Provide a function to set up the RTC ready for use.
Signed-off-by: Simon Glass sjg@chromium.org
---
Changes in v2: - Drop the part of the commit message that talks about using build date - Move CLEAR_CMOS up to the top, indicated to be manually changed - Remove the parameter from rtc_init() and simplify the code
drivers/rtc/mc146818.c | 43 +++++++++++++++++++++++++++++++++++++++---- include/rtc.h | 5 +++++ 2 files changed, 44 insertions(+), 4 deletions(-)
diff --git a/drivers/rtc/mc146818.c b/drivers/rtc/mc146818.c index f7cf106..39e6041 100644 --- a/drivers/rtc/mc146818.c +++ b/drivers/rtc/mc146818.c @@ -14,6 +14,7 @@ #include <common.h> #include <command.h> #include <rtc.h> +#include <version.h>
#if defined(__I386__) || defined(CONFIG_MALTA) #include <asm/io.h> @@ -23,6 +24,9 @@
#if defined(CONFIG_CMD_DATE)
+/* Set this to 1 to clear the CMOS RAM */ +#define CLEAR_CMOS 0 + static uchar rtc_read (uchar reg); static void rtc_write (uchar reg, uchar val);
@@ -41,7 +45,14 @@ static void rtc_write (uchar reg, uchar val); #define RTC_CONFIG_B 0x0B #define RTC_CONFIG_C 0x0C #define RTC_CONFIG_D 0x0D +#define RTC_REG_SIZE 0x80 + +#define RTC_CONFIG_A_REF_CLCK_32KHZ (1 << 5) +#define RTC_CONFIG_A_RATE_1024HZ 6
+#define RTC_CONFIG_B_24H (1 << 1) + +#define RTC_CONFIG_D_VALID_RAM_AND_TIME 0x80
/* ------------------------------------------------------------------------- */
@@ -128,25 +139,49 @@ void rtc_reset (void) */ static uchar rtc_read (uchar reg) { - return(in8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg)); + return in8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg); }
static void rtc_write (uchar reg, uchar val) { - out8(CONFIG_SYS_RTC_REG_BASE_ADDR+reg, val); + out8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg, val); } #else static uchar rtc_read (uchar reg) { out8(RTC_PORT_MC146818,reg); - return(in8(RTC_PORT_MC146818+1)); + return in8(RTC_PORT_MC146818 + 1); }
static void rtc_write (uchar reg, uchar val) { out8(RTC_PORT_MC146818,reg); - out8(RTC_PORT_MC146818+1,val); + out8(RTC_PORT_MC146818+1, val); } #endif
+void rtc_init(void) +{ +#if CLEAR_CMOS + int i; + + rtc_write(RTC_SECONDS_ALARM, 0); + rtc_write(RTC_MINUTES_ALARM, 0); + rtc_write(RTC_HOURS_ALARM, 0); + for (i = RTC_CONFIG_A; i < RTC_REG_SIZE; i++) + rtc_write(i, 0); + printf("RTC: zeroing CMOS RAM\n"); +#endif + + /* Setup the real time clock */ + rtc_write(RTC_CONFIG_B, RTC_CONFIG_B_24H); + /* Setup the frequency it operates at */ + rtc_write(RTC_CONFIG_A, RTC_CONFIG_A_REF_CLCK_32KHZ | + RTC_CONFIG_A_RATE_1024HZ); + /* Ensure all reserved bits are 0 in register D */ + rtc_write(RTC_CONFIG_D, RTC_CONFIG_D_VALID_RAM_AND_TIME); + + /* Clear any pending interrupts */ + rtc_read(RTC_CONFIG_C); +} #endif diff --git a/include/rtc.h b/include/rtc.h index c034966..d11aa8b 100644 --- a/include/rtc.h +++ b/include/rtc.h @@ -50,4 +50,9 @@ void to_tm (int, struct rtc_time *); unsigned long mktime (unsigned int, unsigned int, unsigned int, unsigned int, unsigned int, unsigned int);
+/** + * rtc_init() - Set up the real time clock ready for use + */ +void rtc_init(void); + #endif /* _RTC_H_ */