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 int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
38 				     struct drm_crtc_state *state)
39 {
40 	return drm_atomic_add_affected_planes(state->state, crtc);
41 }
42 
43 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc)
44 {
45 	struct drm_simple_display_pipe *pipe;
46 
47 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
48 	if (!pipe->funcs || !pipe->funcs->enable)
49 		return;
50 
51 	pipe->funcs->enable(pipe, crtc->state);
52 }
53 
54 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc)
55 {
56 	struct drm_simple_display_pipe *pipe;
57 
58 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
59 	if (!pipe->funcs || !pipe->funcs->disable)
60 		return;
61 
62 	pipe->funcs->disable(pipe);
63 }
64 
65 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
66 	.atomic_check = drm_simple_kms_crtc_check,
67 	.disable = drm_simple_kms_crtc_disable,
68 	.enable = drm_simple_kms_crtc_enable,
69 };
70 
71 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
72 	.reset = drm_atomic_helper_crtc_reset,
73 	.destroy = drm_crtc_cleanup,
74 	.set_config = drm_atomic_helper_set_config,
75 	.page_flip = drm_atomic_helper_page_flip,
76 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
77 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
78 };
79 
80 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
81 					struct drm_plane_state *plane_state)
82 {
83 	struct drm_rect clip = { 0 };
84 	struct drm_simple_display_pipe *pipe;
85 	struct drm_crtc_state *crtc_state;
86 	int ret;
87 
88 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
89 	crtc_state = drm_atomic_get_existing_crtc_state(plane_state->state,
90 							&pipe->crtc);
91 	if (crtc_state->enable != !!plane_state->crtc)
92 		return -EINVAL; /* plane must match crtc enable state */
93 
94 	if (!crtc_state->enable)
95 		return 0; /* nothing to check when disabling or disabled */
96 
97 	clip.x2 = crtc_state->adjusted_mode.hdisplay;
98 	clip.y2 = crtc_state->adjusted_mode.vdisplay;
99 
100 	ret = drm_plane_helper_check_state(plane_state, &clip,
101 					   DRM_PLANE_HELPER_NO_SCALING,
102 					   DRM_PLANE_HELPER_NO_SCALING,
103 					   false, true);
104 	if (ret)
105 		return ret;
106 
107 	if (!plane_state->visible)
108 		return -EINVAL;
109 
110 	if (!pipe->funcs || !pipe->funcs->check)
111 		return 0;
112 
113 	return pipe->funcs->check(pipe, plane_state, crtc_state);
114 }
115 
116 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
117 					struct drm_plane_state *pstate)
118 {
119 	struct drm_simple_display_pipe *pipe;
120 
121 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
122 	if (!pipe->funcs || !pipe->funcs->update)
123 		return;
124 
125 	pipe->funcs->update(pipe, pstate);
126 }
127 
128 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
129 					   struct drm_plane_state *state)
130 {
131 	struct drm_simple_display_pipe *pipe;
132 
133 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
134 	if (!pipe->funcs || !pipe->funcs->prepare_fb)
135 		return 0;
136 
137 	return pipe->funcs->prepare_fb(pipe, state);
138 }
139 
140 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
141 					    struct drm_plane_state *state)
142 {
143 	struct drm_simple_display_pipe *pipe;
144 
145 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
146 	if (!pipe->funcs || !pipe->funcs->cleanup_fb)
147 		return;
148 
149 	pipe->funcs->cleanup_fb(pipe, state);
150 }
151 
152 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
153 	.prepare_fb = drm_simple_kms_plane_prepare_fb,
154 	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
155 	.atomic_check = drm_simple_kms_plane_atomic_check,
156 	.atomic_update = drm_simple_kms_plane_atomic_update,
157 };
158 
159 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
160 	.update_plane		= drm_atomic_helper_update_plane,
161 	.disable_plane		= drm_atomic_helper_disable_plane,
162 	.destroy		= drm_plane_cleanup,
163 	.reset			= drm_atomic_helper_plane_reset,
164 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
165 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
166 };
167 
168 /**
169  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
170  * @pipe: simple display pipe object
171  * @bridge: bridge to attach
172  *
173  * Makes it possible to still use the drm_simple_display_pipe helpers when
174  * a DRM bridge has to be used.
175  *
176  * Note that you probably want to initialize the pipe by passing a NULL
177  * connector to drm_simple_display_pipe_init().
178  *
179  * Returns:
180  * Zero on success, negative error code on failure.
181  */
182 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
183 					  struct drm_bridge *bridge)
184 {
185 	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
186 }
187 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
188 
189 /**
190  * drm_simple_display_pipe_init - Initialize a simple display pipeline
191  * @dev: DRM device
192  * @pipe: simple display pipe object to initialize
193  * @funcs: callbacks for the display pipe (optional)
194  * @formats: array of supported formats (DRM_FORMAT\_\*)
195  * @format_count: number of elements in @formats
196  * @connector: connector to attach and register (optional)
197  *
198  * Sets up a display pipeline which consist of a really simple
199  * plane-crtc-encoder pipe.
200  *
201  * If a connector is supplied, the pipe will be coupled with the provided
202  * connector. You may supply a NULL connector when using drm bridges, that
203  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
204  *
205  * Teardown of a simple display pipe is all handled automatically by the drm
206  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
207  * release the memory for the structure themselves.
208  *
209  * Returns:
210  * Zero on success, negative error code on failure.
211  */
212 int drm_simple_display_pipe_init(struct drm_device *dev,
213 			struct drm_simple_display_pipe *pipe,
214 			const struct drm_simple_display_pipe_funcs *funcs,
215 			const uint32_t *formats, unsigned int format_count,
216 			struct drm_connector *connector)
217 {
218 	struct drm_encoder *encoder = &pipe->encoder;
219 	struct drm_plane *plane = &pipe->plane;
220 	struct drm_crtc *crtc = &pipe->crtc;
221 	int ret;
222 
223 	pipe->connector = connector;
224 	pipe->funcs = funcs;
225 
226 	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
227 	ret = drm_universal_plane_init(dev, plane, 0,
228 				       &drm_simple_kms_plane_funcs,
229 				       formats, format_count,
230 				       DRM_PLANE_TYPE_PRIMARY, NULL);
231 	if (ret)
232 		return ret;
233 
234 	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
235 	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
236 					&drm_simple_kms_crtc_funcs, NULL);
237 	if (ret)
238 		return ret;
239 
240 	encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
241 	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
242 			       DRM_MODE_ENCODER_NONE, NULL);
243 	if (ret || !connector)
244 		return ret;
245 
246 	return drm_mode_connector_attach_encoder(connector, encoder);
247 }
248 EXPORT_SYMBOL(drm_simple_display_pipe_init);
249 
250 MODULE_LICENSE("GPL");
251