linux/drivers/net/phy/mdio-mux.c

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/*
* 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_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 mii_bus *mux_bus)
{
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;
if (!mux_bus) {
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) {
ret_val = -EPROBE_DEFER;
goto err_parent_bus;
}
} else {
parent_bus_node = NULL;
parent_bus = mux_bus;
}
pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
if (!pb) {
ret_val = -ENOMEM;
goto err_pb_kz;
}
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) {
int v;
mdio: mux: fix parsing mux registers outside of the PHY address range mdio_mux_init parses the child nodes of the MDIO mux. When using "mdio-mux-mmioreg" the child nodes are describing the register value that is written to switch between the MDIO busses. The change which makes the error messages more verbose changed the parsing of the "reg" property from a simple of_property_read_u32 call to of_mdio_parse_addr. On a Khadas VIM (based on the Meson GXL SoC, which uses mdio-mux-mmioreg) this prevents registering the MDIO mux (because the "reg" values on the MDIO mux child nodes are 0x2009087f and 0xe40908ff) and leads to the following errors: mdio-mux-mmioreg c883455c.eth-phy-mux: /soc/periphs@c8834000/eth-phy-mux/mdio@e40908ff PHY address -469169921 is too large mdio-mux-mmioreg c883455c.eth-phy-mux: Error: Failed to find reg for child /soc/periphs@c8834000/eth-phy-mux/mdio@e40908ff mdio-mux-mmioreg c883455c.eth-phy-mux: /soc/periphs@c8834000/eth-phy-mux/mdio@2009087f PHY address 537462911 is too large mdio-mux-mmioreg c883455c.eth-phy-mux: Error: Failed to find reg for child /soc/periphs@c8834000/eth-phy-mux/mdio@2009087f mdio-mux-mmioreg c883455c.eth-phy-mux: Error: No acceptable child buses found mdio-mux-mmioreg c883455c.eth-phy-mux: failed to register mdio-mux bus /soc/periphs@c8834000/eth-phy-mux (as a result of that ethernet is not working, because the PHY which is connected through the mux' child MDIO bus, which is not being registered). Fix this by reverting the change from of_mdio_parse_addr to of_mdio_parse_addr. Fixes: 342fa1964439 ("mdio: mux: make child bus walking more permissive and errors more verbose") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-10 12:35:23 +00:00
r = of_property_read_u32(child_bus_node, "reg", &v);
if (r) {
dev_err(dev,
"Error: Failed to find reg for child %pOF\n",
child_bus_node);
continue;
}
cb = devm_kzalloc(dev, sizeof(*cb), GFP_KERNEL);
if (!cb) {
ret_val = -ENOMEM;
continue;
}
cb->bus_number = v;
cb->parent = pb;
cb->mii_bus = mdiobus_alloc();
if (!cb->mii_bus) {
ret_val = -ENOMEM;
devm_kfree(dev, cb);
continue;
}
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) {
dev_err(dev,
"Error: Failed to register MDIO bus for child %pOF\n",
child_bus_node);
mdiobus_free(cb->mii_bus);
devm_kfree(dev, cb);
} else {
cb->next = pb->children;
pb->children = cb;
}
}
if (pb->children) {
*mux_handle = pb;
return 0;
}
dev_err(dev, "Error: No acceptable child buses found\n");
devm_kfree(dev, pb);
err_pb_kz:
/* balance the reference of_mdio_find_bus() took */
if (!mux_bus)
put_device(&parent_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_AUTHOR("David Daney");
MODULE_LICENSE("GPL");