add RTC public function.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2164 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/drivers/rtc/SConscript

+from building import *
+
+cwd     = GetCurrentDir()
+src	= Glob('*.c')
+CPPPATH = [cwd + '/../include']
+group = DefineGroup('DeviceDrivers', src, depend = ['RT_USING_RTC'], CPPPATH = CPPPATH)
+
+Return('group')

components/drivers/rtc/rtc.c

+/*
+ * File      : rtc.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
+ *
+ * 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
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2012-01-29     aozima       first version.
+ * 2012-04-12     aozima       optimization: find rtc device only first.
+ * 2012-04-16     aozima       add scheduler lock for set_date and set_time.
+ */
+
+#include <time.h>
+#include <string.h>
+#include <rtthread.h>
+
+/** \brief returns the current time.
+ *
+ * \param time_t * t the timestamp pointer, if not used, keep NULL.
+ * \return time_t return timestamp current.
+ *
+ */
+/* for IAR 6.2 later Compiler */
+#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
+#pragma module_name = "?time"
+time_t (__time32)(time_t *t) /* Only supports 32-bit timestamp */
+#else
+time_t time(time_t* t)
+#endif
+{
+    static rt_device_t device = RT_NULL;
+    time_t time_now = 0;
+
+    /* optimization: find rtc device only first. */
+    if (device == RT_NULL)
+    {
+        device = rt_device_find("rtc");
+    }
+
+    /* read timestamp from RTC device. */
+    if (device != RT_NULL)
+    {
+        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
+    }
+
+    /* if t is not NULL, write timestamp to *t */
+    if (t != RT_NULL)
+    {
+        *t = time_now;
+    }
+
+    return time_now;
+}
+
+/** \brief set system date(time not modify).
+ *
+ * \param rt_uint32_t year  e.g: 2012.
+ * \param rt_uint32_t month e.g: 12 (1~12).
+ * \param rt_uint32_t day   e.g: e.g: 31.
+ * \return rt_err_t if set success, return RT_EOK.
+ *
+ */
+rt_err_t set_date(rt_uint32_t year, rt_uint32_t month, rt_uint32_t day)
+{
+    time_t now;
+    struct tm * p_tm;
+    struct tm tm_new;
+    rt_device_t device;
+
+    /* get current time */
+    now = time(RT_NULL);
+
+    /* lock scheduler. */
+    rt_enter_critical();
+    /* converts calendar time time into local time. */
+    p_tm = localtime(&now);
+    /* copy the statically located variable */
+    memcpy(&tm_new, p_tm, sizeof(struct tm));
+    /* unlock scheduler. */
+    rt_exit_critical();
+
+    /* update date. */
+    tm_new.tm_year = year - 1900;
+    tm_new.tm_mon  = month - 1; /* tm_mon: 0~11 */
+    tm_new.tm_mday = day;
+
+    /* converts the local time in time to calendar time. */
+    now = mktime(&tm_new);
+
+    device = rt_device_find("rtc");
+    if (device == RT_NULL)
+    {
+        return -RT_ERROR;
+    }
+
+    /* update to RTC device. */
+    return rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
+}
+
+/** \brief set system time(date not modify).
+ *
+ * \param rt_uint32_t hour   e.g: 0~23.
+ * \param rt_uint32_t minute e.g: 0~59.
+ * \param rt_uint32_t second e.g: 0~59.
+ * \return rt_err_t if set success, return RT_EOK.
+ *
+ */
+rt_err_t set_time(rt_uint32_t hour, rt_uint32_t minute, rt_uint32_t second)
+{
+    time_t now;
+    struct tm * p_tm;
+    struct tm tm_new;
+    rt_device_t device;
+
+    /* get current time */
+    now = time(RT_NULL);
+
+    /* lock scheduler. */
+    rt_enter_critical();
+    /* converts calendar time time into local time. */
+    p_tm = localtime(&now);
+    /* copy the statically located variable */
+    memcpy(&tm_new, p_tm, sizeof(struct tm));
+    /* unlock scheduler. */
+    rt_exit_critical();
+
+    /* update time. */
+    tm_new.tm_hour = hour;
+    tm_new.tm_min  = minute;
+    tm_new.tm_sec  = second;
+
+    /* converts the local time in time to calendar time. */
+    now = mktime(&tm_new);
+
+    device = rt_device_find("rtc");
+    if (device == RT_NULL)
+    {
+        return RT_ERROR;
+    }
+
+    /* update to RTC device. */
+    return rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
+}
+
+#ifdef RT_USING_FINSH
+#include <finsh.h>
+
+void list_date(void)
+{
+    time_t now;
+
+    now = time(RT_NULL);
+    rt_kprintf("%s\n", ctime(&now));
+}
+FINSH_FUNCTION_EXPORT(list_date, show date and time.)
+
+FINSH_FUNCTION_EXPORT(set_date, set date. e.g: set_date(2010,2,28))
+FINSH_FUNCTION_EXPORT(set_time, set time. e.g: set_time(23,59,59))
+#endif