xref: /openbmc/linux/drivers/video/fbdev/efifb.c (revision 711aab1d)
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 struct pci_dev *efifb_pci_dev;	/* dev with BAR covering the efifb */
153 static struct resource *bar_resource;
154 static u64 bar_offset;
155 
156 static int efifb_probe(struct platform_device *dev)
157 {
158 	struct fb_info *info;
159 	int err;
160 	unsigned int size_vmode;
161 	unsigned int size_remap;
162 	unsigned int size_total;
163 	char *option = NULL;
164 
165 	if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI || pci_dev_disabled)
166 		return -ENODEV;
167 
168 	if (fb_get_options("efifb", &option))
169 		return -ENODEV;
170 	efifb_setup(option);
171 
172 	/* We don't get linelength from UGA Draw Protocol, only from
173 	 * EFI Graphics Protocol.  So if it's not in DMI, and it's not
174 	 * passed in from the user, we really can't use the framebuffer.
175 	 */
176 	if (!screen_info.lfb_linelength)
177 		return -ENODEV;
178 
179 	if (!screen_info.lfb_depth)
180 		screen_info.lfb_depth = 32;
181 	if (!screen_info.pages)
182 		screen_info.pages = 1;
183 	if (!fb_base_is_valid()) {
184 		printk(KERN_DEBUG "efifb: invalid framebuffer address\n");
185 		return -ENODEV;
186 	}
187 	printk(KERN_INFO "efifb: probing for efifb\n");
188 
189 	/* just assume they're all unset if any are */
190 	if (!screen_info.blue_size) {
191 		screen_info.blue_size = 8;
192 		screen_info.blue_pos = 0;
193 		screen_info.green_size = 8;
194 		screen_info.green_pos = 8;
195 		screen_info.red_size = 8;
196 		screen_info.red_pos = 16;
197 		screen_info.rsvd_size = 8;
198 		screen_info.rsvd_pos = 24;
199 	}
200 
201 	efifb_fix.smem_start = screen_info.lfb_base;
202 
203 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE) {
204 		u64 ext_lfb_base;
205 
206 		ext_lfb_base = (u64)(unsigned long)screen_info.ext_lfb_base << 32;
207 		efifb_fix.smem_start |= ext_lfb_base;
208 	}
209 
210 	if (bar_resource &&
211 	    bar_resource->start + bar_offset != efifb_fix.smem_start) {
212 		dev_info(&efifb_pci_dev->dev,
213 			 "BAR has moved, updating efifb address\n");
214 		efifb_fix.smem_start = bar_resource->start + bar_offset;
215 	}
216 
217 	efifb_defined.bits_per_pixel = screen_info.lfb_depth;
218 	efifb_defined.xres = screen_info.lfb_width;
219 	efifb_defined.yres = screen_info.lfb_height;
220 	efifb_fix.line_length = screen_info.lfb_linelength;
221 
222 	/*   size_vmode -- that is the amount of memory needed for the
223 	 *                 used video mode, i.e. the minimum amount of
224 	 *                 memory we need. */
225 	size_vmode = efifb_defined.yres * efifb_fix.line_length;
226 
227 	/*   size_total -- all video memory we have. Used for
228 	 *                 entries, ressource allocation and bounds
229 	 *                 checking. */
230 	size_total = screen_info.lfb_size;
231 	if (size_total < size_vmode)
232 		size_total = size_vmode;
233 
234 	/*   size_remap -- the amount of video memory we are going to
235 	 *                 use for efifb.  With modern cards it is no
236 	 *                 option to simply use size_total as that
237 	 *                 wastes plenty of kernel address space. */
238 	size_remap  = size_vmode * 2;
239 	if (size_remap > size_total)
240 		size_remap = size_total;
241 	if (size_remap % PAGE_SIZE)
242 		size_remap += PAGE_SIZE - (size_remap % PAGE_SIZE);
243 	efifb_fix.smem_len = size_remap;
244 
245 	if (request_mem_region(efifb_fix.smem_start, size_remap, "efifb")) {
246 		request_mem_succeeded = true;
247 	} else {
248 		/* We cannot make this fatal. Sometimes this comes from magic
249 		   spaces our resource handlers simply don't know about */
250 		pr_warn("efifb: cannot reserve video memory at 0x%lx\n",
251 			efifb_fix.smem_start);
252 	}
253 
254 	info = framebuffer_alloc(sizeof(u32) * 16, &dev->dev);
255 	if (!info) {
256 		pr_err("efifb: cannot allocate framebuffer\n");
257 		err = -ENOMEM;
258 		goto err_release_mem;
259 	}
260 	platform_set_drvdata(dev, info);
261 	info->pseudo_palette = info->par;
262 	info->par = NULL;
263 
264 	info->apertures = alloc_apertures(1);
265 	if (!info->apertures) {
266 		err = -ENOMEM;
267 		goto err_release_fb;
268 	}
269 	info->apertures->ranges[0].base = efifb_fix.smem_start;
270 	info->apertures->ranges[0].size = size_remap;
271 
272 	if (nowc)
273 		info->screen_base = ioremap(efifb_fix.smem_start, efifb_fix.smem_len);
274 	else
275 		info->screen_base = ioremap_wc(efifb_fix.smem_start, efifb_fix.smem_len);
276 	if (!info->screen_base) {
277 		pr_err("efifb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
278 			efifb_fix.smem_len, efifb_fix.smem_start);
279 		err = -EIO;
280 		goto err_release_fb;
281 	}
282 
283 	pr_info("efifb: framebuffer at 0x%lx, using %dk, total %dk\n",
284 	       efifb_fix.smem_start, size_remap/1024, size_total/1024);
285 	pr_info("efifb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
286 	       efifb_defined.xres, efifb_defined.yres,
287 	       efifb_defined.bits_per_pixel, efifb_fix.line_length,
288 	       screen_info.pages);
289 
290 	efifb_defined.xres_virtual = efifb_defined.xres;
291 	efifb_defined.yres_virtual = efifb_fix.smem_len /
292 					efifb_fix.line_length;
293 	pr_info("efifb: scrolling: redraw\n");
294 	efifb_defined.yres_virtual = efifb_defined.yres;
295 
296 	/* some dummy values for timing to make fbset happy */
297 	efifb_defined.pixclock     = 10000000 / efifb_defined.xres *
298 					1000 / efifb_defined.yres;
299 	efifb_defined.left_margin  = (efifb_defined.xres / 8) & 0xf8;
300 	efifb_defined.hsync_len    = (efifb_defined.xres / 8) & 0xf8;
301 
302 	efifb_defined.red.offset    = screen_info.red_pos;
303 	efifb_defined.red.length    = screen_info.red_size;
304 	efifb_defined.green.offset  = screen_info.green_pos;
305 	efifb_defined.green.length  = screen_info.green_size;
306 	efifb_defined.blue.offset   = screen_info.blue_pos;
307 	efifb_defined.blue.length   = screen_info.blue_size;
308 	efifb_defined.transp.offset = screen_info.rsvd_pos;
309 	efifb_defined.transp.length = screen_info.rsvd_size;
310 
311 	pr_info("efifb: %s: "
312 	       "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
313 	       "Truecolor",
314 	       screen_info.rsvd_size,
315 	       screen_info.red_size,
316 	       screen_info.green_size,
317 	       screen_info.blue_size,
318 	       screen_info.rsvd_pos,
319 	       screen_info.red_pos,
320 	       screen_info.green_pos,
321 	       screen_info.blue_pos);
322 
323 	efifb_fix.ypanstep  = 0;
324 	efifb_fix.ywrapstep = 0;
325 
326 	info->fbops = &efifb_ops;
327 	info->var = efifb_defined;
328 	info->fix = efifb_fix;
329 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE;
330 
331 	err = sysfs_create_groups(&dev->dev.kobj, efifb_groups);
332 	if (err) {
333 		pr_err("efifb: cannot add sysfs attrs\n");
334 		goto err_unmap;
335 	}
336 	err = fb_alloc_cmap(&info->cmap, 256, 0);
337 	if (err < 0) {
338 		pr_err("efifb: cannot allocate colormap\n");
339 		goto err_groups;
340 	}
341 	err = register_framebuffer(info);
342 	if (err < 0) {
343 		pr_err("efifb: cannot register framebuffer\n");
344 		goto err_fb_dealoc;
345 	}
346 	fb_info(info, "%s frame buffer device\n", info->fix.id);
347 	return 0;
348 
349 err_fb_dealoc:
350 	fb_dealloc_cmap(&info->cmap);
351 err_groups:
352 	sysfs_remove_groups(&dev->dev.kobj, efifb_groups);
353 err_unmap:
354 	iounmap(info->screen_base);
355 err_release_fb:
356 	framebuffer_release(info);
357 err_release_mem:
358 	if (request_mem_succeeded)
359 		release_mem_region(efifb_fix.smem_start, size_total);
360 	return err;
361 }
362 
363 static int efifb_remove(struct platform_device *pdev)
364 {
365 	struct fb_info *info = platform_get_drvdata(pdev);
366 
367 	unregister_framebuffer(info);
368 	sysfs_remove_groups(&pdev->dev.kobj, efifb_groups);
369 	framebuffer_release(info);
370 
371 	return 0;
372 }
373 
374 static struct platform_driver efifb_driver = {
375 	.driver = {
376 		.name = "efi-framebuffer",
377 	},
378 	.probe = efifb_probe,
379 	.remove = efifb_remove,
380 };
381 
382 builtin_platform_driver(efifb_driver);
383 
384 #if defined(CONFIG_PCI)
385 
386 static void record_efifb_bar_resource(struct pci_dev *dev, int idx, u64 offset)
387 {
388 	u16 word;
389 
390 	efifb_pci_dev = dev;
391 
392 	pci_read_config_word(dev, PCI_COMMAND, &word);
393 	if (!(word & PCI_COMMAND_MEMORY)) {
394 		pci_dev_disabled = true;
395 		dev_err(&dev->dev,
396 			"BAR %d: assigned to efifb but device is disabled!\n",
397 			idx);
398 		return;
399 	}
400 
401 	bar_resource = &dev->resource[idx];
402 	bar_offset = offset;
403 
404 	dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
405 }
406 
407 static void efifb_fixup_resources(struct pci_dev *dev)
408 {
409 	u64 base = screen_info.lfb_base;
410 	u64 size = screen_info.lfb_size;
411 	int i;
412 
413 	if (efifb_pci_dev || screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
414 		return;
415 
416 	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
417 		base |= (u64)screen_info.ext_lfb_base << 32;
418 
419 	if (!base)
420 		return;
421 
422 	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
423 		struct resource *res = &dev->resource[i];
424 
425 		if (!(res->flags & IORESOURCE_MEM))
426 			continue;
427 
428 		if (res->start <= base && res->end >= base + size - 1) {
429 			record_efifb_bar_resource(dev, i, base - res->start);
430 			break;
431 		}
432 	}
433 }
434 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_ANY_ID, PCI_ANY_ID, PCI_BASE_CLASS_DISPLAY,
435 			       16, efifb_fixup_resources);
436 
437 #endif
438