[components]add rt_device_ops for adc device and fix finsh_getchar() return wrong value in Big-endian status.

components/drivers/misc/adc.c

@@ -60,19 +60,37 @@ static rt_err_t _adc_control(rt_device_t dev, int cmd, void *args)
     return result;
 }
 
+#ifdef RT_USING_DEVICE_OPS
+const static struct rt_device_ops adc_ops =
+{
+    RT_NULL,
+    RT_NULL,
+    RT_NULL,
+    _adc_read,
+    RT_NULL,
+    _adc_control,
+};
+#endif
+
 rt_err_t rt_hw_adc_register(rt_adc_device_t device, const char *name, const struct rt_adc_ops *ops, const void *user_data)
 {
     rt_err_t result = RT_EOK;
     RT_ASSERT(ops != RT_NULL && ops->convert != RT_NULL);
 
     device->parent.type = RT_Device_Class_Miscellaneous;
+    device->parent.rx_indicate = RT_NULL;
+    device->parent.tx_complete = RT_NULL;
+
+#ifdef RT_USING_DEVICE_OPS
+    device->parent.ops         = &adc_ops;
+#else
     device->parent.init        = RT_NULL;
     device->parent.open        = RT_NULL;
     device->parent.close       = RT_NULL;
     device->parent.read        = _adc_read;
     device->parent.write       = RT_NULL;
     device->parent.control     = _adc_control;
-
+#endif
     device->ops = ops;
     device->parent.user_data = (void *)user_data;
 

components/finsh/shell.c

@@ -139,13 +139,13 @@ static int finsh_getchar(void)
 #ifdef RT_USING_POSIX
     return getchar();
 #else
-    int ch = 0;
+    char ch = 0;
 
     RT_ASSERT(shell != RT_NULL);
     while (rt_device_read(shell->device, -1, &ch, 1) != 1)
         rt_sem_take(&shell->rx_sem, RT_WAITING_FOREVER);
 
-    return ch;
+    return (int)ch;
 #endif
 }