drm_sysfs.c

  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/pci.h>
 22#include <linux/property.h>
 23#include <linux/slab.h>
 24
 25#include <drm/drm_accel.h>
 26#include <drm/drm_connector.h>
 27#include <drm/drm_device.h>
 28#include <drm/drm_file.h>
 29#include <drm/drm_modes.h>
 30#include <drm/drm_print.h>
 31#include <drm/drm_property.h>
 32#include <drm/drm_sysfs.h>
 33
 34#include <asm/video.h>
 35
 36#include "drm_internal.h"
 37#include "drm_crtc_internal.h"
 38
 39#define to_drm_minor(d) dev_get_drvdata(d)
 40#define to_drm_connector(d) dev_get_drvdata(d)
 41
 42/**
 43 * DOC: overview
 44 *
 45 * DRM provides very little additional support to drivers for sysfs
 46 * interactions, beyond just all the standard stuff. Drivers who want to expose
 47 * additional sysfs properties and property groups can attach them at either
 48 * &drm_device.dev or &drm_connector.kdev.
 49 *
 50 * Registration is automatically handled when calling drm_dev_register(), or
 51 * drm_connector_register() in case of hot-plugged connectors. Unregistration is
 52 * also automatically handled by drm_dev_unregister() and
 53 * drm_connector_unregister().
 54 */
 55
 56static struct device_type drm_sysfs_device_minor = {
 57	.name = "drm_minor"
 58};
 59
 60static struct device_type drm_sysfs_device_connector = {
 61	.name = "drm_connector",
 62};
 63
 64struct class *drm_class;
 65
 66#ifdef CONFIG_ACPI
 67static bool drm_connector_acpi_bus_match(struct device *dev)
 68{
 69	return dev->type == &drm_sysfs_device_connector;
 70}
 71
 72static struct acpi_device *drm_connector_acpi_find_companion(struct device *dev)
 73{
 74	struct drm_connector *connector = to_drm_connector(dev);
 75
 76	return to_acpi_device_node(connector->fwnode);
 77}
 78
 79static struct acpi_bus_type drm_connector_acpi_bus = {
 80	.name = "drm_connector",
 81	.match = drm_connector_acpi_bus_match,
 82	.find_companion = drm_connector_acpi_find_companion,
 83};
 84
 85static void drm_sysfs_acpi_register(void)
 86{
 87	register_acpi_bus_type(&drm_connector_acpi_bus);
 88}
 89
 90static void drm_sysfs_acpi_unregister(void)
 91{
 92	unregister_acpi_bus_type(&drm_connector_acpi_bus);
 93}
 94#else
 95static void drm_sysfs_acpi_register(void) { }
 96static void drm_sysfs_acpi_unregister(void) { }
 97#endif
 98
 99static char *drm_devnode(const struct device *dev, umode_t *mode)
100{
101	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
102}
103
104static int typec_connector_bind(struct device *dev,
105				struct device *typec_connector, void *data)
106{
107	int ret;
108
109	ret = sysfs_create_link(&dev->kobj, &typec_connector->kobj, "typec_connector");
110	if (ret)
111		return ret;
112
113	ret = sysfs_create_link(&typec_connector->kobj, &dev->kobj, "drm_connector");
114	if (ret)
115		sysfs_remove_link(&dev->kobj, "typec_connector");
116
117	return ret;
118}
119
120static void typec_connector_unbind(struct device *dev,
121				   struct device *typec_connector, void *data)
122{
123	sysfs_remove_link(&typec_connector->kobj, "drm_connector");
124	sysfs_remove_link(&dev->kobj, "typec_connector");
125}
126
127static const struct component_ops typec_connector_ops = {
128	.bind = typec_connector_bind,
129	.unbind = typec_connector_unbind,
130};
131
132static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
133
134/**
135 * drm_sysfs_init - initialize sysfs helpers
136 *
137 * This is used to create the DRM class, which is the implicit parent of any
138 * other top-level DRM sysfs objects.
139 *
140 * You must call drm_sysfs_destroy() to release the allocated resources.
141 *
142 * Return: 0 on success, negative error code on failure.
143 */
144int drm_sysfs_init(void)
145{
146	int err;
147
148	drm_class = class_create("drm");
149	if (IS_ERR(drm_class))
150		return PTR_ERR(drm_class);
151
152	err = class_create_file(drm_class, &class_attr_version.attr);
153	if (err) {
154		class_destroy(drm_class);
155		drm_class = NULL;
156		return err;
157	}
158
159	drm_class->devnode = drm_devnode;
160
161	drm_sysfs_acpi_register();
162	return 0;
163}
164
165/**
166 * drm_sysfs_destroy - destroys DRM class
167 *
168 * Destroy the DRM device class.
169 */
170void drm_sysfs_destroy(void)
171{
172	if (IS_ERR_OR_NULL(drm_class))
173		return;
174	drm_sysfs_acpi_unregister();
175	class_remove_file(drm_class, &class_attr_version.attr);
176	class_destroy(drm_class);
177	drm_class = NULL;
178}
179
180static void drm_sysfs_release(struct device *dev)
181{
182	kfree(dev);
183}
184
185/*
186 * Connector properties
187 */
188static ssize_t status_store(struct device *device,
189			   struct device_attribute *attr,
190			   const char *buf, size_t count)
191{
192	struct drm_connector *connector = to_drm_connector(device);
193	struct drm_device *dev = connector->dev;
194	enum drm_connector_force old_force;
195	int ret;
196
197	ret = mutex_lock_interruptible(&dev->mode_config.mutex);
198	if (ret)
199		return ret;
200
201	old_force = connector->force;
202
203	if (sysfs_streq(buf, "detect"))
204		connector->force = 0;
205	else if (sysfs_streq(buf, "on"))
206		connector->force = DRM_FORCE_ON;
207	else if (sysfs_streq(buf, "on-digital"))
208		connector->force = DRM_FORCE_ON_DIGITAL;
209	else if (sysfs_streq(buf, "off"))
210		connector->force = DRM_FORCE_OFF;
211	else
212		ret = -EINVAL;
213
214	if (old_force != connector->force || !connector->force) {
215		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
216			    connector->base.id, connector->name,
217			    old_force, connector->force);
218
219		connector->funcs->fill_modes(connector,
220					     dev->mode_config.max_width,
221					     dev->mode_config.max_height);
222	}
223
224	mutex_unlock(&dev->mode_config.mutex);
225
226	return ret ? ret : count;
227}
228
229static ssize_t status_show(struct device *device,
230			   struct device_attribute *attr,
231			   char *buf)
232{
233	struct drm_connector *connector = to_drm_connector(device);
234	enum drm_connector_status status;
235
236	status = READ_ONCE(connector->status);
237
238	return sysfs_emit(buf, "%s\n",
239			  drm_get_connector_status_name(status));
240}
241
242static ssize_t dpms_show(struct device *device,
243			   struct device_attribute *attr,
244			   char *buf)
245{
246	struct drm_connector *connector = to_drm_connector(device);
247	int dpms;
248
249	dpms = READ_ONCE(connector->dpms);
250
251	return sysfs_emit(buf, "%s\n", drm_get_dpms_name(dpms));
252}
253
254static ssize_t enabled_show(struct device *device,
255			    struct device_attribute *attr,
256			   char *buf)
257{
258	struct drm_connector *connector = to_drm_connector(device);
259	bool enabled;
260
261	enabled = READ_ONCE(connector->encoder);
262
263	return sysfs_emit(buf, enabled ? "enabled\n" : "disabled\n");
264}
265
266static ssize_t edid_show(struct file *filp, struct kobject *kobj,
267			 const struct bin_attribute *attr, char *buf, loff_t off,
268			 size_t count)
269{
270	struct device *connector_dev = kobj_to_dev(kobj);
271	struct drm_connector *connector = to_drm_connector(connector_dev);
272	ssize_t ret;
273
274	ret = drm_edid_connector_property_show(connector, buf, off, count);
275
276	return ret;
277}
278
279static ssize_t modes_show(struct device *device,
280			   struct device_attribute *attr,
281			   char *buf)
282{
283	struct drm_connector *connector = to_drm_connector(device);
284	struct drm_display_mode *mode;
285	int written = 0;
286
287	mutex_lock(&connector->dev->mode_config.mutex);
288	list_for_each_entry(mode, &connector->modes, head) {
289		written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
290				    mode->name);
291	}
292	mutex_unlock(&connector->dev->mode_config.mutex);
293
294	return written;
295}
296
297static ssize_t connector_id_show(struct device *device,
298				 struct device_attribute *attr,
299				 char *buf)
300{
301	struct drm_connector *connector = to_drm_connector(device);
302
303	return sysfs_emit(buf, "%d\n", connector->base.id);
304}
305
306static DEVICE_ATTR_RW(status);
307static DEVICE_ATTR_RO(enabled);
308static DEVICE_ATTR_RO(dpms);
309static DEVICE_ATTR_RO(modes);
310static DEVICE_ATTR_RO(connector_id);
311
312static struct attribute *connector_dev_attrs[] = {
313	&dev_attr_status.attr,
314	&dev_attr_enabled.attr,
315	&dev_attr_dpms.attr,
316	&dev_attr_modes.attr,
317	&dev_attr_connector_id.attr,
318	NULL
319};
320
321static const struct bin_attribute edid_attr = {
322	.attr.name = "edid",
323	.attr.mode = 0444,
324	.size = 0,
325	.read = edid_show,
326};
327
328static const struct bin_attribute *const connector_bin_attrs[] = {
329	&edid_attr,
330	NULL
331};
332
333static const struct attribute_group connector_dev_group = {
334	.attrs = connector_dev_attrs,
335	.bin_attrs = connector_bin_attrs,
336};
337
338static const struct attribute_group *connector_dev_groups[] = {
339	&connector_dev_group,
340	NULL
341};
342
343int drm_sysfs_connector_add(struct drm_connector *connector)
344{
345	struct drm_device *dev = connector->dev;
346	struct device *kdev;
347	int r;
348
349	if (connector->kdev)
350		return 0;
351
352	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
353	if (!kdev)
354		return -ENOMEM;
355
356	device_initialize(kdev);
357	kdev->class = drm_class;
358	kdev->type = &drm_sysfs_device_connector;
359	kdev->parent = dev->primary->kdev;
360	kdev->groups = connector_dev_groups;
361	kdev->release = drm_sysfs_release;
362	dev_set_drvdata(kdev, connector);
363
364	r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
365	if (r)
366		goto err_free;
367
368	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] adding connector to sysfs\n",
369		    connector->base.id, connector->name);
370
371	r = device_add(kdev);
372	if (r) {
373		drm_err(dev, "failed to register connector device: %d\n", r);
374		goto err_free;
375	}
376
377	connector->kdev = kdev;
378
379	if (dev_fwnode(kdev)) {
380		r = component_add(kdev, &typec_connector_ops);
381		if (r)
382			drm_err(dev, "failed to add component to create link to typec connector\n");
383	}
384
385	return 0;
386
387err_free:
388	put_device(kdev);
389	return r;
390}
391
392int drm_sysfs_connector_add_late(struct drm_connector *connector)
393{
394	if (connector->ddc)
395		return sysfs_create_link(&connector->kdev->kobj,
396					 &connector->ddc->dev.kobj, "ddc");
397
398	return 0;
399}
400
401void drm_sysfs_connector_remove_early(struct drm_connector *connector)
402{
403	if (connector->ddc)
404		sysfs_remove_link(&connector->kdev->kobj, "ddc");
405}
406
407void drm_sysfs_connector_remove(struct drm_connector *connector)
408{
409	if (!connector->kdev)
410		return;
411
412	if (dev_fwnode(connector->kdev))
413		component_del(connector->kdev, &typec_connector_ops);
414
415	drm_dbg_kms(connector->dev,
416		    "[CONNECTOR:%d:%s] removing connector from sysfs\n",
417		    connector->base.id, connector->name);
418
419	device_unregister(connector->kdev);
420	connector->kdev = NULL;
421}
422
423void drm_sysfs_lease_event(struct drm_device *dev)
424{
425	char *event_string = "LEASE=1";
426	char *envp[] = { event_string, NULL };
427
428	drm_dbg_lease(dev, "generating lease event\n");
429
430	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
431}
432
433/**
434 * drm_sysfs_hotplug_event - generate a DRM uevent
435 * @dev: DRM device
436 *
437 * Send a uevent for the DRM device specified by @dev.  Currently we only
438 * set HOTPLUG=1 in the uevent environment, but this could be expanded to
439 * deal with other types of events.
440 *
441 * Any new uapi should be using the drm_sysfs_connector_status_event()
442 * for uevents on connector status change.
443 */
444void drm_sysfs_hotplug_event(struct drm_device *dev)
445{
446	char *event_string = "HOTPLUG=1";
447	char *envp[] = { event_string, NULL };
448
449	drm_dbg_kms(dev, "generating hotplug event\n");
450
451	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
452}
453EXPORT_SYMBOL(drm_sysfs_hotplug_event);
454
455/**
456 * drm_sysfs_connector_hotplug_event - generate a DRM uevent for any connector
457 * change
458 * @connector: connector which has changed
459 *
460 * Send a uevent for the DRM connector specified by @connector. This will send
461 * a uevent with the properties HOTPLUG=1 and CONNECTOR.
462 */
463void drm_sysfs_connector_hotplug_event(struct drm_connector *connector)
464{
465	struct drm_device *dev = connector->dev;
466	char hotplug_str[] = "HOTPLUG=1", conn_id[21];
467	char *envp[] = { hotplug_str, conn_id, NULL };
468
469	snprintf(conn_id, sizeof(conn_id),
470		 "CONNECTOR=%u", connector->base.id);
471
472	drm_dbg_kms(connector->dev,
473		    "[CONNECTOR:%d:%s] generating connector hotplug event\n",
474		    connector->base.id, connector->name);
475
476	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
477}
478EXPORT_SYMBOL(drm_sysfs_connector_hotplug_event);
479
480/**
481 * drm_sysfs_connector_property_event - generate a DRM uevent for connector
482 * property change
483 * @connector: connector on which property changed
484 * @property: connector property which has changed.
485 *
486 * Send a uevent for the specified DRM connector and property.  Currently we
487 * set HOTPLUG=1 and connector id along with the attached property id
488 * related to the change.
489 */
490void drm_sysfs_connector_property_event(struct drm_connector *connector,
491					struct drm_property *property)
492{
493	struct drm_device *dev = connector->dev;
494	char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
495	char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
496
497	WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
498					   property->base.id));
499
500	snprintf(conn_id, ARRAY_SIZE(conn_id),
501		 "CONNECTOR=%u", connector->base.id);
502	snprintf(prop_id, ARRAY_SIZE(prop_id),
503		 "PROPERTY=%u", property->base.id);
504
505	drm_dbg_kms(connector->dev,
506		    "[CONNECTOR:%d:%s] generating connector property event for [PROP:%d:%s]\n",
507		    connector->base.id, connector->name,
508		    property->base.id, property->name);
509
510	kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
511}
512EXPORT_SYMBOL(drm_sysfs_connector_property_event);
513
514static ssize_t boot_display_show(struct device *dev, struct device_attribute *attr,
515				 char *buf)
516{
517	return sysfs_emit(buf, "1\n");
518}
519static DEVICE_ATTR_RO(boot_display);
520
521static struct attribute *display_attrs[] = {
522	&dev_attr_boot_display.attr,
523	NULL
524};
525
526static umode_t boot_display_visible(struct kobject *kobj,
527				    struct attribute *a, int n)
528{
529	struct device *dev = kobj_to_dev(kobj)->parent;
530
531	if (dev_is_pci(dev)) {
532		struct pci_dev *pdev = to_pci_dev(dev);
533
534		if (video_is_primary_device(&pdev->dev))
535			return a->mode;
536	}
537
538	return 0;
539}
540
541static const struct attribute_group display_attr_group = {
542	.attrs = display_attrs,
543	.is_visible = boot_display_visible,
544};
545
546static const struct attribute_group *card_dev_groups[] = {
547	&display_attr_group,
548	NULL
549};
550
551struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
552{
553	const char *minor_str;
554	struct device *kdev;
555	int r;
556
557	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
558	if (!kdev)
559		return ERR_PTR(-ENOMEM);
560
561	device_initialize(kdev);
562
563	if (minor->type == DRM_MINOR_ACCEL) {
564		minor_str = "accel%d";
565		accel_set_device_instance_params(kdev, minor->index);
566	} else {
567		if (minor->type == DRM_MINOR_RENDER)
568			minor_str = "renderD%d";
569		else
570			minor_str = "card%d";
571
572		kdev->devt = MKDEV(DRM_MAJOR, minor->index);
573		kdev->class = drm_class;
574		kdev->groups = card_dev_groups;
575		kdev->type = &drm_sysfs_device_minor;
576	}
577
578	kdev->parent = minor->dev->dev;
579	kdev->release = drm_sysfs_release;
580	dev_set_drvdata(kdev, minor);
581
582	r = dev_set_name(kdev, minor_str, minor->index);
583	if (r < 0)
584		goto err_free;
585
586	return kdev;
587
588err_free:
589	put_device(kdev);
590	return ERR_PTR(r);
591}
592
593/**
594 * drm_class_device_register - register new device with the DRM sysfs class
595 * @dev: device to register
596 *
597 * Registers a new &struct device within the DRM sysfs class. Essentially only
598 * used by ttm to have a place for its global settings. Drivers should never use
599 * this.
600 */
601int drm_class_device_register(struct device *dev)
602{
603	if (!drm_class || IS_ERR(drm_class))
604		return -ENOENT;
605
606	dev->class = drm_class;
607	return device_register(dev);
608}
609EXPORT_SYMBOL_GPL(drm_class_device_register);
610
611/**
612 * drm_class_device_unregister - unregister device with the DRM sysfs class
613 * @dev: device to unregister
614 *
615 * Unregisters a &struct device from the DRM sysfs class. Essentially only used
616 * by ttm to have a place for its global settings. Drivers should never use
617 * this.
618 */
619void drm_class_device_unregister(struct device *dev)
620{
621	return device_unregister(dev);
622}
623EXPORT_SYMBOL_GPL(drm_class_device_unregister);