rtc, rv3029: add trickle charger support.
Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
diff --git a/README b/README
index beb1cbb..cdbb9de 100644
--- a/README
+++ b/README
@@ -748,6 +748,8 @@
CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
+ CONFIG_SYS_RV3029_TCR - enable trickle charger on
+ RV3029 RTC.
Note that if the RTC uses I2C, then the I2C interface
must also be configured. See I2C Support, below.
diff --git a/drivers/rtc/rv3029.c b/drivers/rtc/rv3029.c
index 3ebc768..e012168 100644
--- a/drivers/rtc/rv3029.c
+++ b/drivers/rtc/rv3029.c
@@ -25,6 +25,12 @@
#include <i2c.h>
#include <rtc.h>
+#define RTC_RV3029_CTRL1 0x00
+#define RTC_RV3029_CTRL1_EERE (1 << 3)
+
+#define RTC_RV3029_CTRL_STATUS 0x03
+#define RTC_RV3029_CTRLS_EEBUSY (1 << 7)
+
#define RTC_RV3029_CTRL_RESET 0x04
#define RTC_RV3029_CTRL_SYS_R (1 << 4)
@@ -42,6 +48,12 @@
#define RV3029C2_REG_HR_12_24 (1 << 6) /* 24h/12h mode */
#define RV3029C2_REG_HR_PM (1 << 5) /* PM/AM bit in 12h mode */
+#define RTC_RV3029_EEPROM_CTRL 0x30
+#define RTC_RV3029_TRICKLE_1K (1 << 4)
+#define RTC_RV3029_TRICKLE_5K (1 << 5)
+#define RTC_RV3029_TRICKLE_20K (1 << 6)
+#define RTC_RV3029_TRICKLE_80K (1 << 7)
+
int rtc_get( struct rtc_time *tmp )
{
int ret;
@@ -113,6 +125,41 @@
return 0;
}
+/* sets EERE-Bit (automatic EEPROM refresh) */
+static void set_eere_bit(int state)
+{
+ int ret;
+ unsigned char reg_ctrl1;
+
+ ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
+ ®_ctrl1, 1);
+
+ if (state)
+ reg_ctrl1 |= RTC_RV3029_CTRL1_EERE;
+ else
+ reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE);
+
+ ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1,
+ ®_ctrl1, 1);
+}
+
+/* waits until EEPROM page is no longer busy (times out after 10ms*loops) */
+static int wait_eebusy(int loops)
+{
+ int i, ret;
+ unsigned char ctrl_status;
+
+ for (i = 0; i < loops; i++) {
+ ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS,
+ 1, &ctrl_status, 1);
+
+ if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0)
+ break;
+ udelay(10000);
+ }
+ return i;
+}
+
void rtc_reset (void)
{
int ret;
@@ -121,4 +168,44 @@
buf[0] = RTC_RV3029_CTRL_SYS_R;
ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1,
buf, 1);
+
+#if defined(CONFIG_SYS_RV3029_TCR)
+ /*
+ * because EEPROM_CTRL register is in EEPROM page it is necessary to
+ * disable automatic EEPROM refresh and check if EEPROM is busy
+ * before EEPORM_CTRL register may be accessed
+ */
+ set_eere_bit(0);
+ wait_eebusy(100);
+ /* read current trickle charger setting */
+ ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL,
+ 1, buf, 1);
+ /* enable automatic EEPROM refresh again */
+ set_eere_bit(1);
+
+ /*
+ * to minimize EEPROM access write trickle charger setting only if it
+ * differs from current value
+ */
+ if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) {
+ buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR;
+ /*
+ * write trickle charger setting (disable autom. EEPROM
+ * refresh and wait until EEPROM is idle)
+ */
+ set_eere_bit(0);
+ wait_eebusy(100);
+ ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR,
+ RTC_RV3029_EEPROM_CTRL, 1, buf, 1);
+ /*
+ * it is necessary to wait 10ms before EEBUSY-Bit may be read
+ * (this is not documented in the data sheet yet, but the
+ * manufacturer recommends it)
+ */
+ udelay(10000);
+ /* wait until EEPROM write access is finished */
+ wait_eebusy(100);
+ set_eere_bit(1);
+ }
+#endif
}