lcd-panel.dtsi

// The "ports" linking lcdc to its panel are officially required, and you
// get a warning for omitting them.  But, if you uncomment them then lcdc
// actually no longer works.  The framebuffer never appears.  Lol.

&lcdc {
    status = "okay";

    // "straight" if d0 is blue, typical for 16-bit color (supports RGB565, BGR888, and XBGR8888)
    // "crossed" if d0 is red, typical for 24-bit color (supports BGR565, RGB888, and XRGB8888)
    blue-and-red-wiring = "straight";

//  port {
//      lcd_output: endpoint {
//          remote-endpoint = <&lcd_input>;
//      };
//  };
};

/ {
    lcd-panel {
        compatible = "ti,tilcdc,panel";

        pinctrl-names = "default";
        pinctrl-0 = <&lcd_pins>;

        enable-gpios = <&gpio1 13 0>;

//      port {
//          lcd_input: endpoint {
//              remote-endpoint = <&lcd_output>;
//          };
//      };

        panel-info {
            // all these properties are required by the driver,
            // even the ones which are completely useless.

            // pixel format
            bpp               = <16>;   // bits/pixel

            // by default, data and OE change on rising pclk edge.
            // following property selects falling edge:
            //invert-pxl-clk;

            // pclk edge on which hsync and vsync change:
            sync-edge         = <1>;    // 0=falling, 1=rising
            // if hsync/vsync don't use same pclk edge as data/OE
            // then sync is delayed by 1/2 clock, increasing the
            // back porch and decreasing the front porch time.

            // useless but must be 1
            sync-ctrl         = <1>;

            // DMA config
            dma-burst-sz      = <16>;   // burst size (words)
            fifo-th           = <4>;    // FIFO threshold

            // for palette mode only, which isn't even supported
            raster-order      = <0>;
            fdd               = <0x80>;
            //tft-alt-mode;

            // for passive matrix only, which isn't even supported
            ac-bias           = <255>;
            ac-bias-intrpt    = <0>;
        };

        display-timings {
            // ranges supported by LCDC:
            //  1-2048  vactive, hactive
            //  1-64    vsync, hsync
            //  0-255   vfront, vback
            //  1-256   hfront, vback
            // hactive must additionally be multiple of 16 pixels.

            native-mode = <&lcd_mode>;

            lcd_mode: 1024x786-60 {
                vactive     = < 768>;
                hactive     = <1024>;

                // our panel specifies:
                //       min     typ     max
                //  hblank   216     320     440    pixels
                //  vblank     6      38      80    lines
                //  vfreq     56      60      75    Hz
                //  pfreq     57.5    64.9    74.4  MHz
                //
                // hsync/vsync not used

                // VESA timings for 1024x768p60:
                // (+/- after sync indicates polarity)
                //       DMT     GTF     CVT
                //  vfront     3       1       3
                //  vsync      6-      3+      4+
                //  vback     29      23      23
                //
                //  vblank    38      27      30
                //  vtotal   806     795     798
                //
                //  hfreq    ~48.4    47.7   ~47.9  kHz
                //
                //  hfront    24      56      48
                //  hsync    136-    104-    104-
                //  hback    160     160     152
                //
                //  hblank   320     320     304
                //  htotal  1344    1344    1328
                //
                //  pfreq    ~65.0   ~64.1   ~63.6  MHz
                //
                // DMT matches panel 'typ', let's use that.

                // note: you can also specify <min typ max>

                vfront-porch    = <   3>;
                vsync-len   = <   6>;
                vback-porch = <  29>;

                hfront-porch    = <  24>;
                hsync-len   = < 136>;
                hback-porch = < 160>;

                clock-frequency = <65000000>;

                // 0 = active low
                // 1 = active high
                // omitted = unused
                de-active   = <1>;  // lcdc ignores this
                pixelclk-active = <1>;  // lcdc ignores this
                vsync-active    = <0>;
                hsync-active    = <1>;
            };
        };
    };
};