Re: [PATCH 4/6] of/irq: Introduce of_irq_foreach_imap

[Rob Herring]

On Fri, Jul 25, 2025 at 05:26:13PM +0200, Herve Codina wrote:
> of_irq_foreach_imap is an iterator designed to help a driver to parse
> an interrupt-map property.
> 
> Indeed some drivers need to know details about the interrupt mapping
> described in the device-tree in order to set internal registers
> accordingly.

I would like to see some existing user converted to make sure it works 
for other cases.

> 
> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
> ---
>  drivers/of/irq.c       | 70 ++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of_irq.h | 11 +++++++
>  2 files changed, 81 insertions(+)
> 
> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> index f8ad79b9b1c9..863b31eb3c1a 100644
> --- a/drivers/of/irq.c
> +++ b/drivers/of/irq.c
> @@ -157,6 +157,76 @@ const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_ph
>  	return imap;
>  }
>  
> +/**
> + * of_irq_foreach_imap - Iterate through interrupt-map items
> + * @np: device node where interrupt-map is available
> + * @func: function called on each interrupt-map items
> + * @data: data passe to @func
> + *
> + * This function iterates through interrupt-map items and calls @func on each
> + * item. The parent interrupt described in the interrupt-map item is parsed
> + * and passed to @func using a pointer to a struct of_phandle_args.
> + * Also the imap raw value is passed in order to allow @func to look at other
> + * values of the interrupt-map (child unit address and child interrupt
> + * specificer)
> + *
> + * If @func returns an error, the iteration stops and this error is returned.
> + */
> +int of_irq_foreach_imap(struct device_node *np,
> +			int (*func)(void *data,
> +				    const __be32 *imap,
> +				    const struct of_phandle_args *parent_args),
> +			void *data)

The func callback is a departure from other DT iterators. Look at the 
'ranges' iterator which keeps the state on each iteration.

Rob