• Christian Lamparter's avatar
    gpio: dt-bindings: add ibm,ppc4xx-gpio binding · 9a0d4404
    Christian Lamparter authored
    This patch adds binding information for IBM/AMCC/APM GPIO
    Controllers of the PowerPC 4XX series and compatible SoCs.
    
    The "PowerPC 405EP Embedded Processor Data Sheet" has the
    following to say about the GPIO controllers: "
    
     - Controller functions and GPIO registers are programmed
       and accessed via memory-mapped OPB bus master accesses
    
     - All GPIOs are pin-shared with other functions. DCRs control
       whether a particular pin that has GPIO capabilities acts
       as a GPIO or is used for another purpose.
    
     - Each GPIO outputs is separately programmable to emulate
       an open-drain driver (i.e. drives to zero, threestated if
       output bit is 1)
    
    "
    The ppc4xx_gpio.c driver is part of the platform/sysdev drivers
    in arch/powerpc/sysdev.
    Signed-off-by: default avatarChristian Lamparter <chunkeey@googlemail.com>
    Signed-off-by: Rob Herring's avatarRob Herring <robh@kernel.org>
    9a0d4404
ibm,ppc4xx-gpio.txt 799 Bytes