4c0facddb7
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: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
32 lines
906 B
C
32 lines
906 B
C
/*
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* This header provides constants for most GPIO bindings.
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*
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* Most GPIO bindings include a flags cell as part of the GPIO specifier.
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* In most cases, the format of the flags cell uses the standard values
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* defined in this header.
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*/
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#ifndef _DT_BINDINGS_GPIO_GPIO_H
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#define _DT_BINDINGS_GPIO_GPIO_H
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/* Bit 0 express polarity */
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#define GPIO_ACTIVE_HIGH 0
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#define GPIO_ACTIVE_LOW 1
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/* Bit 1 express single-endedness */
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#define GPIO_PUSH_PULL 0
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#define GPIO_SINGLE_ENDED 2
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/* Bit 2 express Open drain or open source */
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#define GPIO_LINE_OPEN_SOURCE 0
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#define GPIO_LINE_OPEN_DRAIN 4
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/*
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* Open Drain/Collector is the combination of single-ended open drain interface.
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* Open Source/Emitter is the combination of single-ended open source interface.
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*/
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#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN)
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#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE)
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#endif
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