enetc: Separate C22 and C45 transactions

The enetc MDIO bus driver can perform both C22 and C45 transfers.
Create separate functions for each and register the C45 versions using
the new API calls where appropriate.

This driver is shared with the Felix DSA switch, so update that at the
same time.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

enetc: use correct format characters

When compiling with -Wformat, clang emits the following warning:

drivers/net/ethernet/freescale/enetc/enetc_mdio.c:151:22: warning:
format specifies type 'unsigned char' but the argument has type 'int'
[-Wformat]
phy_id, dev_addr, regnum);
^~~~~~
./include/linux/dev_printk.h:163:47: note: expanded from macro 'dev_dbg'
dev_printk(KERN_DEBUG, dev, dev_fmt(fmt), ##__VA_ARGS__); \
~~~ ^~~~~~~~~~~
./include/linux/dev_printk.h:129:34: note: expanded from macro 'dev_printk'
_dev_printk(level, dev, fmt, ##__VA_ARGS__); \
~~~ ^~~~~~~~~~~

The types of these arguments are unconditionally defined, so this patch
updates the format character to the correct ones for ints and unsigned
ints.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Bill Wendling <morbo@google.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20220316213109.2352015-1-morbo@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

enetc: reorder macros and functions

Now that there aren't any more macros with parameters, move the macros
above any functions.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: drop MDIO_DATA() macro

value is u16, masking with 0xffff is a nop. Drop it.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: don't use macro magic for the readx_poll_timeout() callback

The macro enetc_mdio_rd_reg() is just used in that particular case and
has a hardcoded parameter name "mdio_priv". Define a specific function
to use for readx_poll_timeout() instead. Also drop the TIMEOUT macro
since it is used just once.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: drop unneeded indirection

Before commit 6517798dd343 ("enetc: Make MDIO accessors more generic and
export to include/linux/fsl") these macros actually had some benefits.
But after the commit it just makes the code hard to read. Drop the macro
indirections.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: Workaround for MDIO register access issue

Due to a hardware issue, an access to MDIO registers
that is concurrent with other ENETC register accesses
may lead to the MDIO access being dropped or corrupted.
The workaround introduces locking for all register accesses
to the ENETC register space. To reduce performance impact,
a readers-writers locking scheme has been implemented.
The writer in this case is the MDIO access code (irrelevant
whether that MDIO access is a register read or write), and
the reader is any access code to non-MDIO ENETC registers.
Also, the datapath functions acquire the read lock fewer times
and use _hot accessors. All the rest of the code uses the _wa
accessors which lock every register access.
The commit introducing MDIO support is -
commit ebfcb23d62ab ("enetc: Add ENETC PF level external MDIO support")
but due to subsequent refactoring this patch is applicable on
top of a later commit.

Fixes: 6517798dd343 ("enetc: Make MDIO accessors more generic and export to include/linux/fsl")
Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20201112182608.26177-1-claudiu.manoil@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

enetc: Set MDIO_CFG_HOLD to the recommended value of 2

This increases the MDIO hold time to 5 enet_clk cycles from the previous
value of 0. This is actually the out-of-reset value, that the driver was
previously overwriting with 0. Zero worked for the external MDIO, but
breaks communication with the internal MDIO buses on which the PCS of
ENETC SI's and Felix switch are found.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: Make MDIO accessors more generic and export to include/linux/fsl

Within the LS1028A SoC, the register map for the ENETC MDIO controller
is instantiated a few times: for the central (external) MDIO controller,
for the internal bus of each standalone ENETC port, and for the internal
bus of the Felix switch.

Refactoring is needed to support multiple MDIO buses from multiple
drivers. The enetc_hw structure is made an opaque type and a smaller
enetc_mdio_priv is created.

'mdio_base' - MDIO registers base address - is being parameterized, to
be able to work with different MDIO register bases.

The ENETC MDIO bus operations are exported from the fsl-enetc-mdio
kernel object, the same that registers the central MDIO controller (the
dedicated PF). The ENETC main driver has been changed to select it, and
use its exported helpers to further register its private MDIO bus. The
DSA Felix driver will do the same.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: Add mdio bus driver for the PCIe MDIO endpoint

ENETC ports can manage the MDIO bus via local register
interface. However there's also a centralized way
to manage the MDIO bus, via the MDIO PCIe endpoint
device integrated by the same root complex that also
integrates the ENETC ports (eth controllers).

Depending on board design and use case, centralized
access to MDIO may be better than using local ENETC
port registers. For instance, on the LS1028A QDS board
where MDIO muxing is required. Also, the LS1028A on-chip
switch doesn't have a local MDIO register interface.

The current patch registers the above PCIe endpoint as a
separate MDIO bus and provides a driver for it by re-using
the code used for local MDIO access. It also allows the
ENETC port PHYs to be managed by this driver if the local
"mdio" node is missing from the ENETC port node.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: Clean up local mdio bus allocation

What's needed is basically a pointer to the mdio registers.
This is one way to store it inside bus->priv allocated space,
without upsetting sparse.
Reworked accessors to avoid __iomem casting.
Used devm_* variant to further clean up the init error /
remove paths.

Fixes following sparse warning:
warning: incorrect type in assignment (different address spaces)
expected void *priv
got struct enetc_mdio_regs [noderef] <asn:2>*[assigned] regs

Fixes: ebfcb23d62ab ("enetc: Add ENETC PF level external MDIO support")

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

enetc: Add ENETC PF level external MDIO support

Each ENETC PF has its own MDIO interface, the corresponding
MDIO registers are mapped in the ENETC's Port register block.
The current patch adds a driver for these PF level MDIO buses,
so that each PF can manage directly its own external link.

Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>