xref: /linux/drivers/gpu/drm/drm_simple_kms_helper.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
1 /*
2  * Copyright (C) 2016 Noralf Trønnes
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  */
9 
10 #include <drm/drmP.h>
11 #include <drm/drm_atomic.h>
12 #include <drm/drm_atomic_helper.h>
13 #include <drm/drm_crtc_helper.h>
14 #include <drm/drm_plane_helper.h>
15 #include <drm/drm_simple_kms_helper.h>
16 #include <linux/slab.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 
33 static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs = {
34 	.destroy = drm_encoder_cleanup,
35 };
36 
37 static enum drm_mode_status
38 drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
39 			       const struct drm_display_mode *mode)
40 {
41 	struct drm_simple_display_pipe *pipe;
42 
43 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
44 	if (!pipe->funcs || !pipe->funcs->mode_valid)
45 		/* Anything goes */
46 		return MODE_OK;
47 
48 	return pipe->funcs->mode_valid(crtc, mode);
49 }
50 
51 static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
52 				     struct drm_crtc_state *state)
53 {
54 	bool has_primary = state->plane_mask &
55 			   drm_plane_mask(crtc->primary);
56 
57 	/* We always want to have an active plane with an active CRTC */
58 	if (has_primary != state->enable)
59 		return -EINVAL;
60 
61 	return drm_atomic_add_affected_planes(state->state, crtc);
62 }
63 
64 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
65 				       struct drm_crtc_state *old_state)
66 {
67 	struct drm_plane *plane;
68 	struct drm_simple_display_pipe *pipe;
69 
70 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
71 	if (!pipe->funcs || !pipe->funcs->enable)
72 		return;
73 
74 	plane = &pipe->plane;
75 	pipe->funcs->enable(pipe, crtc->state, plane->state);
76 }
77 
78 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
79 					struct drm_crtc_state *old_state)
80 {
81 	struct drm_simple_display_pipe *pipe;
82 
83 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
84 	if (!pipe->funcs || !pipe->funcs->disable)
85 		return;
86 
87 	pipe->funcs->disable(pipe);
88 }
89 
90 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
91 	.mode_valid = drm_simple_kms_crtc_mode_valid,
92 	.atomic_check = drm_simple_kms_crtc_check,
93 	.atomic_enable = drm_simple_kms_crtc_enable,
94 	.atomic_disable = drm_simple_kms_crtc_disable,
95 };
96 
97 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
98 {
99 	struct drm_simple_display_pipe *pipe;
100 
101 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
102 	if (!pipe->funcs || !pipe->funcs->enable_vblank)
103 		return 0;
104 
105 	return pipe->funcs->enable_vblank(pipe);
106 }
107 
108 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
109 {
110 	struct drm_simple_display_pipe *pipe;
111 
112 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
113 	if (!pipe->funcs || !pipe->funcs->disable_vblank)
114 		return;
115 
116 	pipe->funcs->disable_vblank(pipe);
117 }
118 
119 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
120 	.reset = drm_atomic_helper_crtc_reset,
121 	.destroy = drm_crtc_cleanup,
122 	.set_config = drm_atomic_helper_set_config,
123 	.page_flip = drm_atomic_helper_page_flip,
124 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
125 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
126 	.enable_vblank = drm_simple_kms_crtc_enable_vblank,
127 	.disable_vblank = drm_simple_kms_crtc_disable_vblank,
128 };
129 
130 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
131 					struct drm_plane_state *plane_state)
132 {
133 	struct drm_simple_display_pipe *pipe;
134 	struct drm_crtc_state *crtc_state;
135 	int ret;
136 
137 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
138 	crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
139 						   &pipe->crtc);
140 
141 	ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
142 						  DRM_PLANE_HELPER_NO_SCALING,
143 						  DRM_PLANE_HELPER_NO_SCALING,
144 						  false, true);
145 	if (ret)
146 		return ret;
147 
148 	if (!plane_state->visible)
149 		return 0;
150 
151 	if (!pipe->funcs || !pipe->funcs->check)
152 		return 0;
153 
154 	return pipe->funcs->check(pipe, plane_state, crtc_state);
155 }
156 
157 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
158 					struct drm_plane_state *old_pstate)
159 {
160 	struct drm_simple_display_pipe *pipe;
161 
162 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
163 	if (!pipe->funcs || !pipe->funcs->update)
164 		return;
165 
166 	pipe->funcs->update(pipe, old_pstate);
167 }
168 
169 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
170 					   struct drm_plane_state *state)
171 {
172 	struct drm_simple_display_pipe *pipe;
173 
174 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
175 	if (!pipe->funcs || !pipe->funcs->prepare_fb)
176 		return 0;
177 
178 	return pipe->funcs->prepare_fb(pipe, state);
179 }
180 
181 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
182 					    struct drm_plane_state *state)
183 {
184 	struct drm_simple_display_pipe *pipe;
185 
186 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
187 	if (!pipe->funcs || !pipe->funcs->cleanup_fb)
188 		return;
189 
190 	pipe->funcs->cleanup_fb(pipe, state);
191 }
192 
193 static bool drm_simple_kms_format_mod_supported(struct drm_plane *plane,
194 						uint32_t format,
195 						uint64_t modifier)
196 {
197 	return modifier == DRM_FORMAT_MOD_LINEAR;
198 }
199 
200 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
201 	.prepare_fb = drm_simple_kms_plane_prepare_fb,
202 	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
203 	.atomic_check = drm_simple_kms_plane_atomic_check,
204 	.atomic_update = drm_simple_kms_plane_atomic_update,
205 };
206 
207 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
208 	.update_plane		= drm_atomic_helper_update_plane,
209 	.disable_plane		= drm_atomic_helper_disable_plane,
210 	.destroy		= drm_plane_cleanup,
211 	.reset			= drm_atomic_helper_plane_reset,
212 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
213 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
214 	.format_mod_supported   = drm_simple_kms_format_mod_supported,
215 };
216 
217 /**
218  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
219  * @pipe: simple display pipe object
220  * @bridge: bridge to attach
221  *
222  * Makes it possible to still use the drm_simple_display_pipe helpers when
223  * a DRM bridge has to be used.
224  *
225  * Note that you probably want to initialize the pipe by passing a NULL
226  * connector to drm_simple_display_pipe_init().
227  *
228  * Returns:
229  * Zero on success, negative error code on failure.
230  */
231 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
232 					  struct drm_bridge *bridge)
233 {
234 	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
235 }
236 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
237 
238 /**
239  * drm_simple_display_pipe_init - Initialize a simple display pipeline
240  * @dev: DRM device
241  * @pipe: simple display pipe object to initialize
242  * @funcs: callbacks for the display pipe (optional)
243  * @formats: array of supported formats (DRM_FORMAT\_\*)
244  * @format_count: number of elements in @formats
245  * @format_modifiers: array of formats modifiers
246  * @connector: connector to attach and register (optional)
247  *
248  * Sets up a display pipeline which consist of a really simple
249  * plane-crtc-encoder pipe.
250  *
251  * If a connector is supplied, the pipe will be coupled with the provided
252  * connector. You may supply a NULL connector when using drm bridges, that
253  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
254  *
255  * Teardown of a simple display pipe is all handled automatically by the drm
256  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
257  * release the memory for the structure themselves.
258  *
259  * Returns:
260  * Zero on success, negative error code on failure.
261  */
262 int drm_simple_display_pipe_init(struct drm_device *dev,
263 			struct drm_simple_display_pipe *pipe,
264 			const struct drm_simple_display_pipe_funcs *funcs,
265 			const uint32_t *formats, unsigned int format_count,
266 			const uint64_t *format_modifiers,
267 			struct drm_connector *connector)
268 {
269 	struct drm_encoder *encoder = &pipe->encoder;
270 	struct drm_plane *plane = &pipe->plane;
271 	struct drm_crtc *crtc = &pipe->crtc;
272 	int ret;
273 
274 	pipe->connector = connector;
275 	pipe->funcs = funcs;
276 
277 	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
278 	ret = drm_universal_plane_init(dev, plane, 0,
279 				       &drm_simple_kms_plane_funcs,
280 				       formats, format_count,
281 				       format_modifiers,
282 				       DRM_PLANE_TYPE_PRIMARY, NULL);
283 	if (ret)
284 		return ret;
285 
286 	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
287 	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
288 					&drm_simple_kms_crtc_funcs, NULL);
289 	if (ret)
290 		return ret;
291 
292 	encoder->possible_crtcs = drm_crtc_mask(crtc);
293 	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
294 			       DRM_MODE_ENCODER_NONE, NULL);
295 	if (ret || !connector)
296 		return ret;
297 
298 	return drm_connector_attach_encoder(connector, encoder);
299 }
300 EXPORT_SYMBOL(drm_simple_display_pipe_init);
301 
302 MODULE_LICENSE("GPL");
303