Commit db40c1aa authored by Hannes Schmelzer's avatar Hannes Schmelzer Committed by Joe Hershberger
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drivers/net/phy: add fixed-phy / fixed-link support

This patch adds support for having a "fixed-link" to some other MAC
(like some embedded switch-device).

For this purpose we introduce a new phy-driver, called "Fixed PHY".

Fixed PHY works only with CONFIG_DM_ETH enabled, since the fixed-link is
described with a subnode below ethernet interface.

Most ethernet drivers (unfortunately not all are following same scheme
for searching/attaching phys) are calling "phy_connect(...)" for getting
a phy-device.
At this point we link in, we search here for a subnode called "fixed-
link", once found we start phy_device_create(...) with the special phy-
id PHY_FIXED_ID (0xa5a55a5a).

During init the "Fixed PHY" driver has registered with this id and now
gets probed, during probe we get all the details about fixed-link out of
dts, later on the phy reports this values.
Signed-off-by: default avatarHannes Schmelzer <>
Signed-off-by: default avatarHannes Schmelzer <>
Acked-by: Joe Hershberger's avatarJoe Hershberger <>
Reviewed-by: default avatarChristian Gmeiner <>
parent f8e57c65
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
* '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
* 'asym-pause' (boolean, optional), to indicate that asym_pause should
be enabled.
ethernet@0 {
fixed-link {
speed = <1000>;
......@@ -90,4 +90,14 @@ config PHY_VITESSE
bool "Xilinx Ethernet PHYs support"
config PHY_FIXED
bool "Fixed-Link PHY"
depends on DM_ETH
Fixed PHY is used for having a 'fixed-link' to another MAC with a direct
connection (MII, RGMII, ...).
There is nothing like autoneogation and so
on, the link is always up with fixed speed and fixed duplex-setting.
More information: doc/device-tree-bindings/net/fixed-link.txt
endif #PHYLIB
......@@ -28,3 +28,4 @@ obj-$(CONFIG_PHY_TI) += ti.o
obj-$(CONFIG_PHY_XILINX) += xilinx_phy.o
obj-$(CONFIG_PHY_VITESSE) += vitesse.o
obj-$(CONFIG_PHY_MSCC) += mscc.o
obj-$(CONFIG_PHY_FIXED) += fixed.o
* Fixed-Link phy
* Copyright 2017 Bernecker & Rainer Industrieelektronik GmbH
* SPDX-License-Identifier: GPL-2.0+
#include <config.h>
#include <common.h>
#include <phy.h>
#include <dm.h>
#include <fdt_support.h>
int fixedphy_probe(struct phy_device *phydev)
struct fixed_link *priv;
int ofnode = phydev->addr;
u32 val;
/* check for mandatory properties within fixed-link node */
val = fdt_getprop_u32_default_node(gd->fdt_blob,
ofnode, 0, "speed", 0);
if (val != SPEED_10 && val != SPEED_100 && val != SPEED_1000) {
printf("ERROR: no/invalid speed given in fixed-link node!");
return -EINVAL;
priv = malloc(sizeof(*priv));
if (!priv)
return -ENOMEM;
memset(priv, 0, sizeof(*priv));
phydev->priv = priv;
phydev->addr = 0;
priv->link_speed = val;
priv->duplex = fdtdec_get_bool(gd->fdt_blob, ofnode, "full-duplex");
priv->pause = fdtdec_get_bool(gd->fdt_blob, ofnode, "pause");
priv->asym_pause = fdtdec_get_bool(gd->fdt_blob, ofnode, "asym-pause");
/* fixed-link phy must not be reset by core phy code */
phydev->flags |= PHY_FLAG_BROKEN_RESET;
return 0;
int fixedphy_startup(struct phy_device *phydev)
struct fixed_link *priv = phydev->priv;
phydev->asym_pause = priv->asym_pause;
phydev->pause = priv->pause;
phydev->duplex = priv->duplex;
phydev->speed = priv->link_speed;
phydev->link = 1;
return 0;
int fixedphy_shutdown(struct phy_device *phydev)
return 0;
static struct phy_driver fixedphy_driver = {
.uid = PHY_FIXED_ID,
.mask = 0xffffffff,
.name = "Fixed PHY",
.probe = fixedphy_probe,
.startup = fixedphy_startup,
.shutdown = fixedphy_shutdown,
int phy_fixed_init(void)
return 0;
......@@ -515,7 +515,9 @@ int phy_init(void)
return 0;
......@@ -854,9 +856,24 @@ struct phy_device *phy_connect(struct mii_dev *bus, int addr,
struct eth_device *dev, phy_interface_t interface)
struct phy_device *phydev;
struct phy_device *phydev = NULL;
int sn;
const char *name;
sn = fdt_first_subnode(gd->fdt_blob, dev->of_offset);
while (sn > 0) {
name = fdt_get_name(gd->fdt_blob, sn, NULL);
if (name != NULL && strcmp(name, "fixed-link") == 0) {
phydev = phy_device_create(bus,
sn, PHY_FIXED_ID, interface);
sn = fdt_next_subnode(gd->fdt_blob, sn);
if (phydev == NULL)
phydev = phy_find_by_mask(bus, 1 << addr, interface);
phydev = phy_find_by_mask(bus, 1 << addr, interface);
if (phydev)
phy_connect_dev(phydev, dev);
......@@ -15,6 +15,8 @@
#include <linux/ethtool.h>
#include <linux/mdio.h>
#define PHY_FIXED_ID 0xa5a55a5a
#define PHY_MAX_ADDR 32
#define PHY_FLAG_BROKEN_RESET (1 << 0) /* soft reset not supported */
......@@ -267,6 +269,7 @@ int phy_ti_init(void);
int phy_vitesse_init(void);
int phy_xilinx_init(void);
int phy_mscc_init(void);
int phy_fixed_init(void);
int board_phy_config(struct phy_device *phydev);
int get_phy_id(struct mii_dev *bus, int addr, int devad, u32 *phy_id);
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