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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/device.h>
14#include <linux/err.h>
15#include <linux/export.h>
16#include <linux/gfp.h>
17#include <linux/i2c.h>
18#include <linux/kdev_t.h>
19#include <linux/slab.h>
20
21#include <drm/drm_connector.h>
22#include <drm/drm_device.h>
23#include <drm/drm_file.h>
24#include <drm/drm_modes.h>
25#include <drm/drm_print.h>
26#include <drm/drm_property.h>
27#include <drm/drm_sysfs.h>
28
29#include "drm_internal.h"
30#include "drm_crtc_internal.h"
31
32#define to_drm_minor(d) dev_get_drvdata(d)
33#define to_drm_connector(d) dev_get_drvdata(d)
34
35/**
36 * DOC: overview
37 *
38 * DRM provides very little additional support to drivers for sysfs
39 * interactions, beyond just all the standard stuff. Drivers who want to expose
40 * additional sysfs properties and property groups can attach them at either
41 * &drm_device.dev or &drm_connector.kdev.
42 *
43 * Registration is automatically handled when calling drm_dev_register(), or
44 * drm_connector_register() in case of hot-plugged connectors. Unregistration is
45 * also automatically handled by drm_dev_unregister() and
46 * drm_connector_unregister().
47 */
48
49static struct device_type drm_sysfs_device_minor = {
50 .name = "drm_minor"
51};
52
53struct class *drm_class;
54
55static char *drm_devnode(struct device *dev, umode_t *mode)
56{
57 return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
58}
59
60static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
61
62/**
63 * drm_sysfs_init - initialize sysfs helpers
64 *
65 * This is used to create the DRM class, which is the implicit parent of any
66 * other top-level DRM sysfs objects.
67 *
68 * You must call drm_sysfs_destroy() to release the allocated resources.
69 *
70 * Return: 0 on success, negative error code on failure.
71 */
72int drm_sysfs_init(void)
73{
74 int err;
75
76 drm_class = class_create(THIS_MODULE, "drm");
77 if (IS_ERR(drm_class))
78 return PTR_ERR(drm_class);
79
80 err = class_create_file(drm_class, &class_attr_version.attr);
81 if (err) {
82 class_destroy(drm_class);
83 drm_class = NULL;
84 return err;
85 }
86
87 drm_class->devnode = drm_devnode;
88 drm_setup_hdcp_srm(drm_class);
89 return 0;
90}
91
92/**
93 * drm_sysfs_destroy - destroys DRM class
94 *
95 * Destroy the DRM device class.
96 */
97void drm_sysfs_destroy(void)
98{
99 if (IS_ERR_OR_NULL(drm_class))
100 return;
101 drm_teardown_hdcp_srm(drm_class);
102 class_remove_file(drm_class, &class_attr_version.attr);
103 class_destroy(drm_class);
104 drm_class = NULL;
105}
106
107/*
108 * Connector properties
109 */
110static ssize_t status_store(struct device *device,
111 struct device_attribute *attr,
112 const char *buf, size_t count)
113{
114 struct drm_connector *connector = to_drm_connector(device);
115 struct drm_device *dev = connector->dev;
116 enum drm_connector_force old_force;
117 int ret;
118
119 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
120 if (ret)
121 return ret;
122
123 old_force = connector->force;
124
125 if (sysfs_streq(buf, "detect"))
126 connector->force = 0;
127 else if (sysfs_streq(buf, "on"))
128 connector->force = DRM_FORCE_ON;
129 else if (sysfs_streq(buf, "on-digital"))
130 connector->force = DRM_FORCE_ON_DIGITAL;
131 else if (sysfs_streq(buf, "off"))
132 connector->force = DRM_FORCE_OFF;
133 else
134 ret = -EINVAL;
135
136 if (old_force != connector->force || !connector->force) {
137 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
138 connector->base.id,
139 connector->name,
140 old_force, connector->force);
141
142 connector->funcs->fill_modes(connector,
143 dev->mode_config.max_width,
144 dev->mode_config.max_height);
145 }
146
147 mutex_unlock(&dev->mode_config.mutex);
148
149 return ret ? ret : count;
150}
151
152static ssize_t status_show(struct device *device,
153 struct device_attribute *attr,
154 char *buf)
155{
156 struct drm_connector *connector = to_drm_connector(device);
157 enum drm_connector_status status;
158
159 status = READ_ONCE(connector->status);
160
161 return snprintf(buf, PAGE_SIZE, "%s\n",
162 drm_get_connector_status_name(status));
163}
164
165static ssize_t dpms_show(struct device *device,
166 struct device_attribute *attr,
167 char *buf)
168{
169 struct drm_connector *connector = to_drm_connector(device);
170 int dpms;
171
172 dpms = READ_ONCE(connector->dpms);
173
174 return snprintf(buf, PAGE_SIZE, "%s\n",
175 drm_get_dpms_name(dpms));
176}
177
178static ssize_t enabled_show(struct device *device,
179 struct device_attribute *attr,
180 char *buf)
181{
182 struct drm_connector *connector = to_drm_connector(device);
183 bool enabled;
184
185 enabled = READ_ONCE(connector->encoder);
186
187 return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
188}
189
190static ssize_t edid_show(struct file *filp, struct kobject *kobj,
191 struct bin_attribute *attr, char *buf, loff_t off,
192 size_t count)
193{
194 struct device *connector_dev = kobj_to_dev(kobj);
195 struct drm_connector *connector = to_drm_connector(connector_dev);
196 unsigned char *edid;
197 size_t size;
198 ssize_t ret = 0;
199
200 mutex_lock(&connector->dev->mode_config.mutex);
201 if (!connector->edid_blob_ptr)
202 goto unlock;
203
204 edid = connector->edid_blob_ptr->data;
205 size = connector->edid_blob_ptr->length;
206 if (!edid)
207 goto unlock;
208
209 if (off >= size)
210 goto unlock;
211
212 if (off + count > size)
213 count = size - off;
214 memcpy(buf, edid + off, count);
215
216 ret = count;
217unlock:
218 mutex_unlock(&connector->dev->mode_config.mutex);
219
220 return ret;
221}
222
223static ssize_t modes_show(struct device *device,
224 struct device_attribute *attr,
225 char *buf)
226{
227 struct drm_connector *connector = to_drm_connector(device);
228 struct drm_display_mode *mode;
229 int written = 0;
230
231 mutex_lock(&connector->dev->mode_config.mutex);
232 list_for_each_entry(mode, &connector->modes, head) {
233 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
234 mode->name);
235 }
236 mutex_unlock(&connector->dev->mode_config.mutex);
237
238 return written;
239}
240
241static DEVICE_ATTR_RW(status);
242static DEVICE_ATTR_RO(enabled);
243static DEVICE_ATTR_RO(dpms);
244static DEVICE_ATTR_RO(modes);
245
246static struct attribute *connector_dev_attrs[] = {
247 &dev_attr_status.attr,
248 &dev_attr_enabled.attr,
249 &dev_attr_dpms.attr,
250 &dev_attr_modes.attr,
251 NULL
252};
253
254static struct bin_attribute edid_attr = {
255 .attr.name = "edid",
256 .attr.mode = 0444,
257 .size = 0,
258 .read = edid_show,
259};
260
261static struct bin_attribute *connector_bin_attrs[] = {
262 &edid_attr,
263 NULL
264};
265
266static const struct attribute_group connector_dev_group = {
267 .attrs = connector_dev_attrs,
268 .bin_attrs = connector_bin_attrs,
269};
270
271static const struct attribute_group *connector_dev_groups[] = {
272 &connector_dev_group,
273 NULL
274};
275
276int drm_sysfs_connector_add(struct drm_connector *connector)
277{
278 struct drm_device *dev = connector->dev;
279
280 if (connector->kdev)
281 return 0;
282
283 connector->kdev =
284 device_create_with_groups(drm_class, dev->primary->kdev, 0,
285 connector, connector_dev_groups,
286 "card%d-%s", dev->primary->index,
287 connector->name);
288 DRM_DEBUG("adding \"%s\" to sysfs\n",
289 connector->name);
290
291 if (IS_ERR(connector->kdev)) {
292 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
293 return PTR_ERR(connector->kdev);
294 }
295
296 /* Let userspace know we have a new connector */
297 drm_sysfs_hotplug_event(dev);
298
299 if (connector->ddc)
300 return sysfs_create_link(&connector->kdev->kobj,
301 &connector->ddc->dev.kobj, "ddc");
302 return 0;
303}
304
305void drm_sysfs_connector_remove(struct drm_connector *connector)
306{
307 if (!connector->kdev)
308 return;
309
310 if (connector->ddc)
311 sysfs_remove_link(&connector->kdev->kobj, "ddc");
312
313 DRM_DEBUG("removing \"%s\" from sysfs\n",
314 connector->name);
315
316 device_unregister(connector->kdev);
317 connector->kdev = NULL;
318}
319
320void drm_sysfs_lease_event(struct drm_device *dev)
321{
322 char *event_string = "LEASE=1";
323 char *envp[] = { event_string, NULL };
324
325 DRM_DEBUG("generating lease event\n");
326
327 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
328}
329
330/**
331 * drm_sysfs_hotplug_event - generate a DRM uevent
332 * @dev: DRM device
333 *
334 * Send a uevent for the DRM device specified by @dev. Currently we only
335 * set HOTPLUG=1 in the uevent environment, but this could be expanded to
336 * deal with other types of events.
337 *
338 * Any new uapi should be using the drm_sysfs_connector_status_event()
339 * for uevents on connector status change.
340 */
341void drm_sysfs_hotplug_event(struct drm_device *dev)
342{
343 char *event_string = "HOTPLUG=1";
344 char *envp[] = { event_string, NULL };
345
346 DRM_DEBUG("generating hotplug event\n");
347
348 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
349}
350EXPORT_SYMBOL(drm_sysfs_hotplug_event);
351
352/**
353 * drm_sysfs_connector_status_event - generate a DRM uevent for connector
354 * property status change
355 * @connector: connector on which property status changed
356 * @property: connector property whose status changed.
357 *
358 * Send a uevent for the DRM device specified by @dev. Currently we
359 * set HOTPLUG=1 and connector id along with the attached property id
360 * related to the status change.
361 */
362void drm_sysfs_connector_status_event(struct drm_connector *connector,
363 struct drm_property *property)
364{
365 struct drm_device *dev = connector->dev;
366 char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
367 char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
368
369 WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
370 property->base.id));
371
372 snprintf(conn_id, ARRAY_SIZE(conn_id),
373 "CONNECTOR=%u", connector->base.id);
374 snprintf(prop_id, ARRAY_SIZE(prop_id),
375 "PROPERTY=%u", property->base.id);
376
377 DRM_DEBUG("generating connector status event\n");
378
379 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
380}
381EXPORT_SYMBOL(drm_sysfs_connector_status_event);
382
383static void drm_sysfs_release(struct device *dev)
384{
385 kfree(dev);
386}
387
388struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
389{
390 const char *minor_str;
391 struct device *kdev;
392 int r;
393
394 if (minor->type == DRM_MINOR_RENDER)
395 minor_str = "renderD%d";
396 else
397 minor_str = "card%d";
398
399 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
400 if (!kdev)
401 return ERR_PTR(-ENOMEM);
402
403 device_initialize(kdev);
404 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
405 kdev->class = drm_class;
406 kdev->type = &drm_sysfs_device_minor;
407 kdev->parent = minor->dev->dev;
408 kdev->release = drm_sysfs_release;
409 dev_set_drvdata(kdev, minor);
410
411 r = dev_set_name(kdev, minor_str, minor->index);
412 if (r < 0)
413 goto err_free;
414
415 return kdev;
416
417err_free:
418 put_device(kdev);
419 return ERR_PTR(r);
420}
421
422/**
423 * drm_class_device_register - register new device with the DRM sysfs class
424 * @dev: device to register
425 *
426 * Registers a new &struct device within the DRM sysfs class. Essentially only
427 * used by ttm to have a place for its global settings. Drivers should never use
428 * this.
429 */
430int drm_class_device_register(struct device *dev)
431{
432 if (!drm_class || IS_ERR(drm_class))
433 return -ENOENT;
434
435 dev->class = drm_class;
436 return device_register(dev);
437}
438EXPORT_SYMBOL_GPL(drm_class_device_register);
439
440/**
441 * drm_class_device_unregister - unregister device with the DRM sysfs class
442 * @dev: device to unregister
443 *
444 * Unregisters a &struct device from the DRM sysfs class. Essentially only used
445 * by ttm to have a place for its global settings. Drivers should never use
446 * this.
447 */
448void drm_class_device_unregister(struct device *dev)
449{
450 return device_unregister(dev);
451}
452EXPORT_SYMBOL_GPL(drm_class_device_unregister);
1
2/*
3 * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
4 * extra sysfs attribute from DRM. Normal drm_sysfs_class
5 * does not allow adding attributes.
6 *
7 * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
8 * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
9 * Copyright (c) 2003-2004 IBM Corp.
10 *
11 * This file is released under the GPLv2
12 *
13 */
14
15#include <linux/device.h>
16#include <linux/kdev_t.h>
17#include <linux/gfp.h>
18#include <linux/err.h>
19#include <linux/export.h>
20
21#include <drm/drm_sysfs.h>
22#include <drm/drmP.h>
23#include "drm_internal.h"
24
25#define to_drm_minor(d) dev_get_drvdata(d)
26#define to_drm_connector(d) dev_get_drvdata(d)
27
28static struct device_type drm_sysfs_device_minor = {
29 .name = "drm_minor"
30};
31
32struct class *drm_class;
33
34static char *drm_devnode(struct device *dev, umode_t *mode)
35{
36 return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
37}
38
39static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
40
41/**
42 * drm_sysfs_init - initialize sysfs helpers
43 *
44 * This is used to create the DRM class, which is the implicit parent of any
45 * other top-level DRM sysfs objects.
46 *
47 * You must call drm_sysfs_destroy() to release the allocated resources.
48 *
49 * Return: 0 on success, negative error code on failure.
50 */
51int drm_sysfs_init(void)
52{
53 int err;
54
55 drm_class = class_create(THIS_MODULE, "drm");
56 if (IS_ERR(drm_class))
57 return PTR_ERR(drm_class);
58
59 err = class_create_file(drm_class, &class_attr_version.attr);
60 if (err) {
61 class_destroy(drm_class);
62 drm_class = NULL;
63 return err;
64 }
65
66 drm_class->devnode = drm_devnode;
67 return 0;
68}
69
70/**
71 * drm_sysfs_destroy - destroys DRM class
72 *
73 * Destroy the DRM device class.
74 */
75void drm_sysfs_destroy(void)
76{
77 if (IS_ERR_OR_NULL(drm_class))
78 return;
79 class_remove_file(drm_class, &class_attr_version.attr);
80 class_destroy(drm_class);
81 drm_class = NULL;
82}
83
84/*
85 * Connector properties
86 */
87static ssize_t status_store(struct device *device,
88 struct device_attribute *attr,
89 const char *buf, size_t count)
90{
91 struct drm_connector *connector = to_drm_connector(device);
92 struct drm_device *dev = connector->dev;
93 enum drm_connector_force old_force;
94 int ret;
95
96 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
97 if (ret)
98 return ret;
99
100 old_force = connector->force;
101
102 if (sysfs_streq(buf, "detect"))
103 connector->force = 0;
104 else if (sysfs_streq(buf, "on"))
105 connector->force = DRM_FORCE_ON;
106 else if (sysfs_streq(buf, "on-digital"))
107 connector->force = DRM_FORCE_ON_DIGITAL;
108 else if (sysfs_streq(buf, "off"))
109 connector->force = DRM_FORCE_OFF;
110 else
111 ret = -EINVAL;
112
113 if (old_force != connector->force || !connector->force) {
114 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
115 connector->base.id,
116 connector->name,
117 old_force, connector->force);
118
119 connector->funcs->fill_modes(connector,
120 dev->mode_config.max_width,
121 dev->mode_config.max_height);
122 }
123
124 mutex_unlock(&dev->mode_config.mutex);
125
126 return ret ? ret : count;
127}
128
129static ssize_t status_show(struct device *device,
130 struct device_attribute *attr,
131 char *buf)
132{
133 struct drm_connector *connector = to_drm_connector(device);
134 enum drm_connector_status status;
135
136 status = READ_ONCE(connector->status);
137
138 return snprintf(buf, PAGE_SIZE, "%s\n",
139 drm_get_connector_status_name(status));
140}
141
142static ssize_t dpms_show(struct device *device,
143 struct device_attribute *attr,
144 char *buf)
145{
146 struct drm_connector *connector = to_drm_connector(device);
147 int dpms;
148
149 dpms = READ_ONCE(connector->dpms);
150
151 return snprintf(buf, PAGE_SIZE, "%s\n",
152 drm_get_dpms_name(dpms));
153}
154
155static ssize_t enabled_show(struct device *device,
156 struct device_attribute *attr,
157 char *buf)
158{
159 struct drm_connector *connector = to_drm_connector(device);
160 bool enabled;
161
162 enabled = READ_ONCE(connector->encoder);
163
164 return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
165}
166
167static ssize_t edid_show(struct file *filp, struct kobject *kobj,
168 struct bin_attribute *attr, char *buf, loff_t off,
169 size_t count)
170{
171 struct device *connector_dev = kobj_to_dev(kobj);
172 struct drm_connector *connector = to_drm_connector(connector_dev);
173 unsigned char *edid;
174 size_t size;
175 ssize_t ret = 0;
176
177 mutex_lock(&connector->dev->mode_config.mutex);
178 if (!connector->edid_blob_ptr)
179 goto unlock;
180
181 edid = connector->edid_blob_ptr->data;
182 size = connector->edid_blob_ptr->length;
183 if (!edid)
184 goto unlock;
185
186 if (off >= size)
187 goto unlock;
188
189 if (off + count > size)
190 count = size - off;
191 memcpy(buf, edid + off, count);
192
193 ret = count;
194unlock:
195 mutex_unlock(&connector->dev->mode_config.mutex);
196
197 return ret;
198}
199
200static ssize_t modes_show(struct device *device,
201 struct device_attribute *attr,
202 char *buf)
203{
204 struct drm_connector *connector = to_drm_connector(device);
205 struct drm_display_mode *mode;
206 int written = 0;
207
208 mutex_lock(&connector->dev->mode_config.mutex);
209 list_for_each_entry(mode, &connector->modes, head) {
210 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
211 mode->name);
212 }
213 mutex_unlock(&connector->dev->mode_config.mutex);
214
215 return written;
216}
217
218static DEVICE_ATTR_RW(status);
219static DEVICE_ATTR_RO(enabled);
220static DEVICE_ATTR_RO(dpms);
221static DEVICE_ATTR_RO(modes);
222
223static struct attribute *connector_dev_attrs[] = {
224 &dev_attr_status.attr,
225 &dev_attr_enabled.attr,
226 &dev_attr_dpms.attr,
227 &dev_attr_modes.attr,
228 NULL
229};
230
231static struct bin_attribute edid_attr = {
232 .attr.name = "edid",
233 .attr.mode = 0444,
234 .size = 0,
235 .read = edid_show,
236};
237
238static struct bin_attribute *connector_bin_attrs[] = {
239 &edid_attr,
240 NULL
241};
242
243static const struct attribute_group connector_dev_group = {
244 .attrs = connector_dev_attrs,
245 .bin_attrs = connector_bin_attrs,
246};
247
248static const struct attribute_group *connector_dev_groups[] = {
249 &connector_dev_group,
250 NULL
251};
252
253/**
254 * drm_sysfs_connector_add - add a connector to sysfs
255 * @connector: connector to add
256 *
257 * Create a connector device in sysfs, along with its associated connector
258 * properties (so far, connection status, dpms, mode list & edid) and
259 * generate a hotplug event so userspace knows there's a new connector
260 * available.
261 */
262int drm_sysfs_connector_add(struct drm_connector *connector)
263{
264 struct drm_device *dev = connector->dev;
265
266 if (connector->kdev)
267 return 0;
268
269 connector->kdev =
270 device_create_with_groups(drm_class, dev->primary->kdev, 0,
271 connector, connector_dev_groups,
272 "card%d-%s", dev->primary->index,
273 connector->name);
274 DRM_DEBUG("adding \"%s\" to sysfs\n",
275 connector->name);
276
277 if (IS_ERR(connector->kdev)) {
278 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
279 return PTR_ERR(connector->kdev);
280 }
281
282 /* Let userspace know we have a new connector */
283 drm_sysfs_hotplug_event(dev);
284
285 return 0;
286}
287
288/**
289 * drm_sysfs_connector_remove - remove an connector device from sysfs
290 * @connector: connector to remove
291 *
292 * Remove @connector and its associated attributes from sysfs. Note that
293 * the device model core will take care of sending the "remove" uevent
294 * at this time, so we don't need to do it.
295 *
296 * Note:
297 * This routine should only be called if the connector was previously
298 * successfully registered. If @connector hasn't been registered yet,
299 * you'll likely see a panic somewhere deep in sysfs code when called.
300 */
301void drm_sysfs_connector_remove(struct drm_connector *connector)
302{
303 if (!connector->kdev)
304 return;
305 DRM_DEBUG("removing \"%s\" from sysfs\n",
306 connector->name);
307
308 device_unregister(connector->kdev);
309 connector->kdev = NULL;
310}
311
312/**
313 * drm_sysfs_hotplug_event - generate a DRM uevent
314 * @dev: DRM device
315 *
316 * Send a uevent for the DRM device specified by @dev. Currently we only
317 * set HOTPLUG=1 in the uevent environment, but this could be expanded to
318 * deal with other types of events.
319 */
320void drm_sysfs_hotplug_event(struct drm_device *dev)
321{
322 char *event_string = "HOTPLUG=1";
323 char *envp[] = { event_string, NULL };
324
325 DRM_DEBUG("generating hotplug event\n");
326
327 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
328}
329EXPORT_SYMBOL(drm_sysfs_hotplug_event);
330
331static void drm_sysfs_release(struct device *dev)
332{
333 kfree(dev);
334}
335
336/**
337 * drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
338 * @minor: minor to allocate sysfs device for
339 *
340 * This allocates a new sysfs device for @minor and returns it. The device is
341 * not registered nor linked. The caller has to use device_add() and
342 * device_del() to register and unregister it.
343 *
344 * Note that dev_get_drvdata() on the new device will return the minor.
345 * However, the device does not hold a ref-count to the minor nor to the
346 * underlying drm_device. This is unproblematic as long as you access the
347 * private data only in sysfs callbacks. device_del() disables those
348 * synchronously, so they cannot be called after you cleanup a minor.
349 */
350struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
351{
352 const char *minor_str;
353 struct device *kdev;
354 int r;
355
356 if (minor->type == DRM_MINOR_CONTROL)
357 minor_str = "controlD%d";
358 else if (minor->type == DRM_MINOR_RENDER)
359 minor_str = "renderD%d";
360 else
361 minor_str = "card%d";
362
363 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
364 if (!kdev)
365 return ERR_PTR(-ENOMEM);
366
367 device_initialize(kdev);
368 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
369 kdev->class = drm_class;
370 kdev->type = &drm_sysfs_device_minor;
371 kdev->parent = minor->dev->dev;
372 kdev->release = drm_sysfs_release;
373 dev_set_drvdata(kdev, minor);
374
375 r = dev_set_name(kdev, minor_str, minor->index);
376 if (r < 0)
377 goto err_free;
378
379 return kdev;
380
381err_free:
382 put_device(kdev);
383 return ERR_PTR(r);
384}
385
386/**
387 * drm_class_device_register - Register a struct device in the drm class.
388 *
389 * @dev: pointer to struct device to register.
390 *
391 * @dev should have all relevant members pre-filled with the exception
392 * of the class member. In particular, the device_type member must
393 * be set.
394 */
395
396int drm_class_device_register(struct device *dev)
397{
398 if (!drm_class || IS_ERR(drm_class))
399 return -ENOENT;
400
401 dev->class = drm_class;
402 return device_register(dev);
403}
404EXPORT_SYMBOL_GPL(drm_class_device_register);
405
406void drm_class_device_unregister(struct device *dev)
407{
408 return device_unregister(dev);
409}
410EXPORT_SYMBOL_GPL(drm_class_device_unregister);