drivers/video/screen_info_generic.c

   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
   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
  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
  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
  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
  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  */
  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);