gpiolib: split of_mm_gpio_chip out of linux/of_gpio.h

This is a rarely used feature that has nothing to do with the
client-side of_gpio.h.

Split it out with a separate header file and Kconfig option
so it can be removed on its own timeline aside from removing
the of_gpio consumer interfaces.

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

gpiolib: of: Move enum of_gpio_flags to its only user

GPIO library for OF is the only user for enum of_gpio_flags.
Move it there.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: Remove unused of_mm_gpiochip_add()

of_mm_gpiochip_add() is unused API, remove it for good.

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

gpiolib: of: remove of_get_gpio[_flags]() and of_get_named_gpio_flags()

There are no more users of these APIs in the mainline kernel, remove
them. This leaves of_get_named_gpio() as the only legacy OF-specific
API.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: of: stop exporting of_gpio_named_count()

The only user of this function is gpiolib-of.c so move it there.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: of: remove of_gpio_count()

There are no more users of of_gpio_count() in the mainline kernel,
remove it.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpio: Do not include <linux/kernel.h> when not really needed.

<linux/kernel.h> is included only for using container_of().
Include <linux/container_of.h> instead, it is much lighter.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiolib: of: support bias pull disable

On top of looking at PULL_UP and PULL_DOWN flags, also look at
PULL_DISABLE and set the appropriate GPIO flag. The GPIO core will then
pass down this to controllers that support it.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

gpiolib: constify passed device_node pointer

Several gpiolib functions receive pointer to struct device_node which is
later passed to OF functions. These OF functions accept already pointer
to const, so gpiolib can follow similar approach to indicate they are
not modifying the struct device_node.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

gpio: Avoid kernel.h inclusion where it's possible

Inclusion of kernel.h increases the mess with the header dependencies.
Avoid kernel.h inclusion where it's possible.

Besides that, clean up a bit other inclusions inside GPIO subsystem headers.
It includes:
- removal pin control bits (forward declaration and header) from linux/gpio.h
- removal of.h from asm-generic/gpio.h
- use of explicit headers in gpio/consumer.h
- add FIXME note with regard to gpio.h inclusion in of_gpio,h

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200205134336.20197-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: of: Make of_gpio_simple_xlate() private

Since commit 9a95e8d25a140ba9 ("gpio: remove etraxfs driver"), there are
no more users of of_gpio_simple_xlate() outside gpiolib-of.c.
All GPIO drivers that need it now rely on of_gpiochip_add() setting it
up as the default translate function.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20190906084539.21838-3-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: add core support for pull-up/pull-down configuration

This commit adds support for configuring the pull-up and pull-down
resistors available in some GPIO controllers. While configuring
pull-up/pull-down is already possible through the pinctrl subsystem,
some GPIO controllers, especially simple ones such as GPIO expanders
on I2C, don't have any pinmuxing capability and therefore do not use
the pinctrl subsystem.

This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags,
which can be used from the Device Tree, to enable a pull-up or
pull-down resistor on a given GPIO.

The flag is simply propagated all the way to the core GPIO subsystem,
where it is used to call the gpio_chip ->set_config callback with the
appropriate existing PIN_CONFIG_BIAS_* values.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

of: Use SPDX license tag for DT files

Convert remaining DT files to use SPDX-License-Identifier tags.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Rob Herring <robh@kernel.org>

gpio: gpiolib: Generalise state persistence beyond sleep

General support for state persistence is added to gpiolib with the
introduction of a new pinconf parameter to propagate the request to
hardware. The existing persistence support for sleep is adapted to
include hardware support if the GPIO driver provides it. Persistence
continues to be enabled by default; in-kernel consumers can opt out, but
userspace (currently) does not have a choice.

The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are
renamed, dropping the SLEEP prefix to reflect that the concept is no
longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE
could initially be misinterpreted, so I've further changed the symbols
to *_TRANSITORY and *_PERSISTENT to address this.

The sysfs interface is modified only to keep consistency with the
chardev interface in enforcing persistence for userspace exports.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Fix loose spelling

Literally.

I expect "lose" was meant here, rather than "loose", though you could feasibly
use a somewhat uncommon definition of "loose" to mean what would be meant by
"lose": "Loose the hounds" for instance, as in "Release the hounds".
Substituting in "value" for "hounds" gives "release the value", and makes some
sense, but futher substituting back to loose gives "loose the value" which
overall just seems a bit anachronistic.

Instead, use modern, pragmatic English and save a character.

Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Add new flags to control sleep status of GPIOs

Add new flags to allow users to specify that they are not concerned with
the status of GPIOs whilst in a sleep/low power state.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: core: Decouple open drain/source flag with active low/high

Currently, the GPIO interface is said to Open Drain if it is Single
Ended and active LOW. Similarly, it is said as Open Source if it is
Single Ended and active HIGH.

The active HIGH/LOW is used in the interface for setting the pin
state to HIGH or LOW when enabling/disabling the interface.

In Open Drain interface, pin is set to HIGH by putting pin in
high impedance and LOW by driving to the LOW.

In Open Source interface, pin is set to HIGH by driving pin to
HIGH and set to LOW by putting pin in high impedance.

With above, the Open Drain/Source is unrelated to the active LOW/HIGH
in interface. There is interface where the enable/disable of interface
is ether active LOW or HIGH but it is Open Drain type.

Hence decouple the Open Drain with Single Ended + Active LOW and
Open Source with Single Ended + Active HIGH.

Adding different flag for the Open Drain/Open Source which is valid
only when Single ended flag is enabled.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: OF: localize some gpiochip init functions

of_gpiochip_add() and of_gpiochip_remove() are only used locally
in the gpio subsystem so move these functions to the local
header.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: of: provide optional of_mm_gpiochip_add_data() function

In the same spirit as we add an optional void *data argument
to the gpiochip_add_data() call, we need this also for
of_mm_gpiochip_add().

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: always initialize *flags from of_get_named_gpio_flags

The of_get_named_gpio_flags() function does nothing other than returning
an error when CONFIG_OF_GPIO is disabled, but that causes spurious
warnings about possible use of uninitialized variables in any code that
does not check the of_get_named_gpio_flags() return value before trying
to use the flags:

drivers/input/misc/rotary_encoder.c: In function 'rotary_encoder_probe':
drivers/input/misc/rotary_encoder.c:223:28: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/power/bq24735-charger.c: In function 'bq24735_charger_probe':
drivers/power/bq24735-charger.c:227:12: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/power/sbs-battery.c: In function 'sbs_probe':
drivers/power/sbs-battery.c:782:17: warning: 'gpio_flags' may be used uninitialized in this function [-Wmaybe-uninitialized]

This changes the behavior of the inline helper to set the flags to zero
when OF_GPIO is disabled, to avoid the warnings. In all cases I've
encountered, we don't actually get to the place that uses the flags
if CONFIG_OF is disabled because we won't enter the DT parser code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: Add and use OF_GPIO_SINGLE_ENDED flag

The flag matches the DT GPIO_SINGLE_ENDED flag and allows drivers to
parse and use the DT flag to handle single-ended (open-drain or
open-source) GPIOs.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: defer probe if pinctrl cannot be found

When an OF node has a pin range for its GPIOs, return -EPROBE_DEFER if
the pin controller isn't available.

Otherwise, the GPIO range wouldn't be set at all unless the pin
controller probed always before the GPIO chip.

With this change, the probe of the GPIO chip will be deferred and will
be retried at a later point, hopefully once the pin controller has been
registered and probed already.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio/gpiolib-of: Create of_mm_gpiochip_remove

Create counterpart of of_mm_gpiochip_add(). This way the modules that
can be removable do not duplicate the cleanup code.

Suggested-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: make of_get_named_gpiod_flags() private

of_get_named_gpiod_flags() is visible and directly usable by GPIO
consumers, but it really should not as the gpiod interface relies
on the simpler gpiod_get() to provide properly-configured GPIOs.

of_get_named_gpiod_flags() is just used internally by gpiolib to
implement gpiod_get(), and by the old of_get_named_gpio_flags()
function, therefore it makes sense to make it gpiolib-private.

As a side-effect, the unused (and unneeded) of_get_gpiod_flags()
inline function is also removed, and of_get_named_gpio_flags() is moved
from a static inline function to a regular one in gpiolib-of.c

This results in all references to gpiod_* functions in of_gpio.h being
gone, which is the way it should be since this file is part of the old
integer GPIO interface.

Changes since v1:
- Fixed compilation error when CONFIG_OF_GPIO is not defined
- Fixed warning due to of_gpio_flags enum not being declared
in private gpiolib.h header

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: include gpio/consumer.h in of_gpio.h for desc_to_gpio()

Fixes this build error on sparc:

In file included from drivers/spi/spi.c:33:0:
include/linux/of_gpio.h: In function 'of_get_named_gpio_flags':
include/linux/of_gpio.h:93:3: error: implicit declaration of function 'desc_to_gpio' [-Werror=implicit-function-declaration]

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpiolib: port of_ functions to use gpiod

Refactor the of_ functions of gpiolib to use the now public gpiod
interface, and export of_get_named_gpiod_flags() and
of_get_gpiod_flags() functions.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: Make of_count_named_gpios() use new of_count_phandle_with_args()

This patch replaces the horribly coded of_count_named_gpios() with a
call to of_count_phandle_with_args() which is far more efficient. This
also changes the return value of of_gpio_count() & of_gpio_named_count()
from 'unsigned int' to 'int' so that it can return an error code. All
the users of that function are fixed up to correctly handle a negative
return value.

v2: Split GPIO portion into a separate patch

Tested-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>

gpio: Adjust of_xlate API to support multiple GPIO chips

This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node. This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device. With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.

Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

of_gpio: add support of of_gpio_named_count to be able to count named gpio

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

of: create of_phandle_args to simplify return of phandle parsing data

of_parse_phandle_with_args() needs to return quite a bit of data. Rather
than making each datum a separate **out_ argument, this patch creates
struct of_phandle_args to contain all the returned data and reworks the
user of the function. This patch also enables of_parse_phandle_with_args()
to return the device node pointer for the phandle node.

This patch also ends up being fairly major surgery to
of_parse_handle_with_args(). The existing structure didn't work well
when extending to use of_phandle_args, and I discovered bugs during testing.
I also took the opportunity to rename the function to be like the
existing of_parse_phandle().

v2: - moved declaration of of_phandle_args to fix compile on non-DT builds
- fixed incorrect index in example usage
- fixed incorrect return code handling for empty entries

Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

of/gpio: export of_gpio_simple_xlate

Allow GPIO drivers to use of_gpio_simple_xlate. This is useful for the
generic GPIO driver for example where gpio_chip is embedded in
bgpio_chip and doesn't need of_mm_gpio_chip but has a simple 1:1 GPIO
mapping.

Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

of/gpio: Add new method for getting gpios under different property names

This patch adds a new routine, of_get_named_gpio_flags(), which takes the
property name as a parameter rather than assuming "gpios".

of_get_gpio_flags() is modified to call of_get_named_gpio_flags() with "gpios"
as the property parameter.

Signed-off-by: John Bonesio <bones@secretlab.ca>
[grant.likely: Tidied up whitespace and tweaked kerneldoc comments.]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

of/gpio: add default of_xlate function if device has a node pointer

Implement generic OF gpio hooks and thus make device-enabled GPIO chips
(i.e. the ones that have gpio_chip->dev specified) automatically attach
to the OpenFirmware subsystem. Which means that now we can handle I2C and
SPI GPIO chips almost* transparently.

* "Almost" because some chips still require platform data, and for these
chips OF-glue is still needed, though with this change the glue will
be much smaller.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org

of/gpio: stop using device_node data pointer to find gpio_chip

Currently the kernel uses the struct device_node.data pointer to resolve
a struct gpio_chip pointer from a device tree node. However, the .data
member doesn't provide any type checking and there aren't any rules
enforced on what it should be used for. There's no guarantee that the
data stored in it actually points to an gpio_chip pointer.

Instead of relying on the .data pointer, this patch modifies the code
to add a lookup function which scans through the registered gpio_chips
and returns the gpio_chip that has a pointer to the specified
device_node.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anton Vorontsov <avorontsov@ru.mvista.com>
CC: Grant Likely <grant.likely@secretlab.ca>
CC: David Brownell <dbrownell@users.sourceforge.net>
CC: Bill Gatliff <bgat@billgatliff.com>
CC: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Jean Delvare <khali@linux-fr.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org

of/gpio: Kill of_gpio_chip and add members directly to gpio_chip

The OF gpio infrastructure is great for describing GPIO connections within
the device tree. However, using a GPIO binding still requires changes to
the gpio controller just to add an of_gpio structure. In most cases, the
gpio controller doesn't actually need any special support and the simple
OF gpio mapping function is more than sufficient. Additional, the current
scheme of using of_gpio_chip requires a convoluted scheme to maintain
1:1 mappings between of_gpio_chip and gpio_chip instances.

If the struct of_gpio_chip data members were moved into struct gpio_chip,
then it would simplify the processing of OF gpio bindings, and it would
make it trivial to use device tree OF connections on existing gpiolib
controller drivers.

This patch eliminates the of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO). This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>

of/gpio: Implement of_gpio_count()

This function is used to count how many GPIOs are specified for
a device node.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

of/gpio: Implement of_get_gpio_flags()

This adds a new function, of_get_gpio_flags, which is like
of_get_gpio(), but accepts a new "flags" argument. This new function
will be used by the drivers that need to retrieve additional GPIO
information, such as active-low flag.

Also, this changes the default ("simple") .xlate routine to warn about
bogus (< 2) #gpio-cells usage: the second cell should always be present
for GPIO flags.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

of_gpio: Should use new <linux/gpio.h> header

Since commit 7560fa60fcdcdb0da662f6a9fad9064b554ef46c (gpio: <linux/gpio.h>
and "no GPIO support here" stubs) drivers can use GPIOs if they're available,
but don't require them.

This patch actually enables this feature.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[POWERPC] OF helpers for the GPIO API

This implements various helpers to support OF bindings for the GPIO
LIB API.

Previously this was PowerPC specific, but it seems this code isn't
arch-dependent anyhow, so let's place it into of/.

SPARC will not see this addition yet, real hardware seem to not use
GPIOs at all. But this might change:

http://www.leox.org/docs/faq_MLleon.html

"16-bit I/O port" sounds promising. :-)

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>