Re: [PATCH 4/4] net: dsa: soce: Add initial driver support for MRS switches

On Thu, 2026-07-30 at 11:01 +0200, Krzysztof Kozlowski wrote:

On Wed, Jul 29, 2026 at 06:36:57PM +0200, Vasilij Strassheim wrote:

quoted

+static const struct soce_variant_desc soce_variants[] = {
+	{
+		.compatible		= "soce,mrs-21-01",
+		.mdio_master_offset	= SOCE_MRS_21_01_MDIO_MASTER_OFFSET,
+		.layout			= &soce_mrs_21_01_layout,
+		.mdio_ops		= &soce_mdio_ops_20_03,
+	},
+	{
+		.compatible		= "soce,mrs-23-02",
+		.mdio_master_offset	= SOCE_MRS_21_01_MDIO_MASTER_OFFSET,
+		.layout			= &soce_mrs_24_01_layout,
+		.mdio_ops		= &soce_mdio_ops_c22_c45,
+	},
+	{
+		.compatible		= "soce,mrs-24-01",
+		.mdio_master_offset	= SOCE_MRS_21_01_MDIO_MASTER_OFFSET,
+		.layout			= &soce_mrs_24_01_layout,
+		.mdio_ops		= &soce_mdio_ops_c22_c45,
+	},
+	{ /* sentinel */ },
+};
+
+static const struct soce_variant_desc *
+soce_match_variant(const char *compatible)
+{
+	int i;
+
+	for (i = 0; soce_variants[i].compatible; i++) {
+		if (!strcmp(compatible, soce_variants[i].compatible))
+			return &soce_variants[i];

Do not re-invent OF matching. This is supposed to be of_device_id table.

I will change that.

quoted

+	}
+
+	return NULL;
+}
+
+static int soce_sw_parse_port_mdio_config(struct soce_dsa_local *local,
+					  struct device *dev,
+					  struct device_node *port_node,
+					  u32 port)
+{
+	struct device_node *phy_node;
+	u32 val;
+	int ret;
+
+	if (of_find_property(port_node, "ethernet", NULL) ||
+	    of_find_property(port_node, "link", NULL)) {
+		if (of_find_property(port_node, "phy-handle", NULL)) {
+			dev_err(dev,
+				"phy-handle not allowed on CPU/DSA port %u\n",
+				port);
+			return -EINVAL;
+		}
+
+		return 0;
+	}
+
+	phy_node = of_parse_phandle(port_node, "phy-handle", 0);
+	if (!phy_node) {
+		if (of_phy_is_fixed_link(port_node))
+			return 0;
+
+		dev_err(dev, "user port %u requires phy-handle or fixed-link\n",
+			port);
+		return -EINVAL;
+	}
+
+	ret = of_property_read_u32(phy_node, "soce,mdio-output", &val);
+	if (ret) {
+		dev_err(dev,
+			"missing soce,mdio-output in %pOF referenced by port %u\n",
+			phy_node, port);
+		goto out_put_phy;
+	}
+	local->mdio_info[port].mdio_output = val;
+
+	ret = of_property_read_u32(phy_node, "soce,phy-addr", &val);
+	if (ret) {
+		dev_err(dev,
+			"missing soce,phy-addr in %pOF referenced by port %u\n",
+			phy_node, port);
+		goto out_put_phy;
+	}
+	local->mdio_info[port].phy_addr = val;
+
+out_put_phy:
+	of_node_put(phy_node);
+	return ret;
+}
+
+static int soce_sw_parse_port_mdio(struct soce_priv *priv, struct device *dev,
+				   u32 numports)
+{
+	struct soce_dsa_local *local = &priv->local;
+	struct device_node *ports_node;
+	struct device_node *port_node;
+	u32 port;
+	int ret;
+
+	ports_node = of_get_child_by_name(dev->of_node, "ports");
+	if (!ports_node) {
+		dev_err(dev, "missing ports node\n");
+		return -EINVAL;
+	}
+
+	for_each_available_child_of_node(ports_node, port_node) {

Why not scoped?

I will change it to scoped.

quoted

+		if (of_property_read_u32(port_node, "reg", &port))
+			continue;
+
+		if (port >= numports || port >= SOCE_MAX_NUM_PORTS) {
+			dev_warn(dev,
+				 "ignoring invalid port index %u in %pOF\n",
+				 port, port_node);
+			continue;
+		}
+
+		ret = soce_sw_parse_port_mdio_config(local, dev, port_node,
+						     port);
+		if (ret) {
+			of_node_put(port_node);
+			of_node_put(ports_node);
+			return ret;
+		}
+	}
+
+	of_node_put(ports_node);
+	return 0;
+}
+
+static int soce_sw_probe(struct mdio_device *mdiodev)
+{
+	const struct soce_variant_desc *variant;
+	struct device *dev = &mdiodev->dev;
+	struct device_node *switch_node;
+	struct soce_dsa_local *local;
+	const char *soce_compatible;
+	struct soce_priv *priv;
+	u32 numports;
+	int ret;
+
+	priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->ds = devm_kzalloc(&mdiodev->dev, sizeof(*priv->ds), GFP_KERNEL);
+	if (!priv->ds)
+		return -ENOMEM;
+
+	priv->ds->dev = dev;
+	priv->ds->priv = priv;
+	local = &priv->local;
+
+	switch_node = of_parse_phandle(dev->of_node, "soce,switch-ip", 0);
+	if (!switch_node) {
+		dev_err(dev, "missing or invalid switch IP reference\n");
+		return -EINVAL;
+	}
+
+	ret = of_property_read_string(switch_node, "compatible",
+				      &soce_compatible);
+	if (ret) {
+		dev_err(dev, "missing compatible property in %pOF\n",
+			switch_node);
+		of_node_put(switch_node);
+		return -EINVAL;
+	}
+
+	variant = soce_match_variant(soce_compatible);
+	if (!variant) {
+		dev_err(dev, "unsupported compatible '%s' in %pOF\n",
+			soce_compatible, switch_node);
+		of_node_put(switch_node);

Use proper error handling exit paths with goto.

I will do it.

quoted

+		return -ENODEV;
+	}
+
+	ret = of_property_read_u32(switch_node, "soce,num-ports", &numports);
+	if (ret) {
+		dev_err(dev, "missing soce,num-ports in %pOF\n", switch_node);
+		of_node_put(switch_node);
+		return -EINVAL;
+	}
+	if (numports == 0 || numports > SOCE_MAX_NUM_PORTS) {
+		dev_err(dev, "invalid soce,num-ports %u (max %d)\n", numports,
+			SOCE_MAX_NUM_PORTS);
+		of_node_put(switch_node);
+		return -EINVAL;
+	}
+
+	local->base_addr = devm_of_iomap(dev, switch_node, 0, NULL);
+	if (IS_ERR(local->base_addr)) {
+		dev_err(dev, "failed to map switch register space for %pOF\n",
+			switch_node);
+		of_node_put(switch_node);
+		return PTR_ERR(local->base_addr);
+	}
+
+	priv->ds->ops = &soce_switch_ops;
+	local->mdio_ops = variant->mdio_ops;
+	local->mdio_master_addr =
+		local->base_addr + variant->mdio_master_offset;
+	local->layout = variant->layout;
+	of_node_put(switch_node);
+
+	priv->ds->num_ports = numports;
+	ret = soce_sw_parse_port_mdio(priv, dev, numports);
+	if (ret)
+		return ret;
+
+	dev_set_drvdata(&mdiodev->dev, priv);
+
+	dev_info(dev, "soce %s SDSA driver probed.\n", soce_compatible);

Drop, driver should be silent on success.

Does this really apply to DSA drivers? I see some corresponding dev_info()
entries in mainlined drivers. See for example mv88e6060_probe(),
gswip_probe_common() and sja1105_probe().
And there are others as well, especially if you consider the _detect()
functions that are called from _probe().
I also find it very helpful for troubleshooting, so I'd like to keep it along
with some additional information about the hardware, just like other drivers.

quoted

+
+	return dsa_register_switch(priv->ds);
+}
+
+static void soce_sw_remove(struct mdio_device *mdiodev)
+{
+	struct soce_priv *priv = dev_get_drvdata(&mdiodev->dev);
+
+	dsa_unregister_switch(priv->ds);
+}
+
+static const struct of_device_id soce_of_match[] = {
+	{ .compatible = "soce,switch-dsa" },
+	{ /* sentinel */ },
+};
+
+static struct mdio_driver soce_mdio_driver = {
+	.mdiodrv.driver = {
+		.name = "soce-switch-dsa",
+		.of_match_table = soce_of_match,
+	},
+	.probe  = soce_sw_probe,
+	.remove = soce_sw_remove,
+};

Best regards,
Krzysztof

Thanks,
Vasilij