1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016 Noralf Trønnes
4 */
5
6#include <linux/module.h>
7#include <linux/slab.h>
8
9#include <drm/drm_atomic.h>
10#include <drm/drm_atomic_helper.h>
11#include <drm/drm_bridge.h>
12#include <drm/drm_drv.h>
13#include <drm/drm_gem_atomic_helper.h>
14#include <drm/drm_managed.h>
15#include <drm/drm_probe_helper.h>
16#include <drm/drm_simple_kms_helper.h>
17
18/**
19 * DOC: overview
20 *
21 * This helper library provides helpers for drivers for simple display
22 * hardware.
23 *
24 * drm_simple_display_pipe_init() initializes a simple display pipeline
25 * which has only one full-screen scanout buffer feeding one output. The
26 * pipeline is represented by &struct drm_simple_display_pipe and binds
27 * together &drm_plane, &drm_crtc and &drm_encoder structures into one fixed
28 * entity. Some flexibility for code reuse is provided through a separately
29 * allocated &drm_connector object and supporting optional &drm_bridge
30 * encoder drivers.
31 *
32 * Many drivers require only a very simple encoder that fulfills the minimum
33 * requirements of the display pipeline and does not add additional
34 * functionality. The function drm_simple_encoder_init() provides an
35 * implementation of such an encoder.
36 */
37
38static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = {
39 .destroy = drm_encoder_cleanup,
40};
41
42/**
43 * drm_simple_encoder_init - Initialize a preallocated encoder with
44 * basic functionality.
45 * @dev: drm device
46 * @encoder: the encoder to initialize
47 * @encoder_type: user visible type of the encoder
48 *
49 * Initialises a preallocated encoder that has no further functionality.
50 * Settings for possible CRTC and clones are left to their initial values.
51 * The encoder will be cleaned up automatically as part of the mode-setting
52 * cleanup.
53 *
54 * The caller of drm_simple_encoder_init() is responsible for freeing
55 * the encoder's memory after the encoder has been cleaned up. At the
56 * moment this only works reliably if the encoder data structure is
57 * stored in the device structure. Free the encoder's memory as part of
58 * the device release function.
59 *
60 * Note: consider using drmm_simple_encoder_alloc() instead of
61 * drm_simple_encoder_init() to let the DRM managed resource infrastructure
62 * take care of cleanup and deallocation.
63 *
64 * Returns:
65 * Zero on success, error code on failure.
66 */
67int drm_simple_encoder_init(struct drm_device *dev,
68 struct drm_encoder *encoder,
69 int encoder_type)
70{
71 return drm_encoder_init(dev, encoder,
72 funcs: &drm_simple_encoder_funcs_cleanup,
73 encoder_type, NULL);
74}
75EXPORT_SYMBOL(drm_simple_encoder_init);
76
77void *__drmm_simple_encoder_alloc(struct drm_device *dev, size_t size,
78 size_t offset, int encoder_type)
79{
80 return __drmm_encoder_alloc(dev, size, offset, NULL, encoder_type,
81 NULL);
82}
83EXPORT_SYMBOL(__drmm_simple_encoder_alloc);
84
85static enum drm_mode_status
86drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
87 const struct drm_display_mode *mode)
88{
89 struct drm_simple_display_pipe *pipe;
90
91 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
92 if (!pipe->funcs || !pipe->funcs->mode_valid)
93 /* Anything goes */
94 return MODE_OK;
95
96 return pipe->funcs->mode_valid(pipe, mode);
97}
98
99static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
100 struct drm_atomic_state *state)
101{
102 struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
103 int ret;
104
105 if (!crtc_state->enable)
106 goto out;
107
108 ret = drm_atomic_helper_check_crtc_primary_plane(crtc_state);
109 if (ret)
110 return ret;
111
112out:
113 return drm_atomic_add_affected_planes(state, crtc);
114}
115
116static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
117 struct drm_atomic_state *state)
118{
119 struct drm_plane *plane;
120 struct drm_simple_display_pipe *pipe;
121
122 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
123 if (!pipe->funcs || !pipe->funcs->enable)
124 return;
125
126 plane = &pipe->plane;
127 pipe->funcs->enable(pipe, crtc->state, plane->state);
128}
129
130static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
131 struct drm_atomic_state *state)
132{
133 struct drm_simple_display_pipe *pipe;
134
135 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
136 if (!pipe->funcs || !pipe->funcs->disable)
137 return;
138
139 pipe->funcs->disable(pipe);
140}
141
142static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
143 .mode_valid = drm_simple_kms_crtc_mode_valid,
144 .atomic_check = drm_simple_kms_crtc_check,
145 .atomic_enable = drm_simple_kms_crtc_enable,
146 .atomic_disable = drm_simple_kms_crtc_disable,
147};
148
149static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
150{
151 struct drm_simple_display_pipe *pipe;
152
153 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
154 if (!pipe->funcs || !pipe->funcs->reset_crtc)
155 return drm_atomic_helper_crtc_reset(crtc);
156
157 return pipe->funcs->reset_crtc(pipe);
158}
159
160static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
161{
162 struct drm_simple_display_pipe *pipe;
163
164 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
165 if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
166 return drm_atomic_helper_crtc_duplicate_state(crtc);
167
168 return pipe->funcs->duplicate_crtc_state(pipe);
169}
170
171static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
172{
173 struct drm_simple_display_pipe *pipe;
174
175 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
176 if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
177 drm_atomic_helper_crtc_destroy_state(crtc, state);
178 else
179 pipe->funcs->destroy_crtc_state(pipe, state);
180}
181
182static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
183{
184 struct drm_simple_display_pipe *pipe;
185
186 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
187 if (!pipe->funcs || !pipe->funcs->enable_vblank)
188 return 0;
189
190 return pipe->funcs->enable_vblank(pipe);
191}
192
193static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
194{
195 struct drm_simple_display_pipe *pipe;
196
197 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
198 if (!pipe->funcs || !pipe->funcs->disable_vblank)
199 return;
200
201 pipe->funcs->disable_vblank(pipe);
202}
203
204static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
205 .reset = drm_simple_kms_crtc_reset,
206 .destroy = drm_crtc_cleanup,
207 .set_config = drm_atomic_helper_set_config,
208 .page_flip = drm_atomic_helper_page_flip,
209 .atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
210 .atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
211 .enable_vblank = drm_simple_kms_crtc_enable_vblank,
212 .disable_vblank = drm_simple_kms_crtc_disable_vblank,
213};
214
215static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
216 struct drm_atomic_state *state)
217{
218 struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
219 plane);
220 struct drm_simple_display_pipe *pipe;
221 struct drm_crtc_state *crtc_state;
222 int ret;
223
224 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
225 crtc_state = drm_atomic_get_new_crtc_state(state,
226 crtc: &pipe->crtc);
227
228 ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
229 DRM_PLANE_NO_SCALING,
230 DRM_PLANE_NO_SCALING,
231 can_position: false, can_update_disabled: false);
232 if (ret)
233 return ret;
234
235 if (!plane_state->visible)
236 return 0;
237
238 if (!pipe->funcs || !pipe->funcs->check)
239 return 0;
240
241 return pipe->funcs->check(pipe, plane_state, crtc_state);
242}
243
244static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
245 struct drm_atomic_state *state)
246{
247 struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
248 plane);
249 struct drm_simple_display_pipe *pipe;
250
251 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
252 if (!pipe->funcs || !pipe->funcs->update)
253 return;
254
255 pipe->funcs->update(pipe, old_pstate);
256}
257
258static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
259 struct drm_plane_state *state)
260{
261 struct drm_simple_display_pipe *pipe;
262
263 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
264 if (!pipe->funcs || !pipe->funcs->prepare_fb) {
265 if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
266 return 0;
267
268 WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
269
270 return drm_gem_plane_helper_prepare_fb(plane, state);
271 }
272
273 return pipe->funcs->prepare_fb(pipe, state);
274}
275
276static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
277 struct drm_plane_state *state)
278{
279 struct drm_simple_display_pipe *pipe;
280
281 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
282 if (!pipe->funcs || !pipe->funcs->cleanup_fb)
283 return;
284
285 pipe->funcs->cleanup_fb(pipe, state);
286}
287
288static int drm_simple_kms_plane_begin_fb_access(struct drm_plane *plane,
289 struct drm_plane_state *new_plane_state)
290{
291 struct drm_simple_display_pipe *pipe;
292
293 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
294 if (!pipe->funcs || !pipe->funcs->begin_fb_access)
295 return 0;
296
297 return pipe->funcs->begin_fb_access(pipe, new_plane_state);
298}
299
300static void drm_simple_kms_plane_end_fb_access(struct drm_plane *plane,
301 struct drm_plane_state *new_plane_state)
302{
303 struct drm_simple_display_pipe *pipe;
304
305 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
306 if (!pipe->funcs || !pipe->funcs->end_fb_access)
307 return;
308
309 pipe->funcs->end_fb_access(pipe, new_plane_state);
310}
311
312static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
313 uint32_t format,
314 uint64_t modifier)
315{
316 return modifier == DRM_FORMAT_MOD_LINEAR;
317}
318
319static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
320 .prepare_fb = drm_simple_kms_plane_prepare_fb,
321 .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
322 .begin_fb_access = drm_simple_kms_plane_begin_fb_access,
323 .end_fb_access = drm_simple_kms_plane_end_fb_access,
324 .atomic_check = drm_simple_kms_plane_atomic_check,
325 .atomic_update = drm_simple_kms_plane_atomic_update,
326};
327
328static void drm_simple_kms_plane_reset(struct drm_plane *plane)
329{
330 struct drm_simple_display_pipe *pipe;
331
332 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
333 if (!pipe->funcs || !pipe->funcs->reset_plane)
334 return drm_atomic_helper_plane_reset(plane);
335
336 return pipe->funcs->reset_plane(pipe);
337}
338
339static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
340{
341 struct drm_simple_display_pipe *pipe;
342
343 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
344 if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
345 return drm_atomic_helper_plane_duplicate_state(plane);
346
347 return pipe->funcs->duplicate_plane_state(pipe);
348}
349
350static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
351 struct drm_plane_state *state)
352{
353 struct drm_simple_display_pipe *pipe;
354
355 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
356 if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
357 drm_atomic_helper_plane_destroy_state(plane, state);
358 else
359 pipe->funcs->destroy_plane_state(pipe, state);
360}
361
362static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
363 .update_plane = drm_atomic_helper_update_plane,
364 .disable_plane = drm_atomic_helper_disable_plane,
365 .destroy = drm_plane_cleanup,
366 .reset = drm_simple_kms_plane_reset,
367 .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
368 .atomic_destroy_state = drm_simple_kms_plane_destroy_state,
369 .format_mod_supported = drm_simple_kms_format_mod_supported,
370};
371
372/**
373 * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
374 * @pipe: simple display pipe object
375 * @bridge: bridge to attach
376 *
377 * Makes it possible to still use the drm_simple_display_pipe helpers when
378 * a DRM bridge has to be used.
379 *
380 * Note that you probably want to initialize the pipe by passing a NULL
381 * connector to drm_simple_display_pipe_init().
382 *
383 * Returns:
384 * Zero on success, negative error code on failure.
385 */
386int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
387 struct drm_bridge *bridge)
388{
389 return drm_bridge_attach(encoder: &pipe->encoder, bridge, NULL, flags: 0);
390}
391EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
392
393/**
394 * drm_simple_display_pipe_init - Initialize a simple display pipeline
395 * @dev: DRM device
396 * @pipe: simple display pipe object to initialize
397 * @funcs: callbacks for the display pipe (optional)
398 * @formats: array of supported formats (DRM_FORMAT\_\*)
399 * @format_count: number of elements in @formats
400 * @format_modifiers: array of formats modifiers
401 * @connector: connector to attach and register (optional)
402 *
403 * Sets up a display pipeline which consist of a really simple
404 * plane-crtc-encoder pipe.
405 *
406 * If a connector is supplied, the pipe will be coupled with the provided
407 * connector. You may supply a NULL connector when using drm bridges, that
408 * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
409 *
410 * Teardown of a simple display pipe is all handled automatically by the drm
411 * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
412 * release the memory for the structure themselves.
413 *
414 * Returns:
415 * Zero on success, negative error code on failure.
416 */
417int drm_simple_display_pipe_init(struct drm_device *dev,
418 struct drm_simple_display_pipe *pipe,
419 const struct drm_simple_display_pipe_funcs *funcs,
420 const uint32_t *formats, unsigned int format_count,
421 const uint64_t *format_modifiers,
422 struct drm_connector *connector)
423{
424 struct drm_encoder *encoder = &pipe->encoder;
425 struct drm_plane *plane = &pipe->plane;
426 struct drm_crtc *crtc = &pipe->crtc;
427 int ret;
428
429 pipe->connector = connector;
430 pipe->funcs = funcs;
431
432 drm_plane_helper_add(plane, funcs: &drm_simple_kms_plane_helper_funcs);
433 ret = drm_universal_plane_init(dev, plane, possible_crtcs: 0,
434 funcs: &drm_simple_kms_plane_funcs,
435 formats, format_count,
436 format_modifiers,
437 type: DRM_PLANE_TYPE_PRIMARY, NULL);
438 if (ret)
439 return ret;
440
441 drm_crtc_helper_add(crtc, funcs: &drm_simple_kms_crtc_helper_funcs);
442 ret = drm_crtc_init_with_planes(dev, crtc, primary: plane, NULL,
443 funcs: &drm_simple_kms_crtc_funcs, NULL);
444 if (ret)
445 return ret;
446
447 encoder->possible_crtcs = drm_crtc_mask(crtc);
448 ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
449 if (ret || !connector)
450 return ret;
451
452 return drm_connector_attach_encoder(connector, encoder);
453}
454EXPORT_SYMBOL(drm_simple_display_pipe_init);
455
456MODULE_LICENSE("GPL");
457

source code of linux/drivers/gpu/drm/drm_simple_kms_helper.c