/*
 * stm-fpgacfg.c
 * ----------
 * Functions for accessing the FPGA config memory.
 *
 * Copyright (c) 2016, NORDUnet A/S All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the NORDUnet nor the names of its contributors may
 *   be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "stm32f4xx_hal.h"
#include "stm-fpgacfg.h"

SPI_HandleTypeDef hspi_fpgacfg;

int _n25q128_get_wel_flag(void);


int n25q128_check_id()
{
    // tx, rx buffers
    uint8_t spi_tx[4];
    uint8_t spi_rx[4];

    // result
    HAL_StatusTypeDef ok;

    // send READ ID command
    spi_tx[0] = N25Q128_COMMAND_READ_ID;

    // select, send command & read response, deselect
    _n25q128_select();
    ok = HAL_SPI_TransmitReceive(N25Q128_SPI_HANDLE, spi_tx, spi_rx, 4, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // parse response (note, that the very first byte was received during the
    // transfer of the command byte, so it contains garbage and should
    // be ignored here)
    if (spi_rx[1] != N25Q128_ID_MANUFACTURER) return 0;
    if (spi_rx[2] != N25Q128_ID_DEVICE_TYPE) return 0;
    if (spi_rx[3] != N25Q128_ID_DEVICE_CAPACITY) return 0;

    // done
    return 1;
}


int n25q128_read_page(uint32_t page_offset, uint8_t *page_buffer)
{
    // tx buffer
    uint8_t spi_tx[4];

    // result
    HAL_StatusTypeDef ok;

    // check offset
    if (page_offset >= N25Q128_NUM_PAGES) return 0;

    // calculate byte address
    page_offset *= N25Q128_PAGE_SIZE;

    // prepare READ command
    spi_tx[0] = N25Q128_COMMAND_READ_PAGE;
    spi_tx[1] = (uint8_t)(page_offset >> 16);
    spi_tx[2] = (uint8_t)(page_offset >>  8);
    spi_tx[3] = (uint8_t)(page_offset >>  0);

    // activate, send command
    _n25q128_select();
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, spi_tx, 4, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);

    // check
    if (ok != HAL_OK) {
	_n25q128_deselect();
	return 0;
    }

    // read response, deselect
    ok = HAL_SPI_Receive(N25Q128_SPI_HANDLE, page_buffer, N25Q128_PAGE_SIZE, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // done
    return 1;
}


int n25q128_write_page(uint32_t page_offset, uint8_t *page_buffer)
{
    // tx buffer
    uint8_t spi_tx[4];

    // result
    HAL_StatusTypeDef ok;

    // check offset
    if (page_offset >= N25Q128_NUM_PAGES) return 0;

    // enable writing
    spi_tx[0] = N25Q128_COMMAND_WRITE_ENABLE;

    // activate, send command, deselect
    _n25q128_select();
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, spi_tx, 1, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // make sure, that write enable did the job
    int wel = _n25q128_get_wel_flag();
    if (wel != 1) return 0;

    // calculate byte address
    page_offset *= N25Q128_PAGE_SIZE;

    // prepare PROGRAM PAGE command
    spi_tx[0] = N25Q128_COMMAND_PAGE_PROGRAM;
    spi_tx[1] = (uint8_t)(page_offset >> 16);
    spi_tx[2] = (uint8_t)(page_offset >>  8);
    spi_tx[3] = (uint8_t)(page_offset >>  0);

    // activate, send command
    _n25q128_select();
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, spi_tx, 4, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);

    // check
    if (ok != HAL_OK) {
	_n25q128_deselect();
	return 0;
    }

    // send data, deselect
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, page_buffer, N25Q128_PAGE_SIZE, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // done
    return 1;
}


int n25q128_get_wip_flag(void)
{
    // tx, rx buffers
    uint8_t spi_tx[2];
    uint8_t spi_rx[2];

    // result
    HAL_StatusTypeDef ok;

    // send READ STATUS command
    spi_tx[0] = N25Q128_COMMAND_READ_STATUS;

    // send command, read response, deselect
    _n25q128_select();
    ok = HAL_SPI_TransmitReceive(N25Q128_SPI_HANDLE, spi_tx, spi_rx, 2, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return -1;

    // done
    return (spi_rx[1] & 1);
}


int n25q128_erase_sector(uint32_t sector_offset)
{
    // tx buffer
    uint8_t spi_tx[4];

    // result
    HAL_StatusTypeDef ok;

    // check offset
    if (sector_offset >= N25Q128_NUM_SECTORS) return 0;

    // enable writing
    spi_tx[0] = N25Q128_COMMAND_WRITE_ENABLE;

    // select, send command, deselect
    _n25q128_select();
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, spi_tx, 1, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // make sure, that write enable did the job
    int wel = _n25q128_get_wel_flag();
    if (wel != 1) return 0;

    // calculate byte address
    sector_offset *= N25Q128_SECTOR_SIZE;

    // send ERASE SUBSECTOR command
    spi_tx[0] = N25Q128_COMMAND_ERASE_SECTOR;
    spi_tx[1] = (uint8_t)(sector_offset >> 16);
    spi_tx[2] = (uint8_t)(sector_offset >>  8);
    spi_tx[3] = (uint8_t)(sector_offset >>  0);

    // activate, send command, deselect
    _n25q128_select();
    ok = HAL_SPI_Transmit(N25Q128_SPI_HANDLE, spi_tx, 4, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return 0;

    // done
    return 1;
}


int _n25q128_get_wel_flag(void)
{
    // tx, rx buffers
    uint8_t spi_tx[2];
    uint8_t spi_rx[2];

    // result
    HAL_StatusTypeDef ok;

    // send READ STATUS command
    spi_tx[0] = N25Q128_COMMAND_READ_STATUS;

    // send command, read response, deselect
    _n25q128_select();
    ok = HAL_SPI_TransmitReceive(N25Q128_SPI_HANDLE, spi_tx, spi_rx, 2, N25Q128_SPI_TIMEOUT);
    HAL_Delay(1);
    _n25q128_deselect();

    // check
    if (ok != HAL_OK) return -1;

    // done
    return ((spi_rx[1] >> 1) & 1);
}