From af54a2fbdf45b1fd32cdcab916f422e6d097f430 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 21 Mar 2025 16:49:38 +0100 Subject: [PATCH] gpio: TODO: add an item to track reworking the sysfs interface It seems there really exists the need for a simple sysfs interface that can be easily used from minimal initramfs images that don't contain much more than busybox. However the current interface poses a challenge to the removal of global GPIO numberspace. Add an item that tracks extending the existing ABI with a per-chip export/unexport attribute pair. Reviewed-by: Linus Walleij Link: https://lore.kernel.org/r/20250321-gpio-todo-updates-v1-6-7b38f07110ee@linaro.org Signed-off-by: Bartosz Golaszewski --- drivers/gpio/TODO | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index 3abf4805335f1..b5f0a7a2e1bf1 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -173,3 +173,16 @@ value back to the caller. We've now added new variants - set_rv() and set_multiple_rv() that return an integer. Let's convert all GPIO drivers treewide to use the new callbacks, remove the old ones and finally rename the new ones back to the old names. + +------------------------------------------------------------------------------- + +Extend the sysfs ABI to allow exporting lines by their HW offsets + +The need to support the sysfs GPIO class is one of the main obstacles to +removing the global GPIO numberspace from the kernel. In order to wean users +off using global numbers from user-space, extend the existing interface with +new per-gpiochip export/unexport attributes that allow to refer to GPIOs using +their hardware offsets within the chip. + +Encourage users to switch to using them and eventually remove the existing +global export/unexport attribues. -- 2.47.2