Linux kernel mirror (for testing)
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linux
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 bool __screen_info_vbe_mode_nonvga(const struct screen_info *si)
53{
54 /*
55 * VESA modes typically run on VGA hardware. Set bit 5 signals that this
56 * is not the case. Drivers can then not make use of VGA resources. See
57 * Sec 4.4 of the VBE 2.0 spec.
58 */
59 return si->vesa_attributes & BIT(5);
60}
61
62static inline unsigned int __screen_info_video_type(unsigned int type)
63{
64 switch (type) {
65 case VIDEO_TYPE_MDA:
66 case VIDEO_TYPE_CGA:
67 case VIDEO_TYPE_EGAM:
68 case VIDEO_TYPE_EGAC:
69 case VIDEO_TYPE_VGAC:
70 case VIDEO_TYPE_VLFB:
71 case VIDEO_TYPE_PICA_S3:
72 case VIDEO_TYPE_MIPS_G364:
73 case VIDEO_TYPE_SGI:
74 case VIDEO_TYPE_TGAC:
75 case VIDEO_TYPE_SUN:
76 case VIDEO_TYPE_SUNPCI:
77 case VIDEO_TYPE_PMAC:
78 case VIDEO_TYPE_EFI:
79 return type;
80 default:
81 return 0;
82 }
83}
84
85/**
86 * screen_info_video_type() - Decodes the video type from struct screen_info
87 * @si: an instance of struct screen_info
88 *
89 * Returns:
90 * A VIDEO_TYPE_ constant representing si's type of video display, or 0 otherwise.
91 */
92static inline unsigned int screen_info_video_type(const struct screen_info *si)
93{
94 unsigned int type;
95
96 // check if display output is on
97 if (!si->orig_video_isVGA)
98 return 0;
99
100 // check for a known VIDEO_TYPE_ constant
101 type = __screen_info_video_type(si->orig_video_isVGA);
102 if (type)
103 return si->orig_video_isVGA;
104
105 // check if text mode has been initialized
106 if (!si->orig_video_lines || !si->orig_video_cols)
107 return 0;
108
109 // 80x25 text, mono
110 if (si->orig_video_mode == 0x07) {
111 if ((si->orig_video_ega_bx & 0xff) != 0x10)
112 return VIDEO_TYPE_EGAM;
113 else
114 return VIDEO_TYPE_MDA;
115 }
116
117 // EGA/VGA, 16 colors
118 if ((si->orig_video_ega_bx & 0xff) != 0x10) {
119 if (si->orig_video_isVGA)
120 return VIDEO_TYPE_VGAC;
121 else
122 return VIDEO_TYPE_EGAC;
123 }
124
125 // the rest...
126 return VIDEO_TYPE_CGA;
127}
128
129ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num);
130
131#if defined(CONFIG_PCI)
132void screen_info_apply_fixups(void);
133struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
134#else
135static inline void screen_info_apply_fixups(void)
136{ }
137static inline struct pci_dev *screen_info_pci_dev(const struct screen_info *si)
138{
139 return NULL;
140}
141#endif
142
143extern struct screen_info screen_info;
144
145#endif /* _SCREEN_INFO_H */