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Lars-Peter Clausen 1f1cc4566b gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation
The current line offset validation is off by one. Depending on the data
stored behind the descs array this can either cause undefined behavior or
disclose arbitrary, potentially sensitive, memory to the issuing userspace
application.

Make sure that offset is within the bounds of the desc array.

Cc: stable@vger.kernel.org
Fixes: 521a2ad6f8 ("gpio: add userspace ABI for GPIO line information")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-21 14:36:44 +02:00
Linus Walleij 031ba28a81 gpio: acpi: separation of concerns
The generic GPIO library directly implement code for acpi_find_gpio()
which is only used with CONFIG_ACPI. This was probably done because
OF did the same thing, but I removed that so remove this too.

Rename the internal acpi_find_gpio() in gpiolib-acpi.c to
acpi_populate_gpio_lookup() which seems to be more appropriate anyway
so as to avoid a namespace clash with the same function.

Make the stub return -ENOENT rather than -ENOSYS (as that is for
syscalls!).

For some reason the sunxi pin control driver was including the private
gpiolib header, it works just fine without it so remove that oneliner.

Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-03 23:38:10 +02:00
Linus Walleij ea713bc450 gpio: OF: separation of concerns
The generic GPIO library directly implement code for of_find_gpio()
which is only used with CONFIG_OF and causes compilation problems
on archs that do not even have stubs for OF functions, especially
on UM that does not implement any IO remap functions.

Move the function to gpiolib-of.c, implement a static inline stub
in gpiolib.h returning PTR_ERR(-ENOENT) if CONFIG_OF_GPIO is not
set and be done with it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-10-03 15:27:05 +02:00
Linus Walleij 22a5db98a3 Merge branch 'gpio-irq-validmask' of /home/linus/linux-pinctrl into devel 2016-09-23 14:51:18 +02:00
Mika Westerberg 79b804cb6a gpiolib: Make it possible to exclude GPIOs from IRQ domain
When using GPIO irqchip helpers to setup irqchip for a gpiolib based
driver, it is not possible to select which GPIOs to add to the IRQ domain.
Instead it just adds all GPIOs which is not always desired. For example
there might be GPIOs that for some reason cannot generated normal
interrupts at all.

To support this we add a flag irq_need_valid_mask to struct gpio_chip. When
this flag is set the core allocates irq_valid_mask that holds one bit for
each GPIO the chip has. By default all bits are set but drivers can
manipulate this using set_bit() and clear_bit() accordingly.

Then when gpiochip_irqchip_add() is called, this mask is checked and all
GPIOs with bit is set are added to the IRQ domain created for the GPIO
chip.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-23 14:49:50 +02:00
Mika Westerberg 0a1e005374 gpiolib: Forbid irqchip default trigger for ACPI enumerated devices
Follow DT and forbid default trigger if the GPIO irqchip device is
enumerated from ACPI. Triggering for these devices will be configured
automatically from ACPI interrupt resources provided by the BIOS.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-13 10:45:59 +02:00
Marc Zyngier 332e99d5ae gpio/gpiolib: Forbid irqchip default trigger if probed over DT
Using a default trigger is a bad idea if using DT to configure
interrupts, as the device's interrupt specifier will always contain
the trigger configuration.

Let's warn about that particular situation, and revert to not
having a default. Hopefully, the couple of drivers still using
this feature will quickly be fixed.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-09-12 11:05:03 +02:00
Masahiro Yamada acf06ff76c gpio: refactor gpiochip_find() slightly
The if...else... block after the loop can be dropped with
a slight refactoring.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-08-19 10:55:08 +02:00
Linus Torvalds 1cd04d293c This is the bulk of GPIO changes for the v4.8 kernel cycle.
Core changes:
 
 - The big item is of course the completion of the character
   device ABI. It has now replaced and surpassed the former
   unmaintainable sysfs ABI: we can now hammer (bitbang)
   individual lines or sets of lines and read individual lines
   or sets of lines from userspace, and we can also register
   to listen to GPIO events from userspace. As a tie-in we
   have two new tools in tools/gpio: gpio-hammer and
   gpio-event-mon that illustrate the proper use of the new
   ABI. As someone said: the wild west days of GPIO are now
   over.
 
 - Continued to remove the pointless
   ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB Kconfig symbols.
   I'm patching hexagon, openrisc, powerpc, sh, unicore,
   ia64 and microblaze. These are either ACKed by their
   maintainers or patched anyways after a grace period and
   no response from maintainers. Some archs (ARM) come in from
   their trees, and others (x86) are still not fixed, so I
   might send a second pull request to root it out later in
   this merge window, or just defer to v4.9.
 
 - The GPIO tools are moved to the tools build system.
 
 New drivers:
 
 - New driver for the MAX77620/MAX20024.
 
 - New driver for the Intel Merrifield.
 
 - Enabled PCA953x for the TI PCA9536.
 
 - Enabled PCA953x for the Intel Edison.
 
 - Enabled R8A7792 in the RCAR driver.
 
 Driver improvements:
 
 - The STMPE and F7188x now supports the .get_direction()
   callback.
 
 - The Xilinx driver supports setting multiple lines at
   once.
 
 - ACPI support for the Vulcan GPIO controller.
 
 - The MMIO GPIO driver supports device tree probing.
 
 - The Acer One 10 is supported through the _DEP ACPI
   attribute.
 
 Cleanups:
 
 - A major cleanup of the OF/DT support code. It is way
   easier to read and understand now, probably this improves
   performance too.
 
 - Drop a few redundant .owner assignments.
 
 - Remove CLPS711x boardfile support: we are 100% DT.
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Merge tag 'gpio-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for the v4.8 kernel cycle.  The big
  news is the completion of the chardev ABI which I'm very happy about
  and apart from that it's an ordinary, quite busy cycle.  The details
  are below.

  The patches are tested in linux-next for some time, patches to other
  subsystem mostly have ACKs.

  I got overly ambitious with configureing lines as input for IRQ lines
  but it turns out that some controllers have their interrupt-enable and
  input-enabling in orthogonal settings so the assumption that all IRQ
  lines are input lines does not hold.  Oh well, revert and back to the
  drawing board with that.

  Core changes:

   - The big item is of course the completion of the character device
     ABI.  It has now replaced and surpassed the former unmaintainable
     sysfs ABI: we can now hammer (bitbang) individual lines or sets of
     lines and read individual lines or sets of lines from userspace,
     and we can also register to listen to GPIO events from userspace.

     As a tie-in we have two new tools in tools/gpio: gpio-hammer and
     gpio-event-mon that illustrate the proper use of the new ABI.  As
     someone said: the wild west days of GPIO are now over.

   - Continued to remove the pointless ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
     Kconfig symbols.  I'm patching hexagon, openrisc, powerpc, sh,
     unicore, ia64 and microblaze.  These are either ACKed by their
     maintainers or patched anyways after a grace period and no response
     from maintainers.

     Some archs (ARM) come in from their trees, and others (x86) are
     still not fixed, so I might send a second pull request to root it
     out later in this merge window, or just defer to v4.9.

   - The GPIO tools are moved to the tools build system.

  New drivers:

   - New driver for the MAX77620/MAX20024.

   - New driver for the Intel Merrifield.

   - Enabled PCA953x for the TI PCA9536.

   - Enabled PCA953x for the Intel Edison.

   - Enabled R8A7792 in the RCAR driver.

  Driver improvements:

   - The STMPE and F7188x now supports the .get_direction() callback.

   - The Xilinx driver supports setting multiple lines at once.

   - ACPI support for the Vulcan GPIO controller.

   - The MMIO GPIO driver supports device tree probing.

   - The Acer One 10 is supported through the _DEP ACPI attribute.

  Cleanups:

   - A major cleanup of the OF/DT support code.  It is way easier to
     read and understand now, probably this improves performance too.

   - Drop a few redundant .owner assignments.

   - Remove CLPS711x boardfile support: we are 100% DT"

* tag 'gpio-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (67 commits)
  MAINTAINERS: Add INTEL MERRIFIELD GPIO entry
  gpio: dwapb: add missing fwnode_handle_put() in dwapb_gpio_get_pdata()
  gpio: merrifield: Protect irq_ack() and gpio_set() by lock
  gpio: merrifield: Introduce GPIO driver to support Merrifield
  gpio: intel-mid: Make it depend to X86_INTEL_MID
  gpio: intel-mid: Sort header block alphabetically
  gpio: intel-mid: Remove potentially harmful code
  gpio: rcar: add R8A7792 support
  gpiolib: remove duplicated include from gpiolib.c
  Revert "gpio: convince line to become input in irq helper"
  gpiolib: of_find_gpio(): Don't discard errors
  gpio: of: Allow overriding the device node
  gpio: free handles in fringe cases
  gpio: tps65218: Add platform_device_id table
  gpio: max77620: get gpio value based on direction
  gpio: lynxpoint: avoid potential warning on error path
  tools/gpio: add install section
  tools/gpio: move to tools buildsystem
  gpio: intel-mid: switch to devm_gpiochip_add_data()
  gpio: 74x164: Use spi_write() helper instead of open coding
  ...
2016-07-26 19:16:01 -07:00
Wei Yongjun ee4fc4013e gpiolib: remove duplicated include from gpiolib.c
Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-22 15:30:39 +02:00
Linus Walleij 78456d6ff8 Revert "gpio: convince line to become input in irq helper"
This reverts commit 7e7c059cb5.

I was wrong about trying to do this, as it breaks the
orthogonality between gpiochips and irqchips.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-06 14:40:08 +02:00
Lars-Peter Clausen da17f8a113 gpiolib: of_find_gpio(): Don't discard errors
Since commit dd34c37aa3 ("gpio: of: Allow -gpio suffix for property
names") when requesting a GPIO from the devicetree gpiolib looks for
properties with both the '-gpio' and the '-gpios' suffix. This was
implemented by first searching for the property with the '-gpios' suffix
and if that yields an error try the '-gpio' suffix. This approach has the
issue that any error returned when looking for the '-gpios' suffix is
silently discarded.

Commit 06fc3b70f1 ("gpio: of: Fix handling for deferred probe for -gpio
suffix") partially addressed the issue by treating the EPROBE_DEFER error
as a special condition. This fixed the case when the property is specified,
but the GPIO provider is not ready yet. But there are other cases in which
of_get_named_gpiod_flags() returns an error even though the property is
specified, e.g. if the specification is incorrect.

of_find_gpio() should only try to look for the property with the '-gpio'
suffix if no property with the '-gpios' suffix was found. If the property
was not found of_get_named_gpiod_flags() will return -ENOENT, so update the
condition to abort and propagate the error to the caller in all other
cases.

This is important for gpiod_get_optinal() and friends to behave correctly
in case the specifier contains errors. Without this patch they'll return
NULL if the property uses the '-gpios' suffix and the specifier contains
errors, which falsely indicates to the caller that no GPIO was specified.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-06 14:39:50 +02:00
Thierry Reding acc6e331b6 gpio: of: Allow overriding the device node
When registering a GPIO chip, drivers can override the device tree node
associated with the chip by setting the chip's ->of_node field. If set,
this field is supposed to take precedence over the ->parent->of_node
field, but the code doesn't actually do that.

Commit 762c2e46c0 ("gpio: of: remove of_gpiochip_and_xlate() and
struct gg_data") exposes this because it now no longer matches on the
GPIO chip's ->of_node field, but the GPIO device's ->of_node field that
is set using the procedure described above.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-06 14:39:50 +02:00
Linus Walleij d932cd4918 gpio: free handles in fringe cases
If we fail when copying the ioctl() struct to userspace we still
need to clean up the cruft otherwise left behind or it will stay
around until the issuing process terminates the file handle.

Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-04 16:54:36 +02:00
Johan Hovold 85b03b3033 Revert "gpiolib: Split GPIO flags parsing and GPIO configuration"
This reverts commit 923b93e451.

Make sure consumers do not overwrite gpio flags for pins that have
already been claimed.

While adding support for gpio drivers to refuse a request using
unsupported flags, the order of when the requested flag was checked and
the new flags were applied was reversed to that consumers could
overwrite flags for already requested gpios.

This not only affects device-tree setups where two drivers could request
the same gpio using conflicting configurations, but also allowed user
space to clear gpio flags for already claimed pins simply by attempting
to export them through the sysfs interface. By for example clearing the
FLAG_ACTIVE_LOW flag this way, user space could effectively change the
polarity of a signal.

Reverting this change obviously prevents gpio drivers from doing sanity
checks on the flags in their request callbacks. Fortunately only one
recently added driver (gpio-tps65218 in v4.6) appears to do this, and a
follow up patch could restore this functionality through a different
interface.

Cc: stable <stable@vger.kernel.org>	# 4.4
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-04 16:51:29 +02:00
Linus Walleij 7e7c059cb5 gpio: convince line to become input in irq helper
The generic IRQ helper library just checks if the IRQ line is
set as input before activating it for interrupts. As we
recently started to check things better with .get_dir() it
turns out that it's good to try to convince the line to become
an input before attempting to lock it as IRQ.

Reviewed-by: Björn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-23 11:06:58 +02:00
Ben Dooks 33265b17e0 gpiolib: make lineevent_irq_thread static
The lineevent_irq_thread is not exported, so make it static
to fix the following warning:

drivers/gpio/gpiolib.c:654:13: warning: symbol 'lineevent_irq_thread' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-18 11:04:56 +02:00
Linus Walleij e2f608be64 gpio: make the iterator point to last handle
When initializing the GPIO handles, we use the iterator (i)
to back off if something goes wrong. But since the iterator
is also used after we pass the loop, we must decrement by
one after exiting the loop so that we point at the last
element in the array.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Walter Harms <wharms@bfs.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-18 10:56:43 +02:00
Linus Walleij bfbbe44daf gpio: make library immune to error pointers
Most functions that take a GPIO descriptor in need to check the
descriptor for IS_ERR(). We do this mostly in the VALIDATE_DESC()
macro except for the gpiod_to_irq() function which needs special
handling.

Cc: stable@vger.kernel.org
Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-17 18:12:19 +02:00
Linus Walleij 79bb71bd1d gpio: make sure gpiod_to_irq() returns negative on NULL desc
commit 54d77198fd
("gpio: bail out silently on NULL descriptors")
doesn't work for gpiod_to_irq(): drivers assume that NULL
descriptors will give negative IRQ numbers in return.

It has been pointed out that returning 0 is NO_IRQ and that
drivers should be amended to treat this as an error, but that
is for the longer term: now let us repair the semantics.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-17 18:12:07 +02:00
Arnd Bergmann bc0207a546 gpiolib: avoid uninitialized data in gpio kfifo
gcc reports a theoretical case for returning uninitialized data in
the kfifo when a GPIO interrupt happens and neither
GPIOEVENT_REQUEST_RISING_EDGE nor GPIOEVENT_REQUEST_FALLING_EDGE
are set:

drivers/gpio/gpiolib.c: In function 'lineevent_irq_thread':
drivers/gpio/gpiolib.c:683:87: error: 'ge.id' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This case should not happen, but to be on the safe side, let's
return from the irq handler without adding data to the FIFO
to ensure we can never leak stack data to user space.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-16 12:00:25 +02:00
Linus Walleij 61f922db72 gpio: userspace ABI for reading GPIO line events
This adds an ABI for listening to events on GPIO lines.
The mechanism returns an anonymous file handle to a request
to listen to a specific offset on a specific gpiochip.
To fetch the stream of events from the file handle, userspace
simply reads an event.

- Events can be requested with the same flags as ordinary
  handles, i.e. open drain or open source. An ioctl() call
  GPIO_GET_LINEEVENT_IOCTL is issued indicating the desired
  line.

- Events can be requested for falling edge events, rising
  edge events, or both.

- All events are timestamped using the kernel real time
  nanosecond timestamp (the same as is used by IIO).

- The supplied consumer label will appear in "lsgpio"
  listings of the lines, and in /proc/interrupts as the
  mechanism will request an interrupt from the gpio chip.

- Events are not supported on gpiochips that do not serve
  interrupts (no legal .to_irq() call). The event interrupt
  is threaded to avoid any realtime problems.

- It is possible to also directly read the current value
  of the registered GPIO line by issuing the same
  GPIOHANDLE_GET_LINE_VALUES_IOCTL as used by the
  line handles. Setting the value is not supported: we
  do not listen to events on output lines.

This ABI is strongly influenced by Industrial I/O and surpasses
the old sysfs ABI by providing proper precision timestamps,
making it possible to set flags like open drain, and put
consumer names on the GPIO lines.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-15 09:29:17 +02:00
Linus Walleij d7c51b47ac gpio: userspace ABI for reading/writing GPIO lines
This adds a userspace ABI for reading and writing GPIO lines.
The mechanism returns an anonymous file handle to a request
to read/write n offsets from a gpiochip. This file handle
in turn accepts two ioctl()s: one that reads and one that
writes values to the selected lines.

- Handles can be requested as input/output, active low,
  open drain, open source, however when you issue a request
  for n lines with GPIO_GET_LINEHANDLE_IOCTL, they must all
  have the same flags, i.e. all inputs or all outputs, all
  open drain etc. If a granular control of the flags for
  each line is desired, they need to be requested
  individually, not in a batch.

- The GPIOHANDLE_GET_LINE_VALUES_IOCTL read ioctl() can be
  issued also to output lines to verify that the hardware
  is in the expected state.

- It reads and writes up to GPIOHANDLES_MAX lines at once,
  utilizing the .set_multiple() call in the driver if
  possible, making the call efficient if several lines
  can be written with a single register update.

The limitation of GPIOHANDLES_MAX to 64 lines is done under
the assumption that we may expect hardware that can issue a
transaction updating 64 bits at an instant but unlikely
anything larger than that.

ChangeLog v2->v3:
- Use gpiod_get_value_cansleep() so we support also slowpath
  GPIO drivers.
- Fix up the UAPI docs kerneldoc.
- Allocate the anonymous fd last, so that the release
  function don't get called until that point of something
  fails. After this point, skip the errorpath.
ChangeLog v1->v2:
- Handle ioctl_compat() properly based on a similar patch
  to the other ioctl() handling code.
- Use _IOWR() as we pass pointers both in and out of the
  ioctl()
- Use kmalloc() and kfree() for the linehandled, do not
  try to be fancy with devm_* it doesn't work the way I
  thought.
- Fix const-correctness on the linehandle name field.

Acked-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-15 09:28:50 +02:00
Ricardo Ribalda Delgado f4833b8cc7 gpiolib: Fix unaligned used of reference counters
gpiolib relies on the reference counters to clean up the gpio_device
structure.

Although the number of get/put is properly aligned on gpiolib.c
itself, it does not take into consideration how the referece counters
are affected by other external functions such as cdev_add and device_add.

Because of this, after the last call to put_device, the reference counter
has a value of +3, therefore never calling gpiodevice_release.

Due to the fact that some of the device  has already been cleaned on
gpiochip_remove, the library will end up OOPsing the kernel (e.g. a call
to of_gpiochip_find_and_xlate).

Cc: stable@vger.kernel.org
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08 10:40:29 +02:00
Ricardo Ribalda Delgado 11f33a6d15 gpiolib: Fix NULL pointer deference
Under some circumstances, a gpiochip might be half cleaned from the
gpio_device list.

This patch makes sure that the chip pointer is still valid, before
calling the match function.

[  104.088296] BUG: unable to handle kernel NULL pointer dereference at
0000000000000090
[  104.089772] IP: [<ffffffff813d2045>] of_gpiochip_find_and_xlate+0x15/0x80
[  104.128273] Call Trace:
[  104.129802]  [<ffffffff813d2030>] ? of_parse_own_gpio+0x1f0/0x1f0
[  104.131353]  [<ffffffff813cd910>] gpiochip_find+0x60/0x90
[  104.132868]  [<ffffffff813d21ba>] of_get_named_gpiod_flags+0x9a/0x120
...
[  104.141586]  [<ffffffff8163d12b>] gpio_led_probe+0x11b/0x360

Cc: stable@vger.kernel.org
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08 10:38:03 +02:00
Linus Walleij 545ebd9a9b gpio: drop lock before reading GPIO direction
When adding the gpiochip, the GPIO HW drivers' callback get_direction()
could get called in atomic context. Some of the GPIO HW drivers may
sleep when accessing the register.

Move the lock before initializing the descriptors.

Reported-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 17:11:59 +02:00
Linus Walleij 54d77198fd gpio: bail out silently on NULL descriptors
In fdeb8e1547
("gpio: reflect base and ngpio into gpio_device")
assumed that GPIO descriptors are either valid or error
pointers, but gpiod_get_[index_]optional() actually return
NULL descriptors and then all subsequent calls should just
bail out.

Cc: stable@vger.kernel.org
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Fixes: fdeb8e1547 ("gpio: reflect base and ngpio into gpio_device")
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 16:56:41 +02:00
Linus Walleij 8b92e17efe gpio: handle compatible ioctl() pointers
If we're using the compatible ioctl() we need to handle the
argument pointer in a special way or there will be trouble.

Fixes: 3c702e9987 ("gpio: add a userspace chardev ABI for GPIOs")
Reported-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 16:00:31 +02:00
Linus Walleij 9c10280d85 gpio: flush direction status in gpiochip_lock_as_irq()
As irqchip and gpiochip functions are orthogonal, the IRQ
set-up or something else can have changed the direction of
the GPIO line from what the GPIO descriptor knows when we
get into gpiochip_lock_as_irq(). Make sure to re-read the
direction setting if we have the .get_direction() callback
enabled for the chip.

Else we get problems like this:

iio iio:device2: interrupts on the rising edge
gpio gpiochip2: (8012e080.gpio): gpiochip_lock_as_irq:
  tried to flag a GPIO set as output for IRQ
gpio gpiochip2: (8012e080.gpio): unable to lock HW IRQ 0 for IRQ
genirq: Failed to request resources for l3g4200d-trigger
  (irq 111) on irqchip nmk1-32-63
iio iio:device2: failed to request trigger IRQ.
st-gyro-i2c: probe of 2-0068 failed with error -22

Fixes: 72d3200061 ("gpio: set up initial state from .get_direction()")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:42:03 +02:00
Linus Torvalds 1eccc6e152 This is the bulk of GPIO changes for kernel cycle v4.7:
Core infrastructural changes:
 
 - Support for natively single-ended GPIO driver stages. This
   means that if the hardware has registers to configure open
   drain or open source configuration, we use that rather than
   (as we did before) try to emulate it by switching the line
   to an input to get high impedance. This is also documented
   throughly in Documentation/gpio/driver.txt for those of you
   who did not understand one word of what I just wrote.
 
 - Start to do away with the unnecessarily complex and
   unitelligible ARCH_REQUIRE_GPIOLIB and
   ARCH_WANT_OPTIONAL_GPIOLIB, another evolutional artifact from
   the time when the GPIO subsystem was unmaintained. Archs can
   now just select GPIOLIB and be done with it, cleanups to
   arches will trickle in for the next kernel. Some minor archs
   ACKed the changes immediately so these are included in this
   pull request.
 
 - Advancing the use of the data pointer inside the GPIO device
   for storing driver data by switching the PowerPC, Super-H
   Unicore and a few other subarches or subsystem drivers in
   ALSA SoC, Input, serial, SSB, staging etc to use it.
 
 - The initialization now reads the input/output state of the
   GPIO lines, so that each GPIO descriptor knows - if this
   callback is implemented - whether the line is input or
   output. This also reflects nicely in userspace "lsgpio".
 
 - It is now possible to name GPIO producer names, line names,
   from the device tree. (Platform data has been supported for
   a while.) I bet we will get a similar mechanism for ACPI
   one of those days. This makes is possible to get sensible
   producer names for e.g. GPIO rails in "lsgpio" in userspace.
 
 New drivers:
 
 - New driver for the Loongson1.
 
 - The XLP driver now supports Broadcom Vulcan ARM64.
 
 - The IT87 driver now supports IT8620 and IT8628.
 
 - The PCA953X driver now supports Galileo Gen2.
 
 Driver improvements:
 
 - MCP23S08 was switched to use the gpiolib irqchip helpers and
   now also suppors level-triggered interrupts.
 
 - 74x164 and RCAR now supports the .set_multiple() callback
 
 - AMDPT was converted to use generic GPIO.
 
 - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
   support the new single ended callback for open drain
   and in some cases open source.
 
 - Implement the .get_direction() callback for a few more drivers
   like PL061, Xgene.
 
 Cleanups:
 
 - Paul Gortmaker combed through the drivers and de-modularized
   those who are not really modules.
 
 - Move the GPIO poweroff DT bindings to the power subdir where
   they belong.
 
 - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
   point. That's what it is handling, nothing more, nothing less.
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Merge tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel cycle v4.7:

  Core infrastructural changes:

   - Support for natively single-ended GPIO driver stages.

     This means that if the hardware has registers to configure open
     drain or open source configuration, we use that rather than (as we
     did before) try to emulate it by switching the line to an input to
     get high impedance.

     This is also documented throughly in Documentation/gpio/driver.txt
     for those of you who did not understand one word of what I just
     wrote.

   - Start to do away with the unnecessarily complex and unitelligible
     ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB, another
     evolutional artifact from the time when the GPIO subsystem was
     unmaintained.

     Archs can now just select GPIOLIB and be done with it, cleanups to
     arches will trickle in for the next kernel.  Some minor archs ACKed
     the changes immediately so these are included in this pull request.

   - Advancing the use of the data pointer inside the GPIO device for
     storing driver data by switching the PowerPC, Super-H Unicore and
     a few other subarches or subsystem drivers in ALSA SoC, Input,
     serial, SSB, staging etc to use it.

   - The initialization now reads the input/output state of the GPIO
     lines, so that each GPIO descriptor knows - if this callback is
     implemented - whether the line is input or output.  This also
     reflects nicely in userspace "lsgpio".

   - It is now possible to name GPIO producer names, line names, from
     the device tree.  (Platform data has been supported for a while).
     I bet we will get a similar mechanism for ACPI one of those days.
     This makes is possible to get sensible producer names for e.g.
     GPIO rails in "lsgpio" in userspace.

  New drivers:

   - New driver for the Loongson1.

   - The XLP driver now supports Broadcom Vulcan ARM64.

   - The IT87 driver now supports IT8620 and IT8628.

   - The PCA953X driver now supports Galileo Gen2.

  Driver improvements:

   - MCP23S08 was switched to use the gpiolib irqchip helpers and now
     also suppors level-triggered interrupts.

   - 74x164 and RCAR now supports the .set_multiple() callback

   - AMDPT was converted to use generic GPIO.

   - TC3589x, TPS65218, SX150X, F7188X, MENZ127, VX855, WM831X, WM8994
     support the new single ended callback for open drain and in some
     cases open source.

   - Implement the .get_direction() callback for a few more drivers like
     PL061, Xgene.

  Cleanups:

   - Paul Gortmaker combed through the drivers and de-modularized those
     who are not really modules.

   - Move the GPIO poweroff DT bindings to the power subdir where they
     belong.

   - Rename gpio-generic.c to gpio-mmio.c, which is much more to the
     point.  That's what it is handling, nothing more, nothing less"

* tag 'gpio-v4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (126 commits)
  MIPS: do away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB
  gpio: zevio: make it explicitly non-modular
  gpio: timberdale: make it explicitly non-modular
  gpio: stmpe: make it explicitly non-modular
  gpio: sodaville: make it explicitly non-modular
  pinctrl: sh-pfc: Let gpio_chip.to_irq() return zero on error
  gpio: dwapb: Add ACPI device ID for DWAPB GPIO controller on X-Gene platforms
  gpio: dt-bindings: add wd,mbl-gpio bindings
  gpio: of: make it possible to name GPIO lines
  gpio: make gpiod_to_irq() return negative for NO_IRQ
  gpio: xgene: implement .get_direction()
  gpio: xgene: Enable ACPI support for X-Gene GFC GPIO driver
  gpio: tegra: Implement gpio_get_direction callback
  gpio: set up initial state from .get_direction()
  gpio: rename gpio-generic.c into gpio-mmio.c
  gpio: generic: fix GPIO_GENERIC_PLATFORM is set to module case
  gpio: dwapb: add gpio-signaled acpi event support
  gpio: dwapb: convert device node to fwnode
  gpio: dwapb: remove name from dwapb_port_property
  gpio/qoriq: select IRQ_DOMAIN
  ...
2016-05-17 17:39:42 -07:00
Linus Walleij 4c37ce8608 gpio: make gpiod_to_irq() return negative for NO_IRQ
If a translation returns zero, that means NO_IRQ, so we
should return an error since the function is documented to
return a negative code on error.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-02 13:34:21 +02:00
Linus Walleij 72d3200061 gpio: set up initial state from .get_direction()
If the gpiochip supports the .get_direction() callback, then
the initial state of the descriptor flags should be set up
as output accordingly. Also put in comments explaining what is
going on.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-30 13:01:51 +02:00
Linus Walleij 44c7288f79 gpio: move gpiod_set_array_value_priv()
This renames gpiod_set_array_value_priv() to
gpiod_set_array_value_complex() and moves it to the gpiolib.h
private header file so we can reuse it in the subsystem.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-26 10:51:36 +02:00
Laxman Dewangan c31a571d43 gpio: gpiolib: Print error number if gpio hog failed
Print the error number of GPIO hog failed during its configurations.
This helps in identifying the failure without instrumenting the code.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-14 14:50:49 +02:00
Guenter Roeck 159f3cd92f gpiolib: Defer gpio device setup until after gpiolib initialization
Since commit ff2b135922 ("gpio: make the gpiochip a real device"),
attempts to add a gpio chip prior to gpiolib initialization cause
the system to crash. This happens because gpio_bus_type has not been
registered yet. Defer creating gpio devices until after gpiolib has
been initialized to fix the problem.

Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Fixes: ff2b135922 ("gpio: make the gpiochip a real device")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08 10:10:09 +02:00
Guenter Roeck 476e2fc5cd gpiolib: Do not use devm functions when registering gpio chip
It is possible that a gpio chip is registered before the gpiolib
initialization code has run. This means we can not use devm_ functions
to allocate memory at that time. Do it the old fashioned way.

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08 10:10:09 +02:00
Dmitry Torokhov 25487533ff gpio / ACPI: ignore GpioInt() GPIOs when requesting GPIO_OUT_*
When firmware does not use _DSD properties that allow properly name GPIO
resources, the kernel falls back on parsing _CRS resources, and will
return entries described as GpioInt() as general purpose GPIOs even
though they are meant to be used simply as interrupt sources for the
device:

Device (ETSA)
{
	Name (_HID, "ELAN0001")
	...

	Method(_CRS, 0x0, NotSerialized)
	{
		Name(BUF0,ResourceTemplate ()
		{
			I2CSerialBus(
				0x10,                     /* SlaveAddress */
				ControllerInitiated,      /* SlaveMode */
				400000,                   /* ConnectionSpeed */
				AddressingMode7Bit,       /* AddressingMode */
				"\\_SB.I2C1",             /* ResourceSource */
			)
			GpioInt (Edge, ActiveLow, ExclusiveAndWake, PullNone,,
				 "\\_SB.GPSW") { BOARD_TOUCH_GPIO_INDEX }
		} )
		Return (BUF0)
	}
...
}

This gives troubles with drivers such as Elan Touchscreen driver
(elants_i2c) that uses devm_gpiod_get to look up "reset" GPIO line and
decide whether the driver is responsible for powering up and resetting
the device, or firmware is. In the above case the lookup succeeds, we
map GPIO as output and later fail to request client->irq interrupt that
is mapped to the same GPIO.

Let's ignore resources described as GpioInt() while parsing _CRS when
requesting output GPIOs (but allow them when requesting GPIOD_ASIS or
GPIOD_IN as some drivers, such as i2c-hid, do request GPIO as input and
then map it to interrupt with gpiod_to_irq).

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-08 10:10:08 +02:00
Linus Walleij c663e5f567 gpio: support native single-ended hardware drivers
Some GPIO controllers has a special hardware bit we can flip
to support open drain / source. This means that on these hardwares
we do not need to emulate OD/OS by setting the line to input
instead of actively driving it high/low. Add an optional vtable
callback to the driver set_single_ended() so that driver can
implement this in hardware if they have it.

We may need a pinctrl_gpio_set_config() call at some point to
propagate this down to a backing pin control device on systems
with split GPIO/pin control.

Reported-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-04-05 16:57:15 +02:00
Geert Uytterhoeven 1cfab8f8b3 gpiolib: Fix comment referring to gpio_*() in gpiod_*()
Fixes: 79a9becda8 ("gpiolib: export descriptor-based GPIO interface")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-16 13:11:11 +01:00
Linus Walleij 016bf20829 Merge branch 'devm-gpiochip-add-data' into devel 2016-03-08 14:41:41 +07:00
Bamvor Jian Zhang a961f9b472 gpiolib: rewrite gpiodev_add_to_list
The original code of gpiodev_add_to_list is not very clear which
lead to bugs or compiling warning, reference the following patches:
Bugs:
1.  Commit ef7c755303 ("gpiolib: improve overlap check of range of
    gpio").
2.  Commit 96098df125 ("gpiolib: fix chip order in gpio list")

Warning:
1.  Commit e28ecca6ea ("gpio: fix warning about iterator").
of gpio").

There is a off-list discussion about how to improve it consequently.
This commit try to follow this by rewriting the whole functions.

Tested pass with my gpio mockup driver and test scripts[1].

[1] http://www.spinics.net/lists/linux-gpio/msg09598.html

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-07 12:02:46 +07:00
Linus Walleij 214338e372 gpio: present the consumer of a line to userspace
I named the field representing the current user of GPIO line as
"label" but this is too vague and ambiguous. Before anyone gets
confused, rename it to "consumer" and indicate clearly in the
documentation that this is a string set by the user of the line.

Also clean up leftovers in the documentation.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-25 21:07:23 +01:00
Laxman Dewangan 0cf3292cde gpio: Add devm_ apis for gpiochip_add_data and gpiochip_remove
Add device managed APIs devm_gpiochip_add_data() and
devm_gpiochip_remove() for the APIs gpiochip_add_data()
and gpiochip_remove().

This helps in reducing code in error path and sometimes
removal of .remove callback for driver unbind.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
2016-02-23 19:40:33 +05:30
Linus Walleij 9d8cc89c31 gpio: fixup line flags for userspace ABI
This fixes the wrongly indicated lines in the userspace
ABI: test for the right BITS, do not treat bit numbers as
bitmasks.

Reported-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-22 13:44:53 +01:00
Bamvor Jian Zhang bd203bd56d gpiolib: fix crash when gpiochip removed
Commit cb464a88e1ed ("gpio: make the gpiochip a real device") call
gpiochip_sysfs_unregister after the gpiochip is empty. It lead to the
following crash:

[  163.503994] Unable to handle kernel NULL pointer dereference at virtual address 0000007c
[...]
[  163.525394] [<ffffffc0003719a0>] gpiochip_sysfs_unregister+0x44/0xa4
[  163.525611] [<ffffffc00036f6a0>] gpiochip_remove+0x24/0x154
[  163.525861] [<ffffffbffc00f0a4>] mockup_gpio_remove+0x38/0x64 [gpio_mockup]
[  163.526101] [<ffffffc00042b4b4>] platform_drv_remove+0x24/0x64
[  163.526313] [<ffffffc000429cc8>] __device_release_driver+0x7c/0xfc
[  163.526525] [<ffffffc000429e54>] driver_detach+0xbc/0xc0
[  163.526700] [<ffffffc000429014>] bus_remove_driver+0x58/0xac
[  163.526883] [<ffffffc00042a4cc>] driver_unregister+0x2c/0x4c
[  163.527067] [<ffffffc00042b5c0>] platform_driver_unregister+0x10/0x18
[  163.527284] [<ffffffbffc00f340>] mock_device_exit+0x10/0x38 [gpio_mockup]
[  163.527593] [<ffffffc00011cefc>] SyS_delete_module+0x1b8/0x1fc
[  163.527799] [<ffffffc000085d8c>] __sys_trace_return+0x0/0x4
[  163.528049] Code: 940d74b4 f9019abf aa1303e0 940d7439 (7940fac0)
[  163.536273] ---[ end trace 3d1329be504af609 ]---

This patch fix this by changing the code back.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-20 12:48:34 +01:00
Linus Walleij 521a2ad6f8 gpio: add userspace ABI for GPIO line information
This adds a GPIO line ABI for getting name, label and a few select
flags from the kernel.

This hides the kernel internals and only tells userspace what it
may need to know: the different in-kernel consumers are masked
behind the flag "kernel" and that is all userspace needs to know.

However electric characteristics like active low, open drain etc
are reflected to userspace, as this is important information.

We provide information on all lines on all chips, later on we will
likely add a flag for the chardev consumer so we can filter and
display only the lines userspace actually uses in e.g. lsgpio,
but then we first need an ABI for userspace to grab and use
(get/set/select direction) a GPIO line.

Sample output from "lsgpio" on ux500:

GPIO chip: gpiochip7, "8011e000.gpio", 32 GPIO lines
        line 0: unnamed unlabeled
        line 1: unnamed unlabeled
(...)
        line 25: unnamed "SFH7741 Proximity Sensor" [kernel output open-drain]
        line 26: unnamed unlabeled
(...)

Tested-by: Michael Welling <mwelling@ieee.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:48:46 +01:00
Linus Walleij df4878e969 gpio: store reflect the label to userspace
The gpio_chip label is useful for userspace to understand what
kind of GPIO chip it is dealing with. Let's store a copy of this
label in the gpio_device, add it to the struct passed to userspace
for GPIO_GET_CHIPINFO_IOCTL and modify lsgpio to show it.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 09:48:41 +01:00
Josh Cartwright 969f07b445 gpio: use kzalloc to allocate gpio_device
The use of kmalloc() to allocate the gpio_device leaves the contained struct
device object in an unknown state.  Calling dev_set_name() on a struct device
of unknown state can trigger the free() of an invalid pointer, as seen in the
following backtrace (collected by Tony Lindgren):

  kfree
  kobject_set_name_vargs
  dev_set_name
  gpiochip_add_data
  omap_gpio_probe
  platform_drv_probe
  ...

Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Michael Welling <mwelling@ieee.org>
Reported-by: Tony Lindgren <tony@atomide.com>
Tested-by: Michael Welling <mwelling@ieee.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Josh Cartwright <joshc@ni.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-18 20:45:25 +01:00
Linus Walleij 143b65d677 gpio: create an API to detect open drain/source on lines
My left hand merges code to privatize the descriptor handling
while my right hand merges drivers that poke around and
disrespect with the same gpiolib internals.

So let's expose the proper APIs for drivers to ask the gpiolib
core if a line is marked as open drain or open source and
get some order around things so this driver compiles again.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 15:41:42 +01:00
Linus Walleij 43c54ecade gpio: move the subdriver data pointer into gpio_device
We move to manage this pointer under gpiolib control rather than
leave it in the subdevice's gpio_chip. We can not NULL it after
gpiochip_remove so at to keep things tight.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16 00:20:02 +01:00