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1// SPDX-License-Identifier: MIT
2/*
3 * Copyright 2020 Noralf Trønnes
4 */
5
6#include <linux/dma-buf.h>
7#include <linux/dma-mapping.h>
8#include <linux/lz4.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/string_helpers.h>
12#include <linux/usb.h>
13#include <linux/vmalloc.h>
14#include <linux/workqueue.h>
15
16#include <drm/drm_atomic_helper.h>
17#include <drm/drm_blend.h>
18#include <drm/drm_client_setup.h>
19#include <drm/drm_damage_helper.h>
20#include <drm/drm_debugfs.h>
21#include <drm/drm_drv.h>
22#include <drm/drm_fbdev_shmem.h>
23#include <drm/drm_fourcc.h>
24#include <drm/drm_gem_atomic_helper.h>
25#include <drm/drm_gem_framebuffer_helper.h>
26#include <drm/drm_gem_shmem_helper.h>
27#include <drm/drm_managed.h>
28#include <drm/drm_print.h>
29#include <drm/drm_probe_helper.h>
30#include <drm/drm_simple_kms_helper.h>
31#include <drm/gud.h>
32
33#include "gud_internal.h"
34
35/* Only used internally */
36static const struct drm_format_info gud_drm_format_r1 = {
37 .format = GUD_DRM_FORMAT_R1,
38 .num_planes = 1,
39 .char_per_block = { 1, 0, 0 },
40 .block_w = { 8, 0, 0 },
41 .block_h = { 1, 0, 0 },
42 .hsub = 1,
43 .vsub = 1,
44};
45
46static const struct drm_format_info gud_drm_format_xrgb1111 = {
47 .format = GUD_DRM_FORMAT_XRGB1111,
48 .num_planes = 1,
49 .char_per_block = { 1, 0, 0 },
50 .block_w = { 2, 0, 0 },
51 .block_h = { 1, 0, 0 },
52 .hsub = 1,
53 .vsub = 1,
54};
55
56static int gud_usb_control_msg(struct usb_interface *intf, bool in,
57 u8 request, u16 value, void *buf, size_t len)
58{
59 u8 requesttype = USB_TYPE_VENDOR | USB_RECIP_INTERFACE;
60 u8 ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
61 struct usb_device *usb = interface_to_usbdev(intf);
62 unsigned int pipe;
63
64 if (len && !buf)
65 return -EINVAL;
66
67 if (in) {
68 pipe = usb_rcvctrlpipe(usb, 0);
69 requesttype |= USB_DIR_IN;
70 } else {
71 pipe = usb_sndctrlpipe(usb, 0);
72 requesttype |= USB_DIR_OUT;
73 }
74
75 return usb_control_msg(usb, pipe, request, requesttype, value,
76 ifnum, buf, len, USB_CTRL_GET_TIMEOUT);
77}
78
79static int gud_get_display_descriptor(struct usb_interface *intf,
80 struct gud_display_descriptor_req *desc)
81{
82 void *buf;
83 int ret;
84
85 buf = kmalloc(sizeof(*desc), GFP_KERNEL);
86 if (!buf)
87 return -ENOMEM;
88
89 ret = gud_usb_control_msg(intf, true, GUD_REQ_GET_DESCRIPTOR, 0, buf, sizeof(*desc));
90 memcpy(desc, buf, sizeof(*desc));
91 kfree(buf);
92 if (ret < 0)
93 return ret;
94 if (ret != sizeof(*desc))
95 return -EIO;
96
97 if (desc->magic != le32_to_cpu(GUD_DISPLAY_MAGIC))
98 return -ENODATA;
99
100 DRM_DEV_DEBUG_DRIVER(&intf->dev,
101 "version=%u flags=0x%x compression=0x%x max_buffer_size=%u\n",
102 desc->version, le32_to_cpu(desc->flags), desc->compression,
103 le32_to_cpu(desc->max_buffer_size));
104
105 if (!desc->version || !desc->max_width || !desc->max_height ||
106 le32_to_cpu(desc->min_width) > le32_to_cpu(desc->max_width) ||
107 le32_to_cpu(desc->min_height) > le32_to_cpu(desc->max_height))
108 return -EINVAL;
109
110 return 0;
111}
112
113static int gud_status_to_errno(u8 status)
114{
115 switch (status) {
116 case GUD_STATUS_OK:
117 return 0;
118 case GUD_STATUS_BUSY:
119 return -EBUSY;
120 case GUD_STATUS_REQUEST_NOT_SUPPORTED:
121 return -EOPNOTSUPP;
122 case GUD_STATUS_PROTOCOL_ERROR:
123 return -EPROTO;
124 case GUD_STATUS_INVALID_PARAMETER:
125 return -EINVAL;
126 case GUD_STATUS_ERROR:
127 return -EREMOTEIO;
128 default:
129 return -EREMOTEIO;
130 }
131}
132
133static int gud_usb_get_status(struct usb_interface *intf)
134{
135 int ret, status = -EIO;
136 u8 *buf;
137
138 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
139 if (!buf)
140 return -ENOMEM;
141
142 ret = gud_usb_control_msg(intf, true, GUD_REQ_GET_STATUS, 0, buf, sizeof(*buf));
143 if (ret == sizeof(*buf))
144 status = gud_status_to_errno(*buf);
145 kfree(buf);
146
147 if (ret < 0)
148 return ret;
149
150 return status;
151}
152
153static int gud_usb_transfer(struct gud_device *gdrm, bool in, u8 request, u16 index,
154 void *buf, size_t len)
155{
156 struct usb_interface *intf = to_usb_interface(gdrm->drm.dev);
157 int idx, ret;
158
159 drm_dbg(&gdrm->drm, "%s: request=0x%x index=%u len=%zu\n",
160 in ? "get" : "set", request, index, len);
161
162 if (!drm_dev_enter(&gdrm->drm, &idx))
163 return -ENODEV;
164
165 mutex_lock(&gdrm->ctrl_lock);
166
167 ret = gud_usb_control_msg(intf, in, request, index, buf, len);
168 if (ret == -EPIPE || ((gdrm->flags & GUD_DISPLAY_FLAG_STATUS_ON_SET) && !in && ret >= 0)) {
169 int status;
170
171 status = gud_usb_get_status(intf);
172 if (status < 0) {
173 ret = status;
174 } else if (ret < 0) {
175 dev_err_once(gdrm->drm.dev,
176 "Unexpected status OK for failed transfer\n");
177 ret = -EPIPE;
178 }
179 }
180
181 if (ret < 0) {
182 drm_dbg(&gdrm->drm, "ret=%d\n", ret);
183 gdrm->stats_num_errors++;
184 }
185
186 mutex_unlock(&gdrm->ctrl_lock);
187 drm_dev_exit(idx);
188
189 return ret;
190}
191
192/*
193 * @buf cannot be allocated on the stack.
194 * Returns number of bytes received or negative error code on failure.
195 */
196int gud_usb_get(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t max_len)
197{
198 return gud_usb_transfer(gdrm, true, request, index, buf, max_len);
199}
200
201/*
202 * @buf can be allocated on the stack or NULL.
203 * Returns zero on success or negative error code on failure.
204 */
205int gud_usb_set(struct gud_device *gdrm, u8 request, u16 index, void *buf, size_t len)
206{
207 void *trbuf = NULL;
208 int ret;
209
210 if (buf && len) {
211 trbuf = kmemdup(buf, len, GFP_KERNEL);
212 if (!trbuf)
213 return -ENOMEM;
214 }
215
216 ret = gud_usb_transfer(gdrm, false, request, index, trbuf, len);
217 kfree(trbuf);
218 if (ret < 0)
219 return ret;
220
221 return ret != len ? -EIO : 0;
222}
223
224/*
225 * @val can be allocated on the stack.
226 * Returns zero on success or negative error code on failure.
227 */
228int gud_usb_get_u8(struct gud_device *gdrm, u8 request, u16 index, u8 *val)
229{
230 u8 *buf;
231 int ret;
232
233 buf = kmalloc(sizeof(*val), GFP_KERNEL);
234 if (!buf)
235 return -ENOMEM;
236
237 ret = gud_usb_get(gdrm, request, index, buf, sizeof(*val));
238 *val = *buf;
239 kfree(buf);
240 if (ret < 0)
241 return ret;
242
243 return ret != sizeof(*val) ? -EIO : 0;
244}
245
246/* Returns zero on success or negative error code on failure. */
247int gud_usb_set_u8(struct gud_device *gdrm, u8 request, u8 val)
248{
249 return gud_usb_set(gdrm, request, 0, &val, sizeof(val));
250}
251
252static int gud_get_properties(struct gud_device *gdrm)
253{
254 struct gud_property_req *properties;
255 unsigned int i, num_properties;
256 int ret;
257
258 properties = kcalloc(GUD_PROPERTIES_MAX_NUM, sizeof(*properties), GFP_KERNEL);
259 if (!properties)
260 return -ENOMEM;
261
262 ret = gud_usb_get(gdrm, GUD_REQ_GET_PROPERTIES, 0,
263 properties, GUD_PROPERTIES_MAX_NUM * sizeof(*properties));
264 if (ret <= 0)
265 goto out;
266 if (ret % sizeof(*properties)) {
267 ret = -EIO;
268 goto out;
269 }
270
271 num_properties = ret / sizeof(*properties);
272 ret = 0;
273
274 gdrm->properties = drmm_kcalloc(&gdrm->drm, num_properties, sizeof(*gdrm->properties),
275 GFP_KERNEL);
276 if (!gdrm->properties) {
277 ret = -ENOMEM;
278 goto out;
279 }
280
281 for (i = 0; i < num_properties; i++) {
282 u16 prop = le16_to_cpu(properties[i].prop);
283 u64 val = le64_to_cpu(properties[i].val);
284
285 switch (prop) {
286 case GUD_PROPERTY_ROTATION:
287 /*
288 * DRM UAPI matches the protocol so use the value directly,
289 * but mask out any additions on future devices.
290 */
291 val &= GUD_ROTATION_MASK;
292 ret = drm_plane_create_rotation_property(&gdrm->pipe.plane,
293 DRM_MODE_ROTATE_0, val);
294 break;
295 default:
296 /* New ones might show up in future devices, skip those we don't know. */
297 drm_dbg(&gdrm->drm, "Ignoring unknown property: %u\n", prop);
298 continue;
299 }
300
301 if (ret)
302 goto out;
303
304 gdrm->properties[gdrm->num_properties++] = prop;
305 }
306out:
307 kfree(properties);
308
309 return ret;
310}
311
312/*
313 * FIXME: Dma-buf sharing requires DMA support by the importing device.
314 * This function is a workaround to make USB devices work as well.
315 * See todo.rst for how to fix the issue in the dma-buf framework.
316 */
317static struct drm_gem_object *gud_gem_prime_import(struct drm_device *drm, struct dma_buf *dma_buf)
318{
319 struct gud_device *gdrm = to_gud_device(drm);
320
321 if (!gdrm->dmadev)
322 return ERR_PTR(-ENODEV);
323
324 return drm_gem_prime_import_dev(drm, dma_buf, gdrm->dmadev);
325}
326
327static int gud_stats_debugfs(struct seq_file *m, void *data)
328{
329 struct drm_debugfs_entry *entry = m->private;
330 struct gud_device *gdrm = to_gud_device(entry->dev);
331 char buf[10];
332
333 string_get_size(gdrm->bulk_len, 1, STRING_UNITS_2, buf, sizeof(buf));
334 seq_printf(m, "Max buffer size: %s\n", buf);
335 seq_printf(m, "Number of errors: %u\n", gdrm->stats_num_errors);
336
337 seq_puts(m, "Compression: ");
338 if (gdrm->compression & GUD_COMPRESSION_LZ4)
339 seq_puts(m, " lz4");
340 if (!gdrm->compression)
341 seq_puts(m, " none");
342 seq_puts(m, "\n");
343
344 if (gdrm->compression) {
345 u64 remainder;
346 u64 ratio = div64_u64_rem(gdrm->stats_length, gdrm->stats_actual_length,
347 &remainder);
348 u64 ratio_frac = div64_u64(remainder * 10, gdrm->stats_actual_length);
349
350 seq_printf(m, "Compression ratio: %llu.%llu\n", ratio, ratio_frac);
351 }
352
353 return 0;
354}
355
356static const struct drm_simple_display_pipe_funcs gud_pipe_funcs = {
357 .check = gud_pipe_check,
358 .update = gud_pipe_update,
359 DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS
360};
361
362static const struct drm_mode_config_funcs gud_mode_config_funcs = {
363 .fb_create = drm_gem_fb_create_with_dirty,
364 .atomic_check = drm_atomic_helper_check,
365 .atomic_commit = drm_atomic_helper_commit,
366};
367
368static const u64 gud_pipe_modifiers[] = {
369 DRM_FORMAT_MOD_LINEAR,
370 DRM_FORMAT_MOD_INVALID
371};
372
373DEFINE_DRM_GEM_FOPS(gud_fops);
374
375static const struct drm_driver gud_drm_driver = {
376 .driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
377 .fops = &gud_fops,
378 DRM_GEM_SHMEM_DRIVER_OPS,
379 .gem_prime_import = gud_gem_prime_import,
380 DRM_FBDEV_SHMEM_DRIVER_OPS,
381
382 .name = "gud",
383 .desc = "Generic USB Display",
384 .date = "20200422",
385 .major = 1,
386 .minor = 0,
387};
388
389static int gud_alloc_bulk_buffer(struct gud_device *gdrm)
390{
391 unsigned int i, num_pages;
392 struct page **pages;
393 void *ptr;
394 int ret;
395
396 gdrm->bulk_buf = vmalloc_32(gdrm->bulk_len);
397 if (!gdrm->bulk_buf)
398 return -ENOMEM;
399
400 num_pages = DIV_ROUND_UP(gdrm->bulk_len, PAGE_SIZE);
401 pages = kmalloc_array(num_pages, sizeof(struct page *), GFP_KERNEL);
402 if (!pages)
403 return -ENOMEM;
404
405 for (i = 0, ptr = gdrm->bulk_buf; i < num_pages; i++, ptr += PAGE_SIZE)
406 pages[i] = vmalloc_to_page(ptr);
407
408 ret = sg_alloc_table_from_pages(&gdrm->bulk_sgt, pages, num_pages,
409 0, gdrm->bulk_len, GFP_KERNEL);
410 kfree(pages);
411
412 return ret;
413}
414
415static void gud_free_buffers_and_mutex(void *data)
416{
417 struct gud_device *gdrm = data;
418
419 vfree(gdrm->compress_buf);
420 gdrm->compress_buf = NULL;
421 sg_free_table(&gdrm->bulk_sgt);
422 vfree(gdrm->bulk_buf);
423 gdrm->bulk_buf = NULL;
424 mutex_destroy(&gdrm->ctrl_lock);
425}
426
427static int gud_probe(struct usb_interface *intf, const struct usb_device_id *id)
428{
429 const struct drm_format_info *xrgb8888_emulation_format = NULL;
430 bool rgb565_supported = false, xrgb8888_supported = false;
431 unsigned int num_formats_dev, num_formats = 0;
432 struct usb_endpoint_descriptor *bulk_out;
433 struct gud_display_descriptor_req desc;
434 struct device *dev = &intf->dev;
435 size_t max_buffer_size = 0;
436 struct gud_device *gdrm;
437 struct drm_device *drm;
438 u8 *formats_dev;
439 u32 *formats;
440 int ret, i;
441
442 ret = usb_find_bulk_out_endpoint(intf->cur_altsetting, &bulk_out);
443 if (ret)
444 return ret;
445
446 ret = gud_get_display_descriptor(intf, &desc);
447 if (ret) {
448 DRM_DEV_DEBUG_DRIVER(dev, "Not a display interface: ret=%d\n", ret);
449 return -ENODEV;
450 }
451
452 if (desc.version > 1) {
453 dev_err(dev, "Protocol version %u is not supported\n", desc.version);
454 return -ENODEV;
455 }
456
457 gdrm = devm_drm_dev_alloc(dev, &gud_drm_driver, struct gud_device, drm);
458 if (IS_ERR(gdrm))
459 return PTR_ERR(gdrm);
460
461 drm = &gdrm->drm;
462 drm->mode_config.funcs = &gud_mode_config_funcs;
463 ret = drmm_mode_config_init(drm);
464 if (ret)
465 return ret;
466
467 gdrm->flags = le32_to_cpu(desc.flags);
468 gdrm->compression = desc.compression & GUD_COMPRESSION_LZ4;
469
470 if (gdrm->flags & GUD_DISPLAY_FLAG_FULL_UPDATE && gdrm->compression)
471 return -EINVAL;
472
473 mutex_init(&gdrm->ctrl_lock);
474 mutex_init(&gdrm->damage_lock);
475 INIT_WORK(&gdrm->work, gud_flush_work);
476 gud_clear_damage(gdrm);
477
478 ret = devm_add_action(dev, gud_free_buffers_and_mutex, gdrm);
479 if (ret)
480 return ret;
481
482 drm->mode_config.min_width = le32_to_cpu(desc.min_width);
483 drm->mode_config.max_width = le32_to_cpu(desc.max_width);
484 drm->mode_config.min_height = le32_to_cpu(desc.min_height);
485 drm->mode_config.max_height = le32_to_cpu(desc.max_height);
486
487 formats_dev = devm_kmalloc(dev, GUD_FORMATS_MAX_NUM, GFP_KERNEL);
488 /* Add room for emulated XRGB8888 */
489 formats = devm_kmalloc_array(dev, GUD_FORMATS_MAX_NUM + 1, sizeof(*formats), GFP_KERNEL);
490 if (!formats_dev || !formats)
491 return -ENOMEM;
492
493 ret = gud_usb_get(gdrm, GUD_REQ_GET_FORMATS, 0, formats_dev, GUD_FORMATS_MAX_NUM);
494 if (ret < 0)
495 return ret;
496
497 num_formats_dev = ret;
498 for (i = 0; i < num_formats_dev; i++) {
499 const struct drm_format_info *info;
500 size_t fmt_buf_size;
501 u32 format;
502
503 format = gud_to_fourcc(formats_dev[i]);
504 if (!format) {
505 drm_dbg(drm, "Unsupported format: 0x%02x\n", formats_dev[i]);
506 continue;
507 }
508
509 if (format == GUD_DRM_FORMAT_R1)
510 info = &gud_drm_format_r1;
511 else if (format == GUD_DRM_FORMAT_XRGB1111)
512 info = &gud_drm_format_xrgb1111;
513 else
514 info = drm_format_info(format);
515
516 switch (format) {
517 case GUD_DRM_FORMAT_R1:
518 fallthrough;
519 case DRM_FORMAT_R8:
520 fallthrough;
521 case GUD_DRM_FORMAT_XRGB1111:
522 fallthrough;
523 case DRM_FORMAT_RGB332:
524 fallthrough;
525 case DRM_FORMAT_RGB888:
526 if (!xrgb8888_emulation_format)
527 xrgb8888_emulation_format = info;
528 break;
529 case DRM_FORMAT_RGB565:
530 rgb565_supported = true;
531 if (!xrgb8888_emulation_format)
532 xrgb8888_emulation_format = info;
533 break;
534 case DRM_FORMAT_XRGB8888:
535 xrgb8888_supported = true;
536 break;
537 }
538
539 fmt_buf_size = drm_format_info_min_pitch(info, 0, drm->mode_config.max_width) *
540 drm->mode_config.max_height;
541 max_buffer_size = max(max_buffer_size, fmt_buf_size);
542
543 if (format == GUD_DRM_FORMAT_R1 || format == GUD_DRM_FORMAT_XRGB1111)
544 continue; /* Internal not for userspace */
545
546 formats[num_formats++] = format;
547 }
548
549 if (!num_formats && !xrgb8888_emulation_format) {
550 dev_err(dev, "No supported pixel formats found\n");
551 return -EINVAL;
552 }
553
554 /* Prefer speed over color depth */
555 if (rgb565_supported)
556 drm->mode_config.preferred_depth = 16;
557
558 if (!xrgb8888_supported && xrgb8888_emulation_format) {
559 gdrm->xrgb8888_emulation_format = xrgb8888_emulation_format;
560 formats[num_formats++] = DRM_FORMAT_XRGB8888;
561 }
562
563 if (desc.max_buffer_size)
564 max_buffer_size = le32_to_cpu(desc.max_buffer_size);
565 /* Prevent a misbehaving device from allocating loads of RAM. 4096x4096@XRGB8888 = 64 MB */
566 if (max_buffer_size > SZ_64M)
567 max_buffer_size = SZ_64M;
568
569 gdrm->bulk_pipe = usb_sndbulkpipe(interface_to_usbdev(intf), usb_endpoint_num(bulk_out));
570 gdrm->bulk_len = max_buffer_size;
571
572 ret = gud_alloc_bulk_buffer(gdrm);
573 if (ret)
574 return ret;
575
576 if (gdrm->compression & GUD_COMPRESSION_LZ4) {
577 gdrm->lz4_comp_mem = devm_kmalloc(dev, LZ4_MEM_COMPRESS, GFP_KERNEL);
578 if (!gdrm->lz4_comp_mem)
579 return -ENOMEM;
580
581 gdrm->compress_buf = vmalloc(gdrm->bulk_len);
582 if (!gdrm->compress_buf)
583 return -ENOMEM;
584 }
585
586 ret = drm_simple_display_pipe_init(drm, &gdrm->pipe, &gud_pipe_funcs,
587 formats, num_formats,
588 gud_pipe_modifiers, NULL);
589 if (ret)
590 return ret;
591
592 devm_kfree(dev, formats);
593 devm_kfree(dev, formats_dev);
594
595 ret = gud_get_properties(gdrm);
596 if (ret) {
597 dev_err(dev, "Failed to get properties (error=%d)\n", ret);
598 return ret;
599 }
600
601 drm_plane_enable_fb_damage_clips(&gdrm->pipe.plane);
602
603 ret = gud_get_connectors(gdrm);
604 if (ret) {
605 dev_err(dev, "Failed to get connectors (error=%d)\n", ret);
606 return ret;
607 }
608
609 drm_mode_config_reset(drm);
610
611 usb_set_intfdata(intf, gdrm);
612
613 gdrm->dmadev = usb_intf_get_dma_device(intf);
614 if (!gdrm->dmadev)
615 dev_warn(dev, "buffer sharing not supported");
616
617 drm_debugfs_add_file(drm, "stats", gud_stats_debugfs, NULL);
618
619 ret = drm_dev_register(drm, 0);
620 if (ret) {
621 put_device(gdrm->dmadev);
622 return ret;
623 }
624
625 drm_kms_helper_poll_init(drm);
626
627 drm_client_setup(drm, NULL);
628
629 return 0;
630}
631
632static void gud_disconnect(struct usb_interface *interface)
633{
634 struct gud_device *gdrm = usb_get_intfdata(interface);
635 struct drm_device *drm = &gdrm->drm;
636
637 drm_dbg(drm, "%s:\n", __func__);
638
639 drm_kms_helper_poll_fini(drm);
640 drm_dev_unplug(drm);
641 drm_atomic_helper_shutdown(drm);
642 put_device(gdrm->dmadev);
643 gdrm->dmadev = NULL;
644}
645
646static int gud_suspend(struct usb_interface *intf, pm_message_t message)
647{
648 struct gud_device *gdrm = usb_get_intfdata(intf);
649
650 return drm_mode_config_helper_suspend(&gdrm->drm);
651}
652
653static int gud_resume(struct usb_interface *intf)
654{
655 struct gud_device *gdrm = usb_get_intfdata(intf);
656
657 drm_mode_config_helper_resume(&gdrm->drm);
658
659 return 0;
660}
661
662static const struct usb_device_id gud_id_table[] = {
663 { USB_DEVICE_INTERFACE_CLASS(0x1d50, 0x614d, USB_CLASS_VENDOR_SPEC) },
664 { USB_DEVICE_INTERFACE_CLASS(0x16d0, 0x10a9, USB_CLASS_VENDOR_SPEC) },
665 { }
666};
667
668MODULE_DEVICE_TABLE(usb, gud_id_table);
669
670static struct usb_driver gud_usb_driver = {
671 .name = "gud",
672 .probe = gud_probe,
673 .disconnect = gud_disconnect,
674 .id_table = gud_id_table,
675 .suspend = gud_suspend,
676 .resume = gud_resume,
677 .reset_resume = gud_resume,
678};
679
680module_usb_driver(gud_usb_driver);
681
682MODULE_AUTHOR("Noralf Trønnes");
683MODULE_DESCRIPTION("GUD USB Display driver");
684MODULE_LICENSE("Dual MIT/GPL");