[PATCH net-next v4 0/6] Side MDIO Support for LAN937x Switches

[PATCH net-next v4 0/6] Side MDIO Support for LAN937x Switches

[Oleksij Rempel]

This patch set introduces support for an internal MDIO bus in LAN937x
switches, enabling the use of a side MDIO channel for PHY management
while keeping SPI as the main interface for switch configuration.

changes v3:
- add "net: dsa: microchip: parse PHY config from device tree" patch

other changelogs are added to separate patches.

Oleksij Rempel (6):
  dt-bindings: net: dsa: microchip: add internal MDIO bus description
  dt-bindings: net: dsa: microchip: add mdio-parent-bus property for
    internal MDIO
  net: dsa: microchip: Refactor MDIO handling for side MDIO access
  net: dsa: microchip: cleanup error handling in ksz_mdio_register
  net: dsa: microchip: add support for side MDIO interface in LAN937x
  net: dsa: microchip: parse PHY config from device tree

 .../bindings/net/dsa/microchip,ksz.yaml       |  20 ++
 drivers/net/dsa/microchip/ksz_common.c        | 259 ++++++++++++++++--
 drivers/net/dsa/microchip/ksz_common.h        |  59 ++++
 drivers/net/dsa/microchip/lan937x.h           |   2 +
 drivers/net/dsa/microchip/lan937x_main.c      | 226 +++++++++++++--
 drivers/net/dsa/microchip/lan937x_reg.h       |   4 +
 6 files changed, 538 insertions(+), 32 deletions(-)

[PATCH net-next v4 1/6] dt-bindings: net: dsa: microchip: add internal MDIO bus description

[Oleksij Rempel]

Add description for the internal MDIO bus, including integrated PHY
nodes, to ksz DSA bindings.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 .../devicetree/bindings/net/dsa/microchip,ksz.yaml    | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
index 30c0c3e6f37a4..a4e463819d4d7 100644
--- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
@@ -81,6 +81,17 @@ properties:
   interrupts:
     maxItems: 1
 
+  mdio:
+    $ref: /schemas/net/mdio.yaml#
+    unevaluatedProperties: false
+    patternProperties:
+      "^ethernet-phy@[0-9a-f]$":
+        type: object
+        $ref: /schemas/net/ethernet-phy.yaml#
+        unevaluatedProperties: false
+        description:
+          Integrated PHY node
+
 required:
   - compatible
   - reg
-- 
2.39.5

[PATCH net-next v4 2/6] dt-bindings: net: dsa: microchip: add mdio-parent-bus property for internal MDIO

[Oleksij Rempel]

Introduce `mdio-parent-bus` property in the ksz DSA bindings to
reference the parent MDIO bus when the internal MDIO bus is attached to
it, bypassing the main management interface.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 .../devicetree/bindings/net/dsa/microchip,ksz.yaml       | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
index a4e463819d4d7..121a4bbd147be 100644
--- a/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
+++ b/Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
@@ -84,6 +84,15 @@ properties:
   mdio:
     $ref: /schemas/net/mdio.yaml#
     unevaluatedProperties: false
+    properties:
+      mdio-parent-bus:
+        $ref: /schemas/types.yaml#/definitions/phandle
+        description:
+          Phandle pointing to the MDIO bus controller connected to the
+          secondary MDIO interface. This property should be used when
+          the internal MDIO bus is accessed via a secondary MDIO
+          interface rather than the primary management interface.
+
     patternProperties:
       "^ethernet-phy@[0-9a-f]$":
         type: object
-- 
2.39.5

[PATCH net-next v4 3/6] net: dsa: microchip: Refactor MDIO handling for side MDIO access

[Oleksij Rempel]

Add support for accessing PHYs via a side MDIO interface in LAN937x
switches. The existing code already supports accessing PHYs via main
management interfaces, which can be SPI, I2C, or MDIO, depending on the
chip variant. This patch enables using a side MDIO bus, where SPI is
used for the main switch configuration and MDIO for managing the
integrated PHYs. On LAN937x, this is optional, allowing them to operate
in both configurations: SPI only, or SPI + MDIO. Typically, the SPI
interface is used for switch configuration, while MDIO handles PHY
management.

Additionally, update interrupt controller code to support non-linear
port to PHY address mapping, enabling correct interrupt handling for
configurations where PHY addresses do not directly correspond to port
indexes. This change ensures that the interrupt mechanism properly
aligns with the new, flexible PHY address mappings introduced by side
MDIO support.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
changes v4:
- add Reviewed-by: Andrew Lunn <andrew@lunn.ch>
changes v2:
- fail on phy_side_mdio_supported
- add of_node_put(parent_bus_node)
- add comments
---
 drivers/net/dsa/microchip/ksz_common.c | 175 +++++++++++++++++++++++--
 drivers/net/dsa/microchip/ksz_common.h |  59 +++++++++
 2 files changed, 224 insertions(+), 10 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index f73833e24622a..e9460650d46e0 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2236,16 +2236,100 @@ static int ksz_sw_mdio_write(struct mii_bus *bus, int addr, int regnum,
 	return dev->dev_ops->w_phy(dev, addr, regnum, val);
 }
 
+/**
+ * ksz_parent_mdio_read - Read data from a PHY register on the parent MDIO bus.
+ * @bus: MDIO bus structure.
+ * @addr: PHY address on the parent MDIO bus.
+ * @regnum: Register number to read.
+ *
+ * This function provides a direct read operation on the parent MDIO bus for
+ * accessing PHY registers. By bypassing SPI or I2C, it uses the parent MDIO bus
+ * to retrieve data from the PHY registers at the specified address and register
+ * number.
+ *
+ * Return: Value of the PHY register, or a negative error code on failure.
+ */
+static int ksz_parent_mdio_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct ksz_device *dev = bus->priv;
+
+	return mdiobus_read_nested(dev->parent_mdio_bus, addr, regnum);
+}
+
+/**
+ * ksz_parent_mdio_write - Write data to a PHY register on the parent MDIO bus.
+ * @bus: MDIO bus structure.
+ * @addr: PHY address on the parent MDIO bus.
+ * @regnum: Register number to write to.
+ * @val: Value to write to the PHY register.
+ *
+ * This function provides a direct write operation on the parent MDIO bus for
+ * accessing PHY registers. Bypassing SPI or I2C, it uses the parent MDIO bus
+ * to modify the PHY register values at the specified address.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int ksz_parent_mdio_write(struct mii_bus *bus, int addr, int regnum,
+				 u16 val)
+{
+	struct ksz_device *dev = bus->priv;
+
+	return mdiobus_write_nested(dev->parent_mdio_bus, addr, regnum, val);
+}
+
+/**
+ * ksz_phy_addr_to_port - Map a PHY address to the corresponding switch port.
+ * @dev: Pointer to device structure.
+ * @addr: PHY address to map to a port.
+ *
+ * This function finds the corresponding switch port for a given PHY address by
+ * iterating over all user ports on the device. It checks if a port's PHY
+ * address in `phy_addr_map` matches the specified address and if the port
+ * contains an internal PHY. If a match is found, the index of the port is
+ * returned.
+ *
+ * Return: Port index on success, or -EINVAL if no matching port is found.
+ */
+static int ksz_phy_addr_to_port(struct ksz_device *dev, int addr)
+{
+	struct dsa_switch *ds = dev->ds;
+	struct dsa_port *dp;
+
+	dsa_switch_for_each_user_port(dp, ds) {
+		if (dev->info->internal_phy[dp->index] &&
+		    dev->phy_addr_map[dp->index] == addr)
+			return dp->index;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * ksz_irq_phy_setup - Configure IRQs for PHYs in the KSZ device.
+ * @dev: Pointer to the KSZ device structure.
+ *
+ * Sets up IRQs for each active PHY connected to the KSZ switch by mapping the
+ * appropriate IRQs for each PHY and assigning them to the `user_mii_bus` in
+ * the DSA switch structure. Each IRQ is mapped based on the port's IRQ domain.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
 static int ksz_irq_phy_setup(struct ksz_device *dev)
 {
 	struct dsa_switch *ds = dev->ds;
-	int phy;
+	int phy, port;
 	int irq;
 	int ret;
 
-	for (phy = 0; phy < KSZ_MAX_NUM_PORTS; phy++) {
+	for (phy = 0; phy < PHY_MAX_ADDR; phy++) {
 		if (BIT(phy) & ds->phys_mii_mask) {
-			irq = irq_find_mapping(dev->ports[phy].pirq.domain,
+			port = ksz_phy_addr_to_port(dev, phy);
+			if (port < 0) {
+				ret = port;
+				goto out;
+			}
+
+			irq = irq_find_mapping(dev->ports[port].pirq.domain,
 					       PORT_SRC_PHY_INT);
 			if (irq < 0) {
 				ret = irq;
@@ -2263,40 +2347,109 @@ static int ksz_irq_phy_setup(struct ksz_device *dev)
 	return ret;
 }
 
+/**
+ * ksz_irq_phy_free - Release IRQ mappings for PHYs in the KSZ device.
+ * @dev: Pointer to the KSZ device structure.
+ *
+ * Releases any IRQ mappings previously assigned to active PHYs in the KSZ
+ * switch by disposing of each mapped IRQ in the `user_mii_bus` structure.
+ */
 static void ksz_irq_phy_free(struct ksz_device *dev)
 {
 	struct dsa_switch *ds = dev->ds;
 	int phy;
 
-	for (phy = 0; phy < KSZ_MAX_NUM_PORTS; phy++)
+	for (phy = 0; phy < PHY_MAX_ADDR; phy++)
 		if (BIT(phy) & ds->phys_mii_mask)
 			irq_dispose_mapping(ds->user_mii_bus->irq[phy]);
 }
 
+/**
+ * ksz_mdio_register - Register and configure the MDIO bus for the KSZ device.
+ * @dev: Pointer to the KSZ device structure.
+ *
+ * This function sets up and registers an MDIO bus for the KSZ switch device,
+ * allowing access to its internal PHYs. If the device supports side MDIO,
+ * the function will configure the external MDIO controller specified by the
+ * "mdio-parent-bus" device tree property to directly manage internal PHYs.
+ * Otherwise, SPI or I2C access is set up for PHY access.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
 static int ksz_mdio_register(struct ksz_device *dev)
 {
+	struct device_node *parent_bus_node;
+	struct mii_bus *parent_bus = NULL;
 	struct dsa_switch *ds = dev->ds;
 	struct device_node *mdio_np;
 	struct mii_bus *bus;
-	int ret;
+	struct dsa_port *dp;
+	int ret, i;
 
 	mdio_np = of_get_child_by_name(dev->dev->of_node, "mdio");
 	if (!mdio_np)
 		return 0;
 
+	parent_bus_node = of_parse_phandle(mdio_np, "mdio-parent-bus", 0);
+	if (parent_bus_node && !dev->info->phy_side_mdio_supported) {
+		dev_err(dev->dev, "Side MDIO bus is not supported for this HW, ignoring 'mdio-parent-bus' property.\n");
+		ret = -EINVAL;
+
+		goto put_mdio_node;
+	} else if (parent_bus_node) {
+		parent_bus = of_mdio_find_bus(parent_bus_node);
+		if (!parent_bus) {
+			ret = -EPROBE_DEFER;
+
+			goto put_mdio_node;
+		}
+
+		dev->parent_mdio_bus = parent_bus;
+	}
+
 	bus = devm_mdiobus_alloc(ds->dev);
 	if (!bus) {
 		of_node_put(mdio_np);
 		return -ENOMEM;
 	}
 
+	if (dev->dev_ops->mdio_bus_preinit) {
+		ret = dev->dev_ops->mdio_bus_preinit(dev, !!parent_bus);
+		if (ret)
+			goto put_mdio_node;
+	}
+
+	if (dev->dev_ops->create_phy_addr_map) {
+		ret = dev->dev_ops->create_phy_addr_map(dev, !!parent_bus);
+		if (ret)
+			goto put_mdio_node;
+	} else {
+		for (i = 0; i < dev->info->port_cnt; i++)
+			dev->phy_addr_map[i] = i;
+	}
+
 	bus->priv = dev;
-	bus->read = ksz_sw_mdio_read;
-	bus->write = ksz_sw_mdio_write;
-	bus->name = "ksz user smi";
-	snprintf(bus->id, MII_BUS_ID_SIZE, "SMI-%d", ds->index);
+	if (parent_bus) {
+		bus->read = ksz_parent_mdio_read;
+		bus->write = ksz_parent_mdio_write;
+		bus->name = "KSZ side MDIO";
+		snprintf(bus->id, MII_BUS_ID_SIZE, "ksz-side-mdio-%d",
+			 ds->index);
+	} else {
+		bus->read = ksz_sw_mdio_read;
+		bus->write = ksz_sw_mdio_write;
+		bus->name = "ksz user smi";
+		snprintf(bus->id, MII_BUS_ID_SIZE, "SMI-%d", ds->index);
+	}
+
+	dsa_switch_for_each_user_port(dp, dev->ds) {
+		if (dev->info->internal_phy[dp->index] &&
+		    dev->phy_addr_map[dp->index] < PHY_MAX_ADDR)
+			bus->phy_mask |= BIT(dev->phy_addr_map[dp->index]);
+	}
+
+	ds->phys_mii_mask = bus->phy_mask;
 	bus->parent = ds->dev;
-	bus->phy_mask = ~ds->phys_mii_mask;
 
 	ds->user_mii_bus = bus;
 
@@ -2316,7 +2469,9 @@ static int ksz_mdio_register(struct ksz_device *dev)
 			ksz_irq_phy_free(dev);
 	}
 
+put_mdio_node:
 	of_node_put(mdio_np);
+	of_node_put(parent_bus_node);
 
 	return ret;
 }
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index bec846e20682f..bbb548af201ef 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -65,6 +65,12 @@ struct ksz_chip_data {
 	u8 num_tx_queues;
 	u8 num_ipms; /* number of Internal Priority Maps */
 	bool tc_cbs_supported;
+
+	/**
+	 * @phy_side_mdio_supported: Indicates if the chip supports an additional
+	 * side MDIO channel for accessing integrated PHYs.
+	 */
+	bool phy_side_mdio_supported;
 	const struct ksz_dev_ops *ops;
 	const struct phylink_mac_ops *phylink_mac_ops;
 	bool phy_errata_9477;
@@ -191,6 +197,22 @@ struct ksz_device {
 	struct ksz_switch_macaddr *switch_macaddr;
 	struct net_device *hsr_dev;     /* HSR */
 	u8 hsr_ports;
+
+	/**
+	 * @phy_addr_map: Array mapping switch ports to their corresponding PHY
+	 * addresses.
+	 */
+	u8 phy_addr_map[KSZ_MAX_NUM_PORTS];
+
+	/**
+	 * @parent_mdio_bus: Pointer to the external MDIO bus controller.
+	 *
+	 * This points to an external MDIO bus controller that is used to access
+	 * the  PHYs integrated within the switch. Unlike an integrated MDIO
+	 * bus, this external controller provides a direct path for managing
+	 * the switch’s internal PHYs, bypassing the main SPI interface.
+	 */
+	struct mii_bus *parent_mdio_bus;
 };
 
 /* List of supported models */
@@ -326,6 +348,43 @@ struct ksz_dev_ops {
 	void (*port_cleanup)(struct ksz_device *dev, int port);
 	void (*port_setup)(struct ksz_device *dev, int port, bool cpu_port);
 	int (*set_ageing_time)(struct ksz_device *dev, unsigned int msecs);
+
+	/**
+	 * @mdio_bus_preinit: Function pointer to pre-initialize the MDIO bus
+	 *                    for accessing PHYs.
+	 * @dev: Pointer to device structure.
+	 * @side_mdio: Boolean indicating if the PHYs are accessed over a side
+	 *             MDIO bus.
+	 *
+	 * This function pointer is used to configure the MDIO bus for PHY
+	 * access before initiating regular PHY operations. It enables either
+	 * SPI/I2C or side MDIO access modes by unlocking necessary registers
+	 * and setting up access permissions for the selected mode.
+	 *
+	 * Return:
+	 *  - 0 on success.
+	 *  - Negative error code on failure.
+	 */
+	int (*mdio_bus_preinit)(struct ksz_device *dev, bool side_mdio);
+
+	/**
+	 * @create_phy_addr_map: Function pointer to create a port-to-PHY
+	 *                       address map.
+	 * @dev: Pointer to device structure.
+	 * @side_mdio: Boolean indicating if the PHYs are accessed over a side
+	 *             MDIO bus.
+	 *
+	 * This function pointer is responsible for mapping switch ports to PHY
+	 * addresses according to the configured access mode (SPI or side MDIO)
+	 * and the device’s strap configuration. The mapping setup may vary
+	 * depending on the chip variant and configuration. Ensures the correct
+	 * address mapping for PHY communication.
+	 *
+	 * Return:
+	 *  - 0 on success.
+	 *  - Negative error code on failure (e.g., invalid configuration).
+	 */
+	int (*create_phy_addr_map)(struct ksz_device *dev, bool side_mdio);
 	int (*r_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 *val);
 	int (*w_phy)(struct ksz_device *dev, u16 phy, u16 reg, u16 val);
 	void (*r_mib_cnt)(struct ksz_device *dev, int port, u16 addr,
-- 
2.39.5

[PATCH net-next v4 4/6] net: dsa: microchip: cleanup error handling in ksz_mdio_register

[Oleksij Rempel]

Replace repeated cleanup code with a single error path using a label.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/dsa/microchip/ksz_common.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index e9460650d46e0..26a4a8b49dc83 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2409,8 +2409,8 @@ static int ksz_mdio_register(struct ksz_device *dev)
 
 	bus = devm_mdiobus_alloc(ds->dev);
 	if (!bus) {
-		of_node_put(mdio_np);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto put_mdio_node;
 	}
 
 	if (dev->dev_ops->mdio_bus_preinit) {
@@ -2455,10 +2455,8 @@ static int ksz_mdio_register(struct ksz_device *dev)
 
 	if (dev->irq > 0) {
 		ret = ksz_irq_phy_setup(dev);
-		if (ret) {
-			of_node_put(mdio_np);
-			return ret;
-		}
+		if (ret)
+			goto put_mdio_node;
 	}
 
 	ret = devm_of_mdiobus_register(ds->dev, bus, mdio_np);
-- 
2.39.5

[PATCH net-next v4 5/6] net: dsa: microchip: add support for side MDIO interface in LAN937x

[Oleksij Rempel]

Implement side MDIO channel support for LAN937x switches, providing an
alternative to SPI for PHY management alongside existing SPI-based
switch configuration. This is needed to reduce SPI load, as SPI can be
relatively expensive for small packets compared to MDIO support.

Also, implemented static mappings for PHY addresses for various LAN937x
models to support different internal PHY configurations. Since the PHY
address mappings are not equal to the port indexes, this patch also
provides PHY address calculation based on hardware strapping
configuration.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
changes v4:
- add Reviewed-by: Andrew Lunn <andrew@lunn.ch>
changes v2:
- add lan9371_phy_addr map
- add comments
- add define LAN937X_NO_PHY
---
 drivers/net/dsa/microchip/ksz_common.c   |   7 +
 drivers/net/dsa/microchip/lan937x.h      |   2 +
 drivers/net/dsa/microchip/lan937x_main.c | 226 +++++++++++++++++++++--
 drivers/net/dsa/microchip/lan937x_reg.h  |   4 +
 4 files changed, 223 insertions(+), 16 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 26a4a8b49dc83..19fb090c09ab7 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -411,6 +411,8 @@ static const struct ksz_dev_ops lan937x_dev_ops = {
 	.flush_dyn_mac_table = ksz9477_flush_dyn_mac_table,
 	.port_setup = lan937x_port_setup,
 	.set_ageing_time = lan937x_set_ageing_time,
+	.mdio_bus_preinit = lan937x_mdio_bus_preinit,
+	.create_phy_addr_map = lan937x_create_phy_addr_map,
 	.r_phy = lan937x_r_phy,
 	.w_phy = lan937x_w_phy,
 	.r_mib_cnt = ksz9477_r_mib_cnt,
@@ -1762,6 +1764,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_tx_queues = 8,
 		.num_ipms = 8,
 		.tc_cbs_supported = true,
+		.phy_side_mdio_supported = true,
 		.ops = &lan937x_dev_ops,
 		.phylink_mac_ops = &lan937x_phylink_mac_ops,
 		.mib_names = ksz9477_mib_names,
@@ -1790,6 +1793,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_tx_queues = 8,
 		.num_ipms = 8,
 		.tc_cbs_supported = true,
+		.phy_side_mdio_supported = true,
 		.ops = &lan937x_dev_ops,
 		.phylink_mac_ops = &lan937x_phylink_mac_ops,
 		.mib_names = ksz9477_mib_names,
@@ -1818,6 +1822,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_tx_queues = 8,
 		.num_ipms = 8,
 		.tc_cbs_supported = true,
+		.phy_side_mdio_supported = true,
 		.ops = &lan937x_dev_ops,
 		.phylink_mac_ops = &lan937x_phylink_mac_ops,
 		.mib_names = ksz9477_mib_names,
@@ -1850,6 +1855,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_tx_queues = 8,
 		.num_ipms = 8,
 		.tc_cbs_supported = true,
+		.phy_side_mdio_supported = true,
 		.ops = &lan937x_dev_ops,
 		.phylink_mac_ops = &lan937x_phylink_mac_ops,
 		.mib_names = ksz9477_mib_names,
@@ -1882,6 +1888,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.num_tx_queues = 8,
 		.num_ipms = 8,
 		.tc_cbs_supported = true,
+		.phy_side_mdio_supported = true,
 		.ops = &lan937x_dev_ops,
 		.phylink_mac_ops = &lan937x_phylink_mac_ops,
 		.mib_names = ksz9477_mib_names,
diff --git a/drivers/net/dsa/microchip/lan937x.h b/drivers/net/dsa/microchip/lan937x.h
index 3388d91dbc44e..df13ebbd356f9 100644
--- a/drivers/net/dsa/microchip/lan937x.h
+++ b/drivers/net/dsa/microchip/lan937x.h
@@ -13,6 +13,8 @@ void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port);
 void lan937x_config_cpu_port(struct dsa_switch *ds);
 int lan937x_switch_init(struct ksz_device *dev);
 void lan937x_switch_exit(struct ksz_device *dev);
+int lan937x_mdio_bus_preinit(struct ksz_device *dev, bool side_mdio);
+int lan937x_create_phy_addr_map(struct ksz_device *dev, bool side_mdio);
 int lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data);
 int lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val);
 int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu);
diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index 824d9309a3d35..b7652efd632ea 100644
--- a/drivers/net/dsa/microchip/lan937x_main.c
+++ b/drivers/net/dsa/microchip/lan937x_main.c
@@ -18,6 +18,87 @@
 #include "ksz9477.h"
 #include "lan937x.h"
 
+/* marker for ports without built-in PHY */
+#define LAN937X_NO_PHY U8_MAX
+
+/*
+ * lan9370_phy_addr - Mapping of LAN9370 switch ports to PHY addresses.
+ *
+ * Each entry corresponds to a specific port on the LAN9370 switch,
+ * where ports 1-4 are connected to integrated 100BASE-T1 PHYs, and
+ * Port 5 is connected to an RGMII interface without a PHY. The values
+ * are based on the documentation (DS00003108E, section 3.3).
+ */
+static const u8 lan9370_phy_addr[] = {
+	[0] = 2, /* Port 1, T1 AFE0 */
+	[1] = 3, /* Port 2, T1 AFE1 */
+	[2] = 5, /* Port 3, T1 AFE3 */
+	[3] = 6, /* Port 4, T1 AFE4 */
+	[4] = LAN937X_NO_PHY, /* Port 5, RGMII 2 */
+};
+
+/*
+ * lan9371_phy_addr - Mapping of LAN9371 switch ports to PHY addresses.
+ *
+ * The values are based on the documentation (DS00003109E, section 3.3).
+ */
+static const u8 lan9371_phy_addr[] = {
+	[0] = 2, /* Port 1, T1 AFE0 */
+	[1] = 3, /* Port 2, T1 AFE1 */
+	[2] = 5, /* Port 3, T1 AFE3 */
+	[3] = 8, /* Port 4, TX PHY */
+	[4] = LAN937X_NO_PHY, /* Port 5, RGMII 2 */
+	[5] = LAN937X_NO_PHY, /* Port 6, RGMII 1 */
+};
+
+/*
+ * lan9372_phy_addr - Mapping of LAN9372 switch ports to PHY addresses.
+ *
+ * The values are based on the documentation (DS00003110F, section 3.3).
+ */
+static const u8 lan9372_phy_addr[] = {
+	[0] = 2, /* Port 1, T1 AFE0 */
+	[1] = 3, /* Port 2, T1 AFE1 */
+	[2] = 5, /* Port 3, T1 AFE3 */
+	[3] = 8, /* Port 4, TX PHY */
+	[4] = LAN937X_NO_PHY, /* Port 5, RGMII 2 */
+	[5] = LAN937X_NO_PHY, /* Port 6, RGMII 1 */
+	[6] = 6, /* Port 7, T1 AFE4 */
+	[7] = 4, /* Port 8, T1 AFE2 */
+};
+
+/*
+ * lan9373_phy_addr - Mapping of LAN9373 switch ports to PHY addresses.
+ *
+ * The values are based on the documentation (DS00003110F, section 3.3).
+ */
+static const u8 lan9373_phy_addr[] = {
+	[0] = 2, /* Port 1, T1 AFE0 */
+	[1] = 3, /* Port 2, T1 AFE1 */
+	[2] = 5, /* Port 3, T1 AFE3 */
+	[3] = LAN937X_NO_PHY, /* Port 4, SGMII */
+	[4] = LAN937X_NO_PHY, /* Port 5, RGMII 2 */
+	[5] = LAN937X_NO_PHY, /* Port 6, RGMII 1 */
+	[6] = 6, /* Port 7, T1 AFE4 */
+	[7] = 4, /* Port 8, T1 AFE2 */
+};
+
+/*
+ * lan9374_phy_addr - Mapping of LAN9374 switch ports to PHY addresses.
+ *
+ * The values are based on the documentation (DS00003110F, section 3.3).
+ */
+static const u8 lan9374_phy_addr[] = {
+	[0] = 2, /* Port 1, T1 AFE0 */
+	[1] = 3, /* Port 2, T1 AFE1 */
+	[2] = 5, /* Port 3, T1 AFE3 */
+	[3] = 7, /* Port 4, T1 AFE5 */
+	[4] = LAN937X_NO_PHY, /* Port 5, RGMII 2 */
+	[5] = LAN937X_NO_PHY, /* Port 6, RGMII 1 */
+	[6] = 6, /* Port 7, T1 AFE4 */
+	[7] = 4, /* Port 8, T1 AFE2 */
+};
+
 static int lan937x_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
 {
 	return regmap_update_bits(ksz_regmap_8(dev), addr, bits, set ? bits : 0);
@@ -30,24 +111,144 @@ static int lan937x_port_cfg(struct ksz_device *dev, int port, int offset,
 				  bits, set ? bits : 0);
 }
 
-static int lan937x_enable_spi_indirect_access(struct ksz_device *dev)
+/**
+ * lan937x_create_phy_addr_map - Create port-to-PHY address map for MDIO bus.
+ * @dev: Pointer to device structure.
+ * @side_mdio: Boolean indicating if the PHYs are accessed over a side MDIO bus.
+ *
+ * This function sets up the PHY address mapping for the LAN937x switches,
+ * which support two access modes for internal PHYs:
+ * 1. **SPI Access**: A straightforward one-to-one port-to-PHY address
+ *    mapping is applied.
+ * 2. **MDIO Access**: The PHY address mapping varies based on chip variant
+ *    and strap configuration. An offset is calculated based on strap settings
+ *    to ensure correct PHY addresses are assigned. The offset calculation logic
+ *    is based on Microchip's Article Number 000015828, available at:
+ *    https://microchip.my.site.com/s/article/LAN9374-Virtual-PHY-PHY-Address-Mapping
+ *
+ * The function first checks if side MDIO access is disabled, in which case a
+ * simple direct mapping (port number = PHY address) is applied. If side MDIO
+ * access is enabled, it reads the strap configuration to determine the correct
+ * offset for PHY addresses.
+ *
+ * The appropriate mapping table is selected based on the chip ID, and the
+ * `phy_addr_map` is populated with the correct addresses for each port. Any
+ * port with no PHY is assigned a `LAN937X_NO_PHY` marker.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+int lan937x_create_phy_addr_map(struct ksz_device *dev, bool side_mdio)
+{
+	static const u8 *phy_addr_map;
+	u32 strap_val;
+	u8 offset = 0;
+	size_t size;
+	int ret, i;
+
+	if (!side_mdio) {
+		/* simple direct mapping */
+		for (i = 0; i < dev->info->port_cnt; i++)
+			dev->phy_addr_map[i] = i;
+
+		return 0;
+	}
+
+	ret = ksz_read32(dev, REG_SW_CFG_STRAP_VAL, &strap_val);
+	if (ret < 0)
+		return ret;
+
+	if (!(strap_val & SW_CASCADE_ID_CFG) && !(strap_val & SW_VPHY_ADD_CFG))
+		offset = 0;
+	else if (!(strap_val & SW_CASCADE_ID_CFG) && (strap_val & SW_VPHY_ADD_CFG))
+		offset = 7;
+	else if ((strap_val & SW_CASCADE_ID_CFG) && !(strap_val & SW_VPHY_ADD_CFG))
+		offset = 15;
+	else
+		offset = 22;
+
+	switch (dev->info->chip_id) {
+	case LAN9370_CHIP_ID:
+		phy_addr_map = lan9370_phy_addr;
+		size = ARRAY_SIZE(lan9370_phy_addr);
+		break;
+	case LAN9371_CHIP_ID:
+		phy_addr_map = lan9371_phy_addr;
+		size = ARRAY_SIZE(lan9371_phy_addr);
+		break;
+	case LAN9372_CHIP_ID:
+		phy_addr_map = lan9372_phy_addr;
+		size = ARRAY_SIZE(lan9372_phy_addr);
+		break;
+	case LAN9373_CHIP_ID:
+		phy_addr_map = lan9373_phy_addr;
+		size = ARRAY_SIZE(lan9373_phy_addr);
+		break;
+	case LAN9374_CHIP_ID:
+		phy_addr_map = lan9374_phy_addr;
+		size = ARRAY_SIZE(lan9374_phy_addr);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (size < dev->info->port_cnt)
+		return -EINVAL;
+
+	for (i = 0; i < dev->info->port_cnt; i++) {
+		if (phy_addr_map[i] == LAN937X_NO_PHY)
+			dev->phy_addr_map[i] = phy_addr_map[i];
+		else
+			dev->phy_addr_map[i] = phy_addr_map[i] + offset;
+	}
+
+	return 0;
+}
+
+/**
+ * lan937x_mdio_bus_preinit - Pre-initialize MDIO bus for accessing PHYs.
+ * @dev: Pointer to device structure.
+ * @side_mdio: Boolean indicating if the PHYs are accessed over a side MDIO bus.
+ *
+ * This function configures the LAN937x switch for PHY access either through
+ * SPI or the side MDIO bus, unlocking the necessary registers for each access
+ * mode.
+ *
+ * Operation Modes:
+ * 1. **SPI Access**: Enables SPI indirect access to address clock domain
+ *    crossing issues when SPI is used for PHY access.
+ * 2. **MDIO Access**: Grants access to internal PHYs over the side MDIO bus,
+ *    required when using the MDIO bus for PHY management.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+int lan937x_mdio_bus_preinit(struct ksz_device *dev, bool side_mdio)
 {
 	u16 data16;
 	int ret;
 
-	/* Enable Phy access through SPI */
+	/* Unlock access to the PHYs, needed for SPI and side MDIO access */
 	ret = lan937x_cfg(dev, REG_GLOBAL_CTRL_0, SW_PHY_REG_BLOCK, false);
 	if (ret < 0)
-		return ret;
+		goto print_error;
 
-	ret = ksz_read16(dev, REG_VPHY_SPECIAL_CTRL__2, &data16);
-	if (ret < 0)
-		return ret;
+	if (side_mdio)
+		/* Allow access to internal PHYs over MDIO bus */
+		data16 = VPHY_MDIO_INTERNAL_ENABLE;
+	else
+		/* Enable SPI indirect access to address clock domain crossing
+		 * issue
+		 */
+		data16 = VPHY_SPI_INDIRECT_ENABLE;
 
-	/* Allow SPI access */
-	data16 |= VPHY_SPI_INDIRECT_ENABLE;
+	ret = ksz_rmw16(dev, REG_VPHY_SPECIAL_CTRL__2,
+			VPHY_SPI_INDIRECT_ENABLE | VPHY_MDIO_INTERNAL_ENABLE,
+			data16);
+
+print_error:
+	if (ret < 0)
+		dev_err(dev->dev, "failed to preinit the MDIO bus\n");
 
-	return ksz_write16(dev, REG_VPHY_SPECIAL_CTRL__2, data16);
+	return ret;
 }
 
 static int lan937x_vphy_ind_addr_wr(struct ksz_device *dev, int addr, int reg)
@@ -363,13 +564,6 @@ int lan937x_setup(struct dsa_switch *ds)
 	struct ksz_device *dev = ds->priv;
 	int ret;
 
-	/* enable Indirect Access from SPI to the VPHY registers */
-	ret = lan937x_enable_spi_indirect_access(dev);
-	if (ret < 0) {
-		dev_err(dev->dev, "failed to enable spi indirect access");
-		return ret;
-	}
-
 	/* The VLAN aware is a global setting. Mixed vlan
 	 * filterings are not supported.
 	 */
diff --git a/drivers/net/dsa/microchip/lan937x_reg.h b/drivers/net/dsa/microchip/lan937x_reg.h
index 2f22a9d01de36..4ec93e421da45 100644
--- a/drivers/net/dsa/microchip/lan937x_reg.h
+++ b/drivers/net/dsa/microchip/lan937x_reg.h
@@ -37,6 +37,10 @@
 #define SW_CLK125_ENB			BIT(1)
 #define SW_CLK25_ENB			BIT(0)
 
+#define REG_SW_CFG_STRAP_VAL		0x0200
+#define SW_CASCADE_ID_CFG		BIT(15)
+#define SW_VPHY_ADD_CFG			BIT(0)
+
 /* 2 - PHY Control */
 #define REG_SW_CFG_STRAP_OVR		0x0214
 #define SW_VPHY_DISABLE			BIT(31)
-- 
2.39.5

[PATCH net-next v4 6/6] net: dsa: microchip: parse PHY config from device tree

[Oleksij Rempel]

Introduce ksz_parse_dt_phy_config() to validate and parse PHY
configuration from the device tree for KSZ switches. This function
ensures proper setup of internal PHYs by checking `phy-handle`
properties, verifying expected PHY IDs, and handling parent node
mismatches. Sets the PHY mask on the MII bus if validation is
successful. Returns -EINVAL on configuration errors.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v4:
- remove second internal_phy check
- rename phy_id to phy_addr
---
 drivers/net/dsa/microchip/ksz_common.c | 79 ++++++++++++++++++++++++--
 1 file changed, 73 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 19fb090c09ab7..d57782cdda599 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2371,6 +2371,76 @@ static void ksz_irq_phy_free(struct ksz_device *dev)
 			irq_dispose_mapping(ds->user_mii_bus->irq[phy]);
 }
 
+/**
+ * ksz_parse_dt_phy_config - Parse and validate PHY configuration from DT
+ * @dev: pointer to the KSZ device structure
+ * @bus: pointer to the MII bus structure
+ * @mdio_np: pointer to the MDIO node in the device tree
+ *
+ * This function parses and validates PHY configurations for each user port
+ * defined in the device tree for a KSZ switch device. It verifies that the
+ * `phy-handle` properties are correctly set and that the internal PHYs match
+ * expected addresses and parent nodes. Sets up the PHY mask in the MII bus if
+ * all validations pass. Logs error messages for any mismatches or missing data.
+ *
+ * Return: 0 on success, or a negative error code on failure.
+ */
+static int ksz_parse_dt_phy_config(struct ksz_device *dev, struct mii_bus *bus,
+				   struct device_node *mdio_np)
+{
+	struct device_node *phy_node, *phy_parent_node;
+	bool phys_are_valid = true;
+	struct dsa_port *dp;
+	u32 phy_addr;
+	int ret;
+
+	dsa_switch_for_each_user_port(dp, dev->ds) {
+		if (!dev->info->internal_phy[dp->index])
+			continue;
+
+		phy_node = of_parse_phandle(dp->dn, "phy-handle", 0);
+		if (!phy_node) {
+			dev_err(dev->dev, "failed to parse phy-handle for port %d.\n",
+				dp->index);
+			phys_are_valid = false;
+			continue;
+		}
+
+		phy_parent_node = of_get_parent(phy_node);
+		if (!phy_parent_node) {
+			dev_err(dev->dev, "failed to get PHY-parent node for port %d\n",
+				dp->index);
+			phys_are_valid = false;
+		} else if (phy_parent_node != mdio_np) {
+			dev_err(dev->dev, "PHY-parent node mismatch for port %d, expected %pOF, got %pOF\n",
+				dp->index, mdio_np, phy_parent_node);
+			phys_are_valid = false;
+		} else {
+			ret = of_property_read_u32(phy_node, "reg", &phy_addr);
+			if (ret < 0) {
+				dev_err(dev->dev, "failed to read PHY address for port %d. Error %d\n",
+					dp->index, ret);
+				phys_are_valid = false;
+			} else if (phy_addr != dev->phy_addr_map[dp->index]) {
+				dev_err(dev->dev, "PHY address mismatch for port %d, expected 0x%x, got 0x%x\n",
+					dp->index, dev->phy_addr_map[dp->index],
+					phy_addr);
+				phys_are_valid = false;
+			} else {
+				bus->phy_mask |= BIT(phy_addr);
+			}
+		}
+
+		of_node_put(phy_node);
+		of_node_put(phy_parent_node);
+	}
+
+	if (!phys_are_valid)
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
  * ksz_mdio_register - Register and configure the MDIO bus for the KSZ device.
  * @dev: Pointer to the KSZ device structure.
@@ -2390,7 +2460,6 @@ static int ksz_mdio_register(struct ksz_device *dev)
 	struct dsa_switch *ds = dev->ds;
 	struct device_node *mdio_np;
 	struct mii_bus *bus;
-	struct dsa_port *dp;
 	int ret, i;
 
 	mdio_np = of_get_child_by_name(dev->dev->of_node, "mdio");
@@ -2449,11 +2518,9 @@ static int ksz_mdio_register(struct ksz_device *dev)
 		snprintf(bus->id, MII_BUS_ID_SIZE, "SMI-%d", ds->index);
 	}
 
-	dsa_switch_for_each_user_port(dp, dev->ds) {
-		if (dev->info->internal_phy[dp->index] &&
-		    dev->phy_addr_map[dp->index] < PHY_MAX_ADDR)
-			bus->phy_mask |= BIT(dev->phy_addr_map[dp->index]);
-	}
+	ret = ksz_parse_dt_phy_config(dev, bus, mdio_np);
+	if (ret)
+		goto put_mdio_node;
 
 	ds->phys_mii_mask = bus->phy_mask;
 	bus->parent = ds->dev;
-- 
2.39.5

Re: [PATCH net-next v4 0/6] Side MDIO Support for LAN937x Switches

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Wed,  6 Nov 2024 08:59:35 +0100 you wrote:
> This patch set introduces support for an internal MDIO bus in LAN937x
> switches, enabling the use of a side MDIO channel for PHY management
> while keeping SPI as the main interface for switch configuration.
> 
> changes v3:
> - add "net: dsa: microchip: parse PHY config from device tree" patch
> 
> [...]

Here is the summary with links:
  - [net-next,v4,1/6] dt-bindings: net: dsa: microchip: add internal MDIO bus description
    https://git.kernel.org/netdev/net-next/c/7eb4c2571443
  - [net-next,v4,2/6] dt-bindings: net: dsa: microchip: add mdio-parent-bus property for internal MDIO
    https://git.kernel.org/netdev/net-next/c/698b20a679be
  - [net-next,v4,3/6] net: dsa: microchip: Refactor MDIO handling for side MDIO access
    https://git.kernel.org/netdev/net-next/c/9afaf0eec2ab
  - [net-next,v4,4/6] net: dsa: microchip: cleanup error handling in ksz_mdio_register
    https://git.kernel.org/netdev/net-next/c/8bbba4161b65
  - [net-next,v4,5/6] net: dsa: microchip: add support for side MDIO interface in LAN937x
    https://git.kernel.org/netdev/net-next/c/f47e6e1e79a1
  - [net-next,v4,6/6] net: dsa: microchip: parse PHY config from device tree
    https://git.kernel.org/netdev/net-next/c/34125ac851b8

You are awesome, thank you!
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