From: Vladimir Oltean vladimir.oltean@nxp.com
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 --- Changes in v5: Use the new API for creating a fixed PHY (introduced in patch 1), which is to put the ofnode in phydev->node instead of phydev->addr.
Changes in v4: Patch is new.
drivers/net/phy/phy.c | 35 +++++++++++++++++++++++++++++++++++ include/phy.h | 21 +++++++++++++++++++++ 2 files changed, 56 insertions(+)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index e88c93c4180d..a3b294054d18 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -977,6 +977,41 @@ 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; + struct phy_device *phydev; + 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; + } + + phydev = phy_device_create(NULL, 0, PHY_FIXED_ID, false, interface); + if (phydev) + phydev->node = subnode; + + return phydev; +} + #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 7750efd8bb5c..2754421ed4fb 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
/**