Brightness (Linux): allow specifying busno for ddcutil

Ref: #580

src/modules/brightness/brightness.c

@@ -88,6 +88,10 @@ void ffInitBrightnessOptions(FFBrightnessOptions* options)
 {
     ffOptionInitModuleBaseInfo(&options->moduleInfo, FF_BRIGHTNESS_MODULE_NAME, ffParseBrightnessCommandOptions, ffParseBrightnessJsonObject, ffPrintBrightness, ffGenerateBrightnessJson, ffPrintBrightnessHelpFormat);
     ffOptionInitModuleArg(&options->moduleArgs);
+
+    #ifdef __linux__
+    ffListInit(&options->busNos, sizeof(int));
+    #endif
 }
 
 bool ffParseBrightnessCommandOptions(FFBrightnessOptions* options, const char* key, const char* value)
@@ -103,6 +107,10 @@ bool ffParseBrightnessCommandOptions(FFBrightnessOptions* options, const char* k
 void ffDestroyBrightnessOptions(FFBrightnessOptions* options)
 {
     ffOptionDestroyModuleArg(&options->moduleArgs);
+
+    #ifdef __linux__
+    ffListDestroy(&options->busNos);
+    #endif
 }
 
 void ffParseBrightnessJsonObject(FFBrightnessOptions* options, yyjson_val* module)
@@ -118,6 +126,22 @@ void ffParseBrightnessJsonObject(FFBrightnessOptions* options, yyjson_val* modul
         if (ffJsonConfigParseModuleArgs(key, val, &options->moduleArgs))
             continue;
 
+        #ifdef __linux__
+        if(ffStrEqualsIgnCase(key, "busNos"))
+        {
+            if (!yyjson_is_arr(val)) continue;
+
+            yyjson_val* item;
+            size_t idx, max;
+            yyjson_arr_foreach(val, idx, max, item)
+            {
+                if (!yyjson_is_int(item)) continue;
+                *(int*) ffListAdd(&options->busNos) = yyjson_get_int(item);
+            }
+            continue;
+        }
+        #endif
+
         ffPrintError(FF_BRIGHTNESS_MODULE_NAME, 0, &options->moduleArgs, "Unknown JSON key %s", key);
     }
 }

src/modules/brightness/option.h

@@ -8,4 +8,8 @@ typedef struct FFBrightnessOptions
 {
     FFModuleBaseInfo moduleInfo;
     FFModuleArgs moduleArgs;
+
+#ifdef __linux__
+    FFlist busNos;
+#endif
 } FFBrightnessOptions;