xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/display/ste,mcde.txt

ST-Ericsson Multi Channel Display Engine MCDE

The ST-Ericsson MCDE is a display controller with support for compositing
and displaying several channels memory resident graphics data on DSI or
LCD displays or bridges. It is used in the ST-Ericsson U8500 platform.

Required properties:

- compatible: must be:
  "ste,mcde"
- reg: register base for the main MCDE control registers, should be
  0x1000 in size
- interrupts: the interrupt line for the MCDE
- epod-supply: a phandle to the EPOD regulator
- vana-supply: a phandle to the analog voltage regulator
- clocks: an array of the MCDE clocks in this strict order:
  MCDECLK (main MCDE clock), LCDCLK (LCD clock), PLLDSI
  (HDMI clock), DSI0ESCLK (DSI0 energy save clock),
  DSI1ESCLK (DSI1 energy save clock), DSI2ESCLK (DSI2 energy
  save clock)
- clock-names: must be the following array:
  "mcde", "lcd", "hdmi"
  to match the required clock inputs above.
- #address-cells: should be <1> (for the DSI hosts that will be children)
- #size-cells: should be <1> (for the DSI hosts that will be children)
- ranges: this should always be stated

Required subnodes:

The devicetree must specify subnodes for the DSI host adapters.
These must have the following characteristics:

- compatible: must be:
  "ste,mcde-dsi"
- reg: must specify the register range for the DSI host
- vana-supply: phandle to the VANA voltage regulator
- clocks: phandles to the high speed and low power (energy save) clocks
  the high speed clock is not present on the third (dsi2) block, so it
  should only have the "lp" clock
- clock-names: "hs" for the high speed clock and "lp" for the low power
  (energy save) clock
- #address-cells: should be <1>
- #size-cells: should be <0>

Display panels and bridges will appear as children on the DSI hosts, and
the displays are connected to the DSI hosts using the common binding
for video transmitter interfaces; see
Documentation/devicetree/bindings/media/video-interfaces.txt

If a DSI host is unused (not connected) it will have no children defined.

Example:

mcde@a0350000 {
	compatible = "ste,mcde";
	reg = <0xa0350000 0x1000>;
	interrupts = <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
	epod-supply = <&db8500_b2r2_mcde_reg>;
	vana-supply = <&ab8500_ldo_ana_reg>;
	clocks = <&prcmu_clk PRCMU_MCDECLK>, /* Main MCDE clock */
		 <&prcmu_clk PRCMU_LCDCLK>, /* LCD clock */
		 <&prcmu_clk PRCMU_PLLDSI>; /* HDMI clock */
	clock-names = "mcde", "lcd", "hdmi";
	#address-cells = <1>;
	#size-cells = <1>;
	ranges;

	dsi0: dsi@a0351000 {
		compatible = "ste,mcde-dsi";
		reg = <0xa0351000 0x1000>;
		vana-supply = <&ab8500_ldo_ana_reg>;
		clocks = <&prcmu_clk PRCMU_DSI0CLK>, <&prcmu_clk PRCMU_DSI0ESCCLK>;
		clock-names = "hs", "lp";
		#address-cells = <1>;
		#size-cells = <0>;

		panel {
			compatible = "samsung,s6d16d0";
			reg = <0>;
			vdd1-supply = <&ab8500_ldo_aux1_reg>;
			reset-gpios = <&gpio2 1 GPIO_ACTIVE_LOW>;
		};

	};
	dsi1: dsi@a0352000 {
		compatible = "ste,mcde-dsi";
		reg = <0xa0352000 0x1000>;
		vana-supply = <&ab8500_ldo_ana_reg>;
		clocks = <&prcmu_clk PRCMU_DSI1CLK>, <&prcmu_clk PRCMU_DSI1ESCCLK>;
		clock-names = "hs", "lp";
		#address-cells = <1>;
		#size-cells = <0>;
	};
	dsi2: dsi@a0353000 {
		compatible = "ste,mcde-dsi";
		reg = <0xa0353000 0x1000>;
		vana-supply = <&ab8500_ldo_ana_reg>;
		/* This DSI port only has the Low Power / Energy Save clock */
		clocks = <&prcmu_clk PRCMU_DSI2ESCCLK>;
		clock-names = "lp";
		#address-cells = <1>;
		#size-cells = <0>;
	};
};