Re: [PATCH v10 1/3] spi: export of_find_spi_controller_by_node()

[Rob Herring <robh@kernel.org>]

On Tue, Dec 16, 2025 at 03:18:51PM +0800, Oder Chiou wrote:
> Some devices are primarily described on another bus (e.g. I2C) but also
> have an additional SPI connection that serves as a transport for
> firmware loading. Export of_find_spi_controller_by_node() so drivers can
> obtain the SPI controller referenced by a DT phandle.
> 
> Signed-off-by: Oder Chiou <oder_chiou@realtek.com>
> ---
>  drivers/spi/spi.c       |  3 ++-
>  include/linux/spi/spi.h | 11 +++++++++++
>  2 files changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index e25df9990f82..ecb5281b04a2 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -4771,7 +4771,7 @@ static struct spi_device *of_find_spi_device_by_node(struct device_node *node)
>  }
>  
>  /* The spi controllers are not using spi_bus, so we find it with another way */
> -static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
> +struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
>  {
>  	struct device *dev;
>  
> @@ -4784,6 +4784,7 @@ static struct spi_controller *of_find_spi_controller_by_node(struct device_node
>  	/* Reference got in class_find_device */
>  	return container_of(dev, struct spi_controller, dev);
>  }
> +EXPORT_SYMBOL_GPL(of_find_spi_controller_by_node);
>  
>  static int of_spi_notify(struct notifier_block *nb, unsigned long action,
>  			 void *arg)
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index cb2c2df31089..1eb04a96cc1c 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -882,6 +882,17 @@ extern int devm_spi_register_controller(struct device *dev,
>  					struct spi_controller *ctlr);
>  extern void spi_unregister_controller(struct spi_controller *ctlr);
>  
> +#if IS_ENABLED(CONFIG_OF_DYNAMIC)

This has nothing to do with CONFIG_OF_DYNAMIC. CONFIG_OF is what you 
want, and there's probably a section for that already.

> +extern struct spi_controller *of_find_spi_controller_by_node(
> +	struct device_node *node);
> +#else
> +static inline struct spi_controller *of_find_spi_controller_by_node(
> +	struct device_node *node)
> +{
> +	return NULL;
> +}
> +#endif
> +
>  #if IS_ENABLED(CONFIG_ACPI) && IS_ENABLED(CONFIG_SPI_MASTER)
>  extern struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev);
>  extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
> -- 
> 2.52.0
>