From 094e62a528e95677a16a9465a1decfdc045e7197 Mon Sep 17 00:00:00 2001
From: Amaury Pouly <pamaury@rockbox.org>
Date: Sat, 31 Dec 2011 13:35:45 +0000
Subject: imx233/fuze+: implement rtc (time only, alarm still to implement)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31473 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/drivers/rtc/rtc_imx233.c | 142 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 138 insertions(+), 4 deletions(-)

(limited to 'firmware/drivers/rtc/rtc_imx233.c')

diff --git a/firmware/drivers/rtc/rtc_imx233.c b/firmware/drivers/rtc/rtc_imx233.c
index 4368610875..9e62476be6 100644
--- a/firmware/drivers/rtc/rtc_imx233.c
+++ b/firmware/drivers/rtc/rtc_imx233.c
@@ -22,21 +22,155 @@
 #include "system.h"
 #include "rtc.h"
 #include "timefuncs.h"
+#include "rtc-imx233.h"
+
+#if defined(SANSA_FUZEPLUS)
+#define SECS_ADJUST 315532800   /* seconds between 1970-1-1 and 1980-1-1 */
+#else
+#define SECS_ADJUST 0
+#endif
+
+#define MINUTE_SECONDS      60
+#define HOUR_SECONDS        3600
+#define DAY_SECONDS         86400
+#define WEEK_SECONDS        604800
+#define YEAR_SECONDS        31536000
+#define LEAP_YEAR_SECONDS   31622400
+
+/* Days in each month */
+static unsigned int days_in_month[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+static inline bool is_leapyear(int year)
+{
+    if( ((year%4)==0) && (((year%100)!=0) || ((year%400)==0)) )
+        return true;
+    else
+        return false;
+}
 
 void rtc_init(void)
 {
+    imx233_rtc_init();
 }
 
 int rtc_read_datetime(struct tm *tm)
 {
-    (void) tm;
-    return -1;
+    uint32_t seconds = imx233_rtc_read_seconds() - SECS_ADJUST;
+    #ifdef SANSA_FUZEPLUS
+    /* The OF uses PERSISTENT2 register to keep the adjustment and only changes
+     * SECONDS if necessary. */
+    seconds += imx233_rtc_read_persistent(2);
+    #else
+    /* The Freescale recommended way of keeping time is the number of seconds
+     * since 00:00 1/1/1980 */
+    #endif
+
+    /* Convert seconds since 00:00 1/1/xxxx (xxxx=year) */
+
+    /* weekday */
+    tm->tm_wday = ((seconds % WEEK_SECONDS) / DAY_SECONDS + 2) % 7;
+
+    /* Year */
+    int year = 1980;
+    while(seconds >= LEAP_YEAR_SECONDS)
+    {
+        if(is_leapyear(year))
+            seconds -= LEAP_YEAR_SECONDS;
+        else
+            seconds -= YEAR_SECONDS;
+
+        year++;
+    }
+
+    if(is_leapyear(year))
+        days_in_month[1] = 29;
+    else
+    {
+        days_in_month[1] = 28;
+        if(seconds>YEAR_SECONDS)
+        {
+            year++;
+            seconds -= YEAR_SECONDS;
+        }
+    }
+    tm->tm_year = year % 100 + 100;
+
+    /* Month */
+    for(int i = 0; i < 12; i++)
+    {
+        if(seconds < days_in_month[i] * DAY_SECONDS)
+        {
+            tm->tm_mon = i;
+            break;
+        }
+
+        seconds -= days_in_month[i] * DAY_SECONDS;
+    }
+
+    /* Month Day */
+    int mday = seconds / DAY_SECONDS;
+    seconds -= mday * DAY_SECONDS;
+    tm->tm_mday = mday + 1; /* 1 ... 31 */
+
+    /* Hour */
+    int hour = seconds / HOUR_SECONDS;
+    seconds -= hour*HOUR_SECONDS;
+    tm->tm_hour = hour;
+
+    /* Minute */
+    int min = seconds / MINUTE_SECONDS;
+    seconds -= min*MINUTE_SECONDS;
+    tm->tm_min = min;
+
+    /* Second */
+    tm->tm_sec = seconds;
+
+    return 0;
 }
 
 int rtc_write_datetime(const struct tm *tm)
 {
-    (void) tm;
-    return -1;
+    int i, year;
+    unsigned int year_days = 0;
+    unsigned int month_days = 0;
+    unsigned int seconds = 0;
+
+    year = 2000 + tm->tm_year - 100;
+
+    if(is_leapyear(year))
+        days_in_month[1] = 29;
+    else
+        days_in_month[1] = 28;
+
+    /* Number of days in months gone by this year*/
+    for(i = 0; i < tm->tm_mon; i++)
+        month_days += days_in_month[i];
+
+    /* Number of days in years gone by since 1-Jan-1980 */
+    year_days = 365*(tm->tm_year-100+20) + (tm->tm_year-100-1)/4 + 6;
+
+    /* Convert to seconds since 1-Jan-1980 */
+    seconds = tm->tm_sec
+            + tm->tm_min*MINUTE_SECONDS
+            + tm->tm_hour*HOUR_SECONDS
+            + (tm->tm_mday-1)*DAY_SECONDS
+            + month_days*DAY_SECONDS
+            + year_days*DAY_SECONDS;
+    seconds += SECS_ADJUST;
+
+    #ifdef SANSA_FUZEPLUS
+    /* The OF uses PERSISTENT2 register to keep the adjustment and only changes
+     * SECONDS if necessary.
+     * NOTE: the OF uses this mechanism to prevent roll back in time. Although
+     *       Rockbox will handle a negative PERSISTENT2 value, the OF will detect
+     *       it and won't return in time before SECONDS */
+    imx233_rtc_write_persistent(2, seconds - imx233_rtc_read_seconds());
+    #else
+    /* The Freescale recommended way of keeping time is the number of seconds
+     * since 00:00 1/1/1980 */
+    imx233_rtc_write_seconds(seconds);
+    #endif
+    return 0;
 }
 
 void rtc_set_alarm(int h, int m)
-- 
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