On Sat, Nov 15, 2014 at 9:18 AM, Simon Glass sjg@chromium.org wrote:
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_ */
Reviewed-by: Bin Meng bmeng.cn@gmail.com