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rtc: ds1307: Ensure oscillator is enabled for DS1388

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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 <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200816235731.21071-1-chris.packham@alliedtelesis.co.nz
This commit is contained in:
Chris Packham 2020-08-17 11:57:31 +12:00 committed by Alexandre Belloni
parent 163a512cd9
commit 59ed012715
1 changed files with 14 additions and 0 deletions
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14
drivers/rtc/rtc-ds1307.c
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@ -153,6 +153,7 @@ enum ds_type {
#define DS1388_REG_CONTROL 0x0c #define DS1388_REG_CONTROL 0x0c
# define DS1388_BIT_RST BIT(0) # define DS1388_BIT_RST BIT(0)
# define DS1388_BIT_WDE BIT(1) # define DS1388_BIT_WDE BIT(1)
# define DS1388_BIT_nEOSC BIT(7)
/* negative offset step is -2.034ppm */ /* negative offset step is -2.034ppm */
#define M41TXX_NEG_OFFSET_STEP_PPB 2034 #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); DS1307_REG_HOUR << 4 | 0x08, hour);
} }
break; 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: default:
break; break;
} }