xref: /linux/drivers/video/fbdev/efifb.c (revision c411ed854584a71b0e86ac3019b60e4789d88086)
1 /*
2  * Framebuffer driver for EFI/UEFI based system
3  *
4  * (c) 2006 Edgar Hucek <gimli@dark-green.com>
5  * Original efi driver written by Gerd Knorr <kraxel@goldbach.in-berlin.de>
6  *
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/efi.h>
11 #include <linux/errno.h>
12 #include <linux/fb.h>
13 #include <linux/pci.h>
14 #include <linux/platform_device.h>
15 #include <linux/screen_info.h>
16 #include <video/vga.h>
17 #include <asm/efi.h>
18 
19 static bool request_mem_succeeded = false;
20 static bool nowc = false;
21 
22 static struct fb_var_screeninfo efifb_defined = {
23 	.activate		= FB_ACTIVATE_NOW,
24 	.height			= -1,
25 	.width			= -1,
26 	.right_margin		= 32,
27 	.upper_margin		= 16,
28 	.lower_margin		= 4,
29 	.vsync_len		= 4,
30 	.vmode			= FB_VMODE_NONINTERLACED,
31 };
32 
33 static struct fb_fix_screeninfo efifb_fix = {
34 	.id			= "EFI VGA",
35 	.type			= FB_TYPE_PACKED_PIXELS,
36 	.accel			= FB_ACCEL_NONE,
37 	.visual			= FB_VISUAL_TRUECOLOR,
38 };
39 
40 static int efifb_setcolreg(unsigned regno, unsigned red, unsigned green,
41 			   unsigned blue, unsigned transp,
42 			   struct fb_info *info)
43 {
44 	/*
45 	 *  Set a single color register. The values supplied are
46 	 *  already rounded down to the hardware's capabilities
47 	 *  (according to the entries in the `var' structure). Return
48 	 *  != 0 for invalid regno.
49 	 */
50 
51 	if (regno >= info->cmap.len)
52 		return 1;
53 
54 	if (regno < 16) {
55 		red   >>= 16 - info->var.red.length;
56 		green >>= 16 - info->var.green.length;
57 		blue  >>= 16 - info->var.blue.length;
58 		((u32 *)(info->pseudo_palette))[regno] =
59 			(red   << info->var.red.offset)   |
60 			(green << info->var.green.offset) |
61 			(blue  << info->var.blue.offset);
62 	}
63 	return 0;
64 }
65 
66 static void efifb_destroy(struct fb_info *info)
67 {
68 	if (info->screen_base)
69 		iounmap(info->screen_base);
70 	if (request_mem_succeeded)
71 		release_mem_region(info->apertures->ranges[0].base,
72 				   info->apertures->ranges[0].size);
73 	fb_dealloc_cmap(&info->cmap);
74 }
75 
76 static struct fb_ops efifb_ops = {
77 	.owner		= THIS_MODULE,
78 	.fb_destroy	= efifb_destroy,
79 	.fb_setcolreg	= efifb_setcolreg,
80 	.fb_fillrect	= cfb_fillrect,
81 	.fb_copyarea	= cfb_copyarea,
82 	.fb_imageblit	= cfb_imageblit,
83 };
84 
85 static int efifb_setup(char *options)
86 {
87 	char *this_opt;
88 
89 	if (options && *options) {
90 		while ((this_opt = strsep(&options, ",")) != NULL) {
91 			if (!*this_opt) continue;
92 
93 			efifb_setup_from_dmi(&screen_info, this_opt);
94 
95 			if (!strncmp(this_opt, "base:", 5))
96 				screen_info.lfb_base = simple_strtoul(this_opt+5, NULL, 0);
97 			else if (!strncmp(this_opt, "stride:", 7))
98 				screen_info.lfb_linelength = simple_strtoul(this_opt+7, NULL, 0) * 4;
99 			else if (!strncmp(this_opt, "height:", 7))
100 				screen_info.lfb_height = simple_strtoul(this_opt+7, NULL, 0);
101 			else if (!strncmp(this_opt, "width:", 6))
102 				screen_info.lfb_width = simple_strtoul(this_opt+6, NULL, 0);
103 			else if (!strcmp(this_opt, "nowc"))
104 				nowc = true;
105 		}
106 	}
107 
108 	return 0;
109 }
110 
111 static inline bool fb_base_is_valid(void)
112 {
113 	if (screen_info.lfb_base)
114 		return true;
115 
116 	if (!(screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE))
117 		return false;
118 
119 	if (screen_info.ext_lfb_base)
120 		return true;
121 
122 	return false;
123 }
124 
125 #define efifb_attr_decl(name, fmt)					\
126 static ssize_t name##_show(struct device *dev,				\
127 			   struct device_attribute *attr,		\
128 			   char *buf)					\
129 {									\
130 	return sprintf(buf, fmt "\n", (screen_info.lfb_##name));	\
131 }									\
132 static DEVICE_ATTR_RO(name)
133 
134 efifb_attr_decl(base, "0x%x");
135 efifb_attr_decl(linelength, "%u");
136 efifb_attr_decl(height, "%u");
137 efifb_attr_decl(width, "%u");
138 efifb_attr_decl(depth, "%u");
139 
140 static struct attribute *efifb_attrs[] = {
141 	&dev_attr_base.attr,
142 	&dev_attr_linelength.attr,
143 	&dev_attr_width.attr,
144 	&dev_attr_height.attr,
145 	&dev_attr_depth.attr,
146 	NULL
147 };
148 ATTRIBUTE_GROUPS(efifb);
149 
150 static bool pci_dev_disabled;	/* FB base matches BAR of a disabled device */
151 
152 static int efifb_probe(struct platform_device *dev)
153 {
154 	struct fb_info *info;
155 	int err;
156 	unsigned int size_vmode;
157 	unsigned int size_remap;
158 	unsigned int size_total;
159 	char *option = NULL;
160 
161 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
162 		return -ENODEV;
163 
164 	if (fb_get_options("efifb", &option))
165 		return -ENODEV;
166 	efifb_setup(option);
167 
168 	/* We don't get linelength from UGA Draw Protocol, only from
169 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
170 	 * passed in from the user, we really can't use the framebuffer.
171 	 */
172 	if (!screen_info.lfb_linelength)
173 		return -ENODEV;
174 
175 	if (!screen_info.lfb_depth)
176 		screen_info.lfb_depth = 32;
177 	if (!screen_info.pages)
178 		screen_info.pages = 1;
179 	if (!fb_base_is_valid()) {
180 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
181 		return -ENODEV;
182 	}
183 	printk(KERN_INFO "efifb: probing for efifb\n");
184 
185 	/* just assume they're all unset if any are */
186 	if (!screen_info.blue_size) {
187 		screen_info.blue_size = 8;
188 		screen_info.blue_pos = 0;
189 		screen_info.green_size = 8;
190 		screen_info.green_pos = 8;
191 		screen_info.red_size = 8;
192 		screen_info.red_pos = 16;
193 		screen_info.rsvd_size = 8;
194 		screen_info.rsvd_pos = 24;
195 	}
196 
197 	efifb_fix.smem_start = screen_info.lfb_base;
198 
199 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
200 		u64 ext_lfb_base;
201 
202 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
203 		efifb_fix.smem_start |= ext_lfb_base;
204 	}
205 
206 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
207 	efifb_defined.xres = screen_info.lfb_width;
208 	efifb_defined.yres = screen_info.lfb_height;
209 	efifb_fix.line_length = screen_info.lfb_linelength;
210 
211 	/*   size_vmode -- that is the amount of memory needed for the
212 	 *                 used video mode, i.e. the minimum amount of
213 	 *                 memory we need. */
214 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
215 
216 	/*   size_total -- all video memory we have. Used for
217 	 *                 entries, ressource allocation and bounds
218 	 *                 checking. */
219 	size_total = screen_info.lfb_size;
220 	if (size_total < size_vmode)
221 		size_total = size_vmode;
222 
223 	/*   size_remap -- the amount of video memory we are going to
224 	 *                 use for efifb.  With modern cards it is no
225 	 *                 option to simply use size_total as that
226 	 *                 wastes plenty of kernel address space. */
227 	size_remap  = size_vmode * 2;
228 	if (size_remap > size_total)
229 		size_remap = size_total;
230 	if (size_remap % PAGE_SIZE)
231 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
232 	efifb_fix.smem_len = size_remap;
233 
234 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
235 		request_mem_succeeded = true;
236 	} else {
237 		/* We cannot make this fatal. Sometimes this comes from magic
238 		   spaces our resource handlers simply don't know about */
239 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
240 			efifb_fix.smem_start);
241 	}
242 
243 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
244 	if (!info) {
245 		pr_err("efifb: cannot allocate framebuffer\n");
246 		err = -ENOMEM;
247 		goto err_release_mem;
248 	}
249 	platform_set_drvdata(dev, info);
250 	info->pseudo_palette = info->par;
251 	info->par = NULL;
252 
253 	info->apertures = alloc_apertures(1);
254 	if (!info->apertures) {
255 		err = -ENOMEM;
256 		goto err_release_fb;
257 	}
258 	info->apertures->ranges[0].base = efifb_fix.smem_start;
259 	info->apertures->ranges[0].size = size_remap;
260 
261 	if (nowc)
262 		info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
263 	else
264 		info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
265 	if (!info->screen_base) {
266 		pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
267 			efifb_fix.smem_len, efifb_fix.smem_start);
268 		err = -EIO;
269 		goto err_release_fb;
270 	}
271 
272 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
273 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
274 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
275 	       efifb_defined.xres, efifb_defined.yres,
276 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
277 	       screen_info.pages);
278 
279 	efifb_defined.xres_virtual = efifb_defined.xres;
280 	efifb_defined.yres_virtual = efifb_fix.smem_len /
281 					efifb_fix.line_length;
282 	pr_info("efifb: scrolling: redraw\n");
283 	efifb_defined.yres_virtual = efifb_defined.yres;
284 
285 	/* some dummy values for timing to make fbset happy */
286 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
287 					1000 / efifb_defined.yres;
288 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
289 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
290 
291 	efifb_defined.red.offset    = screen_info.red_pos;
292 	efifb_defined.red.length    = screen_info.red_size;
293 	efifb_defined.green.offset  = screen_info.green_pos;
294 	efifb_defined.green.length  = screen_info.green_size;
295 	efifb_defined.blue.offset   = screen_info.blue_pos;
296 	efifb_defined.blue.length   = screen_info.blue_size;
297 	efifb_defined.transp.offset = screen_info.rsvd_pos;
298 	efifb_defined.transp.length = screen_info.rsvd_size;
299 
300 	pr_info("efifb: %s: "
301 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
302 	       "Truecolor",
303 	       screen_info.rsvd_size,
304 	       screen_info.red_size,
305 	       screen_info.green_size,
306 	       screen_info.blue_size,
307 	       screen_info.rsvd_pos,
308 	       screen_info.red_pos,
309 	       screen_info.green_pos,
310 	       screen_info.blue_pos);
311 
312 	efifb_fix.ypanstep  = 0;
313 	efifb_fix.ywrapstep = 0;
314 
315 	info->fbops = &efifb_ops;
316 	info->var = efifb_defined;
317 	info->fix = efifb_fix;
318 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
319 
320 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
321 	if (err) {
322 		pr_err("efifb: cannot add sysfs attrs\n");
323 		goto err_unmap;
324 	}
325 	err = fb_alloc_cmap(&info->cmap, 256, 0);
326 	if (err < 0) {
327 		pr_err("efifb: cannot allocate colormap\n");
328 		goto err_groups;
329 	}
330 	err = register_framebuffer(info);
331 	if (err < 0) {
332 		pr_err("efifb: cannot register framebuffer\n");
333 		goto err_fb_dealoc;
334 	}
335 	fb_info(info, "%s frame buffer device\n", info->fix.id);
336 	return 0;
337 
338 err_fb_dealoc:
339 	fb_dealloc_cmap(&info->cmap);
340 err_groups:
341 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
342 err_unmap:
343 	iounmap(info->screen_base);
344 err_release_fb:
345 	framebuffer_release(info);
346 err_release_mem:
347 	if (request_mem_succeeded)
348 		release_mem_region(efifb_fix.smem_start, size_total);
349 	return err;
350 }
351 
352 static int efifb_remove(struct platform_device *pdev)
353 {
354 	struct fb_info *info = platform_get_drvdata(pdev);
355 
356 	unregister_framebuffer(info);
357 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
358 	framebuffer_release(info);
359 
360 	return 0;
361 }
362 
363 static struct platform_driver efifb_driver = {
364 	.driver = {
365 		.name = "efi-framebuffer",
366 	},
367 	.probe = efifb_probe,
368 	.remove = efifb_remove,
369 };
370 
371 builtin_platform_driver(efifb_driver);
372 
373 #if defined(CONFIG_PCI) && !defined(CONFIG_X86)
374 
375 static bool pci_bar_found;	/* did we find a BAR matching the efifb base? */
376 
377 static void claim_efifb_bar(struct pci_dev *dev, int idx)
378 {
379 	u16 word;
380 
381 	pci_bar_found = true;
382 
383 	pci_read_config_word(dev, PCI_COMMAND, &word);
384 	if (!(word & PCI_COMMAND_MEMORY)) {
385 		pci_dev_disabled = true;
386 		dev_err(&dev->dev,
387 			"BAR %d: assigned to efifb but device is disabled!\n",
388 			idx);
389 		return;
390 	}
391 
392 	if (pci_claim_resource(dev, idx)) {
393 		pci_dev_disabled = true;
394 		dev_err(&dev->dev,
395 			"BAR %d: failed to claim resource for efifb!\n", idx);
396 		return;
397 	}
398 
399 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
400 }
401 
402 static void efifb_fixup_resources(struct pci_dev *dev)
403 {
404 	u64 base = screen_info.lfb_base;
405 	u64 size = screen_info.lfb_size;
406 	int i;
407 
408 	if (pci_bar_found || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
409 		return;
410 
411 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
412 		base |= (u64)screen_info.ext_lfb_base << 32;
413 
414 	if (!base)
415 		return;
416 
417 	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
418 		struct resource *res = &dev->resource[i];
419 
420 		if (!(res->flags & IORESOURCE_MEM))
421 			continue;
422 
423 		if (res->start <= base && res->end >= base + size - 1) {
424 			claim_efifb_bar(dev, i);
425 			break;
426 		}
427 	}
428 }
429 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
430 			       16, efifb_fixup_resources);
431 
432 #endif
433