On Mon, Jun 20, 2016 at 12:38:58PM +0100, Adam Thomson wrote:
> For device nodes in both DT and ACPI, it possible to have named
> child nodes which contain properties (an existing example being
> gpio-leds). This adds a function to find a named child node for
> a device which can be used by drivers for property retrieval.
>
> For DT data node name matching, of_node_cmp() and similar functions
> are made available outside of CONFIG_OF block so the new function
> can reference these for DT and non-DT builds.
>
> For ACPI data node name matching, a helper function is also added
> which returns false if CONFIG_ACPI is not set, otherwise it
> performs a string comparison on the data node name. This avoids
> using the acpi_data_node struct for non CONFIG_ACPI builds,
> which would otherwise cause a build failure.
>
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
> Tested-by: Sathyanarayana Nujella <sathyanarayana.nujella@xxxxxxxxx>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>
> ---
>
> Changes in v3:
> - Move of_*_cmp() functions in of.h outside of CONFIG_OF block so they are
> available for non-DT builds
> - In device_get_named_child_node(), use of_node_cmp() helper macro instead of
> strcasecmp() (node names not alway case insensitive, depending on platform).
>
> Changes in v2:
> - Rebase to v4.7-rc1
>
> drivers/base/property.c | 28 ++++++++++++++++++++++++++++
> include/acpi/acpi_bus.h | 7 +++++++
> include/linux/acpi.h | 6 ++++++
> include/linux/of.h | 14 +++++++-------
> include/linux/property.h | 3 +++
> 5 files changed, 51 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index f38c21d..43a36d6 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -888,6 +888,34 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev,
> EXPORT_SYMBOL_GPL(device_get_next_child_node);
>
> /**
> + * device_get_named_child_node - Return first matching named child node handle
> + * @dev: Device to find the named child node for.
> + * @childname: String to match child node name against.
> + */
> +struct fwnode_handle *device_get_named_child_node(struct device *dev,
> + const char *childname)
> +{
> + struct fwnode_handle *child;
> +
> + /*
> + * Find first matching named child node of this device.
> + * For ACPI this will be a data only sub-node.
> + */
> + device_for_each_child_node(dev, child) {
> + if (is_of_node(child)) {
> + if (!of_node_cmp(to_of_node(child)->name, childname))
> + return child;
> + } else if (is_acpi_data_node(child)) {
> + if (acpi_data_node_match(child, childname))
> + return child;
> + }
> + }
> +
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(device_get_named_child_node);
> +
> +/**
> * fwnode_handle_put - Drop reference to a device node
> * @fwnode: Pointer to the device node to drop the reference to.
> *
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 788c6c3..993bdd0 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -420,6 +420,13 @@ static inline struct acpi_data_node *to_acpi_data_node(struct fwnode_handle *fwn
> container_of(fwnode, struct acpi_data_node, fwnode) : NULL;
> }
>
> +static inline bool acpi_data_node_match(struct fwnode_handle *fwnode,
> + const char *name)
> +{
> + return is_acpi_data_node(fwnode) ?
> + (!strcasecmp(to_acpi_data_node(fwnode)->name, name)) : false;
> +}
Looks fine to me.
One question - is it expected that matching ACPI data nodes is always
case insensitive?
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