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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Driver for MMIO-Mapped MDIO devices. Some IPs expose internal PHYs or PCS3 * within the MMIO-mapped area4 *5 * Copyright (C) 2023 Maxime Chevallier <maxime.chevallier@bootlin.com>6 */7#include <linux/bitfield.h>8#include <linux/delay.h>9#include <linux/mdio.h>10#include <linux/module.h>11#include <linux/of.h>12#include <linux/of_mdio.h>13#include <linux/phy.h>14#include <linux/platform_device.h>15#include <linux/regmap.h>16#include <linux/mdio/mdio-regmap.h>17 18#define DRV_NAME "mdio-regmap"19 20struct mdio_regmap_priv {21 struct regmap *regmap;22 u8 valid_addr;23};24 25static int mdio_regmap_read_c22(struct mii_bus *bus, int addr, int regnum)26{27 struct mdio_regmap_priv *ctx = bus->priv;28 unsigned int val;29 int ret;30 31 if (ctx->valid_addr != addr)32 return -ENODEV;33 34 ret = regmap_read(ctx->regmap, regnum, &val);35 if (ret < 0)36 return ret;37 38 return val;39}40 41static int mdio_regmap_write_c22(struct mii_bus *bus, int addr, int regnum,42 u16 val)43{44 struct mdio_regmap_priv *ctx = bus->priv;45 46 if (ctx->valid_addr != addr)47 return -ENODEV;48 49 return regmap_write(ctx->regmap, regnum, val);50}51 52struct mii_bus *devm_mdio_regmap_register(struct device *dev,53 const struct mdio_regmap_config *config)54{55 struct mdio_regmap_priv *mr;56 struct mii_bus *mii;57 int rc;58 59 if (!config->parent)60 return ERR_PTR(-EINVAL);61 62 mii = devm_mdiobus_alloc_size(config->parent, sizeof(*mr));63 if (!mii)64 return ERR_PTR(-ENOMEM);65 66 mr = mii->priv;67 mr->regmap = config->regmap;68 mr->valid_addr = config->valid_addr;69 70 mii->name = DRV_NAME;71 strscpy(mii->id, config->name, MII_BUS_ID_SIZE);72 mii->parent = config->parent;73 mii->read = mdio_regmap_read_c22;74 mii->write = mdio_regmap_write_c22;75 76 if (config->autoscan)77 mii->phy_mask = ~BIT(config->valid_addr);78 else79 mii->phy_mask = ~0;80 81 rc = devm_mdiobus_register(dev, mii);82 if (rc) {83 dev_err(config->parent, "Cannot register MDIO bus![%s] (%d)\n", mii->id, rc);84 return ERR_PTR(rc);85 }86 87 return mii;88}89EXPORT_SYMBOL_GPL(devm_mdio_regmap_register);90 91MODULE_DESCRIPTION("MDIO API over regmap");92MODULE_AUTHOR("Maxime Chevallier <maxime.chevallier@bootlin.com>");93MODULE_LICENSE("GPL");94