The kernel doc for gpio-aggregator configfs interface, which was recently
added, states that users should not be able to create an aggregator with a
name prefixed by "_sysfs" via configfs. However, it was found that this
guard does not function as expected (thanks to Dan Carpenter for
identifying and fixing the issue).
Add a test case to verify the guard.
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250412150119.1461023-1-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
For aggregators initialized via configfs, write 1 to 'live' waits for
probe completion and returns an error if the probe fails, unlike the
legacy sysfs interface, which is asynchronous.
Since users control the liveness of the aggregator device and might be
editing configurations while 'live' is 0, deferred probing is both
unnatural and unsafe.
Cancel deferred probe for purely configfs-based aggregators when probe
fails.
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-8-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Expose settings for aggregators created using the sysfs 'new_device'
interface to configfs. Once written to 'new_device', an "_sysfs.<N>" path
appears in the configfs regardless of whether the probe succeeds.
Consequently, users can no longer use that prefix for custom GPIO
aggregator names. The 'live' attribute changes to 1 when the probe
succeeds and the GPIO forwarder is instantiated.
Note that the aggregator device created via sysfs is asynchronous, i.e.
writing into 'new_device' returns without waiting for probe completion,
and the probe may succeed, fail, or eventually succeed via deferred
probe. Thus, the 'live' attribute may change from 0 to 1 asynchronously
without notice. So, editing key/offset/name while it's waiting for
deferred probe is prohibited.
The configfs auto-generation relies on create_default_group(), which
inherently prohibits rmdir(2). To align with the limitation, this commit
also prohibits mkdir(2) for them. When users want to change the number
of lines for an aggregator initialized via 'new_device', they need to
tear down the device using 'delete_device' and reconfigure it from
scratch. This does not break previous behavior; users of legacy sysfs
interface simply gain additional almost read-only configfs exposure.
Still, users can write to the 'live' attribute to toggle the device
unless it's waiting for deferred probe. So once probe succeeds, they can
deactivate it in the same manner as the devices initialized via
configfs.
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-7-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The existing sysfs 'new_device' interface has several limitations:
* No way to determine when GPIO aggregator creation is complete.
* No way to retrieve errors when creating a GPIO aggregator.
* No way to trace a GPIO line of an aggregator back to its
corresponding physical device.
* The 'new_device' echo does not indicate which virtual gpiochip<N>
was created.
* No way to assign names to GPIO lines exported through an aggregator.
Introduce the new configfs interface for gpio-aggregator to address
these limitations. It provides a more streamlined, modern, and
extensible configuration method. For backward compatibility, the
'new_device' interface and its behavior is retained for now.
This commit implements basic functionalities:
/config/gpio-aggregator/<name-of-your-choice>/
/config/gpio-aggregator/<name-of-your-choice>/live
/config/gpio-aggregator/<name-of-your-choice>/dev_name
/config/gpio-aggregator/<name-of-your-choice>/<lineY>/
/config/gpio-aggregator/<name-of-your-choice>/<lineY>/key
/config/gpio-aggregator/<name-of-your-choice>/<lineY>/offset
/config/gpio-aggregator/<name-of-your-choice>/<lineY>/name
Basic setup flow is:
1. Create a directory for a GPIO aggregator.
2. Create subdirectories for each line you want to instantiate.
3. In each line directory, configure the key and offset.
The key/offset semantics are as follows:
* If offset is >= 0:
- key specifies the name of the chip this GPIO belongs to
- offset specifies the line offset within that chip.
* If offset is <0:
- key needs to specify the GPIO line name.
4. Return to the aggregator's root directory and write '1' to the live
attribute.
For example, the command in the existing kernel doc:
echo 'e6052000.gpio 19 e6050000.gpio 20-21' > new_device
is equivalent to:
mkdir /sys/kernel/config/gpio-aggregator/<custom-name>
# Change <custom-name> to name of your choice (e.g. "aggr0")
cd /sys/kernel/config/gpio-aggregator/<custom-name>
mkdir line0 line1 line2 # Only "line<Y>" naming allowed.
echo e6052000.gpio > line0/key
echo 19 > line0/offset
echo e6050000.gpio > line1/key
echo 20 > line1/offset
echo e6050000.gpio > line2/key
echo 21 > line2/offset
echo 1 > live
The corresponding gpio_device id can be identified as follows:
cd /sys/kernel/config/gpio-aggregator/<custom-name>
ls -d /sys/devices/platform/`cat dev_name`/gpiochip*
Also, via configfs, custom GPIO line name can be set like this:
cd /sys/kernel/config/gpio-aggregator/<custom-name>
echo "abc" > line1/name
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-5-koichiro.den@canonical.com
[Bartosz: remove stray newlines]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Unify function names to use gpio_aggregator_ prefix (except GPIO
forwarder implementations, which remain unchanged in subsequent
commits). While at it, rename the pre-existing gpio_aggregator_free() to
gpio_aggregator_destory(), since that name will be used by new
alloc/free functions introduced in the next commit, for which the name
is more appropriate.
No functional change.
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-3-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reorder functions in drivers/gpio/gpio-aggregator.c to prepare for the
configfs-based interface additions in subsequent commits. Arrange the
code so that the configfs implementations will appear above the existing
sysfs-specific code, since the latter will partly depend on the configfs
interface implementations when it starts to expose the settings to
configfs.
The order in drivers/gpio/gpio-aggregator.c will be as follows:
* Basic gpio_aggregator/gpio_aggregator_line representations
* Common utility functions
* GPIO Forwarder implementations
* Configfs interface implementations
* Sysfs interface implementations
* Platform device implementations
* Module init/exit implementations
This separate commit ensures a clean diff for the subsequent commits.
No functional change.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Link: https://lore.kernel.org/r/20250407043019.4105613-2-koichiro.den@canonical.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
gpio irq which using three-cell scheme should always call
instance_match() function to find the correct irqdomain.
The select() function will be called with !DOMAIN_BUS_ANY,
so for specific gpio irq driver, it need to set bus token
explicitly, something like:
irq_domain_update_bus_token(girq->domain, DOMAIN_BUS_WIRED);
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Link: https://lore.kernel.org/r/20250408-04-gpio-irq-threecell-v4-1-fd170d5e2d2b@gentoo.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Add new function *_twothreecell() to extend support to parse three-cell
interrupts which encoded as <instance hwirq irqflag>, the translate
function will retrieve irq number and flag from last two cells.
This API will be used in gpio irq driver which need to work with
two or three cells cases.
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250326-04-gpio-irq-threecell-v3-1-aab006ab0e00@gentoo.org
