1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/export.h>
4 #include <linux/ioport.h>
5 #include <linux/screen_info.h>
6 #include <linux/string.h>
7
resource_init_named(struct resource * r,resource_size_t start,resource_size_t size,const char * name,unsigned int flags)8 static void resource_init_named(struct resource *r,
9 resource_size_t start, resource_size_t size,
10 const char *name, unsigned int flags)
11 {
12 memset(r, 0, sizeof(*r));
13
14 r->start = start;
15 r->end = start + size - 1;
16 r->name = name;
17 r->flags = flags;
18 }
19
resource_init_io_named(struct resource * r,resource_size_t start,resource_size_t size,const char * name)20 static void resource_init_io_named(struct resource *r,
21 resource_size_t start, resource_size_t size,
22 const char *name)
23 {
24 resource_init_named(r, start, size, name, IORESOURCE_IO);
25 }
26
resource_init_mem_named(struct resource * r,resource_size_t start,resource_size_t size,const char * name)27 static void resource_init_mem_named(struct resource *r,
28 resource_size_t start, resource_size_t size,
29 const char *name)
30 {
31 resource_init_named(r, start, size, name, IORESOURCE_MEM);
32 }
33
__screen_info_has_ega_gfx(unsigned int mode)34 static inline bool __screen_info_has_ega_gfx(unsigned int mode)
35 {
36 switch (mode) {
37 case 0x0d: /* 320x200-4 */
38 case 0x0e: /* 640x200-4 */
39 case 0x0f: /* 640x350-1 */
40 case 0x10: /* 640x350-4 */
41 return true;
42 default:
43 return false;
44 }
45 }
46
__screen_info_has_vga_gfx(unsigned int mode)47 static inline bool __screen_info_has_vga_gfx(unsigned int mode)
48 {
49 switch (mode) {
50 case 0x10: /* 640x480-1 */
51 case 0x12: /* 640x480-4 */
52 case 0x13: /* 320-200-8 */
53 case 0x6a: /* 800x600-4 (VESA) */
54 return true;
55 default:
56 return __screen_info_has_ega_gfx(mode);
57 }
58 }
59
60 /**
61 * screen_info_resources() - Get resources from screen_info structure
62 * @si: the screen_info
63 * @r: pointer to an array of resource structures
64 * @num: number of elements in @r:
65 *
66 * Returns:
67 * The number of resources stored in @r on success, or a negative errno code otherwise.
68 *
69 * A call to screen_info_resources() returns the resources consumed by the
70 * screen_info's device or framebuffer. The result is stored in the caller-supplied
71 * array @r with up to @num elements. The function returns the number of
72 * initialized elements.
73 */
screen_info_resources(const struct screen_info * si,struct resource * r,size_t num)74 ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num)
75 {
76 struct resource *pos = r;
77 unsigned int type = screen_info_video_type(si);
78 u64 base, size;
79
80 switch (type) {
81 case VIDEO_TYPE_MDA:
82 if (num > 0)
83 resource_init_io_named(pos++, 0x3b0, 12, "mda");
84 if (num > 1)
85 resource_init_io_named(pos++, 0x3bf, 0x01, "mda");
86 if (num > 2)
87 resource_init_mem_named(pos++, 0xb0000, 0x2000, "mda");
88 break;
89 case VIDEO_TYPE_CGA:
90 if (num > 0)
91 resource_init_io_named(pos++, 0x3d4, 0x02, "cga");
92 if (num > 1)
93 resource_init_mem_named(pos++, 0xb8000, 0x2000, "cga");
94 break;
95 case VIDEO_TYPE_EGAM:
96 if (num > 0)
97 resource_init_io_named(pos++, 0x3bf, 0x10, "ega");
98 if (num > 1)
99 resource_init_mem_named(pos++, 0xb0000, 0x8000, "ega");
100 break;
101 case VIDEO_TYPE_EGAC:
102 if (num > 0)
103 resource_init_io_named(pos++, 0x3c0, 0x20, "ega");
104 if (num > 1) {
105 if (__screen_info_has_ega_gfx(si->orig_video_mode))
106 resource_init_mem_named(pos++, 0xa0000, 0x10000, "ega");
107 else
108 resource_init_mem_named(pos++, 0xb8000, 0x8000, "ega");
109 }
110 break;
111 case VIDEO_TYPE_VGAC:
112 if (num > 0)
113 resource_init_io_named(pos++, 0x3c0, 0x20, "vga+");
114 if (num > 1) {
115 if (__screen_info_has_vga_gfx(si->orig_video_mode))
116 resource_init_mem_named(pos++, 0xa0000, 0x10000, "vga+");
117 else
118 resource_init_mem_named(pos++, 0xb8000, 0x8000, "vga+");
119 }
120 break;
121 case VIDEO_TYPE_VLFB:
122 case VIDEO_TYPE_EFI:
123 base = __screen_info_lfb_base(si);
124 if (!base)
125 break;
126 size = __screen_info_lfb_size(si, type);
127 if (!size)
128 break;
129 if (num > 0)
130 resource_init_mem_named(pos++, base, size, "lfb");
131 break;
132 case VIDEO_TYPE_PICA_S3:
133 case VIDEO_TYPE_MIPS_G364:
134 case VIDEO_TYPE_SGI:
135 case VIDEO_TYPE_TGAC:
136 case VIDEO_TYPE_SUN:
137 case VIDEO_TYPE_SUNPCI:
138 case VIDEO_TYPE_PMAC:
139 default:
140 /* not supported */
141 return -EINVAL;
142 }
143
144 return pos - r;
145 }
146 EXPORT_SYMBOL(screen_info_resources);
147