Add a separate set of PCS operations, which MAC drivers can use to
couple phylink with their associated MAC PCS layer.  The PCS
operations include:

- pcs_get_state() - reads the link up/down, resolved speed, duplex
   and pause from the PCS.
- pcs_config() - configures the PCS for the specified mode, PHY
   interface type, and setting the advertisement.
- pcs_an_restart() - restarts 802.3 in-band negotiation with the
   link partner
- pcs_link_up() - informs the PCS that link has come up, and the
   parameters of the link. Link parameters are used to program the
   PCS for fixed speed and non-inband modes.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename the bland 'ops' member of struct phylink to be a more
descriptive 'mac_ops' - this is necessary as we're about to introduce
another set of operations.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change phylink_mii_c22_pcs_set_advertisement() to take only the PHY
interface and advertisement mask, rather than the full phylink state.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement helpers for PCS accessed via the MII bus using 802.3 clause
45 cycles for 10GBASE-R. Only link up/down is supported, 10G full
duplex is assumed.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement helpers for PCS accessed via the MII bus using 802.3 clause
22 cycles, conforming to 802.3 clause 37 and Cisco SGMII specifications
for the advertisement word.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add XLGMII interface and the list of XLGMII speeds to PHYLINK.
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We may have cases where MAC or PCS do not support Autoneg. Check if it
is supported after validate callback is called.
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

USXGMII also supports these missing backplane speeds.
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This should improve the error message when the PHY validate in the MAC
driver failed. I ran into this problem multiple times that I put wrong
interface values into the device tree and was searching why it is
failing with -22 (-EINVAL). This should make it easier to spot the
problem.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Propagate the resolved link parameters via the mac_link_up() call for
MACs that do not automatically track their PCS state. We propagate the
link parameters via function arguments so that inappropriate members
of struct phylink_link_state can't be accessed, and creating a new
structure just for this adds needless complexity to the API.
Tested-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Improve the initial MAC configuration so we get a configuration which
more represents the final operating mode, in particular with respect
to the flow control settings.

We do this by:
1) more fully initialising our phy state, so we can use this as the
   initial state for PHY based connections.
2) reading the fixed link state.
3) ensuring that in-band mode has sane pause settings for SGMII vs
   802.3z negotiation modes.

In all three cases, we ensure that state->link is false, just in case
any MAC drivers have other ideas by mis-using this member, and we also
take account of manual pause mode configuration at this point.

This avoids MLO_PAUSE_AN being seen in mac_config() when operating in
PHY, fixed mode or inband SGMII mode, thereby giving cleaner semantics
to the pause flags.  As a result of this, the pause flags now indicate
in a mode-independent way what is required from a mac_config()
implementation.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

When ethtool -A is used to change the pause modes, the pause
advertisement is not being changed, but the documentation in
uapi/linux/ethtool.h says we should be. Add that capability to
phylink.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Resolve the fixed link flow control using the recently introduced
linkmode_resolve_pause() helper, which we use in
phylink_get_fixed_state() only when operating in full duplex mode.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the new phy_get_pause() helper to get the resolved pause modes for
a PHY rather than resolving the pause modes ourselves. We temporarily
retain our pause mode resolution for causes where there is no PHY
attached, e.g. for fixed-link modes.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Split the application of manually controlled flow control modes from
phylink_resolve_flow(), so that we can use alternative providers of
flow control resolution.

We also want to clear the MLO_PAUSE_AN flag when autoneg is disabled,
since flow control can't be negotiated in this circumstance.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the ability for ethtool -A to change the pause settings for
fixed links; if this is really required, we can reinstate it later.

Andrew Lunn agrees: "So I think it is safe to not implement ethtool
-A, at least until somebody has a real use case for it."

Lets avoid making things too complex for use cases that aren't being
used.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

USXGMII supports passing link information in-band between PHY and MAC PCS,
add it to the list of protocols that support in-band AN mode.

Being a MAC-PHY protocol that can auto-negotiate link speeds up to 10
Gbps, we populate the initial supported mask with the entire spectrum of
link modes up to 10G that PHYLINK supports, and we let the driver reduce
that mask in its .phylink_validate method.
Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For some reason, PHYLINK does not put the copper modes for 802.3bz
(NBASE-T) and 802.3an-2006 (10GBASE-T) in the PHY's supported mask, when
the PHY-MAC connection is a 10G-capable one (10GBase-KR, 10GBase-R,
USXGMII). One possible way through which the cable side can work at the
lower speed is by having the PHY emit PAUSE frames towards the MAC. So
fix that omission.

Also include the 2500Base-X fiber mode in this list while we're at it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The information about the PHY attached to the PHYLINK instance is useful
but is missing the IRQ prints that phy_attached_info() adds.
phy_attached_info() is a bit long and it would not be possible to use
phylink_info() anyway.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some MAC PCS blocks are unable to provide interrupts when their status
changes. As we already have support in phylink for polling status, use
this to provide a hook for MACs to enable polling mode.

The patch idea was picked up from Russell King's suggestion on the macb
phylink patch thread here [0] but the implementation was changed.
Instead of introducing a new phylink_start_poll() function, which would
make the implementation cumbersome for common PHYLINK implementations
for multiple types of devices, like DSA, just add a boolean property to
the phylink_config structure, which is just as backwards-compatible.

https://lkml.org/lkml/2019/12/16/603Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

QSGMII is a SerDes protocol clocked at 5 Gbaud (4 times higher than
SGMII which is clocked at 1.25 Gbaud), with the same 8b/10b encoding and
some extra symbols for synchronization. Logically it offers 4 SGMII
interfaces multiplexed onto the same physical lanes. Each MAC PCS has
its own in-band AN process with the system side of the QSGMII PHY, which
is identical to the regular SGMII AN process.

So allow QSGMII as a valid in-band AN mode, since it is no different
from software perspective from regular SGMII.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Switch network drivers, phy drivers, and SFP/phylink over to use the
more correct 10GBASE-R, rather than 10GBASE-KR. 10GBASE-KR is backplane
ethernet, which is 10GBASE-R with autonegotiation on top, which our
current usage on the affected platforms does not have.

The only remaining user of PHY_INTERFACE_MODE_10GKR is the Aquantia
PHY, which has a separate mode for 10GBASE-KR.

For Marvell mvpp2, we detect 10GBASE-KR, and rewrite it to 10GBASE-R
for compatibility with existing DT - this is the only network driver
at present that makes use of PHY_INTERFACE_MODE_10GKR.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of fwnode_get_named_gpiod() that I plan to hide away, let's use
the new fwnode_gpiod_get_index() that mimics gpiod_get_index(), but
works with arbitrary firmware node.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The kernel test robot reports a boot failure with qemu in 5.5-rc,
referencing commit 2203cbf2 ("net: sfp: move fwnode parsing into
sfp-bus layer"). This is caused by phylink_create() being passed a
NULL fwnode, causing fwnode_property_get_reference_args() to return
-EINVAL.

Don't attempt to attach to a SFP bus if we have no fwnode, which
avoids this issue.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: 2203cbf2 ("net: sfp: move fwnode parsing into sfp-bus layer")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit e45d1f52 ("net: phylink: support Clause 45 PHYs on SFP+
modules") added a workaround to support clause 45 PHYs which
dynamically switch their interface mode on SFP+ modules.  This was
implemented by validating the PHYs supported/advertising using
PHY_INTERFACE_MODE_NA, rather than the specific interface mode that
we attached the PHY with.

However, we already have a situation where phylink is used to connect
a Marvell 88X3310 PHY which also behaves in exactly the same way, but
which seemingly doesn't need this.  The reason seems to be that the
mvpp2 driver sets a whole bunch of link modes for
PHY_INTERFACE_MODE_10GKR down to 10Mb/s, despite 10GBASE-R not actually
supporting anything but 10Gb/s speeds.

When testing with drivers that (correctly) take the mvneta approach,
where the validate() method only returns what can be supported /
advertised for the specified link mode, we find that Clause 45 PHYs do
not behave as we expect: their advertisement is restricted to what
the current link will support, rather than what the PHY supports
through its dynamic switching.

Extend this workaround to all such cases; if we have a Clause 45 PHY
attaching via any means, except in USXGMII, XAUI and RXAUI which are
all unable to support this dynamic switching or have other solutions
to it, then we need to validate using PHY_INTERFACE_MODE_NA.

This should allow mvpp2 to switch to a more conformant validate()
implementation.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

While testing ethtool with the Methode DM7052 module, it was noticed
that attempting to set the advertising mask results in the mask being
truncated to the support offered by the currently chosen PHY interface
mode.

When a PHY dynamically changes the PHY interface mode, limiting the
advertising mask in this way is not correct - if the PHY happened to
negotiate 10GBASE-T, and selected 10GBASE-R as the host interface, we
don't want to restrict the advertisement to just 10GBASE-* modes.

Rework setting the advertisement to take account of this; do not pass
the requested advertisement through phylink_validate(), but rely on
the advertisement restriction (supported mask) set when the PHY was
initially setup.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

A mismerge between the following two commits:

c6787263 ("net: phylink: ensure consistent phy interface mode")
27755ff8 ("net: phylink: Add phylink_mac_link_{up, down} wrapper functions")

resulted in the wrong interface being passed to the mac_link_up()
function. Fix this up.

Fixes: b4b12b0d ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

of_phy_attach() hides the return value of phy_attach_direct(), forcing
us to return a "generic" ENODEV error code that is indistinguishable
from the lack-of-phy-property case.

Switch to using of_phy_find_device() to find the PHY device, and then
propagating any phy_attach_direct() error back to the caller.

Link: https://lore.kernel.org/lkml/20191210113829.GT25745@shell.armlinux.org.ukSigned-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

The Broadcom BCM84881 does not appear to send the SGMII control word
when operating in SGMII mode, which causes network adapters to fail
to link with the PHY, or decide to operate at fixed 1G speed, even if
the PHY negotiated 100M.

Work around this by detecting the Broadcom BCM84881 and switch to phy
mode rather than inband mode.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Knowing whether we need to delay the MAC configuration because a module
may have a PHY is useful to phylink to allow NBASE-T modules to work on
systems supporting no more than 2.5G speeds.

This commit allows us to delay such configuration until after the PHY
has been probed by recording the parsed capabilities, and if the module
may have a PHY, doing no more until the module_start() notification is
called.  At that point, we either have a PHY, or we don't.

We move the PHY-based setup a little later, and use the PHYs support
capabilities rather than the EEPROM parsed capabilities to determine
whether we can support the PHY.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Split out the configuration step from phylink_sfp_module_insert() so
we can re-use this later.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Split link_an_mode between the configured setting and the current
operating setting.  This is an important distinction to make when we
need to configure PHY mode for a plugged SFP+ module that does not
use in-band signalling.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some SFP+ modules have Clause 45 PHYs embedded on them, which need a
little more handling in order to ensure that they are correctly setup,
as they switch the PHY link mode according to the negotiated speed.

With Clause 22 PHYs, we assumed that they would operate in SGMII mode,
but this assumption is now false.  Adapt phylink to support Clause 45
PHYs on SFP+ modules.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to support Clause 45 PHYs on SFP+ modules, which have an
indeterminant phy interface mode, we need to be able to call
phylink_bringup_phy() with a different interface mode to that used when
binding the PHY. Reduce __phylink_connect_phy() to an attach operation,
and move the call to phylink_bringup_phy() to its call sites.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move phy_start() and phy_stop() into the module_start and module_stop
notifications in phylink, rather than having them in the SFP code.
This gives phylink responsibility for controlling the PHY, rather
than having SFP start and stop the PHY state machine.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

We don't need the EEPROM ID to derive the phy interface mode as we can
derive it merely from the ethtool link modes.  Remove the EEPROM ID
argument to sfp_select_interface().
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename the mac_link_state() method to mac_pcs_get_state() to make it
clear that it should be returning the MACs PCS current state, which
is used for inband negotiation rather than just reading back what the
MAC has been configured for. Update the documentation to explicitly
mention that this is for inband.

We drop the return value as well; most of phylink doesn't check the
return value and it is not clear what it should do on error - instead
arrange for state->link to be false.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Modifying the link settings via phylink_ethtool_ksettings_set() and
phylink_ethtool_set_pauseparam() didn't always work as intended for
PHY based setups, as calling phylink_mac_config() would result in the
unresolved configuration being committed to the MAC, rather than the
configuration with the speed and duplex setting.

This would work fine if the update caused the link to renegotiate,
but if no settings have changed, phylib won't trigger a renegotiation
cycle, and the MAC will be left incorrectly configured.

Avoid calling phylink_mac_config() unless we are using an inband mode
in phylink_ethtool_ksettings_set(), and use phy_set_asym_pause() as
introduced in 4.20 to set the PHY settings in
phylink_ethtool_set_pauseparam().
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Update the documentation on phylink's create and destroy functions to
explicitly state that the rtnl lock must not be held while calling
these.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use phy_support_asym_pause() rather than open-coding it.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>