Re: [PATCH V10 4/9] mfd: pm8008: Add reset-gpios

[Satya Priya Kakitapalli (Temp)]

On 4/27/2022 10:58 AM, Satya Priya Kakitapalli (Temp) wrote:
> On 4/18/2022 10:34 AM, Satya Priya Kakitapalli (Temp) wrote:
> > On 4/15/2022 5:40 AM, Stephen Boyd wrote:
> > > Quoting Satya Priya (2022-04-14 05:30:13)
> > > > diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c
> > > > index c472d7f..97a72da 100644
> > > > --- a/drivers/mfd/qcom-pm8008.c
> > > > +++ b/drivers/mfd/qcom-pm8008.c
> > > > @@ -239,6 +241,13 @@ static int pm8008_probe(struct i2c_client 
> > > > *client)
> > > >                          dev_err(chip->dev, "Failed to probe irq 
> > > > periphs: %d\n", rc);
> > > >          }
> > > >
> > > > +       chip->reset_gpio = devm_gpiod_get(chip->dev, "reset", 
> > > > GPIOD_OUT_HIGH);
> > > > +       if (IS_ERR(chip->reset_gpio)) {
> > > > +               dev_err(chip->dev, "failed to acquire reset gpio\n");
> > > The API looks to print debug messages. This print doesn't look 
> > > required.
> >
> >
> > Okay.
> >
> >
> > > > +               return PTR_ERR(chip->reset_gpio);
> > > > +       }
> > > > +       gpiod_set_value(chip->reset_gpio, 1);
> > > Does this do anything? Does this work just as well?
> > >
> > >     reset_gpio = devm_gpiod_get(chip->dev, "reset", GPIOD_OUT_LOW);
> > >     if (IS_ERR(reset_gpio))
> > >         return PTR_ERR(reset_gpio);
>
> This is not working as expected. We need to add 
> "gpiod_set_value(chip->reset_gpio, 1);"  to actually toggle the line.

I checked again and it is working after using GPIOD_OUT_HIGH instead of LOW.

reset_gpio = devm_gpiod_get(chip->dev, "reset", GPIOD_OUT_HIGH);
    if (IS_ERR(reset_gpio))
        return PTR_ERR(reset_gpio);


> > > Note that there's no point to store the reset gpio in the structure if
> > > it won't be used outside of probe.
> >
> >
> > Okay, I'll use a local variable.
> >
> >
> > > This should work fine? I used
> > > GPIOD_OUT_LOW to indicate that the reset should be returned to this
> > > function deasserted, i.e. taking the PMIC out of reset.
> >
> >
> > I'll try this out.