1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
5  * MDIO implementation for ARC EMAC
15 /* Number of seconds we wait for "MDIO complete" flag to appear */
19  * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
22  * returns:	0 on success, -ETIMEDOUT on a timeout.
34 			/* Reset "MDIO complete" flag */  in arc_mdio_complete_wait()
42 	return -ETIMEDOUT;  in arc_mdio_complete_wait()
46  * arc_mdio_read - MDIO interface read function.
47  * @bus:	Pointer to MII bus structure.
51  * returns:	The register contents on success, -ETIMEDOUT on a timeout.
56 static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)  in arc_mdio_read()  argument
58 	struct arc_emac_priv *priv = bus->priv;  in arc_mdio_read()
71 	dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",  in arc_mdio_read()
78  * arc_mdio_write - MDIO interface write function.
79  * @bus:	Pointer to MII bus structure.
84  * returns:	0 on success, -ETIMEDOUT on a timeout.
88 static int arc_mdio_write(struct mii_bus *bus, int phy_addr,  in arc_mdio_write()  argument
91 	struct arc_emac_priv *priv = bus->priv;  in arc_mdio_write()
93 	dev_dbg(priv->dev,  in arc_mdio_write()
105  * @bus: points to the mii_bus structure
106  * Description: reset the MII bus
108 static int arc_mdio_reset(struct mii_bus *bus)  in arc_mdio_reset()  argument
110 	struct arc_emac_priv *priv = bus->priv;  in arc_mdio_reset()
111 	struct arc_emac_mdio_bus_data *data = &priv->bus_data;  in arc_mdio_reset()
113 	if (data->reset_gpio) {  in arc_mdio_reset()
114 		gpiod_set_value_cansleep(data->reset_gpio, 1);  in arc_mdio_reset()
115 		msleep(data->msec);  in arc_mdio_reset()
116 		gpiod_set_value_cansleep(data->reset_gpio, 0);  in arc_mdio_reset()
123  * arc_mdio_probe - MDIO probe function.
126  * returns:	0 on success, -ENOMEM when mdiobus_alloc
127  * (to allocate memory for MII bus structure) fails.
129  * Sets up and registers the MDIO interface.
133 	struct arc_emac_mdio_bus_data *data = &priv->bus_data;  in arc_mdio_probe()
134 	struct device_node *np = priv->dev->of_node;  in arc_mdio_probe()
135 	const char *name = "Synopsys MII Bus";  in arc_mdio_probe()
137 	struct mii_bus *bus;  in arc_mdio_probe()  local
140 	bus = mdiobus_alloc();  in arc_mdio_probe()
141 	if (!bus)  in arc_mdio_probe()
142 		return -ENOMEM;  in arc_mdio_probe()
144 	priv->bus = bus;  in arc_mdio_probe()
145 	bus->priv = priv;  in arc_mdio_probe()
146 	bus->parent = priv->dev;  in arc_mdio_probe()
147 	bus->name = name;  in arc_mdio_probe()
148 	bus->read = &arc_mdio_read;  in arc_mdio_probe()
149 	bus->write = &arc_mdio_write;  in arc_mdio_probe()
150 	bus->reset = &arc_mdio_reset;  in arc_mdio_probe()
152 	/* optional reset-related properties */  in arc_mdio_probe()
153 	data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",  in arc_mdio_probe()
155 	if (IS_ERR(data->reset_gpio)) {  in arc_mdio_probe()
156 		mdiobus_free(bus);  in arc_mdio_probe()
157 		return dev_err_probe(priv->dev, PTR_ERR(data->reset_gpio),  in arc_mdio_probe()
161 	of_property_read_u32(np, "phy-reset-duration", &data->msec);  in arc_mdio_probe()
163 	if (data->msec > 1000)  in arc_mdio_probe()
164 		data->msec = 1;  in arc_mdio_probe()
166 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);  in arc_mdio_probe()
168 	/* Backwards compatibility for EMAC nodes without MDIO subnode. */  in arc_mdio_probe()
169 	mdio_node = of_get_child_by_name(np, "mdio");  in arc_mdio_probe()
173 	error = of_mdiobus_register(bus, mdio_node);  in arc_mdio_probe()
176 		mdiobus_free(bus);  in arc_mdio_probe()
177 		return dev_err_probe(priv->dev, error,  in arc_mdio_probe()
178 				     "cannot register MDIO bus %s\n", name);  in arc_mdio_probe()
185  * arc_mdio_remove - MDIO remove function.
188  * Unregisters the MDIO and frees any associate memory for MII bus.
192 	mdiobus_unregister(priv->bus);  in arc_mdio_remove()
193 	mdiobus_free(priv->bus);  in arc_mdio_remove()
194 	priv->bus = NULL;  in arc_mdio_remove()