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author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2021-01-25 15:23:52 +0300 |
---|---|---|
committer | Tom Rini <trini@konsulko.com> | 2021-02-16 19:48:20 +0300 |
commit | d0781c95bc448a211546404c779e78b29ada1214 (patch) | |
tree | 0898ff8f87398b37232879fbe53d609c7b75e5f9 | |
parent | 56a558834081af0de84a4402d081f49e00297bab (diff) | |
download | u-boot-d0781c95bc448a211546404c779e78b29ada1214.tar.xz |
net: phy: introduce fixed_phy_create for DSA CPU ports
The DSA (Distributed Switch Architecture) implementation has made a
design decision when it got introduced to the Linux kernel in 2008.
That was to hide away from the user the CPU-facing Ethernet MAC, since
it does not make sense to register it as a struct net_device (UCLASS_ETH
udevice for U-Boot), because that would never be beneficial for a user:
they would not be able to use it for traffic, since conceptually, a
packet delivered to the CPU port should loop back into the system.
Nonetheless, DSA has had numerous growing pains due to the lack of a
struct net_device for the CPU port, but so far it has overcome them.
It is unlikely at this stage of maturity that this aspect of it will
change.
We would like U-Boot to present the same information as Linux, to be at
parity in terms of number of interfaces, so that ethNaddr environment
variables could directly be associated between U-Boot and Linux.
Therefore, we would implicitly like U-Boot to hide the CPU port from the
user as well.
But the paradox is that DSA still needs a struct phy_device to inform
the driver of the parameters of the link that it should configure the
CPU port to. The problem is that the phy_device is typically returned
via a call to phy_connect, which needs an udevice to attach the PHY to,
and to search its ofnode for the 'fixed-link' property. But we don't
have an udevice to present for the CPU port.
Since 99% of DSA setups are MAC-to-MAC connections between the switch
and the host Ethernet controller, the struct phy_device is going to be a
fixed PHY. This simplifies things quite a bit. In U-Boot, a fixed PHY
does not need an MDIO bus, and does not need an attached dev either.
Basically, the phy_connect call doesn't do any connection, it just
creates the fixed PHY.
The proposal of this patch is to introduce a new fixed_phy_create
function which will take a single argument: the ofnode that holds this:
port@4 {
reg = <4>;
phy-mode = "internal";
fixed-link {
speed = <2500>;
full-duplex;
};
};
and probe a fixed PHY driver using the information from this ofnode.
DSA will probably be the only user of this function.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
-rw-r--r-- | drivers/net/phy/phy.c | 31 | ||||
-rw-r--r-- | include/phy.h | 21 |
2 files changed, 52 insertions, 0 deletions
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index a2be398736..89e3076bfd 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -977,6 +977,37 @@ static struct phy_device *phy_connect_gmii2rgmii(struct mii_dev *bus, #endif #ifdef CONFIG_PHY_FIXED +/** + * fixed_phy_create() - create an unconnected fixed-link pseudo-PHY device + * @node: OF node for the container of the fixed-link node + * + * Description: Creates a struct phy_device based on a fixed-link of_node + * description. Can be used without phy_connect by drivers which do not expose + * a UCLASS_ETH udevice. + */ +struct phy_device *fixed_phy_create(ofnode node) +{ + phy_interface_t interface = PHY_INTERFACE_MODE_NONE; + const char *if_str; + ofnode subnode; + + if_str = ofnode_read_string(node, "phy-mode"); + if (!if_str) { + if_str = ofnode_read_string(node, "phy-interface-type"); + } + if (if_str) { + interface = phy_get_interface_by_name(if_str); + } + + subnode = ofnode_find_subnode(node, "fixed-link"); + if (!ofnode_valid(subnode)) { + return NULL; + } + + return phy_device_create(NULL, ofnode_to_offset(subnode), PHY_FIXED_ID, + false, interface); +} + #ifdef CONFIG_DM_ETH static struct phy_device *phy_connect_fixed(struct mii_dev *bus, struct udevice *dev, diff --git a/include/phy.h b/include/phy.h index 7750efd8bb..2754421ed4 100644 --- a/include/phy.h +++ b/include/phy.h @@ -402,6 +402,27 @@ int phy_reset(struct phy_device *phydev); struct phy_device *phy_find_by_mask(struct mii_dev *bus, unsigned phy_mask, phy_interface_t interface); +#ifdef CONFIG_PHY_FIXED + +/** + * fixed_phy_create() - create an unconnected fixed-link pseudo-PHY device + * @node: OF node for the container of the fixed-link node + * + * Description: Creates a struct phy_device based on a fixed-link of_node + * description. Can be used without phy_connect by drivers which do not expose + * a UCLASS_ETH udevice. + */ +struct phy_device *fixed_phy_create(ofnode node); + +#else + +static inline struct phy_device *fixed_phy_create(ofnode node) +{ + return NULL; +} + +#endif + #ifdef CONFIG_DM_ETH /** |