Re: [PATCH v4 02/10] property: Add device_get_child_node_count_named()

Matti Vaittinen
2025-02-25T10:29:36Z

On 25/02/2025 12:21, Andy Shevchenko wrote:
> On Tue, Feb 25, 2025 at 11:40:16AM +0200, Heikki Krogerus wrote:
>>> +/**
>>> + * device_get_child_node_count_named - number of child nodes with given name
>>> + *
>>> + * Scan device's child nodes and find all the nodes with a specific name and
>>> + * return the number of found nodes. Potential '@number' -ending for scanned
>>> + * names is ignored. Eg,
>>> + * device_get_child_node_count(dev, "channel");
>>> + * would match all the nodes:
>>> + * channel { }, channel@0 {}, channel@0xabba {}...
>>> + *
>>> + * @dev: Device to count the child nodes for
>
> This has an inconsistent kernel doc structure in comparison to the rest in this
> file.
>
>>> + * Return: the number of child nodes with a matching name for a given device.
>>> + */
>>> +unsigned int device_get_child_node_count_named(const struct device *dev,
>>> + const char *name)
>>> +{
>>> + struct fwnode_handle *child;
>>> + unsigned int count = 0;
>>> +
>>> + device_for_each_child_node(dev, child)
>>> + if (fwnode_name_eq(child, "channel"))
>>
>> s/"channel"/name/ ?
>>
>>> + count++;
>>> +
>>> + return count;
>>> +}
>>> +EXPORT_SYMBOL_GPL(device_get_child_node_count_named);
>>
>> I did not check how many users are you proposing for this, but if
>> there's only one, then IMO this should not be a global function yet.
>> It just feels to special case to me. But let's see what the others
>> think.
>
> The problem is that if somebody hides it, we might potentially see
> a duplication in the future. So I _slightly_ prefer to publish and
> then drop that after a few cycles if no users appear.

After taking a very quick grep I spotted one other existing place where
we might be able to do direct conversion to use this function.

drivers/net/ethernet/freescale/gianfar.c

That'd be 2 users.

While I looked at it, it seems that a
'device_for_each_named_child_node()' -construct would have a few users.

Yours,
-- Matti