This refactors the changes to the GPIO line naming mechanism to
not have so widespread effects, instead we conclude the patch series
by having created a name attribute in the GPIO descriptor, that need
not be globally unique, and it will be initialized from the old
.names array in struct gpio_chip if it exists, then used in the legacy
sysfs code like the array was used previously.
The associated changes to name lines from the device tree are
controversial and need to stand alone from this. Resulting changes:
1. Remove the export and the header for the gpio_name_to_desc() as so
far the only use is inside gpiolib.c. Staticize gpio_name_to_desc()
and move it above the only function using it.
2. Only print a warning if there are two GPIO lines with the same name.
The reason is to preserve current behaviour: before the previous
changes to the naming mechanism this would not reject probing the
driver, instead the error would occur when trying to export the line
in sysfs, so restore this behaviour, but print a friendly warning
if names collide.
Cc: Johan Hovold <johan@kernel.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The latest gpio hogging mechanism assigns each gpio a 'line-name' in the
devicetree. The 'name' field is different from the 'label' field.
'label' is only used for requested GPIOs to describe its current use by
driver or userspace.
The 'name' field describes the GPIO itself, not the use. This is most
likely identical to the label in the schematic on the GPIO line and
should help to find this particular GPIO.
This is equivalent to the gpiochip->names array. However names should be
stored in the GPIO descriptor. We will use gpiochip->names in the future
only as initializer for the GPIO descriptors for drivers that assign
GPIO names hardcoded. All other GPIO names will be parsed from DT and
directly assigned to the GPIO descriptor.
This patch adds a helper function to find gpio descriptors by name
instead of gpio number.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Now that all[1] users of the gpiod_get functions are converted to make
use of the up to now optional flags parameter, make it mandatory which
allows to remove some cpp magic.
[1] all but etraxfs-uart which is broken anyhow and I'm allowed to
ignore it by Jesper Nilsson :-)
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Pull LED subsystem updates from Bryan Wu:
"In this cycle, we finished to merge patches for LED Flash class
driver.
Other than that we have some bug fixes and new drivers for LED
controllers"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (33 commits)
leds:lp55xx: fix firmware loading error
leds: fix max77693-led build errors
leds: fix aat1290 build errors
leds: aat1290: pass flags parameter to devm_gpiod_get
leds: ktd2692: pass flags parameter to devm_gpiod_get
drivers/leds: don't use module_init in non-modular leds-cobalt-raq.c
leds: aat1290: add support for V4L2 Flash sub-device
DT: aat1290: Document handling external strobe sources
leds: max77693: add support for V4L2 Flash sub-device
media: Add registration helpers for V4L2 flash sub-devices
v4l: async: Add a pointer to of_node to struct v4l2_subdev, match it
Documentation: leds: Add description of v4l2-flash sub-device
leds: add BCM6358 LED driver
leds: add DT binding for BCM6358 LED controller
leds: fix brightness changing when software blinking is active
Documentation: leds-lp5523: describe master fader attributes
leds: lp5523: add master_fader support
leds: leds-gpio: Allow compile test if !GPIOLIB
leds: leds-gpio: Add missing #include <linux/of.h>
gpiolib: Add missing dummies for the unified device properties interface
...
There have been concerns that the function names gpiod_set_array() and
gpiod_get_array() might be confusing to users. One might expect
gpiod_get_array() to return array values, while it is actually the array
counterpart of gpiod_get(). To be consistent with the single descriptor API
we could rename gpiod_set_array() to gpiod_set_array_value(). This makes
some function names a bit lengthy: gpiod_set_raw_array_value_cansleep().
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
If GPIOLIB=n:
drivers/leds/leds-gpio.c: In function ‘gpio_leds_create’:
drivers/leds/leds-gpio.c:187: error: implicit declaration of function ‘devm_get_gpiod_from_child’
drivers/leds/leds-gpio.c:187: warning: assignment makes pointer from integer without a cast
Add dummies for fwnode_get_named_gpiod() and devm_get_gpiod_from_child()
for the !GPIOLIB case to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 40b7318319 ("gpio: Support for unified device properties interface")
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.
Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.
It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.
Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.
There are no in-kernel users of this interface.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add device managed variants of gpiod_get_array() / gpiod_put_array()
functions for conveniently obtaining and disposing of an entire array
of GPIOs with one function call.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Introduce new functions for conveniently obtaining and disposing of
an entire array of GPIOs with one function call.
ACPI parts tested by Mika Westerberg, DT parts tested by Rojhalat
Ibrahim.
Change log:
v5: move the ACPI functions to gpiolib-acpi.c
v4: - use shorter names for members of struct gpio_descs
- rename lut_gpio_count to platform_gpio_count for clarity
- add check for successful memory allocation
- use ERR_CAST()
v3: - rebase on current linux-gpio devel branch
- fix ACPI GPIO counting
- allow for zero-sized arrays
- make the flags argument mandatory for the new functions
- clarify documentation
v2: change interface
Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The gpio binding document says that new code should always use named
gpios. Patch 40b73183 added support to parse a list of gpios from child
nodes, but does not make it possible to use named gpios. This patch adds
the con_id property and implements it is done in gpiolib.c, where the
old-style of using unnamed gpios still works.
Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Acked-by: Bryan Wu <cooloney@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Right now, in consumer.h, there's some vararg hacks that pass 0 as the
flags. What actually is passed however is GPIOD_ASIS, which naturally is
also 0. Using the define/enum rather then the magic 0 makes it the
define more readable to a passer by.
Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
- A new API that allows setting more than one GPIO at the
time. This is implemented for the new descriptor-based
API only and makes it possible to e.g. toggle a clock and
data line at the same time, if the hardware can do this
with a single register write. Both consumers and drivers
need new calls, and the core will fall back to driving
individual lines where needed. Implemented for the MPC8xxx
driver initially.
- Patched the mdio-mux-gpio and the serial mctrl driver
that drives modems to use the new multiple-setting API
to set several signals simultaneously.
- Get rid of the global GPIO descriptor array, and instead
allocate descriptors dynamically for each GPIO on a certain
GPIO chip. This moves us closer to getting rid of the
limitation of using the global, static GPIO numberspace.
- New driver and device tree bindings for 74xx ICs.
- New driver and device tree bindings for the VF610 Vybrid.
- Support the RCAR r8a7793 and r8a7794.
- Guidelines for GPIO device tree bindings trying to get
things a bit more strict with the advent of combined
device properties.
- Suspend/resume support for the MVEBU driver.
- A slew of minor fixes and improvements.
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Merge tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull take two of the GPIO updates:
"Same stuff as last time, now with a fixup patch for the previous
compile error plus I ran a few extra rounds of compile-testing.
This is the bulk of GPIO changes for the v3.19 series:
- A new API that allows setting more than one GPIO at the time. This
is implemented for the new descriptor-based API only and makes it
possible to e.g. toggle a clock and data line at the same time, if
the hardware can do this with a single register write. Both
consumers and drivers need new calls, and the core will fall back
to driving individual lines where needed. Implemented for the
MPC8xxx driver initially
- Patched the mdio-mux-gpio and the serial mctrl driver that drives
modems to use the new multiple-setting API to set several signals
simultaneously
- Get rid of the global GPIO descriptor array, and instead allocate
descriptors dynamically for each GPIO on a certain GPIO chip. This
moves us closer to getting rid of the limitation of using the
global, static GPIO numberspace
- New driver and device tree bindings for 74xx ICs
- New driver and device tree bindings for the VF610 Vybrid
- Support the RCAR r8a7793 and r8a7794
- Guidelines for GPIO device tree bindings trying to get things a bit
more strict with the advent of combined device properties
- Suspend/resume support for the MVEBU driver
- A slew of minor fixes and improvements"
* tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (33 commits)
gpio: mcp23s08: fix up compilation error
gpio: pl061: document gpio-ranges property for bindings file
gpio: pl061: hook request if gpio-ranges avaiable
gpio: mcp23s08: Add option to configure IRQ output polarity as active high
gpio: fix deferred probe detection for legacy API
serial: mctrl_gpio: use gpiod_set_array function
mdio-mux-gpio: Use GPIO descriptor interface and new gpiod_set_array function
gpio: remove const modifier from gpiod_get_direction()
gpio: remove gpio_descs global array
gpio: mxs: implement get_direction callback
gpio: em: Use dynamic allocation of GPIOs
gpio: Check if base is positive before calling gpio_is_valid()
gpio: mcp23s08: Add simple IRQ support for SPI devices
gpio: mcp23s08: request a shared interrupt
gpio: mcp23s08: Do not free unrequested interrupt
gpio: rcar: Add r8a7793 and r8a7794 support
gpio-mpc8xxx: add mpc8xxx_gpio_set_multiple function
gpiolib: allow simultaneous setting of multiple GPIO outputs
gpio: mvebu: add suspend/resume support
gpio: gpio-davinci: remove duplicate check on resource
..
Although gpiod_get_direction() can be considered side-effect free for
consumers, its internals involve setting or clearing bits in the
affected GPIO descriptor, for which we need to force-cast the const
descriptor variable to non-const. This could lead to incorrect behavior
if the compiler decides to optimize here, so remove this const
attribute. The intent is to make gpiod_get_direction() private anyway,
so it does not really matter.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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>
Some drivers need to deal with only firmware representation of its
GPIOs. An example would be a GPIO button array driver where each button
is described as a separate firmware node in device tree. Typically these
child nodes do not have physical representation in the Linux device
model.
In order to help device drivers to handle such firmware child nodes we
add dev[m]_get_named_gpiod_from_child() that takes a child firmware
node pointer as its second argument (the first one is the parent device
itself), finds the GPIO using whatever is the underlying firmware
method, and requests the GPIO properly.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit 39b2bbe3d7
"gpio: add flags argument to gpiod_get*() functions"
added a dynamic flags argument to all the GPIOD getter
functions, however this did not cover the stubs so
when people used gpiod stubs to compile out descriptor
code, compilation failed.
Solve this by:
- Also rename all the stub functions __gpiod_*
- Moving the vararg hack outside of #ifdef CONFIG_GPIOLIB
so these will always be available.
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The GPIOD flags are defined inside the #ifdef CONFIG_GPIOLIB
switch, making the gpiolib stubs fail if these flags are used
by a consumer. This is not correct: the stubs should compile
fine without GPIOLIB.
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The huge majority of GPIOs have their direction and initial value set
right after being obtained by one of the gpiod_get() functions. The
integer GPIO API had gpio_request_one() that took a convenience flags
parameter allowing to specify an direction and value applied to the
returned GPIO. This feature greatly simplifies client code and ensures
errors are always handled properly.
A similar feature has been requested for the gpiod API. Since setting
the direction of a GPIO is so often the very next action done after
obtaining its descriptor, we prefer to extend the existing functions
instead of introducing new functions that would raise the
number of gpiod getters to 16 (!).
The drawback of this approach is that all gpiod clients need to be
updated. To limit the pain, temporary macros are introduced that allow
gpiod_get*() to be called with or without the extra flags argument. They
will be removed once all consumer code has been updated.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Today's linux-next kernel started showing build errors for the
use of WARN_ON in linux/gpio/consumer.h:
In file included from drivers/video/backlight/pwm_bl.c:13:0:
include/linux/gpio/consumer.h: In function 'gpiod_put':
include/linux/gpio/consumer.h:81:2: error: implicit declaration of function 'WARN_ON' [-Werror=implicit-function-declaration]
It's not clear why this never happened before, but this patch
fixes it by including the header that contains the defintion
of this macro.
Signed-off-by: Arnd Bergmann <arnd@arnd.de>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Introduce gpiod_get_optional() and gpiod_get_index_optional() helpers
that make it easier for drivers to handle optional GPIOs.
Currently in order to handle optional GPIOs, a driver needs to special
case error handling for -ENOENT, such as this:
gpio = gpiod_get(dev, "foo");
if (IS_ERR(gpio)) {
if (PTR_ERR(gpio) != -ENOENT)
return PTR_ERR(gpio);
gpio = NULL;
}
if (gpio) {
/* set up GPIO */
}
With these new helpers the above is reduced to:
gpio = gpiod_get_optional(dev, "foo");
if (IS_ERR(gpio))
return PTR_ERR(gpio);
if (gpio) {
/* set up GPIO */
}
While at it, device-managed variants of these functions are also
provided.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-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 documentation was not clear about whether
gpio_direction_output should take a logical value or the physical
level on the output line, i.e. whether the ACTIVE_LOW status
would be taken into account.
This converts gpiod_direction_output to use the logical level
and adds a new gpiod_direction_output_raw for the raw value.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Make sure that the forward declared structs in gpio/consumer.h are also visible
on the else branch of the CONFIG_GPIOLIB #ifdef.
Fixes the following warnings and their associated errors when CONFIG_GPIOLIB is
not selected:
include/linux/gpio/consumer.h:67:14: warning: 'struct device' declared inside parameter list
include/linux/gpio/consumer.h:67:14: warning: its scope is only this definition or declaration, which is probably not what you want
[...]
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
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>
Linus Walleij