From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Add device tree bindings for the Microchip fpga fabric based "core" PWM controller. Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> --- .../bindings/pwm/microchip,corepwm.yaml | 81 +++++++++++++++++++ 1 file changed, 81 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..a7fae1772a81 --- /dev/null +++ b/Documentation/devicetree/bindings/pwm/microchip,corepwm.yaml @@ -0,0 +1,81 @@ +# 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 corePWM controller bindings + +maintainers: + - Conor Dooley <conor.dooley@xxxxxxxxxxxxx> + +description: | + corePWM is an 16 channel pulse width modulator FPGA IP + + https://www.microsemi.com/existing-parts/parts/152118 + +allOf: + - $ref: pwm.yaml# + +properties: + compatible: + items: + - const: microchip,corepwm-rtl-v4 + + reg: + maxItems: 1 + + clocks: + maxItems: 1 + + "#pwm-cells": + const: 2 + + microchip,sync-update-mask: + description: | + Depending on how the IP is instantiated, there are two modes of operation. + In synchronous mode, all channels are updated at the beginning of the PWM period, + and in asynchronous mode updates happen as the control registers are written. + A 16 bit wide "SHADOW_REG_EN" parameter of the IP core controls whether synchronous + mode is possible for each channel, and is set by the bitstream programmed to the + FPGA. If the IP core is instantiated with SHADOW_REG_ENx=1, both registers that + control the duty cycle for channel x have a second "shadow"/buffer reg synthesised. + At runtime a bit wide register exposed to APB can be used to toggle on/off + synchronised mode for all channels it has been synthesised for. + Each bit of "microchip,sync-update-mask" corresponds to a PWM channel & represents + whether synchronous mode is possible for the PWM channel. + + $ref: /schemas/types.yaml#/definitions/uint32 + default: 0 + + microchip,dac-mode-mask: + 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. A 16 bit DAC_MODE module parameter of the IP + core, set at instantiation and by the bitstream programmed to the FPGA, determines + whether a given channel operates in regular PWM or DAC mode. + Each bit corresponds to a PWM channel & represents whether DAC mode is enabled + for that channel. + + $ref: /schemas/types.yaml#/definitions/uint32 + default: 0 + +required: + - compatible + - reg + - clocks + +additionalProperties: false + +examples: + - | + pwm@41000000 { + compatible = "microchip,corepwm-rtl-v4"; + microchip,sync-update-mask = /bits/ 32 <0>; + clocks = <&clkcfg 30>; + reg = <0x41000000 0xF0>; + #pwm-cells = <2>; + }; -- 2.35.1
