driver/uinput: add uinput button support

Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>

include/nuttx/input/buttons.h

@@ -148,6 +148,11 @@ struct btn_lowerhalf_s
   CODE void (*bl_enable)(FAR const struct btn_lowerhalf_s *lower,
                          btn_buttonset_t press, btn_buttonset_t release,
                          btn_handler_t handler, FAR void *arg);
+
+  /* Key write callback function */
+
+  CODE ssize_t (*bl_write)(FAR const struct btn_lowerhalf_s *lower,
+                           FAR const char *buffer, size_t buflen);
 };
 
 /****************************************************************************

include/nuttx/input/uinput.h

@@ -49,4 +49,21 @@
 int uinput_touch_initialize(FAR const char *name, int maxpoint,
                             int buffnums);
 
+/****************************************************************************
+ * Name: uinput_button_initialize
+ *
+ * Description:
+ *   Initialized the uinput button device
+ *
+ * Input Parameters:
+ *   name:      Button devices name
+ *
+ * Returned Value:
+ *   Zero is returned on success. Otherwise, a negated errno value is
+ *   returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int uinput_button_initialize(FAR const char *name);
+
 #endif /* __INCLUDE_NUTTX_INPUT_UINPUT_H */