include/linux/screen_info.h

   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
  14 struct pci_dev;
  15 struct resource;
  16
  17 static inline bool __screen_info_has_lfb(unsigned int type)
  18 {
  19         return (type == VIDEO_TYPE_VLFB) || (type == VIDEO_TYPE_EFI);
  20 }
  21
  22 static 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
  32 static 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
  43 static 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
  52 static 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  */
  82 static 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
 119 ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num);
 120
 121 #if defined(CONFIG_PCI)
 122 void screen_info_apply_fixups(void);
 123 struct pci_dev *screen_info_pci_dev(const struct screen_info *si);
 124 #else
 125 static inline void screen_info_apply_fixups(void)
 126 { }
 127 static inline struct pci_dev *screen_info_pci_dev(const struct screen_info *si)
 128 {
 129         return NULL;
 130 }
 131 #endif
 132
 133 extern struct screen_info screen_info;
 134
 135 #endif /* _SCREEN_INFO_H */