ChipPinSetSelectManager.cpp

Go to the documentation of this file.

/*
 * This file is part of the DUDS project. It is subject to the BSD-style
 * license terms in the LICENSE file found in the top-level directory of this
 * distribution and at https://github.com/jjackowski/duds/blob/master/LICENSE.
 * No part of DUDS, including this file, may be copied, modified, propagated,
 * or distributed except according to the terms contained in the LICENSE file.
 *
 * Copyright (C) 2018  Jeff Jackowski
 */
#include <duds/hardware/interface/ChipPinSetSelectManager.hpp>
#include <duds/hardware/interface/ChipSelectErrors.hpp>

namespace duds { namespace hardware { namespace interface {

bool ChipPinSetSelectManager::validChip(int chipId) const noexcept {
    return selpins && selpins->exists((unsigned int)chipId);
}

void ChipPinSetSelectManager::select() {
    selpins->output(cid, (selstates & (1 << cid)) > 0);
}

void ChipPinSetSelectManager::deselect() {
    selpins->output(cid, (selstates & (1 << cid)) == 0);
}

void ChipPinSetSelectManager::setSelectPins(
    std::unique_ptr<DigitalPinSetAccess> &&dpsa,
    std::uint32_t selectStates
) {
    if (!dpsa || !dpsa->havePins()) {
        DUDS_THROW_EXCEPTION(PinDoesNotExist());
    }
    if (dpsa->size() > 32) {
        DUDS_THROW_EXCEPTION(ChipSelectTooManyPins());
    }
    // require exclusive access
    std::unique_lock<std::mutex> lock(block);
    // is a chip in use?
    if (inUse()) {
        assert(selpins);
        // fail; provide the pin and chip IDs for what is currently in use
        DUDS_THROW_EXCEPTION(ChipSelectInUse() <<
            PinErrorId(selpins->globalId(cid)) << ChipSelectIdError(cid)
        );
    }
    // get the capabilities for inspection
    std::vector<DigitalPinCap> caps = dpsa->capabilities();
    // prepare to configure each pin
    std::vector<DigitalPinConfig> conf;
    conf.reserve(caps.size());
    // iteratate over all the pins
    std::vector<DigitalPinCap>::const_iterator iter = caps.cbegin();
    unsigned int pos = 0;
    for (; iter != caps.cend(); ++pos, ++iter) {
        // check for no output ability
        if (!iter->canOutput()) {
            DUDS_THROW_EXCEPTION(DigitalPinCannotOutputError() <<
                PinErrorId(dpsa->globalId(pos))
            );
        }
        // work out the actual output config
        conf.push_back(DigitalPinConfig(iter->firstOutputDriveConfigFlags()));
    }

    // assure a deselected state prior to requesting output
    dpsa->write(~selectStates & ((1 << dpsa->size()) - 1));
    // work out the actual output config
    dpsa->modifyConfig(conf);
    // store this access object; seems good if it got this far without
    // an exception
    selpins = std::move(dpsa);
    selstates = selectStates;
}

ChipPinSetSelectManager::ChipPinSetSelectManager(
    std::unique_ptr<DigitalPinSetAccess> &&dpsa,
    std::uint32_t selectStates
) {
    setSelectPins(std::move(dpsa), selectStates);
}

ChipPinSetSelectManager::~ChipPinSetSelectManager() {
    shutdown();
}

} } }