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
38 static 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 */
drm_simple_encoder_init(struct drm_device * dev,struct drm_encoder * encoder,int encoder_type)67 int 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 &drm_simple_encoder_funcs_cleanup,
73 encoder_type, NULL);
74 }
75 EXPORT_SYMBOL(drm_simple_encoder_init);
76
__drmm_simple_encoder_alloc(struct drm_device * dev,size_t size,size_t offset,int encoder_type)77 void *__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 }
83 EXPORT_SYMBOL(__drmm_simple_encoder_alloc);
84
85 static enum drm_mode_status
drm_simple_kms_crtc_mode_valid(struct drm_crtc * crtc,const struct drm_display_mode * mode)86 drm_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
drm_simple_kms_crtc_check(struct drm_crtc * crtc,struct drm_atomic_state * state)99 static 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 ret = drm_atomic_helper_check_crtc_state(crtc_state, false);
106 if (ret)
107 return ret;
108
109 return drm_atomic_add_affected_planes(state, crtc);
110 }
111
drm_simple_kms_crtc_enable(struct drm_crtc * crtc,struct drm_atomic_state * state)112 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
113 struct drm_atomic_state *state)
114 {
115 struct drm_plane *plane;
116 struct drm_simple_display_pipe *pipe;
117
118 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
119 if (!pipe->funcs || !pipe->funcs->enable)
120 return;
121
122 plane = &pipe->plane;
123 pipe->funcs->enable(pipe, crtc->state, plane->state);
124 }
125
drm_simple_kms_crtc_disable(struct drm_crtc * crtc,struct drm_atomic_state * state)126 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
127 struct drm_atomic_state *state)
128 {
129 struct drm_simple_display_pipe *pipe;
130
131 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
132 if (!pipe->funcs || !pipe->funcs->disable)
133 return;
134
135 pipe->funcs->disable(pipe);
136 }
137
138 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
139 .mode_valid = drm_simple_kms_crtc_mode_valid,
140 .atomic_check = drm_simple_kms_crtc_check,
141 .atomic_enable = drm_simple_kms_crtc_enable,
142 .atomic_disable = drm_simple_kms_crtc_disable,
143 };
144
drm_simple_kms_crtc_reset(struct drm_crtc * crtc)145 static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
146 {
147 struct drm_simple_display_pipe *pipe;
148
149 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
150 if (!pipe->funcs || !pipe->funcs->reset_crtc)
151 return drm_atomic_helper_crtc_reset(crtc);
152
153 return pipe->funcs->reset_crtc(pipe);
154 }
155
drm_simple_kms_crtc_duplicate_state(struct drm_crtc * crtc)156 static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
157 {
158 struct drm_simple_display_pipe *pipe;
159
160 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
161 if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
162 return drm_atomic_helper_crtc_duplicate_state(crtc);
163
164 return pipe->funcs->duplicate_crtc_state(pipe);
165 }
166
drm_simple_kms_crtc_destroy_state(struct drm_crtc * crtc,struct drm_crtc_state * state)167 static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
168 {
169 struct drm_simple_display_pipe *pipe;
170
171 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
172 if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
173 drm_atomic_helper_crtc_destroy_state(crtc, state);
174 else
175 pipe->funcs->destroy_crtc_state(pipe, state);
176 }
177
drm_simple_kms_crtc_enable_vblank(struct drm_crtc * crtc)178 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
179 {
180 struct drm_simple_display_pipe *pipe;
181
182 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
183 if (!pipe->funcs || !pipe->funcs->enable_vblank)
184 return 0;
185
186 return pipe->funcs->enable_vblank(pipe);
187 }
188
drm_simple_kms_crtc_disable_vblank(struct drm_crtc * crtc)189 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
190 {
191 struct drm_simple_display_pipe *pipe;
192
193 pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
194 if (!pipe->funcs || !pipe->funcs->disable_vblank)
195 return;
196
197 pipe->funcs->disable_vblank(pipe);
198 }
199
200 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
201 .reset = drm_simple_kms_crtc_reset,
202 .destroy = drm_crtc_cleanup,
203 .set_config = drm_atomic_helper_set_config,
204 .page_flip = drm_atomic_helper_page_flip,
205 .atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
206 .atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
207 .enable_vblank = drm_simple_kms_crtc_enable_vblank,
208 .disable_vblank = drm_simple_kms_crtc_disable_vblank,
209 };
210
drm_simple_kms_plane_atomic_check(struct drm_plane * plane,struct drm_atomic_state * state)211 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
212 struct drm_atomic_state *state)
213 {
214 struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state,
215 plane);
216 struct drm_simple_display_pipe *pipe;
217 struct drm_crtc_state *crtc_state;
218 int ret;
219
220 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
221 crtc_state = drm_atomic_get_new_crtc_state(state,
222 &pipe->crtc);
223
224 ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
225 DRM_PLANE_NO_SCALING,
226 DRM_PLANE_NO_SCALING,
227 false, false);
228 if (ret)
229 return ret;
230
231 if (!plane_state->visible)
232 return 0;
233
234 if (!pipe->funcs || !pipe->funcs->check)
235 return 0;
236
237 return pipe->funcs->check(pipe, plane_state, crtc_state);
238 }
239
drm_simple_kms_plane_atomic_update(struct drm_plane * plane,struct drm_atomic_state * state)240 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
241 struct drm_atomic_state *state)
242 {
243 struct drm_plane_state *old_pstate = drm_atomic_get_old_plane_state(state,
244 plane);
245 struct drm_simple_display_pipe *pipe;
246
247 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
248 if (!pipe->funcs || !pipe->funcs->update)
249 return;
250
251 pipe->funcs->update(pipe, old_pstate);
252 }
253
drm_simple_kms_plane_prepare_fb(struct drm_plane * plane,struct drm_plane_state * state)254 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
255 struct drm_plane_state *state)
256 {
257 struct drm_simple_display_pipe *pipe;
258
259 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
260 if (!pipe->funcs || !pipe->funcs->prepare_fb) {
261 if (WARN_ON_ONCE(!drm_core_check_feature(plane->dev, DRIVER_GEM)))
262 return 0;
263
264 WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
265
266 return drm_gem_simple_display_pipe_prepare_fb(pipe, state);
267 }
268
269 return pipe->funcs->prepare_fb(pipe, state);
270 }
271
drm_simple_kms_plane_cleanup_fb(struct drm_plane * plane,struct drm_plane_state * state)272 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
273 struct drm_plane_state *state)
274 {
275 struct drm_simple_display_pipe *pipe;
276
277 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
278 if (!pipe->funcs || !pipe->funcs->cleanup_fb)
279 return;
280
281 pipe->funcs->cleanup_fb(pipe, state);
282 }
283
drm_simple_kms_format_mod_supported(struct drm_plane * plane,uint32_t format,uint64_t modifier)284 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
285 uint32_t format,
286 uint64_t modifier)
287 {
288 return modifier == DRM_FORMAT_MOD_LINEAR;
289 }
290
291 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
292 .prepare_fb = drm_simple_kms_plane_prepare_fb,
293 .cleanup_fb = drm_simple_kms_plane_cleanup_fb,
294 .atomic_check = drm_simple_kms_plane_atomic_check,
295 .atomic_update = drm_simple_kms_plane_atomic_update,
296 };
297
drm_simple_kms_plane_reset(struct drm_plane * plane)298 static void drm_simple_kms_plane_reset(struct drm_plane *plane)
299 {
300 struct drm_simple_display_pipe *pipe;
301
302 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
303 if (!pipe->funcs || !pipe->funcs->reset_plane)
304 return drm_atomic_helper_plane_reset(plane);
305
306 return pipe->funcs->reset_plane(pipe);
307 }
308
drm_simple_kms_plane_duplicate_state(struct drm_plane * plane)309 static struct drm_plane_state *drm_simple_kms_plane_duplicate_state(struct drm_plane *plane)
310 {
311 struct drm_simple_display_pipe *pipe;
312
313 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
314 if (!pipe->funcs || !pipe->funcs->duplicate_plane_state)
315 return drm_atomic_helper_plane_duplicate_state(plane);
316
317 return pipe->funcs->duplicate_plane_state(pipe);
318 }
319
drm_simple_kms_plane_destroy_state(struct drm_plane * plane,struct drm_plane_state * state)320 static void drm_simple_kms_plane_destroy_state(struct drm_plane *plane,
321 struct drm_plane_state *state)
322 {
323 struct drm_simple_display_pipe *pipe;
324
325 pipe = container_of(plane, struct drm_simple_display_pipe, plane);
326 if (!pipe->funcs || !pipe->funcs->destroy_plane_state)
327 drm_atomic_helper_plane_destroy_state(plane, state);
328 else
329 pipe->funcs->destroy_plane_state(pipe, state);
330 }
331
332 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
333 .update_plane = drm_atomic_helper_update_plane,
334 .disable_plane = drm_atomic_helper_disable_plane,
335 .destroy = drm_plane_cleanup,
336 .reset = drm_simple_kms_plane_reset,
337 .atomic_duplicate_state = drm_simple_kms_plane_duplicate_state,
338 .atomic_destroy_state = drm_simple_kms_plane_destroy_state,
339 .format_mod_supported = drm_simple_kms_format_mod_supported,
340 };
341
342 /**
343 * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
344 * @pipe: simple display pipe object
345 * @bridge: bridge to attach
346 *
347 * Makes it possible to still use the drm_simple_display_pipe helpers when
348 * a DRM bridge has to be used.
349 *
350 * Note that you probably want to initialize the pipe by passing a NULL
351 * connector to drm_simple_display_pipe_init().
352 *
353 * Returns:
354 * Zero on success, negative error code on failure.
355 */
drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe * pipe,struct drm_bridge * bridge)356 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
357 struct drm_bridge *bridge)
358 {
359 return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
360 }
361 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
362
363 /**
364 * drm_simple_display_pipe_init - Initialize a simple display pipeline
365 * @dev: DRM device
366 * @pipe: simple display pipe object to initialize
367 * @funcs: callbacks for the display pipe (optional)
368 * @formats: array of supported formats (DRM_FORMAT\_\*)
369 * @format_count: number of elements in @formats
370 * @format_modifiers: array of formats modifiers
371 * @connector: connector to attach and register (optional)
372 *
373 * Sets up a display pipeline which consist of a really simple
374 * plane-crtc-encoder pipe.
375 *
376 * If a connector is supplied, the pipe will be coupled with the provided
377 * connector. You may supply a NULL connector when using drm bridges, that
378 * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
379 *
380 * Teardown of a simple display pipe is all handled automatically by the drm
381 * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
382 * release the memory for the structure themselves.
383 *
384 * Returns:
385 * Zero on success, negative error code on failure.
386 */
drm_simple_display_pipe_init(struct drm_device * dev,struct drm_simple_display_pipe * pipe,const struct drm_simple_display_pipe_funcs * funcs,const uint32_t * formats,unsigned int format_count,const uint64_t * format_modifiers,struct drm_connector * connector)387 int drm_simple_display_pipe_init(struct drm_device *dev,
388 struct drm_simple_display_pipe *pipe,
389 const struct drm_simple_display_pipe_funcs *funcs,
390 const uint32_t *formats, unsigned int format_count,
391 const uint64_t *format_modifiers,
392 struct drm_connector *connector)
393 {
394 struct drm_encoder *encoder = &pipe->encoder;
395 struct drm_plane *plane = &pipe->plane;
396 struct drm_crtc *crtc = &pipe->crtc;
397 int ret;
398
399 pipe->connector = connector;
400 pipe->funcs = funcs;
401
402 drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
403 ret = drm_universal_plane_init(dev, plane, 0,
404 &drm_simple_kms_plane_funcs,
405 formats, format_count,
406 format_modifiers,
407 DRM_PLANE_TYPE_PRIMARY, NULL);
408 if (ret)
409 return ret;
410
411 drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
412 ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
413 &drm_simple_kms_crtc_funcs, NULL);
414 if (ret)
415 return ret;
416
417 encoder->possible_crtcs = drm_crtc_mask(crtc);
418 ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE);
419 if (ret || !connector)
420 return ret;
421
422 return drm_connector_attach_encoder(connector, encoder);
423 }
424 EXPORT_SYMBOL(drm_simple_display_pipe_init);
425
426 MODULE_LICENSE("GPL");
427