pinctrl: aspeed: fix unmet dependencies on MFD_SYSCON for PINCTRL_ASPEED

When PINCTRL_ASPEED_G* is selected,
and MFD_SYSCON is not selected,
Kbuild gives the following warnings:

WARNING: unmet direct dependencies detected for PINCTRL_ASPEED
Depends on [n]: PINCTRL [=y] && (ARCH_ASPEED [=n] || COMPILE_TEST [=y]) && OF [=y] && MFD_SYSCON [=n]
Selected by [y]:
- PINCTRL_ASPEED_G4 [=y] && PINCTRL [=y] && (MACH_ASPEED_G4 [=n] || COMPILE_TEST [=y]) && OF [=y]

WARNING: unmet direct dependencies detected for PINCTRL_ASPEED
Depends on [n]: PINCTRL [=y] && (ARCH_ASPEED [=n] || COMPILE_TEST [=y]) && OF [=y] && MFD_S>
Selected by [y]:
- PINCTRL_ASPEED_G5 [=y] && PINCTRL [=y] && (MACH_ASPEED_G5 [=n] || COMPILE_TEST [=y]) && O>

WARNING: unmet direct dependencies detected for PINCTRL_ASPEED
Depends on [n]: PINCTRL [=y] && (ARCH_ASPEED [=n] || COMPILE_TEST [=y]) && OF [=y] && MFD_S>
Selected by [y]:
- PINCTRL_ASPEED_G6 [=y] && PINCTRL [=y] && (MACH_ASPEED_G6 [=n] || COMPILE_TEST [=y]) && O>

This is because MACH_ASPEED_G* depend on (ARCH_ASPEED || COMPILE_TEST).
ARCH_ASPEED enables the MFD_SYSCON dependency, but COMPILE_TEST doesn't.

These unmet dependency bugs were detected by Kismet,
a static analysis tool for Kconfig. Please advise
if this is not the appropriate solution.

Signed-off-by: Julian Braha <julianbraha@gmail.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20211215214022.146391-1-julianbraha@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: aspeed: Add AST2600 pinmux support

The AST2600 pinmux is fairly similar to the previous generations of
ASPEED BMC SoCs in terms of architecture, though differ in some of the
design details. The complexity of the pin expressions is largely reduced
(e.g. there are no-longer signals with multiple expressions muxing them
to the associated pin), and there are now signals and buses with
multiple pin groups.

The driver implements pinmux support for all 244 GPIO-capable pins plus
a further four pins that are not GPIO capable but which expose multiple
signals. pinconf will be implemented in a follow-up patch.

The implementation has been smoke-tested under qemu, and run on hardware
by ASPEED.

Debugged-by: Johnny Huang <johnny_huang@aspeedtech.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20190711041942.23202-7-andrew@aj.id.au
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

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>

pinctrl: Add pinctrl-aspeed-g5 driver

A small subset of pins and functions are exposed. The selection of pins
and functions is driven by the development of OpenBMC[1] on the
AST2500 SoC, particularly around booting the IBM Witherspoon platform.

[1] https://github.com/openbmc/docs

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: Add pinctrl-aspeed-g4 driver

A subset of the pins and functions are exposed. The selection of
functions and pins is driven by the development of OpenBMC[1] on the
AST2400 SoC, particularly around booting the OpenPOWER Palmetto
development machine.

[1] https://github.com/openbmc/docs

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

pinctrl: Add core support for Aspeed SoCs

The Aspeed SoCs typically provide more than 200 pins for GPIO and other
functions. The signal enabled on a pin is determined on a priority
basis, where a given pin can provide a number of different signal types.

In addition to the priority levels, the Aspeed pin controllers describe
the signal active on a pin by compound logical expressions involving
multiple operators, registers and bits. Some difficulty arises as a
pin's function bit masks for each priority level are frequently not the
same (i.e. we cannot just flip a bit to change from a high to low
priority signal), or even in the same register(s). Some configuration
bits affect multiple pins, while in other cases the signals for a bus
must each be enabled individually.

Together, these features give rise to some complexity in the
implementation. A more complete description of the complexities is
provided in the associated header file.

The patch doesn't implement pinctrl/pinmux/pinconf for any particular
Aspeed SoC, rather it adds the framework for defining pinmux
configurations.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>