gpio: altera-a10sr: remove redundant of_match_ptr

The driver depends on CONFIG_OF, so it is not necessary to use
of_match_ptr() here.

Even for drivers that do not depend on CONFIG_OF, it's almost always
better to leave out the of_match_ptr(), since the only thing it can
possibly do is to save a few bytes of .text if a driver can be used both
with and without it. Hence we remove of_match_ptr().

Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: altera-a10sr: Switch to use fwnode instead of of_node

GPIO library now accepts fwnode as a firmware node, so
switch the driver to use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

gpio: altera-a10sr: remove platform_set_drvdata() + cleanup probe

The platform_set_drvdata() call is only useful if we need to retrieve back
the private information.
Since the driver doesn't do that, it's not useful to have it.

If this is removed, we can also just do a direct return on
devm_gpiochip_add_data(). We don't need to print that this call failed as
there are other ways to log/see this during probe.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

gpio: altera-a10sr: Trivial coding style fix

Change the coding style to make it does error checking first.
This also fixes checkpatch warning about line over 80 characters.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested by: Thor Thayer <thor.thayer@linux.intel.com>
Reviewed by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: altera-a10sr: Set proper output level for direction_output

The altr_a10sr_gpio_direction_output should set proper output level
based on the value argument.

Fixes: 26a48c4cc2f1 ("gpio: altera-a10sr: Add A10 System Resource Chip GPIO support.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Tested by: Thor Thayer <thor.thayer@linux.intel.com>
Reviewed by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: altera-a10sr: constify gpio_chip structure

This structure is only used to copy into another structure, so declare
it as const.

This issue was detected using Coccinelle and the following semantic patch:

@r disable optional_qualifier@
identifier i;
position p;
@@
static struct gpio_chip i@p = { ... };

@ok@
identifier r.i;
expression e;
position p;
@@
e = i@p;

@bad@
position p != {r.p,ok.p};
identifier r.i;
struct gpio_chip e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct gpio_chip i = { ... };

In the following log you can see a significant difference in the code size
and data segment, hence in the dec segment. This log is the output
of the size command, before and after the code change:

before:
text data bss dec hex filename
1954 600 0 2554 9fa drivers/gpio/gpio-altera-a10sr.o

after:
text data bss dec hex filename
1655 512 0 2167 877 drivers/gpio/gpio-altera-a10sr.o

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: altera-a10sr: Set gpio_chip parent property

Set the gpio_chip parent property since some recent functions
such as devprop_gpiochip_set_names() can use it.

Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: altera-a10sr: Drop unnecessary gpiochip_remove

It's not necessary to unregister gpio_chip which registered
with devm_gpiochip_add_data().
Also get rid of useless altr_a10sr_gpio_remove().

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: altera-a10sr: Add A10 System Resource Chip GPIO support.

Add the GPIO functionality for the Altera Arria10 MAX5 System Resource
Chip. The A10 MAX5 has 12 bits of GPIO assigned to switches, buttons,
and LEDs as a GPIO extender on the SPI bus.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>i
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>