third_party/NordicSemiconductor/nrfx/drivers/src/nrfx_temp.c

/*
 * Copyright (c) 2019, Nordic Semiconductor ASA
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. Neither the name of the copyright holder 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 <nrfx.h>

#if NRFX_CHECK(NRFX_TEMP_ENABLED)

#include <nrfx_temp.h>

#if !defined(USE_WORKAROUND_FOR_TEMP_OFFSET_ANOMALY) && defined(NRF51)
// Enable workaround for nRF51 series anomaly 28
// (TEMP: Temperature offset value has to be manually loaded to the TEMP module).
#define USE_WORKAROUND_FOR_TEMP_OFFSET_ANOMALY 1
#endif

/** @brief Time of one check attempt.*/
#define NRFX_TEMP_TIME_US 4

/** @brief Maximum attempts to check whether conversion passed.*/
#define NRFX_TEMP_ATTEMPTS 10

/** @brief Internal state of TEMP driver. */
static nrfx_drv_state_t m_temp_state;

/** @brief Pointer to handler to be called from interrupt routine. */
static nrfx_temp_data_handler_t m_data_handler;

nrfx_err_t nrfx_temp_init(nrfx_temp_config_t const * p_config, nrfx_temp_data_handler_t handler)
{
    NRFX_ASSERT(p_config);

    if (m_temp_state != NRFX_DRV_STATE_UNINITIALIZED)
    {
        return NRFX_ERROR_ALREADY_INITIALIZED;
    }

#if NRFX_CHECK(USE_WORKAROUND_FOR_TEMP_OFFSET_ANOMALY)
    *(uint32_t volatile *)0x4000C504 = 0;
#endif

    m_data_handler = handler;

    if (m_data_handler)
    {
        nrf_temp_int_enable(NRF_TEMP, NRF_TEMP_INT_DATARDY_MASK);
        NRFX_IRQ_PRIORITY_SET(TEMP_IRQn, p_config->interrupt_priority);
        NRFX_IRQ_ENABLE(TEMP_IRQn);
    }

    m_temp_state = NRFX_DRV_STATE_INITIALIZED;
    return NRFX_SUCCESS;
}

void nrfx_temp_uninit(void)
{
    NRFX_ASSERT(m_temp_state == NRFX_DRV_STATE_INITIALIZED);
    nrf_temp_task_trigger(NRF_TEMP, NRF_TEMP_TASK_STOP);

    if (m_data_handler)
    {
        nrf_temp_int_disable(NRF_TEMP, NRF_TEMP_INT_DATARDY_MASK);
        NRFX_IRQ_DISABLE(TEMP_IRQn);
    }

    m_temp_state = NRFX_DRV_STATE_UNINITIALIZED;
}

int32_t nrfx_temp_calculate(int32_t raw_measurement)
{
    /* Raw temperature is a 2's complement signed value. Moreover, it is represented
     * by 0.25[C] intervals, so division by 4 is needed. To preserve
     * fractional part, raw value is multiplied by 100 before division.*/

    return (raw_measurement * 100) / 4;
}

nrfx_err_t nrfx_temp_measure(void)
{
    NRFX_ASSERT(m_temp_state == NRFX_DRV_STATE_INITIALIZED);

    nrfx_err_t result = NRFX_SUCCESS;
    nrf_temp_event_clear(NRF_TEMP, NRF_TEMP_EVENT_DATARDY);
    nrf_temp_task_trigger(NRF_TEMP, NRF_TEMP_TASK_START);

    if (!m_data_handler)
    {
        bool ev_result;
        NRFX_WAIT_FOR(nrf_temp_event_check(NRF_TEMP, NRF_TEMP_EVENT_DATARDY),
                      NRFX_TEMP_ATTEMPTS,
                      NRFX_TEMP_TIME_US,
                      ev_result);
        if (!ev_result)
        {
            result = NRFX_ERROR_INTERNAL;
        }
        else
        {
            nrf_temp_event_clear(NRF_TEMP, NRF_TEMP_EVENT_DATARDY);
        }
        nrf_temp_task_trigger(NRF_TEMP, NRF_TEMP_TASK_STOP);
    }

    return result;
}

void nrfx_temp_irq_handler(void)
{
    NRFX_ASSERT(m_data_handler);

    nrf_temp_task_trigger(NRF_TEMP, NRF_TEMP_TASK_STOP);
    nrf_temp_event_clear(NRF_TEMP, NRF_TEMP_EVENT_DATARDY);

    uint32_t raw_temp = nrfx_temp_result_get();

    m_data_handler(raw_temp);
}

#endif // NRFX_CHECK(NRFX_TEMP_ENABLED)