net: ti: am65-cpsw-nuss: Add devlink support

AM65 NUSS ethernet switch on K3 devices can be configured to work either
in independent mac mode where each port acts as independent network
interface (multi mac) or switch mode.

Add devlink hooks to provide a way to switch b/w these modes.

Rationale to use devlink instead of defaulting to bridge mode is that
SoC use cases require to support multiple independent MAC ports with no
switching so that users can use software bridges with multi-mac
configuration (e.g: to support LAG, HSR/PRP, etc). Also, switching
between multi mac and switch mode requires significant Port and ALE
reconfiguration, therefore is easier to be made as part of mode change
devlink hooks. It also allows to keep user interface similar to what
was implemented for the previous generation of TI CPSW IP
(on AM33/AM43/AM57 SoCs).

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/devlink/am65-nuss-cpsw-switch.rst

@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============================
+am65-cpsw-nuss devlink support
+==============================
+
+This document describes the devlink features implemented by the ``am65-cpsw-nuss``
+device driver.
+
+Parameters
+==========
+
+The ``am65-cpsw-nuss`` driver implements the following driver-specific
+parameters.
+
+.. list-table:: Driver-specific parameters implemented
+   :widths: 5 5 5 85
+
+   * - Name
+     - Type
+     - Mode
+     - Description
+   * - ``switch_mode``
+     - Boolean
+     - runtime
+     - Enable switch mode

Documentation/networking/devlink/index.rst

@@ -45,3 +45,4 @@ parameters, info versions, and other features it supports.
    sja1105
    qed
    ti-cpsw-switch
+   am65-nuss-cpsw-switch

drivers/net/ethernet/ti/Kconfig

@@ -92,6 +92,7 @@ config TI_CPTS
 config TI_K3_AM65_CPSW_NUSS
 	tristate "TI K3 AM654x/J721E CPSW Ethernet driver"
 	depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER
+	select NET_DEVLINK
 	select TI_DAVINCI_MDIO
 	imply PHY_TI_GMII_SEL
 	depends on TI_K3_AM65_CPTS || !TI_K3_AM65_CPTS
@@ -105,6 +106,15 @@ config TI_K3_AM65_CPSW_NUSS
 	  To compile this driver as a module, choose M here: the module
 	  will be called ti-am65-cpsw-nuss.
 
+config TI_K3_AM65_CPSW_SWITCHDEV
+	bool "TI K3 AM654x/J721E CPSW Switch mode support"
+	depends on TI_K3_AM65_CPSW_NUSS
+	depends on NET_SWITCHDEV
+	help
+	 This enables switchdev support for TI K3 CPSWxG Ethernet
+	 Switch. Enable this driver to support hardware switch support for AM65
+	 CPSW NUSS driver.
+
 config TI_K3_AM65_CPTS
 	tristate "TI K3 AM65x CPTS"
 	depends on ARCH_K3 && OF