[PATCH v2 0/6] gpiolib: unify gpio-hog code

[PATCH v2 0/6] gpiolib: unify gpio-hog code

[Bartosz Golaszewski]

GPIO hogs are handled separately in three places: for OF, ACPI and
machine lookup. In addition hogs cannot be set up using software nodes.
A lot of that code is actually redundant and - except for some special
handling of OF nodes - can be unified in one place.

This series moves hogging into GPIO core and bases it on fwnode API
(with a single helper from OF to translate devicetree properties into
lookup flags), converts the two remaining users of machine hogs to using
software node approach and removes machine hog support entirely. In
addition, there's a patch extending the configurability of gpio-sim now
that it uses software nodes for hogs.

For merging: I think this should go through the GPIO tree with an Ack
from OMAP1 maintainers.

Even with the new feature for gpio-sim, this series still removes twice
the number of lines, it adds.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Changes in v2:
- reduce the leakage of OF APIs into GPIO core by replacing
  of_phandle_args with fwnode_reference_args
- fix return value check in patch 2/6
- shrink code in patch 2/6
- don't allow #gpio-cells to be 0
- extend commit message of patch 6/6 to explain the need for this new
  feature
- Link to v1: https://patch.msgid.link/20260305-gpio-hog-fwnode-v1-0-97d7df6bbd17@oss.qualcomm.com

---
Bartosz Golaszewski (6):
      gpio: of: clear OF_POPULATED on hog nodes in remove path
      gpio: move hogs into GPIO core
      gpio: sim: use fwnode-based GPIO hogs
      ARM: omap1: ams-delta: convert GPIO hogs to using firmware nodes
      gpio: remove machine hogs
      gpio: sim: allow to define the active-low setting of a simulated hog

 Documentation/driver-api/gpio/board.rst |  16 ---
 arch/arm/mach-omap1/board-ams-delta.c   |  32 ++++-
 drivers/gpio/gpio-sim.c                 | 200 +++++++++++++++-----------------
 drivers/gpio/gpiolib-acpi-core.c        |  70 -----------
 drivers/gpio/gpiolib-of.c               | 152 ++++--------------------
 drivers/gpio/gpiolib-of.h               |  10 ++
 drivers/gpio/gpiolib.c                  | 137 +++++++++++++---------
 drivers/gpio/gpiolib.h                  |   3 +
 include/linux/gpio/machine.h            |  33 ------
 9 files changed, 238 insertions(+), 415 deletions(-)
---
base-commit: a0ae2a256046c0c5d3778d1a194ff2e171f16e5f
change-id: 20260224-gpio-hog-fwnode-b46a53196253

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

[PATCH v2 1/6] gpio: of: clear OF_POPULATED on hog nodes in remove path

[Bartosz Golaszewski]

The previously set OF_POPULATED flag should be cleared on the hog nodes
when removing the chip.

Cc: stable@vger.kernel.org
Fixes: 63636d956c455 ("gpio: of: Add DT overlay support for GPIO hogs")
Acked-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/gpio/gpiolib-of.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index ef1ac68b94b78f09e768cc740e893632b8817505..08b7b662512b825086cd70440be98b59befc3ffe 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -1210,7 +1210,14 @@ int of_gpiochip_add(struct gpio_chip *chip)
 
 void of_gpiochip_remove(struct gpio_chip *chip)
 {
-	of_node_put(dev_of_node(&chip->gpiodev->dev));
+	struct device_node *np = dev_of_node(&chip->gpiodev->dev);
+
+	for_each_child_of_node_scoped(np, child) {
+		if (of_property_present(child, "gpio-hog"))
+			of_node_clear_flag(child, OF_POPULATED);
+	}
+
+	of_node_put(np);
 }
 
 bool of_gpiochip_instance_match(struct gpio_chip *gc, unsigned int index)

-- 
2.47.3

Re: [PATCH v2 0/6] gpiolib: unify gpio-hog code

[Bartosz Golaszewski]

On Mon, 09 Mar 2026 13:42:36 +0100, Bartosz Golaszewski wrote:
> GPIO hogs are handled separately in three places: for OF, ACPI and
> machine lookup. In addition hogs cannot be set up using software nodes.
> A lot of that code is actually redundant and - except for some special
> handling of OF nodes - can be unified in one place.
> 
> This series moves hogging into GPIO core and bases it on fwnode API
> (with a single helper from OF to translate devicetree properties into
> lookup flags), converts the two remaining users of machine hogs to using
> software node approach and removes machine hog support entirely. In
> addition, there's a patch extending the configurability of gpio-sim now
> that it uses software nodes for hogs.
> 
> [...]

Applied, thanks!

[1/6] gpio: of: clear OF_POPULATED on hog nodes in remove path
      https://git.kernel.org/brgl/c/bbee90e750262bfb406d66dc65c46d616d2b6673
[2/6] gpio: move hogs into GPIO core
      https://git.kernel.org/brgl/c/d1d564ec4992945db853303dc2978256bce8c0b4
[3/6] gpio: sim: use fwnode-based GPIO hogs
      https://git.kernel.org/brgl/c/5cfbd0eb784f19436b5d5a9a7e0dca862619739a
[4/6] ARM: omap1: ams-delta: convert GPIO hogs to using firmware nodes
      https://git.kernel.org/brgl/c/e627fc9fad93d59765dd16adac1b2a9bf68d7523
[5/6] gpio: remove machine hogs
      https://git.kernel.org/brgl/c/dea046e7f46f2357124a465e058c92cac3e351c5
[6/6] gpio: sim: allow to define the active-low setting of a simulated hog
      https://git.kernel.org/brgl/c/696e9ba9a3da3d919d08a1abf05c9288311858f1

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>