Messages in this thread | | | Date | Fri, 1 Dec 2017 16:42:10 +0100 | From | Sebastian Reichel <> | Subject | Re: [PATCH] power: ltc2941-battery-gauge: Disable continuous monitoring on shutdown |
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Hi,
On Thu, Nov 23, 2017 at 03:41:05PM +0100, Mike Looijmans wrote: > The driver sets the fuel gauge to continuous monitoring on startup, for > the models that support this. When the board shuts down, the chip remains > in that mode, causing a few mA drain on the battery every 2 or 10 seconds. > > This patch registers a shutdown handler that turns off the monitoring to > prevent this battery drain. > > Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> > ---
Thanks, queued. I wonder if you need a second patch to also disable the monitoring for suspend (and re-enable on resume)?
-- Sebastian
> drivers/power/supply/ltc2941-battery-gauge.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c > index 08e4fd9..4cfa3f0 100644 > --- a/drivers/power/supply/ltc2941-battery-gauge.c > +++ b/drivers/power/supply/ltc2941-battery-gauge.c > @@ -60,6 +60,7 @@ enum ltc294x_id { > #define LTC294X_REG_CONTROL_PRESCALER_SET(x) \ > ((x << 3) & LTC294X_REG_CONTROL_PRESCALER_MASK) > #define LTC294X_REG_CONTROL_ALCC_CONFIG_DISABLED 0 > +#define LTC294X_REG_CONTROL_ADC_DISABLE(x) ((x) & ~(BIT(7) | BIT(6))) > > struct ltc294x_info { > struct i2c_client *client; /* I2C Client pointer */ > @@ -523,6 +524,29 @@ static int ltc294x_i2c_probe(struct i2c_client *client, > return 0; > } > > +static void ltc294x_i2c_shutdown(struct i2c_client *client) > +{ > + struct ltc294x_info *info = i2c_get_clientdata(client); > + int ret; > + u8 value; > + u8 control; > + > + /* The LTC2941 does not need any special handling */ > + if (info->id == LTC2941_ID) > + return; > + > + /* Read control register */ > + ret = ltc294x_read_regs(info->client, LTC294X_REG_CONTROL, &value, 1); > + if (ret < 0) > + return; > + > + /* Disable continuous ADC conversion as this drains the battery */ > + control = LTC294X_REG_CONTROL_ADC_DISABLE(value); > + if (control != value) > + ltc294x_write_regs(info->client, LTC294X_REG_CONTROL, > + &control, 1); > +} > + > #ifdef CONFIG_PM_SLEEP > > static int ltc294x_suspend(struct device *dev) > @@ -589,6 +613,7 @@ static int ltc294x_resume(struct device *dev) > }, > .probe = ltc294x_i2c_probe, > .remove = ltc294x_i2c_remove, > + .shutdown = ltc294x_i2c_shutdown, > .id_table = ltc294x_i2c_id, > }; > module_i2c_driver(ltc294x_driver); > -- > 1.9.1 > [unhandled content-type:application/pgp-signature] | |