[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;
};

/*
 * 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_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
	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_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
	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;

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

	parent_bus = of_mdio_find_bus(parent_bus_node);
	if (parent_bus == NULL) {
		ret_val = -EPROBE_DEFER;
		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_available_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;
			of_node_put(child_bus_node);
			break;
		}
		cb->bus_number = v;
		cb->parent = pb;

		cb->mii_bus = mdiobus_alloc();
		if (!cb->mii_bus) {
			ret_val = -ENOMEM;
			of_node_put(child_bus_node);
			break;
		}
		cb->mii_bus->priv = cb;

		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;
	}

	/* balance the reference of_mdio_find_bus() took */
	put_device(&pb->mii_bus->dev);

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;
	}

	/* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
	put_device(&pb->mii_bus->dev);
}
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;
0ca2997d DD	37	};
	38
	39	/*
	40	* The parent bus' lock is used to order access to the switch_fn.
	41	*/
	42	static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)
	43	{
	44	struct mdio_mux_child_bus *cb = bus->priv;
	45	struct mdio_mux_parent_bus *pb = cb->parent;
	46	int r;
	47
9a6f2b01	48	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
0ca2997d DD	49	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
	50	if (r)
	51	goto out;
	52
	53	pb->current_child = cb->bus_number;
	54
	55	r = pb->mii_bus->read(pb->mii_bus, phy_id, regnum);
	56	out:
	57	mutex_unlock(&pb->mii_bus->mdio_lock);
	58
	59	return r;
	60	}
	61
	62	/*
	63	* The parent bus' lock is used to order access to the switch_fn.
	64	*/
	65	static int mdio_mux_write(struct mii_bus *bus, int phy_id,
	66	int regnum, u16 val)
	67	{
	68	struct mdio_mux_child_bus *cb = bus->priv;
	69	struct mdio_mux_parent_bus *pb = cb->parent;
	70
	71	int r;
	72
9a6f2b01	73	mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
0ca2997d DD	74	r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
	75	if (r)
	76	goto out;
	77
	78	pb->current_child = cb->bus_number;
	79
	80	r = pb->mii_bus->write(pb->mii_bus, phy_id, regnum, val);
	81	out:
	82	mutex_unlock(&pb->mii_bus->mdio_lock);
	83
	84	return r;
	85	}
	86
	87	static int parent_count;
	88
	89	int mdio_mux_init(struct device *dev,
	90	int (switch_fn)(int cur, int desired, void data),
	91	void **mux_handle,
	92	void *data)
	93	{
	94	struct device_node *parent_bus_node;
	95	struct device_node *child_bus_node;
	96	int r, ret_val;
	97	struct mii_bus *parent_bus;
	98	struct mdio_mux_parent_bus *pb;
	99	struct mdio_mux_child_bus *cb;
	100
	101	if (!dev->of_node)
	102	return -ENODEV;
	103
	104	parent_bus_node = of_parse_phandle(dev->of_node, "mdio-parent-bus", 0);
	105
	106	if (!parent_bus_node)
	107	return -ENODEV;
	108
0ca2997d DD	109	pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
	110	if (pb == NULL) {
	111	ret_val = -ENOMEM;
	112	goto err_parent_bus;
	113	}
	114
a1364421 RK	115	parent_bus = of_mdio_find_bus(parent_bus_node);
	116	if (parent_bus == NULL) {
	117	ret_val = -EPROBE_DEFER;
	118	goto err_parent_bus;
	119	}
	120
0ca2997d DD	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;
	126
	127	ret_val = -ENODEV;
61abcb7b	128	for_each_available_child_of_node(dev->of_node, child_bus_node) {
0ca2997d DD	129	u32 v;
	130
	131	r = of_property_read_u32(child_bus_node, "reg", &v);
	132	if (r)
	133	continue;
	134
	135	cb = devm_kzalloc(dev, sizeof(*cb), GFP_KERNEL);
	136	if (cb == NULL) {
	137	dev_err(dev,
	138	"Error: Failed to allocate memory for child\n");
	139	ret_val = -ENOMEM;
447ed736	140	of_node_put(child_bus_node);
0ca2997d DD	141	break;
	142	}
	143	cb->bus_number = v;
	144	cb->parent = pb;
20b08e1a	145
0ca2997d	146	cb->mii_bus = mdiobus_alloc();
20b08e1a TK	147	if (!cb->mii_bus) {
	148	ret_val = -ENOMEM;
	149	of_node_put(child_bus_node);
	150	break;
	151	}
0ca2997d	152	cb->mii_bus->priv = cb;
e7f4dc35	153
0ca2997d DD	154	cb->mii_bus->name = "mdio_mux";
	155	snprintf(cb->mii_bus->id, MII_BUS_ID_SIZE, "%x.%x",
	156	pb->parent_id, v);
	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);
	161	if (r) {
	162	mdiobus_free(cb->mii_bus);
	163	devm_kfree(dev, cb);
	164	} else {
	165	of_node_get(child_bus_node);
	166	cb->next = pb->children;
	167	pb->children = cb;
	168	}
	169	}
	170	if (pb->children) {
	171	*mux_handle = pb;
	172	dev_info(dev, "Version " DRV_VERSION "\n");
	173	return 0;
	174	}
a1364421 RK	175
	176	/* balance the reference of_mdio_find_bus() took */
	177	put_device(&pb->mii_bus->dev);
	178
0ca2997d DD	179	err_parent_bus:
	180	of_node_put(parent_bus_node);
	181	return ret_val;
	182	}
	183	EXPORT_SYMBOL_GPL(mdio_mux_init);
	184
	185	void mdio_mux_uninit(void *mux_handle)
	186	{
	187	struct mdio_mux_parent_bus *pb = mux_handle;
	188	struct mdio_mux_child_bus *cb = pb->children;
	189
	190	while (cb) {
	191	mdiobus_unregister(cb->mii_bus);
	192	mdiobus_free(cb->mii_bus);
	193	cb = cb->next;
	194	}
a1364421 RK	195
	196	/* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
	197	put_device(&pb->mii_bus->dev);
0ca2997d DD	198	}
	199	EXPORT_SYMBOL_GPL(mdio_mux_uninit);
	200
	201	MODULE_DESCRIPTION(DRV_DESCRIPTION);
	202	MODULE_VERSION(DRV_VERSION);
	203	MODULE_AUTHOR("David Daney");
	204	MODULE_LICENSE("GPL");