1 files changed, 70 insertions, 0 deletions
diff --git a/src/laser.cpp b/src/laser.cpp
new file mode 100644
index 0000000..f23faab
--- /dev/null
+++ b/src/laser.cpp
@@ -0,0 +1,70 @@
+#include "laser.h"
+
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+
+#include "macro.h"
+
+PwmLaser::PwmLaser(const std::string &pwmChip, const std::string &pwm)
+    : INIT_FIELD(pwmChip)
+    , INIT_FIELD(pwm)
+{}
+
+bool PwmLaser::init()
+{
+    if (m_pwmChip.empty() || m_pwm.empty()) {
+        std::cerr << __func__ << ":\tinvalid pwm config: pwmChip == '"
+                  << m_pwmChip << "', pwm == '" << m_pwm << "'" << std::endl;
+        return false;
+    }
+
+    auto writeToFile = [](const auto &path, const auto &value) -> bool {
+        if (!std::filesystem::exists(path)) {
+            std::cerr << __func__ << "\tno such file: " << path << std::endl;
+
+            return false;
+        }
+
+        std::ofstream ofs(path, std::ios::out | std::ios::trunc);
+
+        if (!ofs) {
+            std::cerr << __func__ << "\tcannot open" << path << "for writing"
+                      << std::endl;
+
+            return false;
+        }
+
+        ofs << value;
+
+        return true;
+    };
+
+    const std::filesystem::path pwmSystemRoot{"/sys/class/pwm"};
+    const auto pwmChipRoot = pwmSystemRoot / m_pwmChip;
+    const auto pwmExportFile = pwmChipRoot / "export";
+
+    if (!writeToFile(pwmExportFile, m_pwm))
+        return false;
+
+    const auto pwmRoot = pwmChipRoot / m_pwm;
+    const auto periodFilename = pwmRoot / "period";
+    constexpr unsigned periodHz{50'000};
+
+    if (!writeToFile(periodFilename, periodHz))
+        return false;
+
+    const auto dutyCycleFilename = pwmRoot / "duty_cycle";
+    const unsigned dutyCycle{3'000};
+
+    if (!writeToFile(dutyCycleFilename, dutyCycle))
+        return false;
+
+    const auto enableFilename = pwmRoot / "enable";
+    const int enable{1};
+
+    if (!writeToFile(enableFilename, enable))
+        return false;
+
+    return true;
+}