diff options
author | Maxime Chevallier <maxime.chevallier@bootlin.com> | 2023-06-01 17:14:51 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2023-06-05 11:56:36 +0300 |
commit | 642af0f92cbe01c4b05eb38a0fe94867a3798b34 (patch) | |
tree | 02476954314f58e1eb89f23151df3876d6fb4cd2 /drivers/net/mdio/mdio-regmap.c | |
parent | f69de8aa4752adae750892c71711a5b806ec0dff (diff) | |
download | linux-642af0f92cbe01c4b05eb38a0fe94867a3798b34.tar.xz |
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 <maxime.chevallier@bootlin.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/mdio/mdio-regmap.c')
-rw-r--r-- | drivers/net/mdio/mdio-regmap.c | 93 |
1 files changed, 93 insertions, 0 deletions
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 <maxime.chevallier@bootlin.com> + */ +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/mdio.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_mdio.h> +#include <linux/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/mdio/mdio-regmap.h> + +#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 <maxime.chevallier@bootlin.com>"); +MODULE_LICENSE("GPL"); |