Re: [PATCH v2 2/2] hwmon: (ina2xx) Add device tree support to pass alert polarity

[Amna Waseem]

On 5/29/24 16:11, Guenter Roeck wrote:
> On 5/29/24 02:47, Amna Waseem wrote:
> > The INA230 has an Alert pin which is asserted when the alert
> > function selected in the Mask/Enable register exceeds the
> > value programmed into the Alert Limit register. Assertion is based
> > on the Alert Polarity Bit (APOL, bit 1 of the Mask/Enable register).
> > It is default set to value 0 i.e Normal (active-low open collector).
> > However, hardware can be designed in such a way that expects Alert pin
> > to become active high if a user-defined threshold in Alert limit
> > register has been exceeded. This patch adds a way to pass alert polarity
> > value to the driver via device tree.
> >
> > Signed-off-by: Amna Waseem <Amna.Waseem@xxxxxxxx>
>
> Please address my earlier comments, and in the future please wait a 
> few minutes
> before sending another version to give people time to provide feedback
> on the earlier version(s).
Ok.
> > ---
> >   drivers/hwmon/ina2xx.c | 27 +++++++++++++++++++++++++++
> >   1 file changed, 27 insertions(+)
> >
> > diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
> > index d8415d1f21fc..9afaabdc367d 100644
> > --- a/drivers/hwmon/ina2xx.c
> > +++ b/drivers/hwmon/ina2xx.c
> > @@ -73,6 +73,9 @@
> >   #define INA226_READ_AVG(reg)        (((reg) & INA226_AVG_RD_MASK) 
> > >> 9)
> >   #define INA226_SHIFT_AVG(val)        ((val) << 9)
> >   +#define INA226_ALERT_POLARITY_MASK        0x0002
> > +#define INA226_SHIFT_ALERT_POLARITY(val)    ((val) << 1)
> > +
> >   /* bit number of alert functions in Mask/Enable Register */
> >   #define INA226_SHUNT_OVER_VOLTAGE_BIT    15
> >   #define INA226_SHUNT_UNDER_VOLTAGE_BIT    14
> > @@ -178,6 +181,21 @@ static u16 ina226_interval_to_reg(int interval)
> >       return INA226_SHIFT_AVG(avg_bits);
> >   }
> >   +static int ina2xx_set_alert_polarity(struct ina2xx_data *data,
> > +                     unsigned long val)
> > +{
> > +    int ret;
> > +
> > +    if (val > INT_MAX || !(val == 0 || val == 1))
> > +        return -EINVAL;
> > +
> > +    ret = regmap_update_bits(data->regmap, INA226_MASK_ENABLE,
> > +                 INA226_ALERT_POLARITY_MASK,
> > +                 INA226_SHIFT_ALERT_POLARITY(val));
> > +
> > +    return ret;
>
> ret is an unnecessary variable.
>     return regmap_update_bits(...);
Agreed. Will do it in next patch
> > +}
> > +
> >   /*
> >    * Calibration register is set to the best value, which eliminates
> >    * truncation errors on calculating current register in hardware.
> > @@ -659,6 +677,15 @@ static int ina2xx_probe(struct i2c_client *client)
> >       if (ret)
> >           return dev_err_probe(dev, ret, "failed to enable vs 
> > regulator\n");
> >   +    if (!of_property_read_u32(dev->of_node, "ti,alert-polarity", 
> > &val)) {
> > +        ret = ina2xx_set_alert_polarity(data, val);
> > +        if (ret < 0) {
> > +            return dev_err_probe(
> > +               dev, ret,
> > +               "failed to set APOL bit of Enable/Mask register\n");
>
> Line split is still as bad as before.
>
> Guenter
I have tried to apply clang-format and it still shows the line split as 
follows:

    if (!of_property_read_u32(dev->of_node, "ti,alert-polarity", &val)) {
        ret = ina2xx_set_alert_polarity(data, val);
        if (ret < 0) {
            return dev_err_probe(
                dev, ret,
                "failed to set APOL bit of Enable/Mask register\n");
        }
    }

What format will you suggest for line split? Is there any reference you 
can provide for splitting up the lines in Linux kernel drivers' code?

Amna