drivers/video/of_videomode.c

   1 /*
   2  * generic videomode helper
   3  *
   4  * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
   5  *
   6  * This file is released under the GPLv2
   7  */
   8 #include <linux/errno.h>
   9 #include <linux/export.h>
  10 #include <linux/of.h>
  11 #include <video/display_timing.h>
  12 #include <video/of_display_timing.h>
  13 #include <video/of_videomode.h>
  14 #include <video/videomode.h>
  15
  16 /**
  17  * of_get_videomode - get the videomode #<index> from devicetree
  18  * @np - devicenode with the display_timings
  19  * @vm - set to return value
  20  * @index - index into list of display_timings
  21  *          (Set this to OF_USE_NATIVE_MODE to use whatever mode is
  22  *           specified as native mode in the DT.)
  23  *
  24  * DESCRIPTION:
  25  * Get a list of all display timings and put the one
  26  * specified by index into *vm. This function should only be used, if
  27  * only one videomode is to be retrieved. A driver that needs to work
  28  * with multiple/all videomodes should work with
  29  * of_get_display_timings instead.
  30  **/
  31 int of_get_videomode(struct device_node *np, struct videomode *vm,
  32                      int index)
  33 {
  34         struct display_timings *disp;
  35         int ret;
  36
  37         disp = of_get_display_timings(np);
  38         if (!disp) {
  39                 pr_err("%s: no timings specified\n", of_node_full_name(np));
  40                 return -EINVAL;
  41         }
  42
  43         if (index == OF_USE_NATIVE_MODE)
  44                 index = disp->native_mode;
  45
  46         ret = videomode_from_timings(disp, vm, index);
  47         if (ret)
  48                 return ret;
  49
  50         display_timings_release(disp);
  51
  52         return 0;
  53 }
  54 EXPORT_SYMBOL_GPL(of_get_videomode);