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 device_node; 32 struct drm_connector; 33 struct drm_device; 34 struct drm_panel; 35 struct display_timing; 36 37 /** 38 * struct drm_panel_funcs - perform operations on a given panel 39 * 40 * The .prepare() function is typically called before the display controller 41 * starts to transmit video data. Panel drivers can use this to turn the panel 42 * on and wait for it to become ready. If additional configuration is required 43 * (via a control bus such as I2C, SPI or DSI for example) this is a good time 44 * to do that. 45 * 46 * After the display controller has started transmitting video data, it's safe 47 * to call the .enable() function. This will typically enable the backlight to 48 * make the image on screen visible. Some panels require a certain amount of 49 * time or frames before the image is displayed. This function is responsible 50 * for taking this into account before enabling the backlight to avoid visual 51 * glitches. 52 * 53 * Before stopping video transmission from the display controller it can be 54 * necessary to turn off the panel to avoid visual glitches. This is done in 55 * the .disable() function. Analogously to .enable() this typically involves 56 * turning off the backlight and waiting for some time to make sure no image 57 * is visible on the panel. It is then safe for the display controller to 58 * cease transmission of video data. 59 * 60 * To save power when no video data is transmitted, a driver can power down 61 * the panel. This is the job of the .unprepare() function. 62 */ 63 struct drm_panel_funcs { 64 /** 65 * @prepare: 66 * 67 * Turn on panel and perform set up. 68 */ 69 int (*prepare)(struct drm_panel *panel); 70 71 /** 72 * @enable: 73 * 74 * Enable panel (turn on back light, etc.). 75 */ 76 int (*enable)(struct drm_panel *panel); 77 78 /** 79 * @disable: 80 * 81 * Disable panel (turn off back light, etc.). 82 */ 83 int (*disable)(struct drm_panel *panel); 84 85 /** 86 * @unprepare: 87 * 88 * Turn off panel. 89 */ 90 int (*unprepare)(struct drm_panel *panel); 91 92 /** 93 * @get_modes: 94 * 95 * Add modes to the connector that the panel is attached to and 96 * return the number of modes added. 97 */ 98 int (*get_modes)(struct drm_panel *panel); 99 100 /** 101 * @get_timings: 102 * 103 * Copy display timings into the provided array and return 104 * the number of display timings available. 105 */ 106 int (*get_timings)(struct drm_panel *panel, unsigned int num_timings, 107 struct display_timing *timings); 108 }; 109 110 /** 111 * struct drm_panel - DRM panel object 112 */ 113 struct drm_panel { 114 /** 115 * @drm: 116 * 117 * DRM device owning the panel. 118 */ 119 struct drm_device *drm; 120 121 /** 122 * @connector: 123 * 124 * DRM connector that the panel is attached to. 125 */ 126 struct drm_connector *connector; 127 128 /** 129 * @dev: 130 * 131 * Parent device of the panel. 132 */ 133 struct device *dev; 134 135 /** 136 * @funcs: 137 * 138 * Operations that can be performed on the panel. 139 */ 140 const struct drm_panel_funcs *funcs; 141 142 /** 143 * @list: 144 * 145 * Panel entry in registry. 146 */ 147 struct list_head list; 148 }; 149 150 void drm_panel_init(struct drm_panel *panel); 151 152 int drm_panel_add(struct drm_panel *panel); 153 void drm_panel_remove(struct drm_panel *panel); 154 155 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector); 156 void drm_panel_detach(struct drm_panel *panel); 157 158 int drm_panel_prepare(struct drm_panel *panel); 159 int drm_panel_unprepare(struct drm_panel *panel); 160 161 int drm_panel_enable(struct drm_panel *panel); 162 int drm_panel_disable(struct drm_panel *panel); 163 164 int drm_panel_get_modes(struct drm_panel *panel); 165 166 #if defined(CONFIG_OF) && defined(CONFIG_DRM_PANEL) 167 struct drm_panel *of_drm_find_panel(const struct device_node *np); 168 #else 169 static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) 170 { 171 return ERR_PTR(-ENODEV); 172 } 173 #endif 174 175 #endif 176