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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 DMA Helper Functions Reference
126==========================================
127
128.. kernel-doc:: drivers/gpu/drm/drm_fb_dma_helper.c
129 :doc: framebuffer dma helper functions
130
131.. kernel-doc:: drivers/gpu/drm/drm_fb_dma_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/display/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
188MIPI-DSI bridge operation
189-------------------------
190
191.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
192 :doc: dsi bridge operations
193
194
195Bridge Connector Helper Reference
196---------------------------------
197
198.. kernel-doc:: drivers/gpu/drm/display/drm_bridge_connector.c
199 :export:
200
201Panel-Bridge Helper Reference
202-----------------------------
203
204.. kernel-doc:: drivers/gpu/drm/bridge/panel.c
205 :export:
206
207.. _drm_panel_helper:
208
209Panel Helper Reference
210======================
211
212.. kernel-doc:: drivers/gpu/drm/drm_panel.c
213 :doc: drm panel
214
215.. kernel-doc:: include/drm/drm_panel.h
216 :internal:
217
218.. kernel-doc:: drivers/gpu/drm/drm_panel.c
219 :export:
220
221.. kernel-doc:: drivers/gpu/drm/drm_panel_orientation_quirks.c
222 :export:
223
224.. kernel-doc:: drivers/gpu/drm/drm_panel_backlight_quirks.c
225 :export:
226
227Panel Self Refresh Helper Reference
228===================================
229
230.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
231 :doc: overview
232
233.. kernel-doc:: drivers/gpu/drm/drm_self_refresh_helper.c
234 :export:
235
236HDCP Helper Functions Reference
237===============================
238
239.. kernel-doc:: drivers/gpu/drm/display/drm_hdcp_helper.c
240 :export:
241
242Display Port Helper Functions Reference
243=======================================
244
245.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
246 :doc: dp helpers
247
248.. kernel-doc:: include/drm/display/drm_dp.h
249 :internal:
250
251.. kernel-doc:: include/drm/display/drm_dp_helper.h
252 :internal:
253
254.. kernel-doc:: drivers/gpu/drm/display/drm_dp_helper.c
255 :export:
256
257Display Port CEC Helper Functions Reference
258===========================================
259
260.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
261 :doc: dp cec helpers
262
263.. kernel-doc:: drivers/gpu/drm/display/drm_dp_cec.c
264 :export:
265
266Display Port Dual Mode Adaptor Helper Functions Reference
267=========================================================
268
269.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
270 :doc: dp dual mode helpers
271
272.. kernel-doc:: include/drm/display/drm_dp_dual_mode_helper.h
273 :internal:
274
275.. kernel-doc:: drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
276 :export:
277
278Display Port MST Helpers
279========================
280
281Overview
282--------
283
284.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
285 :doc: dp mst helper
286
287.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
288 :doc: Branch device and port refcounting
289
290Functions Reference
291-------------------
292
293.. kernel-doc:: include/drm/display/drm_dp_mst_helper.h
294 :internal:
295
296.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
297 :export:
298
299Topology Lifetime Internals
300---------------------------
301
302These functions aren't exported to drivers, but are documented here to help make
303the MST topology helpers easier to understand
304
305.. kernel-doc:: drivers/gpu/drm/display/drm_dp_mst_topology.c
306 :functions: drm_dp_mst_topology_try_get_mstb drm_dp_mst_topology_get_mstb
307 drm_dp_mst_topology_put_mstb
308 drm_dp_mst_topology_try_get_port drm_dp_mst_topology_get_port
309 drm_dp_mst_topology_put_port
310 drm_dp_mst_get_mstb_malloc drm_dp_mst_put_mstb_malloc
311
312MIPI DBI Helper Functions Reference
313===================================
314
315.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
316 :doc: overview
317
318.. kernel-doc:: include/drm/drm_mipi_dbi.h
319 :internal:
320
321.. kernel-doc:: drivers/gpu/drm/drm_mipi_dbi.c
322 :export:
323
324MIPI DSI Helper Functions Reference
325===================================
326
327.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
328 :doc: dsi helpers
329
330.. kernel-doc:: include/drm/drm_mipi_dsi.h
331 :internal:
332
333.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
334 :export:
335
336Display Stream Compression Helper Functions Reference
337=====================================================
338
339.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
340 :doc: dsc helpers
341
342.. kernel-doc:: include/drm/display/drm_dsc.h
343 :internal:
344
345.. kernel-doc:: drivers/gpu/drm/display/drm_dsc_helper.c
346 :export:
347
348Output Probing Helper Functions Reference
349=========================================
350
351.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
352 :doc: output probing helper overview
353
354.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
355 :export:
356
357EDID Helper Functions Reference
358===============================
359
360.. kernel-doc:: include/drm/drm_edid.h
361 :internal:
362
363.. kernel-doc:: drivers/gpu/drm/drm_edid.c
364 :export:
365
366.. kernel-doc:: include/drm/drm_eld.h
367 :internal:
368
369.. kernel-doc:: drivers/gpu/drm/drm_eld.c
370 :export:
371
372SCDC Helper Functions Reference
373===============================
374
375.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
376 :doc: scdc helpers
377
378.. kernel-doc:: include/drm/display/drm_scdc_helper.h
379 :internal:
380
381.. kernel-doc:: drivers/gpu/drm/display/drm_scdc_helper.c
382 :export:
383
384HDMI Infoframes Helper Reference
385================================
386
387Strictly speaking this is not a DRM helper library but generally usable
388by any driver interfacing with HDMI outputs like v4l or alsa drivers.
389But it nicely fits into the overall topic of mode setting helper
390libraries and hence is also included here.
391
392.. kernel-doc:: include/linux/hdmi.h
393 :internal:
394
395.. kernel-doc:: drivers/video/hdmi.c
396 :export:
397
398Rectangle Utilities Reference
399=============================
400
401.. kernel-doc:: include/drm/drm_rect.h
402 :doc: rect utils
403
404.. kernel-doc:: include/drm/drm_rect.h
405 :internal:
406
407.. kernel-doc:: drivers/gpu/drm/drm_rect.c
408 :export:
409
410Flip-work Helper Reference
411==========================
412
413.. kernel-doc:: include/drm/drm_flip_work.h
414 :doc: flip utils
415
416.. kernel-doc:: include/drm/drm_flip_work.h
417 :internal:
418
419.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
420 :export:
421
422Auxiliary Modeset Helpers
423=========================
424
425.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
426 :doc: aux kms helpers
427
428.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
429 :export:
430
431OF/DT Helpers
432=============
433
434.. kernel-doc:: drivers/gpu/drm/drm_of.c
435 :doc: overview
436
437.. kernel-doc:: drivers/gpu/drm/drm_of.c
438 :export:
439
440Legacy Plane Helper Reference
441=============================
442
443.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
444 :doc: overview
445
446.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
447 :export:
448
449Legacy CRTC/Modeset Helper Functions Reference
450==============================================
451
452.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
453 :doc: overview
454
455.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
456 :export:
457
458Privacy-screen class
459====================
460
461.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
462 :doc: overview
463
464.. kernel-doc:: include/drm/drm_privacy_screen_driver.h
465 :internal:
466
467.. kernel-doc:: include/drm/drm_privacy_screen_machine.h
468 :internal:
469
470.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
471 :export:
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 :internal:
41
42.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
43 :doc: overview
44
45Atomic Modeset Helper Functions Reference
46=========================================
47
48Overview
49--------
50
51.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
52 :doc: overview
53
54Implementing Asynchronous Atomic Commit
55---------------------------------------
56
57.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
58 :doc: implementing nonblocking commit
59
60Atomic State Reset and Initialization
61-------------------------------------
62
63.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
64 :doc: atomic state reset and initialization
65
66Helper Functions Reference
67--------------------------
68
69.. kernel-doc:: include/drm/drm_atomic_helper.h
70 :internal:
71
72.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
73 :export:
74
75Legacy CRTC/Modeset Helper Functions Reference
76==============================================
77
78.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
79 :doc: overview
80
81.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
82 :export:
83
84Simple KMS Helper Reference
85===========================
86
87.. kernel-doc:: include/drm/drm_simple_kms_helper.h
88 :internal:
89
90.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
91 :export:
92
93.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
94 :doc: overview
95
96fbdev Helper Functions Reference
97================================
98
99.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
100 :doc: fbdev helpers
101
102.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
103 :export:
104
105.. kernel-doc:: include/drm/drm_fb_helper.h
106 :internal:
107
108Framebuffer CMA Helper Functions Reference
109==========================================
110
111.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
112 :doc: framebuffer cma helper functions
113
114.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
115 :export:
116
117Bridges
118=======
119
120Overview
121--------
122
123.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
124 :doc: overview
125
126Default bridge callback sequence
127--------------------------------
128
129.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
130 :doc: bridge callbacks
131
132
133Bridge Helper Reference
134-------------------------
135
136.. kernel-doc:: include/drm/drm_bridge.h
137 :internal:
138
139.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
140 :export:
141
142Panel Helper Reference
143======================
144
145.. kernel-doc:: include/drm/drm_panel.h
146 :internal:
147
148.. kernel-doc:: drivers/gpu/drm/drm_panel.c
149 :export:
150
151.. kernel-doc:: drivers/gpu/drm/drm_panel.c
152 :doc: drm panel
153
154Display Port Helper Functions Reference
155=======================================
156
157.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
158 :doc: dp helpers
159
160.. kernel-doc:: include/drm/drm_dp_helper.h
161 :internal:
162
163.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
164 :export:
165
166Display Port Dual Mode Adaptor Helper Functions Reference
167=========================================================
168
169.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
170 :doc: dp dual mode helpers
171
172.. kernel-doc:: include/drm/drm_dp_dual_mode_helper.h
173 :internal:
174
175.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
176 :export:
177
178Display Port MST Helper Functions Reference
179===========================================
180
181.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
182 :doc: dp mst helper
183
184.. kernel-doc:: include/drm/drm_dp_mst_helper.h
185 :internal:
186
187.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
188 :export:
189
190MIPI DSI Helper Functions Reference
191===================================
192
193.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
194 :doc: dsi helpers
195
196.. kernel-doc:: include/drm/drm_mipi_dsi.h
197 :internal:
198
199.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
200 :export:
201
202Output Probing Helper Functions Reference
203=========================================
204
205.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
206 :doc: output probing helper overview
207
208.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
209 :export:
210
211EDID Helper Functions Reference
212===============================
213
214.. kernel-doc:: include/drm/drm_edid.h
215 :internal:
216
217.. kernel-doc:: drivers/gpu/drm/drm_edid.c
218 :export:
219
220Rectangle Utilities Reference
221=============================
222
223.. kernel-doc:: include/drm/drm_rect.h
224 :doc: rect utils
225
226.. kernel-doc:: include/drm/drm_rect.h
227 :internal:
228
229.. kernel-doc:: drivers/gpu/drm/drm_rect.c
230 :export:
231
232HDMI Infoframes Helper Reference
233================================
234
235Strictly speaking this is not a DRM helper library but generally useable
236by any driver interfacing with HDMI outputs like v4l or alsa drivers.
237But it nicely fits into the overall topic of mode setting helper
238libraries and hence is also included here.
239
240.. kernel-doc:: include/linux/hdmi.h
241 :internal:
242
243.. kernel-doc:: drivers/video/hdmi.c
244 :export:
245
246Flip-work Helper Reference
247==========================
248
249.. kernel-doc:: include/drm/drm_flip_work.h
250 :doc: flip utils
251
252.. kernel-doc:: include/drm/drm_flip_work.h
253 :internal:
254
255.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
256 :export:
257
258Plane Helper Reference
259======================
260
261.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
262 :doc: overview
263
264.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
265 :export:
266
267Auxiliary Modeset Helpers
268=========================
269
270.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
271 :doc: aux kms helpers
272
273.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
274 :export: