xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision 423997ff)
1 /*
2  * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
3  * Copyright (C) 2017 Broadcom
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation; either version 2 of
8  * the License, or (at your option) any later version.
9  */
10 
11 #include <drm/drm_atomic_helper.h>
12 #include <drm/drm_connector.h>
13 #include <drm/drm_encoder.h>
14 #include <drm/drm_modeset_helper_vtables.h>
15 #include <drm/drm_panel.h>
16 #include <drm/drm_print.h>
17 #include <drm/drm_probe_helper.h>
18 
19 struct panel_bridge {
20 	struct drm_bridge bridge;
21 	struct drm_connector connector;
22 	struct drm_panel *panel;
23 	u32 connector_type;
24 };
25 
26 static inline struct panel_bridge *
27 drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
28 {
29 	return container_of(bridge, struct panel_bridge, bridge);
30 }
31 
32 static inline struct panel_bridge *
33 drm_connector_to_panel_bridge(struct drm_connector *connector)
34 {
35 	return container_of(connector, struct panel_bridge, connector);
36 }
37 
38 static int panel_bridge_connector_get_modes(struct drm_connector *connector)
39 {
40 	struct panel_bridge *panel_bridge =
41 		drm_connector_to_panel_bridge(connector);
42 
43 	return drm_panel_get_modes(panel_bridge->panel);
44 }
45 
46 static const struct drm_connector_helper_funcs
47 panel_bridge_connector_helper_funcs = {
48 	.get_modes = panel_bridge_connector_get_modes,
49 };
50 
51 static const struct drm_connector_funcs panel_bridge_connector_funcs = {
52 	.reset = drm_atomic_helper_connector_reset,
53 	.fill_modes = drm_helper_probe_single_connector_modes,
54 	.destroy = drm_connector_cleanup,
55 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
56 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
57 };
58 
59 static int panel_bridge_attach(struct drm_bridge *bridge)
60 {
61 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
62 	struct drm_connector *connector = &panel_bridge->connector;
63 	int ret;
64 
65 	if (!bridge->encoder) {
66 		DRM_ERROR("Missing encoder\n");
67 		return -ENODEV;
68 	}
69 
70 	drm_connector_helper_add(connector,
71 				 &panel_bridge_connector_helper_funcs);
72 
73 	ret = drm_connector_init(bridge->dev, connector,
74 				 &panel_bridge_connector_funcs,
75 				 panel_bridge->connector_type);
76 	if (ret) {
77 		DRM_ERROR("Failed to initialize connector\n");
78 		return ret;
79 	}
80 
81 	drm_connector_attach_encoder(&panel_bridge->connector,
82 					  bridge->encoder);
83 
84 	ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
85 	if (ret < 0)
86 		return ret;
87 
88 	return 0;
89 }
90 
91 static void panel_bridge_detach(struct drm_bridge *bridge)
92 {
93 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
94 
95 	drm_panel_detach(panel_bridge->panel);
96 }
97 
98 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
99 {
100 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
101 
102 	drm_panel_prepare(panel_bridge->panel);
103 }
104 
105 static void panel_bridge_enable(struct drm_bridge *bridge)
106 {
107 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
108 
109 	drm_panel_enable(panel_bridge->panel);
110 }
111 
112 static void panel_bridge_disable(struct drm_bridge *bridge)
113 {
114 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
115 
116 	drm_panel_disable(panel_bridge->panel);
117 }
118 
119 static void panel_bridge_post_disable(struct drm_bridge *bridge)
120 {
121 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
122 
123 	drm_panel_unprepare(panel_bridge->panel);
124 }
125 
126 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
127 	.attach = panel_bridge_attach,
128 	.detach = panel_bridge_detach,
129 	.pre_enable = panel_bridge_pre_enable,
130 	.enable = panel_bridge_enable,
131 	.disable = panel_bridge_disable,
132 	.post_disable = panel_bridge_post_disable,
133 };
134 
135 /**
136  * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
137  * just calls the appropriate functions from &drm_panel.
138  *
139  * @panel: The drm_panel being wrapped.  Must be non-NULL.
140  * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
141  * created.
142  *
143  * For drivers converting from directly using drm_panel: The expected
144  * usage pattern is that during either encoder module probe or DSI
145  * host attach, a drm_panel will be looked up through
146  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
147  * wrap that panel in the new bridge, and the result can then be
148  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
149  * functions can be dropped from the encoder driver (they're now
150  * called by the KMS helpers before calling into the encoder), along
151  * with connector creation.  When done with the bridge (after
152  * drm_mode_config_cleanup() if the bridge has already been attached), then
153  * drm_panel_bridge_remove() to free it.
154  *
155  * See devm_drm_panel_bridge_add() for an automatically manged version of this
156  * function.
157  */
158 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
159 					u32 connector_type)
160 {
161 	struct panel_bridge *panel_bridge;
162 
163 	if (!panel)
164 		return ERR_PTR(-EINVAL);
165 
166 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
167 				    GFP_KERNEL);
168 	if (!panel_bridge)
169 		return ERR_PTR(-ENOMEM);
170 
171 	panel_bridge->connector_type = connector_type;
172 	panel_bridge->panel = panel;
173 
174 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
175 #ifdef CONFIG_OF
176 	panel_bridge->bridge.of_node = panel->dev->of_node;
177 #endif
178 
179 	drm_bridge_add(&panel_bridge->bridge);
180 
181 	return &panel_bridge->bridge;
182 }
183 EXPORT_SYMBOL(drm_panel_bridge_add);
184 
185 /**
186  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
187  * created by drm_panel_bridge_add().
188  *
189  * @bridge: The drm_bridge being freed.
190  */
191 void drm_panel_bridge_remove(struct drm_bridge *bridge)
192 {
193 	struct panel_bridge *panel_bridge;
194 
195 	if (!bridge)
196 		return;
197 
198 	if (bridge->funcs != &panel_bridge_bridge_funcs)
199 		return;
200 
201 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
202 
203 	drm_bridge_remove(bridge);
204 	devm_kfree(panel_bridge->panel->dev, bridge);
205 }
206 EXPORT_SYMBOL(drm_panel_bridge_remove);
207 
208 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
209 {
210 	struct drm_bridge **bridge = res;
211 
212 	drm_panel_bridge_remove(*bridge);
213 }
214 
215 /**
216  * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
217  * that just calls the appropriate functions from &drm_panel.
218  * @dev: device to tie the bridge lifetime to
219  * @panel: The drm_panel being wrapped.  Must be non-NULL.
220  * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
221  * created.
222  *
223  * This is the managed version of drm_panel_bridge_add() which automatically
224  * calls drm_panel_bridge_remove() when @dev is unbound.
225  */
226 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
227 					     struct drm_panel *panel,
228 					     u32 connector_type)
229 {
230 	struct drm_bridge **ptr, *bridge;
231 
232 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
233 			   GFP_KERNEL);
234 	if (!ptr)
235 		return ERR_PTR(-ENOMEM);
236 
237 	bridge = drm_panel_bridge_add(panel, connector_type);
238 	if (!IS_ERR(bridge)) {
239 		*ptr = bridge;
240 		devres_add(dev, ptr);
241 	} else {
242 		devres_free(ptr);
243 	}
244 
245 	return bridge;
246 }
247 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
248