diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2025-03-21 16:49:33 +0100 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2025-03-24 10:35:10 +0100 |
| commit | 0c6dcc49487608e460b89ff7a6a50c084b01f3d8 (patch) | |
| tree | b7846d7b33cf680f0344b886c5bc1aa4106a0d5b | |
| parent | 2eb5dc9a4b0d193b27289281faa05aadab978b41 (diff) | |
gpio: TODO: remove the item about the new debugfs interface
The consensus among core GPIO stakeholders seems to be that a new
debugfs interface will only increase maintenance burden and will fail
to attract users that care about long-term stability of the ABI[1].
Let's not go this way and not add a fourth user-facing interface to the
GPIO subsystem.
[1] https://lore.kernel.org/all/9d3f1ca4-d865-45af-9032-c38cacc7fe93@pengutronix.de/
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250321-gpio-todo-updates-v1-1-7b38f07110ee@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
| -rw-r--r-- | drivers/gpio/TODO | 36 |
1 files changed, 0 insertions, 36 deletions
diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index 942d1cd2bd3c..9cf7b84cdb86 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -156,42 +156,6 @@ multiplexing, pin configuration, GPIO, etc selectable options in one and the same pin control and GPIO subsystem. -Debugfs in place of sysfs - -The old sysfs code that enables simple uses of GPIOs from the -command line is still popular despite the existance of the proper -character device. The reason is that it is simple to use on -root filesystems where you only have a minimal set of tools such -as "cat", "echo" etc. - -The old sysfs still need to be strongly deprecated and removed -as it relies on the global GPIO numberspace that assume a strict -order of global GPIO numbers that do not change between boots -and is independent of probe order. - -To solve this and provide an ABI that people can use for hacks -and development, implement a debugfs interface to manipulate -GPIO lines that can do everything that sysfs can do today: one -directory per gpiochip and one file entry per line: - -/sys/kernel/debug/gpiochip/gpiochip0 -/sys/kernel/debug/gpiochip/gpiochip0/gpio0 -/sys/kernel/debug/gpiochip/gpiochip0/gpio1 -/sys/kernel/debug/gpiochip/gpiochip0/gpio2 -/sys/kernel/debug/gpiochip/gpiochip0/gpio3 -... -/sys/kernel/debug/gpiochip/gpiochip1 -/sys/kernel/debug/gpiochip/gpiochip1/gpio0 -/sys/kernel/debug/gpiochip/gpiochip1/gpio1 -... - -The exact files and design of the debugfs interface can be -discussed but the idea is to provide a low-level access point -for debugging and hacking and to expose all lines without the -need of any exporting. Also provide ample ammunition to shoot -oneself in the foot, because this is debugfs after all. - - Moving over to immutable irq_chip structures Most of the gpio chips implementing interrupt support rely on gpiolib |