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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> | |
26 | ||
27 | #include <drm/drm_crtc.h> | |
28 | ||
29 | #include "drm/drmP.h" | |
30 | ||
2331b4e4 AT |
31 | /** |
32 | * DOC: overview | |
33 | * | |
da024fe5 DV |
34 | * struct &drm_bridge represents a device that hangs on to an encoder. These are |
35 | * handy when a regular &drm_encoder entity isn't enough to represent the entire | |
2331b4e4 AT |
36 | * encoder chain. |
37 | * | |
da024fe5 | 38 | * A bridge is always attached to a single &drm_encoder at a time, but can be |
2331b4e4 AT |
39 | * either connected to it directly, or through an intermediate bridge: |
40 | * | |
da024fe5 | 41 | * encoder ---> bridge B ---> bridge A |
2331b4e4 AT |
42 | * |
43 | * Here, the output of the encoder feeds to bridge B, and that furthers feeds to | |
44 | * bridge A. | |
45 | * | |
46 | * The driver using the bridge is responsible to make the associations between | |
47 | * the encoder and bridges. Once these links are made, the bridges will | |
48 | * participate along with encoder functions to perform mode_set/enable/disable | |
da024fe5 | 49 | * through the ops provided in &drm_bridge_funcs. |
2331b4e4 AT |
50 | * |
51 | * drm_bridge, like drm_panel, aren't drm_mode_object entities like planes, | |
da024fe5 DV |
52 | * CRTCs, encoders or connectors and hence are not visible to userspace. They |
53 | * just provide additional hooks to get the desired output at the end of the | |
54 | * encoder chain. | |
55 | * | |
56 | * Bridges can also be chained up using the next pointer in struct &drm_bridge. | |
57 | * | |
58 | * Both legacy CRTC helpers and the new atomic modeset helpers support bridges. | |
2331b4e4 AT |
59 | */ |
60 | ||
3d3f8b1f AK |
61 | static DEFINE_MUTEX(bridge_lock); |
62 | static LIST_HEAD(bridge_list); | |
63 | ||
2331b4e4 AT |
64 | /** |
65 | * drm_bridge_add - add the given bridge to the global bridge list | |
66 | * | |
67 | * @bridge: bridge control structure | |
68 | * | |
69 | * RETURNS: | |
70 | * Unconditionally returns Zero. | |
71 | */ | |
3d3f8b1f AK |
72 | int drm_bridge_add(struct drm_bridge *bridge) |
73 | { | |
74 | mutex_lock(&bridge_lock); | |
75 | list_add_tail(&bridge->list, &bridge_list); | |
76 | mutex_unlock(&bridge_lock); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | EXPORT_SYMBOL(drm_bridge_add); | |
81 | ||
2331b4e4 AT |
82 | /** |
83 | * drm_bridge_remove - remove the given bridge from the global bridge list | |
84 | * | |
85 | * @bridge: bridge control structure | |
86 | */ | |
3d3f8b1f AK |
87 | void drm_bridge_remove(struct drm_bridge *bridge) |
88 | { | |
89 | mutex_lock(&bridge_lock); | |
90 | list_del_init(&bridge->list); | |
91 | mutex_unlock(&bridge_lock); | |
92 | } | |
93 | EXPORT_SYMBOL(drm_bridge_remove); | |
94 | ||
2331b4e4 AT |
95 | /** |
96 | * drm_bridge_attach - associate given bridge to our DRM device | |
97 | * | |
98 | * @dev: DRM device | |
99 | * @bridge: bridge control structure | |
100 | * | |
101 | * called by a kms driver to link one of our encoder/bridge to the given | |
102 | * bridge. | |
103 | * | |
104 | * Note that setting up links between the bridge and our encoder/bridge | |
105 | * objects needs to be handled by the kms driver itself | |
106 | * | |
107 | * RETURNS: | |
108 | * Zero on success, error code on failure | |
109 | */ | |
43fc884e | 110 | int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) |
3d3f8b1f AK |
111 | { |
112 | if (!dev || !bridge) | |
113 | return -EINVAL; | |
114 | ||
115 | if (bridge->dev) | |
116 | return -EBUSY; | |
117 | ||
118 | bridge->dev = dev; | |
119 | ||
120 | if (bridge->funcs->attach) | |
121 | return bridge->funcs->attach(bridge); | |
122 | ||
123 | return 0; | |
124 | } | |
125 | EXPORT_SYMBOL(drm_bridge_attach); | |
126 | ||
2331b4e4 AT |
127 | /** |
128 | * DOC: bridge callbacks | |
129 | * | |
da024fe5 DV |
130 | * The &drm_bridge_funcs ops are populated by the bridge driver. The DRM |
131 | * internals (atomic and CRTC helpers) use the helpers defined in drm_bridge.c | |
132 | * These helpers call a specific &drm_bridge_funcs op for all the bridges | |
2331b4e4 AT |
133 | * during encoder configuration. |
134 | * | |
da024fe5 | 135 | * For detailed specification of the bridge callbacks see &drm_bridge_funcs. |
2331b4e4 AT |
136 | */ |
137 | ||
862e686c AT |
138 | /** |
139 | * drm_bridge_mode_fixup - fixup proposed mode for all bridges in the | |
140 | * encoder chain | |
141 | * @bridge: bridge control structure | |
142 | * @mode: desired mode to be set for the bridge | |
143 | * @adjusted_mode: updated mode that works for this bridge | |
144 | * | |
da024fe5 | 145 | * Calls ->mode_fixup() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
146 | * encoder chain, starting from the first bridge to the last. |
147 | * | |
148 | * Note: the bridge passed should be the one closest to the encoder | |
149 | * | |
150 | * RETURNS: | |
151 | * true on success, false on failure | |
152 | */ | |
153 | bool drm_bridge_mode_fixup(struct drm_bridge *bridge, | |
154 | const struct drm_display_mode *mode, | |
155 | struct drm_display_mode *adjusted_mode) | |
156 | { | |
157 | bool ret = true; | |
158 | ||
159 | if (!bridge) | |
160 | return true; | |
161 | ||
162 | if (bridge->funcs->mode_fixup) | |
163 | ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); | |
164 | ||
165 | ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode); | |
166 | ||
167 | return ret; | |
168 | } | |
169 | EXPORT_SYMBOL(drm_bridge_mode_fixup); | |
170 | ||
171 | /** | |
da024fe5 | 172 | * drm_bridge_disable - calls ->disable() &drm_bridge_funcs op for all |
862e686c AT |
173 | * bridges in the encoder chain. |
174 | * @bridge: bridge control structure | |
175 | * | |
da024fe5 | 176 | * Calls ->disable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
177 | * chain, starting from the last bridge to the first. These are called before |
178 | * calling the encoder's prepare op. | |
179 | * | |
180 | * Note: the bridge passed should be the one closest to the encoder | |
181 | */ | |
182 | void drm_bridge_disable(struct drm_bridge *bridge) | |
183 | { | |
184 | if (!bridge) | |
185 | return; | |
186 | ||
187 | drm_bridge_disable(bridge->next); | |
188 | ||
189 | bridge->funcs->disable(bridge); | |
190 | } | |
191 | EXPORT_SYMBOL(drm_bridge_disable); | |
192 | ||
193 | /** | |
da024fe5 | 194 | * drm_bridge_post_disable - calls ->post_disable() &drm_bridge_funcs op for |
862e686c AT |
195 | * all bridges in the encoder chain. |
196 | * @bridge: bridge control structure | |
197 | * | |
da024fe5 | 198 | * Calls ->post_disable() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
199 | * encoder chain, starting from the first bridge to the last. These are called |
200 | * after completing the encoder's prepare op. | |
201 | * | |
202 | * Note: the bridge passed should be the one closest to the encoder | |
203 | */ | |
204 | void drm_bridge_post_disable(struct drm_bridge *bridge) | |
205 | { | |
206 | if (!bridge) | |
207 | return; | |
208 | ||
209 | bridge->funcs->post_disable(bridge); | |
210 | ||
211 | drm_bridge_post_disable(bridge->next); | |
212 | } | |
213 | EXPORT_SYMBOL(drm_bridge_post_disable); | |
214 | ||
215 | /** | |
216 | * drm_bridge_mode_set - set proposed mode for all bridges in the | |
217 | * encoder chain | |
218 | * @bridge: bridge control structure | |
219 | * @mode: desired mode to be set for the bridge | |
220 | * @adjusted_mode: updated mode that works for this bridge | |
221 | * | |
da024fe5 | 222 | * Calls ->mode_set() &drm_bridge_funcs op for all the bridges in the |
862e686c AT |
223 | * encoder chain, starting from the first bridge to the last. |
224 | * | |
225 | * Note: the bridge passed should be the one closest to the encoder | |
226 | */ | |
227 | void drm_bridge_mode_set(struct drm_bridge *bridge, | |
228 | struct drm_display_mode *mode, | |
229 | struct drm_display_mode *adjusted_mode) | |
230 | { | |
231 | if (!bridge) | |
232 | return; | |
233 | ||
234 | if (bridge->funcs->mode_set) | |
235 | bridge->funcs->mode_set(bridge, mode, adjusted_mode); | |
236 | ||
237 | drm_bridge_mode_set(bridge->next, mode, adjusted_mode); | |
238 | } | |
239 | EXPORT_SYMBOL(drm_bridge_mode_set); | |
240 | ||
241 | /** | |
da024fe5 | 242 | * drm_bridge_pre_enable - calls ->pre_enable() &drm_bridge_funcs op for all |
862e686c AT |
243 | * bridges in the encoder chain. |
244 | * @bridge: bridge control structure | |
245 | * | |
da024fe5 | 246 | * Calls ->pre_enable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
247 | * chain, starting from the last bridge to the first. These are called |
248 | * before calling the encoder's commit op. | |
249 | * | |
250 | * Note: the bridge passed should be the one closest to the encoder | |
251 | */ | |
252 | void drm_bridge_pre_enable(struct drm_bridge *bridge) | |
253 | { | |
254 | if (!bridge) | |
255 | return; | |
256 | ||
257 | drm_bridge_pre_enable(bridge->next); | |
258 | ||
259 | bridge->funcs->pre_enable(bridge); | |
260 | } | |
261 | EXPORT_SYMBOL(drm_bridge_pre_enable); | |
262 | ||
263 | /** | |
da024fe5 | 264 | * drm_bridge_enable - calls ->enable() &drm_bridge_funcs op for all bridges |
862e686c AT |
265 | * in the encoder chain. |
266 | * @bridge: bridge control structure | |
267 | * | |
da024fe5 | 268 | * Calls ->enable() &drm_bridge_funcs op for all the bridges in the encoder |
862e686c AT |
269 | * chain, starting from the first bridge to the last. These are called |
270 | * after completing the encoder's commit op. | |
271 | * | |
272 | * Note that the bridge passed should be the one closest to the encoder | |
273 | */ | |
274 | void drm_bridge_enable(struct drm_bridge *bridge) | |
275 | { | |
276 | if (!bridge) | |
277 | return; | |
278 | ||
279 | bridge->funcs->enable(bridge); | |
280 | ||
281 | drm_bridge_enable(bridge->next); | |
282 | } | |
283 | EXPORT_SYMBOL(drm_bridge_enable); | |
284 | ||
3d3f8b1f | 285 | #ifdef CONFIG_OF |
2331b4e4 AT |
286 | /** |
287 | * of_drm_find_bridge - find the bridge corresponding to the device node in | |
288 | * the global bridge list | |
289 | * | |
290 | * @np: device node | |
291 | * | |
292 | * RETURNS: | |
293 | * drm_bridge control struct on success, NULL on failure | |
294 | */ | |
3d3f8b1f AK |
295 | struct drm_bridge *of_drm_find_bridge(struct device_node *np) |
296 | { | |
297 | struct drm_bridge *bridge; | |
298 | ||
299 | mutex_lock(&bridge_lock); | |
300 | ||
301 | list_for_each_entry(bridge, &bridge_list, list) { | |
302 | if (bridge->of_node == np) { | |
303 | mutex_unlock(&bridge_lock); | |
304 | return bridge; | |
305 | } | |
306 | } | |
307 | ||
308 | mutex_unlock(&bridge_lock); | |
309 | return NULL; | |
310 | } | |
311 | EXPORT_SYMBOL(of_drm_find_bridge); | |
312 | #endif | |
313 | ||
314 | MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); | |
315 | MODULE_DESCRIPTION("DRM bridge infrastructure"); | |
316 | MODULE_LICENSE("GPL and additional rights"); |