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From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Linus Walleij <linus.walleij@linaro.org>,
	 Bartosz Golaszewski <brgl@bgdev.pl>
Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
	 Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [PATCH 1/6] gpio: TODO: remove the item about the new debugfs interface
Date: Fri, 21 Mar 2025 16:49:33 +0100	[thread overview]
Message-ID: <20250321-gpio-todo-updates-v1-1-7b38f07110ee@linaro.org> (raw)
In-Reply-To: <20250321-gpio-todo-updates-v1-0-7b38f07110ee@linaro.org>

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

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/

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 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


  reply	other threads:[~2025-03-21 15:49 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-21 15:49 [PATCH 0/6] gpio: update the TODO list Bartosz Golaszewski
2025-03-21 15:49 ` Bartosz Golaszewski [this message]
2025-03-22 20:26   ` [PATCH 1/6] gpio: TODO: remove the item about the new debugfs interface Linus Walleij
2025-03-21 15:49 ` [PATCH 2/6] gpio: TODO: remove task duplication Bartosz Golaszewski
2025-03-22 20:27   ` Linus Walleij
2025-03-21 15:49 ` [PATCH 3/6] gpio: TODO: remove the pinctrl integration task Bartosz Golaszewski
2025-03-22 20:28   ` Linus Walleij
2025-03-21 15:49 ` [PATCH 4/6] gpio: TODO: add delimiters between tasks for better readability Bartosz Golaszewski
2025-03-22 20:28   ` Linus Walleij
2025-03-21 15:49 ` [PATCH 5/6] gpio: TODO: add an item to track the conversion to the new value setters Bartosz Golaszewski
2025-03-22 20:30   ` Linus Walleij
2025-03-21 15:49 ` [PATCH 6/6] gpio: TODO: add an item to track reworking the sysfs interface Bartosz Golaszewski
2025-03-22 20:31   ` Linus Walleij
2025-03-24  9:35 ` [PATCH 0/6] gpio: update the TODO list Bartosz Golaszewski

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