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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 | * | |
34 | * drm_bridge represents a device that hangs on to an encoder. These are handy | |
35 | * when a regular drm_encoder entity isn't enough to represent the entire | |
36 | * encoder chain. | |
37 | * | |
38 | * A bridge is always associated to a single drm_encoder at a time, but can be | |
39 | * either connected to it directly, or through an intermediate bridge: | |
40 | * | |
41 | * encoder ---> bridge B ---> bridge A | |
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 | |
49 | * through the ops provided in drm_bridge_funcs. | |
50 | * | |
51 | * drm_bridge, like drm_panel, aren't drm_mode_object entities like planes, | |
52 | * crtcs, encoders or connectors. They just provide additional hooks to get the | |
53 | * desired output at the end of the encoder chain. | |
54 | */ | |
55 | ||
3d3f8b1f AK |
56 | static DEFINE_MUTEX(bridge_lock); |
57 | static LIST_HEAD(bridge_list); | |
58 | ||
2331b4e4 AT |
59 | /** |
60 | * drm_bridge_add - add the given bridge to the global bridge list | |
61 | * | |
62 | * @bridge: bridge control structure | |
63 | * | |
64 | * RETURNS: | |
65 | * Unconditionally returns Zero. | |
66 | */ | |
3d3f8b1f AK |
67 | int drm_bridge_add(struct drm_bridge *bridge) |
68 | { | |
69 | mutex_lock(&bridge_lock); | |
70 | list_add_tail(&bridge->list, &bridge_list); | |
71 | mutex_unlock(&bridge_lock); | |
72 | ||
73 | return 0; | |
74 | } | |
75 | EXPORT_SYMBOL(drm_bridge_add); | |
76 | ||
2331b4e4 AT |
77 | /** |
78 | * drm_bridge_remove - remove the given bridge from the global bridge list | |
79 | * | |
80 | * @bridge: bridge control structure | |
81 | */ | |
3d3f8b1f AK |
82 | void drm_bridge_remove(struct drm_bridge *bridge) |
83 | { | |
84 | mutex_lock(&bridge_lock); | |
85 | list_del_init(&bridge->list); | |
86 | mutex_unlock(&bridge_lock); | |
87 | } | |
88 | EXPORT_SYMBOL(drm_bridge_remove); | |
89 | ||
2331b4e4 AT |
90 | /** |
91 | * drm_bridge_attach - associate given bridge to our DRM device | |
92 | * | |
93 | * @dev: DRM device | |
94 | * @bridge: bridge control structure | |
95 | * | |
96 | * called by a kms driver to link one of our encoder/bridge to the given | |
97 | * bridge. | |
98 | * | |
99 | * Note that setting up links between the bridge and our encoder/bridge | |
100 | * objects needs to be handled by the kms driver itself | |
101 | * | |
102 | * RETURNS: | |
103 | * Zero on success, error code on failure | |
104 | */ | |
43fc884e | 105 | int drm_bridge_attach(struct drm_device *dev, struct drm_bridge *bridge) |
3d3f8b1f AK |
106 | { |
107 | if (!dev || !bridge) | |
108 | return -EINVAL; | |
109 | ||
110 | if (bridge->dev) | |
111 | return -EBUSY; | |
112 | ||
113 | bridge->dev = dev; | |
114 | ||
115 | if (bridge->funcs->attach) | |
116 | return bridge->funcs->attach(bridge); | |
117 | ||
118 | return 0; | |
119 | } | |
120 | EXPORT_SYMBOL(drm_bridge_attach); | |
121 | ||
2331b4e4 AT |
122 | /** |
123 | * DOC: bridge callbacks | |
124 | * | |
125 | * The drm_bridge_funcs ops are populated by the bridge driver. The drm | |
126 | * internals(atomic and crtc helpers) use the helpers defined in drm_bridge.c | |
127 | * These helpers call a specific drm_bridge_funcs op for all the bridges | |
128 | * during encoder configuration. | |
129 | * | |
130 | * When creating a bridge driver, one can implement drm_bridge_funcs op with | |
131 | * the help of these rough rules: | |
132 | * | |
133 | * pre_enable: this contains things needed to be done for the bridge before | |
134 | * its clock and timings are enabled by its source. For a bridge, its source | |
135 | * is generally the encoder or bridge just before it in the encoder chain. | |
136 | * | |
137 | * enable: this contains things needed to be done for the bridge once its | |
138 | * source is enabled. In other words, enable is called once the source is | |
139 | * ready with clock and timing needed by the bridge. | |
140 | * | |
141 | * disable: this contains things needed to be done for the bridge assuming | |
142 | * that its source is still enabled, i.e. clock and timings are still on. | |
143 | * | |
144 | * post_disable: this contains things needed to be done for the bridge once | |
145 | * its source is disabled, i.e. once clocks and timings are off. | |
146 | * | |
147 | * mode_fixup: this should fixup the given mode for the bridge. It is called | |
148 | * after the encoder's mode fixup. mode_fixup can also reject a mode completely | |
149 | * if it's unsuitable for the hardware. | |
150 | * | |
151 | * mode_set: this sets up the mode for the bridge. It assumes that its source | |
152 | * (an encoder or a bridge) has set the mode too. | |
153 | */ | |
154 | ||
862e686c AT |
155 | /** |
156 | * drm_bridge_mode_fixup - fixup proposed mode for all bridges in the | |
157 | * encoder chain | |
158 | * @bridge: bridge control structure | |
159 | * @mode: desired mode to be set for the bridge | |
160 | * @adjusted_mode: updated mode that works for this bridge | |
161 | * | |
162 | * Calls 'mode_fixup' drm_bridge_funcs op for all the bridges in the | |
163 | * encoder chain, starting from the first bridge to the last. | |
164 | * | |
165 | * Note: the bridge passed should be the one closest to the encoder | |
166 | * | |
167 | * RETURNS: | |
168 | * true on success, false on failure | |
169 | */ | |
170 | bool drm_bridge_mode_fixup(struct drm_bridge *bridge, | |
171 | const struct drm_display_mode *mode, | |
172 | struct drm_display_mode *adjusted_mode) | |
173 | { | |
174 | bool ret = true; | |
175 | ||
176 | if (!bridge) | |
177 | return true; | |
178 | ||
179 | if (bridge->funcs->mode_fixup) | |
180 | ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); | |
181 | ||
182 | ret = ret && drm_bridge_mode_fixup(bridge->next, mode, adjusted_mode); | |
183 | ||
184 | return ret; | |
185 | } | |
186 | EXPORT_SYMBOL(drm_bridge_mode_fixup); | |
187 | ||
188 | /** | |
189 | * drm_bridge_disable - calls 'disable' drm_bridge_funcs op for all | |
190 | * bridges in the encoder chain. | |
191 | * @bridge: bridge control structure | |
192 | * | |
193 | * Calls 'disable' drm_bridge_funcs op for all the bridges in the encoder | |
194 | * chain, starting from the last bridge to the first. These are called before | |
195 | * calling the encoder's prepare op. | |
196 | * | |
197 | * Note: the bridge passed should be the one closest to the encoder | |
198 | */ | |
199 | void drm_bridge_disable(struct drm_bridge *bridge) | |
200 | { | |
201 | if (!bridge) | |
202 | return; | |
203 | ||
204 | drm_bridge_disable(bridge->next); | |
205 | ||
206 | bridge->funcs->disable(bridge); | |
207 | } | |
208 | EXPORT_SYMBOL(drm_bridge_disable); | |
209 | ||
210 | /** | |
211 | * drm_bridge_post_disable - calls 'post_disable' drm_bridge_funcs op for | |
212 | * all bridges in the encoder chain. | |
213 | * @bridge: bridge control structure | |
214 | * | |
215 | * Calls 'post_disable' drm_bridge_funcs op for all the bridges in the | |
216 | * encoder chain, starting from the first bridge to the last. These are called | |
217 | * after completing the encoder's prepare op. | |
218 | * | |
219 | * Note: the bridge passed should be the one closest to the encoder | |
220 | */ | |
221 | void drm_bridge_post_disable(struct drm_bridge *bridge) | |
222 | { | |
223 | if (!bridge) | |
224 | return; | |
225 | ||
226 | bridge->funcs->post_disable(bridge); | |
227 | ||
228 | drm_bridge_post_disable(bridge->next); | |
229 | } | |
230 | EXPORT_SYMBOL(drm_bridge_post_disable); | |
231 | ||
232 | /** | |
233 | * drm_bridge_mode_set - set proposed mode for all bridges in the | |
234 | * encoder chain | |
235 | * @bridge: bridge control structure | |
236 | * @mode: desired mode to be set for the bridge | |
237 | * @adjusted_mode: updated mode that works for this bridge | |
238 | * | |
239 | * Calls 'mode_set' drm_bridge_funcs op for all the bridges in the | |
240 | * encoder chain, starting from the first bridge to the last. | |
241 | * | |
242 | * Note: the bridge passed should be the one closest to the encoder | |
243 | */ | |
244 | void drm_bridge_mode_set(struct drm_bridge *bridge, | |
245 | struct drm_display_mode *mode, | |
246 | struct drm_display_mode *adjusted_mode) | |
247 | { | |
248 | if (!bridge) | |
249 | return; | |
250 | ||
251 | if (bridge->funcs->mode_set) | |
252 | bridge->funcs->mode_set(bridge, mode, adjusted_mode); | |
253 | ||
254 | drm_bridge_mode_set(bridge->next, mode, adjusted_mode); | |
255 | } | |
256 | EXPORT_SYMBOL(drm_bridge_mode_set); | |
257 | ||
258 | /** | |
259 | * drm_bridge_pre_enable - calls 'pre_enable' drm_bridge_funcs op for all | |
260 | * bridges in the encoder chain. | |
261 | * @bridge: bridge control structure | |
262 | * | |
263 | * Calls 'pre_enable' drm_bridge_funcs op for all the bridges in the encoder | |
264 | * chain, starting from the last bridge to the first. These are called | |
265 | * before calling the encoder's commit op. | |
266 | * | |
267 | * Note: the bridge passed should be the one closest to the encoder | |
268 | */ | |
269 | void drm_bridge_pre_enable(struct drm_bridge *bridge) | |
270 | { | |
271 | if (!bridge) | |
272 | return; | |
273 | ||
274 | drm_bridge_pre_enable(bridge->next); | |
275 | ||
276 | bridge->funcs->pre_enable(bridge); | |
277 | } | |
278 | EXPORT_SYMBOL(drm_bridge_pre_enable); | |
279 | ||
280 | /** | |
281 | * drm_bridge_enable - calls 'enable' drm_bridge_funcs op for all bridges | |
282 | * in the encoder chain. | |
283 | * @bridge: bridge control structure | |
284 | * | |
285 | * Calls 'enable' drm_bridge_funcs op for all the bridges in the encoder | |
286 | * chain, starting from the first bridge to the last. These are called | |
287 | * after completing the encoder's commit op. | |
288 | * | |
289 | * Note that the bridge passed should be the one closest to the encoder | |
290 | */ | |
291 | void drm_bridge_enable(struct drm_bridge *bridge) | |
292 | { | |
293 | if (!bridge) | |
294 | return; | |
295 | ||
296 | bridge->funcs->enable(bridge); | |
297 | ||
298 | drm_bridge_enable(bridge->next); | |
299 | } | |
300 | EXPORT_SYMBOL(drm_bridge_enable); | |
301 | ||
3d3f8b1f | 302 | #ifdef CONFIG_OF |
2331b4e4 AT |
303 | /** |
304 | * of_drm_find_bridge - find the bridge corresponding to the device node in | |
305 | * the global bridge list | |
306 | * | |
307 | * @np: device node | |
308 | * | |
309 | * RETURNS: | |
310 | * drm_bridge control struct on success, NULL on failure | |
311 | */ | |
3d3f8b1f AK |
312 | struct drm_bridge *of_drm_find_bridge(struct device_node *np) |
313 | { | |
314 | struct drm_bridge *bridge; | |
315 | ||
316 | mutex_lock(&bridge_lock); | |
317 | ||
318 | list_for_each_entry(bridge, &bridge_list, list) { | |
319 | if (bridge->of_node == np) { | |
320 | mutex_unlock(&bridge_lock); | |
321 | return bridge; | |
322 | } | |
323 | } | |
324 | ||
325 | mutex_unlock(&bridge_lock); | |
326 | return NULL; | |
327 | } | |
328 | EXPORT_SYMBOL(of_drm_find_bridge); | |
329 | #endif | |
330 | ||
331 | MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>"); | |
332 | MODULE_DESCRIPTION("DRM bridge infrastructure"); | |
333 | MODULE_LICENSE("GPL and additional rights"); |