On Wed, Nov 20, 2013 at 1:02 AM, Kyungmin Park <kmpark@xxxxxxxxxxxxx> wrote: > On Wed, Nov 20, 2013 at 4:16 AM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: >> I think that last point should be addressed by having a driver that owns >> the GPIO set it to the desired output level, and the implementation of > Some pins are not connected (NC). At that cases, there's no drivers to > handle it. To reduce power leakage, it sets proper configuration with > values instead of reset values. This is correspondant to the PIN_CONFIG_OUTPUT from include/linux/pinctrl/pinconf-generic.h I.e. driving a pin - any pin, even one that cannot do GPIO - high or low as default. One could argue that if you can drive the pin high/low using software then by definition it *is* GPIO. Even if it cannot trigger IRQs or anything. The rationale for having it in pinconf-generic is basically for use cases such that one of the the pin config states the device pass through may relate to what the documentation calls the "GPIO mode fallacy" - a state on the pins that is definately related to the use case of a certain device, but puts the pin in something the manual calls "GPIO mode" in order to save power. But from a use case point of view that is not GPIO, it is the typically the sleep state of a certain pin when used with a certain device. I'll see if I can think of some doc patch to make this more clear... Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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