| Message ID | 20230213132812.38646-1-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v1,1/1] Documentation: firmware-guide: gpio-properties: Clarify Explicit and Implicit | expand |
On Mon, Feb 13, 2023 at 2:27 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> 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@linux.intel.com> > --- > .../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!
On Mon, Feb 13, 2023 at 07:39:10PM +0100, Rafael J. Wysocki wrote: > On Mon, Feb 13, 2023 at 2:27 PM Andy Shevchenko > <andriy.shevchenko@linux.intel.com> wrote: > > ... > > 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! Can you withdraw it for now, please? It has some formatting issues. I will fix and send a new version instead. Thank you!
On Mon, Feb 13, 2023 at 7:55 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Mon, Feb 13, 2023 at 07:39:10PM +0100, Rafael J. Wysocki wrote: > > On Mon, Feb 13, 2023 at 2:27 PM Andy Shevchenko > > <andriy.shevchenko@linux.intel.com> wrote: > > > > > ... > > > > 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! > > Can you withdraw it for now, please? It has some formatting issues. > I will fix and send a new version instead. Sure.
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
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@linux.intel.com> --- .../firmware-guide/acpi/gpio-properties.rst | 25 +++++++++++-------- 1 file changed, 14 insertions(+), 11 deletions(-)