From 642af0f92cbe01c4b05eb38a0fe94867a3798b34 Mon Sep 17 00:00:00 2001 From: Maxime Chevallier Date: Thu, 1 Jun 2023 16:14:51 +0200 Subject: net: mdio: Introduce a regmap-based mdio driver There exists several examples today of devices that embed an ethernet PHY or PCS directly inside an SoC. In this situation, either the device is controlled through a vendor-specific register set, or sometimes exposes the standard 802.3 registers that are typically accessed over MDIO. As phylib and phylink are designed to use mdiodevices, this driver allows creating a virtual MDIO bus, that translates mdiodev register accesses to regmap accesses. The reason we use regmap is because there are at least 3 such devices known today, 2 of them are Altera TSE PCS's, memory-mapped, exposed with a 4-byte stride in stmmac's dwmac-socfpga variant, and a 2-byte stride in altera-tse. The other one (nxp,sja1110-base-tx-mdio) is exposed over SPI. Signed-off-by: Maxime Chevallier Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- MAINTAINERS | 7 +++ drivers/net/mdio/Kconfig | 11 +++++ drivers/net/mdio/Makefile | 1 + drivers/net/mdio/mdio-regmap.c | 93 ++++++++++++++++++++++++++++++++++++++++ include/linux/mdio/mdio-regmap.h | 26 +++++++++++ 5 files changed, 138 insertions(+) create mode 100644 drivers/net/mdio/mdio-regmap.c create mode 100644 include/linux/mdio/mdio-regmap.h diff --git a/MAINTAINERS b/MAINTAINERS index 288d9a5edb9d..5a2ba8567be6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12844,6 +12844,13 @@ F: Documentation/devicetree/bindings/net/ieee802154/mcr20a.txt F: drivers/net/ieee802154/mcr20a.c F: drivers/net/ieee802154/mcr20a.h +MDIO REGMAP DRIVER +M: Maxime Chevallier +L: netdev@vger.kernel.org +S: Maintained +F: drivers/net/mdio/mdio-regmap.c +F: include/linux/mdio/mdio-regmap.h + MEASUREMENT COMPUTING CIO-DAC IIO DRIVER M: William Breathitt Gray L: linux-iio@vger.kernel.org diff --git a/drivers/net/mdio/Kconfig b/drivers/net/mdio/Kconfig index 9ff2e6f22f3f..4a7a303be2f7 100644 --- a/drivers/net/mdio/Kconfig +++ b/drivers/net/mdio/Kconfig @@ -185,6 +185,17 @@ config MDIO_IPQ8064 This driver supports the MDIO interface found in the network interface units of the IPQ8064 SoC +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 + 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. + config MDIO_THUNDER tristate "ThunderX SOCs MDIO buses" depends on 64BIT diff --git a/drivers/net/mdio/Makefile b/drivers/net/mdio/Makefile index 7d4cb4c11e4e..1015f0db4531 100644 --- a/drivers/net/mdio/Makefile +++ b/drivers/net/mdio/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o obj-$(CONFIG_MDIO_MSCC_MIIM) += mdio-mscc-miim.o obj-$(CONFIG_MDIO_MVUSB) += mdio-mvusb.o obj-$(CONFIG_MDIO_OCTEON) += mdio-octeon.o +obj-$(CONFIG_MDIO_REGMAP) += mdio-regmap.o obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o obj-$(CONFIG_MDIO_THUNDER) += mdio-thunder.o obj-$(CONFIG_MDIO_XGENE) += mdio-xgene.o diff --git a/drivers/net/mdio/mdio-regmap.c b/drivers/net/mdio/mdio-regmap.c new file mode 100644 index 000000000000..8a742a8d6387 --- /dev/null +++ b/drivers/net/mdio/mdio-regmap.c @@ -0,0 +1,93 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Driver for MMIO-Mapped MDIO devices. Some IPs expose internal PHYs or PCS + * within the MMIO-mapped area + * + * Copyright (C) 2023 Maxime Chevallier + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "mdio-regmap" + +struct mdio_regmap_priv { + struct regmap *regmap; + u8 valid_addr; +}; + +static int mdio_regmap_read_c22(struct mii_bus *bus, int addr, int regnum) +{ + struct mdio_regmap_priv *ctx = bus->priv; + unsigned int val; + int ret; + + if (ctx->valid_addr != addr) + return -ENODEV; + + ret = regmap_read(ctx->regmap, regnum, &val); + if (ret < 0) + return ret; + + return val; +} + +static int mdio_regmap_write_c22(struct mii_bus *bus, int addr, int regnum, + u16 val) +{ + struct mdio_regmap_priv *ctx = bus->priv; + + if (ctx->valid_addr != addr) + return -ENODEV; + + return regmap_write(ctx->regmap, regnum, val); +} + +struct mii_bus *devm_mdio_regmap_register(struct device *dev, + const struct mdio_regmap_config *config) +{ + struct mdio_regmap_priv *mr; + struct mii_bus *mii; + int rc; + + if (!config->parent) + return ERR_PTR(-EINVAL); + + mii = devm_mdiobus_alloc_size(config->parent, sizeof(*mr)); + if (!mii) + return ERR_PTR(-ENOMEM); + + mr = mii->priv; + mr->regmap = config->regmap; + mr->valid_addr = config->valid_addr; + + mii->name = DRV_NAME; + strscpy(mii->id, config->name, MII_BUS_ID_SIZE); + mii->parent = config->parent; + mii->read = mdio_regmap_read_c22; + mii->write = mdio_regmap_write_c22; + + if (config->autoscan) + mii->phy_mask = ~BIT(config->valid_addr); + else + mii->phy_mask = ~0; + + rc = devm_mdiobus_register(dev, mii); + if (rc) { + dev_err(config->parent, "Cannot register MDIO bus![%s] (%d)\n", mii->id, rc); + return ERR_PTR(rc); + } + + return mii; +} +EXPORT_SYMBOL_GPL(devm_mdio_regmap_register); + +MODULE_DESCRIPTION("MDIO API over regmap"); +MODULE_AUTHOR("Maxime Chevallier "); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mdio/mdio-regmap.h b/include/linux/mdio/mdio-regmap.h new file mode 100644 index 000000000000..679d9069846b --- /dev/null +++ b/include/linux/mdio/mdio-regmap.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Driver for MMIO-Mapped MDIO devices. Some IPs expose internal PHYs or PCS + * within the MMIO-mapped area + * + * Copyright (C) 2023 Maxime Chevallier + */ +#ifndef MDIO_REGMAP_H +#define MDIO_REGMAP_H + +#include + +struct device; +struct regmap; + +struct mdio_regmap_config { + struct device *parent; + struct regmap *regmap; + char name[MII_BUS_ID_SIZE]; + u8 valid_addr; + bool autoscan; +}; + +struct mii_bus *devm_mdio_regmap_register(struct device *dev, + const struct mdio_regmap_config *config); + +#endif -- cgit v1.2.3