[PATCH v2] dt-bindings: staging: mt7621-pci: PCIe binding documentation for MT7621 SoCs

From: Sergio Paracuellos
Date: Sat May 01 2021 - 09:44:14 EST


Add device tree binding documentation for PCIe in MT7621 SoCs.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
---

Changes in v2:
- Correct SoC name in subject.

Hi Rob,

Some concerns here. I was not be able to found any case similar to
this binding where sub-nodes describing each pcie port interface
are needed. I added them to the 'examples' directly without saying
anything about properties in any other place since its properties
seems to be covered in 'pci-bus.yaml' schema definition. I don't
know if this is the way, I have checked against schema and I noticed
I am forced to add 'device_type' property in each subnode because
schema checker complains that this is mandatory. So I have added
it and schema is properly being validated:

Before add the 'device_type' in each subnode:
/home/sergio/staging/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dt.yaml: pcie@0,0: 'device_type' is a required property
>From schema: /home/sergio/.local/lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
/home/sergio/staging/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dt.yaml: pcie@1,0: 'device_type' is a required property
>From schema: /home/sergio/.local/lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml
/home/sergio/staging/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dt.yaml: pcie@2,0: 'device_type' is a required property
>From schema: /home/sergio/.local/lib/python3.9/site-packages/dtschema/schemas/pci/pci-bus.yaml

After adding it:
CHKDT Documentation/devicetree/bindings/processed-schema-examples.json
SCHEMA Documentation/devicetree/bindings/processed-schema-examples.json
DTEX Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dts
DTC Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dt.yaml
CHECK Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.example.dt.yaml

Looks a bit redundant and maybe I am doing something wrong...

Thanks in advance for clarification.

Best regards,
Sergio Paracuellos


.../bindings/pci/mediatek,mt7621-pci.yaml | 144 ++++++++++++++++++
.../mt7621-pci/mediatek,mt7621-pci.txt | 104 -------------
2 files changed, 144 insertions(+), 104 deletions(-)
create mode 100644 Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.yaml
delete mode 100644 drivers/staging/mt7621-pci/mediatek,mt7621-pci.txt

diff --git a/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.yaml b/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.yaml
new file mode 100644
index 000000000000..9c1d05d929a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/mediatek,mt7621-pci.yaml
@@ -0,0 +1,144 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/mediatek,mt7621-pci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek MT7621 PCIe controller
+
+maintainers:
+ - Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
+
+description: |+
+ MediaTek MT7621 PCIe subsys supports single Root complex (RC)
+ with 3 Root Ports. Each Root Ports supports a Gen1 1-lane Link
+
+allOf:
+ - $ref: /schemas/pci/pci-bus.yaml#
+
+properties:
+ compatible:
+ const: mediatek,mt7621-pci
+
+ reg:
+ items:
+ - description: host-pci bridge registers
+ - description: pcie port 0 RC control registers
+ - description: pcie port 1 RC control registers
+ - description: pcie port 2 RC control registers
+
+ ranges:
+ maxItems: 2
+
+ interrupts:
+ maxItems: 3
+
+ resets:
+ items:
+ - description: pcie port 0 reset.
+ - description: pcie port 1 reset.
+ - description: pcie port 2 reset.
+
+ reset-names:
+ items:
+ - const: pcie0
+ - const: pcie1
+ - const: pcie2
+
+ clocks:
+ items:
+ - description: pcie port 0 clock.
+ - description: pcie port 1 clock.
+ - description: pcie port 2 clock.
+
+ clock-names:
+ items:
+ - const: pcie0
+ - const: pcie1
+ - const: pcie2
+
+ phys:
+ items:
+ - description: Dual-ported phy for pcie port 0 and 1.
+ - description: Phy for pcie port 2.
+
+ phy-names:
+ items:
+ - const: pcie-phy0
+ - const: pcie-phy2
+
+required:
+ - compatible
+ - reg
+ - ranges
+ - interrupts
+ - resets
+ - reset-names
+ - clocks
+ - clock-names
+ - phys
+ - phy-names
+ - reset-gpios
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/mips-gic.h>
+
+ pcie: pcie@1e140000 {
+ compatible = "mediatek,mt7621-pci";
+ reg = <0x1e140000 0x100>,
+ <0x1e142000 0x100>,
+ <0x1e143000 0x100>,
+ <0x1e144000 0x100>;
+
+ #address-cells = <3>;
+ #size-cells = <2>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&pcie_pins>;
+ device_type = "pci";
+ bus-range = <0 255>;
+ ranges = <0x02000000 0 0x00000000 0x60000000 0 0x10000000>, /* pci memory */
+ <0x01000000 0 0x00000000 0x1e160000 0 0x00010000>; /* io space */
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SHARED 4 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 24 IRQ_TYPE_LEVEL_HIGH>,
+ <GIC_SHARED 25 IRQ_TYPE_LEVEL_HIGH>;
+ resets = <&rstctrl 24>, <&rstctrl 25>, <&rstctrl 26>;
+ reset-names = "pcie0", "pcie1", "pcie2";
+ clocks = <&clkctrl 24>, <&clkctrl 25>, <&clkctrl 26>;
+ clock-names = "pcie0", "pcie1", "pcie2";
+ phys = <&pcie0_phy 1>, <&pcie2_phy 0>;
+ phy-names = "pcie-phy0", "pcie-phy2";
+ reset-gpios = <&gpio 19 GPIO_ACTIVE_LOW>;
+
+ pcie@0,0 {
+ reg = <0x0000 0 0 0 0>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+ bus-range = <0x00 0xff>;
+ };
+
+ pcie@1,0 {
+ reg = <0x0800 0 0 0 0>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+ bus-range = <0x00 0xff>;
+ };
+
+ pcie@2,0 {
+ reg = <0x1000 0 0 0 0>;
+ #address-cells = <3>;
+ #size-cells = <2>;
+ device_type = "pci";
+ ranges;
+ bus-range = <0x00 0xff>;
+ };
+ };
+...
diff --git a/drivers/staging/mt7621-pci/mediatek,mt7621-pci.txt b/drivers/staging/mt7621-pci/mediatek,mt7621-pci.txt
deleted file mode 100644
index 327a68267309..000000000000
--- a/drivers/staging/mt7621-pci/mediatek,mt7621-pci.txt
+++ /dev/null
@@ -1,104 +0,0 @@
-MediaTek MT7621 PCIe controller
-
-Required properties:
-- compatible: "mediatek,mt7621-pci"
-- device_type: Must be "pci"
-- reg: Base addresses and lengths of the PCIe subsys and root ports.
-- bus-range: Range of bus numbers associated with this controller.
-- #address-cells: Address representation for root ports (must be 3)
-- pinctrl-names : The pin control state names.
-- pinctrl-0: The "default" pinctrl state.
-- #size-cells: Size representation for root ports (must be 2)
-- ranges: Ranges for the PCI memory and I/O regions.
-- #interrupt-cells: Must be 1
-- interrupt-map-mask and interrupt-map: Standard PCI IRQ mapping properties.
- Please refer to the standard PCI bus binding document for a more detailed
- explanation.
-- status: either "disabled" or "okay".
-- resets: Must contain an entry for each entry in reset-names.
- See ../reset/reset.txt for details.
-- reset-names: Must be "pcie0", "pcie1", "pcieN"... based on the number of
- root ports.
-- clocks: Must contain an entry for each entry in clock-names.
- See ../clocks/clock-bindings.txt for details.
-- clock-names: Must be "pcie0", "pcie1", "pcieN"... based on the number of
- root ports.
-- reset-gpios: GPIO specs for the reset pins.
-
-In addition, the device tree node must have sub-nodes describing each PCIe port
-interface, having the following mandatory properties:
-
-Required properties:
-- reg: Only the first four bytes are used to refer to the correct bus number
- and device number.
-- #address-cells: Must be 3
-- #size-cells: Must be 2
-- ranges: Sub-ranges distributed from the PCIe controller node. An empty
- property is sufficient.
-- bus-range: Range of bus numbers associated with this port.
-
-Example for MT7621:
-
- pcie: pcie@1e140000 {
- compatible = "mediatek,mt7621-pci";
- reg = <0x1e140000 0x100 /* host-pci bridge registers */
- 0x1e142000 0x100 /* pcie port 0 RC control registers */
- 0x1e143000 0x100 /* pcie port 1 RC control registers */
- 0x1e144000 0x100>; /* pcie port 2 RC control registers */
-
- #address-cells = <3>;
- #size-cells = <2>;
-
- pinctrl-names = "default";
- pinctrl-0 = <&pcie_pins>;
-
- device_type = "pci";
-
- bus-range = <0 255>;
- ranges = <
- 0x02000000 0 0x00000000 0x60000000 0 0x10000000 /* pci memory */
- 0x01000000 0 0x00000000 0x1e160000 0 0x00010000 /* io space */
- >;
-
- #interrupt-cells = <1>;
- interrupt-map-mask = <0xF0000 0 0 1>;
- interrupt-map = <0x10000 0 0 1 &gic GIC_SHARED 4 IRQ_TYPE_LEVEL_HIGH>,
- <0x20000 0 0 1 &gic GIC_SHARED 24 IRQ_TYPE_LEVEL_HIGH>,
- <0x30000 0 0 1 &gic GIC_SHARED 25 IRQ_TYPE_LEVEL_HIGH>;
-
- status = "disabled";
-
- resets = <&rstctrl 24 &rstctrl 25 &rstctrl 26>;
- reset-names = "pcie0", "pcie1", "pcie2";
- clocks = <&clkctrl 24 &clkctrl 25 &clkctrl 26>;
- clock-names = "pcie0", "pcie1", "pcie2";
-
- reset-gpios = <&gpio 19 GPIO_ACTIVE_LOW>,
- <&gpio 8 GPIO_ACTIVE_LOW>,
- <&gpio 7 GPIO_ACTIVE_LOW>;
-
- pcie@0,0 {
- reg = <0x0000 0 0 0 0>;
- #address-cells = <3>;
- #size-cells = <2>;
- ranges;
- bus-range = <0x00 0xff>;
- };
-
- pcie@1,0 {
- reg = <0x0800 0 0 0 0>;
- #address-cells = <3>;
- #size-cells = <2>;
- ranges;
- bus-range = <0x00 0xff>;
- };
-
- pcie@2,0 {
- reg = <0x1000 0 0 0 0>;
- #address-cells = <3>;
- #size-cells = <2>;
- ranges;
- bus-range = <0x00 0xff>;
- };
- };
-
--
2.25.1