Re: [PATCH v3 5/7] dt-bindings: Add Tegra PMC pad configuration bindings

From: Rob Herring
Date: Mon Jul 16 2018 - 11:43:15 EST


On Thu, Jul 12, 2018 at 03:00:11PM +0300, Aapo Vienamo wrote:
> Document the pinctrl bindings used by the PMC driver for performing pad
> configuration. Both nvidia,tegra186-pmc.txt and nvidia,tegra20-pmc.txt
> are modified as they both cover SoC generations for which these bindings
> apply.
>
> Add a header defining Tegra PMC pad voltage configurations.
>
> Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx>
> Acked-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> ---
> .../bindings/arm/tegra/nvidia,tegra186-pmc.txt | 84 +++++++++++++++++++
> .../bindings/arm/tegra/nvidia,tegra20-pmc.txt | 95 ++++++++++++++++++++++
> include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h | 18 ++++
> 3 files changed, 197 insertions(+)
> create mode 100644 include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h
>
> diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra186-pmc.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra186-pmc.txt
> index 5a3bf7c..9528f41 100644
> --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra186-pmc.txt
> +++ b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra186-pmc.txt
> @@ -34,3 +34,87 @@ Board DTS:
> pmc@c360000 {
> nvidia,invert-interrupt;
> };
> +
> +== Pad Control Nodes ==
> +
> +The PMC can be used to set pad power state and voltage configuration.
> +The pad configuration is done via the pinctrl framework. The driver
> +implements power-source, low-power-enable, and low-power-disable pinconf
> +pin configuration node properties. Each pinctrl pin corresponds to a
> +single Tegra PMC pad. Thus, in the following sections of this document
> +pin refers to the pinctrl frameworks notion of a Tegra PMC pad.

"pinctrl framework" is Linux specific and doesn't belong in the binding.
Neither does what a driver supports. Describe what the h/w supports.

> +
> +The pad configuration state nodes are placed under the pmc node and they
> +are referred to by the pinctrl client device properties. For more

Another driver detail not relevant.

> +information see the examples presented later and

examples don't document bindings. The documentation should be complete
without examples.

> +Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt.
> +
> +The values accepted by power-source property are
> +TEGRA_IO_PAD_VOLTAGE_1V8 and TEGRA_IO_PAD_VOLTAGE_3V3, which are defined
> +in dt-bindings/pinctrl/pinctrl-tegra-io-pad.h.

You need to list out what properties the child nodes can have.

power-source needs a vendor prefix.

> +
> +Following pinctrl pin name strings are present on Tegra186:
> +csia csib dsi mipi-bias
> +pex-clk-bias pex-clk3 pex-clk2 pex-clk1
> +usb0 usb1 usb2 usb-bias
> +uart audio hsic dbg
> +hdmi-dp0 hdmi-dp1 pex-cntrl sdmmc2-hv
> +sdmmc4 cam dsib dsic
> +dsid csic csid csie
> +dsif spi ufs dmic-hv
> +edp sdmmc1-hv sdmmc3-hv conn
> +audio-hv ao-hv
> +
> +All of the listed Tegra186 pins except ao-hv support the
> +low-power-enable and low-power-disable properties. The power-source
> +property is supported following Tegra210 pins: sdmmc2-hv, dmic-hv,
> +sdmmc1-hv, sdmmc3-hv, audio-hv, ao-hv.
> +
> +Pad configuration state example:
> + pmc: pmc@7000e400 {
> + compatible = "nvidia,tegra186-pmc";
> + reg = <0 0x0c360000 0 0x10000>,
> + <0 0x0c370000 0 0x10000>,
> + <0 0x0c380000 0 0x10000>,
> + <0 0x0c390000 0 0x10000>;
> + reg-names = "pmc", "wake", "aotag", "scratch";
> +
> + ...
> +
> + sdmmc1_3v3: sdmmc1-3v3 {
> + pins = "sdmmc1-hv";
> + power-source = <TEGRA_IO_PAD_VOLTAGE_3V3>;
> + };
> +
> + sdmmc1_1v8: sdmmc1-1v8 {
> + pins = "sdmmc1-hv";
> + power-source = <TEGRA_IO_PAD_VOLTAGE_1V8>;
> + };
> +
> + hdmi_off: hdmi-off {
> + pins = "hdmi";
> + low-power-enable;
> + }
> +
> + hdmi_on: hdmi-on {
> + pins = "hdmi";
> + low-power-disable;
> + }
> + };
> +
> +Pinctrl client example:
> + sdmmc1: sdhci@3400000 {
> + ...
> + pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
> + pinctrl-0 = <&sdmmc1_3v3>;
> + pinctrl-1 = <&sdmmc1_1v8>;
> + };
> +
> + ...
> +
> + sor0: sor@15540000 {
> + ...
> + pinctrl-0 = <&hdmi_off>;
> + pinctrl-1 = <&hdmi_on>;
> + pinctrl-names = "hdmi-on", "hdmi-off";
> + };
> diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt
> index a74b37b..d50a505 100644
> --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt
> +++ b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt
> @@ -195,3 +195,98 @@ Example:
> power-domains = <&pd_audio>;
> ...
> };
> +
> +== Pad Control Nodes ==

Similar comments in this file.

> +
> +The PMC can be used to set pad power state and voltage configuration.
> +This functionality is present on SoCs from Tegra124 onwards. The pad
> +configuration is done via the pinctrl framework. The driver implements
> +power-source, low-power-enable, and low-power-disable pinconf pin
> +configuration node properties. Each pinctrl pin corresponds to a single
> +Tegra PMC pad. Thus, in the following sections of this document pin
> +refers to the pinctrl frameworks notion of a Tegra PMC pad.
> +
> +The pad configuration state nodes are placed under the pmc node and they
> +are referred to by the pinctrl client device properties. For more
> +information see the examples presented later and
> +Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt.
> +
> +The values accepted by power-source property are
> +TEGRA_IO_PAD_VOLTAGE_1V8 and TEGRA_IO_PAD_VOLTAGE_3V3, which are defined
> +in dt-bindings/pinctrl/pinctrl-tegra-io-pad.h.
> +
> +Following pinctrl pin name strings are present on Tegra124 and Tegra132:
> +audio bb cam comp
> +csia csb cse dsi
> +dsib dsic dsid hdmi
> +hsic hv lvds mipi-bias
> +nand pex-bias pex-clk1 pex-clk2
> +pex-cntrl sdmmc1 sdmmc3 sdmmc4
> +sys_ddc uart usb0 usb1
> +usb2 usb_bias
> +
> +All of the listed Tegra124 and Tegra132 pins support the
> +low-power-enable and low-power-disable properties. None of the pins
> +support the power-source property.
> +
> +Following pinctrl pin name strings are present on Tegra210:
> +audio audio-hv cam csia
> +csib csic csid csie
> +csif dbg debug-nonao dmic
> +dp dsi dsib dsic
> +dsid emmc emmc2 gpio
> +hdmi hsic lvds mipi-bias
> +pex-bias pex-clk1 pex-clk2 pex-cntrl
> +sdmmc1 sdmmc3 spi spi-hv
> +uart usb0 usb1 usb2
> +usb3 usb-bias
> +
> +All of the listed Tegra210 pins except pex-cntrl support the
> +low-power-enable and low-power-disable properties. The power-source
> +property is supported following Tegra210 pins: audio, audio-hv, cam,
> +dbg, dmic, gpio, pex-cntrl, sdmmc1, sdmmc3, spi, spi-hv, and uart.
> +
> +Pad configuration state example:
> + pmc: pmc@7000e400 {
> + compatible = "nvidia,tegra210-pmc";
> + reg = <0x0 0x7000e400 0x0 0x400>;
> + clocks = <&tegra_car TEGRA210_CLK_PCLK>, <&clk32k_in>;
> + clock-names = "pclk", "clk32k_in";
> +
> + ...
> +
> + sdmmc1_3v3: sdmmc1-3v3 {
> + pins = "sdmmc1";
> + power-source = <TEGRA_IO_PAD_VOLTAGE_3V3>;
> + };
> +
> + sdmmc1_1v8: sdmmc1-1v8 {
> + pins = "sdmmc1";
> + power-source = <TEGRA_IO_PAD_VOLTAGE_1V8>;
> + };
> +
> + hdmi_off: hdmi-off {
> + pins = "hdmi";
> + low-power-enable;
> + }
> +
> + hdmi_on: hdmi-on {
> + pins = "hdmi";
> + low-power-disable;
> + }
> + };
> +
> +Pinctrl client example:
> + sdmmc1: sdhci@700b0000 {
> + ...
> + pinctrl-names = "sdmmc-3v3", "sdmmc-1v8";
> + pinctrl-0 = <&sdmmc1_3v3>;
> + pinctrl-1 = <&sdmmc1_1v8>;
> + };
> + ...
> + sor@54540000 {
> + ...
> + pinctrl-0 = <&hdmi_off>;
> + pinctrl-1 = <&hdmi_on>;
> + pinctrl-names = "hdmi-on", "hdmi-off";
> + };
> diff --git a/include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h b/include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h
> new file mode 100644
> index 0000000..20f4340
> --- /dev/null
> +++ b/include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h
> @@ -0,0 +1,18 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * pinctrl-tegra-io-pad.h: Tegra I/O pad source voltage configuration constants
> + * pinctrl bindings.
> + *
> + * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
> + *
> + * Author: Aapo Vienamo <avienamo@xxxxxxxxxx>
> + */
> +
> +#ifndef _DT_BINDINGS_PINCTRL_TEGRA_IO_PAD_H
> +#define _DT_BINDINGS_PINCTRL_TEGRA_IO_PAD_H
> +
> +/* Voltage levels of the I/O pad's source rail */
> +#define TEGRA_IO_PAD_VOLTAGE_1V8 0
> +#define TEGRA_IO_PAD_VOLTAGE_3V3 1
> +
> +#endif
> --
> 2.7.4
>