drivers/video/fbdev/efifb.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Framebuffer driver for EFI/UEFI based system
   4  *
   5  * (c) 2006 Edgar Hucek <gimli@dark-green.com>
   6  * Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
   7  *
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/efi.h>
  12 #include <linux/errno.h>
  13 #include <linux/fb.h>
  14 #include <linux/pci.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/screen_info.h>
  17 #include <video/vga.h>
  18 #include <asm/efi.h>
  19
  20 static bool request_mem_succeeded = false;
  21 static bool nowc = false;
  22
  23 static struct fb_var_screeninfo efifb_defined = {
  24         .activate               = FB_ACTIVATE_NOW,
  25         .height                 = -1,
  26         .width                  = -1,
  27         .right_margin           = 32,
  28         .upper_margin           = 16,
  29         .lower_margin           = 4,
  30         .vsync_len              = 4,
  31         .vmode                  = FB_VMODE_NONINTERLACED,
  32 };
  33
  34 static struct fb_fix_screeninfo efifb_fix = {
  35         .id                     = "EFI VGA",
  36         .type                   = FB_TYPE_PACKED_PIXELS,
  37         .accel                  = FB_ACCEL_NONE,
  38         .visual                 = FB_VISUAL_TRUECOLOR,
  39 };
  40
  41 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
  42                            unsigned blue, unsigned transp,
  43                            struct fb_info *info)
  44 {
  45         /*
  46          *  Set a single color register. The values supplied are
  47          *  already rounded down to the hardware's capabilities
  48          *  (according to the entries in the `var' structure). Return
  49          *  != 0 for invalid regno.
  50          */
  51
  52         if (regno >= info->cmap.len)
  53                 return 1;
  54
  55         if (regno < 16) {
  56                 red   >>= 16 - info->var.red.length;
  57                 green >>= 16 - info->var.green.length;
  58                 blue  >>= 16 - info->var.blue.length;
  59                 ((u32 *)(info->pseudo_palette))[regno] =
  60                         (red   << info->var.red.offset)   |
  61                         (green << info->var.green.offset) |
  62                         (blue  << info->var.blue.offset);
  63         }
  64         return 0;
  65 }
  66
  67 static void efifb_destroy(struct fb_info *info)
  68 {
  69         if (info->screen_base)
  70                 iounmap(info->screen_base);
  71         if (request_mem_succeeded)
  72                 release_mem_region(info->apertures->ranges[0].base,
  73                                    info->apertures->ranges[0].size);
  74         fb_dealloc_cmap(&info->cmap);
  75 }
  76
  77 static struct fb_ops efifb_ops = {
  78         .owner          = THIS_MODULE,
  79         .fb_destroy     = efifb_destroy,
  80         .fb_setcolreg   = efifb_setcolreg,
  81         .fb_fillrect    = cfb_fillrect,
  82         .fb_copyarea    = cfb_copyarea,
  83         .fb_imageblit   = cfb_imageblit,
  84 };
  85
  86 static int efifb_setup(char *options)
  87 {
  88         char *this_opt;
  89
  90         if (options && *options) {
  91                 while ((this_opt = strsep(&options, ",")) != NULL) {
  92                         if (!*this_opt) continue;
  93
  94                         efifb_setup_from_dmi(&screen_info, this_opt);
  95
  96                         if (!strncmp(this_opt, "base:", 5))
  97                                 screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
  98                         else if (!strncmp(this_opt, "stride:", 7))
  99                                 screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
 100                         else if (!strncmp(this_opt, "height:", 7))
 101                                 screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
 102                         else if (!strncmp(this_opt, "width:", 6))
 103                                 screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
 104                         else if (!strcmp(this_opt, "nowc"))
 105                                 nowc = true;
 106                 }
 107         }
 108
 109         return 0;
 110 }
 111
 112 static inline bool fb_base_is_valid(void)
 113 {
 114         if (screen_info.lfb_base)
 115                 return true;
 116
 117         if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
 118                 return false;
 119
 120         if (screen_info.ext_lfb_base)
 121                 return true;
 122
 123         return false;
 124 }
 125
 126 #define efifb_attr_decl(name, fmt)                                      \
 127 static ssize_t name##_show(struct device *dev,                          \
 128                            struct device_attribute *attr,               \
 129                            char *buf)                                   \
 130 {                                                                       \
 131         return sprintf(buf, fmt "\n", (screen_info.lfb_##name));        \
 132 }                                                                       \
 133 static DEVICE_ATTR_RO(name)
 134
 135 efifb_attr_decl(base, "0x%x");
 136 efifb_attr_decl(linelength, "%u");
 137 efifb_attr_decl(height, "%u");
 138 efifb_attr_decl(width, "%u");
 139 efifb_attr_decl(depth, "%u");
 140
 141 static struct attribute *efifb_attrs[] = {
 142         &dev_attr_base.attr,
 143         &dev_attr_linelength.attr,
 144         &dev_attr_width.attr,
 145         &dev_attr_height.attr,
 146         &dev_attr_depth.attr,
 147         NULL
 148 };
 149 ATTRIBUTE_GROUPS(efifb);
 150
 151 static bool pci_dev_disabled;   /* FB base matches BAR of a disabled device */
 152
 153 static struct pci_dev *efifb_pci_dev;   /* dev with BAR covering the efifb */
 154 static struct resource *bar_resource;
 155 static u64 bar_offset;
 156
 157 static int efifb_probe(struct platform_device *dev)
 158 {
 159         struct fb_info *info;
 160         int err;
 161         unsigned int size_vmode;
 162         unsigned int size_remap;
 163         unsigned int size_total;
 164         char *option = NULL;
 165
 166         if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
 167                 return -ENODEV;
 168
 169         if (fb_get_options("efifb", &option))
 170                 return -ENODEV;
 171         efifb_setup(option);
 172
 173         /* We don't get linelength from UGA Draw Protocol, only from
 174          * EFI Graphics Protocol.  So if it's not in DMI, and it's not
 175          * passed in from the user, we really can't use the framebuffer.
 176          */
 177         if (!screen_info.lfb_linelength)
 178                 return -ENODEV;
 179
 180         if (!screen_info.lfb_depth)
 181                 screen_info.lfb_depth = 32;
 182         if (!screen_info.pages)
 183                 screen_info.pages = 1;
 184         if (!fb_base_is_valid()) {
 185                 printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
 186                 return -ENODEV;
 187         }
 188         printk(KERN_INFO "efifb: probing for efifb\n");
 189
 190         /* just assume they're all unset if any are */
 191         if (!screen_info.blue_size) {
 192                 screen_info.blue_size = 8;
 193                 screen_info.blue_pos = 0;
 194                 screen_info.green_size = 8;
 195                 screen_info.green_pos = 8;
 196                 screen_info.red_size = 8;
 197                 screen_info.red_pos = 16;
 198                 screen_info.rsvd_size = 8;
 199                 screen_info.rsvd_pos = 24;
 200         }
 201
 202         efifb_fix.smem_start = screen_info.lfb_base;
 203
 204         if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
 205                 u64 ext_lfb_base;
 206
 207                 ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
 208                 efifb_fix.smem_start |= ext_lfb_base;
 209         }
 210
 211         if (bar_resource &&
 212             bar_resource->start + bar_offset != efifb_fix.smem_start) {
 213                 dev_info(&efifb_pci_dev->dev,
 214                          "BAR has moved, updating efifb address\n");
 215                 efifb_fix.smem_start = bar_resource->start + bar_offset;
 216         }
 217
 218         efifb_defined.bits_per_pixel = screen_info.lfb_depth;
 219         efifb_defined.xres = screen_info.lfb_width;
 220         efifb_defined.yres = screen_info.lfb_height;
 221         efifb_fix.line_length = screen_info.lfb_linelength;
 222
 223         /*   size_vmode -- that is the amount of memory needed for the
 224          *                 used video mode, i.e. the minimum amount of
 225          *                 memory we need. */
 226         size_vmode = efifb_defined.yres * efifb_fix.line_length;
 227
 228         /*   size_total -- all video memory we have. Used for
 229          *                 entries, ressource allocation and bounds
 230          *                 checking. */
 231         size_total = screen_info.lfb_size;
 232         if (size_total < size_vmode)
 233                 size_total = size_vmode;
 234
 235         /*   size_remap -- the amount of video memory we are going to
 236          *                 use for efifb.  With modern cards it is no
 237          *                 option to simply use size_total as that
 238          *                 wastes plenty of kernel address space. */
 239         size_remap  = size_vmode * 2;
 240         if (size_remap > size_total)
 241                 size_remap = size_total;
 242         if (size_remap % PAGE_SIZE)
 243                 size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
 244         efifb_fix.smem_len = size_remap;
 245
 246         if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
 247                 request_mem_succeeded = true;
 248         } else {
 249                 /* We cannot make this fatal. Sometimes this comes from magic
 250                    spaces our resource handlers simply don't know about */
 251                 pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
 252                         efifb_fix.smem_start);
 253         }
 254
 255         info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
 256         if (!info) {
 257                 pr_err("efifb: cannot allocate framebuffer\n");
 258                 err = -ENOMEM;
 259                 goto err_release_mem;
 260         }
 261         platform_set_drvdata(dev, info);
 262         info->pseudo_palette = info->par;
 263         info->par = NULL;
 264
 265         info->apertures = alloc_apertures(1);
 266         if (!info->apertures) {
 267                 err = -ENOMEM;
 268                 goto err_release_fb;
 269         }
 270         info->apertures->ranges[0].base = efifb_fix.smem_start;
 271         info->apertures->ranges[0].size = size_remap;
 272
 273         if (nowc)
 274                 info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
 275         else
 276                 info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
 277         if (!info->screen_base) {
 278                 pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
 279                         efifb_fix.smem_len, efifb_fix.smem_start);
 280                 err = -EIO;
 281                 goto err_release_fb;
 282         }
 283
 284         pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
 285                efifb_fix.smem_start, size_remap/1024, size_total/1024);
 286         pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
 287                efifb_defined.xres, efifb_defined.yres,
 288                efifb_defined.bits_per_pixel, efifb_fix.line_length,
 289                screen_info.pages);
 290
 291         efifb_defined.xres_virtual = efifb_defined.xres;
 292         efifb_defined.yres_virtual = efifb_fix.smem_len /
 293                                         efifb_fix.line_length;
 294         pr_info("efifb: scrolling: redraw\n");
 295         efifb_defined.yres_virtual = efifb_defined.yres;
 296
 297         /* some dummy values for timing to make fbset happy */
 298         efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
 299                                         1000 / efifb_defined.yres;
 300         efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
 301         efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
 302
 303         efifb_defined.red.offset    = screen_info.red_pos;
 304         efifb_defined.red.length    = screen_info.red_size;
 305         efifb_defined.green.offset  = screen_info.green_pos;
 306         efifb_defined.green.length  = screen_info.green_size;
 307         efifb_defined.blue.offset   = screen_info.blue_pos;
 308         efifb_defined.blue.length   = screen_info.blue_size;
 309         efifb_defined.transp.offset = screen_info.rsvd_pos;
 310         efifb_defined.transp.length = screen_info.rsvd_size;
 311
 312         pr_info("efifb: %s: "
 313                "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
 314                "Truecolor",
 315                screen_info.rsvd_size,
 316                screen_info.red_size,
 317                screen_info.green_size,
 318                screen_info.blue_size,
 319                screen_info.rsvd_pos,
 320                screen_info.red_pos,
 321                screen_info.green_pos,
 322                screen_info.blue_pos);
 323
 324         efifb_fix.ypanstep  = 0;
 325         efifb_fix.ywrapstep = 0;
 326
 327         info->fbops = &efifb_ops;
 328         info->var = efifb_defined;
 329         info->fix = efifb_fix;
 330         info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
 331
 332         err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
 333         if (err) {
 334                 pr_err("efifb: cannot add sysfs attrs\n");
 335                 goto err_unmap;
 336         }
 337         err = fb_alloc_cmap(&info->cmap, 256, 0);
 338         if (err < 0) {
 339                 pr_err("efifb: cannot allocate colormap\n");
 340                 goto err_groups;
 341         }
 342         err = register_framebuffer(info);
 343         if (err < 0) {
 344                 pr_err("efifb: cannot register framebuffer\n");
 345                 goto err_fb_dealoc;
 346         }
 347         fb_info(info, "%s frame buffer device\n", info->fix.id);
 348         return 0;
 349
 350 err_fb_dealoc:
 351         fb_dealloc_cmap(&info->cmap);
 352 err_groups:
 353         sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
 354 err_unmap:
 355         iounmap(info->screen_base);
 356 err_release_fb:
 357         framebuffer_release(info);
 358 err_release_mem:
 359         if (request_mem_succeeded)
 360                 release_mem_region(efifb_fix.smem_start, size_total);
 361         return err;
 362 }
 363
 364 static int efifb_remove(struct platform_device *pdev)
 365 {
 366         struct fb_info *info = platform_get_drvdata(pdev);
 367
 368         unregister_framebuffer(info);
 369         sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
 370         framebuffer_release(info);
 371
 372         return 0;
 373 }
 374
 375 static struct platform_driver efifb_driver = {
 376         .driver = {
 377                 .name = "efi-framebuffer",
 378         },
 379         .probe = efifb_probe,
 380         .remove = efifb_remove,
 381 };
 382
 383 builtin_platform_driver(efifb_driver);
 384
 385 #if defined(CONFIG_PCI)
 386
 387 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
 388 {
 389         u16 word;
 390
 391         efifb_pci_dev = dev;
 392
 393         pci_read_config_word(dev, PCI_COMMAND, &word);
 394         if (!(word & PCI_COMMAND_MEMORY)) {
 395                 pci_dev_disabled = true;
 396                 dev_err(&dev->dev,
 397                         "BAR %d: assigned to efifb but device is disabled!\n",
 398                         idx);
 399                 return;
 400         }
 401
 402         bar_resource = &dev->resource[idx];
 403         bar_offset = offset;
 404
 405         dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
 406 }
 407
 408 static void efifb_fixup_resources(struct pci_dev *dev)
 409 {
 410         u64 base = screen_info.lfb_base;
 411         u64 size = screen_info.lfb_size;
 412         int i;
 413
 414         if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
 415                 return;
 416
 417         if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
 418                 base |= (u64)screen_info.ext_lfb_base << 32;
 419
 420         if (!base)
 421                 return;
 422
 423         for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
 424                 struct resource *res = &dev->resource[i];
 425
 426                 if (!(res->flags & IORESOURCE_MEM))
 427                         continue;
 428
 429                 if (res->start <= base && res->end >= base + size - 1) {
 430                         record_efifb_bar_resource(dev, i, base - res->start);
 431                         break;
 432                 }
 433         }
 434 }
 435 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
 436                                16, efifb_fixup_resources);
 437
 438 #endif