samples: add proper display api functions return value checks

Ensure that display api function return values are checked.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>

Author: Alain Volmat

samples/drivers/display/src/main.c

@@ -222,6 +222,7 @@ int main(void)
 	struct display_buffer_descriptor buf_desc;
 	size_t buf_size = 0;
 	fill_buffer fill_buffer_fnc = NULL;
+	int ret;
 
 	display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
@@ -362,7 +363,15 @@ int main(void)
 		if ((capabilities.y_resolution - idx) < h_step) {
 			buf_desc.height = (capabilities.y_resolution - idx);
 		}
-		display_write(display_dev, 0, idx, &buf_desc, buf);
+		ret = display_write(display_dev, 0, idx, &buf_desc, buf);
+		if (ret < 0) {
+			LOG_ERR("Failed to write to display (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+			posix_exit_main(1);
+#else
+			return 0;
+#endif
+		}
 	}
 
 	buf_desc.pitch = rect_w;
@@ -372,12 +381,28 @@ int main(void)
 	fill_buffer_fnc(TOP_LEFT, 0, buf, buf_size);
 	x = 0;
 	y = 0;
-	display_write(display_dev, x, y, &buf_desc, buf);
+	ret = display_write(display_dev, x, y, &buf_desc, buf);
+	if (ret < 0) {
+		LOG_ERR("Failed to write to display (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+		posix_exit_main(1);
+#else
+		return 0;
+#endif
+	}
 
 	fill_buffer_fnc(TOP_RIGHT, 0, buf, buf_size);
 	x = capabilities.x_resolution - rect_w;
 	y = 0;
-	display_write(display_dev, x, y, &buf_desc, buf);
+	ret = display_write(display_dev, x, y, &buf_desc, buf);
+	if (ret < 0) {
+		LOG_ERR("Failed to write to display (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+		posix_exit_main(1);
+#else
+		return 0;
+#endif
+	}
 
 	/*
 	 * This is the last write of the frame, so turn this off.
@@ -389,9 +414,25 @@ int main(void)
 	fill_buffer_fnc(BOTTOM_RIGHT, 0, buf, buf_size);
 	x = capabilities.x_resolution - rect_w;
 	y = capabilities.y_resolution - rect_h;
-	display_write(display_dev, x, y, &buf_desc, buf);
+	ret = display_write(display_dev, x, y, &buf_desc, buf);
+	if (ret < 0) {
+		LOG_ERR("Failed to write to display (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+		posix_exit_main(1);
+#else
+		return 0;
+#endif
+	}
 
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+		posix_exit_main(1);
+#else
+		return 0;
+#endif
+	}
 
 	grey_count = 0;
 	x = 0;
@@ -400,7 +441,16 @@ int main(void)
 	LOG_INF("Display starts");
 	while (1) {
 		fill_buffer_fnc(BOTTOM_LEFT, grey_count, buf, buf_size);
-		display_write(display_dev, x, y, &buf_desc, buf);
+		ret = display_write(display_dev, x, y, &buf_desc, buf);
+		if (ret < 0) {
+			LOG_ERR("Failed to write to display (error %d)", ret);
+#ifdef CONFIG_ARCH_POSIX
+			posix_exit_main(1);
+#else
+			return 0;
+#endif
+		}
+
 		++grey_count;
 		k_msleep(grey_scale_sleep);
 #if CONFIG_TEST

samples/drivers/video/capture_to_lvgl/src/main.c

@@ -160,7 +160,11 @@ int main(void)
 		return 0;
 	}
 
-	display_blanking_off(display_dev);
+	err = display_blanking_off(display_dev);
+	if (err < 0 && err != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", err);
+		return 0;
+	}
 
 	const lv_img_dsc_t video_img = {
 		.header.w = CONFIG_VIDEO_WIDTH,

samples/modules/lvgl/accelerometer_chart/src/main.c

@@ -68,6 +68,7 @@ static void create_accelerometer_chart(lv_obj_t *parent)
 int main(void)
 {
 	const struct device *display_dev;
+	int ret;
 
 	display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
@@ -86,7 +87,11 @@ int main(void)
 					1000 / CONFIG_SAMPLE_ACCEL_SAMPLING_RATE,
 					NULL);
 	lv_timer_handler();
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return 0;
+	}
 
 	while (1) {
 		uint32_t sleep_ms = lv_timer_handler();

samples/modules/lvgl/demos/src/main.c

@@ -23,6 +23,7 @@ int main(void)
 	k_timepoint_t next_scene_switch;
 	lv_demo_render_scene_t cur_scene = LV_DEMO_RENDER_SCENE_FILL;
 #endif /* CONFIG_LV_Z_DEMO_RENDER_SCENE_DYNAMIC */
+	int ret;
 
 	display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
@@ -61,7 +62,12 @@ int main(void)
 #endif
 	lvgl_unlock();
 
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return 0;
+	}
+
 #ifdef CONFIG_LV_Z_MEM_POOL_SYS_HEAP
 	lvgl_print_heap_info(false);
 #else

samples/modules/lvgl/multi_display/src/main.c

@@ -76,7 +76,14 @@ int main(void)
 
 	lv_timer_handler();
 	for (int i = 0; i < DT_ZEPHYR_DISPLAYS_COUNT; i++) {
-		display_blanking_off(display_dev[i]);
+		int ret;
+
+		ret = display_blanking_off(display_dev[i]);
+		if (ret < 0 && ret != -ENOSYS) {
+			LOG_ERR("Failed to turn display %s blanking off (error %d)",
+				display_dev[i]->name, ret);
+			return 0;
+		}
 	}
 
 #ifdef CONFIG_LV_Z_MEM_POOL_SYS_HEAP

samples/modules/lvgl/screen_transparency/src/main.c

@@ -46,6 +46,7 @@ static void initialize_gui(void)
 int main(void)
 {
 	const struct device *display_dev;
+	int ret;
 
 	display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
@@ -56,7 +57,11 @@ int main(void)
 	initialize_gui();
 
 	lv_timer_handler();
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return 0;
+	}
 
 	while (1) {
 		uint32_t sleep_ms = lv_timer_handler();

samples/subsys/display/lvgl/src/main.c

@@ -60,6 +60,7 @@ int main(void)
 	const struct device *display_dev;
 	lv_obj_t *hello_world_label;
 	lv_obj_t *count_label;
+	int ret;
 
 	display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
 	if (!device_is_ready(display_dev)) {
@@ -142,7 +143,11 @@ int main(void)
 	lv_obj_align(count_label, LV_ALIGN_BOTTOM_MID, 0, 0);
 
 	lv_timer_handler();
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return 0;
+	}
 
 	while (1) {
 		if ((count % 100) == 0U) {

samples/subsys/input/draw_touch_events/src/main.c

@@ -63,10 +63,11 @@ static void touch_event_callback(struct input_event *evt, void *user_data)
 }
 INPUT_CALLBACK_DEFINE(touch_dev, touch_event_callback, NULL);
 
-static void clear_screen(void)
+static int clear_screen(void)
 {
 	int x;
 	int y;
+	int ret;
 
 	for (x = 0; x < WIDTH; x += CROSS_DIM) {
 		for (y = 0; y < HEIGHT; y += CROSS_DIM) {
@@ -78,9 +79,15 @@ static void clear_screen(void)
 			ddesc.height = MIN(buf_desc.height, rem_h);
 			ddesc.buf_size = ddesc.width * ddesc.height * BPP;
 
-			display_write(display_dev, x, y, &ddesc, buffer_cross_empty);
+			ret = display_write(display_dev, x, y, &ddesc, buffer_cross_empty);
+			if (ret < 0) {
+				LOG_ERR("Failed to write to display (error %d)", ret);
+				return ret;
+			}
 		}
 	}
+
+	return 0;
 }
 
 static void fill_cross_buffer(void)
@@ -117,6 +124,7 @@ static int get_draw_position(int value, int upper_bound)
 
 int main(void)
 {
+	int ret;
 
 	LOG_INF("Touch sample for touchscreen: %s, dc: %s", touch_dev->name, display_dev->name);
 
@@ -135,9 +143,18 @@ int main(void)
 		return 0;
 	}
 	fill_cross_buffer();
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return 0;
+	}
+
+	ret = clear_screen();
+	if (ret < 0) {
+		LOG_ERR("Failed to clear the screen");
+		return 0;
+	}
 
-	clear_screen();
 	touch_point_drawn.x = CROSS_DIM / 2;
 	touch_point_drawn.y = CROSS_DIM / 2;
 	touch_point.x = -1;
@@ -151,12 +168,21 @@ int main(void)
 		LOG_INF("TOUCH %s X, Y: (%d, %d)", touch_point.pressed ? "PRESS" : "RELEASE",
 			touch_point.x, touch_point.y);
 
-		display_write(display_dev, get_draw_position(touch_point_drawn.x, WIDTH),
-			      get_draw_position(touch_point_drawn.y, HEIGHT), &buf_desc,
-			      buffer_cross_empty);
+		ret = display_write(display_dev, get_draw_position(touch_point_drawn.x, WIDTH),
+				    get_draw_position(touch_point_drawn.y, HEIGHT), &buf_desc,
+				    buffer_cross_empty);
+		if (ret < 0) {
+			LOG_ERR("Failed to write to display (error %d)", ret);
+			return 0;
+		}
 
-		display_write(display_dev, get_draw_position(touch_point.x, WIDTH),
-			      get_draw_position(touch_point.y, HEIGHT), &buf_desc, buffer_cross);
+		ret = display_write(display_dev, get_draw_position(touch_point.x, WIDTH),
+				    get_draw_position(touch_point.y, HEIGHT), &buf_desc,
+				    buffer_cross);
+		if (ret < 0) {
+			LOG_ERR("Failed to write to display (error %d)", ret);
+			return 0;
+		}
 
 		touch_point_drawn.x = touch_point.x;
 		touch_point_drawn.y = touch_point.y;

samples/subsys/smf/smf_calculator/src/main.c

@@ -112,6 +112,7 @@ static void lv_btn_matrix_click_callback(lv_event_t *e)
 static int setup_display(void)
 {
 	const struct device *display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
+	int ret;
 
 	if (!device_is_ready(display_dev)) {
 		LOG_ERR("Device not ready, aborting setup");
@@ -165,7 +166,11 @@ static int setup_display(void)
 	update_display("0");
 
 	lv_task_handler();
-	display_blanking_off(display_dev);
+	ret = display_blanking_off(display_dev);
+	if (ret < 0 && ret != -ENOSYS) {
+		LOG_ERR("Failed to turn blanking off (error %d)", ret);
+		return ret;
+	}
 
 	return 0;
 }