gpio: adds basic digital i/o support

* Map gpios as D1,2,etc to their gpionum and pinNum as per arduino_nano_r3_connector.dtsi
* pulldown i/p mode gpio by default
* implements pinMode, digitalRead, Write, delay and delayMicroseconds
* Includes examples for push button LED and blink LED and hello world
* For a comprehensive commit history on GPIO refer: DhruvaG2000/Arduino-Core-Zephyr#4

Signed-off-by: Dhruva Gole <[email protected]>

Author: DhruvaG2000

CMakeLists.txt

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+add_subdirectory(cores)

Kconfig

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+#
+# Copyright (c) 2020 Toita, Hiroshi
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config ARDUINO_API
+	bool "ARDUINO_API"
+	depends on CPLUSPLUS
+	default n
+
+if ARDUINO_API
+
+config ARDUINO_MAIN_LOOP
+	bool "ARDUINO_MAIN_LOOP"
+	default n
+
+config ARDUINO_GPIO
+	bool "ARDUINO_API"
+	depends on GPIO
+	default y
+
+config ARDUINO_QUERY_PIN_CONFIG
+	bool
+	depends on ARDUINO_GPIO
+	default n
+
+config ARDUINO_UART
+	bool "ARDUINO_API"
+	depends on SERIAL
+	depends on UART_INTERRUPT_DRIVEN
+	default y
+
+config QEMU_ICOUNT
+	bool "QEMU icount mode"
+	default n
+	depends on QEMU_TARGET
+
+endif

cores/CMakeLists.txt

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+add_subdirectory(arduino)

cores/arduino/Arduino.h

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+#include "api/ArduinoAPI.h"
+
+/* Zephyr libraries */
+#include "arduino_nano_ble_sense_pinmap.h"
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/zephyr.h>

cores/arduino/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+zephyr_include_directories(.)
+
+if(NOT DEFINED ARDUINO_BUILD_PATH)
+
+zephyr_sources(zephyrCommon.cpp)
+zephyr_sources(main.cpp)
+
+endif()
+

cores/arduino/arduino_nano_ble_sense_pinmap.h

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+/*
+All the pins that are 100 + x are gpio1 pins and < 100 are in gpio0
+*/
+#define LED_BUILTIN 13
+
+enum digitalPins {
+  D0 = 103,
+  D1 = 110,
+  D2 = 111,
+  D3 = 112,
+  D4 = 115,
+  D5 = 113,
+  D6 = 114,
+  D7 = 9,
+  D8 = 10,
+  D9 = 27,
+  D10 = 102,
+  D11 = 101,
+  D12 = 108,
+  D13 = 13,
+  D14 = 4,
+  D15 = 5,
+  D16 = 30,
+  D17 = 29,
+  D18 = 14,
+  D19 = 15,
+  D20 = 28,
+  D21 = 103
+};

cores/arduino/main.cpp

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+#include "Arduino.h"
+
+int main(void) {
+  setup();
+
+  for (;;) {
+    loop();
+  }
+
+  return 0;
+}

cores/arduino/zephyrCommon.cpp

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+#include "Arduino.h"
+
+void pinMode(pin_size_t pinNumber, PinMode pinMode) {
+  if (pinNumber >= 100) {
+    pinNumber -= 100;
+    if (pinMode == INPUT || pinMode == INPUT_PULLDOWN) {
+      gpio_pin_configure(DEVICE_DT_GET(DT_NODELABEL(gpio1)), pinNumber,
+                         GPIO_INPUT | GPIO_ACTIVE_LOW);
+    } else {
+      gpio_pin_configure(DEVICE_DT_GET(DT_NODELABEL(gpio1)), pinNumber,
+                         GPIO_OUTPUT);
+    }
+  } else if (pinNumber < 100) {
+    if (pinMode == INPUT || pinMode == INPUT_PULLDOWN) {
+      gpio_pin_configure(DEVICE_DT_GET(DT_NODELABEL(gpio0)), pinNumber,
+                         GPIO_INPUT | GPIO_ACTIVE_LOW);
+    } else {
+      gpio_pin_configure(DEVICE_DT_GET(DT_NODELABEL(gpio0)), pinNumber,
+                         GPIO_OUTPUT);
+    }
+  }
+}
+
+void digitalWrite(pin_size_t pinNumber, PinStatus status) {
+  if (pinNumber >= 100) {
+    pinNumber -= 100;
+    if (status == HIGH) {
+      gpio_pin_set(DEVICE_DT_GET(DT_NODELABEL(gpio1)), pinNumber,
+                   GPIO_ACTIVE_HIGH);
+    } else if (status == LOW) {
+      gpio_pin_set(DEVICE_DT_GET(DT_NODELABEL(gpio1)), pinNumber,
+                   GPIO_ACTIVE_LOW);
+    }
+  } else if (pinNumber < 100) {
+    if (status == HIGH) {
+      gpio_pin_set(DEVICE_DT_GET(DT_NODELABEL(gpio0)), pinNumber,
+                   GPIO_ACTIVE_HIGH);
+    } else if (status == LOW) {
+      gpio_pin_set(DEVICE_DT_GET(DT_NODELABEL(gpio0)), pinNumber,
+                   GPIO_ACTIVE_LOW);
+    }
+  }
+}
+
+PinStatus digitalRead(pin_size_t pinNumber) {
+  if (pinNumber >= 100) {
+    pinNumber -= 100;
+    return (gpio_pin_get(DEVICE_DT_GET(DT_NODELABEL(gpio1)), pinNumber) == 1)
+               ? HIGH
+               : LOW;
+  }
+  return (gpio_pin_get(DEVICE_DT_GET(DT_NODELABEL(gpio0)), pinNumber) == 1)
+             ? HIGH
+             : LOW;
+}
+
+void delay(unsigned long ms) { k_sleep(K_MSEC(ms)); }
+
+void delayMicroseconds(unsigned int us) { k_sleep(K_USEC(us)); }

examples/blinky_arduino/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(blinky)
+
+target_sources(app PRIVATE src/main.cpp)

examples/blinky_arduino/README.rst

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+.. _blinky-sample:
+
+Blinky
+######
+
+Overview
+********
+
+This Arduino Blinky sample blinks an LED forever using the `ArduinoAPI`.
+
+Requirements
+************
+
+Your board must:
+
+#. Have an LED connected via a GPIO pin (these are called "User LEDs" on many of
+   Zephyr's :ref:`boards`).
+#. Have the LED configured using the ``led0`` devicetree alias.
+
+Building and Running
+********************
+
+Build and flash Blinky as follows,
+
+```sh
+$> west build  -p -b arduino_nano_33_ble samples/basic/arduino-blinky/ -DZEPHYR_EXTRA_MODULES=/home/$USER/zephyrproject/modules/lib/Arduino-Core-Zephyr
+
+$> west flash --bossac=/home/$USER/.arduino15/packages/arduino/tools/bossac/1.9.1-arduino2/bossac
+```
+
+After flashing, the LED starts to blink. If a runtime error occurs, the sample
+exits without printing to the console.
+
+Adding board support
+********************
+
+To add support for your board, add something like this to your devicetree:
+
+.. code-block:: DTS
+
+   / {
+   	aliases {
+   		led0 = &myled0;
+   	};
+
+   	leds {
+   		compatible = "gpio-leds";
+   		myled0: led_0 {
+   			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+                };
+   	};
+   };
+
+The above sets your board's ``led0`` alias to use pin 13 on GPIO controller
+``gpio0``. The pin flags :c:macro:`GPIO_ACTIVE_HIGH` mean the LED is on when
+the pin is set to its high state, and off when the pin is in its low state.
+
+Tips:
+
+- See :dtcompatible:`gpio-leds` for more information on defining GPIO-based LEDs
+  in devicetree.
+
+- If you're not sure what to do, check the devicetrees for supported boards which
+  use the same SoC as your target. See :ref:`get-devicetree-outputs` for details.
+
+- See :zephyr_file:`include/zephyr/dt-bindings/gpio/gpio.h` for the flags you can use
+  in devicetree.
+
+- If the LED is built in to your board hardware, the alias should be defined in
+  your :ref:`BOARD.dts file <devicetree-in-out-files>`. Otherwise, you can
+  define one in a :ref:`devicetree overlay <set-devicetree-overlays>`.

examples/blinky_arduino/prj.conf

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+CONFIG_GPIO=y
+CONFIG_CPLUSPLUS=y
+CONFIG_ARDUINO_API=y

examples/blinky_arduino/sample.yaml

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+sample:
+  name: Blinky Sample
+tests:
+  sample.basic.blinky:
+    tags: LED gpio
+    filter: dt_enabled_alias_with_parent_compat("led0", "gpio-leds")
+    depends_on: gpio
+    harness: led
+    integration_platforms:
+      - frdm_k64f

examples/blinky_arduino/src/main.cpp

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+/* Blink inbuilt LED example */
+
+#include <Arduino.h>
+
+/* 1000 msec = 1 sec */
+#define SLEEP_TIME_MS 1000
+
+void setup() { pinMode(LED_BUILTIN, OUTPUT); }
+
+void loop() {
+  digitalWrite(LED_BUILTIN, HIGH);
+  delay(SLEEP_TIME_MS);
+  digitalWrite(LED_BUILTIN, LOW);
+  delay(SLEEP_TIME_MS);
+}

examples/button_press_led/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(blinky)
+
+target_sources(app PRIVATE src/main.cpp)

examples/button_press_led/README.rst

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+Button press LED
+######
+
+Overview
+********
+
+This Arduino sample turns ON an LED if button pressed using the `ArduinoAPI`.
+
+Requirements
+************
+
+Your board must:
+
+#. Have an LED connected via a GPIO pin (these are called "User LEDs" on many of
+   Zephyr's :ref:`boards`).
+#. Have the LED configured using the ``led0`` devicetree alias.
+#. Have a button connected to pin `D9` of the arduino externally (pulled down by default)
+
+Building and Running
+********************
+
+Build and flash as follows,
+
+```sh
+$> west build  -p -b arduino_nano_33_ble samples/button_press_led -DZEPHYR_EXTRA_MODULES=/home/$USER/zephyrproject/modules/lib/Arduino-Core-Zephyr
+
+$> west flash --bossac=/home/$USER/.arduino15/packages/arduino/tools/bossac/1.9.1-arduino2/bossac
+```
+
+Adding board support
+********************
+
+To add support for your board, add something like this to your devicetree:
+
+.. code-block:: DTS
+
+   / {
+   	aliases {
+   		led0 = &myled0;
+   	};
+
+   	leds {
+   		compatible = "gpio-leds";
+   		myled0: led_0 {
+   			gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
+                };
+   	};
+   };
+
+The above sets your board's ``led0`` alias to use pin 13 on GPIO controller
+``gpio0``. The pin flags :c:macro:`GPIO_ACTIVE_HIGH` mean the LED is on when
+the pin is set to its high state, and off when the pin is in its low state.
+
+Tips:
+
+- See :dtcompatible:`gpio-leds` for more information on defining GPIO-based LEDs
+  in devicetree.
+
+- If you're not sure what to do, check the devicetrees for supported boards which
+  use the same SoC as your target. See :ref:`get-devicetree-outputs` for details.
+
+- See :zephyr_file:`include/zephyr/dt-bindings/gpio/gpio.h` for the flags you can use
+  in devicetree.
+
+- If the LED is built in to your board hardware, the alias should be defined in
+  your :ref:`BOARD.dts file <devicetree-in-out-files>`. Otherwise, you can
+  define one in a :ref:`devicetree overlay <set-devicetree-overlays>`.

examples/button_press_led/prj.conf

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+CONFIG_GPIO=y
+CONFIG_CPLUSPLUS=y
+CONFIG_ARDUINO_API=y

examples/button_press_led/sample.yaml

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+sample:
+  name: Blinky Sample
+tests:
+  sample.basic.blinky:
+    tags: LED gpio
+    filter: dt_enabled_alias_with_parent_compat("led0", "gpio-leds")
+    depends_on: gpio
+    harness: led
+    integration_platforms:
+      - frdm_k64f