[add] simple commit

Signed-off-by: liuxinaliang <liuxianliang@rt-thread.com>

sample/cmux_sample_gsm.c

@@ -15,9 +15,6 @@
 #define CMUX_PPP_NAME "cmux_ppp"
 #define  CMUX_AT_NAME "cmux_at"
 
-#define CMUX_PPP_PORT 1
-#define  CMUX_AT_PORT 2
-
 #define DBG_TAG    "cmux.sample"
 
 #ifdef CMUX_DEBUG
@@ -29,10 +26,11 @@
 #include <rtdbg.h>
 
 struct cmux *sample = RT_NULL;
-
+#define
 int cmux_sample(void)
 {
     rt_err_t result;
+    /* find cmux object through the actual serial name < the actual serial has been related in the cmux.c file > */
     sample = cmux_object_find(CMUX_DEPEND_NAME);
     if(sample == RT_NULL)
     {
@@ -40,6 +38,7 @@ int cmux_sample(void)
         LOG_E("Can't find %s", CMUX_DEPEND_NAME);
         goto end;
     }
+    /* startup the cmux receive thread, attach control chananel and open it */
     result =cmux_start(sample);
     if(result != RT_EOK)
     {
@@ -47,8 +46,8 @@ int cmux_sample(void)
         goto end;
     }
     LOG_I("cmux sample (%s) start successful.", CMUX_DEPEND_NAME);
-#ifdef CMUX_AT_NAME
-    result = cmux_attach(sample, CMUX_AT_PORT,  CMUX_AT_NAME, RT_DEVICE_FLAG_DMA_RX, RT_NULL);
+#ifdef CMUX_AT_NAME     /* if defined CMUX_AT_NAME, you can attach AT function into cmux */
+    result = cmux_attach(sample, 2,  CMUX_AT_NAME, RT_DEVICE_FLAG_DMA_RX, RT_NULL);
     if(result != RT_EOK)
     {
         LOG_E("cmux attach (%s) failed.", CMUX_AT_NAME);
@@ -56,8 +55,8 @@ int cmux_sample(void)
     }
     LOG_I("cmux object channel (%s) attach successful.", CMUX_AT_NAME);
 #endif
-#ifdef CMUX_PPP_NAME
-    result = cmux_attach(sample, CMUX_PPP_PORT, CMUX_PPP_NAME, RT_DEVICE_FLAG_DMA_RX, RT_NULL);
+#ifdef CMUX_PPP_NAME    /* if defined CMUX_PPP_NAME, you can attach PPP function into cmux */
+    result = cmux_attach(sample, 1, CMUX_PPP_NAME, RT_DEVICE_FLAG_DMA_RX, RT_NULL);
     if(result != RT_EOK)
     {
         LOG_E("cmux attach %s failed.", CMUX_PPP_NAME);