This patch introduces the ability to configure the PSE PI budget evaluation
strategies. Budget evaluation strategies is utilized by PSE controllers to
determine which ports to turn off first in scenarios such as power budget
exceedance.

The pis_prio_max value is used to define the maximum priority level
supported by the controller. Both the current priority and the maximum
priority are exposed to the user through the pse_ethtool_get_status call.

This patch add support for two mode of budget evaluation strategies.
1. Static Method:

   This method involves distributing power based on PD classification.
   It’s straightforward and stable, the PSE core keeping track of the
   budget and subtracting the power requested by each PD’s class.

   Advantages: Every PD gets its promised power at any time, which
   guarantees reliability.

   Disadvantages: PD classification steps are large, meaning devices
   request much more power than they actually need. As a result, the power
   supply may only operate at, say, 50% capacity, which is inefficient and
   wastes money.

   Priority max value is matching the number of PSE PIs within the PSE.

2. Dynamic Method:

   To address the inefficiencies of the static method, vendors like
   Microchip have introduced dynamic power budgeting, as seen in the
   PD692x0 firmware. This method monitors the current consumption per port
   and subtracts it from the available power budget. When the budget is
   exceeded, lower-priority ports are shut down.

   Advantages: This method optimizes resource utilization, saving costs.

   Disadvantages: Low-priority devices may experience instability.

   Priority max value is set by the PSE controller driver.

For now, budget evaluation methods are not configurable and cannot be
mixed. They are hardcoded in the PSE driver itself, as no current PSE
controller supports both methods.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-7-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Refactor code by introducing a helper function to retrieve the hardware
enabled state of the PI, avoiding redundant implementations in the
future.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-6-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Report the index of the newly introduced PSE power domain to the user,
enabling improved management of the power budget for PSE devices.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-5-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Introduce PSE power domain support as groundwork for upcoming port
priority features. Multiple PSE PIs can now be grouped under a single
PSE power domain, enabling future enhancements like defining available
power budgets, port priority modes, and disconnection policies. This
setup will allow the system to assess whether activating a port would
exceed the available power budget, preventing over-budget states
proactively.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-4-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for devm_pse_irq_helper() to register PSE interrupts and report
events such as over-current or over-temperature conditions. This follows a
similar approach to the regulator API but also sends notifications using a
dedicated PSE ethtool netlink socket.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-2-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In preparation for reporting PSE events via ethtool notifications,
introduce an attached_phydev field in the pse_control structure.
This field stores the phy_device associated with the PSE PI,
ensuring that notifications are sent to the correct network
interface.

The attached_phydev pointer is directly tied to the PHY lifecycle. It
is set when the PHY is registered and cleared when the PHY is removed.
There is no need to use a refcount, as doing so could interfere with
the PHY removal process.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-1-78a1a645e2ee@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Fix a deadlock in pse_pi_get_current_limit and pse_pi_set_current_limit
caused by consecutive mutex_lock calls. One in the function itself and
another in pse_pi_get_voltage.

Resolve the issue by using the unlocked version of pse_pi_get_voltage
instead.

Fixes: e0a5e2bba38a ("net: pse-pd: Use power limit at driver side instead of current limit")
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20250212151751.1515008-1-kory.maincent@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Remove PSE-specific structures from the ethtool header to improve code
modularity, maintain independent headers, and reduce incremental build
time.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The PI of_node was not assigned in the regulator_config structure, leading
to failures in resolving the correct supply when different power supplies
are assigned to multiple PIs of a PSE controller. This fix ensures that the
of_node is properly set in the regulator_config, allowing accurate supply
resolution for each PI.

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The is_enabled callback is now redundant as the admin_state can be obtained
directly from the driver and provides the same information.

To simplify functionality, the core will handle this internally, making
the is_enabled callback unnecessary at the driver level. Remove the
callback from all drivers.

Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>