In 2011 the commit bf859f84
("gpio/dt: Refine GPIO device tree binding") introduced an
experimental BNF notation for defining a regular grammar for
the GPIO phandles used by different devices.

This was an interesting approach, and shows that we have long
nutured the idea to formally verify device tree files using
regular grammar.

Most if not all other bindings use natural language to define
the bindings, and the recent thinking for verifying device
tree files is to use JSON schemas in separate definitions.

Cut the BNF business and replace it with natural language
so that it becomes more human-readable for now.

Cc: devicetree@vger.kernel.org
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Kumar Gala <galak@kernel.crashing.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

These defines, structs and inline functions are used only internally by
the driver, they do not belong in platform_data. Move them.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This macro does nothing and has only one user, remove it.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Previously we created a controller structure per bank of GPIO pins. This
has since been changed to one per controller, but the allocation size
was not changed. Fix this here.

This also leaves the variable 'nbank' unused, instead of removing it,
move it down and use it to clean up a loop. For loops with multiple
initializers and/or iteration expressions, especially ones that don't
use those loop counters are quite hard to follow, fix this.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Use dev_name to get a unique label and use -1 for a base to get our
selection automatically. We pull in all GPIOs per chip now so this
does not have the effect of out of order labels like before.

We do these both together so we can drop all the static data in one
patch. This also lets us normalize the return paths as we don't need
any cleanup after this change.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This was added as part of the patch in the fixes below, but was
not needed or used, remove this here.

Fixes: 8e11047b ("gpio: davinci: Add support for multiple GPIO controllers")
Tested-by: Keerthy <j-keerthy@ti.com>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

A bunch of core gpiolib files still include the <linux/gpio.h>
legacy API header for no good reason. After this only the
gpiolib-legacy.c file includes it, which is fine.

The sysfs ABI code has a pointless wrapper function around
gpio_to_desc() we can just loose.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX license tag for these drivers.

Cc: patches@opensource.cirrus.com
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Mark Brown <broonie@kernel.org>
Acked-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

These are GPIO drivers so just include <linux/gpio/driver.h>.

Cc: patches@opensource.cirrus.com
Cc: Charles Keepax <ckeepax@opensource.cirrus.com>
Cc: Mark Brown <broonie@kernel.org>
Acked-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX license tag for this file.

Cc: Kamlakant Patel <kamlakant.patel@cavium.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so include only <linux/gpio/driver.h>.

Cc: Kamlakant Patel <kamlakant.patel@cavium.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX header for the license.

Cc: Daniel Drake <drake@endlessm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so include only <linux/gpio/driver.h>.

Cc: Daniel Drake <drake@endlessm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX header for the license.

Cc: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so include only <linux/gpio/driver.h>.

Cc: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX header for the license.
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so include only <linux/gpio/driver.h>.
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This API is not used anywhere in the kernel and has remained
unused for years after being introduced.

Over time, we have developed a subsystem to deal with pin
control and this now managed pull up/down.

Delete the old and unused API. If this platform needs it,
we should implement a proper pin controller for it instead.

Cc: Yoichi Yuasa <yuasa@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This switches this file to use the SPDX license tag.

Cc: Yoichi Yuasa <yuasa@linux-mips.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so include only <linux/gpio/driver.h>.

Cc: Yoichi Yuasa <yuasa@linux-mips.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Some drivers use a single irqchip for multiple gpiochips. As a result the
irqchip hooks are overridden for the first gpiochip that was added, but
for the other gpiochip instances this should not happen again, otherwise
we would go into an infinite recursion.

Check for this, but also log a message that the driver should be fixed
since this is bad practice.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

EINVAL is very generic, use ENOTSUPP in case the gpiochip does not
provide this function. While removing the assignment from the 'status'
variable, use better indentation in the declaration block.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This concerns gpio edge detection for GPIO IRQs used from
userspace for GPIO event listeners.

Trying to work out the right event if it's not sure that the
examined gpio actually moved is impossible.

Consider two gpios "gpioA" and "gpioB" that share an interrupt.
gpioA's irq should trigger on any edge, gpioB's on a falling edge.
If now the common irq fires and both gpio lines are high, there
are several possibilities that could have happend:

 a) gpioA just had a low-to-high edge
 b) gpioB just had a high-to-low-to-high spike
 c) a combination of both a) and b)

While c) is unlikely (in most setups) a) and b) alone are bad
enough. Currently the code assumes case a) unconditionally and
doesn't report an event for gpioB. Note that even if there is no
irq sharing involved a spike for a gpio might not result in an
event if it's configured to trigger for a single edge only.

The only way to improve this is to drop support for interrupt
sharing. This way a spike results in an event for the right gpio
at least. Note that apart from dropping IRQF_SHARED this
effectively undoes commit df1e76f2
("gpiolib: skip unwanted events, don't convert them to opposite edge").

This obviously breaks setups that rely on interrupt sharing,
but given that this cannot be reliable, this is probably an
acceptable trade-off.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[Assuming there are no users of interrupt sharing yet]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Just use the SPDX identifier for the license.
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This is a GPIO driver so only include <linux/gpio/driver.h>.
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The ';' was missing. And cosmetic: there was a space too much.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The SPI chipselects are assumed to be active low in the current
binding, so when we want to use GPIO descriptors and handle
the active low/high semantics in gpiolib, we need a special
parsing quirk to deal with this.

We check for the property "spi-cs-high" and if that is
NOT present we assume the CS line is active low.

If the line is tagged as active low in the device tree and
has no "spi-cs-high" property all is fine, the device
tree and the SPI bindings are in agreement.

If the line is tagged as active high in the device tree with
the second cell flag and has no "spi-cs-high" property we
enforce active low semantics (as this is the exception we can
just tag on the flag).

If the line is tagged as active low with the second cell flag
AND tagged with "spi-cs-high" the SPI active high property
takes precedence and we print a warning.

Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Since this driver does not use the gpiolib irqchip helpers it will have to
allocate the irq resources and irq_en/disable itself.

Use the new gpiochip_req/relres_irq helpers to request/release all the
resources.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Ray Jui <rjui@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Document these new functions.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

When using the gpiolib irqchip helpers install irq_enable/disable
hooks for the irqchip to ensure that gpiolib knows when the irq
is enabled or disabled, allowing drivers to disable the irq and then
use it as an output pin, and later switch the direction to input and
re-enable the irq.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

GPIO drivers call gpiochip_(un)lock_as_irq whenever they want to use a gpio
as an interrupt. This is done when the irq is requested and it marks the
gpio as in use by an interrupt.

This is problematic for cases where a gpio pin is used as an interrupt
pin, then, after the irq is disabled, is used as a regular gpio pin.
Currently it is not possible to do this other than by first freeing
the interrupt so gpiochip_unlock_as_irq is called, since an attempt to
switch the gpio direction for output will fail since gpiolib believes
that the gpio is in use for an interrupt and it does not know that it
the irq is actually disabled.

There are currently two drivers that would like to be able to do this:
the tda998x_drv.c driver where a regular gpio pin needs to be temporarily
reconfigured as an interrupt pin during CEC calibration, and the cec-gpio
driver where you want to configure the gpio pin as an interrupt while
waiting for traffic over the CEC bus, or as a regular pin when receiving or
transmitting a CEC message.

The solution is to add a new flag that is set when the irq is enabled,
and have gpiod_direction_output check for that flag.

We also add functions that drivers that do not use GPIOLIB_IRQCHIP
can call when they enable/disable the irq.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Centralize setting the irq_request/release_resources callbacks
in one function since we'll be adding more callbacks to that.

Also fix the removal of the callback overrides: this should
only be done if we actually installed our own callback there.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

GPIO drivers that do not use GPIOLIB_IRQCHIP can hook these into
the irq_request_resource and irq_release_resource callbacks of the
irq_chip so they correctly 'get' the module and lock the gpio line
for IRQ use.

This will simplify driver code.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The problem is that if port == ARRAY_SIZE() and "gc == &epg->gc[port]"
then that should be treated as invalid.

Fixes: fd935fc4 ("gpio: ep93xx: Do not pingpong irq numbers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Currently the while loop checks for the end of the array using
the size of egp->gc rather that the number of elements in the array,
so fix this. Also, perform the array size check first as stylistically
it is always good to bounds check on an array first before referencing
the array (in this case, we're just computing the address of an
element in an array so this is a moot point).

Fixes: fd935fc4 ("gpio: ep93xx: Do not pingpong irq numbers")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Fix kernel-doc warning for missing struct member 'request_key':

../include/linux/gpio/driver.h:142: warning: Function parameter or member 'request_key' not described in 'gpio_irq_chip'

Fixes: 39c3fd58 ("kernel/irq: Extend lockdep class for request mutex")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The gpiolib cannot deduce the fact that every line is output
by itself, implement a .get_direction() callback so we can
inspect this.
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

It's nice to use BIT() macros rather than open coding the same.
It's good practice as sometimes people use BIT(31) and forget
that the constant must be cast unsigned long.
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Use the SPDX header to indicate the license for this driver.
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>