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

[Liu Ying <victor.liu@nxp.com>]

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@kernel.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
---
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@nxp.com>
+
+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