Naming and coding style convention, new linter tool. (#945)

* Makefile, Scripts: new linter
* About: remove ID from IC
* Firmware: remove double define for DIVC/DIVR
* Scripts: check folder names too. Docker: replace syntax check with make lint.
* Reformat Sources and Migrate to new file naming convention
* Docker: symlink clang-format-12 to clang-format
* Add coding style guide

applications/ibutton/helpers/cyfral_decoder.h

@@ -0,0 +1,55 @@
+#pragma once
+#include <stdint.h>
+#include <atomic>
+
+class CyfralDecoder {
+public:
+    bool read(uint8_t* data, uint8_t data_size);
+    void process_front(bool polarity, uint32_t time);
+
+    CyfralDecoder();
+
+private:
+    enum class BitState : uint8_t {
+        WAIT_FRONT_HIGH,
+        WAIT_FRONT_LOW,
+    };
+
+    enum class State : uint8_t {
+        WAIT_START_NIBBLE,
+        READ_NIBBLE,
+        READ_STOP_NIBBLE,
+    };
+
+    State state;
+    BitState bit_state;
+
+    bool process_bit(bool polarity, uint32_t time, bool* readed, bool* readed_value);
+    void reset_state();
+    bool nibble_valid(uint8_t data);
+
+    // high + low period time
+    uint32_t period_time;
+
+    // ready flag, key is readed and valid
+    std::atomic<bool> ready;
+
+    // key data storage
+    uint16_t key_data;
+
+    // temporary nibble storage
+    uint8_t readed_nibble;
+
+    // data valid flag
+    // MUST be checked only in READ_STOP_NIBBLE state
+    bool data_valid;
+
+    // nibble index, we expect 8 nibbles
+    uint8_t index;
+
+    // bit index in nibble, 4 bit per nibble
+    uint8_t bit_index;
+
+    // max period, 230us x clock per us
+    uint32_t max_period;
+};