| Message ID | 20180907193508.24974-5-sam@ravnborg.org |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v1,1/5] dt-binding: rtci-pcf8523: add quartz_load property | expand |
On 07/09/2018 21:35:07+0200, Sam Ravnborg wrote: > From: Søren Andersen <san@skov.dk> > > Add support for specifying the quartz load in the DT node. > The pcf8523 may use either a 7 pF or an 12.5 pF xtal. > If the rtc has the wrong configuration the time will > drift several hours/week. > > If nothing is specified in DT then the factory default of 7 pF is used. > This is a change compared to before where the driver assumed 12.5 pF. > > Note: all kernel dts trees are updated with the new property. > > Signed-off-by: Søren Andersen <san@skov.dk> > Signed-off-by: Sam Ravnborg <sam@ravnborg.org> > Cc: Alessandro Zummo <a.zummo@towertech.it> > Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > drivers/rtc/rtc-pcf8523.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c > index 453615f8ac9a..3c19b4d21a2d 100644 > --- a/drivers/rtc/rtc-pcf8523.c > +++ b/drivers/rtc/rtc-pcf8523.c > @@ -85,7 +85,7 @@ static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value) > return 0; > } > > -static int pcf8523_select_capacitance(struct i2c_client *client, bool high) > +static int pcf8523_select_capacitance(struct i2c_client *client) > { > u8 value; > int err; > @@ -94,7 +94,7 @@ static int pcf8523_select_capacitance(struct i2c_client *client, bool high) > if (err < 0) > return err; > > - if (!high) > + if (!device_property_present(&client->dev, "nxp,quartz_load_12.5pf")) OK, this is super annoying we unfortunately can't change what was done previously without breaking the DT ABI. Honestly, I suspect the 12.5pF value is wrong for most boards anyway. What I would do is use the value from DT (so either 7000fF or 12500fF) and set it if present. If not present, set 12.5pF and print a warning that this differs from the RTC default. Hopefully, at some point, we could leave it as it is as the value should persist across reboot.
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c index 453615f8ac9a..3c19b4d21a2d 100644 --- a/drivers/rtc/rtc-pcf8523.c +++ b/drivers/rtc/rtc-pcf8523.c @@ -85,7 +85,7 @@ static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value) return 0; } -static int pcf8523_select_capacitance(struct i2c_client *client, bool high) +static int pcf8523_select_capacitance(struct i2c_client *client) { u8 value; int err; @@ -94,7 +94,7 @@ static int pcf8523_select_capacitance(struct i2c_client *client, bool high) if (err < 0) return err; - if (!high) + if (!device_property_present(&client->dev, "nxp,quartz_load_12.5pf")) value &= ~REG_CONTROL1_CAP_SEL; else value |= REG_CONTROL1_CAP_SEL; @@ -331,7 +331,7 @@ static int pcf8523_probe(struct i2c_client *client, if (!pcf) return -ENOMEM; - err = pcf8523_select_capacitance(client, true); + err = pcf8523_select_capacitance(client); if (err < 0) return err;