Documentation: gpio: document the active_low field in the sysfs ABI

Exported GPIO lines also have the active_low attribute which is not
documented. Add a short mention for it.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20250610-gpio-sysfs-chip-export-v1-2-a8c7aa4478b1@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/Documentation/ABI/obsolete/sysfs-gpio b/Documentation/ABI/obsolete/sysfs-gpio
index 8203bc2128db7eb9ea6724884e680ed4b669853c..480316fee6d80fb7a0ed61706559838591ec0932 100644 (file)
--- a/Documentation/ABI/obsolete/sysfs-gpio
+++ b/Documentation/ABI/obsolete/sysfs-gpio
@@ -22,6 +22,7 @@ Description:
            /value ... always readable, writes fail for input GPIOs
            /direction ... r/w as: in, out (default low); write: high, low
            /edge ... r/w as: none, falling, rising, both
+           /active_low ... r/w as: 0, 1
        /gpiochipN ... for each gpiochip; #N is its first GPIO
            /base ... (r/o) same as N
            /label ... (r/o) descriptive, not necessarily unique