mbed library sources(for async_print)

Dependents:   AsyncPrint

Fork of mbed-src by mbed official

cpp/SPI.cpp

Committer:
mbed_official
Date:
2012-11-20
Revision:
0:fd0d7bdfcdc2
Child:
2:143cac498751

File content as of revision 0:fd0d7bdfcdc2:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2012 ARM Limited
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
#include "SPI.h"

#if DEVICE_SPI

namespace mbed {

SPI::SPI(PinName mosi, PinName miso, PinName sclk) {
    spi_init(&_spi, mosi, miso, sclk, NC);
    _bits = 8;
    _mode = 0;
    _hz = 1000000;
    spi_format(&_spi, _bits, _mode, 0);
    spi_frequency(&_spi, _hz);
}

void SPI::format(int bits, int mode) {
    _bits = bits;
    _mode = mode;
    SPI::_owner = NULL; // Not that elegant, but works. rmeyer
    aquire();
}

void SPI::frequency(int hz) { 
    _hz = hz;
    SPI::_owner = NULL; // Not that elegant, but works. rmeyer
    aquire();
}

SPI* SPI::_owner = NULL;

// ignore the fact there are multiple physical spis, and always update if it wasnt us last
void SPI::aquire() {
     if (_owner != this) {
        spi_format(&_spi, _bits, _mode, 0);
        spi_frequency(&_spi, _hz);
        _owner = this;
    }
}

int SPI::write(int value) {
    aquire();
    return spi_master_write(&_spi, value);
}

} // namespace mbed

#endif