xref: /openbmc/linux/drivers/gpu/drm/bridge/panel.c (revision c059ee9d)
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 	if (bridge->dev->registered) {
87 		if (connector->funcs->reset)
88 			connector->funcs->reset(connector);
89 		drm_connector_register(connector);
90 	}
91 
92 	return 0;
93 }
94 
95 static void panel_bridge_detach(struct drm_bridge *bridge)
96 {
97 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
98 	struct drm_connector *connector = &panel_bridge->connector;
99 
100 	/*
101 	 * Cleanup the connector if we know it was initialized.
102 	 *
103 	 * FIXME: This wouldn't be needed if the panel_bridge structure was
104 	 * allocated with drmm_kzalloc(). This might be tricky since the
105 	 * drm_device pointer can only be retrieved when the bridge is attached.
106 	 */
107 	if (connector->dev)
108 		drm_connector_cleanup(connector);
109 }
110 
111 static void panel_bridge_pre_enable(struct drm_bridge *bridge)
112 {
113 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
114 
115 	drm_panel_prepare(panel_bridge->panel);
116 }
117 
118 static void panel_bridge_enable(struct drm_bridge *bridge)
119 {
120 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
121 
122 	drm_panel_enable(panel_bridge->panel);
123 }
124 
125 static void panel_bridge_disable(struct drm_bridge *bridge)
126 {
127 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
128 
129 	drm_panel_disable(panel_bridge->panel);
130 }
131 
132 static void panel_bridge_post_disable(struct drm_bridge *bridge)
133 {
134 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
135 
136 	drm_panel_unprepare(panel_bridge->panel);
137 }
138 
139 static int panel_bridge_get_modes(struct drm_bridge *bridge,
140 				  struct drm_connector *connector)
141 {
142 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
143 
144 	return drm_panel_get_modes(panel_bridge->panel, connector);
145 }
146 
147 static void panel_bridge_debugfs_init(struct drm_bridge *bridge,
148 				      struct dentry *root)
149 {
150 	struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
151 	struct drm_panel *panel = panel_bridge->panel;
152 
153 	root = debugfs_create_dir("panel", root);
154 	if (panel->funcs->debugfs_init)
155 		panel->funcs->debugfs_init(panel, root);
156 }
157 
158 static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {
159 	.attach = panel_bridge_attach,
160 	.detach = panel_bridge_detach,
161 	.pre_enable = panel_bridge_pre_enable,
162 	.enable = panel_bridge_enable,
163 	.disable = panel_bridge_disable,
164 	.post_disable = panel_bridge_post_disable,
165 	.get_modes = panel_bridge_get_modes,
166 	.atomic_reset = drm_atomic_helper_bridge_reset,
167 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
168 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
169 	.atomic_get_input_bus_fmts = drm_atomic_helper_bridge_propagate_bus_fmt,
170 	.debugfs_init = panel_bridge_debugfs_init,
171 };
172 
173 /**
174  * drm_panel_bridge_add - Creates a &drm_bridge and &drm_connector that
175  * just calls the appropriate functions from &drm_panel.
176  *
177  * @panel: The drm_panel being wrapped.  Must be non-NULL.
178  *
179  * For drivers converting from directly using drm_panel: The expected
180  * usage pattern is that during either encoder module probe or DSI
181  * host attach, a drm_panel will be looked up through
182  * drm_of_find_panel_or_bridge().  drm_panel_bridge_add() is used to
183  * wrap that panel in the new bridge, and the result can then be
184  * passed to drm_bridge_attach().  The drm_panel_prepare() and related
185  * functions can be dropped from the encoder driver (they're now
186  * called by the KMS helpers before calling into the encoder), along
187  * with connector creation.  When done with the bridge (after
188  * drm_mode_config_cleanup() if the bridge has already been attached), then
189  * drm_panel_bridge_remove() to free it.
190  *
191  * The connector type is set to @panel->connector_type, which must be set to a
192  * known type. Calling this function with a panel whose connector type is
193  * DRM_MODE_CONNECTOR_Unknown will return ERR_PTR(-EINVAL).
194  *
195  * See devm_drm_panel_bridge_add() for an automatically managed version of this
196  * function.
197  */
198 struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel)
199 {
200 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
201 		return ERR_PTR(-EINVAL);
202 
203 	return drm_panel_bridge_add_typed(panel, panel->connector_type);
204 }
205 EXPORT_SYMBOL(drm_panel_bridge_add);
206 
207 /**
208  * drm_panel_bridge_add_typed - Creates a &drm_bridge and &drm_connector with
209  * an explicit connector type.
210  * @panel: The drm_panel being wrapped.  Must be non-NULL.
211  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
212  *
213  * This is just like drm_panel_bridge_add(), but forces the connector type to
214  * @connector_type instead of infering it from the panel.
215  *
216  * This function is deprecated and should not be used in new drivers. Use
217  * drm_panel_bridge_add() instead, and fix panel drivers as necessary if they
218  * don't report a connector type.
219  */
220 struct drm_bridge *drm_panel_bridge_add_typed(struct drm_panel *panel,
221 					      u32 connector_type)
222 {
223 	struct panel_bridge *panel_bridge;
224 
225 	if (!panel)
226 		return ERR_PTR(-EINVAL);
227 
228 	panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),
229 				    GFP_KERNEL);
230 	if (!panel_bridge)
231 		return ERR_PTR(-ENOMEM);
232 
233 	panel_bridge->connector_type = connector_type;
234 	panel_bridge->panel = panel;
235 
236 	panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
237 #ifdef CONFIG_OF
238 	panel_bridge->bridge.of_node = panel->dev->of_node;
239 #endif
240 	panel_bridge->bridge.ops = DRM_BRIDGE_OP_MODES;
241 	panel_bridge->bridge.type = connector_type;
242 
243 	drm_bridge_add(&panel_bridge->bridge);
244 
245 	return &panel_bridge->bridge;
246 }
247 EXPORT_SYMBOL(drm_panel_bridge_add_typed);
248 
249 /**
250  * drm_panel_bridge_remove - Unregisters and frees a drm_bridge
251  * created by drm_panel_bridge_add().
252  *
253  * @bridge: The drm_bridge being freed.
254  */
255 void drm_panel_bridge_remove(struct drm_bridge *bridge)
256 {
257 	struct panel_bridge *panel_bridge;
258 
259 	if (!bridge)
260 		return;
261 
262 	if (bridge->funcs != &panel_bridge_bridge_funcs)
263 		return;
264 
265 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
266 
267 	drm_bridge_remove(bridge);
268 	devm_kfree(panel_bridge->panel->dev, bridge);
269 }
270 EXPORT_SYMBOL(drm_panel_bridge_remove);
271 
272 static void devm_drm_panel_bridge_release(struct device *dev, void *res)
273 {
274 	struct drm_bridge **bridge = res;
275 
276 	drm_panel_bridge_remove(*bridge);
277 }
278 
279 /**
280  * devm_drm_panel_bridge_add - Creates a managed &drm_bridge and &drm_connector
281  * that just calls the appropriate functions from &drm_panel.
282  * @dev: device to tie the bridge lifetime to
283  * @panel: The drm_panel being wrapped.  Must be non-NULL.
284  *
285  * This is the managed version of drm_panel_bridge_add() which automatically
286  * calls drm_panel_bridge_remove() when @dev is unbound.
287  */
288 struct drm_bridge *devm_drm_panel_bridge_add(struct device *dev,
289 					     struct drm_panel *panel)
290 {
291 	if (WARN_ON(panel->connector_type == DRM_MODE_CONNECTOR_Unknown))
292 		return ERR_PTR(-EINVAL);
293 
294 	return devm_drm_panel_bridge_add_typed(dev, panel,
295 					       panel->connector_type);
296 }
297 EXPORT_SYMBOL(devm_drm_panel_bridge_add);
298 
299 /**
300  * devm_drm_panel_bridge_add_typed - Creates a managed &drm_bridge and
301  * &drm_connector with an explicit connector type.
302  * @dev: device to tie the bridge lifetime to
303  * @panel: The drm_panel being wrapped.  Must be non-NULL.
304  * @connector_type: The connector type (DRM_MODE_CONNECTOR_*)
305  *
306  * This is just like devm_drm_panel_bridge_add(), but forces the connector type
307  * to @connector_type instead of infering it from the panel.
308  *
309  * This function is deprecated and should not be used in new drivers. Use
310  * devm_drm_panel_bridge_add() instead, and fix panel drivers as necessary if
311  * they don't report a connector type.
312  */
313 struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
314 						   struct drm_panel *panel,
315 						   u32 connector_type)
316 {
317 	struct drm_bridge **ptr, *bridge;
318 
319 	ptr = devres_alloc(devm_drm_panel_bridge_release, sizeof(*ptr),
320 			   GFP_KERNEL);
321 	if (!ptr)
322 		return ERR_PTR(-ENOMEM);
323 
324 	bridge = drm_panel_bridge_add_typed(panel, connector_type);
325 	if (!IS_ERR(bridge)) {
326 		*ptr = bridge;
327 		devres_add(dev, ptr);
328 	} else {
329 		devres_free(ptr);
330 	}
331 
332 	return bridge;
333 }
334 EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);
335 
336 /**
337  * drm_panel_bridge_connector - return the connector for the panel bridge
338  * @bridge: The drm_bridge.
339  *
340  * drm_panel_bridge creates the connector.
341  * This function gives external access to the connector.
342  *
343  * Returns: Pointer to drm_connector
344  */
345 struct drm_connector *drm_panel_bridge_connector(struct drm_bridge *bridge)
346 {
347 	struct panel_bridge *panel_bridge;
348 
349 	panel_bridge = drm_bridge_to_panel_bridge(bridge);
350 
351 	return &panel_bridge->connector;
352 }
353 EXPORT_SYMBOL(drm_panel_bridge_connector);
354 
355 #ifdef CONFIG_OF
356 /**
357  * devm_drm_of_get_bridge - Return next bridge in the chain
358  * @dev: device to tie the bridge lifetime to
359  * @np: device tree node containing encoder output ports
360  * @port: port in the device tree node
361  * @endpoint: endpoint in the device tree node
362  *
363  * Given a DT node's port and endpoint number, finds the connected node
364  * and returns the associated bridge if any, or creates and returns a
365  * drm panel bridge instance if a panel is connected.
366  *
367  * Returns a pointer to the bridge if successful, or an error pointer
368  * otherwise.
369  */
370 struct drm_bridge *devm_drm_of_get_bridge(struct device *dev,
371 					  struct device_node *np,
372 					  u32 port, u32 endpoint)
373 {
374 	struct drm_bridge *bridge;
375 	struct drm_panel *panel;
376 	int ret;
377 
378 	ret = drm_of_find_panel_or_bridge(np, port, endpoint,
379 					  &panel, &bridge);
380 	if (ret)
381 		return ERR_PTR(ret);
382 
383 	if (panel)
384 		bridge = devm_drm_panel_bridge_add(dev, panel);
385 
386 	return bridge;
387 }
388 EXPORT_SYMBOL(devm_drm_of_get_bridge);
389 #endif
390