Re: [PATCH v3 1/2] mfd: rohm-bd71828: Use software nodes for gpio-keys

[Matti Vaittinen]

On 25/03/2026 02:54, Dmitry Torokhov wrote:
> Refactor the rohm-bd71828 MFD driver to use software nodes for
> instantiating the gpio-keys child device, replacing the old
> platform_data mechanism.
>
> The power key's properties are now defined using software nodes and
> property entries. The IRQ is passed as a resource attached to the
> platform device.
>
> This will allow dropping support for using platform data for configuring
> gpio-keys in the future.
>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> ---
>   drivers/mfd/rohm-bd71828.c | 120 +++++++++++++++++++++++++++++++++------------
>   1 file changed, 88 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/mfd/rohm-bd71828.c b/drivers/mfd/rohm-bd71828.c
> index a79f354bf5cb..e78af75a2115 100644
> --- a/drivers/mfd/rohm-bd71828.c
> +++ b/drivers/mfd/rohm-bd71828.c

// snip

> +static int bd71828_i2c_register_pwrbutton(struct device *dev, int button_irq,
> +					  struct irq_domain *irq_domain)
> +{
> +	static const struct property_entry bd71828_powerkey_parent_props[] = {
> +		PROPERTY_ENTRY_STRING("label", "bd71828-pwrkey"),
> +		{ }
> +	};
> +	static const struct property_entry bd71828_powerkey_props[] = {
> +		PROPERTY_ENTRY_U32("linux,code", KEY_POWER),
> +		PROPERTY_ENTRY_BOOL("wakeup-source"),
> +		{ }
> +	};
> +	const struct resource res[] = {
> +		DEFINE_RES_IRQ_NAMED(button_irq, "bd71828-pwrkey"),
> +	};
> +	struct mfd_cell gpio_keys_cell = {
> +		.name = "gpio-keys",
> +		.resources = res,
> +		.num_resources = ARRAY_SIZE(res),
> +	};
> +	const struct software_node * const *node_group;
> +	struct software_node *nodes;
> +	int error;
> +
> +	nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL);
> +	if (!nodes)
> +		return -ENOMEM;
> +
> +	/* Node corresponding to gpio-keys device itself */
> +	nodes[0].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev));
> +	if (!nodes[0].name)
> +		return -ENOMEM;
> +
> +	nodes[0].properties = bd71828_powerkey_parent_props;
> +
> +	/* Node representing power button within gpio-keys device */
> +	nodes[1].parent = &nodes[0];
> +	nodes[1].properties = bd71828_powerkey_props;
> +
> +	node_group = (const struct software_node *[]){
> +		&nodes[0],
> +		&nodes[1],
> +		NULL
> +	};

Here, same as with the 2/2. This construct seems a tad strange to me, 
but I suppose I can live with it if Lee thinks this is the way to go.

Yours,
-- Matti

--
---
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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