1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCREEN_INFO_H
3#define _SCREEN_INFO_H
4
5#include <uapi/linux/screen_info.h>
6
7#include <linux/bits.h>
8
9/**
10 * SCREEN_INFO_MAX_RESOURCES - maximum number of resources per screen_info
11 */
12#define SCREEN_INFO_MAX_RESOURCES	3
13
14struct pci_dev;
15struct resource;
16
17static inline bool __screen_info_has_lfb(unsigned int type)
18{
19	return (type == VIDEO_TYPE_VLFB) || (type == VIDEO_TYPE_EFI);
20}
21
22static inline u64 __screen_info_lfb_base(const struct screen_info *si)
23{
24	u64 lfb_base = si->lfb_base;
25
26	if (si->capabilities & VIDEO_CAPABILITY_64BIT_BASE)
27		lfb_base |= (u64)si->ext_lfb_base << 32;
28
29	return lfb_base;
30}
31
32static inline void __screen_info_set_lfb_base(struct screen_info *si, u64 lfb_base)
33{
34	si->lfb_base = lfb_base & GENMASK_ULL(31, 0);
35	si->ext_lfb_base = (lfb_base & GENMASK_ULL(63, 32)) >> 32;
36
37	if (si->ext_lfb_base)
38		si->capabilities |= VIDEO_CAPABILITY_64BIT_BASE;
39	else
40		si->capabilities &= ~VIDEO_CAPABILITY_64BIT_BASE;
41}
42
43static inline u64 __screen_info_lfb_size(const struct screen_info *si, unsigned int type)
44{
45	u64 lfb_size = si->lfb_size;
46
47	if (type == VIDEO_TYPE_VLFB)
48		lfb_size <<= 16;
49	return lfb_size;
50}
51
52static inline unsigned int __screen_info_video_type(unsigned int type)
53{
54	switch (type) {
55	case VIDEO_TYPE_MDA:
56	case VIDEO_TYPE_CGA:
57	case VIDEO_TYPE_EGAM:
58	case VIDEO_TYPE_EGAC:
59	case VIDEO_TYPE_VGAC:
60	case VIDEO_TYPE_VLFB:
61	case VIDEO_TYPE_PICA_S3:
62	case VIDEO_TYPE_MIPS_G364:
63	case VIDEO_TYPE_SGI:
64	case VIDEO_TYPE_TGAC:
65	case VIDEO_TYPE_SUN:
66	case VIDEO_TYPE_SUNPCI:
67	case VIDEO_TYPE_PMAC:
68	case VIDEO_TYPE_EFI:
69		return type;
70	default:
71		return 0;
72	}
73}
74
75/**
76 * screen_info_video_type() - Decodes the video type from struct screen_info
77 * @si: an instance of struct screen_info
78 *
79 * Returns:
80 * A VIDEO_TYPE_ constant representing si's type of video display, or 0 otherwise.
81 */
82static inline unsigned int screen_info_video_type(const struct screen_info *si)
83{
84	unsigned int type;
85
86	// check if display output is on
87	if (!si->orig_video_isVGA)
88		return 0;
89
90	// check for a known VIDEO_TYPE_ constant
91	type = __screen_info_video_type(si->orig_video_isVGA);
92	if (type)
93		return si->orig_video_isVGA;
94
95	// check if text mode has been initialized
96	if (!si->orig_video_lines || !si->orig_video_cols)
97		return 0;
98
99	// 80x25 text, mono
100	if (si->orig_video_mode == 0x07) {
101		if ((si->orig_video_ega_bx & 0xff) != 0x10)
102			return VIDEO_TYPE_EGAM;
103		else
104			return VIDEO_TYPE_MDA;
105	}
106
107	// EGA/VGA, 16 colors
108	if ((si->orig_video_ega_bx & 0xff) != 0x10) {
109		if (si->orig_video_isVGA)
110			return VIDEO_TYPE_VGAC;
111		else
112			return VIDEO_TYPE_EGAC;
113	}
114
115	// the rest...
116	return VIDEO_TYPE_CGA;
117}
118
119ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num);
120
121#if defined(CONFIG_PCI)
122void screen_info_apply_fixups(void);
123struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
124#else
125static inline void screen_info_apply_fixups(void)
126{ }
127static inline struct pci_dev *screen_info_pci_dev(const struct screen_info *si)
128{
129	return NULL;
130}
131#endif
132
133extern struct screen_info screen_info;
134
135#endif /* _SCREEN_INFO_H */
136