[PATCH 23/34] iio: inkern: split of_iio_channel_get_by_name()

[Andy Shevchenko]

On Fri, Jun 10, 2022 at 10:48 AM Nuno Sá <nuno.sa at analog.com> wrote:
>
> This change splits of_iio_channel_get_by_name() so that it decouples
> looking for channels in the current node from looking in it's parents
> nodes. This will be helpful when moving to fwnode properties where we
> need to release the handles when looking for channels in parent's nodes.
>
> No functional change intended...

Reviewed-by: Andy Shevchenko <andy.shevchenko at gmail.com>

> Signed-off-by: Nuno Sá <nuno.sa at analog.com>
> ---
>  drivers/iio/inkern.c | 69 ++++++++++++++++++++++++++++----------------
>  1 file changed, 44 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index 31d9c122199a..dde47324b826 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -211,44 +211,63 @@ static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
>         return ERR_PTR(err);
>  }
>
> +struct iio_channel *__of_iio_channel_get_by_name(struct device_node *np,
> +                                                const char *name,
> +                                                bool *parent_lookup)
> +{
> +       struct iio_channel *chan;
> +       int index = 0;
> +
> +       /*
> +        * For named iio channels, first look up the name in the
> +        * "io-channel-names" property.  If it cannot be found, the
> +        * index will be an error code, and of_iio_channel_get()
> +        * will fail.
> +        */
> +       if (name)
> +               index = of_property_match_string(np, "io-channel-names", name);
> +
> +       chan = of_iio_channel_get(np, index);
> +       if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) {
> +               *parent_lookup = false;
> +       } else if (name && index >= 0) {
> +               pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
> +                      np, name ? name : "", index);
> +               *parent_lookup = false;
> +       }
> +
> +       return chan;
> +}
> +
>  struct iio_channel *of_iio_channel_get_by_name(struct device_node *np,
>                                                const char *name)
>  {
>         struct iio_channel *chan;
> +       bool parent_lookup = true;
>
>         /* Walk up the tree of devices looking for a matching iio channel */
> +       chan = __of_iio_channel_get_by_name(np, name, &parent_lookup);
> +       if (!parent_lookup)
> +               return chan;
> +
> +       /*
> +        * No matching IIO channel found on this node.
> +        * If the parent node has a "io-channel-ranges" property,
> +        * then we can try one of its channels.
> +        */
> +       np = np->parent;
>         while (np) {
> -               int index = 0;
> -
> -               /*
> -                * For named iio channels, first look up the name in the
> -                * "io-channel-names" property.  If it cannot be found, the
> -                * index will be an error code, and of_iio_channel_get()
> -                * will fail.
> -                */
> -               if (name)
> -                       index = of_property_match_string(np, "io-channel-names",
> -                                                        name);
> -               chan = of_iio_channel_get(np, index);
> -               if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
> +               if (!of_get_property(np, "io-channel-ranges", NULL))
>                         return chan;
> -               if (name && index >= 0) {
> -                       pr_err("ERROR: could not get IIO channel %pOF:%s(%i)\n",
> -                               np, name ? name : "", index);
> +
> +               chan = __of_iio_channel_get_by_name(np, name, &parent_lookup);
> +               if (!parent_lookup)
>                         return chan;
> -               }
>
> -               /*
> -                * No matching IIO channel found on this node.
> -                * If the parent node has a "io-channel-ranges" property,
> -                * then we can try one of its channels.
> -                */
>                 np = np->parent;
> -               if (np && !of_get_property(np, "io-channel-ranges", NULL))
> -                       return chan;
>         }
>
> -       return ERR_PTR(-ENODEV);
> +       return chan;
>  }
>  EXPORT_SYMBOL_GPL(of_iio_channel_get_by_name);
>
> --
> 2.36.1
>


-- 
With Best Regards,
Andy Shevchenko