[PATCH v4 RESEND 2/2] dt-bindings: bus: Add Freescale i.MX8qxp pixel link MSI bus binding

From: Liu Ying
Date: Mon Oct 17 2022 - 03:39:41 EST

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.

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
---
v3->v4:
* Add child nodes in the example MSI bus node of the MSI bus dt-binding. (Krzysztof)
* Resend v4 to imply this patch is based on v6.0-rc1 so that there are not any
dependencies. (Rob)
* Resend v4 based on v6.1-rc1. (Greg)
* Add Rob's R-b tag.

v2->v3:
* Add a pattern property to allow child nodes. (Rob)

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 | 232 ++++++++++++++++++
1 file changed, 232 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..b568d0ce438d
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/fsl,imx8qxp-pixel-link-msi-bus.yaml
@@ -0,0 +1,232 @@
+# 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:
+ - $ref: simple-pm-bus.yaml#
+
+# We need a select here so we don't match all nodes with 'simple-pm-bus'.
+select:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - fsl,imx8qxp-display-pixel-link-msi-bus
+ - fsl,imx8qm-display-pixel-link-msi-bus
+ required:
+ - compatible
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - fsl,imx8qxp-display-pixel-link-msi-bus
+ - fsl,imx8qm-display-pixel-link-msi-bus
+ - const: simple-pm-bus
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ clocks:
+ items:
+ - description: master gated clock from system
+ - description: AHB clock
+
+ clock-names:
+ items:
+ - const: msi
+ - const: ahb
+
+patternProperties:
+ "^.*@[0-9a-f]+$":
+ description: Devices attached to the bus
+ type: object
+ properties:
+ reg:
+ maxItems: 1
+
+ required:
+ - reg
+
+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>;
+
+ syscon@56221000 {
+ compatible = "fsl,imx8qxp-mipi-lvds-csr", "syscon", "simple-mfd";
+ reg = <0x56221000 0x1000>;
+ clocks = <&mipi_lvds_0_di_mipi_lvds_regs_lpcg IMX_LPCG_CLK_4>;
+ clock-names = "ipg";
+
+ pxl2dpi {
+ compatible = "fsl,imx8qxp-pxl2dpi";
+ fsl,sc-resource = <IMX_SC_R_MIPI_0>;
+ power-domains = <&pd IMX_SC_R_MIPI_0>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0>;
+
+ mipi_lvds_0_pxl2dpi_dc0_pixel_link0: endpoint@0 {
+ reg = <0>;
+ remote-endpoint = <&dc0_pixel_link0_mipi_lvds_0_pxl2dpi>;
+ };
+
+ mipi_lvds_0_pxl2dpi_dc0_pixel_link1: endpoint@1 {
+ reg = <1>;
+ remote-endpoint = <&dc0_pixel_link1_mipi_lvds_0_pxl2dpi>;
+ };
+ };
+
+ port@1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <1>;
+
+ mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch0: endpoint@0 {
+ reg = <0>;
+ remote-endpoint = <&mipi_lvds_0_ldb_ch0_mipi_lvds_0_pxl2dpi>;
+ };
+
+ mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch1: endpoint@1 {
+ reg = <1>;
+ remote-endpoint = <&mipi_lvds_0_ldb_ch1_mipi_lvds_0_pxl2dpi>;
+ };
+ };
+ };
+ };
+
+ ldb {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "fsl,imx8qxp-ldb";
+ clocks = <&clk IMX_SC_R_LVDS_0 IMX_SC_PM_CLK_MISC2>,
+ <&clk IMX_SC_R_LVDS_0 IMX_SC_PM_CLK_BYPASS>;
+ clock-names = "pixel", "bypass";
+ power-domains = <&pd IMX_SC_R_LVDS_0>;
+
+ channel@0 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <0>;
+ phys = <&mipi_lvds_0_phy>;
+ phy-names = "lvds_phy";
+
+ port@0 {
+ reg = <0>;
+
+ mipi_lvds_0_ldb_ch0_mipi_lvds_0_pxl2dpi: endpoint {
+ remote-endpoint = <&mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch0>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ /* ... */
+ };
+ };
+
+ channel@1 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ reg = <1>;
+ phys = <&mipi_lvds_0_phy>;
+ phy-names = "lvds_phy";
+
+ port@0 {
+ reg = <0>;
+
+ mipi_lvds_0_ldb_ch1_mipi_lvds_0_pxl2dpi: endpoint {
+ remote-endpoint = <&mipi_lvds_0_pxl2dpi_mipi_lvds_0_ldb_ch1>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ /* ... */
+ };
+ };
+ };
+ };
+
+ clock-controller@56223004 {
+ compatible = "fsl,imx8qxp-lpcg";
+ reg = <0x56223004 0x4>;
+ #clock-cells = <1>;
+ clocks = <&mipi_lvds_0_ipg_clk>;
+ clock-indices = <IMX_LPCG_CLK_4>;
+ clock-output-names = "mipi_lvds_0_di_mipi_lvds_regs_lpcg_ipg_clk";
+ power-domains = <&pd IMX_SC_R_MIPI_0>;
+ };
+
+ phy@56228300 {
+ compatible = "fsl,imx8qxp-mipi-dphy";
+ reg = <0x56228300 0x100>;
+ clocks = <&clk IMX_SC_R_LVDS_0 IMX_SC_PM_CLK_PHY>;
+ clock-names = "phy_ref";
+ #phy-cells = <0>;
+ fsl,syscon = <&mipi_lvds_0_csr>;
+ power-domains = <&pd IMX_SC_R_MIPI_0>;
+ };
+ };
--
2.37.1