On Thu, Jan 22, 2026 at 12:56:41PM +0200, Vladimir Oltean wrote:
This driver is the standalone variant of drivers/net/dsa/sja1105/sja1105_mdio.c.
In terms of differences:
- this one uses regmaps provided by the parent as a method to abstract
away the sja1105_xfer_u32() calls for register access
- the driver prefix has been changed from sja1105 to sja1110 (this MDIO
controller is not present on the older SJA1105 family)
- in the sja1105 driver, each memory word has 32 bits, so addresses as
seen by regmap need to be multiplied by 4. This affects what
sja1110_base_t1_encode_addr() returns, and is different compared to
sja1105_base_t1_encode_addr().
...
quoted hunk ↗ jump to hunk
+static int sja1110_base_t1_mdio_read_c22(struct mii_bus *bus, int phy, int reg)
+{
+ struct sja1110_base_t1_private *priv = bus->priv;
+ struct regmap *regmap = priv->regmap;
+ unsigned int addr, val;
+ int err;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C22, reg & 0x1f);
GENMASK() ? Or do you have already a defined mask for this?
quoted hunk ↗ jump to hunk
+ err = regmap_read(regmap, priv->base + addr, &val);
+ if (err)
+ return err;
+
+ return val & 0xffff;
lower_16_bits() from wordpart.h?
+}
...
quoted hunk ↗ jump to hunk
+static int sja1110_base_t1_mdio_read_c45(struct mii_bus *bus, int phy,
+ int mmd, int reg)
+{
+ struct sja1110_base_t1_private *priv = bus->priv;
+ struct regmap *regmap = priv->regmap;
+ unsigned int addr, val;
+ int err;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C45_ADDR, mmd);
+ err = regmap_write(regmap, priv->base + addr, reg);
+ if (err)
+ return err;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C45_DATA, mmd);
+ err = regmap_read(regmap, priv->base + addr, &val);
+ if (err)
+ return err;
+
+ return val & 0xffff;
Ditto.
+}
...
quoted hunk ↗ jump to hunk
+static int sja1110_base_t1_mdio_write_c22(struct mii_bus *bus, int phy, int reg,
+ u16 val)
+{
+ struct sja1110_base_t1_private *priv = bus->priv;
+ struct regmap *regmap = priv->regmap;
+ unsigned int addr;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C22, reg & 0x1f);
+ return regmap_write(regmap, priv->base + addr, val & 0xffff);
val is already u16.
+}
...
quoted hunk ↗ jump to hunk
+static int sja1110_base_t1_mdio_write_c45(struct mii_bus *bus, int phy,
+ int mmd, int reg, u16 val)
+{
+ struct sja1110_base_t1_private *priv = bus->priv;
+ struct regmap *regmap = priv->regmap;
+ unsigned int addr;
+ int err;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C45_ADDR, mmd);
+ err = regmap_write(regmap, priv->base + addr, reg);
+ if (err)
+ return err;
+
+ addr = sja1110_base_t1_encode_addr(phy, SJA1110_C45_DATA, mmd);
+ return regmap_write(regmap, priv->base + addr, val & 0xffff);
Ditto.
+}
...
quoted hunk ↗ jump to hunk
+static int sja1110_base_t1_mdio_probe(struct platform_device *pdev)
+{
+ struct sja1110_base_t1_private *priv;
+ struct device *dev = &pdev->dev;
+ struct regmap *regmap;
+ struct resource *res;
+ struct mii_bus *bus;
+ int err;
+ if (!dev->of_node || !dev->parent)
Can we avoid dereferencing? And perhaps dev_fwnode(dev)?
quoted hunk ↗ jump to hunk
+ return -ENODEV;
+
+ regmap = dev_get_regmap(dev->parent, NULL);
+ if (!regmap)
+ return -ENODEV;
+
+ bus = mdiobus_alloc_size(sizeof(*priv));
+ if (!bus)
+ return -ENOMEM;
+
+ bus->name = "SJA1110 100base-T1 MDIO bus";
+ snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
+ bus->read = sja1110_base_t1_mdio_read_c22;
+ bus->write = sja1110_base_t1_mdio_write_c22;
+ bus->read_c45 = sja1110_base_t1_mdio_read_c45;
+ bus->write_c45 = sja1110_base_t1_mdio_write_c45;
+ bus->parent = dev;
+ priv = bus->priv;
+ priv->regmap = regmap;
+
+ res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+ if (res)
+ priv->base = res->start;
+
+ err = of_mdiobus_register(bus, dev->of_node);
+ if (err)
+ goto err_free_bus;
+
+ priv->bus = bus;
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+
+err_free_bus:
+ mdiobus_free(bus);
+
+ return err;
+}
...
+static const struct of_device_id sja1110_base_t1_mdio_match[] = {
+ { .compatible = "nxp,sja1110-base-t1-mdio", },
Inner comma is redundant.
+ {},
Terminator is terminator, trailing comma is confusing here.
+};
...
quoted hunk ↗ jump to hunk
+static struct platform_driver sja1110_base_t1_mdio_driver = {
+ .probe = sja1110_base_t1_mdio_probe,
+ .remove = sja1110_base_t1_mdio_remove,
+ .driver = {
+ .name = "sja1110-base-t1-mdio",
+ .of_match_table = sja1110_base_t1_mdio_match,
+ },
+};
+
Redundant blank line.
+module_platform_driver(sja1110_base_t1_mdio_driver);
--
With Best Regards,
Andy Shevchenko