On 06/26/16 15:47, Benjamin Herrenschmidt wrote:
> This provides an equivalent of of_fdt_match() for non-flat trees.
>
> This is more practical than matching an array of of_device_id structs
> when converting a bunch of existing users of of_fdt_match().
>
> Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> ---
>
> This is a pre-requisite for some work I'm doing to move the platform
> identification in arch/powerpc until after we have unflattened the
> device-tree. Rewriting all those lists as of_device_id's would be
> significantly cumbersome.
>
> Note: untested other than it compiles. I want an agreement on the
> interface ASAP since the conversion of all the platforms is a burden
> I'd like to avoid doing twice.
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index ebf84e3..429c594 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -493,6 +493,28 @@ int of_device_is_compatible(const struct device_node *device,
> }
> EXPORT_SYMBOL(of_device_is_compatible);
>
> +/** Checks if the device is compatible with any of the entries in
> + * a NULL terminated array of strings. Returns the best match
> + * score or 0.
> + */
> +int of_device_compatible_match(struct device_node *device,
> + const char *const *compat)
> +{
> + unsigned int tmp, score = 0;
> +
> + if (!compat)
> + return 0;
> +
> + while (*compat) {
> + tmp = of_device_is_compatible(device, *compat);
> + if (tmp && (score == 0 || (tmp < score)))
> + score = tmp;
> + compat++;
> + }
> +
> + return score;
> +}
> +
of_device_is_compatible() returns a higher value for a better match.
of_fdt_match() returns a lower value for a better match.
So checking for (tmp < score) will give you the opposite of what you want.
And if you are replacing of_fdt_match() with of_device_compatible_match(),
the caller will have the expectation that a smaller score is a better
match.
> /**
> * of_machine_is_compatible - Test root of device tree for a given compatible value
> * @compat: compatible string to look for in root node's compatible property.
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 74eb28c..33c184d 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -324,6 +324,8 @@ extern int of_property_read_string_helper(const struct device_node *np,
> const char **out_strs, size_t sz, int index);
> extern int of_device_is_compatible(const struct device_node *device,
> const char *);
> +extern int of_device_compatible_match(struct device_node *device,
> + const char *const *compat);
> extern bool of_device_is_available(const struct device_node *device);
> extern bool of_device_is_big_endian(const struct device_node *device);
> extern const void *of_get_property(const struct device_node *node,
>
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