[PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[Linus Walleij]

This adds device tree bindings for the IXP4xx ethernet
controller with optional MDIO bridge.

Cc: Zoltan HERPAI <wigyori@uid0.hu>
Cc: Raylynn Knight <rayknight@me.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Designate phy nodes with ethernet-phy@
- Include phy-mode in the schema
ChangeLog v1->v2:
- Add schema for the (optional) embedded MDIO bus inside
  the ethernet controller in an "mdio" node instead of just
  letting the code randomly populate and present it to
  the operating system.
- Reference the standard schemas for ethernet controller and
  MDIO buses.
- Add intel,npe to indentify the NPE unit used with each
  ethernet adapter.
---
 .../bindings/net/intel,ixp4xx-ethernet.yaml   | 82 +++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml

diff --git a/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml b/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml
new file mode 100644
index 000000000000..978e7f236f3a
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2018 Linaro Ltd.
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/net/intel,ixp4xx-ethernet.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Intel IXP4xx ethernet
+
+allOf:
+  - $ref: "ethernet-controller.yaml#"
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  The Intel IXP4xx ethernet makes use of the IXP4xx NPE (Network
+  Processing Engine) and the IXP4xx Queue Mangager to process
+  the ethernet frames. It can optionally contain an MDIO bus to
+  talk to PHYs.
+
+properties:
+  compatible:
+    const: intel,ixp4xx-ethernet
+
+  reg:
+    maxItems: 1
+    description: Ethernet MMIO address range
+
+  queue-rx:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the RX queue on the NPE
+
+  queue-txready:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    maxItems: 1
+    description: phandle to the TX READY queue on the NPE
+
+  phy-mode: true
+
+  phy-handle: true
+
+  intel,npe:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1, 2, 3]
+    description: which NPE (Network Processing Engine) this ethernet
+      instance is using
+
+  mdio:
+    type: object
+    $ref: "mdio.yaml#"
+    description: optional node for embedded MDIO controller
+
+required:
+  - compatible
+  - reg
+  - queue-rx
+  - queue-txready
+
+additionalProperties: false
+
+examples:
+  - |
+    ethernet@c8009000 {
+      compatible = "intel,ixp4xx-ethernet";
+      reg = <0xc8009000 0x1000>;
+      status = "disabled";
+      queue-rx = <&qmgr 3>;
+      queue-txready = <&qmgr 20>;
+      intel,npe = <1>;
+      phy-mode = "rgmii";
+      phy-handle = <&phy1>;
+
+      mdio {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        phy1: ethernet-phy@1 {
+          reg = <1>;
+        };
+      };
+    };
-- 
2.29.2

[PATCH 2/3 net-next v3] net: ethernet: ixp4xx: Retire ancient phy retrieveal

[Linus Walleij]

This driver was using a really dated way of obtaining the
phy by printing a string and using it with phy_connect().
Switch to using more reasonable modern interfaces.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v3:
- New patch
---
 drivers/net/ethernet/xscale/ixp4xx_eth.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c
index 9defaa21a1a9..4df2686ac5b8 100644
--- a/drivers/net/ethernet/xscale/ixp4xx_eth.c
+++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c
@@ -1360,7 +1360,6 @@ static const struct net_device_ops ixp4xx_netdev_ops = {
 
 static int ixp4xx_eth_probe(struct platform_device *pdev)
 {
-	char phy_id[MII_BUS_ID_SIZE + 3];
 	struct phy_device *phydev = NULL;
 	struct device *dev = &pdev->dev;
 	struct eth_plat_info *plat;
@@ -1462,14 +1461,15 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	__raw_writel(DEFAULT_CORE_CNTRL, &port->regs->core_control);
 	udelay(50);
 
-	snprintf(phy_id, MII_BUS_ID_SIZE + 3, PHY_ID_FMT,
-		mdio_bus->id, plat->phy);
-	phydev = phy_connect(ndev, phy_id, &ixp4xx_adjust_link,
-			     PHY_INTERFACE_MODE_MII);
+	phydev = mdiobus_get_phy(mdio_bus, plat->phy);
 	if (IS_ERR(phydev)) {
 		err = PTR_ERR(phydev);
 		goto err_free_mem;
 	}
+	err = phy_connect_direct(ndev, phydev, ixp4xx_adjust_link,
+				 PHY_INTERFACE_MODE_MII);
+	if (err)
+		goto err_free_mem;
 
 	phydev->irq = PHY_POLL;
 
-- 
2.29.2

[PATCH 3/3 net-next v3] net: ethernet: ixp4xx: Support device tree probing

[Linus Walleij]

This adds device tree probing to the IXP4xx ethernet
driver.

Add a platform data bool to tell us whether to
register an MDIO bus for the device or not, as well
as the corresponding NPE.

We need to drop the memory region request as part of
this since the OF core will request the memory for the
device.

Cc: Zoltan HERPAI <wigyori@uid0.hu>
Cc: Raylynn Knight <rayknight@me.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v2->v3:
- Squash in the patch doing the MDIO bus transition to
  OF probing.
ChangeLog v1->v2:
- Do not rely on earlier attempt for identifying which
  ports to use: we split the support clearly in a DT way
  and a playform data way.
- Isolate the DT code better.
---
 drivers/net/ethernet/xscale/Kconfig      |   1 +
 drivers/net/ethernet/xscale/ixp4xx_eth.c | 209 ++++++++++++++++-------
 include/linux/platform_data/eth_ixp4xx.h |   2 +
 3 files changed, 149 insertions(+), 63 deletions(-)

diff --git a/drivers/net/ethernet/xscale/Kconfig b/drivers/net/ethernet/xscale/Kconfig
index 7b83a6e5d894..468ffe3d1707 100644
--- a/drivers/net/ethernet/xscale/Kconfig
+++ b/drivers/net/ethernet/xscale/Kconfig
@@ -22,6 +22,7 @@ config IXP4XX_ETH
 	tristate "Intel IXP4xx Ethernet support"
 	depends on ARM && ARCH_IXP4XX && IXP4XX_NPE && IXP4XX_QMGR
 	select PHYLIB
+	select OF_MDIO if OF
 	select NET_PTP_CLASSIFY
 	help
 	  Say Y here if you want to use built-in Ethernet ports
diff --git a/drivers/net/ethernet/xscale/ixp4xx_eth.c b/drivers/net/ethernet/xscale/ixp4xx_eth.c
index 4df2686ac5b8..ac8049b62337 100644
--- a/drivers/net/ethernet/xscale/ixp4xx_eth.c
+++ b/drivers/net/ethernet/xscale/ixp4xx_eth.c
@@ -28,6 +28,7 @@
 #include <linux/kernel.h>
 #include <linux/net_tstamp.h>
 #include <linux/of.h>
+#include <linux/of_mdio.h>
 #include <linux/phy.h>
 #include <linux/platform_data/eth_ixp4xx.h>
 #include <linux/platform_device.h>
@@ -165,7 +166,6 @@ struct eth_regs {
 };
 
 struct port {
-	struct resource *mem_res;
 	struct eth_regs __iomem *regs;
 	struct npe *npe;
 	struct net_device *netdev;
@@ -250,6 +250,7 @@ static inline void memcpy_swab32(u32 *dest, u32 *src, int cnt)
 static DEFINE_SPINLOCK(mdio_lock);
 static struct eth_regs __iomem *mdio_regs; /* mdio command and status only */
 static struct mii_bus *mdio_bus;
+static struct device_node *mdio_bus_np;
 static int ports_open;
 static struct port *npe_port_tab[MAX_NPES];
 static struct dma_pool *dma_pool;
@@ -533,7 +534,8 @@ static int ixp4xx_mdio_register(struct eth_regs __iomem *regs)
 	mdio_bus->write = &ixp4xx_mdio_write;
 	snprintf(mdio_bus->id, MII_BUS_ID_SIZE, "ixp4xx-eth-0");
 
-	if ((err = mdiobus_register(mdio_bus)))
+	err = of_mdiobus_register(mdio_bus, mdio_bus_np);
+	if (err)
 		mdiobus_free(mdio_bus);
 	return err;
 }
@@ -1358,18 +1360,117 @@ static const struct net_device_ops ixp4xx_netdev_ops = {
 	.ndo_validate_addr = eth_validate_addr,
 };
 
+#ifdef CONFIG_OF
+static struct eth_plat_info *ixp4xx_of_get_platdata(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct of_phandle_args queue_spec;
+	struct eth_plat_info *plat;
+	struct device_node *mdio_np;
+	u32 val;
+	int ret;
+
+	plat = devm_kzalloc(dev, sizeof(*plat), GFP_KERNEL);
+	if (!plat)
+		return NULL;
+
+	ret = of_property_read_u32(np, "intel,npe", &val);
+	if (ret) {
+		dev_err(dev, "no NPE engine specified\n");
+		return NULL;
+	}
+	/* NPE ID 0x00, 0x10, 0x20... */
+	plat->npe = (val << 4);
+
+	/* Check if this device has an MDIO bus */
+	mdio_np = of_get_child_by_name(np, "mdio");
+	if (mdio_np) {
+		plat->has_mdio = true;
+		mdio_bus_np = mdio_np;
+		/* DO NOT put the mdio_np, it will be used */
+	}
+
+	/* Get the rx queue as a resource from queue manager */
+	ret = of_parse_phandle_with_fixed_args(np, "queue-rx", 1, 0,
+					       &queue_spec);
+	if (ret) {
+		dev_err(dev, "no rx queue phandle\n");
+		return NULL;
+	}
+	plat->rxq = queue_spec.args[0];
+
+	/* Get the txready queue as resource from queue manager */
+	ret = of_parse_phandle_with_fixed_args(np, "queue-txready", 1, 0,
+					       &queue_spec);
+	if (ret) {
+		dev_err(dev, "no txready queue phandle\n");
+		return NULL;
+	}
+	plat->txreadyq = queue_spec.args[0];
+
+	return plat;
+}
+#else
+static struct eth_plat_info *ixp4xx_of_get_platdata(struct device *dev)
+{
+	return NULL;
+}
+#endif
+
 static int ixp4xx_eth_probe(struct platform_device *pdev)
 {
 	struct phy_device *phydev = NULL;
 	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
 	struct eth_plat_info *plat;
-	resource_size_t regs_phys;
 	struct net_device *ndev;
 	struct resource *res;
 	struct port *port;
 	int err;
 
-	plat = dev_get_platdata(dev);
+	if (np) {
+		plat = ixp4xx_of_get_platdata(dev);
+		if (!plat)
+			return -ENODEV;
+	} else {
+		plat = dev_get_platdata(dev);
+		if (!plat)
+			return -ENODEV;
+		plat->npe = pdev->id;
+		switch (plat->npe) {
+		case IXP4XX_ETH_NPEA:
+			/* If the MDIO bus is not up yet, defer probe */
+			break;
+		case IXP4XX_ETH_NPEB:
+			/* On all except IXP43x, NPE-B is used for the MDIO bus.
+			 * If there is no NPE-B in the feature set, bail out,
+			 * else we have the MDIO bus here.
+			 */
+			if (!cpu_is_ixp43x()) {
+				if (!(ixp4xx_read_feature_bits() &
+				      IXP4XX_FEATURE_NPEB_ETH0))
+					return -ENODEV;
+				/* Else register the MDIO bus on NPE-B */
+				plat->has_mdio = true;
+			}
+			break;
+		case IXP4XX_ETH_NPEC:
+			/* IXP43x lacks NPE-B and uses NPE-C for the MDIO bus
+			 * access, if there is no NPE-C, no bus, nothing works,
+			 * so bail out.
+			 */
+			if (cpu_is_ixp43x()) {
+				if (!(ixp4xx_read_feature_bits() &
+				      IXP4XX_FEATURE_NPEC_ETH))
+					return -ENODEV;
+				/* Else register the MDIO bus on NPE-B */
+				plat->has_mdio = true;
+			}
+			break;
+		default:
+			return -ENODEV;
+		}
+	}
 
 	if (!(ndev = devm_alloc_etherdev(dev, sizeof(struct port))))
 		return -ENOMEM;
@@ -1377,59 +1478,29 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	SET_NETDEV_DEV(ndev, dev);
 	port = netdev_priv(ndev);
 	port->netdev = ndev;
-	port->id = pdev->id;
+	port->id = plat->npe;
 
 	/* Get the port resource and remap */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;
-	regs_phys = res->start;
 	port->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(port->regs))
 		return PTR_ERR(port->regs);
 
-	switch (port->id) {
-	case IXP4XX_ETH_NPEA:
-		/* If the MDIO bus is not up yet, defer probe */
-		if (!mdio_bus)
-			return -EPROBE_DEFER;
-		break;
-	case IXP4XX_ETH_NPEB:
-		/*
-		 * On all except IXP43x, NPE-B is used for the MDIO bus.
-		 * If there is no NPE-B in the feature set, bail out, else
-		 * register the MDIO bus.
-		 */
-		if (!cpu_is_ixp43x()) {
-			if (!(ixp4xx_read_feature_bits() &
-			      IXP4XX_FEATURE_NPEB_ETH0))
-				return -ENODEV;
-			/* Else register the MDIO bus on NPE-B */
-			if ((err = ixp4xx_mdio_register(port->regs)))
-				return err;
-		}
-		if (!mdio_bus)
-			return -EPROBE_DEFER;
-		break;
-	case IXP4XX_ETH_NPEC:
-		/*
-		 * IXP43x lacks NPE-B and uses NPE-C for the MDIO bus access,
-		 * of there is no NPE-C, no bus, nothing works, so bail out.
-		 */
-		if (cpu_is_ixp43x()) {
-			if (!(ixp4xx_read_feature_bits() &
-			      IXP4XX_FEATURE_NPEC_ETH))
-				return -ENODEV;
-			/* Else register the MDIO bus on NPE-C */
-			if ((err = ixp4xx_mdio_register(port->regs)))
-				return err;
+	/* Register the MDIO bus if we have it */
+	if (plat->has_mdio) {
+		err = ixp4xx_mdio_register(port->regs);
+		if (err) {
+			dev_err(dev, "failed to register MDIO bus\n");
+			return err;
 		}
-		if (!mdio_bus)
-			return -EPROBE_DEFER;
-		break;
-	default:
-		return -ENODEV;
 	}
+	/* If the instance with the MDIO bus has not yet appeared,
+	 * defer probing until it gets probed.
+	 */
+	if (!mdio_bus)
+		return -EPROBE_DEFER;
 
 	ndev->netdev_ops = &ixp4xx_netdev_ops;
 	ndev->ethtool_ops = &ixp4xx_ethtool_ops;
@@ -1443,12 +1514,6 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	if (!(port->npe = npe_request(NPE_ID(port->id))))
 		return -EIO;
 
-	port->mem_res = request_mem_region(regs_phys, REGS_SIZE, ndev->name);
-	if (!port->mem_res) {
-		err = -EBUSY;
-		goto err_npe_rel;
-	}
-
 	port->plat = plat;
 	npe_port_tab[NPE_ID(port->id)] = port;
 	memcpy(ndev->dev_addr, plat->hwaddr, ETH_ALEN);
@@ -1461,15 +1526,26 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	__raw_writel(DEFAULT_CORE_CNTRL, &port->regs->core_control);
 	udelay(50);
 
-	phydev = mdiobus_get_phy(mdio_bus, plat->phy);
-	if (IS_ERR(phydev)) {
-		err = PTR_ERR(phydev);
-		goto err_free_mem;
+	if (np) {
+		phydev = of_phy_get_and_connect(ndev, np, ixp4xx_adjust_link);
+	} else {
+		phydev = mdiobus_get_phy(mdio_bus, plat->phy);
+		if (IS_ERR(phydev)) {
+			err = PTR_ERR(phydev);
+			dev_err(dev, "could not connect phydev (%d)\n", err);
+			goto err_free_mem;
+		}
+		err = phy_connect_direct(ndev, phydev, ixp4xx_adjust_link,
+					 PHY_INTERFACE_MODE_MII);
+		if (err)
+			goto err_free_mem;
+
 	}
-	err = phy_connect_direct(ndev, phydev, ixp4xx_adjust_link,
-				 PHY_INTERFACE_MODE_MII);
-	if (err)
+	if (!phydev) {
+		err = -ENODEV;
+		dev_err(dev, "no phydev\n");
 		goto err_free_mem;
+	}
 
 	phydev->irq = PHY_POLL;
 
@@ -1485,8 +1561,6 @@ static int ixp4xx_eth_probe(struct platform_device *pdev)
 	phy_disconnect(phydev);
 err_free_mem:
 	npe_port_tab[NPE_ID(port->id)] = NULL;
-	release_resource(port->mem_res);
-err_npe_rel:
 	npe_release(port->npe);
 	return err;
 }
@@ -1502,12 +1576,21 @@ static int ixp4xx_eth_remove(struct platform_device *pdev)
 	ixp4xx_mdio_remove();
 	npe_port_tab[NPE_ID(port->id)] = NULL;
 	npe_release(port->npe);
-	release_resource(port->mem_res);
 	return 0;
 }
 
+static const struct of_device_id ixp4xx_eth_of_match[] = {
+	{
+		.compatible = "intel,ixp4xx-ethernet",
+	},
+	{ },
+};
+
 static struct platform_driver ixp4xx_eth_driver = {
-	.driver.name	= DRV_NAME,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(ixp4xx_eth_of_match),
+	},
 	.probe		= ixp4xx_eth_probe,
 	.remove		= ixp4xx_eth_remove,
 };
diff --git a/include/linux/platform_data/eth_ixp4xx.h b/include/linux/platform_data/eth_ixp4xx.h
index 6f652ea0c6ae..114b0940729f 100644
--- a/include/linux/platform_data/eth_ixp4xx.h
+++ b/include/linux/platform_data/eth_ixp4xx.h
@@ -14,6 +14,8 @@ struct eth_plat_info {
 	u8 rxq;		/* configurable, currently 0 - 31 only */
 	u8 txreadyq;
 	u8 hwaddr[6];
+	u8 npe;		/* NPE instance used by this interface */
+	bool has_mdio;	/* If this instance has an MDIO bus */
 };
 
 #endif
-- 
2.29.2

Re: [PATCH 2/3 net-next v3] net: ethernet: ixp4xx: Retire ancient phy retrieveal

[Andrew Lunn]

On Fri, Apr 23, 2021 at 10:22:07AM +0200, Linus Walleij wrote:
> This driver was using a really dated way of obtaining the
> phy by printing a string and using it with phy_connect().
> Switch to using more reasonable modern interfaces.
> 
> Suggested-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[Andrew Lunn]

On Fri, Apr 23, 2021 at 10:22:06AM +0200, Linus Walleij wrote:
> This adds device tree bindings for the IXP4xx ethernet
> controller with optional MDIO bridge.

Hi Linus

That optional MDIO bus sentence is important here. I think it would be
good to give examples for say IXP43x, where the MDIO bus is on NPE-C,
and the phy-handles point from one Ethernet device in the device tree
to the other. It is not unknown, but it is unusual, so giving an
example is good.

Also, looking at the unmodified driver, there is the global variable
mdio_bus. This should contain the one MDIO bus for the cluster. With
the C code, it should be impossible for multiple devices to
instantiate an MDIO bus. But with device tree, is that still true?
Should there be validation that only one device has an MDIO bus in its
device tree?

       Andrew

Re: [PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[Rob Herring]

On Fri, Apr 23, 2021 at 10:22:06AM +0200, Linus Walleij wrote:
> This adds device tree bindings for the IXP4xx ethernet
> controller with optional MDIO bridge.
> 
> Cc: Zoltan HERPAI <wigyori@uid0.hu>
> Cc: Raylynn Knight <rayknight@me.com>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v2->v3:
> - Designate phy nodes with ethernet-phy@
> - Include phy-mode in the schema
> ChangeLog v1->v2:
> - Add schema for the (optional) embedded MDIO bus inside
>   the ethernet controller in an "mdio" node instead of just
>   letting the code randomly populate and present it to
>   the operating system.
> - Reference the standard schemas for ethernet controller and
>   MDIO buses.
> - Add intel,npe to indentify the NPE unit used with each
>   ethernet adapter.
> ---
>  .../bindings/net/intel,ixp4xx-ethernet.yaml   | 82 +++++++++++++++++++
>  1 file changed, 82 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml b/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml
> new file mode 100644
> index 000000000000..978e7f236f3a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/intel,ixp4xx-ethernet.yaml
> @@ -0,0 +1,82 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2018 Linaro Ltd.
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/net/intel,ixp4xx-ethernet.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Intel IXP4xx ethernet
> +
> +allOf:
> +  - $ref: "ethernet-controller.yaml#"
> +
> +maintainers:
> +  - Linus Walleij <linus.walleij@linaro.org>
> +
> +description: |
> +  The Intel IXP4xx ethernet makes use of the IXP4xx NPE (Network
> +  Processing Engine) and the IXP4xx Queue Mangager to process

typo

> +  the ethernet frames. It can optionally contain an MDIO bus to
> +  talk to PHYs.
> +
> +properties:
> +  compatible:
> +    const: intel,ixp4xx-ethernet
> +
> +  reg:
> +    maxItems: 1
> +    description: Ethernet MMIO address range
> +
> +  queue-rx:
> +    $ref: '/schemas/types.yaml#/definitions/phandle-array'
> +    maxItems: 1
> +    description: phandle to the RX queue on the NPE
> +
> +  queue-txready:
> +    $ref: '/schemas/types.yaml#/definitions/phandle-array'
> +    maxItems: 1
> +    description: phandle to the TX READY queue on the NPE
> +
> +  phy-mode: true
> +
> +  phy-handle: true
> +
> +  intel,npe:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [0, 1, 2, 3]
> +    description: which NPE (Network Processing Engine) this ethernet
> +      instance is using

Is there a node for the NPE? If so, make this a phandle.

> +
> +  mdio:
> +    type: object
> +    $ref: "mdio.yaml#"
> +    description: optional node for embedded MDIO controller
> +
> +required:
> +  - compatible
> +  - reg
> +  - queue-rx
> +  - queue-txready
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    ethernet@c8009000 {
> +      compatible = "intel,ixp4xx-ethernet";
> +      reg = <0xc8009000 0x1000>;
> +      status = "disabled";
> +      queue-rx = <&qmgr 3>;
> +      queue-txready = <&qmgr 20>;
> +      intel,npe = <1>;
> +      phy-mode = "rgmii";
> +      phy-handle = <&phy1>;
> +
> +      mdio {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +        phy1: ethernet-phy@1 {
> +          reg = <1>;
> +        };
> +      };
> +    };
> -- 
> 2.29.2
> 

Re: [PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[Linus Walleij]

On Fri, Apr 23, 2021 at 4:49 PM Andrew Lunn <andrew@lunn.ch> wrote:

> (...) it should be impossible for multiple devices to
> instantiate an MDIO bus. But with device tree, is that still true?
> Should there be validation that only one device has an MDIO bus in its
> device tree?

This would be more of a question to Rob.

I am "OK" at writing YAML but not great.

If I were to express that out of 3 nodes in the DT one and only
one *must* contain a certain subnode, but it doesn't matter
which one, I have no idea how to express that.

Since the abstract syntax in YAML is pretty much stateless
this beats me.

Yours,
Linus Walleij

Re: [PATCH 1/3 net-next v3] net: ethernet: ixp4xx: Add DT bindings

[Andrew Lunn]

On Sun, Apr 25, 2021 at 02:24:26AM +0200, Linus Walleij wrote:
> On Fri, Apr 23, 2021 at 4:49 PM Andrew Lunn <andrew@lunn.ch> wrote:
> 
> > (...) it should be impossible for multiple devices to
> > instantiate an MDIO bus. But with device tree, is that still true?
> > Should there be validation that only one device has an MDIO bus in its
> > device tree?
> 
> This would be more of a question to Rob.

Hi Linus

Sorry. I was thinking C code. The driver already has the global
variable mdio_bus. It is initially a NULL pointer. It gets sent when
the first MDIO bus driver probes. If it is not NULL when an MDIO bus
driver probes, throw an error.

       Andrew