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  */
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 
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
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 
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 	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 
112 out:
113 	return drm_atomic_add_affected_planes(state, crtc);
114 }
115 
116 static 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 
130 static 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 
142 static 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 
149 static 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 
160 static 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 
171 static 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 
182 static 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 
193 static 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 
204 static 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 
215 static 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 						   &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 						  false, 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 
244 static 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 
258 static 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 
276 static 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 
288 static 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 
300 static 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 
312 static 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 
319 static 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 
328 static 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 
339 static 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 
350 static 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 
362 static 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  */
386 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
387 					  struct drm_bridge *bridge)
388 {
389 	return drm_bridge_attach(&pipe->encoder, bridge, NULL, 0);
390 }
391 EXPORT_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  */
417 int 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, &drm_simple_kms_plane_helper_funcs);
433 	ret = drm_universal_plane_init(dev, plane, 0,
434 				       &drm_simple_kms_plane_funcs,
435 				       formats, format_count,
436 				       format_modifiers,
437 				       DRM_PLANE_TYPE_PRIMARY, NULL);
438 	if (ret)
439 		return ret;
440 
441 	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
442 	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
443 					&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 }
454 EXPORT_SYMBOL(drm_simple_display_pipe_init);
455 
456 MODULE_LICENSE("GPL");
457