xref: /linux/Documentation/gpu/drm-kms-helpers.rst (revision bba2c3615bd6cfee7456d1130f2e6b01b3f4e9ba)
1=============================
2Mode Setting Helper Functions
3=============================
4
5The DRM subsystem aims for a strong separation between core code and helper
6libraries. Core code takes care of general setup and teardown and decoding
7userspace requests to kernel internal objects. Everything else is handled by a
8large set of helper libraries, which can be combined freely to pick and choose
9for each driver what fits, and avoid shared code where special behaviour is
10needed.
11
12This distinction between core code and helpers is especially strong in the
13modesetting code, where there's a shared userspace ABI for all drivers. This is
14in contrast to the render side, where pretty much everything (with very few
15exceptions) can be considered optional helper code.
16
17There are a few areas these helpers can grouped into:
18
19* Helpers to implement modesetting. The important ones here are the atomic
20  helpers. Old drivers still often use the legacy CRTC helpers. They both share
21  the same set of common helper vtables. For really simple drivers (anything
22  that would have been a great fit in the deprecated fbdev subsystem) there's
23  also the simple display pipe helpers.
24
25* There's a big pile of helpers for handling outputs. First the generic bridge
26  helpers for handling encoder and transcoder IP blocks. Second the panel helpers
27  for handling panel-related information and logic. Plus then a big set of
28  helpers for the various sink standards (DisplayPort, HDMI, MIPI DSI). Finally
29  there's also generic helpers for handling output probing, and for dealing with
30  EDIDs.
31
32* The last group of helpers concerns itself with the frontend side of a display
33  pipeline: Planes, handling rectangles for visibility checking and scissoring,
34  flip queues and assorted bits.
35
36.. contents::
37
38Modeset Helper Reference for Common Vtables
39===========================================
40
41.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
42   :doc: overview
43
44.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
45   :internal:
46
47.. _drm_atomic_helper:
48
49Atomic Modeset Helper Functions Reference
50=========================================
51
52Overview
53--------
54
55.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
56   :doc: overview
57
58Implementing Asynchronous Atomic Commit
59---------------------------------------
60
61.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
62   :doc: implementing nonblocking commit
63
64Helper Functions Reference
65--------------------------
66
67.. kernel-doc:: include/drm/drm_atomic_helper.h
68   :internal:
69
70.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
71   :export:
72
73Atomic State Reset and Initialization
74-------------------------------------
75
76.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
77   :doc: atomic state reset and initialization
78
79Atomic State Helper Reference
80-----------------------------
81
82.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
83   :export:
84
85GEM Atomic Helper Reference
86---------------------------
87
88.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
89   :doc: overview
90
91.. kernel-doc:: include/drm/drm_gem_atomic_helper.h
92   :internal:
93
94.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
95   :export:
96
97VBLANK Helper Reference
98-----------------------
99
100.. kernel-doc:: drivers/gpu/drm/drm_vblank_helper.c
101   :doc: overview
102
103.. kernel-doc:: include/drm/drm_vblank_helper.h
104   :internal:
105
106.. kernel-doc:: drivers/gpu/drm/drm_vblank_helper.c
107   :export:
108
109fbdev Helper Functions Reference
110================================
111
112.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
113   :doc: fbdev helpers
114
115.. kernel-doc:: include/drm/drm_fb_helper.h
116   :internal:
117
118.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
119   :export:
120
121format Helper Functions Reference
122=================================
123
124.. kernel-doc:: drivers/gpu/drm/drm_format_helper.c
125   :export:
126
127Framebuffer DMA Helper Functions Reference
128==========================================
129
130.. kernel-doc:: drivers/gpu/drm/drm_fb_dma_helper.c
131   :doc: framebuffer dma helper functions
132
133.. kernel-doc:: drivers/gpu/drm/drm_fb_dma_helper.c
134   :export:
135
136Framebuffer GEM Helper Reference
137================================
138
139.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
140   :doc: overview
141
142.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
143   :export:
144
145.. _drm_bridges:
146
147Bridges
148=======
149
150Overview
151--------
152
153.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
154   :doc: overview
155
156Display Driver Integration
157--------------------------
158
159.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
160   :doc: display driver integration
161
162Special Care with MIPI-DSI bridges
163----------------------------------
164
165.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
166   :doc: special care dsi
167
168Bridge Operations
169-----------------
170
171.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
172   :doc: bridge operations
173
174Bridge Connector Helper
175-----------------------
176
177.. kernel-doc:: drivers/gpu/drm/display/drm_bridge_connector.c
178   :doc: overview
179
180
181Bridge Helper Reference
182-------------------------
183
184.. kernel-doc:: include/drm/drm_bridge.h
185   :internal:
186
187.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
188   :export:
189
190MIPI-DSI bridge operation
191-------------------------
192
193.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
194   :doc: dsi bridge operations
195
196
197Bridge Connector Helper Reference
198---------------------------------
199
200.. kernel-doc:: drivers/gpu/drm/display/drm_bridge_connector.c
201   :export:
202
203Panel-Bridge Helper Reference
204-----------------------------
205
206.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
207   :export:
208
209.. _drm_panel_helper:
210
211Panel Helper Reference
212======================
213
214.. kernel-doc:: drivers/gpu/drm/drm_panel.c
215   :doc: drm panel
216
217.. kernel-doc:: include/drm/drm_panel.h
218   :internal:
219
220.. kernel-doc:: drivers/gpu/drm/drm_panel.c
221   :export:
222
223.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
224   :export:
225
226.. kernel-doc:: drivers/gpu/drm/drm_panel_backlight_quirks.c
227   :export:
228
229Panel Self Refresh Helper Reference
230===================================
231
232.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
233   :doc: overview
234
235.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
236   :export:
237
238HDMI Atomic State Helpers
239=========================
240
241Overview
242--------
243
244.. kernel-doc:: drivers/gpu/drm/display/drm_hdmi_state_helper.c
245   :doc: hdmi helpers
246
247Functions Reference
248-------------------
249
250.. kernel-doc:: drivers/gpu/drm/display/drm_hdmi_state_helper.c
251   :export:
252
253HDCP Helper Functions Reference
254===============================
255
256.. kernel-doc:: drivers/gpu/drm/display/drm_hdcp_helper.c
257   :export:
258
259Display Port Helper Functions Reference
260=======================================
261
262.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
263   :doc: dp helpers
264
265.. kernel-doc:: include/drm/display/drm_dp.h
266   :internal:
267
268.. kernel-doc:: include/drm/display/drm_dp_helper.h
269   :internal:
270
271.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
272   :export:
273
274Display Port CEC Helper Functions Reference
275===========================================
276
277.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
278   :doc: dp cec helpers
279
280.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
281   :export:
282
283Display Port Dual Mode Adaptor Helper Functions Reference
284=========================================================
285
286.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
287   :doc: dp dual mode helpers
288
289.. kernel-doc:: include/drm/display/drm_dp_dual_mode_helper.h
290   :internal:
291
292.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
293   :export:
294
295Display Port MST Helpers
296========================
297
298Overview
299--------
300
301.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
302   :doc: dp mst helper
303
304.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
305   :doc: Branch device and port refcounting
306
307Functions Reference
308-------------------
309
310.. kernel-doc:: include/drm/display/drm_dp_mst_helper.h
311   :internal:
312
313.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
314   :export:
315
316Topology Lifetime Internals
317---------------------------
318
319These functions aren't exported to drivers, but are documented here to help make
320the MST topology helpers easier to understand
321
322.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
323   :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
324               drm_dp_mst_topology_put_mstb
325               drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
326               drm_dp_mst_topology_put_port
327               drm_dp_mst_get_mstb_malloc drm_dp_mst_put_mstb_malloc
328
329MIPI DBI Helper Functions Reference
330===================================
331
332.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
333   :doc: overview
334
335.. kernel-doc:: include/drm/drm_mipi_dbi.h
336   :internal:
337
338.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
339   :export:
340
341MIPI DSI Helper Functions Reference
342===================================
343
344.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
345   :doc: dsi helpers
346
347.. kernel-doc:: include/drm/drm_mipi_dsi.h
348   :internal:
349
350.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
351   :export:
352
353Display Stream Compression Helper Functions Reference
354=====================================================
355
356.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
357   :doc: dsc helpers
358
359.. kernel-doc:: include/drm/display/drm_dsc.h
360   :internal:
361
362.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
363   :export:
364
365Output Probing Helper Functions Reference
366=========================================
367
368.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
369   :doc: output probing helper overview
370
371.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
372   :export:
373
374EDID Helper Functions Reference
375===============================
376
377.. kernel-doc:: include/drm/drm_edid.h
378   :internal:
379
380.. kernel-doc:: drivers/gpu/drm/drm_edid.c
381   :export:
382
383.. kernel-doc:: include/drm/drm_eld.h
384   :internal:
385
386.. kernel-doc:: drivers/gpu/drm/drm_eld.c
387   :export:
388
389SCDC Helper Functions Reference
390===============================
391
392.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
393   :doc: scdc helpers
394
395.. kernel-doc:: include/drm/display/drm_scdc_helper.h
396   :internal:
397
398.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
399   :export:
400
401HDMI Infoframes Helper Reference
402================================
403
404Strictly speaking this is not a DRM helper library but generally usable
405by any driver interfacing with HDMI outputs like v4l or alsa drivers.
406But it nicely fits into the overall topic of mode setting helper
407libraries and hence is also included here.
408
409.. kernel-doc:: include/linux/hdmi.h
410   :internal:
411
412.. kernel-doc:: drivers/video/hdmi.c
413   :export:
414
415Rectangle Utilities Reference
416=============================
417
418.. kernel-doc:: include/drm/drm_rect.h
419   :doc: rect utils
420
421.. kernel-doc:: include/drm/drm_rect.h
422   :internal:
423
424.. kernel-doc:: drivers/gpu/drm/drm_rect.c
425   :export:
426
427Flip-work Helper Reference
428==========================
429
430.. kernel-doc:: include/drm/drm_flip_work.h
431   :doc: flip utils
432
433.. kernel-doc:: include/drm/drm_flip_work.h
434   :internal:
435
436.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
437   :export:
438
439Auxiliary Modeset Helpers
440=========================
441
442.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
443   :doc: aux kms helpers
444
445.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
446   :export:
447
448OF/DT Helpers
449=============
450
451.. kernel-doc:: drivers/gpu/drm/drm_of.c
452   :doc: overview
453
454.. kernel-doc:: drivers/gpu/drm/drm_of.c
455   :export:
456
457Legacy Plane Helper Reference
458=============================
459
460.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
461   :doc: overview
462
463.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
464   :export:
465
466Legacy CRTC/Modeset Helper Functions Reference
467==============================================
468
469.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
470   :doc: overview
471
472.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
473   :export:
474
475Privacy-screen class
476====================
477
478.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
479   :doc: overview
480
481.. kernel-doc:: include/drm/drm_privacy_screen_driver.h
482   :internal:
483
484.. kernel-doc:: include/drm/drm_privacy_screen_machine.h
485   :internal:
486
487.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
488   :export:
489