PWM beeper forcing PWM to inactive statr

When disabling, some PWM hardware IP leaves the pin in the state it
happens to be in at that very moment. To make sure it is in the
inactive state, the duty cycle is now set to 0 first, before PWM is
being disabled.

Solves: EMP-628

Author: Robert Delien

drivers/input/misc/pwm-beeper.c

@@ -67,11 +67,22 @@ static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
 
 static void pwm_beeper_off(struct pwm_beeper *beeper)
 {
+	struct pwm_state state;
+
 	if (beeper->amplifier_on) {
 		regulator_disable(beeper->amplifier);
 		beeper->amplifier_on = false;
 	}
 
+	/*
+	 * When disabling, some PWM hardware IP leaves the pin in the state it
+	 * happens to be in. To make sure it is in the inactive state, set the
+	 * duty cycle to 0 first.
+	 */
+	pwm_get_state(beeper->pwm, &state);
+	state.duty_cycle = 0;
+	pwm_apply_state(beeper->pwm, &state);
+
 	pwm_disable(beeper->pwm);
 }