Since IRQ chip helpers were introduced drivers lose ability to
register separate lockdep classes for each registered GPIO IRQ
chip and the gpiolib now is using shared lockdep class for
all GPIO IRQ chips (gpiochip_irq_lock_class).
As result, lockdep will produce warning when there are min two
stacked GPIO chips and all of them are interrupt controllers.
HW configuration which generates lockdep warning (TI dra7-evm):
[SOC GPIO bankA.gpioX]
<- irq - [pcf875x.gpioY]
<- irq - DevZ.enable_irq_wake(pcf_gpioY_irq);
The issue was reported in [1] and discussed [2].
=============================================
[ INFO: possible recursive locking detected ]
4.2.0-rc6-00013-g5d050ed-dirty #55 Not tainted
---------------------------------------------
sh/63 is trying to acquire lock:
(class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94
but task is already holding lock:
(class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(class);
lock(class);
*** DEADLOCK ***
May be due to missing lock nesting notation
7 locks held by sh/63:
#0: (sb_writers#4){.+.+.+}, at: [<c016bbb8>] vfs_write+0x13c/0x164
#1: (&of->mutex){+.+.+.}, at: [<c01debf4>] kernfs_fop_write+0x4c/0x1a0
#2: (s_active#36){.+.+.+}, at: [<c01debfc>] kernfs_fop_write+0x54/0x1a0
#3: (pm_mutex){+.+.+.}, at: [<c009758c>] pm_suspend+0xec/0x4c4
#4: (&dev->mutex){......}, at: [<c03f77f8>] __device_suspend+0xd4/0x398
#5: (&gpio->lock){+.+.+.}, at: [<c009b940>] __irq_get_desc_lock+0x74/0x94
#6: (class){......}, at: [<c009b91c>] __irq_get_desc_lock+0x50/0x94
stack backtrace:
CPU: 0 PID: 63 Comm: sh Not tainted 4.2.0-rc6-00013-g5d050ed-dirty #55
Hardware name: Generic DRA74X (Flattened Device Tree)
[<c0016e24>] (unwind_backtrace) from [<c0013338>] (show_stack+0x10/0x14)
[<c0013338>] (show_stack) from [<c05f6b24>] (dump_stack+0x84/0x9c)
[<c05f6b24>] (dump_stack) from [<c00903f4>] (__lock_acquire+0x19c0/0x1e20)
[<c00903f4>] (__lock_acquire) from [<c0091098>] (lock_acquire+0xa8/0x128)
[<c0091098>] (lock_acquire) from [<c05fd61c>] (_raw_spin_lock_irqsave+0x38/0x4c)
[<c05fd61c>] (_raw_spin_lock_irqsave) from [<c009b91c>] (__irq_get_desc_lock+0x50/0x94)
[<c009b91c>] (__irq_get_desc_lock) from [<c009c4f4>] (irq_set_irq_wake+0x20/0xfc)
[<c009c4f4>] (irq_set_irq_wake) from [<c0393ac4>] (pcf857x_irq_set_wake+0x24/0x54)
[<c0393ac4>] (pcf857x_irq_set_wake) from [<c009c560>] (irq_set_irq_wake+0x8c/0xfc)
[<c009c560>] (irq_set_irq_wake) from [<c04a02ac>] (gpio_keys_suspend+0x70/0xd4)
[<c04a02ac>] (gpio_keys_suspend) from [<c03f6a00>] (dpm_run_callback+0x50/0x124)
[<c03f6a00>] (dpm_run_callback) from [<c03f7830>] (__device_suspend+0x10c/0x398)
[<c03f7830>] (__device_suspend) from [<c03f90f0>] (dpm_suspend+0x134/0x2f4)
[<c03f90f0>] (dpm_suspend) from [<c0096e20>] (suspend_devices_and_enter+0xa8/0x728)
[<c0096e20>] (suspend_devices_and_enter) from [<c00977cc>] (pm_suspend+0x32c/0x4c4)
[<c00977cc>] (pm_suspend) from [<c0096060>] (state_store+0x64/0xb8)
[<c0096060>] (state_store) from [<c01dec64>] (kernfs_fop_write+0xbc/0x1a0)
[<c01dec64>] (kernfs_fop_write) from [<c016b280>] (__vfs_write+0x20/0xd8)
[<c016b280>] (__vfs_write) from [<c016bb0c>] (vfs_write+0x90/0x164)
[<c016bb0c>] (vfs_write) from [<c016c330>] (SyS_write+0x44/0x9c)
[<c016c330>] (SyS_write) from [<c000f500>] (ret_fast_syscall+0x0/0x54)
Lets fix it by using separate lockdep class for each registered GPIO
IRQ Chip. This is done by wrapping gpiochip_irqchip_add call into macros.
The implementation of this patch inspired by solution done by Nicolas
Boichat for regmap [3]
[1] http://www.spinics.net/lists/linux-gpio/msg05844.html
[2] http://www.spinics.net/lists/linux-gpio/msg06021.html
[3] http://www.spinics.net/lists/arm-kernel/msg429834.html
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roger Quadros <rogerq@ti.com>
Reported-by: Roger Quadros <rogerq@ti.com>
Tested-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Passing a fixed base in struct gpio_chip is done for legacy
systems that cannot handle dynamic allocation. Discourage this
behaviour in the kerneldoc.
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Clean up chained handler and handler data if they were set by
gpiochip_set_chained_irqchip().
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.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>
These functions do not belong in <asm-generic/gpio.h> since the
split into separate GPIO headers under <linux/gpio/*>. Move them
to <linux/gpio/driver.h> as is apropriate.
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Introduce new functions gpiod_set_array & gpiod_set_raw_array to the consumer
interface which allow setting multiple outputs with just one function call.
Also add an optional set_multiple function to the driver interface. Without an
implementation of that function in the chip driver outputs are set
sequentially.
Implementing the set_multiple function in a chip driver allows for:
- Improved performance for certain use cases. The original motivation for this
was the task of configuring an FPGA. In that specific case, where 9 GPIO
lines have to be set many times, configuration time goes down from 48 s to
20 s when using the new function.
- Simultaneous glitch-free setting of multiple pins on any kind of parallel
bus attached to GPIOs provided they all reside on the same chip and bank.
Limitations:
Performance is only improved for normal high-low outputs. Open drain and
open source outputs are always set separately from each other. Those kinds
of outputs could probably be accelerated in a similar way if we could
forgo the error checking when setting GPIO directions.
Change log:
v6: - rebase on current linux-gpio devel branch
v5: - check can_sleep property per chip
- remove superfluous checks
- supplement documentation
v4: - add gpiod_set_array function for setting logical values
- change interface of the set_multiple driver function to use
unsigned long as type for the bit fields
- use generic bitops (which also use unsigned long for bit fields)
- do not use ARCH_NR_GPIOS any more
v3: - add documentation
- change commit message
v2: - use descriptor interface
- allow arbitrary groups of GPIOs spanning multiple chips
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This function actually operates on a gpio_chip, so its prefix should
reflect that fact for consistency with other functions defined in
gpio/driver.h.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
cycle:
- Increase the default ARCH_NR_GPIO from 256 to 512. This
was done to avoid having a custom <asm/gpio.h> header for
the x86 architecture - GPIO is custom and complicated
enough as it is already! We want to move to a radix to
store the descriptors going forward, and finally get rid
of this fixed array size altogether.
- Endgame patching of the gpio_remove() semantics initiated
by Abdoulaye Berthe. It is not accepted by the system that
the removal of a GPIO chip fails during e.g. reboot or
shutdown, and therefore the return value has now painfully
been refactored away. For special cases like GPIO expanders
on a hot-pluggable bus like USB, we may later add some
gpiochip_try_remove() call, but for the cases we have now,
return values are moot.
- Some incremental refactoring of the gpiolib core and ACPI
GPIO library for more descriptor usage.
- Refactor the chained IRQ handler set-up method to handle
also threaded, nested interrupts and set up the parent IRQ
correctly. Switch STMPE and TC3589x drivers to use this
registration method.
- Add a .irq_not_threaded flag to the struct gpio_chip, so
that also GPIO expanders that block but are still not
using threaded IRQ handlers.
- New drivers for the ARM64 X-Gene SoC GPIO controller.
- The syscon GPIO driver has been improved to handle the
"DSP GPIO" found on the TI Keystone 2 SoC:s.
- ADNP driver switched to use gpiolib irqchip helpers.
- Refactor the DWAPB driver to support being instantiated
from and MFD cell (platform device).
- Incremental feature improvement in the Zynq, MCP23S08,
DWAPB, OMAP, Xilinx and Crystalcove drivers.
- Various minor fixes.
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Merge tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO changes from Linus Walleij:
"This is the bulk of GPIO changes for the v3.18 development cycle:
- Increase the default ARCH_NR_GPIO from 256 to 512. This was done
to avoid having a custom <asm/gpio.h> header for the x86
architecture - GPIO is custom and complicated enough as it is
already! We want to move to a radix to store the descriptors going
forward, and finally get rid of this fixed array size altogether.
- Endgame patching of the gpio_remove() semantics initiated by
Abdoulaye Berthe. It is not accepted by the system that the
removal of a GPIO chip fails during eg reboot or shutdown, and
therefore the return value has now painfully been refactored away.
For special cases like GPIO expanders on a hot-pluggable bus like
USB, we may later add some gpiochip_try_remove() call, but for the
cases we have now, return values are moot.
- Some incremental refactoring of the gpiolib core and ACPI GPIO
library for more descriptor usage.
- Refactor the chained IRQ handler set-up method to handle also
threaded, nested interrupts and set up the parent IRQ correctly.
Switch STMPE and TC3589x drivers to use this registration method.
- Add a .irq_not_threaded flag to the struct gpio_chip, so that also
GPIO expanders that block but are still not using threaded IRQ
handlers.
- New drivers for the ARM64 X-Gene SoC GPIO controller.
- The syscon GPIO driver has been improved to handle the "DSP GPIO"
found on the TI Keystone 2 SoC:s.
- ADNP driver switched to use gpiolib irqchip helpers.
- Refactor the DWAPB driver to support being instantiated from and
MFD cell (platform device).
- Incremental feature improvement in the Zynq, MCP23S08, DWAPB, OMAP,
Xilinx and Crystalcove drivers.
- Various minor fixes"
* tag 'gpio-v3.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (52 commits)
gpio: pch: Build context save/restore only for PM
pinctrl: abx500: get rid of unused variable
gpio: ks8695: fix 'else should follow close brace '}''
gpio: stmpe: add verbose debug code
gpio: stmpe: fix up interrupt enable logic
gpio: staticize xway_stp_init()
gpio: handle also nested irqchips in the chained handler set-up
gpio: set parent irq on chained handlers
gpiolib: irqchip: use irq_find_mapping while removing irqchip
gpio: crystalcove: support virtual GPIO
pinctrl: bcm281xx: make Kconfig dependency more strict
gpio: kona: enable only on BCM_MOBILE or for compile testing
gpio, bcm-kona, LLVMLinux: Remove use of __initconst
gpio: Fix ngpio in gpio-xilinx driver
gpio: dwapb: fix pointer to integer cast
gpio: xgene: Remove unneeded #ifdef CONFIG_OF guard
gpio: xgene: Remove unneeded forward declation for struct xgene_gpio
gpio: xgene: Fix missing spin_lock_init()
gpio: ks8695: fix switch case indentation
gpiolib: add irq_not_threaded flag to gpio_chip
...
Some GPIO chips (e.g. the DLN2 USB adapter) have blocking get/set
operation but do not need a threaded irq handler.
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
These two typos were introduced in commit 1425052097 ("gpio: add IRQ
chip helpers in gpiolib").
The correct symbol name is CONFIG_GPIOLIB_IRQCHIP.
[jkosina@suse.cz: add changelog]
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
The current prototype of gpiochip_request_own_desc() requires to obtain
a pointer to a descriptor. This is in contradiction to all other GPIO
request schemes, and imposes an extra step of obtaining a descriptor to
drivers. Most drivers actually cannot even perform that step since the
function that does it (gpichip_get_desc()) is gpiolib-private.
Change gpiochip_request_own_desc() to return a descriptor from a
(chip, hwnum) tuple and update users of this function (currently
gpiolib-acpi only).
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As per example from the regulator subsystem: put all defines and
functions related to registering board info for GPIO descriptors
into a separate <linux/gpio/machine.h> header.
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Both functions were introduced to let gpio drivers request their own
gpio pins. Without exporting the functions, this can however only be
used by gpio drivers built into the kernel.
Secondary impact is that the functions can not currently be used by
platform initialization code associated with the gpio-pca953x driver.
This code permits auto-export of gpio pins through platform data, but
if this functionality is used, the module can no longer be unloaded due
to the problem solved with the introduction of gpiochip_request_own_desc
and gpiochip_free_own_desc.
Export both function so they can be used from modules and from
platform initialization code.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
gpio_lock/unlock_as_irq() are working with (chip, offset) arguments and
are thus not using the old integer namespace. Therefore, there is no
reason to have gpiod variants of these functions working with
descriptors, especially since the (chip, offset) tuple is more suitable
to the users of these functions (GPIO drivers, whereas GPIO descriptors
are targeted at GPIO consumers).
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As GPIO descriptors are not going to remain unique anymore, having this
function public is not safe. Restrain its use to gpiolib since we have
no user outside of it.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As we start to decomission the return value from gpiochip_remove()
the compilers emit warnings due to the function being tagged
__must_check. So drop this until we remove the return value
altogether.
Cc: Abdoulaye Berthe <berthe.ab@gmail.com>
Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Some off-chip GPIO expanders need to be communicated by I2C or
SPI traffic, but may still support IRQs. By the sleeping nature
of such buses, such IRQ handlers need to be threaded. Support
such handlers in the gpiochip irqchip helpers by flagging IRQs
as threaded if the .can_sleep property of the gpiochip is
true.
Helpfully deny registration of chained IRQ handlers if the
.can_sleep property is set, as such chips will invariably need
a nested handler rather than a chained handler.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
When using the irqchip helper inside the gpiolib, make sure
the IRQs are unmapped/disposed before the irqdomain is removed
as part of removing the gpiochip.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This provides a function gpiochip_irqchip_add() to set
up an irqchip for a GPIO controller, and a function
gpiochip_set_chained_irqchip() to chain it to a parent
irqchip.
Most GPIOs are of the type where a number of lines form
a cascaded interrupt controller chained onto
the primary system interrupt controller (or further down the
chain) so let's add this helper and factor the code to
request the lines to be used as IRQs, the .to_irq() function
and the irqdomain into the core as well.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Some drivers dealing with a gpio_chip might need to act on its
descriptors directly; one example is pinctrl drivers that need to lock a
GPIO for being used as IRQ using gpiod_lock_as_irq().
This patch exports a gpiochip_get_desc() function that returns the
GPIO descriptor at the requested index. It also sweeps the
gpio_to_chip() function out of the consumer interface since any holder
of a gpio_chip reference can manipulate its GPIOs way beyond what a
consumer should be allowed to do.
As a result, gpio_chip is not visible anymore to simple GPIO consumers.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The patch moves description of the fields to the top of struct definition and
converts them to the kernel-doc format.
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Change the format of the platform GPIO lookup tables to make them less
confusing and improve lookup efficiency.
The previous format was a single linked-list that required to compare
the device name and function ID of every single GPIO defined for each
lookup. Switch that to a list of per-device tables, so that the lookup
can be done in two steps, omitting the GPIOs that are not relevant for a
particular device.
The matching rules are now defined as follows:
- The device name must match *exactly*, and can be NULL for GPIOs not
assigned to a particular device,
- If the function ID in the lookup table is NULL, the con_id argument of
gpiod_get() will not be used for lookup. However, if it is defined, it
must match exactly.
- The index must always match.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This switches the two members of struct gpio_chip that were
defined as unsigned foo:1 to bool, because that is indeed what
they are. Switch all users in the gpio and pinctrl subsystems
to assign these values with true/false instead of 0/1. The
users outside these subsystems will survive since true/false
is 1/0, atleast we set some kind of more strict typing example.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add declaration of 'struct of_phandle_args' to avoid the following
warning:
In file included from arch/arm/mach-tegra/board-paz00.c:21:0:
include/linux/gpio/driver.h:102:17: warning: 'struct of_phandle_args' declared inside parameter list
include/linux/gpio/driver.h:102:17: warning: its scope is only this definition or declaration, which is probably not what you want
Also proactively add other definitions/includes that could be missing
in other contexts.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
GPIO mapping properties were defined using the GPIOF_* flags, which are
declared in linux/gpio.h. This file is not included when using the
GPIO descriptor interface.
This patch declares the flags that can be used as GPIO mappings
properties in linux/gpio/driver.h, and uses them in gpiolib, so that no
deprecated declarations are used by the GPIO descriptor interface.
This patch also allows GPIO_OPEN_DRAIN and GPIO_OPEN_SOURCE to be
specified as GPIO mapping properties.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Fixes this build error:
In file included from include/asm-generic/gpio.h:13:0,
from include/linux/gpio.h:51,
from include/linux/of_gpio.h:20,
from arch/powerpc/sysdev/ppc4xx_gpio.c:29:
include/linux/gpio/driver.h:85:14: error: 'struct seq_file' declared inside=
parameter list [-Werror]
include/linux/gpio/driver.h:85:14: error: its scope is only this definition=
or declaration, which is probably not what you want [-Werror]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add gpiod_get(), gpiod_get_index() and gpiod_put() functions that
provide safer management of GPIOs.
These functions put the GPIO framework in line with the conventions of
other frameworks in the kernel, and help ensure every GPIO is declared
properly and valid while it is used.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:
- gpio works with integers, whereas gpiod operates on opaque handlers
which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
the new interface, whereas chips drivers will use
<linux/gpio/driver.h>
The legacy gpio API is now built as inline functions on top of gpiod.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Grygorii Strashko