mips: alchemy: gpio: Include the right header

The local GPIO driver in the MIPS Alchemy is including the legacy
<linux/gpio.h> header but what it wants is to implement a GPIO
driver so include <linux/gpio/driver.h> instead.

Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: linux-gpio@vger.kernel.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

mips: alchemy: remove historic comment on gpio build constraints

In ./arch/mips/alchemy/common/gpiolib.c, the comment points out certain
build constraints on CONFIG_GPIOLIB and CONFIG_ALCHEMY_GPIO_INDIRECT.

The commit 832f5dacfa0b ("MIPS: Remove all the uses of custom gpio.h")
makes all mips machines use the common gpio.h and removes the config
ALCHEMY_GPIO_INDIRECT. So, this makes the comment in alchemy's gpiolib.c
historic and obsolete, and can be removed after the commit above.

The issue on the reference to a non-existing Kconfig symbol was identified
with ./scripts/checkkconfigsymbols.py. This script has been quite useful
to identify a number of bugs with Kconfig symbols and deserves to be
executed and checked regularly.

So, remove the historic comment to reduce the reports made the script and
simplify to use this script, as new issues are easier to spot when the
list of reports is shorter.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Audit and remove any unnecessary uses of module.h

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. In the case of
some code where it is modular, we can extend that to also include
files that are building basic support functionality but not related
to loading or registering the final module; such files also have
no need whatsoever for module.h

The advantage in removing such instances is that module.h itself
sources about 15 other headers; adding significantly to what we feed
cpp, and it can obscure what headers we are effectively using.

Since module.h might have been the implicit source for init.h
(for __init) and for export.h (for EXPORT_SYMBOL) we consider each
instance for the presence of either and replace/add as needed.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

Build coverage of all the mips defconfigs revealed the module.h
header was masking a couple of implicit include instances, so
we add the appropriate headers there.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Daney <david.daney@cavium.com>
Cc: John Crispin <john@phrozen.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "Steven J. Hill" <steven.hill@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15131/
[james.hogan@imgtec.com: Preserve sort order where it already exists]
Signed-off-by: James Hogan <james.hogan@imgtec.com>

MIPS: alchemy: switch to gpiochip_add_data()

We're planning to remove the gpiochip_add() function to swith
to gpiochip_add_data() with NULL for data argument.

Cc: linux-mips@linux-mips.org
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

MIPS: Alchemy: Be sure to clamp return value

As we want gpio_chip .get() calls to be able to return negative
error codes and propagate to drivers, we need to go over all
drivers and make sure their return values are clamped to [0,1].
We do this by using the ret = !!(val) design pattern.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-gpio@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11921/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Whitespace cleanup.

Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Alchemy: Au1300 SoC support

Add basic support for the Au1300 variant(s):
- New GPIO/Interrupt controller
- DBDMA ids
- USB setup
- MMC support
- enable various PSC drivers
- detection code.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2866/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Alchemy: support multiple GPIO styles in one kernel

For GPIOLIB=y decide at runtime which gpiochips to register;
in the GPIOLIB=n case, the gpio headers need to be reshuffled
a bit to make multiple implementations coexist peacefully.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2679/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>