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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
| commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
| tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/ABI/obsolete/sysfs-gpio | |
| parent | Initial commit. (diff) | |
| download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip | |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/ABI/obsolete/sysfs-gpio')
| -rw-r--r-- | Documentation/ABI/obsolete/sysfs-gpio | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/ABI/obsolete/sysfs-gpio b/Documentation/ABI/obsolete/sysfs-gpio new file mode 100644 index 000000000..b8b0fd341 --- /dev/null +++ b/Documentation/ABI/obsolete/sysfs-gpio @@ -0,0 +1,32 @@ +What: /sys/class/gpio/ +Date: July 2008 +KernelVersion: 2.6.27 +Contact: Linus Walleij <linusw@kernel.org> +Description: + + As a Kconfig option, individual GPIO signals may be accessed from + userspace. GPIOs are only made available to userspace by an explicit + "export" operation. If a given GPIO is not claimed for use by + kernel code, it may be exported by userspace (and unexported later). + Kernel code may export it for complete or partial access. + + GPIOs are identified as they are inside the kernel, using integers in + the range 0..INT_MAX. See Documentation/admin-guide/gpio for more information. + + :: + + /sys/class/gpio + /export ... asks the kernel to export a GPIO to userspace + /unexport ... to return a GPIO to the kernel + /gpioN ... for each exported GPIO #N OR + /<LINE-NAME> ... for a properly named GPIO line + /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 + /gpiochipN ... for each gpiochip; #N is its first GPIO + /base ... (r/o) same as N + /label ... (r/o) descriptive, not necessarily unique + /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1) + + This ABI is deprecated and will be removed after 2020. It is + replaced with the GPIO character device. |