Re: [PATCH v6 02/14] of: property: Add fw_devlink support for msi-parent

[Rob Herring <robh@kernel.org>]

On Wed, Jul 19, 2023 at 05:05:30PM +0530, Anup Patel wrote:
> This allows fw_devlink to create device links between consumers of
> a MSI and the supplier of the MSI.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/of/property.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index ddc75cd50825..e4096b79a872 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1325,6 +1325,37 @@ static struct device_node *parse_interrupts(struct device_node *np,
>  	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
>  }
>  
> +static struct device_node *parse_msi_parent(struct device_node *np,
> +					    const char *prop_name, int index)
> +{
> +	struct of_phandle_args sup_args;
> +	struct device_node *msi_np;
> +
> +	if (!IS_ENABLED(CONFIG_OF_IRQ))
> +		return NULL;

Why do we need this? Sparc is not going to have MSI properties to begin 
with. I guess it saves a little bit of code. Though Sparc doesn't need 
any of this file. Or maybe there's a better kconfig symbol to use here 
if MSIs are not supported?

> +
> +	if (strcmp(prop_name, "msi-parent"))
> +		return NULL;
> +
> +	msi_np = of_parse_phandle(np, prop_name, 0);
> +	if (msi_np) {
> +		if (!of_property_read_bool(msi_np, "#msi-cells")) {
> +			if (index) {
> +				of_node_put(msi_np);
> +				return NULL;
> +			}
> +			return msi_np;
> +		}
> +		of_node_put(msi_np);
> +	}
> +
> +	if (of_parse_phandle_with_args(np, prop_name, "#msi-cells", index,
> +				       &sup_args))
> +		return NULL;
> +
> +	return sup_args.np;
> +}
> +
>  static const struct supplier_bindings of_supplier_bindings[] = {
>  	{ .parse_prop = parse_clocks, },
>  	{ .parse_prop = parse_interconnects, },
> @@ -1359,6 +1390,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
>  	{ .parse_prop = parse_regulators, },
>  	{ .parse_prop = parse_gpio, },
>  	{ .parse_prop = parse_gpios, },
> +	{ .parse_prop = parse_msi_parent, },
>  	{}
>  };
>  
> -- 
> 2.34.1
>