rt-thread/bsp/efm32/drv_rtc.c

/******************************************************************//**
 * @file 		drv_rtc.c
 * @brief 	RTC driver of RT-Thread RTOS for EFM32
 * 	COPYRIGHT (C) 2011, RT-Thread Development Team
 * @author 	Bernard, onelife
 * @version 	0.4 beta
 **********************************************************************
 * @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
 * 2009-01-05	Bernard		the first version
 * 2010-12-27	onelife		Modification for EFM32
 *********************************************************************/
 
/******************************************************************//**
 * @addtogroup efm32
 * @{
*********************************************************************/

/* Includes -------------------------------------------------------------------*/
#include "board.h"
#include "hdl_interrupt.h"
#include "drv_rtc.h"

/* Private typedef -------------------------------------------------------------*/
/* Private define --------------------------------------------------------------*/
/* Private macro --------------------------------------------------------------*/
/* Private variables ------------------------------------------------------------*/
static struct rt_device rtc;
static rt_uint32_t rtc_time;

/* Private function prototypes ---------------------------------------------------*/
static void startLfxoForRtc(void);

/* Private functions ------------------------------------------------------------*/
static rt_err_t rt_rtc_open(rt_device_t dev, rt_uint16_t oflag)
{
    if (dev->rx_indicate != RT_NULL)
    {
        /* Open Interrupt */
    }

    return RT_EOK;
}

static rt_size_t rt_rtc_read(
	rt_device_t 	dev, 
	rt_off_t 		pos, 
	void* 			buffer, 
	rt_size_t 		size)
{
    return 0;
}

/******************************************************************//**
* @brief
*	Configure RTC device
*
* @details
*
* @note
*
* @param[in] dev
*	Pointer to device descriptor
*
* @param[in] cmd
*	RTC control command
*
* @param[in] args
*	Arguments
*
* @return
*	Error code
*********************************************************************/
static rt_err_t rt_rtc_control(rt_device_t dev, rt_uint8_t cmd, void *args)
{
    RT_ASSERT(dev != RT_NULL);

    switch (cmd)
    {
    case RT_DEVICE_CTRL_RTC_GET_TIME:
        *(rt_uint32_t *)args = rtc_time + RTC_CounterGet();
        break;

    case RT_DEVICE_CTRL_RTC_SET_TIME:
    {
        rtc_time = *(rt_uint32_t *)args;

		/* Reset counter */
		RTC_Enable(false);
		RTC_Enable(true);
    }
    break;
    }

    return RT_EOK;
}

/******************************************************************//**
 * @brief
 *	 RTC counter overflow interrupt handler
 *
 * @details
 *
 * @note
 *********************************************************************/
void rt_hw_rtc_isr(rt_device_t device)
{
	if (RTC->IF & RTC_IFC_OF)
	{
		rtc_time += _RTC_CNT_MASK;
	}

	RTC->IFC = _RTC_IFC_MASK;
}

/******************************************************************//**
* @brief
*	Register RTC device
*
* @details
*
* @note
*
* @param[in] device
*	Pointer to device descriptor
*
* @param[in] name
*	Device name
*
* @param[in] flag
*	Configuration flags
*
* @return
*	Error code
*********************************************************************/
rt_err_t rt_hw_rtc_register(
	rt_device_t		device, 
	const char		*name, 
	rt_uint32_t		flag)
{
	RT_ASSERT(device != RT_NULL);

	device->type 		= RT_Device_Class_RTC;
	device->rx_indicate = RT_NULL;
	device->tx_complete = RT_NULL;
	device->init 		= RT_NULL;
	device->open		= rt_rtc_open;
	device->close		= RT_NULL;
	device->read 		= rt_rtc_read;
	device->write 		= RT_NULL;
	device->control 	= rt_rtc_control;
	device->user_data	= RT_NULL; /* no private */

	/* register a character device */
	return rt_device_register(device, name, RT_DEVICE_FLAG_RDWR | flag);
}


/******************************************************************//**
* @brief
*	Initialize all RTC module related hardware and register RTC device to kernel
*
* @details
*
* @note
*********************************************************************/
void rt_hw_rtc_init(void)
{
	rt_uint32_t reset;
	
	reset = RMU_ResetCauseGet();

	// TODO: What is the current reset mode?
	if (reset & RMU_RSTCAUSE_PORST || reset & RMU_RSTCAUSE_EXTRST)
    {
    	RTC_Init_TypeDef rtcInit;
		efm32_irq_hook_init_t hook;

		rtcInit.enable = true;
		rtcInit.debugRun = false;
		rtcInit.comp0Top = false;

		rtc_time = 0UL;

        rt_kprintf("rtc is not configured\n");
        rt_kprintf("please configure with set_date and set_time\n");

		/* Configuring clocks in the Clock Management Unit (CMU) */
		startLfxoForRtc();
		
		/* Initialize and enable RTC */
		RTC_Init(&rtcInit);

		hook.type		= efm32_irq_type_rtc;
		hook.unit		= 0;
		hook.cbFunc 	= rt_hw_rtc_isr;
		hook.userPtr	= RT_NULL;
		efm32_irq_hook_register(&hook);

		/* Enabling Interrupt from RTC */
		RTC_IntEnable(RTC_IFC_OF);
		RTC_IntClear(RTC_IFC_OF);

		NVIC_ClearPendingIRQ(RTC_IRQn);
		NVIC_SetPriority(RTC_IRQn, EFM32_IRQ_PRI_DEFAULT);
		NVIC_EnableIRQ(RTC_IRQn);
    }

    /* register rtc device */
	rt_hw_rtc_register(&rtc, RT_RTC_NAME, EFM32_NO_DATA);
}

/******************************************************************//**
* @brief
*	Start LFXO for RTC
*
* @details
*    Starts the LFXO and routes it to the RTC. RTC clock is prescaled to save energy.
*
* @note
*********************************************************************/
static void startLfxoForRtc(void)
{
	/* Starting LFXO and waiting until it is stable */
	CMU_OscillatorEnable(cmuOsc_LFXO, true, true);

	/* Routing the LFXO clock to the RTC */
	CMU_ClockDivSet(cmuClock_RTC,cmuClkDiv_32768);
	CMU_ClockSelectSet(cmuClock_LFA,cmuSelect_LFXO);
	CMU_ClockEnable(cmuClock_RTC, true);
}

/*********************************************************************
* 	Export to FINSH
*********************************************************************/
#ifdef RT_USING_FINSH
#include <finsh.h>
#include <time.h>
time_t time(time_t* t)
{
    rt_device_t device;
    time_t time;

    device = rt_device_find("rtc");
    if (device != RT_NULL)
    {
        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time);
        if (t != RT_NULL) *t = time;
    }

    return time;
}

void set_date(rt_uint32_t year, rt_uint32_t month, rt_uint32_t day)
{
    time_t now;
    struct tm* ti;
    rt_device_t device;

    ti = RT_NULL;
    /* get current time */
    time(&now);

    ti = localtime(&now);
    if (ti != RT_NULL)
    {
        ti->tm_year = year - 1900;
        ti->tm_mon 	= month - 1; /* ti->tm_mon 	= month; */
        ti->tm_mday = day;
    }

    now = mktime(ti);

    device = rt_device_find("rtc");
    if (device != RT_NULL)
    {
        rt_rtc_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
    }
}
FINSH_FUNCTION_EXPORT(set_date, set date. e.g: set_date(2010,2,28))

void set_time(rt_uint32_t hour, rt_uint32_t minute, rt_uint32_t second)
{
    time_t now;
    struct tm* ti;
    rt_device_t device;

    ti = RT_NULL;
    /* get current time */
    time(&now);

    ti = localtime(&now);
    if (ti != RT_NULL)
    {
        ti->tm_hour = hour;
        ti->tm_min 	= minute;
        ti->tm_sec 	= second;
    }

    now = mktime(ti);
    device = rt_device_find("rtc");
    if (device != RT_NULL)
    {
        rt_rtc_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
    }
}
FINSH_FUNCTION_EXPORT(set_time, set time. e.g: set_time(23,59,59))

void list_date()
{
    time_t now;

    time(&now);
    rt_kprintf("%s\n", ctime(&now));
}
FINSH_FUNCTION_EXPORT(list_date, show date and time.)
#endif

/******************************************************************//**
 * @}
*********************************************************************/