[PATCH v3 1/3] dt-bindings: input: Add Qualcomm SPMI PMIC haptics
From: Fenglin Wu <hidden>
Date: 2026-07-14 05:23:01
Also in:
linux-arm-msm, linux-devicetree, lkml
Subsystem:
arm/qualcomm mailing list, input (keyboard, mouse, joystick, touchscreen) drivers, open firmware and flattened device tree bindings, the rest · Maintainers:
Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Add binding document for the haptics module inside Qualcomm PMIC PMIH0108. Assisted-by: Claude:claude-4-8-opus Signed-off-by: Fenglin Wu <redacted> --- .../bindings/input/qcom,spmi-haptics.yaml | 136 +++++++++++++++++++++ 1 file changed, 136 insertions(+)
diff --git a/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml b/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml
new file mode 100644
index 000000000000..b1a69e9886ee
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/qcom,spmi-haptics.yaml@@ -0,0 +1,136 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/input/qcom,spmi-haptics.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Haptics device inside Qualcomm Technologies, Inc. PMIC + +maintainers: + - Fenglin Wu <fenglin.wu@oss.qualcomm.com> + +description: | + Certain Qualcomm PMICs integrate a haptics module, such as the HAP530_HV haptics + module in the PMIH0108 PMIC, which drives an LRA (Linear Resonant Actuator) with + an output voltage up to 10 V. Several play modes are supported in HAP530_HV: + + DIRECT_PLAY: The hardware outputs sinusoidal waveforms whose period is + defined by qcom,lra-period-us and whose peak voltage is defined by + qcom,vmax-microvolt. The driving amplitude can be scaled in the range + [0, 255] via a single register byte. Hardware-based LRA auto-resonance + tracking is enabled by default in this mode, allowing the haptics engine + to follow the actual resonant frequency of the LRA and update the driving + period accordingly to achieve stronger vibration magnitude. + + FIFO: The hardware can play an arbitrary waveform composed of a sequence + of 8-bit samples at a configurable play rate. Samples are pre-filled + into the internal FIFO memory of the haptics module and continuously + replenished via the FIFO-empty IRQ until all samples have been played. + An 8K-byte FIFO memory bank is available in the HAP530_HV haptics module, + shared between the FIFO and PAT_MEM play modes. The memory partition + between the two modes is configurable via registers, and FIFO mode always + uses the 1st partition starting from offset 0. + + PAT_MEM: This mode is very similar to FIFO streaming mode but without the + data refilling capability. It is designed mainly for short, latency-critical + vibrations. The memory space for PAT_MEM mode must be reserved for dedicated + usage, and the waveform data should be preloaded and remain unchanged + thereafter. The haptics module can play the waveform data from the memory + region specified by the PAT_MEM play start address and length registers. + + In either FIFO mode or PAT_MEM mode, the following play rates are supported: + -- 0(T_LRA): each FIFO byte drives one full sinusoidal cycle with the + period defined in qcom,lra-period-us. + -- 1/2/3(T_LRA_DIV_2/4/8): each FIFO byte drives a half/quarter/eighth + sinusoidal cycle with the period defined in qcom,lra-period-us. + -- 4/5/6(T_LRA_X_2/4/8): each FIFO byte drives 2/4/8 sinusoidal cycles + with the period defined in qcom,lra-period-us. + -- 8/9/10/11/12/13(8KHz/16KHz/24KHz/32KHz/44.1KHz/48KHz): the FIFO + data is treated as PCM samples and drives the output with an + arbitrarily shaped waveform. This mode is typically used to define + custom driving waveforms for specific vibration effects such as fast + attack, crisp brake, etc. + + The drive voltage in FIFO or PAT_MEM mode can exceed the value defined in + qcom,vmax-microvolt to achieve a special vibration effect, but the waveform + must be short enough to prevent the LRA from being damaged by operating at + an overvoltage. + + Also, hardware-based LRA auto-resonance tracking is normally disabled in + FIFO or PAT_MEM mode, as these modes are intended to drive arbitrary + waveforms that may not follow the resonant frequency; autonomous hardware + resonance correction would interfere with the intended output. + +properties: + compatible: + items: + - const: qcom,pmih0108-haptics + - const: qcom,spmi-haptics + + reg: + items: + - description: HAP_CFG module base address + - description: HAP_PTN module base address + + reg-names: + items: + - const: cfg + - const: ptn + + interrupts: + maxItems: 1 + + interrupt-names: + items: + - const: fifo-empty + + qcom,vmax-microvolt: + description: + Maximum allowed output driving voltage in microvolts, must be a multiple + of 50,000 uV. This is the peak driving voltage in DIRECT_PLAY mode, + which outputs sinusoidal waveforms. The value should be equal to the + square root of 2 times the Vrms voltage of the LRA. + minimum: 50000 + maximum: 10000000 + multipleOf: 50000 + + qcom,lra-period-us: + description: + LRA actuator initial resonance period in microseconds + (1,000,000 / resonant_freq_hz). Used to configure T_LRA-based play + rates and the auto-resonance zero-crossing window. It could be also used + as the initial period if the LRA wants to be driven off resonance. + minimum: 5 + maximum: 20475 + multipleOf: 5 + +required: + - compatible + - reg + - reg-names + - interrupts + - interrupt-names + - qcom,vmax-microvolt + - qcom,lra-period-us + +additionalProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/irq.h> + + pmic { + #address-cells = <1>; + #size-cells = <0>; + + haptics@f000 { + compatible = "qcom,pmih0108-haptics", "qcom,spmi-haptics"; + reg = <0xf000>, <0xf100>; + reg-names = "cfg", "ptn"; + interrupts = <0x7 0xf0 0x1 IRQ_TYPE_EDGE_RISING>; + interrupt-names = "fifo-empty"; + + qcom,vmax-microvolt = <1300000>; + qcom,lra-period-us = <5880>; + }; + };
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