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Diffstat (limited to '')
| -rw-r--r-- | Documentation/driver-api/gpio/intro.rst | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/Documentation/driver-api/gpio/intro.rst b/Documentation/driver-api/gpio/intro.rst index 74591489d0b5..c9c19243b97f 100644 --- a/Documentation/driver-api/gpio/intro.rst +++ b/Documentation/driver-api/gpio/intro.rst @@ -14,12 +14,12 @@ Due to the history of GPIO interfaces in the kernel, there are two different ways to obtain and use GPIOs: - The descriptor-based interface is the preferred way to manipulate GPIOs, - and is described by all the files in this directory excepted gpio-legacy.txt. + and is described by all the files in this directory excepted legacy.rst. - The legacy integer-based interface which is considered deprecated (but still - usable for compatibility reasons) is documented in gpio-legacy.txt. + usable for compatibility reasons) is documented in legacy.rst. The remainder of this document applies to the new descriptor-based interface. -gpio-legacy.txt contains the same information applied to the legacy +legacy.rst contains the same information applied to the legacy integer-based interface. @@ -27,7 +27,7 @@ What is a GPIO? =============== A "General Purpose Input/Output" (GPIO) is a flexible software-controlled -digital signal. They are provided from many kinds of chip, and are familiar +digital signal. They are provided from many kinds of chips, and are familiar to Linux developers working with embedded and custom hardware. Each GPIO represents a bit connected to a particular pin, or "ball" on Ball Grid Array (BGA) packages. Board schematics show which external hardware connects to @@ -106,11 +106,11 @@ don't. When you need open drain signaling but your hardware doesn't directly support it, there's a common idiom you can use to emulate it with any GPIO pin that can be used as either an input or an output: - LOW: gpiod_direction_output(gpio, 0) ... this drives the signal and overrides - the pullup. + **LOW**: ``gpiod_direction_output(gpio, 0)`` ... this drives the signal and + overrides the pullup. - HIGH: gpiod_direction_input(gpio) ... this turns off the output, so the pullup - (or some other device) controls the signal. + **HIGH**: ``gpiod_direction_input(gpio)`` ... this turns off the output, so + the pullup (or some other device) controls the signal. The same logic can be applied to emulate open source signaling, by driving the high signal and configuring the GPIO as input for low. This open drain/open |