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1/*2 * Copyright (C) 2013, NVIDIA Corporation. All rights reserved.3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * 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 the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice (including the12 * next paragraph) shall be included in all copies or substantial portions13 * of the Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER21 * DEALINGS IN THE SOFTWARE.22 */23 24#ifndef __DRM_PANEL_H__25#define __DRM_PANEL_H__26 27#include <linux/err.h>28#include <linux/errno.h>29#include <linux/list.h>30#include <linux/mutex.h>31 32struct backlight_device;33struct dentry;34struct device_node;35struct drm_connector;36struct drm_device;37struct drm_panel_follower;38struct drm_panel;39struct display_timing;40 41enum drm_panel_orientation;42 43/**44 * struct drm_panel_funcs - perform operations on a given panel45 *46 * The .prepare() function is typically called before the display controller47 * starts to transmit video data. Panel drivers can use this to turn the panel48 * on and wait for it to become ready. If additional configuration is required49 * (via a control bus such as I2C, SPI or DSI for example) this is a good time50 * to do that.51 *52 * After the display controller has started transmitting video data, it's safe53 * to call the .enable() function. This will typically enable the backlight to54 * make the image on screen visible. Some panels require a certain amount of55 * time or frames before the image is displayed. This function is responsible56 * for taking this into account before enabling the backlight to avoid visual57 * glitches.58 *59 * Before stopping video transmission from the display controller it can be60 * necessary to turn off the panel to avoid visual glitches. This is done in61 * the .disable() function. Analogously to .enable() this typically involves62 * turning off the backlight and waiting for some time to make sure no image63 * is visible on the panel. It is then safe for the display controller to64 * cease transmission of video data.65 *66 * To save power when no video data is transmitted, a driver can power down67 * the panel. This is the job of the .unprepare() function.68 *69 * Backlight can be handled automatically if configured using70 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver71 * does not need to implement the functionality to enable/disable backlight.72 */73struct drm_panel_funcs {74 /**75 * @prepare:76 *77 * Turn on panel and perform set up.78 *79 * This function is optional.80 */81 int (*prepare)(struct drm_panel *panel);82 83 /**84 * @enable:85 *86 * Enable panel (turn on back light, etc.).87 *88 * This function is optional.89 */90 int (*enable)(struct drm_panel *panel);91 92 /**93 * @disable:94 *95 * Disable panel (turn off back light, etc.).96 *97 * This function is optional.98 */99 int (*disable)(struct drm_panel *panel);100 101 /**102 * @unprepare:103 *104 * Turn off panel.105 *106 * This function is optional.107 */108 int (*unprepare)(struct drm_panel *panel);109 110 /**111 * @get_modes:112 *113 * Add modes to the connector that the panel is attached to114 * and returns the number of modes added.115 *116 * This function is mandatory.117 */118 int (*get_modes)(struct drm_panel *panel,119 struct drm_connector *connector);120 121 /**122 * @get_orientation:123 *124 * Return the panel orientation set by device tree or EDID.125 *126 * This function is optional.127 */128 enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel);129 130 /**131 * @get_timings:132 *133 * Copy display timings into the provided array and return134 * the number of display timings available.135 *136 * This function is optional.137 */138 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings,139 struct display_timing *timings);140 141 /**142 * @debugfs_init:143 *144 * Allows panels to create panels-specific debugfs files.145 */146 void (*debugfs_init)(struct drm_panel *panel, struct dentry *root);147};148 149struct drm_panel_follower_funcs {150 /**151 * @panel_prepared:152 *153 * Called after the panel has been powered on.154 */155 int (*panel_prepared)(struct drm_panel_follower *follower);156 157 /**158 * @panel_unpreparing:159 *160 * Called before the panel is powered off.161 */162 int (*panel_unpreparing)(struct drm_panel_follower *follower);163};164 165struct drm_panel_follower {166 /**167 * @funcs:168 *169 * Dependent device callbacks; should be initted by the caller.170 */171 const struct drm_panel_follower_funcs *funcs;172 173 /**174 * @list175 *176 * Used for linking into panel's list; set by drm_panel_add_follower().177 */178 struct list_head list;179 180 /**181 * @panel182 *183 * The panel we're dependent on; set by drm_panel_add_follower().184 */185 struct drm_panel *panel;186};187 188/**189 * struct drm_panel - DRM panel object190 */191struct drm_panel {192 /**193 * @dev:194 *195 * Parent device of the panel.196 */197 struct device *dev;198 199 /**200 * @backlight:201 *202 * Backlight device, used to turn on backlight after the call203 * to enable(), and to turn off backlight before the call to204 * disable().205 * backlight is set by drm_panel_of_backlight() or206 * drm_panel_dp_aux_backlight() and drivers shall not assign it.207 */208 struct backlight_device *backlight;209 210 /**211 * @funcs:212 *213 * Operations that can be performed on the panel.214 */215 const struct drm_panel_funcs *funcs;216 217 /**218 * @connector_type:219 *220 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to221 * initialise the drm_connector corresponding to the panel with the222 * correct connector type.223 */224 int connector_type;225 226 /**227 * @list:228 *229 * Panel entry in registry.230 */231 struct list_head list;232 233 /**234 * @followers:235 *236 * A list of struct drm_panel_follower dependent on this panel.237 */238 struct list_head followers;239 240 /**241 * @follower_lock:242 *243 * Lock for followers list.244 */245 struct mutex follower_lock;246 247 /**248 * @prepare_prev_first:249 *250 * The previous controller should be prepared first, before the prepare251 * for the panel is called. This is largely required for DSI panels252 * where the DSI host controller should be initialised to LP-11 before253 * the panel is powered up.254 */255 bool prepare_prev_first;256 257 /**258 * @prepared:259 *260 * If true then the panel has been prepared.261 */262 bool prepared;263 264 /**265 * @enabled:266 *267 * If true then the panel has been enabled.268 */269 bool enabled;270};271 272void drm_panel_init(struct drm_panel *panel, struct device *dev,273 const struct drm_panel_funcs *funcs,274 int connector_type);275 276void drm_panel_add(struct drm_panel *panel);277void drm_panel_remove(struct drm_panel *panel);278 279int drm_panel_prepare(struct drm_panel *panel);280int drm_panel_unprepare(struct drm_panel *panel);281 282int drm_panel_enable(struct drm_panel *panel);283int drm_panel_disable(struct drm_panel *panel);284 285int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector);286 287#if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL)288struct drm_panel *of_drm_find_panel(const struct device_node *np);289int of_drm_get_panel_orientation(const struct device_node *np,290 enum drm_panel_orientation *orientation);291#else292static inline struct drm_panel *of_drm_find_panel(const struct device_node *np)293{294 return ERR_PTR(-ENODEV);295}296 297static inline int of_drm_get_panel_orientation(const struct device_node *np,298 enum drm_panel_orientation *orientation)299{300 return -ENODEV;301}302#endif303 304#if defined(CONFIG_DRM_PANEL)305bool drm_is_panel_follower(struct device *dev);306int drm_panel_add_follower(struct device *follower_dev,307 struct drm_panel_follower *follower);308void drm_panel_remove_follower(struct drm_panel_follower *follower);309int devm_drm_panel_add_follower(struct device *follower_dev,310 struct drm_panel_follower *follower);311#else312static inline bool drm_is_panel_follower(struct device *dev)313{314 return false;315}316 317static inline int drm_panel_add_follower(struct device *follower_dev,318 struct drm_panel_follower *follower)319{320 return -ENODEV;321}322 323static inline void drm_panel_remove_follower(struct drm_panel_follower *follower) { }324static inline int devm_drm_panel_add_follower(struct device *follower_dev,325 struct drm_panel_follower *follower)326{327 return -ENODEV;328}329#endif330 331#if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \332 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE)))333int drm_panel_of_backlight(struct drm_panel *panel);334#else335static inline int drm_panel_of_backlight(struct drm_panel *panel)336{337 return 0;338}339#endif340 341#endif342