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