On Thu, Jun 23, 2016 at 04:59:02PM +0100, Jon Hunter wrote: > On Tegra124, Tegra132 and Tegra210 devices the pads used by the Display > Port Auxiliary (DPAUX) channel are multiplexed such that they can also > be used by one of the internal I2C controllers. Note that this is > different from I2C-over-AUX supported by the DPAUX controller. The > register that configures these pads is part of the DPAUX controllers > register set and so a pinctrl driver is being added for the DPAUX device > to share these pads. Add the device-tree binding documentation for the > DPAUX pad controller. > > Although there is only one group of pads associated with the DPAUX that > can be multiplexed, the group still needs to be described by the binding. > If the 'groups' property is not present in the binding, then the pads > will not be allocated by the pinctrl core for a client and this would > allow another client to re-configure the same pads that may already be > in-use. > > Please note that although the "off" function for the DPAUX pads is not > technically a pin-mux setting but more of a pin-conf setting it is > simpler to expose these as a function so that the user can simply select > either "aux", "i2c" or "off" as the current function/mode. > > Update the main DPAUX binding documentation to reference the DPAUX pad > controller binding document and add the 'i2c-bus' subnode. The 'i2c-bus' > subnode is used for populating I2C slaves for the DPAUX device so that > the I2C driver core does not attempt to add the DPAUX pad controller > nodes as I2C slaves. > > Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> > --- > .../display/tegra/nvidia,tegra20-host1x.txt | 6 +++ > .../pinctrl/nvidia,tegra124-dpaux-padctl.txt | 60 ++++++++++++++++++++++ > 2 files changed, 66 insertions(+) > create mode 100644 Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-dpaux-padctl.txt > > diff --git a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt > index 275f45680892..d0f1dc62550a 100644 > --- a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt > +++ b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.txt > @@ -241,6 +241,12 @@ of the following host1x client modules: > - reset-names: Must include the following entries: > - dpaux > - vdd-supply: phandle of a supply that powers the DisplayPort link > + - i2c-bus: Subnode where I2C slave devices are listed. This subnode > + must be always present. If there are no I2C slave devices, an empty > + node should be added. See ../../i2c/i2c.txt for more information. > + > + See ../pinctrl/nvidia,tegra124-dpaux-padctl.txt for information > + regarding the DPAUX pad controller bindings. > > Example: > > diff --git a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-dpaux-padctl.txt b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-dpaux-padctl.txt > new file mode 100644 > index 000000000000..656e0a04be8f > --- /dev/null > +++ b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-dpaux-padctl.txt > @@ -0,0 +1,60 @@ > +Device tree binding for NVIDIA Tegra DPAUX pad controller > +======================================================== > + > +The Tegra Display Port Auxiliary (DPAUX) pad controller manages two pins > +which can be assigned to either the DPAUX channel or to an I2C > +controller. > + > +This document defines the device-specific binding for the DPAUX pad > +controller. Refer to pinctrl-bindings.txt in this directory for generic > +information about pin controller device tree bindings. Please refer to > +the binding document ../display/tegra/nvidia,tegra20-host1x.txt for more > +details on the DPAUX binding. > + > +Pin muxing: > +----------- > + > +Child nodes contain the pinmux configurations following the conventions > +from the pinctrl-bindings.txt document. > + > +Since only three configurations are possible, only three child nodes are > +needed to describe the pin mux'ing options for the DPAUX pads. > +Furthermore, given that the pad functions are only applicable to a > +single set of pads, the child nodes only need to describe the pad group > +the functions are being applied to rather than the individual pads. > + > +Required properties: > +- groups: Must be "dpaux-io" > +- function: Must be either "aux", "i2c" or "off". > + > +Example: > +-------- > + > + dpaux@545c0000 { > + ... > + > + state_dpaux_aux: pinmux_aux { Use '-' for node names. With that: Acked-by: Rob Herring <robh@xxxxxxxxxx> > + groups = "dpaux-io"; > + function = "aux"; > + }; > + > + state_dpaux_i2c: pinmux_i2c { > + groups = "dpaux-io"; > + function = "i2c"; > + }; > + > + state_dpaux_off: pinmux_off { > + groups = "dpaux-io"; > + function = "off"; > + }; > + }; > + > + ... > + > + i2c@7000d100 { > + ... > + pinctrl-0 = <&state_dpaux_i2c>; > + pinctrl-1 = <&state_dpaux_off>; > + pinctrl-names = "default", "idle"; > + status = "disabled"; > + }; > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html