/* * 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); INIT_LIST_HEAD(&panel->followers); mutex_init(&panel->follower_lock); 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. */ void drm_panel_add(struct drm_panel *panel) { mutex_lock(&panel_lock); list_add_tail(&panel->list, &panel_list); mutex_unlock(&panel_lock); } 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_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) { struct drm_panel_follower *follower; int ret; if (!panel) return -EINVAL; if (panel->prepared) { dev_warn(panel->dev, "Skipping prepare of already prepared panel\n"); return 0; } mutex_lock(&panel->follower_lock); if (panel->funcs && panel->funcs->prepare) { ret = panel->funcs->prepare(panel); if (ret < 0) goto exit; } panel->prepared = true; list_for_each_entry(follower, &panel->followers, list) { ret = follower->funcs->panel_prepared(follower); if (ret < 0) dev_info(panel->dev, "%ps failed: %d\n", follower->funcs->panel_prepared, ret); } ret = 0; exit: mutex_unlock(&panel->follower_lock); return ret; } 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) { struct drm_panel_follower *follower; int ret; if (!panel) return -EINVAL; /* * If you are seeing the warning below it likely means one of two things: * - Your panel driver incorrectly calls drm_panel_unprepare() in its * shutdown routine. You should delete this. * - You are using panel-edp or panel-simple and your DRM modeset * driver's shutdown() callback happened after the panel's shutdown(). * In this case the warning is harmless though ideally you should * figure out how to reverse the order of the shutdown() callbacks. */ if (!panel->prepared) { dev_warn(panel->dev, "Skipping unprepare of already unprepared panel\n"); return 0; } mutex_lock(&panel->follower_lock); list_for_each_entry(follower, &panel->followers, list) { ret = follower->funcs->panel_unpreparing(follower); if (ret < 0) dev_info(panel->dev, "%ps failed: %d\n", follower->funcs->panel_unpreparing, ret); } if (panel->funcs && panel->funcs->unprepare) { ret = panel->funcs->unprepare(panel); if (ret < 0) goto exit; } panel->prepared = false; ret = 0; exit: mutex_unlock(&panel->follower_lock); return ret; } 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->enabled) { dev_warn(panel->dev, "Skipping enable of already enabled panel\n"); return 0; } if (panel->funcs && panel->funcs->enable) { ret = panel->funcs->enable(panel); if (ret < 0) return ret; } panel->enabled = true; 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; /* * If you are seeing the warning below it likely means one of two things: * - Your panel driver incorrectly calls drm_panel_disable() in its * shutdown routine. You should delete this. * - You are using panel-edp or panel-simple and your DRM modeset * driver's shutdown() callback happened after the panel's shutdown(). * In this case the warning is harmless though ideally you should * figure out how to reverse the order of the shutdown() callbacks. */ if (!panel->enabled) { dev_warn(panel->dev, "Skipping disable of already disabled panel\n"); return 0; } 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) { ret = panel->funcs->disable(panel); if (ret < 0) return ret; } panel->enabled = false; 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 0 on * failure (no modes). */ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector) { if (!panel) return 0; if (panel->funcs && panel->funcs->get_modes) { int num; num = panel->funcs->get_modes(panel, connector); if (num > 0) return num; } return 0; } 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); /** * of_drm_get_panel_orientation - look up the orientation of the panel through * the "rotation" binding from a device tree node * @np: device tree node of the panel * @orientation: orientation enum to be filled in * * Looks up the rotation of a panel in the device tree. The orientation of the * panel is expressed as a property name "rotation" in the device tree. The * rotation in the device tree is counter clockwise. * * Return: 0 when a valid rotation value (0, 90, 180, or 270) is read or the * rotation property doesn't exist. Return a negative error code on failure. */ int of_drm_get_panel_orientation(const struct device_node *np, enum drm_panel_orientation *orientation) { int rotation, ret; ret = of_property_read_u32(np, "rotation", &rotation); if (ret == -EINVAL) { /* Don't return an error if there's no rotation property. */ *orientation = DRM_MODE_PANEL_ORIENTATION_UNKNOWN; return 0; } if (ret < 0) return ret; if (rotation == 0) *orientation = DRM_MODE_PANEL_ORIENTATION_NORMAL; else if (rotation == 90) *orientation = DRM_MODE_PANEL_ORIENTATION_RIGHT_UP; else if (rotation == 180) *orientation = DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP; else if (rotation == 270) *orientation = DRM_MODE_PANEL_ORIENTATION_LEFT_UP; else return -EINVAL; return 0; } EXPORT_SYMBOL(of_drm_get_panel_orientation); #endif /** * drm_is_panel_follower() - Check if the device is a panel follower * @dev: The 'struct device' to check * * This checks to see if a device needs to be power sequenced together with * a panel using the panel follower API. * At the moment panels can only be followed on device tree enabled systems. * The "panel" property of the follower points to the panel to be followed. * * Return: true if we should be power sequenced with a panel; false otherwise. */ bool drm_is_panel_follower(struct device *dev) { /* * The "panel" property is actually a phandle, but for simplicity we * don't bother trying to parse it here. We just need to know if the * property is there. */ return of_property_read_bool(dev->of_node, "panel"); } EXPORT_SYMBOL(drm_is_panel_follower); /** * drm_panel_add_follower() - Register something to follow panel state. * @follower_dev: The 'struct device' for the follower. * @follower: The panel follower descriptor for the follower. * * A panel follower is called right after preparing the panel and right before * unpreparing the panel. It's primary intention is to power on an associated * touchscreen, though it could be used for any similar devices. Multiple * devices are allowed the follow the same panel. * * If a follower is added to a panel that's already been turned on, the * follower's prepare callback is called right away. * * At the moment panels can only be followed on device tree enabled systems. * The "panel" property of the follower points to the panel to be followed. * * Return: 0 or an error code. Note that -ENODEV means that we detected that * follower_dev is not actually following a panel. The caller may * choose to ignore this return value if following a panel is optional. */ int drm_panel_add_follower(struct device *follower_dev, struct drm_panel_follower *follower) { struct device_node *panel_np; struct drm_panel *panel; int ret; panel_np = of_parse_phandle(follower_dev->of_node, "panel", 0); if (!panel_np) return -ENODEV; panel = of_drm_find_panel(panel_np); of_node_put(panel_np); if (IS_ERR(panel)) return PTR_ERR(panel); get_device(panel->dev); follower->panel = panel; mutex_lock(&panel->follower_lock); list_add_tail(&follower->list, &panel->followers); if (panel->prepared) { ret = follower->funcs->panel_prepared(follower); if (ret < 0) dev_info(panel->dev, "%ps failed: %d\n", follower->funcs->panel_prepared, ret); } mutex_unlock(&panel->follower_lock); return 0; } EXPORT_SYMBOL(drm_panel_add_follower); /** * drm_panel_remove_follower() - Reverse drm_panel_add_follower(). * @follower: The panel follower descriptor for the follower. * * Undo drm_panel_add_follower(). This includes calling the follower's * unprepare function if we're removed from a panel that's currently prepared. * * Return: 0 or an error code. */ void drm_panel_remove_follower(struct drm_panel_follower *follower) { struct drm_panel *panel = follower->panel; int ret; mutex_lock(&panel->follower_lock); if (panel->prepared) { ret = follower->funcs->panel_unpreparing(follower); if (ret < 0) dev_info(panel->dev, "%ps failed: %d\n", follower->funcs->panel_unpreparing, ret); } list_del_init(&follower->list); mutex_unlock(&panel->follower_lock); put_device(panel->dev); } EXPORT_SYMBOL(drm_panel_remove_follower); static void drm_panel_remove_follower_void(void *follower) { drm_panel_remove_follower(follower); } /** * devm_drm_panel_add_follower() - devm version of drm_panel_add_follower() * @follower_dev: The 'struct device' for the follower. * @follower: The panel follower descriptor for the follower. * * Handles calling drm_panel_remove_follower() using devm on the follower_dev. * * Return: 0 or an error code. */ int devm_drm_panel_add_follower(struct device *follower_dev, struct drm_panel_follower *follower) { int ret; ret = drm_panel_add_follower(follower_dev, follower); if (ret) return ret; return devm_add_action_or_reset(follower_dev, drm_panel_remove_follower_void, follower); } EXPORT_SYMBOL(devm_drm_panel_add_follower); #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");