kernel/linux.git/drivers/gpio/gpio-shared-proxy.c, branch v6.19.12Linux kernel stable tree (mirror)https://git.radix-linux.su/kernel/linux.git/atom?h=v6.19.122025-11-28T08:29:31+00:00gpio: shared-proxy: set suppress_bind_attrs2025-11-28T08:29:31+00:00Bartosz Golaszewskibartosz.golaszewski@linaro.org2025-11-26T19:17:30+00:00urn:sha1:64309e40e357bead3a872db89512df6c071addc5
User-space must not fiddle with shared-proxy auxiliary devices. Disable
bind/unbind attributes in sysfs.
Link: https://lore.kernel.org/r/20251126191730.66277-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
gpio: shared-proxy: implement the shared GPIO proxy driver2025-11-17T09:16:51+00:00Bartosz Golaszewskibartosz.golaszewski@linaro.org2025-11-12T13:55:33+00:00urn:sha1:e992d54c6f970b382ffeacd7c88f68b94a3c6caf
Add a virtual GPIO proxy driver which arbitrates access to a single
shared GPIO by multiple users. It works together with the core shared
GPIO support from GPIOLIB and functions by acquiring a reference to a
shared GPIO descriptor exposed by gpiolib-shared and making sure that
the state of the GPIO stays consistent.
In general: if there's only one user at the moment: allow it to do
anything as if this was a normal GPIO (in essence: just propagate calls
to the underlying real hardware driver). If there are more users: don't
allow to change the direction set by the initial user, allow to change
configuration options but warn about possible conflicts and finally:
treat the output-high value as a reference counted, logical "GPIO
enabled" setting, meaning: the GPIO value is set to high when the first
user requests it to be high and back to low once the last user stops
"voting" for high.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20251112-gpio-shared-v4-4-b51f97b1abd8@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>