Freescale i.MX8qxp pixel link MSI bus is a simple memory-mapped bus. It is used to access peripherals in i.MX8qm/qxp imaging, LVDS, MIPI DSI and HDMI TX subsystems, like I2C controller, PWM controller, MIPI DSI controller and Control and Status Registers (CSR) module. Reference simple-pm-bus bindings and add Freescale i.MX8qxp pixel link MSI bus specific bindings. Signed-off-by: Liu Ying <victor.liu@xxxxxxx> --- v1->v2: Address Krzysztof's comments: * Add a select to explicitly select the MSI bus dt-binding. * List 'simple-pm-bus' explicitly as one item of compatible strings. * Require compatible and reg properties. * Put reg property just after compatible property in example. .../bus/fsl,imx8qxp-pixel-link-msi-bus.yaml | 97 +++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 Documentation/devicetree/bindings/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml diff --git a/Documentation/devicetree/bindings/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml b/Documentation/devicetree/bindings/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml new file mode 100644 index 000000000000..358c032041e5 --- /dev/null +++ b/Documentation/devicetree/bindings/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml @@ -0,0 +1,97 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Freescale i.MX8qxp Pixel Link Medium Speed Interconnect (MSI) Bus + +maintainers: + - Liu Ying <victor.liu@xxxxxxx> + +description: | + i.MX8qxp pixel link MSI bus is used to control settings of PHYs, I/Os + sitting together with the PHYs. It is not the same as the MSI bus coming + from i.MX8 System Controller Unit (SCU) which is used to control power, + clock and reset through the i.MX8 Distributed Slave System Controller (DSC). + + i.MX8qxp pixel link MSI bus is a simple memory-mapped bus. Two input clocks, + that is, MSI clock and AHB clock, need to be enabled so that peripherals + connected to the bus can be accessed. Also, the bus is part of a power + domain. The power domain needs to be enabled before the peripherals can + be accessed. + + Peripherals in i.MX8qm/qxp imaging, LVDS, MIPI DSI and HDMI TX subsystems, + like I2C controller, PWM controller, MIPI DSI controller and Control and + Status Registers (CSR) module, are accessed through the bus. + + The i.MX System Controller Firmware (SCFW) owns and uses the i.MX8qm/qxp + pixel link MSI bus controller and does not allow SCFW user to control it. + So, the controller's registers cannot be accessed by SCFW user. Hence, + the interrupts generated by the controller don't make any sense from SCFW + user's point of view. + +allOf: + - $ref: simple-pm-bus.yaml# + +# We need a select here so we don't match all nodes with 'simple-pm-bus'. +select: + properties: + compatible: + contains: + enum: + - fsl,imx8qxp-display-pixel-link-msi-bus + - fsl,imx8qm-display-pixel-link-msi-bus + required: + - compatible + +properties: + compatible: + items: + - enum: + - fsl,imx8qxp-display-pixel-link-msi-bus + - fsl,imx8qm-display-pixel-link-msi-bus + - const: simple-pm-bus + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clocks: + items: + - description: master gated clock from system + - description: AHB clock + + clock-names: + items: + - const: msi + - const: ahb + +required: + - compatible + - reg + - clocks + - clock-names + - power-domains + +unevaluatedProperties: false + +examples: + - | + #include <dt-bindings/clock/imx8-lpcg.h> + #include <dt-bindings/firmware/imx/rsrc.h> + bus@56200000 { + compatible = "fsl,imx8qxp-display-pixel-link-msi-bus", "simple-pm-bus"; + reg = <0x56200000 0x20000>; + #address-cells = <1>; + #size-cells = <1>; + interrupt-parent = <&dc0_irqsteer>; + interrupts = <320>; + ranges; + clocks = <&dc0_disp_ctrl_link_mst0_lpcg IMX_LPCG_CLK_4>, + <&dc0_disp_ctrl_link_mst0_lpcg IMX_LPCG_CLK_4>; + clock-names = "msi", "ahb"; + power-domains = <&pd IMX_SC_R_DC_0>; + }; -- 2.25.1
