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+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/simple-framebuffer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Simple Framebuffer Device Tree Bindings
+
+maintainers:
+ - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
+ - Hans de Goede <hdegoede@redhat.com>
+
+description: |+
+ A simple frame-buffer describes a frame-buffer setup by firmware or
+ the bootloader, with the assumption that the display hardware has
+ already been set up to scan out from the memory pointed to by the
+ reg property.
+
+ Since simplefb nodes represent runtime information they must be
+ sub-nodes of the chosen node (*). Simplefb nodes must be named
+ framebuffer@<address>.
+
+ If the devicetree contains nodes for the display hardware used by a
+ simplefb, then the simplefb node must contain a property called
+ display, which contains a phandle pointing to the primary display
+ hw node, so that the OS knows which simplefb to disable when handing
+ over control to a driver for the real hardware. The bindings for the
+ hw nodes must specify which node is considered the primary node.
+
+ It is advised to add display# aliases to help the OS determine how
+ to number things. If display# aliases are used, then if the simplefb
+ node contains a display property then the /aliases/display# path
+ must point to the display hw node the display property points to,
+ otherwise it must point directly to the simplefb node.
+
+ If a simplefb node represents the preferred console for user
+ interaction, then the chosen node stdout-path property should point
+ to it, or to the primary display hw node, as with display#
+ aliases. If display aliases are used then it should be set to the
+ alias instead.
+
+ It is advised that devicetree files contain pre-filled, disabled
+ framebuffer nodes, so that the firmware only needs to update the
+ mode information and enable them. This way if e.g. later on support
+ for more display clocks get added, the simplefb nodes will already
+ contain this info and the firmware does not need to be updated.
+
+ If pre-filled framebuffer nodes are used, the firmware may need
+ extra information to find the right node. In that case an extra
+ platform specific compatible and platform specific properties should
+ be used and documented.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - allwinner,simple-framebuffer
+ - amlogic,simple-framebuffer
+ - const: simple-framebuffer
+
+ reg:
+ description: Location and size of the framebuffer memory
+
+ clocks:
+ description: List of clocks used by the framebuffer.
+
+ power-domains:
+ description: List of power domains used by the framebuffer.
+
+ width:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Width of the framebuffer in pixels
+
+ height:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Height of the framebuffer in pixels
+
+ stride:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Number of bytes of a line in the framebuffer
+
+ format:
+ description: >
+ Format of the framebuffer:
+ * `a8b8g8r8` - 32-bit pixels, d[31:24]=a, d[23:16]=b, d[15:8]=g, d[7:0]=r
+ * `r5g6b5` - 16-bit pixels, d[15:11]=r, d[10:5]=g, d[4:0]=b
+ enum:
+ - a8b8g8r8
+ - r5g6b5
+
+ display:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: Primary display hardware node
+
+ allwinner,pipeline:
+ description: Pipeline used by the framebuffer on Allwinner SoCs
+ enum:
+ - de_be0-lcd0
+ - de_be0-lcd0-hdmi
+ - de_be0-lcd0-tve0
+ - de_be1-lcd0
+ - de_be1-lcd1-hdmi
+ - de_fe0-de_be0-lcd0
+ - de_fe0-de_be0-lcd0-hdmi
+ - de_fe0-de_be0-lcd0-tve0
+ - mixer0-lcd0
+ - mixer0-lcd0-hdmi
+ - mixer1-lcd1-hdmi
+ - mixer1-lcd1-tve
+
+ amlogic,pipeline:
+ description: Pipeline used by the framebuffer on Amlogic SoCs
+ enum:
+ - vpu-cvbs
+ - vpu-hdmi
+
+patternProperties:
+ "^[a-zA-Z0-9-]+-supply$":
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description:
+ Regulators used by the framebuffer. These should be named
+ according to the names in the device design.
+
+required:
+ # The binding requires also reg, width, height, stride and format,
+ # but usually they will be filled by the bootloader.
+ - compatible
+
+additionalProperties: false
+
+examples:
+ - |
+ aliases {
+ display0 = &lcdc0;
+ };
+
+ chosen {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ stdout-path = "display0";
+ framebuffer0: framebuffer@1d385000 {
+ compatible = "simple-framebuffer";
+ reg = <0x1d385000 3840000>;
+ width = <1600>;
+ height = <1200>;
+ stride = <3200>;
+ format = "r5g6b5";
+ clocks = <&ahb_gates 36>, <&ahb_gates 43>, <&ahb_gates 44>;
+ lcd-supply = <&reg_dc1sw>;
+ display = <&lcdc0>;
+ };
+ };
+
+ soc@1c00000 {
+ lcdc0: lcdc@1c0c000 {
+ compatible = "allwinner,sun4i-a10-lcdc";
+ };
+ };
+
+...