Interrupt support

- Disable registered interrupts on beginTransaction and re-enable on endTransaction. - Add zephyrInternal.h for APIs not meant for external consumption Signed-off-by: Ayush Singh <ayush@beagleboard.org>

Author: Ayush1325

cores/arduino/zephyrCommon.cpp

@@ -5,6 +5,7 @@
  */
 
 #include <Arduino.h>
+#include "zephyrInternal.h"
 
 namespace {
 
@@ -68,9 +69,14 @@ const int max_ngpios = max_in_list(
  * GPIO callback implementation
  */
 
+struct arduino_callback {
+ voidFuncPtr handler;
+ bool enabled;
+};
+
 struct gpio_port_callback {
  struct gpio_callback callback;
- voidFuncPtr handlers[max_ngpios];
+ struct arduino_callback handlers[max_ngpios];
  gpio_port_pins_t pins;
  const struct device *dev;
 } port_callback[port_num] = {0};
@@ -95,7 +101,7 @@ void setInterruptHandler(pin_size_t pinNumber, voidFuncPtr func)
  struct gpio_port_callback *pcb = find_gpio_port_callback(arduino_pins[pinNumber].port);
 
  if (pcb) {
- pcb->handlers[BIT(arduino_pins[pinNumber].pin)] = func;
+ pcb->handlers[BIT(arduino_pins[pinNumber].pin)].handler = func;
  }
 }
 
@@ -104,8 +110,8 @@ void handleGpioCallback(const struct device *port, struct gpio_callback *cb, uin
  struct gpio_port_callback *pcb = (struct gpio_port_callback *)cb;
 
  for (uint32_t i = 0; i < max_ngpios; i++) {
- if (pins & BIT(i)) {
- pcb->handlers[BIT(i)]();
+ if (pins & BIT(i) && pcb->handlers[BIT(i)].enabled) {
+ pcb->handlers[BIT(i)].handler();
  }
  }
 }
@@ -321,6 +327,7 @@ void attachInterrupt(pin_size_t pinNumber, voidFuncPtr callback, PinStatus pinSt
 
  pcb->pins |= BIT(arduino_pins[pinNumber].pin);
  setInterruptHandler(pinNumber, callback);
+ enableInterrupt(pinNumber);
 
  gpio_pin_interrupt_configure(arduino_pins[pinNumber].port, arduino_pins[pinNumber].pin, intmode);
  gpio_init_callback(&pcb->callback, handleGpioCallback, pcb->pins);
@@ -330,6 +337,7 @@ void attachInterrupt(pin_size_t pinNumber, voidFuncPtr callback, PinStatus pinSt
 void detachInterrupt(pin_size_t pinNumber)
 {
  setInterruptHandler(pinNumber, nullptr);
+ disableInterrupt(pinNumber);
 }
 
 #ifndef CONFIG_MINIMAL_LIBC_RAND
@@ -393,3 +401,19 @@ unsigned long pulseIn(pin_size_t pinNumber, uint8_t state, unsigned long timeout
 }
 
 #endif // CONFIG_GPIO_GET_DIRECTION
+
+void enableInterrupt(pin_size_t pinNumber) {
+ struct gpio_port_callback *pcb = find_gpio_port_callback(arduino_pins[pinNumber].port);
+
+ if (pcb) {
+ pcb->handlers[BIT(arduino_pins[pinNumber].pin)].enabled = true;
+ }
+}
+
+void disableInterrupt(pin_size_t pinNumber) {
+ struct gpio_port_callback *pcb = find_gpio_port_callback(arduino_pins[pinNumber].port);
+
+ if (pcb) {
+ pcb->handlers[BIT(arduino_pins[pinNumber].pin)].enabled = false;
+ }
+}

cores/arduino/zephyrInternal.h

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2024 Ayush Singh <ayush@beagleboard.org>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <Arduino.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void enableInterrupt(pin_size_t);
+void disableInterrupt(pin_size_t);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif

libraries/SPI/SPI.cpp

@@ -5,6 +5,7 @@
  */
 
 #include "SPI.h"
+#include "zephyrInternal.h"
 #include <zephyr/kernel.h>
 
 /* Serial Peripheral Control Register */
@@ -75,23 +76,46 @@ void arduino::ZephyrSPI::transfer(void *buf, size_t count) {
  }
 }
 
-void arduino::ZephyrSPI::usingInterrupt(int interruptNumber) {}
+void arduino::ZephyrSPI::usingInterrupt(int interruptNumber) {
+ interrupt[interrupt_pos++] = interruptNumber;
+}
 
-void arduino::ZephyrSPI::notUsingInterrupt(int interruptNumber) {}
+void arduino::ZephyrSPI::notUsingInterrupt(int interruptNumber) {
+ for (size_t i = 0; i < interrupt_pos; ++i) {
+ if (interrupt[i] == interruptNumber) {
+ memmove(&interrupt[i], &interrupt[i + 1], interrupt_pos - i - 1);
+ interrupt_pos--;
+ break;
+ }
+ }
+}
 
 void arduino::ZephyrSPI::beginTransaction(SPISettings settings) {
  memset(&config, 0, sizeof(config));
  config.frequency = settings.getClockFreq();
  config.operation = ((settings.getBitOrder() ^ 1) << 4) |
  (settings.getDataMode() << 1) | ((SPCR >> MSTR) & 1) |
  SPI_WORD_SET(8);
+
+ detachInterrupt();
 }
 
-void arduino::ZephyrSPI::endTransaction(void) { spi_release(spi_dev, &config); }
+void arduino::ZephyrSPI::endTransaction(void) {
+ spi_release(spi_dev, &config);
+ attachInterrupt();
+}
 
-void arduino::ZephyrSPI::attachInterrupt() {}
+void arduino::ZephyrSPI::attachInterrupt() {
+ for (size_t i = 0; i < interrupt_pos; ++i) {
+ enableInterrupt(interrupt[i]);
+ }
+}
 
-void arduino::ZephyrSPI::detachInterrupt() {}
+void arduino::ZephyrSPI::detachInterrupt() {
+ for (size_t i = 0; i < interrupt_pos; ++i) {
+ disableInterrupt(interrupt[i]);
+ }
+}
 
 void arduino::ZephyrSPI::begin() {}
 

libraries/SPI/SPI.h

@@ -19,6 +19,12 @@
 #define SPE 6
 #define SPIE 7
 
+/* Count the number of GPIOs for limit of number of interrupts */
+#define INTERRUPT_HELPER(n, p, i) 1
+#define INTERRUPT_COUNT \
+ DT_FOREACH_PROP_ELEM_SEP(DT_PATH(zephyr_user), digital_pin_gpios, \
+ INTERRUPT_HELPER, (+))
+
 namespace arduino {
 class ZephyrSPI : public HardwareSPI {
 public:
@@ -43,7 +49,9 @@ class ZephyrSPI : public HardwareSPI {
 
 private:
  const struct device *spi_dev;
-struct spi_config config;
+ struct spi_config config;
+ int interrupt[INTERRUPT_COUNT];
+ size_t interrupt_pos = 0;
 };
 
 } // namespace arduino