[lib][display] update display_get_info to return success/failure

Update all the users to check for error.

dev/virtio/gpu/virtio-gpu.c

@@ -550,18 +550,21 @@ void virtio_gpu_gfx_flush(uint starty, uint endy)
     event_signal(&the_gdev->flush_event, !arch_ints_disabled());
 }
 
-void display_get_info(struct display_info *info)
+status_t display_get_info(struct display_info *info)
 {
     memset(info, 0, sizeof(*info));
 
-    if (the_gdev) {
-        info->framebuffer = the_gdev->fb;
-        info->format = GFX_FORMAT_RGB_x888;
-        info->width = the_gdev->pmode.r.width;
-        info->height = the_gdev->pmode.r.height;
-        info->stride = info->width;
-        info->flush = virtio_gpu_gfx_flush;
-    }
+    if (!the_gdev)
+        return ERR_NOT_FOUND;
+
+    info->framebuffer = the_gdev->fb;
+    info->format = GFX_FORMAT_RGB_x888;
+    info->width = the_gdev->pmode.r.width;
+    info->height = the_gdev->pmode.r.height;
+    info->stride = info->width;
+    info->flush = virtio_gpu_gfx_flush;
+
+    return NO_ERROR;
 }
 
 

include/dev/display.h

@@ -42,7 +42,7 @@ struct display_info {
 	void (*flush)(uint starty, uint endy);
 };
 
-void display_get_info(struct display_info *info);
+status_t display_get_info(struct display_info *info);
 
 #endif
 

include/lib/gfx.h

@@ -31,6 +31,7 @@
 
 // different graphics formats
 typedef enum {
+	GFX_FORMAT_NONE,
 	GFX_FORMAT_RGB_565,
 	GFX_FORMAT_ARGB_8888,
 	GFX_FORMAT_RGB_x888,

lib/gfx/gfx.c

@@ -490,7 +490,8 @@ void gfx_surface_destroy(struct gfx_surface *surface)
 void gfx_draw_pattern(void)
 {
 	struct display_info info;
-	display_get_info(&info);
+	if (display_get_info(&info) < 0)
+		return;
 
 	gfx_surface *surface = gfx_create_surface_from_display(&info);
 
@@ -518,7 +519,8 @@ void gfx_draw_pattern(void)
 void gfx_draw_pattern_white(void)
 {
 	struct display_info info;
-	display_get_info(&info);
+	if (display_get_info(&info) < 0)
+		return;
 
 	gfx_surface *surface = gfx_create_surface_from_display(&info);
 
@@ -586,7 +588,10 @@ static int cmd_gfx(int argc, const cmd_args *argv)
 	}
 
 	struct display_info info;
-	display_get_info(&info);
+	if (display_get_info(&info) < 0) {
+		printf("no display to draw on!\n");
+		return -1;
+	}
 
 	gfx_surface *surface = gfx_create_surface_from_display(&info);
 

lib/gfxconsole/gfxconsole.c

@@ -163,7 +163,9 @@ void gfxconsole_start_on_display(void)
 
 	/* pop up the console */
 	struct display_info info;
-	display_get_info(&info);
+	if (display_get_info(&info) < 0)
+		return;
+
 	gfx_surface *s = gfx_create_surface_from_display(&info);
 	gfxconsole_start(s);
 	started = true;

lib/text/text.c

@@ -77,7 +77,8 @@ void text_draw(int x, int y, const char *string)
 void text_update(void)
 {
 	struct display_info info;
-	display_get_info(&info);
+	if (display_get_info(&info) < 0)
+		return;
 
 	/* get the display's surface */
 	gfx_surface *surface = gfx_create_surface_from_display(&info);

platform/armemu/display.c

@@ -53,10 +53,10 @@ void platform_init_display(void)
 #endif
 }
 
-void display_get_info(struct display_info *info)
+status_t display_get_info(struct display_info *info)
 {
 	if (!has_display())
-		return;
+		return ERR_NOT_FOUND;
 
 	info->framebuffer = display_fb;
 	info->format = GFX_FORMAT_RGB_x888;
@@ -64,5 +64,7 @@ void display_get_info(struct display_info *info)
 	info->height = display_h;
 	info->stride = display_w;
 	info->flush = NULL;
+
+	return NO_ERROR;
 }
 

target/stm32746g-eval2/lcd.c

@@ -389,7 +389,7 @@ uint8_t BSP_LCD_Init(void)
 }
 
 /* LK display api here */
-void display_get_info(struct display_info *info)
+status_t display_get_info(struct display_info *info)
 {
     info->framebuffer = (void *)hLtdcEval.LayerCfg[ActiveLayer].FBStartAdress;
 
@@ -399,12 +399,14 @@ void display_get_info(struct display_info *info)
         info->format = GFX_FORMAT_RGB_565;
     } else {
         panic("unhandled pixel format\n");
-        info->format = GFX_FORMAT_MAX;
+        return ERR_NOT_FOUND;
     }
 
     info->width = BSP_LCD_GetXSize();
     info->height = BSP_LCD_GetYSize();
     info->stride = BSP_LCD_GetXSize();
     info->flush = NULL;
+
+    return NO_ERROR;
 }
 

target/stm32f746g-disco/lcd.c

@@ -395,7 +395,7 @@ uint8_t BSP_LCD_Init(uint32_t fb_address)
 }
 
 /* LK display (lib/gfx.h) calls this function */
-void display_get_info(struct display_info *info)
+status_t display_get_info(struct display_info *info)
 {
     info->framebuffer = (void *)ltdc_handle.LayerCfg[active_layer].FBStartAdress;
 
@@ -405,12 +405,14 @@ void display_get_info(struct display_info *info)
         info->format = GFX_FORMAT_RGB_565;
     } else {
         panic("unhandled pixel format\n");
-        info->format = GFX_FORMAT_MAX;
+        return ERR_NOT_FOUND;
     }
 
     info->width = BSP_LCD_GetXSize();
     info->height = BSP_LCD_GetYSize();
     info->stride = BSP_LCD_GetXSize();
     info->flush = NULL;
+
+    return NO_ERROR;
 }