[PATCH v3 2/3] input: pwm-beeper: add documentation for volume devicetree bindings
From: Frieder Schrempf <hidden>
Date: 2017-01-19 15:26:24
Also in:
linux-input, lkml
Subsystem:
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
This patch adds the documentation for the devicetree bindings to set the volume levels. Signed-off-by: Frieder Schrempf <redacted> --- Changes in v3: - change description of volume-levels to be used for linear levels .../devicetree/bindings/input/pwm-beeper.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt
index be332ae..496b68f 100644
--- a/Documentation/devicetree/bindings/input/pwm-beeper.txt
+++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt@@ -5,3 +5,23 @@ Registers a PWM device as beeper. Required properties: - compatible: should be "pwm-beeper" - pwms: phandle to the physical PWM device + +Optional properties: +- volume-levels: Array of PWM duty cycle values that correspond to + linear volume levels. These need to be in the range of 0 to 500, + while 0 means 0% duty cycle (mute) and 500 means 50% duty cycle + (max volume). + Please note that the actual volume of most beepers is highly + non-linear, which means that low volume levels are probably somewhere + in the range of 1 to 30 (0.1-3% duty cycle). +- default-volume-level: the default volume level (index into the + array defined by the "volume-levels" property) + +Example: + + pwm-beeper { + compatible = "pwm-beeper"; + pwms = <&pwm4 0 5000>; + volume-levels = <0 8 20 40 500>; + default-volume-level = <4>; + };
--
2.7.4