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 	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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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 
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  */
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  */
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