ethtool: add interface to interact with Ethernet Power Equipment

Add interface to support Power Sourcing Equipment. At current step it
provides generic way to address all variants of PSE devices as defined
in IEEE 802.3-2018 but support only objects specified for IEEE 802.3-2018 104.4
PoDL Power Sourcing Equipment (PSE).

Currently supported and mandatory objects are:
IEEE 802.3-2018 30.15.1.1.3 aPoDLPSEPowerDetectionStatus
IEEE 802.3-2018 30.15.1.1.2 aPoDLPSEAdminState
IEEE 802.3-2018 30.15.1.2.1 acPoDLPSEAdminControl

This is minimal interface needed to control PSE on each separate
ethernet port but it provides not all mandatory objects specified in
IEEE 802.3-2018.

Since "PoDL PSE" and "PSE" have similar names, but some different values
I decide to not merge them and keep separate naming schema. This should
allow as to be as close to IEEE 802.3 spec as possible and avoid name
conflicts in the future.

This implementation is connected to PHYs instead of MACs because PSE
auto classification can potentially interfere with PHY auto negotiation.
So, may be some extra PHY related initialization will be needed.

With WIP version of ethtools interaction with PSE capable link looks
as following:

$ ip l
...
5: t1l1@eth0: <BROADCAST,MULTICAST> ..
...

$ ethtool --show-pse t1l1
PSE attributs for t1l1:
PoDL PSE Admin State: disabled
PoDL PSE Power Detection Status: disabled

$ ethtool --set-pse t1l1 podl-pse-admin-control enable
$ ethtool --show-pse t1l1
PSE attributs for t1l1:
PoDL PSE Admin State: enabled
PoDL PSE Power Detection Status: delivering power

Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 09fb1d5ba67f..d578b8bcd8a4 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -220,6 +220,8 @@ Userspace to kernel:
   ``ETHTOOL_MSG_PHC_VCLOCKS_GET``       get PHC virtual clocks info
   ``ETHTOOL_MSG_MODULE_SET``            set transceiver module parameters
   ``ETHTOOL_MSG_MODULE_GET``            get transceiver module parameters
+  ``ETHTOOL_MSG_PSE_SET``               set PSE parameters
+  ``ETHTOOL_MSG_PSE_GET``               get PSE parameters
   ===================================== =================================
 
 Kernel to userspace:
@@ -260,6 +262,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_STATS_GET_REPLY``          standard statistics
   ``ETHTOOL_MSG_PHC_VCLOCKS_GET_REPLY``    PHC virtual clocks info
   ``ETHTOOL_MSG_MODULE_GET_REPLY``         transceiver module parameters
+  ``ETHTOOL_MSG_PSE_GET_REPLY``            PSE parameters
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -1627,6 +1630,62 @@ For SFF-8636 modules, low power mode is forced by the host according to table
 For CMIS modules, low power mode is forced by the host according to table 6-12
 in revision 5.0 of the specification.
 
+PSE_GET
+=======
+
+Gets PSE attributes.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_PSE_HEADER``               nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+  ======================================  ======  =============================
+  ``ETHTOOL_A_PSE_HEADER``                nested  reply header
+  ``ETHTOOL_A_PODL_PSE_ADMIN_STATE``         u32  Operational state of the PoDL
+                                                  PSE functions
+  ``ETHTOOL_A_PODL_PSE_PW_D_STATUS``         u32  power detection status of the
+                                                  PoDL PSE.
+  ======================================  ======  =============================
+
+When set, the optional ``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` attribute identifies
+the operational state of the PoDL PSE functions.  The operational state of the
+PSE function can be changed using the ``ETHTOOL_A_PODL_PSE_ADMIN_CONTROL``
+action. This option is corresponding to ``IEEE 802.3-2018`` 30.15.1.1.2
+aPoDLPSEAdminState. Possible values are:
+
+.. kernel-doc:: include/uapi/linux/ethtool.h
+    :identifiers: ethtool_podl_pse_admin_state
+
+When set, the optional ``ETHTOOL_A_PODL_PSE_PW_D_STATUS`` attribute identifies
+the power detection status of the PoDL PSE.  The status depend on internal PSE
+state machine and automatic PD classification support. This option is
+corresponding to ``IEEE 802.3-2018`` 30.15.1.1.3 aPoDLPSEPowerDetectionStatus.
+Possible values are:
+
+.. kernel-doc:: include/uapi/linux/ethtool.h
+    :identifiers: ethtool_podl_pse_pw_d_status
+
+PSE_SET
+=======
+
+Sets PSE parameters.
+
+Request contents:
+
+  ======================================  ======  =============================
+  ``ETHTOOL_A_PSE_HEADER``                nested  request header
+  ``ETHTOOL_A_PODL_PSE_ADMIN_CONTROL``       u32  Control PoDL PSE Admin state
+  ======================================  ======  =============================
+
+When set, the optional ``ETHTOOL_A_PODL_PSE_ADMIN_CONTROL`` attribute is used
+to control PoDL PSE Admin functions. This option is implementing
+``IEEE 802.3-2018`` 30.15.1.2.1 acPoDLPSEAdminControl. See
+``ETHTOOL_A_PODL_PSE_ADMIN_STATE`` for supported values.
+
 Request translation
 ===================