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 439