summaryrefslogtreecommitdiff
path: root/libdrm/xf86drmMode.c
blob: 5fdcfa47bcbf78698bbe1e31209ccc0208bb900a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
/*
 * \file xf86drmMode.c
 * Header for DRM modesetting interface.
 *
 * \author Jakob Bornecrantz <wallbraker@gmail.com>
 *
 * \par Acknowledgements:
 * Feb 2007, Dave Airlie <airlied@linux.ie>
 */

/*
 * Copyright (c) 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
 * Copyright (c) 2007-2008 Dave Airlie <airlied@linux.ie>
 * Copyright (c) 2007-2008 Jakob Bornecrantz <wallbraker@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

/*
 * TODO the types we are after are defined in diffrent headers on diffrent
 * platforms find which headers to include to get uint32_t
 */
#include <stdint.h>
#include <sys/ioctl.h>
#include <stdio.h>

#include "xf86drmMode.h"
#include "xf86drm.h"
#include <drm.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <errno.h>

#define U642VOID(x) ((void *)(unsigned long)(x))
#define VOID2U64(x) ((uint64_t)(unsigned long)(x))

/*
 * Util functions
 */

void* drmAllocCpy(void *array, int count, int entry_size)
{
	char *r;
	int i;

	if (!count || !array || !entry_size)
		return 0;

	if (!(r = drmMalloc(count*entry_size)))
		return 0;

	for (i = 0; i < count; i++)
		memcpy(r+(entry_size*i), array+(entry_size*i), entry_size);

	return r;
}

/*
 * A couple of free functions.
 */

void drmModeFreeModeInfo(drmModeModeInfoPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr);
}

void drmModeFreeResources(drmModeResPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr);

}

void drmModeFreeFB(drmModeFBPtr ptr)
{
	if (!ptr)
		return;

	/* we might add more frees later. */
	drmFree(ptr);
}

void drmModeFreeCrtc(drmModeCrtcPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr);

}

void drmModeFreeConnector(drmModeConnectorPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr->modes);
	drmFree(ptr);

}

void drmModeFreeEncoder(drmModeEncoderPtr ptr)
{
	drmFree(ptr);
}

/*
 * ModeSetting functions.
 */

drmModeResPtr drmModeGetResources(int fd)
{
	struct drm_mode_card_res res;
	drmModeResPtr r = 0;

	memset(&res, 0, sizeof(struct drm_mode_card_res));

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETRESOURCES, &res))
		return 0;

	if (res.count_fbs)
		res.fb_id_ptr = VOID2U64(drmMalloc(res.count_fbs*sizeof(uint32_t)));
	if (res.count_crtcs)
		res.crtc_id_ptr = VOID2U64(drmMalloc(res.count_crtcs*sizeof(uint32_t)));
	if (res.count_connectors)
		res.connector_id_ptr = VOID2U64(drmMalloc(res.count_connectors*sizeof(uint32_t)));
	if (res.count_encoders)
		res.encoder_id_ptr = VOID2U64(drmMalloc(res.count_encoders*sizeof(uint32_t)));

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETRESOURCES, &res)) {
		r = NULL;
		goto err_allocs;
	}

	/*
	 * return
	 */


	if (!(r = drmMalloc(sizeof(*r))))
		return 0;

	r->min_width     = res.min_width;
	r->max_width     = res.max_width;
	r->min_height    = res.min_height;
	r->max_height    = res.max_height;
	r->count_fbs     = res.count_fbs;
	r->count_crtcs   = res.count_crtcs;
	r->count_connectors = res.count_connectors;
	r->count_encoders = res.count_encoders;
	/* TODO we realy should test if these allocs fails. */
	r->fbs           = drmAllocCpy(U642VOID(res.fb_id_ptr), res.count_fbs, sizeof(uint32_t));
	r->crtcs         = drmAllocCpy(U642VOID(res.crtc_id_ptr), res.count_crtcs, sizeof(uint32_t));
	r->connectors       = drmAllocCpy(U642VOID(res.connector_id_ptr), res.count_connectors, sizeof(uint32_t));
	r->encoders      = drmAllocCpy(U642VOID(res.encoder_id_ptr), res.count_encoders, sizeof(uint32_t));

err_allocs:
	drmFree(U642VOID(res.fb_id_ptr));
	drmFree(U642VOID(res.crtc_id_ptr));
	drmFree(U642VOID(res.connector_id_ptr));
	drmFree(U642VOID(res.encoder_id_ptr));

	return r;
}

int drmModeAddFB(int fd, uint32_t width, uint32_t height, uint8_t depth,
                 uint8_t bpp, uint32_t pitch, uint32_t bo_handle,
		 uint32_t *buf_id)
{
	struct drm_mode_fb_cmd f;
	int ret;

	f.width  = width;
	f.height = height;
	f.pitch  = pitch;
	f.bpp    = bpp;
	f.depth  = depth;
	f.handle = bo_handle;

	if ((ret = drmIoctl(fd, DRM_IOCTL_MODE_ADDFB, &f)))
		return ret;

	*buf_id = f.fb_id;
	return 0;
}

int drmModeRmFB(int fd, uint32_t bufferId)
{
	return drmIoctl(fd, DRM_IOCTL_MODE_RMFB, &bufferId);


}

drmModeFBPtr drmModeGetFB(int fd, uint32_t buf)
{
	struct drm_mode_fb_cmd info;
	drmModeFBPtr r;

	info.fb_id = buf;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETFB, &info))
		return NULL;

	if (!(r = drmMalloc(sizeof(*r))))
		return NULL;

	r->fb_id = info.fb_id;
	r->width = info.width;
	r->height = info.height;
	r->pitch = info.pitch;
	r->bpp = info.bpp;
	r->handle = info.handle;
	r->depth = info.depth;

	return r;
}


/*
 * Crtc functions
 */

drmModeCrtcPtr drmModeGetCrtc(int fd, uint32_t crtcId)
{
	struct drm_mode_crtc crtc;
	drmModeCrtcPtr r;

	crtc.crtc_id = crtcId;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETCRTC, &crtc))
		return 0;

	/*
	 * return
	 */

	if (!(r = drmMalloc(sizeof(*r))))
		return 0;

	r->crtc_id         = crtc.crtc_id;
	r->x               = crtc.x;
	r->y               = crtc.y;
	r->mode_valid      = crtc.mode_valid;
	if (r->mode_valid)
		memcpy(&r->mode, &crtc.mode, sizeof(struct drm_mode_modeinfo));
	r->buffer_id       = crtc.fb_id;
	r->gamma_size      = crtc.gamma_size;
	return r;
}


int drmModeSetCrtc(int fd, uint32_t crtcId, uint32_t bufferId,
                   uint32_t x, uint32_t y, uint32_t *connectors, int count,
		   drmModeModeInfoPtr mode)
{
	struct drm_mode_crtc crtc;

	crtc.x             = x;
	crtc.y             = y;
	crtc.crtc_id       = crtcId;
	crtc.fb_id         = bufferId;
	crtc.set_connectors_ptr = VOID2U64(connectors);
	crtc.count_connectors = count;
	if (mode) {
	  memcpy(&crtc.mode, mode, sizeof(struct drm_mode_modeinfo));
	  crtc.mode_valid = 1;
	} else
	  crtc.mode_valid = 0;

	return drmIoctl(fd, DRM_IOCTL_MODE_SETCRTC, &crtc);
}

/*
 * Cursor manipulation
 */

int drmModeSetCursor(int fd, uint32_t crtcId, uint32_t bo_handle, uint32_t width, uint32_t height)
{
	struct drm_mode_cursor arg;

	arg.flags = DRM_MODE_CURSOR_BO;
	arg.crtc_id = crtcId;
	arg.width = width;
	arg.height = height;
	arg.handle = bo_handle;

	return drmIoctl(fd, DRM_IOCTL_MODE_CURSOR, &arg);
}

int drmModeMoveCursor(int fd, uint32_t crtcId, int x, int y)
{
	struct drm_mode_cursor arg;

	arg.flags = DRM_MODE_CURSOR_MOVE;
	arg.crtc_id = crtcId;
	arg.x = x;
	arg.y = y;

	return drmIoctl(fd, DRM_IOCTL_MODE_CURSOR, &arg);
}

/*
 * Encoder get
 */
drmModeEncoderPtr drmModeGetEncoder(int fd, uint32_t encoder_id)
{
	struct drm_mode_get_encoder enc;
	drmModeEncoderPtr r = NULL;

	enc.encoder_id = encoder_id;
	enc.encoder_type = 0;
	enc.possible_crtcs = 0;
	enc.possible_clones = 0;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETENCODER, &enc))
		return 0;

	if (!(r = drmMalloc(sizeof(*r))))
		return 0;

	r->encoder_id = enc.encoder_id;
	r->crtc_id = enc.crtc_id;
	r->encoder_type = enc.encoder_type;
	r->possible_crtcs = enc.possible_crtcs;
	r->possible_clones = enc.possible_clones;

	return r;
}

/*
 * Connector manipulation
 */

drmModeConnectorPtr drmModeGetConnector(int fd, uint32_t connector_id)
{
	struct drm_mode_get_connector conn;
	drmModeConnectorPtr r = NULL;

	conn.connector_id = connector_id;
	conn.connector_type_id = 0;
	conn.connector_type  = 0;
	conn.count_modes  = 0;
	conn.modes_ptr    = 0;
	conn.count_props  = 0;
	conn.props_ptr    = 0;
	conn.prop_values_ptr = 0;
	conn.count_encoders  = 0;
	conn.encoders_ptr = 0;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETCONNECTOR, &conn))
		return 0;

	if (conn.count_props) {
		conn.props_ptr = VOID2U64(drmMalloc(conn.count_props*sizeof(uint32_t)));
		conn.prop_values_ptr = VOID2U64(drmMalloc(conn.count_props*sizeof(uint64_t)));
	}

	if (conn.count_modes)
		conn.modes_ptr = VOID2U64(drmMalloc(conn.count_modes*sizeof(struct drm_mode_modeinfo)));

	if (conn.count_encoders)
		conn.encoders_ptr = VOID2U64(drmMalloc(conn.count_encoders*sizeof(uint32_t)));

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETCONNECTOR, &conn))
		goto err_allocs;

	if(!(r = drmMalloc(sizeof(*r)))) {
		goto err_allocs;
	}

	r->connector_id = conn.connector_id;
	r->encoder_id = conn.encoder_id;
	r->connection   = conn.connection;
	r->mmWidth      = conn.mm_width;
	r->mmHeight     = conn.mm_height;
	/* convert subpixel from kernel to userspace */
	r->subpixel     = conn.subpixel + 1;
	r->count_modes  = conn.count_modes;
	/* TODO we should test if these alloc & cpy fails. */
	r->count_props  = conn.count_props;
	r->props        = drmAllocCpy(U642VOID(conn.props_ptr), conn.count_props, sizeof(uint32_t));
	r->prop_values  = drmAllocCpy(U642VOID(conn.prop_values_ptr), conn.count_props, sizeof(uint64_t));
	r->modes        = drmAllocCpy(U642VOID(conn.modes_ptr), conn.count_modes, sizeof(struct drm_mode_modeinfo));
	r->count_encoders = conn.count_encoders;
	r->encoders     = drmAllocCpy(U642VOID(conn.encoders_ptr), conn.count_encoders, sizeof(uint32_t));
	r->connector_type  = conn.connector_type;
	r->connector_type_id = conn.connector_type_id;

	if (!r->props || !r->prop_values || !r->modes || !r->encoders)
		goto err_allocs;

err_allocs:
	drmFree(U642VOID(conn.prop_values_ptr));
	drmFree(U642VOID(conn.props_ptr));
	drmFree(U642VOID(conn.modes_ptr));
	drmFree(U642VOID(conn.encoders_ptr));

	return r;
}

int drmModeAttachMode(int fd, uint32_t connector_id, drmModeModeInfoPtr mode_info)
{
	struct drm_mode_mode_cmd res;

	memcpy(&res.mode, mode_info, sizeof(struct drm_mode_modeinfo));
	res.connector_id = connector_id;

	return drmIoctl(fd, DRM_IOCTL_MODE_ATTACHMODE, &res);
}

int drmModeDetachMode(int fd, uint32_t connector_id, drmModeModeInfoPtr mode_info)
{
	struct drm_mode_mode_cmd res;

	memcpy(&res.mode, mode_info, sizeof(struct drm_mode_modeinfo));
	res.connector_id = connector_id;

	return drmIoctl(fd, DRM_IOCTL_MODE_DETACHMODE, &res);
}


drmModePropertyPtr drmModeGetProperty(int fd, uint32_t property_id)
{
	struct drm_mode_get_property prop;
	drmModePropertyPtr r;

	prop.prop_id = property_id;
	prop.count_enum_blobs = 0;
	prop.count_values = 0;
	prop.flags = 0;
	prop.enum_blob_ptr = 0;
	prop.values_ptr = 0;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETPROPERTY, &prop))
		return 0;

	if (prop.count_values)
		prop.values_ptr = VOID2U64(drmMalloc(prop.count_values * sizeof(uint64_t)));

	if (prop.count_enum_blobs && (prop.flags & DRM_MODE_PROP_ENUM))
		prop.enum_blob_ptr = VOID2U64(drmMalloc(prop.count_enum_blobs * sizeof(struct drm_mode_property_enum)));

	if (prop.count_enum_blobs && (prop.flags & DRM_MODE_PROP_BLOB)) {
		prop.values_ptr = VOID2U64(drmMalloc(prop.count_enum_blobs * sizeof(uint32_t)));
		prop.enum_blob_ptr = VOID2U64(drmMalloc(prop.count_enum_blobs * sizeof(uint32_t)));
	}

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETPROPERTY, &prop)) {
		r = NULL;
		goto err_allocs;
	}

	if (!(r = drmMalloc(sizeof(*r))))
		return NULL;

	r->prop_id = prop.prop_id;
	r->count_values = prop.count_values;

	r->flags = prop.flags;
	if (prop.count_values)
		r->values = drmAllocCpy(U642VOID(prop.values_ptr), prop.count_values, sizeof(uint64_t));
	if (prop.flags & DRM_MODE_PROP_ENUM) {
		r->count_enums = prop.count_enum_blobs;
		r->enums = drmAllocCpy(U642VOID(prop.enum_blob_ptr), prop.count_enum_blobs, sizeof(struct drm_mode_property_enum));
	} else if (prop.flags & DRM_MODE_PROP_BLOB) {
		r->values = drmAllocCpy(U642VOID(prop.values_ptr), prop.count_enum_blobs, sizeof(uint32_t));
		r->blob_ids = drmAllocCpy(U642VOID(prop.enum_blob_ptr), prop.count_enum_blobs, sizeof(uint32_t));
		r->count_blobs = prop.count_enum_blobs;
	}
	strncpy(r->name, prop.name, DRM_PROP_NAME_LEN);
	r->name[DRM_PROP_NAME_LEN-1] = 0;

err_allocs:
	drmFree(U642VOID(prop.values_ptr));
	drmFree(U642VOID(prop.enum_blob_ptr));

	return r;
}

void drmModeFreeProperty(drmModePropertyPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr->values);
	drmFree(ptr->enums);
	drmFree(ptr);
}

drmModePropertyBlobPtr drmModeGetPropertyBlob(int fd, uint32_t blob_id)
{
	struct drm_mode_get_blob blob;
	drmModePropertyBlobPtr r;

	blob.length = 0;
	blob.data = 0;
	blob.blob_id = blob_id;

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETPROPBLOB, &blob))
		return NULL;

	if (blob.length)
		blob.data = VOID2U64(drmMalloc(blob.length));

	if (drmIoctl(fd, DRM_IOCTL_MODE_GETPROPBLOB, &blob)) {
		r = NULL;
		goto err_allocs;
	}

	if (!(r = drmMalloc(sizeof(*r))))
		return NULL;

	r->id = blob.blob_id;
	r->length = blob.length;
	r->data = drmAllocCpy(U642VOID(blob.data), 1, blob.length);

err_allocs:
	drmFree(U642VOID(blob.data));
	return r;
}

void drmModeFreePropertyBlob(drmModePropertyBlobPtr ptr)
{
	if (!ptr)
		return;

	drmFree(ptr->data);
	drmFree(ptr);
}

int drmModeConnectorSetProperty(int fd, uint32_t connector_id, uint32_t property_id,
			     uint64_t value)
{
	struct drm_mode_connector_set_property osp;
	int ret;

	osp.connector_id = connector_id;
	osp.prop_id = property_id;
	osp.value = value;

	if ((ret = drmIoctl(fd, DRM_IOCTL_MODE_SETPROPERTY, &osp)))
		return ret;

	return 0;
}

/*
 * checks if a modesetting capable driver has attached to the pci id
 * returns 0 if modesetting supported.
 *  -EINVAL or invalid bus id
 *  -ENOSYS if no modesetting support
*/
int drmCheckModesettingSupported(const char *busid)
{
#ifdef __linux__
	char pci_dev_dir[1024];
	int domain, bus, dev, func;
	DIR *sysdir;
	struct dirent *dent;
	int found = 0, ret;

	ret = sscanf(busid, "pci:%04x:%02x:%02x.%d", &domain, &bus, &dev, &func);
	if (ret != 4)
		return -EINVAL;

	sprintf(pci_dev_dir, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/drm",
		domain, bus, dev, func);

	sysdir = opendir(pci_dev_dir);
	if (sysdir) {
		dent = readdir(sysdir);
		while (dent) {
			if (!strncmp(dent->d_name, "controlD", 8)) {
				found = 1;
				break;
			}

			dent = readdir(sysdir);
		}
		closedir(sysdir);
		if (found)
			return 0;
	}

	sprintf(pci_dev_dir, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/",
		domain, bus, dev, func);

	sysdir = opendir(pci_dev_dir);
	if (!sysdir)
		return -EINVAL;

	dent = readdir(sysdir);
	while (dent) {
		if (!strncmp(dent->d_name, "drm:controlD", 12)) {
			found = 1;
			break;
		}

		dent = readdir(sysdir);
	}

	closedir(sysdir);
	if (found)
		return 0;
#endif
	return -ENOSYS;

}

int drmModeCrtcGetGamma(int fd, uint32_t crtc_id, uint32_t size,
			uint16_t *red, uint16_t *green, uint16_t *blue)
{
	int ret;
	struct drm_mode_crtc_lut l;

	l.crtc_id = crtc_id;
	l.gamma_size = size;
	l.red = VOID2U64(red);
	l.green = VOID2U64(green);
	l.blue = VOID2U64(blue);

	if ((ret = drmIoctl(fd, DRM_IOCTL_MODE_GETGAMMA, &l)))
		return ret;

	return 0;
}

int drmModeCrtcSetGamma(int fd, uint32_t crtc_id, uint32_t size,
			uint16_t *red, uint16_t *green, uint16_t *blue)
{
	int ret;
	struct drm_mode_crtc_lut l;

	l.crtc_id = crtc_id;
	l.gamma_size = size;
	l.red = VOID2U64(red);
	l.green = VOID2U64(green);
	l.blue = VOID2U64(blue);

	if ((ret = drmIoctl(fd, DRM_IOCTL_MODE_SETGAMMA, &l)))
		return ret;

	return 0;
}

int drmHandleEvent(int fd, drmEventContextPtr evctx)
{
	char buffer[1024];
	int len, i;
	struct drm_event *e;
	struct drm_event_vblank *vblank;
	
	/* The DRM read semantics guarantees that we always get only
	 * complete events. */

	len = read(fd, buffer, sizeof buffer);
	if (len == 0)
		return 0;
	if (len < sizeof *e)
		return -1;

	i = 0;
	while (i < len) {
		e = (struct drm_event *) &buffer[i];
		switch (e->type) {
		case DRM_EVENT_VBLANK:
			if (evctx->version < 1 ||
			    evctx->vblank_handler == NULL)
				break;
			vblank = (struct drm_event_vblank *) e;
			evctx->vblank_handler(fd,
					      vblank->sequence, 
					      vblank->tv_sec,
					      vblank->tv_usec,
					      U642VOID (vblank->user_data));
			break;
			
		default:
			break;
		}
		i += e->length;
	}

	return 0;
}