xref: /openbmc/linux/drivers/video/of_videomode.c (revision 12eb4683)
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);
55