Rename active-low helper using common prefix.

Also remove unnecessary manipulation of value argument.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Make sure to deregister the class device (and release the irq) while
holding the sysfs lock in gpio_unexport to prevent racing with
gpio_export.

Note that this requires the recently introduced per-gpio locking to
avoid a deadlock with the kernfs active protection when waiting for the
attribute operations to drain during deregistration.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add a per-gpio mutex to serialise attribute operations rather than use
one global mutex for all gpios and chips.

Having a single global lock for all gpios in a system adds unnecessary
latency to the sysfs interface, and especially when having gpio
controllers connected over slow buses.

Now that the global gpio-sysfs interrupt table is gone and with per-gpio
data in place, we can easily switch to using a more fine-grained locking
scheme.

Keep the global mutex to serialise the global (class) operations of gpio
export and unexport and chip removal.

Also document the locking assumptions made.

Note that this is also needed to fix a race between gpiod_export and
gpiod_unexport.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Drop unnecessary locking from gpiod_export_link. If the class device has
not already been unregistered, class_find_device returns the ref-counted
class device so there's no need for locking.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Remove goto from success path.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add separate helper functions for irq request and free.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Only call irq helper if actually reconfiguring interrupt state.

This is a preparatory step in introducing separate gpio-irq request and
free functions.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Store the value sysfs entry in the gpiod data rather than in a global
table accessed through an index stored in the overloaded gpio-descriptor
flag field.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Remove redundant gpio-descriptor parameters from sysfs_set_active_low and
gpio_setup_irq.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Add gpiod class-device data.

This is a first step in getting rid of the insane gpio-descriptor flag
overloading, backward irq-interface implementation, and course grained
sysfs-interface locking (a single static mutex for every operation on
all exported gpios in a system).
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The attribute operations will never be called for an unregistered device
so remove redundant checks for FLAG_EXPORT.

Note that kernfs will also guarantee that any active sysfs operation has
finished before the attribute is removed during deregistration.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Make sure to release any irq only after the class device has been
deregistered.

This avoids a race between gpiod_unexport and edge_store, where an irq
could be allocated just before the gpio class device is deregistered
without relying on FLAG_EXPORT and the global sysfs lock.

Note that there is no need to hold the sysfs lock when releasing the irq
after the class device is gone as kernfs will prevent further attribute
operations.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Use DEVICE_ATTR_RO and DEVICE_ATTR_RW rather than specifying masks and
callbacks directly.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.

Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.

It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.

Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.

There are no in-kernel users of this interface.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Rename the gpio-chip export/unexport functions to the more descriptive
names gpiochip_sysfs_register and gpiochip_sysfs_unregister.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Clean gpio-chip class device registration and deregistration.

The class device is registered when a gpio-chip is added (or from
gpiolib_sysfs_init post-core init call), and deregistered when the chip
is removed.

Store the class device in struct gpio_chip directly rather than do a
class-device lookup on deregistration. This also removes the need for
the exported flag.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reduce scope of sysfs_lock protection during chip export and unexport,
which is only needed to prevent gpiod (re-)exports during chip removal.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Put the recently introduced gpio-chip pointer to some more use in
gpiod_export.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Drivers should call gpiochip_lock_as_irq (which prevents the pin
direction from being changed) in their irq_request_resources callbacks
but some drivers currently fail to do so.

Instead a second, explicit and often redundant call to lock-as-irq is
made by the sysfs-interface implementation after an irq has been
requested.

Move the explicit call before the irq-request to match the unlock done
after the irq is later released. Note that this also fixes an irq leak,
should the explicit call ever have failed.

Also add a comment about removing the redundant call once the broken
drivers have been fixed.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Clean up gpiochip_remove somewhat and only output warning about removing
chip with GPIOs requested once.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Linux 4.1-rc3

Fix kernel-doc format:
- Add gpio-width description
- Remove additional "inited" variable description
- Add return value description - xgpio_remove
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

priv->irq is allocated using devm_kzalloc so there is no need to memset it.
Signed-off-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

This file is built off of a tristate Kconfig option and also contains
modular function calls so it should explicitly include module.h to
avoid compile breakage during header shuffles done in the future.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

ACPI specification knows two types of GPIOs: GpioIo and GpioInt. The latter
is used to describe that a given device interrupt line is connected to a
specific GPIO pin. Typical ACPI _CRS entry for such device looks like
below:

    Name (_CRS, ResourceTemplate ()
    {
        I2cSerialBus (0x004A, ControllerInitiated, 0x00061A80,
                      AddressingMode7Bit, "\\_SB.PCI0.I2C6",
                      0x00, ResourceConsumer)
        GpioIo (Exclusive, PullDefault, 0x0000, 0x0000,
                IoRestrictionOutputOnly, "\\_SB.GPO0",
                0x00, ResourceConsumer)
        {
            0x004B
        }
        GpioInt (Level, ActiveLow, Shared, PullDefault, 0x0000,
                 "\\_SB.GPO0", 0x00, ResourceConsumer)
        {
            0x004C
        }
    })

Currently drivers need to request a GPIO corresponding to the right GpioInt
and then translate that to Linux IRQ number. This adds unnecessary lines of
boiler-plate code.

We can ease this a bit by introducing acpi_dev_gpio_irq_get() analogous to
of_irq_get(). This function translates given GpioInt resource under the
device in question to the suitable Linux IRQ number.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

All supported iMX GPIO controllers store configured GPIO output value
in GPIO_DR data register, which is represented by GPIO generic reg_set.
Provide a BGPIOF_READ_OUTPUT_REG_SET flag to bgpio_init() to allow
correct getting of previously set output value.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Adding a BGPIOF_READ_OUTPUT_REG_SET initialization flag to GPIO
generic MMIO driver makes possible to remove a private get() value
function from the driver.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

The change introduces BGPIOF_READ_OUTPUT_REG_SET flag for gpio-generic
GPIO chip implementation, which allows to get correct configured value
from reg_set register, input value is still get from reg_dat.
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Pull drm fixes from Dave Airlie:
 "I really need to get back to sending these on my Friday, instead of my
  Monday morning, but nothing too amazing in here: a few amdkfd fixes, a
  few radeon fixes, i915 fixes, one tegra fix and one core fix"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm: Zero out invalid vblank timestamp in drm_update_vblank_count.
  drm/tegra: Don't use vblank_disable_immediate on incapable driver.
  drm/radeon: stop trying to suspend UVD sessions
  drm/radeon: more strictly validate the UVD codec
  drm/radeon: make UVD handle checking more strict
  drm/radeon: make VCE handle check more strict
  drm/radeon: fix userptr lockup
  drm/radeon: fix userptr BO unpin bug v3
  drm/amdkfd: Initialize sdma vm when creating sdma queue
  drm/amdkfd: Don't report local memory size
  drm/amdkfd: allow unregister process with queues
  drm/i915: Drop PIPE-A quirk for 945GSE HP Mini
  drm/i915: Sink rate read should be saved in deca-kHz
  drm/i915/dp: there is no audio on port A
  drm/i915: Add missing MacBook Pro models with dual channel LVDS
  drm/i915: Assume dual channel LVDS if pixel clock necessitates it
  drm/radeon: don't setup audio on asics that don't support it
  drm/radeon: disable semaphores for UVD V1 (v2)

misc i915 fixes.

* tag 'drm-intel-fixes-2015-05-08' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Drop PIPE-A quirk for 945GSE HP Mini
  drm/i915: Sink rate read should be saved in deca-kHz
  drm/i915/dp: there is no audio on port A
  drm/i915: Add missing MacBook Pro models with dual channel LVDS
  drm/i915: Assume dual channel LVDS if pixel clock necessitates it

Since commit 844b03f2 we make
sure that after vblank irq off, we return the last valid
(vblank count, vblank timestamp) pair to clients, e.g., during
modesets, which is good.

An overlooked side effect of that commit for kms drivers without
support for precise vblank timestamping is that at vblank irq
enable, when we update the vblank counter from the hw counter, we
can't update the corresponding vblank timestamp, so now we have a
totally mismatched timestamp for the new count to confuse clients.

Restore old client visible behaviour from before Linux 3.17, but
zero out the timestamp at vblank counter update (instead of disable
as in original implementation) if we can't generate a meaningful
timestamp immediately for the new vblank counter. This will fix
this regression, so callers know they need to retry again later
if they need a valid timestamp, but at the same time preserves
the improvements made in the commit mentioned above.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: <stable@vger.kernel.org> #v3.17+

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Pull ARM fixes from Russell King:
 "A set of ARM fixes:

   - fix an off-by-one error in the iommu DMA ops, which caused errors
     with a 4GiB size.

   - remove comments mentioning the non-existent CONFIG_CPU_ARM1020_CPU_IDLE
     macro.

   - remove useless CONFIG_CPU_ICACHE_STREAMING_DISABLE blocks, where
     this symbol never appeared in any Kconfig.

   - fix Feroceon code to cope with a previous change correctly (it
     incorrectly left an additional word in an assembly structure
     definition)

   - avoid a misleading IRQ affinity warning in the ARM PMU code for
     IRQs which are already affine to their CPUs.

   - fix the node name printed in the IRQ affinity warning"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8352/1: perf: Fix the pmu node name in warning message
  ARM: 8351/1: perf: don't warn about missing interrupt-affinity property for PPIs
  ARM: 8350/1: proc-feroceon: Fix feroceon_proc_info macro
  ARM: 8349/1: arch/arm/mm/proc-arm925.S: remove dead #ifdef block
  ARM: 8348/1: remove comments on CPU_ARM1020_CPU_IDLE
  ARM: 8347/1: dma-mapping: fix off-by-one check in arm_setup_iommu_dma_ops

Pull samsung fixes from Kukjin Kim:
 "Here is Samsung fixes for v4.1.  Since I've missed to send this via
  arm-soc tree before v4.1-rc3, so I'm sending this to you directly

   - fix commit ea08de16 ("ARM: dts: Add DISP1 power domain for
     exynos5420") which causes 'unhandled fault: imprecise external
     abort' error when PD turned off.  ("make DP a consumer of DISP1
     power domain")

   - fix 's3c-rtc' probe failure on Odriod-X2/U2/U3 boards ("add
     'rtc_src' clock to rtc node for source clock of rtc")

   - fix typo for 'cpu-crit-0' trip point on exynos5420/5440

   - fix S2R failure on exynos5250-snow due to card power of Marvell
     WiFi driver (suspend/resume) ("add keep-power-in-susped to WiFi
     SDIO node")"

* tag 'samsung-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: dts: Add keep-power-in-suspend to WiFi SDIO node for exynos5250-snow
  ARM: dts: Fix typo in trip point temperature for exynos5420/5440
  ARM: dts: add 'rtc_src' clock to rtc node for exynos4412-odroid boards
  ARM: dts: Make DP a consumer of DISP1 power domain on Exynos5420

Pull ARM SoC fixes from Arnd Bergmann:
 "A few patches have come up since the merge window.  The largest one is
  a rewrite of the PXA lubbock/mainstone IRQ handling.  This was already
  broken in 2011 by a change to the GPIO code and only noticed now.

  The other changes contained here are:

  MAINTAINERS file updates:

   - Ray Jui and Scott Branden are now co-maintainers for some of the
     mach-bcm chips, while Christian Daudt and Marc Carino have stepped
     down.

   - Andrew Victor is no longer maintaining at91.  Instead, Alexandre
     Belloni now becomes an official maintainer, after having done a
     bulk of the work for a while.

   - Baruch Siach, who added the mach-digicolor platform in 4.1 is now
     listed as maintainer

   - The git URL for mach-socfpga has changed

  Bug fixes:

   - Three bug fixes for new rockchip rk3288 code

   - A regression fix to make SD card support work on certain ux500
     boards

   - multiple smaller dts fixes for imx, omap, mvebu, and shmobile

   - a regression fiix for omap3 power consumption

   - a fix for regression in the ARM CCI bus driver

  Configuration changes:

   - more imx platforms are now enabled in multi_v7_defconfig"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (39 commits)
  MAINTAINERS: add Conexant Digicolor machines entry
  MAINTAINERS: socfpga: update the git repo for SoCFPGA
  ARM: multi_v7_defconfig: Select more FSL SoCs
  MAINTAINERS: replace an AT91 maintainer
  drivers: CCI: fix used_mask init in validate_group()
  bus: omap_l3_noc: Fix master id address decoding for OMAP5
  bus: omap_l3_noc: Fix offset for DRA7 CLK1_HOST_CLK1_2 instance
  ARM: dts: dra7: Fix efuse register size for ABB
  ARM: dts: am57xx-beagle-x15: Switch GPIO fan number
  ARM: dts: am57xx-beagle-x15: Switch UART mux pins
  ARM: dts: am437x-sk: reduce col-scan-delay-us
  ARM: dts: am437x-sk: fix for new newhaven display module revision
  ARM: dts: am57xx-beagle-x15: Fix RTC aliases
  ARM: dts: am57xx-beagle-x15: Fix IRQ type for mcp7941x
  ARM: dts: omap3: Add #iommu-cells to isp and iva iommu
  ARM: omap2plus_defconfig: Enable EXTCON_USB_GPIO
  ARM: dts: OMAP3-N900: Add microphone bias voltages
  ARM: OMAP2+: Fix omap off idle power consumption creeping up
  MAINTAINERS: Update brcmstb entry
  MAINTAINERS: Remove Christian Daudt for mach-bcm
  ...

Pull user-namespace fix from Eric Biederman:
 "Eric Windish recently reported a really bug that allows mounting fresh
  copies of proc and sysfs when it really should not be allowed.  The
  code attempted to verify that proc and sysfs were fully visible but
  there is a test missing to ensure that the root of the filesystem is
  visible.  Doh!

  The following patch fixes that.

  This fixes a containment issue that the docker folks are seeing"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  mnt: Fix fs_fully_visible to verify the root directory is visible

Pull irq updates from Thomas Gleixner:
 "Two patches from the irq departement:

   - a simple fix to make dummy_irq_chip usable for wakeup scenarios

   - removal of the gic arch_extn hackery.  Now that all users are
     converted we really want to get rid of the interface so people wont
     come up with new use cases"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: gic: Drop support for gic_arch_extn
  genirq: Set IRQCHIP_SKIP_SET_WAKE flag for dummy_irq_chip

Pull timer fix from Thomas Gleixner:
 "A simple fix to actually shut down a detached device instead of
  keeping it active"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clockevents: Shutdown detached clockevent device

We cast away the volatile, but really, why make it volatile at all?
We already do a mb() inside the cpumask_empty() loop.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>