[PATCH 01/10] dt-bindings: i3c: Add YAML schema for Cadence I3C controller
dinesh.maniyam at intel.com
dinesh.maniyam at intel.com
Tue Feb 18 03:56:56 CET 2025
From: Dinesh Maniyam <dinesh.maniyam at intel.com>
Add a YAML device tree binding schema for the Cadence I3C controller,
defining required and optional properties for proper integration
and validation with dt-schema.
Signed-off-by: Dinesh Maniyam <dinesh.maniyam at intel.com>
---
.../i3c/cdns,i3c-master.yaml | 51 +++++
doc/device-tree-bindings/i3c/i3c.yaml | 186 ++++++++++++++++++
2 files changed, 237 insertions(+)
create mode 100644 doc/device-tree-bindings/i3c/cdns,i3c-master.yaml
create mode 100644 doc/device-tree-bindings/i3c/i3c.yaml
diff --git a/doc/device-tree-bindings/i3c/cdns,i3c-master.yaml b/doc/device-tree-bindings/i3c/cdns,i3c-master.yaml
new file mode 100644
index 0000000000..0eda16482e
--- /dev/null
+++ b/doc/device-tree-bindings/i3c/cdns,i3c-master.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i3c/cdns,i3c-master.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Cadence I3C master block
+
+maintainers:
+ - Dinesh Maniyam <dinesh.maniyam at intel.com>
+
+allOf:
+ - $ref: i3c.yaml#
+
+properties:
+ compatible:
+ const: snps,dw-i3c-master-1.00a
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 2
+
+ interrupts:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - interrupts
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ i3c-master at 2000 {
+ compatible = "snps,dw-i3c-master-1.00a";
+ reg = <0x02000 0x1000>;
+ interrupts = <0>;
+ clocks = <&i3cclk>;
+ #address-cells = <2>;
+ #size-cells = <0>;
+
+ eeprom at 57{
+ compatible = "atmel,24c01";
+ reg = <0x57 0x0 0x10>;
+ pagesize = <0x8>;
+ };
+ };
diff --git a/doc/device-tree-bindings/i3c/i3c.yaml b/doc/device-tree-bindings/i3c/i3c.yaml
new file mode 100644
index 0000000000..8f9c440db2
--- /dev/null
+++ b/doc/device-tree-bindings/i3c/i3c.yaml
@@ -0,0 +1,186 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i3c/i3c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: I3C bus
+
+maintainers:
+ - Dinesh Maniyam <dinesh.maniyam at intel.com>
+
+description: |
+ I3C busses can be described with a node for the primary I3C controller device
+ and a set of child nodes for each I2C or I3C slave on the bus. Each of them
+ may, during the life of the bus, request mastership.
+
+properties:
+ $nodename:
+ pattern: "^i3c-master@[0-9a-f]+$"
+
+ "#address-cells":
+ const: 3
+ description: |
+ Each I2C device connected to the bus should be described in a subnode.
+
+ All I3C devices are supposed to support DAA (Dynamic Address Assignment),
+ and are thus discoverable. So, by default, I3C devices do not have to be
+ described in the device tree. This being said, one might want to attach
+ extra resources to these devices, and those resources may have to be
+ described in the device tree, which in turn means we have to describe
+ I3C devices.
+
+ Another use case for describing an I3C device in the device tree is when
+ this I3C device has a static I2C address and we want to assign it a
+ specific I3C dynamic address before the DAA takes place (so that other
+ devices on the bus can't take this dynamic address).
+
+ "#size-cells":
+ const: 0
+
+ i3c-scl-hz:
+ description: |
+ Frequency of the SCL signal used for I3C transfers. When undefined, the
+ default value should be 12.5MHz.
+
+ May not be supported by all controllers.
+
+ i2c-scl-hz:
+ description: |
+ Frequency of the SCL signal used for I2C transfers. When undefined, the
+ default should be to look at LVR (Legacy Virtual Register) values of
+ I2C devices described in the device tree to determine the maximum I2C
+ frequency.
+
+ May not be supported by all controllers.
+
+required:
+ - "#address-cells"
+ - "#size-cells"
+
+patternProperties:
+ "@[0-9a-f]+$":
+ type: object
+ description: |
+ I2C child, should be named: <device-type>@<i2c-address>
+
+ All properties described in Documentation/devicetree/bindings/i2c/i2c.txt
+ are valid here, except the reg property whose content is changed.
+
+ properties:
+ compatible:
+ description:
+ Compatible of the I2C device.
+
+ reg:
+ items:
+ - items:
+ - description: |
+ I2C address. 10 bit addressing is not supported. Devices with
+ 10-bit address can't be properly passed through DEFSLVS
+ command.
+ minimum: 0
+ maximum: 0x7f
+ - const: 0
+ - description: |
+ Shall encode the I3C LVR (Legacy Virtual Register):
+ bit[31:8]: unused/ignored
+ bit[7:5]: I2C device index. Possible values:
+ * 0: I2C device has a 50 ns spike filter
+ * 1: I2C device does not have a 50 ns spike filter but
+ supports high frequency on SCL
+ * 2: I2C device does not have a 50 ns spike filter and is
+ not tolerant to high frequencies
+ * 3-7: reserved
+ bit[4]: tell whether the device operates in FM (Fast Mode)
+ or FM+ mode:
+ * 0: FM+ mode
+ * 1: FM mode
+ bit[3:0]: device type
+ * 0-15: reserved
+
+ required:
+ - compatible
+ - reg
+
+ "@[0-9a-f]+,[0-9a-f]+$":
+ type: object
+ description: |
+ I3C child, should be named: <device-type>@<static-i2c-address>,<i3c-pid>
+
+ properties:
+ reg:
+ items:
+ - items:
+ - description: |
+ Encodes the static I2C address. Should be 0 if the device does
+ not have one (0 is not a valid I2C address).
+ minimum: 0
+ maximum: 0x7f
+ - description: |
+ First half of the Provisional ID (following the PID
+ definition provided by the I3C specification).
+
+ Contains the manufacturer ID left-shifted by 1.
+ - description: |
+ Second half of the Provisional ID (following the PID
+ definition provided by the I3C specification).
+
+ Contains the ORing of the part ID left-shifted by 16,
+ the instance ID left-shifted by 12 and extra information.
+
+ assigned-address:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0x1
+ maximum: 0xff
+ description: |
+ Dynamic address to be assigned to this device. In case static address is
+ present (first cell of the reg property != 0), this address is assigned
+ through SETDASA. If static address is not present, this address is assigned
+ through SETNEWDA after assigning a temporary address via ENTDAA.
+
+ required:
+ - reg
+
+additionalProperties: true
+
+examples:
+ - |
+ i3c-master at d040000 {
+ compatible = "cdns,i3c-master";
+ clocks = <&coreclock>, <&i3csysclock>;
+ clock-names = "pclk", "sysclk";
+ interrupts = <3 0>;
+ reg = <0x0d040000 0x1000>;
+ #address-cells = <3>;
+ #size-cells = <0>;
+ i2c-scl-hz = <100000>;
+
+ /* I2C device. */
+ eeprom at 57 {
+ compatible = "atmel,24c01";
+ reg = <0x57 0x0 0x10>;
+ pagesize = <0x8>;
+ };
+
+ /* I3C device with a static I2C address and assigned address. */
+ thermal_sensor: sensor at 68,39200144004 {
+ reg = <0x68 0x392 0x144004>;
+ assigned-address = <0xa>;
+ };
+
+ /* I3C device with only assigned address. */
+ pressure_sensor: sensor at 0,39200124004 {
+ reg = <0x0 0x392 0x124000>;
+ assigned-address = <0xc>;
+ };
+
+ /*
+ * I3C device without a static I2C address but requiring
+ * resources described in the DT.
+ */
+ sensor at 0,39200154004 {
+ reg = <0x0 0x392 0x154004>;
+ clocks = <&clock_provider 0>;
+ };
+ };
--
2.26.2
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