lv_hal: add init funtion to call prior driver registration

lv_hal/lv_hal_disp.c

@@ -40,13 +40,26 @@ static lv_disp_t *active;
  *   GLOBAL FUNCTIONS
  **********************/
 
+/**
+ * Initialize a display driver with default values.
+ * It is used to surly have known values in the fields ant not memory junk.
+ * After it you can set the fields.
+ * @param driver pointer to driver variable to initialize
+ */
+void lv_disp_drv_init(lv_disp_drv_t *driver)
+{
+    driver->fill_fp = NULL;
+    driver->map_fp = NULL;
+    driver->blend_fp = NULL;
+}
+
 /**
  * Register an initialized display driver.
  * Automatically set the first display as active.
  * @param driver pointer to an initialized 'lv_disp_drv_t' variable (can be local variable)
  * @return pointer to the new display or NULL on error
  */
-lv_disp_t * lv_disp_register(lv_disp_drv_t *driver)
+lv_disp_t * lv_disp_drv_register(lv_disp_drv_t *driver)
 {
     lv_disp_t *node;
 

lv_hal/lv_hal_disp.h

@@ -46,6 +46,13 @@ typedef struct _disp_t {
  * GLOBAL PROTOTYPES
  **********************/
 
+/**
+ * Initialize a display driver with default values.
+ * It is used to surly have known values in the fields ant not memory junk.
+ * After it you can set the fields.
+ * @param driver pointer to driver variable to initialize
+ */
+void lv_disp_drv_init(lv_disp_drv_t *driver);
 
 /**
  * Register an initialized display driver.
@@ -53,7 +60,7 @@ typedef struct _disp_t {
  * @param driver pointer to an initialized 'lv_disp_drv_t' variable (can be local variable)
  * @return pointer to the new display or NULL on error
  */
-lv_disp_t * lv_disp_register(lv_disp_drv_t *driver);
+lv_disp_t * lv_disp_drv_register(lv_disp_drv_t *driver);
 
 /**
  * Set the active display

lv_hal/lv_hal_indev.c

@@ -36,6 +36,18 @@ static lv_indev_t *indev_list = NULL;
  *   GLOBAL FUNCTIONS
  **********************/
 
+/**
+ * Initialize an input device driver with default values.
+ * It is used to surly have known values in the fields ant not memory junk.
+ * After it you can set the fields.
+ * @param driver pointer to driver variable to initialize
+ */
+void lv_indev_drv_init(lv_indev_drv_t *driver)
+{
+    driver->read_fp = NULL;
+    driver->type = LV_INDEV_TYPE_NONE;
+}
+
 /**
  * Register an initialized input device driver.
  * @param driver pointer to an initialized 'lv_indev_drv_t' variable (can be local variable)

lv_hal/lv_hal_indev.h

@@ -30,6 +30,7 @@ extern "C" {
 
 /*Possible input device types*/
 typedef enum {
+    LV_INDEV_TYPE_NONE,        /*Show uninitialized state*/
     LV_INDEV_TYPE_TOUCHPAD,    /*Touch pad*/
     LV_INDEV_TYPE_MOUSE,       /*Mouse or similar pointer device*/
     LV_INDEV_TYPE_KEYPAD,      /*Keypad or keyboard*/
@@ -105,6 +106,14 @@ typedef struct _lv_indev_t {
  * GLOBAL PROTOTYPES
  **********************/
 
+/**
+ * Initialize an input device driver with default values.
+ * It is used to surly have known values in the fields ant not memory junk.
+ * After it you can set the fields.
+ * @param driver pointer to driver variable to initialize
+ */
+void lv_indev_drv_init(lv_indev_drv_t *driver);
+
 /**
  * Register an initialized input device driver.
  * @param driver pointer to an initialized 'lv_indev_drv_t' variable (can be local variable)