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-rw-r--r-- | Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt | 135 |
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diff --git a/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt new file mode 100644 index 000000000..02e971c39 --- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/nvidia,tegra124-xusb-padctl.txt @@ -0,0 +1,135 @@ +Device tree binding for NVIDIA Tegra XUSB pad controller +======================================================== + +NOTE: It turns out that this binding isn't an accurate description of the XUSB +pad controller. While the description is good enough for the functional subset +required for PCIe and SATA, it lacks the flexibility to represent the features +needed for USB. For the new binding, see ../phy/nvidia,tegra-xusb-padctl.txt. +The binding described in this file is deprecated and should not be used. + +The Tegra XUSB pad controller manages a set of lanes, each of which can be +assigned to one out of a set of different pads. Some of these pads have an +associated PHY that must be powered up before the pad can be used. + +This document defines the device-specific binding for the XUSB pad controller. + +Refer to pinctrl-bindings.txt in this directory for generic information about +pin controller device tree bindings and ../phy/phy-bindings.txt for details on +how to describe and reference PHYs in device trees. + +Required properties: +-------------------- +- compatible: For Tegra124, must contain "nvidia,tegra124-xusb-padctl". + Otherwise, must contain '"nvidia,<chip>-xusb-padctl", + "nvidia-tegra124-xusb-padctl"', where <chip> is tegra132 or tegra210. +- reg: Physical base address and length of the controller's registers. +- resets: Must contain an entry for each entry in reset-names. + See ../reset/reset.txt for details. +- reset-names: Must include the following entries: + - padctl +- #phy-cells: Should be 1. The specifier is the index of the PHY to reference. + See <dt-bindings/pinctrl/pinctrl-tegra-xusb.h> for the list of valid values. + +Lane muxing: +------------ + +Child nodes contain the pinmux configurations following the conventions from +the pinctrl-bindings.txt document. Typically a single, static configuration is +given and applied at boot time. + +Each subnode describes groups of lanes along with parameters and pads that +they should be assigned to. The name of these subnodes is not important. All +subnodes should be parsed solely based on their content. + +Each subnode only applies the parameters that are explicitly listed. In other +words, if a subnode that lists a function but no pin configuration parameters +implies no information about any pin configuration parameters. Similarly, a +subnode that describes only an IDDQ parameter implies no information about +what function the pins are assigned to. For this reason even seemingly boolean +values are actually tristates in this binding: unspecified, off or on. +Unspecified is represented as an absent property, and off/on are represented +as integer values 0 and 1. + +Required properties: +- nvidia,lanes: An array of strings. Each string is the name of a lane. + +Optional properties: +- nvidia,function: A string that is the name of the function (pad) that the + pin or group should be assigned to. Valid values for function names are + listed below. +- nvidia,iddq: Enables IDDQ mode of the lane. (0: no, 1: yes) + +Note that not all of these properties are valid for all lanes. Lanes can be +divided into three groups: + + - otg-0, otg-1, otg-2: + + Valid functions for this group are: "snps", "xusb", "uart", "rsvd". + + The nvidia,iddq property does not apply to this group. + + - ulpi-0, hsic-0, hsic-1: + + Valid functions for this group are: "snps", "xusb". + + The nvidia,iddq property does not apply to this group. + + - pcie-0, pcie-1, pcie-2, pcie-3, pcie-4, sata-0: + + Valid functions for this group are: "pcie", "usb3", "sata", "rsvd". + + +Example: +======== + +SoC file extract: +----------------- + + padctl@7009f000 { + compatible = "nvidia,tegra124-xusb-padctl"; + reg = <0x0 0x7009f000 0x0 0x1000>; + resets = <&tegra_car 142>; + reset-names = "padctl"; + + #phy-cells = <1>; + }; + +Board file extract: +------------------- + + pcie-controller@1003000 { + ... + + phys = <&padctl 0>; + phy-names = "pcie"; + + ... + }; + + ... + + padctl: padctl@7009f000 { + pinctrl-0 = <&padctl_default>; + pinctrl-names = "default"; + + padctl_default: pinmux { + usb3 { + nvidia,lanes = "pcie-0", "pcie-1"; + nvidia,function = "usb3"; + nvidia,iddq = <0>; + }; + + pcie { + nvidia,lanes = "pcie-2", "pcie-3", + "pcie-4"; + nvidia,function = "pcie"; + nvidia,iddq = <0>; + }; + + sata { + nvidia,lanes = "sata-0"; + nvidia,function = "sata"; + nvidia,iddq = <0>; + }; + }; + }; |