xref: /openbmc/linux/drivers/video/fbdev/core/fbsysfs.c (revision 407e7517)
1 /*
2  * fbsysfs.c - framebuffer device class and attributes
3  *
4  * Copyright (c) 2004 James Simmons <jsimmons@infradead.org>
5  *
6  *	This program is free software you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  */
11 
12 /*
13  * Note:  currently there's only stubs for framebuffer_alloc and
14  * framebuffer_release here.  The reson for that is that until all drivers
15  * are converted to use it a sysfsification will open OOPSable races.
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/fb.h>
21 #include <linux/console.h>
22 #include <linux/module.h>
23 
24 #define FB_SYSFS_FLAG_ATTR 1
25 
26 /**
27  * framebuffer_alloc - creates a new frame buffer info structure
28  *
29  * @size: size of driver private data, can be zero
30  * @dev: pointer to the device for this fb, this can be NULL
31  *
32  * Creates a new frame buffer info structure. Also reserves @size bytes
33  * for driver private data (info->par). info->par (if any) will be
34  * aligned to sizeof(long).
35  *
36  * Returns the new structure, or NULL if an error occurred.
37  *
38  */
39 struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
40 {
41 #define BYTES_PER_LONG (BITS_PER_LONG/8)
42 #define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))
43 	int fb_info_size = sizeof(struct fb_info);
44 	struct fb_info *info;
45 	char *p;
46 
47 	if (size)
48 		fb_info_size += PADDING;
49 
50 	p = kzalloc(fb_info_size + size, GFP_KERNEL);
51 
52 	if (!p)
53 		return NULL;
54 
55 	info = (struct fb_info *) p;
56 
57 	if (size)
58 		info->par = p + fb_info_size;
59 
60 	info->device = dev;
61 	info->fbcon_rotate_hint = -1;
62 
63 #ifdef CONFIG_FB_BACKLIGHT
64 	mutex_init(&info->bl_curve_mutex);
65 #endif
66 
67 	return info;
68 #undef PADDING
69 #undef BYTES_PER_LONG
70 }
71 EXPORT_SYMBOL(framebuffer_alloc);
72 
73 /**
74  * framebuffer_release - marks the structure available for freeing
75  *
76  * @info: frame buffer info structure
77  *
78  * Drop the reference count of the device embedded in the
79  * framebuffer info structure.
80  *
81  */
82 void framebuffer_release(struct fb_info *info)
83 {
84 	if (!info)
85 		return;
86 	kfree(info->apertures);
87 	kfree(info);
88 }
89 EXPORT_SYMBOL(framebuffer_release);
90 
91 static int activate(struct fb_info *fb_info, struct fb_var_screeninfo *var)
92 {
93 	int err;
94 
95 	var->activate |= FB_ACTIVATE_FORCE;
96 	console_lock();
97 	fb_info->flags |= FBINFO_MISC_USEREVENT;
98 	err = fb_set_var(fb_info, var);
99 	fb_info->flags &= ~FBINFO_MISC_USEREVENT;
100 	console_unlock();
101 	if (err)
102 		return err;
103 	return 0;
104 }
105 
106 static int mode_string(char *buf, unsigned int offset,
107 		       const struct fb_videomode *mode)
108 {
109 	char m = 'U';
110 	char v = 'p';
111 
112 	if (mode->flag & FB_MODE_IS_DETAILED)
113 		m = 'D';
114 	if (mode->flag & FB_MODE_IS_VESA)
115 		m = 'V';
116 	if (mode->flag & FB_MODE_IS_STANDARD)
117 		m = 'S';
118 
119 	if (mode->vmode & FB_VMODE_INTERLACED)
120 		v = 'i';
121 	if (mode->vmode & FB_VMODE_DOUBLE)
122 		v = 'd';
123 
124 	return snprintf(&buf[offset], PAGE_SIZE - offset, "%c:%dx%d%c-%d\n",
125 	                m, mode->xres, mode->yres, v, mode->refresh);
126 }
127 
128 static ssize_t store_mode(struct device *device, struct device_attribute *attr,
129 			  const char *buf, size_t count)
130 {
131 	struct fb_info *fb_info = dev_get_drvdata(device);
132 	char mstr[100];
133 	struct fb_var_screeninfo var;
134 	struct fb_modelist *modelist;
135 	struct fb_videomode *mode;
136 	struct list_head *pos;
137 	size_t i;
138 	int err;
139 
140 	memset(&var, 0, sizeof(var));
141 
142 	list_for_each(pos, &fb_info->modelist) {
143 		modelist = list_entry(pos, struct fb_modelist, list);
144 		mode = &modelist->mode;
145 		i = mode_string(mstr, 0, mode);
146 		if (strncmp(mstr, buf, max(count, i)) == 0) {
147 
148 			var = fb_info->var;
149 			fb_videomode_to_var(&var, mode);
150 			if ((err = activate(fb_info, &var)))
151 				return err;
152 			fb_info->mode = mode;
153 			return count;
154 		}
155 	}
156 	return -EINVAL;
157 }
158 
159 static ssize_t show_mode(struct device *device, struct device_attribute *attr,
160 			 char *buf)
161 {
162 	struct fb_info *fb_info = dev_get_drvdata(device);
163 
164 	if (!fb_info->mode)
165 		return 0;
166 
167 	return mode_string(buf, 0, fb_info->mode);
168 }
169 
170 static ssize_t store_modes(struct device *device,
171 			   struct device_attribute *attr,
172 			   const char *buf, size_t count)
173 {
174 	struct fb_info *fb_info = dev_get_drvdata(device);
175 	LIST_HEAD(old_list);
176 	int i = count / sizeof(struct fb_videomode);
177 
178 	if (i * sizeof(struct fb_videomode) != count)
179 		return -EINVAL;
180 
181 	console_lock();
182 	if (!lock_fb_info(fb_info)) {
183 		console_unlock();
184 		return -ENODEV;
185 	}
186 
187 	list_splice(&fb_info->modelist, &old_list);
188 	fb_videomode_to_modelist((const struct fb_videomode *)buf, i,
189 				 &fb_info->modelist);
190 	if (fb_new_modelist(fb_info)) {
191 		fb_destroy_modelist(&fb_info->modelist);
192 		list_splice(&old_list, &fb_info->modelist);
193 	} else
194 		fb_destroy_modelist(&old_list);
195 
196 	unlock_fb_info(fb_info);
197 	console_unlock();
198 
199 	return 0;
200 }
201 
202 static ssize_t show_modes(struct device *device, struct device_attribute *attr,
203 			  char *buf)
204 {
205 	struct fb_info *fb_info = dev_get_drvdata(device);
206 	unsigned int i;
207 	struct list_head *pos;
208 	struct fb_modelist *modelist;
209 	const struct fb_videomode *mode;
210 
211 	i = 0;
212 	list_for_each(pos, &fb_info->modelist) {
213 		modelist = list_entry(pos, struct fb_modelist, list);
214 		mode = &modelist->mode;
215 		i += mode_string(buf, i, mode);
216 	}
217 	return i;
218 }
219 
220 static ssize_t store_bpp(struct device *device, struct device_attribute *attr,
221 			 const char *buf, size_t count)
222 {
223 	struct fb_info *fb_info = dev_get_drvdata(device);
224 	struct fb_var_screeninfo var;
225 	char ** last = NULL;
226 	int err;
227 
228 	var = fb_info->var;
229 	var.bits_per_pixel = simple_strtoul(buf, last, 0);
230 	if ((err = activate(fb_info, &var)))
231 		return err;
232 	return count;
233 }
234 
235 static ssize_t show_bpp(struct device *device, struct device_attribute *attr,
236 			char *buf)
237 {
238 	struct fb_info *fb_info = dev_get_drvdata(device);
239 	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->var.bits_per_pixel);
240 }
241 
242 static ssize_t store_rotate(struct device *device,
243 			    struct device_attribute *attr,
244 			    const char *buf, size_t count)
245 {
246 	struct fb_info *fb_info = dev_get_drvdata(device);
247 	struct fb_var_screeninfo var;
248 	char **last = NULL;
249 	int err;
250 
251 	var = fb_info->var;
252 	var.rotate = simple_strtoul(buf, last, 0);
253 
254 	if ((err = activate(fb_info, &var)))
255 		return err;
256 
257 	return count;
258 }
259 
260 
261 static ssize_t show_rotate(struct device *device,
262 			   struct device_attribute *attr, char *buf)
263 {
264 	struct fb_info *fb_info = dev_get_drvdata(device);
265 
266 	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->var.rotate);
267 }
268 
269 static ssize_t store_virtual(struct device *device,
270 			     struct device_attribute *attr,
271 			     const char *buf, size_t count)
272 {
273 	struct fb_info *fb_info = dev_get_drvdata(device);
274 	struct fb_var_screeninfo var;
275 	char *last = NULL;
276 	int err;
277 
278 	var = fb_info->var;
279 	var.xres_virtual = simple_strtoul(buf, &last, 0);
280 	last++;
281 	if (last - buf >= count)
282 		return -EINVAL;
283 	var.yres_virtual = simple_strtoul(last, &last, 0);
284 
285 	if ((err = activate(fb_info, &var)))
286 		return err;
287 	return count;
288 }
289 
290 static ssize_t show_virtual(struct device *device,
291 			    struct device_attribute *attr, char *buf)
292 {
293 	struct fb_info *fb_info = dev_get_drvdata(device);
294 	return snprintf(buf, PAGE_SIZE, "%d,%d\n", fb_info->var.xres_virtual,
295 			fb_info->var.yres_virtual);
296 }
297 
298 static ssize_t show_stride(struct device *device,
299 			   struct device_attribute *attr, char *buf)
300 {
301 	struct fb_info *fb_info = dev_get_drvdata(device);
302 	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->fix.line_length);
303 }
304 
305 static ssize_t store_blank(struct device *device,
306 			   struct device_attribute *attr,
307 			   const char *buf, size_t count)
308 {
309 	struct fb_info *fb_info = dev_get_drvdata(device);
310 	char *last = NULL;
311 	int err;
312 
313 	console_lock();
314 	fb_info->flags |= FBINFO_MISC_USEREVENT;
315 	err = fb_blank(fb_info, simple_strtoul(buf, &last, 0));
316 	fb_info->flags &= ~FBINFO_MISC_USEREVENT;
317 	console_unlock();
318 	if (err < 0)
319 		return err;
320 	return count;
321 }
322 
323 static ssize_t show_blank(struct device *device,
324 			  struct device_attribute *attr, char *buf)
325 {
326 //	struct fb_info *fb_info = dev_get_drvdata(device);
327 	return 0;
328 }
329 
330 static ssize_t store_console(struct device *device,
331 			     struct device_attribute *attr,
332 			     const char *buf, size_t count)
333 {
334 //	struct fb_info *fb_info = dev_get_drvdata(device);
335 	return 0;
336 }
337 
338 static ssize_t show_console(struct device *device,
339 			    struct device_attribute *attr, char *buf)
340 {
341 //	struct fb_info *fb_info = dev_get_drvdata(device);
342 	return 0;
343 }
344 
345 static ssize_t store_cursor(struct device *device,
346 			    struct device_attribute *attr,
347 			    const char *buf, size_t count)
348 {
349 //	struct fb_info *fb_info = dev_get_drvdata(device);
350 	return 0;
351 }
352 
353 static ssize_t show_cursor(struct device *device,
354 			   struct device_attribute *attr, char *buf)
355 {
356 //	struct fb_info *fb_info = dev_get_drvdata(device);
357 	return 0;
358 }
359 
360 static ssize_t store_pan(struct device *device,
361 			 struct device_attribute *attr,
362 			 const char *buf, size_t count)
363 {
364 	struct fb_info *fb_info = dev_get_drvdata(device);
365 	struct fb_var_screeninfo var;
366 	char *last = NULL;
367 	int err;
368 
369 	var = fb_info->var;
370 	var.xoffset = simple_strtoul(buf, &last, 0);
371 	last++;
372 	if (last - buf >= count)
373 		return -EINVAL;
374 	var.yoffset = simple_strtoul(last, &last, 0);
375 
376 	console_lock();
377 	err = fb_pan_display(fb_info, &var);
378 	console_unlock();
379 
380 	if (err < 0)
381 		return err;
382 	return count;
383 }
384 
385 static ssize_t show_pan(struct device *device,
386 			struct device_attribute *attr, char *buf)
387 {
388 	struct fb_info *fb_info = dev_get_drvdata(device);
389 	return snprintf(buf, PAGE_SIZE, "%d,%d\n", fb_info->var.xoffset,
390 			fb_info->var.yoffset);
391 }
392 
393 static ssize_t show_name(struct device *device,
394 			 struct device_attribute *attr, char *buf)
395 {
396 	struct fb_info *fb_info = dev_get_drvdata(device);
397 
398 	return snprintf(buf, PAGE_SIZE, "%s\n", fb_info->fix.id);
399 }
400 
401 static ssize_t store_fbstate(struct device *device,
402 			     struct device_attribute *attr,
403 			     const char *buf, size_t count)
404 {
405 	struct fb_info *fb_info = dev_get_drvdata(device);
406 	u32 state;
407 	char *last = NULL;
408 
409 	state = simple_strtoul(buf, &last, 0);
410 
411 	console_lock();
412 	if (!lock_fb_info(fb_info)) {
413 		console_unlock();
414 		return -ENODEV;
415 	}
416 
417 	fb_set_suspend(fb_info, (int)state);
418 
419 	unlock_fb_info(fb_info);
420 	console_unlock();
421 
422 	return count;
423 }
424 
425 static ssize_t show_fbstate(struct device *device,
426 			    struct device_attribute *attr, char *buf)
427 {
428 	struct fb_info *fb_info = dev_get_drvdata(device);
429 	return snprintf(buf, PAGE_SIZE, "%d\n", fb_info->state);
430 }
431 
432 #ifdef CONFIG_FB_BACKLIGHT
433 static ssize_t store_bl_curve(struct device *device,
434 			      struct device_attribute *attr,
435 			      const char *buf, size_t count)
436 {
437 	struct fb_info *fb_info = dev_get_drvdata(device);
438 	u8 tmp_curve[FB_BACKLIGHT_LEVELS];
439 	unsigned int i;
440 
441 	/* Some drivers don't use framebuffer_alloc(), but those also
442 	 * don't have backlights.
443 	 */
444 	if (!fb_info || !fb_info->bl_dev)
445 		return -ENODEV;
446 
447 	if (count != (FB_BACKLIGHT_LEVELS / 8 * 24))
448 		return -EINVAL;
449 
450 	for (i = 0; i < (FB_BACKLIGHT_LEVELS / 8); ++i)
451 		if (sscanf(&buf[i * 24],
452 			"%2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx %2hhx\n",
453 			&tmp_curve[i * 8 + 0],
454 			&tmp_curve[i * 8 + 1],
455 			&tmp_curve[i * 8 + 2],
456 			&tmp_curve[i * 8 + 3],
457 			&tmp_curve[i * 8 + 4],
458 			&tmp_curve[i * 8 + 5],
459 			&tmp_curve[i * 8 + 6],
460 			&tmp_curve[i * 8 + 7]) != 8)
461 			return -EINVAL;
462 
463 	/* If there has been an error in the input data, we won't
464 	 * reach this loop.
465 	 */
466 	mutex_lock(&fb_info->bl_curve_mutex);
467 	for (i = 0; i < FB_BACKLIGHT_LEVELS; ++i)
468 		fb_info->bl_curve[i] = tmp_curve[i];
469 	mutex_unlock(&fb_info->bl_curve_mutex);
470 
471 	return count;
472 }
473 
474 static ssize_t show_bl_curve(struct device *device,
475 			     struct device_attribute *attr, char *buf)
476 {
477 	struct fb_info *fb_info = dev_get_drvdata(device);
478 	ssize_t len = 0;
479 	unsigned int i;
480 
481 	/* Some drivers don't use framebuffer_alloc(), but those also
482 	 * don't have backlights.
483 	 */
484 	if (!fb_info || !fb_info->bl_dev)
485 		return -ENODEV;
486 
487 	mutex_lock(&fb_info->bl_curve_mutex);
488 	for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8)
489 		len += scnprintf(&buf[len], PAGE_SIZE - len, "%8ph\n",
490 				fb_info->bl_curve + i);
491 	mutex_unlock(&fb_info->bl_curve_mutex);
492 
493 	return len;
494 }
495 #endif
496 
497 /* When cmap is added back in it should be a binary attribute
498  * not a text one. Consideration should also be given to converting
499  * fbdev to use configfs instead of sysfs */
500 static struct device_attribute device_attrs[] = {
501 	__ATTR(bits_per_pixel, S_IRUGO|S_IWUSR, show_bpp, store_bpp),
502 	__ATTR(blank, S_IRUGO|S_IWUSR, show_blank, store_blank),
503 	__ATTR(console, S_IRUGO|S_IWUSR, show_console, store_console),
504 	__ATTR(cursor, S_IRUGO|S_IWUSR, show_cursor, store_cursor),
505 	__ATTR(mode, S_IRUGO|S_IWUSR, show_mode, store_mode),
506 	__ATTR(modes, S_IRUGO|S_IWUSR, show_modes, store_modes),
507 	__ATTR(pan, S_IRUGO|S_IWUSR, show_pan, store_pan),
508 	__ATTR(virtual_size, S_IRUGO|S_IWUSR, show_virtual, store_virtual),
509 	__ATTR(name, S_IRUGO, show_name, NULL),
510 	__ATTR(stride, S_IRUGO, show_stride, NULL),
511 	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
512 	__ATTR(state, S_IRUGO|S_IWUSR, show_fbstate, store_fbstate),
513 #ifdef CONFIG_FB_BACKLIGHT
514 	__ATTR(bl_curve, S_IRUGO|S_IWUSR, show_bl_curve, store_bl_curve),
515 #endif
516 };
517 
518 int fb_init_device(struct fb_info *fb_info)
519 {
520 	int i, error = 0;
521 
522 	dev_set_drvdata(fb_info->dev, fb_info);
523 
524 	fb_info->class_flag |= FB_SYSFS_FLAG_ATTR;
525 
526 	for (i = 0; i < ARRAY_SIZE(device_attrs); i++) {
527 		error = device_create_file(fb_info->dev, &device_attrs[i]);
528 
529 		if (error)
530 			break;
531 	}
532 
533 	if (error) {
534 		while (--i >= 0)
535 			device_remove_file(fb_info->dev, &device_attrs[i]);
536 		fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
537 	}
538 
539 	return 0;
540 }
541 
542 void fb_cleanup_device(struct fb_info *fb_info)
543 {
544 	unsigned int i;
545 
546 	if (fb_info->class_flag & FB_SYSFS_FLAG_ATTR) {
547 		for (i = 0; i < ARRAY_SIZE(device_attrs); i++)
548 			device_remove_file(fb_info->dev, &device_attrs[i]);
549 
550 		fb_info->class_flag &= ~FB_SYSFS_FLAG_ATTR;
551 	}
552 }
553 
554 #ifdef CONFIG_FB_BACKLIGHT
555 /* This function generates a linear backlight curve
556  *
557  *     0: off
558  *   1-7: min
559  * 8-127: linear from min to max
560  */
561 void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
562 {
563 	unsigned int i, flat, count, range = (max - min);
564 
565 	mutex_lock(&fb_info->bl_curve_mutex);
566 
567 	fb_info->bl_curve[0] = off;
568 
569 	for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
570 		fb_info->bl_curve[flat] = min;
571 
572 	count = FB_BACKLIGHT_LEVELS * 15 / 16;
573 	for (i = 0; i < count; ++i)
574 		fb_info->bl_curve[flat + i] = min + (range * (i + 1) / count);
575 
576 	mutex_unlock(&fb_info->bl_curve_mutex);
577 }
578 EXPORT_SYMBOL_GPL(fb_bl_default_curve);
579 #endif
580