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 			   BIT(drm_plane_index(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_simple_display_pipe *pipe;
68 
69 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
70 	if (!pipe->funcs || !pipe->funcs->enable)
71 		return;
72 
73 	pipe->funcs->enable(pipe, crtc->state);
74 }
75 
76 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
77 					struct drm_crtc_state *old_state)
78 {
79 	struct drm_simple_display_pipe *pipe;
80 
81 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
82 	if (!pipe->funcs || !pipe->funcs->disable)
83 		return;
84 
85 	pipe->funcs->disable(pipe);
86 }
87 
88 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
89 	.mode_valid = drm_simple_kms_crtc_mode_valid,
90 	.atomic_check = drm_simple_kms_crtc_check,
91 	.atomic_enable = drm_simple_kms_crtc_enable,
92 	.atomic_disable = drm_simple_kms_crtc_disable,
93 };
94 
95 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
96 {
97 	struct drm_simple_display_pipe *pipe;
98 
99 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
100 	if (!pipe->funcs || !pipe->funcs->enable_vblank)
101 		return 0;
102 
103 	return pipe->funcs->enable_vblank(pipe);
104 }
105 
106 static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
107 {
108 	struct drm_simple_display_pipe *pipe;
109 
110 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
111 	if (!pipe->funcs || !pipe->funcs->disable_vblank)
112 		return;
113 
114 	pipe->funcs->disable_vblank(pipe);
115 }
116 
117 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
118 	.reset = drm_atomic_helper_crtc_reset,
119 	.destroy = drm_crtc_cleanup,
120 	.set_config = drm_atomic_helper_set_config,
121 	.page_flip = drm_atomic_helper_page_flip,
122 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
123 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
124 	.enable_vblank = drm_simple_kms_crtc_enable_vblank,
125 	.disable_vblank = drm_simple_kms_crtc_disable_vblank,
126 };
127 
128 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
129 					struct drm_plane_state *plane_state)
130 {
131 	struct drm_simple_display_pipe *pipe;
132 	struct drm_crtc_state *crtc_state;
133 	int ret;
134 
135 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
136 	crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
137 						   &pipe->crtc);
138 
139 	ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
140 						  DRM_PLANE_HELPER_NO_SCALING,
141 						  DRM_PLANE_HELPER_NO_SCALING,
142 						  false, true);
143 	if (ret)
144 		return ret;
145 
146 	if (!plane_state->visible)
147 		return 0;
148 
149 	if (!pipe->funcs || !pipe->funcs->check)
150 		return 0;
151 
152 	return pipe->funcs->check(pipe, plane_state, crtc_state);
153 }
154 
155 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
156 					struct drm_plane_state *old_pstate)
157 {
158 	struct drm_simple_display_pipe *pipe;
159 
160 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
161 	if (!pipe->funcs || !pipe->funcs->update)
162 		return;
163 
164 	pipe->funcs->update(pipe, old_pstate);
165 }
166 
167 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
168 					   struct drm_plane_state *state)
169 {
170 	struct drm_simple_display_pipe *pipe;
171 
172 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
173 	if (!pipe->funcs || !pipe->funcs->prepare_fb)
174 		return 0;
175 
176 	return pipe->funcs->prepare_fb(pipe, state);
177 }
178 
179 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
180 					    struct drm_plane_state *state)
181 {
182 	struct drm_simple_display_pipe *pipe;
183 
184 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
185 	if (!pipe->funcs || !pipe->funcs->cleanup_fb)
186 		return;
187 
188 	pipe->funcs->cleanup_fb(pipe, state);
189 }
190 
191 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
192 	.prepare_fb = drm_simple_kms_plane_prepare_fb,
193 	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
194 	.atomic_check = drm_simple_kms_plane_atomic_check,
195 	.atomic_update = drm_simple_kms_plane_atomic_update,
196 };
197 
198 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
199 	.update_plane		= drm_atomic_helper_update_plane,
200 	.disable_plane		= drm_atomic_helper_disable_plane,
201 	.destroy		= drm_plane_cleanup,
202 	.reset			= drm_atomic_helper_plane_reset,
203 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
204 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
205 };
206 
207 /**
208  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
209  * @pipe: simple display pipe object
210  * @bridge: bridge to attach
211  *
212  * Makes it possible to still use the drm_simple_display_pipe helpers when
213  * a DRM bridge has to be used.
214  *
215  * Note that you probably want to initialize the pipe by passing a NULL
216  * connector to drm_simple_display_pipe_init().
217  *
218  * Returns:
219  * Zero on success, negative error code on failure.
220  */
221 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
222 					  struct drm_bridge *bridge)
223 {
224 	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
225 }
226 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
227 
228 /**
229  * drm_simple_display_pipe_init - Initialize a simple display pipeline
230  * @dev: DRM device
231  * @pipe: simple display pipe object to initialize
232  * @funcs: callbacks for the display pipe (optional)
233  * @formats: array of supported formats (DRM_FORMAT\_\*)
234  * @format_count: number of elements in @formats
235  * @format_modifiers: array of formats modifiers
236  * @connector: connector to attach and register (optional)
237  *
238  * Sets up a display pipeline which consist of a really simple
239  * plane-crtc-encoder pipe.
240  *
241  * If a connector is supplied, the pipe will be coupled with the provided
242  * connector. You may supply a NULL connector when using drm bridges, that
243  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
244  *
245  * Teardown of a simple display pipe is all handled automatically by the drm
246  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
247  * release the memory for the structure themselves.
248  *
249  * Returns:
250  * Zero on success, negative error code on failure.
251  */
252 int drm_simple_display_pipe_init(struct drm_device *dev,
253 			struct drm_simple_display_pipe *pipe,
254 			const struct drm_simple_display_pipe_funcs *funcs,
255 			const uint32_t *formats, unsigned int format_count,
256 			const uint64_t *format_modifiers,
257 			struct drm_connector *connector)
258 {
259 	struct drm_encoder *encoder = &pipe->encoder;
260 	struct drm_plane *plane = &pipe->plane;
261 	struct drm_crtc *crtc = &pipe->crtc;
262 	int ret;
263 
264 	pipe->connector = connector;
265 	pipe->funcs = funcs;
266 
267 	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
268 	ret = drm_universal_plane_init(dev, plane, 0,
269 				       &drm_simple_kms_plane_funcs,
270 				       formats, format_count,
271 				       format_modifiers,
272 				       DRM_PLANE_TYPE_PRIMARY, NULL);
273 	if (ret)
274 		return ret;
275 
276 	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
277 	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
278 					&drm_simple_kms_crtc_funcs, NULL);
279 	if (ret)
280 		return ret;
281 
282 	encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
283 	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
284 			       DRM_MODE_ENCODER_NONE, NULL);
285 	if (ret || !connector)
286 		return ret;
287 
288 	return drm_mode_connector_attach_encoder(connector, encoder);
289 }
290 EXPORT_SYMBOL(drm_simple_display_pipe_init);
291 
292 MODULE_LICENSE("GPL");
293