Re: [RFC PATCH 3/6] fpga: dfl: add an API to get the base device for dfl device

[Tom Rix <trix@redhat.com>]

On 10/23/20 1:45 AM, Xu Yilun wrote:
> This patch adds an API for dfl devices to find which physical device
> owns the DFL.
>
> This patch makes preparation for supporting DFL Ether Group private
> feature driver. It uses this information to determine which retimer
> device physically connects to which ether group.
device is physically
>
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> ---
>  drivers/fpga/dfl.c  | 9 +++++++++
>  include/linux/dfl.h | 1 +
>  2 files changed, 10 insertions(+)
>
> diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> index ca3c678..52d18e6 100644
> --- a/drivers/fpga/dfl.c
> +++ b/drivers/fpga/dfl.c
> @@ -558,6 +558,15 @@ int dfl_dev_get_vendor_net_cfg(struct dfl_device *dfl_dev)
>  }
>  EXPORT_SYMBOL_GPL(dfl_dev_get_vendor_net_cfg);
>  
> +struct device *dfl_dev_get_base_dev(struct dfl_device *dfl_dev)
> +{
> +	if (!dfl_dev || !dfl_dev->cdev)
> +		return NULL;
> +
> +	return dfl_dev->cdev->parent;
> +}
> +EXPORT_SYMBOL_GPL(dfl_dev_get_base_dev);

This name is awkward. maybe

dfl_dev_parent() or dfl_dev_base()


> +
>  #define is_header_feature(feature) ((feature)->id == FEATURE_ID_FIU_HEADER)
>  
>  /**
> diff --git a/include/linux/dfl.h b/include/linux/dfl.h
> index 5ee2b1e..dd313f2 100644
> --- a/include/linux/dfl.h
> +++ b/include/linux/dfl.h
> @@ -68,6 +68,7 @@ struct dfl_driver {
>  #define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)
>  
>  int dfl_dev_get_vendor_net_cfg(struct dfl_device *dfl_dev);
> +struct device *dfl_dev_get_base_dev(struct dfl_device *dfl_dev);

Because this is an external interface these should have comments

This is another generic change and should be split out of the patchset.

I believe the generic changes would have an easier time being accepted and could be done in parallel as the harder part of the private features is worked out.

Tom

>  
>  /*
>   * use a macro to avoid include chaining to get THIS_MODULE.