Re: [PATCH v2 2/6] device property: Add fwnode_get_name for returning the name of a node

[Rafael J. Wysocki]

On Tue, Mar 26, 2019 at 1:41 PM Sakari Ailus
<sakari.ailus@xxxxxxxxxxxxxxx> wrote:
>
> The fwnode framework did not have means to obtain the name of a node. Add
> that now, in form of the fwnode_get_name() function and a corresponding
> get_name fwnode op. OF and ACPI support is included.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
>  drivers/acpi/property.c  | 24 ++++++++++++++++++++++++
>  drivers/base/property.c  | 11 +++++++++++
>  drivers/of/property.c    |  6 ++++++
>  include/linux/fwnode.h   |  2 ++
>  include/linux/property.h |  1 +
>  5 files changed, 44 insertions(+)
>
> diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
> index 77abe0ec4043..8c9a4c02cde2 100644
> --- a/drivers/acpi/property.c
> +++ b/drivers/acpi/property.c
> @@ -1291,6 +1291,29 @@ acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
>                                                   args_count, args);
>  }
>
> +static const char *acpi_fwnode_get_name(const struct fwnode_handle *fwnode)
> +{
> +       const struct acpi_device *adev;
> +       struct fwnode_handle *parent;
> +
> +       parent = fwnode_get_parent(fwnode);
> +       /* Is this the root node? */
> +       if (!parent)
> +               return "\\";
> +
> +       fwnode_handle_put(parent);
> +
> +       if (is_acpi_data_node(fwnode)) {
> +               const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
> +
> +               return dn->name;
> +       }
> +
> +       adev = to_acpi_device_node(fwnode);
> +
> +       return adev ? acpi_device_bid(adev) : NULL;

I would do

if (WARN_ON(!adev))
         return NULL;

return acpi_device_bid(adev);

> +}
> +
>  static struct fwnode_handle *
>  acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
>  {
> @@ -1331,6 +1354,7 @@ acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
>                 .get_parent = acpi_node_get_parent,                     \
>                 .get_next_child_node = acpi_get_next_subnode,           \
>                 .get_named_child_node = acpi_fwnode_get_named_child_node, \
> +               .get_name = acpi_fwnode_get_name,                       \
>                 .get_reference_args = acpi_fwnode_get_reference_args,   \
>                 .graph_get_next_endpoint =                              \
>                         acpi_graph_get_next_endpoint,                   \
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 61eb6ceacc3f..04a8591cd1b0 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -533,6 +533,17 @@ int device_add_properties(struct device *dev,
>  EXPORT_SYMBOL_GPL(device_add_properties);
>
>  /**
> + * fwnode_get_name - Return the name of a node
> + * @fwnode: The firmware node
> + *
> + * Returns a pointer to the node name.
> + */
> +const char *fwnode_get_name(const struct fwnode_handle *fwnode)
> +{
> +       return fwnode_call_ptr_op(fwnode, get_name);
> +}
> +
> +/**
>   * fwnode_get_parent - Return parent firwmare node
>   * @fwnode: Firmware whose parent is retrieved
>   *
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index 8631efa1daa1..f0a7b78f2d9f 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -872,6 +872,11 @@ of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
>                 of_property_count_strings(node, propname);
>  }
>
> +static const char *of_fwnode_get_name(const struct fwnode_handle *fwnode)
> +{
> +       return kbasename(to_of_node(fwnode)->full_name);
> +}
> +
>  static struct fwnode_handle *
>  of_fwnode_get_parent(const struct fwnode_handle *fwnode)
>  {
> @@ -993,6 +998,7 @@ const struct fwnode_operations of_fwnode_ops = {
>         .property_present = of_fwnode_property_present,
>         .property_read_int_array = of_fwnode_property_read_int_array,
>         .property_read_string_array = of_fwnode_property_read_string_array,
> +       .get_name = of_fwnode_get_name,
>         .get_parent = of_fwnode_get_parent,
>         .get_next_child_node = of_fwnode_get_next_child_node,
>         .get_named_child_node = of_fwnode_get_named_child_node,
> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> index faebf0ca0686..85b7fa4dc727 100644
> --- a/include/linux/fwnode.h
> +++ b/include/linux/fwnode.h
> @@ -59,6 +59,7 @@ struct fwnode_reference_args {
>   *                              otherwise.
>   * @property_read_string_array: Read an array of string properties. Return zero
>   *                             on success, a negative error code otherwise.
> + * @get_name: Return the name of an fwnode.
>   * @get_parent: Return the parent of an fwnode.
>   * @get_next_child_node: Return the next child node in an iteration.
>   * @get_named_child_node: Return a child node with a given name.
> @@ -85,6 +86,7 @@ struct fwnode_operations {
>         (*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
>                                       const char *propname, const char **val,
>                                       size_t nval);
> +       const char *(*get_name)(const struct fwnode_handle *fwnode);
>         struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
>         struct fwnode_handle *
>         (*get_next_child_node)(const struct fwnode_handle *fwnode,
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 1164ac974ee8..2f5df900e310 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -78,6 +78,7 @@ int fwnode_property_get_reference_args(const struct fwnode_handle *fwnode,
>                                        unsigned int nargs, unsigned int index,
>                                        struct fwnode_reference_args *args);
>
> +const char *fwnode_get_name(const struct fwnode_handle *fwnode);
>  struct fwnode_handle *fwnode_get_parent(const struct fwnode_handle *fwnode);
>  struct fwnode_handle *fwnode_get_next_parent(
>         struct fwnode_handle *fwnode);
> --