net: dsa: sja1105: register the MDIO buses for 100base-T1 and 100base-TX

The SJA1110 contains two types of integrated PHYs: one 100base-TX PHY
and multiple 100base-T1 PHYs.

The access procedure for the 100base-T1 PHYs is also different than it
is for the 100base-TX one. So we register 2 MDIO buses, one for the
base-TX and the other for the base-T1. Each bus has an OF node which is
a child of the "mdio" subnode of the switch, and they are recognized by
compatible string.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 288 insertions, 0 deletions

diff --git a/drivers/net/dsa/sja1105/sja1105_mdio.c b/drivers/net/dsa/sja1105/sja1105_mdio.c
new file mode 100644
index 000000000000..8dfd06318b23
--- /dev/null
+++ b/drivers/net/dsa/sja1105/sja1105_mdio.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright 2021, NXP Semiconductors
+ */
+#include <linux/of_mdio.h>
+#include "sja1105.h"
+
+enum sja1105_mdio_opcode {
+	SJA1105_C45_ADDR = 0,
+	SJA1105_C22 = 1,
+	SJA1105_C45_DATA = 2,
+	SJA1105_C45_DATA_AUTOINC = 3,
+};
+
+static u64 sja1105_base_t1_encode_addr(struct sja1105_private *priv,
+				       int phy, enum sja1105_mdio_opcode op,
+				       int xad)
+{
+	const struct sja1105_regs *regs = priv->info->regs;
+
+	return regs->mdio_100base_t1 | (phy << 7) | (op << 5) | (xad << 0);
+}
+
+static int sja1105_base_t1_mdio_read(struct mii_bus *bus, int phy, int reg)
+{
+	struct sja1105_mdio_private *mdio_priv = bus->priv;
+	struct sja1105_private *priv = mdio_priv->priv;
+	u64 addr;
+	u32 tmp;
+	int rc;
+
+	if (reg & MII_ADDR_C45) {
+		u16 mmd = (reg >> MII_DEVADDR_C45_SHIFT) & 0x1f;
+
+		addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C45_ADDR,
+						   mmd);
+
+		tmp = reg & MII_REGADDR_C45_MASK;
+
+		rc = sja1105_xfer_u32(priv, SPI_WRITE, addr, &tmp, NULL);
+		if (rc < 0)
+			return rc;
+
+		addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C45_DATA,
+						   mmd);
+
+		rc = sja1105_xfer_u32(priv, SPI_READ, addr, &tmp, NULL);
+		if (rc < 0)
+			return rc;
+
+		return tmp & 0xffff;
+	}
+
+	/* Clause 22 read */
+	addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C22, reg & 0x1f);
+
+	rc = sja1105_xfer_u32(priv, SPI_READ, addr, &tmp, NULL);
+	if (rc < 0)
+		return rc;
+
+	return tmp & 0xffff;
+}
+
+static int sja1105_base_t1_mdio_write(struct mii_bus *bus, int phy, int reg,
+				      u16 val)
+{
+	struct sja1105_mdio_private *mdio_priv = bus->priv;
+	struct sja1105_private *priv = mdio_priv->priv;
+	u64 addr;
+	u32 tmp;
+	int rc;
+
+	if (reg & MII_ADDR_C45) {
+		u16 mmd = (reg >> MII_DEVADDR_C45_SHIFT) & 0x1f;
+
+		addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C45_ADDR,
+						   mmd);
+
+		tmp = reg & MII_REGADDR_C45_MASK;
+
+		rc = sja1105_xfer_u32(priv, SPI_WRITE, addr, &tmp, NULL);
+		if (rc < 0)
+			return rc;
+
+		addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C45_DATA,
+						   mmd);
+
+		tmp = val & 0xffff;
+
+		rc = sja1105_xfer_u32(priv, SPI_WRITE, addr, &tmp, NULL);
+		if (rc < 0)
+			return rc;
+
+		return 0;
+	}
+
+	/* Clause 22 write */
+	addr = sja1105_base_t1_encode_addr(priv, phy, SJA1105_C22, reg & 0x1f);
+
+	tmp = val & 0xffff;
+
+	return sja1105_xfer_u32(priv, SPI_WRITE, addr, &tmp, NULL);
+}
+
+static int sja1105_base_tx_mdio_read(struct mii_bus *bus, int phy, int reg)
+{
+	struct sja1105_mdio_private *mdio_priv = bus->priv;
+	struct sja1105_private *priv = mdio_priv->priv;
+	const struct sja1105_regs *regs = priv->info->regs;
+	u32 tmp;
+	int rc;
+
+	rc = sja1105_xfer_u32(priv, SPI_READ, regs->mdio_100base_tx + reg,
+			      &tmp, NULL);
+	if (rc < 0)
+		return rc;
+
+	return tmp & 0xffff;
+}
+
+static int sja1105_base_tx_mdio_write(struct mii_bus *bus, int phy, int reg,
+				      u16 val)
+{
+	struct sja1105_mdio_private *mdio_priv = bus->priv;
+	struct sja1105_private *priv = mdio_priv->priv;
+	const struct sja1105_regs *regs = priv->info->regs;
+	u32 tmp = val;
+
+	return sja1105_xfer_u32(priv, SPI_WRITE, regs->mdio_100base_tx + reg,
+				&tmp, NULL);
+}
+
+static int sja1105_mdiobus_base_tx_register(struct sja1105_private *priv,
+					    struct device_node *mdio_node)
+{
+	struct sja1105_mdio_private *mdio_priv;
+	struct device_node *np;
+	struct mii_bus *bus;
+	int rc = 0;
+
+	np = of_find_compatible_node(mdio_node, NULL,
+				     "nxp,sja1110-base-tx-mdio");
+	if (!np)
+		return 0;
+
+	if (!of_device_is_available(np))
+		goto out_put_np;
+
+	bus = mdiobus_alloc_size(sizeof(*mdio_priv));
+	if (!bus) {
+		rc = -ENOMEM;
+		goto out_put_np;
+	}
+
+	bus->name = "SJA1110 100base-TX MDIO bus";
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-base-tx",
+		 dev_name(priv->ds->dev));
+	bus->read = sja1105_base_tx_mdio_read;
+	bus->write = sja1105_base_tx_mdio_write;
+	bus->parent = priv->ds->dev;
+	mdio_priv = bus->priv;
+	mdio_priv->priv = priv;
+
+	rc = of_mdiobus_register(bus, np);
+	if (rc) {
+		mdiobus_free(bus);
+		goto out_put_np;
+	}
+
+	priv->mdio_base_tx = bus;
+
+out_put_np:
+	of_node_put(np);
+
+	return 0;
+}
+
+static void sja1105_mdiobus_base_tx_unregister(struct sja1105_private *priv)
+{
+	if (!priv->mdio_base_tx)
+		return;
+
+	mdiobus_unregister(priv->mdio_base_tx);
+	mdiobus_free(priv->mdio_base_tx);
+	priv->mdio_base_tx = NULL;
+}
+
+static int sja1105_mdiobus_base_t1_register(struct sja1105_private *priv,
+					    struct device_node *mdio_node)
+{
+	struct sja1105_mdio_private *mdio_priv;
+	struct device_node *np;
+	struct mii_bus *bus;
+	int rc = 0;
+
+	np = of_find_compatible_node(mdio_node, NULL,
+				     "nxp,sja1110-base-t1-mdio");
+	if (!np)
+		return 0;
+
+	if (!of_device_is_available(np))
+		goto out_put_np;
+
+	bus = mdiobus_alloc_size(sizeof(*mdio_priv));
+	if (!bus) {
+		rc = -ENOMEM;
+		goto out_put_np;
+	}
+
+	bus->name = "SJA1110 100base-T1 MDIO bus";
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-base-t1",
+		 dev_name(priv->ds->dev));
+	bus->read = sja1105_base_t1_mdio_read;
+	bus->write = sja1105_base_t1_mdio_write;
+	bus->parent = priv->ds->dev;
+	mdio_priv = bus->priv;
+	mdio_priv->priv = priv;
+
+	rc = of_mdiobus_register(bus, np);
+	if (rc) {
+		mdiobus_free(bus);
+		goto out_put_np;
+	}
+
+	priv->mdio_base_t1 = bus;
+
+out_put_np:
+	of_node_put(np);
+
+	return rc;
+}
+
+static void sja1105_mdiobus_base_t1_unregister(struct sja1105_private *priv)
+{
+	if (!priv->mdio_base_t1)
+		return;
+
+	mdiobus_unregister(priv->mdio_base_t1);
+	mdiobus_free(priv->mdio_base_t1);
+	priv->mdio_base_t1 = NULL;
+}
+
+int sja1105_mdiobus_register(struct dsa_switch *ds)
+{
+	struct sja1105_private *priv = ds->priv;
+	const struct sja1105_regs *regs = priv->info->regs;
+	struct device_node *switch_node = ds->dev->of_node;
+	struct device_node *mdio_node;
+	int rc;
+
+	mdio_node = of_get_child_by_name(switch_node, "mdios");
+	if (!mdio_node)
+		return 0;
+
+	if (!of_device_is_available(mdio_node))
+		goto out_put_mdio_node;
+
+	if (regs->mdio_100base_tx != SJA1105_RSV_ADDR) {
+		rc = sja1105_mdiobus_base_tx_register(priv, mdio_node);
+		if (rc)
+			goto err_put_mdio_node;
+	}
+
+	if (regs->mdio_100base_t1 != SJA1105_RSV_ADDR) {
+		rc = sja1105_mdiobus_base_t1_register(priv, mdio_node);
+		if (rc)
+			goto err_free_base_tx_mdiobus;
+	}
+
+out_put_mdio_node:
+	of_node_put(mdio_node);
+
+	return 0;
+
+err_free_base_tx_mdiobus:
+	sja1105_mdiobus_base_tx_unregister(priv);
+err_put_mdio_node:
+	of_node_put(mdio_node);
+
+	return rc;
+}
+
+void sja1105_mdiobus_unregister(struct dsa_switch *ds)
+{
+	struct sja1105_private *priv = ds->priv;
+
+	sja1105_mdiobus_base_t1_unregister(priv);
+	sja1105_mdiobus_base_tx_unregister(priv);
+}