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

[Aapo Vienamo <avienamo@nvidia.com>]

On Mon, 16 Jul 2018 09:43:09 -0600
Rob Herring <robh@kernel.org> wrote:

> 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@nvidia.com>
> > Acked-by: Jon Hunter <jonathanh@nvidia.com>
> > ---
> >  .../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.

Isn't it a generic pinctrl property?

> > +
> > +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@nvidia.com>
> > + */
> > +
> > +#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
> >   

 -Aapo