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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/gpu/drm/drm_panel.c
2 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.
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:
11 * The above copyright notice and this permission notice (including the
12 * next paragraph) shall be included in all copies or substantial portions
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.
24 #include <linux/backlight.h>
25 #include <linux/err.h>
26 #include <linux/module.h>
28 #include <drm/drm_crtc.h>
29 #include <drm/drm_panel.h>
30 #include <drm/drm_print.h>
32 static DEFINE_MUTEX(panel_lock
);
33 static LIST_HEAD(panel_list
);
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
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().
47 * drm_panel_init - initialize a panel
49 * @dev: parent device of the panel
50 * @funcs: panel operations
51 * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to
54 * Initialize the panel structure for subsequent registration with
57 void drm_panel_init(struct drm_panel
*panel
, struct device
*dev
,
58 const struct drm_panel_funcs
*funcs
, int connector_type
)
60 INIT_LIST_HEAD(&panel
->list
);
63 panel
->connector_type
= connector_type
;
65 EXPORT_SYMBOL(drm_panel_init
);
68 * drm_panel_add - add a panel to the global registry
69 * @panel: panel to add
71 * Add a panel to the global registry so that it can be looked up by display
74 * Return: 0 on success or a negative error code on failure.
76 int drm_panel_add(struct drm_panel
*panel
)
78 mutex_lock(&panel_lock
);
79 list_add_tail(&panel
->list
, &panel_list
);
80 mutex_unlock(&panel_lock
);
84 EXPORT_SYMBOL(drm_panel_add
);
87 * drm_panel_remove - remove a panel from the global registry
90 * Removes a panel from the global registry.
92 void drm_panel_remove(struct drm_panel
*panel
)
94 mutex_lock(&panel_lock
);
95 list_del_init(&panel
->list
);
96 mutex_unlock(&panel_lock
);
98 EXPORT_SYMBOL(drm_panel_remove
);
101 * drm_panel_attach - attach a panel to a connector
103 * @connector: DRM connector
105 * After obtaining a pointer to a DRM panel a display driver calls this
106 * function to attach a panel to a connector.
108 * An error is returned if the panel is already attached to another connector.
110 * When unloading, the driver should detach from the panel by calling
111 * drm_panel_detach().
113 * Return: 0 on success or a negative error code on failure.
115 int drm_panel_attach(struct drm_panel
*panel
, struct drm_connector
*connector
)
119 EXPORT_SYMBOL(drm_panel_attach
);
122 * drm_panel_detach - detach a panel from a connector
125 * Detaches a panel from the connector it is attached to. If a panel is not
126 * attached to any connector this is effectively a no-op.
128 * This function should not be called by the panel device itself. It
129 * is only for the drm device that called drm_panel_attach().
131 void drm_panel_detach(struct drm_panel
*panel
)
134 EXPORT_SYMBOL(drm_panel_detach
);
137 * drm_panel_prepare - power on a panel
140 * Calling this function will enable power and deassert any reset signals to
141 * the panel. After this has completed it is possible to communicate with any
142 * integrated circuitry via a command bus.
144 * Return: 0 on success or a negative error code on failure.
146 int drm_panel_prepare(struct drm_panel
*panel
)
151 if (panel
->funcs
&& panel
->funcs
->prepare
)
152 return panel
->funcs
->prepare(panel
);
156 EXPORT_SYMBOL(drm_panel_prepare
);
159 * drm_panel_unprepare - power off a panel
162 * Calling this function will completely power off a panel (assert the panel's
163 * reset, turn off power supplies, ...). After this function has completed, it
164 * is usually no longer possible to communicate with the panel until another
165 * call to drm_panel_prepare().
167 * Return: 0 on success or a negative error code on failure.
169 int drm_panel_unprepare(struct drm_panel
*panel
)
174 if (panel
->funcs
&& panel
->funcs
->unprepare
)
175 return panel
->funcs
->unprepare(panel
);
179 EXPORT_SYMBOL(drm_panel_unprepare
);
182 * drm_panel_enable - enable a panel
185 * Calling this function will cause the panel display drivers to be turned on
186 * and the backlight to be enabled. Content will be visible on screen after
187 * this call completes.
189 * Return: 0 on success or a negative error code on failure.
191 int drm_panel_enable(struct drm_panel
*panel
)
198 if (panel
->funcs
&& panel
->funcs
->enable
) {
199 ret
= panel
->funcs
->enable(panel
);
204 ret
= backlight_enable(panel
->backlight
);
206 DRM_DEV_INFO(panel
->dev
, "failed to enable backlight: %d\n",
211 EXPORT_SYMBOL(drm_panel_enable
);
214 * drm_panel_disable - disable a panel
217 * This will typically turn off the panel's backlight or disable the display
218 * drivers. For smart panels it should still be possible to communicate with
219 * the integrated circuitry via any command bus after this call.
221 * Return: 0 on success or a negative error code on failure.
223 int drm_panel_disable(struct drm_panel
*panel
)
230 ret
= backlight_disable(panel
->backlight
);
232 DRM_DEV_INFO(panel
->dev
, "failed to disable backlight: %d\n",
235 if (panel
->funcs
&& panel
->funcs
->disable
)
236 return panel
->funcs
->disable(panel
);
240 EXPORT_SYMBOL(drm_panel_disable
);
243 * drm_panel_get_modes - probe the available display modes of a panel
245 * @connector: DRM connector
247 * The modes probed from the panel are automatically added to the connector
248 * that the panel is attached to.
250 * Return: The number of modes available from the panel on success or a
251 * negative error code on failure.
253 int drm_panel_get_modes(struct drm_panel
*panel
,
254 struct drm_connector
*connector
)
259 if (panel
->funcs
&& panel
->funcs
->get_modes
)
260 return panel
->funcs
->get_modes(panel
, connector
);
264 EXPORT_SYMBOL(drm_panel_get_modes
);
268 * of_drm_find_panel - look up a panel using a device tree node
269 * @np: device tree node of the panel
271 * Searches the set of registered panels for one that matches the given device
272 * tree node. If a matching panel is found, return a pointer to it.
274 * Return: A pointer to the panel registered for the specified device tree
275 * node or an ERR_PTR() if no panel matching the device tree node can be found.
277 * Possible error codes returned by this function:
279 * - EPROBE_DEFER: the panel device has not been probed yet, and the caller
281 * - ENODEV: the device is not available (status != "okay" or "ok")
283 struct drm_panel
*of_drm_find_panel(const struct device_node
*np
)
285 struct drm_panel
*panel
;
287 if (!of_device_is_available(np
))
288 return ERR_PTR(-ENODEV
);
290 mutex_lock(&panel_lock
);
292 list_for_each_entry(panel
, &panel_list
, list
) {
293 if (panel
->dev
->of_node
== np
) {
294 mutex_unlock(&panel_lock
);
299 mutex_unlock(&panel_lock
);
300 return ERR_PTR(-EPROBE_DEFER
);
302 EXPORT_SYMBOL(of_drm_find_panel
);
305 #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE)
307 * drm_panel_of_backlight - use backlight device node for backlight
310 * Use this function to enable backlight handling if your panel
311 * uses device tree and has a backlight phandle.
313 * When the panel is enabled backlight will be enabled after a
314 * successful call to &drm_panel_funcs.enable()
316 * When the panel is disabled backlight will be disabled before the
317 * call to &drm_panel_funcs.disable().
319 * A typical implementation for a panel driver supporting device tree
320 * will call this function at probe time. Backlight will then be handled
321 * transparently without requiring any intervention from the driver.
322 * drm_panel_of_backlight() must be called after the call to drm_panel_init().
324 * Return: 0 on success or a negative error code on failure.
326 int drm_panel_of_backlight(struct drm_panel
*panel
)
328 struct backlight_device
*backlight
;
330 if (!panel
|| !panel
->dev
)
333 backlight
= devm_of_find_backlight(panel
->dev
);
335 if (IS_ERR(backlight
))
336 return PTR_ERR(backlight
);
338 panel
->backlight
= backlight
;
341 EXPORT_SYMBOL(drm_panel_of_backlight
);
344 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
345 MODULE_DESCRIPTION("DRM panel infrastructure");
346 MODULE_LICENSE("GPL and additional rights");