xref: /linux/drivers/gpu/drm/drm_connector.c (revision 80d443e8876602be2c130f79c4de81e12e2a700d)
1 /*
2  * Copyright (c) 2016 Intel Corporation
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that copyright
7  * notice and this permission notice appear in supporting documentation, and
8  * that the name of the copyright holders not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  The copyright holders make no representations
11  * about the suitability of this software for any purpose.  It is provided "as
12  * is" without express or implied warranty.
13  *
14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20  * OF THIS SOFTWARE.
21  */
22 
23 #include <drm/drmP.h>
24 #include <drm/drm_connector.h>
25 #include <drm/drm_edid.h>
26 
27 #include "drm_crtc_internal.h"
28 #include "drm_internal.h"
29 
30 /**
31  * DOC: overview
32  *
33  * In DRM connectors are the general abstraction for display sinks, and include
34  * als fixed panels or anything else that can display pixels in some form. As
35  * opposed to all other KMS objects representing hardware (like CRTC, encoder or
36  * plane abstractions) connectors can be hotplugged and unplugged at runtime.
37  * Hence they are reference-counted using drm_connector_reference() and
38  * drm_connector_unreference().
39  *
40  * KMS driver must create, initialize, register and attach at a struct
41  * &drm_connector for each such sink. The instance is created as other KMS
42  * objects and initialized by setting the following fields.
43  *
44  * The connector is then registered with a call to drm_connector_init() with a
45  * pointer to the connector functions and a connector type, and exposed through
46  * sysfs with a call to drm_connector_register().
47  *
48  * Connectors must be attached to an encoder to be used. For devices that map
49  * connectors to encoders 1:1, the connector should be attached at
50  * initialization time with a call to drm_mode_connector_attach_encoder(). The
51  * driver must also set the struct &drm_connector encoder field to point to the
52  * attached encoder.
53  *
54  * For connectors which are not fixed (like built-in panels) the driver needs to
55  * support hotplug notifications. The simplest way to do that is by using the
56  * probe helpers, see drm_kms_helper_poll_init() for connectors which don't have
57  * hardware support for hotplug interrupts. Connectors with hardware hotplug
58  * support can instead use e.g. drm_helper_hpd_irq_event().
59  */
60 
61 struct drm_conn_prop_enum_list {
62 	int type;
63 	const char *name;
64 	struct ida ida;
65 };
66 
67 /*
68  * Connector and encoder types.
69  */
70 static struct drm_conn_prop_enum_list drm_connector_enum_list[] = {
71 	{ DRM_MODE_CONNECTOR_Unknown, "Unknown" },
72 	{ DRM_MODE_CONNECTOR_VGA, "VGA" },
73 	{ DRM_MODE_CONNECTOR_DVII, "DVI-I" },
74 	{ DRM_MODE_CONNECTOR_DVID, "DVI-D" },
75 	{ DRM_MODE_CONNECTOR_DVIA, "DVI-A" },
76 	{ DRM_MODE_CONNECTOR_Composite, "Composite" },
77 	{ DRM_MODE_CONNECTOR_SVIDEO, "SVIDEO" },
78 	{ DRM_MODE_CONNECTOR_LVDS, "LVDS" },
79 	{ DRM_MODE_CONNECTOR_Component, "Component" },
80 	{ DRM_MODE_CONNECTOR_9PinDIN, "DIN" },
81 	{ DRM_MODE_CONNECTOR_DisplayPort, "DP" },
82 	{ DRM_MODE_CONNECTOR_HDMIA, "HDMI-A" },
83 	{ DRM_MODE_CONNECTOR_HDMIB, "HDMI-B" },
84 	{ DRM_MODE_CONNECTOR_TV, "TV" },
85 	{ DRM_MODE_CONNECTOR_eDP, "eDP" },
86 	{ DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },
87 	{ DRM_MODE_CONNECTOR_DSI, "DSI" },
88 	{ DRM_MODE_CONNECTOR_DPI, "DPI" },
89 };
90 
91 void drm_connector_ida_init(void)
92 {
93 	int i;
94 
95 	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
96 		ida_init(&drm_connector_enum_list[i].ida);
97 }
98 
99 void drm_connector_ida_destroy(void)
100 {
101 	int i;
102 
103 	for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
104 		ida_destroy(&drm_connector_enum_list[i].ida);
105 }
106 
107 /**
108  * drm_connector_get_cmdline_mode - reads the user's cmdline mode
109  * @connector: connector to quwery
110  *
111  * The kernel supports per-connector configuration of its consoles through
112  * use of the video= parameter. This function parses that option and
113  * extracts the user's specified mode (or enable/disable status) for a
114  * particular connector. This is typically only used during the early fbdev
115  * setup.
116  */
117 static void drm_connector_get_cmdline_mode(struct drm_connector *connector)
118 {
119 	struct drm_cmdline_mode *mode = &connector->cmdline_mode;
120 	char *option = NULL;
121 
122 	if (fb_get_options(connector->name, &option))
123 		return;
124 
125 	if (!drm_mode_parse_command_line_for_connector(option,
126 						       connector,
127 						       mode))
128 		return;
129 
130 	if (mode->force) {
131 		const char *s;
132 
133 		switch (mode->force) {
134 		case DRM_FORCE_OFF:
135 			s = "OFF";
136 			break;
137 		case DRM_FORCE_ON_DIGITAL:
138 			s = "ON - dig";
139 			break;
140 		default:
141 		case DRM_FORCE_ON:
142 			s = "ON";
143 			break;
144 		}
145 
146 		DRM_INFO("forcing %s connector %s\n", connector->name, s);
147 		connector->force = mode->force;
148 	}
149 
150 	DRM_DEBUG_KMS("cmdline mode for connector %s %dx%d@%dHz%s%s%s\n",
151 		      connector->name,
152 		      mode->xres, mode->yres,
153 		      mode->refresh_specified ? mode->refresh : 60,
154 		      mode->rb ? " reduced blanking" : "",
155 		      mode->margins ? " with margins" : "",
156 		      mode->interlace ?  " interlaced" : "");
157 }
158 
159 static void drm_connector_free(struct kref *kref)
160 {
161 	struct drm_connector *connector =
162 		container_of(kref, struct drm_connector, base.refcount);
163 	struct drm_device *dev = connector->dev;
164 
165 	drm_mode_object_unregister(dev, &connector->base);
166 	connector->funcs->destroy(connector);
167 }
168 
169 /**
170  * drm_connector_init - Init a preallocated connector
171  * @dev: DRM device
172  * @connector: the connector to init
173  * @funcs: callbacks for this connector
174  * @connector_type: user visible type of the connector
175  *
176  * Initialises a preallocated connector. Connectors should be
177  * subclassed as part of driver connector objects.
178  *
179  * Returns:
180  * Zero on success, error code on failure.
181  */
182 int drm_connector_init(struct drm_device *dev,
183 		       struct drm_connector *connector,
184 		       const struct drm_connector_funcs *funcs,
185 		       int connector_type)
186 {
187 	struct drm_mode_config *config = &dev->mode_config;
188 	int ret;
189 	struct ida *connector_ida =
190 		&drm_connector_enum_list[connector_type].ida;
191 
192 	drm_modeset_lock_all(dev);
193 
194 	ret = drm_mode_object_get_reg(dev, &connector->base,
195 				      DRM_MODE_OBJECT_CONNECTOR,
196 				      false, drm_connector_free);
197 	if (ret)
198 		goto out_unlock;
199 
200 	connector->base.properties = &connector->properties;
201 	connector->dev = dev;
202 	connector->funcs = funcs;
203 
204 	ret = ida_simple_get(&config->connector_ida, 0, 0, GFP_KERNEL);
205 	if (ret < 0)
206 		goto out_put;
207 	connector->index = ret;
208 	ret = 0;
209 
210 	connector->connector_type = connector_type;
211 	connector->connector_type_id =
212 		ida_simple_get(connector_ida, 1, 0, GFP_KERNEL);
213 	if (connector->connector_type_id < 0) {
214 		ret = connector->connector_type_id;
215 		goto out_put_id;
216 	}
217 	connector->name =
218 		kasprintf(GFP_KERNEL, "%s-%d",
219 			  drm_connector_enum_list[connector_type].name,
220 			  connector->connector_type_id);
221 	if (!connector->name) {
222 		ret = -ENOMEM;
223 		goto out_put_type_id;
224 	}
225 
226 	INIT_LIST_HEAD(&connector->probed_modes);
227 	INIT_LIST_HEAD(&connector->modes);
228 	connector->edid_blob_ptr = NULL;
229 	connector->status = connector_status_unknown;
230 
231 	drm_connector_get_cmdline_mode(connector);
232 
233 	/* We should add connectors at the end to avoid upsetting the connector
234 	 * index too much. */
235 	list_add_tail(&connector->head, &config->connector_list);
236 	config->num_connector++;
237 
238 	if (connector_type != DRM_MODE_CONNECTOR_VIRTUAL)
239 		drm_object_attach_property(&connector->base,
240 					      config->edid_property,
241 					      0);
242 
243 	drm_object_attach_property(&connector->base,
244 				      config->dpms_property, 0);
245 
246 	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
247 		drm_object_attach_property(&connector->base, config->prop_crtc_id, 0);
248 	}
249 
250 	connector->debugfs_entry = NULL;
251 out_put_type_id:
252 	if (ret)
253 		ida_simple_remove(connector_ida, connector->connector_type_id);
254 out_put_id:
255 	if (ret)
256 		ida_simple_remove(&config->connector_ida, connector->index);
257 out_put:
258 	if (ret)
259 		drm_mode_object_unregister(dev, &connector->base);
260 
261 out_unlock:
262 	drm_modeset_unlock_all(dev);
263 
264 	return ret;
265 }
266 EXPORT_SYMBOL(drm_connector_init);
267 
268 /**
269  * drm_mode_connector_attach_encoder - attach a connector to an encoder
270  * @connector: connector to attach
271  * @encoder: encoder to attach @connector to
272  *
273  * This function links up a connector to an encoder. Note that the routing
274  * restrictions between encoders and crtcs are exposed to userspace through the
275  * possible_clones and possible_crtcs bitmasks.
276  *
277  * Returns:
278  * Zero on success, negative errno on failure.
279  */
280 int drm_mode_connector_attach_encoder(struct drm_connector *connector,
281 				      struct drm_encoder *encoder)
282 {
283 	int i;
284 
285 	/*
286 	 * In the past, drivers have attempted to model the static association
287 	 * of connector to encoder in simple connector/encoder devices using a
288 	 * direct assignment of connector->encoder = encoder. This connection
289 	 * is a logical one and the responsibility of the core, so drivers are
290 	 * expected not to mess with this.
291 	 *
292 	 * Note that the error return should've been enough here, but a large
293 	 * majority of drivers ignores the return value, so add in a big WARN
294 	 * to get people's attention.
295 	 */
296 	if (WARN_ON(connector->encoder))
297 		return -EINVAL;
298 
299 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
300 		if (connector->encoder_ids[i] == 0) {
301 			connector->encoder_ids[i] = encoder->base.id;
302 			return 0;
303 		}
304 	}
305 	return -ENOMEM;
306 }
307 EXPORT_SYMBOL(drm_mode_connector_attach_encoder);
308 
309 static void drm_mode_remove(struct drm_connector *connector,
310 			    struct drm_display_mode *mode)
311 {
312 	list_del(&mode->head);
313 	drm_mode_destroy(connector->dev, mode);
314 }
315 
316 /**
317  * drm_connector_cleanup - cleans up an initialised connector
318  * @connector: connector to cleanup
319  *
320  * Cleans up the connector but doesn't free the object.
321  */
322 void drm_connector_cleanup(struct drm_connector *connector)
323 {
324 	struct drm_device *dev = connector->dev;
325 	struct drm_display_mode *mode, *t;
326 
327 	/* The connector should have been removed from userspace long before
328 	 * it is finally destroyed.
329 	 */
330 	if (WARN_ON(connector->registered))
331 		drm_connector_unregister(connector);
332 
333 	if (connector->tile_group) {
334 		drm_mode_put_tile_group(dev, connector->tile_group);
335 		connector->tile_group = NULL;
336 	}
337 
338 	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
339 		drm_mode_remove(connector, mode);
340 
341 	list_for_each_entry_safe(mode, t, &connector->modes, head)
342 		drm_mode_remove(connector, mode);
343 
344 	ida_simple_remove(&drm_connector_enum_list[connector->connector_type].ida,
345 			  connector->connector_type_id);
346 
347 	ida_simple_remove(&dev->mode_config.connector_ida,
348 			  connector->index);
349 
350 	kfree(connector->display_info.bus_formats);
351 	drm_mode_object_unregister(dev, &connector->base);
352 	kfree(connector->name);
353 	connector->name = NULL;
354 	list_del(&connector->head);
355 	dev->mode_config.num_connector--;
356 
357 	WARN_ON(connector->state && !connector->funcs->atomic_destroy_state);
358 	if (connector->state && connector->funcs->atomic_destroy_state)
359 		connector->funcs->atomic_destroy_state(connector,
360 						       connector->state);
361 
362 	memset(connector, 0, sizeof(*connector));
363 }
364 EXPORT_SYMBOL(drm_connector_cleanup);
365 
366 /**
367  * drm_connector_register - register a connector
368  * @connector: the connector to register
369  *
370  * Register userspace interfaces for a connector
371  *
372  * Returns:
373  * Zero on success, error code on failure.
374  */
375 int drm_connector_register(struct drm_connector *connector)
376 {
377 	int ret;
378 
379 	if (connector->registered)
380 		return 0;
381 
382 	ret = drm_sysfs_connector_add(connector);
383 	if (ret)
384 		return ret;
385 
386 	ret = drm_debugfs_connector_add(connector);
387 	if (ret) {
388 		goto err_sysfs;
389 	}
390 
391 	if (connector->funcs->late_register) {
392 		ret = connector->funcs->late_register(connector);
393 		if (ret)
394 			goto err_debugfs;
395 	}
396 
397 	drm_mode_object_register(connector->dev, &connector->base);
398 
399 	connector->registered = true;
400 	return 0;
401 
402 err_debugfs:
403 	drm_debugfs_connector_remove(connector);
404 err_sysfs:
405 	drm_sysfs_connector_remove(connector);
406 	return ret;
407 }
408 EXPORT_SYMBOL(drm_connector_register);
409 
410 /**
411  * drm_connector_unregister - unregister a connector
412  * @connector: the connector to unregister
413  *
414  * Unregister userspace interfaces for a connector
415  */
416 void drm_connector_unregister(struct drm_connector *connector)
417 {
418 	if (!connector->registered)
419 		return;
420 
421 	if (connector->funcs->early_unregister)
422 		connector->funcs->early_unregister(connector);
423 
424 	drm_sysfs_connector_remove(connector);
425 	drm_debugfs_connector_remove(connector);
426 
427 	connector->registered = false;
428 }
429 EXPORT_SYMBOL(drm_connector_unregister);
430 
431 void drm_connector_unregister_all(struct drm_device *dev)
432 {
433 	struct drm_connector *connector;
434 
435 	/* FIXME: taking the mode config mutex ends up in a clash with sysfs */
436 	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
437 		drm_connector_unregister(connector);
438 }
439 
440 int drm_connector_register_all(struct drm_device *dev)
441 {
442 	struct drm_connector *connector;
443 	int ret;
444 
445 	/* FIXME: taking the mode config mutex ends up in a clash with
446 	 * fbcon/backlight registration */
447 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
448 		ret = drm_connector_register(connector);
449 		if (ret)
450 			goto err;
451 	}
452 
453 	return 0;
454 
455 err:
456 	mutex_unlock(&dev->mode_config.mutex);
457 	drm_connector_unregister_all(dev);
458 	return ret;
459 }
460 
461 /**
462  * drm_get_connector_status_name - return a string for connector status
463  * @status: connector status to compute name of
464  *
465  * In contrast to the other drm_get_*_name functions this one here returns a
466  * const pointer and hence is threadsafe.
467  */
468 const char *drm_get_connector_status_name(enum drm_connector_status status)
469 {
470 	if (status == connector_status_connected)
471 		return "connected";
472 	else if (status == connector_status_disconnected)
473 		return "disconnected";
474 	else
475 		return "unknown";
476 }
477 EXPORT_SYMBOL(drm_get_connector_status_name);
478 
479 static const struct drm_prop_enum_list drm_subpixel_enum_list[] = {
480 	{ SubPixelUnknown, "Unknown" },
481 	{ SubPixelHorizontalRGB, "Horizontal RGB" },
482 	{ SubPixelHorizontalBGR, "Horizontal BGR" },
483 	{ SubPixelVerticalRGB, "Vertical RGB" },
484 	{ SubPixelVerticalBGR, "Vertical BGR" },
485 	{ SubPixelNone, "None" },
486 };
487 
488 /**
489  * drm_get_subpixel_order_name - return a string for a given subpixel enum
490  * @order: enum of subpixel_order
491  *
492  * Note you could abuse this and return something out of bounds, but that
493  * would be a caller error.  No unscrubbed user data should make it here.
494  */
495 const char *drm_get_subpixel_order_name(enum subpixel_order order)
496 {
497 	return drm_subpixel_enum_list[order].name;
498 }
499 EXPORT_SYMBOL(drm_get_subpixel_order_name);
500 
501 static const struct drm_prop_enum_list drm_dpms_enum_list[] = {
502 	{ DRM_MODE_DPMS_ON, "On" },
503 	{ DRM_MODE_DPMS_STANDBY, "Standby" },
504 	{ DRM_MODE_DPMS_SUSPEND, "Suspend" },
505 	{ DRM_MODE_DPMS_OFF, "Off" }
506 };
507 DRM_ENUM_NAME_FN(drm_get_dpms_name, drm_dpms_enum_list)
508 
509 /**
510  * drm_display_info_set_bus_formats - set the supported bus formats
511  * @info: display info to store bus formats in
512  * @formats: array containing the supported bus formats
513  * @num_formats: the number of entries in the fmts array
514  *
515  * Store the supported bus formats in display info structure.
516  * See MEDIA_BUS_FMT_* definitions in include/uapi/linux/media-bus-format.h for
517  * a full list of available formats.
518  */
519 int drm_display_info_set_bus_formats(struct drm_display_info *info,
520 				     const u32 *formats,
521 				     unsigned int num_formats)
522 {
523 	u32 *fmts = NULL;
524 
525 	if (!formats && num_formats)
526 		return -EINVAL;
527 
528 	if (formats && num_formats) {
529 		fmts = kmemdup(formats, sizeof(*formats) * num_formats,
530 			       GFP_KERNEL);
531 		if (!fmts)
532 			return -ENOMEM;
533 	}
534 
535 	kfree(info->bus_formats);
536 	info->bus_formats = fmts;
537 	info->num_bus_formats = num_formats;
538 
539 	return 0;
540 }
541 EXPORT_SYMBOL(drm_display_info_set_bus_formats);
542 
543 /* Optional connector properties. */
544 static const struct drm_prop_enum_list drm_scaling_mode_enum_list[] = {
545 	{ DRM_MODE_SCALE_NONE, "None" },
546 	{ DRM_MODE_SCALE_FULLSCREEN, "Full" },
547 	{ DRM_MODE_SCALE_CENTER, "Center" },
548 	{ DRM_MODE_SCALE_ASPECT, "Full aspect" },
549 };
550 
551 static const struct drm_prop_enum_list drm_aspect_ratio_enum_list[] = {
552 	{ DRM_MODE_PICTURE_ASPECT_NONE, "Automatic" },
553 	{ DRM_MODE_PICTURE_ASPECT_4_3, "4:3" },
554 	{ DRM_MODE_PICTURE_ASPECT_16_9, "16:9" },
555 };
556 
557 static const struct drm_prop_enum_list drm_dvi_i_select_enum_list[] = {
558 	{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
559 	{ DRM_MODE_SUBCONNECTOR_DVID,      "DVI-D"     }, /* DVI-I  */
560 	{ DRM_MODE_SUBCONNECTOR_DVIA,      "DVI-A"     }, /* DVI-I  */
561 };
562 DRM_ENUM_NAME_FN(drm_get_dvi_i_select_name, drm_dvi_i_select_enum_list)
563 
564 static const struct drm_prop_enum_list drm_dvi_i_subconnector_enum_list[] = {
565 	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
566 	{ DRM_MODE_SUBCONNECTOR_DVID,      "DVI-D"     }, /* DVI-I  */
567 	{ DRM_MODE_SUBCONNECTOR_DVIA,      "DVI-A"     }, /* DVI-I  */
568 };
569 DRM_ENUM_NAME_FN(drm_get_dvi_i_subconnector_name,
570 		 drm_dvi_i_subconnector_enum_list)
571 
572 static const struct drm_prop_enum_list drm_tv_select_enum_list[] = {
573 	{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
574 	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
575 	{ DRM_MODE_SUBCONNECTOR_SVIDEO,    "SVIDEO"    }, /* TV-out */
576 	{ DRM_MODE_SUBCONNECTOR_Component, "Component" }, /* TV-out */
577 	{ DRM_MODE_SUBCONNECTOR_SCART,     "SCART"     }, /* TV-out */
578 };
579 DRM_ENUM_NAME_FN(drm_get_tv_select_name, drm_tv_select_enum_list)
580 
581 static const struct drm_prop_enum_list drm_tv_subconnector_enum_list[] = {
582 	{ DRM_MODE_SUBCONNECTOR_Unknown,   "Unknown"   }, /* DVI-I and TV-out */
583 	{ DRM_MODE_SUBCONNECTOR_Composite, "Composite" }, /* TV-out */
584 	{ DRM_MODE_SUBCONNECTOR_SVIDEO,    "SVIDEO"    }, /* TV-out */
585 	{ DRM_MODE_SUBCONNECTOR_Component, "Component" }, /* TV-out */
586 	{ DRM_MODE_SUBCONNECTOR_SCART,     "SCART"     }, /* TV-out */
587 };
588 DRM_ENUM_NAME_FN(drm_get_tv_subconnector_name,
589 		 drm_tv_subconnector_enum_list)
590 
591 /**
592  * DOC: standard connector properties
593  *
594  * DRM connectors have a few standardized properties:
595  *
596  * EDID:
597  * 	Blob property which contains the current EDID read from the sink. This
598  * 	is useful to parse sink identification information like vendor, model
599  * 	and serial. Drivers should update this property by calling
600  * 	drm_mode_connector_update_edid_property(), usually after having parsed
601  * 	the EDID using drm_add_edid_modes(). Userspace cannot change this
602  * 	property.
603  * DPMS:
604  * 	Legacy property for setting the power state of the connector. For atomic
605  * 	drivers this is only provided for backwards compatibility with existing
606  * 	drivers, it remaps to controlling the "ACTIVE" property on the CRTC the
607  * 	connector is linked to. Drivers should never set this property directly,
608  * 	it is handled by the DRM core by calling the ->dpms() callback in
609  * 	&drm_connector_funcs. Atomic drivers should implement this hook using
610  * 	drm_atomic_helper_connector_dpms(). This is the only property standard
611  * 	connector property that userspace can change.
612  * PATH:
613  * 	Connector path property to identify how this sink is physically
614  * 	connected. Used by DP MST. This should be set by calling
615  * 	drm_mode_connector_set_path_property(), in the case of DP MST with the
616  * 	path property the MST manager created. Userspace cannot change this
617  * 	property.
618  * TILE:
619  * 	Connector tile group property to indicate how a set of DRM connector
620  * 	compose together into one logical screen. This is used by both high-res
621  * 	external screens (often only using a single cable, but exposing multiple
622  * 	DP MST sinks), or high-res integrated panels (like dual-link DSI) which
623  * 	are not gen-locked. Note that for tiled panels which are genlocked, like
624  * 	dual-link LVDS or dual-link DSI, the driver should try to not expose the
625  * 	tiling and virtualize both &drm_crtc and &drm_plane if needed. Drivers
626  * 	should update this value using drm_mode_connector_set_tile_property().
627  * 	Userspace cannot change this property.
628  *
629  * Connectors also have one standardized atomic property:
630  *
631  * CRTC_ID:
632  * 	Mode object ID of the &drm_crtc this connector should be connected to.
633  */
634 
635 int drm_connector_create_standard_properties(struct drm_device *dev)
636 {
637 	struct drm_property *prop;
638 
639 	prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
640 				   DRM_MODE_PROP_IMMUTABLE,
641 				   "EDID", 0);
642 	if (!prop)
643 		return -ENOMEM;
644 	dev->mode_config.edid_property = prop;
645 
646 	prop = drm_property_create_enum(dev, 0,
647 				   "DPMS", drm_dpms_enum_list,
648 				   ARRAY_SIZE(drm_dpms_enum_list));
649 	if (!prop)
650 		return -ENOMEM;
651 	dev->mode_config.dpms_property = prop;
652 
653 	prop = drm_property_create(dev,
654 				   DRM_MODE_PROP_BLOB |
655 				   DRM_MODE_PROP_IMMUTABLE,
656 				   "PATH", 0);
657 	if (!prop)
658 		return -ENOMEM;
659 	dev->mode_config.path_property = prop;
660 
661 	prop = drm_property_create(dev,
662 				   DRM_MODE_PROP_BLOB |
663 				   DRM_MODE_PROP_IMMUTABLE,
664 				   "TILE", 0);
665 	if (!prop)
666 		return -ENOMEM;
667 	dev->mode_config.tile_property = prop;
668 
669 	return 0;
670 }
671 
672 /**
673  * drm_mode_create_dvi_i_properties - create DVI-I specific connector properties
674  * @dev: DRM device
675  *
676  * Called by a driver the first time a DVI-I connector is made.
677  */
678 int drm_mode_create_dvi_i_properties(struct drm_device *dev)
679 {
680 	struct drm_property *dvi_i_selector;
681 	struct drm_property *dvi_i_subconnector;
682 
683 	if (dev->mode_config.dvi_i_select_subconnector_property)
684 		return 0;
685 
686 	dvi_i_selector =
687 		drm_property_create_enum(dev, 0,
688 				    "select subconnector",
689 				    drm_dvi_i_select_enum_list,
690 				    ARRAY_SIZE(drm_dvi_i_select_enum_list));
691 	dev->mode_config.dvi_i_select_subconnector_property = dvi_i_selector;
692 
693 	dvi_i_subconnector = drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
694 				    "subconnector",
695 				    drm_dvi_i_subconnector_enum_list,
696 				    ARRAY_SIZE(drm_dvi_i_subconnector_enum_list));
697 	dev->mode_config.dvi_i_subconnector_property = dvi_i_subconnector;
698 
699 	return 0;
700 }
701 EXPORT_SYMBOL(drm_mode_create_dvi_i_properties);
702 
703 /**
704  * drm_create_tv_properties - create TV specific connector properties
705  * @dev: DRM device
706  * @num_modes: number of different TV formats (modes) supported
707  * @modes: array of pointers to strings containing name of each format
708  *
709  * Called by a driver's TV initialization routine, this function creates
710  * the TV specific connector properties for a given device.  Caller is
711  * responsible for allocating a list of format names and passing them to
712  * this routine.
713  */
714 int drm_mode_create_tv_properties(struct drm_device *dev,
715 				  unsigned int num_modes,
716 				  const char * const modes[])
717 {
718 	struct drm_property *tv_selector;
719 	struct drm_property *tv_subconnector;
720 	unsigned int i;
721 
722 	if (dev->mode_config.tv_select_subconnector_property)
723 		return 0;
724 
725 	/*
726 	 * Basic connector properties
727 	 */
728 	tv_selector = drm_property_create_enum(dev, 0,
729 					  "select subconnector",
730 					  drm_tv_select_enum_list,
731 					  ARRAY_SIZE(drm_tv_select_enum_list));
732 	if (!tv_selector)
733 		goto nomem;
734 
735 	dev->mode_config.tv_select_subconnector_property = tv_selector;
736 
737 	tv_subconnector =
738 		drm_property_create_enum(dev, DRM_MODE_PROP_IMMUTABLE,
739 				    "subconnector",
740 				    drm_tv_subconnector_enum_list,
741 				    ARRAY_SIZE(drm_tv_subconnector_enum_list));
742 	if (!tv_subconnector)
743 		goto nomem;
744 	dev->mode_config.tv_subconnector_property = tv_subconnector;
745 
746 	/*
747 	 * Other, TV specific properties: margins & TV modes.
748 	 */
749 	dev->mode_config.tv_left_margin_property =
750 		drm_property_create_range(dev, 0, "left margin", 0, 100);
751 	if (!dev->mode_config.tv_left_margin_property)
752 		goto nomem;
753 
754 	dev->mode_config.tv_right_margin_property =
755 		drm_property_create_range(dev, 0, "right margin", 0, 100);
756 	if (!dev->mode_config.tv_right_margin_property)
757 		goto nomem;
758 
759 	dev->mode_config.tv_top_margin_property =
760 		drm_property_create_range(dev, 0, "top margin", 0, 100);
761 	if (!dev->mode_config.tv_top_margin_property)
762 		goto nomem;
763 
764 	dev->mode_config.tv_bottom_margin_property =
765 		drm_property_create_range(dev, 0, "bottom margin", 0, 100);
766 	if (!dev->mode_config.tv_bottom_margin_property)
767 		goto nomem;
768 
769 	dev->mode_config.tv_mode_property =
770 		drm_property_create(dev, DRM_MODE_PROP_ENUM,
771 				    "mode", num_modes);
772 	if (!dev->mode_config.tv_mode_property)
773 		goto nomem;
774 
775 	for (i = 0; i < num_modes; i++)
776 		drm_property_add_enum(dev->mode_config.tv_mode_property, i,
777 				      i, modes[i]);
778 
779 	dev->mode_config.tv_brightness_property =
780 		drm_property_create_range(dev, 0, "brightness", 0, 100);
781 	if (!dev->mode_config.tv_brightness_property)
782 		goto nomem;
783 
784 	dev->mode_config.tv_contrast_property =
785 		drm_property_create_range(dev, 0, "contrast", 0, 100);
786 	if (!dev->mode_config.tv_contrast_property)
787 		goto nomem;
788 
789 	dev->mode_config.tv_flicker_reduction_property =
790 		drm_property_create_range(dev, 0, "flicker reduction", 0, 100);
791 	if (!dev->mode_config.tv_flicker_reduction_property)
792 		goto nomem;
793 
794 	dev->mode_config.tv_overscan_property =
795 		drm_property_create_range(dev, 0, "overscan", 0, 100);
796 	if (!dev->mode_config.tv_overscan_property)
797 		goto nomem;
798 
799 	dev->mode_config.tv_saturation_property =
800 		drm_property_create_range(dev, 0, "saturation", 0, 100);
801 	if (!dev->mode_config.tv_saturation_property)
802 		goto nomem;
803 
804 	dev->mode_config.tv_hue_property =
805 		drm_property_create_range(dev, 0, "hue", 0, 100);
806 	if (!dev->mode_config.tv_hue_property)
807 		goto nomem;
808 
809 	return 0;
810 nomem:
811 	return -ENOMEM;
812 }
813 EXPORT_SYMBOL(drm_mode_create_tv_properties);
814 
815 /**
816  * drm_mode_create_scaling_mode_property - create scaling mode property
817  * @dev: DRM device
818  *
819  * Called by a driver the first time it's needed, must be attached to desired
820  * connectors.
821  */
822 int drm_mode_create_scaling_mode_property(struct drm_device *dev)
823 {
824 	struct drm_property *scaling_mode;
825 
826 	if (dev->mode_config.scaling_mode_property)
827 		return 0;
828 
829 	scaling_mode =
830 		drm_property_create_enum(dev, 0, "scaling mode",
831 				drm_scaling_mode_enum_list,
832 				    ARRAY_SIZE(drm_scaling_mode_enum_list));
833 
834 	dev->mode_config.scaling_mode_property = scaling_mode;
835 
836 	return 0;
837 }
838 EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);
839 
840 /**
841  * drm_mode_create_aspect_ratio_property - create aspect ratio property
842  * @dev: DRM device
843  *
844  * Called by a driver the first time it's needed, must be attached to desired
845  * connectors.
846  *
847  * Returns:
848  * Zero on success, negative errno on failure.
849  */
850 int drm_mode_create_aspect_ratio_property(struct drm_device *dev)
851 {
852 	if (dev->mode_config.aspect_ratio_property)
853 		return 0;
854 
855 	dev->mode_config.aspect_ratio_property =
856 		drm_property_create_enum(dev, 0, "aspect ratio",
857 				drm_aspect_ratio_enum_list,
858 				ARRAY_SIZE(drm_aspect_ratio_enum_list));
859 
860 	if (dev->mode_config.aspect_ratio_property == NULL)
861 		return -ENOMEM;
862 
863 	return 0;
864 }
865 EXPORT_SYMBOL(drm_mode_create_aspect_ratio_property);
866 
867 /**
868  * drm_mode_create_suggested_offset_properties - create suggests offset properties
869  * @dev: DRM device
870  *
871  * Create the the suggested x/y offset property for connectors.
872  */
873 int drm_mode_create_suggested_offset_properties(struct drm_device *dev)
874 {
875 	if (dev->mode_config.suggested_x_property && dev->mode_config.suggested_y_property)
876 		return 0;
877 
878 	dev->mode_config.suggested_x_property =
879 		drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "suggested X", 0, 0xffffffff);
880 
881 	dev->mode_config.suggested_y_property =
882 		drm_property_create_range(dev, DRM_MODE_PROP_IMMUTABLE, "suggested Y", 0, 0xffffffff);
883 
884 	if (dev->mode_config.suggested_x_property == NULL ||
885 	    dev->mode_config.suggested_y_property == NULL)
886 		return -ENOMEM;
887 	return 0;
888 }
889 EXPORT_SYMBOL(drm_mode_create_suggested_offset_properties);
890 
891 /**
892  * drm_mode_connector_set_path_property - set tile property on connector
893  * @connector: connector to set property on.
894  * @path: path to use for property; must not be NULL.
895  *
896  * This creates a property to expose to userspace to specify a
897  * connector path. This is mainly used for DisplayPort MST where
898  * connectors have a topology and we want to allow userspace to give
899  * them more meaningful names.
900  *
901  * Returns:
902  * Zero on success, negative errno on failure.
903  */
904 int drm_mode_connector_set_path_property(struct drm_connector *connector,
905 					 const char *path)
906 {
907 	struct drm_device *dev = connector->dev;
908 	int ret;
909 
910 	ret = drm_property_replace_global_blob(dev,
911 	                                       &connector->path_blob_ptr,
912 	                                       strlen(path) + 1,
913 	                                       path,
914 	                                       &connector->base,
915 	                                       dev->mode_config.path_property);
916 	return ret;
917 }
918 EXPORT_SYMBOL(drm_mode_connector_set_path_property);
919 
920 /**
921  * drm_mode_connector_set_tile_property - set tile property on connector
922  * @connector: connector to set property on.
923  *
924  * This looks up the tile information for a connector, and creates a
925  * property for userspace to parse if it exists. The property is of
926  * the form of 8 integers using ':' as a separator.
927  *
928  * Returns:
929  * Zero on success, errno on failure.
930  */
931 int drm_mode_connector_set_tile_property(struct drm_connector *connector)
932 {
933 	struct drm_device *dev = connector->dev;
934 	char tile[256];
935 	int ret;
936 
937 	if (!connector->has_tile) {
938 		ret  = drm_property_replace_global_blob(dev,
939 		                                        &connector->tile_blob_ptr,
940 		                                        0,
941 		                                        NULL,
942 		                                        &connector->base,
943 		                                        dev->mode_config.tile_property);
944 		return ret;
945 	}
946 
947 	snprintf(tile, 256, "%d:%d:%d:%d:%d:%d:%d:%d",
948 		 connector->tile_group->id, connector->tile_is_single_monitor,
949 		 connector->num_h_tile, connector->num_v_tile,
950 		 connector->tile_h_loc, connector->tile_v_loc,
951 		 connector->tile_h_size, connector->tile_v_size);
952 
953 	ret = drm_property_replace_global_blob(dev,
954 	                                       &connector->tile_blob_ptr,
955 	                                       strlen(tile) + 1,
956 	                                       tile,
957 	                                       &connector->base,
958 	                                       dev->mode_config.tile_property);
959 	return ret;
960 }
961 EXPORT_SYMBOL(drm_mode_connector_set_tile_property);
962 
963 /**
964  * drm_mode_connector_update_edid_property - update the edid property of a connector
965  * @connector: drm connector
966  * @edid: new value of the edid property
967  *
968  * This function creates a new blob modeset object and assigns its id to the
969  * connector's edid property.
970  *
971  * Returns:
972  * Zero on success, negative errno on failure.
973  */
974 int drm_mode_connector_update_edid_property(struct drm_connector *connector,
975 					    const struct edid *edid)
976 {
977 	struct drm_device *dev = connector->dev;
978 	size_t size = 0;
979 	int ret;
980 
981 	/* ignore requests to set edid when overridden */
982 	if (connector->override_edid)
983 		return 0;
984 
985 	if (edid)
986 		size = EDID_LENGTH * (1 + edid->extensions);
987 
988 	ret = drm_property_replace_global_blob(dev,
989 					       &connector->edid_blob_ptr,
990 	                                       size,
991 	                                       edid,
992 	                                       &connector->base,
993 	                                       dev->mode_config.edid_property);
994 	return ret;
995 }
996 EXPORT_SYMBOL(drm_mode_connector_update_edid_property);
997 
998 int drm_mode_connector_set_obj_prop(struct drm_mode_object *obj,
999 				    struct drm_property *property,
1000 				    uint64_t value)
1001 {
1002 	int ret = -EINVAL;
1003 	struct drm_connector *connector = obj_to_connector(obj);
1004 
1005 	/* Do DPMS ourselves */
1006 	if (property == connector->dev->mode_config.dpms_property) {
1007 		ret = (*connector->funcs->dpms)(connector, (int)value);
1008 	} else if (connector->funcs->set_property)
1009 		ret = connector->funcs->set_property(connector, property, value);
1010 
1011 	/* store the property value if successful */
1012 	if (!ret)
1013 		drm_object_property_set_value(&connector->base, property, value);
1014 	return ret;
1015 }
1016 
1017 int drm_mode_connector_property_set_ioctl(struct drm_device *dev,
1018 				       void *data, struct drm_file *file_priv)
1019 {
1020 	struct drm_mode_connector_set_property *conn_set_prop = data;
1021 	struct drm_mode_obj_set_property obj_set_prop = {
1022 		.value = conn_set_prop->value,
1023 		.prop_id = conn_set_prop->prop_id,
1024 		.obj_id = conn_set_prop->connector_id,
1025 		.obj_type = DRM_MODE_OBJECT_CONNECTOR
1026 	};
1027 
1028 	/* It does all the locking and checking we need */
1029 	return drm_mode_obj_set_property_ioctl(dev, &obj_set_prop, file_priv);
1030 }
1031 
1032 static struct drm_encoder *drm_connector_get_encoder(struct drm_connector *connector)
1033 {
1034 	/* For atomic drivers only state objects are synchronously updated and
1035 	 * protected by modeset locks, so check those first. */
1036 	if (connector->state)
1037 		return connector->state->best_encoder;
1038 	return connector->encoder;
1039 }
1040 
1041 static bool drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
1042 					 const struct drm_file *file_priv)
1043 {
1044 	/*
1045 	 * If user-space hasn't configured the driver to expose the stereo 3D
1046 	 * modes, don't expose them.
1047 	 */
1048 	if (!file_priv->stereo_allowed && drm_mode_is_stereo(mode))
1049 		return false;
1050 
1051 	return true;
1052 }
1053 
1054 int drm_mode_getconnector(struct drm_device *dev, void *data,
1055 			  struct drm_file *file_priv)
1056 {
1057 	struct drm_mode_get_connector *out_resp = data;
1058 	struct drm_connector *connector;
1059 	struct drm_encoder *encoder;
1060 	struct drm_display_mode *mode;
1061 	int mode_count = 0;
1062 	int encoders_count = 0;
1063 	int ret = 0;
1064 	int copied = 0;
1065 	int i;
1066 	struct drm_mode_modeinfo u_mode;
1067 	struct drm_mode_modeinfo __user *mode_ptr;
1068 	uint32_t __user *encoder_ptr;
1069 
1070 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
1071 		return -EINVAL;
1072 
1073 	memset(&u_mode, 0, sizeof(struct drm_mode_modeinfo));
1074 
1075 	mutex_lock(&dev->mode_config.mutex);
1076 
1077 	connector = drm_connector_lookup(dev, out_resp->connector_id);
1078 	if (!connector) {
1079 		ret = -ENOENT;
1080 		goto out_unlock;
1081 	}
1082 
1083 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
1084 		if (connector->encoder_ids[i] != 0)
1085 			encoders_count++;
1086 
1087 	if (out_resp->count_modes == 0) {
1088 		connector->funcs->fill_modes(connector,
1089 					     dev->mode_config.max_width,
1090 					     dev->mode_config.max_height);
1091 	}
1092 
1093 	/* delayed so we get modes regardless of pre-fill_modes state */
1094 	list_for_each_entry(mode, &connector->modes, head)
1095 		if (drm_mode_expose_to_userspace(mode, file_priv))
1096 			mode_count++;
1097 
1098 	out_resp->connector_id = connector->base.id;
1099 	out_resp->connector_type = connector->connector_type;
1100 	out_resp->connector_type_id = connector->connector_type_id;
1101 	out_resp->mm_width = connector->display_info.width_mm;
1102 	out_resp->mm_height = connector->display_info.height_mm;
1103 	out_resp->subpixel = connector->display_info.subpixel_order;
1104 	out_resp->connection = connector->status;
1105 
1106 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
1107 	encoder = drm_connector_get_encoder(connector);
1108 	if (encoder)
1109 		out_resp->encoder_id = encoder->base.id;
1110 	else
1111 		out_resp->encoder_id = 0;
1112 
1113 	/*
1114 	 * This ioctl is called twice, once to determine how much space is
1115 	 * needed, and the 2nd time to fill it.
1116 	 */
1117 	if ((out_resp->count_modes >= mode_count) && mode_count) {
1118 		copied = 0;
1119 		mode_ptr = (struct drm_mode_modeinfo __user *)(unsigned long)out_resp->modes_ptr;
1120 		list_for_each_entry(mode, &connector->modes, head) {
1121 			if (!drm_mode_expose_to_userspace(mode, file_priv))
1122 				continue;
1123 
1124 			drm_mode_convert_to_umode(&u_mode, mode);
1125 			if (copy_to_user(mode_ptr + copied,
1126 					 &u_mode, sizeof(u_mode))) {
1127 				ret = -EFAULT;
1128 				goto out;
1129 			}
1130 			copied++;
1131 		}
1132 	}
1133 	out_resp->count_modes = mode_count;
1134 
1135 	ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
1136 			(uint32_t __user *)(unsigned long)(out_resp->props_ptr),
1137 			(uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
1138 			&out_resp->count_props);
1139 	if (ret)
1140 		goto out;
1141 
1142 	if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
1143 		copied = 0;
1144 		encoder_ptr = (uint32_t __user *)(unsigned long)(out_resp->encoders_ptr);
1145 		for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
1146 			if (connector->encoder_ids[i] != 0) {
1147 				if (put_user(connector->encoder_ids[i],
1148 					     encoder_ptr + copied)) {
1149 					ret = -EFAULT;
1150 					goto out;
1151 				}
1152 				copied++;
1153 			}
1154 		}
1155 	}
1156 	out_resp->count_encoders = encoders_count;
1157 
1158 out:
1159 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
1160 
1161 	drm_connector_unreference(connector);
1162 out_unlock:
1163 	mutex_unlock(&dev->mode_config.mutex);
1164 
1165 	return ret;
1166 }
1167 
1168 
1169 /**
1170  * DOC: Tile group
1171  *
1172  * Tile groups are used to represent tiled monitors with a unique integer
1173  * identifier. Tiled monitors using DisplayID v1.3 have a unique 8-byte handle,
1174  * we store this in a tile group, so we have a common identifier for all tiles
1175  * in a monitor group. The property is called "TILE". Drivers can manage tile
1176  * groups using drm_mode_create_tile_group(), drm_mode_put_tile_group() and
1177  * drm_mode_get_tile_group(). But this is only needed for internal panels where
1178  * the tile group information is exposed through a non-standard way.
1179  */
1180 
1181 static void drm_tile_group_free(struct kref *kref)
1182 {
1183 	struct drm_tile_group *tg = container_of(kref, struct drm_tile_group, refcount);
1184 	struct drm_device *dev = tg->dev;
1185 	mutex_lock(&dev->mode_config.idr_mutex);
1186 	idr_remove(&dev->mode_config.tile_idr, tg->id);
1187 	mutex_unlock(&dev->mode_config.idr_mutex);
1188 	kfree(tg);
1189 }
1190 
1191 /**
1192  * drm_mode_put_tile_group - drop a reference to a tile group.
1193  * @dev: DRM device
1194  * @tg: tile group to drop reference to.
1195  *
1196  * drop reference to tile group and free if 0.
1197  */
1198 void drm_mode_put_tile_group(struct drm_device *dev,
1199 			     struct drm_tile_group *tg)
1200 {
1201 	kref_put(&tg->refcount, drm_tile_group_free);
1202 }
1203 EXPORT_SYMBOL(drm_mode_put_tile_group);
1204 
1205 /**
1206  * drm_mode_get_tile_group - get a reference to an existing tile group
1207  * @dev: DRM device
1208  * @topology: 8-bytes unique per monitor.
1209  *
1210  * Use the unique bytes to get a reference to an existing tile group.
1211  *
1212  * RETURNS:
1213  * tile group or NULL if not found.
1214  */
1215 struct drm_tile_group *drm_mode_get_tile_group(struct drm_device *dev,
1216 					       char topology[8])
1217 {
1218 	struct drm_tile_group *tg;
1219 	int id;
1220 	mutex_lock(&dev->mode_config.idr_mutex);
1221 	idr_for_each_entry(&dev->mode_config.tile_idr, tg, id) {
1222 		if (!memcmp(tg->group_data, topology, 8)) {
1223 			if (!kref_get_unless_zero(&tg->refcount))
1224 				tg = NULL;
1225 			mutex_unlock(&dev->mode_config.idr_mutex);
1226 			return tg;
1227 		}
1228 	}
1229 	mutex_unlock(&dev->mode_config.idr_mutex);
1230 	return NULL;
1231 }
1232 EXPORT_SYMBOL(drm_mode_get_tile_group);
1233 
1234 /**
1235  * drm_mode_create_tile_group - create a tile group from a displayid description
1236  * @dev: DRM device
1237  * @topology: 8-bytes unique per monitor.
1238  *
1239  * Create a tile group for the unique monitor, and get a unique
1240  * identifier for the tile group.
1241  *
1242  * RETURNS:
1243  * new tile group or error.
1244  */
1245 struct drm_tile_group *drm_mode_create_tile_group(struct drm_device *dev,
1246 						  char topology[8])
1247 {
1248 	struct drm_tile_group *tg;
1249 	int ret;
1250 
1251 	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
1252 	if (!tg)
1253 		return ERR_PTR(-ENOMEM);
1254 
1255 	kref_init(&tg->refcount);
1256 	memcpy(tg->group_data, topology, 8);
1257 	tg->dev = dev;
1258 
1259 	mutex_lock(&dev->mode_config.idr_mutex);
1260 	ret = idr_alloc(&dev->mode_config.tile_idr, tg, 1, 0, GFP_KERNEL);
1261 	if (ret >= 0) {
1262 		tg->id = ret;
1263 	} else {
1264 		kfree(tg);
1265 		tg = ERR_PTR(ret);
1266 	}
1267 
1268 	mutex_unlock(&dev->mode_config.idr_mutex);
1269 	return tg;
1270 }
1271 EXPORT_SYMBOL(drm_mode_create_tile_group);
1272