[PATCH v4 08/14] dt-bindings: pwm: add microchip corepwm binding

conor.dooley at microchip.com conor.dooley at microchip.com
Mon Jan 17 03:07:49 PST 2022


From: Conor Dooley <conor.dooley at microchip.com>

Add device tree bindings for the Microchip fpga fabric based "core" PWM
controller.

Signed-off-by: Conor Dooley <conor.dooley at microchip.com>
---
 .../bindings/pwm/microchip,corepwm.yaml       | 75 +++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pwm/microchip,corepwm.yaml

diff --git a/Documentation/devicetree/bindings/pwm/microchip,corepwm.yaml b/Documentation/devicetree/bindings/pwm/microchip,corepwm.yaml
new file mode 100644
index 000000000000..26a77cde2465
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/microchip,corepwm.yaml
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/microchip,corepwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip ip core PWM controller bindings
+
+maintainers:
+  - Conor Dooley <conor.dooley at microchip.com>
+
+description: |
+  corePWM is an 16 channel pulse width modulator FPGA IP
+
+  https://www.microsemi.com/existing-parts/parts/152118
+
+properties:
+  compatible:
+    items:
+      - const: microchip,corepwm-rtl-v4
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 2
+
+  microchip,sync-update:
+    description: |
+      In synchronous mode, all channels are updated at the beginning of the PWM period.
+      Asynchronous mode is relevant to applications such as LED control, where
+      synchronous updates are not required. Asynchronous mode lowers the area size,
+      reducing shadow register requirements. This can be set at run time, provided
+      SHADOW_REG_EN is asserted. SHADOW_REG_EN is set by the FPGA bitstream programmed
+      to the device.
+      Each bit corresponds to a PWM channel & represents whether synchronous mode is
+      possible for the PWM channel.
+
+    $ref: /schemas/types.yaml#/definitions/uint16
+    default: 0
+
+  microchip,dac-mode:
+    description: |
+      Optional, per-channel Low Ripple DAC mode is possible on this IP core. It creates
+      a minimum period pulse train whose High/Low average is that of the chosen duty
+      cycle. This "DAC" will have far better bandwidth and ripple performance than the
+      standard PWM algorithm can achieve.
+      Each bit corresponds to a PWM channel & represents whether dac mode is enabled
+      that PWM channel.
+
+    $ref: /schemas/types.yaml#/definitions/uint16
+    default: 0
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - "#pwm-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include "dt-bindings/clock/microchip,mpfs-clock.h"
+    pwm at 41000000 {
+      compatible = "microchip,corepwm-rtl-v4";
+      microchip,sync-update = /bits/ 16 <0>;
+      clocks = <&clkcfg CLK_FIC3>;
+      reg = <0x41000000 0xF0>;
+      #pwm-cells = <2>;
+    };
-- 
2.32.0




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