/*
 * Copyright (C) 2019  Max Regan
 *
 * 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"

#include "stm32l0xx.h"
#include "macros.h"

void spi_send_blocking(SPI_TypeDef *spi, const uint8_t *data, size_t len)
{
    if (len <= 0) {
        return;
    }

    spi->CR1 |= SPI_CR1_SPE;

    for (size_t i = 0; i < len; i++) {
        while (!(spi->SR & SPI_SR_TXE)) {}
        spi->DR = data[i];
    }

    while (!(spi->SR & SPI_SR_TXE)) {}

    // Ensure that NSS is held for long enough to meet the display's thSCS
    for (int i = 0; i < 4; i++);

    spi->CR1 &= ~SPI_CR1_SPE;
}