1 // SPDX-License-Identifier: GPL-2.0
7 #include <linux/mdio-mux.h>
13 #define DRV_DESCRIPTION "MDIO bus multiplexer driver"
30 	struct mdio_mux_parent_bus *parent;  member
36  * The parent bus' lock is used to order access to the switch_fn.
38 static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)  in mdio_mux_read()  argument
40 	struct mdio_mux_child_bus *cb = bus->priv;  in mdio_mux_read()
41 	struct mdio_mux_parent_bus *pb = cb->parent;  in mdio_mux_read()
44 	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);  in mdio_mux_read()
45 	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);  in mdio_mux_read()
49 	pb->current_child = cb->bus_number;  in mdio_mux_read()
51 	r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum);  in mdio_mux_read()
53 	mutex_unlock(&pb->mii_bus->mdio_lock);  in mdio_mux_read()
58 static int mdio_mux_read_c45(struct mii_bus *bus, int phy_id, int dev_addr,  in mdio_mux_read_c45()  argument
61 	struct mdio_mux_child_bus *cb = bus->priv;  in mdio_mux_read_c45()
62 	struct mdio_mux_parent_bus *pb = cb->parent;  in mdio_mux_read_c45()
65 	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);  in mdio_mux_read_c45()
66 	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);  in mdio_mux_read_c45()
70 	pb->current_child = cb->bus_number;  in mdio_mux_read_c45()
72 	r = pb->mii_bus->read_c45(pb->mii_bus, phy_id, dev_addr, regnum);  in mdio_mux_read_c45()
74 	mutex_unlock(&pb->mii_bus->mdio_lock);  in mdio_mux_read_c45()
80  * The parent bus' lock is used to order access to the switch_fn.
82 static int mdio_mux_write(struct mii_bus *bus, int phy_id,  in mdio_mux_write()  argument
85 	struct mdio_mux_child_bus *cb = bus->priv;  in mdio_mux_write()
86 	struct mdio_mux_parent_bus *pb = cb->parent;  in mdio_mux_write()
90 	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);  in mdio_mux_write()
91 	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);  in mdio_mux_write()
95 	pb->current_child = cb->bus_number;  in mdio_mux_write()
97 	r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val);  in mdio_mux_write()
99 	mutex_unlock(&pb->mii_bus->mdio_lock);  in mdio_mux_write()
104 static int mdio_mux_write_c45(struct mii_bus *bus, int phy_id, int dev_addr,  in mdio_mux_write_c45()  argument
107 	struct mdio_mux_child_bus *cb = bus->priv;  in mdio_mux_write_c45()
108 	struct mdio_mux_parent_bus *pb = cb->parent;  in mdio_mux_write_c45()
112 	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);  in mdio_mux_write_c45()
113 	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);  in mdio_mux_write_c45()
117 	pb->current_child = cb->bus_number;  in mdio_mux_write_c45()
119 	r = pb->mii_bus->write_c45(pb->mii_bus, phy_id, dev_addr, regnum, val);  in mdio_mux_write_c45()
121 	mutex_unlock(&pb->mii_bus->mdio_lock);  in mdio_mux_write_c45()
130 	struct mdio_mux_child_bus *cb = pb->children;  in mdio_mux_uninit_children()
133 		mdiobus_unregister(cb->mii_bus);  in mdio_mux_uninit_children()
134 		mdiobus_free(cb->mii_bus);  in mdio_mux_uninit_children()
135 		cb = cb->next;  in mdio_mux_uninit_children()
154 		return -ENODEV;  in mdio_mux_init()
158 						   "mdio-parent-bus", 0);  in mdio_mux_init()
161 			return -ENODEV;  in mdio_mux_init()
165 			ret_val = -EPROBE_DEFER;  in mdio_mux_init()
171 		get_device(&parent_bus->dev);  in mdio_mux_init()
176 		ret_val = -ENOMEM;  in mdio_mux_init()
180 	pb->switch_data = data;  in mdio_mux_init()
181 	pb->switch_fn = switch_fn;  in mdio_mux_init()
182 	pb->current_child = -1;  in mdio_mux_init()
183 	pb->parent_id = parent_count++;  in mdio_mux_init()
184 	pb->mii_bus = parent_bus;  in mdio_mux_init()
186 	ret_val = -ENODEV;  in mdio_mux_init()
200 			ret_val = -ENOMEM;  in mdio_mux_init()
203 		cb->bus_number = v;  in mdio_mux_init()
204 		cb->parent = pb;  in mdio_mux_init()
206 		cb->mii_bus = mdiobus_alloc();  in mdio_mux_init()
207 		if (!cb->mii_bus) {  in mdio_mux_init()
208 			ret_val = -ENOMEM;  in mdio_mux_init()
211 		cb->mii_bus->priv = cb;  in mdio_mux_init()
213 		cb->mii_bus->name = "mdio_mux";  in mdio_mux_init()
214 		snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x.%x",  in mdio_mux_init()
215 			 cb->mii_bus->name, pb->parent_id, v);  in mdio_mux_init()
216 		cb->mii_bus->parent = dev;  in mdio_mux_init()
217 		cb->mii_bus->read = mdio_mux_read;  in mdio_mux_init()
218 		cb->mii_bus->write = mdio_mux_write;  in mdio_mux_init()
219 		if (parent_bus->read_c45)  in mdio_mux_init()
220 			cb->mii_bus->read_c45 = mdio_mux_read_c45;  in mdio_mux_init()
221 		if (parent_bus->write_c45)  in mdio_mux_init()
222 			cb->mii_bus->write_c45 = mdio_mux_write_c45;  in mdio_mux_init()
223 		r = of_mdiobus_register(cb->mii_bus, child_bus_node);  in mdio_mux_init()
225 			mdiobus_free(cb->mii_bus);  in mdio_mux_init()
226 			if (r == -EPROBE_DEFER) {  in mdio_mux_init()
232 				"Error: Failed to register MDIO bus for child %pOF\n",  in mdio_mux_init()
235 			cb->next = pb->children;  in mdio_mux_init()
236 			pb->children = cb;  in mdio_mux_init()
239 	if (pb->children) {  in mdio_mux_init()
250 	put_device(&parent_bus->dev);  in mdio_mux_init()
262 	put_device(&pb->mii_bus->dev);  in mdio_mux_uninit()