summaryrefslogtreecommitdiffstats
path: root/Documentation/gpu/drm-kms-helpers.rst
blob: c075aadd7078c7d86b5065a5429fc75aef99c7ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
=============================
Mode Setting Helper Functions
=============================

The DRM subsystem aims for a strong separation between core code and helper
libraries. Core code takes care of general setup and teardown and decoding
userspace requests to kernel internal objects. Everything else is handled by a
large set of helper libraries, which can be combined freely to pick and choose
for each driver what fits, and avoid shared code where special behaviour is
needed.

This distinction between core code and helpers is especially strong in the
modesetting code, where there's a shared userspace ABI for all drivers. This is
in contrast to the render side, where pretty much everything (with very few
exceptions) can be considered optional helper code.

There are a few areas these helpers can grouped into:

* Helpers to implement modesetting. The important ones here are the atomic
  helpers. Old drivers still often use the legacy CRTC helpers. They both share
  the same set of common helper vtables. For really simple drivers (anything
  that would have been a great fit in the deprecated fbdev subsystem) there's
  also the simple display pipe helpers.

* There's a big pile of helpers for handling outputs. First the generic bridge
  helpers for handling encoder and transcoder IP blocks. Second the panel helpers
  for handling panel-related information and logic. Plus then a big set of
  helpers for the various sink standards (DisplayPort, HDMI, MIPI DSI). Finally
  there's also generic helpers for handling output probing, and for dealing with
  EDIDs.

* The last group of helpers concerns itself with the frontend side of a display
  pipeline: Planes, handling rectangles for visibility checking and scissoring,
  flip queues and assorted bits.

Modeset Helper Reference for Common Vtables
===========================================

.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
   :doc: overview

.. kernel-doc:: include/drm/drm_modeset_helper_vtables.h
   :internal:

.. _drm_atomic_helper:

Atomic Modeset Helper Functions Reference
=========================================

Overview
--------

.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
   :doc: overview

Implementing Asynchronous Atomic Commit
---------------------------------------

.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
   :doc: implementing nonblocking commit

Atomic State Reset and Initialization
-------------------------------------

.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
   :doc: atomic state reset and initialization

Helper Functions Reference
--------------------------

.. kernel-doc:: include/drm/drm_atomic_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_atomic_helper.c
   :export:

Legacy CRTC/Modeset Helper Functions Reference
==============================================

.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
   :doc: overview

.. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
   :export:

Simple KMS Helper Reference
===========================

.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
   :doc: overview

.. kernel-doc:: include/drm/drm_simple_kms_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_simple_kms_helper.c
   :export:

fbdev Helper Functions Reference
================================

.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
   :doc: fbdev helpers

.. kernel-doc:: include/drm/drm_fb_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_fb_helper.c
   :export:

Framebuffer CMA Helper Functions Reference
==========================================

.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
   :doc: framebuffer cma helper functions

.. kernel-doc:: drivers/gpu/drm/drm_fb_cma_helper.c
   :export:

.. _drm_bridges:

Bridges
=======

Overview
--------

.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
   :doc: overview

Default bridge callback sequence
--------------------------------

.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
   :doc: bridge callbacks


Bridge Helper Reference
-------------------------

.. kernel-doc:: include/drm/drm_bridge.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_bridge.c
   :export:

.. _drm_panel_helper:

Panel Helper Reference
======================

.. kernel-doc:: drivers/gpu/drm/drm_panel.c
   :doc: drm panel

.. kernel-doc:: include/drm/drm_panel.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_panel.c
   :export:

Display Port Helper Functions Reference
=======================================

.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
   :doc: dp helpers

.. kernel-doc:: include/drm/drm_dp_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_dp_helper.c
   :export:

Display Port Dual Mode Adaptor Helper Functions Reference
=========================================================

.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
   :doc: dp dual mode helpers

.. kernel-doc:: include/drm/drm_dp_dual_mode_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_dp_dual_mode_helper.c
   :export:

Display Port MST Helper Functions Reference
===========================================

.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
   :doc: dp mst helper

.. kernel-doc:: include/drm/drm_dp_mst_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_dp_mst_topology.c
   :export:

MIPI DSI Helper Functions Reference
===================================

.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
   :doc: dsi helpers

.. kernel-doc:: include/drm/drm_mipi_dsi.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_mipi_dsi.c
   :export:

Output Probing Helper Functions Reference
=========================================

.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
   :doc: output probing helper overview

.. kernel-doc:: drivers/gpu/drm/drm_probe_helper.c
   :export:

EDID Helper Functions Reference
===============================

.. kernel-doc:: include/drm/drm_edid.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_edid.c
   :export:

SCDC Helper Functions Reference
===============================

.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
   :doc: scdc helpers

.. kernel-doc:: include/drm/drm_scdc_helper.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_scdc_helper.c
   :export:

Rectangle Utilities Reference
=============================

.. kernel-doc:: include/drm/drm_rect.h
   :doc: rect utils

.. kernel-doc:: include/drm/drm_rect.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_rect.c
   :export:

HDMI Infoframes Helper Reference
================================

Strictly speaking this is not a DRM helper library but generally useable
by any driver interfacing with HDMI outputs like v4l or alsa drivers.
But it nicely fits into the overall topic of mode setting helper
libraries and hence is also included here.

.. kernel-doc:: include/linux/hdmi.h
   :internal:

.. kernel-doc:: drivers/video/hdmi.c
   :export:

Flip-work Helper Reference
==========================

.. kernel-doc:: include/drm/drm_flip_work.h
   :doc: flip utils

.. kernel-doc:: include/drm/drm_flip_work.h
   :internal:

.. kernel-doc:: drivers/gpu/drm/drm_flip_work.c
   :export:

Plane Helper Reference
======================

.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
   :doc: overview

.. kernel-doc:: drivers/gpu/drm/drm_plane_helper.c
   :export:

Auxiliary Modeset Helpers
=========================

.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
   :doc: aux kms helpers

.. kernel-doc:: drivers/gpu/drm/drm_modeset_helper.c
   :export:
OpenPOWER on IntegriCloud