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Commit 3be2a49e authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by David S. Miller
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of: provide a binding for fixed link PHYs 



Some Ethernet MACs have a "fixed link", and are not connected to a
normal MDIO-managed PHY device. For those situations, a Device Tree
binding allows to describe a "fixed link" using a special PHY node.

This patch adds:

 * A documentation for the fixed PHY Device Tree binding.

 * An of_phy_is_fixed_link() function that an Ethernet driver can call
   on its PHY phandle to find out whether it's a fixed link PHY or
   not. It should typically be used to know if
   of_phy_register_fixed_link() should be called.

 * An of_phy_register_fixed_link() function that instantiates the
   fixed PHY into the PHY subsystem, so that when the driver calls
   of_phy_connect(), the PHY device associated to the OF node will be
   found.

These two additional functions also support the old fixed-link Device
Tree binding used on PowerPC platforms, so that ultimately, the
network device drivers for those platforms could be converted to use
of_phy_is_fixed_link() and of_phy_register_fixed_link() instead of
of_phy_connect_fixed_link(), while keeping compatibility with their
respective Device Tree bindings.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a7595121

Documentation/devicetree/bindings/net/fixed-link.txt

0 → 100644
+30 −0
Original line number Diff line number Diff line 
Fixed link Device Tree binding

------------------------------



Some Ethernet MACs have a "fixed link", and are not connected to a

normal MDIO-managed PHY device. For those situations, a Device Tree

binding allows to describe a "fixed link".



Such a fixed link situation is described by creating a 'fixed-link'

sub-node of the Ethernet MAC device node, with the following

properties:



* 'speed' (integer, mandatory), to indicate the link speed. Accepted

  values are 10, 100 and 1000

* 'full-duplex' (boolean, optional), to indicate that full duplex is

  used. When absent, half duplex is assumed.

* 'pause' (boolean, optional), to indicate that pause should be

  enabled.

* 'asym-pause' (boolean, optional), to indicate that asym_pause should

  be enabled.



Example:



ethernet@0 {

	...

	fixed-link {

	      speed = <1000>;

	      full-duplex;

	};

	...

};

drivers/of/of_mdio.c

+67 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/netdevice.h>

#include <linux/err.h>

#include <linux/phy.h>

#include <linux/phy_fixed.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/of_mdio.h>
@@ -301,3 +302,69 @@ struct phy_device *of_phy_attach(struct net_device *dev, 
	return phy_attach_direct(dev, phy, flags, iface) ? 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;



	/* New binding */

	dn = of_get_child_by_name(np, "fixed-link");

	if (dn) {

		of_node_put(dn);

		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 len;



	/* 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(np, "full-duplex");

		if (of_property_read_u32(fixed_link_node, "speed", &status.speed))

			return -EINVAL;

		status.pause = of_property_read_bool(np, "pause");

		status.asym_pause = of_property_read_bool(np, "asym-pause");

		of_node_put(fixed_link_node);

		return fixed_phy_register(PHY_POLL, &status, np);

	}



	/* 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]);

		return fixed_phy_register(PHY_POLL, &status, np);

	}



	return -ENODEV;

}

EXPORT_SYMBOL(of_phy_register_fixed_link);

#endif

include/linux/of_mdio.h

+15 −0
Original line number Diff line number Diff line
@@ -72,4 +72,19 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np) 
}

#endif /* CONFIG_OF */



#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)

extern int of_phy_register_fixed_link(struct device_node *np);

extern bool of_phy_is_fixed_link(struct device_node *np);

#else

static inline int of_phy_register_fixed_link(struct device_node *np)

{

	return -ENOSYS;

}

static inline bool of_phy_is_fixed_link(struct device_node *np)

{

	return false;

}

#endif





#endif /* __LINUX_OF_MDIO_H */