Add mozc dial version.

Co-authored-by: Takashi Toyoshima <toyoshim@google.com>
Co-authored-by: Shun Ikejima <ikejima@google.com>

mozc-dial/firmware/common/photo_sensor.h

@@ -0,0 +1,33 @@
+// Copyright 2025 Google Inc.
+// Use of this source code is governed by an Apache License that can be found
+// in the LICENSE file.
+
+#ifndef COMMON_PHOTO_SENSOR_H_
+#define COMMON_PHOTO_SENSOR_H_
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+
+class PhotoSensor final {
+ public:
+  PhotoSensor(int8_t bit0,
+              int8_t bit1 = kNotUsed,
+              int8_t bit2 = kNotUsed,
+              int8_t bit3 = kNotUsed,
+              int8_t bit4 = kNotUsed,
+              int8_t bit5 = kNotUsed);
+  PhotoSensor(const PhotoSensor&) = delete;
+  PhotoSensor& operator=(const PhotoSensor&) = delete;
+  ~PhotoSensor() = default;
+
+  uint8_t Read();
+
+ private:
+  static constexpr int8_t kNotUsed = -1;
+  static constexpr size_t kMaxWidth = 6;
+
+  std::array<int8_t, kMaxWidth> bits;
+};
+
+#endif  // COMMON_PHOTO_SENSOR_H_