xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision 34fa67e7)
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_of.h>
13 #include <drm/drm_panel.h>
14 #include <drm/drm_print.h>
15 #include <drm/drm_probe_helper.h>
16 
17 struct panel_bridge {
18 	struct drm_bridge bridge;
19 	struct drm_connector connector;
20 	struct drm_panel *panel;
21 	u32 connector_type;
22 };
23 
24 static inline struct panel_bridge *
25 drm_bridge_to_panel_bridge(struct drm_bridge *bridge)
26 {
27 	return container_of(bridge, struct panel_bridge, bridge);
28 }
29 
30 static inline struct panel_bridge *
31 drm_connector_to_panel_bridge(struct drm_connector *connector)
32 {
33 	return container_of(connector, struct panel_bridge, connector);
34 }
35 
36 static int panel_bridge_connector_get_modes(struct drm_connector *connector)
37 {
38 	struct panel_bridge *panel_bridge =
39 		drm_connector_to_panel_bridge(connector);
40 
41 	return drm_panel_get_modes(panel_bridge->panel, connector);
42 }
43 
44 static const struct drm_connector_helper_funcs
45 panel_bridge_connector_helper_funcs = {
46 	.get_modes = panel_bridge_connector_get_modes,
47 };
48 
49 static const struct drm_connector_funcs panel_bridge_connector_funcs = {
50 	.reset = drm_atomic_helper_connector_reset,
51 	.fill_modes = drm_helper_probe_single_connector_modes,
52 	.destroy = drm_connector_cleanup,
53 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
54 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
55 };
56 
57 static int panel_bridge_attach(struct drm_bridge *bridge,
58 			       enum drm_bridge_attach_flags flags)
59 {
60 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
61 	struct drm_connector *connector = &panel_bridge->connector;
62 	int ret;
63 
64 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
65 		return 0;
66 
67 	if (!bridge->encoder) {
68 		DRM_ERROR("Missing encoder\n");
69 		return -ENODEV;
70 	}
71 
72 	drm_connector_helper_add(connector,
73 				 &panel_bridge_connector_helper_funcs);
74 
75 	ret = drm_connector_init(bridge->dev, connector,
76 				 &panel_bridge_connector_funcs,
77 				 panel_bridge->connector_type);
78 	if (ret) {
79 		DRM_ERROR("Failed to initialize connector\n");
80 		return ret;
81 	}
82 
83 	drm_connector_attach_encoder(&panel_bridge->connector,
84 					  bridge->encoder);
85 
86 	return 0;
87 }
88 
89 static void panel_bridge_detach(struct drm_bridge *bridge)
90 {
91 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
92 	struct drm_connector *connector = &panel_bridge->connector;
93 
94 	/*
95 	 * Cleanup the connector if we know it was initialized.
96 	 *
97 	 * FIXME: This wouldn't be needed if the panel_bridge structure was
98 	 * allocated with drmm_kzalloc(). This might be tricky since the
99 	 * drm_device pointer can only be retrieved when the bridge is attached.
100 	 */
101 	if (connector->dev)
102 		drm_connector_cleanup(connector);
103 }
104 
105 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
106 {
107 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
108 
109 	drm_panel_prepare(panel_bridge->panel);
110 }
111 
112 static void panel_bridge_enable(struct drm_bridge *bridge)
113 {
114 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
115 
116 	drm_panel_enable(panel_bridge->panel);
117 }
118 
119 static void panel_bridge_disable(struct drm_bridge *bridge)
120 {
121 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
122 
123 	drm_panel_disable(panel_bridge->panel);
124 }
125 
126 static void panel_bridge_post_disable(struct drm_bridge *bridge)
127 {
128 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
129 
130 	drm_panel_unprepare(panel_bridge->panel);
131 }
132 
133 static int panel_bridge_get_modes(struct drm_bridge *bridge,
134 				  struct drm_connector *connector)
135 {
136 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
137 
138 	return drm_panel_get_modes(panel_bridge->panel, connector);
139 }
140 
141 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
142 	.attach = panel_bridge_attach,
143 	.detach = panel_bridge_detach,
144 	.pre_enable = panel_bridge_pre_enable,
145 	.enable = panel_bridge_enable,
146 	.disable = panel_bridge_disable,
147 	.post_disable = panel_bridge_post_disable,
148 	.get_modes = panel_bridge_get_modes,
149 	.atomic_reset = drm_atomic_helper_bridge_reset,
150 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
151 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
152 	.atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
153 };
154 
155 /**
156  * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
157  * just calls the appropriate functions from &drm_panel.
158  *
159  * @panel: The drm_panel being wrapped.  Must be non-NULL.
160  *
161  * For drivers converting from directly using drm_panel: The expected
162  * usage pattern is that during either encoder module probe or DSI
163  * host attach, a drm_panel will be looked up through
164  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
165  * wrap that panel in the new bridge, and the result can then be
166  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
167  * functions can be dropped from the encoder driver (they're now
168  * called by the KMS helpers before calling into the encoder), along
169  * with connector creation.  When done with the bridge (after
170  * drm_mode_config_cleanup() if the bridge has already been attached), then
171  * drm_panel_bridge_remove() to free it.
172  *
173  * The connector type is set to @panel->connector_type, which must be set to a
174  * known type. Calling this function with a panel whose connector type is
175  * DRM_MODE_CONNECTOR_Unknown will return ERR_PTR(-EINVAL).
176  *
177  * See devm_drm_panel_bridge_add() for an automatically managed version of this
178  * function.
179  */
180 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
181 {
182 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
183 		return ERR_PTR(-EINVAL);
184 
185 	return drm_panel_bridge_add_typed(panel, panel->connector_type);
186 }
187 EXPORT_SYMBOL(drm_panel_bridge_add);
188 
189 /**
190  * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
191  * an explicit connector type.
192  * @panel: The drm_panel being wrapped.  Must be non-NULL.
193  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
194  *
195  * This is just like drm_panel_bridge_add(), but forces the connector type to
196  * @connector_type instead of infering it from the panel.
197  *
198  * This function is deprecated and should not be used in new drivers. Use
199  * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
200  * don't report a connector type.
201  */
202 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
203 					      u32 connector_type)
204 {
205 	struct panel_bridge *panel_bridge;
206 
207 	if (!panel)
208 		return ERR_PTR(-EINVAL);
209 
210 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
211 				    GFP_KERNEL);
212 	if (!panel_bridge)
213 		return ERR_PTR(-ENOMEM);
214 
215 	panel_bridge->connector_type = connector_type;
216 	panel_bridge->panel = panel;
217 
218 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
219 #ifdef CONFIG_OF
220 	panel_bridge->bridge.of_node = panel->dev->of_node;
221 #endif
222 	panel_bridge->bridge.ops = DRM_BRIDGE_OP_MODES;
223 	panel_bridge->bridge.type = connector_type;
224 
225 	drm_bridge_add(&panel_bridge->bridge);
226 
227 	return &panel_bridge->bridge;
228 }
229 EXPORT_SYMBOL(drm_panel_bridge_add_typed);
230 
231 /**
232  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
233  * created by drm_panel_bridge_add().
234  *
235  * @bridge: The drm_bridge being freed.
236  */
237 void drm_panel_bridge_remove(struct drm_bridge *bridge)
238 {
239 	struct panel_bridge *panel_bridge;
240 
241 	if (!bridge)
242 		return;
243 
244 	if (bridge->funcs != &panel_bridge_bridge_funcs)
245 		return;
246 
247 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
248 
249 	drm_bridge_remove(bridge);
250 	devm_kfree(panel_bridge->panel->dev, bridge);
251 }
252 EXPORT_SYMBOL(drm_panel_bridge_remove);
253 
254 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
255 {
256 	struct drm_bridge **bridge = res;
257 
258 	drm_panel_bridge_remove(*bridge);
259 }
260 
261 /**
262  * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
263  * that just calls the appropriate functions from &drm_panel.
264  * @dev: device to tie the bridge lifetime to
265  * @panel: The drm_panel being wrapped.  Must be non-NULL.
266  *
267  * This is the managed version of drm_panel_bridge_add() which automatically
268  * calls drm_panel_bridge_remove() when @dev is unbound.
269  */
270 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
271 					     struct drm_panel *panel)
272 {
273 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
274 		return ERR_PTR(-EINVAL);
275 
276 	return devm_drm_panel_bridge_add_typed(dev, panel,
277 					       panel->connector_type);
278 }
279 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
280 
281 /**
282  * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
283  * &drm_connector with an explicit connector type.
284  * @dev: device to tie the bridge lifetime to
285  * @panel: The drm_panel being wrapped.  Must be non-NULL.
286  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
287  *
288  * This is just like devm_drm_panel_bridge_add(), but forces the connector type
289  * to @connector_type instead of infering it from the panel.
290  *
291  * This function is deprecated and should not be used in new drivers. Use
292  * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
293  * they don't report a connector type.
294  */
295 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
296 						   struct drm_panel *panel,
297 						   u32 connector_type)
298 {
299 	struct drm_bridge **ptr, *bridge;
300 
301 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
302 			   GFP_KERNEL);
303 	if (!ptr)
304 		return ERR_PTR(-ENOMEM);
305 
306 	bridge = drm_panel_bridge_add_typed(panel, connector_type);
307 	if (!IS_ERR(bridge)) {
308 		*ptr = bridge;
309 		devres_add(dev, ptr);
310 	} else {
311 		devres_free(ptr);
312 	}
313 
314 	return bridge;
315 }
316 EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);
317 
318 /**
319  * drm_panel_bridge_connector - return the connector for the panel bridge
320  * @bridge: The drm_bridge.
321  *
322  * drm_panel_bridge creates the connector.
323  * This function gives external access to the connector.
324  *
325  * Returns: Pointer to drm_connector
326  */
327 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge)
328 {
329 	struct panel_bridge *panel_bridge;
330 
331 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
332 
333 	return &panel_bridge->connector;
334 }
335 EXPORT_SYMBOL(drm_panel_bridge_connector);
336 
337 #ifdef CONFIG_OF
338 /**
339  * devm_drm_of_get_bridge - Return next bridge in the chain
340  * @dev: device to tie the bridge lifetime to
341  * @np: device tree node containing encoder output ports
342  * @port: port in the device tree node
343  * @endpoint: endpoint in the device tree node
344  *
345  * Given a DT node's port and endpoint number, finds the connected node
346  * and returns the associated bridge if any, or creates and returns a
347  * drm panel bridge instance if a panel is connected.
348  *
349  * Returns a pointer to the bridge if successful, or an error pointer
350  * otherwise.
351  */
352 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
353 					  struct device_node *np,
354 					  u32 port, u32 endpoint)
355 {
356 	struct drm_bridge *bridge;
357 	struct drm_panel *panel;
358 	int ret;
359 
360 	ret = drm_of_find_panel_or_bridge(np, port, endpoint,
361 					  &panel, &bridge);
362 	if (ret)
363 		return ERR_PTR(ret);
364 
365 	if (panel)
366 		bridge = devm_drm_panel_bridge_add(dev, panel);
367 
368 	return bridge;
369 }
370 EXPORT_SYMBOL(devm_drm_of_get_bridge);
371 #endif
372