xref: /linux/Documentation/gpu/drm-kms-helpers.rst (revision cbac924200b838cfb8d8b1415113d788089dc50b)
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
36Modeset Helper Reference for Common Vtables
37===========================================
38
39.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
40   :doc: overview
41
42.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
43   :internal:
44
45.. _drm_atomic_helper:
46
47Atomic Modeset Helper Functions Reference
48=========================================
49
50Overview
51--------
52
53.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
54   :doc: overview
55
56Implementing Asynchronous Atomic Commit
57---------------------------------------
58
59.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
60   :doc: implementing nonblocking commit
61
62Helper Functions Reference
63--------------------------
64
65.. kernel-doc:: include/drm/drm_atomic_helper.h
66   :internal:
67
68.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
69   :export:
70
71Atomic State Reset and Initialization
72-------------------------------------
73
74.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
75   :doc: atomic state reset and initialization
76
77Atomic State Helper Reference
78-----------------------------
79
80.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
81   :export:
82
83GEM Atomic Helper Reference
84---------------------------
85
86.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
87   :doc: overview
88
89.. kernel-doc:: include/drm/drm_gem_atomic_helper.h
90   :internal:
91
92.. kernel-doc:: drivers/gpu/drm/drm_gem_atomic_helper.c
93   :export:
94
95Simple KMS Helper Reference
96===========================
97
98.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
99   :doc: overview
100
101.. kernel-doc:: include/drm/drm_simple_kms_helper.h
102   :internal:
103
104.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
105   :export:
106
107fbdev Helper Functions Reference
108================================
109
110.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
111   :doc: fbdev helpers
112
113.. kernel-doc:: include/drm/drm_fb_helper.h
114   :internal:
115
116.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
117   :export:
118
119format Helper Functions Reference
120=================================
121
122.. kernel-doc:: drivers/gpu/drm/drm_format_helper.c
123   :export:
124
125Framebuffer CMA Helper Functions Reference
126==========================================
127
128.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
129   :doc: framebuffer cma helper functions
130
131.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
132   :export:
133
134Framebuffer GEM Helper Reference
135================================
136
137.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
138   :doc: overview
139
140.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
141   :export:
142
143.. _drm_bridges:
144
145Bridges
146=======
147
148Overview
149--------
150
151.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
152   :doc: overview
153
154Display Driver Integration
155--------------------------
156
157.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
158   :doc: display driver integration
159
160Special Care with MIPI-DSI bridges
161----------------------------------
162
163.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
164   :doc: special care dsi
165
166Bridge Operations
167-----------------
168
169.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
170   :doc: bridge operations
171
172Bridge Connector Helper
173-----------------------
174
175.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
176   :doc: overview
177
178
179Bridge Helper Reference
180-------------------------
181
182.. kernel-doc:: include/drm/drm_bridge.h
183   :internal:
184
185.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
186   :export:
187
188Bridge Connector Helper Reference
189---------------------------------
190
191.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
192   :export:
193
194Panel-Bridge Helper Reference
195-----------------------------
196
197.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
198   :export:
199
200.. _drm_panel_helper:
201
202Panel Helper Reference
203======================
204
205.. kernel-doc:: drivers/gpu/drm/drm_panel.c
206   :doc: drm panel
207
208.. kernel-doc:: include/drm/drm_panel.h
209   :internal:
210
211.. kernel-doc:: drivers/gpu/drm/drm_panel.c
212   :export:
213
214.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
215   :export:
216
217Panel Self Refresh Helper Reference
218===================================
219
220.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
221   :doc: overview
222
223.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
224   :export:
225
226HDCP Helper Functions Reference
227===============================
228
229.. kernel-doc:: drivers/gpu/drm/drm_hdcp.c
230   :export:
231
232Display Port Helper Functions Reference
233=======================================
234
235.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c
236   :doc: dp helpers
237
238.. kernel-doc:: include/drm/dp/drm_dp_helper.h
239   :internal:
240
241.. kernel-doc:: drivers/gpu/drm/dp/drm_dp.c
242   :export:
243
244Display Port CEC Helper Functions Reference
245===========================================
246
247.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c
248   :doc: dp cec helpers
249
250.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_cec.c
251   :export:
252
253Display Port Dual Mode Adaptor Helper Functions Reference
254=========================================================
255
256.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c
257   :doc: dp dual mode helpers
258
259.. kernel-doc:: include/drm/dp/drm_dp_dual_mode_helper.h
260   :internal:
261
262.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_dual_mode_helper.c
263   :export:
264
265Display Port MST Helpers
266========================
267
268Overview
269--------
270
271.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
272   :doc: dp mst helper
273
274.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
275   :doc: Branch device and port refcounting
276
277Functions Reference
278-------------------
279
280.. kernel-doc:: include/drm/dp/drm_dp_mst_helper.h
281   :internal:
282
283.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
284   :export:
285
286Topology Lifetime Internals
287---------------------------
288
289These functions aren't exported to drivers, but are documented here to help make
290the MST topology helpers easier to understand
291
292.. kernel-doc:: drivers/gpu/drm/dp/drm_dp_mst_topology.c
293   :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
294               drm_dp_mst_topology_put_mstb
295               drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
296               drm_dp_mst_topology_put_port
297               drm_dp_mst_get_mstb_malloc drm_dp_mst_put_mstb_malloc
298
299MIPI DBI Helper Functions Reference
300===================================
301
302.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
303   :doc: overview
304
305.. kernel-doc:: include/drm/drm_mipi_dbi.h
306   :internal:
307
308.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
309   :export:
310
311MIPI DSI Helper Functions Reference
312===================================
313
314.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
315   :doc: dsi helpers
316
317.. kernel-doc:: include/drm/drm_mipi_dsi.h
318   :internal:
319
320.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
321   :export:
322
323Display Stream Compression Helper Functions Reference
324=====================================================
325
326.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
327   :doc: dsc helpers
328
329.. kernel-doc:: include/drm/drm_dsc.h
330   :internal:
331
332.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
333   :export:
334
335Output Probing Helper Functions Reference
336=========================================
337
338.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
339   :doc: output probing helper overview
340
341.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
342   :export:
343
344EDID Helper Functions Reference
345===============================
346
347.. kernel-doc:: include/drm/drm_edid.h
348   :internal:
349
350.. kernel-doc:: drivers/gpu/drm/drm_edid.c
351   :export:
352
353SCDC Helper Functions Reference
354===============================
355
356.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
357   :doc: scdc helpers
358
359.. kernel-doc:: include/drm/drm_scdc_helper.h
360   :internal:
361
362.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
363   :export:
364
365HDMI Infoframes Helper Reference
366================================
367
368Strictly speaking this is not a DRM helper library but generally useable
369by any driver interfacing with HDMI outputs like v4l or alsa drivers.
370But it nicely fits into the overall topic of mode setting helper
371libraries and hence is also included here.
372
373.. kernel-doc:: include/linux/hdmi.h
374   :internal:
375
376.. kernel-doc:: drivers/video/hdmi.c
377   :export:
378
379Rectangle Utilities Reference
380=============================
381
382.. kernel-doc:: include/drm/drm_rect.h
383   :doc: rect utils
384
385.. kernel-doc:: include/drm/drm_rect.h
386   :internal:
387
388.. kernel-doc:: drivers/gpu/drm/drm_rect.c
389   :export:
390
391Flip-work Helper Reference
392==========================
393
394.. kernel-doc:: include/drm/drm_flip_work.h
395   :doc: flip utils
396
397.. kernel-doc:: include/drm/drm_flip_work.h
398   :internal:
399
400.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
401   :export:
402
403Auxiliary Modeset Helpers
404=========================
405
406.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
407   :doc: aux kms helpers
408
409.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
410   :export:
411
412OF/DT Helpers
413=============
414
415.. kernel-doc:: drivers/gpu/drm/drm_of.c
416   :doc: overview
417
418.. kernel-doc:: drivers/gpu/drm/drm_of.c
419   :export:
420
421Legacy Plane Helper Reference
422=============================
423
424.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
425   :doc: overview
426
427.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
428   :export:
429
430Legacy CRTC/Modeset Helper Functions Reference
431==============================================
432
433.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
434   :doc: overview
435
436.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
437   :export:
438
439Privacy-screen class
440====================
441
442.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
443   :doc: overview
444
445.. kernel-doc:: include/drm/drm_privacy_screen_driver.h
446   :internal:
447
448.. kernel-doc:: include/drm/drm_privacy_screen_machine.h
449   :internal:
450
451.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
452   :export:
453