net: dsa: b53: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert these drivers from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: remove unnecessary set_drvdata()

Remove unnecessary set_drvdata(NULL) function in ->remove(),
the driver_data will be set to NULL in device_unbind_cleanup()
after calling ->remove().

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: b53: convert to phylink_pcs

Convert B53 to use phylink_pcs for the serdes rather than hooking it
into the MAC-layer callbacks.

Fixes: 81c1681cbb9f ("net: dsa: b53: mark as non-legacy")
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: switch to using phylink_generic_validate()

Switch the Broadcom b53 driver to using the phylink_generic_validate()
implementation by removing its own .phylink_validate method and
associated code.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: populate supported_interfaces and mac_capabilities

Populate the supported interfaces and MAC capabilities for the Broadcom
B53 DSA switches in preparation to using these for the generic
validation functionality.

The interface modes are derived from:
- b53_serdes_phylink_validate()
- SRAB mux configuration

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: be compatible with masters which unregister on shutdown

Lino reports that on his system with bcmgenet as DSA master and KSZ9897
as a switch, rebooting or shutting down never works properly.

What does the bcmgenet driver have special to trigger this, that other
DSA masters do not? It has an implementation of ->shutdown which simply
calls its ->remove implementation. Otherwise said, it unregisters its
network interface on shutdown.

This message can be seen in a loop, and it hangs the reboot process there:

unregister_netdevice: waiting for eth0 to become free. Usage count = 3

So why 3?

A usage count of 1 is normal for a registered network interface, and any
virtual interface which links itself as an upper of that will increment
it via dev_hold. In the case of DSA, this is the call path:

dsa_slave_create
-> netdev_upper_dev_link
-> __netdev_upper_dev_link
-> __netdev_adjacent_dev_insert
-> dev_hold

So a DSA switch with 3 interfaces will result in a usage count elevated
by two, and netdev_wait_allrefs will wait until they have gone away.

Other stacked interfaces, like VLAN, watch NETDEV_UNREGISTER events and
delete themselves, but DSA cannot just vanish and go poof, at most it
can unbind itself from the switch devices, but that must happen strictly
earlier compared to when the DSA master unregisters its net_device, so
reacting on the NETDEV_UNREGISTER event is way too late.

It seems that it is a pretty established pattern to have a driver's
->shutdown hook redirect to its ->remove hook, so the same code is
executed regardless of whether the driver is unbound from the device, or
the system is just shutting down. As Florian puts it, it is quite a big
hammer for bcmgenet to unregister its net_device during shutdown, but
having a common code path with the driver unbind helps ensure it is well
tested.

So DSA, for better or for worse, has to live with that and engage in an
arms race of implementing the ->shutdown hook too, from all individual
drivers, and do something sane when paired with masters that unregister
their net_device there. The only sane thing to do, of course, is to
unlink from the master.

However, complications arise really quickly.

The pattern of redirecting ->shutdown to ->remove is not unique to
bcmgenet or even to net_device drivers. In fact, SPI controllers do it
too (see dspi_shutdown -> dspi_remove), and presumably, I2C controllers
and MDIO controllers do it too (this is something I have not researched
too deeply, but even if this is not the case today, it is certainly
plausible to happen in the future, and must be taken into consideration).

Since DSA switches might be SPI devices, I2C devices, MDIO devices, the
insane implication is that for the exact same DSA switch device, we
might have both ->shutdown and ->remove getting called.

So we need to do something with that insane environment. The pattern
I've come up with is "if this, then not that", so if either ->shutdown
or ->remove gets called, we set the device's drvdata to NULL, and in the
other hook, we check whether the drvdata is NULL and just do nothing.
This is probably not necessary for platform devices, just for devices on
buses, but I would really insist for consistency among drivers, because
when code is copy-pasted, it is not always copy-pasted from the best
sources.

So depending on whether the DSA switch's ->remove or ->shutdown will get
called first, we cannot really guarantee even for the same driver if
rebooting will result in the same code path on all platforms. But
nonetheless, we need to do something minimally reasonable on ->shutdown
too to fix the bug. Of course, the ->remove will do more (a full
teardown of the tree, with all data structures freed, and this is why
the bug was not caught for so long). The new ->shutdown method is kept
separate from dsa_unregister_switch not because we couldn't have
unregistered the switch, but simply in the interest of doing something
quick and to the point.

The big question is: does the DSA switch's ->shutdown get called earlier
than the DSA master's ->shutdown? If not, there is still a risk that we
might still trigger the WARN_ON in unregister_netdevice that says we are
attempting to unregister a net_device which has uppers. That's no good.
Although the reference to the master net_device won't physically go away
even if DSA's ->shutdown comes afterwards, remember we have a dev_hold
on it.

The answer to that question lies in this comment above device_link_add:

* A side effect of the link creation is re-ordering of dpm_list and the
* devices_kset list by moving the consumer device and all devices depending
* on it to the ends of these lists (that does not happen to devices that have
* not been registered when this function is called).

so the fact that DSA uses device_link_add towards its master is not
exactly for nothing. device_shutdown() walks devices_kset from the back,
so this is our guarantee that DSA's shutdown happens before the master's
shutdown.

Fixes: 2f1e8ea726e9 ("net: dsa: link interfaces with the DSA master to get rid of lockdep warnings")
Link: https://lore.kernel.org/netdev/20210909095324.12978-1-LinoSanfilippo@gmx.de/
Reported-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: remove redundant null check on dev

The pointer dev can never be null, the null check is redundant
and can be removed. Cleans up a static analysis warning that
pointer priv is dereferencing dev before dev is being null
checked.

Addresses-Coverity: ("Dereference before null check")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix return value about devm_platform_ioremap_resource()

When call function devm_platform_ioremap_resource(), we should use IS_ERR()
to check the return value and return PTR_ERR() if failed.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: per-port interrupts are optional

Make use of platform_get_irq_byname_optional() to avoid printing
messages on the kernel console that interrupts cannot be found.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Fix for failure when irq is not defined in dt

Fixes the issues with non BCM58XX chips in the b53 driver
failing, when the irq is not specified in the device tree.

Removed the check for BCM58XX in b53_srab_prepare_irq(),
so the 'port->irq' will be set to '-EXIO' if the irq is not
specified in the device tree.

Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Fixes: b2ddc48a81b5 ("net: dsa: b53: Do not fail when IRQ are not initialized")
Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Do not fail when IRQ are not initialized

When the Device Tree is not providing the per-port interrupts, do not fail
during b53_srab_irq_enable() but instead bail out gracefully. The SRAB driver
is used on the BCM5301X (Northstar) platforms which do not yet have the SRAB
interrupts wired up.

Fixes: 16994374a6fc ("net: dsa: b53: Make SRAB driver manage port interrupts")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Only call b53_port_event() for SGMII ports

Built-in PHY ports are still being polled, avoid generating spurious
and duplicate events which the PHY library resolves through polling
anyways.

Fixes: 0e01491de646 ("net: dsa: b53: Add SerDes support")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Fix build with B53_SRAB enabled and not B53_SERDES

In case B53_SRAB is enabled, but not B53_SERDES, we can get the
following linking error:

ERROR: "b53_serdes_init" [drivers/net/dsa/b53/b53_srab.ko] undefined!

We also need to ifdef the body of b53_srab_serdes_map_lane() since it
would not be used when B53_SERDES is disabled and that would produce a
warning.

Fixes: 0e01491de646 ("net: dsa: b53: Add SerDes support")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Add SerDes support

Add support for the Northstar Plus SerDes which is accessed through a
special page of the switch. Since this is something that most people
probably will not want to use, make it a configurable option with a
default on ARCH_BCM_NSP where it is the most useful currently.

The SerDes supports both SGMII and 1000baseX modes for both lanes, and
2500baseX for one of the lanes, and is internally looking like a
seemingly standard MII PHY, except for the few bits that got repurposed.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Make SRAB driver manage port interrupts

Update the SRAB driver to manage per-port interrupts. Since we cannot
sleep during b53_io_ops, schedule a workqueue whenever we get a port
specific interrupt. We will later make use of this to call back into
PHYLINK when there is e.g: a link state change.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Add support for Broadcom Omega SoC internal switch

Add support for the Broadcom Omega SoC internal ethernet switch
to the b53 srab driver in the DSA framework.

Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Fix for brcm tag issue in Cygnus SoC

In the Broadcom Cygnus SoC, the brcm tag needs to be inserted
in between the mac address and the ether type (should use
'DSA_PROTO_TAG_BRCM') for the packets sent to the internal
b53 switch.

Since the Cygnus was added with the BCM58XX device id and the
BCM58XX uses 'DSA_PROTO_TAG_BRCM_PREPEND', the data path is
broken, due to the incorrect brcm tag location.

Add a new b53 device id (BCM583XX) for Cygnus family to fix the
issue. Add the new device id to the BCM58XX family as Cygnus
is similar to the BCM58XX in most other functionalities.

Fixes: 11606039604c ("net: dsa: b53: Support prepended Broadcom tags")

Signed-off-by: Arun Parameswaran <arun.parameswaran@broadcom.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Reported-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Add compatible strings for the Cygnus-family BCM11360.

Cygnus is a small family of SoCs, of which we currently have
devicetree for BCM11360 and BCM58300. The 11360's B53 is mostly the
same as 58xx, just requiring a tiny bit of setup that was previously
missing.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: constify b53_io_ops structures

The b53_io_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

b53: Fix build warning.

drivers/net/dsa/b53/b53_srab.c: In function 'b53_srab_probe':
>> drivers/net/dsa/b53/b53_srab.c:388:20: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
pdata->chip_id = (u32)of_id->data;
^

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Add support for BCM585xx/586xx/88312 integrated switch

Update the SRAB, core driver and binding document to support the
BCM585xx/586xx/88312 integrated switch (Northstar Plus SoCs family).

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Allow SRAB driver to specify platform data

For Northstart Plus SoCs, we cannot detect the switch because only the
revision information is provied in the Management page, instead, rely on
Device Tree to tell us the chip id, and pass it down using the
b53_platform_data structure.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: b53: Add support for Broadcom RoboSwitch

This patch adds support for Broadcom's BCM53xx switch family, also known
as RoboSwitch. Some of these switches are ubiquituous, found in home
routers, Wi-Fi routers, DSL and cable modem gateways and other
networking related products.

This drivers adds the library driver (b53_common.c) as well as a few bus
glue drivers for MDIO, SPI, Switch Register Access Block (SRAB) and
memory-mapped I/O into a SoC's address space (Broadcom BCM63xx/33xx).

Basic operations are supported to bring the Layer 1/2 up and running,
but not much more at this point, subsequent patches add the remaining
features.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>