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3d3f8b1f AK |
1 | /* |
2 | * Copyright (c) 2014 Samsung Electronics Co., Ltd | |
3 | * | |
4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
5 | * copy of this software and associated documentation files (the "Software"), | |
6 | * to deal in the Software without restriction, including without limitation | |
7 | * the rights to use, copy, modify, merge, publish, distribute, sub license, | |
8 | * and/or sell copies of the Software, and to permit persons to whom the | |
9 | * Software is furnished to do so, subject to the following conditions: | |
10 | * | |
11 | * The above copyright notice and this permission notice (including the | |
12 | * next paragraph) shall be included in all copies or substantial portions | |
13 | * of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
20 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER | |
21 | * DEALINGS IN THE SOFTWARE. | |
22 | */ | |
23 | ||
24 | #include <linux/err.h> | |
25 | #include <linux/module.h> | |
199e4e96 | 26 | #include <linux/mutex.h> |
3d3f8b1f | 27 | |
199e4e96 | 28 | #include <drm/drm_bridge.h> |
3d3f8b1f | 29 | |
2331b4e4 AT |
30 | /** |
31 | * DOC: overview | |
32 | * | |
da024fe5 DV |
33 | * struct &drm_bridge represents a device that hangs on to an encoder. These are |
34 | * handy when a regular &drm_encoder entity isn't enough to represent the entire | |
2331b4e4 AT |
35 | * encoder chain. |
36 | * | |
da024fe5 | 37 | * A bridge is always attached to a single &drm_encoder at a time, but can be |
da5335b8 | 38 | * either connected to it directly, or through an intermediate bridge:: |
2331b4e4 | 39 | * |
da024fe5 | 40 | * encoder ---> bridge B ---> bridge A |
2331b4e4 AT |
41 | * |
42 | * Here, the output of the encoder feeds to bridge B, and that furthers feeds to | |
43 | * bridge A. | |
44 | * | |
45 | * The driver using the bridge is responsible to make the associations between | |
46 | * the encoder and bridges. Once these links are made, the bridges will | |
47 | * participate along with encoder functions to perform mode_set/enable/disable | |
da024fe5 | 48 | * through the ops provided in &drm_bridge_funcs. |
2331b4e4 AT |
49 | * |
50 | * drm_bridge, like drm_panel, aren't drm_mode_object entities like planes, | |
da024fe5 DV |
51 | * CRTCs, encoders or connectors and hence are not visible to userspace. They |
52 | * just provide additional hooks to get the desired output at the end of the | |
53 | * encoder chain. | |
54 | * | |
55 | * Bridges can also be chained up using the next pointer in struct &drm_bridge. | |
56 | * | |
57 | * Both legacy CRTC helpers and the new atomic modeset helpers support bridges. | |
2331b4e4 AT |
58 | */ |
59 | ||
3d3f8b1f AK |
60 | static DEFINE_MUTEX(bridge_lock); |
61 | static LIST_HEAD(bridge_list); | |
62 | ||
2331b4e4 AT |
63 | /** |
64 | * drm_bridge_add - add the given bridge to the global bridge list | |
65 | * | |
66 | * @bridge: bridge control structure | |
67 | * | |
68 | * RETURNS: | |
69 | * Unconditionally returns Zero. | |
70 | */ | |
3d3f8b1f AK |
71 | int drm_bridge_add(struct drm_bridge *bridge) |
72 | { | |
73 | mutex_lock(&bridge_lock); | |
74 | list_add_tail(&bridge->list, &bridge_list); | |
75 | mutex_unlock(&bridge_lock); | |
76 | ||
77 | return 0; | |
78 | } | |
79 | EXPORT_SYMBOL(drm_bridge_add); | |
80 | ||
2331b4e4 AT |
81 | /** |
82 | * drm_bridge_remove - remove the given bridge from the global bridge list | |
83 | * | |
84 | * @bridge: bridge control structure | |
85 | */ | |
3d3f8b1f AK |
86 | void drm_bridge_remove(struct drm_bridge *bridge) |
87 | { | |
88 | mutex_lock(&bridge_lock); | |
89 | list_del_init(&bridge->list); | |
90 | mutex_unlock(&bridge_lock); | |
91 | } | |
92 | EXPORT_SYMBOL(drm_bridge_remove); | |
93 | ||
2331b4e4 AT |
94 | /** |
95 | * drm_bridge_attach - associate given bridge to our DRM device | |
96 | * | |
97 | * @dev: DRM device | |
98 | * @bridge: bridge control structure | |
99 | * | |
cf3bef95 | 100 | * Called by a kms driver to link one of our encoder/bridge to the given |
2331b4e4 AT |
101 | * bridge. |
102 | * | |
103 | * Note that setting up links between the bridge and our encoder/bridge | |
cf3bef95 | 104 | * objects needs to be handled by the kms driver itself. |
2331b4e4 AT |
105 | * |
106 | * RETURNS: | |
107 | * Zero on success, error code on failure | |
108 | */ | |
43fc884e | 109 | int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) |
3d3f8b1f AK |
110 | { |
111 | if (!dev || !bridge) | |
112 | return -EINVAL; | |
113 | ||
114 | if (bridge->dev) | |
115 | return -EBUSY; | |
116 | ||
117 | bridge->dev = dev; | |
118 | ||
119 | if (bridge->funcs->attach) | |
120 | return bridge->funcs->attach(bridge); | |
121 | ||
122 | return 0; | |
123 | } | |
124 | EXPORT_SYMBOL(drm_bridge_attach); | |
125 | ||
cf3bef95 AM |
126 | /** |
127 | * drm_bridge_detach - deassociate given bridge from its DRM device | |
128 | * | |
129 | * @bridge: bridge control structure | |
130 | * | |
131 | * Called by a kms driver to unlink the given bridge from its DRM device. | |
132 | * | |
133 | * Note that tearing down links between the bridge and our encoder/bridge | |
134 | * objects needs to be handled by the kms driver itself. | |
135 | */ | |
136 | void drm_bridge_detach(struct drm_bridge *bridge) | |
137 | { | |
138 | if (WARN_ON(!bridge)) | |
139 | return; | |
140 | ||
141 | if (WARN_ON(!bridge->dev)) | |
142 | return; | |
143 | ||
144 | if (bridge->funcs->detach) | |
145 | bridge->funcs->detach(bridge); | |
146 | ||
147 | bridge->dev = NULL; | |
148 | } | |
149 | EXPORT_SYMBOL(drm_bridge_detach); | |
150 | ||
2331b4e4 AT |
151 | /** |
152 | * DOC: bridge callbacks | |
153 | * | |
da024fe5 DV |
154 | * The &drm_bridge_funcs ops are populated by the bridge driver. The DRM |
155 | * internals (atomic and CRTC helpers) use the helpers defined in drm_bridge.c | |
156 | * These helpers call a specific &drm_bridge_funcs op for all the bridges | |
2331b4e4 AT |
157 | * during encoder configuration. |
158 | * | |
da024fe5 | 159 | * For detailed specification of the bridge callbacks see &drm_bridge_funcs. |
2331b4e4 AT |
160 | */ |
161 | ||
862e686c AT |
162 | /** |
163 | * drm_bridge_mode_fixup - fixup proposed mode for all bridges in the | |
164 | * encoder chain | |
165 | * @bridge: bridge control structure | |
166 | * @mode: desired mode to be set for the bridge | |
167 | * @adjusted_mode: updated mode that works for this bridge | |
168 | * | |
da024fe5 | 169 | * Calls ->mode_fixup() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
170 | * encoder chain, starting from the first bridge to the last. |
171 | * | |
172 | * Note: the bridge passed should be the one closest to the encoder | |
173 | * | |
174 | * RETURNS: | |
175 | * true on success, false on failure | |
176 | */ | |
177 | bool drm_bridge_mode_fixup(struct drm_bridge *bridge, | |
178 | const struct drm_display_mode *mode, | |
179 | struct drm_display_mode *adjusted_mode) | |
180 | { | |
181 | bool ret = true; | |
182 | ||
183 | if (!bridge) | |
184 | return true; | |
185 | ||
186 | if (bridge->funcs->mode_fixup) | |
187 | ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); | |
188 | ||
189 | ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode); | |
190 | ||
191 | return ret; | |
192 | } | |
193 | EXPORT_SYMBOL(drm_bridge_mode_fixup); | |
194 | ||
195 | /** | |
da024fe5 | 196 | * drm_bridge_disable - calls ->disable() &drm_bridge_funcs op for all |
862e686c AT |
197 | * bridges in the encoder chain. |
198 | * @bridge: bridge control structure | |
199 | * | |
da024fe5 | 200 | * Calls ->disable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
201 | * chain, starting from the last bridge to the first. These are called before |
202 | * calling the encoder's prepare op. | |
203 | * | |
204 | * Note: the bridge passed should be the one closest to the encoder | |
205 | */ | |
206 | void drm_bridge_disable(struct drm_bridge *bridge) | |
207 | { | |
208 | if (!bridge) | |
209 | return; | |
210 | ||
211 | drm_bridge_disable(bridge->next); | |
212 | ||
c8a3b2ae LP |
213 | if (bridge->funcs->disable) |
214 | bridge->funcs->disable(bridge); | |
862e686c AT |
215 | } |
216 | EXPORT_SYMBOL(drm_bridge_disable); | |
217 | ||
218 | /** | |
da024fe5 | 219 | * drm_bridge_post_disable - calls ->post_disable() &drm_bridge_funcs op for |
862e686c AT |
220 | * all bridges in the encoder chain. |
221 | * @bridge: bridge control structure | |
222 | * | |
da024fe5 | 223 | * Calls ->post_disable() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
224 | * encoder chain, starting from the first bridge to the last. These are called |
225 | * after completing the encoder's prepare op. | |
226 | * | |
227 | * Note: the bridge passed should be the one closest to the encoder | |
228 | */ | |
229 | void drm_bridge_post_disable(struct drm_bridge *bridge) | |
230 | { | |
231 | if (!bridge) | |
232 | return; | |
233 | ||
c8a3b2ae LP |
234 | if (bridge->funcs->post_disable) |
235 | bridge->funcs->post_disable(bridge); | |
862e686c AT |
236 | |
237 | drm_bridge_post_disable(bridge->next); | |
238 | } | |
239 | EXPORT_SYMBOL(drm_bridge_post_disable); | |
240 | ||
241 | /** | |
242 | * drm_bridge_mode_set - set proposed mode for all bridges in the | |
243 | * encoder chain | |
244 | * @bridge: bridge control structure | |
245 | * @mode: desired mode to be set for the bridge | |
246 | * @adjusted_mode: updated mode that works for this bridge | |
247 | * | |
da024fe5 | 248 | * Calls ->mode_set() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
249 | * encoder chain, starting from the first bridge to the last. |
250 | * | |
251 | * Note: the bridge passed should be the one closest to the encoder | |
252 | */ | |
253 | void drm_bridge_mode_set(struct drm_bridge *bridge, | |
254 | struct drm_display_mode *mode, | |
255 | struct drm_display_mode *adjusted_mode) | |
256 | { | |
257 | if (!bridge) | |
258 | return; | |
259 | ||
260 | if (bridge->funcs->mode_set) | |
261 | bridge->funcs->mode_set(bridge, mode, adjusted_mode); | |
262 | ||
263 | drm_bridge_mode_set(bridge->next, mode, adjusted_mode); | |
264 | } | |
265 | EXPORT_SYMBOL(drm_bridge_mode_set); | |
266 | ||
267 | /** | |
da024fe5 | 268 | * drm_bridge_pre_enable - calls ->pre_enable() &drm_bridge_funcs op for all |
862e686c AT |
269 | * bridges in the encoder chain. |
270 | * @bridge: bridge control structure | |
271 | * | |
da024fe5 | 272 | * Calls ->pre_enable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
273 | * chain, starting from the last bridge to the first. These are called |
274 | * before calling the encoder's commit op. | |
275 | * | |
276 | * Note: the bridge passed should be the one closest to the encoder | |
277 | */ | |
278 | void drm_bridge_pre_enable(struct drm_bridge *bridge) | |
279 | { | |
280 | if (!bridge) | |
281 | return; | |
282 | ||
283 | drm_bridge_pre_enable(bridge->next); | |
284 | ||
c8a3b2ae LP |
285 | if (bridge->funcs->pre_enable) |
286 | bridge->funcs->pre_enable(bridge); | |
862e686c AT |
287 | } |
288 | EXPORT_SYMBOL(drm_bridge_pre_enable); | |
289 | ||
290 | /** | |
da024fe5 | 291 | * drm_bridge_enable - calls ->enable() &drm_bridge_funcs op for all bridges |
862e686c AT |
292 | * in the encoder chain. |
293 | * @bridge: bridge control structure | |
294 | * | |
da024fe5 | 295 | * Calls ->enable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
296 | * chain, starting from the first bridge to the last. These are called |
297 | * after completing the encoder's commit op. | |
298 | * | |
299 | * Note that the bridge passed should be the one closest to the encoder | |
300 | */ | |
301 | void drm_bridge_enable(struct drm_bridge *bridge) | |
302 | { | |
303 | if (!bridge) | |
304 | return; | |
305 | ||
c8a3b2ae LP |
306 | if (bridge->funcs->enable) |
307 | bridge->funcs->enable(bridge); | |
862e686c AT |
308 | |
309 | drm_bridge_enable(bridge->next); | |
310 | } | |
311 | EXPORT_SYMBOL(drm_bridge_enable); | |
312 | ||
3d3f8b1f | 313 | #ifdef CONFIG_OF |
2331b4e4 AT |
314 | /** |
315 | * of_drm_find_bridge - find the bridge corresponding to the device node in | |
316 | * the global bridge list | |
317 | * | |
318 | * @np: device node | |
319 | * | |
320 | * RETURNS: | |
321 | * drm_bridge control struct on success, NULL on failure | |
322 | */ | |
3d3f8b1f AK |
323 | struct drm_bridge *of_drm_find_bridge(struct device_node *np) |
324 | { | |
325 | struct drm_bridge *bridge; | |
326 | ||
327 | mutex_lock(&bridge_lock); | |
328 | ||
329 | list_for_each_entry(bridge, &bridge_list, list) { | |
330 | if (bridge->of_node == np) { | |
331 | mutex_unlock(&bridge_lock); | |
332 | return bridge; | |
333 | } | |
334 | } | |
335 | ||
336 | mutex_unlock(&bridge_lock); | |
337 | return NULL; | |
338 | } | |
339 | EXPORT_SYMBOL(of_drm_find_bridge); | |
340 | #endif | |
341 | ||
342 | MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); | |
343 | MODULE_DESCRIPTION("DRM bridge infrastructure"); | |
344 | MODULE_LICENSE("GPL and additional rights"); |