Documentation/devicetree/bindings/input/pwm-vibrator.txt

   1 * PWM vibrator device tree bindings
   2
   3 Registers a PWM device as vibrator. It is expected, that the vibrator's
   4 strength increases based on the duty cycle of the enable PWM channel
   5 (100% duty cycle meaning strongest vibration, 0% meaning no vibration).
   6
   7 The binding supports an optional direction PWM channel, that can be
   8 driven at fixed duty cycle. If available this is can be used to increase
   9 the vibration effect of some devices.
  10
  11 Required properties:
  12 - compatible: should contain "pwm-vibrator"
  13 - pwm-names: Should contain "enable" and optionally "direction"
  14 - pwms: Should contain a PWM handle for each entry in pwm-names
  15
  16 Optional properties:
  17 - vcc-supply: Phandle for the regulator supplying power
  18 - direction-duty-cycle-ns: Duty cycle of the direction PWM channel in
  19                            nanoseconds, defaults to 50% of the channel's
  20                            period.
  21
  22 Example from Motorola Droid 4:
  23
  24 &omap4_pmx_core {
  25         vibrator_direction_pin: pinmux_vibrator_direction_pin {
  26                 pinctrl-single,pins = <
  27                 OMAP4_IOPAD(0x1ce, PIN_OUTPUT | MUX_MODE1) /* dmtimer8_pwm_evt (gpio_27) */
  28                 >;
  29         };
  30
  31         vibrator_enable_pin: pinmux_vibrator_enable_pin {
  32                 pinctrl-single,pins = <
  33                 OMAP4_IOPAD(0X1d0, PIN_OUTPUT | MUX_MODE1) /* dmtimer9_pwm_evt (gpio_28) */
  34                 >;
  35         };
  36 };
  37
  38 / {
  39         pwm8: dmtimer-pwm {
  40                 pinctrl-names = "default";
  41                 pinctrl-0 = <&vibrator_direction_pin>;
  42
  43                 compatible = "ti,omap-dmtimer-pwm";
  44                 #pwm-cells = <3>;
  45                 ti,timers = <&timer8>;
  46                 ti,clock-source = <0x01>;
  47         };
  48
  49         pwm9: dmtimer-pwm {
  50                 pinctrl-names = "default";
  51                 pinctrl-0 = <&vibrator_enable_pin>;
  52
  53                 compatible = "ti,omap-dmtimer-pwm";
  54                 #pwm-cells = <3>;
  55                 ti,timers = <&timer9>;
  56                 ti,clock-source = <0x01>;
  57         };
  58
  59         vibrator {
  60                 compatible = "pwm-vibrator";
  61                 pwms = <&pwm9 0 1000000000 0>,
  62                        <&pwm8 0 1000000000 0>;
  63                 pwm-names = "enable", "direction";
  64                 direction-duty-cycle-ns = <1000000000>;
  65         };
  66 };