Re: [PATCH v2 01/11] of: Add wrappers to match root node with OF device ID tables

[Lukasz Luba <lukasz.luba@arm.com>]

Hi Krzysztof,

On 11/12/25 10:28, Krzysztof Kozlowski wrote:
> Several drivers duplicate same code for getting reference to the root
> node, matching it against 'struct of_device_id' table and getting out
> the match data from the table entry.
> 
> There is a of_machine_compatible_match() wrapper but it takes array of
> strings, which is not suitable for many drivers since they want the
> driver data associated with each compatible.
> 
> Add two wrappers, similar to existing of_device_get_match_data():
> 1. of_machine_device_match() doing only matching against 'struct
>     of_device_id' and returning bool.
> 2. of_machine_get_match_data() doing the matching and returning
>     associated driver data for found compatible.
> 
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---
> 
> All further patches depend on this.
> ---
>   drivers/of/base.c  | 47 +++++++++++++++++++++++++++++++++++++++++++++++
>   include/linux/of.h | 13 +++++++++++++
>   2 files changed, 60 insertions(+)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 7043acd971a0..0b65039ece53 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -434,6 +434,53 @@ bool of_machine_compatible_match(const char *const *compats)
>   }
>   EXPORT_SYMBOL(of_machine_compatible_match);
>   
> +/**
> + * of_machine_device_match - Test root of device tree against a of_device_id array
> + * @matches:	NULL terminated array of of_device_id match structures to search in
> + *
> + * Returns true if the root node has any of the given compatible values in its
> + * compatible property.
> + */
> +bool of_machine_device_match(const struct of_device_id *matches)
> +{
> +	struct device_node *root;
> +	const struct of_device_id *match = NULL;
> +
> +	root = of_find_node_by_path("/");
> +	if (root) {
> +		match = of_match_node(matches, root);
> +		of_node_put(root);
> +	}
> +
> +	return match != NULL;
> +}
> +EXPORT_SYMBOL(of_machine_device_match);
> +
> +/**
> + * of_machine_get_match_data - Tell if root of device tree has a matching of_match structure
> + * @matches:	NULL terminated array of of_device_id match structures to search in
> + *
> + * Returns data associated with matched entry or NULL
> + */
> +const void *of_machine_get_match_data(const struct of_device_id *matches)
> +{
> +	const struct of_device_id *match;
> +	struct device_node *root;
> +
> +	root = of_find_node_by_path("/");
> +	if (!root)
> +		return NULL;
> +
> +	match = of_match_node(matches, root);
> +	of_node_put(root);
> +
> +	if (!match)
> +		return NULL;
> +
> +	return match->data;
> +}
> +EXPORT_SYMBOL(of_machine_get_match_data);
> +
>   static bool __of_device_is_status(const struct device_node *device,
>   				  const char * const*strings)
>   {
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 121a288ca92d..01bb3affcd49 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -407,6 +407,8 @@ extern int of_alias_get_id(const struct device_node *np, const char *stem);
>   extern int of_alias_get_highest_id(const char *stem);
>   
>   bool of_machine_compatible_match(const char *const *compats);
> +bool of_machine_device_match(const struct of_device_id *matches);
> +const void *of_machine_get_match_data(const struct of_device_id *matches);
>   
>   /**
>    * of_machine_is_compatible - Test root of device tree for a given compatible value
> @@ -855,6 +857,17 @@ static inline bool of_machine_compatible_match(const char *const *compats)
>   	return false;
>   }
>   
> +static inline bool of_machine_device_match(const struct of_device_id *matches)
> +{
> +	return false;
> +}
> +
> +static inline const void *
> +of_machine_get_match_data(const struct of_device_id *matches)
> +{
> +	return NULL;
> +}
> +
>   static inline bool of_console_check(const struct device_node *dn, const char *name, int index)
>   {
>   	return false;
> 

Makes sense based on the clean-up in dtpm.c (since I've been there
I looked here as well).

LGTM

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

Regards,
Lukasz