[PATCH v2 net-next 11/15] net: dsa: sja1105: fill device tree with ethernet-pcs sub-devices under "regs" node

@@ -7,6 +7,7 @@ tristate "NXP SJA1105 Ethernet switch family support"
 	select PCS_XPCS
 	select PACKING
 	select CRC32
+	select OF_DYNAMIC
 	help
 	  This is the driver for the NXP SJA1105 (5-port) and SJA1110 (10-port)
 	  automotive Ethernet switch family. These are managed over an SPI

@@ -113,6 +113,13 @@ enum sja1105_internal_phy_t {
 	SJA1105_PHY_BASE_T1,
 };
 
+struct sja1105_pcs_resource {
+	struct resource res;
+	int port;
+	u32 tx_polarity;
+	const char *compatible;
+};
+
 struct sja1105_info {
 	u64 device_id;
 	/* Needed for distinction between P and R, and between Q and S

@@ -165,6 +172,8 @@ struct sja1105_info {
 	bool supports_2500basex[SJA1105_MAX_NUM_PORTS];
 	enum sja1105_internal_phy_t internal_phy[SJA1105_MAX_NUM_PORTS];
 	const u64 port_speed[SJA1105_SPEED_MAX];
+	const struct sja1105_pcs_resource *pcs_resources;
+	size_t num_pcs_resources;
 };
 
 enum sja1105_key_type {

@@ -278,6 +287,8 @@ struct sja1105_private {
 	struct sja1105_cbs_entry *cbs;
 	struct mii_bus *mdio_pcs;
 	struct phylink_pcs *pcs[SJA1105_MAX_NUM_PORTS];
+	struct fwnode_handle *pcs_fwnode[SJA1105_MAX_NUM_PORTS];
+	struct of_changeset of_cs;
 	struct sja1105_ptp_data ptp_data;
 	struct sja1105_tas_data tas_data;
 };

@@ -3330,6 +3330,13 @@ static int sja1105_probe(struct spi_device *spi)
 		return rc;
 	}
 
+	rc = devm_sja1105_fill_device_tree(ds);
+	if (rc) {
+		dev_err(ds->dev, "Failed to fill device tree: %pe\n",
+			ERR_PTR(rc));
+		return rc;
+	}
+
 	rc = devm_sja1105_add_subdevs(ds);
 	if (rc) {
 		dev_err(ds->dev, "Failed to create child devices: %pe\n",

@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: BSD-3-Clause
-/* Copyright 2016-2018 NXP
+/* Copyright 2016-2018, 2026 NXP
  * Copyright (c) 2018, Sensor-Technik Wiedemann GmbH
  * Copyright (c) 2018-2019, Vladimir Oltean <olteanv@gmail.com>
  */
+#include <linux/phy/phy-common-props.h>
 #include <linux/spi/spi.h>
 #include <linux/packing.h>
 #include "sja1105.h"

@@ -619,6 +620,28 @@ static const struct sja1105_regs sja1110_regs = {
 		     SJA1105_RSV_ADDR, SJA1105_RSV_ADDR, SJA1105_RSV_ADDR},
 };
 
+/* See port compatibility matrix in Documentation/networking/dsa/sja1105.rst */
+static const struct sja1105_pcs_resource sja1105rs_pcs_resources[] = {
+	{ DEFINE_RES_REG_NAMED(0x0, 0x800000, "direct"), 4,
+	  PHY_POL_INVERT, "nxp,sja1105-pcs"
+	},
+};
+
+static const struct sja1105_pcs_resource sja1110_pcs_resources[] = {
+	{ DEFINE_RES_REG_NAMED(0x705000, 0x1000, "indirect"), 1,
+	  PHY_POL_NORMAL, "nxp,sja1110-pcs"
+	},
+	{ DEFINE_RES_REG_NAMED(0x706000, 0x1000, "indirect"), 2,
+	  PHY_POL_NORMAL, "nxp,sja1110-pcs"
+	},
+	{ DEFINE_RES_REG_NAMED(0x707000, 0x1000, "indirect"), 3,
+	  PHY_POL_NORMAL, "nxp,sja1110-pcs"
+	},
+	{ DEFINE_RES_REG_NAMED(0x708000, 0x1000, "indirect"), 4,
+	  PHY_POL_NORMAL, "nxp,sja1110-pcs"
+	},
+};
+
 const struct sja1105_info sja1105e_info = {
 	.device_id		= SJA1105E_DEVICE_ID,
 	.part_no		= SJA1105ET_PART_NO,

@@ -782,6 +805,8 @@ const struct sja1105_info sja1105r_info = {
 	.supports_rmii		= {true, true, true, true, true},
 	.supports_rgmii		= {true, true, true, true, true},
 	.supports_sgmii		= {false, false, false, false, true},
+	.pcs_resources		= sja1105rs_pcs_resources,
+	.num_pcs_resources	= ARRAY_SIZE(sja1105rs_pcs_resources),
 	.name			= "SJA1105R",
 };
 

@@ -818,6 +843,8 @@ const struct sja1105_info sja1105s_info = {
 	.supports_rmii		= {true, true, true, true, true},
 	.supports_rgmii		= {true, true, true, true, true},
 	.supports_sgmii		= {false, false, false, false, true},
+	.pcs_resources		= sja1105rs_pcs_resources,
+	.num_pcs_resources	= ARRAY_SIZE(sja1105rs_pcs_resources),
 	.name			= "SJA1105S",
 };
 

@@ -869,6 +896,8 @@ const struct sja1105_info sja1110a_info = {
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_PHY_BASE_T1},
+	.pcs_resources		= sja1110_pcs_resources,
+	.num_pcs_resources	= ARRAY_SIZE(sja1110_pcs_resources),
 	.name			= "SJA1110A",
 };
 

@@ -920,6 +949,8 @@ const struct sja1105_info sja1110b_info = {
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_NO_PHY},
+	.pcs_resources		= &sja1110_pcs_resources[2], /* ports 3 and 4 */
+	.num_pcs_resources	= ARRAY_SIZE(sja1110_pcs_resources) - 2,
 	.name			= "SJA1110B",
 };
 

@@ -971,6 +1002,8 @@ const struct sja1105_info sja1110c_info = {
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_NO_PHY, SJA1105_NO_PHY,
 				   SJA1105_NO_PHY},
+	.pcs_resources		= &sja1110_pcs_resources[3], /* port 4 */
+	.num_pcs_resources	= ARRAY_SIZE(sja1110_pcs_resources) - 3,
 	.name			= "SJA1110C",
 };
 

@@ -1022,5 +1055,7 @@ const struct sja1105_info sja1110d_info = {
 				   SJA1105_PHY_BASE_T1, SJA1105_PHY_BASE_T1,
 				   SJA1105_NO_PHY, SJA1105_NO_PHY,
 				   SJA1105_NO_PHY},
+	.pcs_resources		= sja1110_pcs_resources,
+	.num_pcs_resources	= ARRAY_SIZE(sja1110_pcs_resources),
 	.name			= "SJA1110D",
 };

@@ -152,3 +152,193 @@ int devm_sja1105_add_subdevs(struct dsa_switch *ds)
 
 	return 0;
 }
+
+static bool of_child_node_exists(struct device_node *np, const char *name)
+{
+	for_each_child_of_node_scoped(np, child)
+		if (!strcmp(of_node_full_name(child), name))
+			return true;
+
+	return false;
+}
+
+static int sja1105_create_pcs_nodes(struct sja1105_private *priv,
+				    struct device_node *regs_node)
+{
+	struct dsa_switch *ds = priv->ds;
+	struct device *dev = ds->dev;
+	struct device_node *pcs_node;
+	char node_name[32];
+	u32 reg_props[2];
+	int rc;
+
+	for (int i = 0; i < priv->info->num_pcs_resources; i++) {
+		const struct sja1105_pcs_resource *pcs_res;
+
+		pcs_res = &priv->info->pcs_resources[i];
+
+		/* phys_addr_t has variable size depending on the value of
+		 * CONFIG_PHYS_ADDR_T_64BIT, cast to the larger unsigned long
+		 * long type for printf.
+		 */
+		snprintf(node_name, sizeof(node_name), "ethernet-pcs@%llx",
+			 (unsigned long long)pcs_res->res.start);
+
+		if (of_child_node_exists(regs_node, node_name))
+			continue;
+
+		pcs_node = of_changeset_create_node(&priv->of_cs, regs_node,
+						    node_name);
+		if (!pcs_node) {
+			dev_err(dev, "Failed to create PCS node %s\n", node_name);
+			return -ENOMEM;
+		}
+
+		rc = of_changeset_add_prop_string(&priv->of_cs, pcs_node,
+						  "compatible",
+						  pcs_res->compatible);
+		if (rc) {
+			dev_err(dev, "Failed to add compatible property to %s: %pe\n",
+				node_name, ERR_PTR(rc));
+			return rc;
+		}
+
+		reg_props[0] = pcs_res->res.start;
+		reg_props[1] = resource_size(&pcs_res->res);
+		rc = of_changeset_add_prop_u32_array(&priv->of_cs, pcs_node,
+						     "reg", reg_props, 2);
+		if (rc) {
+			dev_err(dev, "Failed to add reg property to %s: %pe\n",
+				node_name, ERR_PTR(rc));
+			return rc;
+		}
+
+		rc = of_changeset_add_prop_string(&priv->of_cs, pcs_node,
+						  "reg-names",
+						  pcs_res->res.name);
+		if (rc) {
+			dev_err(dev, "Failed to add reg-names property to %s: %pe\n",
+				node_name, ERR_PTR(rc));
+			return rc;
+		}
+
+		rc = of_changeset_add_prop_u32(&priv->of_cs, pcs_node,
+					       "reg-io-width", 4);
+		if (rc) {
+			dev_err(dev, "Failed to add reg-io-width property to %s: %pe\n",
+				node_name, ERR_PTR(rc));
+			return rc;
+		}
+
+		/* The SJA1105 XPCS is integrated with a TX-inverting custom
+		 * PMA. We need to invert the polarity in the PCS to obtain a
+		 * non-inverted signal at the pins.
+		 */
+		rc = of_changeset_add_prop_u32(&priv->of_cs, pcs_node, "tx-polarity",
+					       pcs_res->tx_polarity);
+		if (rc) {
+			dev_err(dev, "Failed to add tx-polarity property to %s: %pe\n",
+				node_name, ERR_PTR(rc));
+			return rc;
+		}
+
+		dev_dbg(dev, "Created OF node %pOF\n", pcs_node);
+		priv->pcs_fwnode[pcs_res->port] = of_fwnode_handle(pcs_node);
+	}
+
+	return 0;
+}
+
+static struct device_node *sja1105_create_regs_node(struct sja1105_private *priv,
+						    struct device_node *switch_node)
+{
+	struct device *dev = priv->ds->dev;
+	struct device_node *regs_node;
+	int rc;
+
+	regs_node = of_changeset_create_node(&priv->of_cs, switch_node, "regs");
+	if (!regs_node) {
+		dev_err(dev, "Failed to create 'regs' device tree node\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	rc = of_changeset_add_prop_u32(&priv->of_cs, regs_node, "#address-cells", 1);
+	if (rc) {
+		dev_err(dev, "Failed to add #address-cells property: %pe\n",
+			ERR_PTR(rc));
+		return ERR_PTR(rc);
+	}
+
+	rc = of_changeset_add_prop_u32(&priv->of_cs, regs_node, "#size-cells", 1);
+	if (rc) {
+		dev_err(dev, "Failed to add #size-cells property: %pe\n",
+			ERR_PTR(rc));
+		return ERR_PTR(rc);
+	}
+
+	return regs_node;
+}
+
+static void sja1105_restore_device_tree(void *data)
+{
+	struct sja1105_private *priv = data;
+	struct device *dev = priv->ds->dev;
+	int rc;
+
+	rc = of_changeset_revert(&priv->of_cs);
+	if (rc) {
+		dev_err(dev, "Failed to revert device tree changeset: %pe\n",
+			ERR_PTR(rc));
+	}
+
+	of_changeset_destroy(&priv->of_cs);
+}
+
+int devm_sja1105_fill_device_tree(struct dsa_switch *ds)
+{
+	struct device_node *switch_node, *regs_node;
+	struct sja1105_private *priv = ds->priv;
+	bool regs_node_created = false;
+	struct device *dev = ds->dev;
+	int rc;
+
+	if (!priv->info->num_pcs_resources)
+		return 0;
+
+	switch_node = dev_of_node(dev);
+	of_changeset_init(&priv->of_cs);
+
+	regs_node = of_get_child_by_name(switch_node, "regs");
+	if (!regs_node) {
+		regs_node = sja1105_create_regs_node(priv, switch_node);
+		if (IS_ERR(regs_node)) {
+			rc = PTR_ERR(regs_node);
+			goto out_destroy_changeset;
+		}
+
+		regs_node_created = true;
+		dev_dbg(dev, "Created OF node %pOF\n", regs_node);
+	}
+
+	rc = sja1105_create_pcs_nodes(priv, regs_node);
+	if (rc)
+		goto out_destroy_changeset;
+
+	rc = of_changeset_apply(&priv->of_cs);
+	if (rc) {
+		dev_err(dev, "Failed to apply device tree changeset: %pe\n",
+			ERR_PTR(rc));
+		goto out_destroy_changeset;
+	}
+
+	rc = devm_add_action_or_reset(dev, sja1105_restore_device_tree, priv);
+	goto out_put_regs_node;
+
+out_destroy_changeset:
+	of_changeset_destroy(&priv->of_cs);
+out_put_regs_node:
+	if (!regs_node_created)
+		of_node_put(regs_node);
+
+	return rc;
+}

@@ -5,5 +5,6 @@
 #define _SJA1105_SUBDEV_H
 
 int devm_sja1105_add_subdevs(struct dsa_switch *ds);
+int devm_sja1105_fill_device_tree(struct dsa_switch *ds);
 
 #endif