[U-Boot] [PATCH] rtc: ds1307: add support for MCP7941x RTCs
Soeren Moch
smoch at web.de
Thu Nov 27 11:32:08 CET 2014
MCP7941x RTCs are very similar to ds1307. So add support in the ds1307 driver,
as it is done in the linux kernel
Signed-off-by: Soeren Moch <smoch at web.de>
---
Cc: Tom Rini <trini at ti.com>
---
drivers/rtc/ds1307.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/drivers/rtc/ds1307.c b/drivers/rtc/ds1307.c
index 03ab1a8..20da43a 100644
--- a/drivers/rtc/ds1307.c
+++ b/drivers/rtc/ds1307.c
@@ -10,6 +10,10 @@
/*
* Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
* DS1307 and DS1338/9 Real Time Clock (RTC).
+ * i2c address 0x68
+ *
+ * Date & Time support (no alarms) for MCP7941x Real Time Clock (RTC).
+ * i2c address 0x6f
*
* based on ds1337.c
*/
@@ -52,12 +56,24 @@
#define RTC_CTL_REG_ADDR 0x07
#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
+#define RTC_SEC_CH 0x80 /* Clock Halt (in Register 0) */
+
+#define RTC_DAY_VBATEN 0x00 /* Battery EN (in Register 3) */
#define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
#define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
#define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
#define RTC_CTL_BIT_OUT 0x80 /* Output Control */
+#if CONFIG_SYS_I2C_RTC_ADDR == 0x6f
+#undef RTC_SEC_CH
+#undef RTC_DAY_VBATEN
+#undef RTC_CTL_BIT_SQWE
+#define RTC_SEC_CH 0x00 /* Clock Halt (in Register 0) */
+#define RTC_DAY_VBATEN 0x08 /* Battery EN (in Register 3) */
+#define RTC_CTL_BIT_SQWE 0x40 /* Square Wave Enable */
+#endif
+
static uchar rtc_read (uchar reg);
static void rtc_write (uchar reg, uchar val);
@@ -81,11 +97,11 @@ int rtc_get (struct rtc_time *tmp)
"hr: %02x min: %02x sec: %02x\n",
year, mon, mday, wday, hour, min, sec);
- if (sec & RTC_SEC_BIT_CH) {
+ if ((sec & RTC_SEC_BIT_CH) == RTC_SEC_CH) {
printf ("### Warning: RTC oscillator has stopped\n");
- /* clear the CH flag */
+ /* start clock */
rtc_write (RTC_SEC_REG_ADDR,
- rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
+ rtc_read (RTC_SEC_REG_ADDR) ^ RTC_SEC_BIT_CH);
rel = -1;
}
@@ -112,6 +128,9 @@ int rtc_get (struct rtc_time *tmp)
*/
int rtc_set (struct rtc_time *tmp)
{
+ uchar clk_en = RTC_SEC_BIT_CH & ~RTC_SEC_CH;
+ uchar bat_en = RTC_DAY_VBATEN;
+
DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
@@ -121,11 +140,11 @@ 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));
- rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
+ rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1) | bat_en);
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));
- rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
+ rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | clk_en);
return 0;
}
@@ -142,7 +161,6 @@ void rtc_reset (void)
{
struct rtc_time tmp;
- rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
tmp.tm_year = 1970;
--
1.9.1
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