100
Revision:
635:a11c0372f0ba
Parent:
563:536c9fb088a0 
Synchronized with git revision d29c98dae61be0946ddf3a3c641c7726056f9452



Full URL: https://github.com/mbedmicro/mbed/commit/d29c98dae61be0946ddf3a3c641c7726056f9452/



Added support for SAMW25

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 13:0645d8841f51 1 /* mbed Microcontroller Library
mbed_official 525:c320967f86b9 2 * Copyright (c) 2006-2015 ARM Limited
bogdanm 13:0645d8841f51 3 *
bogdanm 13:0645d8841f51 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 13:0645d8841f51 5 * you may not use this file except in compliance with the License.
bogdanm 13:0645d8841f51 6 * You may obtain a copy of the License at
bogdanm 13:0645d8841f51 7 *
bogdanm 13:0645d8841f51 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 13:0645d8841f51 9 *
bogdanm 13:0645d8841f51 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 13:0645d8841f51 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 13:0645d8841f51 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 13:0645d8841f51 13 * See the License for the specific language governing permissions and
bogdanm 13:0645d8841f51 14 * limitations under the License.
bogdanm 13:0645d8841f51 15 */
bogdanm 13:0645d8841f51 16 #include "I2C.h"
bogdanm 13:0645d8841f51 17
bogdanm 13:0645d8841f51 18 #if DEVICE_I2C
bogdanm 13:0645d8841f51 19
bogdanm 13:0645d8841f51 20 namespace mbed {
bogdanm 13:0645d8841f51 21
bogdanm 13:0645d8841f51 22 I2C *I2C::_owner = NULL;
bogdanm 13:0645d8841f51 23
mbed_official 525:c320967f86b9 24 I2C::I2C(PinName sda, PinName scl) :
mbed_official 525:c320967f86b9 25 #if DEVICE_I2C_ASYNCH
mbed_official 525:c320967f86b9 26 _irq(this), _usage(DMA_USAGE_NEVER),
mbed_official 525:c320967f86b9 27 #endif
mbed_official 525:c320967f86b9 28 _i2c(), _hz(100000) {
bogdanm 13:0645d8841f51 29 // The init function also set the frequency to 100000
bogdanm 13:0645d8841f51 30 i2c_init(&_i2c, sda, scl);
bogdanm 13:0645d8841f51 31
bogdanm 13:0645d8841f51 32 // Used to avoid unnecessary frequency updates
bogdanm 13:0645d8841f51 33 _owner = this;
bogdanm 13:0645d8841f51 34 }
bogdanm 13:0645d8841f51 35
bogdanm 13:0645d8841f51 36 void I2C::frequency(int hz) {
bogdanm 13:0645d8841f51 37 _hz = hz;
bogdanm 13:0645d8841f51 38
bogdanm 13:0645d8841f51 39 // We want to update the frequency even if we are already the bus owners
bogdanm 13:0645d8841f51 40 i2c_frequency(&_i2c, _hz);
bogdanm 13:0645d8841f51 41
bogdanm 13:0645d8841f51 42 // Updating the frequency of the bus we become the owners of it
bogdanm 13:0645d8841f51 43 _owner = this;
bogdanm 13:0645d8841f51 44 }
bogdanm 13:0645d8841f51 45
bogdanm 13:0645d8841f51 46 void I2C::aquire() {
bogdanm 13:0645d8841f51 47 if (_owner != this) {
bogdanm 13:0645d8841f51 48 i2c_frequency(&_i2c, _hz);
bogdanm 13:0645d8841f51 49 _owner = this;
bogdanm 13:0645d8841f51 50 }
bogdanm 13:0645d8841f51 51 }
bogdanm 13:0645d8841f51 52
bogdanm 13:0645d8841f51 53 // write - Master Transmitter Mode
bogdanm 13:0645d8841f51 54 int I2C::write(int address, const char* data, int length, bool repeated) {
bogdanm 13:0645d8841f51 55 aquire();
bogdanm 13:0645d8841f51 56
bogdanm 13:0645d8841f51 57 int stop = (repeated) ? 0 : 1;
bogdanm 13:0645d8841f51 58 int written = i2c_write(&_i2c, address, data, length, stop);
bogdanm 13:0645d8841f51 59
bogdanm 13:0645d8841f51 60 return length != written;
bogdanm 13:0645d8841f51 61 }
bogdanm 13:0645d8841f51 62
bogdanm 13:0645d8841f51 63 int I2C::write(int data) {
bogdanm 13:0645d8841f51 64 return i2c_byte_write(&_i2c, data);
bogdanm 13:0645d8841f51 65 }
bogdanm 13:0645d8841f51 66
bogdanm 13:0645d8841f51 67 // read - Master Reciever Mode
bogdanm 13:0645d8841f51 68 int I2C::read(int address, char* data, int length, bool repeated) {
bogdanm 13:0645d8841f51 69 aquire();
bogdanm 13:0645d8841f51 70
bogdanm 13:0645d8841f51 71 int stop = (repeated) ? 0 : 1;
bogdanm 13:0645d8841f51 72 int read = i2c_read(&_i2c, address, data, length, stop);
bogdanm 13:0645d8841f51 73
bogdanm 13:0645d8841f51 74 return length != read;
bogdanm 13:0645d8841f51 75 }
bogdanm 13:0645d8841f51 76
bogdanm 13:0645d8841f51 77 int I2C::read(int ack) {
bogdanm 13:0645d8841f51 78 if (ack) {
bogdanm 13:0645d8841f51 79 return i2c_byte_read(&_i2c, 0);
bogdanm 13:0645d8841f51 80 } else {
bogdanm 13:0645d8841f51 81 return i2c_byte_read(&_i2c, 1);
bogdanm 13:0645d8841f51 82 }
bogdanm 13:0645d8841f51 83 }
bogdanm 13:0645d8841f51 84
bogdanm 13:0645d8841f51 85 void I2C::start(void) {
bogdanm 13:0645d8841f51 86 i2c_start(&_i2c);
bogdanm 13:0645d8841f51 87 }
bogdanm 13:0645d8841f51 88
bogdanm 13:0645d8841f51 89 void I2C::stop(void) {
bogdanm 13:0645d8841f51 90 i2c_stop(&_i2c);
bogdanm 13:0645d8841f51 91 }
bogdanm 13:0645d8841f51 92
mbed_official 525:c320967f86b9 93 #if DEVICE_I2C_ASYNCH
mbed_official 525:c320967f86b9 94
mbed_official 563:536c9fb088a0 95 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)
mbed_official 525:c320967f86b9 96 {
mbed_official 525:c320967f86b9 97 if (i2c_active(&_i2c)) {
mbed_official 525:c320967f86b9 98 return -1; // transaction ongoing
mbed_official 525:c320967f86b9 99 }
mbed_official 525:c320967f86b9 100 aquire();
mbed_official 525:c320967f86b9 101
mbed_official 525:c320967f86b9 102 _callback = callback;
mbed_official 525:c320967f86b9 103 int stop = (repeated) ? 0 : 1;
mbed_official 525:c320967f86b9 104 _irq.callback(&I2C::irq_handler_asynch);
mbed_official 525:c320967f86b9 105 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
mbed_official 525:c320967f86b9 106 return 0;
mbed_official 525:c320967f86b9 107 }
mbed_official 525:c320967f86b9 108
mbed_official 525:c320967f86b9 109 void I2C::abort_transfer(void)
mbed_official 525:c320967f86b9 110 {
mbed_official 525:c320967f86b9 111 i2c_abort_asynch(&_i2c);
mbed_official 525:c320967f86b9 112 }
mbed_official 525:c320967f86b9 113
mbed_official 525:c320967f86b9 114 void I2C::irq_handler_asynch(void)
mbed_official 525:c320967f86b9 115 {
mbed_official 525:c320967f86b9 116 int event = i2c_irq_handler_asynch(&_i2c);
mbed_official 525:c320967f86b9 117 if (_callback && event) {
mbed_official 525:c320967f86b9 118 _callback.call(event);
mbed_official 525:c320967f86b9 119 }
mbed_official 525:c320967f86b9 120
mbed_official 525:c320967f86b9 121 }
mbed_official 525:c320967f86b9 122
mbed_official 525:c320967f86b9 123
mbed_official 525:c320967f86b9 124 #endif
mbed_official 525:c320967f86b9 125
bogdanm 13:0645d8841f51 126 } // namespace mbed
bogdanm 13:0645d8841f51 127
bogdanm 13:0645d8841f51 128 #endif