[PATCH 4/4] docs: networking: ti: Add driver doc for AM65 NUSS switch driver

[Vignesh Raghavendra]

J721e, J7200 and AM64 have multi port switches which can work in multi
mac mode and in switch mode. Add documentation explaining how to use
different modes.

Borrowed from:
Documentation/networking/device_drivers/ethernet/ti/cpsw_switchdev.rst

Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
---
 .../device_drivers/ethernet/index.rst         |   1 +
 .../ethernet/ti/am65_nuss_cpsw_switchdev.rst  | 143 ++++++++++++++++++
 2 files changed, 144 insertions(+)
 create mode 100644 Documentation/networking/device_drivers/ethernet/ti/am65_nuss_cpsw_switchdev.rst

diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index cbb75a1818c0..6b5dc203da2b 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -49,6 +49,7 @@ Contents:
    stmicro/stmmac
    ti/cpsw
    ti/cpsw_switchdev
+   ti/am65_nuss_cpsw_switchdev
    ti/tlan
    toshiba/spider_net
 
diff --git a/Documentation/networking/device_drivers/ethernet/ti/am65_nuss_cpsw_switchdev.rst b/Documentation/networking/device_drivers/ethernet/ti/am65_nuss_cpsw_switchdev.rst
new file mode 100644
index 000000000000..f24adfab6a1b
--- /dev/null
+++ b/Documentation/networking/device_drivers/ethernet/ti/am65_nuss_cpsw_switchdev.rst
@@ -0,0 +1,143 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================================================
+Texas Instruments K3 AM65 CPSW NUSS switchdev based ethernet driver
+===================================================================
+
+:Version: 1.0
+
+Port renaming
+=============
+
+In order to rename via udev::
+
+    ip -d link show dev sw0p1 | grep switchid
+
+    SUBSYSTEM=="net", ACTION=="add", ATTR{phys_switch_id}==<switchid>, \
+	    ATTR{phys_port_name}!="", NAME="sw0$attr{phys_port_name}"
+
+
+Multi mac mode
+==============
+
+- The driver is operating in multi-mac mode by default, thus
+  working as N individual network interfaces.
+
+Devlink configuration parameters
+================================
+
+See Documentation/networking/devlink/am65-nuss-cpsw-switch.rst
+
+Enabling "switch"
+=================
+
+The Switch mode can be enabled by configuring devlink driver parameter
+"switch_mode" to 1/true::
+
+        devlink dev param set platform/c000000.ethernet \
+        name switch_mode value true cmode runtime
+
+This can be done regardless of the state of Port's netdev devices - UP/DOWN, but
+Port's netdev devices have to be in UP before joining to the bridge to avoid
+overwriting of bridge configuration as CPSW switch driver completely reloads its
+configuration when first port changes its state to UP.
+
+When the both interfaces joined the bridge - CPSW switch driver will enable
+marking packets with offload_fwd_mark flag.
+
+All configuration is implemented via switchdev API.
+
+Bridge setup
+============
+
+::
+
+        devlink dev param set platform/c000000.ethernet \
+        name switch_mode value true cmode runtime
+
+	ip link add name br0 type bridge
+	ip link set dev br0 type bridge ageing_time 1000
+	ip link set dev sw0p1 up
+	ip link set dev sw0p2 up
+	ip link set dev sw0p1 master br0
+	ip link set dev sw0p2 master br0
+
+	[*] bridge vlan add dev br0 vid 1 pvid untagged self
+
+	[*] if vlan_filtering=1. where default_pvid=1
+
+	Note. Steps [*] are mandatory.
+
+
+On/off STP
+==========
+
+::
+
+	ip link set dev BRDEV type bridge stp_state 1/0
+
+VLAN configuration
+==================
+
+::
+
+  bridge vlan add dev br0 vid 1 pvid untagged self <---- add cpu port to VLAN 1
+
+Note. This step is mandatory for bridge/default_pvid.
+
+Add extra VLANs
+===============
+
+ 1. untagged::
+
+	bridge vlan add dev sw0p1 vid 100 pvid untagged master
+	bridge vlan add dev sw0p2 vid 100 pvid untagged master
+	bridge vlan add dev br0 vid 100 pvid untagged self <---- Add cpu port to VLAN100
+
+ 2. tagged::
+
+	bridge vlan add dev sw0p1 vid 100 master
+	bridge vlan add dev sw0p2 vid 100 master
+	bridge vlan add dev br0 vid 100 pvid tagged self <---- Add cpu port to VLAN100
+
+FDBs
+----
+
+FDBs are automatically added on the appropriate switch port upon detection
+
+Manually adding FDBs::
+
+    bridge fdb add aa:bb:cc:dd:ee:ff dev sw0p1 master vlan 100
+    bridge fdb add aa:bb:cc:dd:ee:fe dev sw0p2 master <---- Add on all VLANs
+
+MDBs
+----
+
+MDBs are automatically added on the appropriate switch port upon detection
+
+Manually adding MDBs::
+
+  bridge mdb add dev br0 port sw0p1 grp 239.1.1.1 permanent vid 100
+  bridge mdb add dev br0 port sw0p1 grp 239.1.1.1 permanent <---- Add on all VLANs
+
+Multicast flooding
+==================
+CPU port mcast_flooding is always on
+
+Turning flooding on/off on swithch ports:
+bridge link set dev sw0p1 mcast_flood on/off
+
+Access and Trunk port
+=====================
+
+::
+
+ bridge vlan add dev sw0p1 vid 100 pvid untagged master
+ bridge vlan add dev sw0p2 vid 100 master
+
+
+ bridge vlan add dev br0 vid 100 self
+ ip link add link br0 name br0.100 type vlan id 100
+
+Note. Setting PVID on Bridge device itself works only for
+default VLAN (default_pvid).
-- 
2.29.2