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/list.h> 28 29 struct drm_connector; 30 struct drm_device; 31 struct drm_panel; 32 33 /** 34 * struct drm_panel_funcs - perform operations on a given panel 35 * @disable: disable panel (turn off back light, etc.) 36 * @unprepare: turn off panel 37 * @prepare: turn on panel and perform set up 38 * @enable: enable panel (turn on back light, etc.) 39 * @get_modes: add modes to the connector that the panel is attached to and 40 * return the number of modes added 41 * 42 * The .prepare() function is typically called before the display controller 43 * starts to transmit video data. Panel drivers can use this to turn the panel 44 * on and wait for it to become ready. If additional configuration is required 45 * (via a control bus such as I2C, SPI or DSI for example) this is a good time 46 * to do that. 47 * 48 * After the display controller has started transmitting video data, it's safe 49 * to call the .enable() function. This will typically enable the backlight to 50 * make the image on screen visible. Some panels require a certain amount of 51 * time or frames before the image is displayed. This function is responsible 52 * for taking this into account before enabling the backlight to avoid visual 53 * glitches. 54 * 55 * Before stopping video transmission from the display controller it can be 56 * necessary to turn off the panel to avoid visual glitches. This is done in 57 * the .disable() function. Analogously to .enable() this typically involves 58 * turning off the backlight and waiting for some time to make sure no image 59 * is visible on the panel. It is then safe for the display controller to 60 * cease transmission of video data. 61 * 62 * To save power when no video data is transmitted, a driver can power down 63 * the panel. This is the job of the .unprepare() function. 64 */ 65 struct drm_panel_funcs { 66 int (*disable)(struct drm_panel *panel); 67 int (*unprepare)(struct drm_panel *panel); 68 int (*prepare)(struct drm_panel *panel); 69 int (*enable)(struct drm_panel *panel); 70 int (*get_modes)(struct drm_panel *panel); 71 }; 72 73 struct drm_panel { 74 struct drm_device *drm; 75 struct drm_connector *connector; 76 struct device *dev; 77 78 const struct drm_panel_funcs *funcs; 79 80 struct list_head list; 81 }; 82 83 static inline int drm_panel_unprepare(struct drm_panel *panel) 84 { 85 if (panel && panel->funcs && panel->funcs->unprepare) 86 return panel->funcs->unprepare(panel); 87 88 return panel ? -ENOSYS : -EINVAL; 89 } 90 91 static inline int drm_panel_disable(struct drm_panel *panel) 92 { 93 if (panel && panel->funcs && panel->funcs->disable) 94 return panel->funcs->disable(panel); 95 96 return panel ? -ENOSYS : -EINVAL; 97 } 98 99 static inline int drm_panel_prepare(struct drm_panel *panel) 100 { 101 if (panel && panel->funcs && panel->funcs->prepare) 102 return panel->funcs->prepare(panel); 103 104 return panel ? -ENOSYS : -EINVAL; 105 } 106 107 static inline int drm_panel_enable(struct drm_panel *panel) 108 { 109 if (panel && panel->funcs && panel->funcs->enable) 110 return panel->funcs->enable(panel); 111 112 return panel ? -ENOSYS : -EINVAL; 113 } 114 115 static inline int drm_panel_get_modes(struct drm_panel *panel) 116 { 117 if (panel && panel->funcs && panel->funcs->get_modes) 118 return panel->funcs->get_modes(panel); 119 120 return panel ? -ENOSYS : -EINVAL; 121 } 122 123 void drm_panel_init(struct drm_panel *panel); 124 125 int drm_panel_add(struct drm_panel *panel); 126 void drm_panel_remove(struct drm_panel *panel); 127 128 int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector); 129 int drm_panel_detach(struct drm_panel *panel); 130 131 #ifdef CONFIG_OF 132 struct drm_panel *of_drm_find_panel(struct device_node *np); 133 #else 134 static inline struct drm_panel *of_drm_find_panel(struct device_node *np) 135 { 136 return NULL; 137 } 138 #endif 139 140 #endif 141