ui/pixman: Add qemu_pixman_to_drm_format()

This new function to get the drm_format associated with a pixman
format will be useful while creating a dmabuf.

Based-on-patch-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Message-Id: <20210526231429.1045476-11-vivek.kasireddy@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

include/ui/qemu-pixman.h

@@ -62,6 +62,7 @@ typedef struct PixelFormat {
 PixelFormat qemu_pixelformat_from_pixman(pixman_format_code_t format);
 pixman_format_code_t qemu_default_pixman_format(int bpp, bool native_endian);
 pixman_format_code_t qemu_drm_format_to_pixman(uint32_t drm_format);
+uint32_t qemu_pixman_to_drm_format(pixman_format_code_t pixman);
 int qemu_pixman_get_type(int rshift, int gshift, int bshift);
 pixman_format_code_t qemu_pixman_get_format(PixelFormat *pf);
 bool qemu_pixman_check_format(DisplayChangeListener *dcl,

ui/qemu-pixman.c

@@ -89,21 +89,34 @@ pixman_format_code_t qemu_default_pixman_format(int bpp, bool native_endian)
 }
 
 /* Note: drm is little endian, pixman is native endian */
+static const struct {
+    uint32_t drm_format;
+    pixman_format_code_t pixman_format;
+} drm_format_pixman_map[] = {
+    { DRM_FORMAT_RGB888,   PIXMAN_LE_r8g8b8   },
+    { DRM_FORMAT_ARGB8888, PIXMAN_LE_a8r8g8b8 },
+    { DRM_FORMAT_XRGB8888, PIXMAN_LE_x8r8g8b8 }
+};
+
 pixman_format_code_t qemu_drm_format_to_pixman(uint32_t drm_format)
 {
-    static const struct {
-        uint32_t drm_format;
-        pixman_format_code_t pixman;
-    } map[] = {
-        { DRM_FORMAT_RGB888,   PIXMAN_LE_r8g8b8   },
-        { DRM_FORMAT_ARGB8888, PIXMAN_LE_a8r8g8b8 },
-        { DRM_FORMAT_XRGB8888, PIXMAN_LE_x8r8g8b8 }
-    };
     int i;
 
-    for (i = 0; i < ARRAY_SIZE(map); i++) {
-        if (drm_format == map[i].drm_format) {
-            return map[i].pixman;
+    for (i = 0; i < ARRAY_SIZE(drm_format_pixman_map); i++) {
+        if (drm_format == drm_format_pixman_map[i].drm_format) {
+            return drm_format_pixman_map[i].pixman_format;
+        }
+    }
+    return 0;
+}
+
+uint32_t qemu_pixman_to_drm_format(pixman_format_code_t pixman_format)
+{
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(drm_format_pixman_map); i++) {
+        if (pixman_format == drm_format_pixman_map[i].pixman_format) {
+            return drm_format_pixman_map[i].drm_format;
         }
     }
     return 0;