Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) What:		/sys/class/gpio/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) Date:		July 2008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) KernelVersion:	2.6.27
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) Contact:	Linus Walleij <linusw@kernel.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)   As a Kconfig option, individual GPIO signals may be accessed from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)   userspace.  GPIOs are only made available to userspace by an explicit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)   "export" operation.  If a given GPIO is not claimed for use by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)   kernel code, it may be exported by userspace (and unexported later).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)   Kernel code may export it for complete or partial access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)   GPIOs are identified as they are inside the kernel, using integers in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)   the range 0..INT_MAX.  See Documentation/admin-guide/gpio for more information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)   ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)     /sys/class/gpio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	/export ... asks the kernel to export a GPIO to userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	/unexport ... to return a GPIO to the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	/gpioN ... for each exported GPIO #N OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	/<LINE-NAME> ... for a properly named GPIO line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	    /value ... always readable, writes fail for input GPIOs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	    /direction ... r/w as: in, out (default low); write: high, low
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	    /edge ... r/w as: none, falling, rising, both
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	/gpiochipN ... for each gpiochip; #N is its first GPIO
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	    /base ... (r/o) same as N
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	    /label ... (r/o) descriptive, not necessarily unique
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	    /ngpio ... (r/o) number of GPIOs; numbered N to N + (ngpio - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)   This ABI is deprecated and will be removed after 2020. It is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)   replaced with the GPIO character device.