xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision 82e6fdd6)
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/drmP.h>
12 #include <drm/drm_panel.h>
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_connector.h>
15 #include <drm/drm_crtc_helper.h>
16 #include <drm/drm_encoder.h>
17 #include <drm/drm_modeset_helper_vtables.h>
18 #include <drm/drm_panel.h>
19 
20 struct panel_bridge {
21 	struct drm_bridge bridge;
22 	struct drm_connector connector;
23 	struct drm_panel *panel;
24 	u32 connector_type;
25 };
26 
27 static inline struct panel_bridge *
28 drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
29 {
30 	return container_of(bridge, struct panel_bridge, bridge);
31 }
32 
33 static inline struct panel_bridge *
34 drm_connector_to_panel_bridge(struct drm_connector *connector)
35 {
36 	return container_of(connector, struct panel_bridge, connector);
37 }
38 
39 static int panel_bridge_connector_get_modes(struct drm_connector *connector)
40 {
41 	struct panel_bridge *panel_bridge =
42 		drm_connector_to_panel_bridge(connector);
43 
44 	return drm_panel_get_modes(panel_bridge->panel);
45 }
46 
47 static const struct drm_connector_helper_funcs
48 panel_bridge_connector_helper_funcs = {
49 	.get_modes = panel_bridge_connector_get_modes,
50 };
51 
52 static const struct drm_connector_funcs panel_bridge_connector_funcs = {
53 	.reset = drm_atomic_helper_connector_reset,
54 	.fill_modes = drm_helper_probe_single_connector_modes,
55 	.destroy = drm_connector_cleanup,
56 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
57 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
58 };
59 
60 static int panel_bridge_attach(struct drm_bridge *bridge)
61 {
62 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
63 	struct drm_connector *connector = &panel_bridge->connector;
64 	int ret;
65 
66 	if (!bridge->encoder) {
67 		DRM_ERROR("Missing encoder\n");
68 		return -ENODEV;
69 	}
70 
71 	drm_connector_helper_add(connector,
72 				 &panel_bridge_connector_helper_funcs);
73 
74 	ret = drm_connector_init(bridge->dev, connector,
75 				 &panel_bridge_connector_funcs,
76 				 panel_bridge->connector_type);
77 	if (ret) {
78 		DRM_ERROR("Failed to initialize connector\n");
79 		return ret;
80 	}
81 
82 	drm_mode_connector_attach_encoder(&panel_bridge->connector,
83 					  bridge->encoder);
84 
85 	ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
86 	if (ret < 0)
87 		return ret;
88 
89 	return 0;
90 }
91 
92 static void panel_bridge_detach(struct drm_bridge *bridge)
93 {
94 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
95 
96 	drm_panel_detach(panel_bridge->panel);
97 }
98 
99 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
100 {
101 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
102 
103 	drm_panel_prepare(panel_bridge->panel);
104 }
105 
106 static void panel_bridge_enable(struct drm_bridge *bridge)
107 {
108 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
109 
110 	drm_panel_enable(panel_bridge->panel);
111 }
112 
113 static void panel_bridge_disable(struct drm_bridge *bridge)
114 {
115 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
116 
117 	drm_panel_disable(panel_bridge->panel);
118 }
119 
120 static void panel_bridge_post_disable(struct drm_bridge *bridge)
121 {
122 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
123 
124 	drm_panel_unprepare(panel_bridge->panel);
125 }
126 
127 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
128 	.attach = panel_bridge_attach,
129 	.detach = panel_bridge_detach,
130 	.pre_enable = panel_bridge_pre_enable,
131 	.enable = panel_bridge_enable,
132 	.disable = panel_bridge_disable,
133 	.post_disable = panel_bridge_post_disable,
134 };
135 
136 /**
137  * drm_panel_bridge_add - Creates a drm_bridge and drm_connector that
138  * just calls the appropriate functions from drm_panel.
139  *
140  * @panel: The drm_panel being wrapped.  Must be non-NULL.
141  * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
142  * created.
143  *
144  * For drivers converting from directly using drm_panel: The expected
145  * usage pattern is that during either encoder module probe or DSI
146  * host attach, a drm_panel will be looked up through
147  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
148  * wrap that panel in the new bridge, and the result can then be
149  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
150  * functions can be dropped from the encoder driver (they're now
151  * called by the KMS helpers before calling into the encoder), along
152  * with connector creation.  When done with the bridge,
153  * drm_bridge_detach() should be called as normal, then
154  * drm_panel_bridge_remove() to free it.
155  */
156 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
157 					u32 connector_type)
158 {
159 	struct panel_bridge *panel_bridge;
160 
161 	if (!panel)
162 		return ERR_PTR(-EINVAL);
163 
164 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
165 				    GFP_KERNEL);
166 	if (!panel_bridge)
167 		return ERR_PTR(-ENOMEM);
168 
169 	panel_bridge->connector_type = connector_type;
170 	panel_bridge->panel = panel;
171 
172 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
173 #ifdef CONFIG_OF
174 	panel_bridge->bridge.of_node = panel->dev->of_node;
175 #endif
176 
177 	drm_bridge_add(&panel_bridge->bridge);
178 
179 	return &panel_bridge->bridge;
180 }
181 EXPORT_SYMBOL(drm_panel_bridge_add);
182 
183 /**
184  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
185  * created by drm_panel_bridge_add().
186  *
187  * @bridge: The drm_bridge being freed.
188  */
189 void drm_panel_bridge_remove(struct drm_bridge *bridge)
190 {
191 	struct panel_bridge *panel_bridge;
192 
193 	if (!bridge)
194 		return;
195 
196 	if (bridge->funcs != &panel_bridge_bridge_funcs)
197 		return;
198 
199 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
200 
201 	drm_bridge_remove(bridge);
202 	devm_kfree(panel_bridge->panel->dev, bridge);
203 }
204 EXPORT_SYMBOL(drm_panel_bridge_remove);
205 
206 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
207 {
208 	struct drm_bridge **bridge = res;
209 
210 	drm_panel_bridge_remove(*bridge);
211 }
212 
213 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
214 					     struct drm_panel *panel,
215 					     u32 connector_type)
216 {
217 	struct drm_bridge **ptr, *bridge;
218 
219 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
220 			   GFP_KERNEL);
221 	if (!ptr)
222 		return ERR_PTR(-ENOMEM);
223 
224 	bridge = drm_panel_bridge_add(panel, connector_type);
225 	if (!IS_ERR(bridge)) {
226 		*ptr = bridge;
227 		devres_add(dev, ptr);
228 	} else {
229 		devres_free(ptr);
230 	}
231 
232 	return bridge;
233 }
234 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
235