zephyrCommon: Improved tone implementation

Improved to align more closely with the standard Arduino implementation.

- Eliminated the end timer and used counting to determine the end.
- Improved to handle infinity correctly.
- Added a guard to prevent the timeout value from reaching 0.
- Set the GPIO value to 0 when the timer starts.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

Author: soburi

cores/arduino/zephyrCommon.cpp

@@ -230,12 +230,32 @@ PinStatus digitalRead(pin_size_t pinNumber) {
 	return (gpio_pin_get_dt(&arduino_pins[pinNumber]) == 1) ? HIGH : LOW;
 }
 
-struct k_timer arduino_pin_timers[ARRAY_SIZE(arduino_pins)];
-struct k_timer arduino_pin_timers_timeout[ARRAY_SIZE(arduino_pins)];
+#ifndef MAX_TONE_PINS
+#define MAX_TONE_PINS DT_PROP_LEN(DT_PATH(zephyr_user), digital_pin_gpios)
+#endif
+
+#define TOGGLES_PER_CYCLE 2ULL
+
+static struct pin_timer {
+	struct k_timer timer;
+	uint32_t count;
+	pin_size_t pin;
+	bool infinity;
+} arduino_pin_timers[MAX_TONE_PINS];
 
 void tone_expiry_cb(struct k_timer *timer) {
-	const struct gpio_dt_spec *spec = (gpio_dt_spec *)k_timer_user_data_get(timer);
-	gpio_pin_toggle_dt(spec);
+	struct pin_timer *pt = CONTAINER_OF(timer, struct pin_timer, timer);
+	const struct gpio_dt_spec *spec = &arduino_pins[pt->pin];
+
+	if (pt->count == 0) {
+		k_timer_stop(timer);
+		gpio_pin_set_dt(spec, 0);
+	} else {
+		gpio_pin_toggle_dt(spec);
+		if (!pt->infinity) {
+			pt->count--;
+		}
+	}
 }
 
 void tone_timeout_cb(struct k_timer *timer) {
@@ -244,35 +264,44 @@ void tone_timeout_cb(struct k_timer *timer) {
 }
 
 void tone(pin_size_t pinNumber, unsigned int frequency, unsigned long duration) {
-	struct k_timer *timer = &arduino_pin_timers[pinNumber];
 	const struct gpio_dt_spec *spec = &arduino_pins[pinNumber];
+	struct k_timer *timer;
 	k_timeout_t timeout;
 
+	if (pinNumber >= MAX_TONE_PINS) {
+		return;
+	}
+
+	timer = &arduino_pin_timers[pinNumber].timer;
+
 	pinMode(pinNumber, OUTPUT);
+	k_timer_stop(&arduino_pin_timers[pinNumber].timer);
 
 	if (frequency == 0) {
 		gpio_pin_set_dt(spec, 0);
 		return;
 	}
 
-	timeout = K_NSEC(NSEC_PER_SEC / (2 * frequency));
+	timeout = K_NSEC(NSEC_PER_SEC / (TOGGLES_PER_CYCLE * frequency));
+	if (timeout.ticks == 0) {
+		timeout.ticks = 1;
+	}
 
+	arduino_pin_timers[pinNumber].infinity = (duration == 0);
+	arduino_pin_timers[pinNumber].count = (uint64_t)duration * frequency *
+					(MSEC_PER_SEC / TOGGLES_PER_CYCLE);
+	arduino_pin_timers[pinNumber].pin = pinNumber;
 	k_timer_init(timer, tone_expiry_cb, NULL);
-	k_timer_user_data_set(timer, (void *)spec);
-	gpio_pin_set_dt(spec, 1);
-	k_timer_start(timer, timeout, timeout);
 
-	if (duration > 0) {
-		timer = &arduino_pin_timers_timeout[pinNumber];
-		k_timer_init(timer, tone_timeout_cb, NULL);
-		k_timer_user_data_set(timer, (void *)(uintptr_t)pinNumber);
-		k_timer_start(timer, K_MSEC(duration), K_NO_WAIT);
-	}
+	gpio_pin_set_dt(spec, 0);
+	k_timer_start(timer, timeout, timeout);
 }
 
 void noTone(pin_size_t pinNumber) {
-	k_timer_stop(&arduino_pin_timers[pinNumber]);
-	gpio_pin_set_dt(&arduino_pins[pinNumber], 0);
+	const struct gpio_dt_spec *spec = &arduino_pins[pinNumber];
+
+	k_timer_stop(&arduino_pin_timers[pinNumber].timer);
+	gpio_pin_set_dt(spec, 0);
 }
 
 __attribute__((always_inline)) void delay(unsigned long ms) {