rt-thread-official/bsp/stm32f10x/drivers/stm32f1_rtc.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2009-01-05     Bernard      the first version.
 * 2011-11-26     aozima       implementation time.
 * 2015-07-16     FlyM         rename rtc to stm32f1_rtc. remove finsh export function
 */

#include <rtthread.h>
#include <stm32f10x.h>
#include "stm32f1_rtc.h"

static struct rt_device rtc;
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;
}

static rt_err_t rt_rtc_control(rt_device_t dev, int cmd, void *args)
{
    rt_time_t *time;
    RT_ASSERT(dev != RT_NULL);

    switch (cmd)
    {
    case RT_DEVICE_CTRL_RTC_GET_TIME:
        time = (rt_time_t *)args;
        /* read device */
        *time = RTC_GetCounter();
        break;

    case RT_DEVICE_CTRL_RTC_SET_TIME:
    {
        time = (rt_time_t *)args;

        /* Enable PWR and BKP clocks */
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

        /* Allow access to BKP Domain */
        PWR_BackupAccessCmd(ENABLE);

        /* Wait until last write operation on RTC registers has finished */
        RTC_WaitForLastTask();

        /* Change the current time */
        RTC_SetCounter(*time);

        /* Wait until last write operation on RTC registers has finished */
        RTC_WaitForLastTask();

        BKP_WriteBackupRegister(BKP_DR1, 0xA5A5);
    }
    break;
    }

    return RT_EOK;
}

/*******************************************************************************
* Function Name  : RTC_Configuration
* Description    : Configures the RTC.
* Input          : None
* Output         : None
* Return         : 0 reday,-1 error.
*******************************************************************************/
int RTC_Configuration(void)
{
    u32 count=0x200000;

    /* Enable PWR and BKP clocks */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);

    /* Allow access to BKP Domain */
    PWR_BackupAccessCmd(ENABLE);

    /* Reset Backup Domain */
    BKP_DeInit();

    /* Enable LSE */
    RCC_LSEConfig(RCC_LSE_ON);
    /* Wait till LSE is ready */
    while ( (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET) && (--count) );
    if ( count == 0 )
    {
        return -1;
    }

    /* Select LSE as RTC Clock Source */
    RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

    /* Enable RTC Clock */
    RCC_RTCCLKCmd(ENABLE);

    /* Wait for RTC registers synchronization */
    RTC_WaitForSynchro();

    /* Wait until last write operation on RTC registers has finished */
    RTC_WaitForLastTask();

    /* Set RTC prescaler: set RTC period to 1sec */
    RTC_SetPrescaler(32767); /* RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1) */

    /* Wait until last write operation on RTC registers has finished */
    RTC_WaitForLastTask();

    return 0;
}

void rt_hw_rtc_init(void)
{
    rtc.type	= RT_Device_Class_RTC;

    if (BKP_ReadBackupRegister(BKP_DR1) != 0xA5A5)
    {
        rt_kprintf("rtc is not configured\n");
        rt_kprintf("please configure with set_date and set_time\n");
        if ( RTC_Configuration() != 0)
        {
            rt_kprintf("rtc configure fail...\r\n");
            return ;
        }
    }
    else
    {
        /* Wait for RTC registers synchronization */
        RTC_WaitForSynchro();
    }

    /* register rtc device */
    rtc.init 	= RT_NULL;
    rtc.open 	= rt_rtc_open;
    rtc.close	= RT_NULL;
    rtc.read 	= rt_rtc_read;
    rtc.write	= RT_NULL;
    rtc.control = rt_rtc_control;

    /* no private */
    rtc.user_data = RT_NULL;

    rt_device_register(&rtc, "rtc", RT_DEVICE_FLAG_RDWR);

    return;
}