fb: select device file by name

modules/video_output/fb.c

@@ -80,6 +80,11 @@ static void GfxMode        ( int i_tty );
 #define DEVICE_LONGTEXT N_( \
     "Framebuffer device to use for rendering (usually /dev/fb0).")
 
+#define NAME_TEXT N_("Framebuffer device's name")
+#define NAME_LONGTEXT N_( \
+    "If set, select framebuffer device by name rather than by path. " \
+    "Example: cat /sys/class/graphics/fb0/name" )
+
 #define TTY_TEXT N_("Run fb on current tty.")
 #define TTY_LONGTEXT N_( \
     "Run framebuffer on current TTY device (default enabled). " \
@@ -110,6 +115,9 @@ vlc_module_begin ()
     set_subcategory( SUBCAT_VIDEO_VOUT )
     add_file( FB_DEV_VAR, "/dev/fb0", NULL, DEVICE_TEXT, DEVICE_LONGTEXT,
               false )
+    add_string( "fb-name", "dm_vid0_fb", NULL, NAME_TEXT, NAME_LONGTEXT,
+              false );
+
     add_bool( "fb-tty", 1, NULL, TTY_TEXT, TTY_LONGTEXT, true )
     add_string( "fb-chroma", NULL, NULL, CHROMA_TEXT, CHROMA_LONGTEXT,
                 true )
@@ -754,7 +762,39 @@ static void SetPalette( vout_thread_t *p_vout, uint16_t *red, uint16_t *green,
 }
 #endif
 
-/* following functions are local */
+/*****************************************************************************
+ * OpenFbByName: select framebuffer by name
+ *****************************************************************************/
+static int OpenFbByName( const char *psz_name )
+{
+    int i_fd = -1;
+    int i; /* begins with /dev/fb0 */
+    char *psz_device;
+    struct fb_fix_screeninfo info;
+
+    for( i = 0; i < FB_MAX; i++ )
+    {
+        if( asprintf( &psz_device, "/dev/fb%d", i++ ) == -1 )
+            return -1;
+        i_fd = open( psz_device, O_RDWR);
+        free( psz_device );
+
+        if( i_fd == -1 )
+            return -1; /* check errno */
+
+        if( ioctl( i_fd, FBIOGET_FSCREENINFO, &info ) == -1 )
+        {
+            close( i_fd );
+            continue;
+        }
+
+        if( !strcmp( info.id, psz_name ) )
+            return i_fd;
+
+        close( i_fd );
+    }
+    return -1;
+}
 
 /*****************************************************************************
  * OpenDisplay: initialize framebuffer
@@ -766,19 +806,30 @@ static int OpenDisplay( vout_thread_t *p_vout )
     struct fb_fix_screeninfo    fix_info;     /* framebuffer fix information */
 
     /* Open framebuffer device */
-    if( !(psz_device = config_GetPsz( p_vout, FB_DEV_VAR )) )
+    if( (psz_device = config_GetPsz( p_vout, "fb-name" )) )
     {
-        msg_Err( p_vout, "don't know which fb device to open" );
+        if( (p_sys->i_fd = OpenFbByName( psz_device )) == -1 )
+        {
+            msg_Err( p_vout, "cannot open fb by name %s (%m)", psz_device );
+            free( psz_device );
             return VLC_EGENERIC;
         }
-
-    p_sys->i_fd = open( psz_device, O_RDWR);
+    }
+    else if( (psz_device = config_GetPsz( p_vout, FB_DEV_VAR )) )
+    {
+        p_sys->i_fd = open( psz_device, O_RDWR );
         if( p_sys->i_fd == -1 )
         {
             msg_Err( p_vout, "cannot open %s (%m)", psz_device );
             free( psz_device );
             return VLC_EGENERIC;
         }
+    }
+    else
+    {
+        msg_Err( p_vout, "don't know which fb device to open" );
+        return VLC_EGENERIC;
+    }
     free( psz_device );
 
     /* Get framebuffer device information */