[PATCH 1/3] dt-bindings: pwm: Add binding for RPi firmware PWM bus

Nicolas Saenz Julienne nsaenzjulienne at suse.de
Fri Oct 9 11:30:28 EDT 2020


The PWM bus controlling the fan in RPi's official PoE hat can only be
controlled by the board's co-processor.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
---
 .../arm/bcm/raspberrypi,bcm2835-firmware.yaml | 21 +++++++++++++++++++
 .../pwm/raspberrypi,firmware-pwm.h            | 13 ++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 include/dt-bindings/pwm/raspberrypi,firmware-pwm.h

diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
index a2c63c8b1d10..dcaf00e8602e 100644
--- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
+++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
@@ -64,6 +64,22 @@ properties:
       - compatible
       - "#reset-cells"
 
+  pwm:
+    type: object
+
+    properties:
+      compatible:
+        const: raspberrypi,firmware-pwm
+
+      "#pwm-cells":
+        const: 1
+        description: >
+          The argument is the PWM bus number.
+
+    required:
+      - compatible
+      - "#pwm-cells"
+
     additionalProperties: false
 
 required:
@@ -87,5 +103,10 @@ examples:
             compatible = "raspberrypi,firmware-reset";
             #reset-cells = <1>;
         };
+
+        pwm: pwm {
+            compatible = "raspberrypi,firmware-pwm";
+            #pwm-cells = <1>;
+        };
     };
 ...
diff --git a/include/dt-bindings/pwm/raspberrypi,firmware-pwm.h b/include/dt-bindings/pwm/raspberrypi,firmware-pwm.h
new file mode 100644
index 000000000000..27c5ce68847b
--- /dev/null
+++ b/include/dt-bindings/pwm/raspberrypi,firmware-pwm.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2020 Nicolas Saenz Julienne
+ * Author: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
+ */
+
+#ifndef _DT_BINDINGS_RASPBERRYPI_FIRMWARE_PWM_H
+#define _DT_BINDINGS_RASPBERRYPI_FIRMWARE_PWM_H
+
+#define RASPBERRYPI_FIRMWARE_PWM_POE		0
+#define RASPBERRYPI_FIRMWARE_PWM_NUM		1
+
+#endif
-- 
2.28.0




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