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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#include <linux/dma-fence.h>
13
14#include <drm/drm_crtc.h>
15#include <drm/drm_device.h>
16#include <drm/drm_drv.h>
17#include <drm/drm_framebuffer.h>
18#include <drm/drm_modeset_helper_vtables.h>
19#include <drm/drm_property.h>
20#include <drm/drm_writeback.h>
21
22/**
23 * DOC: overview
24 *
25 * Writeback connectors are used to expose hardware which can write the output
26 * from a CRTC to a memory buffer. They are used and act similarly to other
27 * types of connectors, with some important differences:
28 *
29 * * Writeback connectors don't provide a way to output visually to the user.
30 *
31 * * Writeback connectors are visible to userspace only when the client sets
32 * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS.
33 *
34 * * Writeback connectors don't have EDID.
35 *
36 * A framebuffer may only be attached to a writeback connector when the
37 * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the
38 * framebuffer applies only to a single commit (see below). A framebuffer may
39 * not be attached while the CRTC is off.
40 *
41 * Unlike with planes, when a writeback framebuffer is removed by userspace DRM
42 * makes no attempt to remove it from active use by the connector. This is
43 * because no method is provided to abort a writeback operation, and in any
44 * case making a new commit whilst a writeback is ongoing is undefined (see
45 * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished,
46 * the framebuffer will automatically no longer be in active use. As it will
47 * also have already been removed from the framebuffer list, there will be no
48 * way for any userspace application to retrieve a reference to it in the
49 * intervening period.
50 *
51 * Writeback connectors have some additional properties, which userspace
52 * can use to query and control them:
53 *
54 * "WRITEBACK_FB_ID":
55 * Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the
56 * framebuffer to be written by the writeback connector. This property is
57 * similar to the FB_ID property on planes, but will always read as zero
58 * and is not preserved across commits.
59 * Userspace must set this property to an output buffer every time it
60 * wishes the buffer to get filled.
61 *
62 * "WRITEBACK_PIXEL_FORMATS":
63 * Immutable blob property to store the supported pixel formats table. The
64 * data is an array of u32 DRM_FORMAT_* fourcc values.
65 * Userspace can use this blob to find out what pixel formats are supported
66 * by the connector's writeback engine.
67 *
68 * "WRITEBACK_OUT_FENCE_PTR":
69 * Userspace can use this property to provide a pointer for the kernel to
70 * fill with a sync_file file descriptor, which will signal once the
71 * writeback is finished. The value should be the address of a 32-bit
72 * signed integer, cast to a u64.
73 * Userspace should wait for this fence to signal before making another
74 * commit affecting any of the same CRTCs, Planes or Connectors.
75 * **Failure to do so will result in undefined behaviour.**
76 * For this reason it is strongly recommended that all userspace
77 * applications making use of writeback connectors *always* retrieve an
78 * out-fence for the commit and use it appropriately.
79 * From userspace, this property will always read as zero.
80 */
81
82#define fence_to_wb_connector(x) container_of(x->lock, \
83 struct drm_writeback_connector, \
84 fence_lock)
85
86static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
87{
88 struct drm_writeback_connector *wb_connector =
89 fence_to_wb_connector(fence);
90
91 return wb_connector->base.dev->driver->name;
92}
93
94static const char *
95drm_writeback_fence_get_timeline_name(struct dma_fence *fence)
96{
97 struct drm_writeback_connector *wb_connector =
98 fence_to_wb_connector(fence);
99
100 return wb_connector->timeline_name;
101}
102
103static const struct dma_fence_ops drm_writeback_fence_ops = {
104 .get_driver_name = drm_writeback_fence_get_driver_name,
105 .get_timeline_name = drm_writeback_fence_get_timeline_name,
106};
107
108static int create_writeback_properties(struct drm_device *dev)
109{
110 struct drm_property *prop;
111
112 if (!dev->mode_config.writeback_fb_id_property) {
113 prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
114 "WRITEBACK_FB_ID",
115 DRM_MODE_OBJECT_FB);
116 if (!prop)
117 return -ENOMEM;
118 dev->mode_config.writeback_fb_id_property = prop;
119 }
120
121 if (!dev->mode_config.writeback_pixel_formats_property) {
122 prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
123 DRM_MODE_PROP_ATOMIC |
124 DRM_MODE_PROP_IMMUTABLE,
125 "WRITEBACK_PIXEL_FORMATS", 0);
126 if (!prop)
127 return -ENOMEM;
128 dev->mode_config.writeback_pixel_formats_property = prop;
129 }
130
131 if (!dev->mode_config.writeback_out_fence_ptr_property) {
132 prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
133 "WRITEBACK_OUT_FENCE_PTR", 0,
134 U64_MAX);
135 if (!prop)
136 return -ENOMEM;
137 dev->mode_config.writeback_out_fence_ptr_property = prop;
138 }
139
140 return 0;
141}
142
143static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
144 .destroy = drm_encoder_cleanup,
145};
146
147/**
148 * drm_writeback_connector_init - Initialize a writeback connector and its properties
149 * @dev: DRM device
150 * @wb_connector: Writeback connector to initialize
151 * @con_funcs: Connector funcs vtable
152 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
153 * @formats: Array of supported pixel formats for the writeback engine
154 * @n_formats: Length of the formats array
155 * @possible_crtcs: possible crtcs for the internal writeback encoder
156 *
157 * This function creates the writeback-connector-specific properties if they
158 * have not been already created, initializes the connector as
159 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
160 * values. It will also create an internal encoder associated with the
161 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
162 * the encoder helper.
163 *
164 * Drivers should always use this function instead of drm_connector_init() to
165 * set up writeback connectors.
166 *
167 * Returns: 0 on success, or a negative error code
168 */
169int drm_writeback_connector_init(struct drm_device *dev,
170 struct drm_writeback_connector *wb_connector,
171 const struct drm_connector_funcs *con_funcs,
172 const struct drm_encoder_helper_funcs *enc_helper_funcs,
173 const u32 *formats, int n_formats,
174 u32 possible_crtcs)
175{
176 int ret = 0;
177
178 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
179
180 wb_connector->encoder.possible_crtcs = possible_crtcs;
181
182 ret = drm_encoder_init(dev, &wb_connector->encoder,
183 &drm_writeback_encoder_funcs,
184 DRM_MODE_ENCODER_VIRTUAL, NULL);
185 if (ret)
186 return ret;
187
188 ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
189 con_funcs, formats, n_formats);
190
191 if (ret)
192 drm_encoder_cleanup(&wb_connector->encoder);
193
194 return ret;
195}
196EXPORT_SYMBOL(drm_writeback_connector_init);
197
198/**
199 * drm_writeback_connector_init_with_encoder - Initialize a writeback connector with
200 * a custom encoder
201 *
202 * @dev: DRM device
203 * @wb_connector: Writeback connector to initialize
204 * @enc: handle to the already initialized drm encoder
205 * @con_funcs: Connector funcs vtable
206 * @formats: Array of supported pixel formats for the writeback engine
207 * @n_formats: Length of the formats array
208 *
209 * This function creates the writeback-connector-specific properties if they
210 * have not been already created, initializes the connector as
211 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
212 * values.
213 *
214 * This function assumes that the drm_writeback_connector's encoder has already been
215 * created and initialized before invoking this function.
216 *
217 * In addition, this function also assumes that callers of this API will manage
218 * assigning the encoder helper functions, possible_crtcs and any other encoder
219 * specific operation.
220 *
221 * Drivers should always use this function instead of drm_connector_init() to
222 * set up writeback connectors if they want to manage themselves the lifetime of the
223 * associated encoder.
224 *
225 * Returns: 0 on success, or a negative error code
226 */
227int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
228 struct drm_writeback_connector *wb_connector, struct drm_encoder *enc,
229 const struct drm_connector_funcs *con_funcs, const u32 *formats,
230 int n_formats)
231{
232 struct drm_property_blob *blob;
233 struct drm_connector *connector = &wb_connector->base;
234 struct drm_mode_config *config = &dev->mode_config;
235 int ret = create_writeback_properties(dev);
236
237 if (ret != 0)
238 return ret;
239
240 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
241 formats);
242 if (IS_ERR(blob))
243 return PTR_ERR(blob);
244
245
246 connector->interlace_allowed = 0;
247
248 ret = drm_connector_init(dev, connector, con_funcs,
249 DRM_MODE_CONNECTOR_WRITEBACK);
250 if (ret)
251 goto connector_fail;
252
253 ret = drm_connector_attach_encoder(connector, enc);
254 if (ret)
255 goto attach_fail;
256
257 INIT_LIST_HEAD(&wb_connector->job_queue);
258 spin_lock_init(&wb_connector->job_lock);
259
260 wb_connector->fence_context = dma_fence_context_alloc(1);
261 spin_lock_init(&wb_connector->fence_lock);
262 snprintf(wb_connector->timeline_name,
263 sizeof(wb_connector->timeline_name),
264 "CONNECTOR:%d-%s", connector->base.id, connector->name);
265
266 drm_object_attach_property(&connector->base,
267 config->writeback_out_fence_ptr_property, 0);
268
269 drm_object_attach_property(&connector->base,
270 config->writeback_fb_id_property, 0);
271
272 drm_object_attach_property(&connector->base,
273 config->writeback_pixel_formats_property,
274 blob->base.id);
275 wb_connector->pixel_formats_blob_ptr = blob;
276
277 return 0;
278
279attach_fail:
280 drm_connector_cleanup(connector);
281connector_fail:
282 drm_property_blob_put(blob);
283 return ret;
284}
285EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
286
287int drm_writeback_set_fb(struct drm_connector_state *conn_state,
288 struct drm_framebuffer *fb)
289{
290 WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
291
292 if (!conn_state->writeback_job) {
293 conn_state->writeback_job =
294 kzalloc(sizeof(*conn_state->writeback_job), GFP_KERNEL);
295 if (!conn_state->writeback_job)
296 return -ENOMEM;
297
298 conn_state->writeback_job->connector =
299 drm_connector_to_writeback(conn_state->connector);
300 }
301
302 drm_framebuffer_assign(&conn_state->writeback_job->fb, fb);
303 return 0;
304}
305
306int drm_writeback_prepare_job(struct drm_writeback_job *job)
307{
308 struct drm_writeback_connector *connector = job->connector;
309 const struct drm_connector_helper_funcs *funcs =
310 connector->base.helper_private;
311 int ret;
312
313 if (funcs->prepare_writeback_job) {
314 ret = funcs->prepare_writeback_job(connector, job);
315 if (ret < 0)
316 return ret;
317 }
318
319 job->prepared = true;
320 return 0;
321}
322EXPORT_SYMBOL(drm_writeback_prepare_job);
323
324/**
325 * drm_writeback_queue_job - Queue a writeback job for later signalling
326 * @wb_connector: The writeback connector to queue a job on
327 * @conn_state: The connector state containing the job to queue
328 *
329 * This function adds the job contained in @conn_state to the job_queue for a
330 * writeback connector. It takes ownership of the writeback job and sets the
331 * @conn_state->writeback_job to NULL, and so no access to the job may be
332 * performed by the caller after this function returns.
333 *
334 * Drivers must ensure that for a given writeback connector, jobs are queued in
335 * exactly the same order as they will be completed by the hardware (and
336 * signaled via drm_writeback_signal_completion).
337 *
338 * For every call to drm_writeback_queue_job() there must be exactly one call to
339 * drm_writeback_signal_completion()
340 *
341 * See also: drm_writeback_signal_completion()
342 */
343void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
344 struct drm_connector_state *conn_state)
345{
346 struct drm_writeback_job *job;
347 unsigned long flags;
348
349 job = conn_state->writeback_job;
350 conn_state->writeback_job = NULL;
351
352 spin_lock_irqsave(&wb_connector->job_lock, flags);
353 list_add_tail(&job->list_entry, &wb_connector->job_queue);
354 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
355}
356EXPORT_SYMBOL(drm_writeback_queue_job);
357
358void drm_writeback_cleanup_job(struct drm_writeback_job *job)
359{
360 struct drm_writeback_connector *connector = job->connector;
361 const struct drm_connector_helper_funcs *funcs =
362 connector->base.helper_private;
363
364 if (job->prepared && funcs->cleanup_writeback_job)
365 funcs->cleanup_writeback_job(connector, job);
366
367 if (job->fb)
368 drm_framebuffer_put(job->fb);
369
370 if (job->out_fence)
371 dma_fence_put(job->out_fence);
372
373 kfree(job);
374}
375EXPORT_SYMBOL(drm_writeback_cleanup_job);
376
377/*
378 * @cleanup_work: deferred cleanup of a writeback job
379 *
380 * The job cannot be cleaned up directly in drm_writeback_signal_completion,
381 * because it may be called in interrupt context. Dropping the framebuffer
382 * reference can sleep, and so the cleanup is deferred to a workqueue.
383 */
384static void cleanup_work(struct work_struct *work)
385{
386 struct drm_writeback_job *job = container_of(work,
387 struct drm_writeback_job,
388 cleanup_work);
389
390 drm_writeback_cleanup_job(job);
391}
392
393/**
394 * drm_writeback_signal_completion - Signal the completion of a writeback job
395 * @wb_connector: The writeback connector whose job is complete
396 * @status: Status code to set in the writeback out_fence (0 for success)
397 *
398 * Drivers should call this to signal the completion of a previously queued
399 * writeback job. It should be called as soon as possible after the hardware
400 * has finished writing, and may be called from interrupt context.
401 * It is the driver's responsibility to ensure that for a given connector, the
402 * hardware completes writeback jobs in the same order as they are queued.
403 *
404 * Unless the driver is holding its own reference to the framebuffer, it must
405 * not be accessed after calling this function.
406 *
407 * See also: drm_writeback_queue_job()
408 */
409void
410drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
411 int status)
412{
413 unsigned long flags;
414 struct drm_writeback_job *job;
415 struct dma_fence *out_fence;
416
417 spin_lock_irqsave(&wb_connector->job_lock, flags);
418 job = list_first_entry_or_null(&wb_connector->job_queue,
419 struct drm_writeback_job,
420 list_entry);
421 if (job)
422 list_del(&job->list_entry);
423
424 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
425
426 if (WARN_ON(!job))
427 return;
428
429 out_fence = job->out_fence;
430 if (out_fence) {
431 if (status)
432 dma_fence_set_error(out_fence, status);
433 dma_fence_signal(out_fence);
434 dma_fence_put(out_fence);
435 job->out_fence = NULL;
436 }
437
438 INIT_WORK(&job->cleanup_work, cleanup_work);
439 queue_work(system_long_wq, &job->cleanup_work);
440}
441EXPORT_SYMBOL(drm_writeback_signal_completion);
442
443struct dma_fence *
444drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
445{
446 struct dma_fence *fence;
447
448 if (WARN_ON(wb_connector->base.connector_type !=
449 DRM_MODE_CONNECTOR_WRITEBACK))
450 return NULL;
451
452 fence = kzalloc(sizeof(*fence), GFP_KERNEL);
453 if (!fence)
454 return NULL;
455
456 dma_fence_init(fence, &drm_writeback_fence_ops,
457 &wb_connector->fence_lock, wb_connector->fence_context,
458 ++wb_connector->fence_seqno);
459
460 return fence;
461}
462EXPORT_SYMBOL(drm_writeback_get_out_fence);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
4 * Author: Brian Starkey <brian.starkey@arm.com>
5 *
6 * This program is free software and is provided to you under the terms of the
7 * GNU General Public License version 2 as published by the Free Software
8 * Foundation, and any use by you of this program is subject to the terms
9 * of such GNU licence.
10 */
11
12#include <linux/dma-fence.h>
13
14#include <drm/drm_crtc.h>
15#include <drm/drm_device.h>
16#include <drm/drm_drv.h>
17#include <drm/drm_framebuffer.h>
18#include <drm/drm_modeset_helper_vtables.h>
19#include <drm/drm_property.h>
20#include <drm/drm_writeback.h>
21
22/**
23 * DOC: overview
24 *
25 * Writeback connectors are used to expose hardware which can write the output
26 * from a CRTC to a memory buffer. They are used and act similarly to other
27 * types of connectors, with some important differences:
28 *
29 * * Writeback connectors don't provide a way to output visually to the user.
30 *
31 * * Writeback connectors are visible to userspace only when the client sets
32 * DRM_CLIENT_CAP_WRITEBACK_CONNECTORS.
33 *
34 * * Writeback connectors don't have EDID.
35 *
36 * A framebuffer may only be attached to a writeback connector when the
37 * connector is attached to a CRTC. The WRITEBACK_FB_ID property which sets the
38 * framebuffer applies only to a single commit (see below). A framebuffer may
39 * not be attached while the CRTC is off.
40 *
41 * Unlike with planes, when a writeback framebuffer is removed by userspace DRM
42 * makes no attempt to remove it from active use by the connector. This is
43 * because no method is provided to abort a writeback operation, and in any
44 * case making a new commit whilst a writeback is ongoing is undefined (see
45 * WRITEBACK_OUT_FENCE_PTR below). As soon as the current writeback is finished,
46 * the framebuffer will automatically no longer be in active use. As it will
47 * also have already been removed from the framebuffer list, there will be no
48 * way for any userspace application to retrieve a reference to it in the
49 * intervening period.
50 *
51 * Writeback connectors have some additional properties, which userspace
52 * can use to query and control them:
53 *
54 * "WRITEBACK_FB_ID":
55 * Write-only object property storing a DRM_MODE_OBJECT_FB: it stores the
56 * framebuffer to be written by the writeback connector. This property is
57 * similar to the FB_ID property on planes, but will always read as zero
58 * and is not preserved across commits.
59 * Userspace must set this property to an output buffer every time it
60 * wishes the buffer to get filled.
61 *
62 * "WRITEBACK_PIXEL_FORMATS":
63 * Immutable blob property to store the supported pixel formats table. The
64 * data is an array of u32 DRM_FORMAT_* fourcc values.
65 * Userspace can use this blob to find out what pixel formats are supported
66 * by the connector's writeback engine.
67 *
68 * "WRITEBACK_OUT_FENCE_PTR":
69 * Userspace can use this property to provide a pointer for the kernel to
70 * fill with a sync_file file descriptor, which will signal once the
71 * writeback is finished. The value should be the address of a 32-bit
72 * signed integer, cast to a u64.
73 * Userspace should wait for this fence to signal before making another
74 * commit affecting any of the same CRTCs, Planes or Connectors.
75 * **Failure to do so will result in undefined behaviour.**
76 * For this reason it is strongly recommended that all userspace
77 * applications making use of writeback connectors *always* retrieve an
78 * out-fence for the commit and use it appropriately.
79 * From userspace, this property will always read as zero.
80 */
81
82#define fence_to_wb_connector(x) container_of(x->lock, \
83 struct drm_writeback_connector, \
84 fence_lock)
85
86static const char *drm_writeback_fence_get_driver_name(struct dma_fence *fence)
87{
88 struct drm_writeback_connector *wb_connector =
89 fence_to_wb_connector(fence);
90
91 return wb_connector->base.dev->driver->name;
92}
93
94static const char *
95drm_writeback_fence_get_timeline_name(struct dma_fence *fence)
96{
97 struct drm_writeback_connector *wb_connector =
98 fence_to_wb_connector(fence);
99
100 return wb_connector->timeline_name;
101}
102
103static bool drm_writeback_fence_enable_signaling(struct dma_fence *fence)
104{
105 return true;
106}
107
108static const struct dma_fence_ops drm_writeback_fence_ops = {
109 .get_driver_name = drm_writeback_fence_get_driver_name,
110 .get_timeline_name = drm_writeback_fence_get_timeline_name,
111 .enable_signaling = drm_writeback_fence_enable_signaling,
112};
113
114static int create_writeback_properties(struct drm_device *dev)
115{
116 struct drm_property *prop;
117
118 if (!dev->mode_config.writeback_fb_id_property) {
119 prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
120 "WRITEBACK_FB_ID",
121 DRM_MODE_OBJECT_FB);
122 if (!prop)
123 return -ENOMEM;
124 dev->mode_config.writeback_fb_id_property = prop;
125 }
126
127 if (!dev->mode_config.writeback_pixel_formats_property) {
128 prop = drm_property_create(dev, DRM_MODE_PROP_BLOB |
129 DRM_MODE_PROP_ATOMIC |
130 DRM_MODE_PROP_IMMUTABLE,
131 "WRITEBACK_PIXEL_FORMATS", 0);
132 if (!prop)
133 return -ENOMEM;
134 dev->mode_config.writeback_pixel_formats_property = prop;
135 }
136
137 if (!dev->mode_config.writeback_out_fence_ptr_property) {
138 prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
139 "WRITEBACK_OUT_FENCE_PTR", 0,
140 U64_MAX);
141 if (!prop)
142 return -ENOMEM;
143 dev->mode_config.writeback_out_fence_ptr_property = prop;
144 }
145
146 return 0;
147}
148
149static const struct drm_encoder_funcs drm_writeback_encoder_funcs = {
150 .destroy = drm_encoder_cleanup,
151};
152
153/**
154 * drm_writeback_connector_init - Initialize a writeback connector and its properties
155 * @dev: DRM device
156 * @wb_connector: Writeback connector to initialize
157 * @con_funcs: Connector funcs vtable
158 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder
159 * @formats: Array of supported pixel formats for the writeback engine
160 * @n_formats: Length of the formats array
161 * @possible_crtcs: possible crtcs for the internal writeback encoder
162 *
163 * This function creates the writeback-connector-specific properties if they
164 * have not been already created, initializes the connector as
165 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
166 * values. It will also create an internal encoder associated with the
167 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for
168 * the encoder helper.
169 *
170 * Drivers should always use this function instead of drm_connector_init() to
171 * set up writeback connectors.
172 *
173 * Returns: 0 on success, or a negative error code
174 */
175int drm_writeback_connector_init(struct drm_device *dev,
176 struct drm_writeback_connector *wb_connector,
177 const struct drm_connector_funcs *con_funcs,
178 const struct drm_encoder_helper_funcs *enc_helper_funcs,
179 const u32 *formats, int n_formats,
180 u32 possible_crtcs)
181{
182 int ret = 0;
183
184 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs);
185
186 wb_connector->encoder.possible_crtcs = possible_crtcs;
187
188 ret = drm_encoder_init(dev, &wb_connector->encoder,
189 &drm_writeback_encoder_funcs,
190 DRM_MODE_ENCODER_VIRTUAL, NULL);
191 if (ret)
192 return ret;
193
194 ret = drm_writeback_connector_init_with_encoder(dev, wb_connector, &wb_connector->encoder,
195 con_funcs, formats, n_formats);
196
197 if (ret)
198 drm_encoder_cleanup(&wb_connector->encoder);
199
200 return ret;
201}
202EXPORT_SYMBOL(drm_writeback_connector_init);
203
204/**
205 * drm_writeback_connector_init_with_encoder - Initialize a writeback connector with
206 * a custom encoder
207 *
208 * @dev: DRM device
209 * @wb_connector: Writeback connector to initialize
210 * @enc: handle to the already initialized drm encoder
211 * @con_funcs: Connector funcs vtable
212 * @formats: Array of supported pixel formats for the writeback engine
213 * @n_formats: Length of the formats array
214 *
215 * This function creates the writeback-connector-specific properties if they
216 * have not been already created, initializes the connector as
217 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property
218 * values.
219 *
220 * This function assumes that the drm_writeback_connector's encoder has already been
221 * created and initialized before invoking this function.
222 *
223 * In addition, this function also assumes that callers of this API will manage
224 * assigning the encoder helper functions, possible_crtcs and any other encoder
225 * specific operation.
226 *
227 * Drivers should always use this function instead of drm_connector_init() to
228 * set up writeback connectors if they want to manage themselves the lifetime of the
229 * associated encoder.
230 *
231 * Returns: 0 on success, or a negative error code
232 */
233int drm_writeback_connector_init_with_encoder(struct drm_device *dev,
234 struct drm_writeback_connector *wb_connector, struct drm_encoder *enc,
235 const struct drm_connector_funcs *con_funcs, const u32 *formats,
236 int n_formats)
237{
238 struct drm_property_blob *blob;
239 struct drm_connector *connector = &wb_connector->base;
240 struct drm_mode_config *config = &dev->mode_config;
241 int ret = create_writeback_properties(dev);
242
243 if (ret != 0)
244 return ret;
245
246 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats),
247 formats);
248 if (IS_ERR(blob))
249 return PTR_ERR(blob);
250
251
252 connector->interlace_allowed = 0;
253
254 ret = drm_connector_init(dev, connector, con_funcs,
255 DRM_MODE_CONNECTOR_WRITEBACK);
256 if (ret)
257 goto connector_fail;
258
259 ret = drm_connector_attach_encoder(connector, enc);
260 if (ret)
261 goto attach_fail;
262
263 INIT_LIST_HEAD(&wb_connector->job_queue);
264 spin_lock_init(&wb_connector->job_lock);
265
266 wb_connector->fence_context = dma_fence_context_alloc(1);
267 spin_lock_init(&wb_connector->fence_lock);
268 snprintf(wb_connector->timeline_name,
269 sizeof(wb_connector->timeline_name),
270 "CONNECTOR:%d-%s", connector->base.id, connector->name);
271
272 drm_object_attach_property(&connector->base,
273 config->writeback_out_fence_ptr_property, 0);
274
275 drm_object_attach_property(&connector->base,
276 config->writeback_fb_id_property, 0);
277
278 drm_object_attach_property(&connector->base,
279 config->writeback_pixel_formats_property,
280 blob->base.id);
281 wb_connector->pixel_formats_blob_ptr = blob;
282
283 return 0;
284
285attach_fail:
286 drm_connector_cleanup(connector);
287connector_fail:
288 drm_property_blob_put(blob);
289 return ret;
290}
291EXPORT_SYMBOL(drm_writeback_connector_init_with_encoder);
292
293int drm_writeback_set_fb(struct drm_connector_state *conn_state,
294 struct drm_framebuffer *fb)
295{
296 WARN_ON(conn_state->connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
297
298 if (!conn_state->writeback_job) {
299 conn_state->writeback_job =
300 kzalloc(sizeof(*conn_state->writeback_job), GFP_KERNEL);
301 if (!conn_state->writeback_job)
302 return -ENOMEM;
303
304 conn_state->writeback_job->connector =
305 drm_connector_to_writeback(conn_state->connector);
306 }
307
308 drm_framebuffer_assign(&conn_state->writeback_job->fb, fb);
309 return 0;
310}
311
312int drm_writeback_prepare_job(struct drm_writeback_job *job)
313{
314 struct drm_writeback_connector *connector = job->connector;
315 const struct drm_connector_helper_funcs *funcs =
316 connector->base.helper_private;
317 int ret;
318
319 if (funcs->prepare_writeback_job) {
320 ret = funcs->prepare_writeback_job(connector, job);
321 if (ret < 0)
322 return ret;
323 }
324
325 job->prepared = true;
326 return 0;
327}
328EXPORT_SYMBOL(drm_writeback_prepare_job);
329
330/**
331 * drm_writeback_queue_job - Queue a writeback job for later signalling
332 * @wb_connector: The writeback connector to queue a job on
333 * @conn_state: The connector state containing the job to queue
334 *
335 * This function adds the job contained in @conn_state to the job_queue for a
336 * writeback connector. It takes ownership of the writeback job and sets the
337 * @conn_state->writeback_job to NULL, and so no access to the job may be
338 * performed by the caller after this function returns.
339 *
340 * Drivers must ensure that for a given writeback connector, jobs are queued in
341 * exactly the same order as they will be completed by the hardware (and
342 * signaled via drm_writeback_signal_completion).
343 *
344 * For every call to drm_writeback_queue_job() there must be exactly one call to
345 * drm_writeback_signal_completion()
346 *
347 * See also: drm_writeback_signal_completion()
348 */
349void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
350 struct drm_connector_state *conn_state)
351{
352 struct drm_writeback_job *job;
353 unsigned long flags;
354
355 job = conn_state->writeback_job;
356 conn_state->writeback_job = NULL;
357
358 spin_lock_irqsave(&wb_connector->job_lock, flags);
359 list_add_tail(&job->list_entry, &wb_connector->job_queue);
360 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
361}
362EXPORT_SYMBOL(drm_writeback_queue_job);
363
364void drm_writeback_cleanup_job(struct drm_writeback_job *job)
365{
366 struct drm_writeback_connector *connector = job->connector;
367 const struct drm_connector_helper_funcs *funcs =
368 connector->base.helper_private;
369
370 if (job->prepared && funcs->cleanup_writeback_job)
371 funcs->cleanup_writeback_job(connector, job);
372
373 if (job->fb)
374 drm_framebuffer_put(job->fb);
375
376 if (job->out_fence)
377 dma_fence_put(job->out_fence);
378
379 kfree(job);
380}
381EXPORT_SYMBOL(drm_writeback_cleanup_job);
382
383/*
384 * @cleanup_work: deferred cleanup of a writeback job
385 *
386 * The job cannot be cleaned up directly in drm_writeback_signal_completion,
387 * because it may be called in interrupt context. Dropping the framebuffer
388 * reference can sleep, and so the cleanup is deferred to a workqueue.
389 */
390static void cleanup_work(struct work_struct *work)
391{
392 struct drm_writeback_job *job = container_of(work,
393 struct drm_writeback_job,
394 cleanup_work);
395
396 drm_writeback_cleanup_job(job);
397}
398
399/**
400 * drm_writeback_signal_completion - Signal the completion of a writeback job
401 * @wb_connector: The writeback connector whose job is complete
402 * @status: Status code to set in the writeback out_fence (0 for success)
403 *
404 * Drivers should call this to signal the completion of a previously queued
405 * writeback job. It should be called as soon as possible after the hardware
406 * has finished writing, and may be called from interrupt context.
407 * It is the driver's responsibility to ensure that for a given connector, the
408 * hardware completes writeback jobs in the same order as they are queued.
409 *
410 * Unless the driver is holding its own reference to the framebuffer, it must
411 * not be accessed after calling this function.
412 *
413 * See also: drm_writeback_queue_job()
414 */
415void
416drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
417 int status)
418{
419 unsigned long flags;
420 struct drm_writeback_job *job;
421 struct dma_fence *out_fence;
422
423 spin_lock_irqsave(&wb_connector->job_lock, flags);
424 job = list_first_entry_or_null(&wb_connector->job_queue,
425 struct drm_writeback_job,
426 list_entry);
427 if (job)
428 list_del(&job->list_entry);
429
430 spin_unlock_irqrestore(&wb_connector->job_lock, flags);
431
432 if (WARN_ON(!job))
433 return;
434
435 out_fence = job->out_fence;
436 if (out_fence) {
437 if (status)
438 dma_fence_set_error(out_fence, status);
439 dma_fence_signal(out_fence);
440 dma_fence_put(out_fence);
441 job->out_fence = NULL;
442 }
443
444 INIT_WORK(&job->cleanup_work, cleanup_work);
445 queue_work(system_long_wq, &job->cleanup_work);
446}
447EXPORT_SYMBOL(drm_writeback_signal_completion);
448
449struct dma_fence *
450drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector)
451{
452 struct dma_fence *fence;
453
454 if (WARN_ON(wb_connector->base.connector_type !=
455 DRM_MODE_CONNECTOR_WRITEBACK))
456 return NULL;
457
458 fence = kzalloc(sizeof(*fence), GFP_KERNEL);
459 if (!fence)
460 return NULL;
461
462 dma_fence_init(fence, &drm_writeback_fence_ops,
463 &wb_connector->fence_lock, wb_connector->fence_context,
464 ++wb_connector->fence_seqno);
465
466 return fence;
467}
468EXPORT_SYMBOL(drm_writeback_get_out_fence);