This code is poking around in the gpio_chip:s internal structures
to achieve some kind of pin to GPIO mappings.

- It is wrong to poke around in these structs and the pinctrl
  maintainer was stupid to let it pass unnoticed, mea culpa.

- The right interface to use is gpiochip_add_pin_range()

- The code appears unused: the pin control part of the driver
  is not adding any ranges, so we're iterating over an empty
  list. Maybe it is poking around in some other pin controllers
  GPIO ranges, and that's just totally wrong, again use
  gpiochip_add_pin_range() and specify the right pin
  controller.

Cc: Barry Song <baohua@kernel.org>
Cc: Guoying Zhang <Guoying.Zhang@csr.com>
Cc: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the WinSystems WS16C48 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the SMSC SCH311x GPIO driver, a
corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the Intel ICH series GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.

Cc: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the AMD 8111 GPIO driver, a
corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the ACCES 104-IDIO-16 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the ACCES 104-IDI-48 GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

By the time request_region is called in the ACCES 104-DIO-48E GPIO
driver, a corresponding device structure has already been allocated. The
devm_request_region function should be used to help simplify the cleanup
code and reduce the possible points of failure.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO driver copyright boilerplate lacks the "or
later" verbiage regarding GPL compliant distribution. The MODULE_LICENSE
string should reflect the actual copyright license terms used.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Every time a descriptor is retrieved from the gpiolib, we issue
module_get() to reference count the module supplying the GPIOs.
We also need to call device_get() and device_put() as we also
reference the backing gpio_device when doing this.

Since the sysfs GPIO interface is using gpiod_get() this will
also reference count the sysfs requests until all GPIOs are
unexported.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Some information about the GPIO chip need to stay around also
after the gpio_chip has been removed and only the gpio_device
persist. The base and ngpio are such things, for example we
don't want a new chip arriving to overlap the number space
of a dangling gpio_device, and the chardev may still query
the device for the number of lines etc.

Note that the code that assigns base and insert gpio_device
into the global list no longer check for a missing gpio_chip:
we respect the number space allocated by any other gpio_device.

As a consequence of the gdev being referenced directly from
the gpio_desc, we need to verify it differently from all
in-kernel API calls that fall through to direct queries to
the gpio_chip vtable: we first check that desc is !NULL, then
that desc->gdev is !NULL, then, if desc->gdev->chip is NULL,
we *BAIL OUT* without any error, so as to manage the case
where operations are requested on a device that is gone.

These checks were non-uniform and partly missing in the past:
so to simplify: create the macros VALIDATE_DESC() that will
return -EINVAL if the desc or desc->gdev is missing and just
0 if the chip is gone, and conversely VALIDATE_DESC_VOID()
for the case where the function does not return an error.
By using these macros, we get warning messages about missing
gdev with reference to the right function in the kernel log.

Despite the macro business this simplifies the code and make
it more readable than if we copy/paste the same descriptor
checking code into all code ABI call sites (IMHO).
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This kind of hacks disturbs the refactoring of the gpiolib.

The descriptor table belongs to the gpiolib, if we want to know
something about something in it, use or define the proper accessor
functions. Let's add this gpiochip_lins_is_irq() to do what the
sunxi driver is trying at so we can privatize the descriptors
properly.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We need gpio_device to hold the descriptors so that they can
be lifecycled with the struct gpio_device held from userspace.
Move the descriptor array into gpio_device. Also rename it from
"desc" (singularis) to "descs" (pluralis) to reflect the fact
that it is an array.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Since gpio_device is the struct that survives if the backing
gpio_chip is removed, move the sysfs mock device to this state
container so it becomes part of the dangling state of the
GPIO device on removal.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When the device core reference count for the device goes to
0 and it calls .release() we free resources and so can also
finally free up the GPIO state container, struct gpio_device.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Driver for the GPIO block found in ti's tps65218 pmics.

The device has two GPIOs and one GPO pin which can be configured as follows:
GPIO1:
	-general-purpose, open-drain output controlled by GPO1 user bit and/or
	 sequencer
	-DDR3 reset input signal from SOC. Signal is either latched or
	 passed-trough to GPO2 pin. See below for details.
GPO2:
	-general-purpose output controlled by GPO2 user bit
	-DDR3 reset output signal. Signal is controlled by GPIO1 and PGOOD.
	 See below for details.
	-Output buffer can be configured as open-drain or push-pull.
GPIO3:
	-general-purpose, open-drain output controlled by GPO3 user bit and/or
	 sequencer
	-reset input-signal for DCDC1 and DCDC2.

The input configurations are not meant to be used by the user so the driver
only offers GPOs.

v2: Added request routine that evaluates the fw config flags and removed module
    owner
v3: Added .direction_input() routine, and took care of all Linus Walleij
suggestions (clamp to bool, use proper include)
Signed-off-by: NNicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add driver for TI TPIC2810 8-Bit LED Driver with I2C Interface.

The TPIC2810 has 8 open-drain outputs that can but used to drive
LEDs and other low-side switched resistive loads.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add generic parallel-in/serial-out shift register GPIO driver.

This includes SPI compatible devices like SN74165 serial-out shift
registers and the SN65HVS88x series of industrial serializers that can
be read over the SPI bus and used for GPI (General Purpose Input).
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Tested-by: NSean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add myself to the copyright list and remove the reference to Atheros'
BSP as nothing is left of this code.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add support for the interrupt controller using GPIOLIB_IRQCHIP.
Both edges isn't supported by the chip and has to be emulated
by switching the polarity on each interrupt.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

As we now allow the driver to be built as a module it should be
removable.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

To allow building the driver in compile tests we must drop the
dependency on asm/mach-ath79/ar71xx_regs.h. For this we replace the
include with local definition of the registers needed for this driver.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Drop most of the code in favor of the generic MMIO GPIO driver.
As the driver now depend on CONFIG_GPIO_GENERIC also add a Kconfig
entry to make the driver optional.

We leave the base pointer and lock in the data struct because they are
needed for the IRQ support.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This marks the (optional) sysfs GPIO ABI as obsolete and schedules
it for removal in 2020.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Put in some documentation for the new character device ABI
so we can properly etch it in stone.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This creates GPIO tools under tools/gpio/* and adds a single
example program to list the GPIOs on a system. When proper
devices are created it provides this minimal output:

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

A new chardev that is to be used for userspace GPIO access is
added in this patch. It is intended to gradually replace the
horribly broken sysfs ABI.

Using a chardev has many upsides:

- All operations are per-gpiochip, which is the actual
  device underlying the GPIOs, making us tie in to the
  kernel device model properly.

- Hotpluggable GPIO controllers can come and go, as this
  kind of problem has been know to userspace for character
  devices since ages, and if a gpiochip handle is held in
  userspace we know we will break something, whereas the
  sysfs is stateless.

- The one-value-per-file rule of sysfs is really hard to
  maintain when you want to twist more than one knob at a time,
  for example have in-kernel APIs to switch several GPIO
  lines at the same time, and this will be possible to do
  with a single ioctl() from userspace, saving a lot of
  context switching.

We also need to add a new bus type for GPIO. This is
necessary for example for userspace coldplug, where sysfs is
traversed to find the boot-time device nodes and create the
character devices in /dev.

This new chardev ABI is *non* *optional* and can be counted
on to be present in the future, emphasizing the preference
of this ABI.

The ABI only implements one single ioctl() to get the name
and number of GPIO lines of a chip. Even this is debatable:
see it as a minimal example for review. This ABI shall be
ruthlessly reviewed and etched in stone.

The old /sys/class/gpio is still optional to compile in,
but will be deprecated.

Unique device IDs are created using IDR, which is overkill
and insanely scalable, but also well tested.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We use the new struct device inside gpio_chip to related debug
prints and warnings, and we also add it to the debugfs dump.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

GPIO chips have been around for years, but were never real devices,
instead they were piggy-backing on a parent device (such as a
platform_device or amba_device) but this was always optional.
GPIO chips could also exist without any device at all, with its
struct device *parent (ex *dev) pointer being set to null.

When sysfs was in use, a mock device would be created, with the
optional parent assigned, or just floating orphaned with NULL
as parent.

If sysfs is active, it will use this device as parent.

We now create a gpio_device struct containing a real
struct device and move the subsystem over to using that. The
list of struct gpio_chip:s is augmented to hold struct
gpio_device:s and we find gpio_chips:s by first looking up
the struct gpio_device.

The struct gpio_device is designed to stay around even if the
gpio_chip is removed, so as to satisfy users in userspace
that need a backing data structure to hold the state of the
session initiated with e.g. a character device even if there is
no physical chip anymore.

From this point on, gpiochips are devices.

Cc: Johan Hovold <johan@kernel.org>
Cc: Michael Welling <mwelling@ieee.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The new Layerscape platforms has the same ip block/controller
as GPIO on PowerPC platforms(MPC8XXX), but the GPIO registers
may be big or little endian. So the code needs to get the
endian property from DTB, then make additional functions to
fit all the PowerPC/Layerscape GPIO register read/write
operations.

gpio-generic.c provides an universal infrastructure for both
big and little endian register operations. So switch the
gpio-mpc8xxx to use gpio-generic can simplify the driver and
reduce a lot of code.

The IRQ and some workaround parts in gpio-mpc8xxx.c will be
updated with the new API interfaces but following the
original functionalities.
Signed-off-by: NLiu Gang <Gang.Liu@nxp.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The TS-4800 GPIO driver provide support for the GPIOs available
on the Technologic Sytems board FPGA. It allows to set
direction and read/write states.

It uses the generic gpio driver.
Signed-off-by: NJulien Grossholtz <julien.grossholtz@savoirfairelinux.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Device tree binding documentation for the TS-4800
GPIO controller.
Signed-off-by: NJulien Grossholtz <julien.grossholtz@savoirfairelinux.com>
[Point ngpios to gpio.txt]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use irq_data_get_chip_type() instead of container_of().
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The gpio-mpc8xxx.c should can support qoriq and
Layerscape platforms.
Signed-off-by: NLiu Gang <Gang.Liu@nxp.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add F81866 GPIO supports

Fintek F81866 is a SuperIO. It contains HWMON/GPIO/Serial Ports.
and it has totally 72(9x8 sets) gpio pins.

Here is the PDF spec:
http://www.alldatasheet.com/datasheet-pdf/pdf/459085/FINTEK/F81866AD-I.html

The control method is the same with F7188x, but we should care the address
of GPIO8x.

GPIO address is below:
    GPIO0x based: 0xf0
    GPIO1x based: 0xe0
    GPIO2x based: 0xd0
    GPIO3x based: 0xc0
    GPIO4x based: 0xb0
    GPIO5x based: 0xa0
    GPIO6x based: 0x90
    GPIO7x based: 0x80
    GPIO8x based: 0x88 <-- not 0x70.
Signed-off-by: NPeter Hung <hpeter+linux_kernel@gmail.com>
Acked-by: NSimon Guinot <simon.guinot@sequanux.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The ACCES 104-DIO-48E device provides 48 lines digital I/O via two
Programmable Peripheral Interface (PPI) chips of type 82C55. Bit C3 at
each 24-bit Group can be used as an external interrupt, triggered by a
rising edge.

This driver provides GPIO and IRQ support for these 48 channels of
digital I/O. The base port address for the device may be configured via
the dio_48e_base module parameter. The interrupt line number for the
device may be configured via the dio_48e_irq module parameter.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The WinSystems WS16C48 device provides 48 lines of digital I/O. In
addition, the first 24 lines may be used for interrupt-handled edge
detection; rising edge detection and falling edge detection are
supported.

This driver provides GPIO and IRQ support for these 48 channels of
digital I/O. The base port address for the device may be configured via
the ws16c48_base module parameter. The interrupt line number for the
device may be configured via the ws16c48_irq module parameter.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The ACCES 104-IDI-48 can differentiate between its own and other
devices' interrupt requests. Therefore, IRQ sharing is possible and
should be permitted.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>