This is the standalone variant of drivers/net/dsa/sja1105/sja1105_mdio.c. Same kind of differences between this driver and the embedded DSA one apply: regmap is being used for register access, and addresses are multiplied by 4 with regmap. In fact this is so generic that there is nothing NXP SJA1110 specific about it at all, and just instantiates mdio-regmap. I decided to name it mdio-regmap-simple.c in the style of drivers/mfd/simple-mfd-i2c.c which has support for various vendor compatible strings. Cc: Maxime Chevallier Signed-off-by: Vladimir Oltean --- v1->v2: - reorder MAINTAINERS entry to be alphabetic - clarify that platform_get_resource() is optional (thanks to Maxime) - update copyright to 2026 MAINTAINERS | 1 + drivers/net/mdio/Kconfig | 15 ++++- drivers/net/mdio/Makefile | 1 + drivers/net/mdio/mdio-regmap-simple.c | 80 +++++++++++++++++++++++++++ 4 files changed, 94 insertions(+), 3 deletions(-) create mode 100644 drivers/net/mdio/mdio-regmap-simple.c diff --git a/MAINTAINERS b/MAINTAINERS index d3fec699c577..2b910fdd1122 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -15671,6 +15671,7 @@ MDIO REGMAP DRIVER M: Maxime Chevallier L: netdev@vger.kernel.org S: Maintained +F: drivers/net/mdio/mdio-regmap-simple.c F: drivers/net/mdio/mdio-regmap.c F: include/linux/mdio/mdio-regmap.h diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig index 9819d1dc18de..c6e824baf228 100644 --- a/drivers/net/mdio/Kconfig +++ b/drivers/net/mdio/Kconfig @@ -179,14 +179,23 @@ config MDIO_REALTEK_RTL9300 config MDIO_REGMAP tristate help - This driver allows using MDIO devices that are not sitting on a - regular MDIO bus, but still exposes the standard 802.3 register + This support module allows using MDIO devices that are not sitting on + a regular MDIO bus, but still exposes the standard 802.3 register layout. It's regmap-based so that it can be used on integrated, memory-mapped PHYs, SPI PHYs and so on. A new virtual MDIO bus is created, and its read/write operations are mapped to the underlying - regmap. Users willing to use this driver must explicitly select + regmap. Users willing to use this module must explicitly select REGMAP. +config MDIO_REGMAP_SIMPLE + tristate + select MDIO_REGMAP + help + Generic platform driver for MDIO buses with a linear address space + that can be directly accessed using the MDIO_REGMAP support code and + need no special handling. The regmap is provided by the parent + device. + config MDIO_THUNDER tristate "ThunderX SOCs MDIO buses" depends on 64BIT diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile index 9abf20d1b030..95f201b73a7d 100644 --- a/drivers/net/mdio/Makefile +++ b/drivers/net/mdio/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_MDIO_MVUSB) += mdio-mvusb.o obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o obj-$(CONFIG_MDIO_REALTEK_RTL9300) += mdio-realtek-rtl9300.o obj-$(CONFIG_MDIO_REGMAP) += mdio-regmap.o +obj-$(CONFIG_MDIO_REGMAP_SIMPLE) += mdio-regmap-simple.o obj-$(CONFIG_MDIO_SJA1110_CBT1) += mdio-sja1110-cbt1.o obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o obj-$(CONFIG_MDIO_THUNDER) += mdio-thunder.o diff --git a/drivers/net/mdio/mdio-regmap-simple.c b/drivers/net/mdio/mdio-regmap-simple.c new file mode 100644 index 000000000000..5db1ca50c374 --- /dev/null +++ b/drivers/net/mdio/mdio-regmap-simple.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright 2025-2026 NXP + * + * Generic MDIO bus driver for simple regmap-based MDIO devices + * + * This driver creates MDIO buses for devices that expose their internal + * PHYs or PCS through a regmap interface. It's intended to be a simple, + * generic driver similar to simple-mfd-i2c.c. + */ +#include +#include +#include +#include +#include +#include + +struct mdio_regmap_simple_data { + u8 valid_addr; + bool autoscan; +}; + +static const struct mdio_regmap_simple_data nxp_sja1110_base_tx = { + .valid_addr = 0, + .autoscan = false, +}; + +static int mdio_regmap_simple_probe(struct platform_device *pdev) +{ + const struct mdio_regmap_simple_data *data; + struct mdio_regmap_config config = {}; + struct device *dev = &pdev->dev; + struct regmap *regmap; + struct mii_bus *bus; + + if (!dev->of_node || !dev->parent) + return -ENODEV; + + regmap = dev_get_regmap(dev->parent, NULL); + if (!regmap) + return -ENODEV; + + data = device_get_match_data(dev); + + config.regmap = regmap; + config.parent = dev; + config.name = dev_name(dev); + /* The resource is optional, provided for finding the registers + * within a device-wide non-MMIO regmap + */ + config.resource = platform_get_resource(pdev, IORESOURCE_REG, 0); + if (data) { + config.valid_addr = data->valid_addr; + config.autoscan = data->autoscan; + } + + return PTR_ERR_OR_ZERO(devm_mdio_regmap_register(dev, &config)); +} + +static const struct of_device_id mdio_regmap_simple_match[] = { + { + .compatible = "nxp,sja1110-base-tx-mdio", + .data = &nxp_sja1110_base_tx, + }, + {} +}; +MODULE_DEVICE_TABLE(of, mdio_regmap_simple_match); + +static struct platform_driver mdio_regmap_simple_driver = { + .probe = mdio_regmap_simple_probe, + .driver = { + .name = "mdio-regmap-simple", + .of_match_table = mdio_regmap_simple_match, + }, +}; + +module_platform_driver(mdio_regmap_simple_driver); + +MODULE_DESCRIPTION("Generic MDIO bus driver for simple regmap-based devices"); +MODULE_AUTHOR("Vladimir Oltean "); +MODULE_LICENSE("GPL"); -- 2.34.1