Convert .ino -> .cpp (#2228)

- general conversion from .ino modules into a separate .cpp files
- clean-up internal headers, place libraries into .h. guard .cpp with _SUPPORT flags 
- fix some instances of shared variables instead of public methods
- tweak build system to still build a single source file via os environment variable ESPURNA_BUILD_SINGLE_SOURCE

code/espurna/gpio.cpp

@@ -0,0 +1,89 @@
+/*
+
+GPIO MODULE
+
+Copyright (C) 2017-2019 by Xose Pérez <xose dot perez at gmail dot com>
+
+*/
+
+#include "gpio.h"
+
+#include <bitset>
+
+// We need to explicitly call the constructor, because we need to set the const `pin`:
+// https://isocpp.org/wiki/faq/multiple-inheritance#virtual-inheritance-ctors
+GpioPin::GpioPin(unsigned char pin) :
+    BasePin(pin)
+{}
+
+inline void GpioPin::pinMode(int8_t mode) {
+    ::pinMode(this->pin, mode);
+}
+
+inline void GpioPin::digitalWrite(int8_t val) {
+    ::digitalWrite(this->pin, val);
+}
+
+inline int GpioPin::digitalRead() {
+    return ::digitalRead(this->pin);
+}
+
+// --------------------------------------------------------------------------
+
+std::bitset<GpioPins> _gpio_locked;
+std::bitset<GpioPins> _gpio_available;
+
+bool gpioValid(unsigned char gpio) {
+    if (gpio >= GpioPins) return false;
+
+    return _gpio_available.test(gpio);
+}
+
+bool gpioGetLock(unsigned char gpio) {
+    if (gpioValid(gpio)) {
+        if (!_gpio_locked.test(gpio)) {
+            _gpio_locked.set(gpio);
+            DEBUG_MSG_P(PSTR("[GPIO] GPIO%u locked\n"), gpio);
+            return true;
+        }
+    }
+    DEBUG_MSG_P(PSTR("[GPIO] Failed getting lock for GPIO%u\n"), gpio);
+    return false;
+}
+
+bool gpioReleaseLock(unsigned char gpio) {
+    if (gpioValid(gpio)) {
+        _gpio_locked.reset(gpio);
+        DEBUG_MSG_P(PSTR("[GPIO] GPIO%u lock released\n"), gpio);
+        return true;
+    }
+    DEBUG_MSG_P(PSTR("[GPIO] Failed releasing lock for GPIO%u\n"), gpio);
+    return false;
+}
+
+void gpioSetup() {
+
+    // https://github.com/espressif/esptool/blob/f04d34bcab29ace798d2d3800ba87020cccbbfdd/esptool.py#L1060-L1070
+    // "One or the other efuse bit is set for ESP8285"
+    // https://github.com/espressif/ESP8266_RTOS_SDK/blob/3c055779e9793e5f082afff63a011d6615e73639/components/esp8266/include/esp8266/efuse_register.h#L20-L21
+    // "define EFUSE_IS_ESP8285    (1 << 4)"
+    const uint32_t efuse_blocks[4] {
+        READ_PERI_REG(0x3ff00050),
+        READ_PERI_REG(0x3ff00054),
+        READ_PERI_REG(0x3ff00058),
+        READ_PERI_REG(0x3ff0005c)
+    };
+
+    const bool esp8285 = (
+        (efuse_blocks[0] & (1 << 4))
+        || (efuse_blocks[2] & (1 << 16))
+    );
+
+    // TODO: GPIO16 is only for basic I/O, gpioGetLock before attachInterrupt should check for that
+    for (unsigned char pin=0; pin < GpioPins; ++pin) {
+        if (pin <= 5) _gpio_available.set(pin);
+        if (((pin == 9) || (pin == 10)) && (esp8285)) _gpio_available.set(pin);
+        if (12 <= pin && pin <= 16) _gpio_available.set(pin);
+    }
+
+}