This commit adds support for configuring the pull-up and pull-down
resistors available in some GPIO controllers. While configuring
pull-up/pull-down is already possible through the pinctrl subsystem,
some GPIO controllers, especially simple ones such as GPIO expanders
on I2C, don't have any pinmuxing capability and therefore do not use
the pinctrl subsystem.
This commit implements the GPIO_PULL_UP and GPIO_PULL_DOWN flags,
which can be used from the Device Tree, to enable a pull-up or
pull-down resistor on a given GPIO.
The flag is simply propagated all the way to the core GPIO subsystem,
where it is used to call the gpio_chip ->set_config callback with the
appropriate existing PIN_CONFIG_BIAS_* values.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds the two new functions gpiochip_irq_domain_activate and
gpiochip_irq_domain_deactivate that can be used as the activate and
deactivate functions in the struct irq_domain_ops. This is for
situations where only gpiochip_{lock,unlock}_as_irq needs to be called.
SPMI and SSBI GPIO are two users that will initially use these
functions.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.21 kernel series.
Core changes:
- Some core changes are already in outside of this pull request as
they came through the regulator tree, most notably
devm_gpiod_unhinge() that removes devres refcount management from a
GPIO descriptor. This is needed in subsystems such as regulators
where the regulator core need to take over the reference counting
and lifecycle management for a GPIO descriptor.
- We dropped devm_gpiochip_remove() and devm_gpio_chip_match() as
nothing needs it. We can bring it back if need be.
- Add a global TODO so people see where we are going. This helps
setting the direction now that we are two GPIO maintainers.
- Handle the MMC CD/WP properties in the device tree core. (The bulk
of patches activating this code is already merged through the
MMC/SD tree.)
- Augment gpiochip_request_own_desc() to pass a flag so we as
gpiochips can request lines as active low or open drain etc even
from ourselves.
New drivers:
- New driver for Cadence GPIO blocks.
- New driver for Atmel SAMA5D2 PIOBU GPIO lines.
Driver improvements:
- A major refactoring of the PCA953x driver - this driver has been
around for ages, and is now modernized to reduce code duplication
that has stacked up and is using regmap to read write and cache
registers.
- Intel drivers are now maintained in a separate tree and start with
a round of cleanups and unifications"
* tag 'gpio-v4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (99 commits)
gpio: sama5d2-piobu: Depend on OF_GPIO
gpio: Add Cadence GPIO driver
dt-bindings: gpio: Add bindings for Cadence GPIO
gpiolib-acpi: remove unused variable 'err', cleans up build warning
gpio: mxs: read pin level directly instead of using .get
gpio: aspeed: remove duplicated statement
gpio: add driver for SAMA5D2 PIOBU pins
dt-bindings: arm: atmel: describe SECUMOD usage as a GPIO controller
gpio/mmc/of: Respect polarity in the device tree
dt-bindings: gpio: rcar: Add r8a774c0 (RZ/G2E) support
memory: omap-gpmc: Get the header of the enum
ARM: omap1: Fix new user of gpiochip_request_own_desc()
gpio: pca953x: Add regmap dependency for PCA953x driver
gpio: raspberrypi-exp: decrease refcount on firmware dt node
gpiolib: Fix return value of gpio_to_desc() stub if !GPIOLIB
gpio: pca953x: Restore registers after suspend/resume cycle
gpio: pca953x: Zap single use of pca953x_read_single()
gpio: pca953x: Zap ad-hoc reg_output cache
gpio: pca953x: Zap ad-hoc reg_direction cache
gpio: pca953x: Perform basic regmap conversion
...
If CONFIG_GPOILIB is not set, the stub of gpio_to_desc() should return
the same type of error as regular version: NULL. All the callers
compare the return value of gpio_to_desc() against NULL, so returned
ERR_PTR would be treated as non-error case leading to dereferencing of
error value.
Fixes: 79a9becda8 ("gpiolib: export descriptor-based GPIO interface")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This adds a function named devm_gpiod_unhinge() that removes
the resource management from a GPIO descriptor.
I am not sure if this is the best anglosaxon name for the
function, no other managed resources have an equivalent
currently, but I chose "unhinge" as the closest intuitive
thing I could imagine that fits Rusty Russell's API design
criterions "the obvious use is the correct one" and
"the name tells you how to use it".
The idea came out of a remark from Mark Brown that it should
be possible to handle over management of a resource from
devres to the regulator core, and indeed we can do that.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This function already exist inside gpiolib, we were just
reluctant to make it available to the kernel at large as
the devm_* seemed to be enough for anyone.
However we found out that regulators need to do their own
lifecycle/refcounting on GPIO descriptors and explicitly
call gpiod_put() when done with a descriptor, so export
this function so we can hand the refcounting over to the
regulator core for these descriptors after retrieveal.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Drop the broken to_gpio_irq_chip() container_of() helper, which would
break the build for anyone who tries to use it.
Specifically, struct gpio_irq_chip only holds a pointer to a struct
irq_chip so using container_of() on an irq-chip pointer makes no sense.
Fixes: da80ff81a8 ("gpio: Move irqchip into struct gpio_irq_chip")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
gpiod_request_commit() copies the pointer to the label passed as
an argument only to be used later. But there's a chance the caller
could immediately free the passed string(e.g., local variable).
This could trigger a use after free when we use gpio label(e.g.,
gpiochip_unlock_as_irq(), gpiochip_is_requested()).
To be on the safe side: duplicate the string with kstrdup_const()
so that if an unaware user passes an address to a stack-allocated
buffer, we won't get the arbitrary label.
Also fix gpiod_set_consumer_name().
Signed-off-by: Muchun Song <smuchun@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
There is hardly any reason to call devm_gpiochip_remove() because the
driver core handles calling gpiochip_remove() automatically.
To make it harder to introduce new (and probably unneeded) callers, drop
the function.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for the v4.20 series:
Core changes:
- A patch series from Hans Verkuil to make it possible to
enable/disable IRQs on a GPIO line at runtime and drive GPIO lines
as output without having to put/get them from scratch.
The irqchip callbacks have been improved so that they can use only
the fastpatch callbacks to enable/disable irqs like any normal
irqchip, especially the gpiod_lock_as_irq() has been improved to be
callable in fastpath context.
A bunch of rework had to be done to achieve this but it is a big
win since I never liked to restrict this to slowpath. The only call
requireing slowpath was try_module_get() and this is kept at the
.request_resources() slowpath callback. In the GPIO CEC driver this
is a big win sine a single line is used for both outgoing and
incoming traffic, and this needs to use IRQs for incoming traffic
while actively driving the line for outgoing traffic.
- Janusz Krzysztofik improved the GPIO array API to pass a "cookie"
(struct gpio_array) and a bitmap for setting or getting multiple
GPIO lines at once.
This improvement orginated in a specific need to speed up an OMAP1
driver and has led to a much better API and real performance gains
when the state of the array can be used to bypass a lot of checks
and code when we want things to go really fast.
The previous code would minimize the number of calls down to the
driver callbacks assuming the CPU speed was orders of magnitude
faster than the I/O latency, but this assumption was wrong on
several platforms: what we needed to do was to profile and improve
the speed on the hot path of the array functions and this change is
now completed.
- Clean out the painful and hard to grasp BNF experiments from the
device tree bindings. Future approaches are looking into using JSON
schema for this purpose. (Rob Herring is floating a patch series.)
New drivers:
- The RCAR driver now supports r8a774a1 (RZ/G2M).
- Synopsys GPIO via CREGs driver.
Major improvements:
- Modernization of the EP93xx driver to use irqdomain and other
contemporary concepts.
- The ingenic driver has been merged into the Ingenic pin control
driver and removed from the GPIO subsystem.
- Debounce support in the ftgpio010 driver"
* tag 'gpio-v4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (116 commits)
gpio: Clarify kerneldoc on gpiochip_set_chained_irqchip()
gpio: Remove unused 'irqchip' argument to gpiochip_set_cascaded_irqchip()
gpio: Drop parent irq assignment during cascade setup
mmc: pwrseq_simple: Fix incorrect handling of GPIO bitmap
gpio: fix SNPS_CREG kconfig dependency warning
gpiolib: Initialize gdev field before is used
gpio: fix kernel-doc after devres.c file rename
gpio: fix doc string for devm_gpiochip_add_data() to not talk about irq_chip
gpio: syscon: Fix possible NULL ptr usage
gpiolib: Show correct direction from the beginning
pinctrl: msm: Use init_valid_mask exported function
gpiolib: Add init_valid_mask exported function
GPIO: add single-register GPIO via CREG driver
dt-bindings: Document the Synopsys GPIO via CREG bindings
gpio: mockup: use device properties instead of platform_data
gpio: Slightly more helpful debugfs
gpio: omap: Remove set but not used variable 'dev'
gpio: omap: drop omap_gpio_list
Accept partial 'gpio-line-names' property.
gpio: omap: get rid of the conditional PM runtime calls
...
This allows nonexclusive (simultaneous) access to a single
GPIO line for the fixed regulator enable line. This happens
when several regulators use the same GPIO for enabling and
disabling a regulator, and all need a handle on their GPIO
descriptor.
This solution with a special flag is not entirely elegant
and should ideally be replaced by something more careful as
this makes it possible for several consumers to
enable/disable the same GPIO line to the left and right
without any consistency. The current use inside the regulator
core should however be fine as it takes special care to
handle this.
For the state of the GPIO backend, this is still the
lesser evil compared to going back to global GPIO
numbers.
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Fixes: efdfeb079c ("regulator: fixed: Convert to use GPIO descriptor only")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
gpiochip_set_cascaded_irqchip() is passed 'parent_irq' as an argument
and then the address of that argument is assigned to the gpio chips
gpio_irq_chip 'parents' pointer shortly thereafter. This can't ever
work, because we've just assigned some stack address to a pointer that
we plan to dereference later in gpiochip_irq_map(). I ran into this
issue with the KASAN report below when gpiochip_irq_map() tried to setup
the parent irq with a total junk pointer for the 'parents' array.
BUG: KASAN: stack-out-of-bounds in gpiochip_irq_map+0x228/0x248
Read of size 4 at addr ffffffc0dde472e0 by task swapper/0/1
CPU: 7 PID: 1 Comm: swapper/0 Not tainted 4.14.72 #34
Call trace:
[<ffffff9008093638>] dump_backtrace+0x0/0x718
[<ffffff9008093da4>] show_stack+0x20/0x2c
[<ffffff90096b9224>] __dump_stack+0x20/0x28
[<ffffff90096b91c8>] dump_stack+0x80/0xbc
[<ffffff900845a350>] print_address_description+0x70/0x238
[<ffffff900845a8e4>] kasan_report+0x1cc/0x260
[<ffffff900845aa14>] __asan_report_load4_noabort+0x2c/0x38
[<ffffff900897e098>] gpiochip_irq_map+0x228/0x248
[<ffffff900820cc08>] irq_domain_associate+0x114/0x2ec
[<ffffff900820d13c>] irq_create_mapping+0x120/0x234
[<ffffff900820da78>] irq_create_fwspec_mapping+0x4c8/0x88c
[<ffffff900820e2d8>] irq_create_of_mapping+0x180/0x210
[<ffffff900917114c>] of_irq_get+0x138/0x198
[<ffffff9008dc70ac>] spi_drv_probe+0x94/0x178
[<ffffff9008ca5168>] driver_probe_device+0x51c/0x824
[<ffffff9008ca6538>] __device_attach_driver+0x148/0x20c
[<ffffff9008ca14cc>] bus_for_each_drv+0x120/0x188
[<ffffff9008ca570c>] __device_attach+0x19c/0x2dc
[<ffffff9008ca586c>] device_initial_probe+0x20/0x2c
[<ffffff9008ca18bc>] bus_probe_device+0x80/0x154
[<ffffff9008c9b9b4>] device_add+0x9b8/0xbdc
[<ffffff9008dc7640>] spi_add_device+0x1b8/0x380
[<ffffff9008dcbaf0>] spi_register_controller+0x111c/0x1378
[<ffffff9008dd6b10>] spi_geni_probe+0x4dc/0x6f8
[<ffffff9008cab058>] platform_drv_probe+0xdc/0x130
[<ffffff9008ca5168>] driver_probe_device+0x51c/0x824
[<ffffff9008ca59cc>] __driver_attach+0x100/0x194
[<ffffff9008ca0ea8>] bus_for_each_dev+0x104/0x16c
[<ffffff9008ca58c0>] driver_attach+0x48/0x54
[<ffffff9008ca1edc>] bus_add_driver+0x274/0x498
[<ffffff9008ca8448>] driver_register+0x1ac/0x230
[<ffffff9008caaf6c>] __platform_driver_register+0xcc/0xdc
[<ffffff9009c4b33c>] spi_geni_driver_init+0x1c/0x24
[<ffffff9008084cb8>] do_one_initcall+0x240/0x3dc
[<ffffff9009c017d0>] kernel_init_freeable+0x378/0x468
[<ffffff90096e8240>] kernel_init+0x14/0x110
[<ffffff9008086fcc>] ret_from_fork+0x10/0x18
The buggy address belongs to the page:
page:ffffffbf037791c0 count:0 mapcount:0 mapping: (null) index:0x0
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: ffffffbf037791e0 ffffffbf037791e0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffffffc0dde47180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffc0dde47200: f1 f1 f1 f1 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f2 f2
>ffffffc0dde47280: f2 f2 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3
^
ffffffc0dde47300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffc0dde47380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Let's leave around one unsigned int in the gpio_irq_chip struct for the
single parent irq case and repoint the 'parents' array at it. This way
code is left mostly intact to setup parents and we waste an extra few
bytes per structure of which there should be only a handful in a system.
Cc: Evan Green <evgreen@chromium.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Fixes: e0d8972898 ("gpio: Implement tighter IRQ chip integration")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add a function that allows initializing the valid_mask from
gpiochip_add_data.
This prevents race conditions during gpiochip initialization.
If the function is not exported, then the old behaviour is respected,
this is, set all gpios as valid.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Internal helper function gpiod_set_array_value_complex() was changed to
return an error value, but not all gpiolib callers were updated to
propagate the new error up.
Fixes: 3027743f83 ("gpio: Remove VLA from gpiolib")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
A patch from Ricardo got me thinking about some gpio chip
semantics so let's drop in some comments to make things
more clear around that.
Cc: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Certain GPIO array lookup results may map directly to GPIO pins of a
single GPIO chip in hardware order. If that condition is recognized
and handled efficiently, significant performance gain of get/set array
functions may be possible.
While processing a request for an array of GPIO descriptors, identify
those which represent corresponding pins of a single GPIO chip. Skip
over pins which require open source or open drain special processing.
Moreover, identify pins which require inversion. Pass a pointer to
that information with the array to the caller so it can benefit from
enhanced performance as soon as get/set array functions can accept and
make efficient use of it.
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
When using the gpiolib irqchip helpers install irq_enable/disable
hooks for the irqchip to ensure that gpiolib knows when the irq
is enabled or disabled, allowing drivers to disable the irq and then
use it as an output pin, and later switch the direction to input and
re-enable the irq.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
GPIO drivers call gpiochip_(un)lock_as_irq whenever they want to use a gpio
as an interrupt. This is done when the irq is requested and it marks the
gpio as in use by an interrupt.
This is problematic for cases where a gpio pin is used as an interrupt
pin, then, after the irq is disabled, is used as a regular gpio pin.
Currently it is not possible to do this other than by first freeing
the interrupt so gpiochip_unlock_as_irq is called, since an attempt to
switch the gpio direction for output will fail since gpiolib believes
that the gpio is in use for an interrupt and it does not know that it
the irq is actually disabled.
There are currently two drivers that would like to be able to do this:
the tda998x_drv.c driver where a regular gpio pin needs to be temporarily
reconfigured as an interrupt pin during CEC calibration, and the cec-gpio
driver where you want to configure the gpio pin as an interrupt while
waiting for traffic over the CEC bus, or as a regular pin when receiving or
transmitting a CEC message.
The solution is to add a new flag that is set when the irq is enabled,
and have gpiod_direction_output check for that flag.
We also add functions that drivers that do not use GPIOLIB_IRQCHIP
can call when they enable/disable the irq.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
