apps/examples/lcd_test/: Add example test case for callback touch fun…

…ctionality

    Touch hold/move event
    Total touch points 3
    TOUCH COORDINATES id: 0, x : 313 y : 162 touch type: 2
    Touch hold/move event
    TOUCH COORDINATES id: 1, x : 398 y : 282 touch type: 2
    Touch hold/move event
    TOUCH COORDINATES id: 2, x : 561 y : 321 touch type: 2
    Touch hold/move event
    Total touch points 3
    TOUCH COORDINATES id: 0, x : 313 y : 162 touch type: 2
    Touch hold/move event

apps/examples/lcd_test/example_lcd.c

@@ -85,6 +85,10 @@ static int yres;
 #define EXAMPLE_LCD_FPS_TEST 5000
 #endif
 
+#if defined(CONFIG_TOUCH) && defined(CONFIG_TOUCH_CALLBACK) 
+static struct touch_set_callback_s touch_set_callback;
+#endif
+
 static void putarea(int x1, int x2, int y1, int y2, int color)
 {
 	struct lcddev_area_s area;
@@ -370,6 +374,9 @@ static void test_fps(void)
 }
 
 #ifdef CONFIG_TOUCH
+
+#ifdef CONFIG_TOUCH_POLL
+
 static void touch_test(void)
 {
 	/* read first 10 events */
@@ -408,6 +415,37 @@ static void touch_test(void)
 	}
 	close(fd);
 }
+
+#elif CONFIG_TOUCH_CALLBACK
+
+void is_touch_detected(int status)
+{
+	if (status == OK) {
+		printf("Total touch points %d\n", touch_set_callback.touch_points->npoints);
+		for (int i = 0; i < touch_set_callback.touch_points->npoints; i++) {
+			printf("TOUCH COORDINATES id: %d, x : %d y : %d touch type: %d\n", touch_set_callback.touch_points->point[i].id, touch_set_callback.touch_points->point[i].x, touch_set_callback.touch_points->point[i].y, touch_set_callback.touch_points->point[i].flags);
+			if (touch_set_callback.touch_points->point[i].flags == TOUCH_DOWN) {
+				printf("Touch press event \n");
+			} else if (touch_set_callback.touch_points->point[i].flags == TOUCH_MOVE) {
+				printf("Touch hold/move event \n");
+			} else if (touch_set_callback.touch_points->point[i].flags == TOUCH_UP) {
+				printf("Touch release event \n");
+			}
+		}
+	} else if (status == -EINVAL) {	// -EINVAL Error signifies touch_set_callback.touch_points is NULL
+		if (touch_set_callback.touch_points == NULL) {
+			touch_set_callback.touch_points = (struct touch_sample_s *)malloc(sizeof(struct touch_sample_s));
+			if (!touch_set_callback.touch_points) {
+				printf("Error: Touch point buffer memory allocation failed\n");
+			}
+		}
+	} else {
+		printf("Error: Touch detection failed\n");
+	}
+}
+
+#endif
+
 #endif
 
 #ifdef CONFIG_BUILD_KERNEL
@@ -422,10 +460,35 @@ int lcd_test_main(int argc, char *argv[])
 	int p = 0;
 	char port[20] = { '\0' };
 #ifdef CONFIG_TOUCH
+
+#ifdef CONFIG_TOUCH_POLL
 	pid_t touch = task_create("touch", SCHED_PRIORITY_DEFAULT, 8096, touch_test, NULL);
 	if (touch < 0) {
 		printf("Error: Failed to create touch reader, error : %d\n", get_errno());
 	}
+
+#elif CONFIG_TOUCH_CALLBACK
+
+	touch_set_callback.touch_points = (struct touch_sample_s *)malloc(sizeof(struct touch_sample_s));
+	if (!touch_set_callback.touch_points) {
+		printf("Error: Touch point buffer memory allocation failed\n");
+		return;
+	}
+	touch_set_callback.is_touch_detected = is_touch_detected;
+	int touch_fd = open(TOUCH_DEV_PATH, O_RDWR);
+	if (touch_fd < 0) {
+		printf("Error: Failed to open /dev/touch0, errno : %d\n", get_errno());
+		return;
+	}
+	int ret = ioctl(touch_fd, TSIOC_SETAPPNOTIFY, &touch_set_callback);
+	if (ret != OK) {
+		printf("ERROR: Touch callback register from application to touch driver failed\n");
+		close(touch_fd);
+		return;
+	}
+
+#endif
+
 #endif
 
 	sprintf(port, LCD_DEV_PATH, p);
@@ -447,7 +510,12 @@ int lcd_test_main(int argc, char *argv[])
 	test_fps();
 	close(fd);
 #ifdef CONFIG_TOUCH
+#ifdef CONFIG_TOUCH_POLL
 	task_delete(touch);
+#elif CONFIG_TOUCH_CALLBACK
+	close(touch_fd);
+#endif
+
 #endif
 	return OK;
 }