1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>
4 *
5 * description of display timings
6 */
7
8#ifndef __LINUX_DISPLAY_TIMING_H
9#define __LINUX_DISPLAY_TIMING_H
10
11#include <linux/bitops.h>
12#include <linux/types.h>
13
14enum display_flags {
15	DISPLAY_FLAGS_HSYNC_LOW		= BIT(0),
16	DISPLAY_FLAGS_HSYNC_HIGH	= BIT(1),
17	DISPLAY_FLAGS_VSYNC_LOW		= BIT(2),
18	DISPLAY_FLAGS_VSYNC_HIGH	= BIT(3),
19
20	/* data enable flag */
21	DISPLAY_FLAGS_DE_LOW		= BIT(4),
22	DISPLAY_FLAGS_DE_HIGH		= BIT(5),
23	/* drive data on pos. edge */
24	DISPLAY_FLAGS_PIXDATA_POSEDGE	= BIT(6),
25	/* drive data on neg. edge */
26	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= BIT(7),
27	DISPLAY_FLAGS_INTERLACED	= BIT(8),
28	DISPLAY_FLAGS_DOUBLESCAN	= BIT(9),
29	DISPLAY_FLAGS_DOUBLECLK		= BIT(10),
30	/* drive sync on pos. edge */
31	DISPLAY_FLAGS_SYNC_POSEDGE	= BIT(11),
32	/* drive sync on neg. edge */
33	DISPLAY_FLAGS_SYNC_NEGEDGE	= BIT(12),
34};
35
36/*
37 * A single signal can be specified via a range of minimal and maximal values
38 * with a typical value, that lies somewhere inbetween.
39 */
40struct timing_entry {
41	u32 min;
42	u32 typ;
43	u32 max;
44};
45
46/*
47 * Single "mode" entry. This describes one set of signal timings a display can
48 * have in one setting. This struct can later be converted to struct videomode
49 * (see include/video/videomode.h). As each timing_entry can be defined as a
50 * range, one struct display_timing may become multiple struct videomodes.
51 *
52 * Example: hsync active high, vsync active low
53 *
54 *				    Active Video
55 * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
56 *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
57 *	  |	     |	 porch  |		     |	 porch	 |
58 *
59 * HSync _|��������������������|___________________________________________|������������������
60 *
61 * VSync ��|__________|��������������������������������������������������������������������������������������|_________
62 */
63struct display_timing {
64	struct timing_entry pixelclock;
65
66	struct timing_entry hactive;		/* hor. active video */
67	struct timing_entry hfront_porch;	/* hor. front porch */
68	struct timing_entry hback_porch;	/* hor. back porch */
69	struct timing_entry hsync_len;		/* hor. sync len */
70
71	struct timing_entry vactive;		/* ver. active video */
72	struct timing_entry vfront_porch;	/* ver. front porch */
73	struct timing_entry vback_porch;	/* ver. back porch */
74	struct timing_entry vsync_len;		/* ver. sync len */
75
76	enum display_flags flags;		/* display flags */
77};
78
79/*
80 * This describes all timing settings a display provides.
81 * The native_mode is the default setting for this display.
82 * Drivers that can handle multiple videomodes should work with this struct and
83 * convert each entry to the desired end result.
84 */
85struct display_timings {
86	unsigned int num_timings;
87	unsigned int native_mode;
88
89	struct display_timing **timings;
90};
91
92/* get one entry from struct display_timings */
93static inline struct display_timing *display_timings_get(const struct
94							 display_timings *disp,
95							 unsigned int index)
96{
97	if (disp->num_timings > index)
98		return disp->timings[index];
99	else
100		return NULL;
101}
102
103void display_timings_release(struct display_timings *disp);
104
105#endif
106