net: dsa: modularize DSA_TAG_PROTO_NONE

There is no reason that I can see why the no-op tagging protocol should
be registered manually, so make it a module and make all drivers which
have any sort of reference to DSA_TAG_PROTO_NONE select it.

Note that I don't know if ksz_get_tag_protocol() really needs this,
or if it's just the logic which is poorly written. All switches seem to
have their own tagging protocol, and DSA_TAG_PROTO_NONE is just a
fallback that never gets used.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dsa: b53: support legacy tags

These tags are used on BCM5325, BCM5365 and BCM63xx switches.

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

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: dsa: b53: Fix build with B53_SRAB enabled and B53_SERDES=m

When B53_SERDES is a loadable module, a built-in srab driver still
cannot reach it, so the previous fix is incomplete:

b53_srab.c:(.text+0x3f4): undefined reference to `b53_serdes_init'
drivers/net/dsa/b53/b53_srab.o:(.rodata+0xe64): undefined reference to `b53_serdes_link_state'
drivers/net/dsa/b53/b53_srab.o:(.rodata+0xe74): undefined reference to `b53_serdes_link_set'
drivers/net/dsa/b53/b53_srab.o:(.rodata+0xe88): undefined reference to `b53_serdes_an_restart'
drivers/net/dsa/b53/b53_srab.o:(.rodata+0xea0): undefined reference to `b53_serdes_phylink_validate'
drivers/net/dsa/b53/b53_srab.o:(.rodata+0xea4): undefined reference to `b53_serdes_config'

Add a Kconfig dependency that forces srab to also be a module
in this case, but allow it to be built-in when serdes is
disabled or built-in.

Fixes: 7a8c7f5c30f9 ("net: dsa: b53: Fix build with B53_SRAB enabled and not B53_SERDES")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
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: Provide sensible defaults

The SRAB driver is the default way to communicate with the integrated
switch on iProc platforms and the MMAP driver is the way to communicate
with the integrated switch on DSL BCM63xx and CM BCM33xx.

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

net: dsa: b53: Support prepended Broadcom tags

On BCM58xx devices (Northstar Plus), there is an accelerator attached to
port 8 which would only work if we use prepended Broadcom tags. Resolve
that difference in our get_tag_protocol() function by setting the
appropriate tagging protocol in that case. We need to change
b53_brcm_hdr_setup() a little bit now since we can deal with two types
of Broadcom tags.

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: Turn on Broadcom tags

Enable Broadcom tags for b53 devices, except 5325 and 5365 which use a
different Broadcom tag format not yet supported by net/dsa/tag_brcm.c.

We also make sure that we can turn on Broadcom tags on a CPU port number
that is capable of that: 5, 7 or 8.

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 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>