Add ESP8266 core v2.6.2 (#905)

* Add ESP8266 core v2.6.2

* Upstream ESP8266 Wifi fixes

* Replace disable_interrupt with InterruptLock C++ class

* Update code to use InterruptLock

* Lint

* Update dht.cpp

* Improve InterruptLock docs, mark as ICACHE_RAM_ATTR

* Fixes

esphome/core/helpers.cpp

@@ -156,21 +156,6 @@ ParseOnOffState parse_on_off(const char *str, const char *on, const char *off) {
 
 const char *HOSTNAME_CHARACTER_WHITELIST = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_";
 
-void disable_interrupts() {
-#ifdef ARDUINO_ARCH_ESP32
-  portDISABLE_INTERRUPTS();
-#else
-  noInterrupts();
-#endif
-}
-void enable_interrupts() {
-#ifdef ARDUINO_ARCH_ESP32
-  portENABLE_INTERRUPTS();
-#else
-  interrupts();
-#endif
-}
-
 uint8_t crc8(uint8_t *data, uint8_t len) {
   uint8_t crc = 0;
 
@@ -193,8 +178,8 @@ void delay_microseconds_accurate(uint32_t usec) {
   if (usec <= 16383UL) {
     delayMicroseconds(usec);
   } else {
-    delay(usec / 1000UL);
-    delayMicroseconds(usec % 1000UL);
+    delay(usec / 16383UL);
+    delayMicroseconds(usec % 16383UL);
   }
 }
 
@@ -330,4 +315,13 @@ std::string hexencode(const uint8_t *data, uint32_t len) {
   return res;
 }
 
+#ifdef ARDUINO_ARCH_ESP8266
+ICACHE_RAM_ATTR InterruptLock::InterruptLock() { xt_state_ = xt_rsil(15); }
+ICACHE_RAM_ATTR InterruptLock::~InterruptLock() { xt_wsr_ps(xt_state_); }
+#endif
+#ifdef ARDUINO_ARCH_ESP32
+ICACHE_RAM_ATTR InterruptLock::InterruptLock() { portENABLE_INTERRUPTS(); }
+ICACHE_RAM_ATTR InterruptLock::~InterruptLock() { portDISABLE_INTERRUPTS(); }
+#endif
+
 }  // namespace esphome

esphome/core/helpers.h

@@ -133,16 +133,38 @@ uint16_t encode_uint16(uint8_t msb, uint8_t lsb);
 /// Decode a 16-bit unsigned integer into an array of two values: most significant byte, least significant byte.
 std::array<uint8_t, 2> decode_uint16(uint16_t value);
 
-/** Cross-platform method to disable interrupts.
+/***
+ * An interrupt helper class.
  *
- * Useful when you need to do some timing-dependent communication.
+ * This behaves like std::lock_guard. As long as the value is visible in the current stack, all interrupts
+ * (including flash reads) will be disabled.
  *
- * @see Do not forget to call `enable_interrupts()` again or otherwise things will go very wrong.
+ * Please note all functions called when the interrupt lock must be marked ICACHE_RAM_ATTR (loading code into
+ * instruction cache is done via interrupts; disabling interrupts prevents data not already in cache from being
+ * pulled from flash).
+ *
+ * Example:
+ *
+ * ```cpp
+ * // interrupts are enabled
+ * {
+ *   InterruptLock lock;
+ *   // do something
+ *   // interrupts are disabled
+ * }
+ * // interrupts are enabled
+ * ```
  */
-void disable_interrupts();
+class InterruptLock {
+ public:
+  InterruptLock();
+  ~InterruptLock();
 
-/// Cross-platform method to enable interrupts after they have been disabled.
-void enable_interrupts();
+ protected:
+#ifdef ARDUINO_ARCH_ESP8266
+  uint32_t xt_state_;
+#endif
+};
 
 /// Calculate a crc8 of data with the provided data length.
 uint8_t crc8(uint8_t *data, uint8_t len);

esphome/core/preferences.cpp

@@ -105,16 +105,18 @@ void ESPPreferences::save_esp8266_flash_() {
     return;
 
   ESP_LOGVV(TAG, "Saving preferences to flash...");
-  disable_interrupts();
-  auto erase_res = spi_flash_erase_sector(get_esp8266_flash_sector());
+  SpiFlashOpResult erase_res, write_res = SPI_FLASH_RESULT_OK;
+  {
+    InterruptLock lock;
+    erase_res = spi_flash_erase_sector(get_esp8266_flash_sector());
+    if (erase_res == SPI_FLASH_RESULT_OK) {
+      write_res = spi_flash_write(get_esp8266_flash_address(), this->flash_storage_, ESP8266_FLASH_STORAGE_SIZE * 4);
+    }
+  }
   if (erase_res != SPI_FLASH_RESULT_OK) {
-    enable_interrupts();
     ESP_LOGV(TAG, "Erase ESP8266 flash failed!");
     return;
   }
-
-  auto write_res = spi_flash_write(get_esp8266_flash_address(), this->flash_storage_, ESP8266_FLASH_STORAGE_SIZE * 4);
-  enable_interrupts();
   if (write_res != SPI_FLASH_RESULT_OK) {
     ESP_LOGV(TAG, "Write ESP8266 flash failed!");
     return;
@@ -173,9 +175,11 @@ ESPPreferences::ESPPreferences()
 void ESPPreferences::begin() {
   this->flash_storage_ = new uint32_t[ESP8266_FLASH_STORAGE_SIZE];
   ESP_LOGVV(TAG, "Loading preferences from flash...");
-  disable_interrupts();
-  spi_flash_read(get_esp8266_flash_address(), this->flash_storage_, ESP8266_FLASH_STORAGE_SIZE * 4);
-  enable_interrupts();
+
+  {
+    InterruptLock lock;
+    spi_flash_read(get_esp8266_flash_address(), this->flash_storage_, ESP8266_FLASH_STORAGE_SIZE * 4);
+  }
 }
 
 ESPPreferenceObject ESPPreferences::make_preference(size_t length, uint32_t type, bool in_flash) {