From 59ed0127155201863db49f3dc5fb41316433340a Mon Sep 17 00:00:00 2001 From: Chris Packham Date: Mon, 17 Aug 2020 11:57:31 +1200 Subject: [PATCH] rtc: ds1307: Ensure oscillator is enabled for DS1388 Similar to the other variants the DS1388 has a bit to stop the oscillator to reduce the power consumption from VBAT. Ensure that the oscillator is enabled when the system is up. Signed-off-by: Chris Packham Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20200816235731.21071-1-chris.packham@alliedtelesis.co.nz --- drivers/rtc/rtc-ds1307.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 54c85cdd019d..2182f4e97c0a 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -153,6 +153,7 @@ enum ds_type { #define DS1388_REG_CONTROL 0x0c # define DS1388_BIT_RST BIT(0) # define DS1388_BIT_WDE BIT(1) +# define DS1388_BIT_nEOSC BIT(7) /* negative offset step is -2.034ppm */ #define M41TXX_NEG_OFFSET_STEP_PPB 2034 @@ -1881,6 +1882,19 @@ static int ds1307_probe(struct i2c_client *client, DS1307_REG_HOUR << 4 | 0x08, hour); } break; + case ds_1388: + err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + /* oscillator off? turn it on, so clock can tick. */ + if (tmp & DS1388_BIT_nEOSC) { + tmp &= ~DS1388_BIT_nEOSC; + regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp); + } + break; default: break; }