net: dsa: Add KSZ8567 switch support

This commit introduces support for the KSZ8567, a robust 7-port
Ethernet switch. The KSZ8567 features two RGMII/MII/RMII interfaces,
each capable of gigabit speeds, complemented by five 10/100 Mbps
MAC/PHYs.

Signed-off-by: Philippe Schenker <philippe.schenker@impulsing.ch>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240130083419.135763-2-dev@pschenker.ch
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: dsa: microchip: Refactor switch shutdown routine for WoL preparation

Centralize the switch shutdown routine in a dedicated function,
ksz_switch_shutdown(), to enhance code maintainability and reduce
redundancy. This change abstracts the common shutdown operations
previously duplicated in ksz9477_i2c_shutdown() and ksz_spi_shutdown().

This refactoring is a preparatory step for an upcoming patch to avoid
reset on shutdown if Wake-on-LAN (WoL) is enabled.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20231026051051.2316937-5-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: Switch i2c drivers back to use .probe()

After commit b8a1a4cd5a98 ("i2c: Provide a temporary .probe_new()
call-back type"), all drivers being converted to .probe_new() and then
03c835f498b5 ("i2c: Switch .probe() to not take an id parameter") convert
back to (the new) .probe() to be able to eventually drop .probe_new() from
struct i2c_driver.

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

net: dsa: microchip: add an enum for regmap widths

It is not immediately obvious that this driver allocates, via the
KSZ_REGMAP_TABLE() macro, 3 regmaps for register access: dev->regmap[0]
for 8-bit access, dev->regmap[1] for 16-bit and dev->regmap[2] for
32-bit access.

In future changes that add support for reg_fields, each field will have
to specify through which of the 3 regmaps it's going to go. Add an enum
now, to denote one of the 3 register access widths, and make the code go
through some wrapper functions for easier review and further
modification.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: dsa: ksz9477: drop of_match_ptr for ID table

The driver will match mostly by DT table (even thought there is regular
ID table) so there is little benefit in of_match_ptr (this also allows
ACPI matching via PRP0001, even though it might not be relevant here).

drivers/net/dsa/microchip/ksz9477_i2c.c:84:34: error: ‘ksz9477_dt_ids’ defined but not used [-Werror=unused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: fix probe of I2C-connected KSZ8563

Starting with commit eee16b147121 ("net: dsa: microchip: perform the
compatibility check for dev probed"), the KSZ switch driver now bails
out if it thinks the DT compatible doesn't match the actual chip ID
read back from the hardware:

ksz9477-switch 1-005f: Device tree specifies chip KSZ9893 but found
KSZ8563, please fix it!

For the KSZ8563, which used ksz_switch_chips[KSZ9893], this was fine
at first, because it indeed shares the same chip id as the KSZ9893.

Commit b44908095612 ("net: dsa: microchip: add separate struct
ksz_chip_data for KSZ8563 chip") started differentiating KSZ9893
compatible chips by consulting the 0x1F register. The resulting breakage
was fixed for the SPI driver in the same commit by introducing the
appropriate ksz_switch_chips[KSZ8563], but not for the I2C driver.

Fix this for I2C-connected KSZ8563 now to get it probing again.

Fixes: b44908095612 ("net: dsa: microchip: add separate struct ksz_chip_data for KSZ8563 chip").
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230120110933.1151054-1-a.fatoum@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: microchip: ksz9477: Convert to i2c's .probe_new()

The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: microchip: add dev_err_probe in probe functions

Probe functions uses normal dev_err() to check error conditions
and print messages. Replace dev_err() with dev_err_probe() to
have more standardized format and error logging.

Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: add irq in i2c probe

add device irq in i2c probe function.

Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: add ksz9563 in ksz_switch_ops and select based on compatible string

Add KSZ9563 inside ksz_switch_chips structure with
port_nirq as 3. KSZ9563 use KSZ9893 switch parameters
but port_nirq count is 3 for KSZ9563 whereas 2 for
KSZ9893. Add KSZ9563 inside ksz_switch_chips as a separate
member and from device tree map compatible string into
KSZ9563 inside ksz_spi.c and ksz9477_i2c.c.
Global Chip ID 1 and 2 registers read value 9893, select
sku based on Global Chip ID 4 Register which read 0x1c
for KSZ9563.

Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: ksz9477: remove unnecessary i2c_set_clientdata()

Remove unnecessary i2c_set_clientdata() 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: microchip: add KSZ9896 to KSZ9477 I2C driver

Add support for the KSZ9896 6-port Gigabit Ethernet Switch to the
ksz9477 driver. The KSZ9896 supports both SPI (already in) and I2C.

Signed-off-by: Romain Naour <romain.naour@skf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

i2c: Make remove callback return void

The value returned by an i2c driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Reviewed-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Reviewed-by: Benjamin Mugnier <benjamin.mugnier@foss.st.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Crt Mori <cmo@melexis.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Behún <kabel@kernel.org> # for leds-turris-omnia
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for surface3_power
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> # for bmc150-accel-i2c + kxcjk-1013
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # for media/* + staging/media/*
Acked-by: Miguel Ojeda <ojeda@kernel.org> # for auxdisplay/ht16k33 + auxdisplay/lcd2s
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # for versaclock5
Reviewed-by: Ajay Gupta <ajayg@nvidia.com> # for ucsi_ccg
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for iio
Acked-by: Peter Rosin <peda@axentia.se> # for i2c-mux-*, max9860
Acked-by: Adrien Grassein <adrien.grassein@gmail.com> # for lontium-lt8912b
Reviewed-by: Jean Delvare <jdelvare@suse.de> # for hwmon, i2c-core and i2c/muxes
Acked-by: Corey Minyard <cminyard@mvista.com> # for IPMI
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> # for drivers/power
Acked-by: Krzysztof Hałasa <khalasa@piap.pl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

net: dsa: microchip: remove the ksz8/ksz9477_switch_register

This patch delete the ksz8_switch_register and ksz9477_switch_register
since both are calling the ksz_switch_register function. Instead the
ksz_switch_register is called from the probe function.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: rename shutdown to reset in ksz_dev_ops

This patch renames the shutdown to reset in ksz_dev_ops in order to use
the reset dev_ops in the ksz_setup.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: perform the compatibility check for dev probed

This patch perform the compatibility check for the device after the chip
detect is done. It is to prevent the mismatch between the device
compatible specified in the device tree and actual device found during
the detect. The ksz9477 device doesn't use any .data in the
of_device_id. But the ksz8795_spi uses .data for assigning the regmap
between 8830 family and 87xx family switch. Changed the regmap
assignment based on the chip_id from the .data.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: add ksz8563 to ksz9477 I2C driver

The KSZ9477 SPI driver already has support for the KSZ8563. The same switch
chip can also be managed via i2c and we have an KSZ9477 I2C driver, but
that one lacks the relevant compatible entry. Add it.

DT bindings already describe this compatible.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
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: microchip: add ksz9563 to ksz9477 I2C driver

Add support for the KSZ9563 3-Port Gigabit Ethernet Switch to the
ksz9477 driver. The KSZ9563 supports both SPI (already in) and I2C. The
ksz9563 is already in the device tree binding documentation.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: microchip: enable ksz9893 via i2c in the ksz9477 driver

The KSZ9893 3-Port Gigabit Ethernet Switch can be controlled via SPI,
I²C or MDIO (very limited and not supported by this driver). While there
is already a compatible entry for the SPI bus, it was missing for I²C.

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

net: dsa: microchip: Add shared regmap mutex

The KSZ driver uses one regmap per register width (8/16/32), each with
it's own lock, but accessing the same set of registers. In theory, it
is possible to create a race condition between these regmaps, although
the underlying bus (SPI or I2C) locking should assure nothing bad will
really happen and the accesses would be correct.

To make the driver do the right thing, add one single shared mutex for
all the regmaps used by the driver instead. This assures that even if
some future hardware is on a bus which does not serialize the accesses
the same way SPI or I2C does, nothing bad will happen.

Note that the status_mutex was unused and only initied, hence it was
renamed and repurposed as the regmap mutex.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: David S. Miller <davem@davemloft.net>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: George McCollister <george.mccollister@gmail.com>
Cc: Tristram Ha <Tristram.Ha@microchip.com>
Cc: Woojung Huh <woojung.huh@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: ksz9477: fix platform_no_drv_owner.cocci warning

Remove .owner field if calls are used which set it automatically
Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

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

net: dsa: microchip: add ksz9567 to ksz9477 driver

Add support for the KSZ9567 7-Port Gigabit Ethernet Switch to the
ksz9477 driver. The KSZ9567 supports both SPI and I2C. Oddly the
ksz9567 is already in the device tree binding documentation.

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: microchip: add KSZ9477 I2C driver

Add KSZ9477 I2C driver support. The code ksz9477.c and ksz_common.c are
used together to generate the I2C driver.

Signed-off-by: Tristram Ha <Tristram.Ha@microchip.com>
[george.mccollister@gmail.com: bring up to date, use ksz_common regmap macros]
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>