[FAQ] DRA829V: How do I find documentation for Linux Kernel device tree files

In general all the device tree documentation is captured in Linus Kernel documentation folder - Documentation/devicetree/bindings/

Below is an example on how to find the devicetree documentation file and the corresponding driver by using the compatible field of a node.

MMC node:

        main_sdhci0: sdhci@4f80000 {
                compatible = "ti,j721e-sdhci-8bit";
                reg = <0x0 0x4f80000 0x0 0x1000>, <0x0 0x4f88000 0x0 0x400>;
                interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
                power-domains = <&k3_pds 91 TI_SCI_PD_EXCLUSIVE>;
                clock-names = "clk_xin", "clk_ahb";
                clocks = <&k3_clks 91 1>, <&k3_clks 91 0>;
                assigned-clocks = <&k3_clks 91 1>;
                assigned-clock-parents = <&k3_clks 91 2>;
                bus-width = <8>;
                mmc-ddr-1_8v;
                ti,otap-del-sel-legacy = <0x0>;
                ti,otap-del-sel-mmc-hs = <0x0>;
                ti,otap-del-sel-ddr52 = <0x5>;
                ti,otap-del-sel-hs200 = <0x6>;
                ti,otap-del-sel-hs400 = <0x0>;
                ti,trm-icp = <0x8>;
                ti,strobe-sel = <0x77>;
                dma-coherent;
        };

Identifying the devicetree documentation:

Looking for the compatible string in the Documentation folder will help in finding the documentation associated with this node.
In this example, sdhci-am654.txt file will have details of the properties used in this node.

ti-linux-kernel$ git grep "ti,j721e-sdhci-8bit" Documentation/devicetree/bindings/
Documentation/devicetree/bindings/mmc/sdhci-am654.txt: "ti,j721e-sdhci-8bit": 8 bit SDHCI on J721E device.
Documentation/devicetree/bindings/mmc/sdhci-am654.txt: ti,j721e-sdhci-8bit,


Identifying the Kernel driver associated:

Looking for the same compatible field in the driver folder will help in identifying the driver associated with the node.
In this example, sdhci_am654.c is the driver associated with this node.

ti-linux-kernel$ git grep "ti,j721e-sdhci-8bit" drivers/
drivers/mmc/host/sdhci_am654.c: .compatible = "ti,j721e-sdhci-8bit",