diff options
Diffstat (limited to 'c/src/lib/libcpu/bfin/clock/rtc.c')
| -rw-r--r-- | c/src/lib/libcpu/bfin/clock/rtc.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/c/src/lib/libcpu/bfin/clock/rtc.c b/c/src/lib/libcpu/bfin/clock/rtc.c new file mode 100644 index 0000000000..dace52eae2 --- /dev/null +++ b/c/src/lib/libcpu/bfin/clock/rtc.c @@ -0,0 +1,184 @@ +/* Real Time Clock Driver for Blackfin + * + * Copyright (c) 2006 by Atos Automacao Industrial Ltda. + * written by Alain Schaefer <alain.schaefer@easc.ch> + * and Antonio Giovanini <antonio@atos.com.br> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + + +#include <rtems.h> +#include "tod.h" +#include <rtems/libio.h> +#include <rtems/score/tod.h> +#include <rtems/rtems/types.h> +#include <bsp.h> +#include <libcpu/rtcRegs.h> + +/* The following are inside RTEMS -- we are violating visibility!!! + * Perhaps an API could be defined to get days since 1 Jan. + */ +extern const uint16_t _TOD_Days_to_date[2][13]; + +/* + * Prototypes and routines used below + */ +int Leap_years_until_now (int year); + +void Init_RTC(void) +{ + *((uint16_t*)RTC_PREN) = RTC_PREN_PREN; /* Enable Prescaler */ +} + +rtems_device_driver rtc_initialize( + rtems_device_major_number major, + rtems_device_minor_number minor_arg, + void *arg +) +{ + rtems_status_code status; + + /* + * Register and initialize the primary RTC's + */ + + status = rtems_io_register_name( "/dev/rtc", major, 0 ); + if (status != RTEMS_SUCCESSFUL) { + rtems_fatal_error_occurred(status); + } + + Init_RTC(); + + setRealTimeToRTEMS(); + return RTEMS_SUCCESSFUL; +} + +/* + * Read time from RTEMS' clock manager and set it to RTC + */ + +void setRealTimeFromRTEMS (void) +{ + rtems_time_of_day time_buffer; + rtems_status_code status; + + status = rtems_clock_get( RTEMS_CLOCK_GET_TOD, &time_buffer ); + if (status == RTEMS_SUCCESSFUL){ + setRealTime(&time_buffer); + } +} + +/* + * Read real time from RTC and set it to RTEMS' clock manager + */ + +void setRealTimeToRTEMS (void) +{ + rtems_time_of_day time_buffer; + + getRealTime(&time_buffer); + rtems_clock_set( &time_buffer ); +} + + /* + * Set the RTC time + */ +int setRealTime( + rtems_time_of_day *tod +) +{ + uint32_t days; + rtems_time_of_day tod_temp; + + tod_temp = *tod; + + days = (tod_temp.year - TOD_BASE_YEAR) * 365 + \ + _TOD_Days_to_date[0][tod_temp.month] + tod_temp.day - 1; + if (tod_temp.month < 3) + days += Leap_years_until_now (tod_temp.year - 1); + else + days += Leap_years_until_now (tod_temp.year); + + *((uint32_t volatile *)RTC_STAT) = (days << RTC_STAT_DAYS_SHIFT)| + (tod_temp.hour << RTC_STAT_HOURS_SHIFT)| + (tod_temp.minute << RTC_STAT_MINUTES_SHIFT)| + tod_temp.second; + + return 0; +} + + /* + * Get the time from the RTC. + */ + +void getRealTime( + rtems_time_of_day *tod +) +{ + uint32_t days, rtc_reg; + rtems_time_of_day tod_temp; + int n, Leap_year; + + rtc_reg = *((uint32_t volatile *)RTC_STAT); + + days = (rtc_reg >> RTC_STAT_DAYS_SHIFT) + 1; + + /* finding year */ + tod_temp.year = days/365 + TOD_BASE_YEAR; + if (days%365 > Leap_years_until_now (tod_temp.year - 1)) { + days = (days%365) - Leap_years_until_now (tod_temp.year - 1); + } else { + tod_temp.year--; + days = (days%365) + 365 - Leap_years_until_now (tod_temp.year - 1); + } + + /* finding month and day */ + Leap_year = (((!(tod_temp.year%4)) && (tod_temp.year%100)) || + (!(tod_temp.year%400)))?1:0; + for (n=1; n<=12; n++) { + if (days <= _TOD_Days_to_date[Leap_year][n+1]) { + tod_temp.month = n; + tod_temp.day = days - _TOD_Days_to_date[Leap_year][n]; + break; + } + } + + tod_temp.hour = (rtc_reg & RTC_STAT_HOURS_MASK) >> RTC_STAT_HOURS_SHIFT; + tod_temp.minute = (rtc_reg & RTC_STAT_MINUTES_MASK) >> RTC_STAT_MINUTES_SHIFT; + tod_temp.second = (rtc_reg & RTC_STAT_SECONDS_MASK); + tod_temp.ticks = 0; + *tod = tod_temp; +} + +/* + * Return the difference between RTC and RTEMS' clock manager time in minutes. + * If the difference is greater than 1 day, this returns 9999. + */ + +int checkRealTime (void) +{ + rtems_time_of_day rtems_tod; + rtems_time_of_day rtc_tod; + uint32_t rtems_time; + uint32_t rtc_time; + + rtems_clock_get( RTEMS_CLOCK_GET_TOD, &rtems_tod ); + getRealTime ( &rtc_tod ); + + rtems_time = _TOD_To_seconds( &rtems_tod ); + rtc_time = _TOD_To_seconds( &rtc_tod ); + + return rtems_time - rtc_time; +} + +int Leap_years_until_now (int year) +{ + return ((year/4 - year/100 + year/400) - + ((TOD_BASE_YEAR - 1)/4 - (TOD_BASE_YEAR - 1)/100 + + (TOD_BASE_YEAR - 1)/400)); +} |