It is fine to ignore the return value (and encouraged),
so no need to cast away the return value, you will not get
a build warning at all.

Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NJon Hunter <jonathanh@nvidia.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It is fine to ignore the return value (and encouraged), so need to cast
away the return value, you will not get a build warning at all.

Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Sort the definitions for the individual GPIO drivers
in the Makefile by object file name. Align all entries
while we're at it.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Reduce driver init boilerplate by using the new
module_siox_driver() macro.
Signed-off-by: NEnrico Weigelt <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add more helper macros for trivial driver init cases, similar to the
already existing module_platform_driver() or module_i2c_driver().

This helps to reduce driver init boilerplate.
Signed-off-by: NEnrico Weigelt <info@metux.net>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Reviewed-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.

this driver deserves a bit more cleanup, to get rid of the global
variable giu_base, which makes it single-instance-only.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

don't need the temporary variable "dev", directly use &pdev->dev
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We already have the struct device* pointer in a local variable,
so we can write this a bit shorter.
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

A tab sneaked in, where it shouldn't be.
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NEnrico Weigelt, metux IT consult <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Improve readability a bit by commenting #if/#else/#endif statements
with the checked preprocessor symbols.
Signed-off-by: NEnrico Weigelt <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The pointer to the struct platform_device in the driver's private
data struct is never used and therefore can be dropped.
Signed-off-by: NEnrico Weigelt <info@metux.net>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We already have an array named "parents" so instead
of letting one point to the other, simply allocate a
dynamic array to hold the parents, just one if desired
and drop the number of members in gpio_irq_chip by
1. Rename gpiochip to gc in the process.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We now have two APIs for registering GPIOLIB_IRQCHIP, this is not
working and creating confusion. Add a TODO item to fix it up.

Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We need to convert all old gpio irqchips to pass the irqchip
setup along when adding the gpio_chip.

For chained irqchips this is a pretty straight-forward
conversion.

Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

If an edge interrupt triggers while entering idle just before we save
GPIO datain register to saved_datain, the triggered GPIO will not be
noticed on wake-up. This is because the saved_datain and GPIO datain
are the same on wake-up in omap_gpio_unidle(). Let's fix this by
ignoring any pending edge interrupts for saved_datain.

This issue affects only idle states where the GPIO module internal
wake-up path is operational. For deeper idle states where the GPIO
module gets powered off, Linux generic wakeirqs must be used for
the padconf wake-up events with pinctrl-single driver. For examples,
please see "interrupts-extended" dts usage in many drivers.

This issue can be somewhat easily reproduced by pinging an idle system
with smsc911x Ethernet interface configured IRQ_TYPE_EDGE_FALLING. At
some point the smsc911x interrupts will just stop triggering. Also if
WLCORE WLAN is used with EDGE interrupt like it's documentation specifies,
we can see lost interrupts without this patch.

Note that in the long run we may be able to cancel entering idle by
returning an error in gpio_omap_cpu_notifier() on pending interrupts.
But let's fix the bug first.

Also note that because of the recent clean-up efforts this patch does
not apply directly to older kernels. This does fix a long term issue
though, and can be backported as needed.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The FMC subsystem was created in 2012 with the ambition to
drive development of drivers for this hardware upstream.

The current implementation has architectural flaws and would
need to be revamped using real hardware to something that can
reuse existing kernel abstractions in the subsystems for e.g.
I2C, FPGA and GPIO.

We have concluded that for the mainline kernel it will be
better to delete the subsystem and start over with a clean
slate when/if an active maintainer steps up.

For details see:
https://lkml.org/lkml/2018/10/29/534Suggested-by: NFederico Vaga <federico.vaga@cern.ch>
Cc: Pat Riehecky <riehecky@fnal.gov>
Acked-by: NAlessandro Rubini <rubini@gnudd.com>
Signed-off-by: NFederico Vaga <federico.vaga@cern.ch>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The irq_startup() method returns an unsigned int, but in __irq_startup()
it is assigned to an int.  However, nothing checks for errors, so any
error that is returned is ignored.

Remove the check for GPIO-input mode and the error return.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We must never alter the register tables; these are read-only as far
as the driver is concerned.  Constify these tables.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Use local variables to store the base iomem address and regs table
pointer like omap_gpio_init_context() does. Not only does this make
the function neater, it also avoids unnecessary reloads of the same
data multiple times.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

When a GPIO block has the set/clear dataout registers implemented, it
also has the normal dataout register implemented. Reading this register
reads the current GPIO output state, and writing it sets the GPIOs to
the explicit state. This is the behaviour that we want when saving and
restoring the context, so use the dataout register exclusively.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

omap_set_gpio_irqenable() calls two helpers that are almost the same
apart from whether they set or clear bits. We can consolidate these:

- in the set/clear bit register case, we can perform the operation on
  our saved context copy and write the appropriate set/clear register.
- otherwise, we can use our read-modify-write helper and invert enable
  if irqenable_inv is set.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This function open-codes an exclusive-or bitwise operation using an
if() statement and explicitly setting or clearing the bit. Instead,
use an exclusive-or operation instead, and simplify the function.

We can combine the preprocessor conditional using IS_ENABLED() and
gain some additional compilation coverage.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

We already have a read-modify-write helper, but there's more that can
be done with a read-modify-write helper if it returned the new value.
Modify the existing helper to return the new value, and arrange for
it to take one less argument by having the caller compute the register
address.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

bank->level_mask is merely the bitwise or of the level detection
context which we have already read in this function.  Rather than
repeating additional reads, compute it from the values already
read.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

One of the reasons for set_multiple() to exist is to allow multiple
GPIOs on the same chip to be changed simultaneously - see commit
5f424243 ("gpiolib: allow simultaneous setting of multiple GPIO
outputs"):

 - Simultaneous glitch-free setting of multiple pins on any kind of
   parallel bus attached to GPIOs provided they all reside on the
   same chip and bank.

In order for this to work, we should not use the atomic set/clear
registers, but instead read-modify-write the dataout register.  We
already take the spinlock to ensure that happens atomically, so
move the code into the set_multiple() function and kill the two
helper functions.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

There is no reason to have helper functions to read the datain and
dataout registers when they are only used in one location.  Simplify
this code to make it more readable.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

omap_gpio_get() calls omap_get_gpio_datain() or omap_get_gpio_dataout()
to read the GPIO state. These two functions are only called from this
method, so they don't add much value.  Move their contents into
omap_gpio_get() method and simplify.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Architectures are single-copy atomic, which means that simply reading
a register is an inherently atomic operation.  There is no need to
take a spinlock here.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Move these two functions to live beside the rest of the gpio chip
implementation, rather than in the middle of the irq chip
implementation.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The irq_ack method does not fit our hardware requirements. Edge
interrupts must be cleared before we handle them, and level interrupts
must be cleared after handling them.

We handle the interrupt clearance in our interrupt handler for edge IRQs
and in the unmask method for level IRQs.

Replace the irq_ack method with the no-op method from the dummy irq
chip.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The edge interrupt handling was effectively:

	isr = ISR_reg & enabled;
	if (bank->level_mask)
		level_mask = bank->level_mask & enabled;
	else
		level_mask = 0;

	edge = isr & ~level_mask;

When bank->level_mask is zero, level_mask will be computed as zero
anyway, so the if() statement is redundant.  We are then left with:

	isr = ISR_reg & enabled;
	level_mask = bank->level_mask & enabled;
	edge = isr & ~level_mask;

This can be simplified further to:

	isr = ISR_reg & enabled;
	edge = isr & ~bank->level_mask;

since the second mask with 'enabled' is redundant.

Improve the associated comment as well.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Commit c4791bc6 ("gpio: omap: drop omap_gpio_list") removed the
list head and addition to the list head of each gpio bank, but failed
to remove the list_del() call and the node inside struct gpio_bank.
Remove these too.

Fixes: c4791bc6 ("gpio: omap: drop omap_gpio_list")
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Commit 384ebe1c ("gpio/omap: Add DT support to GPIO driver") added
the register definition tables to the gpio-omap driver. Subsequently to
that commit, commit 4e962e89 ("gpio/omap: remove cpu_is_omapxxxx()
checks from *_runtime_resume()") added definitions for irqstatus_raw*
registers to the legacy OMAP4 definitions, but missed the DT
definitions.

This causes an unintentional change of behaviour for the 1.101 errata
workaround on OMAP4 platforms. Fix this oversight.

Fixes: 4e962e89 ("gpio/omap: remove cpu_is_omapxxxx() checks from *_runtime_resume()")
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Documentation states:

  NOTE: There must be a correlation between the wake-up enable and
  interrupt-enable registers. If a GPIO pin has a wake-up configured
  on it, it must also have the corresponding interrupt enabled (on
  one of the two interrupt lines).

Ensure that this condition is always satisfied by enabling the detection
events after enabling the interrupt, and disabling the detection before
disabling the interrupt.  This ensures interrupt/wakeup events can not
happen until both the wakeup and interrupt enables correlate.

If we do any clearing, clear between the interrupt enable/disable and
trigger setting.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>