rt-thread/bsp/efm32/dev_misc.c

/***************************************************************************//**
 * @file    dev_misc.c
 * @brief   Miscellaneous driver of RT-Thread RTOS for EFM32
 *  COPYRIGHT (C) 2012, RT-Thread Development Team
 * @author  onelife
 * @version 1.0
 *******************************************************************************
 * @section License
 * The license and distribution terms for this file may be found in the file
 * LICENSE in this distribution or at http://www.rt-thread.org/license/LICENSE
 *******************************************************************************
 * @section Change Logs
 * Date         Author      Notes
 * 2011-02-22   onelife     Initial creation for EFM32
 * 2011-07-27   onelife     Modify according to ADC driver changes
 ******************************************************************************/

/***************************************************************************//**
 * @addtogroup efm32
 * @{
 ******************************************************************************/

/* Includes ------------------------------------------------------------------*/
#include "board.h"
#include "drv_adc.h"

#if defined(RT_USING_MISC)
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
#ifdef RT_MISC_DEBUG
#define misc_debug(format,args...)          rt_kprintf(format, ##args)
#else
#define misc_debug(format,args...)
#endif

/* Private constants ---------------------------------------------------------*/
static rt_device_t                  adc0;
static struct efm32_adc_control_t   control = \
    {ADC_MODE_SINGLE, {}, {0, (rt_uint8_t)EFM32_NO_DMA}};

/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
rt_int32_t efm32_misc_getCelsius(rt_uint32_t adcSample);

/* Private functions ---------------------------------------------------------*/
/***************************************************************************//**
 * @brief
 *   Get current temperature value in degree celsius
 *
 * @details
 *
 * @note
 *
 * @return
 *   Temperature value (signed integer) in degree celsius times 100
 *
 ******************************************************************************/
rt_int32_t rt_hw_get_temp(void)
{
    ADC_InitSingle_TypeDef      singleInit = ADC_INITSINGLE_DEFAULT;
    struct efm32_adc_result_t   result;
    rt_uint32_t                 temp;

    /* Set input to temperature sensor. Acquisition time must be 256 cycles.
       Reference must be 1.25V */
    singleInit.acqTime      = adcAcqTime32;
    singleInit.reference    = adcRef1V25;
    singleInit.input        = adcSingleInpTemp;

    control.single.init     = &singleInit;
    adc0->control(adc0, RT_DEVICE_CTRL_ADC_MODE, &control);
    result.mode             = control.mode;
    result.buffer           = (void *)&temp;
    adc0->control(adc0, RT_DEVICE_CTRL_RESUME, &result);
    adc0->control(adc0, RT_DEVICE_CTRL_ADC_RESULT, &result);

    return efm32_misc_getCelsius(temp);
}

/***************************************************************************//**
 * @brief
 *   Get current VDD value in volt
 *
 * @details
 *
 * @note
 *
 * @return
 *   VDD value (unsigned integer) in volt times 100
 *
 ******************************************************************************/
rt_uint32_t rt_hw_get_vdd(void)
{
    ADC_InitSingle_TypeDef      singleInit = ADC_INITSINGLE_DEFAULT;
    struct efm32_adc_result_t   result;
    rt_uint32_t                 vdd;

    /* Set input to temperature sensor. Reference must be 1.25V */
    singleInit.acqTime      = adcAcqTime32;
    singleInit.reference    = adcRef1V25;
    singleInit.input        = adcSingleInpVDDDiv3;

    control.single.init     = &singleInit;
    adc0->control(adc0, RT_DEVICE_CTRL_ADC_MODE, &control);
    result.mode             = control.mode;
    result.buffer           = (void *)&vdd;
    adc0->control(adc0, RT_DEVICE_CTRL_RESUME, &result);
    adc0->control(adc0, RT_DEVICE_CTRL_ADC_RESULT, &result);

    return (vdd * 125 * 3) / 4096;
}

/***************************************************************************//**
 * @brief
 *   Initialize all the miscellaneous drivers
 *
 * @details
 *
 * @note
 *
 * @return
 *   Error code
 ******************************************************************************/
rt_err_t rt_hw_misc_init(void)
{
    do
    {
        /* Find ADC device */
        adc0 = rt_device_find(RT_ADC0_NAME);
        if (adc0 == RT_NULL)
        {
            misc_debug("Misc err: Can't find device: %s!\n", RT_ADC0_NAME);
            break;
        }
        misc_debug("Misc: Find device %s\n", RT_ADC0_NAME);

        return RT_EOK;
    } while (0);

    misc_debug("Misc err: Init failed!\n");
    return -RT_ERROR;
}

/***************************************************************************//**
 * @brief
 *   Convert ADC result to degree celsius.
 *
 * @details
 *
 * @note
 *   See section 2.3.4 in the reference manual for details on this calculatoin
 *
 * @param adcResult
 *   Raw value from ADC to be converted to celsius
 *
 * @return
 *   The temperature value (signed integer) in degrees celsius times 100
 *
 ******************************************************************************/
rt_int32_t efm32_misc_getCelsius(rt_uint32_t adcResult)
{
    /* Factory calibration temperature from device information page. */
    rt_int32_t cal_temp     = ((DEVINFO->CAL & _DEVINFO_CAL_TEMP_MASK) \
                                >> _DEVINFO_CAL_TEMP_SHIFT) * 100;

    /* Factory calibration value from device information page. */
    rt_int32_t cal_value    = ((DEVINFO->ADC0CAL2 & _DEVINFO_ADC0CAL2_TEMP1V25_MASK) \
                                >> _DEVINFO_ADC0CAL2_TEMP1V25_SHIFT) * 10000;

    /* Temperature gradient (from datasheet) in (ADC unit / degree celsius * 100) */
    rt_int32_t t_grad       = -385;

    return (cal_temp - (cal_value - (rt_int32_t)adcResult * 10000) / t_grad);
}

/*******************************************************************************
 *  Export to FINSH
 ******************************************************************************/
#ifdef RT_USING_FINSH
#include <finsh.h>

void list_temp(void)
{
    rt_int32_t temp = rt_hw_get_temp();

    rt_kprintf("Temperature is %2d.%02d C\n", temp / 100, temp % 100);
}
FINSH_FUNCTION_EXPORT(list_temp, list current temperature value.)

void list_vdd(void)
{
    rt_uint32_t vdd = rt_hw_get_vdd();

    rt_kprintf("VDD is %1d.%02d V\n", vdd / 100, vdd % 100);
}
FINSH_FUNCTION_EXPORT(list_vdd, list current VDD value.)

#endif /* RT_USING_FINSH */

#endif /* defined(RT_USING_MISC) */
/***************************************************************************//**
 * @}
 ******************************************************************************/