2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2011, 2012 Cavium, Inc.
9 #include <linux/platform_device.h>
10 #include <linux/mdio-mux.h>
11 #include <linux/of_mdio.h>
12 #include <linux/device.h>
13 #include <linux/module.h>
14 #include <linux/phy.h>
16 #define DRV_VERSION "1.0"
17 #define DRV_DESCRIPTION "MDIO bus multiplexer driver"
19 struct mdio_mux_child_bus
;
21 struct mdio_mux_parent_bus
{
22 struct mii_bus
*mii_bus
;
26 int (*switch_fn
)(int current_child
, int desired_child
, void *data
);
28 /* List of our children linked through their next fields. */
29 struct mdio_mux_child_bus
*children
;
32 struct mdio_mux_child_bus
{
33 struct mii_bus
*mii_bus
;
34 struct mdio_mux_parent_bus
*parent
;
35 struct mdio_mux_child_bus
*next
;
40 * The parent bus' lock is used to order access to the switch_fn.
42 static int mdio_mux_read(struct mii_bus
*bus
, int phy_id
, int regnum
)
44 struct mdio_mux_child_bus
*cb
= bus
->priv
;
45 struct mdio_mux_parent_bus
*pb
= cb
->parent
;
48 mutex_lock_nested(&pb
->mii_bus
->mdio_lock
, MDIO_MUTEX_MUX
);
49 r
= pb
->switch_fn(pb
->current_child
, cb
->bus_number
, pb
->switch_data
);
53 pb
->current_child
= cb
->bus_number
;
55 r
= pb
->mii_bus
->read(pb
->mii_bus
, phy_id
, regnum
);
57 mutex_unlock(&pb
->mii_bus
->mdio_lock
);
63 * The parent bus' lock is used to order access to the switch_fn.
65 static int mdio_mux_write(struct mii_bus
*bus
, int phy_id
,
68 struct mdio_mux_child_bus
*cb
= bus
->priv
;
69 struct mdio_mux_parent_bus
*pb
= cb
->parent
;
73 mutex_lock_nested(&pb
->mii_bus
->mdio_lock
, MDIO_MUTEX_MUX
);
74 r
= pb
->switch_fn(pb
->current_child
, cb
->bus_number
, pb
->switch_data
);
78 pb
->current_child
= cb
->bus_number
;
80 r
= pb
->mii_bus
->write(pb
->mii_bus
, phy_id
, regnum
, val
);
82 mutex_unlock(&pb
->mii_bus
->mdio_lock
);
87 static int parent_count
;
89 int mdio_mux_init(struct device
*dev
,
90 int (*switch_fn
)(int cur
, int desired
, void *data
),
94 struct device_node
*parent_bus_node
;
95 struct device_node
*child_bus_node
;
97 struct mii_bus
*parent_bus
;
98 struct mdio_mux_parent_bus
*pb
;
99 struct mdio_mux_child_bus
*cb
;
104 parent_bus_node
= of_parse_phandle(dev
->of_node
, "mdio-parent-bus", 0);
106 if (!parent_bus_node
)
109 pb
= devm_kzalloc(dev
, sizeof(*pb
), GFP_KERNEL
);
115 parent_bus
= of_mdio_find_bus(parent_bus_node
);
116 if (parent_bus
== NULL
) {
117 ret_val
= -EPROBE_DEFER
;
121 pb
->switch_data
= data
;
122 pb
->switch_fn
= switch_fn
;
123 pb
->current_child
= -1;
124 pb
->parent_id
= parent_count
++;
125 pb
->mii_bus
= parent_bus
;
128 for_each_available_child_of_node(dev
->of_node
, child_bus_node
) {
131 r
= of_property_read_u32(child_bus_node
, "reg", &v
);
135 cb
= devm_kzalloc(dev
, sizeof(*cb
), GFP_KERNEL
);
138 "Error: Failed to allocate memory for child\n");
140 of_node_put(child_bus_node
);
146 cb
->mii_bus
= mdiobus_alloc();
149 of_node_put(child_bus_node
);
152 cb
->mii_bus
->priv
= cb
;
154 cb
->mii_bus
->name
= "mdio_mux";
155 snprintf(cb
->mii_bus
->id
, MII_BUS_ID_SIZE
, "%x.%x",
157 cb
->mii_bus
->parent
= dev
;
158 cb
->mii_bus
->read
= mdio_mux_read
;
159 cb
->mii_bus
->write
= mdio_mux_write
;
160 r
= of_mdiobus_register(cb
->mii_bus
, child_bus_node
);
162 mdiobus_free(cb
->mii_bus
);
165 of_node_get(child_bus_node
);
166 cb
->next
= pb
->children
;
172 dev_info(dev
, "Version " DRV_VERSION
"\n");
176 /* balance the reference of_mdio_find_bus() took */
177 put_device(&pb
->mii_bus
->dev
);
180 of_node_put(parent_bus_node
);
183 EXPORT_SYMBOL_GPL(mdio_mux_init
);
185 void mdio_mux_uninit(void *mux_handle
)
187 struct mdio_mux_parent_bus
*pb
= mux_handle
;
188 struct mdio_mux_child_bus
*cb
= pb
->children
;
191 mdiobus_unregister(cb
->mii_bus
);
192 mdiobus_free(cb
->mii_bus
);
196 /* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
197 put_device(&pb
->mii_bus
->dev
);
199 EXPORT_SYMBOL_GPL(mdio_mux_uninit
);
201 MODULE_DESCRIPTION(DRV_DESCRIPTION
);
202 MODULE_VERSION(DRV_VERSION
);
203 MODULE_AUTHOR("David Daney");
204 MODULE_LICENSE("GPL");
This page took 0.076082 seconds and 5 git commands to generate.