core: Add option to reinit devices before Arduino use

Add ARDUINO_DEVICE_REINIT_ON_USE to optionally call the underlying
Zephyr device init callback before Arduino peripheral operations.

This keeps the current pinmux workaround opt-in while boards move
toward a proper pin/function handoff model.

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

Author: soburi

Kconfig

@@ -42,6 +42,16 @@ config ARDUINO_MAX_TONES
 	  If set to a negative value, the maximum number will be determined from the
 	  system's digital pin configuration.
 
+config ARDUINO_DEVICE_REINIT_ON_USE
+	bool "Reinitialize devices before Arduino peripheral use"
+	help
+	  Call the underlying Zephyr device init callback before using
+	  Arduino peripherals such as Serial, SPI, Wire, ADC, DAC, or PWM.
+
+	  This is a temporary workaround for boards that need to re-apply
+	  peripheral pinmux settings when a sketch switches a pin between GPIO
+	  and another function.
+
 module = ARDUINO_API
 module-str = arduino_api
 source "subsys/logging/Kconfig.template.log_config"

cores/arduino/zephyrCommon.cpp

@@ -9,6 +9,7 @@
 
 #include <zephyr/spinlock.h>
 
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 // create an array of arduino_pins with functions to reinitialize pins if needed
 static const struct device *pinmux_array[DT_PROP_LEN(DT_PATH(zephyr_user), digital_pin_gpios)] = {
 	nullptr};
@@ -21,6 +22,10 @@ void _reinit_peripheral_if_needed(pin_size_t pin, const struct device *dev) {
 		}
 	}
 }
+#else
+void _reinit_peripheral_if_needed(pin_size_t pin, const struct device *dev) {
+}
+#endif
 
 static const struct gpio_dt_spec arduino_pins[] = {
 	DT_FOREACH_PROP_ELEM_SEP(

cores/arduino/zephyrSerial.cpp

@@ -58,7 +58,9 @@ void arduino::ZephyrSerial::begin(unsigned long baud, uint16_t conf) {
 		.flow_ctrl = UART_CFG_FLOW_CTRL_NONE,
 	};
 
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 	uart->ops.init(uart);
+#endif
 
 	uart_configure(uart, &config);
 	uart_irq_callback_user_data_set(uart, arduino::ZephyrSerial::IrqDispatch, this);

cores/arduino/zephyrSerial.h

@@ -76,10 +76,12 @@ class ZephyrSerial : public HardwareSerial {
 	}
 
 	void end() {
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 #ifdef CONFIG_DEVICE_DEINIT_SUPPORT
 		if (uart->ops.deinit) {
 			uart->ops.deinit(uart);
 		}
+#endif
 #endif
 	}
 

libraries/SPI/SPI.cpp

@@ -118,15 +118,19 @@ void arduino::ZephyrSPI::detachInterrupt() {
 }
 
 void arduino::ZephyrSPI::begin() {
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 	spi_dev->ops.init(spi_dev);
+#endif
 }
 
 void arduino::ZephyrSPI::end() {
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 #ifdef CONFIG_DEVICE_DEINIT_SUPPORT
 	if (spi_dev->ops.deinit) {
 		spi_dev->ops.deinit(spi_dev);
 	}
 #endif
+#endif
 }
 
 #if DT_NODE_HAS_PROP(DT_PATH(zephyr_user), spis)

libraries/Wire/Wire.cpp

@@ -15,18 +15,22 @@ arduino::ZephyrI2C::ZephyrI2C(const struct device *i2c) : i2c_dev(i2c) {
 
 void arduino::ZephyrI2C::begin() {
 	ring_buf_init(&rxRingBuffer.rb, sizeof(rxRingBuffer.buffer), rxRingBuffer.buffer);
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 	i2c_dev->ops.init(i2c_dev);
+#endif
 }
 
 void arduino::ZephyrI2C::begin(uint8_t slaveAddr) {
 }
 
 void arduino::ZephyrI2C::end() {
+#ifdef CONFIG_ARDUINO_DEVICE_REINIT_ON_USE
 #ifdef CONFIG_DEVICE_DEINIT_SUPPORT
 	if (i2c_dev->ops.deinit) {
 		i2c_dev->ops.deinit(i2c_dev);
 	}
 #endif
+#endif
 }
 
 void arduino::ZephyrI2C::setClock(uint32_t freq) {