Yihui Xiong
/
Seeed_nRF51822_Motion
initial
Diff: mbed-src/common/I2C.cpp
- Revision:
- 1:9d3b497333c0
- Parent:
- 0:638edba3adf6
--- a/mbed-src/common/I2C.cpp Mon Jan 11 02:32:24 2016 +0000 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,128 +0,0 @@ -/* mbed Microcontroller Library - * Copyright (c) 2006-2015 ARM Limited - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ -#include "I2C.h" - -#if DEVICE_I2C - -namespace mbed { - -I2C *I2C::_owner = NULL; - -I2C::I2C(PinName sda, PinName scl) : -#if DEVICE_I2C_ASYNCH - _irq(this), _usage(DMA_USAGE_NEVER), -#endif - _i2c(), _hz(100000) { - // The init function also set the frequency to 100000 - i2c_init(&_i2c, sda, scl); - - // Used to avoid unnecessary frequency updates - _owner = this; -} - -void I2C::frequency(int hz) { - _hz = hz; - - // We want to update the frequency even if we are already the bus owners - i2c_frequency(&_i2c, _hz); - - // Updating the frequency of the bus we become the owners of it - _owner = this; -} - -void I2C::aquire() { - if (_owner != this) { - i2c_frequency(&_i2c, _hz); - _owner = this; - } -} - -// write - Master Transmitter Mode -int I2C::write(int address, const char* data, int length, bool repeated) { - aquire(); - - int stop = (repeated) ? 0 : 1; - int written = i2c_write(&_i2c, address, data, length, stop); - - return length != written; -} - -int I2C::write(int data) { - return i2c_byte_write(&_i2c, data); -} - -// read - Master Reciever Mode -int I2C::read(int address, char* data, int length, bool repeated) { - aquire(); - - int stop = (repeated) ? 0 : 1; - int read = i2c_read(&_i2c, address, data, length, stop); - - return length != read; -} - -int I2C::read(int ack) { - if (ack) { - return i2c_byte_read(&_i2c, 0); - } else { - return i2c_byte_read(&_i2c, 1); - } -} - -void I2C::start(void) { - i2c_start(&_i2c); -} - -void I2C::stop(void) { - i2c_stop(&_i2c); -} - -#if DEVICE_I2C_ASYNCH - -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) -{ - if (i2c_active(&_i2c)) { - return -1; // transaction ongoing - } - aquire(); - - _callback = callback; - int stop = (repeated) ? 0 : 1; - _irq.callback(&I2C::irq_handler_asynch); - i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage); - return 0; -} - -void I2C::abort_transfer(void) -{ - i2c_abort_asynch(&_i2c); -} - -void I2C::irq_handler_asynch(void) -{ - int event = i2c_irq_handler_asynch(&_i2c); - if (_callback && event) { - _callback.call(event); - } - -} - - -#endif - -} // namespace mbed - -#endif