This patch converts TI OMAP GPIO driver to use generic irq handler
instead of chained IRQ handler. This way OMAP GPIO driver will be
compatible with RT kernel where it will be forced thread IRQ handler
while in non-RT kernel it still will be executed in HW IRQ context.
As part of this change the IRQ wakeup configuration is applied to
GPIO Bank IRQ as it now will be under control of IRQ PM Core during
suspend.

There are also additional benefits:
 - on-RT kernel there will be no complains any more about PM runtime usage
   in atomic context  "BUG: sleeping function called from invalid context";
 - GPIO bank IRQs will appear in /proc/interrupts and its usage statistic
    will be  visible;
 - GPIO bank IRQs could be configured through IRQ proc_fs interface and,
   as result, could be a part of IRQ balancing process if needed;
 - GPIO bank IRQs will be under control of IRQ PM Core during
   suspend to RAM.

Disadvantage:
 - additional runtime overhed as call chain till
   omap_gpio_irq_handler() will be longer now
 - necessity to use wa_lock in omap_gpio_irq_handler() to W/A warning
   in handle_irq_event_percpu()
   WARNING: CPU: 1 PID: 35 at kernel/irq/handle.c:149 handle_irq_event_percpu+0x51c/0x638()

This patch doesn't fully follows recommendations provided by Sebastian
Andrzej Siewior [1], because It's required to go through and check all
GPIO IRQ pin states as fast as possible and pass control to handle_level_irq
or handle_edge_irq. handle_level_irq or handle_edge_irq will perform actions
specific for IRQ triggering type and wakeup corresponding registered
threaded IRQ handler (at least it's expected to be threaded).
IRQs can be lost if handle_nested_irq() will be used, because excecution
time of some pin specific GPIO IRQ handler can be very significant and
require accessing ext. devices (I2C).

Idea of such kind reworking was also discussed in [2].

[1] http://www.spinics.net/lists/linux-omap/msg120665.html
[2] http://www.spinics.net/lists/linux-omap/msg119516.htmlTested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NAustin Schuh <austin@peloton-tech.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The PM runtime API can't be used in atomic contex on -RT even if
it's configured as irqsafe. As result, below error report can
be seen when PM runtime API called from IRQ chip's callbacks
irq_startup/irq_shutdown/irq_set_type, because they are
protected by RAW spinlock:

BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 128, pid: 96, name: insmod
3 locks held by insmod/96:
 #0:  (&dev->mutex){......}, at: [<c04752c8>] __driver_attach+0x54/0xa0
 #1:  (&dev->mutex){......}, at: [<c04752d4>] __driver_attach+0x60/0xa0
 #2:  (class){......}, at: [<c00a408c>] __irq_get_desc_lock+0x60/0xa4
irq event stamp: 1834
hardirqs last  enabled at (1833): [<c06ab2a4>] _raw_spin_unlock_irqrestore+0x88/0x90
hardirqs last disabled at (1834): [<c06ab068>] _raw_spin_lock_irqsave+0x2c/0x64
softirqs last  enabled at (0): [<c003d220>] copy_process.part.52+0x410/0x19d8
softirqs last disabled at (0): [<  (null)>]   (null)
Preemption disabled at:[<  (null)>]   (null)

CPU: 1 PID: 96 Comm: insmod Tainted: G        W  O    4.1.3-rt3-00618-g57e2387-dirty #184
Hardware name: Generic DRA74X (Flattened Device Tree)
[<c00190f4>] (unwind_backtrace) from [<c0014734>] (show_stack+0x20/0x24)
[<c0014734>] (show_stack) from [<c06a62ec>] (dump_stack+0x88/0xdc)
[<c06a62ec>] (dump_stack) from [<c006ca44>] (___might_sleep+0x198/0x2a8)
[<c006ca44>] (___might_sleep) from [<c06ab6d4>] (rt_spin_lock+0x30/0x70)
[<c06ab6d4>] (rt_spin_lock) from [<c04815ac>] (__pm_runtime_resume+0x68/0xa4)
[<c04815ac>] (__pm_runtime_resume) from [<c04123f4>] (omap_gpio_irq_type+0x188/0x1d8)
[<c04123f4>] (omap_gpio_irq_type) from [<c00a64e4>] (__irq_set_trigger+0x68/0x130)
[<c00a64e4>] (__irq_set_trigger) from [<c00a7bc4>] (irq_set_irq_type+0x44/0x6c)
[<c00a7bc4>] (irq_set_irq_type) from [<c00abbf8>] (irq_create_of_mapping+0x120/0x174)
[<c00abbf8>] (irq_create_of_mapping) from [<c0577b74>] (of_irq_get+0x48/0x58)
[<c0577b74>] (of_irq_get) from [<c0540a14>] (i2c_device_probe+0x54/0x15c)
[<c0540a14>] (i2c_device_probe) from [<c04750dc>] (driver_probe_device+0x184/0x2c8)
[<c04750dc>] (driver_probe_device) from [<c0475310>] (__driver_attach+0x9c/0xa0)
[<c0475310>] (__driver_attach) from [<c0473238>] (bus_for_each_dev+0x7c/0xb0)
[<c0473238>] (bus_for_each_dev) from [<c0474af4>] (driver_attach+0x28/0x30)
[<c0474af4>] (driver_attach) from [<c0474760>] (bus_add_driver+0x154/0x200)
[<c0474760>] (bus_add_driver) from [<c0476348>] (driver_register+0x88/0x108)
[<c0476348>] (driver_register) from [<c0541600>] (i2c_register_driver+0x3c/0x90)
[<c0541600>] (i2c_register_driver) from [<bf003018>] (pcf857x_init+0x18/0x24 [gpio_pcf857x])
[<bf003018>] (pcf857x_init [gpio_pcf857x]) from [<c000998c>] (do_one_initcall+0x128/0x1e8)
[<c000998c>] (do_one_initcall) from [<c06a4220>] (do_init_module+0x6c/0x1bc)
[<c06a4220>] (do_init_module) from [<c00dd0c8>] (load_module+0x18e8/0x21c4)
[<c00dd0c8>] (load_module) from [<c00ddaa0>] (SyS_init_module+0xfc/0x158)
[<c00ddaa0>] (SyS_init_module) from [<c000ff40>] (ret_fast_syscall+0x0/0x54)

The IRQ chip interface defines only two callbacks which are executed in
non-atomic contex - irq_bus_lock/irq_bus_sync_unlock, so lets move
PM runtime calls there.
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NAustin Schuh <austin@peloton-tech.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch adds support for the GPIOs found on the ITE super-I/O chips
IT87xx.
Signed-off-by: NDiego Elio Pettenò <flameeyes@flameeyes.eu>
Signed-off-by: NChristophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The parameter offset is an unsigned, so it makes no sense to compare
it for >= 0. Fix the compiler warning regarding this by removing this
comparison.

As the macro GPIO_OFFSET_VALID is only used at this single place, simplify
the code by dropping the macro completely and dropping the invert, too.

No functional change.
Signed-off-by: NDirk Behme <dirk.behme@gmail.com>
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Signed-off-by: NRichard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This fixes error checking in the function device_pca957x_init
to properly check and return error code values from the calls
to the function pca953x_write_regs if they fail as to properly
signal callers when a error occurs due a failure when writing
registers for this gpio based device.
Signed-off-by: NNicholas Krause <xerofoify@gmail.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Turn the ath79 driver into a true driver supporting multiple
instances. While at it also removed unneed includes and make use of
the BIT() macro.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Remove this driver now that Bjorn has introduced a pinctrl driver
for msm8660 and the dts files have been updated with the pinctrl
compatibles.

Cc: Andy Gross <agross@codeaurora.org>
Reviewed-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The state container of the Zynq GPIO driver is sometimes
extracted from the gpio_chip exploiting the fact that offsetof()
the struct gpio_chip inside the struct zynq_gpio is 0, so
the container_of() is in practice a noop. However if a member
is added to struct zynq_gpio in front of struct gpio_chip,
things will break. Using proper container_of() avoids this
problem.

Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.

Also replace some explicit container_of() calls with the helper
function.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Ezra Savard <ezra.savard@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Acked-by: NHarini Katakam <harinik@xilinx.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The state container of the vf610 GPIO driver is sometimes
extracted from the gpio_chip exploiting the fact that offsetof()
the struct gpio_chip inside the struct vf610_gpio_port is 0, so
the container_of() is in practice a noop. However if a member
is added to struct vf610_gpio_port in front of struct gpio_chip,
things will break. Using proper container_of() avoids this
problem.

Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.

Also replace some explicit container_of() calls with the helper
function.
Acked-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The state container of the sx150x GPIO driver is sometimes
extracted from the gpio_chip exploiting the fact that offsetof()
the struct gpio_chip inside the struct sx150x_chip is 0, so
the container_of() is in practice a noop. However if a member
is added to struct sx150_chip in front of struct gpio_chip, things
will break. Using proper container_of() avoids this problem.

Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.

Cc: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The state container of the Altera GPIO driver is extracted from
the gpio_chip exploiting the fact that offsetof() the
struct gpio_chip inside the struct of_mm_gpio_chip are both 0, so
the container_of() is in practice a noop. However if a member
is added to struct altera_gpio_chip in front of
struct of_mm_gpio_chip, things will break. Using proper
container_of() avoids this problem.

Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.

Cc: Tien Hock Loh <thloh@altera.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The state container of the etraxfs GPIO driver is extracted from
the gpio_chip exploiting the fact that offsetof() the
struct gpio_chip inside the struct bgpio_chip are both 0, so
the container_of() is in practice a noop. However if a member
is added to struct etraxfs_gpio_chip in front of
struct bgpio_chip, things will break. Using proper container_of()
avoids this problem.

Semantically this is a noop, the compiler will optimize it away,
but syntactically it makes me happier.
Acked-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

I couldn't follow this code flow. Make it dirt simple to figure
out what is going on and get proper debug prints. Warn if we
set up an IRQ without any trigger. Should make no semantic
difference.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This refactors the changes to the GPIO line naming mechanism to
not have so widespread effects, instead we conclude the patch series
by having created a name attribute in the GPIO descriptor, that need
not be globally unique, and it will be initialized from the old
.names array in struct gpio_chip if it exists, then used in the legacy
sysfs code like the array was used previously.

The associated changes to name lines from the device tree are
controversial and need to stand alone from this. Resulting changes:

1. Remove the export and the header for the gpio_name_to_desc() as so
far the only use is inside gpiolib.c. Staticize gpio_name_to_desc()
and move it above the only function using it.

2. Only print a warning if there are two GPIO lines with the same name.
The reason is to preserve current behaviour: before the previous
changes to the naming mechanism this would not reject probing the
driver, instead the error would occur when trying to export the line
in sysfs, so restore this behaviour, but print a friendly warning
if names collide.

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

Add some information about gpio names to the debugfs gpio file. name and
label of a GPIO are then displayed next to each other. This way it is
easy to see what the real name of GPIO is and what the driver requested
it for.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
[Dropped unsolicited sysfs ABI patch hunk]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The name is now stored in the gpio descriptor as well, for example to
allow to store names from DT. This patch changes the sysfs gpio files
to use the gpio descriptor name.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch adds GPIO names to the GPIO descriptors when initializing the
gpiochip. It also introduces a check whether any of the new names will
conflict with an existing GPIO name.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The latest gpio hogging mechanism assigns each gpio a 'line-name' in the
devicetree. The 'name' field is different from the 'label' field.
'label' is only used for requested GPIOs to describe its current use by
driver or userspace.

The 'name' field describes the GPIO itself, not the use. This is most
likely identical to the label in the schematic on the GPIO line and
should help to find this particular GPIO.

This is equivalent to the gpiochip->names array. However names should be
stored in the GPIO descriptor. We will use gpiochip->names in the future
only as initializer for the GPIO descriptors for drivers that assign
GPIO names hardcoded. All other GPIO names will be parsed from DT and
directly assigned to the GPIO descriptor.

This patch adds a helper function to find gpio descriptors by name
instead of gpio number.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The gpio hogging functions are currently only used for gpio-hogging. But
these functions are widely generic ones which parse gpio device nodes in
the DT.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor. Search and replacement was done with coccinelle:
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org

If gpio-omap probe fails with -EPROBE_DEFER, the GPIO numbering
keeps increasing. Only increase the gpio count if gpiochip_add()
was successful as otherwise the numbers will increase for each
probe attempt.

Cc: Javier Martinez Canillas <javier@dowhile0.org>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently we gpio-omap breaks if gpiochip_add() returns -EPROBE_DEFER:

[    0.570000] gpiochip_add: GPIOs 0..31 (gpio) failed to register
[    0.570000] omap_gpio 48310000.gpio: Could not register gpio chip -517
...
[    3.670000] omap_gpio 48310000.gpio: Unbalanced pm_runtime_enable!

Let's fix the issue by adding the missing pm_runtime_put() on error.

Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Javier Martinez Canillas <javier@dowhile0.org>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The driver has a I2C device id table that is used to create the module
aliases and also "sx150x" isn't a supported I2C id, so it's never used.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

It's possible to have gpio chips hanging off unreliable remote buses
where the get() operation will fail to acquire a readout of the current
gpio state. Propagate these errors to the consumer so that they can
act on, retry or ignore these failing reads, instead of treating them as
the line being held high.
Signed-off-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

8cd14702("gpio: rcar: Add r8a7795 (R-Car H3) support") added
GPIO support for r8a7795. r8a7795 based on CONFIG_ARM64.
OTOH, GPIO_RCAR driver can be compiled fine on non-ARM.
This patch removed ARM dependency for it.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Need to check return value of irq_alloc_generic_chip, because
it may return NULL.
1. Change mxs_gpio_init_gc return type from void to int.
2. Add a new lable out_irqdomain_remove to remove the irq domain
   when mxc_gpio_init_gc fail.
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Need to check return value of irq_alloc_generic_chip, because
it may return NULL.
1. Change mxc_gpio_init_gc return type from void to int.
2. Add a new lable out_irqdomain_remove to remove the irq domain
   when mxc_gpio_init_gc fail.
Signed-off-by: NPeng Fan <van.freenix@gmail.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
[Manually rebased]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Currently CONFIG_ARCH_HAVE_CUSTOM_GPIO_H is defined for all MIPS
machines, and each machine type provides its own gpio.h. However
only a handful really implement the GPIO API, most just forward
everythings to gpiolib.

The Alchemy machine is notable as it provides a system to allow
implementing the GPIO API at the board level. But it is not used by
any board currently supported, so it can also be removed.

For most machine types we can just remove the custom gpio.h, as well
as the custom wrappers if some exists. Some of the code found in
the wrappers must be moved to the respective GPIO driver.

A few more fixes are need in some drivers as they rely on linux/gpio.h
to provides some machine specific definitions, or used asm/gpio.h
instead of linux/gpio.h for the gpio API.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Rafał Miłecki <zajec5@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Daniel Walter <dwalter@google.com>
Cc: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: James Hartley <james.hartley@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Varka Bhadram <varkabhadram@gmail.com>
Cc: Masanari Iida <standby24x7@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Michael Buesch <m@bues.ch>
Cc: abdoulaye berthe <berthe.ab@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-ide@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: netdev@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10828/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

GPIO drivers should be in drivers/gpio
Signed-off-by: NAlban Bedel <albeu@free.fr>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10597/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This reverts commit 5e22ec01.

There is a helper function to do the container_of() magic for
the tc3589x GPIO, so use it.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Return a negative error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The GPIO IRQ controller is able to generate level triggered
interrupts, however, these were handled by handle_simple_irq so far
which did not take care of IRQ masking. This lead to "nobody cared
(try booting with the "irqpoll" option)" stack traces.

Use the generic interrupt handlers depending on the IRQ type.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This fixes error handling in the function max732x_probe by checking
if the calls to the function max732x_readb fail by returning a error
code.
Signed-off-by: NNicholas Krause <xerofoify@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

As per CCF documentation (clk.txt) the clk_prepare/unprepare APIs
are not allowed in atomic context. But now OMAP GPIO driver
uses them while applying debounce settings and as part
of PM runtime irqsafe operations:

- omap_gpio_debounce() is holding the lock with IRQs off.
  + omap2_set_gpio_debounce()
   + clk_prepare_enable()
    + clk_prepare() this one might sleep.

- pm_runtime_get_sync() is holding the lock with IRQs off
  + omap_gpio_runtime_suspend()
    + raw_spin_lock_irqsave()
    + omap_gpio_dbck_disable()
      + clk_disable_unprepare()

Hence, fix it by moeving dbclk prepare/unprepare in OMAP GPIO
omap_gpio_probe/omap_gpio_remove. Also, while here, ensure that
debounce functionality is disabled if clk_get() failed,
because otherwise kernel will carsh in omap2_set_gpio_debounce().
Reported-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

The access to HW registers has to be be protected in
omap_gpio_irq_handler(), as it may race with code executed on
another CPUs.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

According to TRMs:

Required input line stable =
  (the value of the GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) × 31,
where the value of the GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME bit field
is from 0 to 255.

But now omap2_set_gpio_debounce() will calculate debounce time and
behave incorrectly in the following cases:
1) requested debounce time is !0 and <32
   calculated DEBOUNCETIME = 0x1 == 62 us;
   expected value of DEBOUNCETIME = 0x0 == 31us
2) requested debounce time is 0
   calculated DEBOUNCETIME = 0x1 == 62 us;
   expected: disable debounce and DEBOUNCETIME = 0x0
3) requested debounce time is >32 and <63
   calculated DEBOUNCETIME = 0x0 and debounce will be disabled;
   expected: enable debounce and DEBOUNCETIME = 0x1 == 62 us

Hence, rework omap2_set_gpio_debounce() to fix above cases:
1) introduce local variable "enable" and use it to identify
when debounce need to be enabled or disabled. Disable debounce
if requested debounce time is 0.
2) use below formula for debounce time calculation:
   debounce = (DIV_ROUND_UP(debounce, 31) - 1) & 0xFF;
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Switch OMAP GPIO driver to use platform_get_irq(), because
it is not recommened to use platform_get_resource(pdev, IORESOURCE_IRQ, ..)
for requesting IRQ resources any more, as they can be not ready yet
in case of DT-boot.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>