[deliverable/linux.git] / drivers / net / phy / mdio-mux.c

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2011, 2012 Cavium, Inc.
 */

#include <linux/platform_device.h>
#include <linux/mdio-mux.h>
#include <linux/of_mdio.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/phy.h>

#define DRV_VERSION "1.0"
#define DRV_DESCRIPTION "MDIO bus multiplexer driver"

struct mdio_mux_child_bus;

struct mdio_mux_parent_bus {
	struct mii_bus *mii_bus;
	int current_child;
	int parent_id;
	void *switch_data;
	int (*switch_fn)(int current_child, int desired_child, void *data);

	/* List of our children linked through their next fields. */
	struct mdio_mux_child_bus *children;
};

struct mdio_mux_child_bus {
	struct mii_bus *mii_bus;
	struct mdio_mux_parent_bus *parent;
	struct mdio_mux_child_bus *next;
	int bus_number;
	int phy_irq[PHY_MAX_ADDR];
};

/*
 * The parent bus' lock is used to order access to the switch_fn.
 */
static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)
{
	struct mdio_mux_child_bus *cb = bus->priv;
	struct mdio_mux_parent_bus *pb = cb->parent;
	int r;

	mutex_lock(&pb->mii_bus->mdio_lock);
	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
	if (r)
		goto out;

	pb->current_child = cb->bus_number;

	r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum);
out:
	mutex_unlock(&pb->mii_bus->mdio_lock);

	return r;
}

/*
 * The parent bus' lock is used to order access to the switch_fn.
 */
static int mdio_mux_write(struct mii_bus *bus, int phy_id,
			  int regnum, u16 val)
{
	struct mdio_mux_child_bus *cb = bus->priv;
	struct mdio_mux_parent_bus *pb = cb->parent;

	int r;

	mutex_lock(&pb->mii_bus->mdio_lock);
	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
	if (r)
		goto out;

	pb->current_child = cb->bus_number;

	r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val);
out:
	mutex_unlock(&pb->mii_bus->mdio_lock);

	return r;
}

static int parent_count;

int mdio_mux_init(struct device *dev,
		  int (*switch_fn)(int cur, int desired, void *data),
		  void **mux_handle,
		  void *data)
{
	struct device_node *parent_bus_node;
	struct device_node *child_bus_node;
	int r, ret_val;
	struct mii_bus *parent_bus;
	struct mdio_mux_parent_bus *pb;
	struct mdio_mux_child_bus *cb;

	if (!dev->of_node)
		return -ENODEV;

	parent_bus_node = of_parse_phandle(dev->of_node, "mdio-parent-bus", 0);

	if (!parent_bus_node)
		return -ENODEV;

	parent_bus = of_mdio_find_bus(parent_bus_node);
	if (parent_bus == NULL) {
		ret_val = -EPROBE_DEFER;
		goto err_parent_bus;
	}

	pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
	if (pb == NULL) {
		ret_val = -ENOMEM;
		goto err_parent_bus;
	}

	pb->switch_data = data;
	pb->switch_fn = switch_fn;
	pb->current_child = -1;
	pb->parent_id = parent_count++;
	pb->mii_bus = parent_bus;

	ret_val = -ENODEV;
	for_each_child_of_node(dev->of_node, child_bus_node) {
		u32 v;

		r = of_property_read_u32(child_bus_node, "reg", &v);
		if (r)
			continue;

		cb = devm_kzalloc(dev, sizeof(*cb), GFP_KERNEL);
		if (cb == NULL) {
			dev_err(dev,
				"Error: Failed to allocate memory for child\n");
			ret_val = -ENOMEM;
			break;
		}
		cb->bus_number = v;
		cb->parent = pb;
		cb->mii_bus = mdiobus_alloc();
		cb->mii_bus->priv = cb;

		cb->mii_bus->irq = cb->phy_irq;
		cb->mii_bus->name = "mdio_mux";
		snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x",
			 pb->parent_id, v);
		cb->mii_bus->parent = dev;
		cb->mii_bus->read = mdio_mux_read;
		cb->mii_bus->write = mdio_mux_write;
		r = of_mdiobus_register(cb->mii_bus, child_bus_node);
		if (r) {
			mdiobus_free(cb->mii_bus);
			devm_kfree(dev, cb);
		} else {
			of_node_get(child_bus_node);
			cb->next = pb->children;
			pb->children = cb;
		}
	}
	if (pb->children) {
		*mux_handle = pb;
		dev_info(dev, "Version " DRV_VERSION "\n");
		return 0;
	}
err_parent_bus:
	of_node_put(parent_bus_node);
	return ret_val;
}
EXPORT_SYMBOL_GPL(mdio_mux_init);

void mdio_mux_uninit(void *mux_handle)
{
	struct mdio_mux_parent_bus *pb = mux_handle;
	struct mdio_mux_child_bus *cb = pb->children;

	while (cb) {
		mdiobus_unregister(cb->mii_bus);
		mdiobus_free(cb->mii_bus);
		cb = cb->next;
	}
}
EXPORT_SYMBOL_GPL(mdio_mux_uninit);

MODULE_DESCRIPTION(DRV_DESCRIPTION);
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");
Commit	Line	Data
0ca2997d DD	1	/*
	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
	4	* for more details.
	5	*
	6	* Copyright (C) 2011, 2012 Cavium, Inc.
	7	*/
	8
	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>
	15
	16	#define DRV_VERSION "1.0"
	17	#define DRV_DESCRIPTION "MDIO bus multiplexer driver"
	18
	19	struct mdio_mux_child_bus;
	20
	21	struct mdio_mux_parent_bus {
	22	struct mii_bus *mii_bus;
	23	int current_child;
	24	int parent_id;
	25	void *switch_data;
	26	int (switch_fn)(int current_child, int desired_child, void data);
	27
	28	/* List of our children linked through their next fields. */
	29	struct mdio_mux_child_bus *children;
	30	};
	31
	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;
	36	int bus_number;
	37	int phy_irq[PHY_MAX_ADDR];
	38	};
	39
	40	/*
	41	* The parent bus' lock is used to order access to the switch_fn.
	42	*/
	43	static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)
	44	{
	45	struct mdio_mux_child_bus *cb = bus->priv;
	46	struct mdio_mux_parent_bus *pb = cb->parent;
	47	int r;
	48
	49	mutex_lock(&pb->mii_bus->mdio_lock);
	50	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
	51	if (r)
	52	goto out;
	53
	54	pb->current_child = cb->bus_number;
	55
	56	r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum);
	57	out:
	58	mutex_unlock(&pb->mii_bus->mdio_lock);
	59
	60	return r;
	61	}
	62
	63	/*
	64	* The parent bus' lock is used to order access to the switch_fn.
65	*/
66	static int mdio_mux_write(struct mii_bus *bus, int phy_id,
67	int regnum, u16 val)
68	{
69	struct mdio_mux_child_bus *cb = bus->priv;
70	struct mdio_mux_parent_bus *pb = cb->parent;
71
72	int r;
73
74	mutex_lock(&pb->mii_bus->mdio_lock);
75	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
76	if (r)
77	goto out;
78
79	pb->current_child = cb->bus_number;
80
81	r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val);
82	out:
83	mutex_unlock(&pb->mii_bus->mdio_lock);
84
85	return r;
86	}
87
88	static int parent_count;
89
90	int mdio_mux_init(struct device *dev,
91	int (switch_fn)(int cur, int desired, void data),
92	void **mux_handle,
93	void *data)
94	{
95	struct device_node *parent_bus_node;
96	struct device_node *child_bus_node;
97	int r, ret_val;
98	struct mii_bus *parent_bus;
99	struct mdio_mux_parent_bus *pb;
100	struct mdio_mux_child_bus *cb;
101
102	if (!dev->of_node)
103	return -ENODEV;
104
105	parent_bus_node = of_parse_phandle(dev->of_node, "mdio-parent-bus", 0);
106
107	if (!parent_bus_node)
108	return -ENODEV;
109
110	parent_bus = of_mdio_find_bus(parent_bus_node);
111	if (parent_bus == NULL) {
112	ret_val = -EPROBE_DEFER;
113	goto err_parent_bus;
114	}
115
116	pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
117	if (pb == NULL) {
118	ret_val = -ENOMEM;
119	goto err_parent_bus;
120	}
121
122	pb->switch_data = data;
123	pb->switch_fn = switch_fn;
124	pb->current_child = -1;
125	pb->parent_id = parent_count++;
126	pb->mii_bus = parent_bus;
127
128	ret_val = -ENODEV;
129	for_each_child_of_node(dev->of_node, child_bus_node) {
130	u32 v;
131
132	r = of_property_read_u32(child_bus_node, "reg", &v);
133	if (r)
134	continue;
135
136	cb = devm_kzalloc(dev, sizeof(*cb), GFP_KERNEL);
137	if (cb == NULL) {
138	dev_err(dev,
139	"Error: Failed to allocate memory for child\n");
140	ret_val = -ENOMEM;
141	break;
142	}
143	cb->bus_number = v;
144	cb->parent = pb;
145	cb->mii_bus = mdiobus_alloc();
146	cb->mii_bus->priv = cb;
147
148	cb->mii_bus->irq = cb->phy_irq;
149	cb->mii_bus->name = "mdio_mux";
150	snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x",
151	pb->parent_id, v);
152	cb->mii_bus->parent = dev;
153	cb->mii_bus->read = mdio_mux_read;
154	cb->mii_bus->write = mdio_mux_write;
155	r = of_mdiobus_register(cb->mii_bus, child_bus_node);
156	if (r) {
157	mdiobus_free(cb->mii_bus);
158	devm_kfree(dev, cb);
159	} else {
160	of_node_get(child_bus_node);
161	cb->next = pb->children;
162	pb->children = cb;
163	}
164	}
165	if (pb->children) {
166	*mux_handle = pb;
167	dev_info(dev, "Version " DRV_VERSION "\n");
168	return 0;
169	}
170	err_parent_bus:
171	of_node_put(parent_bus_node);
172	return ret_val;
173	}
174	EXPORT_SYMBOL_GPL(mdio_mux_init);
175
176	void mdio_mux_uninit(void *mux_handle)
177	{
178	struct mdio_mux_parent_bus *pb = mux_handle;
179	struct mdio_mux_child_bus *cb = pb->children;
180
181	while (cb) {
182	mdiobus_unregister(cb->mii_bus);
183	mdiobus_free(cb->mii_bus);
184	cb = cb->next;
185	}
186	}
187	EXPORT_SYMBOL_GPL(mdio_mux_uninit);
188
189	MODULE_DESCRIPTION(DRV_DESCRIPTION);
190	MODULE_VERSION(DRV_VERSION);
191	MODULE_AUTHOR("David Daney");
192	MODULE_LICENSE("GPL");