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From:   Rob Herring <robh+dt@kernel.org>
Date:   Wed, 14 Oct 2020 13:39:26 -0500
Message-ID: <CAL_Jsq+qdcHc9H7qUVwLieHrLM8E20HZXa8DkarMiuXfCh8WOQ@mail.gmail.com>
Subject: Re: [PATCH 1/7] of: base: Add of_count_phandle_with_fixed_args()
To:     Richard Fitzgerald <rf@opensource.cirrus.com>
Cc:     Mark Brown <broonie@kernel.org>,
        Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
        - <patches@opensource.cirrus.com>,
        Linux-ALSA <alsa-devel@alsa-project.org>,
        devicetree@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        "moderated list:BROADCOM BCM2835 ARM ARCHITECTURE" 
        <linux-rpi-kernel@lists.infradead.org>
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On Wed, Oct 14, 2020 at 9:54 AM Richard Fitzgerald
<rf@opensource.cirrus.com> wrote:
>
> Add an equivalent of of_count_phandle_with_args() for fixed argument
> sets, to pair with of_parse_phandle_with_fixed_args().
>
> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
> ---
>  drivers/of/base.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h |  9 +++++++++
>  2 files changed, 51 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index ea44fea99813..45d8b0e65345 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1772,6 +1772,48 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
>  }
>  EXPORT_SYMBOL(of_count_phandle_with_args);
>
> +/**
> + * of_count_phandle_with_fixed_args() - Find the number of phandles references in a property
> + * @np:                pointer to a device tree node containing a list
> + * @list_name: property name that contains a list
> + * @cell_count: number of argument cells following the phandle
> + *
> + * Returns the number of phandle + argument tuples within a property. It
> + * is a typical pattern to encode a list of phandle and variable
> + * arguments into a single property.
> + */
> +int of_count_phandle_with_fixed_args(const struct device_node *np,
> +                                    const char *list_name,
> +                                    int cells_count)
> +{

Looks to me like you can refactor of_count_phandle_with_args to handle
both case and then make this and of_count_phandle_with_args simple
wrapper functions.

> +       struct of_phandle_iterator it;
> +       int rc, cur_index = 0;
> +
> +       if (!cells_count) {
> +               const __be32 *list;
> +               int size;
> +
> +               list = of_get_property(np, list_name, &size);
> +               if (!list)
> +                       return -ENOENT;
> +
> +               return size / sizeof(*list);
> +       }
> +
> +       rc = of_phandle_iterator_init(&it, np, list_name, NULL, cells_count);
> +       if (rc)
> +               return rc;
> +
> +       while ((rc = of_phandle_iterator_next(&it)) == 0)
> +               cur_index += 1;
> +
> +       if (rc != -ENOENT)
> +               return rc;
> +
> +       return cur_index;
> +}
> +EXPORT_SYMBOL(of_count_phandle_with_fixed_args);
> +
>  /**
>   * __of_add_property - Add a property to a node without lock operations
>   */
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 5cf7ae0465d1..9f315da4e9da 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -377,6 +377,8 @@ extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
>         struct of_phandle_args *out_args);
>  extern int of_count_phandle_with_args(const struct device_node *np,
>         const char *list_name, const char *cells_name);
> +extern int of_count_phandle_with_fixed_args(const struct device_node *np,
> +       const char *list_name, int cells_count);
>
>  /* phandle iterator functions */
>  extern int of_phandle_iterator_init(struct of_phandle_iterator *it,
> @@ -886,6 +888,13 @@ static inline int of_count_phandle_with_args(struct device_node *np,
>         return -ENOSYS;
>  }
>
> +static inline int of_count_phandle_with_fixed_args(const struct device_node *np,
> +                                                  const char *list_name,
> +                                                  int cells_count)
> +{
> +       return -ENOSYS;
> +}
> +
>  static inline int of_phandle_iterator_init(struct of_phandle_iterator *it,
>                                            const struct device_node *np,
>                                            const char *list_name,
> --
> 2.20.1
>