/**
* Shift Register library
*
* Author: Jan Dvořák z Vozerovic
* E-mail: dvorkaman@gmail.com
* Web: dvorkaman.asp2.cz
* Created: 2014
*/

/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/

#ifndef __dvorkaman_shiftRegister_base_c__
#define __dvorkaman_shiftRegister_base_c__

#include "libShiftRegister_Base.h"
#include "libGPIO_base.h"
#include "libSystemTime_base.h"

/**
* Initialize shift register - simple only
*/
void shiftRegister_initialize(libShiftRegister* shiftRegister, GPIO_TypeDef* gpio, uint16_t clockPin, uint16_t dataPin,
                              uint16_t storagePin)
{
    shiftRegister_initializeBits(shiftRegister, gpio, clockPin, dataPin, storagePin, SHIFT_REGISTER_STORAGE_BITS);
}

/**
* Initialize shift register - BITS
*/
void shiftRegister_initializeBits(libShiftRegister* shiftRegister, GPIO_TypeDef* gpio, uint16_t clockPin,
                                  uint16_t dataPin, uint16_t storagePin, uint8_t bits)
{
    shiftRegister_initializeFull(shiftRegister, gpio, clockPin, dataPin, storagePin, bits, SHIFT_REGISTER_CLOCK_PULSE,
                                 SHIFT_REGISTER_DATA_SETUP, SHIFT_REGISTER_STORAGE_PULSE, SHIFT_REGISTER_STORAGE_PULSE_SETUP);
}

/**
* Initialize shift register - FULL
*/
void shiftRegister_initializeFull(libShiftRegister* shiftRegister, GPIO_TypeDef* gpio, uint16_t clockPin,
                                  uint16_t dataPin, uint16_t storagePin, uint8_t bits, uint8_t clockPulse,
                                  uint8_t dataSetup, uint8_t storagePulse, uint8_t storagePulseSetup)
{
    if (clockPulse <= dataSetup) { return; }  // not valid data

    // set pins
    gpio_initializeOutputPin(gpio, clockPin);
    gpio_initializeOutputPin(gpio, dataPin);
    gpio_initializeOutputPin(gpio, storagePin);

    // create structure
    shiftRegister->gpio = gpio;
    shiftRegister->clockPin = clockPin;
    shiftRegister->dataPin = dataPin;
    shiftRegister->storagePin = storagePin;

    shiftRegister->bits = bits;

    shiftRegister->clockPulse = clockPulse; // ns
    shiftRegister->dataSetup = dataSetup; // ns
    shiftRegister->storagePulse = storagePulse; // ns
    shiftRegister->storagePulseSetup = storagePulseSetup; // ns

    // clear values
    gpio_writeOutputPin(gpio, clockPin, Bit_RESET);
    gpio_writeOutputPin(gpio, storagePin, Bit_RESET);
}

/**
* Write value to shift register
*/
void shiftRegister_write(libShiftRegister* shiftRegister, uint16_t value)
{
    uint8_t i;
    BitAction b;
    uint16_t mask = 0x1 << (shiftRegister->bits - 1); // MSB first
    int16_t storageSetup = shiftRegister->storagePulseSetup - shiftRegister->clockPulse - shiftRegister->dataSetup;

    // Set data
    for (i = 0; i < shiftRegister->bits; i++)
    {
        b = (value & mask) > 0 ? Bit_SET : Bit_RESET; // true or false

        // Set Data
        gpio_writeOutputPin(shiftRegister->gpio, shiftRegister->dataPin, b);
        systemTime_delayNs(shiftRegister->dataSetup);

        // - clock is 0 -> raise
        gpio_writeOutputPin(shiftRegister->gpio, shiftRegister->clockPin, Bit_SET); // data hold is covered here
        systemTime_delayNs(shiftRegister->clockPulse);

        // - put down clock
        gpio_writeOutputPin(shiftRegister->gpio, shiftRegister->clockPin, Bit_RESET);
        systemTime_delayNs(shiftRegister->clockPulse - shiftRegister->dataSetup); // covered partially in setup

        value = value << 1; // shift left - make another MSB
    }

    // Store data
    if (storageSetup > 0) { systemTime_delayNs(storageSetup); } // wait before storage
    gpio_writeOutputPin(shiftRegister->gpio, shiftRegister->storagePin, Bit_SET);
    systemTime_delayNs(shiftRegister->storagePulse);
    gpio_writeOutputPin(shiftRegister->gpio, shiftRegister->storagePin, Bit_RESET);
}

#endif