/* * Copyright (C) 2013, NVIDIA Corporation. All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sub license, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #include #include #include #include #include #include static DEFINE_MUTEX(panel_lock); static LIST_HEAD(panel_list); /** * DOC: drm panel * * The DRM panel helpers allow drivers to register panel objects with a * central registry and provide functions to retrieve those panels in display * drivers. * * For easy integration into drivers using the &drm_bridge infrastructure please * take look at drm_panel_bridge_add() and devm_drm_panel_bridge_add(). */ /** * drm_panel_init - initialize a panel * @panel: DRM panel * @dev: parent device of the panel * @funcs: panel operations * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to * the panel interface * * Initialize the panel structure for subsequent registration with * drm_panel_add(). */ void drm_panel_init(struct drm_panel *panel, struct device *dev, const struct drm_panel_funcs *funcs, int connector_type) { INIT_LIST_HEAD(&panel->list); panel->dev = dev; panel->funcs = funcs; panel->connector_type = connector_type; } EXPORT_SYMBOL(drm_panel_init); /** * drm_panel_add - add a panel to the global registry * @panel: panel to add * * Add a panel to the global registry so that it can be looked up by display * drivers. * * Return: 0 on success or a negative error code on failure. */ int drm_panel_add(struct drm_panel *panel) { mutex_lock(&panel_lock); list_add_tail(&panel->list, &panel_list); mutex_unlock(&panel_lock); return 0; } EXPORT_SYMBOL(drm_panel_add); /** * drm_panel_remove - remove a panel from the global registry * @panel: DRM panel * * Removes a panel from the global registry. */ void drm_panel_remove(struct drm_panel *panel) { mutex_lock(&panel_lock); list_del_init(&panel->list); mutex_unlock(&panel_lock); } EXPORT_SYMBOL(drm_panel_remove); /** * drm_panel_attach - attach a panel to a connector * @panel: DRM panel * @connector: DRM connector * * After obtaining a pointer to a DRM panel a display driver calls this * function to attach a panel to a connector. * * An error is returned if the panel is already attached to another connector. * * When unloading, the driver should detach from the panel by calling * drm_panel_detach(). * * Return: 0 on success or a negative error code on failure. */ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) { return 0; } EXPORT_SYMBOL(drm_panel_attach); /** * drm_panel_detach - detach a panel from a connector * @panel: DRM panel * * Detaches a panel from the connector it is attached to. If a panel is not * attached to any connector this is effectively a no-op. * * This function should not be called by the panel device itself. It * is only for the drm device that called drm_panel_attach(). */ void drm_panel_detach(struct drm_panel *panel) { } EXPORT_SYMBOL(drm_panel_detach); /** * drm_panel_prepare - power on a panel * @panel: DRM panel * * Calling this function will enable power and deassert any reset signals to * the panel. After this has completed it is possible to communicate with any * integrated circuitry via a command bus. * * Return: 0 on success or a negative error code on failure. */ int drm_panel_prepare(struct drm_panel *panel) { if (!panel) return -EINVAL; if (panel->funcs && panel->funcs->prepare) return panel->funcs->prepare(panel); return 0; } EXPORT_SYMBOL(drm_panel_prepare); /** * drm_panel_unprepare - power off a panel * @panel: DRM panel * * Calling this function will completely power off a panel (assert the panel's * reset, turn off power supplies, ...). After this function has completed, it * is usually no longer possible to communicate with the panel until another * call to drm_panel_prepare(). * * Return: 0 on success or a negative error code on failure. */ int drm_panel_unprepare(struct drm_panel *panel) { if (!panel) return -EINVAL; if (panel->funcs && panel->funcs->unprepare) return panel->funcs->unprepare(panel); return 0; } EXPORT_SYMBOL(drm_panel_unprepare); /** * drm_panel_enable - enable a panel * @panel: DRM panel * * Calling this function will cause the panel display drivers to be turned on * and the backlight to be enabled. Content will be visible on screen after * this call completes. * * Return: 0 on success or a negative error code on failure. */ int drm_panel_enable(struct drm_panel *panel) { int ret; if (!panel) return -EINVAL; if (panel->funcs && panel->funcs->enable) { ret = panel->funcs->enable(panel); if (ret < 0) return ret; } ret = backlight_enable(panel->backlight); if (ret < 0) DRM_DEV_INFO(panel->dev, "failed to enable backlight: %d\n", ret); return 0; } EXPORT_SYMBOL(drm_panel_enable); /** * drm_panel_disable - disable a panel * @panel: DRM panel * * This will typically turn off the panel's backlight or disable the display * drivers. For smart panels it should still be possible to communicate with * the integrated circuitry via any command bus after this call. * * Return: 0 on success or a negative error code on failure. */ int drm_panel_disable(struct drm_panel *panel) { int ret; if (!panel) return -EINVAL; ret = backlight_disable(panel->backlight); if (ret < 0) DRM_DEV_INFO(panel->dev, "failed to disable backlight: %d\n", ret); if (panel->funcs && panel->funcs->disable) return panel->funcs->disable(panel); return 0; } EXPORT_SYMBOL(drm_panel_disable); /** * drm_panel_get_modes - probe the available display modes of a panel * @panel: DRM panel * @connector: DRM connector * * The modes probed from the panel are automatically added to the connector * that the panel is attached to. * * Return: The number of modes available from the panel on success or a * negative error code on failure. */ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector) { if (!panel) return -EINVAL; if (panel->funcs && panel->funcs->get_modes) return panel->funcs->get_modes(panel, connector); return -EOPNOTSUPP; } EXPORT_SYMBOL(drm_panel_get_modes); #ifdef CONFIG_OF /** * of_drm_find_panel - look up a panel using a device tree node * @np: device tree node of the panel * * Searches the set of registered panels for one that matches the given device * tree node. If a matching panel is found, return a pointer to it. * * Return: A pointer to the panel registered for the specified device tree * node or an ERR_PTR() if no panel matching the device tree node can be found. * * Possible error codes returned by this function: * * - EPROBE_DEFER: the panel device has not been probed yet, and the caller * should retry later * - ENODEV: the device is not available (status != "okay" or "ok") */ struct drm_panel *of_drm_find_panel(const struct device_node *np) { struct drm_panel *panel; if (!of_device_is_available(np)) return ERR_PTR(-ENODEV); mutex_lock(&panel_lock); list_for_each_entry(panel, &panel_list, list) { if (panel->dev->of_node == np) { mutex_unlock(&panel_lock); return panel; } } mutex_unlock(&panel_lock); return ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL(of_drm_find_panel); #endif #if IS_REACHABLE(CONFIG_BACKLIGHT_CLASS_DEVICE) /** * drm_panel_of_backlight - use backlight device node for backlight * @panel: DRM panel * * Use this function to enable backlight handling if your panel * uses device tree and has a backlight phandle. * * When the panel is enabled backlight will be enabled after a * successful call to &drm_panel_funcs.enable() * * When the panel is disabled backlight will be disabled before the * call to &drm_panel_funcs.disable(). * * A typical implementation for a panel driver supporting device tree * will call this function at probe time. Backlight will then be handled * transparently without requiring any intervention from the driver. * drm_panel_of_backlight() must be called after the call to drm_panel_init(). * * Return: 0 on success or a negative error code on failure. */ int drm_panel_of_backlight(struct drm_panel *panel) { struct backlight_device *backlight; if (!panel || !panel->dev) return -EINVAL; backlight = devm_of_find_backlight(panel->dev); if (IS_ERR(backlight)) return PTR_ERR(backlight); panel->backlight = backlight; return 0; } EXPORT_SYMBOL(drm_panel_of_backlight); #endif MODULE_AUTHOR("Thierry Reding "); MODULE_DESCRIPTION("DRM panel infrastructure"); MODULE_LICENSE("GPL and additional rights");