xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision dc6a81c3)
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_bridge.h>
9 #include <drm/drm_connector.h>
10 #include <drm/drm_encoder.h>
11 #include <drm/drm_modeset_helper_vtables.h>
12 #include <drm/drm_panel.h>
13 #include <drm/drm_print.h>
14 #include <drm/drm_probe_helper.h>
15 
16 struct panel_bridge {
17 	struct drm_bridge bridge;
18 	struct drm_connector connector;
19 	struct drm_panel *panel;
20 	u32 connector_type;
21 };
22 
23 static inline struct panel_bridge *
24 drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
25 {
26 	return container_of(bridge, struct panel_bridge, bridge);
27 }
28 
29 static inline struct panel_bridge *
30 drm_connector_to_panel_bridge(struct drm_connector *connector)
31 {
32 	return container_of(connector, struct panel_bridge, connector);
33 }
34 
35 static int panel_bridge_connector_get_modes(struct drm_connector *connector)
36 {
37 	struct panel_bridge *panel_bridge =
38 		drm_connector_to_panel_bridge(connector);
39 
40 	return drm_panel_get_modes(panel_bridge->panel, connector);
41 }
42 
43 static const struct drm_connector_helper_funcs
44 panel_bridge_connector_helper_funcs = {
45 	.get_modes = panel_bridge_connector_get_modes,
46 };
47 
48 static const struct drm_connector_funcs panel_bridge_connector_funcs = {
49 	.reset = drm_atomic_helper_connector_reset,
50 	.fill_modes = drm_helper_probe_single_connector_modes,
51 	.destroy = drm_connector_cleanup,
52 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
53 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
54 };
55 
56 static int panel_bridge_attach(struct drm_bridge *bridge)
57 {
58 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
59 	struct drm_connector *connector = &panel_bridge->connector;
60 	int ret;
61 
62 	if (!bridge->encoder) {
63 		DRM_ERROR("Missing encoder\n");
64 		return -ENODEV;
65 	}
66 
67 	drm_connector_helper_add(connector,
68 				 &panel_bridge_connector_helper_funcs);
69 
70 	ret = drm_connector_init(bridge->dev, connector,
71 				 &panel_bridge_connector_funcs,
72 				 panel_bridge->connector_type);
73 	if (ret) {
74 		DRM_ERROR("Failed to initialize connector\n");
75 		return ret;
76 	}
77 
78 	drm_connector_attach_encoder(&panel_bridge->connector,
79 					  bridge->encoder);
80 
81 	ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
82 	if (ret < 0)
83 		return ret;
84 
85 	return 0;
86 }
87 
88 static void panel_bridge_detach(struct drm_bridge *bridge)
89 {
90 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
91 
92 	drm_panel_detach(panel_bridge->panel);
93 }
94 
95 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
96 {
97 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
98 
99 	drm_panel_prepare(panel_bridge->panel);
100 }
101 
102 static void panel_bridge_enable(struct drm_bridge *bridge)
103 {
104 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
105 
106 	drm_panel_enable(panel_bridge->panel);
107 }
108 
109 static void panel_bridge_disable(struct drm_bridge *bridge)
110 {
111 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
112 
113 	drm_panel_disable(panel_bridge->panel);
114 }
115 
116 static void panel_bridge_post_disable(struct drm_bridge *bridge)
117 {
118 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
119 
120 	drm_panel_unprepare(panel_bridge->panel);
121 }
122 
123 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
124 	.attach = panel_bridge_attach,
125 	.detach = panel_bridge_detach,
126 	.pre_enable = panel_bridge_pre_enable,
127 	.enable = panel_bridge_enable,
128 	.disable = panel_bridge_disable,
129 	.post_disable = panel_bridge_post_disable,
130 };
131 
132 /**
133  * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
134  * just calls the appropriate functions from &drm_panel.
135  *
136  * @panel: The drm_panel being wrapped.  Must be non-NULL.
137  *
138  * For drivers converting from directly using drm_panel: The expected
139  * usage pattern is that during either encoder module probe or DSI
140  * host attach, a drm_panel will be looked up through
141  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
142  * wrap that panel in the new bridge, and the result can then be
143  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
144  * functions can be dropped from the encoder driver (they're now
145  * called by the KMS helpers before calling into the encoder), along
146  * with connector creation.  When done with the bridge (after
147  * drm_mode_config_cleanup() if the bridge has already been attached), then
148  * drm_panel_bridge_remove() to free it.
149  *
150  * The connector type is set to @panel->connector_type, which must be set to a
151  * known type. Calling this function with a panel whose connector type is
152  * DRM_MODE_CONNECTOR_Unknown will return NULL.
153  *
154  * See devm_drm_panel_bridge_add() for an automatically manged version of this
155  * function.
156  */
157 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
158 {
159 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
160 		return NULL;
161 
162 	return drm_panel_bridge_add_typed(panel, panel->connector_type);
163 }
164 EXPORT_SYMBOL(drm_panel_bridge_add);
165 
166 /**
167  * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
168  * an explicit connector type.
169  * @panel: The drm_panel being wrapped.  Must be non-NULL.
170  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
171  *
172  * This is just like drm_panel_bridge_add(), but forces the connector type to
173  * @connector_type instead of infering it from the panel.
174  *
175  * This function is deprecated and should not be used in new drivers. Use
176  * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
177  * don't report a connector type.
178  */
179 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
180 					      u32 connector_type)
181 {
182 	struct panel_bridge *panel_bridge;
183 
184 	if (!panel)
185 		return ERR_PTR(-EINVAL);
186 
187 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
188 				    GFP_KERNEL);
189 	if (!panel_bridge)
190 		return ERR_PTR(-ENOMEM);
191 
192 	panel_bridge->connector_type = connector_type;
193 	panel_bridge->panel = panel;
194 
195 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
196 #ifdef CONFIG_OF
197 	panel_bridge->bridge.of_node = panel->dev->of_node;
198 #endif
199 
200 	drm_bridge_add(&panel_bridge->bridge);
201 
202 	return &panel_bridge->bridge;
203 }
204 EXPORT_SYMBOL(drm_panel_bridge_add_typed);
205 
206 /**
207  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
208  * created by drm_panel_bridge_add().
209  *
210  * @bridge: The drm_bridge being freed.
211  */
212 void drm_panel_bridge_remove(struct drm_bridge *bridge)
213 {
214 	struct panel_bridge *panel_bridge;
215 
216 	if (!bridge)
217 		return;
218 
219 	if (bridge->funcs != &panel_bridge_bridge_funcs)
220 		return;
221 
222 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
223 
224 	drm_bridge_remove(bridge);
225 	devm_kfree(panel_bridge->panel->dev, bridge);
226 }
227 EXPORT_SYMBOL(drm_panel_bridge_remove);
228 
229 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
230 {
231 	struct drm_bridge **bridge = res;
232 
233 	drm_panel_bridge_remove(*bridge);
234 }
235 
236 /**
237  * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
238  * that just calls the appropriate functions from &drm_panel.
239  * @dev: device to tie the bridge lifetime to
240  * @panel: The drm_panel being wrapped.  Must be non-NULL.
241  *
242  * This is the managed version of drm_panel_bridge_add() which automatically
243  * calls drm_panel_bridge_remove() when @dev is unbound.
244  */
245 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
246 					     struct drm_panel *panel)
247 {
248 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
249 		return NULL;
250 
251 	return devm_drm_panel_bridge_add_typed(dev, panel,
252 					       panel->connector_type);
253 }
254 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
255 
256 /**
257  * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
258  * &drm_connector with an explicit connector type.
259  * @dev: device to tie the bridge lifetime to
260  * @panel: The drm_panel being wrapped.  Must be non-NULL.
261  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
262  *
263  * This is just like devm_drm_panel_bridge_add(), but forces the connector type
264  * to @connector_type instead of infering it from the panel.
265  *
266  * This function is deprecated and should not be used in new drivers. Use
267  * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
268  * they don't report a connector type.
269  */
270 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
271 						   struct drm_panel *panel,
272 						   u32 connector_type)
273 {
274 	struct drm_bridge **ptr, *bridge;
275 
276 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
277 			   GFP_KERNEL);
278 	if (!ptr)
279 		return ERR_PTR(-ENOMEM);
280 
281 	bridge = drm_panel_bridge_add_typed(panel, connector_type);
282 	if (!IS_ERR(bridge)) {
283 		*ptr = bridge;
284 		devres_add(dev, ptr);
285 	} else {
286 		devres_free(ptr);
287 	}
288 
289 	return bridge;
290 }
291 EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);
292 
293 /**
294  * drm_panel_bridge_connector - return the connector for the panel bridge
295  *
296  * drm_panel_bridge creates the connector.
297  * This function gives external access to the connector.
298  *
299  * Returns: Pointer to drm_connector
300  */
301 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge)
302 {
303 	struct panel_bridge *panel_bridge;
304 
305 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
306 
307 	return &panel_bridge->connector;
308 }
309 EXPORT_SYMBOL(drm_panel_bridge_connector);
310