[PATCH 3/9] net: dsa: allow drivers to get the port OF node

[Ramon Fried]

On Tue, Sep 28, 2021 at 2:48 AM Vladimir Oltean <vladimir.oltean at nxp.com> wrote:
>
> In the current DSA switch driver API, only the udevice of the switch
> (belonging to UCLASS_DSA) is exposed, as well as an "int port" argument.
> So drivers do not have access to the udevice of individual ports
> (belonging to UCLASS_ETH), one of the reasons being that not all ports
> have an associated UCLASS_ETH udevice.
>
> However, all DSA ports have an OF node, and in some cases the driver
> needs a handle to it, for all ports including the CPU port. Example: the
> following Linux per-port device tree property:
>
>         managed = "in-band-status";
>
> states whether a port should operate with clause 37 in-band autoneg
> enabled or not.
>
> This patch exposes a function which can be called by individual drivers
> as needed.
>
> Signed-off-by: Vladimir Oltean <vladimir.oltean at nxp.com>
> ---
>  include/net/dsa.h | 12 ++++++++++++
>  net/dsa-uclass.c  | 20 ++++++++++++++++++++
>  2 files changed, 32 insertions(+)
>
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index ab2a9dfbea2d..d165427fcd4c 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -6,6 +6,7 @@
>  #ifndef __DSA_H__
>  #define __DSA_H__
>
> +#include <dm/ofnode.h>
>  #include <phy.h>
>  #include <net.h>
>
> @@ -145,6 +146,17 @@ int dsa_set_tagging(struct udevice *dev, ushort headroom, ushort tailroom);
>   */
>  struct udevice *dsa_get_master(struct udevice *dev);
>
> +/**
> + * dsa_port_get_ofnode() - Return a reference to the given port's OF node
> + *
> + * Can be called at driver probe time or later.
> + *
> + * @dev:       DSA switch udevice pointer
> + * @port:      Port index
> + * @return OF node reference if OK, NULL on error
> + */
> +ofnode dsa_port_get_ofnode(struct udevice *dev, int port);
> +
>  /**
>   * dsa_port_get_pdata() - Helper that returns the platdata of an active
>   *                     (non-CPU) DSA port device.
> diff --git a/net/dsa-uclass.c b/net/dsa-uclass.c
> index a9b4484d6d24..61bb47d0102d 100644
> --- a/net/dsa-uclass.c
> +++ b/net/dsa-uclass.c
> @@ -44,6 +44,26 @@ int dsa_set_tagging(struct udevice *dev, ushort headroom, ushort tailroom)
>         return 0;
>  }
>
> +ofnode dsa_port_get_ofnode(struct udevice *dev, int port)
> +{
> +       struct dsa_pdata *pdata = dev_get_uclass_plat(dev);
> +       struct dsa_port_pdata *port_pdata;
> +       struct udevice *pdev;
> +
> +       if (port == pdata->cpu_port)
> +               return pdata->cpu_port_node;
> +
> +       for (device_find_first_child(dev, &pdev);
> +            pdev;
> +            device_find_next_child(&pdev)) {
> +               port_pdata = dev_get_parent_plat(pdev);
> +               if (port_pdata->index == port)
> +                       return dev_ofnode(pdev);
> +       }
> +
> +       return ofnode_null();
> +}
> +
>  /* returns the DSA master Ethernet device */
>  struct udevice *dsa_get_master(struct udevice *dev)
>  {
> --
> 2.25.1
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>