Re: [PATCH v1 1/1] Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit

From: Rafael J. Wysocki
Date: Mon Feb 13 2023 - 13:39:28 EST


On Mon, Feb 13, 2023 at 2:27 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> Clarify the Explicit and Implicit meanings in the table of Pull Bias.
>
> While at it, distinguish pull bias keywords used in ACPI by using bold
> font in the table of the respective terms.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> .../firmware-guide/acpi/gpio-properties.rst | 25 +++++++++++--------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/firmware-guide/acpi/gpio-properties.rst b/Documentation/firmware-guide/acpi/gpio-properties.rst
> index eaec732cc77c..ae87aa64cb7b 100644
> --- a/Documentation/firmware-guide/acpi/gpio-properties.rst
> +++ b/Documentation/firmware-guide/acpi/gpio-properties.rst
> @@ -67,17 +67,20 @@ state of the output pin which driver should use during its initialization.
> Linux tries to use common sense here and derives the state from the bias
> and polarity settings. The table below shows the expectations:
>
> -========= ============= ==============
> -Pull Bias Polarity Requested...
> -========= ============= ==============
> -Implicit x AS IS (assumed firmware configured for us)
> -Explicit x (no _DSD) as Pull Bias (Up == High, Down == Low),
> - assuming non-active (Polarity = !Pull Bias)
> -Down Low as low, assuming active
> -Down High as low, assuming non-active
> -Up Low as high, assuming non-active
> -Up High as high, assuming active
> -========= ============= ==============
> +========= ============= ==============
> +Pull Bias Polarity Requested...
> +========= ============= ==============
> +Implicit x AS IS (assumed firmware configured it for us)
> +(**Default**)
> +Explicit x (no _DSD) as Pull Bias (**Up** == high, **Down** == low),
> +(**Up**, **Down**, assuming non-active (Polarity = !Pull Bias);
> + **None**) or AS IS (assumed firmware configured it for us)
> + with no Pull Bias
> +**Down** Low as low, assuming active
> +**Down** High as low, assuming non-active
> +**Up** Low as high, assuming non-active
> +**Up** High as high, assuming active
> +========= ============= ==============
>
> That said, for our above example the both GPIOs, since the bias setting
> is explicit and _DSD is present, will be treated as active with a high
> --

Applied as 6.3 material, thanks!