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 */
drm_panel_init(struct drm_panel * panel,struct device * dev,const struct drm_panel_funcs * funcs,int connector_type)57 void drm_panel_init(struct drm_panel *panel, struct device *dev,
58 const struct drm_panel_funcs *funcs, int connector_type)
59 {
60 INIT_LIST_HEAD(&panel->list);
61 panel->dev = dev;
62 panel->funcs = funcs;
63 panel->connector_type = connector_type;
64 }
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 */
drm_panel_add(struct drm_panel * panel)74 void drm_panel_add(struct drm_panel *panel)
75 {
76 mutex_lock(&panel_lock);
77 list_add_tail(&panel->list, &panel_list);
78 mutex_unlock(&panel_lock);
79 }
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 */
drm_panel_remove(struct drm_panel * panel)88 void drm_panel_remove(struct drm_panel *panel)
89 {
90 mutex_lock(&panel_lock);
91 list_del_init(&panel->list);
92 mutex_unlock(&panel_lock);
93 }
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 */
drm_panel_prepare(struct drm_panel * panel)106 int drm_panel_prepare(struct drm_panel *panel)
107 {
108 if (!panel)
109 return -EINVAL;
110
111 if (panel->funcs && panel->funcs->prepare)
112 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 */
drm_panel_unprepare(struct drm_panel * panel)129 int drm_panel_unprepare(struct drm_panel *panel)
130 {
131 if (!panel)
132 return -EINVAL;
133
134 if (panel->funcs && panel->funcs->unprepare)
135 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 */
drm_panel_enable(struct drm_panel * panel)151 int drm_panel_enable(struct drm_panel *panel)
152 {
153 int ret;
154
155 if (!panel)
156 return -EINVAL;
157
158 if (panel->funcs && panel->funcs->enable) {
159 ret = panel->funcs->enable(panel);
160 if (ret < 0)
161 return ret;
162 }
163
164 ret = backlight_enable(panel->backlight);
165 if (ret < 0)
166 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 */
drm_panel_disable(struct drm_panel * panel)183 int drm_panel_disable(struct drm_panel *panel)
184 {
185 int ret;
186
187 if (!panel)
188 return -EINVAL;
189
190 ret = backlight_disable(panel->backlight);
191 if (ret < 0)
192 DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n",
193 ret);
194
195 if (panel->funcs && panel->funcs->disable)
196 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 */
drm_panel_get_modes(struct drm_panel * panel,struct drm_connector * connector)213 int drm_panel_get_modes(struct drm_panel *panel,
214 struct drm_connector *connector)
215 {
216 if (!panel)
217 return -EINVAL;
218
219 if (panel->funcs && panel->funcs->get_modes)
220 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 */
of_drm_find_panel(const struct device_node * np)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 */
of_drm_get_panel_orientation(const struct device_node * np,enum drm_panel_orientation * orientation)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 */
drm_panel_of_backlight(struct drm_panel * panel)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");
350