Morpheus / mbed-hal

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Dependencies:   target-freescale

common/I2C.cpp@0:9c59db1fbc9e, 2016-03-23 (annotated)

Committer:
screamer
Date:
Wed Mar 23 21:36:09 2016 +0000
Revision:
0:9c59db1fbc9e
Initial revision

Who changed what in which revision?

UserRevisionLine numberNew contents of line
screamer 0:9c59db1fbc9e 1 /* mbed Microcontroller Library
screamer 0:9c59db1fbc9e 2 * Copyright (c) 2006-2015 ARM Limited
screamer 0:9c59db1fbc9e 3 *
screamer 0:9c59db1fbc9e 4 * Licensed under the Apache License, Version 2.0 (the "License");
screamer 0:9c59db1fbc9e 5 * you may not use this file except in compliance with the License.
screamer 0:9c59db1fbc9e 6 * You may obtain a copy of the License at
screamer 0:9c59db1fbc9e 7 *
screamer 0:9c59db1fbc9e 8 * http://www.apache.org/licenses/LICENSE-2.0
screamer 0:9c59db1fbc9e 9 *
screamer 0:9c59db1fbc9e 10 * Unless required by applicable law or agreed to in writing, software
screamer 0:9c59db1fbc9e 11 * distributed under the License is distributed on an "AS IS" BASIS,
screamer 0:9c59db1fbc9e 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
screamer 0:9c59db1fbc9e 13 * See the License for the specific language governing permissions and
screamer 0:9c59db1fbc9e 14 * limitations under the License.
screamer 0:9c59db1fbc9e 15 */
screamer 0:9c59db1fbc9e 16 #include "I2C.h"
screamer 0:9c59db1fbc9e 17
screamer 0:9c59db1fbc9e 18 #if DEVICE_I2C
screamer 0:9c59db1fbc9e 19
screamer 0:9c59db1fbc9e 20 namespace mbed {
screamer 0:9c59db1fbc9e 21
screamer 0:9c59db1fbc9e 22 I2C *I2C::_owner = NULL;
screamer 0:9c59db1fbc9e 23
screamer 0:9c59db1fbc9e 24 I2C::I2C(PinName sda, PinName scl) :
screamer 0:9c59db1fbc9e 25 #if DEVICE_I2C_ASYNCH
screamer 0:9c59db1fbc9e 26 _irq(this), _usage(DMA_USAGE_NEVER),
screamer 0:9c59db1fbc9e 27 #endif
screamer 0:9c59db1fbc9e 28 _i2c(), _hz(100000) {
screamer 0:9c59db1fbc9e 29 // The init function also set the frequency to 100000
screamer 0:9c59db1fbc9e 30 i2c_init(&_i2c, sda, scl);
screamer 0:9c59db1fbc9e 31
screamer 0:9c59db1fbc9e 32 // Used to avoid unnecessary frequency updates
screamer 0:9c59db1fbc9e 33 _owner = this;
screamer 0:9c59db1fbc9e 34 }
screamer 0:9c59db1fbc9e 35
screamer 0:9c59db1fbc9e 36 void I2C::frequency(int hz) {
screamer 0:9c59db1fbc9e 37 _hz = hz;
screamer 0:9c59db1fbc9e 38
screamer 0:9c59db1fbc9e 39 // We want to update the frequency even if we are already the bus owners
screamer 0:9c59db1fbc9e 40 i2c_frequency(&_i2c, _hz);
screamer 0:9c59db1fbc9e 41
screamer 0:9c59db1fbc9e 42 // Updating the frequency of the bus we become the owners of it
screamer 0:9c59db1fbc9e 43 _owner = this;
screamer 0:9c59db1fbc9e 44 }
screamer 0:9c59db1fbc9e 45
screamer 0:9c59db1fbc9e 46 void I2C::aquire() {
screamer 0:9c59db1fbc9e 47 if (_owner != this) {
screamer 0:9c59db1fbc9e 48 i2c_frequency(&_i2c, _hz);
screamer 0:9c59db1fbc9e 49 _owner = this;
screamer 0:9c59db1fbc9e 50 }
screamer 0:9c59db1fbc9e 51 }
screamer 0:9c59db1fbc9e 52
screamer 0:9c59db1fbc9e 53 // write - Master Transmitter Mode
screamer 0:9c59db1fbc9e 54 int I2C::write(int address, const char* data, int length, bool repeated) {
screamer 0:9c59db1fbc9e 55 aquire();
screamer 0:9c59db1fbc9e 56
screamer 0:9c59db1fbc9e 57 int stop = (repeated) ? 0 : 1;
screamer 0:9c59db1fbc9e 58 int written = i2c_write(&_i2c, address, data, length, stop);
screamer 0:9c59db1fbc9e 59
screamer 0:9c59db1fbc9e 60 return length != written;
screamer 0:9c59db1fbc9e 61 }
screamer 0:9c59db1fbc9e 62
screamer 0:9c59db1fbc9e 63 int I2C::write(int data) {
screamer 0:9c59db1fbc9e 64 return i2c_byte_write(&_i2c, data);
screamer 0:9c59db1fbc9e 65 }
screamer 0:9c59db1fbc9e 66
screamer 0:9c59db1fbc9e 67 // read - Master Reciever Mode
screamer 0:9c59db1fbc9e 68 int I2C::read(int address, char* data, int length, bool repeated) {
screamer 0:9c59db1fbc9e 69 aquire();
screamer 0:9c59db1fbc9e 70
screamer 0:9c59db1fbc9e 71 int stop = (repeated) ? 0 : 1;
screamer 0:9c59db1fbc9e 72 int read = i2c_read(&_i2c, address, data, length, stop);
screamer 0:9c59db1fbc9e 73
screamer 0:9c59db1fbc9e 74 return length != read;
screamer 0:9c59db1fbc9e 75 }
screamer 0:9c59db1fbc9e 76
screamer 0:9c59db1fbc9e 77 int I2C::read(int ack) {
screamer 0:9c59db1fbc9e 78 if (ack) {
screamer 0:9c59db1fbc9e 79 return i2c_byte_read(&_i2c, 0);
screamer 0:9c59db1fbc9e 80 } else {
screamer 0:9c59db1fbc9e 81 return i2c_byte_read(&_i2c, 1);
screamer 0:9c59db1fbc9e 82 }
screamer 0:9c59db1fbc9e 83 }
screamer 0:9c59db1fbc9e 84
screamer 0:9c59db1fbc9e 85 void I2C::start(void) {
screamer 0:9c59db1fbc9e 86 i2c_start(&_i2c);
screamer 0:9c59db1fbc9e 87 }
screamer 0:9c59db1fbc9e 88
screamer 0:9c59db1fbc9e 89 void I2C::stop(void) {
screamer 0:9c59db1fbc9e 90 i2c_stop(&_i2c);
screamer 0:9c59db1fbc9e 91 }
screamer 0:9c59db1fbc9e 92
screamer 0:9c59db1fbc9e 93 #if DEVICE_I2C_ASYNCH
screamer 0:9c59db1fbc9e 94
screamer 0:9c59db1fbc9e 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)
screamer 0:9c59db1fbc9e 96 {
screamer 0:9c59db1fbc9e 97 if (i2c_active(&_i2c)) {
screamer 0:9c59db1fbc9e 98 return -1; // transaction ongoing
screamer 0:9c59db1fbc9e 99 }
screamer 0:9c59db1fbc9e 100 aquire();
screamer 0:9c59db1fbc9e 101
screamer 0:9c59db1fbc9e 102 _callback = callback;
screamer 0:9c59db1fbc9e 103 int stop = (repeated) ? 0 : 1;
screamer 0:9c59db1fbc9e 104 _irq.callback(&I2C::irq_handler_asynch);
screamer 0:9c59db1fbc9e 105 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
screamer 0:9c59db1fbc9e 106 return 0;
screamer 0:9c59db1fbc9e 107 }
screamer 0:9c59db1fbc9e 108
screamer 0:9c59db1fbc9e 109 void I2C::abort_transfer(void)
screamer 0:9c59db1fbc9e 110 {
screamer 0:9c59db1fbc9e 111 i2c_abort_asynch(&_i2c);
screamer 0:9c59db1fbc9e 112 }
screamer 0:9c59db1fbc9e 113
screamer 0:9c59db1fbc9e 114 void I2C::irq_handler_asynch(void)
screamer 0:9c59db1fbc9e 115 {
screamer 0:9c59db1fbc9e 116 int event = i2c_irq_handler_asynch(&_i2c);
screamer 0:9c59db1fbc9e 117 if (_callback && event) {
screamer 0:9c59db1fbc9e 118 _callback.call(event);
screamer 0:9c59db1fbc9e 119 }
screamer 0:9c59db1fbc9e 120
screamer 0:9c59db1fbc9e 121 }
screamer 0:9c59db1fbc9e 122
screamer 0:9c59db1fbc9e 123
screamer 0:9c59db1fbc9e 124 #endif
screamer 0:9c59db1fbc9e 125
screamer 0:9c59db1fbc9e 126 } // namespace mbed
screamer 0:9c59db1fbc9e 127
screamer 0:9c59db1fbc9e 128 #endif
screamer 0:9c59db1fbc9e 129