xref: /openbmc/linux/drivers/video/of_videomode.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * generic videomode helper
4  *
5  * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix
6  */
7 #include <linux/errno.h>
8 #include <linux/export.h>
9 #include <linux/of.h>
10 #include <video/display_timing.h>
11 #include <video/of_display_timing.h>
12 #include <video/of_videomode.h>
13 #include <video/videomode.h>
14 
15 /**
16  * of_get_videomode - get the videomode #<index> from devicetree
17  * @np - devicenode with the display_timings
18  * @vm - set to return value
19  * @index - index into list of display_timings
20  *	    (Set this to OF_USE_NATIVE_MODE to use whatever mode is
21  *	     specified as native mode in the DT.)
22  *
23  * DESCRIPTION:
24  * Get a list of all display timings and put the one
25  * specified by index into *vm. This function should only be used, if
26  * only one videomode is to be retrieved. A driver that needs to work
27  * with multiple/all videomodes should work with
28  * of_get_display_timings instead.
29  **/
30 int of_get_videomode(struct device_node *np, struct videomode *vm,
31 		     int index)
32 {
33 	struct display_timings *disp;
34 	int ret;
35 
36 	disp = of_get_display_timings(np);
37 	if (!disp) {
38 		pr_err("%pOF: no timings specified\n", np);
39 		return -EINVAL;
40 	}
41 
42 	if (index == OF_USE_NATIVE_MODE)
43 		index = disp->native_mode;
44 
45 	ret = videomode_from_timings(disp, vm, index);
46 
47 	display_timings_release(disp);
48 
49 	return ret;
50 }
51 EXPORT_SYMBOL_GPL(of_get_videomode);
52