[v3,1/1] device property: Add fwnode_name_eq()

Add fwnode_name_eq() to implement the functionality of of_node_name_eq()
on fwnode property API. The same convention of ending the comparison at
'@' (besides NUL) is applied on also both ACPI and swnode. The function
is intended for comparing unit address-less node names on DT and firmware
or swnodes compliant with DT bindings.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Hi Rafael,

Could we merge this via the media tree (pending further review comments,
if any)? There'a a patch to be merged via that tree which will depend on
fwnode_name_eq(), namely:
<URL:https://lore.kernel.org/linux-media/20231030133247.11243-1-laurent.pinchart@ideasonboard.com/T/#m489b7e83cbc755815c5002f85454a76bfb41adb2>.

since v2:

- Use NUL instead of '\0' and "at" instead of "to" (before "stopping
  comparison").

 drivers/base/property.c  | 28 ++++++++++++++++++++++++++++
 include/linux/property.h |  1 +
 2 files changed, 29 insertions(+)

On Thu, Nov 2, 2023 at 9:22 AM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Add fwnode_name_eq() to implement the functionality of of_node_name_eq()
> on fwnode property API. The same convention of ending the comparison at
> '@' (besides NUL) is applied on also both ACPI and swnode. The function
> is intended for comparing unit address-less node names on DT and firmware
> or swnodes compliant with DT bindings.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> Hi Rafael,
>
> Could we merge this via the media tree (pending further review comments,
> if any)?

This would be fine with me, so please feel free to add

Acked-by: Rafael J. Wysocki <rafael@kernel.org>

to this patch (when ready), but you need to ask Greg about it, because
he's been handling device properties changes lately.

> There'a a patch to be merged via that tree which will depend on
> fwnode_name_eq(), namely:
> <URL:https://lore.kernel.org/linux-media/20231030133247.11243-1-laurent.pinchart@ideasonboard.com/T/#m489b7e83cbc755815c5002f85454a76bfb41adb2>.
>
> since v2:
>
> - Use NUL instead of '\0' and "at" instead of "to" (before "stopping
>   comparison").
>
>  drivers/base/property.c  | 28 ++++++++++++++++++++++++++++
>  include/linux/property.h |  1 +
>  2 files changed, 29 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 8667b13639d2..572e065e8797 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -595,6 +595,34 @@ const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
>         return fwnode_call_ptr_op(fwnode, get_name_prefix);
>  }
>
> +/**
> + * fwnode_name_eq - Return true if node name is equal
> + * @fwnode: The firmware node
> + * @name: The name to which to compare the node name
> + *
> + * Compare the name provided as an argument to the name of the node, stopping
> + * the comparison at either NUL or '@' character, whichever comes first. This
> + * function is generally used for comparing node names while ignoring the
> + * possible unit address of the node.
> + *
> + * Return: true if the node name matches with the name provided in the @name
> + * argument, false otherwise.
> + */
> +bool fwnode_name_eq(const struct fwnode_handle *fwnode, const char *name)
> +{
> +       const char *node_name;
> +       size_t len;
> +
> +       node_name = fwnode_get_name(fwnode);
> +       if (!node_name)
> +               return false;
> +
> +       len = strchrnul(node_name, '@') - node_name;
> +
> +       return str_has_prefix(node_name, name) == len;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_name_eq);
> +
>  /**
>   * fwnode_get_parent - Return parent firwmare node
>   * @fwnode: Firmware whose parent is retrieved
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 083a1f41364b..096ade186601 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -108,6 +108,7 @@ struct fwnode_handle *fwnode_find_reference(const struct fwnode_handle *fwnode,
>
>  const char *fwnode_get_name(const struct fwnode_handle *fwnode);
>  const char *fwnode_get_name_prefix(const struct fwnode_handle *fwnode);
> +bool fwnode_name_eq(const struct fwnode_handle *fwnode, const char *name);
>
>  struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
>  struct fwnode_handle *fwnode_get_next_parent(struct fwnode_handle *fwnode);
> --
> 2.39.2
>