xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
4  * Copyright (C) 2017 Broadcom
5  */
6 
7 #include <drm/drm_atomic_helper.h>
8 #include <drm/drm_connector.h>
9 #include <drm/drm_encoder.h>
10 #include <drm/drm_modeset_helper_vtables.h>
11 #include <drm/drm_panel.h>
12 #include <drm/drm_print.h>
13 #include <drm/drm_probe_helper.h>
14 
15 struct panel_bridge {
16 	struct drm_bridge bridge;
17 	struct drm_connector connector;
18 	struct drm_panel *panel;
19 	u32 connector_type;
20 };
21 
22 static inline struct panel_bridge *
23 drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
24 {
25 	return container_of(bridge, struct panel_bridge, bridge);
26 }
27 
28 static inline struct panel_bridge *
29 drm_connector_to_panel_bridge(struct drm_connector *connector)
30 {
31 	return container_of(connector, struct panel_bridge, connector);
32 }
33 
34 static int panel_bridge_connector_get_modes(struct drm_connector *connector)
35 {
36 	struct panel_bridge *panel_bridge =
37 		drm_connector_to_panel_bridge(connector);
38 
39 	return drm_panel_get_modes(panel_bridge->panel);
40 }
41 
42 static const struct drm_connector_helper_funcs
43 panel_bridge_connector_helper_funcs = {
44 	.get_modes = panel_bridge_connector_get_modes,
45 };
46 
47 static const struct drm_connector_funcs panel_bridge_connector_funcs = {
48 	.reset = drm_atomic_helper_connector_reset,
49 	.fill_modes = drm_helper_probe_single_connector_modes,
50 	.destroy = drm_connector_cleanup,
51 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
52 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
53 };
54 
55 static int panel_bridge_attach(struct drm_bridge *bridge)
56 {
57 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
58 	struct drm_connector *connector = &panel_bridge->connector;
59 	int ret;
60 
61 	if (!bridge->encoder) {
62 		DRM_ERROR("Missing encoder\n");
63 		return -ENODEV;
64 	}
65 
66 	drm_connector_helper_add(connector,
67 				 &panel_bridge_connector_helper_funcs);
68 
69 	ret = drm_connector_init(bridge->dev, connector,
70 				 &panel_bridge_connector_funcs,
71 				 panel_bridge->connector_type);
72 	if (ret) {
73 		DRM_ERROR("Failed to initialize connector\n");
74 		return ret;
75 	}
76 
77 	drm_connector_attach_encoder(&panel_bridge->connector,
78 					  bridge->encoder);
79 
80 	ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
81 	if (ret < 0)
82 		return ret;
83 
84 	return 0;
85 }
86 
87 static void panel_bridge_detach(struct drm_bridge *bridge)
88 {
89 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
90 
91 	drm_panel_detach(panel_bridge->panel);
92 }
93 
94 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
95 {
96 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
97 
98 	drm_panel_prepare(panel_bridge->panel);
99 }
100 
101 static void panel_bridge_enable(struct drm_bridge *bridge)
102 {
103 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
104 
105 	drm_panel_enable(panel_bridge->panel);
106 }
107 
108 static void panel_bridge_disable(struct drm_bridge *bridge)
109 {
110 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
111 
112 	drm_panel_disable(panel_bridge->panel);
113 }
114 
115 static void panel_bridge_post_disable(struct drm_bridge *bridge)
116 {
117 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
118 
119 	drm_panel_unprepare(panel_bridge->panel);
120 }
121 
122 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
123 	.attach = panel_bridge_attach,
124 	.detach = panel_bridge_detach,
125 	.pre_enable = panel_bridge_pre_enable,
126 	.enable = panel_bridge_enable,
127 	.disable = panel_bridge_disable,
128 	.post_disable = panel_bridge_post_disable,
129 };
130 
131 /**
132  * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
133  * just calls the appropriate functions from &drm_panel.
134  *
135  * @panel: The drm_panel being wrapped.  Must be non-NULL.
136  * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
137  * created.
138  *
139  * For drivers converting from directly using drm_panel: The expected
140  * usage pattern is that during either encoder module probe or DSI
141  * host attach, a drm_panel will be looked up through
142  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
143  * wrap that panel in the new bridge, and the result can then be
144  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
145  * functions can be dropped from the encoder driver (they're now
146  * called by the KMS helpers before calling into the encoder), along
147  * with connector creation.  When done with the bridge (after
148  * drm_mode_config_cleanup() if the bridge has already been attached), then
149  * drm_panel_bridge_remove() to free it.
150  *
151  * See devm_drm_panel_bridge_add() for an automatically manged version of this
152  * function.
153  */
154 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,
155 					u32 connector_type)
156 {
157 	struct panel_bridge *panel_bridge;
158 
159 	if (!panel)
160 		return ERR_PTR(-EINVAL);
161 
162 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
163 				    GFP_KERNEL);
164 	if (!panel_bridge)
165 		return ERR_PTR(-ENOMEM);
166 
167 	panel_bridge->connector_type = connector_type;
168 	panel_bridge->panel = panel;
169 
170 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
171 #ifdef CONFIG_OF
172 	panel_bridge->bridge.of_node = panel->dev->of_node;
173 #endif
174 
175 	drm_bridge_add(&panel_bridge->bridge);
176 
177 	return &panel_bridge->bridge;
178 }
179 EXPORT_SYMBOL(drm_panel_bridge_add);
180 
181 /**
182  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
183  * created by drm_panel_bridge_add().
184  *
185  * @bridge: The drm_bridge being freed.
186  */
187 void drm_panel_bridge_remove(struct drm_bridge *bridge)
188 {
189 	struct panel_bridge *panel_bridge;
190 
191 	if (!bridge)
192 		return;
193 
194 	if (bridge->funcs != &panel_bridge_bridge_funcs)
195 		return;
196 
197 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
198 
199 	drm_bridge_remove(bridge);
200 	devm_kfree(panel_bridge->panel->dev, bridge);
201 }
202 EXPORT_SYMBOL(drm_panel_bridge_remove);
203 
204 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
205 {
206 	struct drm_bridge **bridge = res;
207 
208 	drm_panel_bridge_remove(*bridge);
209 }
210 
211 /**
212  * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
213  * that just calls the appropriate functions from &drm_panel.
214  * @dev: device to tie the bridge lifetime to
215  * @panel: The drm_panel being wrapped.  Must be non-NULL.
216  * @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
217  * created.
218  *
219  * This is the managed version of drm_panel_bridge_add() which automatically
220  * calls drm_panel_bridge_remove() when @dev is unbound.
221  */
222 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
223 					     struct drm_panel *panel,
224 					     u32 connector_type)
225 {
226 	struct drm_bridge **ptr, *bridge;
227 
228 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
229 			   GFP_KERNEL);
230 	if (!ptr)
231 		return ERR_PTR(-ENOMEM);
232 
233 	bridge = drm_panel_bridge_add(panel, connector_type);
234 	if (!IS_ERR(bridge)) {
235 		*ptr = bridge;
236 		devres_add(dev, ptr);
237 	} else {
238 		devres_free(ptr);
239 	}
240 
241 	return bridge;
242 }
243 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
244