linux/drivers/of/of_mdio.c
Russell King f018ae7a8c of_mdio: fix MDIO phy device refcounting
bus_find_device() is defined as:

 * This is similar to the bus_for_each_dev() function above, but it
 * returns a reference to a device that is 'found' for later use, as
 * determined by the @match callback.

and it does indeed return a reference-counted pointer to the device:

        while ((dev = next_device(&i)))
                if (match(dev, data) && get_device(dev))
                                        ^^^^^^^^^^^^^^^
                        break;
        klist_iter_exit(&i);
        return dev;

What that means is that when we're done with the struct device, we must
drop that reference.  Neither of_phy_connect() nor of_phy_attach() did
this when phy_connect_direct() or phy_attach_direct() failed.

With our previous patch, phy_connect_direct() and phy_attach_direct()
take a new refcount on the phy device when successful, so we can drop
our local reference immediatley after these functions, whether or not
they succeeded.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 23:04:52 -07:00

368 lines
9.4 KiB
C

/*
* OF helpers for the MDIO (Ethernet PHY) API
*
* Copyright (c) 2009 Secret Lab Technologies, Ltd.
*
* This file is released under the GPLv2
*
* This file provides helper functions for extracting PHY device information
* out of the OpenFirmware device tree and using it to populate an mii_bus.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/netdevice.h>
#include <linux/err.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/of_mdio.h>
#include <linux/module.h>
MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
MODULE_LICENSE("GPL");
/* Extract the clause 22 phy ID from the compatible string of the form
* ethernet-phy-idAAAA.BBBB */
static int of_get_phy_id(struct device_node *device, u32 *phy_id)
{
struct property *prop;
const char *cp;
unsigned int upper, lower;
of_property_for_each_string(device, "compatible", prop, cp) {
if (sscanf(cp, "ethernet-phy-id%4x.%4x", &upper, &lower) == 2) {
*phy_id = ((upper & 0xFFFF) << 16) | (lower & 0xFFFF);
return 0;
}
}
return -EINVAL;
}
static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child,
u32 addr)
{
struct phy_device *phy;
bool is_c45;
int rc;
u32 phy_id;
is_c45 = of_device_is_compatible(child,
"ethernet-phy-ieee802.3-c45");
if (!is_c45 && !of_get_phy_id(child, &phy_id))
phy = phy_device_create(mdio, addr, phy_id, 0, NULL);
else
phy = get_phy_device(mdio, addr, is_c45);
if (!phy || IS_ERR(phy))
return 1;
rc = irq_of_parse_and_map(child, 0);
if (rc > 0) {
phy->irq = rc;
if (mdio->irq)
mdio->irq[addr] = rc;
} else {
if (mdio->irq)
phy->irq = mdio->irq[addr];
}
if (of_property_read_bool(child, "broken-turn-around"))
mdio->phy_ignore_ta_mask |= 1 << addr;
/* Associate the OF node with the device structure so it
* can be looked up later */
of_node_get(child);
phy->dev.of_node = child;
/* All data is now stored in the phy struct;
* register it */
rc = phy_device_register(phy);
if (rc) {
phy_device_free(phy);
of_node_put(child);
return 1;
}
dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
child->name, addr);
return 0;
}
int of_mdio_parse_addr(struct device *dev, const struct device_node *np)
{
u32 addr;
int ret;
ret = of_property_read_u32(np, "reg", &addr);
if (ret < 0) {
dev_err(dev, "%s has invalid PHY address\n", np->full_name);
return ret;
}
/* A PHY must have a reg property in the range [0-31] */
if (addr >= PHY_MAX_ADDR) {
dev_err(dev, "%s PHY address %i is too large\n",
np->full_name, addr);
return -EINVAL;
}
return addr;
}
EXPORT_SYMBOL(of_mdio_parse_addr);
/**
* of_mdiobus_register - Register mii_bus and create PHYs from the device tree
* @mdio: pointer to mii_bus structure
* @np: pointer to device_node of MDIO bus.
*
* This function registers the mii_bus structure and registers a phy_device
* for each child node of @np.
*/
int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
{
struct device_node *child;
const __be32 *paddr;
bool scanphys = false;
int addr, rc, i;
/* Mask out all PHYs from auto probing. Instead the PHYs listed in
* the device tree are populated after the bus has been registered */
mdio->phy_mask = ~0;
/* Clear all the IRQ properties */
if (mdio->irq)
for (i=0; i<PHY_MAX_ADDR; i++)
mdio->irq[i] = PHY_POLL;
mdio->dev.of_node = np;
/* Register the MDIO bus */
rc = mdiobus_register(mdio);
if (rc)
return rc;
/* Loop over the child nodes and register a phy_device for each one */
for_each_available_child_of_node(np, child) {
addr = of_mdio_parse_addr(&mdio->dev, child);
if (addr < 0) {
scanphys = true;
continue;
}
rc = of_mdiobus_register_phy(mdio, child, addr);
if (rc)
continue;
}
if (!scanphys)
return 0;
/* auto scan for PHYs with empty reg property */
for_each_available_child_of_node(np, child) {
/* Skip PHYs with reg property set */
paddr = of_get_property(child, "reg", NULL);
if (paddr)
continue;
for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
/* skip already registered PHYs */
if (mdio->phy_map[addr])
continue;
/* be noisy to encourage people to set reg property */
dev_info(&mdio->dev, "scan phy %s at address %i\n",
child->name, addr);
rc = of_mdiobus_register_phy(mdio, child, addr);
if (rc)
continue;
}
}
return 0;
}
EXPORT_SYMBOL(of_mdiobus_register);
/* Helper function for of_phy_find_device */
static int of_phy_match(struct device *dev, void *phy_np)
{
return dev->of_node == phy_np;
}
/**
* of_phy_find_device - Give a PHY node, find the phy_device
* @phy_np: Pointer to the phy's device tree node
*
* If successful, returns a pointer to the phy_device with the embedded
* struct device refcount incremented by one, or NULL on failure.
*/
struct phy_device *of_phy_find_device(struct device_node *phy_np)
{
struct device *d;
if (!phy_np)
return NULL;
d = bus_find_device(&mdio_bus_type, NULL, phy_np, of_phy_match);
return d ? to_phy_device(d) : NULL;
}
EXPORT_SYMBOL(of_phy_find_device);
/**
* of_phy_connect - Connect to the phy described in the device tree
* @dev: pointer to net_device claiming the phy
* @phy_np: Pointer to device tree node for the PHY
* @hndlr: Link state callback for the network device
* @iface: PHY data interface type
*
* If successful, returns a pointer to the phy_device with the embedded
* struct device refcount incremented by one, or NULL on failure. The
* refcount must be dropped by calling phy_disconnect() or phy_detach().
*/
struct phy_device *of_phy_connect(struct net_device *dev,
struct device_node *phy_np,
void (*hndlr)(struct net_device *), u32 flags,
phy_interface_t iface)
{
struct phy_device *phy = of_phy_find_device(phy_np);
int ret;
if (!phy)
return NULL;
phy->dev_flags = flags;
ret = phy_connect_direct(dev, phy, hndlr, iface);
/* refcount is held by phy_connect_direct() on success */
put_device(&phy->dev);
return ret ? NULL : phy;
}
EXPORT_SYMBOL(of_phy_connect);
/**
* of_phy_attach - Attach to a PHY without starting the state machine
* @dev: pointer to net_device claiming the phy
* @phy_np: Node pointer for the PHY
* @flags: flags to pass to the PHY
* @iface: PHY data interface type
*
* If successful, returns a pointer to the phy_device with the embedded
* struct device refcount incremented by one, or NULL on failure. The
* refcount must be dropped by calling phy_disconnect() or phy_detach().
*/
struct phy_device *of_phy_attach(struct net_device *dev,
struct device_node *phy_np, u32 flags,
phy_interface_t iface)
{
struct phy_device *phy = of_phy_find_device(phy_np);
int ret;
if (!phy)
return NULL;
ret = phy_attach_direct(dev, phy, flags, iface);
/* refcount is held by phy_attach_direct() on success */
put_device(&phy->dev);
return ret ? NULL : phy;
}
EXPORT_SYMBOL(of_phy_attach);
#if defined(CONFIG_FIXED_PHY)
/*
* of_phy_is_fixed_link() and of_phy_register_fixed_link() must
* support two DT bindings:
* - the old DT binding, where 'fixed-link' was a property with 5
* cells encoding various informations about the fixed PHY
* - the new DT binding, where 'fixed-link' is a sub-node of the
* Ethernet device.
*/
bool of_phy_is_fixed_link(struct device_node *np)
{
struct device_node *dn;
int len, err;
const char *managed;
/* New binding */
dn = of_get_child_by_name(np, "fixed-link");
if (dn) {
of_node_put(dn);
return true;
}
err = of_property_read_string(np, "managed", &managed);
if (err == 0 && strcmp(managed, "auto") != 0)
return true;
/* Old binding */
if (of_get_property(np, "fixed-link", &len) &&
len == (5 * sizeof(__be32)))
return true;
return false;
}
EXPORT_SYMBOL(of_phy_is_fixed_link);
int of_phy_register_fixed_link(struct device_node *np)
{
struct fixed_phy_status status = {};
struct device_node *fixed_link_node;
const __be32 *fixed_link_prop;
int link_gpio;
int len, err;
struct phy_device *phy;
const char *managed;
err = of_property_read_string(np, "managed", &managed);
if (err == 0) {
if (strcmp(managed, "in-band-status") == 0) {
/* status is zeroed, namely its .link member */
phy = fixed_phy_register(PHY_POLL, &status, -1, np);
return IS_ERR(phy) ? PTR_ERR(phy) : 0;
}
}
/* New binding */
fixed_link_node = of_get_child_by_name(np, "fixed-link");
if (fixed_link_node) {
status.link = 1;
status.duplex = of_property_read_bool(fixed_link_node,
"full-duplex");
if (of_property_read_u32(fixed_link_node, "speed", &status.speed))
return -EINVAL;
status.pause = of_property_read_bool(fixed_link_node, "pause");
status.asym_pause = of_property_read_bool(fixed_link_node,
"asym-pause");
link_gpio = of_get_named_gpio_flags(fixed_link_node,
"link-gpios", 0, NULL);
of_node_put(fixed_link_node);
if (link_gpio == -EPROBE_DEFER)
return -EPROBE_DEFER;
phy = fixed_phy_register(PHY_POLL, &status, link_gpio, np);
return IS_ERR(phy) ? PTR_ERR(phy) : 0;
}
/* Old binding */
fixed_link_prop = of_get_property(np, "fixed-link", &len);
if (fixed_link_prop && len == (5 * sizeof(__be32))) {
status.link = 1;
status.duplex = be32_to_cpu(fixed_link_prop[1]);
status.speed = be32_to_cpu(fixed_link_prop[2]);
status.pause = be32_to_cpu(fixed_link_prop[3]);
status.asym_pause = be32_to_cpu(fixed_link_prop[4]);
phy = fixed_phy_register(PHY_POLL, &status, -1, np);
return IS_ERR(phy) ? PTR_ERR(phy) : 0;
}
return -ENODEV;
}
EXPORT_SYMBOL(of_phy_register_fixed_link);
#endif