1// SPDX-License-Identifier: GPL-2.0-only
2
3/*
4 * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
5 * extra sysfs attribute from DRM. Normal drm_sysfs_class
6 * does not allow adding attributes.
7 *
8 * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
9 * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
10 * Copyright (c) 2003-2004 IBM Corp.
11 */
12
13#include <linux/acpi.h>
14#include <linux/component.h>
15#include <linux/device.h>
16#include <linux/err.h>
17#include <linux/export.h>
18#include <linux/gfp.h>
19#include <linux/i2c.h>
20#include <linux/kdev_t.h>
21#include <linux/property.h>
22#include <linux/slab.h>
23
24#include <drm/drm_accel.h>
25#include <drm/drm_connector.h>
26#include <drm/drm_device.h>
27#include <drm/drm_file.h>
28#include <drm/drm_modes.h>
29#include <drm/drm_print.h>
30#include <drm/drm_property.h>
31#include <drm/drm_sysfs.h>
32
33#include "drm_internal.h"
34#include "drm_crtc_internal.h"
35
36#define to_drm_minor(d) dev_get_drvdata(d)
37#define to_drm_connector(d) dev_get_drvdata(d)
38
39/**
40 * DOC: overview
41 *
42 * DRM provides very little additional support to drivers for sysfs
43 * interactions, beyond just all the standard stuff. Drivers who want to expose
44 * additional sysfs properties and property groups can attach them at either
45 * &drm_device.dev or &drm_connector.kdev.
46 *
47 * Registration is automatically handled when calling drm_dev_register(), or
48 * drm_connector_register() in case of hot-plugged connectors. Unregistration is
49 * also automatically handled by drm_dev_unregister() and
50 * drm_connector_unregister().
51 */
52
53static struct device_type drm_sysfs_device_minor = {
54 .name = "drm_minor"
55};
56
57static struct device_type drm_sysfs_device_connector = {
58 .name = "drm_connector",
59};
60
61struct class *drm_class;
62
63#ifdef CONFIG_ACPI
64static bool drm_connector_acpi_bus_match(struct device *dev)
65{
66 return dev->type == &drm_sysfs_device_connector;
67}
68
69static struct acpi_device *drm_connector_acpi_find_companion(struct device *dev)
70{
71 struct drm_connector *connector = to_drm_connector(dev);
72
73 return to_acpi_device_node(connector->fwnode);
74}
75
76static struct acpi_bus_type drm_connector_acpi_bus = {
77 .name = "drm_connector",
78 .match = drm_connector_acpi_bus_match,
79 .find_companion = drm_connector_acpi_find_companion,
80};
81
82static void drm_sysfs_acpi_register(void)
83{
84 register_acpi_bus_type(&drm_connector_acpi_bus);
85}
86
87static void drm_sysfs_acpi_unregister(void)
88{
89 unregister_acpi_bus_type(&drm_connector_acpi_bus);
90}
91#else
92static void drm_sysfs_acpi_register(void) { }
93static void drm_sysfs_acpi_unregister(void) { }
94#endif
95
96static char *drm_devnode(const struct device *dev, umode_t *mode)
97{
98 return kasprintf(GFP_KERNEL, fmt: "dri/%s", dev_name(dev));
99}
100
101static int typec_connector_bind(struct device *dev,
102 struct device *typec_connector, void *data)
103{
104 int ret;
105
106 ret = sysfs_create_link(kobj: &dev->kobj, target: &typec_connector->kobj, name: "typec_connector");
107 if (ret)
108 return ret;
109
110 ret = sysfs_create_link(kobj: &typec_connector->kobj, target: &dev->kobj, name: "drm_connector");
111 if (ret)
112 sysfs_remove_link(kobj: &dev->kobj, name: "typec_connector");
113
114 return ret;
115}
116
117static void typec_connector_unbind(struct device *dev,
118 struct device *typec_connector, void *data)
119{
120 sysfs_remove_link(kobj: &typec_connector->kobj, name: "drm_connector");
121 sysfs_remove_link(kobj: &dev->kobj, name: "typec_connector");
122}
123
124static const struct component_ops typec_connector_ops = {
125 .bind = typec_connector_bind,
126 .unbind = typec_connector_unbind,
127};
128
129static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
130
131/**
132 * drm_sysfs_init - initialize sysfs helpers
133 *
134 * This is used to create the DRM class, which is the implicit parent of any
135 * other top-level DRM sysfs objects.
136 *
137 * You must call drm_sysfs_destroy() to release the allocated resources.
138 *
139 * Return: 0 on success, negative error code on failure.
140 */
141int drm_sysfs_init(void)
142{
143 int err;
144
145 drm_class = class_create(name: "drm");
146 if (IS_ERR(ptr: drm_class))
147 return PTR_ERR(ptr: drm_class);
148
149 err = class_create_file(class: drm_class, attr: &class_attr_version.attr);
150 if (err) {
151 class_destroy(cls: drm_class);
152 drm_class = NULL;
153 return err;
154 }
155
156 drm_class->devnode = drm_devnode;
157
158 drm_sysfs_acpi_register();
159 return 0;
160}
161
162/**
163 * drm_sysfs_destroy - destroys DRM class
164 *
165 * Destroy the DRM device class.
166 */
167void drm_sysfs_destroy(void)
168{
169 if (IS_ERR_OR_NULL(ptr: drm_class))
170 return;
171 drm_sysfs_acpi_unregister();
172 class_remove_file(class: drm_class, attr: &class_attr_version.attr);
173 class_destroy(cls: drm_class);
174 drm_class = NULL;
175}
176
177static void drm_sysfs_release(struct device *dev)
178{
179 kfree(objp: dev);
180}
181
182/*
183 * Connector properties
184 */
185static ssize_t status_store(struct device *device,
186 struct device_attribute *attr,
187 const char *buf, size_t count)
188{
189 struct drm_connector *connector = to_drm_connector(device);
190 struct drm_device *dev = connector->dev;
191 enum drm_connector_force old_force;
192 int ret;
193
194 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
195 if (ret)
196 return ret;
197
198 old_force = connector->force;
199
200 if (sysfs_streq(s1: buf, s2: "detect"))
201 connector->force = 0;
202 else if (sysfs_streq(s1: buf, s2: "on"))
203 connector->force = DRM_FORCE_ON;
204 else if (sysfs_streq(s1: buf, s2: "on-digital"))
205 connector->force = DRM_FORCE_ON_DIGITAL;
206 else if (sysfs_streq(s1: buf, s2: "off"))
207 connector->force = DRM_FORCE_OFF;
208 else
209 ret = -EINVAL;
210
211 if (old_force != connector->force || !connector->force) {
212 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
213 connector->base.id,
214 connector->name,
215 old_force, connector->force);
216
217 connector->funcs->fill_modes(connector,
218 dev->mode_config.max_width,
219 dev->mode_config.max_height);
220 }
221
222 mutex_unlock(lock: &dev->mode_config.mutex);
223
224 return ret ? ret : count;
225}
226
227static ssize_t status_show(struct device *device,
228 struct device_attribute *attr,
229 char *buf)
230{
231 struct drm_connector *connector = to_drm_connector(device);
232 enum drm_connector_status status;
233
234 status = READ_ONCE(connector->status);
235
236 return sysfs_emit(buf, fmt: "%s\n",
237 drm_get_connector_status_name(status));
238}
239
240static ssize_t dpms_show(struct device *device,
241 struct device_attribute *attr,
242 char *buf)
243{
244 struct drm_connector *connector = to_drm_connector(device);
245 int dpms;
246
247 dpms = READ_ONCE(connector->dpms);
248
249 return sysfs_emit(buf, fmt: "%s\n", drm_get_dpms_name(val: dpms));
250}
251
252static ssize_t enabled_show(struct device *device,
253 struct device_attribute *attr,
254 char *buf)
255{
256 struct drm_connector *connector = to_drm_connector(device);
257 bool enabled;
258
259 enabled = READ_ONCE(connector->encoder);
260
261 return sysfs_emit(buf, fmt: enabled ? "enabled\n" : "disabled\n");
262}
263
264static ssize_t edid_show(struct file *filp, struct kobject *kobj,
265 struct bin_attribute *attr, char *buf, loff_t off,
266 size_t count)
267{
268 struct device *connector_dev = kobj_to_dev(kobj);
269 struct drm_connector *connector = to_drm_connector(connector_dev);
270 unsigned char *edid;
271 size_t size;
272 ssize_t ret = 0;
273
274 mutex_lock(&connector->dev->mode_config.mutex);
275 if (!connector->edid_blob_ptr)
276 goto unlock;
277
278 edid = connector->edid_blob_ptr->data;
279 size = connector->edid_blob_ptr->length;
280 if (!edid)
281 goto unlock;
282
283 if (off >= size)
284 goto unlock;
285
286 if (off + count > size)
287 count = size - off;
288 memcpy(buf, edid + off, count);
289
290 ret = count;
291unlock:
292 mutex_unlock(lock: &connector->dev->mode_config.mutex);
293
294 return ret;
295}
296
297static ssize_t modes_show(struct device *device,
298 struct device_attribute *attr,
299 char *buf)
300{
301 struct drm_connector *connector = to_drm_connector(device);
302 struct drm_display_mode *mode;
303 int written = 0;
304
305 mutex_lock(&connector->dev->mode_config.mutex);
306 list_for_each_entry(mode, &connector->modes, head) {
307 written += scnprintf(buf: buf + written, PAGE_SIZE - written, fmt: "%s\n",
308 mode->name);
309 }
310 mutex_unlock(lock: &connector->dev->mode_config.mutex);
311
312 return written;
313}
314
315static ssize_t connector_id_show(struct device *device,
316 struct device_attribute *attr,
317 char *buf)
318{
319 struct drm_connector *connector = to_drm_connector(device);
320
321 return sysfs_emit(buf, fmt: "%d\n", connector->base.id);
322}
323
324static DEVICE_ATTR_RW(status);
325static DEVICE_ATTR_RO(enabled);
326static DEVICE_ATTR_RO(dpms);
327static DEVICE_ATTR_RO(modes);
328static DEVICE_ATTR_RO(connector_id);
329
330static struct attribute *connector_dev_attrs[] = {
331 &dev_attr_status.attr,
332 &dev_attr_enabled.attr,
333 &dev_attr_dpms.attr,
334 &dev_attr_modes.attr,
335 &dev_attr_connector_id.attr,
336 NULL
337};
338
339static struct bin_attribute edid_attr = {
340 .attr.name = "edid",
341 .attr.mode = 0444,
342 .size = 0,
343 .read = edid_show,
344};
345
346static struct bin_attribute *connector_bin_attrs[] = {
347 &edid_attr,
348 NULL
349};
350
351static const struct attribute_group connector_dev_group = {
352 .attrs = connector_dev_attrs,
353 .bin_attrs = connector_bin_attrs,
354};
355
356static const struct attribute_group *connector_dev_groups[] = {
357 &connector_dev_group,
358 NULL
359};
360
361int drm_sysfs_connector_add(struct drm_connector *connector)
362{
363 struct drm_device *dev = connector->dev;
364 struct device *kdev;
365 int r;
366
367 if (connector->kdev)
368 return 0;
369
370 kdev = kzalloc(size: sizeof(*kdev), GFP_KERNEL);
371 if (!kdev)
372 return -ENOMEM;
373
374 device_initialize(dev: kdev);
375 kdev->class = drm_class;
376 kdev->type = &drm_sysfs_device_connector;
377 kdev->parent = dev->primary->kdev;
378 kdev->groups = connector_dev_groups;
379 kdev->release = drm_sysfs_release;
380 dev_set_drvdata(dev: kdev, data: connector);
381
382 r = dev_set_name(dev: kdev, name: "card%d-%s", dev->primary->index, connector->name);
383 if (r)
384 goto err_free;
385
386 DRM_DEBUG("adding \"%s\" to sysfs\n",
387 connector->name);
388
389 r = device_add(dev: kdev);
390 if (r) {
391 drm_err(dev, "failed to register connector device: %d\n", r);
392 goto err_free;
393 }
394
395 connector->kdev = kdev;
396
397 if (dev_fwnode(kdev)) {
398 r = component_add(kdev, &typec_connector_ops);
399 if (r)
400 drm_err(dev, "failed to add component to create link to typec connector\n");
401 }
402
403 return 0;
404
405err_free:
406 put_device(dev: kdev);
407 return r;
408}
409
410int drm_sysfs_connector_add_late(struct drm_connector *connector)
411{
412 if (connector->ddc)
413 return sysfs_create_link(kobj: &connector->kdev->kobj,
414 target: &connector->ddc->dev.kobj, name: "ddc");
415
416 return 0;
417}
418
419void drm_sysfs_connector_remove_early(struct drm_connector *connector)
420{
421 if (connector->ddc)
422 sysfs_remove_link(kobj: &connector->kdev->kobj, name: "ddc");
423}
424
425void drm_sysfs_connector_remove(struct drm_connector *connector)
426{
427 if (!connector->kdev)
428 return;
429
430 if (dev_fwnode(connector->kdev))
431 component_del(connector->kdev, &typec_connector_ops);
432
433 DRM_DEBUG("removing \"%s\" from sysfs\n",
434 connector->name);
435
436 device_unregister(dev: connector->kdev);
437 connector->kdev = NULL;
438}
439
440void drm_sysfs_lease_event(struct drm_device *dev)
441{
442 char *event_string = "LEASE=1";
443 char *envp[] = { event_string, NULL };
444
445 DRM_DEBUG("generating lease event\n");
446
447 kobject_uevent_env(kobj: &dev->primary->kdev->kobj, action: KOBJ_CHANGE, envp);
448}
449
450/**
451 * drm_sysfs_hotplug_event - generate a DRM uevent
452 * @dev: DRM device
453 *
454 * Send a uevent for the DRM device specified by @dev. Currently we only
455 * set HOTPLUG=1 in the uevent environment, but this could be expanded to
456 * deal with other types of events.
457 *
458 * Any new uapi should be using the drm_sysfs_connector_status_event()
459 * for uevents on connector status change.
460 */
461void drm_sysfs_hotplug_event(struct drm_device *dev)
462{
463 char *event_string = "HOTPLUG=1";
464 char *envp[] = { event_string, NULL };
465
466 DRM_DEBUG("generating hotplug event\n");
467
468 kobject_uevent_env(kobj: &dev->primary->kdev->kobj, action: KOBJ_CHANGE, envp);
469}
470EXPORT_SYMBOL(drm_sysfs_hotplug_event);
471
472/**
473 * drm_sysfs_connector_hotplug_event - generate a DRM uevent for any connector
474 * change
475 * @connector: connector which has changed
476 *
477 * Send a uevent for the DRM connector specified by @connector. This will send
478 * a uevent with the properties HOTPLUG=1 and CONNECTOR.
479 */
480void drm_sysfs_connector_hotplug_event(struct drm_connector *connector)
481{
482 struct drm_device *dev = connector->dev;
483 char hotplug_str[] = "HOTPLUG=1", conn_id[21];
484 char *envp[] = { hotplug_str, conn_id, NULL };
485
486 snprintf(buf: conn_id, size: sizeof(conn_id),
487 fmt: "CONNECTOR=%u", connector->base.id);
488
489 drm_dbg_kms(connector->dev,
490 "[CONNECTOR:%d:%s] generating connector hotplug event\n",
491 connector->base.id, connector->name);
492
493 kobject_uevent_env(kobj: &dev->primary->kdev->kobj, action: KOBJ_CHANGE, envp);
494}
495EXPORT_SYMBOL(drm_sysfs_connector_hotplug_event);
496
497/**
498 * drm_sysfs_connector_property_event - generate a DRM uevent for connector
499 * property change
500 * @connector: connector on which property changed
501 * @property: connector property which has changed.
502 *
503 * Send a uevent for the specified DRM connector and property. Currently we
504 * set HOTPLUG=1 and connector id along with the attached property id
505 * related to the change.
506 */
507void drm_sysfs_connector_property_event(struct drm_connector *connector,
508 struct drm_property *property)
509{
510 struct drm_device *dev = connector->dev;
511 char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
512 char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
513
514 WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
515 property->base.id));
516
517 snprintf(buf: conn_id, ARRAY_SIZE(conn_id),
518 fmt: "CONNECTOR=%u", connector->base.id);
519 snprintf(buf: prop_id, ARRAY_SIZE(prop_id),
520 fmt: "PROPERTY=%u", property->base.id);
521
522 drm_dbg_kms(connector->dev,
523 "[CONNECTOR:%d:%s] generating connector property event for [PROP:%d:%s]\n",
524 connector->base.id, connector->name,
525 property->base.id, property->name);
526
527 kobject_uevent_env(kobj: &dev->primary->kdev->kobj, action: KOBJ_CHANGE, envp);
528}
529EXPORT_SYMBOL(drm_sysfs_connector_property_event);
530
531struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
532{
533 const char *minor_str;
534 struct device *kdev;
535 int r;
536
537 kdev = kzalloc(size: sizeof(*kdev), GFP_KERNEL);
538 if (!kdev)
539 return ERR_PTR(error: -ENOMEM);
540
541 device_initialize(dev: kdev);
542
543 if (minor->type == DRM_MINOR_ACCEL) {
544 minor_str = "accel%d";
545 accel_set_device_instance_params(kdev, index: minor->index);
546 } else {
547 if (minor->type == DRM_MINOR_RENDER)
548 minor_str = "renderD%d";
549 else
550 minor_str = "card%d";
551
552 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
553 kdev->class = drm_class;
554 kdev->type = &drm_sysfs_device_minor;
555 }
556
557 kdev->parent = minor->dev->dev;
558 kdev->release = drm_sysfs_release;
559 dev_set_drvdata(dev: kdev, data: minor);
560
561 r = dev_set_name(dev: kdev, name: minor_str, minor->index);
562 if (r < 0)
563 goto err_free;
564
565 return kdev;
566
567err_free:
568 put_device(dev: kdev);
569 return ERR_PTR(error: r);
570}
571
572/**
573 * drm_class_device_register - register new device with the DRM sysfs class
574 * @dev: device to register
575 *
576 * Registers a new &struct device within the DRM sysfs class. Essentially only
577 * used by ttm to have a place for its global settings. Drivers should never use
578 * this.
579 */
580int drm_class_device_register(struct device *dev)
581{
582 if (!drm_class || IS_ERR(ptr: drm_class))
583 return -ENOENT;
584
585 dev->class = drm_class;
586 return device_register(dev);
587}
588EXPORT_SYMBOL_GPL(drm_class_device_register);
589
590/**
591 * drm_class_device_unregister - unregister device with the DRM sysfs class
592 * @dev: device to unregister
593 *
594 * Unregisters a &struct device from the DRM sysfs class. Essentially only used
595 * by ttm to have a place for its global settings. Drivers should never use
596 * this.
597 */
598void drm_class_device_unregister(struct device *dev)
599{
600 return device_unregister(dev);
601}
602EXPORT_SYMBOL_GPL(drm_class_device_unregister);
603

source code of linux/drivers/gpu/drm/drm_sysfs.c