GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / gpu / drm / drm_simple_kms_helper.c
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
36 static 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  */
64 int 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 }
72 EXPORT_SYMBOL(drm_simple_encoder_init);
73
74 static enum drm_mode_status
75 drm_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
88 static 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
101 static 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
115 static 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
127 static 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
134 static 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
145 static 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
156 static 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
167 static 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
194 static 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
206 static 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
218 static 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
230 static 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
237 static 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
244 static 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  */
268 int 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 }
273 EXPORT_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  */
299 int 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 }
336 EXPORT_SYMBOL(drm_simple_display_pipe_init);
337
338 MODULE_LICENSE("GPL");