RIOT/drivers/cc110x/cc110x_communication.c

/*
 * Copyright (C) 2018 Otto-von-Guericke-Universität Magdeburg
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

/**
 * @ingroup     drivers_cc110x
 * @{
 *
 * @file
 * @brief       Functions to communicate with the CC1100/CC1101 transceiver
 *
 * @author      Marian Buschsieweke <marian.buschsieweke@ovgu.de>
 * @}
 */

#include <errno.h>

#include "cc110x.h"
#include "cc110x_communication.h"
#include "cc110x_constants.h"
#include "cc110x_internal.h"
#include "periph/gpio.h"
#include "periph/spi.h"
#include "xtimer.h"

int cc110x_power_on_and_acquire(cc110x_t *dev)
{
    gpio_t cs = dev->params.cs;

    if (gpio_init(cs, GPIO_OUT)) {
        return -EIO;
    }
    gpio_clear(cs);
    xtimer_usleep(CC110X_WAKEUP_TIME_US);
    gpio_set(cs);
    spi_init_cs(dev->params.spi, dev->params.cs);

    cc110x_acquire(dev);

    while (cc110x_state_from_status(cc110x_status(dev)) != CC110X_STATE_IDLE) {
        cc110x_cmd(dev, CC110X_STROBE_IDLE);
        xtimer_usleep(CC110X_WAKEUP_TIME_US);
    }

    return 0;
}

uint8_t cc110x_read(cc110x_t *dev, uint8_t addr, uint8_t *dest)
{
    uint8_t status;

    addr |= CC110X_SINGLE_BYTE_READ;
    spi_transfer_bytes(dev->params.spi, dev->params.cs, true,
                       &addr, &status, 1);
    spi_transfer_bytes(dev->params.spi, dev->params.cs, false, NULL, dest, 1);
    return status;
}

uint8_t cc110x_read_reliable(cc110x_t *dev, uint8_t addr, uint8_t *dest)
{
    uint8_t status, tmp;

    do {
        cc110x_read(dev, addr, &tmp);
        status = cc110x_read(dev, addr, dest);
    } while (*dest != tmp);

    return status;
}

uint8_t cc110x_write(cc110x_t *dev, uint8_t addr, uint8_t data)
{
    uint8_t status;

    addr |= CC110X_SINGLE_BYTE_WRITE;
    spi_transfer_bytes(dev->params.spi, dev->params.cs, true,
                       &addr, &status, 1);
    spi_transfer_bytes(dev->params.spi, dev->params.cs, false, &data, NULL, 1);
    return status;
}

uint8_t cc110x_burst_read(cc110x_t *dev, uint8_t addr, void *dest, size_t len)
{
    uint8_t status;

    addr |= CC110X_BURST_READ;
    spi_transfer_bytes(dev->params.spi, dev->params.cs, true,
                       &addr, &status, 1);
    spi_transfer_bytes(dev->params.spi, dev->params.cs, false, NULL, dest, len);
    return status;
}

uint8_t cc110x_burst_write(cc110x_t *dev, uint8_t addr,
                           const void *src, size_t len)
{
    uint8_t status;

    addr |= CC110X_BURST_WRITE;
    spi_transfer_bytes(dev->params.spi, dev->params.cs, true,
                       &addr, &status, 1);
    spi_transfer_bytes(dev->params.spi, dev->params.cs, false, src, NULL, len);
    return status;
}

uint8_t cc110x_cmd(cc110x_t *dev, uint8_t cmd_strobe)
{
    uint8_t status;

    spi_transfer_bytes(dev->params.spi, dev->params.cs, false,
                       &cmd_strobe, &status, 1);
    return status;
}

uint8_t cc110x_status(cc110x_t *dev)
{
    uint8_t status;

    do {
        status = cc110x_cmd(dev, CC110X_STROBE_STATUS);
    } while (status != cc110x_cmd(dev, CC110X_STROBE_STATUS));
    return status;
}