From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> 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@xxxxxxxxxxxxxx/ Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> --- drivers/gpio/TODO | 36 ------------------------------------ 1 file changed, 36 deletions(-) diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index 942d1cd2bd3c9..9cf7b84cdb869 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 -- 2.45.2