cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

sysfs-gpio (1334B)


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