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