[PATCH v5 01/11] dt-bindings: arm: add cznic,turris-omnia-mcu binding

Marek Behún
2024-03-23T16:44:08Z

Add binding for cznic,turris-omnia-mcu, the device-tree node
representing the system-controller features provided by the MCU on the
Turris Omnia router.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
Changes from v4:
- #gpio-cells changed from 2 (pin number, flags) to 3 (bank, pin number,
flags). This is because two years ago we added device-tree fixing code
into U-Boot [1] which adds reset-gpios to PCIe controller nodes if
these GPIOs are controllable via MCU, and the code adds the gpio
specifiers to have 3 cells. Implementing this driver with twocell
specifier breaks PCIe functionality for users which have upgraded U-Boot
- added documentation for #interrupt-cells and #gpio-cells

[1] https://source.denx.de/u-boot/u-boot/-/commit/1da53ae26afc
---
.../bindings/arm/cznic,turris-omnia-mcu.yaml | 86 +++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 87 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml

diff --git a/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml b/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
new file mode 100644
index 000000000000..dd9ee21ee24d
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/cznic,turris-omnia-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: CZ.NIC's Turris Omnia MCU
+
+maintainers:
+ - Marek Behún <kabel@kernel.org>
+
+description:
+ The MCU on Turris Omnia acts as a system controller providing additional
+ GPIOs, interrupts, watchdog, system power off and wakeup configuration.
+
+properties:
+ compatible:
+ const: cznic,turris-omnia-mcu
+
+ reg:
+ description: MCU I2C slave address
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ interrupt-controller: true
+
+ '#interrupt-cells':
+ const: 2
+ description: |
+ The first cell specifies the interrupt number (0 to 63), the second cell
+ specifies interrupt type (which can be one of IRQ_TYPE_EDGE_RISING,
+ IRQ_TYPE_EDGE_FALLING or IRQ_TYPE_EDGE_BOTH).
+ The interrupt numbers correspond sequentially to GPIO numbers, taking the
+ GPIO banks into account:
+ IRQ number GPIO bank GPIO pin within bank
+ 0 - 15 0 0 - 15
+ 16 - 47 1 0 - 31
+ 48 - 63 2 0 - 15
+ There are several exceptions:
+ IRQ number meaning
+ 11 LED panel brightness changed by button press
+ 13 TRNG entropy ready
+ 14 ECDSA message signature computation done
+
+ gpio-controller: true
+
+ '#gpio-cells':
+ const: 3
+ description:
+ The first cell is bank number (0, 1 or 2), the second cell is pin number
+ within the bank (0 to 15 for banks 0 and 2, 0 to 31 for bank 1), and the
+ third cell specifies consumer flags.
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - interrupt-controller
+ - gpio-controller
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ system-controller@2a {
+ compatible = "cznic,turris-omnia-mcu";
+ reg = <0x2a>;
+
+ interrupt-parent = <&gpio1>;
+ interrupts = <11 IRQ_TYPE_NONE>;
+
+ gpio-controller;
+ #gpio-cells = <3>;
+
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index aa3b947fb080..89edfc2b875b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2141,6 +2141,7 @@ W: https://www.turris.cz/
F: Documentation/ABI/testing/debugfs-moxtet
F: Documentation/ABI/testing/sysfs-bus-moxtet-devices
F: Documentation/ABI/testing/sysfs-firmware-turris-mox-rwtm
+F: Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
F: Documentation/devicetree/bindings/bus/moxtet.txt
F: Documentation/devicetree/bindings/firmware/cznic,turris-mox-rwtm.txt
F: Documentation/devicetree/bindings/gpio/gpio-moxtet.txt
--
2.43.2