Commit d7c6082f authored by Maxime Chevallier's avatar Maxime Chevallier Committed by Jakub Kicinski
Browse files

net: phy: Introduce generic SFP handling for PHY drivers 



There are currently 4 PHY drivers that can drive downstream SFPs:
marvell.c, marvell10g.c, at803x.c and marvell-88x2222.c. Most of the
logic is boilerplate, either calling into generic phylib helpers (for
SFP PHY attach, bus attach, etc.) or performing the same tasks with a
bit of validation :
 - Getting the module's expected interface mode
 - Making sure the PHY supports it
 - Optionaly perform some configuration to make sure the PHY outputs
   the right mode

This can be made more generic by leveraging the phy_port, and its
configure_mii() callback which allows setting a port's interfaces when
the port is a serdes.

Introduce a generic PHY SFP support. If a driver doesn't probe the SFP
bus itself, but an SFP phandle is found in devicetree/firmware, then the
generic PHY SFP support will be used, relying on port ops.

PHY driver need to :
 - Register a .attach_port() callback
 - When a serdes port is registered to the PHY, drivers must set
   port->interfaces to the set of PHY_INTERFACE_MODE the port can output
 - If the port has limitations regarding speed, duplex and aneg, the
   port can also fine-tune the final linkmodes that can be supported
 - The port may register a set of ops, including .configure_mii(), that
   will be called at module_insert time to adjust the interface based on
   the module detected.

Reviewed-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Tested-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMaxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-8-maxime.chevallier@bootlin.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 07f3ca9e

drivers/net/phy/phy_device.c

+107 −0
Original line number Diff line number Diff line
@@ -1598,6 +1598,86 @@ void phy_sfp_detach(void *upstream, struct sfp_bus *bus) 
}

EXPORT_SYMBOL(phy_sfp_detach);



static int phy_sfp_module_insert(void *upstream, const struct sfp_eeprom_id *id)

{

	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);

	struct phy_device *phydev = upstream;

	const struct sfp_module_caps *caps;

	struct phy_port *port;



	phy_interface_t iface;



	linkmode_zero(sfp_support);



	port = phy_get_sfp_port(phydev);

	if (!port)

		return -EINVAL;



	caps = sfp_get_module_caps(phydev->sfp_bus);



	linkmode_and(sfp_support, port->supported, caps->link_modes);

	if (linkmode_empty(sfp_support)) {

		dev_err(&phydev->mdio.dev, "incompatible SFP module inserted, no common linkmode\n");

		return -EINVAL;

	}



	iface = sfp_select_interface(phydev->sfp_bus, sfp_support);

	if (iface == PHY_INTERFACE_MODE_NA) {

		dev_err(&phydev->mdio.dev, "PHY %s does not support the SFP module's requested MII interfaces\n",

			phydev_name(phydev));

		return -EINVAL;

	}



	if (phydev->n_ports == 1)

		phydev->port = caps->port;



	if (port->ops && port->ops->configure_mii)

		return port->ops->configure_mii(port, true, iface);



	return 0;

}



static void phy_sfp_module_remove(void *upstream)

{

	struct phy_device *phydev = upstream;

	struct phy_port *port = phy_get_sfp_port(phydev);



	if (port && port->ops && port->ops->configure_mii)

		port->ops->configure_mii(port, false, PHY_INTERFACE_MODE_NA);



	if (phydev->n_ports == 1)

		phydev->port = PORT_NONE;

}



static void phy_sfp_link_up(void *upstream)

{

	struct phy_device *phydev = upstream;

	struct phy_port *port = phy_get_sfp_port(phydev);



	if (port && port->ops && port->ops->link_up)

		port->ops->link_up(port);

}



static void phy_sfp_link_down(void *upstream)

{

	struct phy_device *phydev = upstream;

	struct phy_port *port = phy_get_sfp_port(phydev);



	if (port && port->ops && port->ops->link_down)

		port->ops->link_down(port);

}



static const struct sfp_upstream_ops sfp_phydev_ops = {

	.attach = phy_sfp_attach,

	.detach = phy_sfp_detach,

	.module_insert = phy_sfp_module_insert,

	.module_remove = phy_sfp_module_remove,

	.link_up = phy_sfp_link_up,

	.link_down = phy_sfp_link_down,

	.connect_phy = phy_sfp_connect_phy,

	.disconnect_phy = phy_sfp_disconnect_phy,

};



static int phy_add_port(struct phy_device *phydev, struct phy_port *port)

{

	int ret = 0;
@@ -1658,6 +1738,7 @@ static int phy_setup_sfp_port(struct phy_device *phydev) 
	 * is a MII port.

	 */

	port->is_mii = true;

	port->is_sfp = true;



	/* The port->supported and port->interfaces list will be populated

	 * when attaching the port to the phydev.
@@ -3505,6 +3586,13 @@ static int phy_setup_ports(struct phy_device *phydev) 
	if (ret)

		return ret;



	/* Use generic SFP probing only if the driver didn't do so already */

	if (!phydev->sfp_bus) {

		ret = phy_sfp_probe(phydev, &sfp_phydev_ops);

		if (ret)

			goto out;

	}



	if (phydev->n_ports < phydev->max_n_ports) {

		ret = phy_default_setup_single_port(phydev);

		if (ret)
@@ -3540,6 +3628,25 @@ static int phy_setup_ports(struct phy_device *phydev) 
	return ret;

}



/**

 * phy_get_sfp_port() - Returns the first valid SFP port of a PHY

 * @phydev: pointer to the PHY device to get the SFP port from

 *

 * Returns: The first active SFP (serdes) port of a PHY device, NULL if none

 * exist.

 */

struct phy_port *phy_get_sfp_port(struct phy_device *phydev)

{

	struct phy_port *port;



	list_for_each_entry(port, &phydev->ports, head)

		if (port->active && port->is_sfp)

			return port;



	return NULL;

}

EXPORT_SYMBOL_GPL(phy_get_sfp_port);



/**

 * fwnode_mdio_find_device - Given a fwnode, find the mdio_device

 * @fwnode: pointer to the mdio_device's fwnode

include/linux/phy.h

+2 −0
Original line number Diff line number Diff line
@@ -2455,6 +2455,8 @@ int __phy_hwtstamp_set(struct phy_device *phydev, 
		       struct kernel_hwtstamp_config *config,

		       struct netlink_ext_ack *extack);



struct phy_port *phy_get_sfp_port(struct phy_device *phydev);



extern const struct bus_type mdio_bus_type;

extern const struct class mdio_bus_class;

include/linux/phy_port.h

+2 −0
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct phy_port_ops { 
 * @active: Indicates if the port is currently part of the active link.

 * @is_mii: Indicates if this port is MII (Media Independent Interface),

 *          or MDI (Media Dependent Interface).

 * @is_sfp: Indicates if this port drives an SFP cage.

 */

struct phy_port {

	struct list_head head;
@@ -67,6 +68,7 @@ struct phy_port { 
	unsigned int not_described:1;

	unsigned int active:1;

	unsigned int is_mii:1;

	unsigned int is_sfp:1;

};



struct phy_port *phy_port_alloc(void);