xref: /linux/drivers/video/fbdev/core/fbmem.c (revision b509c16e1d7cba8d0fd3843f6641fcafb3761432)
1 /*
2  *  linux/drivers/video/fbmem.c
3  *
4  *  Copyright (C) 1994 Martin Schaller
5  *
6  *	2001 - Documented with DocBook
7  *	- Brad Douglas <brad@neruo.com>
8  *
9  * This file is subject to the terms and conditions of the GNU General Public
10  * License.  See the file COPYING in the main directory of this archive
11  * for more details.
12  */
13 
14 #include <linux/console.h>
15 #include <linux/export.h>
16 #include <linux/fb.h>
17 #include <linux/fbcon.h>
18 
19 #include <video/nomodeset.h>
20 
21 #include "fb_internal.h"
22 
23     /*
24      *  Frame buffer device initialization and setup routines
25      */
26 
27 #define FBPIXMAPSIZE	(1024 * 8)
28 
29 struct class *fb_class;
30 
31 DEFINE_MUTEX(registration_lock);
32 struct fb_info *registered_fb[FB_MAX] __read_mostly;
33 int num_registered_fb __read_mostly;
34 #define for_each_registered_fb(i)		\
35 	for (i = 0; i < FB_MAX; i++)		\
36 		if (!registered_fb[i]) {} else
37 
38 struct fb_info *get_fb_info(unsigned int idx)
39 {
40 	struct fb_info *fb_info;
41 
42 	if (idx >= FB_MAX)
43 		return ERR_PTR(-ENODEV);
44 
45 	mutex_lock(&registration_lock);
46 	fb_info = registered_fb[idx];
47 	if (fb_info)
48 		refcount_inc(&fb_info->count);
49 	mutex_unlock(&registration_lock);
50 
51 	return fb_info;
52 }
53 
54 void put_fb_info(struct fb_info *fb_info)
55 {
56 	if (!refcount_dec_and_test(&fb_info->count))
57 		return;
58 	if (fb_info->fbops->fb_destroy)
59 		fb_info->fbops->fb_destroy(fb_info);
60 }
61 
62 /*
63  * Helpers
64  */
65 
66 int fb_get_color_depth(struct fb_var_screeninfo *var,
67 		       struct fb_fix_screeninfo *fix)
68 {
69 	int depth = 0;
70 
71 	if (fix->visual == FB_VISUAL_MONO01 ||
72 	    fix->visual == FB_VISUAL_MONO10)
73 		depth = 1;
74 	else {
75 		if (var->green.length == var->blue.length &&
76 		    var->green.length == var->red.length &&
77 		    var->green.offset == var->blue.offset &&
78 		    var->green.offset == var->red.offset)
79 			depth = var->green.length;
80 		else
81 			depth = var->green.length + var->red.length +
82 				var->blue.length;
83 	}
84 
85 	return depth;
86 }
87 EXPORT_SYMBOL(fb_get_color_depth);
88 
89 /*
90  * Data padding functions.
91  */
92 void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
93 {
94 	__fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
95 }
96 EXPORT_SYMBOL(fb_pad_aligned_buffer);
97 
98 void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
99 				u32 shift_high, u32 shift_low, u32 mod)
100 {
101 	u8 mask = (u8) (0xfff << shift_high), tmp;
102 	int i, j;
103 
104 	for (i = height; i--; ) {
105 		for (j = 0; j < idx; j++) {
106 			tmp = dst[j];
107 			tmp &= mask;
108 			tmp |= *src >> shift_low;
109 			dst[j] = tmp;
110 			tmp = *src << shift_high;
111 			dst[j+1] = tmp;
112 			src++;
113 		}
114 		tmp = dst[idx];
115 		tmp &= mask;
116 		tmp |= *src >> shift_low;
117 		dst[idx] = tmp;
118 		if (shift_high < mod) {
119 			tmp = *src << shift_high;
120 			dst[idx+1] = tmp;
121 		}
122 		src++;
123 		dst += d_pitch;
124 	}
125 }
126 EXPORT_SYMBOL(fb_pad_unaligned_buffer);
127 
128 /*
129  * we need to lock this section since fb_cursor
130  * may use fb_imageblit()
131  */
132 char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
133 {
134 	u32 align = buf->buf_align - 1, offset;
135 	char *addr = buf->addr;
136 
137 	/* If IO mapped, we need to sync before access, no sharing of
138 	 * the pixmap is done
139 	 */
140 	if (buf->flags & FB_PIXMAP_IO) {
141 		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
142 			info->fbops->fb_sync(info);
143 		return addr;
144 	}
145 
146 	/* See if we fit in the remaining pixmap space */
147 	offset = buf->offset + align;
148 	offset &= ~align;
149 	if (offset + size > buf->size) {
150 		/* We do not fit. In order to be able to re-use the buffer,
151 		 * we must ensure no asynchronous DMA'ing or whatever operation
152 		 * is in progress, we sync for that.
153 		 */
154 		if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
155 			info->fbops->fb_sync(info);
156 		offset = 0;
157 	}
158 	buf->offset = offset + size;
159 	addr += offset;
160 
161 	return addr;
162 }
163 EXPORT_SYMBOL(fb_get_buffer_offset);
164 
165 int
166 fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
167 {
168 	struct fb_fix_screeninfo *fix = &info->fix;
169 	unsigned int yres = info->var.yres;
170 	int err = 0;
171 
172 	if (var->yoffset > 0) {
173 		if (var->vmode & FB_VMODE_YWRAP) {
174 			if (!fix->ywrapstep || (var->yoffset % fix->ywrapstep))
175 				err = -EINVAL;
176 			else
177 				yres = 0;
178 		} else if (!fix->ypanstep || (var->yoffset % fix->ypanstep))
179 			err = -EINVAL;
180 	}
181 
182 	if (var->xoffset > 0 && (!fix->xpanstep ||
183 				 (var->xoffset % fix->xpanstep)))
184 		err = -EINVAL;
185 
186 	if (err || !info->fbops->fb_pan_display ||
187 	    var->yoffset > info->var.yres_virtual - yres ||
188 	    var->xoffset > info->var.xres_virtual - info->var.xres)
189 		return -EINVAL;
190 
191 	if ((err = info->fbops->fb_pan_display(var, info)))
192 		return err;
193 	info->var.xoffset = var->xoffset;
194 	info->var.yoffset = var->yoffset;
195 	if (var->vmode & FB_VMODE_YWRAP)
196 		info->var.vmode |= FB_VMODE_YWRAP;
197 	else
198 		info->var.vmode &= ~FB_VMODE_YWRAP;
199 	return 0;
200 }
201 EXPORT_SYMBOL(fb_pan_display);
202 
203 static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
204 			 u32 activate)
205 {
206 	struct fb_blit_caps caps, fbcaps;
207 	int err = 0;
208 
209 	memset(&caps, 0, sizeof(caps));
210 	memset(&fbcaps, 0, sizeof(fbcaps));
211 	caps.flags = (activate & FB_ACTIVATE_ALL) ? 1 : 0;
212 	fbcon_get_requirement(info, &caps);
213 	info->fbops->fb_get_caps(info, &fbcaps, var);
214 
215 	if (!bitmap_subset(caps.x, fbcaps.x, FB_MAX_BLIT_WIDTH) ||
216 	    !bitmap_subset(caps.y, fbcaps.y, FB_MAX_BLIT_HEIGHT) ||
217 	    (fbcaps.len < caps.len))
218 		err = -EINVAL;
219 
220 	return err;
221 }
222 
223 int
224 fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
225 {
226 	int ret = 0;
227 	u32 activate;
228 	struct fb_var_screeninfo old_var;
229 	struct fb_videomode mode;
230 	struct fb_event event;
231 	u32 unused;
232 
233 	if (var->activate & FB_ACTIVATE_INV_MODE) {
234 		struct fb_videomode mode1, mode2;
235 
236 		fb_var_to_videomode(&mode1, var);
237 		fb_var_to_videomode(&mode2, &info->var);
238 		/* make sure we don't delete the videomode of current var */
239 		ret = fb_mode_is_equal(&mode1, &mode2);
240 		if (!ret) {
241 			ret = fbcon_mode_deleted(info, &mode1);
242 			if (!ret)
243 				fb_delete_videomode(&mode1, &info->modelist);
244 		}
245 
246 		return ret ? -EINVAL : 0;
247 	}
248 
249 	if (!(var->activate & FB_ACTIVATE_FORCE) &&
250 	    !memcmp(&info->var, var, sizeof(struct fb_var_screeninfo)))
251 		return 0;
252 
253 	activate = var->activate;
254 
255 	/* When using FOURCC mode, make sure the red, green, blue and
256 	 * transp fields are set to 0.
257 	 */
258 	if ((info->fix.capabilities & FB_CAP_FOURCC) &&
259 	    var->grayscale > 1) {
260 		if (var->red.offset     || var->green.offset    ||
261 		    var->blue.offset    || var->transp.offset   ||
262 		    var->red.length     || var->green.length    ||
263 		    var->blue.length    || var->transp.length   ||
264 		    var->red.msb_right  || var->green.msb_right ||
265 		    var->blue.msb_right || var->transp.msb_right)
266 			return -EINVAL;
267 	}
268 
269 	if (!info->fbops->fb_check_var) {
270 		*var = info->var;
271 		return 0;
272 	}
273 
274 	/* bitfill_aligned() assumes that it's at least 8x8 */
275 	if (var->xres < 8 || var->yres < 8)
276 		return -EINVAL;
277 
278 	/* Too huge resolution causes multiplication overflow. */
279 	if (check_mul_overflow(var->xres, var->yres, &unused) ||
280 	    check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused))
281 		return -EINVAL;
282 
283 	ret = info->fbops->fb_check_var(var, info);
284 
285 	if (ret)
286 		return ret;
287 
288 	/* verify that virtual resolution >= physical resolution */
289 	if (var->xres_virtual < var->xres ||
290 	    var->yres_virtual < var->yres) {
291 		pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
292 			info->fix.id,
293 			var->xres_virtual, var->yres_virtual,
294 			var->xres, var->yres);
295 		return -EINVAL;
296 	}
297 
298 	if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
299 		return 0;
300 
301 	if (info->fbops->fb_get_caps) {
302 		ret = fb_check_caps(info, var, activate);
303 
304 		if (ret)
305 			return ret;
306 	}
307 
308 	old_var = info->var;
309 	info->var = *var;
310 
311 	if (info->fbops->fb_set_par) {
312 		ret = info->fbops->fb_set_par(info);
313 
314 		if (ret) {
315 			info->var = old_var;
316 			printk(KERN_WARNING "detected "
317 				"fb_set_par error, "
318 				"error code: %d\n", ret);
319 			return ret;
320 		}
321 	}
322 
323 	fb_pan_display(info, &info->var);
324 	fb_set_cmap(&info->cmap, info);
325 	fb_var_to_videomode(&mode, &info->var);
326 
327 	if (info->modelist.prev && info->modelist.next &&
328 	    !list_empty(&info->modelist))
329 		ret = fb_add_videomode(&mode, &info->modelist);
330 
331 	if (ret) {
332 		info->var = old_var;
333 		return ret;
334 	}
335 
336 	event.info = info;
337 	event.data = &mode;
338 	fb_notifier_call_chain(FB_EVENT_MODE_CHANGE, &event);
339 
340 	return 0;
341 }
342 EXPORT_SYMBOL(fb_set_var);
343 
344 int
345 fb_blank(struct fb_info *info, int blank)
346 {
347 	struct fb_event event;
348 	int ret = -EINVAL;
349 
350 	if (blank > FB_BLANK_POWERDOWN)
351 		blank = FB_BLANK_POWERDOWN;
352 
353 	event.info = info;
354 	event.data = &blank;
355 
356 	if (info->fbops->fb_blank)
357 		ret = info->fbops->fb_blank(blank, info);
358 
359 	if (!ret)
360 		fb_notifier_call_chain(FB_EVENT_BLANK, &event);
361 
362 	return ret;
363 }
364 EXPORT_SYMBOL(fb_blank);
365 
366 static int fb_check_foreignness(struct fb_info *fi)
367 {
368 	const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;
369 
370 	fi->flags &= ~FBINFO_FOREIGN_ENDIAN;
371 
372 #ifdef __BIG_ENDIAN
373 	fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
374 #else
375 	fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
376 #endif /* __BIG_ENDIAN */
377 
378 	if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
379 		pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
380 		       "support this framebuffer\n", fi->fix.id);
381 		return -ENOSYS;
382 	} else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
383 		pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
384 		       "support this framebuffer\n", fi->fix.id);
385 		return -ENOSYS;
386 	}
387 
388 	return 0;
389 }
390 
391 static int do_register_framebuffer(struct fb_info *fb_info)
392 {
393 	int i, err = 0;
394 	struct fb_videomode mode;
395 
396 	if (fb_check_foreignness(fb_info))
397 		return -ENOSYS;
398 
399 	if (num_registered_fb == FB_MAX)
400 		return -ENXIO;
401 
402 	for (i = 0 ; i < FB_MAX; i++)
403 		if (!registered_fb[i])
404 			break;
405 
406 	if (!fb_info->modelist.prev || !fb_info->modelist.next)
407 		INIT_LIST_HEAD(&fb_info->modelist);
408 
409 	fb_var_to_videomode(&mode, &fb_info->var);
410 	err = fb_add_videomode(&mode, &fb_info->modelist);
411 	if (err < 0)
412 		return err;
413 
414 	fb_info->node = i;
415 	refcount_set(&fb_info->count, 1);
416 	mutex_init(&fb_info->lock);
417 	mutex_init(&fb_info->mm_lock);
418 
419 	fb_device_create(fb_info);
420 
421 	if (fb_info->pixmap.addr == NULL) {
422 		fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
423 		if (fb_info->pixmap.addr) {
424 			fb_info->pixmap.size = FBPIXMAPSIZE;
425 			fb_info->pixmap.buf_align = 1;
426 			fb_info->pixmap.scan_align = 1;
427 			fb_info->pixmap.access_align = 32;
428 			fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
429 		}
430 	}
431 	fb_info->pixmap.offset = 0;
432 
433 	if (bitmap_empty(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH))
434 		bitmap_fill(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);
435 
436 	if (bitmap_empty(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT))
437 		bitmap_fill(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT);
438 
439 	if (fb_info->skip_vt_switch)
440 		pm_vt_switch_required(fb_info->device, false);
441 	else
442 		pm_vt_switch_required(fb_info->device, true);
443 
444 	num_registered_fb++;
445 	registered_fb[i] = fb_info;
446 
447 #ifdef CONFIG_GUMSTIX_AM200EPD
448 	{
449 		struct fb_event event;
450 		event.info = fb_info;
451 		fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
452 	}
453 #endif
454 
455 	return fbcon_fb_registered(fb_info);
456 }
457 
458 static void unbind_console(struct fb_info *fb_info)
459 {
460 	int i = fb_info->node;
461 
462 	if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
463 		return;
464 
465 	fbcon_fb_unbind(fb_info);
466 }
467 
468 static void unlink_framebuffer(struct fb_info *fb_info)
469 {
470 	int i;
471 
472 	i = fb_info->node;
473 	if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
474 		return;
475 
476 	fb_device_destroy(fb_info);
477 	pm_vt_switch_unregister(fb_info->device);
478 	unbind_console(fb_info);
479 }
480 
481 static void do_unregister_framebuffer(struct fb_info *fb_info)
482 {
483 	unlink_framebuffer(fb_info);
484 	if (fb_info->pixmap.addr &&
485 	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) {
486 		kfree(fb_info->pixmap.addr);
487 		fb_info->pixmap.addr = NULL;
488 	}
489 
490 	fb_destroy_modelist(&fb_info->modelist);
491 	registered_fb[fb_info->node] = NULL;
492 	num_registered_fb--;
493 #ifdef CONFIG_GUMSTIX_AM200EPD
494 	{
495 		struct fb_event event;
496 		event.info = fb_info;
497 		fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
498 	}
499 #endif
500 	fbcon_fb_unregistered(fb_info);
501 
502 	/* this may free fb info */
503 	put_fb_info(fb_info);
504 }
505 
506 /**
507  *	register_framebuffer - registers a frame buffer device
508  *	@fb_info: frame buffer info structure
509  *
510  *	Registers a frame buffer device @fb_info.
511  *
512  *	Returns negative errno on error, or zero for success.
513  *
514  */
515 int
516 register_framebuffer(struct fb_info *fb_info)
517 {
518 	int ret;
519 
520 	mutex_lock(&registration_lock);
521 	ret = do_register_framebuffer(fb_info);
522 	mutex_unlock(&registration_lock);
523 
524 	return ret;
525 }
526 EXPORT_SYMBOL(register_framebuffer);
527 
528 /**
529  *	unregister_framebuffer - releases a frame buffer device
530  *	@fb_info: frame buffer info structure
531  *
532  *	Unregisters a frame buffer device @fb_info.
533  *
534  *	Returns negative errno on error, or zero for success.
535  *
536  *      This function will also notify the framebuffer console
537  *      to release the driver.
538  *
539  *      This is meant to be called within a driver's module_exit()
540  *      function. If this is called outside module_exit(), ensure
541  *      that the driver implements fb_open() and fb_release() to
542  *      check that no processes are using the device.
543  */
544 void
545 unregister_framebuffer(struct fb_info *fb_info)
546 {
547 	mutex_lock(&registration_lock);
548 	do_unregister_framebuffer(fb_info);
549 	mutex_unlock(&registration_lock);
550 }
551 EXPORT_SYMBOL(unregister_framebuffer);
552 
553 static void devm_unregister_framebuffer(void *data)
554 {
555 	struct fb_info *info = data;
556 
557 	unregister_framebuffer(info);
558 }
559 
560 /**
561  *	devm_register_framebuffer - resource-managed frame buffer device registration
562  *	@dev: device the framebuffer belongs to
563  *	@fb_info: frame buffer info structure
564  *
565  *	Registers a frame buffer device @fb_info to device @dev.
566  *
567  *	Returns negative errno on error, or zero for success.
568  *
569  */
570 int
571 devm_register_framebuffer(struct device *dev, struct fb_info *fb_info)
572 {
573 	int ret;
574 
575 	ret = register_framebuffer(fb_info);
576 	if (ret)
577 		return ret;
578 
579 	return devm_add_action_or_reset(dev, devm_unregister_framebuffer, fb_info);
580 }
581 EXPORT_SYMBOL(devm_register_framebuffer);
582 
583 /**
584  *	fb_set_suspend - low level driver signals suspend
585  *	@info: framebuffer affected
586  *	@state: 0 = resuming, !=0 = suspending
587  *
588  *	This is meant to be used by low level drivers to
589  * 	signal suspend/resume to the core & clients.
590  *	It must be called with the console semaphore held
591  */
592 void fb_set_suspend(struct fb_info *info, int state)
593 {
594 	WARN_CONSOLE_UNLOCKED();
595 
596 	if (state) {
597 		fbcon_suspended(info);
598 		info->state = FBINFO_STATE_SUSPENDED;
599 	} else {
600 		info->state = FBINFO_STATE_RUNNING;
601 		fbcon_resumed(info);
602 	}
603 }
604 EXPORT_SYMBOL(fb_set_suspend);
605 
606 static int __init fbmem_init(void)
607 {
608 	int ret;
609 
610 	fb_class = class_create("graphics");
611 	if (IS_ERR(fb_class)) {
612 		ret = PTR_ERR(fb_class);
613 		pr_err("Unable to create fb class; errno = %d\n", ret);
614 		goto err_fb_class;
615 	}
616 
617 	ret = fb_init_procfs();
618 	if (ret)
619 		goto err_class_destroy;
620 
621 	ret = fb_register_chrdev();
622 	if (ret)
623 		goto err_fb_cleanup_procfs;
624 
625 	fb_console_init();
626 
627 	return 0;
628 
629 err_fb_cleanup_procfs:
630 	fb_cleanup_procfs();
631 err_class_destroy:
632 	class_destroy(fb_class);
633 err_fb_class:
634 	fb_class = NULL;
635 	return ret;
636 }
637 
638 #ifdef MODULE
639 static void __exit fbmem_exit(void)
640 {
641 	fb_console_exit();
642 	fb_unregister_chrdev();
643 	fb_cleanup_procfs();
644 	class_destroy(fb_class);
645 }
646 
647 module_init(fbmem_init);
648 module_exit(fbmem_exit);
649 MODULE_LICENSE("GPL");
650 MODULE_DESCRIPTION("Framebuffer base");
651 #else
652 subsys_initcall(fbmem_init);
653 #endif
654 
655 int fb_new_modelist(struct fb_info *info)
656 {
657 	struct fb_var_screeninfo var = info->var;
658 	struct list_head *pos, *n;
659 	struct fb_modelist *modelist;
660 	struct fb_videomode *m, mode;
661 	int err;
662 
663 	list_for_each_safe(pos, n, &info->modelist) {
664 		modelist = list_entry(pos, struct fb_modelist, list);
665 		m = &modelist->mode;
666 		fb_videomode_to_var(&var, m);
667 		var.activate = FB_ACTIVATE_TEST;
668 		err = fb_set_var(info, &var);
669 		fb_var_to_videomode(&mode, &var);
670 		if (err || !fb_mode_is_equal(m, &mode)) {
671 			list_del(pos);
672 			kfree(pos);
673 		}
674 	}
675 
676 	if (list_empty(&info->modelist))
677 		return 1;
678 
679 	fbcon_new_modelist(info);
680 
681 	return 0;
682 }
683 
684 bool fb_modesetting_disabled(const char *drvname)
685 {
686 	bool fwonly = video_firmware_drivers_only();
687 
688 	if (fwonly)
689 		pr_warn("Driver %s not loading because of nomodeset parameter\n",
690 			drvname);
691 
692 	return fwonly;
693 }
694 EXPORT_SYMBOL(fb_modesetting_disabled);
695 
696 MODULE_LICENSE("GPL");
697