Report FPGA temperature

sw/src/userspace/remotectl.cpp

@@ -403,6 +403,40 @@ bool run_calibration_script()
 }
 
 
+/* ********  Temperature  ******** */
+
+/** Read FPGA temperature. */
+bool read_fpga_temperature(double& temp)
+{
+    const std::string xadc_dir =
+        "/sys/devices/soc0/axi/f8007100.adc/iio:device0";
+
+    std::ifstream is(xadc_dir + "/in_temp0_raw");
+    double temp_raw;
+    is >> temp_raw;
+    if (!is) {
+        return false;
+    }
+
+    is = std::ifstream(xadc_dir + "/in_temp0_offset");
+    double temp_offset;
+    is >> temp_offset;
+    if (!is) {
+        return false;
+    }
+
+    is = std::ifstream(xadc_dir + "/in_temp0_scale");
+    double temp_scale;
+    is >> temp_scale;
+    if (!is) {
+        return false;
+    }
+
+    temp = (temp_raw + temp_offset) * temp_scale / 1000.0;
+    return true;
+}
+
+
 /* ********  class CommandHandler  ******** */
 
 // Forward declaration.
@@ -902,6 +936,16 @@ private:
         return "ERROR Unconfigured";
     }
 
+    /** Handle command TEMP:FPGA? */
+    std::string qry_temp_fpga(CommandEnvironment env)
+    {
+        double temp;
+        if (! read_fpga_temperature(temp)) {
+            return "ERROR Reading temperature failed";
+        }
+        return str_format("%.1f", temp);
+    }
+
     /** Handle command RESET */
     std::string cmd_reset(CommandEnvironment env)
     {
@@ -1331,6 +1375,7 @@ private:
         { "tt:event:mask?",         &CommandHandler::qry_tt_event_mask },
         { "ipcfg?",                 &CommandHandler::qry_ipcfg },
         { "ipcfg:saved?",           &CommandHandler::qry_ipcfg },
+        { "temp:fpga?",             &CommandHandler::qry_temp_fpga },
         { "reset",                  &CommandHandler::cmd_reset },
         { "halt",                   &CommandHandler::cmd_halt },
         { "reboot",                 &CommandHandler::cmd_reboot },