xref: /linux/Documentation/gpu/drm-kms-helpers.rst (revision e999db587312e5b798421d803495f41d1283d7d7)
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
83Simple KMS Helper Reference
84===========================
85
86.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
87   :doc: overview
88
89.. kernel-doc:: include/drm/drm_simple_kms_helper.h
90   :internal:
91
92.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
93   :export:
94
95fbdev Helper Functions Reference
96================================
97
98.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
99   :doc: fbdev helpers
100
101.. kernel-doc:: include/drm/drm_fb_helper.h
102   :internal:
103
104.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
105   :export:
106
107format Helper Functions Reference
108=================================
109
110.. kernel-doc:: drivers/gpu/drm/drm_format_helper.c
111   :export:
112
113Framebuffer CMA Helper Functions Reference
114==========================================
115
116.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
117   :doc: framebuffer cma helper functions
118
119.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
120   :export:
121
122Framebuffer GEM Helper Reference
123================================
124
125.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
126   :doc: overview
127
128.. kernel-doc:: drivers/gpu/drm/drm_gem_framebuffer_helper.c
129   :export:
130
131.. _drm_bridges:
132
133Bridges
134=======
135
136Overview
137--------
138
139.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
140   :doc: overview
141
142Bridge Operations
143-----------------
144
145.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
146   :doc: bridge operations
147
148Bridge Connector Helper
149-----------------------
150
151.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
152   :doc: overview
153
154
155Bridge Helper Reference
156-------------------------
157
158.. kernel-doc:: include/drm/drm_bridge.h
159   :internal:
160
161.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
162   :export:
163
164Bridge Connector Helper Reference
165---------------------------------
166
167.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
168   :export:
169
170Panel-Bridge Helper Reference
171-----------------------------
172
173.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
174   :export:
175
176.. _drm_panel_helper:
177
178Panel Helper Reference
179======================
180
181.. kernel-doc:: drivers/gpu/drm/drm_panel.c
182   :doc: drm panel
183
184.. kernel-doc:: include/drm/drm_panel.h
185   :internal:
186
187.. kernel-doc:: drivers/gpu/drm/drm_panel.c
188   :export:
189
190.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
191   :export:
192
193Panel Self Refresh Helper Reference
194===================================
195
196.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
197   :doc: overview
198
199.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
200   :export:
201
202HDCP Helper Functions Reference
203===============================
204
205.. kernel-doc:: drivers/gpu/drm/drm_hdcp.c
206   :export:
207
208Display Port Helper Functions Reference
209=======================================
210
211.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
212   :doc: dp helpers
213
214.. kernel-doc:: include/drm/drm_dp_helper.h
215   :internal:
216
217.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
218   :export:
219
220Display Port CEC Helper Functions Reference
221===========================================
222
223.. kernel-doc:: drivers/gpu/drm/drm_dp_cec.c
224   :doc: dp cec helpers
225
226.. kernel-doc:: drivers/gpu/drm/drm_dp_cec.c
227   :export:
228
229Display Port Dual Mode Adaptor Helper Functions Reference
230=========================================================
231
232.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
233   :doc: dp dual mode helpers
234
235.. kernel-doc:: include/drm/drm_dp_dual_mode_helper.h
236   :internal:
237
238.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
239   :export:
240
241Display Port MST Helpers
242========================
243
244Overview
245--------
246
247.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
248   :doc: dp mst helper
249
250.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
251   :doc: Branch device and port refcounting
252
253Functions Reference
254-------------------
255
256.. kernel-doc:: include/drm/drm_dp_mst_helper.h
257   :internal:
258
259.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
260   :export:
261
262Topology Lifetime Internals
263---------------------------
264
265These functions aren't exported to drivers, but are documented here to help make
266the MST topology helpers easier to understand
267
268.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
269   :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
270               drm_dp_mst_topology_put_mstb
271               drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
272               drm_dp_mst_topology_put_port
273               drm_dp_mst_get_mstb_malloc drm_dp_mst_put_mstb_malloc
274
275MIPI DBI Helper Functions Reference
276===================================
277
278.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
279   :doc: overview
280
281.. kernel-doc:: include/drm/drm_mipi_dbi.h
282   :internal:
283
284.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
285   :export:
286
287MIPI DSI Helper Functions Reference
288===================================
289
290.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
291   :doc: dsi helpers
292
293.. kernel-doc:: include/drm/drm_mipi_dsi.h
294   :internal:
295
296.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
297   :export:
298
299Display Stream Compression Helper Functions Reference
300=====================================================
301
302.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
303   :doc: dsc helpers
304
305.. kernel-doc:: include/drm/drm_dsc.h
306   :internal:
307
308.. kernel-doc:: drivers/gpu/drm/drm_dsc.c
309   :export:
310
311Output Probing Helper Functions Reference
312=========================================
313
314.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
315   :doc: output probing helper overview
316
317.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
318   :export:
319
320EDID Helper Functions Reference
321===============================
322
323.. kernel-doc:: include/drm/drm_edid.h
324   :internal:
325
326.. kernel-doc:: drivers/gpu/drm/drm_edid.c
327   :export:
328
329SCDC Helper Functions Reference
330===============================
331
332.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
333   :doc: scdc helpers
334
335.. kernel-doc:: include/drm/drm_scdc_helper.h
336   :internal:
337
338.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
339   :export:
340
341HDMI Infoframes Helper Reference
342================================
343
344Strictly speaking this is not a DRM helper library but generally useable
345by any driver interfacing with HDMI outputs like v4l or alsa drivers.
346But it nicely fits into the overall topic of mode setting helper
347libraries and hence is also included here.
348
349.. kernel-doc:: include/linux/hdmi.h
350   :internal:
351
352.. kernel-doc:: drivers/video/hdmi.c
353   :export:
354
355Rectangle Utilities Reference
356=============================
357
358.. kernel-doc:: include/drm/drm_rect.h
359   :doc: rect utils
360
361.. kernel-doc:: include/drm/drm_rect.h
362   :internal:
363
364.. kernel-doc:: drivers/gpu/drm/drm_rect.c
365   :export:
366
367Flip-work Helper Reference
368==========================
369
370.. kernel-doc:: include/drm/drm_flip_work.h
371   :doc: flip utils
372
373.. kernel-doc:: include/drm/drm_flip_work.h
374   :internal:
375
376.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
377   :export:
378
379Auxiliary Modeset Helpers
380=========================
381
382.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
383   :doc: aux kms helpers
384
385.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
386   :export:
387
388OF/DT Helpers
389=============
390
391.. kernel-doc:: drivers/gpu/drm/drm_of.c
392   :doc: overview
393
394.. kernel-doc:: drivers/gpu/drm/drm_of.c
395   :export:
396
397Legacy Plane Helper Reference
398=============================
399
400.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
401   :doc: overview
402
403.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
404   :export:
405
406Legacy CRTC/Modeset Helper Functions Reference
407==============================================
408
409.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
410   :doc: overview
411
412.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
413   :export:
414