[PATCH v6 4/9] spi: Add API to count spi acpi resources

[Hans de Goede]

Hi,

On 1/21/22 18:24, Stefan Binding wrote:
> Some ACPI nodes may have more than one Spi Resource.
> To be able to handle these case, its necessary to have
> a way of counting these resources.
> 
> Signed-off-by: Stefan Binding <sbinding at opensource.cirrus.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans


> ---
>  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 06c0a308b38b..ec9f2ed579e3 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -2324,6 +2324,46 @@ struct acpi_spi_lookup {
>  	int			index;
>  };
>  
> +static int acpi_spi_count(struct acpi_resource *ares, void *data)
> +{
> +	struct acpi_resource_spi_serialbus *sb;
> +	int *count = data;
> +
> +	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
> +		return 1;
> +
> +	sb = &ares->data.spi_serial_bus;
> +	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_SPI)
> +		return 1;
> +
> +	*count = *count + 1;
> +
> +	return 1;
> +}
> +
> +/**
> + * acpi_spi_count_resources - Count the number of SpiSerialBus resources
> + * @adev:	ACPI device
> + *
> + * Returns the number of SpiSerialBus resources in the ACPI-device's
> + * resource-list; or a negative error code.
> + */
> +int acpi_spi_count_resources(struct acpi_device *adev)
> +{
> +	LIST_HEAD(r);
> +	int count = 0;
> +	int ret;
> +
> +	ret = acpi_dev_get_resources(adev, &r, acpi_spi_count, &count);
> +	if (ret < 0)
> +		return ret;
> +
> +	acpi_dev_free_resource_list(&r);
> +
> +	return count;
> +}
> +EXPORT_SYMBOL_GPL(acpi_spi_count_resources);
> +
>  static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
>  					    struct acpi_spi_lookup *lookup)
>  {
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index e5bbb9cbd3d7..394b4241d989 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -764,6 +764,7 @@ extern void spi_unregister_controller(struct spi_controller *ctlr);
>  extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
>  						struct acpi_device *adev,
>  						int index);
> +int acpi_spi_count_resources(struct acpi_device *adev);
>  #endif
>  
>  /*
>