Daiki Kato / mbed-os-lychee

mbed-os for GR-LYCHEE

Dependents:   mbed-os-example-blinky-gr-lychee GR-Boads_Camera_sample GR-Boards_Audio_Recoder GR-Boads_Camera_DisplayApp ... more

drivers/I2C.cpp@0:f782d9c66c49, 2018-02-02 (annotated)

Committer:
dkato
Date:
Fri Feb 02 05:42:23 2018 +0000
Revision:
0:f782d9c66c49
mbed-os for GR-LYCHEE

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dkato 0:f782d9c66c49 1 /* mbed Microcontroller Library
dkato 0:f782d9c66c49 2 * Copyright (c) 2006-2015 ARM Limited
dkato 0:f782d9c66c49 3 *
dkato 0:f782d9c66c49 4 * Licensed under the Apache License, Version 2.0 (the "License");
dkato 0:f782d9c66c49 5 * you may not use this file except in compliance with the License.
dkato 0:f782d9c66c49 6 * You may obtain a copy of the License at
dkato 0:f782d9c66c49 7 *
dkato 0:f782d9c66c49 8 * http://www.apache.org/licenses/LICENSE-2.0
dkato 0:f782d9c66c49 9 *
dkato 0:f782d9c66c49 10 * Unless required by applicable law or agreed to in writing, software
dkato 0:f782d9c66c49 11 * distributed under the License is distributed on an "AS IS" BASIS,
dkato 0:f782d9c66c49 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
dkato 0:f782d9c66c49 13 * See the License for the specific language governing permissions and
dkato 0:f782d9c66c49 14 * limitations under the License.
dkato 0:f782d9c66c49 15 */
dkato 0:f782d9c66c49 16 #include "drivers/I2C.h"
dkato 0:f782d9c66c49 17
dkato 0:f782d9c66c49 18 #if DEVICE_I2C
dkato 0:f782d9c66c49 19
dkato 0:f782d9c66c49 20 namespace mbed {
dkato 0:f782d9c66c49 21
dkato 0:f782d9c66c49 22 I2C *I2C::_owner = NULL;
dkato 0:f782d9c66c49 23 SingletonPtr<PlatformMutex> I2C::_mutex;
dkato 0:f782d9c66c49 24
dkato 0:f782d9c66c49 25 I2C::I2C(PinName sda, PinName scl) :
dkato 0:f782d9c66c49 26 #if DEVICE_I2C_ASYNCH
dkato 0:f782d9c66c49 27 _irq(this), _usage(DMA_USAGE_NEVER),
dkato 0:f782d9c66c49 28 #endif
dkato 0:f782d9c66c49 29 _i2c(), _hz(100000) {
dkato 0:f782d9c66c49 30 // No lock needed in the constructor
dkato 0:f782d9c66c49 31
dkato 0:f782d9c66c49 32 // The init function also set the frequency to 100000
dkato 0:f782d9c66c49 33 i2c_init(&_i2c, sda, scl);
dkato 0:f782d9c66c49 34
dkato 0:f782d9c66c49 35 // Used to avoid unnecessary frequency updates
dkato 0:f782d9c66c49 36 _owner = this;
dkato 0:f782d9c66c49 37 }
dkato 0:f782d9c66c49 38
dkato 0:f782d9c66c49 39 void I2C::frequency(int hz) {
dkato 0:f782d9c66c49 40 lock();
dkato 0:f782d9c66c49 41 _hz = hz;
dkato 0:f782d9c66c49 42
dkato 0:f782d9c66c49 43 // We want to update the frequency even if we are already the bus owners
dkato 0:f782d9c66c49 44 i2c_frequency(&_i2c, _hz);
dkato 0:f782d9c66c49 45
dkato 0:f782d9c66c49 46 // Updating the frequency of the bus we become the owners of it
dkato 0:f782d9c66c49 47 _owner = this;
dkato 0:f782d9c66c49 48 unlock();
dkato 0:f782d9c66c49 49 }
dkato 0:f782d9c66c49 50
dkato 0:f782d9c66c49 51 void I2C::aquire() {
dkato 0:f782d9c66c49 52 lock();
dkato 0:f782d9c66c49 53 if (_owner != this) {
dkato 0:f782d9c66c49 54 i2c_frequency(&_i2c, _hz);
dkato 0:f782d9c66c49 55 _owner = this;
dkato 0:f782d9c66c49 56 }
dkato 0:f782d9c66c49 57 unlock();
dkato 0:f782d9c66c49 58 }
dkato 0:f782d9c66c49 59
dkato 0:f782d9c66c49 60 // write - Master Transmitter Mode
dkato 0:f782d9c66c49 61 int I2C::write(int address, const char* data, int length, bool repeated) {
dkato 0:f782d9c66c49 62 lock();
dkato 0:f782d9c66c49 63 aquire();
dkato 0:f782d9c66c49 64
dkato 0:f782d9c66c49 65 int stop = (repeated) ? 0 : 1;
dkato 0:f782d9c66c49 66 int written = i2c_write(&_i2c, address, data, length, stop);
dkato 0:f782d9c66c49 67
dkato 0:f782d9c66c49 68 unlock();
dkato 0:f782d9c66c49 69 return length != written;
dkato 0:f782d9c66c49 70 }
dkato 0:f782d9c66c49 71
dkato 0:f782d9c66c49 72 int I2C::write(int data) {
dkato 0:f782d9c66c49 73 lock();
dkato 0:f782d9c66c49 74 int ret = i2c_byte_write(&_i2c, data);
dkato 0:f782d9c66c49 75 unlock();
dkato 0:f782d9c66c49 76 return ret;
dkato 0:f782d9c66c49 77 }
dkato 0:f782d9c66c49 78
dkato 0:f782d9c66c49 79 // read - Master Reciever Mode
dkato 0:f782d9c66c49 80 int I2C::read(int address, char* data, int length, bool repeated) {
dkato 0:f782d9c66c49 81 lock();
dkato 0:f782d9c66c49 82 aquire();
dkato 0:f782d9c66c49 83
dkato 0:f782d9c66c49 84 int stop = (repeated) ? 0 : 1;
dkato 0:f782d9c66c49 85 int read = i2c_read(&_i2c, address, data, length, stop);
dkato 0:f782d9c66c49 86
dkato 0:f782d9c66c49 87 unlock();
dkato 0:f782d9c66c49 88 return length != read;
dkato 0:f782d9c66c49 89 }
dkato 0:f782d9c66c49 90
dkato 0:f782d9c66c49 91 int I2C::read(int ack) {
dkato 0:f782d9c66c49 92 lock();
dkato 0:f782d9c66c49 93 int ret;
dkato 0:f782d9c66c49 94 if (ack) {
dkato 0:f782d9c66c49 95 ret = i2c_byte_read(&_i2c, 0);
dkato 0:f782d9c66c49 96 } else {
dkato 0:f782d9c66c49 97 ret = i2c_byte_read(&_i2c, 1);
dkato 0:f782d9c66c49 98 }
dkato 0:f782d9c66c49 99 unlock();
dkato 0:f782d9c66c49 100 return ret;
dkato 0:f782d9c66c49 101 }
dkato 0:f782d9c66c49 102
dkato 0:f782d9c66c49 103 void I2C::start(void) {
dkato 0:f782d9c66c49 104 lock();
dkato 0:f782d9c66c49 105 i2c_start(&_i2c);
dkato 0:f782d9c66c49 106 unlock();
dkato 0:f782d9c66c49 107 }
dkato 0:f782d9c66c49 108
dkato 0:f782d9c66c49 109 void I2C::stop(void) {
dkato 0:f782d9c66c49 110 lock();
dkato 0:f782d9c66c49 111 i2c_stop(&_i2c);
dkato 0:f782d9c66c49 112 unlock();
dkato 0:f782d9c66c49 113 }
dkato 0:f782d9c66c49 114
dkato 0:f782d9c66c49 115 void I2C::lock() {
dkato 0:f782d9c66c49 116 _mutex->lock();
dkato 0:f782d9c66c49 117 }
dkato 0:f782d9c66c49 118
dkato 0:f782d9c66c49 119 void I2C::unlock() {
dkato 0:f782d9c66c49 120 _mutex->unlock();
dkato 0:f782d9c66c49 121 }
dkato 0:f782d9c66c49 122
dkato 0:f782d9c66c49 123 #if DEVICE_I2C_ASYNCH
dkato 0:f782d9c66c49 124
dkato 0:f782d9c66c49 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)
dkato 0:f782d9c66c49 126 {
dkato 0:f782d9c66c49 127 lock();
dkato 0:f782d9c66c49 128 if (i2c_active(&_i2c)) {
dkato 0:f782d9c66c49 129 unlock();
dkato 0:f782d9c66c49 130 return -1; // transaction ongoing
dkato 0:f782d9c66c49 131 }
dkato 0:f782d9c66c49 132 aquire();
dkato 0:f782d9c66c49 133
dkato 0:f782d9c66c49 134 _callback = callback;
dkato 0:f782d9c66c49 135 int stop = (repeated) ? 0 : 1;
dkato 0:f782d9c66c49 136 _irq.callback(&I2C::irq_handler_asynch);
dkato 0:f782d9c66c49 137 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
dkato 0:f782d9c66c49 138 unlock();
dkato 0:f782d9c66c49 139 return 0;
dkato 0:f782d9c66c49 140 }
dkato 0:f782d9c66c49 141
dkato 0:f782d9c66c49 142 void I2C::abort_transfer(void)
dkato 0:f782d9c66c49 143 {
dkato 0:f782d9c66c49 144 lock();
dkato 0:f782d9c66c49 145 i2c_abort_asynch(&_i2c);
dkato 0:f782d9c66c49 146 unlock();
dkato 0:f782d9c66c49 147 }
dkato 0:f782d9c66c49 148
dkato 0:f782d9c66c49 149 void I2C::irq_handler_asynch(void)
dkato 0:f782d9c66c49 150 {
dkato 0:f782d9c66c49 151 int event = i2c_irq_handler_asynch(&_i2c);
dkato 0:f782d9c66c49 152 if (_callback && event) {
dkato 0:f782d9c66c49 153 _callback.call(event);
dkato 0:f782d9c66c49 154 }
dkato 0:f782d9c66c49 155
dkato 0:f782d9c66c49 156 }
dkato 0:f782d9c66c49 157
dkato 0:f782d9c66c49 158
dkato 0:f782d9c66c49 159 #endif
dkato 0:f782d9c66c49 160
dkato 0:f782d9c66c49 161 } // namespace mbed
dkato 0:f782d9c66c49 162
dkato 0:f782d9c66c49 163 #endif