Line data Source code
1 : /*
2 : * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
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/backlight.h>
25 : #include <linux/err.h>
26 : #include <linux/module.h>
27 :
28 : #include <drm/drm_crtc.h>
29 : #include <drm/drm_panel.h>
30 : #include <drm/drm_print.h>
31 :
32 : static DEFINE_MUTEX(panel_lock);
33 : static LIST_HEAD(panel_list);
34 :
35 : /**
36 : * DOC: drm panel
37 : *
38 : * The DRM panel helpers allow drivers to register panel objects with a
39 : * central registry and provide functions to retrieve those panels in display
40 : * drivers.
41 : *
42 : * For easy integration into drivers using the &drm_bridge infrastructure please
43 : * take look at drm_panel_bridge_add() and devm_drm_panel_bridge_add().
44 : */
45 :
46 : /**
47 : * drm_panel_init - initialize a panel
48 : * @panel: DRM panel
49 : * @dev: parent device of the panel
50 : * @funcs: panel operations
51 : * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
52 : * the panel interface
53 : *
54 : * Initialize the panel structure for subsequent registration with
55 : * drm_panel_add().
56 : */
57 0 : void drm_panel_init(struct drm_panel *panel, struct device *dev,
58 : const struct drm_panel_funcs *funcs, int connector_type)
59 : {
60 0 : INIT_LIST_HEAD(&panel->list);
61 0 : panel->dev = dev;
62 0 : panel->funcs = funcs;
63 0 : panel->connector_type = connector_type;
64 0 : }
65 : EXPORT_SYMBOL(drm_panel_init);
66 :
67 : /**
68 : * drm_panel_add - add a panel to the global registry
69 : * @panel: panel to add
70 : *
71 : * Add a panel to the global registry so that it can be looked up by display
72 : * drivers.
73 : */
74 0 : void drm_panel_add(struct drm_panel *panel)
75 : {
76 0 : mutex_lock(&panel_lock);
77 0 : list_add_tail(&panel->list, &panel_list);
78 0 : mutex_unlock(&panel_lock);
79 0 : }
80 : EXPORT_SYMBOL(drm_panel_add);
81 :
82 : /**
83 : * drm_panel_remove - remove a panel from the global registry
84 : * @panel: DRM panel
85 : *
86 : * Removes a panel from the global registry.
87 : */
88 0 : void drm_panel_remove(struct drm_panel *panel)
89 : {
90 0 : mutex_lock(&panel_lock);
91 0 : list_del_init(&panel->list);
92 0 : mutex_unlock(&panel_lock);
93 0 : }
94 : EXPORT_SYMBOL(drm_panel_remove);
95 :
96 : /**
97 : * drm_panel_prepare - power on a panel
98 : * @panel: DRM panel
99 : *
100 : * Calling this function will enable power and deassert any reset signals to
101 : * the panel. After this has completed it is possible to communicate with any
102 : * integrated circuitry via a command bus.
103 : *
104 : * Return: 0 on success or a negative error code on failure.
105 : */
106 0 : int drm_panel_prepare(struct drm_panel *panel)
107 : {
108 0 : if (!panel)
109 : return -EINVAL;
110 :
111 0 : if (panel->funcs && panel->funcs->prepare)
112 0 : return panel->funcs->prepare(panel);
113 :
114 : return 0;
115 : }
116 : EXPORT_SYMBOL(drm_panel_prepare);
117 :
118 : /**
119 : * drm_panel_unprepare - power off a panel
120 : * @panel: DRM panel
121 : *
122 : * Calling this function will completely power off a panel (assert the panel's
123 : * reset, turn off power supplies, ...). After this function has completed, it
124 : * is usually no longer possible to communicate with the panel until another
125 : * call to drm_panel_prepare().
126 : *
127 : * Return: 0 on success or a negative error code on failure.
128 : */
129 0 : int drm_panel_unprepare(struct drm_panel *panel)
130 : {
131 0 : if (!panel)
132 : return -EINVAL;
133 :
134 0 : if (panel->funcs && panel->funcs->unprepare)
135 0 : return panel->funcs->unprepare(panel);
136 :
137 : return 0;
138 : }
139 : EXPORT_SYMBOL(drm_panel_unprepare);
140 :
141 : /**
142 : * drm_panel_enable - enable a panel
143 : * @panel: DRM panel
144 : *
145 : * Calling this function will cause the panel display drivers to be turned on
146 : * and the backlight to be enabled. Content will be visible on screen after
147 : * this call completes.
148 : *
149 : * Return: 0 on success or a negative error code on failure.
150 : */
151 0 : int drm_panel_enable(struct drm_panel *panel)
152 : {
153 : int ret;
154 :
155 0 : if (!panel)
156 : return -EINVAL;
157 :
158 0 : if (panel->funcs && panel->funcs->enable) {
159 0 : ret = panel->funcs->enable(panel);
160 0 : if (ret < 0)
161 : return ret;
162 : }
163 :
164 0 : ret = backlight_enable(panel->backlight);
165 0 : if (ret < 0)
166 0 : DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n",
167 : ret);
168 :
169 : return 0;
170 : }
171 : EXPORT_SYMBOL(drm_panel_enable);
172 :
173 : /**
174 : * drm_panel_disable - disable a panel
175 : * @panel: DRM panel
176 : *
177 : * This will typically turn off the panel's backlight or disable the display
178 : * drivers. For smart panels it should still be possible to communicate with
179 : * the integrated circuitry via any command bus after this call.
180 : *
181 : * Return: 0 on success or a negative error code on failure.
182 : */
183 0 : int drm_panel_disable(struct drm_panel *panel)
184 : {
185 : int ret;
186 :
187 0 : if (!panel)
188 : return -EINVAL;
189 :
190 0 : ret = backlight_disable(panel->backlight);
191 0 : if (ret < 0)
192 0 : DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
193 : ret);
194 :
195 0 : if (panel->funcs && panel->funcs->disable)
196 0 : return panel->funcs->disable(panel);
197 :
198 : return 0;
199 : }
200 : EXPORT_SYMBOL(drm_panel_disable);
201 :
202 : /**
203 : * drm_panel_get_modes - probe the available display modes of a panel
204 : * @panel: DRM panel
205 : * @connector: DRM connector
206 : *
207 : * The modes probed from the panel are automatically added to the connector
208 : * that the panel is attached to.
209 : *
210 : * Return: The number of modes available from the panel on success or a
211 : * negative error code on failure.
212 : */
213 0 : int drm_panel_get_modes(struct drm_panel *panel,
214 : struct drm_connector *connector)
215 : {
216 0 : if (!panel)
217 : return -EINVAL;
218 :
219 0 : if (panel->funcs && panel->funcs->get_modes)
220 0 : return panel->funcs->get_modes(panel, connector);
221 :
222 : return -EOPNOTSUPP;
223 : }
224 : EXPORT_SYMBOL(drm_panel_get_modes);
225 :
226 : #ifdef CONFIG_OF
227 : /**
228 : * of_drm_find_panel - look up a panel using a device tree node
229 : * @np: device tree node of the panel
230 : *
231 : * Searches the set of registered panels for one that matches the given device
232 : * tree node. If a matching panel is found, return a pointer to it.
233 : *
234 : * Return: A pointer to the panel registered for the specified device tree
235 : * node or an ERR_PTR() if no panel matching the device tree node can be found.
236 : *
237 : * Possible error codes returned by this function:
238 : *
239 : * - EPROBE_DEFER: the panel device has not been probed yet, and the caller
240 : * should retry later
241 : * - ENODEV: the device is not available (status != "okay" or "ok")
242 : */
243 : struct drm_panel *of_drm_find_panel(const struct device_node *np)
244 : {
245 : struct drm_panel *panel;
246 :
247 : if (!of_device_is_available(np))
248 : return ERR_PTR(-ENODEV);
249 :
250 : mutex_lock(&panel_lock);
251 :
252 : list_for_each_entry(panel, &panel_list, list) {
253 : if (panel->dev->of_node == np) {
254 : mutex_unlock(&panel_lock);
255 : return panel;
256 : }
257 : }
258 :
259 : mutex_unlock(&panel_lock);
260 : return ERR_PTR(-EPROBE_DEFER);
261 : }
262 : EXPORT_SYMBOL(of_drm_find_panel);
263 :
264 : /**
265 : * of_drm_get_panel_orientation - look up the orientation of the panel through
266 : * the "rotation" binding from a device tree node
267 : * @np: device tree node of the panel
268 : * @orientation: orientation enum to be filled in
269 : *
270 : * Looks up the rotation of a panel in the device tree. The orientation of the
271 : * panel is expressed as a property name "rotation" in the device tree. The
272 : * rotation in the device tree is counter clockwise.
273 : *
274 : * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the
275 : * rotation property doesn't exist. Return a negative error code on failure.
276 : */
277 : int of_drm_get_panel_orientation(const struct device_node *np,
278 : enum drm_panel_orientation *orientation)
279 : {
280 : int rotation, ret;
281 :
282 : ret = of_property_read_u32(np, "rotation", &rotation);
283 : if (ret == -EINVAL) {
284 : /* Don't return an error if there's no rotation property. */
285 : *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
286 : return 0;
287 : }
288 :
289 : if (ret < 0)
290 : return ret;
291 :
292 : if (rotation == 0)
293 : *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL;
294 : else if (rotation == 90)
295 : *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP;
296 : else if (rotation == 180)
297 : *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP;
298 : else if (rotation == 270)
299 : *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP;
300 : else
301 : return -EINVAL;
302 :
303 : return 0;
304 : }
305 : EXPORT_SYMBOL(of_drm_get_panel_orientation);
306 : #endif
307 :
308 : #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
309 : /**
310 : * drm_panel_of_backlight - use backlight device node for backlight
311 : * @panel: DRM panel
312 : *
313 : * Use this function to enable backlight handling if your panel
314 : * uses device tree and has a backlight phandle.
315 : *
316 : * When the panel is enabled backlight will be enabled after a
317 : * successful call to &drm_panel_funcs.enable()
318 : *
319 : * When the panel is disabled backlight will be disabled before the
320 : * call to &drm_panel_funcs.disable().
321 : *
322 : * A typical implementation for a panel driver supporting device tree
323 : * will call this function at probe time. Backlight will then be handled
324 : * transparently without requiring any intervention from the driver.
325 : * drm_panel_of_backlight() must be called after the call to drm_panel_init().
326 : *
327 : * Return: 0 on success or a negative error code on failure.
328 : */
329 : int drm_panel_of_backlight(struct drm_panel *panel)
330 : {
331 : struct backlight_device *backlight;
332 :
333 : if (!panel || !panel->dev)
334 : return -EINVAL;
335 :
336 : backlight = devm_of_find_backlight(panel->dev);
337 :
338 : if (IS_ERR(backlight))
339 : return PTR_ERR(backlight);
340 :
341 : panel->backlight = backlight;
342 : return 0;
343 : }
344 : EXPORT_SYMBOL(drm_panel_of_backlight);
345 : #endif
346 :
347 : MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
348 : MODULE_DESCRIPTION("DRM panel infrastructure");
349 : MODULE_LICENSE("GPL and additional rights");
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