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authorAndy Fleming <afleming@gmail.com>2015-10-21 18:59:06 -0500
committerYork Sun <yorksun@freescale.com>2015-11-04 15:19:12 -0800
commitc79e1c1ce9e5c1ddf6fac631e4741999f8a0cc58 (patch)
tree25c73a8290d30891b3773b6f188a620bfa9c367e /drivers/rtc/ds1307.c
parent83bf005710a1e01341de5e2f44a3ce082717e313 (diff)
downloadtalos-obmc-uboot-c79e1c1ce9e5c1ddf6fac631e4741999f8a0cc58.tar.gz
talos-obmc-uboot-c79e1c1ce9e5c1ddf6fac631e4741999f8a0cc58.zip
rtc: Add MCP79411 support to DS1307 rtc driver
The code is from Adrian Cox, and is patterned after similar support in Linux (drivers/rtc/rtc-ds1307.c:1121-1135). This chip is used on the Cyrus board from Varisys. Signed-off-by: Andy Fleming <afleming@gmail.com> Reviewed-by: York Sun <yorksun@freescale.com>
Diffstat (limited to 'drivers/rtc/ds1307.c')
-rw-r--r--drivers/rtc/ds1307.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/rtc/ds1307.c b/drivers/rtc/ds1307.c
index 03ab1a8c5d..3be1da6873 100644
--- a/drivers/rtc/ds1307.c
+++ b/drivers/rtc/ds1307.c
@@ -58,6 +58,10 @@
#define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
#define RTC_CTL_BIT_OUT 0x80 /* Output Control */
+/* MCP7941X-specific bits */
+#define MCP7941X_BIT_ST 0x80
+#define MCP7941X_BIT_VBATEN 0x08
+
static uchar rtc_read (uchar reg);
static void rtc_write (uchar reg, uchar val);
@@ -69,6 +73,9 @@ int rtc_get (struct rtc_time *tmp)
int rel = 0;
uchar sec, min, hour, mday, wday, mon, year;
+#ifdef CONFIG_RTC_MCP79411
+read_rtc:
+#endif
sec = rtc_read (RTC_SEC_REG_ADDR);
min = rtc_read (RTC_MIN_REG_ADDR);
hour = rtc_read (RTC_HR_REG_ADDR);
@@ -81,6 +88,7 @@ int rtc_get (struct rtc_time *tmp)
"hr: %02x min: %02x sec: %02x\n",
year, mon, mday, wday, hour, min, sec);
+#ifdef CONFIG_RTC_DS1307
if (sec & RTC_SEC_BIT_CH) {
printf ("### Warning: RTC oscillator has stopped\n");
/* clear the CH flag */
@@ -88,6 +96,23 @@ int rtc_get (struct rtc_time *tmp)
rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
rel = -1;
}
+#endif
+
+#ifdef CONFIG_RTC_MCP79411
+ /* make sure that the backup battery is enabled */
+ if (!(wday & MCP7941X_BIT_VBATEN)) {
+ rtc_write(RTC_DAY_REG_ADDR,
+ wday | MCP7941X_BIT_VBATEN);
+ }
+
+ /* clock halted? turn it on, so clock can tick. */
+ if (!(sec & MCP7941X_BIT_ST)) {
+ rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
+ printf("Started RTC\n");
+ goto read_rtc;
+ }
+#endif
+
tmp->tm_sec = bcd2bin (sec & 0x7F);
tmp->tm_min = bcd2bin (min & 0x7F);
@@ -121,11 +146,20 @@ int rtc_set (struct rtc_time *tmp)
rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
+#ifdef CONFIG_RTC_MCP79411
+ rtc_write (RTC_DAY_REG_ADDR,
+ bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
+#else
rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
+#endif
rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
+#ifdef CONFIG_RTC_MCP79411
+ rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
+#else
rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
+#endif
return 0;
}
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