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 #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 31 struct backlight_device; 32 struct dentry; 33 struct device_node; 34 struct drm_connector; 35 struct drm_device; 36 struct drm_panel; 37 struct display_timing; 38 39 enum drm_panel_orientation; 40 41 /** 42 * struct drm_panel_funcs - perform operations on a given panel 43 * 44 * The .prepare() function is typically called before the display controller 45 * starts to transmit video data. Panel drivers can use this to turn the panel 46 * on and wait for it to become ready. If additional configuration is required 47 * (via a control bus such as I2C, SPI or DSI for example) this is a good time 48 * to do that. 49 * 50 * After the display controller has started transmitting video data, it's safe 51 * to call the .enable() function. This will typically enable the backlight to 52 * make the image on screen visible. Some panels require a certain amount of 53 * time or frames before the image is displayed. This function is responsible 54 * for taking this into account before enabling the backlight to avoid visual 55 * glitches. 56 * 57 * Before stopping video transmission from the display controller it can be 58 * necessary to turn off the panel to avoid visual glitches. This is done in 59 * the .disable() function. Analogously to .enable() this typically involves 60 * turning off the backlight and waiting for some time to make sure no image 61 * is visible on the panel. It is then safe for the display controller to 62 * cease transmission of video data. 63 * 64 * To save power when no video data is transmitted, a driver can power down 65 * the panel. This is the job of the .unprepare() function. 66 * 67 * Backlight can be handled automatically if configured using 68 * drm_panel_of_backlight() or drm_panel_dp_aux_backlight(). Then the driver 69 * does not need to implement the functionality to enable/disable backlight. 70 */ 71 struct drm_panel_funcs { 72 /** 73 * @prepare: 74 * 75 * Turn on panel and perform set up. 76 * 77 * This function is optional. 78 */ 79 int (*prepare)(struct drm_panel *panel); 80 81 /** 82 * @enable: 83 * 84 * Enable panel (turn on back light, etc.). 85 * 86 * This function is optional. 87 */ 88 int (*enable)(struct drm_panel *panel); 89 90 /** 91 * @disable: 92 * 93 * Disable panel (turn off back light, etc.). 94 * 95 * This function is optional. 96 */ 97 int (*disable)(struct drm_panel *panel); 98 99 /** 100 * @unprepare: 101 * 102 * Turn off panel. 103 * 104 * This function is optional. 105 */ 106 int (*unprepare)(struct drm_panel *panel); 107 108 /** 109 * @get_modes: 110 * 111 * Add modes to the connector that the panel is attached to 112 * and returns the number of modes added. 113 * 114 * This function is mandatory. 115 */ 116 int (*get_modes)(struct drm_panel *panel, 117 struct drm_connector *connector); 118 119 /** 120 * @get_orientation: 121 * 122 * Return the panel orientation set by device tree or EDID. 123 * 124 * This function is optional. 125 */ 126 enum drm_panel_orientation (*get_orientation)(struct drm_panel *panel); 127 128 /** 129 * @get_timings: 130 * 131 * Copy display timings into the provided array and return 132 * the number of display timings available. 133 * 134 * This function is optional. 135 */ 136 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings, 137 struct display_timing *timings); 138 139 /** 140 * @debugfs_init: 141 * 142 * Allows panels to create panels-specific debugfs files. 143 */ 144 void (*debugfs_init)(struct drm_panel *panel, struct dentry *root); 145 }; 146 147 /** 148 * struct drm_panel - DRM panel object 149 */ 150 struct drm_panel { 151 /** 152 * @dev: 153 * 154 * Parent device of the panel. 155 */ 156 struct device *dev; 157 158 /** 159 * @backlight: 160 * 161 * Backlight device, used to turn on backlight after the call 162 * to enable(), and to turn off backlight before the call to 163 * disable(). 164 * backlight is set by drm_panel_of_backlight() or 165 * drm_panel_dp_aux_backlight() and drivers shall not assign it. 166 */ 167 struct backlight_device *backlight; 168 169 /** 170 * @funcs: 171 * 172 * Operations that can be performed on the panel. 173 */ 174 const struct drm_panel_funcs *funcs; 175 176 /** 177 * @connector_type: 178 * 179 * Type of the panel as a DRM_MODE_CONNECTOR_* value. This is used to 180 * initialise the drm_connector corresponding to the panel with the 181 * correct connector type. 182 */ 183 int connector_type; 184 185 /** 186 * @list: 187 * 188 * Panel entry in registry. 189 */ 190 struct list_head list; 191 }; 192 193 void drm_panel_init(struct drm_panel *panel, struct device *dev, 194 const struct drm_panel_funcs *funcs, 195 int connector_type); 196 197 void drm_panel_add(struct drm_panel *panel); 198 void drm_panel_remove(struct drm_panel *panel); 199 200 int drm_panel_prepare(struct drm_panel *panel); 201 int drm_panel_unprepare(struct drm_panel *panel); 202 203 int drm_panel_enable(struct drm_panel *panel); 204 int drm_panel_disable(struct drm_panel *panel); 205 206 int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector); 207 208 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL) 209 struct drm_panel *of_drm_find_panel(const struct device_node *np); 210 int of_drm_get_panel_orientation(const struct device_node *np, 211 enum drm_panel_orientation *orientation); 212 #else 213 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) 214 { 215 return ERR_PTR(-ENODEV); 216 } 217 218 static inline int of_drm_get_panel_orientation(const struct device_node *np, 219 enum drm_panel_orientation *orientation) 220 { 221 return -ENODEV; 222 } 223 #endif 224 225 #if IS_ENABLED(CONFIG_DRM_PANEL) && (IS_BUILTIN(CONFIG_BACKLIGHT_CLASS_DEVICE) || \ 226 (IS_MODULE(CONFIG_DRM) && IS_MODULE(CONFIG_BACKLIGHT_CLASS_DEVICE))) 227 int drm_panel_of_backlight(struct drm_panel *panel); 228 #else 229 static inline int drm_panel_of_backlight(struct drm_panel *panel) 230 { 231 return 0; 232 } 233 #endif 234 235 #endif 236