Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux

[cascardo/linux.git] / drivers / gpu / drm / drm_fourcc.c

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 0645c85..29c56b4 100644 (file)
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -35,20 +35,61 @@ static char printable_char(int c)
        return isascii(c) && isprint(c) ? c : '?';
 }
 
+/**
+ * drm_mode_legacy_fb_format - compute drm fourcc code from legacy description
+ * @bpp: bits per pixels
+ * @depth: bit depth per pixel
+ *
+ * Computes a drm fourcc pixel format code for the given @bpp/@depth values.
+ * Useful in fbdev emulation code, since that deals in those values.
+ */
+uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
+{
+       uint32_t fmt;
+
+       switch (bpp) {
+       case 8:
+               fmt = DRM_FORMAT_C8;
+               break;
+       case 16:
+               if (depth == 15)
+                       fmt = DRM_FORMAT_XRGB1555;
+               else
+                       fmt = DRM_FORMAT_RGB565;
+               break;
+       case 24:
+               fmt = DRM_FORMAT_RGB888;
+               break;
+       case 32:
+               if (depth == 24)
+                       fmt = DRM_FORMAT_XRGB8888;
+               else if (depth == 30)
+                       fmt = DRM_FORMAT_XRGB2101010;
+               else
+                       fmt = DRM_FORMAT_ARGB8888;
+               break;
+       default:
+               DRM_ERROR("bad bpp, assuming x8r8g8b8 pixel format\n");
+               fmt = DRM_FORMAT_XRGB8888;
+               break;
+       }
+
+       return fmt;
+}
+EXPORT_SYMBOL(drm_mode_legacy_fb_format);
+
 /**
  * drm_get_format_name - return a string for drm fourcc format
  * @format: format to compute name of
  *
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
+ * Note that the buffer returned by this function is owned by the caller
+ * and will need to be freed using kfree().
  */
-const char *drm_get_format_name(uint32_t format)
+char *drm_get_format_name(uint32_t format)
 {
-       static char buf[32];
+       char *buf = kmalloc(32, GFP_KERNEL);
 
-       snprintf(buf, sizeof(buf),
+       snprintf(buf, 32,
                 "%c%c%c%c %s-endian (0x%08x)",
                 printable_char(format & 0xff),
                 printable_char((format >> 8) & 0xff),
@@ -73,6 +114,8 @@ EXPORT_SYMBOL(drm_get_format_name);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
                          int *bpp)
 {
+       char *format_name;
+
        switch (format) {
        case DRM_FORMAT_C8:
        case DRM_FORMAT_RGB332:
@@ -127,8 +170,9 @@ void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
                *bpp = 32;
                break;
        default:
-               DRM_DEBUG_KMS("unsupported pixel format %s\n",
-                             drm_get_format_name(format));
+               format_name = drm_get_format_name(format);
+               DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
+               kfree(format_name);
                *depth = 0;
                *bpp = 0;
                break;