Implement GSPLCD::GetBrightness

libctru/include/3ds/services/gsplcd.h

@@ -35,4 +35,10 @@ Result GSPLCD_PowerOffBacklight(u32 screen);
  * @brief Gets the LCD screens' vendors. Stubbed on old 3ds.
  * @param vendor Pointer to output the screen vendors to.
  */
-Result GSPLCD_GetVendors(u8 *vendors);
+Result GSPLCD_GetVendors(u8 *vendors);
+
+/**
+ * @brief Gets the LCD screens' brightness. Stubbed on old 3ds.
+ * @param screen to get the brightness value.
+ */
+Result GSPLCD_GetBrightness(u32 *screen);

libctru/source/services/gsplcd.c

@@ -66,3 +66,17 @@ Result GSPLCD_GetVendors(u8 *vendors)
 	return cmdbuf[1];
 }
 
+Result GSPLCD_GetBrightness(u32 *screen)
+{
+    u32 *cmdbuf = getThreadCommandBuffer();
+ 
+    cmdbuf[0] = IPC_MakeHeader(0x15,1,0); // 0x150040
+    cmdbuf[1] = *screen;
+ 
+    Result ret = 0;
+    if (R_FAILED(ret = svcSendSyncRequest(gspLcdHandle))) return ret;
+   
+    *screen = cmdbuf[2];
+   
+    return cmdbuf[1];
+}