Re: [PATCH v3 2/5] spi: add devm_spi_new_ancillary_device()

[Nuno Sá]

On Fri, 2026-02-13 at 16:47 +0200, Antoniu Miclaus wrote:
> Add a devres-managed version of spi_new_ancillary_device() that
> automatically unregisters the ancillary SPI device when the parent
> device is removed.
> 
> This follows the same devm_add_action_or_reset() pattern used by the
> other managed SPI functions (devm_spi_optimize_message,
> devm_spi_register_controller, etc.) and eliminates the need for drivers
> to open-code their own devm cleanup callbacks for ancillary devices.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> ---

Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>

> Changes in v3:
>   - New patch
> 
>  drivers/spi/spi.c       | 40 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/spi/spi.h |  1 +
>  2 files changed, 41 insertions(+)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 693bdcc5a12a..1b48ec67b8e0 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -2612,6 +2612,46 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
>  }
>  EXPORT_SYMBOL_GPL(spi_new_ancillary_device);
>  
> +static void devm_spi_unregister_device(void *spi)
> +{
> +	spi_unregister_device(spi);
> +}
> +
> +/**
> + * devm_spi_new_ancillary_device() - Register managed ancillary SPI device
> + * @spi:         Pointer to the main SPI device registering the ancillary device
> + * @chip_select: Chip Select of the ancillary device
> + *
> + * Register an ancillary SPI device; for example some chips have a chip-select
> + * for normal device usage and another one for setup/firmware upload.
> + *
> + * This is the managed version of spi_new_ancillary_device(). The ancillary
> + * device will be unregistered automatically when the parent SPI device is
> + * unregistered.
> + *
> + * This may only be called from main SPI device's probe routine.
> + *
> + * Return: Pointer to new ancillary device on success; ERR_PTR on failure
> + */
> +struct spi_device *devm_spi_new_ancillary_device(struct spi_device *spi,
> +						 u8 chip_select)
> +{
> +	struct spi_device *ancillary;
> +	int ret;
> +
> +	ancillary = spi_new_ancillary_device(spi, chip_select);
> +	if (IS_ERR(ancillary))
> +		return ancillary;
> +
> +	ret = devm_add_action_or_reset(&spi->dev, devm_spi_unregister_device,
> +				       ancillary);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	return ancillary;
> +}
> +EXPORT_SYMBOL_GPL(devm_spi_new_ancillary_device);
> +
>  #ifdef CONFIG_ACPI
>  struct acpi_spi_lookup {
>  	struct spi_controller 	*ctlr;
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index cb2c2df31089..9aef1987b12f 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -374,6 +374,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
>  }
>  
>  extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);
> +extern struct spi_device *devm_spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);
>  
>  /* Use a define to avoid include chaining to get THIS_MODULE */
>  #define spi_register_driver(driver) \