• Laxman Dewangan's avatar
    gpio: core: Decouple open drain/source flag with active low/high · 4c0facdd
    Laxman Dewangan authored
    Currently, the GPIO interface is said to Open Drain if it is Single
    Ended and active LOW. Similarly, it is said as Open Source if it is
    Single Ended and active HIGH.
    
    The active HIGH/LOW is used in the interface for setting the pin
    state to HIGH or LOW when enabling/disabling the interface.
    
    In Open Drain interface, pin is set to HIGH by putting pin in
    high impedance and LOW by driving to the LOW.
    
    In Open Source interface, pin is set to HIGH by driving pin to
    HIGH and set to LOW by putting pin in high impedance.
    
    With above, the Open Drain/Source is unrelated to the active LOW/HIGH
    in interface. There is interface where the enable/disable of interface
    is ether active LOW or HIGH but it is Open Drain type.
    
    Hence decouple the Open Drain with Single Ended + Active LOW and
    Open Source with Single Ended + Active HIGH.
    
    Adding different flag for the Open Drain/Open Source which is valid
    only when Single ended flag is enabled.
    Signed-off-by: default avatarLaxman Dewangan <ldewangan@nvidia.com>
    Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
    4c0facdd
of_gpio.h 4.36 KB