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 	bool has_primary = state->plane_mask &
41 			   BIT(drm_plane_index(crtc->primary));
42 
43 	/* We always want to have an active plane with an active CRTC */
44 	if (has_primary != state->enable)
45 		return -EINVAL;
46 
47 	return drm_atomic_add_affected_planes(state->state, crtc);
48 }
49 
50 static void drm_simple_kms_crtc_enable(struct drm_crtc *crtc,
51 				       struct drm_crtc_state *old_state)
52 {
53 	struct drm_simple_display_pipe *pipe;
54 
55 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
56 	if (!pipe->funcs || !pipe->funcs->enable)
57 		return;
58 
59 	pipe->funcs->enable(pipe, crtc->state);
60 }
61 
62 static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
63 					struct drm_crtc_state *old_state)
64 {
65 	struct drm_simple_display_pipe *pipe;
66 
67 	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
68 	if (!pipe->funcs || !pipe->funcs->disable)
69 		return;
70 
71 	pipe->funcs->disable(pipe);
72 }
73 
74 static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
75 	.atomic_check = drm_simple_kms_crtc_check,
76 	.atomic_enable = drm_simple_kms_crtc_enable,
77 	.atomic_disable = drm_simple_kms_crtc_disable,
78 };
79 
80 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
81 	.reset = drm_atomic_helper_crtc_reset,
82 	.destroy = drm_crtc_cleanup,
83 	.set_config = drm_atomic_helper_set_config,
84 	.page_flip = drm_atomic_helper_page_flip,
85 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
86 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
87 };
88 
89 static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
90 					struct drm_plane_state *plane_state)
91 {
92 	struct drm_rect clip = { 0 };
93 	struct drm_simple_display_pipe *pipe;
94 	struct drm_crtc_state *crtc_state;
95 	int ret;
96 
97 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
98 	crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
99 						   &pipe->crtc);
100 	if (!crtc_state->enable)
101 		return 0; /* nothing to check when disabling or disabled */
102 
103 	clip.x2 = crtc_state->adjusted_mode.hdisplay;
104 	clip.y2 = crtc_state->adjusted_mode.vdisplay;
105 
106 	ret = drm_plane_helper_check_state(plane_state, &clip,
107 					   DRM_PLANE_HELPER_NO_SCALING,
108 					   DRM_PLANE_HELPER_NO_SCALING,
109 					   false, true);
110 	if (ret)
111 		return ret;
112 
113 	if (!plane_state->visible)
114 		return -EINVAL;
115 
116 	if (!pipe->funcs || !pipe->funcs->check)
117 		return 0;
118 
119 	return pipe->funcs->check(pipe, plane_state, crtc_state);
120 }
121 
122 static void drm_simple_kms_plane_atomic_update(struct drm_plane *plane,
123 					struct drm_plane_state *old_pstate)
124 {
125 	struct drm_simple_display_pipe *pipe;
126 
127 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
128 	if (!pipe->funcs || !pipe->funcs->update)
129 		return;
130 
131 	pipe->funcs->update(pipe, old_pstate);
132 }
133 
134 static int drm_simple_kms_plane_prepare_fb(struct drm_plane *plane,
135 					   struct drm_plane_state *state)
136 {
137 	struct drm_simple_display_pipe *pipe;
138 
139 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
140 	if (!pipe->funcs || !pipe->funcs->prepare_fb)
141 		return 0;
142 
143 	return pipe->funcs->prepare_fb(pipe, state);
144 }
145 
146 static void drm_simple_kms_plane_cleanup_fb(struct drm_plane *plane,
147 					    struct drm_plane_state *state)
148 {
149 	struct drm_simple_display_pipe *pipe;
150 
151 	pipe = container_of(plane, struct drm_simple_display_pipe, plane);
152 	if (!pipe->funcs || !pipe->funcs->cleanup_fb)
153 		return;
154 
155 	pipe->funcs->cleanup_fb(pipe, state);
156 }
157 
158 static const struct drm_plane_helper_funcs drm_simple_kms_plane_helper_funcs = {
159 	.prepare_fb = drm_simple_kms_plane_prepare_fb,
160 	.cleanup_fb = drm_simple_kms_plane_cleanup_fb,
161 	.atomic_check = drm_simple_kms_plane_atomic_check,
162 	.atomic_update = drm_simple_kms_plane_atomic_update,
163 };
164 
165 static const struct drm_plane_funcs drm_simple_kms_plane_funcs = {
166 	.update_plane		= drm_atomic_helper_update_plane,
167 	.disable_plane		= drm_atomic_helper_disable_plane,
168 	.destroy		= drm_plane_cleanup,
169 	.reset			= drm_atomic_helper_plane_reset,
170 	.atomic_duplicate_state	= drm_atomic_helper_plane_duplicate_state,
171 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
172 };
173 
174 /**
175  * drm_simple_display_pipe_attach_bridge - Attach a bridge to the display pipe
176  * @pipe: simple display pipe object
177  * @bridge: bridge to attach
178  *
179  * Makes it possible to still use the drm_simple_display_pipe helpers when
180  * a DRM bridge has to be used.
181  *
182  * Note that you probably want to initialize the pipe by passing a NULL
183  * connector to drm_simple_display_pipe_init().
184  *
185  * Returns:
186  * Zero on success, negative error code on failure.
187  */
188 int drm_simple_display_pipe_attach_bridge(struct drm_simple_display_pipe *pipe,
189 					  struct drm_bridge *bridge)
190 {
191 	return drm_bridge_attach(&pipe->encoder, bridge, NULL);
192 }
193 EXPORT_SYMBOL(drm_simple_display_pipe_attach_bridge);
194 
195 /**
196  * drm_simple_display_pipe_init - Initialize a simple display pipeline
197  * @dev: DRM device
198  * @pipe: simple display pipe object to initialize
199  * @funcs: callbacks for the display pipe (optional)
200  * @formats: array of supported formats (DRM_FORMAT\_\*)
201  * @format_count: number of elements in @formats
202  * @format_modifiers: array of formats modifiers
203  * @connector: connector to attach and register (optional)
204  *
205  * Sets up a display pipeline which consist of a really simple
206  * plane-crtc-encoder pipe.
207  *
208  * If a connector is supplied, the pipe will be coupled with the provided
209  * connector. You may supply a NULL connector when using drm bridges, that
210  * handle connectors themselves (see drm_simple_display_pipe_attach_bridge()).
211  *
212  * Teardown of a simple display pipe is all handled automatically by the drm
213  * core through calling drm_mode_config_cleanup(). Drivers afterwards need to
214  * release the memory for the structure themselves.
215  *
216  * Returns:
217  * Zero on success, negative error code on failure.
218  */
219 int drm_simple_display_pipe_init(struct drm_device *dev,
220 			struct drm_simple_display_pipe *pipe,
221 			const struct drm_simple_display_pipe_funcs *funcs,
222 			const uint32_t *formats, unsigned int format_count,
223 			const uint64_t *format_modifiers,
224 			struct drm_connector *connector)
225 {
226 	struct drm_encoder *encoder = &pipe->encoder;
227 	struct drm_plane *plane = &pipe->plane;
228 	struct drm_crtc *crtc = &pipe->crtc;
229 	int ret;
230 
231 	pipe->connector = connector;
232 	pipe->funcs = funcs;
233 
234 	drm_plane_helper_add(plane, &drm_simple_kms_plane_helper_funcs);
235 	ret = drm_universal_plane_init(dev, plane, 0,
236 				       &drm_simple_kms_plane_funcs,
237 				       formats, format_count,
238 				       format_modifiers,
239 				       DRM_PLANE_TYPE_PRIMARY, NULL);
240 	if (ret)
241 		return ret;
242 
243 	drm_crtc_helper_add(crtc, &drm_simple_kms_crtc_helper_funcs);
244 	ret = drm_crtc_init_with_planes(dev, crtc, plane, NULL,
245 					&drm_simple_kms_crtc_funcs, NULL);
246 	if (ret)
247 		return ret;
248 
249 	encoder->possible_crtcs = 1 << drm_crtc_index(crtc);
250 	ret = drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs,
251 			       DRM_MODE_ENCODER_NONE, NULL);
252 	if (ret || !connector)
253 		return ret;
254 
255 	return drm_mode_connector_attach_encoder(connector, encoder);
256 }
257 EXPORT_SYMBOL(drm_simple_display_pipe_init);
258 
259 MODULE_LICENSE("GPL");
260