Re: [PATCH 13/13] ALSA: hda/cs35l56: Add driver for Cirrus Logic CS35L56 amplifier

[Richard Fitzgerald]

On 26/5/23 05:40, Claudiu.Beznea@xxxxxxxxxxxxx wrote:
> On 25.05.2023 18:06, Richard Fitzgerald wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >
> > From: Simon Trimmer <simont@xxxxxxxxxxxxxxxxxxxxx>
> >
> > Add a driver for the Cirrus Logic CS35L56 amplifier. This uses the same
> > component binding API as the CS35L41 driver. This is not a standalone
> > HDA device; it provides control of the CS35L56 for systems that use a
> > combination of an HDA codec and CS35L56 amplifiers with audio routed
> > through the HDA codec.

<SNIP>

> > +
> > +       cs35l56->base.reset_gpio = devm_gpiod_get_index_optional(cs35l56->base.dev,
> > +                                                                "reset",
> > +                                                                cs35l56->index,
> > +                                                                GPIOD_OUT_LOW);
> > +       if (IS_ERR(cs35l56->base.reset_gpio)) {
>
> devm_gpiod_get_index_optional() can also return NULL.

Yes, that is expected. It's optional. It's not an error.
In that case cs35l56->base.reset_gpio will already be NULL.

> > +               ret = PTR_ERR(cs35l56->base.reset_gpio);
> > +
> > +               /*
> > +                * If RESET is shared the first amp to probe will grab the reset
> > +                * line and reset all the amps
> > +                */
> > +               if (ret != -EBUSY)
> > +                       return dev_err_probe(cs35l56->base.dev, ret, "Failed to get reset GPIO\n");
> > +
> > +               dev_info(cs35l56->base.dev, "Reset GPIO busy, assume shared reset\n");
> > +               cs35l56->base.reset_gpio = NULL;
> > +       }
> > +
> > +       return 0;
> > +
> > +err:
> > +       dev_err(cs35l56->base.dev, "Failed property %s: %d\n", property, ret);
> > +
> > +       return ret;
> > +}