RE: [Patch-V2 1/4] dt-binding: Tegra194 pinctrl support

[Krishna Yarlagadda]

> -----Original Message-----
> From: Jonathan Hunter <jonathanh@xxxxxxxxxx>
> Sent: Thursday, May 9, 2019 3:12 PM
> To: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>; linus.walleij@xxxxxxxxxx;
> thierry.reding@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-
> gpio@xxxxxxxxxxxxxxx; linux-tegra@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx
> Cc: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>; Joseph Lo
> <josephl@xxxxxxxxxx>; Suresh Mangipudi <smangipudi@xxxxxxxxxx>;
> Laxman Dewangan <ldewangan@xxxxxxxxxx>; Vidya Sagar
> <vidyas@xxxxxxxxxx>
> Subject: Re: [Patch-V2 1/4] dt-binding: Tegra194 pinctrl support
> 
> 
> On 09/05/2019 09:08, Krishna Yarlagadda wrote:
> > Add binding doc for Tegra 194 pinctrl driver
> >
> > Signed-off-by: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx>
> > ---
> > Changes in V2:
> > created new binding doc to handle Tegra194 pinctrl driver
> >
> >  .../bindings/pinctrl/nvidia,tegra194-pinmux.txt    | 116
> +++++++++++++++++++++
> >  1 file changed, 116 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/pinctrl/nvidia,tegra194-pinmux.txt
> >
> > diff --git
> > a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra194-pinmux.txt
> > b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra194-pinmux.txt
> > new file mode 100644
> > index 0000000..80e36c7
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra194-pinmux
> > +++ .txt
> > @@ -0,0 +1,116 @@
> > +NVIDIA Tegra194 pinmux controller
> > +
> > +Required properties:
> > +- compatible: "nvidia,tegra194-pinmux"
> > +- reg: Should contain a list of base address and size pairs for:
> > +  - first entry: The APB_MISC_GP_*_PADCTRL registers (pad control)
> > +  - second entry: The PINMUX_AUX_* registers (pinmux)
> > +
> > +Please refer to pinctrl-bindings.txt in this directory for details of
> > +the common pinctrl bindings used by client devices, including the
> > +meaning of the phrase "pin configuration node".
> > +
> > +Tegra's pin configuration nodes act as a container for an arbitrary
> > +number of subnodes. Each of these subnodes represents some desired
> > +configuration for a pin, a group, or a list of pins or groups. This
> > +configuration can include the mux function to select on those
> > +pin(s)/group(s), and various pin configuration parameters, such as pull-up,
> tristate, drive strength, etc.
> > +
> > +See the TRM to determine which properties and values apply to each
> pin/group.
> > +Macro values for property values are defined in
> > +include/dt-binding/pinctrl/pinctrl-tegra.h.
> > +
> > +Required subnode-properties:
> > +- nvidia,pins : An array of strings. Each string contains the name of a pin or
> > +    group. Valid values for these names are listed below.
> > +
> > +Optional subnode-properties:
> > +- nvidia,function: A string containing the name of the function to mux to
> the
> > +    pin or group.
> > +- nvidia,pull: Integer, representing the pull-down/up to apply to the pin.
> > +    0: none, 1: down, 2: up.
> > +- nvidia,tristate: Integer.
> > +    0: drive, 1: tristate.
> > +- nvidia,enable-input: Integer. Enable the pin's input path.
> > +    enable :TEGRA_PIN_ENABLE and
> > +    disable or output only: TEGRA_PIN_DISABLE.
> > +- nvidia,open-drain: Integer.
> > +    enable: TEGRA_PIN_ENABLE.
> > +    disable: TEGRA_PIN_DISABLE.
> > +- nvidia,lock: Integer. Lock the pin configuration against further changes
> > +    until reset.
> > +    enable: TEGRA_PIN_ENABLE.
> > +    disable: TEGRA_PIN_DISABLE.
> > +- nvidia,io-hv: Integer. Select high-voltage receivers.
> > +    normal: TEGRA_PIN_DISABLE
> > +    high: TEGRA_PIN_ENABLE
> > +- nvidia,high-speed-mode: Integer. Enable high speed mode the pins.
> > +    normal: TEGRA_PIN_DISABLE
> > +    high: TEGRA_PIN_ENABLE
> > +- nvidia,schmitt: Integer. Enables Schmitt Trigger on the input.
> > +    normal: TEGRA_PIN_DISABLE
> > +    high: TEGRA_PIN_ENABLE
> > +- nvidia,drive-type: Integer. Valid range 0...3.
> > +- nvidia,pull-down-strength: Integer. Controls drive strength. 0 is weakest.
> > +    The range of valid values depends on the pingroup. See "CAL_DRVDN"
> in the
> > +    Tegra TRM.
> > +- nvidia,pull-up-strength: Integer. Controls drive strength. 0 is weakest.
> > +    The range of valid values depends on the pingroup. See "CAL_DRVUP"
> in the
> > +    Tegra TRM.
> > +- nvidia,slew-rate-rising: Integer. Controls rising signal slew rate. 0 is
> > +    fastest. The range of valid values depends on the pingroup. See
> > +    "DRVDN_SLWR" in the Tegra TRM.
> > +- nvidia,slew-rate-falling: Integer. Controls falling signal slew rate. 0 is
> > +    fastest. The range of valid values depends on the pingroup. See
> > +    "DRVUP_SLWF" in the Tegra TRM.
> 
> Are all these properties applicable to the pex_l5_clkreq and pex_l5_rst pins?
> Particularly the slew-rate properties?
> 
> Cheers
> Jon
Slew-rate, high-speed-mode are supported by driver but not these pins.
Will remove properties not supported by pex pins in next version.
> 
> --
> nvpublic