When locking a GPIO line as IRQ, we go to lengths to
double-check that the line is really set as input before
marking it as used for IRQ. This is not good on GPIO chips
that can sleep, because this function is called in IRQ-safe
context. Just skip this if it can't be checked quickly.
Currently this happens on sleeping expanders such as STMPE
or TC3589x:
BUG: scheduling while atomic: swapper/1/0x00000002
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc1+ #38
Hardware name: Nomadik STn8815
[<c000f2e0>] (unwind_backtrace) from [<c000d244>] (show_stack+0x10/0x14)
[<c000d244>] (show_stack) from [<c0037b78>] (__schedule_bug+0x54/0x80)
[<c0037b78>] (__schedule_bug) from [<c042df14>] (__schedule+0x3a0/0x460)
[<c042df14>] (__schedule) from [<c042e028>] (schedule+0x54/0xb8)
(...)
This patch fixes that problem and relies on the direction
read from the chip when it was added.
Cc: stable@vger.kernel.org
Fixes: 9c10280d85 ("gpio: flush direction status in gpiochip_lock_as_irq()")
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
When allocating a new line handle or event a file is allocated that it is
associated to. The file is attached to a file descriptor of the current
process and the file descriptor is returned to userspace using
copy_to_user(). If this copy operation fails the line handle or event
allocation is aborted, all acquired resources are freed and an error is
returned.
But the file struct is not freed and left attached to the userspace
application and even though the file descriptor number was not copied it is
trivial to guess. If a userspace application performs a IOCTL on such a
left over file descriptor it will trigger a use-after-free and if the file
descriptor is closed (latest when the application exits) a double-free is
triggered.
anon_inode_getfd() performs 3 tasks, allocate a file struct, allocate a
file descriptor for the current process and install the file struct in the
file descriptor. As soon as the file struct is installed in the file
descriptor it is accessible by userspace (even if the IOCTL itself hasn't
completed yet), this means uninstalling the fd on the error path is not an
option, since userspace might already got a reference to the file.
Instead anon_inode_getfd() needs to be broken into its individual steps.
The allocation of the file struct and file descriptor is done first, then
the copy_to_user() is executed and only if it succeeds the file is
installed.
Since the file struct is reference counted it can not be just freed, but
its reference needs to be dropped, which will also call the release()
callback, which will free the state attached to the file. So in this case
the normal error cleanup path should not be taken.
Cc: stable@vger.kernel.org
Fixes: d932cd4918 ("gpio: free handles in fringe cases")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIO_GET_LINEEVENT_IOCTL currently ignores unknown or undefined
linehandle and lineevent flags. From a backwards and forwards compatibility
viewpoint it is highly desirable to reject unknown flags though.
On one hand an application that is using newer flags and is running on
an older kernel has no way to detect if the new flags were handled
correctly if they are silently discarded.
On the other hand an application that (accidentally) passes undefined flags
will run fine on an older kernel, but may break on a newer kernel when
these flags get defined.
Ensure that requests that have undefined flags set are rejected with an
error, rather than silently discarding the undefined flags.
Cc: stable@vger.kernel.org
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIO_GET_LINEHANDLE_IOCTL currently ignores unknown or undefined
linehandle flags. From a backwards and forwards compatibility viewpoint it
is highly desirable to reject unknown flags though.
On one hand an application that is using newer flags and is running on
an older kernel has no way to detect if the new flags were handled
correctly if they are silently discarded.
On the other hand an application that (accidentally) passes undefined flags
will run fine on an older kernel, but may break on a newer kernel when
these flags get defined.
Ensure that requests that have undefined flags set are rejected with an
error, rather than silently discarding the undefined flags.
Cc: stable@vger.kernel.org
Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIOHANDLE_GET_LINE_VALUES_IOCTL handler allocates a gpiohandle_data
struct on the stack and then passes it to copy_to_user(). But depending on
the number of requested line handles the struct is only partially
initialized.
This exposes the previous, potentially sensitive, stack content to the
issuing userspace application. To avoid this make sure that the struct is
fully initialized.
Cc: stable@vger.kernel.org
Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The line offset that is used as an index into the descs array is provided
by userspace and might go beyond the bounds of the array. If that happens
undefined behavior will occur.
Make sure that the offset is within the bounds of the desc array and reject
any requests that specify a value outside of it.
Cc: stable@vger.kernel.org
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIOHANDLE_GET_LINE_VALUES_IOCTL handler allocates a gpiohandle_data
struct on the stack and then passes it to copy_to_user(). But only the
first element of the values array in the struct is set, which leaves the
struct partially initialized.
This exposes the previous, potentially sensitive, stack content to the
issuing userspace application. To avoid this make sure that the struct is
fully initialized.
Cc: stable@vger.kernel.org
Fixes: 61f922db72 ("gpio: userspace ABI for reading GPIO line events")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The line offset that is used as an index into the descs array is provided
by userspace and might go beyond the bounds of the array. If that happens
undefined behavior will occur.
Make sure that the offset is within the bounds of the desc array and reject
any requests that specify a value outside of it.
Cc: stable@vger.kernel.org
Fixes: d7c51b47ac ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIO_GET_CHIPINFO_IOCTL handler allocates a gpiochip_info struct on the
stack and then passes it to copy_to_user(). But depending on the length of
the GPIO chip name and label the struct is only partially initialized.
This exposes the previous, potentially sensitive, stack content to the
issuing userspace application. To avoid this make sure that the struct is
fully initialized.
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>
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>
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>
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>
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>
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>
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>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
