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