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Diffstat (limited to 'Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt')
-rw-r--r-- | Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt index a74b37b07e5c..cb12f33a247f 100644 --- a/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt +++ b/Documentation/devicetree/bindings/arm/tegra/nvidia,tegra20-pmc.txt @@ -195,3 +195,106 @@ Example: power-domains = <&pd_audio>; ... }; + +== Pad Control == + +On Tegra SoCs a pad is a set of pins which are configured as a group. +The pin grouping is a fixed attribute of the hardware. The PMC can be +used to set pad power state and signaling voltage. A pad can be either +in active or power down mode. The support for power state and signaling +voltage configuration varies depending on the pad in question. 3.3 V and +1.8 V signaling voltages are supported on pins where software +controllable signaling voltage switching is available. + +The pad configuration state nodes are placed under the pmc node and they +are referred to by the pinctrl client properties. For more information +see Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt. +The pad name should be used as the value of the pins property in pin +configuration nodes. + +The following pads 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 + +The following pads 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 + +Required pin configuration properties: + - pins: Must contain name of the pad(s) to be configured. + +Optional pin configuration properties: + - low-power-enable: Configure the pad into power down mode + - low-power-disable: Configure the pad into active mode + - power-source: Must contain either TEGRA_IO_PAD_VOLTAGE_1V8 + or TEGRA_IO_PAD_VOLTAGE_3V3 to select between signaling voltages. + The values are defined in + include/dt-bindings/pinctrl/pinctrl-tegra-io-pad.h. + +Note: The power state can be configured on all of the Tegra124 and + Tegra132 pads. None of the Tegra124 or Tegra132 pads support + signaling voltage switching. + +Note: All of the listed Tegra210 pads except pex-cntrl support power + state configuration. Signaling voltage switching is supported on + following Tegra210 pads: 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"; + }; |