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 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 62 static 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 */ 92 static 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 } 128 129 static inline u32 __screen_info_vesapm_info_base(const struct screen_info *si) 130 { 131 if (si->vesapm_seg < 0xc000) 132 return 0; 133 return (si->vesapm_seg << 4) + si->vesapm_off; 134 } 135 136 ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num); 137 138 u32 __screen_info_lfb_bits_per_pixel(const struct screen_info *si); 139 140 #if defined(CONFIG_PCI) 141 void screen_info_apply_fixups(void); 142 struct pci_dev *screen_info_pci_dev(const struct screen_info *si); 143 #else 144 static inline void screen_info_apply_fixups(void) 145 { } 146 static inline struct pci_dev *screen_info_pci_dev(const struct screen_info *si) 147 { 148 return NULL; 149 } 150 #endif 151 152 extern struct screen_info screen_info; 153 154 #endif /* _SCREEN_INFO_H */ 155