The rv3028 chip is kind of strange.
The chip has two inputs one for the buffer battery
(V_backup) and one for the main power supply (V_dd).
By default a clk out of the chip is enabled, drawing a big amount of
current, draining the buffer battery of our board in 3 days.
There is a mode that would shut down the clk out if powered from
V_backup, but that would have to be configured as well. In our
application the battery is connected via V_dd. So disabling the clk by
default is the way to go for us.
Signed-off-by: Johannes Kirchmair <johannes.kirchmair@xxxxxxxxxxx>
---
drivers/rtc/rtc-rv3028.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
index 12c807306893..9e2aaa7a533e 100644
--- a/drivers/rtc/rtc-rv3028.c
+++ b/drivers/rtc/rtc-rv3028.c
@@ -787,7 +787,7 @@ static const struct regmap_config regmap_config = {
static int rv3028_probe(struct i2c_client *client)
{
struct rv3028_data *rv3028;
- int ret, status;
+ int ret, status, buf;
u32 ohms;
struct nvmem_config nvmem_cfg = {
.name = "rv3028_nvram",
@@ -826,6 +826,16 @@ static int rv3028_probe(struct i2c_client *client)
if (status & RV3028_STATUS_AF)
dev_warn(&client->dev, "An alarm may have been missed.\n");
+ ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &buf);
+ if (ret < 0)
+ return ret;
+
+ if (buf != RV3028_CLKOUT_FD_MASK) {
+ ret = rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff, RV3028_CLKOUT_FD_MASK); // disable clk out
+ if (ret < 0)
+ return ret;
+ }
+
rv3028->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(rv3028->rtc))
return PTR_ERR(rv3028->rtc);
--
2.25.1
